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Effect of leaf chemicals from susceptible and resistant alternate hosts of Cronartium on in vitro germination of aeciospores of Cronartium pini and C. ribicola
No full textThe chemical compounds of plant leaves may be used to defend against rust diseases. The effect of methanolic leaf extracts from four resistant and four susceptible alternate hosts of Cronartium pini and C. ribicola, and two pure phenolic chemicals, such as chlorogenic acid and quercitrin, were tested on the germination of C. pini and C. ribicola spores. Aeciospores of these rusts were dusted on water agar amended with the leaf extracts and chemicals in three concentrations and a methanol control, and germination of the aeciospores was counted after 24 h incubation. Germination of the rusts was compared between extracts and concentrations. All plant extracts tended to stimulate the germination of both rusts at 50 and 100 ppm, but the highest concentration, 500 ppm, inhibited the germination of both rusts regardless of the extract. The germination of C. pini spores was inhibited strongly by extracts from Veronica chamaedrys, V. longifolia, Ribes rubrum and Impatiens glandulifera, chlorogenic acid, quercitrin and methanol, and weakly by extracts of Ribes nigrum, Melampyrum pratense, M. sylvaticum and Impatiens balsamina at 500 ppm. The growth of C. ribicola was strongly inhibited by all extracts at 500 ppm. Since the results indicate stronger inhibition by the extracts from resistant host species, more research is required to identify the active compounds for bio-based control of Cronartium rusts
What can the statistics tell us? : A comparative study of collisions and groundings for vessels with and without pilotage.
No full textDenna systematiska litteraturstudie undersöker olycksstatistik under tidsperioden 2018 till 2023 gällande grundstötningar och kollisioner inom svenska hamnområden för tre av studien indelade huvudkategorier. Dessa kategorier är fartyg med lots, fartyg med lotsdispens samt fartyg utan lots. Genom att jämföra mot tidigare forskning, i synnerhet mot en tidigare studie som undersökt liknande data under tidsperioden 2003 till 2013, ämnar den här studien att utröna hur statistiken förändrats under de studerade tidsperioderna, samt presentera bakomliggande teorier som kan förklara det statistiska underlaget. Resultatet i denna studie pekar fortsatt på att kategorin fartyg utan lots är överrepresenterad i olycksstatistiken, likt vad tidigare studie kommit fram till. Kollision med annat fartyg utgör dessutom den mest frekventa olyckstypen för denna kategori. För övriga kategorier var kollision med fast konstruktion den mest förekommande olyckstypen. Denna studie har detekterat en rad olika teorier till varför genom att studera tidigare forskning, ett axplock är bland annat brist på vilotid för besättningen, frångående av befintliga regelverk, bristande språkkunskaper i engelska samt samarbetssvårigheter med exempelvis lotsar. Det går även att utläsa en ökning av antalet kollisioner och grundstötningar orsakade av yttre faktorer i studiens resultat, jämfört med tidigare studie. Varför denna ökning skett har inte kunnat bevisas. En ny lotsningsföreskrift har även trätt i kraft sedan den första december år 2023, den har medfört att fler fartyg som tidigare kunde anlöpa en hamn utan lots nu behöver anlita lots, vilket troligtvis på sikt kommer medföra en förändring i det statistiska underlaget den här studien är baserad på. Därav ges i nuläget inga rekommendationer då effekterna samt eventuella justeringar av den nya föreskriften behöver påvisa ett resultat först.This systematic literature study examines accident statistics during the period 2018 to 2023 regarding groundings and collisions within Swedish port areas for three main categories divided by the study. These categories are vessels with pilots, vessels with pilot exemption and vessels without pilots. By comparing with previous research, in particular with a previous study that examined similar data during the period 2003 to 2013, this study aims to find out how the statistics have changed during the studied time periods, and to present underlying theories that can explain the statistical basis. The results of this study continue to indicate that the category of vessels without a pilot is overrepresented in accident statistics, similar to what the previous study concluded in its results. Collision with another vessel is also the most frequent accident type for this category. For the other categories where collision with fixed structure the most common accident type. This study has detected a number of different theories as to why by studying previous research, a selection of examples includes lack of rest time for the crew, departure from existing regulations, lack of English language skills and difficulties in cooperation with, for example, pilots. It is also possible to see an increase in the number of collisions and groundings caused by external factors in the study's results, compared to previous studies. It has not been possible to prove why this increase. A new pilotage regulation has also come into force since December 1, 2023, which has meant that more ships that were previously able to call at a port without a pilot now need to take pilot, which will probably lead to a change in the statistical basis, on which this study is based, in the long term. Therefore, no recommendations are given at this moment as the effects and any adjustments to the new regulation need to demonstrate a result first
