Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-03-20T19:43:46Z No. of bitstreams: 2 Dissertação - Ligia da Cunha Moreira - 2014.pdf: 1675032 bytes, checksum: abbce36de279a092b9f81566a296fbc8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-03-20T19:45:14Z (GMT) No. of bitstreams: 2 Dissertação - Ligia da Cunha Moreira - 2014.pdf: 1675032 bytes, checksum: abbce36de279a092b9f81566a296fbc8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-20T19:45:14Z (GMT). No. of bitstreams: 2 Dissertação - Ligia da Cunha Moreira - 2014.pdf: 1675032 bytes, checksum: abbce36de279a092b9f81566a296fbc8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Genetic selection of animals with potential for improved carcass and meat quality is a strategy that should be employed in Brazilian livestock. The country occupies a prominent position in global agribusiness, possessing the largest commercial cattle herd in the world and being one of the largest exporters of beef. However, Brazilian beef is classified as medium to low quality. The aim of the present study was to evaluate quantitative and qualitative characteristics of the carcass and beef in Polled Nellore belonging to a segregating population selected for meat tenderness. There were 68 male animals, with age average six months and initial weights 215.5 kg. The animals were slaughtered when they reached a minimum weight of 500 kg and 5 millimeters of fat backfat, forming groups of 17 or 18 animals of each slaughter. The slaughter occurred in a commercial slaughterhouse under Federal Inspection (SIF 431). The experimental design was a randomized block design with two treatment types (low and high WBSF). Data were subjected to an analysis of variance using the GLM procedure in SAS. The treatment means were compared by the Duncan test at 5% significance. Sensory analyses were submitted to the NPAR1WAY procedure, and means were compared by the non-parametric Kruskal- Wallis test. There weren’t significant differences for the carcasses characteristics evaluated. The shear force was high for animals with high WBSF analyzed in both methods (1.55 kgf and 2.48 kgf texturometer Warner Bratzler). The high group WBSF had a value of 5.99 for pH, higher than the low group WBSF, which showed a pH of 6.36. The animals of the low WBSF group had lower cooking losses, 18.1% and higher water retention capacity of 77.01%. It is suggested that these differences may have been due to the high pH value observed for animals in this group. Color parameters were better for animals with high WBSF. In the sensory panel, the animals with low WBSF were better for both, tenderness (8.38 vs. 5.01) and juiciness (6.12 vs. 5.26), compared to the high WBSF group. The two groups did not differ in carcass characteristics, but animals with low WBSF produced superior beef according to objective and taste panel evaluations. Genetic selection for meat tenderness didn’t influence carcass characteristics, but was effective / A seleção genética de animais com potencial para produção de carcaça e carne de melhor qualidade é uma estratégia que deve ser mais adotada pela pecuária brasileira. O país ocupa posição de destaque no agronegócio mundial, detentor do maior rebanho bovino comercial do mundo, e um dos maiores exportadores de carne bovina, no entanto, a carne brasileira é tida como de média a baixa qualidade. Objetivou-se avaliar as características quantitativas e qualitativas da carcaça e da carne de bovinos Nelore Mocho, pertencentes a uma população segregante selecionada para maciez da carne. Foram utilizados 68 animais machos inteiros sendo 27 deles pertencentes ao grupo de baixo WBSF (força de cisalhamento <3,5 kgf) e 41 pertencentes ao grupo de alto WBSF (força de cisalhamento >3,5 kgf). A idade e peso inicial dos animais foram, em média de seis meses e 215,5 kg, respectivamente. Os animais foram abatidos quando atingiram peso mínimo de 500 kg e cinco milímetros de espessura de gordura, formando grupos com 17 ou 18 animais por abate. O abate ocorreu em frigorifico comercial sob Inspeção Federal (SIF 431). O delineamento experimental foi em blocos casualizados com dois tratamentos (baixo e alto WBSF). Os dados foram submetidos à análise de variância utilizando o procedimento GLM, disponibilizados no programa estatístico SAS. As médias dos tratamentos foram comparadas pelo teste de Duncan a 5% de significância. As análises sensoriais foram submetidas ao procedimento NPAR1WAY, e as médias foram comparadas pelo teste não paramétrico de Kruskal-Wallis. Não houve diferença significativa para as características de carcaça avaliadas. A força de cisalhamento foi menor para os animais de baixo WBSF nos dois métodos analisados (1,55 kgf no texturômetro e 2,48 kgf no Warner Bratzler). O grupo de alto WBSF apresentou valor médio de 5,99 para pH, sendo superior ao grupo baixo WBSF, que apresentou pH de 6,36 em média. A carne dos animais de baixo WBSF apresentam menores perdas por cocção (18,1%) e maior capacidade de retenção de água (77,01%), sugere-se que essas diferenças possam ter sido devido ao alto valor de pH observado para os bovinos deste grupo. Os parâmetros de cor foram superiores para os animais de alto WBSF. No painel sensorial, a carne dos animais de baixo WBSF foram superiores, tanto para a característica de maciez (8,38 vs. 5,01) como para suculência (6,12 vs. 5,26), em relação ao grupo alto WBSF. Os dois grupos não diferiram em relação às características de carcaça, mas a carne dos animais de baixo WBSF apresentaram superioridade para as características de qualidade medidas objetivamente pelo painel sensorial. Dessa forma, pode-se afirmar que a seleção genética para maciez da carne não influenciou nas características de carcaça, mas foi eficiente na melhoria das características de qualidade da carne proveniente de bovinos da raça Nelore.

