Publikationer från Umeå universitet
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Intervalence plasmons in boron-doped diamond
No full textDoped semiconductors can exhibit metallic-like properties ranging from superconductivity to tunable localized surface plasmon resonances. Diamond is a wide-bandgap semiconductor that is rendered electronically active by incorporating a hole dopant, boron. While the effects of boron doping on the electronic band structure of diamond are well-studied, any link between charge carriers and plasmons has never been shown. Here, we report intervalence plasmons in boron-doped diamond, defined as collective electronic excitations between the valence subbands, opened up by the presence of holes. Evidence for these low-energy excitations is provided by valence electron energy loss spectroscopy and near-field infrared spectroscopy. The measured spectra are subsequently reproduced by first-principles calculations based on the contribution of intervalence band transitions to the dielectric function. Our calculations also reveal that the real part of the dielectric function exhibits a crossover characteristic of metallicity. These results suggest a new mechanism for inducing plasmon-like behavior in doped semiconductors, and the possibility of attaining such properties in diamond, a key emerging material for quantum information technologies
New simplification rules for databases with positive and negative attributes
No full textIn this paper, new logical equivalences are presented within the simplification logic with mixed attributes paradigm, which allow the obtention of bases of shorter, easier-to-read attribute implications. In addition to the theoretical results which show that the proposed equivalences indeed hold in simplification logic with mixed attributes, experimental results which showcase the effectiveness of this method are also provided. Furthermore, the simplification method presented is iterative and gives sufficiently good results in only one or two iterations, therefore presenting itself as a reasonable procedure in time-sensitive experiments
Fiktionens sändebud : En ekokritisk och metafiktiv läsning av Jeff VanderMeers Annihilation
No full textDenna uppsats utforskar Jeff VanderMeers roman Annihilation utifrån Jane Bennetts begrepp agentiska assemblage samt Linda Hutcheons teoribildning kring den metafiktiva paradoxen. Dessa teoretiska ramverk används för att diskutera hur romanen bryter ner uppdelningen mellan koncepten insida och utsida. Detta görs både i relation till insidan/utsidan av människan/ickemänniskan och läsaren/texten. Uppsatsen når slutsatsen att romanens metafiktiva grepp fungerar som förfrämligandeefekter vilka distansierar läsaren från fiktionen samtidigt som det aktualiserar romanens ekokritiska budskap. I en vidare diskussion överväger uppsatsen hur metafiktiva grepp och ekokritiska perspektiv kan fungera i samspel i genren weird fiction för att aktualisera samtida världsproblem och imspirera läsare till handling.This essay explores Jeff VanderMeer’s novel Annihilation in relation to Jane Bennet’s concept of agentic assemblages and Linda Hutcheon’s theory of the metafictional paradox.These theoretical frameworks are used to discuss how the novel deconstructs the dichotomyof inside/outside, both in relation to the human/nonhuman and of the reader/text. The essay concludes that the metafictional strategies work to defamiliarize the reader from the novel’sfiction and thus actualizes its ecocritical perspectives. In a broader discussion the essay considers of how metafiction and ecocritical perspectives can work together in Weird Fictionto raise awareness of issues in the Anthropocene and inspire action.</p
Development of operational parameters for cashew shell gasification and validation in a 1 MW aDFB steam gasifier
No full textAfter years of development of the dual fluidized bed gasification process with woody biomass, new challenges arise with a wider range of feedstocks, such as agricultural residues or waste fractions, gaining importance. This work presents the results from the operation of a 1 MW advanced dual fluidized bed (aDFB) gasifier at the Syngas Platform Vienna, with cashew shells (CS) as feedstock and pure olivine or olivine mixed with 33% limestone as the bed material. Two operation points, different in their main process parameters, with CS as feedstock were performed for a minimum of 16 h. Due to the high calorific value (22.7 MJ/kg dry) and high content of volatile components (81.7 wt % dry), CS are well suited for gasification. During the operation, a product gas with a H2/CO ratio of 1.93-2.29 was produced, which suits the use of the syngas as input for Fischer-Tropsch synthesis. Due to the low ash softening temperature of CS of about 840 °C, determined in ash fusion tests and predicted by thermodynamic equilibrium calculations, the operating temperature in the gasifier was kept below 820 °C in the first operation point with around 20 h of runtime. Bed material samples after the operation revealed the formation of agglomerates, which were analyzed by SEM and EDS for their morphology and composition. During the second operation point, temperatures in the gasifier were increased to 870 °C for 16 h, while no agglomeration tendencies were observed. Both operations did not show changes in fluidization behavior compared to operations with wood chips (WC). The evaluated key performance indicators were compared to aDFB steam gasification of WC as the reference
Respiratory morbidity before and during the COVID-19 pandemic from birth to 18 months in a Swedish birth cohort
