| 1. |
- Aldaeus, Fredrik, et al.
(author)
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Towards a cellulose-based society : current market and consumer trends
- 2017
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In: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017. - Stockholm : RISE Bioekonomi. - 9789186018207 ; , s. 1-
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Conference paper (other academic/artistic)abstract
- It has been proposed that the future of the forest industry will involve the traditional value chains combined with the needs and demands of a bio-based economy. A global consumer survey was undertaken, together with interviews and workshops with various representatives through the bio-economy. Sources also included in-depth literature studies and research reviews. Based on this input, several current trends have been identified that will affect the route towards a cellulose-based society. These trends describe the effects of urbanization, consumer behaviour, new business models, material recycling, open innovation and the necessity for early demonstration of new research. Four different but equally plausible scenarios have been identified describing the society and the role of cellulose in 2030, highlighting the role of the wood-based biorefinery.
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| 2. |
- Aldaeus, Fredrik, et al.
(author)
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Towards a cellulose-based society : current trends, future scenarios, and the role of the wood biorefinery
- 2016
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In: Proceedings of the 14th European workshop on lignocellulosics and pulp. - 9791090188020 ; , s. 125-127
-
Conference paper (other academic/artistic)abstract
- There is a great need to maintain research for a future in which the traditional value chains of the forest industry are combined with the needs and demands of a bio-based economy. In such a future, the pulp mill biorefinery will be a crucial node. In order to map the transformation from a fossil-based society to a cellulose-based society, a global consumer survey has been made. In addition, interviews and workshops with various players throughout the bio-economy field have been accomplished. Several current trends that affect the road to a cellulose-based society have been identified. These trends are describing the effects of urbanization, consumer behaviour, new business models, material recycling, open innovation, and the need for early demonstration of new research. The trends have been combined with uncertainties into a number of plausible scenarios describing the society and the role of cellulose in the year 2030.
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| 3. |
- Bäckström, Erik, 1983-, et al.
(author)
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Storing keV negative ions for an hour : The lifetime of the metastable 2P1/2 level in 32S−
- 2015
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:14
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Journal article (peer-reviewed)abstract
- We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p 5 P 2 o 1/2 →3p 5 P 2 o 3/2 spontaneous radiative decay in S − 32 to be 503±54 sec . This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10 −14 mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction.
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| 4. |
- Chartkunchand, Kiattichart C., et al.
(author)
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Dianion diagnostics in DESIREE : High-sensitivity detection of C-n(2-) from a sputter ion source
- 2018
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In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 89:3
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Journal article (peer-reviewed)abstract
- A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, C-n(2-), with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot C-n(2-) dianions injected into the ring yielded C-n(2-) anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90 degrees analyzing magnet on the ion injection line reflect the production of internally hot C-7(2-) - C-24(2-) dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C-6(2-) was found while there was a clear C-7(2-) signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C-6(2-) signal that is two orders-of-magnitude smaller than that for C-7(2-). In addition, CnO2- and CnCu2- dianions were detected.
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| 5. |
- Chartkunchand, Kiattichart C., et al.
(author)
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Radiative lifetimes of the bound excited states of Pt-
- 2016
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In: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 94:3
-
Journal article (peer-reviewed)abstract
- © 2016 American Physical Society.The intrinsic radiative lifetimes of the 5d106sS1/22 and 5d96s2 D3/22 bound excited states in the platinum anion Pt- have been studied at cryogenic temperatures at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The intrinsic lifetime of the higher-lying 5d106s S1/22 state was measured to be 2.54±0.10s, while only a lifetime in the range of 50-200 ms could be estimated for the 5d96s2 D3/22 fine-structure level. The storage lifetime of the Pt- ion beam was measured to be a little over 15 min at a ring temperature of 13K. The present study reports the lifetime of an atomic negative ion in an excited bound state with an electron configuration different from that of the ground state.
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| 6. |
- Kamińska, Magdalena, et al.
(author)
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Lifetime of the bound excited level in Ni
- 2016
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In: Physical Review A. - 1050-2947 .- 1094-1622. ; 93:1
-
Journal article (peer-reviewed)abstract
- The intrinsic lifetime of the upper level in the bound-bound 3d(9) 4s(2) D-2(3/2) -> 3d(9) 4s(2) D-2(5/2) radiative transition in Ni- was measured to be 15.1 +/- 0.4 s. The experiment was performed at cryogenic temperatures in one of the ion-beam storage rings of the Double ElectroStatic Ion Ring ExpEriment facility at Stockholm University. The storage lifetime of the Ni- ion beam was measured to be close to 5 min at a ring temperature of 13 K.