CFD-driven investigation on improving heat recovery in centrifugal wet scrubbers
No full textMitigating global warming requires a rapid transition to carbon-neutral energy sources, with biomass-based heat production being a significant contributor. Wet scrubbers equipped with heat recovery enhance fuel efficiency by utilizing waste heat while removing particulate matter from flue gas. In this study, a Computational Fluid Dynamics (CFD) model was developed to investigate heat recovery and flow dynamics in a centrifugal wet scrubber installed at a 3MWth biomass-fired district heating facility, achieving an annual heat recovery of approximately 2 GWh. The model was validated against process data, showing a prediction error of 3.4 %, which is lower than other simulation models for similar purposes. This model, complemented by an Analysis of Variance (ANOVA), was used to explore different optimization strategies, including enlarging the contact zone opening, pre-scrubber moisture addition to the flue gas, and new compact geometries. Three scrubber designs were examined in-depth, focusing on gas flow, as well as heat and mass transfer. Increasing the contact zone opening from 100 to 150 mm yielded a 2 % boost in heat recovery. Coupling this design improvement with moisture addition can potentially elevate heat recovery by approximately 9 % over the conventional design. The new compact scrubber design can potentially increase heat recovery by 2.7 %, and further up to 9 % when combined with the moisture addition strategy. Notably, this compact geometry showed superior radial velocity and heat recovery, offering significant potential for material and space savings. This study provides valuable insights into the optimization of centrifugal wet scrubbers for improved heat recovery efficiency
Finite Element modelling of dowel-type connections in CLT structures : From timber embedment behaviour to CLT shear walls
No full textCross-Laminated Timber (CLT) is a pre-engineered timber product that has gainedmuch popularity over the last three decades as a sustainable construction material.CLT has excellent mechanical properties, and connections between CLT elementsand other structural elements in CLT structures are often critical in the engineeringdesign. The aim of this thesis is to develop a Finite Element Method (FEM)model for connections with dowel-type fasteners in CLT structures. Through athorough analysis from the embedment behaviour of timber to the simulation ofCLT structures with connections, this thesis aims to deepen the understandingof the load transfer and deformation behaviour of connections. Papers I and IIinvestigate with own and previous experiments the embedment behaviour ofdowel-type fasteners in timber and CLT. A non-linear analytical spring model forthe prediction of CLT embedment behaviour from the embedment behaviour ofthe constituent layers is proposed and shows good agreement with experiments.A Finite Element Method (FEM) model for the non-linear force-displacementbehaviour of single-fastener CLT connections is presented in Papers III andIV. A ‘Beam-on-Foundation’ (BoF) model is implemented in the FEM modelfor simulating the connection behaviour. The BoF model is validated withexperiments on steel-to-CLT and concrete-to-CLT connections, before it is usedto investigate the influence of various parameters on both the strength and slipmodulus of CLT connections. In Paper V, several single-fastener BoF models areintegrated into a multiple-fastener CLT connection model. The FEM model isvalidated with experiments on laterally loaded multiple-fastener steel-to-CLTconnections and used to investigate the influence of various parameters on thestrength and slip modulus of multiple-fastener CLT connections. From theresulting database, a design equation for the group effect in the slip modulusof steel-to-CLT connections with multiple-fasteners is derived. In Paper VI, theFEM model is applied to simulate angle bracket and hold-down bracket CLTconnections, as well as full-scale CLT shear walls with multiple connections.Due to the integrated BoF models, the FEM model provides insight into theload distribution between various connections. The developed FEM model is aneffective tool for the prediction of the force-displacement behaviour, the ductilestrength and the slip modulus of CLT connections with dowel-type fasteners.As it is implemented using a parametrised python script, the FEM model ishighly adaptable to accommodate numerous material and geometrical parameters.In addition to the effectiveness of the developed FEM model, the study alsohighlights the need for further developments in the simulation of the interactionof loading conditions and experimental validation.Korslimmat trä (KL-trä) är en hållbar träbaserad byggprodukt som har blivitmycket populär under de senaste tre decennierna. KL-trä har utmärkta mekaniskaegenskaper och utformningen av förband mellan element av KL-trä och andradelar av stommen är ofta avgörande för den tekniska utformningen ochdimensioneringen. Syftet med detta avhandlingsarbete har varit att utveckla enberäkningsmodell baserad på finita elementmetoden för mekaniska förband iKL-träkonstruktioner. Genom noggrann analys av såväl detaljer såsom betydelsenav hålkanttryck mot trä till simuleringen av fullskaliga KL-träbaserade skjuvväggarmed flera samverkande förband syftar denna avhandling till en fördjupadförståelse av lastöverföring och deformationer i förband i KL-träkonstruktioner.I artikel I och II undersöks experimentellt hålkanttryck mellan