No full textBackground: Respiratory infections in early life are an identified risk factor for asthma. We hypothesized that infection-prevention measures during the coronavirus disease 2019 (COVID-19) pandemic influenced the risk of respiratory morbidity and aeroallergen sensitization in early childhood. Objective: We compared respiratory morbidity and aeroallergen sensitization in children born before and during the pandemic. Methods: We compared a COVID-19 category (exposed children; n = 1661) to a pre–COVID-19 category (nonexposed children; n = 1676) by using data from the prospective population-based NorthPop Birth Cohort study in Sweden. Data on respiratory morbidity and concomitant medication were retrieved from national registers. Prospectively collected data on respiratory morbidity using web-based questionnaires at 9 and 18 months of age were applied. At age 18 months, serum IgE levels to aeroallergens were determined (n = 1702). Results: The risk of developing any respiratory tract infection (adjusted odds ratio [aOR] = 0.33 [95% CI, 0.26-0.42]), bronchitis (aOR = 0.50 [95% CI, 0.27-0.95]) and croup (aOR = 0.59 [95% CI, 0.37-0.94]) were decreased in the COVID-19 category. The risk of wheeze in the first 9 months was lower in the COVID-19 category (aOR = 0.70 [95% CI, 0.55-0.89]). There were also fewer prescriptions of antibiotics in the COVID-19 category. The prevalence of aeroallergen sensitization was similar between categories. Conclusion: Children born during the COVID-19 pandemic demonstrated significantly decreased risks of respiratory infections and prescribed antibiotics until 18 months of age compared to children born before the COVID-19 pandemic. Whether this will affect the risk of developing asthma in childhood is being followed
Looking for Adventure : Backpackers informationsbeteende utifrån Hektors modell om informationsaktiviteter
No full textDenna uppsats undersöker backpackers informationsbeteende med hjälp av Anders Hektors(2001) modell om informationsaktiviteter. Forskningsfrågan är: 1. Vilka informationsbeteenden förknippat med reseplanering går att finna inför, under,och efter en backpacking-resa utomlands? Denna besvaras med hjälp av fem semistrukturerade intervjuer med backpackers över 18 årsom rest under de senaste åren och som varit aktiva i reseplaneringen. Efter intervjuernagenomfördes en tematisk analys, och resultatdelen bygger på de teman som synliggjordes. Andra backpackers tidigare erfarenheter visade sig vara den källa respondenterna hade mesttillit till. Att söka upp vloggar på bland annat Youtube var populärt att göra inför en resa, medanrespondenterna under resan fick många tips från andra resenärer de stötte på. Dock tyckerrespondenterna inte att alla tidigare erfarenheter är pålitliga. Kommentarer och recensioner påhemsidor som Booking.com var de mer kritiska till då dessa kunde skrivits av personer somgav höga betyg för att marknadsföra. Andra människors erfarenheter blir pålitliga då det finnsett namn och ett ansikte som står bakom dessa. Informationsaktiviteter kopplade till sökande och samlande av information är vadrespondenterna använde sig mest av inför en backpackingresa. Under resan var de vanligastförekommande aktiviteterna de som kopplas till att kommunicera och ge information. Efter enresa var informationsaktiviteterna uttrycka och publicera vanligast. Hektors modell om informationsaktiviteter kunde beskriva nästan alla deinformationsbeteenden som respondenterna beskrev. Dock fanns det en aspekt som var viktigför respondenterna som inte täcktes av Hektors modell- respondenternas egna tidigareerfarenheter. Enligt den definition av information som Hektor använt räknas inte dessaerfarenheter som information, vilket gör att dessa inte blir informationsaktiviteter. (Hektor2001, s. 149-211
Det riktiga straffet börjar när man kliver utanför murarna : En kvalitativ studie om återanpassning för individer med brottsregister
No full textThis essay examines the effect of stigmatization on convicted individuals in Sweden regarding their reintegration into the labor market after release from prison. The focus is on depicting how stigmatization impacts reintegration efforts and identifying the barriers that staff within related organizations perceive as problematic for successful reentry into the labor market. Using a qualitative method, including thematic analysis through interviews, this study explores individual conditions, challenges, and what is needed to secure employment. The findings suggest that addressing stigmatization, alongside personalized support with an emphasis on guidance and collaboration between different authorities, is key to successful reintegration into the labor market. Based on the study, we find that further research into the feelings and experiences of formerly incarcerated individuals is much needed. Additionally, more research is required within the Swedish context regarding collaboration between authorities and reintegration
Can university teachers escape curriculum planning? : Reflections on building and experiencing an educational escape room in university pedagogy training
No full textDue to their interactive and engaging nature, escape rooms haveincreasingly been used not only for recreational purposes but alsoin various educational contexts. This study explores the design andimplementation of an educational escape room in university peda-gogy, a discipline lacking prior studies on utilising escape rooms.The escape room focused on curriculum planning and employedthe principles of constructive alignment. Feedback from universityteachers and doctoral students (N = 25) was collected viaa questionnaire and analysed using data-driven content analysis.Results indicate high engagement and perceived educational valuein terms of revision, with recommendations for future applicationstargeting basic-level studies and including smaller groups sizes andmore homogenous groups
Do directed and non-directed oocyte donors differ regarding their motives, ambivalence, satisfaction and openness about donating?
