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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.
371

Ácaros na cultura de soja: genótipos, danos e tamanho de amostra / Spider mites on soybean: genotypes, damage and sample size

Fiorin, Rubens Alex 29 August 2014 (has links)
The study aimed to evaluate the influence of soybeans genotypes on spider mites populations, quantify the occurring damage from spider mite attack and determinate leaflet number collected from different genotypes to estimate the spider mite population. Two studies were carried, in São Sepé (20 genotypes) and in Santa Maria (25 genotypes). The experiments were carried in randomized block design with four replications in 4,5 and 5,0 x 25 m experimental units. Weekly samplings were carried collecting 25 leaflets from the medium stratum and 25 leaflets from the superior soybean plant stratum in each genotype and evaluated an area of 20 cm2 of each leaflet. To determinate the sample size was used the data from evaluations which at least one genotype presented average population superior to one spider mite cm-2. To estimate spider mite number was considered the number of immature + adults spider mites, averages were compared with t bootstrap test. Sample size was estimated for an amplitude of 2 and 4 spider mites 20cm-2 and the optimal sample size calculus. To quantify spider mite damage in each genotype was maintained infested plots and not infested plots by pulverizations of acaricide. The predominant specie was Mononychellus planki. Population of spider mites vary in different genotypes and concentrates on the plant superior stratum. The necessary sample size is crescent as population grows, at the beginning of the infestation, 50 leaflets are enough with CIA95% (confidence interval amplitude with 1-p=0,95) maximum equal to 2 spider mites 20cm-2. To quantify higher populations 150 leaflets is necessary with CIA95% maximum equal to 4 spider mites 20cm-2. Yield variation as response to spider mite populations attack depend on the studied genotype and to all genotypes there is difference between the infested and not-infested plots. Average damage on Santa Maria experiment was 493 kg ha-1 and São Sepé 427 kg ha-1 and average gain of 33,4%. / Este trabalho teve por objetivo avaliar a influência de genótipos de soja na população de ácaros, quantificar os danos decorrentes do ataque de ácaros e determinar o número de folíolos a serem coletados em diferentes genótipos para a quantificação de sua população. Para isto, foram realizados dois experimentos localizados nos municípios de São Sepé (20 genótipos) e Santa Maria (25 genótipos). Os experimentos foram conduzidos no delineamento blocos ao acaso, com quatro repetições em parcelas de 4,5 e 5,0 x 25 m. Foram realizadas amostragens semanais através da coleta de 25 folíolos do extrato médio e 25 do extrato superior das plantas em cada genótipo, avaliando uma área de 20 cm2 por folíolo. Para a determinação do tamanho de amostra foram utilizados os dados das avaliações em que pelo menos um genótipo apresentou população média superior a um ácaro.cm-². Para o número de ácaros, utilizou-se os valores de imaturos + adultos, comparando as médias dos genótipos pelo teste t bootstrap. Foi estimado o tamanho de amostra para amplitudes de 2 e 4 ácaros 20cm-2 e realizado o cálculo do tamanho ótimo de amostra. Para quantificação dos danos dos ácaros manteve-se, em cada genótipo, parcelas infestadas e sem infestação, através de aplicação de acaricidas. A espécie predominante foi Mononychellus planki. A população de ácaros é diferente em função do genótipo e concentra-se na parte superior das plantas. O tamanho de amostras necessário é crescente em função do incremento da população de ácaros, no início das infestações 50 folíolos suficientes com AIC95% (amplitude do intervalo de confiança com 1-p=0,95) máxima igual a 2 ácaros 20cm-2. Para quantificação de populações mais elevadas são necessários 150 folíolos com AIC95% máxima igual a 4 ácaros 20cm-2. A variação no rendimento de grãos pelo ataque de ácaros depende do genótipo avaliado e, comparando a área controlada com a não controlada, há diferença para todos os genótipos. O dano médio no experimento de Santa Maria foi de 493 kg ha-1 e no de São Sepé 427 kg ha-1, com ganho médio de 33,4%.
372

Odpovědnost za škodu při pracovních úrazech a nemocech z povolání / Liability for damage regarding occupational accidents and illness