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| 7. |
- Mattsson, C. Mikael, et al.
(author)
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Träna för en svensk klassiker och andra långlopp
- 2015
-
Book (pop. science, debate, etc.)abstract
- Förbered dig rätt inför långlopp. Att under ett år genomföra Vätternrundan, Vansbrosimningen, Lidingöloppet och Engelbrektsloppet/Vasaloppet, är ett av de mest populära sätten att skörda frukten av sin träning och nå sitt mål. För att lyckas krävs goda förberedelser, och ju bättre förberedd du är desto mer positiv blir upplevelsen. Innehållet i denna bok är en fördjupning av samlad kunskap och erfarenhet inom simning, cykel, löpning, längdskidåkning och triathlon samt hur man på bästa sätt kombinerar de olika idrotterna – deras olika moment – i träning och tävling. Här hittar du också kapitel om träningslära, idrottsnutrition, mental träning, förebyggande av idrottsskador och träningsplanering för att öka förståelsen av vad som påverkar en idrottsprestation.Extramaterial på webbplatsen: För att kunna erbjuda mer än vad som ryms i en bok, har vi också skapat en webbplats. Med hjälp av koden som följer med i boken kan du registrera dig för att ta del av fördjupande texter, träningsprogram och kostupplägg, övningar och intressanta länkar.(Text från förlaget)
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| 8. |
- Thomas, Richard D., et al.
(author)
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DESIREE : Physics with cold stored ion beams
- 2015
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In: DR2013. - : EDP Sciences. ; 84, s. 01004-01004
-
Conference paper (peer-reviewed)abstract
- Here we will briefly describe the commissioning of the Double ElectroStatic Ion Ring ExpEriment (DESIREE) facility at Stockholm University, Sweden. This device uses purely electrostatic focussing and deflection elements and allows ion beams of opposite charge to be confined under extreme high vacuum and cryogenic conditions in separate rings and then merged over a common straight section. This apparatus allows for studies of interactions between cations and anions at very low and well-defined centre-of-mass energies (down to a few meV) and at very low internal temperatures (down to a few K).
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| 9. |
- Alehagen, Urban, et al.
(author)
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Relatively high mortality risk in elderly Swedish subjects with low selenium status
- 2016
-
In: European Journal of Clinical Nutrition. - : Nature Publishing Group. - 0954-3007 .- 1476-5640. ; 70:1, s. 91-96
-
Journal article (peer-reviewed)abstract
- Background/Objectives: The daily dietary intake of selenium (Se), an essential trace element, is still low in Sweden in spite of decades of nutritional information campaigns and the effect of this on the public health is presently not well known. The objective of this study was to determine the serum Se levels in an elderly Swedish population and to analyze whether a low Se status had any influence on mortality.Subjects/Methods: Six-hundred sixty-eight (n=668) elderly participants were invited from a municipality and evaluated in an observational study. Individuals were followed for 6.8 years and Se levels were re-evaluated in 98 individuals after 48 months. Clinical examination of all individuals included functional classification, echocardiography, electrocardiogram and serum Se measurement. All mortality was registered and endpoints of mortality were assessed by Kaplan–Meier plots, and Cox proportional hazard ratios adjusted for potential confounding factors were calculated.Results: The mean serum Se level of the study population (n=668) was 67.1 μg/l, corresponding to relatively low Se intake. After adjustment for male gender, smoking, ischemic heart disease, diabetes, chronic obstructive pulmonary disease and impaired heart function, persons with serum Se in the lowest quartile had 43% (95% confidence interval (CI): 1.02–2.00) and 56% (95% CI: 1.03–2.36) increased risk for all-cause and cardiovascular mortality, respectively. The result was not driven by inflammatory effects on Se concentration in serum.Conclusion: The mean serum Se concentration in an elderly Swedish population was 67.1 μg/l, which is below the physiological saturation level for several selenoprotein enzymes. This result may suggest the value of modest Se supplementation in order to improve the health of the Swedish population.
