| 1. |
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| 2. |
- Ravry, Victor Falgas, et al.
(författare)
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Turan H-densities for 3-graphs
- 2012
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Ingår i: The Electronic Journal of Combinatorics. - Newark : The Electronic Journal of Combinatorics. - 1097-1440 .- 1077-8926. ; 19:3, s. P40-
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Tidskriftsartikel (refereegranskat)abstract
- Given an r-graph H on h vertices, and a family F of forbidden subgraphs, we define ex H (n, F) to be the maximum number of induced copies of H in an F-free r-graph on n vertices. Then the Turan H-density of F is the limit pi(H)(F) = (lim)(n ->infinity) ex(H)(n, F)/((n)(h)) This generalises the notions of Turan-density (when H is an r-edge), and inducibility (when F is empty). Although problems of this kind have received some attention, very few results are known. We use Razborov's semi-definite method to investigate Turan H-densities for 3-graphs. In particular, we show that pi(-)(K4)(K-4) = 16/27, with Turans construction being optimal. We prove a result in a similar flavour for K-5 and make a general conjecture on the value of pi(Kt)-(K-t). We also establish that pi(4.2)(empty set) = 3/4, where 4: 2 denotes the 3-graph on 4 vertices with exactly 2 edges. The lower bound in this case comes from a random geometric construction strikingly different from previous known extremal examples in 3-graph theory. We give a number of other results and conjectures for 3-graphs, and in addition consider the inducibility of certain directed graphs. Let (S) over right arrow (k) be the out-star on k vertices; i.e. the star on k vertices with all k 1 edges oriented away from the centre. We show that pi((S) over right arrow3)(empty set) = 2 root 3 - 3, with an iterated blow-up construction being extremal. This is related to a conjecture of Mubayi and Rodl on the Turan density of the 3-graph C-5. We also determine pi((S) over right arrowk) (empty set) when k = 4, 5, and conjecture its value for general k.
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| 3. |
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| 4. |
- Szabo, Zoltan, et al.
(författare)
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Potentiometric and multinuclear NMR study of the binary and ternary uranium(VI)-L-fluoride systems, where L is alpha-hydroxycarboxylate or glycine
- 2000
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 39:22, s. 5036-5043
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Tidskriftsartikel (refereegranskat)abstract
- Equilibria, structures, and ligand-exchange dynamics in binary and ternary U(VI)-L-F- systems, where L is glycolate, alpha -hydroxyisobutyrate, or glycine, have been investigated in 1.0 M NaClO4 by potentiometry and H-1, O-17, and F-19 NMR spectroscopy. L may be bonded in two ways: either through the carboxylate end or by the formation of a chelate. In the glycolate system, the chelate is formed by proton dissociation from the -alpha hydroxy group at around pH 3, indicating a dramatic increase, a factor of at least 10(13), of its dissociation constant on coordination to uranium(VI). The L exchange in carboxylate-coordinated UO2LF32- follows an Eigen-Wilkins mechanism, as previously found for acetate. The water exchange rate, k(aq) = 4.2 x 10(5) s(-1), is in excellent agreement with the value determined earlier for UO22+(aq). The ligand-exchange dynamics of UO2(O-CH2-COO)(2)F-3 and the activation parameters for the fluoride exchange in D2O (k(obs) = 12 s(-1), DeltaH(double dagger) = 45.8 +/- 2.2 kJ mol(-1), and DeltaS(double dagger) = -55.8 +/- 3.6 J K-1 mol(-1)) are very similar to those in the corresponding oxalate complex, with two parallel pathways, one for fluoride and one for the alpha -oxocarboxylate. The same is true for the L exchange in UO2(O-CH2-COO)(2)(2-) and UO2(oxalate)(2)(2-), The exchange of alpha -oxocarboxylate takes place by a proton-assisted chelate ring opening followed by dissociation. Because we cannot decide if there is also a parallel H+-independent pathway, only an upper limit for the rate constant, k(1) < 1,2 s(-1), can be given. This value is smaller than those in previously studied ternary systems. Equilibria and dynamics in the ternary uranium(VI)-glycine-fluoride system, investigated by F-19 NMR spectroscopy, indicate the formation of one major ternary complex, UO2LF32- and one binary complex, UO2L2 (L = H2N-CH2COO-), with chelate-bonded glycine; log beta>(*) over bar * (9) = 13.80 +/- 0.05 for the equilibrium UO22+ + H2N-CH2COO- + 3F(-) = UO2(H2N-CH2COO)F-3(2-) and log beta>(*) over bar * (11) = 13.0 +/- 0.05 for the reaction UO22+ + 2H(2)N-CH2COO- = UO2(H2N-CH2COO)(2). The glycinate exchange consists of a ring opening followed by proton-assisted steps. The rate of ring opening, 139 +/- 9 s(-1), is independent of both the concentration of H+ and the solvent, H2O or D2O.
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| 5. |
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| 6. |
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| 7. |
- Goodfellow, Bradley, et al.
(författare)
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Weathering processes and Quaternary origin of an alpine blockfield in Arctic Sweden
- 2009
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Ingår i: Boreas. - : Wiley Interscience. - 0300-9483 .- 1502-3885. ; 38:2, s. 379-398
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Tidskriftsartikel (refereegranskat)abstract
- The weathering and origin of an autochthonous blockfield in the northern Swedish mountains were investigatedthrough an examination of fine matrix and clasts from two pits excavated across ridge-top sorted circles; one on asummit, the other in a saddle. At the summit, fine matrix chemical weathering is limited to the production of poorlycrystallized Al- and Fe-oxyhydroxides, whereas some additional vermiculitization and gibbsite crystallization occursin the saddle. In both locations, volumes of clay-sized matrix are low, mass balance calculations indicate onlyminor elemental losses and no chemically etched grains are visible under a scanning electron microscope (SEM). Inaddition, soil horizons are absent and chemical weathering intensity is uniformly low across both excavated sortedcircles. Minor clast chemical weathering consists of Fe oxidation, which dominates in the matrix-rich circle centres,and some rind development, which increases in frequency in the clast-rich rings. The dominance of physicalweathering processes and the presence of only minor chemical weathering, in both fine matrix and clasts, indicatethat the blockfield is not a Neogene weathering remnant. Rather, the blockfield has a Quaternary origin, developingduring interglacials, interstadials and the Holocene, primarily through subsurface weathering processes.
