| 1. |
- Wanzhu, Cai, et al.
(author)
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Dedoping-induced interfacial instability of poly(ethylene imine)s-treated PEDOT:PSS as a low-work-function electrode
- 2020
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In: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 8:1, s. 328-336
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Journal article (peer-reviewed)abstract
- Transparent organic electrodes printed from high-conductivity PEDOT:PSS have become essential for upscaling all-carbon based, low-cost optoelectronic devices. In the printing process, low-work-function PEDOT:PSS electrodes (cathode) are achieved by coating an ultra-thin, non-conjugated polyelectrolyte that is rich in amine groups, such as poly(ethylene imine) (PEI) or its ethoxylated derivative (PEIE), onto PEDOT:PSS surfaces. Here, we mapped the physical and chemical processes that occur at the interface between thin PEIx (indicating either PEI or PEIE) and PEDOT:PSS during printing. We identify that there is a dedoping effect of PEDOT induced by the PEIx. Using infrared spectroscopy, we found that the amine-rich PEIx can form chemical bonds with the dopant, PSS. At lower PSS concentration, PEIx also shows an electron-transfer effect to the charged PEDOT chain. These interface reactions lock the surface morphology of PEDOT:PSS, preventing the redistribution of PSS, and reduce the work function. Subsequent exposure to oxygen during the device fabrication process, on the other hand, can result in redoping of the low-work-function PEDOT:PSS interface, causing problems for printing reproducible devices under ambient conditions.
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| 2. |
- Allamani, Allaman, et al.
(author)
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Contextual Determinants of Alcohol Consumption Changes and Preventive Alcohol Policies : A 12-Country European Study in Progress 2011
- 2011
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In: Substance Use & Misuse. - : Informa UK Limited. - 1082-6084 .- 1532-2491. ; 46:10, s. 1288-1303
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Journal article (peer-reviewed)abstract
- Beginning with France in the 1950s, alcohol consumption has decreased in Southern European countries with few or no preventive alcohol policy measures being implemented, while alcohol consumption has been increasing in Northern European countries where historically more restrictive alcohol control policies were in place, even though more recently they were loosened. At the same time, Central and Eastern Europe have shown an intermediate behavior. We propose that country-specific changes in alcohol consumption between 1960 and 2008 are explained by a combination of a number of factors: (1) preventive alcohol policies and (2) social, cultural, economic, and demographic determinants. This article describes the methodology of a research study designed to understand the complex interactions that have occurred throughout Europe over the past five decades. These include changes in alcohol consumption, drinking patterns and alcohol-related harm, and the actual determinants of such changes
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| 3. |
- Beigi, Farideh, et al.
(author)
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Immobilized liposome and biomembrane partitioning chromatography of drugs for prediction of drug transport
- 1998
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In: International Journal of Pharmaceutics. - 0378-5173 .- 1873-3476. ; 164:1-2, s. 129-137
-
Journal article (peer-reviewed)abstract
- Drug partitioning into lipid bilayers was studied by chromatography on liposomes and biomembranes immobilized in gel beads by freeze–thawing. The drug retention volume was expressed as a capacity factor, Ks, normalized with respect to the amount of immobilized phospholipid. Log Ks values for positively charged drugs on brain phosphatidylserine (PS)/egg phosphatidylcholine (PC) liposomes decreased as the ionic strength was increased, increased as the PS:PC ratio or the pH was increased and varied linearly with the temperature. Log Ks values for beta-blockers, phenothiazines and benzodiazepines on egg phospholipid (EPL) liposomes correlated well with corresponding values on red cell membrane lipid liposomes (r2=0.96), and on human red cell membrane vesicles containing transmembrane proteins (r2=0.96). A fair correlation was observed between the values on EPL liposomes and those on native membranes of adsorbed red cells (r2=0.86). Compared to the data obtained with liposomes, the retentions of hydrophilic drugs became larger and the range of log Ks values more narrow on the vesicles and the membranes, which expose hydrophilic protein surfaces and oligosaccharides. Lower correlations were observed between drug retention on EPL liposomes and egg PC liposomes; and between retention on liposomes (or vesicles) and immobilized artificial membrane (IAM) monolayers of PC analogues. Absorption of orally administered drugs in humans (literature data) was nearly complete for drugs of log Ks values in the interval 1.2–2.5 on vesicles. Both vesicles and liposomes can thus be used for chromatographic analysis of drug–membrane interaction and prediction of drug absorption.
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| 4. |
- Bergqvist, Jonas, et al.
