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Remiss: Ett mer heltäckande straffansvar vid angrepp på företagshemligheter Ju2020/04525
No full textChemical kinetics study of nitrogen-containing fuels in flames – experiments and modeling
No full textClimate change is strongly linked to the quantity of carbon dioxide (CO2) released by burning fossil fuels, which contain carbon. To address the problem, ammonia (NH3) has recently gained significant attention as a potential alternative fuel due to its carbon-free nature, ease of storage, and good energy density. However, ammonia combustion in practical devices presents challenges, particularly its high nitrogen oxides (NOₓ) emissions and combustion behavior that differs significantly from conventional fuels.Besides ammonia, nitrogen atoms are also commonly found in other fuels, such as coal, coal-derived oils, biomass, bio-oils, and wastes, predominantly incorporated in the form of pyrrolic and pyridinic heterocyclic functional groups. These nitrogen-containing compounds serve as precursors to fuel-NOₓ during combustion. Developing accurate chemical kinetic models is essential for understanding the reaction mechanisms of the combustion of nitrogen-containing fuels, as well as for predicting and optimizing fuel performance and reducing emissions. However, even for ammonia, a relatively light N-containing species, there is a lack of consensus regarding its reaction mechanisms and the associated kinetic parameters across existing models. To achieve a reliable and unified chemical kinetic model for these fuels, validations through fundamental combustion experiments are necessary. These experiments are specifically used to isolate and scrutinize detailed chemistry problems by minimizing the influence of complex flow and mixing effects. Besides, they provide valuable fundamental-level combustion data that characterizes the behavior of each fuel. Therefore, this study conducted fundamental combustion experiments on nitrogen-containing fuels to provide two types of key fundamental combustion data—laminar burning velocity (LBV) and flame structure. LBVs were measured using the heat flux method, while flame structure was measured using a flat-flame configuration with the aid of Raman spectroscopy. In addition, related fundamental combustion data from the literature, obtained using methods such as spherical flame experiments, shock tubes, and flow reactors, were also used to support a more comprehensive model validation. All the modeling work was performed using ANSYS Chemkin-Pro software. The research is based on five experimental and modeling studies, encompassing various fuel compositions, oxidizer environments, and temperature conditions. Each study explored a specifically designed fuel mixture aimed at addressing existing knowledge gaps. Variations in the fuel compositions alter the flame radical pools, allowing for the investigation of different dominant chemistries within nitrogen combustion chemistry.In the first study, pyrrole (C4H5N), the simplest five-membered nitrogen-containing aromatic molecule, was used as a model compound to investigate the fuel-bound nitrogen conversion mechanisms in the pyrrolic functional group. LBVs of pyrrole+air flames were measured, and the comprehensive kinetic model from our group was updated by incorporating reactions involving pyrrole and its intermediates. Subsequent investigations focus on ammonia flames. Argon (Ar) was used as a diluent instead of conventional nitrogen (N2) to elucidate specific ammonia flame chemistry. LBVs of ammonia+oxygen+argon mixtures were measured, and nine literature kinetic models were evaluated. The rate constants of three key reactions in ammonia chemistry were reviewed and updated in our model. Further experiments were carried out to explore the LBVs of oxygen-enriched ammonia flames, which revealed discrepancies with previously reported LBV data, prompting model re-evaluations. A separate study employs Raman spectroscopy for non-intrusive detection and quantification of nitric oxide (NO) and nitrous oxide (N2O) in ammonia+oxygen+argon flames, providing valuable data for model validations.Finally, ammonia was blended with nitromethane (CH3NO2), a precursor to NO, to elucidate the impact of NH3–NOx interactions. Interestingly, the results show that adding NH3 has a non-monotonic effect on the LBV of the fuel blend, increasing the LBV only when the NH3 fraction was below 70%. Kinetic analysis tools were used to explain this behavior, and our model was updated with a focus on CH3NO2 chemistry.These findings collectively advance the understanding of the combustion characteristics of nitrogen-containing fuels and support the validation and refinement of existing chemical kinetic models
Time-dependent diffusion MRI with free gradient waveforms: From theory development to initial applications
