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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Samband mellan fysisk aktivitet och psykiskt mående : En populationsbaserad tvärsnittsstudie

Eriksson, Johannes, Ruuth, Mats January 2016 (has links)
Fysisk aktivitet ger flertalet positiva fysiologiska hälsoeffekter och har vid ett antal studier även visat sig bidra till positiva hälsoeffekter avseende psykisk hälsa. Det finns dock studier som inte kunnat påvisa effekterna på psykisk hälsa. Syftet med uppsatsen var att undersöka samband mellan fysisk aktivitet och depression, stress, och välmående, med kontroll för eventuellt samvarierande demografiska faktorer. Urvalet bestod av 357 (ålder 25-80år, 49.3% kvinnor) deltagare från Betulastudien. Välmående undersöktes med två frågor som skattades 0-10. Depressiva symtom undersöktes med The Center for Epidemiologic Studies Depression Scale. Stress undersöktes med Perceived Stress Questionnaire. Mängd fysisk aktivitet undersöktes genom tre frågor som efterfrågade mängd fysisk aktivitet: (1) de senaste 12 månaderna, (2) en vanlig vecka och (3) jämfört med andra. Samband undersöktes med hierarkisk regression, med kontroll för civilstånd, kön, utbildning och ålder. Fysisk aktivitet var svagt associerat med Välmående (ΔR² = .023) och endast aktivitet i jämfört med andra (β = .132) var signifikant. Fysisk aktivitet var positivt associerat med välmående men förklarade endast en liten del i variansen. Avsaknad av statistiskt signifikanta samband mellan fysisk aktivitet, depression och stress skiljer sig från tidigare populationsbaserade studier. Dessa skillnader i resultat skulle kunna förklaras med kulturella och metodologiska skillnader. Ytterligare forskning på sambandet mellan fysisk aktivitet och psykisk hälsa behövs. / Physical activity contributes to several positive physiological health benefits and has also, in a number of studies, proven to contribute to psychological health. There are nonetheless studies which have not been able to prove the positive effects on psychological health. The goal of the paper was to investigate correlations between physical activity and depression, stress, and wellbeing, while controlling for the influence of demographical factors. The sample was from the Betula study and consisted of 357 participants aged 25-80, with 49.3% women. Wellbeing was assessed by ratings (0-10) in response to two questions. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale. Stress was measured by Perceived Stress Questionnaire. Amount of physical activity was investigated through three questions which asked for the amount of physical activity: (1) in the last 12 months, (2) a normal week, and (3) compared to others. Relationships between activity level and aspects of psychological health were investigated through hierarchical regression analysis, controlling for civil status, gender, education, and age. Physical activity was weakly associated with Wellbeing (ΔR² = .023) and only activity compared to others (β = .132) was significant. Physical activity had a positive association with wellbeing, but only accounts for a small amount of the variance. The absence of statistical significant relationship between physical activity, depression and stress is not in line with previous population-based studies. These differences could possibly be explained by cultural and methodological difference between studies. Additional studies on the correlation between physical activity and mental health is needed.
2

Livscykelanalys: Pelletspanna från kvänum energi

Junefjäll, Johan, Bäckerstam, Valentina January 2012 (has links)
This study will identify the environmental impact in terms of carbon dioxide for a boiler house on behalf of Kvänum energi. The boiler central consists of a main building, which in turn contains multiple components such as boilers, pipes, etc, the boiler central uses pellets fuel. It also includes a silo and an ash container. The total weight of the boiler is about 63 tons. Each boiler has an output of 600 kW; the central includes three boilers with room for a fourth if necessary. The study has followed the ISO 14040 as far as it has been possible. The boiler central is manufactured at Kvänum Energi’s plant in Kvänum and then assembled on-site for the customer. When analyzing the system the entire product has been divided into smaller parts to make the analysis more manageable. The breakdown was made regarding the material. The conclusions from the calculations of emissions were that material was of greater importance to the environment than transportation. Design improvement proposal was mainly focused on materials and how any change of material would affect the environment and energy consumption. The ability to construct the building and silo in aluminum was investigated from the strength, price and environmental impact point of views. From design point of view, steel and aluminum are equivalent for the purpose, but in terms of cost, aluminum is more expensive. However the recycling option is significantly better for aluminum. EPS (Environmental Priority Strategies), which is a Swedish method developed for engineers at Volvo, was used for the calculation of environmental impact. When comparing steel and aluminum, the aluminum construction received a lower value regarding carbon dioxide i.e. better from an environmental perspective. The study includes a short survey on a transport to a fossil fuel dependent country, and it is investigated whether such a transport would be justified. The transport would be by boat and truck and the resulting emissions from the transport is about 1 ton of CO2. In the study, Lithuania has been chosen as an example because it has the same climate as in Sweden, i.e. a large need for heating during winter, and also because that Lithuania has a high dependence of oil and gas for heating.
3

