| 1. |
- Olande, Oduor
(författare)
-
Students' narratives from graphical artefacts : Exploring the use of mathematics tools and forms of expression in students' graphicacy
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The research concerns presented in this dissertation addresses aspects of students’ interaction with commonly occurring graphical artefacts in teaching and learning environments. In particular, focus is on how the students make sense of these artefacts in relation to subject specific tools and forms of expression.The dissertation comprises of four studies guided by a semiotics cultural- historical perspective to cognition. The first study which is largely quantitative, analyses the percentage scores from students’ responses to selected items from OECD PISA surveys for items containing graphical elements. The second and the third studies in keeping with a more sociocultural perspective to learning as point of departure, examine the students’ collaborative interaction around tasks containing graphical elements. The fourth study explores the nature of students’ solutions from the Swedish national test in mathematics based on a tools and forms of expression sensitive empirically derived construct of Identification contra Critical-analytical approach to graphicacy.The main outcomes of these studies can be summarised as follows: first there is justification for re-examining the predominant characterisation of students’ interaction with graphical artefacts. Secondly, while it is not uncommon for students to take a more visual-perceptive and intuitive approach to graphicacy, results from task items interactions indicate that a Critical-analytical approach seems to be more reliable and capable of yielding desirable outcomes. The outcomes of these studies call for vigilance on the type of tasks used in relation to graphicacy and how these can be used to foster students’ Critical-analytical disposition.
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| 2. |
- Olsson, Helén, 1961-
(författare)
-
Att minska risken för våld och att främja återhämtning i den rättspsykiatriska vården : Patienters och personalens erfarenheter av vägen mot återhämtning
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Detta avhandlingsarbete är utfört inom en rättspsykiatrisk vårdkontext och återspeglar patienters[1] och personals[2] erfarenheter och upplevelser av vändpunkter i samband med minskad risk för våld och återhämtning. Med utgångspunkt från ett holistiskt och salutogent hälsovetenskapligt perspektiv har avhandlingen ett tvärvetenskapligt förhållningssätt. Teoretiska ämnesdiscipliner såsom psykiatrisk omvårdnad, kriminologi och sociologi har influerat arbetet.Avhandlingens övergripande syfte var att utifrån de salutogena aspekterna i det rättspsykiatriska omvårdnadsarbetet undersöka vad som är relaterat till vändpunkter i samband med minskad risk för våld och vad som bidrar till återhämtning. Avhandlingen baseras på fyra olika studier. Syftet med den inledande kvantitativa delstudien (I) var att identifiera och jämföra rättspsykiatriska patienter som sänkt sin bedömda risk för våld med 30 % eller mer enligt riskbedömningsinstrument HCR-20. Resultatet visade att den bedömda risken för våld minskade över tid. En demografisk analys genomfördes för att studera skillnader mellan de patienter som sänkt sin bedömda risk för våld och de som inte sänkt sin risk. Det framgick att rättspsykiatriska patienter som bedömts med hjälp av riskbedömningsinstrumentet HCR-20, minskade den bedömda risken för våld, både på kort och på lång sikt. Den rättspsykiatriska vården fungerade bäst när det gällde att förbättra de kliniska riskfaktorerna (C-skalan).Riskhanteringen (R-skalan) gällande eventuell utskrivning och framtida friförmåner visade inte samma goda progress. Demografiska karaktäristika såsom ålder, alkohol och drogmissbruk och psykiatriska diagnoser var inte relaterade till minskad risk för våld, dock var kvinnliga patienter och patienter utan psykopatidiagnos mer benägna att sänka sin risk för våld. Ett urval av de patienter som minskade sin risk för våld med 30 % eller mer utgjorde basen för delstudie II och III.I delstudie II intervjuades tretton rättspsykiatriska patienter om upplevelser och erfarenheter kring vad som bidrar till minskad respektive ökad risk för våld inne på en rättspsykiatrisk avdelning. Data analyserades med hjälp av en tolkande beskrivning (Interpretive Description). Studien visade att orsakerna till ökad respektive minskad risk för våld var processrelaterad, där interaktioner mellan personal och patienter bidrog till en utveckling som antingen präglades av välbefinnande eller disharmoni. Delstudie II utgjorde en viktig kunskapskälla som präglade ansatsen i delstudie III och IV. Detta med hänvisning till att flertalet patienter i delstudie II lämnade intressanta beskrivningar av vändpunkter i samband med minskad risk för våld och återhämtning.Sålunda intervjuades i delstudie III, tio rättspsykiatriska patienter om deras upplevelser av förändringsprocesser i samband med vändpunkter och återhämtning. Dataanalysen skedde med hjälp av en kvalitativ innehållsanalys. Processen beskrevs utifrån tre faser där man i högriskfasen upplevde kaotiska och överväldigande känslor. Vändpunkten upplevdes som ett känsligt skede som präglades av att tvingas hitta en ny, konstruktiv väg i livet. Återhämtningsfasen präglades av ett accepterande och en mognad. Stöd och erkännande från omgivningen ansåg främja dessa processer.Delstudie IV bestod av intervjuer med tretton personal. Syftet var att belysa upplevelser och erfarenheter kring rättspsykiatriska patienters vändpunkter och återhämtning. Kvalitativ innehållsanalys användes för att analysera data. Beskrivningar kring hur en vändpunkt kunde bevaras och främjas baserades på vikten av att vara uppmärksam, lyhörd och att inte skynda på processen. En vändpunkt upplevdes genom att patienten uppvisade synbara positiva förändringar. Sammansättningen på personalen och patienterna ansågs påverka atmosfären på avdelningen, och bidrog till huruvida processen mot vändpunkter och återhämtning underlättades eller försvårades.Avhandlingen visar hur ett ständigt växelspel mellan patienter och mellan personal bidrog till huruvida vårdatmosfären upplevdes såsom hälsofrämjande eller ej. Vidare framgår att processer kring vändpunkter i samband med minskad risk för våld och återhämtning präglades av känslor av sårbarhet och utsatthet. Processen beskrevs som ett känsligt förlopp som behövde understödjas av förtroendefulla relationer med andra, samt möjligheter att få vistas i en trygg miljö.[1] Den vetenskapliga litteraturen använder sig av begrepp såsom client, consumer, service user eller forensic patient för att beteckna människor som är inskrivna inom den rättspsykiatriska vården. Inom det psykiatriska svenska fältet kan begreppen brukare, vårdtagare eller patient förekomma. I denna avhandling kommer begreppet patient och vårdtagare omväxlande att användas för att beteckna de människor som är föremål för den rättspsykiatriska vården. De patienter som deltagit i avhandlingens två delstudier kommer omväxlande att benämnas såsom deltagare eller patienter, för att åstadkomma en varierande och läsvänlig text.[2] I denna avhandling anser begreppet personal den personalkategori som arbetar med omvårdnad inom en rättspsykiatrisk kontext. Det är främst sjuksköterskor och skötare som inkluderas i begreppet omvårdnadspersonal inom den vetenskapliga litteraturen. Sjuksköterskor benämns såsom registered mental health nurses eller registered nurses. Övrig omvårdnadspersonal tituleras till exempel som nurse manager eller assistant nurses. När begreppen personal, vårdare eller omvårdnadspersonal används i denna avhandling avses då den personalkategori som arbetar närmast patienten med omvårdnad och ingen åtskillnad kommer att göras mellan de båda yrkesgrupperna. Personalen som deltar i delstudie IV har omväxlande kallats för personal eller vårdare.
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| 3. |
- Nydahl, Erik, 1983-
(författare)
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I fyrkens tid : Politisk kultur i två ångermanländska landskommuner
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Abstract Nydahl, Erik; I fyrkens tid. Politisk kultur i två ångermanländska landskommuner 1860-1930 [Voting by income: The political culture of two Swedish municipalities, 1860–1930] Department of Humanities, Mid Sweden University, SE-871 88 Härnösand, Sweden ISBN: 978-91-86694-05-0, ISSN 1652-893X, Doctoral thesis nr: 100 (2010). Swedish text with a summary in English This dissertation analyses the development of political culture in two Swedish municipalities between the 1860s and the 1930s – a period during which Swedish society underwent major changes. The purpose is to examine the direct and indirect consequences of an evolving industrial society's economic, social and political structures on political culture at local levels. The following factors are the base of the study. At the start of the 1860s, a long-standing Swedish tradition of local self-government was reinforced through a major reform, the Local Government Ordinance of 1862 (1862 års kommunalförfattningar). From this point, each parish formed its own municipality. The new municipalities were given the right to levy taxes and made responsible for welfare and schools, thereby becoming a prominent arena for the exercise of power at local levels. The municipal reform of 1862 was carried out at a time when Swedish society was transitioning as the industrialisation process accelerated during the latter part of the 1800s. Gradually, the old structure of an agricultural society was cast aside in favour of a new, modern industrial society. Naturally, also the municipalities changed – directly and indirectly. For some municipalities, adjustments were significant; for others, less so. Part of this process was the reformation of voting rights from plutocratic to public and equal. Another part was the reorganisation of municipal government from direct government via municipal meetings to representative government via municipal councils. Two main issues are formulated and answered in the dissertation. The one addresses who or which had the power over local politics and how the situation changed over time. The second addresses in what way municipal representation changed form with the modernisation of the municipalities. The empirical survey comprises a comparative case study between two municipalities in the northern part of Sweden. The one municipality, Ytterlännäs, was early the site for large-scale sawmill industry. The second municipality, Stigsjö, retained its agricultural structure throughout the entire period in question. The comparison makes it possible to analyse the impending industrial society from two different poles. In the 1800s, local politics was considered to be a completely different sort than politics at a national level. The difference was that local politics, referred to as “the municipal”, was seen as non-political and unaffiliated with those conflicts addressed at national levels, referred to as “the political”. The dissertation demonstrates two different models of how modern municipal politics evolved from the municipal meetings of the 1800s. While the starting point was the same in both municipalities, the paths diverged in the early 1870s. In the agricultural municipality of Stigsjö, it was “business as usual”. In the industrial municipality of Ytterlännäs, however, confrontation arose between enterprises and farmers and eventually, a labour movement emerged demanding the right of participation. The dissertation shows that the distinction between “municipal” and “political” was obliterated in the beginning of the 1900s, paving the way for a new concept – municipal politics. This process occurred in a very palpable way in Ytterlännäs but eventually, Stigsjö was forced to conform. The new municipal politics was, so to speak, the final station in both municipalities. In conjunction with party politicisation of local politics, the criteria and seats for the municipal representatives changed. When party affiliation became an important criterion, professional affiliation became less relevant. Party bloc seats replaced the independent seats, and representatives were eventually paid remuneration. Keywords: Political culture, politics, voting right, municipal politics, industrial society, industrialisation, elected representatives, representation, temperance movement, labour movement, popular movements, political parties, modernisation
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| 4. |
- Abbasi, Seyed
(författare)
-
Determinants of social inequalities in cardiovascular disease among Iranian patients
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background and objectives: Cardiovascular disease (CVD) is the single largest cause of mortality in the world. Similar to other health issues, CVD is generally affected either by individual risk factors, which may influence the risk for developing an illness or its complications, or by social indicators (social determinants of health). There is evidence from developed countries which shows that the so-called "upstream factors"—including social determinants such as political, social, spiritual, cultural, and economic factors—may affect the prevalence and incidence of CVD. Scarce evidence from studies in low- and middle-income countries also suggests that social factors may affect the distribution of CVD across population groups. However, there is a dearth of such data in Iran, where only a few small-sizedstudies have focused on the social determinants of health. Therefore, the present thesis sought to fill this gap by assessing the effects of socioeconomic status (SES) on the distribution of CVD and the relevant inequalities within the Iranian context.Methods: This thesis is based on four studies, which used data from the Tehran Heart Center’s Databases. In Study I, a total of 44,820 patients who underwent coronary angiography at Tehran Heart Center between 2005 and 2010 were recruited. Then, their pre- and post-procedural data—including demographics, CVD risk factors, symptoms, and laboratory tests—were compared between men and women. In Study II, 6,246 patients with acutecoronary syndrome who were hospitalized between March 2004 and August 2011 were included and, based on their education and their employment status, were divided into high- and low-SES groups. Thereafter, the effect of SES on the in-hospital death of the patients was evaluated. In Study III, 20,165 patients with documented coronary artery disease who underwent coronary angiography at Tehran Heart Center were enrolled and CVD risk factors and severity (measured by the Gensini score) were assessed among the six major Iranian ethnic groups. In Study IV, 9,088 patients with acute coronary syndrome who were hospitalized at Tehran Heart Center between May 2007and June 2014 were recruited and the association between in-hospital death due to acute coronary syndrome and place of residence (rural/urban) was assessed using logistic regression adjusted for potential confounders.Results: In this thesis, the data analyses were based on the hypothesis that there is a potential association between the different socioeconomic indicators and the selected cardiovascular outcomes. In Study I, among the recruited participant, 25,363 men and 11,995 women had coronary artery disease and the women not only were significantly older, less educated, and more overweight but also had higher blood levels of triglyceride, cholesterol, low-density lipoprotein, high-density lipoprotein, and fasting blood sugar than the men. Moreover, hypertension and diabetes mellitus showed the strongest association in the women with coronary artery disease (OR=3.45, 95% CI: 3.28to 3.61 and OR=2.37, 95% CI: 2.26 to 2.48, respectively). In addition, the frequency of post-procedural recommendations for non-invasive procedures was higher in the women than in the men (20.1% vs 18.6%; P<0.001). In StudyII, of the 6,246 recruited patients with acute coronary syndrome, 3,290individuals were considered low-SES and 2,956 high-SES individuals. In-hospital death occurred in 79 (1.26%) patients: 1.9% in the low-SES and 0.6% in the high-SES groups. After adjustment for the possible cofounders, our multivariate analysis demonstrated a significant effect of the patients’ SES on their in-hospital death and a lower in-hospital mortality rate was shown in the high-SES patients (OR=0.30, 95% CI: 0.09 to 0.98; P=0.046). In Study III, the Fars (8.7%) and Gilak (8.6%) ethnic groups had the highest frequency of having at least four simultaneous risk factors. Additionally, the mean Gensini score was lowest in the Lurs (67.5±52.8) and highest among the Gilaks (77.1±55.9). The multivariable regression analysis indicated that the Gilaks showed the worst CVD severity (β: 0.056, 95% CI: 0.009 to 0.102; P=0.018), followed by the Turks (β: 0.032, 95% CI: 0.005 to 0.059; P=0.020), and the lowest CVD severity, was detected in the Lurs (β: -0.087, 95% CI: -0.146 to -0.027;P=0.004). Study IV showed that while smoking (P=0.002), positive family history of coronary artery disease (P=0.003), higher body mass index (P=0.013),and hyperlipidemia (P=0.026) were more prevalent in the urban patients, the rural patients showed lower educational levels (P<0.001) and higher frequency of unemployment (P=0.009). Meanwhile, in-hospital death occurred in 135 (1.5%) patients: 125 (1.5%) urban and 10 (1.2%) rural. To adjust the effects of the possible confounders, we utilized the Firth regression model, which showed no significant difference regarding in-hospital death betweenthe rural and urban patients (OR=1.57, 95% CI: 0.376 to 7.450; P=0.585).Conclusions: The aim of this thesis was to investigate the effects of social determinants (particularly SES) on CVD and its modifiable risk factors among Iranian patients. Results showed that medical treatment for CVD was more recommended (by treating physicians) to the women than the men, and the low-SES patients with acute coronary syndrome were more likely to die in the hospital than their high-SES counterparts. In addition, the thesis found heterogeneity in the distribution of the traditional risk factors for CVD as well as CVD severity in the major Iranian ethnic groups. Further, there were no differences concerning the in-hospital death rates due to acute coronary syndrome between the urban and rural patients after adjustment for the potential confounders.
