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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.
161

Avaliação do uso glicerina em dietas para frangos de corte nas fases pré-inicial e final / Evaluation of the use glycerin in diets for broilers in the pre-starter and final phases

Leonardo Willian de Freitas 01 February 2013 (has links)
Dois experimentos foram conduzidos com o objetivo de avaliar a utilização de dietas com níveis crescentes de glicerina de biodiesel apenas na fase pré-inicial (1 a 7 dias) e apenas na fase final (35 a 42 dias de idade) de frangos de corte, respectivamente. As variáveis analisadas incluíram o desempenho, o rendimento de carcaça e cortes, a retenção de umidade em pintos aos 7 dias, a umidade de cama, a incidência de pododermatite, os níveis plasmáticos de colesterol e triglicerídeos e o custo da ração referente ao ganho de peso. Os tratamentos consistiram de dietas formuladas com 0%, 5% ou 10% de glicerina, sendo isonutritivas e formuladas à base de milho, farelo de soja e óleo de milho. A glicerina usada continha 83,6% de glicerol, 11,2% de água, 1,83% de sódio e 397 mg/kg de metanol, com energia metabolizável estimada de 3258 kcal/kg. No Experimento I, as dietas com glicerina foram fornecidas apenas na fase pré-inicial ou durante todo o ciclo de criação com 1610 aves em um delineamento inteiramente casualizado com 5 tratamentos e 7 repetições. Na primeira semana, as dietas com glicerina promoveram melhora significativa no ganho de peso e na conversão alimentar, sem afetar o consumo de ração e viabilidade. Essa melhora não foi mantida após os 14 dias de idade. Não houve efeito de tratamentos sobre o ganho de peso, consumo de ração e conversão alimentar. Entretanto, houve redução significativa na viabilidade aos 35 dias de idade das aves com 10% de glicerina por todo ciclo, mas não aos 42 dias; ao final do experimento, o índice de eficiência produtiva desse tratamento sofreu redução significativa. A umidade da cama das aves do tratamento com 10% de glicerina por todo ciclo de criação foi mais alta que dos demais a partir dos 21 dias, entretanto a incidência de pododermatite foi mais severa tanto para 5% como para 10% de glicerina por todo ciclo. Os níveis e tempos de fornecimento de glicerina não afetaram o rendimento de carcaça e de cortes ou a gordura abdominal. No experimento II, as dietas experimentais foram fornecidas a 819 frangos apenas na semana final de criação em um experimento inteiramente casualizado com 3 tratamentos e 7 repetições. O desempenho e o custo de ração por kg de ganho de peso não foram afetados pelos tratamentos. Nos Experimentos I e II, as rações contendo glicerina durante todo o ciclo ou apenas na última semana não resultaram em alteração nas concentrações plasmáticas de triglicerídeos e colesterol dos frangos. Dietas contendo 5% ou 10% de glicerina na fase pré-inicial ou 5% de glicerina continuamente não afetam a produtividade de frangos de corte, enquanto o nível de 10% durante todo o ciclo foi prejudicial. Esse mesmo nível de glicerina pode ser usado na dieta dos 35 aos 42 dias de idade sem afetar as aves. / Two experiments were conducted to evaluate the use of diets with increasing levels of biodiesel glycerin only in pre-starter (1-7 days) and only in the final phase (35-42 days of age) of broilers, respectively. The variables analyzed included the performance, carcass and parts yield, moisture retention in chicks at 7 days, litter moisture, incidence of foot pad dermatitis, plasma levels of cholesterol and triglycerides and diet cost related to weight gain. Treatments were isonutritive diets based on corn, soybean meal and corn oil containing 0, 5 and 10% glycerin. The glycerin used contained 83.6% glycerol, 11.2% water, 1.83% sodium and 397 mg/kg methanol, with estimated metabolizable energy value of 3,258 kcal/kg. In the first experiment, diets with glycerin were provided only in the pre-starter or for the entire growth period with 1610 birds in a completely randomized design with 5 treatments and 7 replications. In the first week, diets with glycerin resulted in significant improvement in weight gain and feed conversion without affecting feed intake and viability. This improvement was not sustained after 14 days of age. There was no effect of treatments on weight gain, feed intake and feed conversion. However, there was a significant reduction in viability at 35 days of age for the birds with 10% glycerin throughout the cycle, but not at 42 days; at the end of the experiment, the productivity index of this treatment was significantly decreased. Litter moisture for the treatment with 10% glycerin throughout the cycle was higher than the for the others from the 21 days, however the incidence of foot pad dermatitis was more severe for both 5% and 10% glycerin treatments for the entire period. The levels and periods of glycerin feeding did not affect carcass and parts yield and abdominal fat. In experiment II, the experimental diets were provided to 819 chickens only in the final week of growth in a completely randomized design with 3 treatments and 7 replications. The performance and feed cost per kg of weight gain were not affected by treatments. In Experiments I and II, the diets containing glycerin throughout the cycle or just in the last week resulted in no change in plasma concentrations of triglycerides and cholesterol of chickens. Diets containing 5% or 10% glycerin in the pre-starter phase or 5% glycerin continually did not affect the productivity of broilers, while the 10% level throughout the cycle was detrimental. This same level of glycerin can be used in the diet from 35 to 42 days without affecting the birds.
162