(author)
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Asymmetric photocurrent extraction in semitransparent laminated flexible organic solar cells
- 2018
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In: npj Flexible Electronics. - : Springer Science and Business Media LLC. - 2397-4621. ; 2:1
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Journal article (peer-reviewed)abstract
- Scalable production methods and low-cost materials with low embodied energy are key to success for organic solar cells. PEDOT(PSS) electrodes meet these criteria and allow for low-cost and all solution-processed solar cells. However, such devices are prone to shunting. In this work we introduce a roll-to-roll lamination method to construct semitransparent solar cells with a PEDOT(PSS) anode and an polyethyleneimine (PEI) modified PEDOT(PSS) cathode. We use the polymer:PCBM active layer coated on the electrodes as the lamination adhesive. Our lamination method efficiently eliminates any shunting. Extended exposure to ambient degrades the laminated devices, which manifests in a significantly reduced photocurrent extraction when the device is illuminated through the anode, despite the fact that the PEDOT(PSS) electrodes are optically equivalent. We show that degradation-induced electron traps lead to increased trap-assisted recombination at the anode side of the device. By limiting the exposure time to ambient during production, degradation is significantly reduced. We show that lamination using the active layer as the adhesive can result in device performance equal to that of conventional sequential coating.
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| 5. |
- Billberg, Peter, et al.
(author)
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Form Pressures Generated by Self-Consolidating Concrete
- 2005
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In: Concrete International. - 0162-4075 .- 1944-7388. ; 27:10, s. 35-42
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Journal article (peer-reviewed)abstract
- Since its development, it has been generally assumed that self-consolidating concrete (SCC) would generate hydrostatic formwork pressure due to the rate at which it can be cast and the long time before it starts to set. However, in 1998 when the first bridges were cast using SCC in Sweden, measured form pressures were even lower than the design values for conventional concrete. To investigate the need for special formwork design considerations when using SCC, a series of eight wall specimens were cast, and the resulting form pressures were monitored.
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| 6. |
- Billberg, Peter, et al.
(author)
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Självkompakterande betong. : Användningsteknik
- 2002
-
Reports (peer-reviewed)abstract
- During an earlier performed R&D project on self-compacting concrete, SCC, reported in [1], lack of knowledge was revealed on a number of issues such as for example how form pressure develops relative to different concrete mix designs, casting rates and form types. Also surface damages at the level of the interface between concrete layers was discovered. These questions, along with the experience gained through the construction of civil engineering structures using SCC between the years 1997 and 2000, has been the basis for the formation of the present R&D project. _x000D_ _x000D_ The aims of this project have been to study the thixotropic structural build-up of SCC at rest and to develop new test methods for the quantification of this structural build-up. Both existing as well as newly developed methods was to be investigated. _x000D_ _x000D_ It was also included in the plan to perform full-scale test where the form pressure should be monitored at the same time as the structural build-up was measured using the developed test methods. The goal was to find relationships between the development of form pressures and the variables stated in the project plan and to correlate them to the thixotropic structural build-up. _x000D_ _x000D_ The project started with a literature study on "Thixotropy of cement based materials" which resulted poorly, at least on the topic structural build-up at rest. However, a relatively great deal of information on thixotropy of cement paste was found but very little on the same subject for concrete. Nothing at all was found on the connection between thixotropy and form pressure. _x000D_ _x000D_ To characterise the thixotropic properties of SCC it is necessary to develop new test methods, or at least to modify existing ones. Four methods have been evaluated in the project: undisturbed slump-flow, tixometer, Rap-Act Plasticity meter and a BML viscometer where the measuring sequence was modified. All these methods have shown the ability to verify some kind of structural build up of SCC at rest. _x000D_ _x000D_ A laboratory investigation has been carried out where the mentioned methods were used for characterisation of the thixotropic properties of six different concrete mix designs. The concrete mixes were designed to have different particle concentration within their paste-phase. All methods were capable to register different structural build-ups in correlation with the varied particle concentrations. Unfortunately it was obvious during the laboratory investigation, and throughout of the whole project, that all tested concrete’s showed very short open times compared to those who were obtained in 1998 when three whole bridges was cast using only SCC. I can therefore be stated that the structural build-up of the concrete mixes tested within the framework of this