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| 5. |
- Afewerki, Samson, 1985-
(författare)
-
Development of catalytic enantioselective C-C bond-forming and cascade transformations by merging homogeneous or heterogeneous transition metal catalysis with asymmetric aminocatalysis
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chiral molecules play a central role in our daily life and in nature, for instance the different enantiomers or diastereomers of a chiral molecule may show completely different biological activity. For this reason, it is a vital goal for synthetic chemists to design selective and efficient methodologies that allow the synthesis of the desired enantiomer. In this context, it is highly important that the concept of green chemistry is considered while designing new approaches that eventually will provide more environmental and sustainable chemical synthesis.The aim of this thesis is to develop the concept of combining transition metal catalysis and aminocatalysis in one process (dual catalysis). This strategy would give access to powerful tools to promote reactions that were not successful with either transition metal catalyst or the organocatalyst alone. The protocols presented in this thesis based on organocatalytic transformations via enamine or iminium intermediates or both, in combination with transition metal catalysis, describes new enantioselective organocatalytic procedures that afford valuable compounds with high chemo- and enantioselectivity from inexpensive commercial available starting materials. In paper I, we present a successful example of dual catalysis: the combination of transition metal activation of an electrophile and aminocatalyst activation of a nucleophile via enamine intermediate. In paper II, the opposite scenario is presented, here the transition metal activates the nucleophile and the aminocatalyst activates the electrophile via an iminium intermediate. In paper III,we present a domino Michael/carbocyclisation reaction that is catalysed by a chiral amine (via iminium/enamine activation) in combination with a transition metal catalysts activation of an electrophile. In paper IV, the concept of dual catalysis was further extended and applied for the highly enantioselective synthesis of valuable structural scaffolds, namely poly-substituted spirocyclic oxindoles. Finally, in paper V the concept of dual catalysis was expanded, by investigating more challenging and environmentally benign processes, such as the successful combination of a heterogeneous palladium and amine catalysts for the highly enantioselective synthesis of functionalised cyclopentenes, containing an all carbonquaternary stereocenter, dihydrofurans and dihydropyrrolidines.
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| 6. |
- Ahlin, Karin, 1963-
(författare)
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Benefits of Digital Technical Information
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In our daily work life, we use a wealth of information, including a category of information produced as a part of products and their life-cycle phases, named digital technical information (DTI). Manufacturing organizations focus more often on the product than on DTI, because DTI’s impact seems almost invisible, despite its crucial role to the product and its life-cycle phases, development, production, maintenance, and destruction. Hence, the aim of this thesis is to describe DTI’s benefits and the research questions: “What are the benefits of the DTI?” and “What are the perceptions of how to measure benefits of DTI?” The thesis contains five studies related to identifying and measuring DTI’s benefits. The empirical material is based on semi-structured interviews and group interviews within five organizations and a survey among manufacturing organizations in Sweden.I used three characteristics of the DTI and two pairs of previously known benefit categories to analyse the benefits. The analysis shows that the benefits are recognized in the particular product’s life cycle phase where the DTI is published. However, the DTI continues to offer benefits in the product’s other life cycle phases. In relationship to the product, the benefits evolve from supporting an individual product to supporting more general product lines or all products and a more complex product is said to increase DTI’s benefits. DTI’s structure adds benefits as synthesized or aggregated DTI, where the DTI is synthesized or aggregated automatically or manually. The categorization predetermined benefits related to the change are less numerous than the emerging benefits. The predetermined benefits are strategic by nature, and the emerging ones are mainly used to achieve operational goals. Measuring DTI’s benefits is of importance for a formal comparison of its development and is of special interest for managers. Perceptions from the initial stages on how to measure show that to establish common interpretations among the stakeholders of the measurement process is of importance, especially when it comes to what is viewed as a benefit. The benefits are viewed as intangible by the respondents, which creates difficulties when one is evaluating, using conventional measurement methods. The only perceived way to measure is when DTI reduces co-worker’s workload and efficiency is achieved. The thesis’s contribution to academia consists of the analysis of DTI’s benefits, showing details of the relationships between the DTI and its benefits. For practice, the contributions focus on the systematic evaluation process, which can be used for further development of the DTI and comparison of the evolvement of the DTI itself and relating to other resources. One proposal for future research is to use the analysed benefits and compare various approaches to digitizing DTI, e.g. Industry 4.0. Another proposal is to list, in detail, various ways on how to measure DTI’s benefits and their usefulness. The latter can positively impact on any intangible benefits due to the general approach we have established of how to measure those benefits.
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| 7. |
- Ahmad, Jawad, 1985-
(författare)
-
Development and Characterization of Large Area Pressure Sensors and Sitting Posture Monitoring Systems
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With the emergence of the Internet and rapid development of science and technology over the past few decades, many individuals worldwide now rely on the Internet to conduct daily activities ranging from education, business and creativity to communication and shopping. As we tend to spend more and more time on the Internet and engage less in physical activities, this persistent behaviour could result in some health-related issues within a relatively short period of time. This behaviour, known as sedentary lifestyle, may be related to a higher risk of cardiovascular disease, osteoporosis, obesity, anxiety, pressure ulcers and many other illnesses. As a consequence, there has been great interest in developing non-invasive and unobtrusive measurement techniques for a variety of health care-monitoring applications, such as for blood oxygen saturation, stress levels, electrocardiograms and glucose monitoring. In such systems, wearable and flexible electronics technologies may enable monitoring of vital signs, offering significant potential for early screening as well as long-term behaviour modelling.In this thesis, large area pressure sensors based on non-conventional materials are proposed and realised by screen printing technique for monitoring sitting postures. The developed pressure sensing system measures distributed pressure when an individual sits on a chair equipped with a pressure sensor array. This technology could provide grounding for the advancement of health-related monitoring systems for both able-bodied and disabled individuals and inform them of their sitting time and sitting posture, and this could be used to establish a sitting pattern. To accomplish this, pressure sensors have been designed using non-conventional flexible electronics. A blend of non-conductive and low-resistance ink is used as pressure-sensitive material to enable the realization of screen-printed sensors. To characterise the performance of the suggested pressure sensor, several tests, such as repeatability, drift and flexibility, are conducted. The sensor has also been exposed to different humidity and temperature conditions in a climate chamber to examine its functionalities.A graphical user interface was developed for real-time demonstration of data from distributed pressure points in the form of a pressure map to display the pressure values. Four sitting postures are identified: forward, backward, left, and right leaning. Furthermore, a stretchable pressure sensor is proposed that could follow slight stretching with regard to changes in the shape of the human skin. Machine learning algorithms have been employed to further enhance the sitting posture identification, and accuracy of 99.03% is attained. A standalone embedded system capable of illustrating real-time pressure data has been developed with the potential to be used in portable health monitoring systems. In summary, this work provides a promising framework for measuring pressure distribution and identifying irregular sitting postures that may help to reduce the potential risks of developing health-related issues associated with prolonged sitting time.
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| 8. |
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| 9. |
- Ahmad, Waqas
(författare)
-
High Efficiency Light Field Image Compression : Hierarchical Bit Allocation and Shearlet-based View Interpolation
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Over the years, the pursuit of capturing the precise visual information of a scenehas resulted in various enhancements in digital camera technology, such as highdynamic range, extended depth of field, and high resolution. However, traditionaldigital cameras only capture the spatial information of the scene and cannot pro-vide an immersive presentation of it. Light field (LF) capturing is a new-generationimaging technology that records the spatial and angular information of the scene. Inrecent years, LF imaging has become increasingly popular among the industry andresearch community mainly for two reasons: (1) the advancements made in optical and computational technology have facilitated the process of capturing and processing LF information and (2) LF data have the potential to offer various post-processing applications, such as refocusing at different depth planes, synthetic aperture, 3Dscene reconstruction, and novel view generation. Generally, LF-capturing devicesacquire large amounts of data, which poses a challenge for storage and transmissionresources. Off-the-shelf image and video compression schemes, built on assump-tions drawn from natural images and video, tend to exploit spatial and temporalcorrelations. However, 4D LF data inherit different properties, and hence there is aneed to advance the current compression methods to efficiently address the correla-tion present in LF data.In this thesis, compression of LF data captured using a plenoptic camera andmulti-camera system (MCS) is considered. Perspective views of a scene capturedfrom different positions are interpreted as a frame of multiple pseudo-video se-quences and given as an input to a multi-view extension of high-efficiency videocoding (MV-HEVC). A 2D prediction and hierarchical coding scheme is proposedin MV-HEVC to improve the compression efficiency of LF data. To further increasethe compression efficiency of views captured using an MCS, an LF reconstructionscheme based on shearlet transform is introduced in LF compression. A sparse set of views is coded using MV-HEVC and later used to predict the remaining views by applying shearlet transform. The prediction error is also coded to further increase the compression efficiency. Publicly available LF datasets are used to benchmark the proposed compression schemes. The anchor scheme specified in the JPEG Plenocommon test conditions is used to evaluate the performance of the proposed scheme. Objective evaluations show that the proposed scheme outperforms state-of-the-art schemes in the compression of LF data captured using a plenoptic camera and an MCS. Moreover, the introduction of shearlet transform in LF compression further improves the compression efficiency at low bitrates, at which the human vision sys-tem is sensitive to the perceived quality.The work presented in this thesis has been published in four peer-reviewed con-ference proceedings and two scientific journals. The proposed compression solu-tions outlined in this thesis significantly improve the rate-distortion efficiency forLF content, which reduces the transmission and storage resources. The MV-HEVC-based LF coding scheme is made publicly available, which can help researchers totest novel compression tools and it can serve as an anchor scheme for future researchstudies. The shearlet-transform-based LF compression scheme presents a compre-hensive framework for testing LF reconstruction methods in the context of LF com-pression.
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| 10. |
- Ainegren, Mats
(författare)
-
Roller skis' rolling resistance and grip characteristics : influences on physiological and performance measures in cross-country skiers
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.
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| 11. |
- Alam, Mohammad Anzar
(författare)
-
Online optical method for real-time surface measurement using line-of-light triangulation
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Real time paper surface-web measurement is one of the challenging research fields. The traditional laboratory method has many limitations and is unable to measure the entire tambour during the manufacturing process. It has been necessary to develop an online technique that could measure the surface topography in real time. An optical technique was developed, based on laser triangulation, and is applied to develop a new prototype device, which characterizes high speed paper-web surfaces over a wide scale of spatial wavelengths spectrum and computes the surface roughness in real time. The used multi channel pulsed laser diode, source of illumination onto the paper-web, is of benefit due to its low coherence length and is capable to deliver a powerful burst of light beam over a 1 µs duration, which delivers energy of 100 µJ per pulse. The short exposure time avoids blurriness in the acquired images which could possible due to the high speed and vibrations on the paper-web.The laser beam is shaped into a narrow line-of-light using cylindrical lenses and is projected onto a paper-web surface, which covers a physical length of about 210 mm. The created line-of-light cross section full width at half maximum, FWHM Gaussian distribution, is 2-3 pixels on the image. The line-of-light is projected onto the paper-web perpendicular to the plane of the surface. The low angled, low specular, reduced coherence length, scattered reflected laser line is captured by the 3 CCD sensors, which are synchronized with the laser source. The low specular light ensures to avoid saturation of the imaging sensors if the surface is very smooth, and obliquely captures the z-directional fine feature of the surface.The scattered phenomenon of the reflected light is responsible for the surface irregularity measurements. The basic image processing algorithm is applied in order to remove noise and cropped the images widthwise so that only pixels above a preset threshold gray level can be processed, which enables efficient real time measurement. The image is transformed into a 1D array using the center of gravity, COG. The accuracy and precision of the COG depends on the line-of-light FWHM, which, in turn, is responsible for the accuracy, noise and the resolution of the developed technique. The image subpixel resolution achieved is 0.01 times a pixel and uuncertainty in the raw data is 0.43 µm while it is 0.05 µm in the rms roughness.The signal processing steps combining the B-Spline filter and the filter in the spatial frequency domain were employed in order to separate roughness, waviness, and form and position error in the raw profile. The prototype is designed to measure online surface roughness and to characterize surface in a spatial wavelength spectrum from 0.09 to 30 mm, which is extendable to any required spatial range in order to cover a wide scale surface feature such as micro roughness, macro roughness and waviness. It is proven that exploitation of a simple laser triangulation technique could lead to an improvement in the overall quality and efficiency in the paper and paperboard industries and it can also be of potential interest for the other surface characterization problems.
