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Determinants and consequences of intra-year error in annual effective tax rate estimatesDong, Qi 08 April 2016 (has links)
This paper investigates the determinants of intra-year error in annual effective tax
rate estimates, relative to the actual annual effective tax rate (“ETR Miss”) and examines whether ETR Miss contains value relevant information. I find that ETR Miss is affected by both unbiased estimation errors related to the predictability of business fundamentals and biased estimation related to varying managerial incentives within the year. Firms with higher ETR Miss exhibit less persistent pre-tax earnings and earnings components, consistent with ETR Miss containing information on earnings quality. Finally, for firms with higher ETR Miss, investors place a lower weight on accounting earnings, consistent with the market incorporating information in ETR Miss for valuation assessments.
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Vliv různých způsobů obhospodařování na travní porosty / Effect of different management practices on grasslandSEJPKOVÁ, Jana January 2014 (has links)
The aim of this thesis is to assess the impact of farming on grassland and assess the frequency of use of grassland on yield and quality of forage biomass. A part of this thesis is also a recommendation of possible management changes of evaluated grasslands. Botanical inventory surveys were conducted on agricultural lands Bílovské zemědělské a.s., in the northern Plzeň region. There have been selected three sites, two meadows and one pasture vegetation. The comprehensive analysis of the stand composition was created by agrotechnology of meadows. An important part of this thesis is to assess the impact of different grassland management practices with regard to their economic, social and ecological importance.
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Vliv vodního režimu na vybrané travní energetické druhy (suchovzdornost) ovsík vyvýšený (Arrhenatherum elatius), sveřep horský (Bromus carharticus) a bojínek luční (Phleum pratense) / Influence of water regime on growth and quality of selected grass speciesBÁRTA, Ondřej January 2014 (has links)
This thesis describes the importance and use of permanent grasslands, or more so-called energy grasses used in the energy sector. For our study we examined these three grasses: Ovsík vyvýšený (Arrhenatherum elatius), Sveřep horský (Bromus carharticus) and Bojínek luční (Phleum pratense). Another, the main task was to determine their resistance to drought. The results based on laboratory work, which between them compared the two variants. One was simulated normal emergence of the species and the second emergence stressed by lack of water. Based on these results, we conclude that we can not say that it would be a downright drought-resistant types. For the two studied species of grasses (Bojínek and Ovsík) are obvious differences in resistance to drought. Sveřep horský (variety - Tacit), however, proved to be the most drought-resistant species. While most sprouted out bojínek luční (variety - Sobol).
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Estudo das propriedades magnéticas e da microestrutura em imãs permanentes à base de Pr-Fe-B-Co-Nd obtidos pelos processos HD e HDDR / Microstructure and magnetic properties of Pr-Fe-B-Co-Nb sintered magnets produced from HD and HDDR powderFERREIRA, ELINER A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:50Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:59Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
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Contribuição ao modelamento e simulação de motores com imãs permanentes e comutação eletrônica de alta rotaçãoSILVA, WANDERLEI M. da 09 October 2014 (has links)
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12437.pdf: 4743815 bytes, checksum: 224eec9c107091a47a85eb64ff2540c5 (MD5) / Dissertacao (Mestrado) / IPEN/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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Estudo das propriedades magnéticas e da microestrutura em imãs permanentes à base de Pr-Fe-B-Co-Nd obtidos pelos processos HD e HDDR / Microstructure and magnetic properties of Pr-Fe-B-Co-Nb sintered magnets produced from HD and HDDR powderFERREIRA, ELINER A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:50Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:59Z (GMT). No. of bitstreams: 0 / Ímãs sinterizados foram produzidos utilizando o pó obtido pelo processo de Hidrogenação, Desproporção, Dessorção e Recombinação (Processo HDDR). O processo HDDR na produção de ímãs sinterizados foi adotado visando uma redução no tempo de moagem e investigar seu efeito nas propriedades magnéticas e na microestrutura. As ligas utilizadas nesse trabalho apresentaram a seguinte composição: Pr14FebalCoxB6Nb0,1 (x= 0; 4; 8; 10; 12; 16) e Pr20,5Fe72,5B5Cu2,0 (utilizada como aditivo de sinterização). O pó HDDR foi utilizado para produzir ímãs sinterizados com uma mistura dessas ligas (liga principal + aditivo), nas seguintes proporções: 80 % em peso da liga principal e 20% em peso do aditivo de sinterização (Pr20,5Fe72,5B5Cu2,0). O processo de decrepitação por hidrogênio (Processo HD) na produção de ímãs também foi utilizado nesse trabalho para efeito de comparação (tempos de moagem: 20, 15, 10 e 5 horas). A temperatura e o tempo de sinterização foram mantidos constantes para todos os ímãs (1050 º C por 60 minutos). O ímã sinterizado produzido pelo processo HD apresentou melhor remanência (1220 mT).Esse ímã foi fabricado com a liga Pr14Fe75,9B6Co4Nb0,1 utilizando um tempo de 20 horas de moagem. A melhor coercividade intrínseca foi obtida com a liga Pr14Fe75,9B6Co4Nb0,1 em ambos os processos, de 1020 mT para o processo D (5 horas de moagem) e de 1190 mT para o processo HD (20 horas de moagem). As microestruturas dos ímãs permanentes foram analisadas por microscopia eletrônica de varredura (MEV) e por dispersão de energia de raios-X (EDS). / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
