957 resultados para retorno elástico
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For the development of this graduate work of fractal fracture behavior, it is necessary to establish references for fractal analysis on fracture surfaces, evaluating, from tests of fracture tenacity on modes I, II and combined I / II, the behavior of fractures in fragile materials, on linear elastic regime. Fractures in the linear elastic regime are described by your fractal behavior by several researchers, especially Mecholsky JJ. The motivation of that present proposal stems from work done by the group and accepted for publication in the journal Materials Science and Engineering A (Horovistiz et al, 2010), where the model of Mecholsky could not be proven for fractures into grooved specimens for tests of diametric compression of titania on mode I. The general objective of this proposal is to quantify the distinguish surface regions formed by different mechanisms of fracture propagation in linear elastic regime in polymeric specimens (phenolic resin), relating tenacity, thickness of the specimens and fractal dimension. The analyzed fractures were obtained from SCB tests in mode I loading, and the acquisition of images taken using an optical reflection microscope and the surface topographies obtained by the extension focus method of reconstruction, calculating the values of fractal dimension with the use of maps of elevations. The fractal dimension was classified as monofractal dimension (Df), when the fracture is described by a single value, or texture size (Dt), which is a macroscopic analysis of the fracture, combined with the structural dimension (Ds), which is a microscopic analysis. The results showed that there is no clear relationship between tenacity, thickness and fractal values for the material investigated. On the other hand it is clear that the fractal values change with the evolution of cracks during the fracture process ... (Complete abstract click electronic access below)
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The common vampire bat Desmodus rotundus has as main food source blood of medium and large sizes mammals, but sporadically is observed feeding on birds, causing occasionally excessive bleeding and economic losses. Due to this D. rotundus is one of the most studied species of bats in the Americas. Once known that the lunar clarity might influence the nocturnal activities of the common vampire bats, the present study was carried out to know the behavior and schedules of emergencies and returns of bats to the shelter, its social behavior at the shelter´s entrance, especially of the dominant male, and the size and composition of the colony in different moon phases. The colony was composed by 105 individuals (65 females and 40 males) harboring in a hollow-tree of Farm Edgardia in Botucatu Municipality, State of São Paulo. Through the eight filming sessions, two for each moon phase, it was possible to observe that the distribution of emergences and returns to the shelter thought the night followed a specific pattern for each moon phase. The greatest number of emerging bats occurred in periods in which the moon was not born yet and the largest number of returns just before moon has been reached its maximum level in the sky. Therefore, the time period that bats are staying outside the shelter seems to be directly influenced by lunar light. This factor can influence the social activity of the colony and, in particular, the dominant male, who remains still on tree’s trunk, near the entrance of the shelter with greater frequency during periods of low moon light
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The Therapy with proton beam has shown more e ective than Radiotherapy for oncology treatment. However, to its planning use photon beam Computing Tomography that not considers the fundamentals di erences the interaction with the matter between X-rays and Protons. Nowadays, there is a great e ort to develop Tomography with proton beam. In this way it is necessary to know the most likely trajectory of proton beam to image reconstruction. In this work was realized calculus of the most likely trajectory of proton beam in homogeneous target compound with water that was considered the inelastic nuclear interaction. Other calculus was the analytical calculation of lateral de ection of proton beam. In the calculation were utilized programs that use Monte Carlo Method: SRIM 2006 (Stopping and Range of Ions in Matter ), MCNPX (Monte Carlo N-Particle eXtended) v2.50. And to analytical calculation was employed the software Wolfram Mathematica v7.0. We obtained how di erent nuclear reaction models modify the trajectory of proton beam and the comparative between analytical and Monte Carlo method
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The goal of this work is to study the process of interaction of protons with matter through Monte Carlo simulation. For this purpose, it was employed the SRIM program (Stopping and Range of Ions in Matter ) and MCNPX (Monte Carlo N-Particle eXtended) v2.50. This work is going to support the development of a tomography system with protons. It was studied the interaction of proton with the follow materials: Polimethyl Mehacralate (PMMA), MS20 Tissue Substitute and water. This work employed energies in range of 50 MeV and 250 MeV, that is the range of clinical interest. The energy loss of proton after cross a material layer, the decreasing of its intensity, the angular and lateral de ection of incident beam, including and excluding nuclear interactions. This work is related with Medical Physics and Material Physics, like interaction of radiation with matter, particle transport phenomena, and the experimental methods in Nuclear Physics like simulation and computational by Monte Carlo method
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This paper consists in applying the Modern Theory of Portfolio (MPT) using central position measurements for modeling the return on investment fund of a renowned financial institution and compare with the Medium- CVaR model. The measurement of risks and returns becomes increasingly important for investors to minimize their losses to maximize thus their possibilities of earnings, taking into account sudden change scenarios. We present concepts of investment funds used as data and research on central position measurements to determine which measure was more suitable. To assemble the Efficient Frontier of assets considering the method proposed measure of central position-CVaR position is used MatLab. Then, after getting the Frontier, it was possible to compare it with the Medium-CVaR model, already proven effective. Finally, we analyze the viability of the proposed model in portfolio management
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The aim of this study was to evaluate the vertical and horizontal dentoskeletal changes induced by the Klammt Open Elastic Activator in the treatment of the Class II Division 1 malocclusion. The sample of 34 children was divided into two groups of 17 subjects each (ten girls, seven boys), matched by age and gender and with an initial mean age of 8.5 years. The data was analyzed using a Student's t-test for intragroup and intergroup comparison. The results showed that the appliance promoted dentoalveolar restriction of the maxilar growth within normal anteroposterior and vertical growth of the maxillary apical base; increment in the vertical displacement the mandibular symphysis associated with normal horizontal growth of the mandible; palatal tipping of the upper incisors; restriction of the anterior migration of the upper molars; greater eruption pattern and normal anterior displacement of the lower incisors and molars. It was concluded that Klammt appliance induce changes that are predominantly horizontal dentoalveolar in upper arch and vertical dentoalveolar in lower arch and vertical skeletal changes in the mandible.