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| 12. |
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| 13. |
- Alimadadi, Majid
(författare)
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Foam-formed Fiber Networks: Manufacturing, Characterization, and Numerical Modeling : With a Note on the Orientation Behavior of Rod-like Particles in Newtonian Fluids
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fiber networks are ubiquitous and are seen in both industrial materials (paper and nonwovens) and biological materials (plant cells and animal tissues). Nature intricately manipulates these network structures by varying their density, aggregation, and fiber orientation to create a variety of functionalities.In conventional papermaking, fibrous materials are dispersed in water to form a sheet of a highly oriented two-dimensional (2D) network. In such a structure, the in-plane mechanical and transport properties are very different from those in the out-of-plane direction. A three-dimensional (3D) network, however, may offer unique properties not seen in conventional paper products.Foam, i.e., a dispersed system of gas and liquid, is widely used as the suspending medium in different industries. Recently, foam forming was studied extensively to develop the understanding of foam-fiber interactions in order to find potential applications of this technology in papermaking.In this thesis, a method for producing low-density, 3D fiber networks by utilizing foam forming is investigated and the structures and mechanical properties of such networks are studied. Micro-computed tomography is used to capture the 3D structure of the network and subsequently to reproduce artificial networks. The finite element method is utilized to model the compression behavior of both the reproduced physical network and the artificial networks in order to understand how the geometry and constitutive elements of the foam-formed network affect its bulk mechanical properties. Additionally, a method was studied in order to quantify the orientation behavior of particles in a laminar Newtonian flow based on the key parameters of the flow which control the orientation.The resulting foam-formed structures were extremely bulky. Yet despite this high bulk, the fiber networks retained good structural integrity. The compression behavior in the thickness direction was characterized by extreme compressibility and high strain recovery after compression. The results from the modeling showed that the finite-deformation mechanical response of the fiber network in compression was satisfactorily captured by the simulation. However, the artificial network shows higher stiffness than the simulated physical network and the experiment. This discrepancy in stiffness was attributed to macroscopic structural non-uniformities in the physical network, which result in increased local compliance. It was also found that the friction between the fibers, as well as the fiber curvature, had a negligible impact on the compression response of the fiber network, while defects (in the form of kinks) had an effect on the response in the last stages of compression. The study of the orientation behavior of particles at different flow velocities, particle sizes, and channel geometries suggests that it might be possible to utilize the flow shear rate as a means to quantify the orientation behavior.
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| 14. |
- Alimohammadzadeh, Rana
(författare)
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Eco-friendly and Catalytic Surface Engineering of Cellulose and Nanocellulose
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The non-stop use of petroleum-based materials such as plastics can generate significant environmental problems, including pollution of the oceans and increased CO2 levels, and cause diseases like cancer due to the starting monomers. Consequently, increased use of sustainable and non-toxic polymers and monomers is required to address these issues. Cellulose, generously supplied by Mother Nature, is the most abundant biopolymer on Earth. Nanocellulose is a sustainable polymer extracted from the cellulose inwood or produced by bacteria and algae. This biodegradable nanomaterialhas recently been receiving intense research attention, since it has great potential for use in a broad range of industrial and biomedical applications. However, it has limitations such as moisture sensitivity and incompatibility with hydrophobic materials due to its hydrophilic nature. Chemical modification is necessary for it to fulfill the requirements for applications that require high moisture resistance and water repellency. Unfortunately, several of the existing methods involve harsh and toxic conditions or reagents. In this thesis, together with my co-workers, I have employed the toolbox of organocatalysis for accomplishing eco-friendly and innovative surface modification of cellulose and nanocellulose. The organocatalysts we usedmost in our research are the naturally abundant and industrially relevantorganic acids tartaric acid and citric acid.Direct catalytic esterification of cellulose nanocrystal (CNC) with thioglycolicacid was performed either in suspension or on solid surfaces such as films and foams. We found that the reaction was accelerated by tartaric acid but could also be autocatalytic with respect to the thioglycolic acid under certain conditions. The synthesized CNC-SH was further exploited as a heterogeneous reducing agent as well as a handle for further nanocellulose modifications. This was demonstrated by using CNC-SH as a heterogenous reducing agent of Cu(II) to Cu(I), which is essential for allowing the Cu to actas a catalyst for 2,3-dipolar cycloaddition reactions between azides andalkynes. We also showed that the thia-modified CNC could undergo further functionalizing via thiol-ene click chemistry reactions, for example, we attached fluorescent compounds such as TAMRA and quinidine.Herein we provide a fluorine-free method to prepare superhydrophobic CNC film with excellent water-resistance properties by combining self-assemblyand organocatalysis. Self-assembly of CNC via vacuum filtration resulted in xa film with a specific roughness at the microscale. Next, the catalytic silylation with a variety of alkoxysilanes in the presence of natural organic acids such as tartaric acid and citric acid was performed. The successful implementation of our method resulted in a super-hydrophobic CNC film (water contact angleover 150°) with excellent water-resistance. Thus, the combination of the selfassembly of a rough surface with catalytic surface modification resulted in a phenomenon like the “lotus effect” as exhibited by the leaves of the lotus flower. An investigation of the oxygen permeability of the octadecyltrimethoxysilane-modified CNC film revealed that it significantly decreased at high relative humidity compared with unmodified CNC films.In this thesis, the fabrication of hydrophobic and functionalized MTM/CNF nanocomposites using organocatalytic surface modification with a large variety of alkoxysilanes is also performed. The surface modifications are mildand the mechanical strength of the Nacre-mimetic nanocomposites is preserved. Elemental mapping analysis revealed that the silane modification occurred predominantly on the surface.A combination of organocatalyst and biopolyelectrolyte complex was appliedfor surface engineering of chemi-thermomechanical pulp (CTMP) and bleached sulfite pulp (BSP). The reaction was performed using a synergistic combination of an organocatalyst with a polyelectrolyte (PE) complex. Using this method, the strength properties of CTMP and BSP sheets were significantly increased (up to 100% in Z-strength for CTMP). Further investigations of the distribution of the PE complex were then performed using TAMRA and quinidine labeling and confocal laser scanningmicroscopy. This revealed that an even distribution of the cationic starch component of the PE complex had occurred within the CTMP-based paper sheets, which follows its lignin distribution pattern.
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| 15. |
- Alirani, Gertrud, 1976-
(författare)
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Miljöintegrering i praktisk tillämpning : En policystudie av två lokala stadsutvecklingsprocesser
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dealing with environmental problems has become one of the most challenging political issues of our time. Since the Brundtland report in 1987, environmental policy integration (EPI) that is, the mainstreaming of environmental issues in all policy sectors has emerged as a viable policy solution. This has meant that responsibility for implementing environmental policy rests to a large extent on local authorities where environmental problems with both local and global consequences are expected to be handled. However, there is still a disagreement on what EPI means in day-to-day decision making. With a theoretical framework drawing from theory on policy change, policy entrepreneurship and the neoinstitutional “logic of appropriateness” the aim of this dissertation is to analyze how the integration of environmental considerations manifests itself in local policy processes, highlighting what factors foster or hinder EPI. To reach this aim, I have followed two urban development processes in Kristianstad. This research offers insights on how EPI varies through the policy process and how focus is placed mainly on certain environmental issues and chiefly defined as of local importance. My study suggest that arenas for coordination are critical to overcoming the perceived “gap” between EPI on a strategic level and its implementation. This can help to clarify responsibility allocation among bureaucrats and their leeway for interpretation when new issues comes up continuously during the processes and affect the conditions for EPI. Furthermore, the dissertation gives insights on how acting “entrepreneurially” can enable an environmental issue to be included and given priority. This can also be a barrier if the ones acting entrepreneurially are not part of the entire process because the issue might receive less attention. In addition, if too much attention is given to one issue it might overshadow other environmental issues. Conversely, acting according to “the logic of appropriateness” can enable EPI by enhancing a more all-encompassing perspective on environmental considerations and also function as a cautious approach to radical change by preventing measures taken in absence of democratic legitimacy. By using the two theoretical perspectives, “entrepreneurial” and “appropriate” agency, this dissertation offers important insights into how different ways of acting interact and affect EPI and its outcome.
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| 16. |
- Almén, Niclas, 1971-
(författare)
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Intervening Stress Recovery Behaviors in Everyday Life
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. High levels of perceived stress and stress-related ill health, such as burnout, are common in many countries. Several theories postulate that stress behaviors promote adaption to environmental changes and if sustained they are potentially harmful for the body. In accordance, impaired stress recovery behaviors, i.e., psychophysiological deactivation after periods of stress behaviors, have been suggested to be a critical factor in explaining stress-related ill health. Whereas research shows that interventions targeting stress reactivity can have beneficial effects on stress-related variables, studies on interventions targeting stress recovery are surprisingly few. Also, the number of validated instruments for measuring behaviors important for stress recovery are few, in particular easily used self-rating scales. Aims. The primary aim of the thesis was to evaluate stress and health-related effects of an intervention targeting stress recovery behaviors in everyday life among people perceiving high levels of stress in life. A secondary aim was to validate a self-report scale measuring behaviors important for stress recovery in everyday life. Method. Three empirical studies were conducted to evaluate effects of the behavioral stress recovery intervention “balance in everyday life”, which solely aims at strengthening stress recovery behaviors in everyday life. First, a brief version of the intervention was investigated through a small pilot study in which a single-subject experimental design was used (study 1). After that, the intervention was exploratively tested in a group format in which a quasi-experimental design was used (study 2). Due to the positive results of these two studies, a larger scale study using a randomized controlled design was conducted in order to further investigate the effects of the intervention when delivered in a group format (study 3). To fulfill the secondary aim of the thesis, the Recovery Experience Questionnaire was translated into Swedish and analyzed using exploratory factor analysis and confirmatory factor analysis (study 4). Results. In study 1, data demonstrated immediate reduction of stress symptoms as a function of the intervention. The improvements were maintained at 1-year and 5-year follow-up assessments. In study 2, in comparison with a waiting-list-control group, the intervention yielded statistically significant improvements between pre- and postintervention assessment on eleven out of twelve stress and health-related variables. Medium to large between-groups effect sizes were demonstrated for the primary outcome measures covering (potential) recovery behaviors, perceived stress and rest and experiences of being recovered. In the third study, statistically significant improvements for all outcome measures at postintervention assessment and at the 3-month follow-up were demonstrated. The between-groups effect sizes for the primary measures - perceived stress, tension, and burnout - were medium-to-high at postintervention assessment and at follow-up. In addition, in all studies the intervention was associated with beneficial changes in levels of anxiety and depression. In the last study, support was found for the proposed four-factor structure of the Swedish version of the Recovery Experience Questionnaire. Conclusions. The results clearly indicate that the intervention “balance in everyday life” improves stress and health-related factors in a relatively satisfactory way among people perceiving high levels of stress in life. The empirical support is strongest for the reduction in tension, perceived stress, burnout, anxiety and depression, and to deliver the intervention in a group format. The studies demonstrated results that warrant further investigation of the effects of “balance in everyday life”, for example in different contexts, and to study other behavioral recovery interventions. To test (potential) recovery facilitating behaviors as mediators of intervention effects, such as reduction in burnout, the Swedish version of the Recovery Experience Questionnaire could be used.
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| 17. |
- Alqaysi, Hiba
(författare)
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Cost Optimization of Volumetric Surveillance for Sky Monitoring : Towards Flying Object Detection and Positioning
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Unlike surface surveillance, volumetric monitoring deals with three-dimensional target space and moving objects within it. In sky monitoring, objects fly within outdoor and often remote volumes, such as wind farms and airport runways. Therefore, multiple cameras should be implemented to monitor these volumes and analyze flying activities.Due to that, challenges in designing and deploying volumetric surveillance systems for these applications arise. These include configuring the multi-camera node placement, coverage, cost, and the system's ability to detect and position flying objects.The research in this dissertation focuses on three aspects to optimize volumetric surveillance systems in sky monitoring applications. First, the node placement and coverage should be considered in accordance with the monitoring constraints. Also, the node architecture should be configured to minimize the design cost and maximize the coverage. Last, the system should detect small flying objects with good accuracy.Placing the multi-camera nodes in a hexagonal pattern while allowing overlap between adjacent nodes optimizes the placement. The inclusion of monitoring constraints like monitoring altitude and detection pixel resolution influences the node design. Furthermore, presented results show that modeling the multi-camera nodes as a cylinder rather than a hemisphere minimizes the cost of each node. The design exploration in this thesis provides a method to minimize the node cost based on defined design constraints. It also maximizes the coverage in terms of the number of square meters per dollar. Surveillance systems for sky monitoring should be able to detect and position flying objects. Therefore, two new annotated datasets were introduced that can be used for developing in-flight birds detection methods. The datasets were collected by Mid Sweden University at two locations in Denmark. A YOLOv4-based model for birds detection in 4k grayscale videos captured in wind farms is developed. The model overcomes the problem of detecting small objects in dynamic background, and it improves detection accuracy through tiling and temporal information incorporation, compared to the standard YOLOv4 and background subtraction.
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| 18. |
- An, Siwen
(författare)
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Spectroscopic and Microscopic X-ray Fluorescence Analysis for Environmental and Industrial Applications
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Heavy metals are well-known environmental pollutants due to its potential impact on associated ecosystems and human health. Thus, it is important to monitor the levels of heavy metals in the environment. X-ray fluorescence (XRF) analysis is a powerful and effective screening tool in measuring the concentration of multi-elements simultaneously.This thesis provides insight into development and implementation of XRF instruments for environmental monitoring and industrial process control. The XRF method was compared with a commercial scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) for fly ash samples. Qualitative analysis and semi-quantitative analysis of Na, S, Cl, K and Cd in incineration fly ash were performed with these two similar techniques. One of the challenges of using XRF is the scattering background noise from the primary beam, which decreases the detection limit and the sensitivity of the measurement system. Hence, an X-ray beam filter was chosen to suppress the background noise for a specific element, Cr, in leachate. Numerical simulations and experiments were developed to find the proper filter material and thickness by calculating the X-ray fluorescence intensities and the signal-to-noise ratio. The developed system is capable of online monitoring of Cr levels, to certify that the concentration is below the threshold level in leachate. An XRF prototype was built and calibrated for underwater Hg analysis in maritime wet sediment using a radioisotope source. The presented results show that it is possible to detect Hg by K-shell emission thus enabling XRF analysis for sediment underwater.For non-homogeneous samples, an image revealing the elemental distribution can be achieved by micro-XRF (µ-XRF). XRF mapping of element distributions on a microscopic level was obtained by using scanning XRF microscopy and full-field XRF projection microscopy (FF-XRF). The spatial resolution of the scanning XRF imaging setup using an X-ray tube is in the order of 100 µm, but need to be further improved to measure the homogeneity of S on individual fiber level in pulp and paper industry. For the scanning technique, it is a tradeoff between resolution and measurement time. Another technique is FF-XRF imaging, and a setup was implemented using an energy resolving pixel detector and X-ray optics. The capabilities and limitations of using X-ray optics in XRF imaging systems have been identified. These microscopy measurements can guide further comprehensive environmental and industrial monitoring missions, utilizing elemental distribution information.