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Contribuição ao modelamento e simulação de motores com imãs permanentes e comutação eletrônica de alta rotaçãoSILVA, WANDERLEI M. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:14Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:14Z (GMT). No. of bitstreams: 1
12437.pdf: 4743815 bytes, checksum: 224eec9c107091a47a85eb64ff2540c5 (MD5) / Dissertacao (Mestrado) / IPEN/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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Análise do custo de materiais utilizados em restaurações dentárias posteriores diretas em resina composta / Cost analysis of materials used in composite resin direct posterior dental restorationsTrentin, Élcio Ferreira, 1967- 18 August 2018 (has links)
Orientador: Eduardo Hebling / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T23:12:40Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: O custo dos materiais faz parte do cálculo do valor dos honorários odontológicos. As resinas compostas são materiais usualmente utilizados em restaurações dentárias diretas de dentes posteriores. O objetivo desse trabalho foi determinar o valor total do custo dos materiais diretos e indiretos utilizados em restaurações de dentes posteriores em resina composta. O cálculo dos custos foi baseado no método de sistema de custeio variável. As repetições foram obtidas de preparos classes I e II em dentes pré-molares e molares artificiais. A lista dos materiais foi obtida por meio de consulta a uma banca de juízes e baseada nos padrões de excelência comprovados na literatura. Os valores dos materiais foram obtidos de uma média dos valores consultados no mercado fornecedor. Os materiais foram quantificados para cada tipo de preparo com uso de balança de precisão. Os dados foram avaliados por estatística descritiva e pelos testes de Mann-Whitney e Kruskal-Wallis. A análise foi feita para os materiais utilizados em biossegurança (Capítulo 1) e para a realização da restauração (Capítulo 2). O custo encontrado para a biossegurança foi de R$ 8,85. Para os demais materiais para restauração de Classe I foi de R$ 8,69 e para a de Classe II de R$ 8,86. Não houve diferença estatística no custo entre os tipos de preparos para restauração, sendo a média total dos materiais de R$ 17,63. Os valores encontrados podem ser utilizados no cálculo do valor final do procedimento restaurador, auxiliando na gestão de serviços odontológicos públicos ou privados / Abstract: The cost of the materials is part of the calculation of the value of dental fees. The composite resins are materials commonly used in direct posterior dental restorations. The aim of this study was to determine the total value of the cost of the direct and indirect materials used in composite resin posterior dental restorations. The calculation of costs was based on the method of variable costing system. The repetitions were obtained from classes I and II cavities in artificial premolars and molars teeth. A list of the materials was obtained by an experts panel and based on the excellence standards established in the literature. The values of the materials were obtained from an average of the values founded in the supplier market. The materials were quantified for each type of cavity with the use of precision balance. The data were assessed by descriptive statistics and by Mann-Whitney and Kruskal-Wallis tests. The analysis was performed for the materials used in biosafety (Chapter 1) and on the restoration (Chapter 2). The founded cost (Brazilian current coin) was R$8.85 for biosafety. The others materials for Class I restorations was R$8.69 and for Class II restorations was R$ 8.86. There was no statistically significant difference in cost between the types of cavities, with an average of total materials of R$ 17.63. These values might be used in the calculation of the final value of the restorative procedure, aiding in the management of public or private dental care services / Mestrado / Mestre em Odontologia em Saúde Coletiva
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Investigation of intrinsic activity of cobalt and iron based Fischer-Tropsch catalysts using transient kinetic methods / Étude de l'activité intrinsèque des catalyseurs Fischer-Tropsch à base de cobalt et de fer par des méthodes cinétiques transitoiresBento Carvalho, Alexandre Antônio 23 November 2017 (has links)
Les travaux exposés dans ce manuscrit portent sur l’étude de l’activité intrinsèque et de la localisation des sites actifs des catalyseurs à base de cobalt et de fer par une combinaison des méthodes cinétiques transitoires telles que le SSITKA, de la caractérisation physico-chimique étendue et des tests catalytiques. La promotion des catalyseurs à base de fer avec des métaux utilisés pour la soudure (Bi et Pb) conduit à une augmentation remarquable de la vitesse de production des oléfines légères avec la possibilité d’effectuer la synthèse Fischer-Tropsch dans des conditions très douces (basse pression) voire pression atmosphérique. Parmi tous les catalyseurs étudiés, les catalyseurs à base de zéolite de type mordenite ont présenté la valeur la plus élevée de la constante de vitesse SSITKA. La localisation des sites actifs de cobalt dans les catalyseurs bifonctionnels à base de zéolite a un impact