project has not been of thixotropic nature but instead, of an irreversible kind. In other words: the definition of thixotropy has not been fulfilled. _x000D_ _x000D_ In an extension of the laboratory investigations, financed by Cementa AB, a new combination of constituent materials were tested, i.e. superplasticizer and filler material. However, no significant change in open time could be traced from these tests. _x000D_ _x000D_ The formwork used at the full-scale castings on Betongindustris ready mix concrete plant in Tumba south of Stockholm showed to be statically well defined and therefore easy to evaluate by means of form pressures. _x000D_ _x000D_ Totally eight full-scale trials have been performed. Water to cement ratio, W/C, was varied between 0.40 and 0.45 in the two different mix designs used. Casting rates was varied in three levels: approximately 1.0 m/h, 1.4 m/h and 2.2 m/h. Form surfaces consisted of board on one side and of form plywood on the other. Each half area of the form surfaces was oiled while the other was kept untreated. _x000D_ _x000D_ Measured form pressures showed strong correlation with casting rates. But also an increased concrete flowability and shorter time between finished mixing and casting resulted in a relatively higher form pressure. The conventionally vibrated concrete resulted in a form pressure lower than the calculated according to [24] and also lower than the one obtained when casting with the corresponding SCC at the same rate. _x000D_ _x000D_ The overall conclusions that can be drawn from this project are the following: _x000D_ _x000D_ 1) Form pressures obtained when casting with SCC is dominated by chosen casting rates in that an increased rate results in a higher pressure and vice versa. The results also indicate that concrete age and flowability have a clear influence on the form pressure. A shorter duration between mixing and casting increases the form pressure relative to a longer duration and stiffer concrete. _x000D_ 2) The formwork used showed to be statically well defined. _x000D_ _x000D_ 3) All developed methods can register the concrete structural build-up at rest. _x000D_ _x000D_ 4) A throughout problem has been short open time of the concrete tested within the project. This stiffening has not been of thixotropic nature but to a major part irreversible._x000D_
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| 7. |
- Fröjmark, Anders
(author)
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Mirakler och helgonkult : Linköpings biskopdöme under senmedeltid
- 1992
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Doctoral thesis (other academic/artistic)abstract
- This work studies the introduction of three new cults of saints in the Linköping Bishopric during the Late Middle Ages. Two of them were based at Vadstena Convent: the Holy Bridgel (Birgitta, d. 1373) cult which had its beginning in 1374 and the cult of Katarina Ulfsdotter (d. 1381), which started during the 1410's. The third, the cult of Bishop Nils Hermansson (d. 1391), which originated at the latest in I40l. was associaled w ith the cathedral in Linköping.The introduction of a saint's cult may be relaled to the need of many people in medieval society for healing and protection. The tales about the saint's posthumous miracles played a key role in the introductory phase of the cults. In the dissertation such tales are used as the foundation for the analysis of the varied geographic and social patterns of distnbution of the three cults.The cult of the Holy Bridget was as much an intemational as a Swedish cult. The other cults studied were two of manv attempts to ride on the wave created by the successes of the Bridget cult. They may furthermore be regarded a response to various types of crises which the sponsoring institutions experienced.
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| 8. |
- Helou, Khalil, 1966, et al.
(author)
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Comparative genome hybridization reveals specific genomic imbalances during the genesis from benign through borderline to malignant ovarian tumors.
- 2006
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In: Cancer genetics and cytogenetics. - : Elsevier BV. - 0165-4608. ; 170:1, s. 1-8
-
Journal article (peer-reviewed)abstract
- Ovarian cancer is one of the most common types of malignancy in women throughout the developed world. Despite recent therapeutic advances, long-term survival is poor because ovarian cancer is largely asymptomatic in its early stages. Comparative genomic hybridization (CGH) was applied to a series of 8 benign, 8 borderline, and 17 malignant ovarian to establish genomic imbalances associated with tumor progression. Benign and borderline tumors were characterized by losses at 1p32 approximately p11, 2q14 approximately q34, 4q13 approximately q34, 5q11 approximately q23, and 6q12 approximately q24, as well as gains of 6p and chromosome 12. Similar chromosomal changes were also detected in malignant tumors but included additional chromosomal changes: gains at 1q21 approximately q31, 2p, 3q, 5p, 7, 10p, 12p, 16p, 17, 19q, 20q, and 22q, as well as losses at X, 3p, 8p, 9, 11p, 13, 14, and 18. Some individual cases of benign and borderline tumors revealed no genetic alterations detectable by CGH, suggesting that these tumors may represent a subset of tumors that originate by an alternative mechanism of tumorigenesis. Furthermore, our findings reveal that borderline tumors are more similar to benign tumors than to malignant tumors with respect to their genetic profiles.
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| 9. |
- Jonsson, Emma, 1981-, et al.