Almofada de apoio de compósito de cimento para ligações em concreto pré-moldado / Bearing pad of cement composite for connections in precast concrete

Gustavo Henrique Siqueira 30 March 2007 (has links)
Esta pesquisa apresenta um estudo de uma argamassa modificada para uso como elemento de ligação entre elementos de concreto pré-moldado. A argamassa utilizada nesta pesquisa é obtida pela introdução de látex estireno-butadieno (SB) e fibras de polipropileno a uma argamassa de cimento e areia. Estas adições modificam suas propriedades mecânicas, proporcionando o aumento da deformabilidade por diminuição do módulo de elasticidade do compósito, conferindo-lhe características favoráveis ao uso como elemento de apoio para elementos pré-moldados de concreto. Foram realizados ensaios de caracterização do compósito por meio da obtenção das resistências à compressão e à tração e, do módulo de elasticidade para corpos-de-prova cilíndricos com 50 mm de diâmetro com 100 mm de altura. Ensaios de capacidade de deformação, capacidade de rotação e capacidade de acomodação de imperfeições e distribuição das tensões foram realizados em almofadas de 150 mm x 150 mm com espessura de 10 mm. Os resultados mostraram que o material possui boa capacidade de se deformar em níveis de tensão da ordem de 10 a 20 MPa mantendo sua resiliência. Valores de rotações entre 0,01 e 0,02 rad foram obtidos nos ensaios, sendo estas maiores que os valores necessários para a maioria dos casos convencionais de projeto. Na acomodação e distribuição das tensões, a presença das almofadas promoveu uma melhora de 25% no desempenho de ligações submetidas à compressão uniforme, com rugosidades de 1,0 mm. / This research presents a study of a mortar modified to use as bearing pad between precast concrete elements. The mortar used in this research is achieved by the introduction of styrene-butadiene latex (SB) and polypropylene fibers into a cement mortar and sand, modifying their mechanical properties, as increase of the potential deformation by decrease of the composite modulus of elasticity, providing favorable characteristics to the use as bearing pad for precast concrete elements. Cylindrical samples of 50 mm of diameter with height of 100 mm were molded and tested to determination the compressive and the tensile strength and also the modulus of elasticity of the composite. Compression tests with cushions of 150 mm x 150 mm of base with thickness of 10 mm were done to determinate the deformation capacity, rotation capacity and capacity of accommodation of imperfections and distribution of the stresses between precast elements. The results showed that the material has a capacity to deform in levels of tension from 10 to 20 MPa maintaining his resilience. Values of rotations among 0,01 and 0,02 rad were obtained, being these larger ones than the necessary values for most of the conventional cases of project. In the accommodation and distribution of the stresses, the presence of the bearing pad promoted an improvement of 25% in the strength of connections subject to uniform compressive stresses, with surface irregularities of 1,0 mm.
163