majeur sur la vitesse de réaction et en particulier sur la sélectivité en hydrocarbures. La proximité entre les sites actifs de cobalt et les sites actifs de Bronsted a été considérée comme un paramètre clef pour obtenir une sélectivité et un rendement plus élevés en hydrocarbures ramifiés. Le SSITKA couplé à des techniques de caractérisation a révélé que le dépôt de carbone et l'agglomération des nanoparticules de cobalt étaient responsables de la désactivation du catalyseur cobalt supporté par la silice. La régénération des catalyseurs sous hydrogène diminue le nombre d'espèces de carbone déposées et libère partiellement les sites les plus actifs d’adsorption dissociative et les sites les plus forts d'adsorption réversible du monoxyde de carbone. / The work exposed in this manuscript concerns the study of the intrinsic activity and localization of active sites in cobalt and iron based catalysts using a combination of transient kinetic methods such as SSITKA, extended physicochemical characterization and catalytic tests under quasi steady state conditions. Promotion of iron catalysts with metals used for soldering (Bi and Pb) results a remarkable increase in the light olefin production rate with the possibility to conduct Fischer-Tropsch synthesis at very mild reaction conditions (low pressure) and even at atmospheric pressure. Transient kinetic experiments showed facilitation of CO dissociation in the presence of promoters by scavenging O atoms from iron carbide. Cobalt catalyst supported by mordenite zeolite presented higher value of SSITKA rate constant. Localization of cobalt active sites in bifunctional cobalt-zeolite catalysts has a major impact on the reaction rate and in particular on the hydrocarbon selectivity. A proximity between the cobalt active site and Bronsted active sites was found to be a key parameter to obtain higher selectivity and yield of isomerized hydrocarbons. SSITKA combined with catalyst characterization revealed that carbon deposition and cobalt nanoparticle agglomeration were responsible for the deactivation of silica supported cobalt catalysts. Catalyst rejuvenation in hydrogen lessened the amounts of deposited carbon species and partially released the most active sites of carbon monoxide dissociative adsorption and stronger sites of carbon monoxide reversible adsorption.
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Modélisation numérique par la méthode des éléments finis des systèmes électrotechniques : recherche du régime permanent / Numerical modeling by finite element method for electrotechnical systems : steady state investigationCaron, Guillaume 05 December 2017 (has links)
Dans le domaine du Génie Électrique, la méthode des éléments finis (MEF) associée à une approche pas à pas dans le temps est la plus simple, la plus précise et la plus robuste des méthodes pour modéliser les champs magnétiques dans des dispositifs électromagnétiques en basse fréquence. Néanmoins, cette méthode peut conduire à des temps de calcul extrêmement importants lorsque la constante de temps du système étudié est relativement petite en comparaison de la durée du régime transitoire. C'est dans ce contexte que s'inscrit ces travaux de thèse intitulés « Modélisation numérique par la méthode des éléments finis des systèmes électrotechniques: recherche du régime permanent ». Dans ce manuscrit, une méthode numérique nommée Waveform Relaxation-Newton Method (WR-NM) a été développée. Celle-ci est basée sur la Waveform Relaxation Method (WRM) à laquelle des conditions de périodicité sont appliquées afin d'imposer le régime permanent directement pour des problèmes électromagnétiques couplés à des équations de circuit. La convergence de cette méthode étant similaire à celle d'une méthode point-fixe, elle a été combinée à la méthode de Newton-Raphson dont la convergence est quadratique. Afin de valider et de tester la robustesse de la WR-NM, plusieurs applications sont présentées dans le manuscrit. Des gains importants en temps de calcul sont signifiés en comparaison à l'approche classique et ce pour une précision de la solution identique. Un dernier exemple concernant la modélisation d'une machine à griffes couplés à un pont redresseur montre que la WR-NM peut également être employé dans un cadre industriel. / In electrical engineering, the Finite Element Method (FEM) associated to the time stepping numerical scheme is the most used approach today. This method is simple, accurate and efficient to modeling magnetic fields in low frequency electromagnetic devices. Nevertheless according to the studied cases, the time constant of the device can lead to prohibitive computation time to obtain the steady state. It is in this context that this PhD thesis is written "Numerical modeling by finite element method for electrotechnical systems: steady state investigation". The Waveform Relaxation-Newton Method (WR-NM) was developed, this method is based on the waveform relaxation method (WRM) in which periodicity conditions are applied to impose the steady state for electromagnetic problems coupled to circuit equations. The convergence of this method is similar to a fixed-point method, thus the method is combined to the method of Newton-Raphson whose convergence is quadratic. In order to validate and test the robustness of WR-NM, several applications are presented in the manuscript. Significant gains in computation time are shown in comparison with the conventional approach and for the same precision of the solution. A final example on the modeling of a claw-pole machine coupled to a bridge rectifier shows that the WR-NM can also be employed in an industrial setting.
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