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| 10. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(author)
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Metod och effektsamband för identifiering, bedömning och prioritering av åtgärder för klimatanpassning av vägar och järnvägar : en förstudie
- 2019
-
Reports (other academic/artistic)abstract
- Syftet med den förstudie som redovisas i denna rapport var att ta fram grunden för en metod till stöd för Trafikverkets planering av klimatanpassningsåtgärder för väg och järnväg. Rapporten fokuserar på effektsamband för identifiering, bedömning och prioritering av åtgärder för klimatanpassning av vägar och järnvägar. Metoden och resultaten som presenteras i denna rapport är baserade på litteraturstudier och intervjuer med experter inom väg och järnvägsområdet.I rapporten beaktas de konsekvenser och risker som förväntas uppkomma till följd av klimatrelaterade händelser, exempelvis den konsekvens som uppstår vid en specifik klimatrelaterad händelse, såsom de konsekvenser som uppstår vid ett specifikt översvämningsdjup, och åtgärder som kan vidtas för att minska sannolikheten för negativa konsekvenser samt de negativa konsekvenserna i sig.För att bedöma eller beräkna hur stor risken är krävs kännedom om sannolikheten för att en viss klimatrelaterad händelse ska inträffa under en given period, samt storlek och typ av skada. Skadekostnaden är summan av försenings- och/eller avstängningskostnad som kan innefatta omledningskostnader och kostnader för byte mellan transportslag med mera samt återställningskostnad. Dessutom ingår även skador på människor och miljön som kan uppkomma till följd av händelsen, till exempel vid skred.
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| 11. |
- Azasu, S, et al.
(author)
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CDIO in Africa
- 2019
-
In: <em>Proceedings of the 15th International CDIO Conference</em>.
-
Conference paper (peer-reviewed)
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| 12. |
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| 13. |
- Godang, Kristin, et al.
(author)
-
The effect of surgery on fat mass, lipid and glucose metabolism in mild primary hyperparathyroidism
- 2018
-
In: Endocrine connections. - 2049-3614. ; 7:8, s. 941-948
-
Journal article (peer-reviewed)abstract
- Mild primary hyperparathyroidism has been associated with increased body fat mass and unfavorable cardiovascular risk factors.To assess the effect of parathyroidectomy on fat mass, glucose and lipid metabolism.119 patients previously randomized to observation (OBS; n=58) or parathyroidectomy (PTX; n=61) within the Scandinavian Investigation of Primary Hyperparathyroidism (SIPH) trial, an open randomized multicenter study, were included. Main outcome measures for this study were the differences in fat mass, markers for lipid and glucose metabolism between OBS and PTX 5 years after randomization.In the OBS group, total cholesterol (Total-C) decreased from mean 5.9 (±1.1) to 5.6 (±1.0)mmol/L (P=0.037) and LDL cholesterol (LDL-C) decreased from 3.7 (±1.0) to 3.3 (±0.9)mmol/L (P=0.010). In the PTX group, the Total-C and LDL-C remained unchanged resulting in a significant between-group difference over time (P=0.013 and P=0.026, respectively). This difference was driven by patients who started with lipid-lowering medication during the study period (OBS: 5; PTX: 1). There was an increase in trunk fat mass in the OBS group, but no between-group differences over time. Mean 25(OH) vitamin D increased in the PTX group (P<0.001), but did not change in the OBS group. No difference in parameters of glucose metabolism was detected.In mild PHPT, the measured metabolic and cardiovascular risk factors were not modified by PTX. Observation seems safe and cardiovascular risk reduction should not be regarded as a separate indication for parathyroidectomy based on the results from this study.