förbindare ochträmaterial. En icke-linjär analytisk fjädermodell för hålkanttryck hos KL-trä,härledd från hålkanttryck hos enskilda lameller eller lager av lameller, visar godöverensstämmelse med experimentella resultat. I artikel III och IV presenterasen finita elementmodell (FE-modell) för det icke-linjära sambandet mellan kraftoch förskjutning hos förbindare i KL-träförband. I FE-modellen representeras enenskild förbindare, och dess lastöverföringen mot angränsande material, av enbalk på fjädrande bädd. Modellen valideras genom experiment där komponenterav stål respektive betong trycks mot KL-trä, innan FE-modellen används för attundersöka effekten av olika parametrar på hållfasthet och förskjutningsmodul hosförband i KL-trä. I artikel V integreras flera förbindare, representerade av balkarpå fjäderbäddar, i en FE-modell av ett sammansatt KL-träförband. Modellenvalideras med experiment på förband med stål mot KL-trä och används för attundersöka betydelsen av olika parametrar på hållfasthet och förskjutningsmodulhos förband med flera förbindare. Den resulterande databasen används för attutveckla en dimensioneringsmodell som fångar gruppeffekten med avseendepå förskjutningsmodulen för stål mot KL-trä i förband med flera förbindare. Iartikel VI tillämpas FE-modellen för att simulera beteenden hos vinkelbeslag ochdragankare med flera förbindare, samt fullskaliga KL-träbaserade skjuvväggarsom omfattar flera förband. Genom att enskilda förbindare och deras kontakttryckrepresenteras av balkar på fjädrande bädd ger FE-modellen insikt i lastfördelningenmellan olika förband och hur olika förbindare bidrar i lastöverföringen. Denutvecklade FE-modellen av KL-träförband är ett effektivt verktyg för att förutsägakraft-förskjutningsegenskaper, hållfasthet och förskjutningsmodul för duktilaKL-trä-förband. Eftersom FE-modellen är implementerad i ett parametriseratPython-skript är den flexibel och kan anpassas för att utvärdera många olikamaterial- och geometriparametrar. Utöver att visa på användbarheten hos denutvecklade FE-modellen visar även studien på behovet av fortsatta, fördjupadestudier avseende fleraxiella belastning, modellering och experimentell valideringav mekaniska förband i KL-träkonstruktioner
Is It the Social Blaze That Gives the Caffeine Craze? : A quantitative study of how social factors influence the consumption habits of energy drinks among adolescents.
No full textThis thesis explores the long-term influence of social factors during adolescence on continued energy drink consumption into adulthood. With Theory of Planned Behavior and Social Learning Theory, the study tested seven hypotheses related to attitudes, subjective norms, perceived behavioral control, reciprocal determinism, observational learning, social reinforcement and media influence. A quantitative research design was employed using a digital questionnaire targeting Swedish adults aged 18-24 who initiated consumption as adolescents between ages 10-17. The data analysis involved the use of descriptive statistics, Spearman’s rank correlation, and multiple linear regression. The findings revealed that attitudes during adolescence were the strongest predictor of continued consumption, supporting the Theory of Planned Behavior. In contrast, subjective norms and perceived behavioral control showed no significant or even negative relationships with long-term behavior. Regarding the Social Learning Theory variables, observational learning and reciprocal determinism were not predictive, while social reinforcement and media influence showed weak but statistically significant effects in the regression model only. These results suggest that although social factors may initiate consumption, long-term habits are more closely tied to internalized personal attitudes than to sustained social or environmental influence. This study contributes to behavioral research demonstrating that the Theory of Planned Behavior, particularly the role of attitudes, is more effective than the Social Learning Theory, in explaining habits extending from adolescence into adulthood. It offers implications for public health, policymakers, marketers, retailers, and educators with the goal of regulating energy drink consumption by focusing early interventions on shaping adolescents’ personal beliefs and attitudes, rather than relying exclusively on external or environmental factors
From Threat Perception to Policy Action : A Study on Sweden's Securitization of Russian Hybrid Threats and the Reimplementation of Sweden's Total Defence
No full textThe rapid advancements in technology and globalization have resulted in new threats to national security which differ from those of traditional military warfare. In its annexation of Crimea, Russia utilized hybrid warfare to target Ukrainian infrastructure through economic, political, cyber, and informational means, and in light of these aggressions, Sweden made the decision to reimplement its total defence system. This thesis examines to what extent Russian hybrid threats have been securitized by the Swedish government and how it connects to its reimplementation of the total defence system, as well as how this connection can be explained through the lens of constructivism. The thesis builds on a case study of the reimplementation of the Swedish total defence and analyses policy documents published by the Swedish riksdag through a qualitative content analysis with the theoretical framework of definitions of hybrid warfare, securitization theory, and constructivism. The results show that the Swedish government have, between 2014 and 2016, securitized Russian hybrid threats and made them a prioritized security issue which led to the decision to resume the planning of the total defence system in 2015. Additionally, the results present that, through the lens of constructivism, this connection can be explained by Sweden's shift in its perception of Russia and Russia's actions after its annexation of Crimea, after having dismantled its total defence after the fall of the Soviet Union at the end of the Cold War and switching security prioritizations until the annexation of Crimea in 2014
