As gramíneas forrageiras representam plantas de grande interesse econômico. Diversas são as espécies tropicais que apresentam-se como opções para a formação de pastagens no Brasil, desta forma objetivou-se neste trabalho a determinação de fatores que devem ser considerados em modelos para a predição da produção de forragem em cultivares de Brachiaria brizantha; gerar e testar modelos empíricos para a predição da taxa de acúmulo de matéria seca no capim-marandu; e parametrizar e comparar modelos mecanicistas, na estimativa de produção de matéria seca do capim-marandu. Para isso, foi conduzido um experimento no campo experimental da Embrapa Pecuária Sudeste, localizada no município de São Carlos SP. O delineamento experimental utilizado foi em blocos completos inteiramente casualizado com quatro repetições. Os cultivares de Brachiaria brizantha cv. Marandu, Xaraés e Piatã foram avaliados em crescimento livre e com freqüência de corte a cada 35 dias, em esquema fatorial 3x2. Foram avaliados: acúmulo de forragem, índice de área foliar (IAF), área foliar específica (AFE), altura do meristema apical, altura de plantas e estádio de desenvolvimento do perfilho. O corte influenciou a massa seca de forragem acumulada por corte acima do resíduo em todos os cultivares de B. brizantha, sendo que o cultivar Xaraés apresentou o maior acúmulo quando comparado aos cultivares Marandu e Piatã. Na avaliação da AFE, houve efeito de cultivar, onde o cultivar Piatã apresentou a menor média (136,3 cm2.g-1), entretanto, os cultivares Marandu e Xaraés foram semelhantes (163,6 e 156,7 cm2.g-1; P>0,05). O corte não influenciou nos valores de AFE, mas a AFE diminuiu ao longo do tempo. No acúmulo de forragem ao longo do ano, destacou-se o cultivar Xaraés quando comparado aos cultivares Marandu e Piatã (25.539 contra 18.148 e 19.292 kg MS.ha-1.ano-1). O IAF acima do resíduo apresentou altas correlações com o acúmulo de forragem ao longo do ano com valores de r de 0,95, 0,93 e 0,94 para os cultivares Marandu, Piatã e Xaraés, respectivamente (P<0,0001). A partição de massa seca da parte aérea foi influenciada pelo corte e pelas variações estacionais de temperatura e luminosidade. Em todos os cultivares foram observados períodos de juvenilidade, sendo um importante fator a ser considerado em modelos envolvendo o crescimento de Brachiaria brizantha. A abordagem de modelos empíricos mostrou-se uma alternativa prática e viável, capaz de estimar a produção de forragem. O modelo que relacionou a variável climática de graus-dias corrigida pela relação ETR/ETP apresentou a melhor predição da taxa média de acúmulo de matéria seca para a cidade de São Carlos. O CROPGRO apresentou subestimativas na produção de matéria seca nos diferentes anos, principalmente no período de primavera/verão, responsável pelas maiores produções. Já o GRAZPLAN simulou satisfatoriamente as produções de massa seca, estimando valores bem próximos aos valores reais de produção, tanto no período de menor produção (outono/inverno) quanto no período de maior produção (primavera/verão). / The grasses represent plants of great economic interest. Several tropical species that are presented as options for pasture establishment in Brazil, so the objective of this work is to determine the factors that should be considered in models for prediction of forage in Brachiaria brizantha generate and test empirical models for predicting the rate of dry matter accumulation in Marandu grass, and parameterize and compare mechanistic models to estimate the dry matter production of Marandu grass. For this, an experiment was conducted at Embrapa Southeast Cattle, located in São Carlos - SP. The experimental design was randomized complete block with four replications. The cultivars of Brachiaria brizantha cv. Marandu, Xaraés and Piatã were valued at free growth and with a cut each 35 days in a factorial 3x2. It was evaluated: herbage accumulation, leaf area index (LAI), at specific leaf area (SLA), height of apical meristem, plant height and tiller growth stage. The cut affected the herbage dry matter accumulated by cutting up the residue in all cultivars of B. brizantha, and the Xaraés cultivar showed the greatest accumulation when compared to the cultivars and Marandu Piatã. In the evaluation of ERA, there was no effect of cultivar, where the Piatã had the lowest average (136,3 cm2.g-1), however Xaraés and Marandu cultivars were similar (163,6 and 156,7cm2.g-1, P> 0.05). The cut did not affect the values of AFE, but the SLA has decreased over time. In herbage accumulation over the years, the highlight was the cultivar Xaraés compared to cultivars Marandu and Piatã (25,539 against 18,148 and 19,292 kg MS.ha-1.year-1). LAI above the