Lachnit, Ondřej January 2011 (has links)
Ondřej Lachnit Liability for Damage Regarding Occupational Accidents and Illness The following thesis deals with the issue of liability for damage regarding occupational accidents and illness in the Czech Republic. At the present time, employer's liability conforms to the Labour Code from 2006, which builds on the preceding Labour Code from the year 1965. A rich judicature concerning occupational accidents and illness has been formed since the 1960s. In this thesis, I often quote from this judicature. The current Labour Code, however, only provisionally deals with this issue; an ensuing change is about to take place due to the passing of a new law concerning the workers' compensation insurance. This law is already valid, but has yet to become operative. The law will come into effect on January 1st, 2013. Whether the law will become operative is questionable as its legal effect depends on the political situation in the Czech Republic. Currently, the right-wing government does not favour the new law, since it would burden the state budget more than the current system. In the Czech Republic, the employer's liability for damage regarding occupational accidents is defined very broadly:...
373

Régulation de l’arrêt du cycle cellulaire en réponse à l’exposition UV : implications du facteur de transcription USF1 dans le contrôle de la disponibilité de la protéine p53 / Cell cycle arrest regulation in response to UV exposure : implications of USF1 transcription factor in the control of p53 availability

Bouafia, Amine 27 March 2014 (has links)
L'exposition aux ultraviolets solaires constitue un facteur de risque majeur dans le développement de cancers cutanés. L'initiation de ces cancers est cependant pondérée par des mécanismes cellulaires de protection qui contrecarrent l'instabilité génomique éventuellement promue par les UV. Dans ces mécanismes, le suppresseur de tumeur p53 joue un rôle fondamental en régulant l'expression de nombreux gènes permettant de bloquer le cycle cellulaire et de réparer l'ADN ou, si les dommages cellulaires sont trop importants, d'activer l'apoptose. Les régulateurs de la stabilité de la protéine p53 en réponse au stress UV sont ainsi capitaux pour assurer la stabilité du génome. En réponse au stress UV in vivo et in vitro, nous mettons en évidence que le facteur de transcription USF1 est primordial à l'activation du programme génétique contrôlé par la protéine p53. Nos données convergent vers un modèle dans lequel USF1 agit sur la voie p53 par deux moyens. D'une part, USF1, assure par interaction physique la stabilité de p53 en contrecarrant de manière mutuellement exclusive l'association du suppresseur de tumeur à MDM2 son inhibiteur physiologique. D'autre part, USF1 agit synergiquement avec le suppresseur de tumeur pour transcrire certains gènes cibles de p53 comme le régulateur du cycle cellulaire CDKN1A (p21). Ces deux niveaux de régulation dépendent étroitement du niveau de stress et permettent d'assurer un contrôle optimal de l'arrêt du cycle cellulaire en réponse à l'exposition UV. Collectivement, nos données montrent qu'USF1, par le contrôle de la voie p53, est un facteur essentiel contre l'instabilité génomique induite par les UV. / Ultraviolets (UV) solar exposure is a critical risk factor in skin cancers development. Initiation of these cancers is however lowered by cellular protective mechanisms that counteract the genomic instability potentially promoted by UV. In these mechanisms p53 protein is critical in regulating a large number of genes that blocks the cell cycle to allow DNA repair or, if damages are beyond repair, to activate apoptosis. The regulators of p53 stability in response to UV are thus crucial to ensure genomic stability. In response to UV stress, we found by in vivo and in vitro studies that USF1 is essential in the activation of p53 genetic program. Our data converge to a model whereby USF1 acts on p53 pathway by two means. On one hand, USF1 stabilizes p53 from MDM2 mediated degradation by a physical association to the tumor suppressor in a MDM2 mutually exclusive manner. On the other hand USF1 synergizes with the tumor suppressor in the transcription of several targets of p53 protein and particularly the CDKN1A inhibitor of the cell cycle. These two levels of regulation are closely dependent in the stress level and ensure an optimal control of the cell cycle progression in response to UV. Collectively, our results show that USF1, by controlling p53 pathway, is a critical factor against the genomic instability promoted by UV.
374

Comparação entre métodos de inspeção não-destrutiva aplicados a peças compósitas laminadas sólidas estruturais aeronáuticas / Comparing nondestructive inspection methods applied to aeronautical grade solid structural composite laminated parts