Den långvariga kampen om Mellanöstern : En komparativ fallstudie av Irans och Saudiarabiens utrikespolitiska strategier och inflytande i Syrien sedan 2011
No full textUngerns autokratisering : Socialt kapital och demokratisk tillbakagång: En tillämpning av Putnams analytiska ramverk på Ungern 2008–2023
No full textIn recent decades, central democratic institutions around the world have been weakened and replaced by authoritarian elements and power concentration. Hungary, under the leadership of Viktor Orbán, is a prominent example of this development. Despite extensive research on the macrostructural dimensions of autocratization, there is a lack of knowledge about how these changes have affected the citizen level. Therefore, this study aims to analyze how autocratization on a microstructural level in Hungary has affected political trust, political participation, and social norms. Based on Robert Putnam's theory of social capital, a quantitative analysis is conducted based on data from the European Social Survey (2008–2023). The result shows a development where political trust has increased during Orbán's time in power. However this does not seem to reflect a genuine democratic social capital. Instead, the results indicate that trust is partly formed in an authoritarian context characterized by control, self-censorship and limited opportunities for collective organization. Electoral participation and social networks persist, but associational engagement and norms of reciprocity are weak. Overall, the study indicates that social capital in Hungary may have been transformed into a tool for stabilizing the authoritarian regime, rather than strengthening democracy
Med fokus på det salutogena perspektivet : Om sjukhusbibliotekariers biblioterapeutiska praktiker
No full textFocusing on the salutogenic perspective: About the bibliotherapeutic practices of hospital librarians From the perspective of Library and Information Science (LIS), the objective of this study is to find out what theoretical starting points do hospital librarians use in regard to reading and health-promoting bibliotherapy practices for patients in Sweden today? Bibliotherapy has its roots in ancient history and the understanding that words are helpful for human beings. Since then, bibliotherapy has developed systematically in different interdisciplinary research areas, such as psychology, practical medicine and LIS. There are many definitions of bibliotherapy practices, theories and methods and the term bibliotherapy is often inconsequently utilized. This thesis has a phenomenological perspective, focusing on a practice-oriented approach of the Social Practice theory by Shove, Pantzar and Watson (2012) that is used to analyze the elements of practice and their mutual interactions. The research method was performed through qualitative interviews with seven hospital librarians who carry out bibliotherapy practices for patients via hospital libraries throughout Sweden. The aim is to contribute to an understanding of bibliotherapy practices and how useful theories can be applied, to spread knowledge about the potentials of bibliotherapy in LIS as well as other interdisciplinary research areas
"The students must not feel like I'm just ticking a box" : An interview study on how social studies teachers integrate a gender equality perspective
No full textThe aim of this study is to examine how teaching in the subject of Social Studies incorporates a gender equality perspective, both in terms of content and pedagogical approach. The study focuses on how upper secondary school teachers define and understand the gender equality perspective in relation to their teaching, as well as the challenges they encounter in integrating this perspective. In addition, the study investigates how gender is constructed and expressed through teachers’choices of methods and content. Through semi-structured interviews involving five upper secondary school teachers at a school in the south of Sweden, several perspectives on the matter of gender have been identified. Furthermore, the interview responses were analyzed using Judith Butler’s theory on gender and performativity, as well as ”the didactic triangle” developed by Gunnar Lindström och Lars Åke Pennlert. The results show that the teachers consider the gender equality perspective to be relevant to Social Studies education. However, the degree of integration varies. The teachers are aware of how their teaching – both in terms of content and structure – affects how gender is constructed in the classroom. Several examples emerged of teaching practices that challenge gender stereotypes and norms. Furthermore, the results highlight the need for both didactic and subject-specific competence for teaching about and for gender equality for it to be meaningful. Social competence was also emphasized in the conclusions as a key requirement for managing the challenges associated with integrating a gender equality perspective into teaching.