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Item Desempenho das argamassas de rejuntamento no sistema de revestimento cerâmico(2002-06) Paes, Isaura Nazaré Lobato; Carasek, HelenaItem Influência do preparo da base na aderência e na permeabilidade à água dos revestimentos de argamassa(2002-06) Scartezini, Luis Mauricio Bessa; Jucá, Tatiana Renata Pereira; Melo, Henrique Linhares; Teixeira, Fernando Alves; Antonelli, Glydson Ribeiro; Cascudo, Oswaldo; Carasek, HelenaItem Estabilidade global de estruturas reticuladas em concreto pré-moldado: influência da plastificação da ligação(2006-08) Araújo, Daniel de Lima; Ferreira, Marcelo Araujo; Debs, Mounir Khalil elItem Transient stability of empty and fluid-filled circular cylindrical shells(2006-09) Silva, Frederico Martins Alves da; Gonçalves, Paulo Batista; Guzmán del Prado, Zenón JoséIn the present work a qualitatively accurate low dimensional model is used to study the non-linear dynamic behavior of shallow cylindrical shells under axial loading. The dynamic version of the Donnell non-linear shallow shell equations are discretized by the Galerkin method. The shell is considered to be initially at rest, in a position corresponding to a pre-buckling configuration. Then, a harmonic excitation is applied and conditions to escape from this configuration are sought. By defining steady state and transient stability boundaries, frequency regimes of instability may be identified such that they may be avoided in design. Initially a steady state analysis is performed; resonance response curves in the forcing plane are presented and the main instabilities are identified. Finally, the global transient response of the system is investigated in order to quantify the degree of safety of the shell in the presence of small perturbations. Since the initial conditions, or even the shell parameters, may vary widely, and indeed are often unknown, attention is given to all possible transient motions. As parameters are varied, transient basins of attraction can undergo quantitative and qualitative changes; hence a stability analysis which only considers the steady-state and neglects this global transient behavior, may be seriously non-conservative.Item Estudo multitemporal e alteração na paisagem na região do distrito de Luiz Alves, município de São Miguel do Araguaia-GO, a partir de método indireto, sensoriamento remoto(2007-12) Santos, Alex Mota dos; Romão, Patrícia de AraújoThe article presents a study multitemporal of changes in the landscape in the district of Luiz Alves, municipality of São Miguel do Araguaia, northwestern state of Goias, from the decade of 1960 to 2007. The study was motivated by the indication of the area cited as relevant to the nature conservation at WWF-Brazil and Ministry of Environment. So that the objective were achieved using up indirect methods, images of sensors orbital (LANDSAT and CBERS), and images of sensors subortitais (aerial photographs of the USAF / USA). The images were analyzed in the GIS, from techniques for Geoprocessing. It is understood that the satellite data is not landscape, but the possibility of their representation. Thus it was necessary to integrate data and orbital suborbitais the empirical analysis and bibliographic data. This enabled the recognition of the physical characteristics of the area in question and the whole process migration to the region, which resulted in the amendment of the harmful elements of the landscape. The results showed that the livestock and irrigated agriculture are the main economic activities that alter the landscape of the area of the study. Revealed that State is the main manager of economic activities and that all changes undertake especially the track of wetland, preferential habitat of many species of wildlife. Many of these species are already on the verge of extinction, highlight done to the largest fish scales of freshwater in the world, the Pirarucu, until the decade of 1980 was easily found on this landscape.Item Modelos de análise hidráulica de redes de distribuição de água considerando demanda dirigida pela pressão e vazamentos(2008-06) Formiga, Klebber Teodomiro Martins; Chaudhry, Fazal HussainThe hydraulic analysis tools are important in the performance evaluation of water distribution networks. Various methods are available for such analysis. However, the hydraulic models that solve the system of equations describing the flow problem through Newton-Raphson or through its successive linearizations are the most efficient. It is the purpose of this paper to compare Newton-Raphson, Linear Theory, Hybrid and Gradient methods for steady-state hydraulic network analysis, considering leakage and pressure driven demand modeling. The network layout with hydraulic components frequently used in the literature was employed for this analysis. The Gradient method was found to produce best results in terms of number of iterations for the more simple networks, whereas the Hybrid method was better for more complex networks.Item Sistemas de drenagem na fonte por poços de infiltração de águas pluviais(2008-06) Reis, Ricardo Prado Abreu; Oliveira, Lúcia Helena de; Sales, Maurício MartinesThe building of large impermeable surfaces in urban spaces hinders rain water infiltration in occupied surfaces, causing natural water unbalance due to the increase in surface water flow volume and urban floods. On-lot drainage systems may help to reestablish the water balance that existed before occupation. The objective of this article is to propose design parameters for rain water infiltration wells. An experimental infiltration well was built, and tests were carried out to assess the performance and to determine the main operational characteristics of this system. The following parameters were evaluated: infiltration rate, soil structural