Marcos Miranda 27 June 2011 (has links)
Diversos métodos de ensaios não-destrutivos (Ultrasom, Radiografia, Termografia e Shearografia) foram empregados na inspeção de peças laminadas estruturais compósitas sólidas de matriz polimérica manufaturadas pela indústria aeronáutica. Concluiu-se que Ultrasom pulso-eco convencional de contato foi a técnica mais abrangente na indicação de descontinuidades (danos/defeitos de manufatura) considerando-se peças planas e curvas, não obstante tenha falhado na detecção de trincas longas e bem definidas localizada na alma de componentes co-curados. Radiografia convencional por filmes exibiu um potencial interessante como método alternativo, ou complementar ao de Ultrasom. Termografia infravermelha foi a técnica mais veloz na indicação de descontinuidades, sendo uma valiosa alternativa para um mapeamento rápido em inspeções preliminares seguidas pela aplicação de técnicas complementares. Shearografia realizada com equipamento da empresa Photonita detectou inclusões em peça plana compósita, porém a interpretação dos resultados obtidos em geometrias mais complexas se mostrou duvidosa. O uso de equipamento shearográfico da empresa Dantec indicou posições em regiões curvas que podem estar associadas à presença de defeitos/danos locais, porém uma confirmação cabal desta relação não foi efetivada. Evidências visuais da profusa presença de danos/defeitos de manufatura, além da existência de detalhes construtivos nas peças compósitas mais complexas, sugerem que estas descontinuidades podem ter sensibilizado, em maior ou menor extensão, os equipamentos END, juntamente com a eventual presença de delaminações/falhas de adesão nas respectivas peças avaliadas. / Several nondestructive methods (Ultrasonics, Radiography, Thermography and Shearography) were employed for inspection of structural polymer matrix composite laminated parts manufactured by aircraft industry. Is has been concluded that conventional pulse-echo contact Ultrasonics was the most comprehensive technique to indicate discontinuities (manufacture damages/defects) in flat and curved parts, although it has failed to detect long and well-defined cracks in co-cured components. Conventional film radiography exhibited good potential as alternative or complementary method to Ultrasonics. Infrared thermography was the fastest technique to indicate discontinuities, so that it is a valuable option for rapid mapping in preliminary inspection followed by the application of complementary techniques. Sherography by means of Photonita equipment detected inclusions in flat panels, but the interpretation of results from pieces with more complex geometries was dubious. A shearographic of the Dantec device indicated positions in curved regions which might possibly be associated to the presence of damages/defects, however this relationship could not be definitively established. Visual evidences of the profuse existence of manufacture damages/defects, besides constructive details in more complex composite parts, suggest that theses discontinuities might have affected to some extent the NDT equipments, along with the eventual presence of delaminations/lack of adhesion on the respective evaluated parts.
375

Élaboration et comparaison de deux modèles de durée de vie des fils d’interconnexion des modules de puissance, l’un basé sur les déformations et l’autre sur les dégradations / Establishment and comparison of two lifetime model dedicated to wire bonds damage in power modules, with an approach based on deformation and an approach based on degradation