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| 19. |
- Andersson, Ewa, 1980-
(författare)
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Oberoendets praktik
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Independent PracticeDuring the last hundred years, the music industry has evolved with the record labels playing a central role. However, many argue that this situation is about to change as record sales have decreased during the last ten years. This imminent change in the music industry will not only affect the multinational record labels, but also the independent record labels. As record sales have decreased during the last ten years, the number of members in the Swedish Independent Music Producers Association (SOM) has increased and the association now includes 300 independent record labels which are responsible for around 30 percent of the music being produced in Sweden. However, they can be considered a dominated group within the music industry, since they only have around 10 percent of the total market shares when it comes to selling figures. Considering the changes in record sales, the domination of the major record labels and the somewhat fascinating growth of independent actors during turbulent times, this thesis will study how the Swedish independent actors relate to the practices and ideals relevant in the daily work of running an independent record label. The practices studied in this thesis are the practice of work, the practice of recognition and the practice of content production.The purpose of this thesis is to analyse how independence is constructed among the members of SOM. The thesis is based on material collected in a web survey as well as seven interviews with representatives of indie labels. The web survey was distributed to all members of SOM, and the interviewed informants were selected by snowball sampling, using a locator to find informants. The survey material was analysed with cluster and variance analysis, while the interview material was analysed using content analysis – searching for themes connected to the practices. All material is understood through the theoretical frame of the field theory.The main results of the study are that there are different ways of relating to practices among the Swedish independent actors, and that these ways of relating are closely connected to their position within the field. There are common ways of relating to practices such as always promoting DIY, the importance of music and the need to resist the dominance of the major labels. However, the independent actors are not consistent in how these commonalities work in practice. For example, DIY is not applied if it is not economically necessary, and the need to resist the major labels is only apparent when the independent actor has a weaker position within the field. The more established an independent actor is within the field, the lesser resistant he is against the dominating structures of the music industry. As a result of a weakening resistance against the major labels, the independent actors turn to struggle each other.
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| 20. |
- Andersson, Erik, 1984-
(författare)
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PHYSIOLOGICAL AND BIOMECHANICAL FACTORS DETERMINING CROSS-COUNTRY SKIING PERFORMANCE
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cross-country (c.c.) skiing is a complex sport discipline from both physiological and biomechanical perspectives, with varying course topographies that require different proportions of the involved sub-techniques to be utilised. A relatively new event in c.c. skiing is the sprint race, involving four separate heats, each lasting 2-4 min, with diverse demands from distance races associated with longer durations. Therefore, the overall aim of the current thesis has been to examine the biomechanical and physiological factors associated with sprint c.c. skiing performance through novel measurements conducted both in the field (Studies I-III) and the laboratory (Studies IV and V).In Study I sprint skiing velocities and sub-techniques were analysed with a differential global navigation satellite system in combination with video recording. In Studies II and III the effects of an increasing velocity (moderate, high and maximal) on the biomechanics of uphill classical skiing with the diagonal stride (DS) (Study II) and herringbone (HB) (Study III) sub-techniques were examined.In Study I the skiers completed the 1,425 m (2 x 712 m) sprint time trial (STT) in 207 s, at an average velocity of 24.8 km/h, with multiple technique transitions (range: 21-34) between skiing techniques (i.e., the different gears [G2-7]). A pacing strategy involving a fast start followed by a gradual slowing down (i.e., positive pacing) was employed as indicated by the 2.9% faster first than second lap. The slower second lap was primarily related to a slower (12.9%) uphill velocity with a shift from G3 towards a greater use of G2. The maximal oxygen uptake ( O2max) was related to the ability to maintain uphill skiing velocity and the fastest skiers used G3 to a greater extent than G2. In addition, maximal speed over short distances (50 and 20 m) with the G3 and double poling (DP) sub-techniques exerted an important impact on STT performance.Study II demonstrated that during uphill skiing (7.5°) with DS, skiers increased cycle rate and cycle length from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal velocity. Absolute poling, gliding and kick times became gradually shorter with an elevated velocity. The rate of pole and leg force development increased with elevated velocity and the development of leg force in the normal direction was substantially faster during skiing on snow than previous findings for roller skiing, although the peak force was similar in both cases. The fastest skiers applied greater peak leg forces over shorter durations.Study III revealed that when employing the HB technique on a steep uphill slope (15°), the skiers positioned their skis laterally (“V” between 25 to 30°) and planted their poles at a slight lateral angle (8 to 12°), with most of the propulsive force being exerted on the inside forefoot. Of the total propulsive force, 77% was generated by the legs. The cycle rate increased across all three velocities (from 1.20 to 1.60 Hz), while cycle length only increased from moderate to high velocity (from 2.0 to 2.3 m). Finally, the magnitude and rate of leg force generation are important determinants of both DS and HB skiing performance, although the rate is more important in connection with DS, since this sub-technique involves gliding.In Studies IV and V skiers performed pre-tests for determination of gross efficiency (GE), O2max, and Vmax on a treadmill. The main performance test involved four self-paced STTs on a treadmill over a 1,300-m simulated course including three flat (1°) DP sections interspersed with two uphill (7°) DS sections.The modified GE method for estimating anaerobic energy production during skiing on varying terrain employed in Study IV revealed that the relative aerobic and anaerobic energy contributions were 82% and 18%, respectively, during the 232 s of skiing, with an accumulated oxygen (O2) deficit of 45 mL/kg. The STT performance time was largely explained by the GE (53%), followed by O2 (30%) and O2 deficit (15%). Therefore, training strategies designed to reduce energetic cost and improve GE should be examined in greater detail.In Study V metabolic responses and pacing strategies during the four successive STTs were investigated. The first and the last trials were the fastest (both 228 s) and were associated with both a substantially larger and a more rapid anaerobic energy supply, while the average O2 during all four STTs was similar. The individual variation in STT performance was explained primarily (69%) by the variation in O2 deficit. Furthermore, positive pacing was employed throughout all the STTs, but the pacing strategy became more even after the first trial. In addition, considerably higher (~ 30%) metabolic rates were generated on the uphill than on the flat sections of the course, reflecting an irregular production of anaerobic energy. Altogether, a fast start appears important for STT performance and high work rates during uphill skiing may exert a more pronounced impact on skiing performance outdoors, due to the reduction in velocity fluctuations and thereby overall air-drag.
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| 21. |
- Andersson, Henrik, 1975-
(författare)
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Position Sensitive Detectors : Device Technology and Applications in Spectroscopy
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the development, processing and characterization of position sensitive detectors and, in addition, to the development of compact and cost effective spectrometers. Position sensitive detectors are used to measure, with great accuracy and speed, the position of a light spot incident on the surface. Their main use is for triangulation, displacement and vibration measurements. A type of position sensitive detector based on the MOS principle and using optically transparent indium tin oxide as a gate contact has been developed. This type of detector utilizes the MOS principle where an induced channel forms beneath the gate oxide in the surface of the Silicon substrate. One and two dimensional detectors have both been fabricated and characterized. The first measurements showed that the linearity did not fulfil expectations and it was suspected that stress induced by the gate contact could be the reason for the seemingly high nonlinearity. Further investigations into both the p-n junction and the MOS type position sensitive detectors lead to the conclusion that the indium tin oxide gate is responsible for inducing a substantial stress in the surface of the detector, thus giving rise to increased position nonlinearity. The heat treatment step which was conducted was determined to be critical as either a too short or too long heat treatment resulted in stress in the gate and channel leading to position nonlinearity. If a correctly timed heat treatment is performed then the detector’s linearity is in parity with the best commercial position sensitive detectors. In addition, the development of very small, compact and cost effective spectrometers has been performed with the aim of constructing devices for use in the process industry. The development of a wedge shaped array of Fabry-Perot interferometers that can be mounted directly on top of a detector makes it possible to construct a very compact spectrometer using the minimum amount of optics. This wedge interferometer has been evaluated by means of array pixel detectors and position sensitive detectors for both the infrared and the visible wavelength ranges. When used with a position sensitive detector it is necessary to use a slit to record the intensity of the interferogram for many points over the detector, equivalent to pixels on an array detector. Usually the use of moving parts in a spectrometer will impose the use of high precision scanning mechanisms and calibration. By using a position sensitive detector for the interferogram readout both the position and the intensity are known for every measurement point and thus the demands placed on the scanning system are minimized.
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| 22. |
- Andreassen Devik, Siri
(författare)
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Hjemmesykepleie til eldre som bor på bygda med uhelbredelig kreft
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The need to deliver high-quality palliative homecare has been underscored in current professional guidelines and demands for efficacy, as well as in the preferences of patients and their families. Indeed, demographic changes and an increased risk of cancer among older people pose challenges to the home healthcare settings in Norway and the rest of the world. Yet, little is known about how older persons experience living with incurable cancer and how palliative home nursing care may increase their quality of life. Moreover, few studies have focused on rural contexts or explored such settings can influence the delivery and outcome of care. In rural contexts, long distances and limited health-related human resources challenge the provision of specialised services, and palliative patients living in rural municipalities most often receive services from district nurses without special training in oncological or palliative care. The aim of this thesis was thus to explore experiences with, and meanings of, rural home nursing care among older persons living with incurable cancer. The thesis consists of five studies, all with qualitative designs, and performed in rural municipalities.Study I was designed as a case study involving individual interviews and observations to explore how older persons diagnosed with incurable cancer and living alone have experienced daily life while commuting for policlinic palliative chemotherapy. By extension, the aim of Study II, conducted as a secondary analysis of material collected in study I, was to illuminate and interpret the meanings of the lived experiences of the participants in that study. By contrast, Study III used individual interviews to illuminate and interpret the meaning of the lived experience of older persons with incurable cancer, yet who have received home nursing care. Meanwhile, Study IV entailed individual interviews with nurses working in home nursing care. Its aim was to illuminate and interpret the meaning of nurses' lived experiences among severely ill patients in their homes. Lastly, Study V involved individual interviews with bereaved family members; its aim was to explore their perceptions of suffering in older persons receiving palliative home nursing care during their final phase of life. The findings of Study I showed that older persons interviewed hovered between hope and fear, experienced stressful commutes, and were constantly exhausted. Experiences with long, tiring taxi trips, of having few supportive people nearby, and of being offered hardly any local healthcare services made these persons highly vulnerable. Nevertheless, their demands were few, and they rarely complained. The findings of Study II showed a complex, yet comprehensive situation in which physical symptoms and emotions had become entangled. Four themes were found: enduring by keeping hope alive, becoming aware of being one one's own, living up to expectations of being a good patient, and being at risk of losing identity and value. Suffering related to care, or the lack therefore, was the most striking discovery, and the older persons seemed to endure by keeping hope alive. Besides hoping for survival, their hopes also included a desire to be recognised and treated with respect, though such often seemed to go unnoticed. The findings of Study III revealed three themes: being content with what one gets, falling into place, and losing one's place. The phrase picking up the pieces was found useful for summing up the meaning of one's lived experience. In that sense, the three themes referred to how the pieces symbolized the remaining parts of life or services available in their environment and how the older persons might see themselves as pieces in a puzzle. Participants exhibited strong place attachment, involving physical insideness, social insideness, and autobiographical insideness, which suggested that the rural context might provide and advantageous healthcare environment. Interestingly, nurses' personal engagement and willingness to be involved in caring relationship appeared to be more important than any special competence or technical skills. The findings of Study IV showed that patients' expressions left impressions that caused emotional waves in the nurses. Four themes were found: being open for the presence of the Other, being satisfied, being frustrated, and being ambivalent. Understanding and balancing this emotional dimension in care seemed to cause confusion and distress for the nurses, and realizing how their feelings might prompt either generosity or aloofness towards the patient was upsetting. Thatinterpretation suggested confusion regarding what it means to be a professional nurse.Lastly, the findings of Study V showed that bereaved family members perceived suffering related to the illness, to the care, and to the life of their ill relatives during their final phase of life. Well-being emerged as having significant, contrasting elements. Well-being related to other people, to the home, and to activity, in all of which the essence referred to a state of dwelling-mobility. The findings suggested that nurses in this context need to seek out patients' and their families members' experiences with comfort and with disturbance. Nursing and palliative care that become purely disease- and symptom-focused can end with all parties' giving up and divert attention from social and cultural factors that may contribute to well-being when cure is not the goal.The findings of this thesis could alter some current knowledge in the field. From a patient perspective, the rural context is not necessarily disadvantaged, care is not necessarily caring, and the alleviation of suffering and cultivation of wellbeing are not necessarily two sides of the same coin. Home nursing care is often seen as a precondition for staying at home. Working in patients' homes allows nurses to witness and become involved in each patient's unique situation. However, impressions of patients' expressions awake feelings in nurses that have the power to bring about caring actions. At the same time, the fear of being unprofessional or unable to deliver proper care bothers nurses and might threaten the closeness that patients desire. Home nursing is care organized in a system in which services are predefined, apportioned, and bound to specific procedures, and the holistic ideals of the palliative care philosophy are often not within the framework of the system in which district nurses work.
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| 23. |
- Andres, Britta, 1986-
(författare)
-
Low-Cost, Environmentally Friendly Electric Double-Layer Capacitors : Concept, Materials and Production
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today’s society is currently performing an exit from fossilfuel energy sources. The change to sustainable alternativesrequires inexpensive and environmentally friendly energy storagedevices. However, most current devices contain expensive,rare or toxic materials. These materials must be replaced bylow-cost, abundant, nontoxic components.In this thesis, I suggest the production of paper-based electricdouble-layer capacitors (EDLCs) to meet the demand oflow-cost energy storage devices that provide high power density.To fulfill the requirements of sustainable and environmentallyfriendly devices, production of EDLCs that consist of paper,graphite and saltwater is proposed. Paper can be used as aseparator between the electrodes and as a substrate for theelectrodes. Graphite is suited for use as an active material in theelectrodes, and saltwater can be employed as an electrolyte.Westudied and developed different methods for the productionof nanographite and graphene from graphite. Composites containingthese materials and similar advanced carbon materialshave been tested as electrode materials in EDLCs. I suggest theuse of cellulose nanofibers (CNFs) or microfibrillated cellulose(MFC) as a binder in the electrodes. In addition to improvedmechanical stability, the nanocellulose improved the stabilityof graphite dispersions and the electrical performance of theelectrodes. The influence of the cellulose quality on the electricalproperties of the electrodes and EDLCs was investigated.The results showed that the finest nanocellulose quality is notthe best choice for EDLC electrodes; MFC is recommended forthis application instead. The results also demonstrated thatthe capacitance of EDLCs can be increased if the electrodemasses are adjusted according to the size of the electrolyte ions.Moreover, we investigated the issue of high contact resistancesat the interface between porous carbon electrodes and metalcurrent collectors. To reduce the contact resistance, graphitefoil can be used as a current collector instead of metal foils.Using the suggested low-cost materials, production methodsand conceptual improvements, it is possible to reduce the material costs by more than 90% in comparison with commercialunits. This confirms that paper-based EDLCs are apromising alternative to conventional EDLCs. Our findings andadditional research can be expected to substantially supportthe design and commercialization of sustainable EDLCs andother green energy technologies.
