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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.
11

Supersymmetry on Curved Space and Localization: An Example on S3

Lundin, Jim January 2019 (has links)
We present a basic introduction to the Super Poincaré algebra in 4D, then constructthe N = 1 Super Yang-Mills in 4D. By analogue we expand to the case of N = 1 Super Yang-Mills in 10D. Then by a method of dimensional reduction we getcertain supersymmetric theories in d <= 7 and restrict to spherical backgrounds. Wethen introduce a localization argument by ways of a cohomology on the configuration space of our theory. Finally we apply both techniques to acquire N = 2 Super Yang-Mills on S3, adding the Chern-Simons term and computing the exact partitionfunction, additionally giving an example for the case of U(N) gauge theories.
12

Sudden Death of Entanglement for non-locality and concurrence : A review of entanglement sudden death behaviour of non-locality and concurrence in commonly used entangled state classes under inuence of decay and dephasing noise dynamics

Herterich, Emmi January 2019 (has links)
No description available.
13

Förslag på riktvärden för sulfathalter i ytvatten

Jonsson, Julia January 2019 (has links)
Detta examensarbete kommer att vara den avslutande delen i mina studier inom samhällsbyggnads-programmet vid Luleå tekniska universitet. Under min verksamhetsförlagda utbildning, på WSP Sverige AB har jag fått arbeta i uppdrag där kunskaper om vattenkemi och biologi har behövts. Syftet med examenarbetet är att undersöka möjliga förslag på riktvärden för sulfathalter i ytvatten. Examensarbetet tog sin början med att formulera frågeställningar att forma arbetet kring. Utifrån frågeställningarna har jag sedan börjat undersöka vilka länder som har riktvärden för sulfathalter implementerat i miljölagstiftningen. Valet var självklart, att hitta ett land med liknande klimat som norra Sverige för att riktvärdena skulle vara relevanta och trovärdiga. Valet blev att undersöka riktvärden i Kanada. Under examensarbetets gång har jag fått lära mig mycket. Till exempel att kunna läsa och ta till mig information om toxikologiska undersökningar och förstå dess relevans. Detta har i sin tur lett till att jag lärt mig nya begrepp som används inom området miljö och vatten. Jag har även fått en inblick över hur komplext och stort arbetet området miljö och vatten är och fått en bra grund att stå på inför kommande utmaningar i mitt framtida yrkesliv.
14

Visualization of Ellipsoids

Götz, Holger January 2018 (has links)
No description available.
15

Wave study Seaflex mooring system : Wave study to illuminate how first and second order wave force transfer to and affects the loading of flexible Seaflex mooring system

Berggren, Magnus January 2018 (has links)
When constructing a marina, one must consider many factors for calculating the mooring forces transferred to the mooring system of the docks. The forces transferred from waves is of course one of the most important. The wave induced forces may be described in different orders, the first-order wave forces from the frequency domain and the second-order wave forces determined from a wave field of different standing waves acting together. All floating objects are subjected to these wave forces, but for different mooring systems the transferred mooring force may vary. To describe the need for different calculations depending on the mooring system, a comparison to a spring system is made for both a Seaflex hawser and a guided pile system, which illustrates a significant difference in transferred mooring load. This is due to the hysteresis giving a low spring constant to the Seaflex hawser, which in turn transfers very little of the frequency induced first-order forces to the mooring system. This gives the conclusion that different methods for scaling the Seaflex mooring system is needed, since the first-order wave forces are not as significant than for a semi-rigid mooring system.
16

Investigation of factors affecting cracking during forming of truck cab body parts / Undersökning av faktorer som påverkar sprickbildning vid plåtformning av karossdetaljer till lastbilar

