A presente pesquisa apresenta um estudo comparativo a respeito dos procedimentos para o projeto de dentes de concreto. O dente de concreto é um elemento estrutural bastante utilizado em ligações de estruturas de concreto pré-moldado. Atualmente existem vários procedimentos para o dimensionamento ou estimativa da capacidade resistente dessa ligação, entre os quais destacam-se o da ABNT (NBR 9062 e NBR 6118), PCI, ACI 318-14, Eurocode 2, entre outros. Neste contexto, a presente pesquisa objetiva à análise comparativa desses procedimentos de projeto com resultados experimentais disponíveis. Assim, esses procedimentos de projeto foram aplicados em 38 modelos experimentais de uma base de dados. Normalmente, as ruínas dos dentes de concreto são: a) escoamento da armadura do tirante; b) escoamento da armadura de suspensão; c) ruptura do concreto na região do dente. A relação entre a força de ruína experimental e a força de ruína calculada, designada por Fr,exp/Fr,cal, foi um dos parâmetros utilizados para avaliar as estimativas de força de ruína dos dentes de concreto. Na análise comparativa das estimativas para força de ruína por escoamento da armadura do tirante, a ABNT (NBR 9062 e NBR 6118) apresentou uma média de 1,26 e coeficiente de variação de 16,90%. A ACI 318-14 e o Eurocode 2 forneceram estimativas com uma média de 1,29 e coeficiente de variação de 17,6%. As estimativas do PCI tiveram uma média de 1,12 e coeficiente de variação de 17,9%. Para a ruína por escoamento da armadura de suspensão, as estimativas da ABNT (NBR 9062 e NBR 6118), PCI e ACI 318-14 (Modelos II e III) tiveram uma média de 1,22 e coeficiente de variação de 12,5%. O Eurocode 2 e a ACI 318-14 (Modelo I) apresentaram uma média de 1,87 para as estimativas e coeficiente de variação igual a 17,9%. Para a ruína por ruptura do concreto na região do dente, as estimativas da ACI 318-14 (Modelos II e III) apresetaram uma média de 1,56 e coeficiente de variação de 18,8%. Com o Modelo I, as estimativas da ACI 318-14 tiveram uma média de 1,60 e coeficiente de variação de 19,0%. O Eurocode 2 forneceu estimativas com uma média de 1,63 e coeficiente de variação de 14,6%. O PCI teve a pior estimativa com uma média de 3,29 e coeficiente de variação de 32,4%. O estudo ainda serviu como subsídio para o desenvolvimento de uma proposta para verificação da tensão de compressão no concreto. Para a região do dente, a proposta foi aplicada em 9 modelos experimentais da base de dados e apresentou uma média de 1,33 e um coeficiente de variação de 14,9%. / This research presents a comparative study about procedures for the design of dapped end beam. The dapped end beam is a structural element widely used in connections of precast concrete structures. Currently there are several procedures for the dimensioning or evaluation of the strength capacity of this connection, like as ABNT (NBR 9062 and NBR 6118), PCI, ACI 318-14 and Eurocode 2. In this context, the present research objetives to the comparative analysis of these design procedures with available experimental results. Thus, these design procedures were applied 38 experimental models of a database. Normally, the dapped end beam failures were: a) reinforcement yielding of the tie; b) yielding of the hanger bars; c) concrete rupture in the nib. The relation between the experimental failure force and calculated failure force, designated by Fr,exp/Fr,cal, was one of the parameters used to evaluate the estimates of failure force of dapped end beam. The ABNT (NBR 9062 e NBR 6118) presented an average of 1,26 and a coefficient of variation of 16,90% in the comparative analysis of the estimates for failure by the yielding of the tie. The ACI 318-14 and Eurocode 2 provided estimates with an average of 1,29 and coefficient of variation of 17,6%. The PCI estimates had an average of 1,12 and coefficient of variation of 17,9%. For failure by the yielding of hanger bars, estimates of ABNT (NBR 9062 and NBR 6118), PCI and ACI 318-14 (Models II and III) had an average of 1,22 and a coefficient of variation of 12,5%. Eurocode 2 and ACI 318-14 (Model I) presented an average of 1,87 for the estimates and coefficient of variation equal to 17,9%. For the rupture of concrete in nib, the ACI 318-14 (Models II and III) estimates presented an average of 1,56 and a coefficient of variation of 18,8%. With Model I, the estimates of ACI 318-14 had an average of 1,60 and a coefficient of variation of 19,0%. Eurocode 2 provided estimates with an average of 1,63 and a coefficient of variation of 14,6%. The PCI had the worst estimate with an average of 3,29 and coefficient of variation of 32,4%. The study also served as a subsidy for the development of a proposal for checking the concrete compressive stress. For nib, the simplified proposal was applied in 9 experimental models of the database and presented an average of 1,33 and a coefficient of variation of 14,9%.