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| 8. |
- Schwanen, Wout, et al.
(författare)
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Evaluation of uncertainty in spectral analysis of surface texture
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- ISO/TC 43/SC 1/WG 39 is a working group under the Acoustics/Noise committee of ISO, working on standardization of the subject “Measurement of pavement surface texture using a profiling method”. The standardization focuses on road surface properties in the texture range, i.e. texture wavelengths under 500 mm. The main topic is to characterize road surface texture by using surface profiles and providing standardized measures for road condition investigations. Such conditions are essential in studies of, for example, noise, rolling resistance and skid resistance properties of pavement surfaces. The spectral analysis is especially used to distinguish different surface properties within the texture wavelength range, for instance high energy for a specific wavelength that could explain a uniformity at the surface.One of the documents developed by WG 39 is ISO/TS 13473-4, Characterization of pavement texture by use of surface profiles — Part 4: Spectral analysis of surface profiles (Part 4 in the following text). This document has been under revision since 2020. The revised version aims to convert Part 4 to an international standard (ISO) from the current format, technical specification (TS). The future ISO describes two ways of doing spectral analysis, one mandatory Method 1 and one informative Method 2.Method 1: constant-percentage bandwidth obtained by digital filtering (main method);Method 2: constant narrow bandwidth frequency analysis by means of Discrete Fourier Transform (DFT), followed by a transformation of the narrow-band spectrum to an octave- or one-third-octave-band spectrum.During this revision of Part 4 there have been significant improvements to the whole document, in almost every step of the calculation. Special attention has been given to the uncertainty analysis and the influence on various input quantities to the texture spectrum. Uncertainty is an important and mandatory part of a standard that estimates the uncertainty magnitude or impact on the result. The studies done to complete the uncertainty chapter of Part 4 have been compiled into this document, and it could be seen as a model of how to work with uncertainties in a standard.
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| 9. |
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| 10. |
- Jerre, Kristina, 1974-
(författare)
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Contradictory Expectations on Society's Reaction to Crime : A Qualitative Study of How People View the Objectives of Society's Reaction to Crime and How These Objectives Can Be Fulfilled
-
Ingår i: Journal of Scandinavian Studies in Criminology and Crime Prevention. - 1404-3858 .- 1651-2340.
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Tidskriftsartikel (refereegranskat)abstract
- The intention of this study was to develop an understanding of the views of the public on, first, what the objective(s) of society’s reaction to crime should be, and second, how different types of sanctions are perceived as being able to fulfill these objectives. A thematic analysis was conducted on the basis of transcripts of group interviews. The participants argued that society’s reaction should signal condemnation of the crime and at the same time be beneficial in relation to the re-socialisation of the offender. Sanctions that were perceived to fulfill the signaling of condemnation, i.e. tangible custodial sanctions, were described as being counterproductive in relation to the resocialisation of the offender. On the other hand, the signal of caring for the offender was perceived as having a neutralizing effect on the signal of condemnation. For the objective of society’s reaction to be fulfilled it thus has to give the illusion of being tangible and harsh but at the same time, in reality, must serve as an effective, lasting deterrent to the offender. It is suggested that the contradictions and tensions surrounding the objectives of society’s reaction to crime, and the issue of how these contradictions might be considered when framing crime policy, should be opened up as a matter for discussion in the public debate.
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| 11. |
- Zetterström Dahlqvist, Heléne, et al.
(författare)
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Dimensions of Peer Sexual Harassment Victimization and Depressive Symptoms in Adolescence : A Longitudinal Cross-Lagged Study in a Swedish Sample
- 2016
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Ingår i: Journal of Youth and Adolescence. - : Springer. - 0047-2891 .- 1573-6601. ; 45:5, s. 858-873
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Tidskriftsartikel (refereegranskat)abstract
- Sexual harassment is commonly considered unwanted sexual attention and a form of gender-based violence that can take physical, verbal and visual forms and it is assumed to cause later depression in adolescents. There is a dearth of research explicitly testing this assumption and the directional pathway remains unclear. The purpose of this study was to use a feminist theoretical framework to test competing models in respect of the direction of the relationships between dimensions of peer sexual harassment victimization and dimensions of depressive symptoms from ages 14 to 16 in adolescents. The study also aimed to investigate gender differences in these pathways. Cross-lagged models were conducted using a three-wave (2010, 2011 and 2012) longitudinal study of 2330 students (51 % females) from Sweden, adjusted for social background. Girls subjected to sexual harassment in grade seven continued to experience sexual harassment the following 2 years. There was weaker evidence of repeated experience of sexual harassment among boys. Depressive symptoms were stable over time in both genders. Sexual name-calling was the dimension that had the strongest associations to all dimensions of depressive symptoms irrespective of gender. In girls, name-calling was associated with later somatic symptoms and negative affect, while anhedonia (reduced ability to experience pleasure) preceded later name-calling. Physical sexual harassment had a reciprocal relationship to somatic symptoms in girls. In boys, name-calling was preceded by all dimensions of depressive symptoms. It is an urgent matter to prevent sexual harassment victimization, as it is most likely to both cause depressive symptoms or a reciprocal cycle of victimization and depression symptoms in girls as well as boys.
