Understanding static and dynamic nonlinear behavior of pipes and risers is crucial for the design aspects in offshore engineering fields. In this work, we examine two nonlinear problems in offshore engineering field: vortex Induced vibration of straight horizontal pipes, and boundary layer static solution of inclined risers. In the first study, we analyze the effect of the internal velocity of straight horizontal pipe and obtain the vortex induced vibration forces via coupling the pipe equation of motion with the recently modified Van Der Pol oscillator governing the lift coefficient. Our numerical results are obtained for two different pipe configurations: hinged-hinged, and clamped- clamped. The results show that the internal velocity reduces the vibration and the oscillation amplitudes. Also, it is shown that the clamped-clamped pipe configuration offers a wider range of internal velocities before buckling instability occurs. The results also demonstrate the effect of the end condition on the amplitudes of vibration. In the second study, we develop a boundary layer perturbation static solution to govern and simulate the static behavior of inclined risers. In the boundary layer analysis, we take in consideration the effects of the axial stretch, applied tension, and internal velocity. Our numerical simulation results show good agreement with the exact solutions for special cases. In addition, our developed method overcomes the mathematical and numerical limitations of the previous methods used before.

For a bridge engineer, it is very important to estimate the maximum scour depth around the piers as accurately as possible, in order to design the footing safely. Many experimental studies have been performed by several investigators until now, in order to obtain information about scouring mechanism. The aim of this experimental study is to examine the effect of inclination of the dual bridge piers on scour depth. The experiments have been conducted with dual pier models under clear-water conditions, for various uniform flow depths. Scour depths had been measured at four different points around the piers / namely upstream and downstream faces of both piers. Dimensional and non-dimensional scour curves have been developed and presented to show the temporal variation of scour depth. The depths of local scour around inclined piers have been observed to be smaller than the scour depths around vertical piers.

Resumo: Avaliou-se o efeito do IAF residual sob a estrutura do pasto de capim-Tanzânia e o comportamento ingestivo de cabras Boer X Saanen sob lotação intermitente. O experimento foi conduzido no período de fevereiro/2008 a agosto/2008. A área foi subdividida em 18 piquetes de 243 m2 para o estudo de 3 tratamentos dispostos segundo um delineamento em blocos casualizados com 6 repetições para avaliações referentes à gramínea. As avaliações referentes ao comportamento ingestivo das cabras foram realizadas, na mesma área, em 12 piquetes, alocados em blocos casualizados, com 4 repetições. Os tratamentos consistiram em 3 IAF residuais (0,8 - 1,6 - 2,4). O período de descanso foi adotado segundo o critério de 95% de IL ou quando as leituras permanecerem constantes durante 3 semanas consecutivas. Antes do pastejo foi feito a medição da altura da vegetação em 20 pontos distintos e colheu-se 6 amostras ao nível do solo por piquete. Os animais pastejaram até atingir o IAF pré-determinado para o resíduo. Foi aferido o índice de área foliar (IAF) e da interceptação luminosa (IL) com o aparelho analisador de dossel (AccuPAR LP-80 da Decagon - USA). As amostras colhidas foram pesadas e, por conseguinte, retirada um alíquota de 400 g para a separação dos componentes morfológicos (folha, colmo + bainha e material morto), estes foram secados em estufa (55 ºC) por 72h e pesados, a fim de estimar as características estruturais. Avaliou-se a densidade volumétrica da forragem, com o auxílio do "ponto inclinado" e feita as análises laboratoriais a fim de estimar o que os caprinos consumiram durante o pastejo. As amostras analisadas foram colhidas pelo método do pastejo simulado. Também foram mensuradas variáveis que refletem o comportamento ingestivo em pastejo como a massa, a área, a profundidade e a taxa do bocado. No pré-pastejo, os valores de interceptação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The effect residual LAI was evaluate under structural characteristics of tanzania grass and the ingestivo behavior by goats Saanen X Boer at rotational stocking. The experiment was conducted in the period on February/2008 to August/2008. The area was divided into 18 paddocks