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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.
111

Discriminatory Taxes are Unpopular Even when they are Efficient and Distributionally Fair

Sausgruber, Rupert, Tyran, Jean-Robert 11 1900 (has links) (PDF)
We explore the political acceptance of taxation in commodity markets. Participants in our experiment earn incomes by trading and must collectively choose one of two tax regimes to raise a given tax revenue. A "uniform tax" (UT) imposes the same tax rate on all markets and is fair in that it yields the same - but low - income to participants in all markets. The "discriminatory tax" (DT) imposes a higher burden on markets with inelastic demand and is therefore efficient but it is also unfair in that incomes are unequal across markets. We find that DT are unpopular, as predicted. Surprisingly, however, DT remain unpopular when they are both efficient and produce a fair (equal) distribution. We conclude that non-discrimination (equal treatment) is a salient fairness principle in taxation that shapes voting on commodity taxes above and beyond concerns for efficiency and equal distribution. (authors' abstract) / Series: WU International Taxation Research Paper Series
112

Contemporary Flat-Tax Reforms in Eastern Europe. Causes of Diverse Approaches : A comparison of Slovakia, Czech Republic and Germany.

Antalova, Livia January 2010 (has links) (PDF)
The paper deals with the issue of contemporary flat-tax reforms in Eastern Europe and aims to account for the different approaches that various European countries adopted towards the idea of a flat-tax. Empirically, the work is based on detailed studies of Slovakia, the Czech Republic and Germany. The analysis considers three factors being decisive for the flat-tax feasibility: 1./ party system institutionalization, 2./ coalition/opposition cohesiveness, 3./ labor union institutionalization. First, the study is concerned with each of the factor's influence on the political decision-making process in the three country cases. Secondly, on country paired comparisons the findings for each of the countries are mutually contrasted. Although all identified factors seem to be at play with regard to flat-tax feasibility, I argue that it is either the strength or the weakness of labor unions' institutionalization and welfare identity that underlie the political decision-making in the East and the West and as a result determine the flat-tax (un-)feasibility. The absence of welfare identity in the East allows for higher coalition cohesion in favor and weaker opposition against the flattax adoption in contrast to the West. / Series: Discussion Papers SFB International Tax Coordination
113

Effects of HALSs and Nano-ZnO Worked as UV Stabilizers of Polypropylene

Lu, Xinyao 12 1900 (has links)
This work reports the outdoor weathering performance of ultraviolet (UV)-stabilized polypropylene (PP) products (using PP resins from Encore Wire). Different hindered amine light stabilizers (HALSs) and nano-ZnO were used to stabilize PP-film-based formulations that were exposed under UV light for 6 weeks simulating for in harsh outdoor weather of Dallas, Texas, USA in 2016. Characterization of the exposed PP film products was done in terms of mechanical and friction spectroscopic properties. The PP film formulations were divided into 15 categories based on the type of HALS and nano-ZnO incorporated. This was done to derive meaningful comparison of the various film formulations. Following exposure under UV light, the lifetimes of certain formulations were determined. On the basis of the mechanical and friction properties, it was determined that generally, the HALS or nano-ZnO stabilized PP film give better properties and if those two kinds of UV stabilizers can work together.
114

Vliv adhezní mezivrstvy na lomově-mechanické chování kompozitu PP + anorganické plnivo. / Influence of adhesive layer on the mechanical behavior of PP+ inorganic filler composite.