Dornic, Nausicaa 31 October 2019 (has links)
Dans de nombreux domaines, tels que l’industrie des transports ou bien des infrastructures, la tendance est à l’introduction toujours plus importante d’équipements électriques. De ce fait, les industriels sont de plus en plus confrontés à la nécessité de fournir des dispositifs robustes et fiables avec un minimum de maintenance. Les composants électroniques, tels que les transistors IGBTs ou MOSFETs et les diodes rassemblés dans des modules de puissance, sont au cœur de la conversion d'énergie électrique. En conséquence, ils sont soumis en opération à de fortes contraintes environnementales et fonctionnelles (température, humidité…). L’ensemble de ces contraintes a un impact sur la durée de vie des composants, et donc sur la fiabilité des dispositifs. D’un point de vue économique, le remplacement d’un équipement défectueux est moins pénalisant qu’une défaillance brutale du système. Ainsi, l’utilisation d’outils de diagnostic est nécessaire pour prédire la durée de vie restante des dispositifs en opération, et mettre en place une maintenance adaptée et efficace.Pour déterminer la durée de vie restante des modules de puissance en opération, des modèles de durée de vie sont utilisés. La plupart de ces modèles sont établis soit de manière empirique, soit de manière physique, soit de manière statistique. Les modèles empiriques sont les plus courants, car leur réalisation et implémentation sont maintenant bien connues. Ils se basent sur des résultats issus de tests de cyclage accélérés qui reproduisent les contraintes endurées par le module de puissance sous des conditions "accélérées" de fonctionnement. Une extrapolation est ensuite nécessaire pour obtenir l’état de santé du dispositif dans des conditions normales de fonctionnement. Le principal inconvénient de ces modèles réside dans le manque de description des mécanismes physiques responsables de l’endommagement. Ce manque peut mener potentiellement à des erreurs, notamment lors de l’extrapolation. C’est pourquoi les modèles basés sur la physique connaissent un intérêt grandissant.Dans cette thèse, deux modèles de durée de vie basés sur la physique et appliqués aux modules de puissance IGBTs sont proposés et comparés. La première approche est basée sur les déformations induites à l’intérieur de l’assemblage du module lorsque soumis à des contraintes thermiques. Dans ce cas, la dégradation est décrite via la quantification des déformations pour un stress thermique donné. Dans la seconde approche, le modèle de durée de vie est basé directement sur l’endommagement via l’établissement d’un modèle de dégradation. La comparaison des deux modèles met en lumière les défauts et qualités de chacun. D’une manière plus générale, l’établissement et la comparaison de ces modèles s’inscrit dans une démarche de développement d’outils de diagnostic afin de prédire la durée de vie restante des modules de puissance en opération. / The domain of power electronics reliability has become an important center of interest with the recent massive system electrification. The manufacturers are more and more confronted to the necessity of producing reliable devices with optimized maintenance. Electronics components, such as IGBTs, diodes and MOSFETs assembled in power modules, are at the center of the systems conversion, and as a consequence, are subjected to high environmental and functional stresses (ambient temperature, vibrations…). All these factors have a strong impact on the components lifetime and thus on the devices reliability. Economically, scheduling a maintenance with a system replacement is less detrimental than a brutal failure of the system. As a consequence, the use of lifetime prognostic tools is necessary. The problematic consists in the health state prediction of power modules in functioning to be able to schedule a maintenance before the failure of the equipment.To be able to determine the remaining useful lifetime of power modules in functioning, lifetime models are used. These models can either be empirical, physical or statistical. The empirical models are the most common ones, because of their easy establishment and implementation. They are based on results from accelerated power cycling tests, which reproduce the stresses endured by the power modules in severe conditions. An extrapolation is then needed to obtain the power module health state in normal functioning conditions. The main drawback of these models is the lack of description of the physical mechanisms leading to damage, resulting potentially in errors in particular during extrapolation. That’s the reason why physical models start to draw more attention.In the thesis, two physical lifetime models of IGBT power modules are proposed. The first approach is based on deformation induced inside the device assembly in operation. The degradation is in this case described by the quantification of deformation related to thermal stresses. In the second approach, the lifetime model is based directly on damage through the establishment of a degradation model. These two lifetime models are finally compared to show the benefits and disadvantages of each. More generally, the establishment and comparison of these models is part of an approach to develop diagnostic tools so that the remaining useful lifetime of power modules can be predicted in operation.
376

A forecasting approach to estimating cartel damages : The importance of considering estimation uncertainty

Prohorenko, Didrik January 2020 (has links)
In this study, I consider the performance of simple forecast models frequently applied in counterfactual analysis when the information at hand is limited. Furthermore, I discuss the robustness of the standard t-test commonly used to statistically detect cartels. I empirically verify that the standard t-statistics encompasses parameter estimation uncertainty when one of the time series in a two-sided t-test has been estimated. Thereafter, I compare the results with those from a corrected t-test, recently proposed, where the uncertainty has been accounted for. The results from the study show that a simple OLS-model can be used to detect a cartel and to compute a counterfactual price when data is limited, at least as long as the price overcharge inflicted by the cartel members is relatively large. Yet, the level of accuracy may vary and at a point where the data used for estimating the model become relatively limited, the model predictions tend to be inaccurate.
377

Lex Aquilia a římský delikt damnum iniuria datum / Lex Aquilia and delict damnum iniuria datum of roman law

