| 1. |
- Balliu, Enkeleda, PhD student, et al.
(författare)
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Laser processing of graphene oxide on different coated paper substrates
- 2016
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Ingår i: 14th TAPPI Advanced Coating Symposium 2016. - : TAPPI Press. - 9781510877658 ; , s. 97-101
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Konferensbidrag (refereegranskat)abstract
- Development of printed electronics is increasing each year, where many electrical components such as transistors and sensors are now printable. The most commonly used substrate have been plastics, but there is an increasing interest in using paper as substrate. The paper industry is a very large and mature industry with large production capacity and well developed processes. It is therefore of interest to investigate how it would be possible to combine printed electronics and paper based products. This can for example be to print sensors on packages, to use large scale roll-to-roll production for solar cells. To be able to achieve such goals it is of importance to develop methods of applying electrically active materials in the large, high speed roll-to-roll processes used in the paper industry. In this article we discuss coating of graphene oxide (GO) on large areas after which it is selectively reduced into electrically conductive reduced graphene oxide (rGO) by laser processing. Graphene oxide is an inexpensive, carbon based material very suitable to be deposited as a coating, and the selective activation of makes it possible to fabricate conductive patterns at high speeds. We have evaluated several different paper substrates on which GO was coated. The reduction was performed using an 532 nm laser source and the results are promising, showing that it is possible to fabricate selectively conductive patterns on paper substrates by coating and reduction of GO.
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| 2. |
- Bjerg, Anders, et al.
(författare)
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Increased Prevalence of Symptoms of Rhinitis but Not of Asthma between 1990 and 2008 in Swedish Adults : Comparisons of the ECRHS and GA(2)LEN Surveys
- 2011
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:2, s. e16082-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The increase in asthma prevalence until 1990 has been well described. Thereafter, time trends are poorly known, due to the low number of high quality studies. The preferred method for studying time trends in prevalence is repeated surveys of similar populations. This study aimed to compare the prevalence of asthma symptoms and their major determinants, rhinitis and smoking, in Swedish young adults in 1990 and 2008. Methods: In 1990 the European Community Respiratory Health Survey (ECRHS) studied respiratory symptoms, asthma, rhinitis and smoking in a population-based sample (86% participation) in Sweden. In 2008 the same symptom questions were included in the Global Allergy and Asthma European Network (GA(2)LEN) survey (60% participation). Smoking questions were however differently worded. The regions (Gothenburg, Uppsala, Umea) and age interval (20-44 years) surveyed both in 1990 (n = 8,982) and 2008 (n = 9,156) were analysed. Results: The prevalence of any wheeze last 12 months decreased from 20% to 16% (p<0.001), and the prevalence of "asthma-related symptoms" was unchanged at 7%. However, either having asthma attacks or using asthma medications increased from 6% to 8% (p<0.001), and their major risk factor, rhinitis, increased from 22% to 31%. Past and present smoking decreased. Conclusion: From 1990 to 2008 the prevalence of obstructive airway symptoms common in asthma did not increase in Swedish young adults. This supports the few available international findings suggesting the previous upward trend in asthma has recently reached a plateau. The fact that wheeze did not increase despite the significant increment in rhinitis, may at least in part be due to the decrease in smoking.
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| 3. |
- Dahlstedt, Magnus, et al.
(författare)
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Systemet med fritt skolval måste bytas ut
- 2018
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Ingår i: Svenska Dagbladet.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Ökad segregation och deprofessionalisering av läraryrket är några av effekterna av det fria skolvalet. Nu krävs en grundlig utredning med siktet inställt på att hitta alternativ till nuvarande marknadssystem, skriver ett flertal forskare.
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| 4. |
- Fjellström, Helena, 1977-, et al.
(författare)
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A novel method for studying the photo-stabilising properties of coating layers
- 2006
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A new model system was developed which made it possible to study the reflectance and transmittance of thin coating layers (<10 g/m2) in a reproducible way, and to link this to the inhibition of the light-induced yellowing (Figure 1). The UV/VIS-screening properties of coatings of different coat weights containing common pigments such as kaolin, calcium carbonate (ground or precipitated) and titanium dioxide will be reported. The ability of a coating layer to protect a birch CTMP from light-induced discoloration will be exemplified using the evolved model system. An estimation of the contribution of different wavelength regions of the illuminating light to the photo-yellowing of various types of materials will also be shown. The developed method is a valuable tool for future photo-yellowing studies as well as for optimisation of the pigment coating formulation for various paper grades.
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| 5. |
- Forward, Sonja, 1956-, et al.
(författare)
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Förnybara drivmedel : möjligheter och hinder sett utifrån privatbilisters och aktörers perspektiv
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I detta projekt ingick tre olika delstudier med syfte att tillhandahålla en fördjupad förståelse för användarnas behov av och inställning till bilar som drivs med alternativa drivmedel såsom, el, vätgas och biogas. Förutom detta undersöktes inställningen till bilar och klimatfrågor i allmänhet men också vilka förutsättningar man ser för olika bilar med alternativa drivmedel. De olika studierna använde sig av tre olika metoder; fokusgrupp, enkät och intervjuer. I fokusgrupperna ingick sex personer. I enkätstudien deltog 487 slumpmässigt utvalda trafikanter och i intervjustudien nio aktörer från myndigheter, branschorganisationer och media. Resultaten visar att vid köp av bil är säkerhet och tillförlitlighet viktigare än utsläppen av CO2. Synen på bilar som drivs med alternativa drivmedel (elbil, bränslecellsbil, biogasbil), skiljer sig inte markant åt. Priset man är villig att betala för en sådan bil är betydligt lägre än vad dessa bilar kostar i nuläget. Rent allmänt kan man hävda att konsumenterna vill att en bil som drivs med alternativa drivmedel liknar eller är bättre än en konventionell bil. Studien visar också att politiker har en avgörande roll för hur utvecklingen av framtida alternativa drivmedel och infrastruktur för sådana ska kunna utformas. Enligt de intervjuade är det största problemet inte tekniken utan hur man ska få till stånd en infrastruktur för dessa fordon, och att de kommer ut på marknaden. Näringslivet är en viktig aktör som är villiga att satsa om de kan se att verksamheten kan bli lönsam. Långsiktighet är ett nyckelord som nämns både då det gäller politiska beslut och informationsspridning. I det senare fallet eftersom studierna visar att det finns stora brister i kunskapen hos allmänheten samtidigt som det finns en misstro mot den information som sprids. Slutligen visar studierna att det behövs ett helhetsgrepp där fokus inte enbart ligger på bränslen utan även utvecklandet av attraktiva och tillgängliga städer.