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| 24. |
- Andresen, Edith
(författare)
-
Dressed for success : designing and managing regional strategic networks
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inter-organizational network initiatives such as regional strategic networks (RSNs) are often used by firms and public agencies to support regional development and competitiveness. RSNs are designed networks managed by a hub and financed by public or private means. RSN management is complex as members are autonomous and initially often loosely connected. The effects of RSNs on regional development are disputed as engineered relationship development may interfere with ongoing business relationships. Despite this, vast public funds are being invested in collaborative initiatives. Identifying factors affecting RSN performance will provide a better basis for evaluating and managing such initiatives.Based on concepts such as actors, resources, and activities findings are reported from longitudinal case-studies built on interviews with 68 members and hubs in four RSNs. Data were also collected through participant observation, conversations, archival data and emails. Findings indicate that factors such as evaluation criteria, member composition, relationships, location, goals, the hub, physical and human resources, knowledge sharing and development, resources, policies and norms, social activities, and communication exert an impact on entrepreneurship and cooperation.The first paper focuses on factors such as actor composition, actor goals, number of actors, and activities facilitating relationship development and commitment. The second paper identifies a framework of seven tasks to be performed by the hub. The effects on development of preferences and atmosphere are dealt with in the third paper. Effects of cooperation between public/private sector and universities are addressed in the fourth paper, and entrepreneurial processes in network contexts are analyzed in the fifth one.The important management role of the hub is emphasized as is carefully considered member composition. Relationships and commitment are found to be crucial. These factors are not covered by national and regional performance criteria. They merit a place of their own.
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| 25. |
- Aranda, Jesus Javier Lechuga
(författare)
-
Towards Self-Powered Devices Via Pressure Fluctuation Energy Harvesters
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The growing interest in the Internet of Things has created a need for wireless sensing systems for industrial and consumer applications. In hydraulic systems, a widely used method of power transmission in industry, wireless condition monitoring can lead to reduced maintenance costs and increase the capacity for sensor deployment. A major problem with the adoption of wireless sensors is the battery dependence of current technologies. Energy harvesting from pressure fluctuations in hydraulic systems can serve as an alternative power supply and enable self-powered devices. Energy harvesting from pressure fluctuations is the process of converting small pressure fluctuations in hydraulic fluid into a regulated energy supply to power low power electronics. Previous studies have shown the feasibility of pressure fluctuation harvesting. However, for the development of self-powered sensor systems, the methods and techniques for converting pressure fluctuations into electrical energy should be further investigated.This thesis explores the methods, limitations, opportunities and trade-offs involved in the development of pressure fluctuation energy harvesters in the context of self-powered wireless devices. The focus is on exploring and characterizing the various mechanisms required to convert pressure fluctuations into electrical energy. In this work, an energy harvesting device consisting of a fluid-to-mechanical interface, an acoustic resonator, a piezoelectric stack, and an interface circuit is proposed and evaluated. Simulations and experimental analysis were used to analyse these different components for excitation relevant to hydraulic motors.The results of this work provide new insights into the development of power supplies for self-powered sensors for hydraulic systems using pressure fluctuation energy harvesters. It is shown that with the introduction of the space coiling resonator for pressure fluctuation amplification and a detailed analysis of the fluid interface and power conditioning circuits, the understanding of the design and optimization of efficient pressure fluctuation energy harvesters is further advanced.
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| 26. |
- Aronsson, K. Andreas
(författare)
-
Effects of wood ash on freshwater organisms and aquatic forest ecosystems
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wood ash application (WAA) has been recommended mainly for two reasons; i) to avoid depletion of minerals in the soil due to whole tree harvest in the forestry and ii) to mitigate harmful effects of acidification of soil and surface waters. In conclusion, the effects on terrestrial ecosystems and, especially, tree growth, can be attributed to the properties of the ash, the dose applied and the specific site at which the ash is applied. The research conducted on the effects of WAA on limnological ecosystems is very limited, and the major purpose of the present thesis was to gain knowledge of the effects of wood ash to different freshwater organisms, and the more comprehensive, limnological effects of WAA in the first stream in Bispgården, Sweden. Effects of wood ash solutions on the unicellular alga Euglena gracilis Klebs, the amphipod Gammarus pulex L., and the moss Fontinalis antipyretica Hedw. were investigated under laboratory conditions. Common in all three species was the decline in performance (growth/velocity/respiration/oxygen evolution) when the concentration of wood ash exceeded 5 g/l and no adjustment of pH was done (alkaline solution). In contrast, different movement parameters (motility, upwards swimming and velocity) in E. gracilis (neutral conditions), and increased growth of F. antipyretica with increased concentrations of wood ash indicated that nutrients in the ash was bioavailable for these organisms. There was no evidence of toxic effects on the organisms from metals or other compounds as a result from exposure to wood ash solutions in the present studies. The field study was conducted in a forest area close to Bispgården, about 100 km NW from Sundsvall, Sweden. The catchment area (50 ha) of the stream Fanbergsbäcken was treated with wood ash in September of 2004 (3,000 kg/ha;selfhardened crush-ash). In general, both biological (diatoms) and chemical (pH, alkalinity, and aluminum (Al) measurements) indicators have shown no significant effect on acidification parameters from the addition of wood ash. There was, however, evidence of an increased pH during spring flood, accompanied with a decrease in the frequency of low pH values (<5.6) during spring flood. In addition to this, alkalinity was significantly higher in the period 2005-2006, compared to that of 2003. High concentrations of toxic forms of Al repeatedly occured in the stream Fanbergsbäcken, and the WAA did not affect the frequencies of high concentrations of toxic Al forms (<50 μg/l). Both the moss F. antipyretica and the leaves from Alnus incana displayed increased potassium (K) concentrations, although other nutrients did not increase from WAA. In conclusion, no evidence of WAA being effective in restoring or improving the ecological status of freshwater environments has been established, either in the literature or in the present field study. On the other hand, there were no indications of harmful effects due to WAA, either. However, we still do not know the effects of wood ash on several organisms (predominantly invertebrates) inhabiting small ponds and other, temporary or permanent, freshwater ecosystems. In the context of WAA, these environments and organisms have not attended any attention in the research published to date, and future studies are strongly encouraged.
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| 27. |
- Arvidson, Catarina, 1959-
(författare)
-
Genuspedagogers berättelser om makt och kontroll
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis 14 gender pedagogues’ stories about power and control are described and analysed. Here the term gender pedagogue refers to educators who have participated in further training in gender and gender equality studies. The training programme was the result of an initiative taken by the former Social Democratic government. The intention of the government was that those who participated in the training programme would then work as resource persons in the work for gender equality in preschools and schools (Frånberg, 2010; Regeringen, 2001a, 2001b; Wahlgren, 2009). The purpose of this study is to describe and analyse the gender pedagogues’ access to power and control in work for change. The theoretical framework chosen for the study consists of Basil Bernsteins concepts classification and framing (Bernstein, 1977, 2000) and Hildur Ve’s (1999a, 1999b) use of the concepts technical limited rationality and care work rationality. The empirical evidence is based on observations in a seminar series on gender issues and semi-structured interviews. The results of the interviews are presented as stories which have been created in the interplay between the gender pedagogues and the interviewer. One conclusion that can be drawn from the stories is that power relations and gender patterns on many different levels influenced the possibilities of the gender pedagogues for power and control. Power and control in the relation between technical limited rationality and care work rationality is expressed in different ways. It is seen in the possibilities and descriptions of resistance and difficulties. Resistance and difficulties depended, according to the gender pedagogues, on the differences between their own view of knowledge and that of others. If gender and gender equality was not considered to be an important area of knowledge, possibilities for power and control decreased.
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| 28. |
- Ashraf, Shakeel, 1984-
(författare)
-
Thermal detector with integrated absorber structure for mid-IR gas detection
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Measurement of the concentration of greenhouse gases, such as carbon dioxide(CO 2 ) and methane (CH 4 ), in the atmosphere has received significant attention in the last few decades. This work focusses on the development of high-performance thermopile detectors for use with the non-dispersive infrared (NDIR) measurements of such gases. The performance of the thermopile detectors could effectively be increased by selecting membrane materials with a low thermal conductivity value and an efficient infrared (IR) absorbing material and by selecting the materials with high Seebeck coefficient values. Graphite black paint can be used as a radiation absorber, as it has high absorption (80—93%) for a wide spectral range (2.5 μm — 20 μm). By using spray paint or a paint brush, the application of the absorber is simple and fast. However, the control over the processing process suffers with these simple methods. The thermal capacitance of the detector will rapidly increase due to uneven distribution and unknown thickness of the absorber, although the response of the thermopile detector will be maximum due to high absorption; however, the response time (τ th )for the detector will be longer.In order to improve the performance, IR absorbers have been designed to utilise the membrane (SU-8 epoxy) of the detector as an active part of the IR absorber. This utilisation of the SU-8 epoxy membrane will result in a maximum detector sensitivity and a minimum increase in both the thermal capacitance and thermal conductance of the thermopile detector. Absorber structures, based on SU-8 epoxy, with a narrow absorption band at 4.26 µm and a wider multi-layered absorption band at 3-6 µm, were designed, simulated, and fabricated, and their integration into the membrane of thermopile detectors have been presented. The response of the thermopile detector could also be increased by using materials with high Seebeck coefficient [1] values such as semiconductor materials, as they have higher Seebeckvalues compared to the metals. In the thesis, molybdenum disulfide (MoS 2 ) flakes were characterised, and Seebeck values were estimated through a measurement setup as a function of temperature difference (ΔT). The fabricated thermopile detectors were characterised, and the response time(τ th ) of a thermocouple with a multi-layered absorber structure has been estimated to be 21 ms. The detector has shown high responsivity value in the wavelength range of 3 µm – 4.5 µm, which is used for CO 2 and CH 4 detection. The thermopile detector was evaluated for CO 2 gas through a long-path-length NDIR platform. The results show that the evaluated thermopile could be used for the measurement of gas concentration down to levels of a few parts per million (ppm) by using the long-path-length NDIR platform.
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| 29. |
- Bader, Sebastian
(författare)
-
On the lifetime and usability of environmental monitoring wireless sensor networks
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wireless sensor networks have been demonstrated, at an early stage in their development, to be a useful measurement technology for environmental monitoring applications. Based on their independence from existing infrastructures, wireless sensor networks can be deployed in virtually any location and provide sensor samples in a spatial and temporal resolution, which otherwise would only be achievable at high cost or involve significant work by humans.The feasibility of the usage of wireless sensor networks in real-world applications, however, is only maintained if certain technological challenges are overcome. Amongst these challenges, are the limited lifetime of the distributed sensor nodes, and user interfaces, which allow for the technology to be utilized in an efficient manner. Contributions to the solution of these challenges have been the objective of this thesis.After an analysis of the contributions wireless sensor networks can provideto the application domain of environmental monitoring, and the introductionto the restrictions, which are posed by a limited operational lifetime and lowsystem usability, these issues are addressed at the system level of sensor nodedevices.The lifetime of sensor nodes, which is closely linked to the lifetime of thecomplete wireless sensor network, is addressed with regards to the energyefficiency of nodes, as well as the utilization of solar energy harvesting inorder to increase the available energy resources. With respect to energyefficiency, an analysis has been performed of the contributions to the energyconsumption of environmental monitoring sensor nodes, which leads to thedesire to minimize the nodes' duty cycles and quiescent currents. A sensornode design is presented, which features energy efficiency as a key attribute by utilizingmodern semiconductor architectures. Moreover, an argument for the usage of synchronization-based, contention-free communication is madein order to reduce active communication periods and, thus, the duty cycleof a sensor node. A synchronization method with its focus on low protocoloverhead is introduced as a basis for such communication forms. After an initial feasibility study in relation to using battery-less solar energyharvesting architectures in locations with limited solar irradiation, multiplearchitectural implementations are analyzed in a comparative manner.Among these comparisons is an analysis of short-termenergy storage devices in the form of double-layer capacitors and thin-film batteries, which provide prolonged component lifetimes than those for conventional secondary batteries, but which can only buffer for short periods of time due to their limited energy capacity. In order to be able to dimension such energy harvesting systems with respect to the individual application constraints at hand, state of charge simulations are proposed. Amethod for such simulations is presented and demonstrated for the implementation of an energy harvester model on a component basis. While the modeling in this manner is time consuming, the model can predict the state of charge of the energy buffer in the architecture with a high level of accuracy. Finally, a method for the systematic evaluation of solar energy harvesting architectures is presented. The presented method can be summarized as a solar energy harvesting testbed, which utilizes configurable energy harvesting circuits in order to create a deploy-once-test-many type of system. The output results of this testbed can significantly improvethe efficiency of architecture comparisons and system modeling.Contributions to the improvement of the usability of wireless sensor nodesare made on two separate levels, namely, developer usability and end userusability. A method for the programming of sensor nodes based on hierarchical finite state machines is presented, which improves the usability of software development by creating familiarity for technically experiencedusers. Moreover, the utilization of finite state machine principles allowsfor the software to be developed in a systematic andmodular manner. Asimplemented applications typically require to be verified, which, in the environmental monitoring domain, usually results in outdoor deployments,usability considerations for sensor nodes are presented, which can simplifythis process. Special attention has been paid in order for these improvements to be achieved with low overheads. While software development is a familiar concept for most system developers, this is not the case for the end users of these systems, who are typically domain experts. In order to allow for wireless sensor nodes to be operatedby domain experts, a method for the configuration of sensor nodes has been proposed.The method uses a combination of graphical specification of the node behavior and a configurable sensor node. Theevaluation of this method, which has been based on a proof-of-concept implementation, demonstrated that the performance can remain high, while end users, without technical experience, are enabled to configure sensor nodes without prior training.In summary, the contributions, presented in this thesis, address systemlifetime and usability with regards to the sensor node level. The results haveled to the implementation of an energy efficient sensor node, which allows for the operation frombattery-less solar energy harvesting sources. Furthermore, support tools for the implementation of these nodes, both on the hardware and software level, have been proposed.
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| 30. |
- Bakar, Muhammad Abu, 1969-
(författare)
-
Wide Range Isolated Power Converters
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Power electronics technology is rapidly growing in most industrialapplications. There is an increasing demand for efficient and low profilepower converters in the industry like automotive, power grids, renewableenergy systems, electric rail systems, home appliances, and informationtechnology. In some applications, there is an increasing demand for powerconverters showing a stable performance over a wide variation in inputvoltage, whereas in others the demand is for converters showing a stableperformance over a wide variation of output voltage. In this regard, not somuch work has been done to combine both requirements into one solution;this is the primary focus of the dissertation. It presents a unique solution tothe industry, which addresses both requirements. The technique can beapplied in a one size fits all solution which not only extends the range of theline voltage and the output voltage but also provides the flexibility to adjustthe required set of line/output voltage. The variation in line voltage severelydegrades the performance of power converters because of the extendedfreewheeling interval, more circulating current, narrow range of zero voltageswitching and increased EMI. To overcome this, the converter consists of tworeconfigurable modes on the input side that can be configured following thevariation in line voltage to maintain a stable performance. In addition, itproposes three reconfigurable steps for the output voltage, which can be usedto adjust the output voltage from base level X to 2X and 4X in discrete stepsand/or from X - 4X volt while showing stable performance. This makes theproposal a 2x3 reconfigurable modes power converter, which means that thegain of the proposed converter can be raised to 4 or 8. Furthermore, theflexibility in the reconfigurable structure simplifies the implementation of theproposed single solution in a range of applications. Each concept proposed inthe thesis is verified analytically, experimentally and modelling it into aSPICE simulation. Then the whole concept is confined into a single entity,which is applied in an example application of a phase shifted full bridgeconverter. The full converter is characterized for input voltage 100-400Vdc, theoutput voltage 24-96Vdc, and up to the load power of 1kW.