of 243 m2 for the study with 3 treatments arranged in a randomized blocks design with 6 replications for the grasses evaluations. The evaluations relating to the ingestive behavior of the goats were carried out, in the same area, in 12 paddocks, allocated in randomized blocks design with 4 replications. The treatments consisted in 3 levels of residual LAI (0,8 - 1,6 - 2,4). The period of rest was adopted according to the criterion of 95% of LI or when the readability remained constant during 3 consecutive weeks. Before each period of grazing have been done 20 points of height of vegetation were taken, 6 samples at the level of the soil were collected for each paddock . The animals grazed until the the remainder LAI pre-determined. Measurements were made of leaf area index (LAI) and the light interception (LI) with the equipment AccuPAR LP-80 Decagon - USA. Samples were weighed and, 400 g were kept for the separation of morphologic components (leaf, stem lap and dead). These were dried at 55° C for 72h and weighed in order to estimate the herbage mass. Density was evaluated by volume of forage with the inclined point quadrat. Laboratory analyzes were done in order to estimate the goats fed during the grazing and the samples were collected by the handing plucking method. They were measured variables which reflect the ingestive behavior in grazing as the bite mass, area, depth and the rate . Pre-grazing, the values of light interception and leaf area index were not significantly affected by treatments (P>0.05). The values of time of pre grazing of the animals... (Complete abstract click electronic access below) / Orientadora: Ana Cláudia Ruggieri / Coorientadora: Izabelle Auxiliadora Molina de Almeida Teixeira / Banca: Ricardo Andrade Reis / Banca: Carlos Augusto de Miranda Gomide / Mestre

Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-20Bitstream added on 2014-06-13T18:57:29Z : No. of bitstreams: 1 ferreira_ds_me_jabo.pdf: 216506 bytes, checksum: 2e2ea2e29aad730dfad15d9dfd69a80d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi determinar a estrutura do pasto de capim-Tanzânia manejado em sistema de lotação rotacionada, sob dois resíduos póspastejo (alto e baixo) e o comportamento ingestivo de cabras ¾ Boer x ¼ Saanen. A área experimental foi dividida em 6 blocos, sendo dois piquetes em cada bloco, totalizando 12 piquetes. Foram estudados 3 ciclos de pastejo adotando-se 36 dias cada. Determinou-se a massa de forragem, a altura do dossel forrageiro, o teor de matéria seca do pasto e foram separados os componentes morfológicos da forragem, realizando-se estudo da distribuição espacial desses componentes. Foram calculadas a massa e a densidade volumétrica do estrato potencialmente pastejável de cada estrutura morfológica. Para análise do comportamento ingestivo, foram avaliados tempo de pastejo, ócio e ruminação, porcentagem do tempo em pastejo, ócio e ruminação. Analisando os parâmetros de estrutura de forragem, observou-se que não ocorreu diferença significativa em relação aos tratamentos testados e as principais diferenças encontradas foram em relação aos ciclos. O tempo de ruminação foi superior no tratamento de alto resíduo pós-pastejo e esses animais permaneceram mais tempo em ócio, em relação às cabras do tratamento de menor resíduo pós-pastejo que dispenderam mais tempo pastejando, permanecendo menos tempo ruminando e em ócio. Quanto aos dias de pastejo não houveram diferenças significativas entre os dias de pastejo em relação a ruminação e ócio. / The aim of this study was to determine the sward structure of Tanzania grass in rotational stocking with two post grazing residues (high and low) and ingestive behavior of ¾ Boer x ¼ Saanen goats. The area was allocated in six blocks with two paddocks in each one, totalizing 12 paddocks. It was analyzed three consecutives grazing cycles of 36 days. Forage mass, sward height, dry matter grazing were determined and the morphological components were separated to evaluate the spatial distribution. The mass and bulk density of the stratum grazed potentially were measured. It was estimated the grazing behavior by grazing time, rest time and rumination time, percentage of the grazing time, rest and rumination. The sward structure did not differ in relation of the treatments and the main differences occurred among cycles. The rumination time was higher in high residue post grazing treatment and these animals stayed more time in rest in relation the goats of the low residue treatment that used more time grazing and low rumination time and in rest. The rumination time and rest time did not differ among days.