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| 6. |
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| 7. |
- Kumar, Vinay, et al.
(författare)
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Conductive nanographite-nanocellulose coatings on paper
- 2017
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Ingår i: Flexible And Printed Electronics. - : IOP Publishing. - 2058-8585. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- Paper products with active and functional coatings have attracted interest in recent years to counter the stagnating demand for traditional graphic paper grades. Conductive coatings have potential uses in various energy generation and storage applications, e.g. in batteries, supercapacitors, and photovoltaics. The current work aims to demonstrate large-scale production of flexible low-cost nanographite coatings on paper-based substrate. The large aspect ratio of graphene present in the suspension limits solids content to very low values, which makes it challenging to create thick coating layers required for high conductivity. The use of nanocellulose binder together with a custom-built slot-coating device enables roll-to-roll coating of thick conductive coatings on paper. The rheological and water-retention properties of nanographite-nanocellulose suspensions are reported. The influence of coat weight, carbon black addition, and calendering on coating structure and the resulting conductivity of the coatings is investigated. Impact of humidity and bending/creasing of coated samples on their electrical performance is explored as well. The lowest surface resistances obtained were in the range 1-2 Ohm/square, for 15 g m(-2) coat weight. Increasing the coat weight and calendering nip load resulted in higher conductivity of coatings. Carbon black addition deteriorated the conductivity somewhat, probably due to increased porosity of coatings. Moisture and creasing did not affect significantly the conductivity of high coat weight and calendered samples. The results reported are very encouraging for future research on further improving the electrical performance of such carbon coatings.
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| 8. |
- Mogensen, Ida, et al.
(författare)
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Fixed airflow obstruction relates to eosinophil activation in asthmatics
- 2019
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 49:2, s. 155-162
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Some asthmatics develop irreversible chronic airflow obstruction, for example, fixed airflow obstruction (fixed-AO). This is probably a consequence of airway remodelling, but neither its relation to inflammation nor which asthma biomarkers can be clinically useful are elucidated. We hypothesized that the presence of type 2 inflammation relates to fixed-AO.OBJECTIVES: To evaluate the presence of four markers for type 2 inflammation in fixed airflow obstruction among asthmatics.METHODS: This was a cross-sectional study of 403 participants with asthma, aged 17-75 years, from three Swedish centres. Fixed airflow obstruction was defined as forced expiratory volume during the first second (FEV1 ) over forced vital capacity (FVC) being below the lower limit of normal (LLN). The following type 2 inflammation markers were assessed: exhaled nitric oxide (FeNO), serum periostin, serum eosinophil cationic protein (S-ECP), and urinary eosinophil-derived neurotoxin (U-EDN).RESULTS: Elevated U-EDN (values in the highest tertile, ≥65.95 mg/mol creatinine) was more common in subjects with fixed-AO vs. subjects without fixed-AO: 55% vs. 29%, P < 0.001. Elevated U-EDN related to increased likelihood of having fixed-AO in both all subjects and never-smoking subjects, with adjusted (adjusted for sex, age group, use of inhaled corticosteroids last week, atopy, early-onset asthma, smoking history, and packyears) odds ratios (aOR) of 2.38 (1.28-4.41) and 2.51 (1.04-6.07), respectively. In a separate analysis, having both elevated S-ECP (>20 μg/L) and U-EDN was related to having the highest likelihood of fixed-AO (aOR (95% CI) 6.06 (2.32-15.75)). Elevated serum periostin or FeNO did not relate to fixed-AO.CONCLUSIONS AND CLINICAL RELEVANCE: These findings support that type 2 inflammation, and in particular eosinophil inflammation, is found in asthma with fixed-AO. This could indicate a benefit from eosinophil-directed therapies. Further longitudinal studies are warranted to investigate causality and relation to lung function decline.
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| 9. |
- Phadatare, Manisha R., et al.
(författare)
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Silicon-Nanographite Aerogel-Based Anodes for High Performance Lithium Ion Batteries
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- To increase the energy storage density of lithium-ion batteries, silicon anodes have been explored due to their high capacity. One of the main challenges for silicon anodes are large volume variations during the lithiation processes. Recently, several high-performance schemes have been demonstrated with increased life cycles utilizing nanomaterials such as nanoparticles, nanowires, and thin films. However, a method that allows the large-scale production of silicon anodes remains to be demonstrated. Herein, we address this question by suggesting new scalable nanomaterial-based anodes. Si nanoparticles were grown on nanographite flakes by aerogel fabrication route from Si powder and nanographite mixture using polyvinyl alcohol (PVA). This silicon-nanographite aerogel electrode has stable specific capacity even at high current rates and exhibit good cyclic stability. The specific capacity is 455 mAh g−1 for 200th cycles with a coulombic efficiency of 97% at a current density 100 mA g−1.
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| 10. |
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