No full textResearch question: Do directed oocyte donors differ from non-directed identity-release oocyte donors regarding pre-donation motives and ambivalence, and post-donation satisfaction and openness? Design: The study is part of the longitudinal Swedish Study on Gamete Donation where consecutive samples of identity-release gamete donors at seven Swedish University Hospitals were approached during a 3-year period (2005–2008). The participants of the current study were 16 women who donated oocytes to family members or friends (directed donation) and 123 women who donated to unknown recipients (non-directed donation). Survey data on motivation, ambivalence, post-donation satisfaction and openness were collected at five time points between acceptance as a donor and 14–17 years post-donation. Statistical group comparisons and longitudinal analyses were conducted. Results: In contrast to non-directed donors, who reported general altruism as their main motivation, directed donors were primarily motivated by empathy with the recipients. Pre-donation ambivalence was present in a quarter of donors and did not differ between groups (P = 0.601). Post-donation satisfaction was similar between groups (P = 0.17) and stable over time (P = 0.37). One directed donor reported regretting her donation, and this was attributed to negative relations with the recipients. Donors from both groups were generally open about having donated, but some directed donors felt restricted by the recipients’ wishes. Conclusions: Despite being differently motivated, the current findings suggest that directed oocyte donors are comparable to non-directed oocyte donors in terms of pre-donation ambivalence and post-donation satisfaction and openness. The findings also highlight how directed donation may be associated with specific challenges, which emphasizes the need for pre- and post-donation counselling
Physiotherapists’ challenges and strategies in treating people with dementia
No full textIntroduktion: De allmänna rekommendationerna om fysisk aktivitet är riktade till alla och även till personer med demens. Därför är fysioterapeuters roll viktigt för att träning samt rehabilitering ska kunna utföras. Demenssjukdomar beror på skador i hjärnan och beroende på vilka delar av hjärnan som drabbas yttrar sig sjukdomen på olika sätt. Detta försvårar rehabilitering och utmanar fysioterapeuters strategier att bemöta denna patientgrupp. Syfte: Syftet med studien var att utforska vilka utmaningar fysioterapeuter möter i behandling av personer med demens, samt vilka strategier de använder. Metod: I denna kvalitativa studie genomfördes semistrukturerade intervjuer med fyra fysioterapeuter. Dessa var 27–58 år. Sammantaget för alla fysioterapeuter var att de generellt sett hade hög utbildningsnivå och goda erfarenheter av yrkeslivet. Urvalet var ett bekvämlighetsurval då fysioterapeuter inom Umeå kommun, och som arbetar på Umeå universitetssjukhus, kontaktades. Intervjuerna analyserades med kvalitativ innehållsanalys. Resultat: Resultatet av denna studie resulterade i tre kategorier: ”Främja förutsättningar för rehabilitering”, ”De kognitiva sätter stopp för de fysiska” och ”Samhället och vårdens behov av utveckling”. I intervjuerna berättar fysioterapeuterna att det finns strategier som fysioterapeuter använder vid bemötande och rehabilitering av personer med demens, som underlättar arbetet. De stöter även på svårigheter med patientgruppen som fysioterapeuterna behöver jobba runt. Enligt de intervjuade fysioterapeuterna behövs fler fysioterapeutresurser för att säkerställa god vård och mer kunskap för att skapa ett samhälle där patientgruppen känner sig inkluderade. Konklusion: Studien har gett en översikt kring vilka svårigheter fysioterapeuterna upplever i samband med rehabilitering och i bemötande, samt vilka strategier de använder sig av för att arbeta runt utmaningarna. Den har även belyst behovet för framtida fysioterapeuter att ständigt uppdatera sina kunskaper och vara nyfiken på att lära sig mer om denna patientgrupp för att kunna fortsätta erbjuda god vård till de äldre