(Not) Flying into the future : International Business Air Travel from a Corporate Environmental Sustainability perspective

Eriksson, Ida, Levander, Lisa January 2020 (has links)
Environmental sustainability has grown to become a widely discussed topic in today's society, putting great pressure on companies to limit their climate impact. Still, companies continue to use International Business Air Travel for strategic benefits, in an era where concepts such as “flight shame” are emerging. Hence, the balance of attaining the advantages of IBAT, while simultaneously increasing the focus on Corporate Environmental Sustainability, is a challenge faced by companies today. The main purpose of this study is to investigate how Swedish it-companies work with Corporate Environmental Sustainability in the different strategic phases of International Business Air Travel.
4

Barnets efterfrågan av idrott

Krona, Åsa January 2006 (has links)
<p>Jag har i uppsatsen härlett barnets efterfrågan av idrott där kostnaderna för idrotten utgjort priset för den och summan av priserna för två idrotter utgjort den andel av inkomsten som avsatts speciellt för barnets idrottande. Vidare har jag antagit att barnets preferenser kunnat formuleras i en nyttofunktion av typen CES som anpassats för att de två idrotterna inte ska vara perfekta vare sig substitut eller komplement. Substitutionselasticiteten i funktionen har uppgått till 2/3. Detta har resulterat i en efterfrågefunktion vilken reagerar svagt negativt vid en prisökning. Jag har belyst resultaten med ett empiriskt exempel och där konstaterat att funktionen uppfyller de antaganden jag gjort om dess reaktioner vid prisförändringar.</p>
5

Barnets efterfrågan av idrott

Krona, Åsa January 2006 (has links)
Jag har i uppsatsen härlett barnets efterfrågan av idrott där kostnaderna för idrotten utgjort priset för den och summan av priserna för två idrotter utgjort den andel av inkomsten som avsatts speciellt för barnets idrottande. Vidare har jag antagit att barnets preferenser kunnat formuleras i en nyttofunktion av typen CES som anpassats för att de två idrotterna inte ska vara perfekta vare sig substitut eller komplement. Substitutionselasticiteten i funktionen har uppgått till 2/3. Detta har resulterat i en efterfrågefunktion vilken reagerar svagt negativt vid en prisökning. Jag har belyst resultaten med ett empiriskt exempel och där konstaterat att funktionen uppfyller de antaganden jag gjort om dess reaktioner vid prisförändringar.
6

Physical Modelling and Automatic Configuration of CES Valve

Gällsjö, Anders, Johansson, Mattias January 2012 (has links)
This thesis has been performed at Öhlins Racing AB which is known world-wide for its high quality racing shock absorbers. Öhlins have been developing shock absorbers for more than 30 years and in addition to this they also develop a technology for semi-active suspension. Semi-active suspension technology makes it possible to achieve an intelligent and dynamic vehicle chassis control. Compared to standard passive suspensions, semiactive dampers allow improving vehicle cornering performance while still providing good comfort when cruising. This is achieved by a real time adjustment of the suspensions damping characteristics. Öhlins system for semi-active suspension is called CES (Continuously controlled Electronic Suspension). The systems consist of electronically controlled hydraulic valves for uniflow dampers. These valves are mounted on all four dampers of the vehicle and are controlled individually to provide the desired ride quality. The valves are configurable to suit many types of vehicles by changing internal parts. The first goal of this thesis project was to study the behaviour of the CES valve and uniflow damper. In order to achieve this a simulation model was created using Hopsan which is a 1-dimensional multi-domain modelling tool developed at the division of Fluid and Mechatronic Systems at Linköping University. The model considers mechanical forces from for example springs together with hydraulic forces. It was validated against static and dynamic measurements made in a flow bench and a dynamometer. The second goal was to use the simulation model as part of a tool that configures the CES valve according to a requirements specification. To achieve this goal a method of estimating the characteristics of the internal damper valves was developed. This estimation method, together with the simulation model, was used to choose the best valve configuration by using weighted least-squares. The result is presented in a Matlab-based graphical user interface.
7