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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Pós-graduação em Engenharia Civil e Ambiental - FEB
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The main disturbs affecting the genital segment of bulls are balanitis, phimosis and preputial injuries, abscesses or prolapses, resulting in decreased libido or mating ability. One case of traumatic phimosis with partial obliteration of preputial lumen is reported in Aberdeen Angus bull. During anamnesis, it was reported that the animal was unable to expose the penis and presented increased penile and preputial volume of unknown etiology after being submitted to a libido test. During clinical examination, a firm preputial mass of 15 cm in diameter was observed in the middle third of the prepuce and stenosis of preputial lumen was detected approximately 17 cm from the preputial orifice. Reconstructive surgery was the chosen therapy, with amputation of the affected foreskin portion. A skin segment of about 12 cm and affected mucosal portion were removed. Postoperative therapy consisted of dressing with chlorhexidine digluconate based ointment, povidone iodine and topical insect repellent (cypermethrin and carbamyl), systemic antibiotic therapy with benzathine penicillin (30,000 IU / kg, repeated after 48 hours) and anti-inflammatory therapy with flunixin meglumine (2 , 0 mg / kg SID) for three days. After twenty days, semen was collected by massage of the accessory glands. The ejaculate volume was 3 mL, with 200x106 spermatozoa / mL, white color, "suis generis" odor, 88% of motile sperm, 64% of progressively motile sperm and 82% of rapid sperm. Thus, the chosen surgical treatment was effective to correct the pathology and reintroduce the animal into reproductive activity
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Modelos de apreçamento de ativos têm sido um tema sob constante investigação em finanças. Desde o capital asset pricing model (CAPM) proposto por Sharpe (1964), tais modelos relacionam, geralmente de maneira linear, a taxa de retorno esperada de um ativo ou carteira de ativos com fatores de risco sistêmico. Esta pesquisa apresenta um teste de um modelo de apreçamento, com dados brasileiros, introduzindo em sua formulação fatores de risco baseados em comomentos estatísticos. O modelo proposto é uma extensão do CAPM original acrescido da coassimetria e da cocurtose entre as taxas de retorno das ações das empresas que compõem a amostra e as taxas de retorno da carteira de mercado. Os efeitos de outras variáveis, como o valor de mercado sobre valor contábil, a alavancagem financeira e um índice de negociabilidade em bolsa, serviram de variáveis de controle. A amostra foi composta de 179 empresas brasileiras não financeiras negociadas na BM&FBovespa e com dados disponíveis entre os anos de 2003 a 2007. A metodologia consistiu em calcular os momentos sistêmicos anuais a partir de taxas de retornos semanais e em seguida testá-los em um modelo de apreçamento, a fim de verificar se há um prêmio pelo risco associado a cada uma dessas medidas de risco. Foi empregada a técnica de análise de dados em painel, estimada pelo método dos momentos generalizado (GMM). O emprego do GMM visa lidar com potenciais problemas de determinação simultânea e endogeneidade nos dados, evitando a ocorrência de viés nas estimações. Os resultados das estimações mostram que a relação das taxas de retorno dos ativos com a covariância e a cocurtose são estatisticamente significantes. Os resultados se mostraram robustos a especificações alternativas do modelo. O artigo contribui para a literatura por apresentar evidências empíricas brasileiras de que há um prêmio pelo risco associado aos momentos sistêmicos.
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[von] R. Cansinos-Assens