The sectional beam is the essential detail of an overhead conveyor. The construction element is stressed by time-varying mechanical and tribological loads. Here, we discuss the influence of the manufacturing process on the mechanical properties and the serviceability of the extruded profile in a selected application. The development of existing formulas and processing parameters are shown with the objective to expand the material application from WPC-decking to use in mechanical engineering. / Das Tragprofil ist das zentrale Element in einem Hängefördersystem. Das Bauteil wird durch zeitlich veränderliche mechanische und tribologische Lasten beansprucht. Nachfolgend wird der Einfluss des Herstellungsprozesses auf die mechanischen Eigenschaften und die Gebrauchsfähigkeit eines extrudierten Trag- und Gleitprofils aus WPC im gewählten Anwendungsfall vorgestellt. Die notwendige Weiterentwicklung bestehender Rezepturen und Verarbeitungsverfahren wird aufgezeigt, um den Anwendungsbereich des Werkstoffes WPC vom Bereich Terassendielen auf den Maschinenbau zu erweitern.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Currently, there is an increase in the demand for tall buildings in the city of Lima. This research proposes to reduce the dynamic amplification factor through the seismic design of tall buildings based on the requirements of Peruvian code considering that they are regular in plan and height. Minimum base shear values according to the comparison of static seismic shear and dynamic shear from the spectral modal analysis were reviewed for cases of buildings larger than 120 m. The study of 28 reinforced concrete buildings was proposed, with different heights - varying from 24 to 36 floors, with different floor configurations, as well as the arrangement of the walls considering as a rigid core structural system. Additionally, the characteristics of the materials, the loads and combinations were defined. The responses of these buildings were determined by the response spectrum analysis (RSA) and then compared with those obtained by the lineal response history analysis (LRHA), for the last analysis, five Peruvian seismic records were used and scaled to 0.45 g. The seismic responses of the LRHA procedure were taken as a benchmark. The result of this study is the analysis and proposal of the C/R factor for high-rise buildings, as well as obtaining the base shear and drift verification. Minimum base shear values can be reduced for high or long-term buildings, being regular in plan and height. / Revisión por pares

The following project presents in silico investigation of axonal damage in Diffuse Axonal Injury (DAI). When axons face a shear force, orientation of the lipids in the axonal membrane gets disrupted. Depending on the value of the force, a tensile strain causes the axons to get partially or fully deformed and in some cases a pore forms in the membrane. Using Molecular Dynamic (MD) simulation and a coarse grain model, a series of bilayers with various bilayer structure (single bilayer, parallel bilayer and cylindrical bilayer) and similar composition to biological axonal membrane were simulated. This was initially done to investigate the strain rate dependency of the bilayers, and their viscoelastic ability on returning to their original shape from their deformed forms. To achieve this, various deformation velocities were applied to the bilayers reaching 20% strain and relaxing the bilayer after. Additionally, the bilayers were deformed further until they reached a pore. It was found that the bilayers can almost recover from their deformed forms to their original length when they were deformed at 20% strain level. In conjunction, no correlation between the deformation velocity and lipid deformation was observed. Further, it was found that bilayers with different lipid percentage to axonal bilayer has different strain values for water penetration and for pore formation. The strain value for cylindrical bilayer was found very high compared to the strain values found in vitro. The strain for pore formation of parallel and single bilayer was found to be around 80% to 90% and for water penetration was found to be 70% for single bilayer and 50% for parallel bilayer. A slight difference in strain for pore formation between single and parallel bilayer was found which showed the bilayer structure can play a role in simulation results. The effect of the length in the simulations results was also observed where shorter bilayers showed lower strain for pore formation compared to longer bilayers.