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| 14. |
- Holmér, Gunnel, 1955-
(author)
-
Flaskor på löpande band : Arbete och arbetskraftsrekrytering vid Surte glasbruk 1943-1978
- 2017
-
Doctoral thesis (other academic/artistic)abstract
- This dissertation considers how the transition from craft manufacture to mechanized glass production affected the organization of work and the consequences for the recruitment of labour. Based on gender and ethnicity, the dissertation studies the composition of the workforce, the significance of qualifications, and differences in career paths and length of stay have been investigated at Surte glassworks 1943–1978. Charles Tilly’s theory of durable inequality is applied to analyse whether primarily gender and ethnicity had any effect on the assignment of tasks and on discrimination. In conclusion, the results from Surte are compared with conditions at Kosta glassworks. Whereas Surte’s specialty was machine-made bottles, Kosta was geared to craft production of utility glass and art glass.After mechanization at Surte, machine-tenders were counted among the most qualified category, instead of the glass-blowers who had previously been in demand. Manufacture at a pace regulated by machines led to more routine chores such as inspection and packaging. At Kosta, with its focus on craft, glass-blowers still had the highest positions and had learned glass-blowing in the traditional way through practical exercise. At neither Surte nor Kosta did women have any opportunity to receive comparable training.After the Second World War there was a growing need for labour at both Surte and Kosta, and to keep production going the main alternative was foreign labour. The peak was reached in the 1960s, and of roughly 660 collectively employed workers at Surte in November 1964, almost 40% were immigrants, chiefly from Finland. Kosta at the same time, with just under 330 employees, had slightly under 10% foreign workers, mainly from Greece. Kosta attracted a number of skilled glass-workers from abroad, but the majority of immigrants there, and all those at Surte, lacked experience of glass manufactureAt neither Surte nor Kosta, with their different production methods, is there any evidence of durable inequality based on ethnicity. The assignment of tasks was guided rather by the functions in demand at the companies and by the applicants’ qualifications. Internal training and career opportunities were open to all male workers, regardless of which country they came from. On the other hand, the gender division of labour at both glassworks created durable inequality for all women regardless of nationality.
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| 15. |
- Lundstam, Karolina, et al.
(author)
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Effect of Surgery Versus Observation : Skeletal 5-Year Outcomes in a Randomized Trial of Patients With Primary HPT (the SIPH Study)
- 2017
-
In: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 32:9, s. 1907-1914
-
Journal article (peer-reviewed)abstract
- Mild primary hyperparathyroidism (PHPT) is known to affect the skeleton, even though patients usually are asymptomatic. Treatment strategies have been widely discussed. However, long-term randomized studies comparing parathyroidectomy to observation are lacking. The objective was to study the effect of parathyroidectomy (PTX) compared with observation (OBS) on bone mineral density (BMD) in g/cm(2) and T-scores and on biochemical markers of bone turnover (P1NP and CTX-1) in a prospective randomized controlled study of patients with mild PHPT after 5 years of follow-up. Of 191 patients with mild PHPT randomized to either PTX or OBS, 145 patients remained for analysis after 5 years (110 with validated DXA scans). A significant decrease in P1NP (p<0.001) and CTX-1 (p<0.001) was found in the PTX group only. A significant positive treatment effect of surgery compared with observation on BMD (g/cm(2)) was found for the lumbar spine (LS) (p = 0.011), the femoral neck (FN) (p<0.001), the ultradistal radius (UDR) (p = 0.042), and for the total body (TB) (p<0.001) but not for the radius 33% (Rad33), where BMD decreased significantly also in the PTX group (p = 0.012). However, compared with baseline values, there was no significant BMD increase in the PTX group, except for the lumbar spine. In the OBS group, there was a significant decrease in BMD (g/cm(2)) for all compartments (FN, p<0.001; Rad33, p = 0.001; UDR, p = 0.006; TB, p<0.001) with the exception of the LS, whereBMDwas stable. In conclusion, parathyroidectomy improves BMD and observation leads to a small but statistically significant decrease in BMD after 5 years. Thus, bone health appears to be a clinical concern with long-term observation in patients with mild PHPT.
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| 16. |
- Lundstam, Karolina, et al.