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| 31. |
- Balliu, Enkeleda, PhD student
(författare)
-
Power Scaling of Highly Compact Single-Frequency Yb-Doped Fiber Amplifiers
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Both scientific interests and industrial applications have stimulated the advance of single-frequency laser technology. The high spatial and temporal coherence of this technology has facilitated many applications such as gravitational wave detection, high-precision fiber sensors, high-resolution spectroscopy, holography, and nonlinear optical conversion. However, this is currently achieved through large footprint lasers with limited portability and mobility. Therefore, there is a need to reduce the size of these lasers into a compact format. Power performance of hundreds of watts in the near-infrared spectrum and tens of watts in the visible and UV spectra for continuous (CW) operation mode and pulse energies up to several tens of mJ in pulsed operation mode are needed. An amplification structure for single-frequency lasers that meets these requirements is the master oscillator power amplifier (MOPA). However, compactness imposes several constraints on the MOPA design. The main challenge is the limited output power of the single-frequency fiber MOPA due to the onset of stimulated Brillouin scattering (SBS) in the amplifier fiber. SBS arises from the interaction of acoustic phonons with the propagating signal wave and is converted into a frequency-shifted, backward-propagating wave. SBS is manifested through high-intensity pulses propagating in the backward direction, which can be very harmful for optical components and the seed laser itself. Hence, the suppression of SBS is crucial to the power optimization of the MOPA. This thesis therefore focuses on investigating different SBS suppression techniques that fit a compact MOPA design. More specifically, this is implemented by studying the efficiency of the strain distribution technique applied to the amplifier fiber and the use of custom and commercial highly Yb- doped fibers both in CW and pulse operating MOPAs. Using highly Yb-doped fibers presents challenges with respect to the composition of the fiber material and in high- power operation that can have undesirable degradational effects, such as photodarkening and thermal load generation, and these have been investigated and discussed in this thesis. As a result of the different mitigation approaches, output power approaching 100 W in CW mode operation and pulse energies near mJ in pulse mode operation are demonstrated in only one amplification stage, showing the feasibility of a MOPA design with high performance and a small footprint. This may facilitate many applications in the visible and UV spectral ranges that require mobility and portability.
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| 32. |
- Barac, Filip
(författare)
-
Error mitigation in industrial wireless sensor networks : Corrupted packet forensics and recovery
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wireless sensor networks (WSN) are gradually penetrating the industrial automation domain. This process is, however, inhibited by a number of challenges that need to be considered and addressed before WSN can serve the most demanding industrial applications. In the context of process automation, existing technology can only serve the three least critical application classes related to non-critical monitoring of slowly-changing physical variables. The main issue in that respect is the insufficient communication timeliness and reliability, caused by the influence of harsh radio environment and the infeasibility of applying advanced communication techniques, due to the poor computational power of low-cost specialized hardware. The goal of this work is to improve wireless communication reliability in industrial environments, where the proposed solutions are generally applicable to other WSN domains as well as radio environments. This research is based on the notion that corrupt packets contain valuable channel state information that can be leveraged to improve communication robustness. The research methodology used in this work is rather unconventional, compared to existing research, but also highly intuitive, bearing in mind that counteracting a phenomenon requires a thorough knowledge of its properties. In order to rectify the aforementioned challenges, this work makes the following three contributions. The first contribution is a comprehensive analysis of communication errors recorded in practically relevant scenarios in a number of industrial environments. The related literature is seemingly rich, but essentially poor, due to inadequate measurement objectives, environments, and scenarios. The main research outcome of this measurement campaign is a set of practically relevant conclusions, which can be used for the design of coding, interleaving and packet recovery schemes. The second contribution is the design of two packet recovery schemes, based on the knowledge about error patterns obtained in the industrial measurement campaign. The first scheme is a proposal for redefinition of the IEEE 802.15.4 physical layer, where digital errors are counteracted at the earliest stage in the receiver chain. The second scheme exploits the determinism in packet structure inherent to industrial communication. Both schemes significantly improve the correctability of corrupted packets received. The third contribution is a channel diagnostics algorithm that determines whether a packet was corrupt by multipath fading and attenuation or by wireless local area network interference. The algorithm is derived from the error traces collected in three industrial environments and tested at a fourth, previously unused, industrial site. The results of live tests verify the ability of the proposed algorithm to promptly reestablish communication after a sudden deterioration of channel quality.
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| 33. |
- Bayat, Nazlin
(författare)
-
Investigation of Surface Formation in As-Cast and Homogenized 6xxx Aluminium Billets
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The direct chill (DC) casting technique to produce billets for extrusion and ingots for rollingwas developed in the 1930s. The principle, which is still valid, is a two-stage cooling with a primary cooling at a mould surface followed by water spraying directly on the surface. Improvements of this technique have mainly focused on changes to the primary cooling, where a water-cooled metal mould has been replaced by different techniques to minimize cooling at this stage. The drive for development comes from the extrusion industry, which can increase the productivity and quality of extruded profiles by improving the billet surface appearance and structure. Hot top casting supported by airflow against the casting surface during the primary cooling is currently the standard procedure to achieve acceptable billet surfaces. The goal is to minimize the depth of the surface segregation zone, which is the governing factor for the appearance of different phases in the surface region. Billet surface quality is evaluated by quantifying surface appearance, segregation zone thickness, and occurrence of large Mg2Si and β-particles near the surface. The β-Al5FeSi intermetallic phase and coarse Mg2Si particles have negative effects on extrudability and workability of 6xxx Al alloys billets. To achieve extruded products with a high surface quality the as-cast billets are heat-treated before extrusion. During heat treatment the undesired intermetallic particles, i.e., β-AlFeSi platelets are transformed to rounded α-Al(FeMn)Si intermetallic phases.In this research the formation of the surface segregation for smooth defect-free surfaces in both as-cast and homogenized billets was studied. In addition, the surfaces with defects such as wavy, spot and vertical drag defects were investigated and possible mechanisms for initiation of those defects were explained. Moreover, for a better understanding of the homogenization process in-situ studies of the heat treatment of 6082, 6005, 6060 and 6063 Al alloys were carried out by using a transmission electron microscope (TEM). Based on the observations, an explanation of the probable mechanisms taking place during transformation from β-to α-phase was presented.
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| 34. |
- Bellman, Lina
(författare)
-
In the mind of the property appraiser : Studies of commercial property valuation
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A transparent market provides participants with as much information as possible. In Sweden, where the environment of commercial properties is highly transparent various actors still need to minimise some continuing information asymmetry, and one possibility is to hire property appraisers.Transparent commercial property markets are often regulated by governments and professional institutions. The combination of regulation and socialisation through memberships in professional associations and shared educational backgrounds, training, work experience, and institutional frameworks serve to produce and reproduce professional values and identities. The overall aim of this thesis is to describe and analyse the Swedish profession of property appraisers as expressed through members’ perceptions and use of various standards and methods, ways of gathering information gathering, assessments of value-influencing factors, and their confidence in their own assessments when valuing commercial properties.The repertory grid technique was used to collect and analyse empirical data and to map the thought patterns of respondents in two main samples. The repertory grid interviews in 2010/2011 included about half of the appraisers in Sweden (67 of 138), and in 2015 just over half (81 of 145).This thesis concludes that Swedish authorised property appraisers use country dependent valuation standards and methods, but there are signs of their increased adoption internationally. Swedish appraisers gather and assess information in a similar way. Their aggregated thought patterns demonstrate relatively strong homogeneity and moderate complexity. However, the findings also reveal that appraisers’ thought patterns differ depending on the university from which they graduated. The appraisers graduated from the highest ranked university simplify their valuation judgements more than do other appraisers.During the valuation process, property appraisers gather and assess a large amount of information considered relevant for estimations of a property object’s market value. Four types of information (local environment, location, rental income, and discount rate) seem to have the greatest impact on the estimated market value. The appraisers further perceive that these information types is common in that the decisions in the information gathering stage is critical to the entire valuation process when using clients as information sources. This seems to affect their perceived confidence at the assessment stage and, in turn, the final estimated market value. In situations where the appraisers have low confidence, they are left dependent on the clients, which risks reducing their independence.
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| 35. |
- Berg, Jan-Erik, 1957-
(författare)
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Wood and fibre mechanics related to the thermomechanical pulping process
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this thesis was to improve the understanding of some aspects on wood and fibre mechanics related to conditions in the thermomechanical pulping process. Another objective was to measure the power distribution between the rotating plates in a refiner. The thesis comprises the following parts: –A literature review aimed at describing fracture in wood and fibres as related to the thermomechanical pulping process –An experimental study of fracture in wood under compression, at conditions similar to those in feeding of chips into preheaters and chip refiners –An experimental study of the effect of impact velocity on the fracture of wood, related to conditions of fibre separation in the breaker bar zone in a chip refiner –A micromechanical model of the deterioration of wood fibres, related to the development of fibre properties during the intense treatment in the small gap in the refining zone –Measurements of the power distribution in a refiner. The fracture in wood under compression was investigated by use of acoustic emission monitoring. The wood was compressed in both lateral and longitudinal directions to predict preferred modes of deformation in order to achieve desired irreversible changes in the wood structure. It was concluded that the most efficient compression direction in this respect is longitudinal. Preferable temperature at which the compression should be carried out and specific energy input needed in order to achieve substantial changes in the wood structure were also given. The fibre separation step and specifically the effect of impact velocity on the fracture energy were studied by use of a falling weight impact tester. The fracture surfaces were also examined under a microscope. An increase in impact velocity resulted in an increase in fracture energy. In the thermomechanical pulping process the fibres are subjected to lateral compression, tension and shear which causes the creation of microcracks in the fibre wall. This damage reduces the fibre wall stiffness. A simplified analytical model is presented for the prediction of the stiffness degradation due to the damage state in a wood fibre, loaded in uni-axial tension or shear. The model was based on an assumed displacement field together with the minimum total potential energy theorem. For the damage development an energy criterion was employed. The model was applied to calculate the relevant stiffness coefficients as a function of the damage state. The energy consumption in order to achieve a certain damage state in a softwood fibre by uniaxial tension or shear load was also calculated. The energy consumption was found to be dependent on the microfibril angle in the middle secondary wall, the loading case, the thicknesses of the fibre cell wall layers, and conditions such as moisture content and temperature. At conditions, prevailing at the entrance of the gap between the plates in a refiner and at relative high damage states, more energy was needed to create cracks at higher microfibril angles. The energy consumption was lower for earlywood compared to latewood fibres. For low microfibril angles, the energy consumption was lower for loading in shear compared to tension for both earlywood and latewood fibres. Material parameters, such as initial damage state and specific fracture energy, were determined by fitting of input parameters to experimental data. Only a part of the electrical energy demand in the thermomechanical pulping process is considered to be effective in fibre separation and developing fibre properties. Therefore it is important to improve the understanding of how this energy is distributed along the refining zone. Investigations have been carried out in a laboratory single-disc refiner. It was found that a new developed force sensor is an effective way of measuring the power distribution within the refining zone. The collected data show that the tangential force per area and consequently also the power per unit area increased with radial position. The results in this thesis improve the understanding of the influence of some process parameters in thermomechanical pulping related wood and fibre mechanics such as loading rate, loading direction, moisture content and temperature to separate the fibres from the wood and to achieve desired irreversible changes in the fibre structure. Further, the thesis gives an insight of the spatial energy distribution in a refiner during thermomechanical pulping.
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| 36. |
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| 37. |
- Bergstrand, Ulrika
(författare)
-
Styrning och re-kontextualisering av värden i utbildningspolicy på nationell och lokal nivå
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this study, governing as re-contextualization of values in Swedish educational policy has been described and analyzed. Two levels have been central to the study: the national level, in the form of the Swedish Schools Inspectorate's (SSI) survey to school personnel, and the municipal level, examined by interviews with superintendents in sparsely populated and rural areas. Three qualitative content analyses were performed, in two of which Rokeach’s theory of values as desirable actions and goals was used. The results presented that the dominant policy goal and the value expressed was that schools should promote students' knowledge, which is in line with the values underlying the PISA survey. The SSI survey expressed that schools should be quality assured to enhance students' knowledge development. Desirable actions to achieve this were: the principals evaluating, the teachers adapting to individual students, strengthening an environment conducive to learning with codes of conduct, and the guardians being informed about their children’s development. However, the superintendents expressed a lack of competence and qualified teachers for equivalent assessments, a need to upskill teachers, and that the information to the guardians did not always reach them. The study also showed an expressed value to include all students in teaching, which is in line with the values underlying the Salamanca statement. The SSI survey expressed this value as the students' participation in individualized teaching, an increased efficiency in special support, a socialization through codes of conduct, and that the students should know their rights. The superintendents expressed this value as motivating students, particularly boys, to study, adapting education for students in need of special support, preventing violations of newcomers, addressing girls' mental health, and the strengthening of democratic attitudes. In summary, the study shows that the values at the national level promoted increased individual rights, while at the local level, the values were expressed as a need to increase democratic values. Nonetheless, the values underlying the education of democratic citizens in sparsely populated and rural areas cannot be considered a closed chapter, even though policies at the national level continue to emphasize the values of promoting students' development of knowledge and their individual rights.