No full textDiffusion magnetic resonance imaging (dMRI) is a powerful non-invasive technique for probing tissuemicrostructure. While highly sensitive, conventional dMRI methods suffer from low specificity, due in part toexperimental designs that conflate multiple contrast mechanisms. This thesis aims to address these limitations bydeveloping advanced time-dependent dMRI techniques to disentangle competing sources of contrast—specificallyrestricted diffusion, intercompartmental exchange, anisotropy, and intra-compartmental kurtosis.In Paper I, we developed a theoretical framework and experimental design using free gradient waveforms, termedRestriction-Exchange (ResEx), to disentangle restricted diffusion from exchange, and validated the approach usingMonte Carlo simulations. In Paper II, we applied ResEx in the healthy human brain on a high-performance scanner(300 mT/m), and isolated distinct exchange- and restriction-driven signal contrasts. Furthermore, in Paper VI, weapplied the ResEx framework in gliomas on a clinical scanner (80 mT/m) and observed substantial and spatiallyheterogeneous exchange-driven contrasts in tumour tissue, with potential implications for non-invasive tumourcharacterisation. Additionally, in Paper III, we used the framework to correct crusher gradient-induced bias in filterexchange imaging (FEXI), enabling more accurate estimation of the apparent exchange rate (AXR).To enhance specificity further, we also developed a tensor-valued encoding approach in Paper IV to enablemeasurement of exchange in the presence of anisotropy and intra-compartmental kurtosis, using variable-mixing-time double diffusion encoding acquisitions.Finally, in Paper V, we studied the interplay between dendritic spine-driven geometric exchange and permeativeexchange in simulations, and used the framework from Paper IV to separate the two, offering a potential route formapping spine density in vivo with dMRI.Together, these contributions establish a set of theoretical and experimental tools to improve the specificity andinterpretability of dMRI. They position advanced diffusion encoding—particularly when combined with ultra-strong gradient systems—as a promising avenue for non-invasive microstructure imaging in both clinical andresearch settings
Does new public management repel talent? : findings from a choice experiment among German researchers
No full textThis paper analyses the effects of new public management governance on academics’ job choices. Based on a choice experiment carried out with faculty from a sample of Germany’s leading technical universities, we find that working environments characterized by varying levels of administrative burdens and high expectations concerning third-party funding acquisition are detrimental to self-actualization and hence tend to repel potential candidates. More specifically, we find this effect to be most pronounced for those candidates that universities would be strategically most interested in: researchers with a strong track record and those with an interdisciplinary profile. Without denying potential benefits of external incentives for existing faculty, we therefore suggest acknowledging intrinsic motivation as the key driving factor of academics’ choices and to design future governance structures accordingly
Clinical Relevance of Contact Allergy to Gold Sodium Thiosulphate in Fibromyalgia
No full textFibromyalgia is a chronic syndrome characterized by pain, fatigue, and cognitive disturbances. The increased prevalence of contact allergy to gold in individuals with fibromyalgia when compared with the general population has previously been described. Gold contact allergy can manifest as a systemic contact dermatitis, with cutaneous and extracutaneous manifestations presenting upon systemic administration of gold. This study aimed to establish whether gold allergy is of significance in the fibromyalgia population. Prior to patch testing with the Swedish baseline series and an extended dental series, 119 females with fibromyalgia answered questionnaires including details of past medical history, dental history, and previous cutaneous and mucous membrane intolerance to metals. Prevalence of allergy to gold sodium thiosulphate (2.0% and 5.0%) was 33.6% (40 individuals). There was a statistically significant overrepresentation of gold allergy among individuals who experienced cutaneous symptoms upon direct contact with gold (p = 0.010). Contact allergy to gold was more frequent among patients with oral symptoms (p = 0.024). This study demonstrates concordance between reported cutaneous symptomatology related to gold exposure and gold allergy in the fibromyalgia population. Whether individuals with oral symptoms and gold allergy have objective oral clinical findings and relevant gold exposure is the focus of ongoing study