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| 12. |
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| 13. |
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| 14. |
- Nistor, Mihaela
(författare)
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Biosensors for Food Analysis: Development and Applications
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reliable analytical methods are increasingly needed in the food and beverage industry for the determination of specific components (e.g. sugars, proteins, vitamins, fats) and for detecting and quantifying chemical contaminants such as pesticides, heavy metals, antibiotics, and pathogenic microorganisms. The need arises from numerous regulatory actions and increased consumer concern about food composition and safety. The producers conventionally utilize analytical techniques such as spectrophotometry and chromatography, which do not always allow easy and continuous monitoring, are rather expensive, need well trained operators and often require sample pre-treatment steps, resulting in increased time and low cost-effectiveness of the analysis. Biosensors offer a promising alternative to the classical analytical methods. Besides their good selectivity and low cost, they can easily be integrated in automation schemes and used to develop simple and even portable equipment, allowing fast in-situ monitoring of raw materials and food processing steps.The aim of this thesis is to review the current situation and future possibilities for the development and applications of biosensors in the food and beverage industry. Focus is placed on particular aspects related to elucidation of the working mechanisms of biosensing systems, optimisation of operating parameters, miniaturization, automation, and determination of food constituents in real samples.
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| 15. |
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| 16. |
- Van Noije, Twan, et al.
(författare)
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EC-Earth3-AerChem : A global climate model with interactive aerosols and atmospheric chemistry participating in CMIP6
- 2021
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 14:9, s. 5637-5668
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Tidskriftsartikel (refereegranskat)abstract
- This paper documents the global climate model EC-Earth3-AerChem, one of the members of the EC-Earth3 family of models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). EC-Earth3-AerChem has interactive aerosols and atmospheric chemistry and contributes to the Aerosols and Chemistry Model Intercomparison Project (AerChemMIP). In this paper, we give an overview of the model, describe in detail how it differs from the other EC-Earth3 configurations, and outline the new features compared with the previously documented version of the model (EC-Earth 2.4). We explain how the model was tuned and spun up under preindustrial conditions and characterize the model's general performance on the basis of a selection of coupled simulations conducted for CMIP6. The net energy imbalance at the top of the atmosphere in the preindustrial control simulation is on average -0.09 W m-2 with a standard deviation due to interannual variability of 0.25 W m-2, showing no significant drift. The global surface air temperature in the simulation is on average 14.08 ∼ C with an interannual standard deviation of 0.17 ∼ C, exhibiting a small drift of 0.015 ± 0.005 ∼ C per century. The model's effective equilibrium climate sensitivity is estimated at 3.9 ∼ C, and its transient climate response is estimated at 2.1 ∼ C. The CMIP6 historical simulation displays spurious interdecadal variability in Northern Hemisphere temperatures, resulting in a large spread across ensemble members and a tendency to underestimate observed annual surface temperature anomalies from the early 20th century onwards. The observed warming of the Southern Hemisphere is well reproduced by the model. Compared with the ECMWF (European Centre for Medium-Range Weather Forecasts) Reanalysis version 5 (ERA5), the surface air temperature climatology for 1995-2014 has an average bias of -0.86 ± 0.05 ∼ C with a standard deviation across ensemble members of 0.35 ∼ C in the Northern Hemisphere and 1.29 ± 0.02 ∼ C with a corresponding standard deviation of 0.05 ∼ C in the Southern Hemisphere. The Southern Hemisphere warm bias is largely caused by errors in shortwave cloud radiative effects over the Southern Ocean, a deficiency of many climate models. Changes in the emissions of near-term climate forcers (NTCFs) have significant effects on the global climate from the second half of the 20th century onwards. For the SSP3-7.0 Shared Socioeconomic Pathway, the model gives a global warming at the end of the 21st century (2091-2100) of 4.9 ∼ C above the preindustrial mean. A 0.5 ∼ C stronger warming is obtained for the AerChemMIP scenario with reduced emissions of NTCFs. With concurrent reductions of future methane concentrations, the warming is projected to be reduced by 0.5 ∼ C.
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| 17. |
- Drobyshev, Igor, et al.
(författare)
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Masting behaviour and dendrochronology of European beech (Fagus sylvatica L.) in southern Sweden
- 2010
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 1872-7042 .- 0378-1127. ; 259:11, s. 2160-2171
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Tidskriftsartikel (refereegranskat)abstract
- To identify weather controls of beech diameter growth and masting in southern Sweden, we analyze records of monthly weather, regional masting record, and tree-ring chronologies from five beech-dominated stands. The results indicate a strong weather control of temporal pattern of masting events in southern Sweden over the second half of the 20th century. Negative summer temperature anomaly 2 years prior to a mast year, coupled with positive temperature anomaly in the year immediately preceding the same mast year, is a characteristic weather pattern associated with known mast years. Strong dependence of beech masting behavior on temperature explains the high degree of regional synchronization of masting events. Growth of beech in southern Sweden is strongly and negatively correlated with previous year's summer temperature and positively - with previous year's October temperature. The present study does not provide a conclusive answer in identifying a full set of direct and indirect effects of climatic variables controlling tree-ring growth, since the negative effect of previous year's summer temperature may be a result of a temperature-controlled increase in the beech nut production in the current year. Consistent and significant negative departures of ring-width index during mast years support the hypothesis about a trade-off between investment of bioassimilates into production of beech nuts and tree-ring growth. Alternative explanation of growth anomalies in mast years, relating such anomaly to a negative impact of previous year's growing season, was not supported by the data. We found a limited effect of masting on diameter growth in the following years, indicating that decline in the overall wood production, associated with heavy masting, is short term and typically occurs in the year of actual masting. (C) 2010 Elsevier B.V. All rights reserved.