Submitted by SILVANA ROCHA DA SILVEIRA null (silvana.silveira@anhanguera.com) on 2017-11-29T13:04:22Z No. of bitstreams: 1 Análise do comportamento do centro de pressão (CoP) na posição ereta quieta em situação de aclive, declive e horizontal diante da movimentação cefálica..pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2017-11-29T14:23:36Z (GMT) No. of bitstreams: 1 silveira_sr_dr_guara.pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) / Made available in DSpace on 2017-11-29T14:23:36Z (GMT). No. of bitstreams: 1 silveira_sr_dr_guara.pdf: 2182243 bytes, checksum: fd39ef1b65f1cbb09db1e3c1d618854b (MD5) Previous issue date: 2017-09-29 / O controle postural é um requisito imprescindível para a execução das habilidades motoras durante as tarefas das atividades de vida diária, logo, há a necessidade constante de ajuste dos segmentos corporais para garantir a autonomia e independência da mobilidade humana, dentro da conjuntura da acessibilidade. Os ajustes posturais são resultantes da interação do sistema sensório–motor e da sua correlação com o meio ambiente, produzindo orientação e estabilidade postural esperada durante a execução das atividades diárias, sendo ela estática ou dinâmica. Deste modo, o objetivo do estudo foi analisar e comparar o comportamento do centro de pressão na posição ereta quieta em situação de aclive, declive e horizontal diante da movimentação cefálica, entre três grupos com faixas etárias diferentes. O estudo transversal foi composto de 28 indivíduos, de ambos os gêneros, divididos em três grupos por faixas etárias (20 a 29 anos, 30 a 59 anos e acima de 60 anos), de acordo com os critérios de inclusão. O instrumento de avaliação constituiu-se por uma plataforma de força acoplada numa rampa com 15° e em um platô horizontal. A coleta dos dados seguiu um protocolo pré-determinado, envolvendo a posição ereta quieta com olhos abertos (OA), em quatro condições cefálicas, em três situações: aclive, declive e horizontal. Os dados obtidos foram trabalhados por meio do programa Matlab® e para a análise estatística foi aplicado o programa Action Start, utilizando a análise descritiva dos dados e o Teste Anova: fator único, Teste-t: duas amostras em par para média e Teste-t: duas amostras presumindo variâncias diferentes. Os resultados do presente estudo apontaram que a oscilação do CoP na posição ereta quieta com olhos abertos, se alteram diante das condições em que o segmento cefálico encontra – se em movimento, independente das situações de aclive, declive e horizontal, principalmente nos grupos com faixa etária igual ou superior a 60 anos / Postural control is an essential requirement for the performance of motor skills during daily activities, so there is a constant need to adjust the body segments to ensure the autonomy and independence of human mobility, within the context of accessibility. Postural adjustments result from the interaction of the sensor - motor system and its correlation with the environment, producing orientation and postural stability expected during the execution of daily activities, being static or dynamic. Thus, the objective of the study was to analyze and compare the behavior of the pressure center in the standing upright position in slope, slope and horizontal situation in front of the head movement, between three groups with different age groups. The cross-sectional study consisted of 28 individuals of both genders, divided into three groups by age group (20 to 29 years, 30 to 59 years and above 60 years), according to the inclusion criteria. The evaluation instrument consisted of a force platform coupled on a ramp with 15 ° and a horizontal plateau. Data collection followed a predetermined protocol, involving the standing upright position with open eyes (OA), in four cephalic conditions, in three situations - slope, slope and horizontal. The data obtained were worked through the Matlab® program and for the statistical analysis the Action program was applied using descriptive data analysis and the Anova test: single factor, t-test: two samples in pairs for mean and t-test: Two samples assuming different variances. The results of the present study pointed out that the oscillation of the CoP in the quiet standing position with open eyes, are altered by the conditions in which the cephalic segment is in motion, independent of slope, slope and horizontal situations, Aged 60 years or over