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| 38. |
- Billmayer, Jakob, 1983-
(författare)
-
Ska dörren vara öppen? : Disciplin i klassrummet i Sverige och Tyskland
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study is to investigate discipline in German and Swedish classrooms and describe its cultural contexts. In countries with compulsory education, it must be assumed that not all students voluntarily attend classes. The mandatory presence of students combined with the ban on corporal punishment in schools means that classroom interaction has to be organized according to certain manners and rules (Luhmann, 2002a:108a). These rules are understood here as discipline meaning the organization and control of individuals and their actions over space and time (Foucault, 1987/1975). This study assumes similarities in the fundamental disciplinary mechanisms, although different contexts (here Germany and Sweden) will create different concrete manifestations of the phenomenon. Since the observation of cultural contexts is not as self-evident and direct as the observation of classroom interactions of teachers and students, the theoretical considerations here include a detailed discussion of methodology for observing culture. Starting with Alfred Schütz’ concept of ideal types and Niklas Luhmann’s theory on massmedia, it is argued that culture can be observed through the products of mass media. The empirical data for this study consists of field studies in the form of observations in German and Swedish classrooms as well as the examination of Germanand Swedish films and television series about teachers and students. The classroom observations were used to create ideal typical descriptions of different implementations of disciplinary procedure. Based on the analysis of teacher figures in various German and Swedish films and television series, several “good” and “bad” teacher types were initially identified. Combining the two results allowed conclusions tobe made about correlations between disciplinary order and whether a teacher is considered “good” or “bad”. This review of the various types of order is the basis for the description of cultural contexts. The results of classroom observations and film studies and their discussion in relation to prior Swedish research, gives the picture of a cultural context in which various forms of classroom order are avail-able, in which they are critically discussed and also can exist in parallel to each other. On the other hand, the German context seems to allow only one form of classroom order, both in actual school operations as well as in the mass media representation and scientific reflection.
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| 39. |
- Bjärtå, Anna, 1974-
(författare)
-
FEAR - A process influenced by concurrent processing demands
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fear is a central aspect in mammalian evolution, prompting escape from and avoidance of threat and dangers. Therefore, it is reasonable to believe that we have a well developed system to detect dangers and quickly respond to them. It has been shown that threatening information has an advantage in information processing; it seems to promote a rapid capture of selective attention and puts demand on processing resources. It has been suggested that the elicitation of fear occurs automatically, and that it is independent of and impenetrable to cognition.The idea with the present research is that fear processing is dependent on all concurrent internal or external processing demands. One visual search study (Study II) and two secondary task studies (Study I & III) have been conducted to investigate if external or internal distraction can interfere with fear processing. In order to provoke fear responses, spider or snake fearful individuals have been exposed to pictures of their feared stimulus. The aim of Study II was to investigate if the selective attention to fear stimuli could be influenced by contextual factors, such as the nature of the distracting stimuli in a visual search. Study I and III aimed to investigate manipulation of resources allocated to fear stimuli. In Study I, task demand was used as the manipulation, and in Study III an internal cognitive directive was used. The results from these studies indicate that fear is susceptible to manipulation by both external and internal means. By changing circumstances in the surrounding or in the individuals’ internal states, responses to threatening stimuli can be altered. This means that processing of threatening stimuli is influenced by other concurrent processing demands, suggesting that a fear response is not occurring as an isolated and impenetrable process. In an evolutionary perspective, a fear system that is easily triggered but has access to cognitive evaluation at all times ought to be far more flexible, thus creating a better chance for survival than a modular and impenetrable fear system.
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| 40. |
- Björk, Annette
(författare)
-
Stödjande gemenskap : Utveckling och utvärdering av en intervention för livsstilsförändring bland vuxna med adhd
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The entire project revolves around a lifestyle intervention that has been developed, implemented and evaluated. The intervention included adults with ADHD and comorbid mental illness. ADHD (Attention Deficiency Hyperactive Disorder) is a neuropsychiatric diagnosis/disability characterized by attention problems, impulsivity and hyperactivity and can affect education, working life, social relationships and form the basis for impaired lifestyle habits. Previous research shows shortened life expectancy in adults with ADHD, which related to deteriorating lifestyle habits. In the long run, the disability may be the basis for impaired living conditions and lifestyle habits and contribute to the individual's well-being and quality of life. In the field of health sciences, it is important to alleviate suffering, promote health and prevent ill health. Thus, the overall aim of this dissertation is to analyze living conditions among people with ADHD and mental illness, as well as to develop and evaluate a lifestyle intervention for this group.The PhD project includes four sub-studies: Study I, a qualitative interview study (n = 20) of adults with ADHD and mental illness, aimed at describing experiences of everyday suffering in this group. The analysis showed experiences of both suffering and well-being in living with ADHD. The focus of the suffering was the experience of loneliness, both regarding relationships in life, relationships in health care, but also to ADHD diagnosis and mental illness. Well-being was experienced when diagnosed with ADHD but also in relation to supportive social relationships. Study II, a quantitative descriptive and comparative study, aimed to gain more knowledge about people withADHD and their health situation. One group of people with ADHD (n = 48)was compared to the normal population without ADHD (n = 42). The results showed poorer health outcomes regarding self-perceived general health and the group with ADHD was less weekly physical active but nevertheless had no decreased aerobic fitness compared to the normal population. Study III, aquantitative descriptive study (n = 25), aimed to examine the degree of acceptance of the intervention and its impact on lifestyle habits, health and well-being, MBI and physical fitness. The tests before and after completing intervention showed small positive effects regarding weekly physical activity, quality of life and general- and mental health. Study IV, a qualitative study(n = 15), with adults with ADHD and comorbid mental illness aimed to investigate the experience of participating in a nurse-led lifestyle intervention. The analysis, based on material from interviews, showed that the participants perceived the intervention as supportive, which is related to the interpersonal relationships that arose in the intervention. Through supportive kindship with the other participants in the intervention, lifestyle habits and health experience were improved.The conclusion of the thesis is that the lifestyle intervention, based on interpersonal relationships and supported kindship, can be useful for making lifestyle changes in adults with ADHD and mental illness. Such support is important because adults with ADHD and mental illness experience a lack of and a desire for social support and has an increased risk of deteriorating health and unhealthy lifestyles. However, future adjustments to the content of the intervention must be made to improve the lifestyle intervention towards more sustainable lifestyle changes. Above all, the lifestyle intervention ought to be continuous. It is also of great importance for further research that insider perspective is used, that is, investigate the professionals' experiences regarding the intervention.
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| 41. |
- Björklund, Glenn, 1972-
(författare)
-
Metabolic and Cardiovascular Responses During Variable Intensity Exercise
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Previous research investigating endurance sports from a physiological perspectivehas mainly used constant or graded exercise protocols, although the nature ofsports like cross-country skiing and road cycling leads to continuous variations inworkload. Current knowledge is thus limited as regards physiological responses tovariations in exercise intensity. Therefore, the overall objective of the present thesiswas to investigate cardiovascular and metabolic responses to fluctuations inexercise intensity during exercise. The thesis is based on four studies (Studies I-IV);the first two studies use a variable intensity protocol with cardiorespiratory andblood measurements during cycling (Study I) and diagonal skiing (Study II). InStudy III one-legged exercise was used to investigate muscle blood flow duringvariable intensity exercise using PET scanning, and Study IV was performed toinvestigate the transition from high to low exercise intensity in diagonal skiing,with both physiological and biomechanical measurements. The current thesisdemonstrates that the reduction in blood lactate concentration after high-intensityworkloads is an important performance characteristic of prolonged variableintensity exercise while cycling and diagonal skiing (Studies I-II). Furthermore,during diagonal skiing, superior blood lactate recovery was associated with a highaerobic power (VO2max) (Study II). Respiratory variables such as VE/VO2, VE/VCO2and RER recovered independently of VO2max and did not reflect the blood lactate oracid base levels during variable intensity exercise during either cycling or diagonalskiing (Studies I-II). There was an upward drift in HR over time, but not inpulmonary VO2, with variable intensity exercise during both prolonged cyclingand diagonal skiing. As a result, the linear HR-VO2 relationship that wasestablished with a graded protocol was not present during variable intensityexercise (Studies I-II). In Study III, blood flow heterogeneity during one-leggedexercise increased when the exercise intensity decreased, but remained unchangedbetween the high intensity workloads. Furthermore, there was an excessiveincrease in muscular VO2 in the consecutive high-intensity workloads, mainlyexplained by increased O2 extraction, as O2 delivery and blood flow remainedunchanged. In diagonal skiing (Study IV) the arms had a lower O2 extraction thanthe legs, which could partly be explained by their longer contact phase along withmuch higher muscle activation. Furthermore, in Study IV, the O2 extraction in botharms and legs was at the upper limit during the high intensity workload with nofurther margin for increase. This could explain why no excessive increase inpulmonary VO2 occurred during diagonal skiing (Study II), as increased O2extraction is suggested to be the main reason for this excessive increase in VO2(Study III).
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| 42. |
- Björkman Randström, Kerstin
(författare)
-
Hemmet som arena för äldres rehabilitering
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avhandlingens övergripande syfte var att studera multidisciplinära teams, äldre personers och familjemedlemmars erfarenheter av hemrehabilitering. Avhandlingen baseras på fyra studier (I-IV). Alla studierna har en kvalitativa beskrivande design. Datamaterialet utgjordes av fokusgruppsintervjuer med personal arbetande i team i kommunal hälso- och sjukvård (I), intervjuer med äldre personer, över 65 år, som vårdats på sjukhuset och därefter fortsatt rehabilitering i hemmet (II,III,IV), samt familjemedlemmar involverade i de äldres rehabilitering (II).Studie I visade på betydelsen av att möta äldres individuella behov och att arbeta utifrån ett rehabiliterande förhållningssätt i avsikt att ge en hjälp som inte innebär att ta över handlingar från den äldre. Väsentligt var att i teamet reflektera över hur man agerar utifrån den egna professionen för att kunna utveckla ett rehabiliterande förhållningssätt i det dagliga arbetet. I resultatet framkom att teamen uppfattade hemrehabilitering som positiv för de äldre, men mindre lämpligt om de äldre var svårt sjuka och de kände sig otrygga i sitt hem. Respekt för de äldres integritet i deras hem och att göra de närstående delaktiga i rehabiliteringen betonades. Resultatet visade på att för att kunna utveckla samarbetet i teamet finns behov av att diskutera varje professions ansvarsområde och klargöra gränser mellan varandras ansvarområden. Behovet av att tillföra psykosocial kompetens i teamet framhölls för att möta de äldres behov. I studie II framkom att de äldre upplevde rehabiliteringen vara en balansgång i att känna av vad kroppen orkar med för dagen och vad som är realistiskt att uppnå för att känna välbefinnande. Tryggheten i att ha någon i familjen nära sig i hemmet var oumbärligt för att våga utföra träning och vardagliga aktiviteter. Resultatet visar på de äldres upplevelse av otillfredsställelse med att vara beroende av andra. Familjemedlemmar var engagerade i de äldres rehabilitering genom att finnas till hands, hjälpa till och vara stödjande, vilket var en självklar handling men också utmanande i att kunna hjälpa på rätt sätt. Bristande information om hjälpmedels funktion och användning skapade frustration. Resultatet visar att både de äldre och deras familjemedlemmar ser hemmiljön bidra till att underlätta rehabilitering. Det som försvårar är när gränsen för det egna hemmet inskränkts i och med att och personal ofta gick "in och ut" i det egna hemmet.Studie III visar på ett flertal faktorer i de äldres vardag och i det omgivande samhället som inverkat underlättande eller hindrande på aktiviteter och delaktighet vid hemrehabilitering. Resultatet beskrivs utifrån Klassifikation av funktionstillstånd, funktionshinder och hälsa (ICF) i 19 kategorier i domänen omgivningsfaktorer. Som underlättande faktorer framträder bl.a. tillgång till hjälpmedel, en fysisk miljö tillgänglig för aktiviteter samt att få stöd från närstående, vänner och personal i hälso- och sjukvård och omsorg. I resultatet framkom betydelsen av ett empatiskt förhållningssätt när personal möter den äldre personen i dennes hem. Resultatet indikerar att hemrehabilitering inte till fullo tillgodoser äldres behov av rehabilitering. I studie IV framkommer personliga faktorer som inre styrka, motivation, engagemang och tålamod för att nå positiva resultat i en rehabilitering som sträcker sig över flera år. Rehabilitering beskrivs i fysiska och psykiska faser som övergick i att hantera en fysisk funktionsnedsättning med svårigheter att gå i dagligt liv. Resultatet visar på betydelsen av adekvat information, vikten av socialt stöd och tillgänglighet till hälso- och sjukvårdspersonal under rehabiliteringsprocessen.Avhandlingen bidrar till en ökad kunskap om hur multidisciplinära team, äldre personer och familjemedlemmar upplever rehabilitering i hemmiljö. Nyttan med avhandlingen kan medföra att hemrehabilitering som vårdform kan bli föremål för diskussioner om hur det utformas och organiseras för att på bästa sätt stödja de äldre och närstående med utgångspunkt från de äldres och närståendes erfarenheter och upplevelser. Detta kan ses gagna deltagarna på individnivå men även för utveckling inom yrkesprofessionen. Avhandlingen har även visat på möjligheten att implementera ICF i rehabiliterande omvårdnad.