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| 18. |
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| 19. |
- Kjær, C., et al.
(författare)
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Gas-phase Förster resonance energy transfer in mass-selected ions with methylene or peptide linkers between two dyes: a concerted dance of charges
- 2020
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Ingår i: Physical chemistry chemical physics : PCCP. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 22:19, s. 11095-11100
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Tidskriftsartikel (refereegranskat)abstract
- Förster Resonance Energy Transfer (FRET) between a photoexcited and a ground-state dye is dictated by how far apart the two dyes are compared to the Förster distance. While there is a significant number of studies on the process for biomacromolecules in solution, there are only a few reports on gas-phase FRET. Here we report on a simple gas-phase model system, synthesized with the rhodamine 575 (R575+) and rhodamine 640 (R640+) FRET pair and a covalent linker with four methylenes, R575+-(CH2)4-R640+. Each dye carries a positive charge which allows for mass-spectroscopy experiments. We have recorded gas-phase dispersed fluorescence spectra of the mass-selected dications excited at different wavelengths using the homebuilt LUNA (LUminescence iNstrument in Aarhus) setup and find in all cases that emission is exclusively from the R640+ acceptor dye. The linker does not interfere electronically with the dyes and simply acts as a spacer. We can therefore establish the direct effect of the interaction between the two dyes when it comes to emission band maximum. Indeed, we find that R640+ experiences a significant shift in its maximum from 560 ± 1 nm for the monomer cation to 577 ± 2 nm in the presence of R575+, independent of initial excitation of R575+ or R640+. This redshift is ascribed to the large polarizability along the long axis of the xanthene core structure, and that this polarizability is larger in the excited state than in the ground state. Experiments were also done on a triply charged 11-mer peptide labelled with the same two dyes, R575+-(Gly-Gln)5-Lys-R640+ + H+ (Gly = glycine, Gln = glutamine, and Lys = lysine) where the extra positive charge is located on the peptide. Again a redshifted emission spectrum of the donor is observed with maximum at 582 ± 2 nm. Our work clearly demonstrates strong sensitivity of the photophysics of one dye to the nearby environment, and that caution is needed when using the energy transfer efficiency to infer dye-dye separations in gas-phase experiments.
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| 20. |
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| 21. |
- Vigsø, Orla, 1962
(författare)
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Editorial
- 2021
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Ingår i: Journal of Visual Political Communication. - : Intellect. - 2633-3732 .- 2633-3740. ; 7:1, s. 3-10
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Tidskriftsartikel (refereegranskat)abstract
- An analysis of the pictures from the storming of Capitol.
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| 22. |
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| 23. |
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| 24. |
- Bogefeldt, Johan, 1969-
(författare)
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Low Back Pain : With Special Reference to Prevalence, Diagnosis, Treatment and Prognosis
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Objectives. Ascertain if there has been a secular trend in 3-months prevalence of casually reported back pain. Evaluate if such back pain predicts concurrent health as well as future sick leave, disability pension, hospitalization and survival. Study differences in diagnostic assessment and labelling between physicians. Evaluate if a comprehensive manual therapy programme reduces sickness absence. Materials and methods. Combined population samples from 1973 to 2003 with a total of 12,891 observations with self-reported back pain and covariates. 7,074 of these individuals were followed for an average of 8.5 years and outcomes were self-reported health as well as official register data on sick leave, disability pension, hospitalisation and mortality. The Gotland Low Back Pain Study, a randomised controlled trial with participation of two general practitioners and two orthopaedic surgeons treating 160 patients with acute/subacute low back pain, with 10 weeks diagnostic evaluation and treatment and a two-year follow up. Results. Back pain prevalence increased 16% per ten years (OR 1.16, 95%CI 1.11-1.22). Back pain was negatively associated with self-rated health (p<0.0001), increased the risk of disability pension (p<0.002), and hospital admissions (p<0.0005), but not number of days in hospital, sick leave or mortality. General practitioners used terms from manual medicine and reported more pseudoradicular pain, while orthopaedic surgeons used non-specific pain labels, reported more true radicular pain and used more x-ray examinations. Among those on sick leave at baseline, manual therapy patients showed faster return to work (HR 1.62, 95%CI 1.006–2.60) and a lower point-prevalence of sick leave than reference patients at end of treatment period (ratio 0.35, 95% CI 0.13–0.97) but not after two years. Conclusions. There was a strong secular trend towards increase in self-reported back pain from 1973 to 2003. Such pain had a negative effect on some of the health outcomes and does not appear to be harmless. Physicians from different specialities labelled the condition differently. The manual therapy programme proved to be more effective than the established treatment regarding return to work.
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| 25. |
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| 26. |
- Dille, T., et al.
(författare)
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Managing inter-institutional projects : The significance of isochronism, timing norms and temporal misfits
- 2011
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Ingår i: International Journal of Project Management. - : Elsevier. - 0263-7863 .- 1873-4634. ; 29:4, s. 480-490
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Tidskriftsartikel (refereegranskat)abstract
- Conventional analysis of project organization has paid limited attention to projects in their institutional environment. Such analysis would be particularly relevant and important when dealing with projects in which actors represent different institutional environments. Accordingly, this paper suggests and defines the notion of “inter-institutional projects” and develops a conceptual framework consisting of three concepts and a set of guiding propositions. The following concepts are singled out: (1) isochronism highlights an important aspect of institutions and particularly how organizations within the same organizational field come to resemble each other in the tempos and phases of their activity cycles; (2) the notion of timing norms is used to analyze the surrounding rhythms and beats of the project at the institutional level and recognizes that different actors and involved units in the project adhere to conflicting timing norms; and (3) the concept of temporal fit/misfit is used to analyze the conflicting timing norms among organizations within the same project. The paper ends with implications and ideas for future research
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| 27. |
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| 28. |
- Drobysheva, Arina V., et al.