Švestková, Dana January 2011 (has links)
The diploma thesis was dealt with the study of system PP and particular filler, specifically PPH and like a filler was used commercially available CaCO3 (SOCAL P3). This type of filler is declared by the producer as a filler without surface treatment. The submitted thesis had a goal to find and testing the suitable method and methodology for defined surface treatment of the filler. This is the first step for systematic study of influence the various types of adhesive layer on mechanical properties of declared composite. The plasma discharge behind static pressure was used for the surface treatment of the fillers. These fillers were afterwards analyzed by using of sedimentation analysis, infra - red spectroscopy (FT-IR) and scan electron microscopy (SEM). The composites with various volume part of the fillers were prepared in PIB and studied by short-time tests. Regarding to experimental demand there wasn't possible to realize the whole originally intended program i. e. study of influence the different types of adhesive layer, including to form the model for FEM approach. Nevertheless finding and testing the suitable method of surface treatment is completely basic for the others study. The above mentioned method was used in this application for the first time and it is possible to consider this process like an original approach.
115

The effect of the shoe sole on Plantar Pressure distribution / Påverkan av skosulans utformning på fotens tryckfördelning

Ejimadu, Geraldine January 2020 (has links)
Patients affected by Diabetes Mellitus have reduced tactile sensitivity and atrophy of the small muscles in the foot, resulting in high-pressure points that may remain unnoticed. The increased pressure can cause micro-trauma leading to wounds. Because of the Diabetes Mellitus, DFUs do not heal easily. Up to 25% of them will develop diabetic foot ulcers (DFU), and 25% of DFUs that do not heal ultimately result in amputation. This Master Thesis will describe and gather results of a newly acquired large international collaborative EU project (EIT Health 2020-2022) between three universities and three companies across Europe. This collaborative group will be the first to tackle the Diabetic Foot Ulcers problem preventatively with an innovative shoe concept, with seven different apex settings, which can be easily modified to avoid ulcerations in different areas of the foot. As an initial pilot, this master thesis project focuses on the analysis of the plantar pressure distribution by using the innovative shoes DR Comfort based on the adjustable rocker profiles, used as a prototype for the prevention of the Diabetic Foot Ulcer (DFU) formation in patients affected by Diabetes. This project captures the motion data of healthy people with different shoe soles while walking at different levels of speed and assess the values of the peak plantar pressure, with the use of the Pedar-X, a measuring system device for the in-shoe plantar pressure. The evaluation of the adjustable rocker profiles is made through the calculation and analysis of the significant differences and p-values in peak plantar pressure, as well as the analysis of the Mean Plantar Pressure (MMP). The results of this study show a reduction (although not pronounced) of the areas that are more affected by DFU. This study cannot be generalized to diabetic patients since ethical approval has not yet been received. / Patienter med DM har minskad taktil känslighet och atrofi i de små musklerna i foten, vilket resulterar i högatryckpunkter som kan för bli obemärkta. Det ökade trycket kan orsaka mikrotrauma som leder till sår. På grund av Diabetes Mellitus, läker inte DFU lätt. Upp till 25% av dem kommer att utveckla diabetiska fotsår (DFU), och 25% av DFU: er som inte läker leder slutligen till amputation. Detta examensarbete kommer att beskriva och samla resultat från ett nyförvärvat stort internationellt EU-projekt (EIT Health 2020-2022) mellan tre universitet och tre företag i hela Europa. Denna samarbetsgrupp kommer att vara den första att förebygga problemet med diabetiska fotsår med ett innovativt skokoncept diabetiska fotsår med ett innovativt skokoncept. De kommer utföras med sju olika inställningar som lätt kan modifieras för att undvika sår på olika områden i foten. Som en första pilot fokuserar detta examensarbete på analys av plantartryckfördelning genom att använda de innovativa DR Comfort-skorna baserade på de justerbara ”rocker”-profilerna, som används som en prototyp för att förebygga bildningen av Diabetic Foot Ulcer (DFU) hos patienter som drabbats av Diabetes. Den här avhandlingen fångar rörelsen hos friska personer med olika skosulor medan de går i olika hastighet och analyserar värdena för det maximala plantartrycket med användning av pedar-x. Pedar-x är en mätanordning för plantorns tryck i skon. Utvärderingen av de justerbara ”rocker”-profilerna gjordes genom beräkning och analys av de signifikanta skillnaderna i top plantartrycket samt analysen av plantartryckets maximala medelvärde (MMP). Resultaten av denna studie visar en minskning (även om den inte betydlig) av de områden som mest drabbats av DFU. Denna studie kan inte generaliseras till diabetespatienter eftersom etiskt godkännande ännu saknas.
116