Salomonsson, Evelina January 2018 (has links)
Sheet metal forming is a technique widely used in todays industries as it enables fast transformation of metal sheets into parts of various shapes and sizes. Volvo GTO EBM in Umeå uses sheet metal forming in their production of truck cab body parts, and a challenge common for all industries using this technique is to avoid cracking in the formed metal. The present study has been conducted in order to increase the understanding of why produced articles sometimes crack, so that cracking can be prevented in future production. This has been done by studying how different variations in the production process are affecting the robustness of produced articles, partly by investigating variations in material properties and partly by running robustness simulations of a chosen article prone to crack. Material properties have been gathered for both cracked and non-cracked details of different articles, and thereafter been compared to each other using multivariate analysis. Furthermore, simulations have been run using the software AutoForm with the purpose to investigate factors such as feeding direction of metal sheets, variations in material properties and different forces and velocities used during forming. Experiments have also been conducted in order to compare the simulation model and simulation results with reality. From the material property analysis it could be seen that differences in material properties do exist between cracked and non-cracked materials, but that these differences vary between different articles. The robustness simulations indicated that a certain force called draw cushion force do affect the final robustness of an article the most, compared to the other affecting factors investigated in this study. Moreover, the simulation set-up did seem to agree with reality, while the simulated material thinning deviates more than 20 \% from the real one. This may result from an inadequate modeling of friction in the simulations. In conclusion, material properties are important concerning cracking during sheet metal forming, and the draw cushion force seems to have the strongest influence on article's final robustness.
17

Theoretical and Experimental Studies of Dielectrophoresis on sub 20 nm Spaced Gold Electrodes

Hayat, Aqib January 2018 (has links)
No description available.
18

Modigare mörtar : En beteendestudie av oxazepams påverkan på vild mört

Nordling, Johanna January 2018 (has links)
No description available.
19

Testing of micro-fluidic systems for Raman spectroscopic measurements on biological cells

Berger, Malin January 2018 (has links)
Pulmonary Artery Hypertension (PAH) is a condition that can affect people as a consequence of infections or diseases such as lung disease, high blood pressure or pneumonia. When afflicted by these diseases, low oxygen content in the lung tissue causes the pulmonary arterial soft muscle cells (PASMC) located in the walls of the pulmonary arteries to chronically swell up. As a result, the arteries are constantly narrowed. This can in many cases be fatal as the arteries become clogged and the heart is forced to pump more blood to the lungs, causing an enlargement of the right heart chamber which eventually may lead to heart failure. This irreversible swelling of the PASMC is the cause for PAH. To find a treatment for this incurable disease, the mechanisms of the vasoconstriction need to be investigated.  Spectroscopy is the study of the interactions between light and matter and is a tool that can be used to gain knowledge in the matter of the expansions of the PASMC. In particular, Raman spectroscopy that targets the inelastic interactions can be used since it registers dynamic changes of cells.  To simulate an oxygen deprived environment, a micro-fluidic system designed for use in cellular experiments has been developed. Tests of the prototypes showed strong Raman signals from the polymeric material of the system itself. These signals overshadowed the signals from the observed sample. The objective of the experiments presented in this report was to test whether the signals from the micro-fluidic system could be eliminated by adding spacing between the polymer and the sample.  The experiment was conducted by collecting data of samples from baker's yeast prepared in the micro-fluidic system at different z-distances. By this the optimal spacing between the polymer of the micro-fluidic system and the sample could be determined. This experiment concluded that the sample needed to be placed 1.54 mm further from the micro-fluidic system in order to test human lung tissue at 2 mW laser intensity.
20

Simulation of LiDAR data for forestry applications / Simulering av LiDAR data i skogsbrukssyfte

Öhman, Nikanor January 2018 (has links)
In forestry it is important to have accurate information about the forest. LiDAR (laser scanning) can be used to scan vast areas of forest and from the data extract information about the trees. The purpose of this thesis is to develop a simulator for LiDAR data. The simulator will be tested on a method for tree localization (Holmgren and Lindberg 2013) to see how parameters like tree density and laser frequency effects the accuracy of the localization. First a simulator which uses simple shaped trees (in the shape of cones) is written. Later on a tree model based on real laser data is created by the use of histogram density estimation. Ray-tracing is used to simulate the LiDAR data which the trees give rise to. This is done by following each ray of laser and see where it is reflected. The tree localization method is tested on the data and we report the following findings: 1: The percentage of correctly located trees decreases with increasing tree density. 2: Larger trees yields an increase in false trees found by the localization method. 3: Higher laser pulse density decreases the number of false trees. 4: The minimum radius at which the localization method start fitting ellipsoids greatly effects the number of false trees. Smaller radius yield more false trees.

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