(författare)
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Structure and function of virion RNA polymerase of a crAss-like phage
- 2021
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 589:7841, s. 306-309
-
Tidskriftsartikel (refereegranskat)abstract
- The RNA polymerase from the crAss-like bacteriophage phi14:2, which is translocated into the host cell with phage DNA and transcribes early phage genes, is structurally most similar to eukaryotic RNA interference polymerases, suggesting that the latter have a phage origin. CrAss-like phages are a recently described expansive group of viruses that includes the most abundant virus in the human gut(1-3). The genomes of all crAss-like phages encode a large virion-packaged protein(2,4) that contains a DFDxD sequence motif, which forms the catalytic site in cellular multisubunit RNA polymerases (RNAPs)(5). Here, using Cellulophaga baltica crAss-like phage phi14:2 as a model system, we show that this protein is a DNA-dependent RNAP that is translocated into the host cell along with the phage DNA and transcribes early phage genes. We determined the crystal structure of this 2,180-residue enzyme in a self-inhibited state, which probably occurs before virion packaging. This conformation is attained with the help of a cleft-blocking domain that interacts with the active site and occupies the cavity in which the RNA-DNA hybrid binds. Structurally, phi14:2 RNAP is most similar to eukaryotic RNAPs that are involved in RNA interference(6,7), although most of the phi14:2 RNAP structure (nearly 1,600 residues) maps to a new region of the protein fold space. Considering this structural similarity, we propose that eukaryal RNA interference polymerases have their origins in phage, which parallels the emergence of the mitochondrial transcription apparatus(8).
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| 29. |
- Fatehi, Hesameddin, et al.
(författare)
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Gas phase combustion in the vicinity of a biomass particle during devolatilization : model development and experimental verification
- 2018
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Ingår i: Combustion and Flame. - : Elsevier. - 0010-2180 .- 1556-2921. ; 196, s. 351-363
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Tidskriftsartikel (refereegranskat)abstract
- A numerical and experimental study on the devolatilization of a large biomass particle is carried out to quantify the effect of homogeneous volatile combustion on the conversion of the particle and on the temperature and species distribution at the particle vicinity. A global chemical kinetic mechanism and a detailed reaction mechanism are considered in a one dimensional numerical model that takes into account preferential diffusivity and a detailed composition of tar species. An adaptive moving mesh is employed to capture the changes in the domain due to particle shrinkage. The effect of gas phase reactions on pyrolysis time, temperature and species distribution close to the particle is studied and compared to experiments. Online in situ measurements of average H2O mole fraction and gas temperature above a softwood pellet are conducted in a reactor using tunable diode laser absorption spectroscopy (TDLAS) while recording the particle mass loss. The results show that the volatile combustion plays an important role in the prediction of biomass conversion during the devolatilization stage. It is shown that the global reaction mechanism predicts a thin flame front in the vicinity of the particle deviating from the measured temperature and H2O distribution over different heights above the particle. A better agreement between numerical and experimental results is obtained using the detailed reaction mechanism, which predicts a wider reaction zone.
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| 30. |
- Fissum, Kevin
(författare)
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Q^2 Dependence of Quadrupole Strength in the \gamma*p -> Delta^+(1232) -> p\pi^0 transition
- 2002
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Ingår i: Physical Review Letters. - 1079-7114. ; 88, s. 122001-122001
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Tidskriftsartikel (refereegranskat)abstract
- Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the γ∗p→Δ+→pπ0 transition. We report new experimental values for the ratios E1+/M1+ and S1+/M1+ over the range Q2=0.4–1.8GeV2, extracted from precision p(e,e′p)π0 data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.
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| 31. |
- Holmér, Gunnel, 1955-
(författare)
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Flaskor på löpande band : Arbete och arbetskraftsrekrytering vid Surte glasbruk 1943-1978
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)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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| 32. |
- Holmer, Helene, et al.
(författare)
-
Fracture incidence in GH-deficient patients on complete hormone replacement including GH
- 2007
-
Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 22:12, s. 1842-1850
-
Tidskriftsartikel (refereegranskat)abstract
- Fracture risk in GHD patients is not definitely established. Studying fracture incidence in 832 patients on GH therapy and 2581 matched population controls, we recorded a doubled fracture risk in CO GHD women, but a significantly lower fracture risk in AO GHD men. Introduction: The objective of this study was to evaluate fracture incidence in patients wilh confirmed growth hormone deficiency (GHD) on replacement therapy (including growth hormone [GH]) compared with population controls, while also taking potential confounders and effect modifiers into account. Materials and Methods: Eight hundred thirty-two patients with GHD and 2581 matched population controls answered a questionnaire about fractures and other background information. Incidence rate ratio (IRR) and 95% CI for first fracture were estimated. The median time on GH therapy for childhood onset (CO) GHD men and women was 15 and 12 yr, respectively, and 6 and 5 yr for adult onset (AO) GHD men and women, respectively. Results: A more than doubled risk (IRR, 2.29; 95% CI, 1.23-4.28) for nonosteoporotic fractures was recorded in women with CO GHD, whereas no risk increase was observed among CO GHD men (IRR. 0.61) and AO GHD women (IRR, 1.08). A significantly decreased incidence of fractures (IRR, 0.54; 95% CI 0.34-0.86) was recorded in AO GHD men. Conclusions: Increased fracture risk in CO GHD women can most likely be explained by interaction between oral estrogen and the GH-IGF-I axis. The adequate substitution rate of testosterone (90%) and GH (94%) may have resulted in significantly lower fracture risk in AO GHD men.