Estudo teórico-experimental de ligação viga-pilar com almofada de argamassa e chumbador para estruturas de concreto pré-moldado / Theoretical and experimental study of beam-to-column connection with pad of mortar and bolts for precast concrete structures

Fábio Yoshio Sawasaki 05 May 2010 (has links)
As ligações com chumbador e almofada, sem continuidade estrutural, são comumente empregadas em obras de concreto pré-moldado como galpões, edifícios de poucos pavimentos e no topo de pilares. Na análise estrutural, este tipo de ligação é caracterizado como articulado. Este trabalho teve como objetivo fazer um estudo com este tipo de ligação levando em conta que a transferência de momento fletor ocorrerá em função da rigidez proporcionada por uma almofada de compósito de argamassa e por chumbadores de aço. A idéia é considerar o benefício da redução das solicitações nos elementos de concreto pré-moldado, particularmente, na base dos pilares. A análise experimental foi feita com modelos em escala reduzida 1:2. Foram ensaiados quatro modelos da ligação que são: a) Modelo 1 - chumbadores de aço CA-25 e almofada de compósito de argamassa; b) Modelo 2 - chumbadores de aço CA-25 e almofada de policloropreno; c) Modelo 3 - chumbadores de aço CA-50 e almofada de compósito de argamassa e; d) Modelo 4 - chumbadores de aço CA-50 e pilar com largura igual a 50% maior que os casos anteriores e almofada de argamassa. Foi feita ainda a análise numérica tridimensional dos modelos da ligação utilizando o software Ansys e análises de pórtico plano para avaliar a distribuição de solicitações ao longo de estruturas representativas. Foi desenvolvido um modelo de projeto para prever o comportamento da ligação. Com as simulações de pórtico plano, onde foram consideradas as semirigidezes das ligações, obteve-se uma redução de até 48% do momento fletor na base dos pilares para um edifício de quatro pavimentos, cujas ligações viga-pilares apresentavam um consolo de 40 cm, e de 21,8% para um edifício de um pavimento do tipo galpão, cujas ligações continham quatro chumbadores, considerando apenas a carga de frenagem. A análise de deslocamentos nos pórticos planos também aponta o benefício da consideração da semirigidez nas ligações. Uma redução de deslocamento horizontal do topo do pórtico do tipo galpão de até 32,8% para o modelo com ligações com quatro chumbadores e somente força horizontal, e de até 71,9% para o edifício de quatro pavimentos considerando as ligações semirígidas com consolos de 40 cm. / Connections with bolts and pad, without structural continuity, are commonly used in construction of precast concrete as one-storey building, building with a few storeys and on top of columns. In structural analysis, this type of connection is characterized as pinned, that is, without restriction of the rotation on the connection. This work aims to make a study of this type of connection taking into account that the transfer of bending moment will occur due to the stiffness provided by a pad of mortar composite and the steel bolts. The idea is to consider the benefit of reducing the demands on the elements of precast concrete, particularly at the base of the columns. The experimental analysis was done with models scale 1:2. Four models of connection were tested: a) Model 1 - steel bolts CA-25 and pad of mortar composite, b) Model 2 - steel bolts CA-25 and chloroprene rubber pad, c) Model 3 - bolts of CA-50 steel and pad of mortar composite, and d) Model 4 - steel bolts CA-50 and column with a width of 50% larger that the others and mortar pad. It was still a three-dimensional numerical analysis of the lead models using Ansys software and frame plan analysis to evaluate the stress distribution along the representative structures. A model design to predict the behavior of the connection was developed. Based on the numerical simulations on precast concrete frames, semi-rigidity of connections was take in to account, it was obtained a reduction of up to 48% of the bending moment at the base of the columns of a four-storey building, which beam-to-column connections had a corbel 40 cm, and 21,8% for a one-storey building, which connections contained four bolts, considering only the horizontal load. The analysis of displacements in the plane frame also shows the benefit of considering the semi-rigidity connections. Reduction in horizontal displacement of the top of the one-storey building to 32,8% for the model with four bolts in the connections with only horizontal force, and 71,9% for the four-storey buildings with semi-rigid connections considering the corbels of 40 cm.
164