Development of a PP-MOCVD System and its Design and Operational Parameters for Uniform Industrial Coatings on 3D Objects

Lee, Darryl Liang Wee January 2014 (has links)
Increase in demand for uniform ceramic coatings on larger industrial components have led to a need for a PP-MOCVD coating system scale up. The objective of this thesis is to develop a fully functional coating system operating in the PP-MOCVD regime that is able to deposit thin film ceramic coatings on commercial or industrial components with complex 3D geometries. This can be achieved by applying engineering and vacuum science theories, coupled with the established fundamentals of PP-MOCVD. A larger system was designed and assembled around the boundaries set by the dimensions and geometry of a stainless steel water pump impellor acting as the base substrate. Most of the components were sourced off the shelf from vacuum and fluid specialists. Components which were unavailable for various reasons were designed, and machined in-house by the departmental workshop. Initial test depositions were conducted using small stainless steel disk substrates, heated using a resistive heater similar to the one utilised on the research scale system. The test depositions were performed with the heater and substrate combination placed in strategic locations. This is to test the overall uniformity of precursor flux in the chamber volume. The resulting coating uniformity on the disk surfaces were fair but problems such as the large collection of unreacted precursor on the chamber viewport and valve timing issues had to be addressed. Before making any improvements to the system, each of the process areas leading to a successful deposition needed to be understood. Five process areas were developed: ‘Liquid Delivery’, ‘Atomization’, ‘Evaporation’, ‘Transport and Reactor Geometry’, and ‘Droplet Management’. Each of the process areas were analysed individually and changes were made to push for a maximum evaporation efficiency. xviii The improved system provided opportunities to perform depositions that were once not possible for PP-MOCVD. Two sets of deposition tests were designed and conducted. Firstly, the improvements were justified with a series of depositions using flat stainless steel plates with dimensions 65x65x5mm. The other set of 3D case study depositions involve observing the effects of the operational parameters of PP-MOCVD on the uniformity and penetration depths of the coatings into different sized macro blind trenches. Five geometric setup conditions were used to justify the improvements made to the system. These are: ‘Substrate positioned in the direct line of spray’, ‘Use of an unheated receptor’, ‘Use of a heated receptor’, ‘Use of an unheated receptor with a non-axial substrate setup’, and “Choked Flow’. As expected, the uniformity of the coatings on both sides of the plate varied significantly when the substrate is placed over the line of sight of the precursor spray. Similarly, the coating produced under the induced choked flow condition resulted in low conformality. The introduction of an unheated receptor plate resulted in an increase in uniformity on both sides of the plate. Further prove that PP-MOCVD is geometry independent is provided by the deposition made with the non-axial substrate placement resulting in a coating of similar result to the unheated receptor. The use of a heated receptor provided a source for a secondary evaporation of the larger precursor droplets collected resulting in an increase in coating thickness while maintaining good conformality. The effects of temperature, pressure, injection volume, and concentration were explored in the final case study. With maximum depths of 50mm, the macro blind trenches has an aspect ratio of 1:1 and cross-sectional areas of 3x3mm, 9x9mm, and 15x15mm. The final results show that as the temperature rises, the depth penetrated into the trench decreases. This could be due to the change in rate limiting steps as homogeneous reactions begin to increase at higher temperatures. Similar trends were observed with increasing pressure. As the pressure difference between the volume of the trenches and the rest of the chamber decreases, the push needed to xix force the precursor down the trench also decreases, resulting in less depth penetration. The effects of injection volume and concentration observed, can be explained by how much precursor molecules are present during one pulse cycle. The more that is available at any given time, the more likely a reaction will occur and deeper the penetration will get. Of course a ceiling or a limit exists where the molecules in the chamber will get evacuated without being reacted. The future work made possible as a result of the scaled up system are proposed. These include a scale up of the operational parameters to suit any given substrate geometry, improvements to the heating source to achieve greater thermal uniformity, further improvements to the overall system accessibility, and performing other depositions using different substrate materials and precursor types.
117