(author)
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Multifaceted Conscription : A Comparative Study of Six European Countries
- 2024
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In: Scandinavian Journal of Military Studies. - 2596-3856. ; 7:1, s. 19-33
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Journal article (peer-reviewed)abstract
- Although the last few decades have witnessed a shift from conscription to all-volunteer forces in many European countries, recent changes in the European security environment have raised new concerns and prompted several countries to reconsider conscription. However, modern conscription systems have also had to adapt to changing societies and an increasing emphasis on individualistic and neoliberal values. This study aims to examine the various forms of military conscription and illuminate the continuing viability of the conscription model in six European countries: Estonia, Finland, Lithuania, Norway, Sweden, and Switzerland. Four of these countries have consistently maintained conscription (Estonia, Finland, Norway, and Switzerland), while Lithuania and Sweden have recently reinstated conscription. Although conscription systems differ among these countries, there is overall an increasing emphasis on conscript motivation and female participation. Three key aspects are identified to describe different conscription systems: the proportion of conscripted individuals in the birth cohort, motivation to serve, and the approach to female conscripts. Combining these aspects, the study identifies three types of conscription system in these six countries. This article demonstrates that conscription has evolved and adapted to changing societies and security situations instead of merely retaining its traditional form.
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| 10. |
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| 11. |
- Kruskopf Österberg, Marita, 1970-
(author)
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From QTLs to Genes: Flowering Time Variation and CONSTANS-LIKE Genes in the Black Mustard (Brassica nigra)
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- The transition to flowering is a major developmental switch in angiosperms, the timing of which is expected to be important for fitness. In this thesis the focus has been on identification of genes affecting natural variation in flowering time in Brassica nigra. The background for this thesis is an earlier QTL-mapping study in B. nigra. The genomic area with the greatest effect on flowering time in that study contained a homolog to the CONSTANS gene, which is known to affect flowering time in A. thaliana. When studied more closely this gene did not seem to affect flowering time variation in B. nigra. Near the B.nigra CO gene (BniCOa), however, we identified a homolog to the related CONSTANS LIKE 1 (COL1) gene. In A. thaliana COL1 has not been shown to be associated with induction of flowering but since the B. nigra homolog (BniCOL1) in the QTL area showed surprising amounts of variation between early and late flowering plants we set out to test if this variation was associated with flowering time variation. In the first paper we found a significant association between flowering time and one indel (Ind2) in the coding region. Motivated by the results in paper one, we searched for evidence of selection at the BniCOL1(paper two). In paper three the aim was to validate the results from the first paper in a larger sample of populations, and to check whether the association found in paper I could reflect linkage disequilibrium with areas outside of the gene. Finally, in paper four we investigate the general evolution of three CONSTANS-LIKE genes in B. nigra, namely BniCOL1, BniCOa and BniCOb.
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| 12. |
- Rodriguez Martinez, Xabier, et al.
(author)
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Matching electron transport layers with a non-halogenated and low synthetic complexity polymer:fullerene blend for efficient outdoor and indoor organic photovoltaics
- 2022
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In: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 10:19, s. 10768-10779
-
Journal article (peer-reviewed)abstract
- The desired attributes of organic photovoltaics (OPV) as a low cost and sustainable energy harvesting technology demand the use of non-halogenated solvent processing for the photoactive layer (PAL) materials, preferably of low synthetic complexity (SC) and without compromising the power conversion efficiency (PCE). Despite their record PCEs, most donor-acceptor conjugated copolymers in combination with non-fullerene acceptors are still far from upscaling due to their high cost and SC. Here we present a non-halogenated and low SC ink formulation for the PAL of organic solar cells, comprising PTQ10 and PC61BM as donor and acceptor materials, respectively, showing a record PCE of 7.5% in blade coated devices under 1 sun, and 19.9% under indoor LED conditions. We further study the compatibility of the PAL with 5 different electron transport layers (ETLs) in inverted architecture. We identify that commercial ZnO-based formulations together with a methanol-based polyethyleneimine-Zn (PEI-Zn) chelated ETL ink are the most suitable interlayers for outdoor conditions, providing fill factors as high as 74% and excellent thickness tolerance (up to 150 nm for the ETL, and >200 nm for the PAL). In indoor environments, SnO2 shows superior performance as it does not require UV photoactivation. Semi-transparent devices manufactured entirely in air via lamination show indoor PCEs exceeding 10% while retaining more than 80% of the initial performance after 400 and 350 hours of thermal and light stress, respectively. As a result, PTQ10:PC61BM combined with either PEI-Zn or SnO2 is currently positioned as a promising system for industrialisation of low cost, multipurpose OPV modules.
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| 13. |
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| 14. |
- Sorgard, Trygve, et al.