Algorithms for the matrix exponential and its Fréchet derivative

Al-Mohy, Awad January 2011 (has links)
New algorithms for the matrix exponential and its Fréchet derivative are presented. First, we derive a new scaling and squaring algorithm (denoted expm[new]) for computing eA, where A is any square matrix, that mitigates the overscaling problem. The algorithm is built on the algorithm of Higham [SIAM J.Matrix Anal. Appl., 26(4): 1179-1193, 2005] but improves on it by two key features. The first, specific to triangular matrices, is to compute the diagonal elements in the squaring phase as exponentials instead of powering them. The second is to base the backward error analysis that underlies the algorithm on members of the sequence {||Ak||1/k} instead of ||A||. The terms ||Ak||1/k are estimated without computing powers of A by using a matrix 1-norm estimator. Second, a new algorithm is developed for computing the action of the matrix exponential on a matrix, etAB, where A is an n x n matrix and B is n x n₀ with n₀ << n. The algorithm works for any A, its computational cost is dominated by the formation of products of A with n x n₀ matrices, and the only input parameter is a backward error tolerance. The algorithm can return a single matrix etAB or a sequence etkAB on an equally spaced grid of points tk. It uses the scaling part of the scaling and squaring method together with a truncated Taylor series approximation to the exponential. It determines the amount of scaling and the Taylor degree using the strategy of expm[new].Preprocessing steps are used to reduce the cost of the algorithm. An important application of the algorithm is to exponential integrators for ordinary differential equations. It is shown that the sums of the form $\sum_{k=0}^p\varphi_k(A)u_k$ that arise in exponential integrators, where the $\varphi_k$ are related to the exponential function, can be expressed in terms of a single exponential of a matrix of dimension $n+p$ built by augmenting $A$ with additional rows and columns. Third, a general framework for simultaneously computing a matrix function, $f(A)$, and its Fréchet derivative in the direction $E$, $L_f(A,E)$, is established for a wide range of matrix functions. In particular, we extend the algorithm of Higham and $\mathrm{expm_{new}}$ to two algorithms that intertwine the evaluation of both $e^A$ and $L(A,E)$ at a cost about three times that for computing $e^A$ alone. These two extended algorithms are then adapted to algorithms that simultaneously calculate $e^A$ together with an estimate of its condition number. Finally, we show that $L_f(A,E)$, where $f$ is a real-valued matrix function and $A$ and $E$ are real matrices, can be approximated by $\Im f(A+ihE)/h$ for some suitably small $h$. This approximation generalizes the complex step approximation known in the scalar case, and is proved to be of second order in $h$ for analytic functions $f$ and also for the matrix sign function. It is shown that it does not suffer the inherent cancellation that limits the accuracy of finite difference approximations in floating point arithmetic. However, cancellation does nevertheless vitiate the approximation when the underlying method for evaluating $f$ employs complex arithmetic. The complex step approximation is attractive when specialized methods for evaluating the Fréchet derivative are not available.
165