Génération in situ de dioxyde de titane par réactions d’hydrolysecondensations dans une matrice polymère fondu / In situ synthesis of titanium dioxide by hydrolysis-condensation reactions in molten polypropylene matrix

Bahloul, Walid 20 July 2010 (has links)
L’objectif de ce travail est de générer in situ des particules de dioxyde de titane dans une matrice polypropylène fondu au cours du procédé d’extrusion. La synthèse est basée sur des réactions d’hydrolyse-condensations d’un alkoxyde de titane (le n-tétrabutoxyde de titane). Une approche en milieu modèle a tout d’abord été développée offrant l’avantage de pouvoir travailler en milieu liquide sans prendre en compte de la viscosité du PP ni des effets de cisaillement. En se basant sur les données cinétiques déterminées en milieu modèle, la génération de ces particules de dioxyde titane a été ensuite transposée et modélisée dans le milieu polymère de masse molaire plus élevée. Les analyses chimique, structurale et morphologique ont permis de mettre au point l’élaboration in situ de nanocomposites PP/TiO2 présentant unestructure fractale avec des propriétés viscoélastiques particulières. Enfin l’étude des propriétés bactérienne de ce nanocomposite a mis en avant son pouvoir bactéricide (6Log) pour un taux de charge de 9 % massique. / Polypropylene/Titanium dioxide (PP/TiO2) nanocomposites were prepared from an original method based on the hydrolysis-condensation reactions of titanium alkoxide inorganic precursor premixed with PP under molten conditions. The synthesis is based on sol-gel method without solvent through extrusion process. A second treatment in hot water was applied in order to improve final conversion degree. First, hydrolysis-condensation reactions of titanium n-butoxide precursor were studied in model medium. Based on a kinetic equation carried out in the model medium, then the synthesis of titanium dioxide particles was transposed and modelled in polypropylene medium with high molar mass. Chemical, structural and morphological analyses highlight the in situ synthesis of bactericides PP/TiO2 nanocomposites andpresenting a particular morphological and rheological behaviour.
118

Which agile methodology suits you? By applying the results on a multi-disciplinary project in a small company

Saadatmand, Fatemeh January 2013 (has links)
Choosing the Software Development Methodology is the very first step of any project; thus,has been a hot topic among, both, practitioners and academic people. After using plandrivensoftware development methodologies software development researchers came up withthe idea of agile software development methodologies as a masterpiece. Although, failurestories of some teams brought about fading the idea that agile methodologies are thebest recipe for any kind of development project. Considering the lack of studies in helpingpractitioners to select the most appropriate agile software methodology, this study aims atprovide the software development manager with a thorough knowledge of agile methodologiesand the criteria that should be considered, while selecting one of them. A case study is used asan empirical support. / Program: Magisterutbildning i informatik
119

Bergsmänniskans dilemma : Hållbarhetsstudie av skalplagg

AEJMELAEUS-LINDSTRÖM, FELIX January 2014 (has links)
Vid extrema bergsaktiviteter som klättring och skidåkning ställs stora krav på utrustningen. Den här studien har fokuserat på skalplagg för alpin miljö. Skalplaggens huvuduppgift är att skydda mot vind och fukt samtidigt som de skall transportera fukt från insidan till utsidan. För att kunna designa och utveckla bästa möjliga skalplagg krävs det kunskap om vilken miljö produkten/plagget ska användas i, vem som ska använda det, hur mycket ska plagget användas, i kombination med vilka andra produkter/plagg och vilken kunskap har användaren? Det är också viktigt att förstå vilka materialkrav som ställs på produkten. Det leder till vikten att även förstå materialens egenskaper, vad det minsta, alternativt största mängden av en viss komponent som krävs för att produkten ska leva upp till de ställda kraven. Kunskap om kraven och funktionerna bakom mekanismerna som uppfyller kraven leder till en möjlighet att optimera plaggets funktion och miljöpåverkan. I denna studie har kunskaper inom textilteknik, fysiologi, termodynamik, kemisk dynamik och teknisk byggteknik kombinerats för att härleda och undersöka kraven på maximalt ånggenomsläpplighetsmotstånd beroende på grad av fysisk aktivitet. Resultatet visar tydligt att det maximala ånggenomsläpplighetmotståndet som accepteras vid en given intensitet sjunker med en avtagande temperatur. Detta beror på att fuktgradienten ökar med en avtagande temperatur, under premissen att temperaturen och fukthalten innanför membranet hålls konstant. / Program: Textilingenjörsutbildningen
120