residue showed a high correlation with herbage accumulation over the years with r values of 0,95, 0,93 and 0,94 for cultivars Marandu Piata and Xaraés, respectively (P <0,0001) . The partitioning of dry mass of shoots was influenced by the cut and the seasonal variations in temperature and luminosity. In all cultivars were observed periods of juvenility, being an important factor to be considered in models involving the growth of Brachiaria brizantha. The approach of empirical models proved to be a practical and viable alternative, capable of estimating forage production. The model relating the variable climate of degree-days adjusted by the ratio AE/PE showed the best prediction of the rate of accumulation of dry matter to the city of São Carlos. The CROPGRO had underestimated the dry matter production in different years, especially during the spring/summer, responsible for higher yields. Already the GRAZPLAN simulated satisfactorily dry mass production, estimating values very close to the real values of production, both in periods of low production (fall/winter) and in the period of peak production (spring/summer).

Submitted by Nara Lays Domingues Viana Oliveira (naradv) on 2015-07-14T19:59:40Z No. of bitstreams: 1 dieter.pdf: 18462192 bytes, checksum: 60a4b11114f9b22cbd27bd9bcf034aa8 (MD5) / Made available in DSpace on 2015-07-14T19:59:40Z (GMT). No. of bitstreams: 1 dieter.pdf: 18462192 bytes, checksum: 60a4b11114f9b22cbd27bd9bcf034aa8 (MD5) Previous issue date: 2012-06-15 / UNISINOS - Universidade do Vale do Rio dos Sinos / O modelo de simulação computacional por eventos discretos é uma poderosa ferramenta para a solução de problemas complexos na indústria. A tendência, segundo especialistas, é de que esta se transforme em uma importante ferramenta no processo decisório das organizações. Encontram-se, no entanto dificuldades no processo de integração e manutenção da ferramenta em longo prazo nas organizações, fazendo com que tal previsão não seja concretizada. A pesquisa propõe uma forma de integrar, e, principalmente, garantir o uso continuado de modelos de simulação por eventos discretos, por meio de uma estrutura de governança. O desenvolvimento da pesquisa transcorreu, primeiramente, sobre uma pesquisa empírica junto a especialistas do tema e um estudo do referencial teórico nacional e internacional sobre os motivos, pelos quais a longevidade funcional dos modelos de simulação é interrompida. O processo de Pensamento da Teoria das Restrições (TOC) além de auxiliar na análise e prescrição de uma solução para o problema também contribuiu para a o entendimento do processo de implementação da mudança. O resultado da pesquisa foi um framework dividido em três etapas: preparação da empresa, desenvolvimento do sistema e manutenção com desdobramentos em processos, que, juntamente com uma estrutura de contabilidade de ganhos busca explicitar uma nova forma de entender os custos e os possíveis ganhos que o modelo pode proporcionar à organização. A contribuição da pesquisa versa sobre uma proposta de governança que possa garantir o uso continuado de modelos de simulação computacional e gerar ganhos à organização. / The Discrete Event Simulation is a powerful tool in the solution of complex problems in industry. The tendency, according to experts, is that it will become an important tool in the decision making process of the organizations. There are, however, difficulties in the process of integration and maintenance of the tool in long term in the organizations, so that this prevision does not become concrete. This research proposes a way to integrate and, most importantly, guarantee the continuous suitable usage of Discrete Event Simulation Models, by the means of a governance structure. The development of the research was, firstly, an empirical research with experts in the subject and a national and international theoretical reference about the reasons of the interruption of the functional longevity on the Simulation Models. The Thinking Process of Theory of Constraints (TOC) besides helping the analyses and prescription of a solution to the problem, also contributes to the understanding of the changing implementation process. The result of the research was a framework divided in three steps: preparation of the company, development of the system and maintenance with reflection in processes which, together with the accountant structure of benefits, tries to explain a new way of understanding the costs and possible gains that the model will suggest to the organization. The contribution of the research is about a governance proposal which can guarantee the continuous usage of computational simulation models and generate gains to the organization.