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| 43. |
- Blid, Mats, 1951-
(författare)
-
Ett folkhem för alla? : Kommunala insatser mot hemlöshet
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overarching aim of this dissertation is to explore and describe Swedish local authorities’ measures to prevent and manage homelessness; how these measures diverge between different municipal categories; what factors predict homelessness, provisions of accommodation and cov-erage rates between the number of accommodations and the respective municipalities’ housing interventions. Measures studied are policies and housing interventions. The housing interventions re-ferred to here are those provided by or through the social welfare authorities to persons living with unstable housing or who are homeless. The interventions can be divided into two main categories: 1) preventive interventions in the form of daily-life support, usually in the form of personnel support in the individual’s own apartment, designed to help persons at risk of becom-ing homeless to remain housed and prevent eviction; 2) accommodation support for persons who are already homeless and in need of housing. Such accommodations may be more or less temporary, more or less integrated and include a greater or lesser amount of care. Two sets of data were collected for the study: 1) a case study of two category-housing programmes using both qualitative and quantitative data; 2) a survey of 147 randomly chosen municipalities (about half of the municipalities in Sweden) to explore the prevalence and charac-teristics of policies and housing interventions. Findings from the case study show that special-category housing has positive direct effects on the housing stability of the residents and their feelings regarding their quality of life, but does not have a direct effect on their substance misuse. Moreover, the increased housing stability seems to be more a direct effect of the person having stayed on the programme, rather than a long-term effect. Furthermore, although their quality of life improves, the residents still experi-ence a lack of belonging and feel that their lives lack meaningful content. On the national level, the findings show that an array of housing interventions divided into 12 sub-categories is offered to counteract homelessness. These categories vary along two central dimensions: care and normality. The two most frequent types of housing interventions in all types of municipalities are daily-life support and social contracts. Other housing interventions are marginal compared with these two. There is greater fluctuation between municipalities in the level of care provided than in the level of normality. Furthermore, the more densely populated municipalities are more highly engaged in developing housing policies and the administrative means to handle them. Such policies, however, seem to decrease the level of normality without promoting levels of care. When exploring factors that predict homelessness, the findings show that urbanisation is central to understanding variations in homelessness, not only in the largest cities but also in less densely populated areas. In addition, higher rent levels and more of aggregated psychiatric prob-lems in the municipality seem to increase homelessness. The apartment rate and the proportion of public housing within the stock of apartments are both important for the possibility to pro-vide accommodations. Moreover, the proportion of single-parent households seems to enhance the need to provide such accommodations. Political majority and the functional organisation of the social services both seem to have an impact on the coverage rates. Thus, the findings indicate that the municipalities have various options for managing factors that impact on the homeless-ness rate. Keywords: housing interventions, level of care, level of normality, policies, municipality, predicting homelessness
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| 44. |
- Blomquist, Nicklas, 1987-
(författare)
-
Large-Scale Graphene Production for Environmentally Friendly and Low-Cost Energy Storage : Production, Coating, and Applications
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is great demand for energy-efficient, environmentally sustainable, and cost-effective electrical energy storage devices. One important aspect of this demand is the need for automotive electrification to achieve more energy-efficient transportation at a reasonable cost, thus supporting a fossil-fuel free society. Another important aspect is the requirement for energy storage in the growing field of renewable energy production from wind and solar sources, which generates an irregular supply of electricity due to weather conditions.Much of the research in this area has been conducted in the field of battery technology with impressive results, but the need for rapid storage devices such as supercapacitors is growing. Due to the excellent ability of supercapacitors to handle short peak power pulses with high efficiency along with their long lifetime and superior cyclability, their implementations range from small consumer electronics to electric vehicles and stationary grid applications. Supercapacitors also have the potential to complement batteries to improve pulse efficiency and lifetime of the system, however, the cost of supercapacitors is a significant issue for large-scale commercial use, leading to a demand for sustainable, low-cost materials and simplified manufacturing processes. An important way to address this need is to develop a cost-efficient and environment-friendly large-scale process to produce highly conductive nanographites, such as graphene and graphite nanoplatelets, along with methods to manufacture low-cost electrodes from large area coating.In this thesis, I present a novel process to mechanically exfoliate industrial quantities of nanographite from graphite in an aqueous environment with low energy consumption and at controlled shear conditions. The process is based on hydrodynamic tube-shearing and can produce both multilayer graphene and nanometer-thick and micrometer-wide flakes of nanographite. I also describe the production of highly conductive and robust carbon composites based on the addition of nanocellulose during production; these are suitable as electrodes in applications ranging from supercapacitors and batteries to printed electronics and solar cells.Furthermore I demonstrate a scalable route for roll-to-roll coating of the nanographite-nanocellulose electrode material and propose a novel aqueous, low-cost, and metal-free supercapacitor concept with graphite foil functioning as the current collector. The supercapacitors possessedmore than half the specific capacitance of commercial units but achieved a material cost reduction of more than 90 %, demonstrating anenvironment-friendly, low-cost alternative to conventional supercapacitors.
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| 45. |
- Blusi, Madeleine, 1968-
(författare)
-
E-health and information- and communication technology (ICT) as support systems for older family caregivers in rural areas
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall objective of the thesis was to investigate how older family caregivers in rural areas experienced participation in an e-health based caregiver support system. Participants were 95 caregivers allocated to intervention group (n=63) and control group (n=32). The thesis had a mixed method design and is based on four original articles (I-IV). Data was collected through web-camera interviews (I-III), telephone interviews (II,IV) and questionnaires (II,IV) after 1.5 years of using e-health support. Quantitative data was analyzed using comparative statistics, multiple linear regression and logistic regression. Qualitative data was analyzed with content analysis. Article I showed that the caregivers, despite lacking experience from using computers, were able to adopt the new technology, with help from support nurses and family. Caregivers felt e-health helped them to regain social inclusion. Article II had a comparative design, comparing e-health support with conventional caregiver support. Caregivers using e-health were more satisfied with their support and found it to be available, flexible and helping them enhance caregiver competence. Control group caregivers were less satisfied with support and experienced unmet needs. Article III showed that e-health can reduce caregivers’ feelings of isolation. Two themes were created, Expanding the concept of place and Developing networks. Article IV revealed that caregivers used e-health frequently, experienced benefits from using it and had become more independent. Support nurses were disappointed about the decrease in contact with caregivers, and also acknowledged a need for developing the professional nursing role while working with e-health. Conclusions drawn from the findings were that participants experienced benefits from e-health support and it helped them become more independent. Swedish municipalities are obliged to provide caregiver support, the findings from the study are valid to conclude that e-health support are as good as, or even more effective, than conventional support for older family caregivers in rural areas.
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| 46. |
- Bogren, Maria, 1962-
(författare)
-
Socialt kapital - relationer och tillit - för utveckling av kvinnors företagande
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Kvinnors företag ses som en resurs i regioners och länders utveckling. Tidigare forskning har dock visat att kvinnors företag inte växer i lika stor utsträckning som mäns företag. Frågan är då vilka problem och hinder som företagande kvinnor stöter på och som påverkar att deras företag inte utvecklas, samt hur stödjande insatser på bästa sätt kan utformas? Tidigare studier har visat att bristande tillgång till finansiellt kapital varit ett betydande hinder för utveckling av kvinnors företag liksom att företagandet varit manligt kodat, med mannen som företagare som norm i samhället. Dessutom har tidigare studier visat att företagande kvinnor har begränsade nätverksrelationer och inte använder dem så effektivt samt att de saknar förebilder. Med ett utvecklat socialt kapital ges möjlighet att få tillgång till resurser som kan utveckla kvinnors företag. Tidigare studier om socialt kapital, som ett bidrag till företagsutveckling, fokuserar ofta antingen på relationer eller på tillit och det efterfrågas ytterligare studier om processer där socialt kapital utvecklas. Syftet med avhandlingen är att öka kunskapen om hur utveckling av socialt kapital kan förstås genom att belysa och analysera vad som utmärker relationer och tillit samt att ge exempel på hur detta kan stimuleras i utvecklingsprogram för företagande kvinnor.Avhandlingen utgår ifrån tre genomförda studier. En fallstudie genomfördes under två års tid i ett utvecklingsprogram med företagande kvinnor från Norge och Sverige. En enkätstudie riktades till företagande kvinnor i Norge och Sverige och en annan till projektledare av utvecklingsprojekt för att stimulera kvinnors företagande i Sverige.Avhandlingens resultatet, som presenteras i fyra artiklar, visar att personliga nätverk, familj och släktingar samt vänner uppfattas som stödjande relationer för företagande kvinnor. De som har ett heterogent nätverk uppvisar en större villighet att ingå i nya relationer jämfört med dem som inte har det och graden av tillit påverkar villigheten att utveckla relationer i utvecklingsprogram. Homogenitet i deltagargruppen visar sig vara viktigt inledningsvis, medan heterogenitet blir betydelsefullare efter en tid. När företagaridentiteten utvecklas uppvisas en ökad professionalisering av företagarens nätverk. Social aktivitet, med nedlagd tid och engagemang i utvecklingsprogram, bidrar till utveckling av både relationer och tillit, och tidsaspekten är viktig när det gäller tillit till programorganisatörer.Utifrån avhandlingens resultat synliggörs flera aspekter av relationer och tillit som kan stimuleras i utvecklingsprogram. Uppvisad villighet hos kvinnorna för att utveckla sina företag kan avspegla hur motiverade och intresserade de är för att medverka i utvecklingsprogram. Vid sammansättning av deltagargrupper, i utvecklingsprogram, bör homogenitet och heterogenitet beaktas. Social aktivitet, genom nedlagd tid och visat engagemang, är något som stärker utvecklingsprocessen av relationer och tillit. Ett symboliskt dokument, sekretessavtalet, bidrar till ökad tillit. Programorganisatörernas sociala meriter, kompetens och organisationstillhörighet är sådant som kan uppmärksammas för institutionell tillit liksom även deras sociala aktivitet i programmet. För att stimulera utveckling av både relationer och tillit finns det anledning att se över programmets upplägg och innehåll.Slutsatserna från avhandlingen visar att företagande kvinnor med ett heterogent nätverk är villiga att ingå i nya relationer, att både relationsbyggande och tillitsprocesser har betydelse för utvecklingen av socialt kapital samt att kontexten behöver beaktas vid utformandet av utvecklingsprogram.
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| 47. |
- Borglund, Erik A.M. 1969-
(författare)
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Design for Recordkeeping: Areas of Improvement
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is about problems related to design of information systems in which records are born and managed. The proactive approach has been derived from new archival theories suited for electronic recordkeeping, and implies that electronic records must, at the time of creation fulfil their current and future requirements. Information systems where records are born and managed should, based upon a proactive approach, meet recordkeeping requirements. This thesis is based upon a four-year research effort and consists of seven research articles that present the results of the research. The objective is to contribute to knowledge of design recommendations for information systems, in which records are born and managed. The main result of this thesis is identification of five areas that can affect and improve the design of information systems in which records are born and managed. First: A set of empirically and theoretical grounded characteristics of records are presented. Those characteristics have to be complemented with organization-defined characteristics. Second: this research has contributed a conceptualization of use of records and users of records. The notion of known use/user, and unknown use/user has been introduced. Design becomes difficult because requirements of unknown users are difficult to conceptualize. Third: The Recordkeeping Quality Assessment model (RQAM) is presented. The model implies a holistic quality approach to recordkeeping, and intends to be used as a basis for quality assessment, and as a reference model in design situations to achieve high recordkeeping quality. Fourth: Two dominant different views on records are presented. Private organizations appraise records principally upon business values, and public organisations base their appraisal criteria upon accountability and legislative values. The two views on records should be brought into one view and form a risk management-like appraisal. Fifth: Proactivity is a way of thinking and should be applied on several levels in the recordkeeping environment: to the electronic record, to the information system where the electronic record is born and managed, to the organization, and to the user.
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| 48. |
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| 49. |
- Brouder, Patrick
(författare)
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Tourism Development in Peripheral Areas : Processes of Local Innovation and Change in Northern Sweden
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tourism has reached almost all regions of the world and has had a notable growth in the peripheral regions of Europe. Attempts at tourism development in rural and peripheral areas have resulted in widely varying outcomes and have often been undertaken as a last resort by communities. Despite mixed results, tourism persists as a tool for regional development. There has not been so much research on the evolving nature of tourism entrepreneurship in regions where tourism is relatively new as a commercial/entrepreneurial activity, e.g., the rural and peripheral north of Europe. This thesis presents Northern Sweden as a regional case study but it is reasonable to assume that the research results are transferable to similar regions with a similar range of nature-based tourism in small communities. The results show that tourism stakeholders co-evolve over time even though formal networks are loose and project-based (Article 1). Tourism firm survival improves for entrepreneurs with previous related experience but there is not necessarily an outsider advantage and new tourism firms contribute to job creation despite high rates of attrition (Article II). Protected areas with unique attributes (e.g., Laponia) can attract distant entrepreneurs but must manage these stakeholders more proactively (Article III). Climate change is a long-term challenge with firms not needing to adapt yet but facing differing exposures dependent on location and firm mobility (Article IV). Finally, evolutionary economic geography helps to better understand the processes of change in tourism in rural and peripheral areas (Article V).
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| 50. |
- Bång, Joakim
(författare)
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Purification, Stereoisomeric Analysis and Quantification of Biologically Active Compounds in Extracts from Pine Sawflies, African Butterflies and Orchid Bees
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Stereochemistry plays an important role in nature because biologically important molecules such as amino acids, nucleotides and sugars, only exist in enantiomerically pure forms. Semiochemicals carry messages, between the same species (pheromones) and between different species (allelochemicals). Both pheromones and allelochemicals can be used as environmentally friendly pest management. Many semiochemicals, i.e. behaviour modifying chemicals, consist of pure or well-defined mixtures of stereoisomers, where some of the other stereoisomers can be repellent. It is therefore important to be able to separate them to produce a synthetic pheromone in a mixture that is attractive.Pine sawflies are a family of insects that in some cases can be severe defoliators of conifer trees. Diprion pini, Diprion similis and Neodiprion sertifer are severe pests for these trees and have got the most attention in pine sawfly pheromone studies. The pheromone precursors are stored in the female body as long-chain secondary alcohols, which, when released, are esterified to acetates or propionates. The alcohols are chiral, and normally one of the stereoisomer is the main pheromone component, sometimes possible together with other stereoisomers as essential minor components.Bicyclus is a genus of African butterflies, and especially Bicyclus anynana has become a popular model for the study of life history evolution, morphology, mating choice and genetics. The wing pattern of Bicyclus differs depending on the season, with large eyespots during the rain-season and small or absent spots during the dry season. Euglossa is one of the genera among the orchid bees in the Neotropics that does not produce its own pheromone. Instead, the males collect fragrances from orchids and other sources and store them in a pocket in their hind legs. Both Bicyclus and Euglossa use semiochemicals similar to pine sawflies, and thus can be analysed by the same methods.Pheromones and other semiochemicals in insects are often present in low amounts in a complex matrix, and purification of the sample before chemical analysis is often required. A common method is gradient elution on a solid phase silica column. Separation of stereoisomers can be achieved either by using a column with a chiral stationary phase (CSP) or with pre-column derivatisation using a column with an achiral stationary phase (ASP) or a combination of both, with mass detection as the dominant detection method. The purpose of this work has been to improve the purification method, find suitable methods to separate the stereoisomers of secondary alcohols, and to apply this on extracts of insects.By selecting the right fractions to collect during gradient elution the purification method was optimised. To reduce plasticizer contamination from ordinary columns, solid phase columns of Teflon or glass were used. For pre-column derivatisation of different chiral alcohols various acid chlorides were tested. For the pine sawfly pheromone precursors enantiopure (2S)-2-acetoxypropionyl chloride was the best choice. To separate some of the stereoisomers achiral 2-naphthoyl chloride was used. For derivatisation of 6,10,14-trimethylpentadecan-2-ol (R)-trans-chrysanthemoyl chloride was the best choice. The derivatised alcohols were separated on different columns, both chiral and non-chiral. Varian FactorFour VF-23ms was chosen as a general-purpose column, the Agilent HP-88 column was the best column with an ASP of those tested, and the Chiraldex B-PA column (CSP) was the only one that could separate all eight stereoisomers of derivatised 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, and 3,7-dimethyltridecan-2-ol.To determine the stereoisomeric purity of standard solutions used in field experiments and extracts of different species of insects the optimised methods were applied. For extracts from B. anynana, Euglossa and Neodiprion lecontei this work describe the first determination of the stereochemistry of some of their semiochemicals.For the determination of the stereochemistry of chiral semiochemicals the methods for purification and separation presented herein have shown to be of great value. The results will hopefully contribute to a better understanding of the communication among insects, and ultimately to a more environmentally friendly pest control.
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