Mechanisms of thermomechanical pulp refining

Illikainen, M. (Mirja) 21 October 2008 (has links)
Abstract The objective of this thesis was to obtain new information about mechanisms of thermomechanical pulp refining in the inner area of a refiner disc gap by studying inter-fibre refining and by calculating the distribution of energy consumption in the refiner disc gap. The energy consumption of thermomechanical pulping process is very high although theoretically a small amount of energy is needed to create new fibre surfaces. Mechanisms of refining have been widely studied in order to understand the high energy consumption of the process, however, phenomena in the inner area of disc gap has had less attention. It is likely that this important position is causing high energy consumption due to the high residence time of pulp located there. The power distribution as a function of the refiner disc gap was calculated in this work. The calculation was based on mass and energy balances, as well as temperature and consistency profiles determined by mill trials. The power distribution was found to be dependent on segment geometry and the refining stage. However, in the first stage refiner with standard refiner segments, a notable amount of power was consumed in the inner area of the disc gap. Fibre-to-fibre refining is likely to be the most important mechanism in the inner area of disc gap from the point of view of energy consumption. In this work the inter-fibre refining was studied using equipment for shear and compression. Fibre-to-fibre refining was found to be an effective way to refine fibres from coarse pulp to separated, fibrillated and peeled fibres if frictional forces inside the compressed pulp were high enough. It was proposed that high energy of today’s thermomechanical pulping process could derive from too low frictional forces that heated pulp and evaporated water without any changes in fibre structure. The method to calculate power distribution and results of fibre-to-fibre refining experiments may give ideas for developing today’s thermomechanical pulp refiners’ or for developing totally new energy saving mechanical pulping processes.
166

Évaluation et compréhension des limitations fonctionnelles dans l'artériopathie oblitérante des membres inférieurs : validation du géo-positionnement par satellites pour l’étude de la dépense énergétique lors de la marche en extérieur & étude de l’effet de la durée de récupération sur la capacité de marche / Evaluation and understanding of the functional limitations in the arteriopathy oblitérante lower limbs : validation of geography-positioning by satellites for the study of the energy expenditure during the walking

Müllenheim Rosenbourg, Pierre-Yves de 07 December 2016 (has links)
L’Artériopathie Oblitérante des Membres Inférieurs (AOMI) est une maladie chronique grave, associée au processus d’athérosclérose, et qui se traduit chez la plupart des patients par une ischémie (apports sanguins insuffisants) à l’exercice.L’ischémie d’exercice peut causer l’apparition de douleurs au niveau des membres inférieurs lors de la marche, limitant de fait la capacité de marche des patients. L’évaluation de la capacité de marche occupe une place importante dans la prise en charge des patients. Grâce au développement de moniteurs d’activité tels que le géo-positionnement par satellites (GPS), cette évaluation peut être conduite en situation écologique de marche via des mesures réalisées en extérieur. Ces mesures GPS ont notamment permis de mettre en évidence une variabilité de la capacité de marche avec une influence probable de la durée de récupération entre deux marches symptômes-limitées. Ceci reste cependant à démontrer expérimentalement. Par ailleurs, méthodologiquement, il est nécessaire de pouvoir standardiser et exprimer de façon plusadéquate les données GPS obtenues afin de juger de la capacité de marche des patients. L’objet du présent travail de thèse était par conséquent double : i) valider une méthodologie pour estimer la dépense énergétique (DE) associée à la marche en extérieur chez le sujet sain et qui serait à terme applicable chez les patients avec AOMI pour pouvoir comparer les résultats de capacité de marche obtenus par mesure GPS ; ii) déterminer dans quelle mesure la durée de récupération suite à une marche symptômes-limitée influence la capacité de marche des patients lors de la marche subséquente. Les résultats des travaux de recherche qui ont été menés dans le cadre de cette thèse montrent que le GPS permet une estimation relativement précise de la DE en extérieur chez le sujet sain en conditions de vitesse et de pente variées. De plus, nos résultats mettent en évidence que la durée de récupération faisant suite à une marche symptômes-limitée influence clairement la capacité de marche des patients. La nature logarithmique de la relation permet d’envisager àmoyen terme l’identification d’une durée minimale de récupération à partir de laquelle les patients pourraient maximiser leur capacité de marche. Des perspectives intéressantes pourraient alors être envisagées dans le réentraînement à l’effort des patients et/ou pour les aider à mieux gérer leurs douleurs au quotidien. / Lower-extremity peripheral artery disease (PAD) is a non-communicable disease that is associated with atherosclerosis and that leads, in most patients, to ischemia (mismatch between blood demand and blood supply) during exercise. Exercise-induced ischemia may lead to the occurrence of pain in the lower extremities during walking, thus limitingwalking capacity. Assessing walking capacity is an important step in the management of PAD patients. Thanks to the development of activity monitors such as global positioning system (GPS), it is possible to assess walking capacity under real-life conditions with measurements performed in outdoor settings. These GPS measurements have highlighted thefact that walking capacity seems variable and is likely to be influenced by the recovery duration between two symptoms-limited walks. However, this remains to be demonstrated in standardized conditions. Moreover, methodological advances are needed to standardize and express more adequately GPS data in order to better interpret walking capacity measurements. Therefore, the aim of the present thesis was two-fold: i) to validate a method for estimating walking energy expenditure (EE) in healthy subjects in outdoor setting, and that could be used in the future in PAD patients in order to compare walking capacity results obtained in outdoor setting; ii) to determine to which extent the duration of the recovery period that follows a first symptom-limited walk influences walking capacity measured during the subsequent walk in PADpatients. Our results show that GPS allows accurate estimations of walking EE in healthy subjects in outdoor setting and with various conditions of speed and grade. Moreover, our results clearly show that recovery duration influences walking capacity in PAD patients. The logarithmic shape of the relationship supports further analyses to determine a minimum recovery duration that could maximize patients walking capacity. This could have interesting implications for the development of new exercise walking programs in PAD and/or to help patients to better manage their pain during daily life.
167