O objetivo desta pesquisa é investigar como o fluxo de pedestres interfere na concepção arquitetônica dos espaços que envolvem multidões. Tendo como objeto inicial as estações metroferroviárias, realizou-se um abrangente levantamento bibliográfico sobre o tema, buscando abordá-lo na complexidade que envolve o comportamento humano, a engenharia, a arquitetura e a construção. Conceitos sobre modelagem e simulação de fluxos de pedestres são apresentados e servem de base para o desenvolvimento de um estudo de caso sobre a concepção de distintos espaços arquitetônicos: O Estádio Arena das Dunas, em Natal; o Estádio Mineirão, em Belo Horizonte; o Parque Olímpico, no Rio de Janeiro; e a interligação metroviária Paulista-Consolação, em São Paulo. A presente pesquisa não tem a pretensão de apresentar soluções ou diretrizes de projeto para espaços que envolvem multidões, mas busca investigar como a concepção desses espaços pode ser alterada a partir de uma abordagem que coloca os pedestres como elemento determinante da arquitetura. / This essay aims at investigating how the pedestrian flow interferes the architectural design of the places full of people. Regarding the subway and rail stations as the initial objective, it was made a comprehensive bibliographic survey about this subject in order to speaking about the human behavior engineering, architecture and construction complexity. It is presented the modeling and simulation concepts of pedestrian flows which function as the basis for the development of a case study of different architectural spaces design: the Arena das Dunas Stadium in Natal, the Mineirão Stadium in Belo Horizonte, the Olympics Park in Rio de Janeiro and the subway stations interconnection Consolação-Paulista in São Paulo. This essay does not intend to present solutions or design guide lines for places full of people, but investigate how the design of these places can be changed from an approach that is considering the pedestrians as a determinant element of the architecture.

Performance-based landfill design approach is a relatively new design approach adopted recently in solid waste management and applied in USA, European Union countries and some developing-economy countries like South Africa. This approach rejects the strict design criteria and accommodates a design that selects the most appropriate design components of a landfill (final cover, bottom liner, and leachate collection system) and their design details to result in the best overall performance with respect to performance criteria (groundwater contamination and stability) considering the system variables (climatic conditions of the site, site hydrogeology, and size of the landfill). These design components, performance criteria and design variables involved in decision process make performance-based landfill design a complex environmental problem. Decision support systems (DSS) are among the most promising approaches to confront this complexity. The fact that different tools can be integrated under different architectures confers DSSs ability to confront complex problems, and capability to support decision-making processes. In this thesis study, a DSS to aid in the selection of design components considering the design variables and performance criteria for performance-based landfill design was developed. System simulation models and calculation modules were integrated under a unique DSS architecture. A decision support framework composed of preliminary design and detailed design phases were developed. The decision of appropriate design components leading to desired performance was made based on stability issues and vulnerability of groundwater, using knowledge gathered from DSS. Capabilities and use of the developed DSS were demonstrated by one real and one hypothetical landfill case studies.

Producing since 1995, Bozova Field is a mature oil field to be re-evaluated. When evaluating an oil field, the common approach followed in a reservoir simulation study is: Generating a geological model that is expected to represent the reservoir / building simulation models by using the most representative dynamic data / and doing sensitivity analysis around a best case in order to get a history-matched simulation model. Each step deals with a great variety of uncertainty and changing one parameter at a time does not comprise the entire uncertainty space. Not only knowing the impact of uncertainty related to each individual parameter but also their combined effects can help better understanding of the reservoir and better reservoir management. In this study, uncertainties associated only to fluid properties, rock physics functions and water oil contact (WOC) depth are examined thoroughly. Since sensitivity analysis around a best case will cover only a part of uncertainty, a full factorial experimental design technique is used. Without pursuing the goal of a history matched case, simulation runs are conducted for all possible combinations of: 19 sets of capillary pressure/relative permeability (Pc/krel) curves taken from special core analysis (SCAL) data / 2 sets of pressure, volume, temperature (PVT) analysis data / and 3 sets of WOC depths. As a result, historical production and pressure profiles from 114 (2 x 3 x 19) cases are presented for screening the impact of uncertainty related to aforementioned parameters in the history matching of Bozova field. The reservoir simulation models that give the best match with the history data are determined by the calculation of an objective function / and they are ranked according to their goodness of fit. It is found that the uncertainty of Pc/krel curves has the highest impact on the history match values / uncertainty of WOC depth comes next and the least effect arises from the uncertainty of PVT data. This study constitutes a solid basis for further studies which is to be done on the selection of the best matched models for history matching purposes.