Bridge edge beam system is an increasing concern in Sweden. Because it is the mostvisible part of the structure which is subjected to harsh weather. The edge beamcontributes to the stiffness of overhang slab and helps to distribute the concentratedload. The design of edge beam is not only affected by the structural members, but it isalso affected by non-structural members.The aim of the thesis is to investigate the influence of edge beam on the structuralbehavior of reinforced concrete overhang slab. A three-dimensional (3D) non-linearfinite element model is developed by using the commercial software ABAQUS version6.1.14. The load displacement curves and failure modes were observed. The bendingmoment and shear capacity of the cantilever slab is studied.The validated model from non-linear analysis of reinforced concrete slab gives morestiffer result and leads to the high value of load capacity when comparing with theexperimental test. The presence of the edge beam in the overhang slab of length 2.4 mslightly increases the load capacity and shows ductile behavior due to the self-weightof the edge beam. The non-linear FE-analysis of overhang slab of length 10 m leads tomuch higher load capacity and gives stiffer response as compare to the overhang slabof 2.4 m. The presence of the edge beam in the overhang slab of length 10 m giveshigher load capacity and shows stiffer response when comparing with the overhangslab of length 10 m. This might be due to the self-weight of the edge beam and theoverhang slab is restrained at the right side of the slab.

No description available.

No description available.

A new version of EN 1992-1-1, Eurocode 2 for Design of Concrete Structures, is under development and one of the most discussed topics is shear capacity for prestressed concrete beams without shear reinforcement, partly because shear failure occurs suddenly and can have catastrophic consequences. For the new version of Eurocode, there are a total of three proposed equations to replace the two equations that currently exist in EN 1992-1-1 for shear capacity of prestressed concrete beams without shear reinforcement. One of the proposed equations is intended to replace the equation intended for beam regions where bending cracks do not occur. The other two equations are proposed for beam regions where bending cracks occur. One of the proposed equations for beam regions with bending cracks, is based on critical shear crack theory and takes the normal force in consideration, while the other equation for beam regions with bending cracks is like the one found today in Eurocode, an empirical equation, where the contribution of normal force is empirical. In this thesis, all equations have been set against each other and compared with the help of nonlinear finite element analyzes and experiments which Dr. De Wilder has done in his doctoral thesis. The impact of the prestressing force on the shear force capacity of beams has also been investigated. The results show that the equations for beam regions that do not have bending cracks give identical shear force capacities. While the equation which is based on critical shear crack theory takes the shear span into consideration and captures the effect of the shear span correctly, which the other proposed equation and the one found in Eurocode today do not and are on the unsafe side for increasing shear spans. Furthermore, it turned out that the equation which is based on critical shear crack theory was rather conservative, while the equation that exists today in Eurocode gives approximately the same shear capacity as the other proposed equation. Furthermore, it was found that if the amount of longitudinal reinforcement is reduced, at the same time as the prestressing force is unchanged, an insignificant reduction in the shear capacity on prestressed concrete beams is obtained. / En ny version av EN 1992-1-1, Eurokod 2 Dimensionering av betongkonstruktioner, är under utveckling och ett av de mest diskuterade ämnena är tvärkraftskapacitet för förspända betongbalkar utan skjuvarmering, bland annat eftersom huvudspänningsskjuvbrott uppstår plötsligt och kan få katastrofala konsekvenser. Till den nya versionen av Eurokoden finns det totalt tre föreslagna ekvationer för att ersätta de två ekvationer som för närvarande finns i EN 1992-1-1 för tvärkraftskapacitet för förspända betongbalkar utan skjuvarmering. En av de föreslagna ekvationerna är tänkt att ersätta ekvationen avsedd för balkregioner där böjsprickor ej uppstår. De andra två ekvationerna är föreslagna för balkregioner där böjsprickor uppstår. En av de föreslagna ekvationerna för balkregioner med böjsprickor är baserad på kritisk skjuvsprickteorin och tar hänsyn till normalkraftens bidrag till tvärkraftskapaciteten, medan den andra föreslagna ekvationen för balkregioner med böjsprickor är likt den som idag finns i Eurokoden, en empirisk ekvation, där normala kraftens bidrag är baserad på ett empiriskt tillägg. I detta examensarbete har alla ekvationer ställts mot varandra och jämförts med hjälp utav icke-linjär finit-elementanalyser samt experiment som Dr. De Wilder gjort i sin doktorsavhandling. Vidare har också förspänningskraftens påverkan på balkars tvärkraftskapacitet undersökts. Resultaten visar att ekvationerna för balkregioner som ej har böjsprickor ger identiska tvärkraftskapaciteter. Medan ekvationen som är baserad på kritisk skjuvsprickteorin tar hänsyn till skjuvspännvidd och fångar effekten av skjuvspännvidden korrekt, vilket den andra föreslagna ekvationen och den som finns i Eurokoden idag inte gör och är på den osäkra sidan för ökad skjuvspännvidd. Dessutom visade det sig att ekvationen som är baserad på kritisk skjuvsprickteori är tämligen konservativ, medan ekvationen som finns idag i Eurokoden ger ungefär samma tvärkraftskapacitet som den andra föreslagna ekvationen. Vidare visade det sig att ifall man minskar mängden längsgående armering, samtidigt som förspänningskraften är oförändrad, så fås en obetydlig minskning utav tvärkraftskapaciteten på förspända betongbalkar.