(author)
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Effects of parathyroidectomy versus observation on the development of vertebral fractures in mild primary hyperparathyroidism
- 2015
-
In: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 100:4, s. 1359-1367
-
Journal article (peer-reviewed)abstract
- Context: Mild primary hyperparathyroidism (PHPT) is a common disease especially in middle-aged and elderly women. The diagnosis is frequently made incidentally and treatment strategies are widely discussed. Objective: To study the effect of parathyroidectomy (PTX) compared with observation (OBS) on biochemistry, safety, bone mineral density (BMD), and new fractures. Design: Prospective, randomized controlled study (SIPH study), 5-year follow-up. Setting: Multicenter, tertiary referral centers. Patients: Of 191 randomized patients with mild PHPT, biochemical data were available for 145 patients after 5 years, mean age at inclusion 62.8 years (OBS group, 9 males) and 62.1 years (PTX group, 10 males). Intervention: Parathyroidectomy vs observation. Main outcome measures: Biochemistry, BMD and new radiographic vertebral fractures. Results: Serum-calcium and PTH-levels normalized after surgery and did not deteriorate by observation. BMD Z-scores were normal at inclusion in the lumbar spine (LS) and femoral neck (FN). For LS, BMD Z-scores were stable for 5 years with observation, but decreased in FN (P<0.02). After surgery, BMD Z-scores increased significantly in both compartments (P<0.02 for both), with a highly significant treatment effect of surgery compared to observation (P<0.001). During follow-up, 5 new clinically unrecognized vertebral fractures were found in 5 females, all in the OBS group (P=0.058). Conclusion: Even though new vertebral fractures occurred only in the observation group, the frequency was not significantly different from the surgery group. Longer follow-up is needed before firm conclusions can be drawn about the long-term safety of observation, as opposed to surgery.
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| 17. |
- Nilsson, Joakim, et al.
(author)
-
FASTIGHETSNÄRA SÄSONGSLAGRING AV FJÄRRVÄRME
- 2016
-
Reports (other academic/artistic)abstract
- Projektet bygger på en idé om att industriell spillvärme och annan tillgänglig basproduktion av värme under sommaren kan distribueras via befintliga fjärrvärmesystem och lagras lokalt i fastighetsnära säsongslager för att sedan användas under den kalla delen av året, utan att ytterligare energi tillförs. Projektets övergripande mål har varit att bedöma möjligheterna för fastighetsnära säsongslagring i kombination med lågenergi- och lågtemperaturbyggande i Sverige. Arbetet har genomförts i samarbete mellan Devcco och SP Sveriges Tekniska Forskningsinstitut. Till projektets förfogande har funnits en referensgrupp med representanter från Energiföretagen, Skanska, Akademiska hus, Göteborg Energi, Tekniska Verken i Linköping, Eon samt Umeå Energi. I ett systemperspektiv skulle fastighetsnära säsongslagring av fjärrvärme på marginalen betyda ökad produktion på sommaren och minskad på vintern under förutsättning att alternativet för en fastighet är en vanlig leverans av fjärrvärme. För att utvärdera lönsamheten har fastighetsnära säsongslagring av fjärrvärme jämförts med ”vanlig” fjärrvärme i ett LCC-perspektiv. Miljöpåverkan har beräknats baserat på ett antal olika alternativ för miljövärdering av el samt allokeringsprinciper för fjärrvärme. Lagren som simulerats består av standardmässiga borrhålslager som laddas med fjärrvärme under maj till och med september. I slutet på april antas lagret vara mer eller mindre tömt. Tre typbyggnader som representerar vanligt förekommande större byggnader och kvarter av olika storlek har ingått i studien. De tre typerna är 1) nybyggt energieffektivt kontor, 2) äldre energirenoverat kontor och 3) energirenoverat miljonprogram. Beräkningar av de miljömässiga samt de ekonomiska för- och nackdelarna baseras på vilka produktionsslag som används på marginalen under olika delar av året för ett givet fjärrvärmesystem. Analysen baseras huvudsakligen på två olika produktionsmixer inspirerade av systemen i Stockholm respektive Göteborg. Miljömässigt finns under vissa förutsättningar goda möjligheter att åstadkomma positiva resultat med fastighetsnära säsongslagring av fjärrvärme. Använder man kraftbonusmetoden i kombination med marginalel så resulterar säsongslagring i miljönytta både i göteborgs- och stockholmsfallet. Använder man energimetoden i kombination med nordisk elmix blir resultatet det motsatta. Ur ett ekonomiskt perspektiv kan fastighetsnära säsongslagring för två av tre typbyggnader konkurrera med konventionell fjärrvärme under förutsättning att man kan åstadkomma en marginalproduktionskostnad i storleksordning 50 kr/MWh. Resultaten är starkt beroende av lokala förutsättningar samt av vilken metod som används för att beräkna miljöpåverkan. Därför har som en del av projektet en modell utvecklats där användaren utifrån relativt grundläggande indata om fastighet och fjärrvärmesystem kan göra egna indikativa beräkningar av ekonomiska och miljömässiga aspekter av fastighetsnära säsongslagring av fjärrvärme.