Energy shortage, escalation of energy cost and climate change have led to an increased focus on energy conservation worldwide. In order to curb the increase in electricity demand, Eskom has introduced demand-side management (DSM) to improve energy efficiency and to shift peak-time load to off-peak periods in order to postpone additional capacity requirements. In the past, several mine DSM projects have been implemented without the use of system simulations as part of the analysis of project planning. Many of these projects are characterised by contractual energy saving targets that have not been met, projects that are delayed, potential energy savings projects that have been overlooked and additional savings that have not realised. This study demonstrates the potential of simulations to plan new and correct implemented DSM solutions. This is done by allowing analysis of energy consumption in complex technical systems and quantification of the savings potential of DSM interventions to inform design changes in order to attain energy savings. In applying simulations to a well-instrumented compressed air system, it was possible to compare the theoretical and measured values for system parameters. The simulation was fine-tuned for low-pressure operation (with the system operating well within design constraints) by incorporating estimated flow losses. By simulating high-pressure operation in which the system operates closer to design limits, the constraints that were experienced, were revealed. This application exemplifies the approach that has been adopted in the case studies to follow. The value of the use of simulation models for mine DSM projects Simulations that have been applied to four case studies demonstrate the use in improving existing DSM projects as well as in planning new DSM projects. Two case studies demonstrate the use of simulations in rectifying problems that have been encountered during the implementation of existing mine DSM projects. Simulations have been employed to propose corrections to these project implementations; this demonstrates significant value for the customer. In two additional case studies, the value of simulation models is demonstrated where simulations have been developed prior to the implementation of DSM projects. It demonstrates that projects can be implemented with less effort, in a shorter time span and at a reduced cost (both capital and man-hours) by using simulations in the planning phases of DSM projects. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.

Energy shortage, escalation of energy cost and climate change have led to an increased focus on energy conservation worldwide. In order to curb the increase in electricity demand, Eskom has introduced demand-side management (DSM) to improve energy efficiency and to shift peak-time load to off-peak periods in order to postpone additional capacity requirements. In the past, several mine DSM projects have been implemented without the use of system simulations as part of the analysis of project planning. Many of these projects are characterised by contractual energy saving targets that have not been met, projects that are delayed, potential energy savings projects that have been overlooked and additional savings that have not realised. This study demonstrates the potential of simulations to plan new and correct implemented DSM solutions. This is done by allowing analysis of energy consumption in complex technical systems and quantification of the savings potential of DSM interventions to inform design changes in order to attain energy savings. In applying simulations to a well-instrumented compressed air system, it was possible to compare the theoretical and measured values for system parameters. The simulation was fine-tuned for low-pressure operation (with the system operating well within design constraints) by incorporating estimated flow losses. By simulating high-pressure operation in which the system operates closer to design limits, the constraints that were experienced, were revealed. This application exemplifies the approach that has been adopted in the case studies to follow. The value of the use of simulation models for mine DSM projects Simulations that have been applied to four case studies demonstrate the use in improving existing DSM projects as well as in planning new DSM projects. Two case studies demonstrate the use of simulations in rectifying problems that have been encountered during the implementation of existing mine DSM projects. Simulations have been employed to propose corrections to these project implementations; this demonstrates significant value for the customer. In two additional case studies, the value of simulation models is demonstrated where simulations have been developed prior to the implementation of DSM projects. It demonstrates that projects can be implemented with less effort, in a shorter time span and at a reduced cost (both capital and man-hours) by using simulations in the planning phases of DSM projects. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.