Racial discrimination in the marriage market? : An exploration of Swedish adoption data
No full textObjectiveRecent studies suggest that immigrants trade youth when partnering with members of the White majority population. This study contributes to this emerging literature by examining whether this trade should be understood as differential treatment based on immigrant status or as a broader dynamic of racial preferences in the marriage market.MethodsThis study compares age gaps in unions of international adoptees with those in cross-national immigrant unions and White Swedish unions. By using unique Swedish register data containing a sample of international adoptees (N = 3872), this study isolates the role of racial phenotype from cultural and migration-related factors.ResultsThe findings show that both adoptee unions and cross-national immigrant unions exhibit larger age gaps compared to White Swedish unions. This suggests that youth-trading patterns are not solely linked to immigrant status but also to racial preferences in the partner market.ConclusionSince international adoptees share their racial phenotype with immigrants but not their cultural background or migration experience, the results indicate that racially different partners may not be viewed as equal by the White majority but are more readily accepted if they offer a compensatory trait, such as youth
Larger boats, longer voyages, and powerful leaders : comparing Maritime Modes of Production in Scandinavia and California
No full textIsland and coastal societies around the world followed several unique developmental pathways that allowed for the formation of economically and politically complex systems. In this paper we argue that marine resources allow levels of intensification comparable to that of terrestrially focused societies, while seaworthy boats amplified the ability of emergent leaders to trade and raid over long distances. Many of these factors are summarized in the Maritime Mode of Production (MMP), a model which explains the development of decentralized chiefdoms in Scandinavia through the nexus of mobile wealth, advanced boat technology, and maritime trading and raiding. These characteristics are shared by other early maritime societies such as those in British Columbia and North-east Asia, suggesting that the MMP may have wide cross-cultural applicability as a pathway towards social complexity. By using the MMP to help explain the development of social complexity in another well-documented maritime society, the Chumash of southern California, we argue that innovation in watercraft technology combined with the ownership of boats by emergent elites led to a powerful positive feedback system which propelled the formation of maritime chiefdoms along similar trajectories to those hypothesised for Bronze Age Scandinavia. We use this comparison as a springboard to evaluate the applicability of the MMP as a comparative model for the development of social complexity in maritime societies around the world and suggest promising areas for future research
Associations between the EAT-Lancet planetary health diet and incident dementia
No full textBACKGROUND: The impact of the environmentally sustainable EAT-Lancet diet on dementia risk remains poorly understood. The aim was to investigate associations between the EAT-Lancet diet and incident dementia.METHODS: Associations of the EAT-Lancet diet with all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were investigated among 25,898 participants from the Malmö Diet and Cancer study, Sweden. Participants aged 45-73 years were recruited for the baseline examination between 1991 and 1996, and the mean follow-up time was 18 years. To assess robustness of estimations, we used seven previously constructed EAT-Lancet diet scores. Multi-adjusted Cox proportional hazard analyses were performed, with results presented per 10 % in increment scores. Additionally, we explored the potentially modifying effect of APOE ε4 status in this context.RESULTS: With one of the scores, higher adherence to the EAT-Lancet diet was associated with a reduced risk of AD and all-cause dementia. Moreover, the results suggest an interplay between the EAT-Lancet diet and APOE ε4 status. A risk-reducing effect was observed among APOE ε4 non-carriers with three of the scores in relation to AD, and with five of the scores in relation to all-cause dementia. No associations were observed among APOE ε4 carriers, or in relation to VaD.CONCLUSION: The results indicate a risk reducing effect of adhering to the EAT-Lancet diet among APOE ε4 non-carriers, and no negative effects on dementia risk were detected. Future studies should consider the potentially modifying effect of APOE ε4 status, and the implications of methodological differences in measuring adherence to the EAT-Lancet diet