Tomographie des temps d'arrivée au-delà de la théorie des rayons

Montelli, Raffaella 16 December 2003 (has links) (PDF)
La théorie de la diffraction prévoit que les temps de trajet des ondes avec une fréquence dominante finie sont affectés seulement par des hétérogénéités dans un volume autour du rayon obtenu par la théorie asymptotique fréquence infinie. Ce volume s'appelle la zone de Fresnel. A cause de la diffraction qui assure la continuité du front d'onde au travers des hétérogénéités, les hétérogénéités de taille inférieure à celle de la zone de Fresnel n'ont qu'un effet réduit sur le temps de trajet de l'onde arrivant à une station. Dahlen et al (2000) montrent qu'il est possible decorriger des effets de cette diffraction par une méthode de tomographie volumique qui introduit de nouveau la notion de contenu fréquentiel dans l'estimation des temps de trajet et donc dans la reconstruction du milieu. Dans cette thèse, j'étudie l'influence de cette technique d'imagerie à fréquence finie en tomographie globale sismologique des temps d'arrivée. Pour réduire les effets du à la distribution des rayons dans la Terre,distribution qui n'est pas uniformej j'introduis un maillage non-structuré pour représenter les vitesses dans la Terre. Pour définir l'influence des phénomènes de diffraction dans les résultats tomographiques, j'utilise un nombre limité de données à longue période de très haute qualité obtenues par Guy Masters (Scripps). Je fais l'inversion en utilisant l'approche classique de tomographie des temps se fondant sur la théorie des rayons et l'approche nouvelle de tomographie des temps en se fondant sur l'approche à fréquence finie. La comparaison des deux tomographies montre que les anomalies de vitesse sont sous-estimées par la théorie des rayons d'un facteur 30-60% en fonction de la profondeur. C'est bien le signe que la théorie des rayons est une approximation trop grossière pour les données à basse fréquence que l'on utilise. Pour augmenter la résolution de mon modèle tomographique, j'inverse conjointement les données à longue période déjà mentionnées avec des données haute fréquence retraitées par Bob Engdahl (Boulder). L'analyse de la compatibilité des deux bases de données est nécessaire avant de procéder à l'inversion conjointe. L'étude des temps eux-même (en fait, des écarts dans un modèle de référence) et les inversions des deux jeux de données independament montrent un très bon niveau de compatibilité. Tous les modèles obtenus montrent une très forte corrélation entre les anomalies de basse vitesse ct la position d'un très grand nombre de points chauds déjà connus. Pour estimer la validité de ces anomalies, des tests de résolution ont été réalisés de façon à identifier la profondeur des panaches. A la suite de ces tests, on peut conclure positivement que des panaches profonds se trouvent au-dessous des structures suivantes: Ascension, Açores, Canaries, Easter, Hawai, Samoa et Tahiti. Pour d'autres, l'origine profonde n'est pas confirmée et une origine plus superficielle est probable autour de 660 km comme la zone islandaise. D'autres n'ont jamais été vus avant comme au Seychelles et dans l'Ocean Indien. Enfin, dans la zone de la Mer de Coral et au Sud de Java, la tomographie a détecté des panaches montant de la frontière entre le noyau ct le manteau mais qui n'arrivent pas encore à la surface.

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