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| 33. |
- Issa, F., et al.
(författare)
-
Characterization of neutron beam monitors for the European spallation source
- 2017
-
Ingår i: 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781509016426
-
Konferensbidrag (refereegranskat)abstract
- The European Spallation Source aspires to become the world's leading neutron source for the studies of materials during the next decade. At ESS 16 different instruments will be built. These instruments will require neutron beam monitors with high precision, low gamma sensitivity, high time and space resolution. Such neutron beam monitors are essential in various neutron experiments to continuously diagnose the delivered beam. In this work different types of neutron beam monitors from different suppliers have been characterized using the R2D2 beamline at IFE in Norway and using a Be-based neutron source. For the gamma sensitivity measurements different gamma sources have been used. The evaluation of these monitors includes the study of their efficiency, attenuation, uniformity, stability, and their sensitivity to gamma. In this work we report the results of this characterization.
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| 34. |
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| 35. |
- Kann, D. A., et al.
(författare)
-
THE AFTERGLOWS OF SWIFT-ERA GAMMA-RAY BURSTS. I. COMPARING PRE-SWIFT AND SWIFT-ERA LONG/SOFT (TYPE II) GRB OPTICAL AFTERGLOWS
- 2010
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 720:2, s. 1513-1558
-
Tidskriftsartikel (refereegranskat)abstract
- We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present an additional three pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840 additional new photometry data points on a total of 42 GRB afterglows, including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A, and 080810. We analyzed the light curves of all GRBs in the sample and derived spectral energy distributions for the sample with the best data quality, allowing us to estimate the host-galaxy extinction. We transformed the afterglow light curves into an extinction-corrected z = 1 system and compared their luminosities with a sample of pre-Swift afterglows. The results of a former study, which showed that GRB afterglows clustered and exhibited a bimodal distribution in luminosity space, are weakened by the larger sample. We found that the luminosity distribution of the two afterglow samples (Swift-era and pre-Swift) is very similar, and that a subsample for which we were not able to estimate the extinction, which is fainter than the main sample, can be explained by assuming a moderate amount of line-of-sight host extinction. We derived bolometric isotropic energies for all GRBs in our sample, and found only a tentative correlation between the prompt energy release and the optical afterglow luminosity at 1 day after the GRB in the z = 1 system. A comparative study of the optical luminosities of GRB afterglows with echelle spectra (which show a high number of foreground absorbing systems) and those without, reveals no indication that the former are statistically significantly more luminous. Furthermore, we propose the existence of an upper ceiling on afterglow luminosities and study the luminosity distribution at early times, which was not accessible before the advent of the Swift satellite. Most GRBs feature afterglows that are dominated by the forward shock from early times on. Finally, we present the first indications of a class of long GRBs, which form a bridge between the typical high-luminosity, high-redshift events and nearby low-luminosity events (which are also associated with spectroscopic supernovae) in terms of energetics and observed redshift distribution, indicating a continuous distribution overall.
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| 36. |
- Kizza, Michael, et al.
(författare)
-
Modelling catchment inflows into Lake Victoria : uncertainties in rainfall-runoff modelling for the Nzoia River
- 2011
-
Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 56:7, s. 1210-1226
-
Tidskriftsartikel (refereegranskat)abstract
- Climate and soil characteristics vary considerably around the Lake Victoria basin resulting in high spatial and temporal variability in catchment inflows. However, data for estimating the inflows are usually sparsely distributed and error-prone. Therefore, modelled estimates of the flows are highly uncertain, which could explain early difficulties in reproducing the lake water balance. The aim of this study was to improve the estimates of catchment flow to Lake Victoria. The WASMOD model was applied to the Nzoia River, one of the major tributaries to Lake Victoria. Uncertainty was assessed within the GLUE framework. During calibration, log-transformation was performed on both simulated and observed flows. The results showed that, despite its simple structure, WASMOD produces acceptable results for the basin. For a Nash-Sutcliffe efficiency (NS) threshold of 0.6, the percentage of observations bracketed by simulations (POBS) was 74%, the average relative interval length (ARIL) was 0.93, and the maximum NS value was 0.865. The residuals were shown to be homoscedastic, normally distributed and nearly independent. When the NS threshold was increased to 0.8, POBS decreased to 54% with an improvement of ARIL to 0.49, highlighting the effect of the subjective choice of likelihood threshold.
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| 37. |
- Kizza, Michael, et al.
(författare)
-
Temporal rainfall variability in the Lake Victoria Basin in East Africa during the twentieth century
- 2009
-
Ingår i: Journal of Theoretical and Applied Climatology. - : Springer Science and Business Media LLC. - 0177-798X .- 1434-4483. ; 98:1-2, s. 119-135
-
Tidskriftsartikel (refereegranskat)abstract
- Water resources systems are designed and operated on assumption of stationary hydrology. Existence of trends and other changes in the data invalidates this assumption, and detection of the changes in hydrological time series should help us revise the approaches used in assessing, designing and operating our systems. In addition, trend and step change studies help us understand the impact of man’s activities (e. g. urbanisation, deforestation, dam construction, agricultural activities, etc.) on the hydrological cycle. Trends and step changes in the seasonal and annual total rainfall for 20 stations in the Lake Victoria basin were analysed. The seasonal rainfall for any station in a given year was defined in two ways: (1) fixed time period where the rainy seasons were taken as occurring from March-May (long rains) and from October-December (short rains); and (2) variable periods where the rainy seasons were taken as the three consecutive months with maximum total rainfall covering the period of January-June (long rains) and July-December (short rains), to take into account the fact that the onset of rainy seasons within the basin varies from year to year and from one station to the next. For each station, sub datasets were derived covering different periods (all available data at the station, 1941-1980, 1961-1990, 1971-end of each station’s time series). The trends were analysed using the Mann-Kendall method, while the step changes were analysed using the Worsley Likelihood method. The results show that positive trends predominate, with most stations showing trend being located in the northern part of the basin, though this pattern is not conclusive. In all, 17% of the cases have trends, of which 67% are positive. The 1960s represent a significant upward jump in the basin rainfall. Seasonal rainfall analysis shows that the short rains tend to have more trends than the long rains. The impact of the varying month of onset of the rainy season is that the results from analyzing the fixed-period and variable-period time series are rarely the same, meaning the two series have different characteristics. It may be argued that the variable-period time series are more reliable as a basis for analysing trends and step changes, since these time series reflect more closely the actual variability in rainy seasons from one year to the next. The fixed-period analysis would, on the other hand, find more practical use in planning.