Svátek, Jan January 2020 (has links)
I Lex Aquilia and delict damnum iniuria datum of roman law Abstract The subject of this thesis is the Lex Aquilia and the delict of unlawfully caused damage (damnum iniuria datum) contained in this law. The aim of the thesis is a comprehensive analysis of the Lex Aquilia as one of the most important Roman laws and the introduction of damnum iniuria datum contained in it as a universal delict for cases of damage claims in a wide range of cases of killing animals or slaves, cases of damaged things or complete destruction of property. The first part of the thesis serves as an explanation of key concepts from a general point of view, which are necessary to grasp the subject. The concepts of obligation and delictual liability, Roman categorisation of delicts into delicta privata and crimens, and the role of lawsuits (actio) and standing in Roman law are introduced. Furthermore, the sources of the regulation of delict law, primary sources including the Corpus Iuris Civilis, and also various authors most notably Roman lawyer Ulpian, are presented in a brief manner. The aim of the work is achieved in the second part of the thesis by analysis of interrelated institutes, whether they are specific lawsuits of the Lex Aquilia, or introduction of diverse ways of committing this delict by killing (occidere), damaging the...
378

Ekonomická analýza deliktního práva / The Economic Analysis of Tort Law

Sztefek, Martin January 2020 (has links)
The Economic Analysis of Tort Law Abstract In the presented thesis I discuss the economic analysis of tort law. The economic analysis of law can be described as the application of economic theory - primarily microeconomics and the basic concepts of welfare economics - to examine the formation, structure, processes, and economic impact of law and legal institutions. The economic analysis of tort law can help understand the impact of tort liability on individuals' behavior, why some areas of human activity are governed by negligence or strict liability, or why, in some cases, the amout of damages is limited. First two chapters describe the economic approach to law as such, they serve as an introduction into this field of study and present the most important methodological approaches. In the first chapter, I also discuss the basic tendencies that have shaped the economic analysis of law throughout its development. Second chapter then discusses some of the fundamental concepts of the economic analysis of law, namely the assumption of rational action, the concept of transaction costs, the efficiency criterion, the importance of the Coase theorem, and the distinction between property rules and liability rules. Following the examination of the concept of economic efficiency, an alternative approach based on the...
379

Odškodnění pozůstalých při pracovních úrazech a nemocech z povolání / Compensation for the bereaved in the case of work accidents and occupational diseases

Pivničková, Kateřina January 2019 (has links)
Compensation for the bereaved in the case of work accidents and occupational diseases Abstract The topic of my diploma thesis is compensation for the bereaved in the case of work accidents and occupational diseases. It is a topic with a relatively settled legislation and a subject which is present - nevertheless, ground-breaking changes in this issue cannot be really anticipated any more. Introductory part of my thesis deals primarily with a theoretical definition of a term liability and liability in labor law. It deals with the conditions of inception of liability, the reasons that allow release from liability and finally, with the obligation of an employer to compensate damages or non-material damage in the cases of work accidents and occupational diseases. I also devote myself to define terms work accident and occupational disease, and for better understanding and explanation of disputable questions, I refer to judicature of the Supreme Court and the Constitutional Court. The mainstay of my thesis is dedicated to the particular types of compensation provided either directly to the aggrieved employees as the consequence of work accident or occupational disease, or to the bereaved in the case of death due to the work accident or occupational disease. I also compare the labor law regulation to the...
380

En vänlig grönskas rika dräkt : En undersökning av tillgänglig rönn, asp, sälg och ek efter röjning / The rich costume of a friendly green : a study of available rowan/mountain ash, aspen, sallow and oak after pre-commercial thinning

Hjälte, Kenny, Larsson, Björn January 2020 (has links)
Röjningsinstruktioner och virkesinköpare anser att rönn, asp, sälg/salix och ek (RASE) ska sparas i ungskogsröjningar för att det ska finnas annat foder åt skogslevande vilt än produktionsskog. Dessutom är ett vanligt råd till skogsägare av virkesköparna att satsa på foderskapande åtgärder för att avleda hjortdjuren. Undersökningen av ungskogsröjning visar dock att teori och praktik inte går ihop, där få stammar av RASE sparas och det är troligare att björk sparas. Enstaka RASE kan sparas i lucka där de inte kan konkurrera med en huvudstam av det planterade trädslaget. En alternativ skogsskötsel, som Öster Malma-modellen, ser blandskog som en mer ekonomiskt stabilt skogsbestånd och det bidrar samtidigt med mer lövskog än traditionell skötsel som sköter bestånd utifrån monokulturer. Forskning har även visat att foderkonkurrens mellan hjortdjuren kan göra att älg betar mer tall än bärris. En kunskapsbaserad viltförvaltning som omfamnar fler arter än en skulle kunna vara en del av lösningen.

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