Simulace vlivů vyhřívané podložky na tisknutý model u 3D tiskárny / Simulation of Impact The Heated Bed on Printet Model in 3D Printer

Sodomka, Petr January 2015 (has links)
This diploma thesis solves the 3D printing problematics for non-commercial printers. Firstly possibilities of its using, heat diffusion and printing materials are described. Next part of thesis is focused on heating pads and printing nozzles for which 3D models in SolidWorks software are created. The temperature analyzes are tested with these models and then comparing of results is done. Working models for SolidWorks Plastics and SolidWorks Simulation software is created in following part. Thanks to this software tools printing model is simulated and deformation creating in printing process is observed. The most suitable solutions are chosen from gained solutions.
168

Návrh a posouzení sportovní haly / Design of a Sports Hall

Konečný, Vlastimil January 2015 (has links)
Aim of the diploma's thesis is to design selectedelements of sports hall. It is a single-storey object, where the main structural system consists of a frame of columns and prestressed girder. Design of elements is done according to limit states. To determine the effects of internal forces is used computational software Scia Engineer 2008.Outputs from computational software are compared with simplified manual calculation. There’s performed assessment and reinforcement of selected elements. For each element are drawn production drawings and reinforcement drawings. There are also prepared drawings of parts of construction and foundation drawing. Design and evaluation is conducted according to valid standards. The proposed design meets the requirements according to the ultimate and serviceability limit state.
169

Technologie výroby plechového dílu / Technology of production part of sheet

Bartusek, Břetislav January 2012 (has links)
The aim of diploma thesis is to design technology components production orders. For a given part of the technology will be used non conventional deep drawing Wheelon method. For manufacturing lengthwise recesses and consequent cutting of shaped holes using a plasma cutting. The suitability of technological applications will be tested using the cost functions.
170

Účet / Bank account

Mezenský, Adam January 2020 (has links)
Bank Account Abstract The thesis deals with the payment account agreement from the European and Czech national legislation point of view focusing on specific issues resulting from European directive 2014/92/EU (a. k. a. PAD) and the implementation of those institutes in the Czech Legislative Act No. 370/2017 Sb. The thesis is divided into two parts, whereas the first part includes theoretical introduction to the subject of the payment account agreement while the second part deals with particular four selected issues related to the payment account agreement resulting from PAD. In the first chapter of the first part the historical background of the concept of bank account or precisely payment account existence is outlined together with theoretical conclusions of different approaches towards this concept in current legal environment. Second and third chapter provide overview of relevant legislation passed on Czech national and European Union level. Effective and enforceable regulations alongside with some of the ineffective ones that are or have been substantially significant for formation relationships between bank account users and payment services providers providing bank accounts to users are part of the provided overview. The second part is divided into four chapters, each of them analysing one of the...

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