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| 38. |
- Krediet, RT, et al.
(författare)
-
Pathophysiology of peritoneal membrane failure
- 2000
-
Ingår i: Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis. - 0896-8608. ; 2020 Suppl 4, s. S22-S42
-
Tidskriftsartikel (refereegranskat)
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| 39. |
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| 40. |
- Liao, Xiaoqi, et al.
(författare)
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Low-field-induced spin-glass behavior and controllable anisotropy in nanoparticle assemblies at a liquid-air interface
- 2022
-
Ingår i: SCIENCE CHINA-MATERIALS. - : Springer Nature. - 2095-8226 .- 2199-4501. ; 65:1, s. 193-200
-
Tidskriftsartikel (refereegranskat)abstract
- Stacking nanoscale-building blocks into one-dimensional (1D) assemblies with collective physical properties is a frontier in designing materials. However, the formation of 1D arrays using weak magnetic fields and an in-depth understanding of their magnetic properties remain challenging. Here, low-dimensional assemblies of iron oxide nanocubes with a disordered arrangement are fabricated at the diethylene-glycol/air interface in the presence of assembly fields (0/1/3/5/30/50 mT). Ring-shaped assemblies gradually transform as the assembly field increases from 0 to 50 mT, first to a porous network consisting of elongated assemblies and then to an aligned array of filaments, in which the aligned filaments are formed when the assembly field is >= 3 mT and duration t > 14 min. Spin-glass characteristics and static (dynamic) anisotropy factors similar to 2(3) are achieved by tuning the strength of the assembly field. In the presence of a relatively weak assembly field, the interplay between dipolar interactions and disorder with respect to magnetic easy axis alignment leads to spin-glass characteristics. The alignment of the magnetic easy axes and the strength of the dipolar interactions increase with increasing assembly field, resulting in the disappearance of spin-glass characteristics and enhancement of the magnetic anisotropy. This study presents a strategy for obtaining magnetic assemblies with spin-glass behavior and controllable anisotropy while shedding light on the magnetic interactions of low-dimensional assemblies.
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| 41. |
- Maraev, Vladislav, 1986, et al.
(författare)
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Integrating laughter into spoken dialogue systems: preliminary analysis and suggested programme
- 2018
-
Ingår i: FAIM/ISCA Workshop on Artificial Intelligence for Multimodal Human Robot Interaction, 14-15 July 2018, Stockholm, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an exploratory scheme, which aims at investigating perceptual features that characterise laughables (the arguments laughter is related to) in dialogue context. We present the results of a preliminary study and sketch an updated questionnaire on laughables types and laughter functions aimed to be used for Amazon Mechanical Turk experiments. Furthermore we present preliminary programme for integrating laughter into spoken dialogue systems.
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| 42. |
- Nydén, Magnus
(författare)
-
NMR Diffusion Studies in Heterogeneous Systems. Surfactant solutions, Polymer solutions and Gels
- 1998
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study has been to investigate the self-diffusion behaviour in polymer solutions and in surfactant solutions using the pulsed field gradient (PFG) NMR technique. The NMR self-diffusion experiment was shown to provide detailed information in complex surfactant mixtures. In particular, the microemulsion phase and the hexagonal phase of Didodecyldimethylammoniumsulphate (DDAS) formed with water and oil was investigated. It is argued that the microemulsion phase contains spherical micelles of normal curvature close to the emulsification failure line. When decreasing the oil content the micelles grow, presumably in one dimension, to form a bicontinuous micellar phase. In mixtures of a microemulsion of normal curvature (DDAS) with a microemulsion of reversed curvature (DDAB) it was found that a one-phase solution was formed. In this phase the diffusion coefficients of all three components revealed detailed information about the structure in the system. In particular, the lateral diffusion coefficient of the surfactant could be directly measured. When applied to polymer solutions, the PFG NMR experiment is argued to convay detailed information about both structure and dynamics in many different polymer solutions. In particular, the echo decay in a PFG NMR experiment displays features that are closely connected with both the structure and the dynamics in these systems. However, separation of the different diffusion mechanisms that give rise to the observed features, is sometimes difficult and great care must be taken when evaluating the PFG NMR data. The diffusion work in the polymer part of this thesis is focused on extracting information about structure and dynamics in self-associating aqueous polymer systems. More specifically, ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue, HMEHEC, has been investigated. In these systems the polymers display a varying degree of association depending on the chemical structure, concentration and temperature. A novel result is the conclusion that a static network is formed in the polymer solution, the presence of which was seen as a very slowly diffusing component in comparison to the rest of the matrix that diffused much faster. It is argued that the presence of this slowly diffusing component could to some extent explain the anomalous scaling behaviour that is found in semi-dilute polymer solutions. It is further suggested that in order to obtain more detailed information and to elucidate some of the still remaining questions in the field of polymer dynamics, the slow component should be further investigated using the PFG NMR technique.