(author)
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All-optical high-speed modulation of THz transmission through silicon core optical fibers
- 2021
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In: Optics Express. - : The Optical Society. - 1094-4087. ; 29:3, s. 3543-3552
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Journal article (peer-reviewed)abstract
- High speed optical modulation of THz radiation is of interest for information processing and communications applications. In this paper infrared femtosecond pulses are used to generate free carriers that reduce the THz transmission of silicon based waveguides over a broad spectral range. Up to 96 6 70 modulation is observed from 0.5 to 7 THz in an optical fiber with a 210 mu m diameter gold-doped silicon core. The observed carrier recombination time of 2.0 +/- 0.2 ns makes this material suitable for high speed all-optical signal processing. These results show both enhanced modulation depth and reduced carrier lifetime when compared to the performance of a high resistivity float zone silicon rectangular guide with comparable cross sectional area.
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| 15. |
- Sorgard, Trygve, et al.
(author)
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Broadband infrared and THz transmitting silicon core optical fiber
- 2020
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In: Optical Materials Express. - : The Optical Society. - 2159-3930 .- 2159-3930. ; 10:10, s. 2491-2499
-
Journal article (peer-reviewed)abstract
- Silicon waveguide structures are a viable alternative for the transmission of signals over a wide range of frequencies, and new fabrication methods are key to increased applications. In this work, THz transparency of silicon-core, silica clad fibers, refined using a traveling solvent method, is demonstrated. The approximate to 200 mu m core of these fibers is shown to have good transmission from 4.8-9 mu m and 1-7 THz. Fibers were drawn on a conventional optical fiber tower using the scalable molten core technique and CO2 laser annealed, resulting in large-grain crystalline cores with broadband transmission. The spectral properties are comparable to those of rectangular guides of similar cross-sectional area cut from high resistivity float zone silicon wafers.
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| 16. |
- Yuen, Katarina, et al.
(author)
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Matching a permanent magnet synchronous generator to a fixed pitch vertical axis turbine for marine current energy conversion
- 2009
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In: IEEE Journal of Oceanic Engineering. - 0364-9059 .- 1558-1691. ; 34:1, s. 24-31
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Journal article (peer-reviewed)abstract
- Extracting energy from a free-flow marine current using a vertical axis fixed pitch turbine requires a generator that can handle varying speeds and loads, since such a turbine gives maximum power capture for a fixed tip speed ratio. A prototype of such a generator has been designed and constructed. In this paper, its variable speed and load operation is evaluated, both in terms of how the constructed generator performs in relation to simulations, and in terms of how the generator could perform with three different fixed pitch turbines. Measurements of root mean square (RMS) voltage and current differ 10% from simulations. Performance analysis with example turbines shows that the generator can match fixed tip speed ratio operation of several turbines for current speeds between 0.5 and 2.5 m/s.
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| 17. |
- Österberg, Thomas
(author)
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Modelling and prediction of drug transport processes with experimental and calculated molecular properties : A multivariate approach
- 2000
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Doctoral thesis (other academic/artistic)abstract
- Less than 2% of the lead compounds generated by the pharmaceutical industry enter the exploratory drug-development phase, from which point they stand only a 10% chance of becoming a commercial medicine. A large proportion of the compounds fail due to poor biopharmaceutical properties, such as permeability and solubility. The main theme of this thesis is, therefore, the development of better experimental and computational methods for modelling and predicting the biopharmaceutical properties of drug candidates. Immobilised liposome chromatography (ILC) was used for studying drug-membrane interactions and for the prediction of passive drug transport. For the drugs studied in this thesis, ILC and octanol/water partitioning showed a similar performance with regard to the prediction of passive drug transport.The theoretical work was directed at the modelling and prediction of drag transport processes using calculated molecular properties and PLS analysis. In the initial studies, the molecular properties were calculated with an advanced computational tool (MolSurf) that takes the three-dimensional structural information and electronic properties of the compound into consideration. Statistical models well suited to the prediction of drug transport processes such as Caco-2 cell permeability, intestinal absorption and CNS penetration were derived.This approach was also successfully applied to the modelling of the interaction of drugs with P-glycoprotein. Subsequently, rapidly calculated descriptors based on two-dimensional structural information and PLS analysis were also found to give good predictive models of drug transport properties. The preferred use of the latter models is for screening compound collections and virtual libraries. It can be concluded that calculated molecular properties in conjunction with PLS analysis are well suited to the modelling and prediction of drug transport processes and to identifying compounds with potential biopharmaceutical problems at an early stage of the drug-development process.
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