Orientador: Enrique Ortega Rodriguez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T11:41:59Z (GMT). No. of bitstreams: 1 Takahashi_Fabio_M.pdf: 1666534 bytes, checksum: e3f3856c1777c40bd5655d85ba32fcef (MD5) Previous issue date: 2007 / Resumo: Este trabalho teve como objetivo o desenvolvimento de ferramentas computacionais para a realização da avaliação emergética de sistemas agrícolas utilizando as tecnologias XML, XSLT, Java, JSP, Struts e banco de dados MySQL. Na primeira etapa do trabalho, foram desenvolvidos documentos XML para representar os sistemas de agricultura química da Flórida e do Brasil. Um arquivo XSLT foi criado para processar e calcular o fluxo de emergia para cada recurso e visualizar os resultados utilizando o navegador Internet Explorer. As informações registradas nos arquivos XML são: tipo de recurso (contribuição da natureza e da economia humana), quantidade utilizada, unidade de medida, fator de conversão de unidades e transformidades solares. A análise emergética dos sistemas agrícolas pode ser feita de maneira fácil, através da modificação dos campos ¿quantidade de recursos utilizados¿ nos arquivos XML. Na segunda etapa um aplicativo java foi desenvolvido para abrir os arquivos XML e modificar esses campos. Na terceira etapa foram desenvolvidas páginas web dinâmicas utilizando-se as tecnologias JSP e Struts. Com esta ferramenta o usuário pode escolher o sistema, alterar os valores dos recursos utilizados, gravar esses dados no banco de dados e visualizar os resultados. As principais conclusões deste trabalho são: (a) a utilização da tecnologia XML e Java facilita a análise emergética dos sistemas agrícolas; (b) disponibilizando estas ferramentas na internet, o diagnóstico emergético pode ser difundido e amplamente utilizado, sem perder seus padrões de qualidade; (c) esta metodologia pode ser adaptada para representar todos os sistemas agrícolas brasileiros, incluindo os modelos ecológicos como também os químicos / Abstract: This work had the goal of developing computational tools to make the emergy evaluation of agricultural systems using the technologies XML, XSLT, Java, JSP, Struts and the MySQL database. At the first stage of this work, XML documents were developed to represent the chemical agricultural systems of Florida and Brazil. A XSLT archive was created to process and to calculate the emergy flows for each resource and to visualize the results using the Internet Explorer Navigator. The information stored on the XML archives are: type of resources (contribution of nature and economy), amount used, units of measure, units conversion factors and solar transformities. The emergy analysis of agricultural systems can be done in an easy way, through the modification of the ¿quantity of resources used¿ fields on the XML archives. At the second stage, a java application was developed to open the XML archives and to modify these fields. At the third stage dynamic web pages were developed using the technologies JSP and Struts. With this tool the user can choose the system, modify the values of used resources, save these data on the database and visualize the results. The main conclusions of this work are: (a) the use of XML and Java technologies make easier the emergy analysis of agricultural systems; (b) making these tools available at the internet, the emergy diagnosis can be spread out and widely used, without losing its quality standards; (c) these methodologies can be adapted to represent all the Brazilian agricultural systems, including the ecological models as well as the chemical models / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