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| 18. |
- Razola, Mikael, 1984-
(author)
-
New Perspectives on Analysis and Design of High-Speed Craft with Respect to Slamming
- 2016
-
Doctoral thesis (other academic/artistic)abstract
- High-speed craft are in high demand in the maritime industry, for example, in maintenance operations for offshore structures, for search and rescue, for patrolling operations, or as leisure craft to deliver speed and excitement. Design and operation of high-speed craft are often governed by the hydrodynamic phenomena of slamming, which occur when the craft impact the wave surface. Slamming loads affect the high-speed craft system; the crew, the structure and various sub-systems and limit the operation. To meet the ever-increasing demands on safety, economy and reduced environmental impact, there is a need to develop more efficient high-speed craft. This progression is however limited by the prevailing semi-empirical design methods for high-speed planing craft structures. These methods provide only a basic description of the involved physics, and their validity has been questioned.This thesis contributes to improving the conditions for designing efficient highspeed craft by focusing on two key topics: evaluation and development of the prevailing design methods for high-speed craft structures, and development towards structural design based on first principles modeling of the slamming process. In particular a methodological framework that enables detailed studies of the slamming phenomena using numerical simulations and experimental measurements is synthesized and evaluated. The methodological framework involves modeling of the wave environment, the craft hydromechanics and structural mechanics, and statistical characterization of the response processes. The framework forms the foundation for an extensive evaluation and development of the prevailing semi-empirical design methods for high-speed planing craft. Through the work presented in this thesis the framework is also shown to be a viable approach in the introduction of simulation-based design methods based on first principles modeling of the involved physics. Summarizing, the presented methods and results provide important steppingstones towards designing more efficient high-speed planing craft.
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| 19. |
- Razola, Mikael, et al.
(author)
-
On high-speed craft acceleration statistics
- 2016
-
In: Ocean Engineering. - : Elsevier BV. - 0029-8018 .- 1873-5258. ; 114, s. 115-133
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Journal article (peer-reviewed)abstract
- Design and operation of high-speed planing craft is ruled by the hydrodynamic impact loads and the related craft responses occurring at violent wave encounters. Simulation, measurement and characterization of these loads and responses is however far from trivial. Hereby the general knowledge about these processes is actually rather limited and it is common to rely on simple semi-empirical formulas when designing and analyzing high-speed craft. This paper presents a unique set of impact acceleration data for a high-speed craft in waves, generated based on non-linear strip simulations. Methods and measures for statistical characterization of the acceleration process are established and evaluated, and by application of these methods on the simulation data a number of issues are clarified, for example: slamming time scales and selection of appropriate sampling rates and filtering levels; identification of peak values in acceleration signals; statistical distributions and convergence; and the relation between the statistical peak fraction averages that are commonly used as design parameters and the actual extreme values. The established methods and generated results form a valuable basis for setting up and analyzing high-speed craft experiments and simulations, and for validating and updating the prevailing semi-empirical methods.
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| 20. |
- Rosén, Anders, et al.
(author)
-
High-speed craft dynamics in waves: challenges and opportunities related to the current safety philosophy
- 2017
-
Conference paper (other academic/artistic)abstract
- This paper considers the assessment of vertical accelerations of high speed planing craft in waves as the principal element for the risk management approach, i.e. formulation and application of operational limitations and operational guidance. Semi-empirical methods used by classification societies for vertical acceleration assessment are scrutinized. Insights from model experiments performed at the University of Naples “Federico II” (UNINA) and simulations performed at the Royal Institute of Technology (KTH) are presented. Deficiencies of the prevailing semi-empirical methods, and challenges and opportunities with a combined experimental-numerical approach, are discussed in perspective of the IMO high-speed craft safety philosophy.
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| 21. |
- Rosén, Anders, 1970, et al.
(author)
-
Serum tau concentration after diving - an observational pilot study.