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| 43. |
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| 44. |
- Nydén, Magnus, 1970, et al.
(författare)
-
Stoppa havstulpanerna
- 2006
-
Ingår i: Kemivärlden Biotech med Kemisk tidskrift. ; 5:Maj, s. 22-24
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 45. |
- Nydén, Thomas, et al.
(författare)
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Vandringshinder för fisk i Bräkneån - förslag på förbättrade möjligheter till fiskvandring
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport redovisar förslag på förbättrade möjligheter till fiskvandring vid de frånÖstersjön första tio (10) förekommande vandringshindren för fisk i Bräkneån inom Blekingelän. Bräkneån är ett av Blekinge läns många havsöringsförande vattendrag och hyser i övrigtintressant och värdefull fauna och flora.
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| 46. |
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| 47. |
- Nye, Taylor M., et al.
(författare)
-
Ring-fused 2-pyridones effective against multidrug-resistant Gram-positive pathogens and synergistic with standard-of-care antibiotics
- 2022
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : PNAS. - 0027-8424 .- 1091-6490. ; 119:43
-
Tidskriftsartikel (refereegranskat)abstract
- The alarming rise of multidrug-resistant Gram-positive bacteria has precipitated a healthcare crisis, necessitating the development of new antimicrobial therapies. Here we describe a new class of antibiotics based on a ring-fused 2-pyridone backbone, which are active against vancomycin-resistant enterococci (VRE), a serious threat as classified by the Centers for Disease Control and Prevention, and other multidrug-resistant Gram-positive bacteria. Ring-fused 2-pyridone antibiotics have bacteriostatic activity against actively dividing exponential phase enterococcal cells and bactericidal activity against nondividing stationary phase enterococcal cells. The molecular mechanism of drug-induced killing of stationary phase cells mimics aspects of fratricide observed in enterococcal biofilms, where both are mediated by the Atn autolysin and the GelE protease. In addition, combinations of sublethal concentrations of ring-fused 2-pyridones and standard-of-care antibiotics, such as vancomycin, were found to synergize to kill clinical strains of VRE. Furthermore, a broad range of antibiotic resistant Gram-positive pathogens, including those responsible for the increasing incidence of antibiotic resistant healthcare-associated infections, are susceptible to this new class of 2-pyridone antibiotics. Given the broad antibacterial activities of ring-fused 2-pyridone compounds against Gram-positive (GmP) bacteria we term these compounds GmPcides, which hold promise in combating the rising tide of antibiotic resistant Gram-positive pathogens.
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| 48. |
- Nyeanchi, Emmanuel B., et al.
(författare)
-
Ferromagnetic ground state in La0.5Ca0.5MnO3 thin films
- 1999
-
Ingår i: Europhysics letters. - : Institute of Physics (IOP). - 0295-5075 .- 1286-4854. ; 48:2, s. 228-232
-
Tidskriftsartikel (refereegranskat)abstract
- Resistivity and magnetisation measurements were done with bulk and thin-film samples of La0.05Ca0.05MnO3. Bulk samples showed an antiferromagnetic insulating ground state as expected for this composition, whereas thin films demonstrated a ferromagnetic metallic ground state. This effect is attributed to the film adhesion to the substrate which prevents the lattice distortions necessary for the charge and antiferromagnetic ordering that occur in the bulk samples.
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| 49. |
- Nyeng, Pia, et al.
(författare)
-
Fibroblast growth factor 10 represses premature cell differentiation during establishment of the intestinal progenitor niche
- 2011
-
Ingår i: Developmental Biology. - : Elsevier BV. - 1095-564X .- 0012-1606. ; 349:1, s. 20-34
-
Tidskriftsartikel (refereegranskat)abstract
- Spatio-temporal regulation of the balance between cell renewal and cell differentiation is of vital importance for embryonic development and adult homeostasis. Fibroblast growth factor signaling relayed from the mesenchyme to the epithelium is necessary for progenitor maintenance during organogenesis of most endoderm-derived organs, but it is still ambiguous whether the signal is exclusively mitogenic. Furthermore, the downstream mechanisms are largely unknown. In order to elucidate these questions we performed a complementary analysis of fibroblast growth factor 10 (Fgf10), gain-of-function and loss-of-function in the embryonic mouse duodenum, where the progenitor niche is clearly defined and differentiation proceeds in a spatially organized manner. In agreement with a role in progenitor maintenance, FGF10 is expressed in the duodenal mesenchyme during early development while the cognate receptor FGFR2b is expressed in the epithelial progenitor niche. Fgf10 gain-of-function in the epithelium leads to spatial expansion of the progenitor niche and repression of cell differentiation, while loss-of-function results in premature cell differentiation and subsequent epithelial hypoplasia. We conclude that FGF10 mediated mesenchymal-to-epithelial signaling maintains the progenitor niche in the embryonic duodenum primarily by repressing cell differentiation, rather than through mitogenic signaling. Furthermore, we demonstrate that FGF10-signaling targets include ETS-family transcription factors, which have previously been shown to regulate epithelial maturation and tumor progression. (C) 2010 Elsevier Inc. All rights reserved.
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| 50. |
- Parmenius-Swärd, Suzanne, 1955-
(författare)
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Forskningsprocessen – från tanke till färdig text
- 2018
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Denna artikel handlar om den lite snåriga vägen till resultatet av en undersökning och hur resultat kan presenteras, således om vägen från att samla in ett material, göra analys, dokumentera analysen och till att presentera resultatet.
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