Orientador: Kleber Tomás de Resende / Banca: Ana Cláudia Ruggieri / Banca: Renata Helena Branco / Resumo: O objetivo deste estudo foi determinar a estrutura do pasto de capim-Tanzânia manejado em sistema de lotação rotacionada, sob dois resíduos póspastejo (alto e baixo) e o comportamento ingestivo de cabras ¾ Boer x ¼ Saanen. A área experimental foi dividida em 6 blocos, sendo dois piquetes em cada bloco, totalizando 12 piquetes. Foram estudados 3 ciclos de pastejo adotando-se 36 dias cada. Determinou-se a massa de forragem, a altura do dossel forrageiro, o teor de matéria seca do pasto e foram separados os componentes morfológicos da forragem, realizando-se estudo da distribuição espacial desses componentes. Foram calculadas a massa e a densidade volumétrica do estrato potencialmente pastejável de cada estrutura morfológica. Para análise do comportamento ingestivo, foram avaliados tempo de pastejo, ócio e ruminação, porcentagem do tempo em pastejo, ócio e ruminação. Analisando os parâmetros de estrutura de forragem, observou-se que não ocorreu diferença significativa em relação aos tratamentos testados e as principais diferenças encontradas foram em relação aos ciclos. O tempo de ruminação foi superior no tratamento de alto resíduo pós-pastejo e esses animais permaneceram mais tempo em ócio, em relação às cabras do tratamento de menor resíduo pós-pastejo que dispenderam mais tempo pastejando, permanecendo menos tempo ruminando e em ócio. Quanto aos dias de pastejo não houveram diferenças significativas entre os dias de pastejo em relação a ruminação e ócio. / Abstract: The aim of this study was to determine the sward structure of Tanzania grass in rotational stocking with two post grazing residues (high and low) and ingestive behavior of ¾ Boer x ¼ Saanen goats. The area was allocated in six blocks with two paddocks in each one, totalizing 12 paddocks. It was analyzed three consecutives grazing cycles of 36 days. Forage mass, sward height, dry matter grazing were determined and the morphological components were separated to evaluate the spatial distribution. The mass and bulk density of the stratum grazed potentially were measured. It was estimated the grazing behavior by grazing time, rest time and rumination time, percentage of the grazing time, rest and rumination. The sward structure did not differ in relation of the treatments and the main differences occurred among cycles. The rumination time was higher in high residue post grazing treatment and these animals stayed more time in rest in relation the goats of the low residue treatment that used more time grazing and low rumination time and in rest. The rumination time and rest time did not differ among days. / Mestre

Esse trabalho constitui o desenvolvimento da modelagem térmica e simulação por métodos numéricos de dois componentes fundamentais do ciclo de refrigeração por absorção de calor com o par amônia/água: o absorvedor e o gerador. A função do absorvedor é produzir mistura líquida com alta fração mássica de amônia a partir de mistura líquida com baixa fração mássica de amônia e mistura vapor mediante retirada de calor. A função do gerador é produzir mistura líquido/vapor a partir de mistura líquida mediante o fornecimento de calor. É proposto o uso da tecnologia de filmes descendentes sobre placas inclinadas e o método de diferenças finitas para dividir o comprimento da placa em volumes de controle discretos e realizar os balanços de massa, espécie de amônia e energia juntamente com as equações de transferência de calor e massa para o filme descendente. O objetivo desse trabalho é obter um modelo matemático simplificado para ser utilizado em controle e otimização. Esse modelo foi utilizado para calcular as trocas de calor e massa no absorvedor e gerador para diversas condições a partir de dados operacionais, tais como: dimensões desses componentes, ângulo de inclinação da placa, temperatura de superfície e condições de entrada da fase líquida e vapor. Esses resultados foram utilizados para estabelecer relações de causa e efeito entre as variáveis e parâmetros do problema. Os resultados mostraram que o ângulo de inclinação da placa ótimo tanto para o absorvedor como para o gerador é a posição vertical, ou 90°. A posição vertical proporciona o menor comprimento de equilíbrio (0,85 m para o absorvedor e 1,27 m para o gerador com as condições testadas) e se mostrou estável, pois até 75° não foram verificadas variações no funcionamento do absorvedor e gerador. Dentre as condições testadas para uma placa de 0,5 m verificou-se que as maiores efetividades térmicas no absorvedor e gerador foram respectivamente 0,9 e 0,7 e as maiores efetividades mássicas no absorvedor e gerador foram respectivamente 0,6 e 0,5. É esperado que os dados obtidos sejam utilizados em trabalhos futuros para a construção de um protótipo laboratorial e na validação do modelo. / This work presents the development of thermal modeling and