- 2019
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In: Diving and hyperbaric medicine. - : Diving and Hyperbaric Medicine Journal. - 1833-3516 .- 2209-1491. ; 49:2, s. 88-95
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Journal article (peer-reviewed)abstract
- Increased concentrations of tau protein are associated with medical conditions involving the central nervous system, such as Alzheimer's disease, traumatic brain injury and hypoxia. Diving, by way of an elevated ambient pressure, can affect the nervous system, however it is not known whether it causes a rise in tau protein levels in serum. A prospective observational pilot study was performed to investigate changes in tau protein concentrations in serum after diving and also determine their relationship, if any, to the amount of inert gas bubbling in the venous blood.Subjects were 10 navy divers performing one or two dives per day, increasing in depth, over four days. Maximum dive depths ranged from 52-90 metres' sea water (msw). Air or trimix (nitrogen/oxygen/helium) was used as the breathing gas and the oxygen partial pressure did not exceed 160 kPa. Blood samples taken before the first and after the last dives were analyzed. Divers were monitored for the presence of venous gas emboli (VGE) at 10 to15 minute intervals for up to 120 minutes using precordial Doppler ultrasound.Median tau protein before diving was 0.200 pg·mL⁻¹ (range 0.100 to 1.10 pg·mL⁻¹) and after diving was 0.450 pg·mL⁻¹ (range 0.100 to 1.20 pg·mL⁻¹; P = 0.016). Glial fibrillary acidic protein and neurofilament light protein concentrations analyzed in the same assay did not change after diving. No correlation was found between serum tau protein concentration and the amount of VGE.Repeated diving to between 52-90 msw is associated with a statistically significant increase in serum tau protein concentration, which could indicate neuronal stress.
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| 22. |
- Sundström, Mikael, et al.
(author)
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Centerpartiet – samling efter den ideologiska stormen
- 2015
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In: Statsvetenskaplig tidskrift. - 0039-0747. ; 117:2, s. 203-218
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Journal article (peer-reviewed)abstract
- The Centre party weathered what amounted to an almost existential mid-term public opinion crisis, to end up outperforming its coalition partners in the 2014 general election. Although it too fell back, it shed a notable proportion of tactical support voters, and actually increased its share of genuine, first-preference, voters. The Centre party has revisited and refreshed its ideological foundation, which, after a stormy interval, appears to have knitted party factions closer together. This process, like the one leading up to the election of party leader Annie Lööf in 2011, was characterised by unprecedented transparency and deliberation opportunities, and we argue that this has favourably impacted the party-internal arena. In the parliamentary arena, the Centre Party has been overshadowed by the much larger government coalition partner, the Moderate Party. There is some evidence to suggest that a level of resurgence may be on the cards as the party has now switched roles to become a freer and relatively strong-voiced opposition party.
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| 23. |
- Söder, Carl-Johan, et al.
(author)
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Assessment of ship roll damping through full scale and model scale experiments and semi-empirical methods
- 2019
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In: Contemporary Ideas on Ship Stability. - Cham : Springer. - 9783030005160 ; 119, s. 177-190
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Book chapter (peer-reviewed)abstract
- This chapter presents unique experimental set-ups in model scale and fullscale for evaluating roll damping properties of a Panamax Pure Car and Truck Carrierat speed. The purpose of this study is to develop a method for the assessment of rolldamping based on full scale trials and to validate the use of roll damping derivedfrom model tests for full scale vessels. Experimental data are also used to assess asemi-empirical method that today provides input for the prediction of critical rollingevents such as parametric rolling and severe rolling motions in general.
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| 24. |
- Söder, Carl-Johan, 1982-, et al.
(author)
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Ikeda Revisited
- 2019
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In: Journal of Marine Science and Technology. - : Springer. - 0948-4280 .- 1437-8213. ; 24:1, s. 306-316
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Research review (peer-reviewed)abstract
- In this paper Ikeda’s method for roll damping prediction is revisited and the applicability of the method to modern volume carriers is considered. For volume carriers the hull lift and bilge keel components are the dominating components and the estimation of these components in the original method are benchmarked and scrutinized. It is concluded that the speed dependence of the bilge keels damping is underestimated by the original method. This is partially explained by that Ikeda seems to have underestimated the lift force of the bilge keels in his analytical expressions. Correcting for this and taking account of the lift force generated pressure on the hull surface gives overall better agreement with model tests. It is also concluded that the hull lift damping component is significantly overestimated with the original method. Non-viscid CFD is used to propose a new generic expression for estimating the lift coefficients for volume carriers which greatly improve the accuracy in comparison to model test results. With these improvements Ikeda’s method is revitalized and the applicability is extended to unconventional volume carriers.
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