Das Prinzip „Leicht Bauen mit Beton“ kann durch stabförmige Bauelemente außerordentlich gut umgesetzt werden, da einwirkende Beanspruchungen konzentriert und optimiert aufgenommen werden können. Stabförmige Bauelemente gehören zu den maßgebenden Bestandteilen von Mast- und Turmkonstruktionen sowie Fachwerk- und Rahmenstrukturen (Bild 1). Obgleich die Stäbe in diesen Konstruktionen überwiegend normalkraftbeansprucht sind, führen horizontale Beanspruchungen z. B. infolge Wind sowie Einspannungen in den Verbindungsknoten zu Biege- und Querkraftbeanspruchungen. Daneben sind nahezu alle räumlichen Konstruktionen durch einseitige oder unsymmetrische Beanspruchungen einer gewollten oder ungewollten Torsionsbeanspruchung unterworfen. [Aus: Einleitung] / The principles of “Concrete Light“ apply extraordinarily well to tubular concrete members, as applied stresses can be absorbed in a concentrated and optimized way. Tubular members are decisive components of mast and tower constructions as well as of truss and frame structures (Fig. 1). Although tubular members in such constructions are predominantly subjected to normal forces, horizontal loads (e.g. due to wind) and rigid joints lead to secondary bending moments and shear forces. In addition, as a result of one-sided or asymmetrical loads, almost all spatial constructions are subjected to intentional or unintentional torsion. [Off: Introduction]

A resistência à força cortante em lajes de pontes sem armadura transversal têm sido um aspecto preocupante nas verificações de estruturas de concreto estrutural construídas décadas passadas e está diretamente relacionado aos modelos de cálculo de resistência à força cortante e de largura colaborante empregados no caso de cargas parcialmente distribuídas próximas do apoio. Entretanto, não existem ainda estudos nacionais relacionados ao nível de acurácia e precisão das abordagens geralmente empregadas na prática de projetos de pontes no Brasil. Por esta razão, propõem-se apresentar uma contribuição às análises de resistência à força cortante em lajes de pontes com ênfase no modelo de cálculo da ABNT NBR 6118:2014. Para isto foram comparados os resultados experimentais e teóricos utilizando diferentes modelos de resistência à força cortante e uma base de dados construída a partir de 642 resultados experimentais. Posteriormente, alguns modelos experimentais foram explorados por meio de simulações numéricas em elementos finitos no intuito de avaliar o nível de aproximações desta abordagem e investigar a influência de parâmetros como mísulas na proximidade dos apoios. Dentre os principais resultados desta pesquisa destaca-se que o valor médio da relação entre a resistência à força cortante teórica e experimental Vexp/Vcal utilizando a ABNT NBR 6118:2014 variou de 2,145 a 1,140 conforme o modelo de largura colaborante utilizado. Enquanto isso, os modelos numéricos calibrados apresentaram relação Vexp/VMEF variando entre 0,95 e 1,01 e com coeficientes de variação menores que 15%. De maneira geral, identificou-se que os modelos de resistência à força cortante apresentam elevados níveis de dispersão entre resultados teóricos e experimentais no caso de lajes e faixas de laje e que os modelos mais usuais de definição da largura colaborante não são precisamente adequados para o caso de cargas parcialmente distribuídas próximas do apoio. / The shear strength in bridge slabs without transverse reinforcement has been a matter of concern in structural concrete structures checks built in the past decades and is directly related to the shear force and effective width calculation models employed in the case of partially distributed loads close to the support. However, there are still no national studies related to the level of accuracy and precision of the approaches commonly used in the practice of bridge projects in Brazil. For this reason, it is proposed to contribute to the shear strength analyzes in bridge slabs with emphasis on the calculation model of ABNT NBR 6118: 2014. For this, we compared the experimental and theoretical results using different models of shear strength and a database constructed from 642 experimental results. Subsequently, some experimental models were explored by means of numerical simulations in finite elements in order to evaluate the level of approximations of this approach and to investigate the influence of parameters such as greater thickness close to the supports. Among the main results of this research, it is worth noting that the average value of the relationship between theoretical and experimental shear strength Vexp/Vcal using ABNT NBR 6118: 2014 varied from 2,145 to 1,140 according to the effective width model used. Meanwhile, the calibrated numerical models showed Vexp/VMEF ratio varying between 0.95 and 1.01 and with coefficients of variation lower than 15%. In general, it was identified that the shear strength models present high levels of dispersion between theoretical and experimental results in the case of slabs and slab strips and that the most usual models of defining the effective width are not precisely adequate for the partially distributed loads close to the support in slabs.