simulation by numerical methods of two fundamental components of an ammonia/water heat absorption refrigeration cycle: absorber and generator. The function of the absorber is produce high ammonia mass fraction liquid mixture from low ammonia mass fraction liquid mixture and vapor mixture by heat removal. The function of the generator is produce vapor mixture from liquid mixture by heat addition. It is used the falling film technology over Inclined plates and the finite difference method to slice the plate length in discreet control volumes and do the mass, ammonia specie and energy balances along with the heat and mass transfer equations to the falling film. The aim of this work was obtain a simplified mathematical model to be used in control and optimization. This model was used to calculate the exchanges of heat and mass of both absorber and generator in many conditions from operational data such as: components dimensions, plate angle, surface temperature and inlet condition of liquid and vapor phase. These results were used to establish relations of cause and effect between the problem variables and parameters. The results showed that the optimum plate angle for both absorber and generator is the vertical position, or 90°. The vertical position provides the smallest equilibrium length (0,85 m to the absorber and 1,27 to the generator in tested conditions) and it proves itself to be stable, because until 75° no variations in the function of absorber and generator were detected. Among the tested condition for a 0,5 m plate length the highest thermal effectiveness for absorber and generator were respectively 0,9 and 0,7 and the highest mass effectiveness for absorber and generator were respectively 0,6 and 0,5. The obtained data is expected to be used in future works for the construction of a laboratorial prototype and in the model validation.

Discharge of brine wastewater produced from industrial plants into adjacent coastal water bodies is considered as a preferable and common method currently used in many offshore industrial plants. Therefore, it is important to carefully study the behavior of jets and their environmental impacts on water bodies close to the discharge points, especially when the density is different between the jets and the receiving water. The main goal of this study is to improve the understanding of the mixing behaviour of jet trajectories for positively (offset) and negatively (inclined) buoyant jets when density is considered a significant factor, and also to examine the accuracy of some RANS turbulence models and one type of artificial neural network in predicting jet trajectory behaviours. In the first part of this study, experiments using a PIV system for offset buoyant jets were conducted in order to study the effect of the density differences (due to salinity [nonthermal] or temperature [thermal]) between the discharge and the receiving water body on the jet behavior, and the results showed that the nonthermal jets behaved differently as compared to the thermal jets, even though the densimetric Froude numbers (Frd) and density differences (∆ρ) were similar. In addition, a Reynolds-averaged Navier-Stokes (RANS) numerical model was performed using open-source CFD code (OpenFOAM) with a developed solver (modified form of the pisoFoam solver). The realizable k-ε model showed the best prediction among the models. Secondly, an extensive experimental study of an inclined dense jet for two angles (15°and 52°) was conducted to study the effect of these angles on the jets’ geometrical characteristics in the presence of a wide range of densimetric Froude numbers as well as with different discharge densities. More experimental data were obtained for these angles to be added to the previous data for the purpose of calibrating, validating, and comparing the various numerical models for future studies. The results of these experiments are used to evaluate the performance of a type of artificial neural network method called the group method of data handling (GMDH), and the GMDH results are then compared with existing analytical solutions in order to prove the accuracy of the GMDH method in simulating mixing behaviors in water bodies. Thirdly, a comprehensive study on predicting the geometrical characteristics of inclined negatively-buoyant jests using GMDH approach was conducted. The superiority of this model was demonstrated statistically by comparing to several previous analytical models. The results obtained from this study confirm that the GMDH model was highly accurate and was the best among others for predicting the geometrical characteristics of inclined negatively-buoyant jests.