Cultural Ecosystem Services as a Framework for Evaluating Wilderness Values in Public Land Settings

Sharp, Christopher John January 2013 (has links)
The Wilderness Act of 1964 states the purpose of the National Wilderness Preservation System is "to secure for the American people of present and future generations the benefits of an enduring resource of wilderness." But, how to accomplish this mandate is a complex task. The application of the Ecosystem Services model is ideal for facilitating the complex duel goals of securing benefits and preserving wilderness resources. Ecosystem Services directly addresses benefits derived from a landscape, even if the specifics of the benefits change over time. This dissertation employs Ecosystem Services as a framework to provide a more complete understanding of wilderness values. In three separate studies conducted in wilderness areas in Southern Arizona, (Assessing Border-Related Human Impacts at Organ Pipe Cactus National Monument, Linking Visitor Flows and Patterns of Use with General Management Planning in Saguaro National Park and Monitoring and Estimating Visitor Use at the Madrona Ranger Station and Surrounding Landscape) elements of Cultural Ecosystem Services (CES) are illuminated.I found that the more holistic epistemology of Ecosystem Services allowed for the inclusion of better scientific data in the management process. The inclusion of quantitative, repeatable, defensible studies of user behavior in wildlands allows for dynamic management options that are rooted in real conditions (mutable, undesirable or unique). Specifically Cultural Ecosystem Services address the value and significance of the unique landscape of wilderness. Previous models for wildland management sought specific metrics of carrying capacity to limit use and control impact. Ecosystem Services combines diverse scientific fields to provide real understanding of the landscape. The addition of ES to manager's decision processes allows for better understanding of real conditions.
8

SEDIMENT 2011 Sediments: Archives of the Earth System

11 July 2011 (has links) (PDF)
This volume comprises ninety-one contributions to the Sediment 2011 conference of the Central European section of the Society for Sedimentary Geology (SEPM-CES) and the Geologische Vereinigung (GV) at the University of Leipzig held in June 2011. The central theme of this meeting was “Sediments: Archives of the Earth System” in order to bring together young and established researchers from all fields of soft-rock geology and beyond to shape a stimulating interdisciplinary program on the role of sediments in understanding the System Earth and the evolution of paleoenvironments and climate through time.
9

Differentialgeometrische Kleinste-Quadrate-Schätzung in nichtlinearen Regressionsmodellen mit normalverteilten Störgrößen /

Krätschmer, Volker. January 1994 (has links)
Universiẗat, Diss.--Saarbrücken, 1995.
10

Quality of life and depressive symptoms as predictors of participant adherence in a randomized trial conducted among older adults at risk of mobility disability

Zhu, Hao 12 March 2016 (has links)
Poor adherence is an issue in clinical trials with a striking magnitude and negative impact. Recent studies indicate that two widely used clinical screening tools, Short Form (SF-36) Health Survey and Center for Epidemiologic Studies Depression Scale (CES-D) can be used as risk stratifiers to identify participants who require extra interaction to stay adherent in specific population. There is, however, little evidence to support the implication of these tools in elderly individuals with mobility limitations. These individuals may be particularly vulnerable to the risks of poor adherence in the context of a demanding interventional scheme. This study fulfills this gap by analyzing the quality of life and adherence data from the VIVE2 study, which is a double-blinded randomized explanatory clinical trial assessing the benefits of nutritional supplements and daily exercises to elderly patients with mobility limitation. The preliminary results showed that in clinical studies targeting elderly population with mobility limitations, the summary scores of SF-36 trended to have weak and nonsignificant association with a decreased risk of poor adherence to both exercise completion and product consumption while CES-D has no association.

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