Mine haul road maintenance is traditionally done at scheduled intervals or after regular inspection. Both these methods can lead to unwarranted expenditure, either through over-maintaining the road, or failure to recognise significant deterioration, resulting in an increase in vehicle operating costs. Predictive maintenance management models for unpaved roads have been developed in recent years. These methods work well in a trivial environment where variables such as traffic volume can be predicted. However, many mining systems are too complex for such models to be effective. This work investigates the possibility of using haul truck response to aid haul road maintenance management. The approach adopted for the study was twofold: Firstly, can truck response data be used to recognise specific road defects, in terms of location, type and size? This is important since different defect types require different road maintenance strategies. Secondly, can road roughness be measured on a qualitative basis? With the emphasis on road defect reconstruction, a mathematical modelling approach was adopted. The truck was characterised in terms of its suspension and tyre properties. Dynamic truck response data was acquired during field measurements in which the vehicle was driven over defects of known dimensions. With these data sets available, mathematical modelling and simulation was possible. Quarter vehicle and seven degree of freedom vehicle models played a vital role in this work by laying a foundation in the use of haul truck response for the purpose of road defect reconstruction. A modelling methodology that is based on dynamic equilibrium of an independent front unsprung mass of the truck is proposed in which the vertical dynamic tyre force and eventually the road geometry is calculated. It is shown that defects can be reconstructed from measured truck response data with an accuracy sufficient to fulfil the requirements of defect recognition for road maintenance management purposes. Secondly, a preliminary investigation into the qualitative assessment of road condition via truck response measurements was conducted. The inherent response properties of the truck pertaining to road roughness measurement were studied and some correlation between measured suspension motion and road roughness measured with a high speed profilometer was found. / Dissertation (MEng (Mechanical))--University of Pretoria, 2005. / Mechanical and Aeronautical Engineering / MEng / Unrestricted

Made available in DSpace on 2014-12-17T14:55:13Z (GMT). No. of bitstreams: 1 GleydsonAFL.pdf: 2185056 bytes, checksum: 094b58b4341884e4f12979b1aa1e99e0 (MD5) Previous issue date: 2007-02-02 / The lava Platform is increasing1y being adopted in the development of distributed sys?tems with higb user demando This kind of application is more complex because it needs beyond attending the functional requirements, to fulfil1 the pre-established performance parameters. This work makes a study on the Java Vutual Machine (JVM), approaching its intemal aspects and exploring the garbage collection strategies existing in the literature and used by the NM. It also presents a set of tools that helps in the job of optimizing applications and others that help in the monitoring of applications in the production envi?ronment. Doe to the great amount of technologies that aim to solve problems which are common to the application layer, it becomes difficult to choose the one with best time response and less memory usage. This work presents a brief introduction to each one of tbe possible technologies and realize comparative tests through a statistical analysis of the response time and garbage collection activity random variables. The obtained results supply engineers and managers with a subside to decide which technologies to use in large applications through the knowledge of how they behave in their environments and the amount of resources that they consume. The relation between the productivity of the technology and its performance is also considered ao important factor in this choice / A plataforma Java vem sendo crescentemente adotada no desenvolvimento de siste?mas distribu?dos de alta demanda de usu?rios. Este tipo de aplica??o ? mais complexa pois necessita al?m de atender os requisitos funcionais cumprir os par?metros de desem?penho pr?-estabelecidos. Este trabalho realiza um estudo da m?quina virtual lava (NM) abordando seus aspectos internos e explorando as pol?ticas de coleta de lixo existentes na literatura e as usadas pela JVM. Apresenta tamb?m um conjunto de ferramentas que auxiliam Da tarefa de otimizar aplica??es e outras que auxiliam no monitoramento das aplica??es em produ??o. Diante da grande quantidade de tecnologias que se apresentam para solucionar pro?blemas inerentes ?s camadas das aplica??es, toma-se dif?cil realizar escolha daquela que possui o melhor tempo de resposta e o menor uso de mem?ria. O trabalho apresenta um breve referencial te?rico de cada uma das poss?veis tecnologias e realiza testes compara?tivos atrav?s de uma an?lise estat?stica da vari?vel aleat?ria do tempo de resposta e das atividades de coleta de lixo. Os resultados obtidos fornecem um subs?dio para engenheiros e gerentes decidirem quais tecnologias utilizarem em aplica??es de grande porte atrav?s do conhecimento de como elas se comportam nestes ambientes e a quantidade de recursos que consomem. A rela??o entre produtividade da tecnologia e seu desempenho tamb?m ? considerada como um fator importante nesta escolha

The main purpose of this project is to build a bank system that offers a friendly and simple interface to let users easily manage their lightweight currencies. The Lightweight Currency Protocol (LCP) was originally proposed to solve the problem of fairness in resource cooperatives. However, there are other possible applications of the protocol, including the control of spam and as a general purpose medium of exchange for low value transactions. This project investigates the implementation issues of the LCP, and also investigates LCP bank services to provide human interface to currency operations.

No description available.