Most of the tall buildings that are built today have a straight and vertical shape, because vertical buildings are more stable and easily built than slanted ones. In the case of vertical building, bending moments in the base only exists from horizontal loads such as wind and seismic loads, but in slanted buildings there will also be bending moments from dead and live loads. In addition, transportation inside the building is also a challenge when it comes to slanted buildings. However, a new elevator system that ThyssenKrupp has developed will solve that problem. This new elevator has an ability to move in all direction both vertically and horizontally. The new structural system, Tube Mega Frame (TMF), has been studied and proved to have better efficiency than the central core with outriggers. Moving the bearing structure to the perimeter of the building, gives smaller overturning moment and better stability due to longer lever arm from the center. This thesis focuses on applying the Tube Mega Frame system to a slanted building which has a tripod structure. Different types of TMFs were used to compare the efficiency of the buildings performance. The TMF contains perimeter frame and mega columns with different binding systems such as belt walls and bracings. A pre-study has been carried out in order to see the overall behavior of the tripod shape. Different heights and inclinations have been analyzed with stick models. The analysis has been performed in the finite element software SAP2000 and deflections due to dead load was compared. The buildings with least deflection considering maximum height and maximum inclination was chosen for further model analysis in finite element software ETABS. Furthermore, a short study of different bracings system has been performed for the lateral loads and it concluded that X-bracing have better performance. The main study of this thesis focused on the two building models of 450 m with 7° inclination and 270 and 15° inclination. For each model, five different TMF systems were applied and analyzed. The TMF includes perimeter frame, perimeter frame with belt wall, mega columns, mega columns with belt wall and mega columns with bracings. Deformations due to wind load, seismic load and modal vibration has been compared. It concluded that the least deformation is achieved by the TMF mega columns with bracings for both models with two different heights. The periods of the building are comparatively lower than other systems. The deflection from TMF mega columns with belt walls did not differ much from the TMF mega columns with bracings. For the 270 m high building, the top story displacement was remarkably small because of the three legs, making it stiffer and stable. Even with the p delta effect, there were only millimeters of difference in top story displacement. TMF perimeter frame had a lower deflection than with belt wall, which should have been exact opposite. The reason was while making the total volume of buildings equal, the addition of belt walls led to thinner columns in the perimeter and lower stiffness.

Skewed bridges have exhibited poorer performance during lateral earthquake loading in comparison to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Results from numerical modeling by Shamsabadi et al. (2006), small-scale laboratory tests by Rollins and Jessee (2012), and several large-scale tests performed by Rollins et al. at Brigham Young University (Franke 2013; Marsh 2013; Palmer 2013; Smith 2014; Frederickson 2015) led to the proposal of a reduction curve used to determine a passive force skew reduction factor depending on abutment skew angle (Shamsabadi and Rollins 2014). In all previous tests, a uniform longitudinal load has been applied to the simulated bridge abutment. During seismic events, however, it is unlikely that bridge abutments would experience pure longitudinal loading. Rather, an inclined loading situation would be expected, causing rotation of the abutment backwall into the backfill. In this study, a large-scale test was performed where inclined loading was applied to a 30° skewed bridge abutment with sand backfill and compared to a baseline test with uniform loading and a non-skewed abutment. The impact of rotational force on the passive resistance of the backfill and the skew adjust factor was then evaluated. It was determined that inclined loading does not have a significant effect on the passive force skew reduction factor. However, the reduction factor was somewhat higher than predicted by the proposed reduction curve from Shamsabadi and Rollins 2014. This can be explained by a reduction in the effective skew angle caused by the friction between the side walls and the back wall. The inclined loading did not change the amount of movement required to mobilize passive resistance with ultimate passive force developing for displacements equal to 3 to 6% of the wall height. The rotation of the pile cap due to inclined loading produced higher earth pressure on the obtuse side of the skew wedge, as was expected.These findings largely resolve the concern that inclined loading situations during an earthquake may render the proposed passive force skew reduction curve invalid. We suggest that the proposed reduction curve remains accurate during inclined loading and should be implemented in current codes and practices to properly account for skew angle in bridge design.