capacity, and void-filling development. Results showed improvement of soil infiltration capacity, the need of regular maintenance, and care with soil structural stability. Design parameters and minimum performance requirements for infiltration wells were proposed.Item O uso de Sistemas de Informações Geográficas na operação de sistemas de distribuição de água(2009) Oliveira, Roberta Mara; Formiga, Klebber Teodoro MartinsItem Influence of steel fibers and mineral additions on cracking behavior of reinforced concrete tension members(2009-06) Oliveira Júnior, Luiz Álvaro de; Araújo, Daniel de Lima; Toledo Filho, Romildo Dias; Fairbairn, Eduardo de Moraes Rego; Andrade, M. A. S.In this work the influence of steel fibers and mineral additions (silica fume and fly-ash) on cracking behavior of reinforced concrete tension members was investigated. Hooked-end steel fibers with aspect ratio of 65 were used in volumes of 0.75%, 1.00% e 1.50%. Sixteen tension tests were performed in tension members 800 mm long with square cross section of 150 mm of side reinforced with single bar of CA-50 steel with diameter of 20 mm for determining crack widths. The results showed that steel fibers reduced the average crack width up to 75% and mineral additions improved cracking behavior of concrete. Crack widths were compared with suggested values by Brazilian, American and European recommendations, which were unsuitable for estimating crack width in steel fiber reinforced concrete.Item Influência dos parâmetros de ensaio na determinação da resistência de aderência de revestimentos de argamassa(2009-12) Costa, Eliane Betânia Carvalho; Carasek, HelenaThe testing of tensile bond strength, one of the main parameters to evaluate the performance of mortar renderings, is prescribed by different national and international standards. However, the existence of conflicting or under-specified parameters causes high variability of results for the same test situation. Hence, the aim of this study is to evaluate the influence of certain test parameters in the variability of the results for bond strength. The study was done in two stages: using a computer model using the Finite Element Method (Ansys® program), and an experimental study (in a laboratory), by doing tensile bond strength tests on mortar renderings applied on concrete slabs, with a total of 530 specimens. The results show that the geometry and dimension of the test specimen, the cutting procedure, the equipment type, loading rates and eccentricity contribute to the variability of the results. Additionally, there was a direct relationship between bond strength and the moisture of the rendering at the time the test was undertaken.Item Avaliação sanitária do líquido percolado em área irrigada com efluente anaeróbico(Ricardo Prado Abreu Reis, 2010) Souza, Saulo Bruno Silveira e; Coraucci Filho, Bruno; Bertoncini, E.; Stefanutti, Ronaldo; Figueiredo, R. R.Item Stress-strain curves for steel fiber-reinforced concrete in compression(2010) Oliveira Júnior, Luiz Álvaro de; Borges, Vanessa Elizabeth dos Santos; Danin, Alice Ribeiro; Machado, Daiane Vitória Ramos; Araújo, Daniel de Lima; Debs, Mounir Khalil el; Rodrigues, Paulo FernandoThis paper presents a study on the compressive behavior of steel fiber-reinforced concrete. In this study, an analytical model for stress-strain curve for steel fiber-reinforced concrete is derived for concretes with strengths of 40 MPa and 60 MPa at the age of 28 days. Those concretes were reinforced with steel fibers with hooked ends 35 mm long and with aspect ratio of 65. The analytical model was compared with some experimental stress-strain curves and with some models reported in technical literature. Also, the accuracy of the proposed stress-strain curve was evaluated by comparison of the area under stress-strain curve. The results showed good agreement between analytical and experimental data and the benefits of the using of fibers in the compressive behavior of concrete.Item Dynamic stability of imperfect cable stayed masts(2010) Guzmán del Prado, Zenón José; Carvalho, Eulher Chaves; Gonçalves, Paulo BatistaCable stayed masts are used in several engineering applications. In this work, the nonlinear finite element method, using an updated Lagrangian formulation, is used to study the effect of initial geometric imperfections on the non-linear vibrations of cable stayed masts subjected to axial time dependent loads. The non-linear equations are solved using the Newton-Raphson method associated to an arc-length technique and the Newmark method is used to calculate the time responses of the system. Validation examples are presented and the influence of initial geometric imperfections and cable tensioning is studied when stayed towers are subjected to different types of axial loads. The Budianski´s criterion is used to study the loss of stability under sudden and harmonic loads. Obtained numerical results show the great influence of both cable tensioning and cable positioning on the nonlinear behavior of the system and could be used as a tool for an analysis of the nonlinear dynamics of the structure previous to design.Item Computational modeling of steel fiber reinforced concrete beams subjected to shear(2010-03) Araújo, Daniel de Lima; Carmo, Luciano Caetano do; Nunes, Fernanda Gabrielle Tibúrcio; Toledo Filho, Romildo DiasComputational modeling has become a common activity to Civil Engineering researchers and professionals. Therefore, the knowledge about the mechanical behavior of materials is very important. To correctly model the mechanical behavior of concrete structures subjected to shear stress, it is necessary to determine the shear retention factor that accounts for the friction between the two surfaces of a crack. The objective of this study is to show how the shear retention factor of steel fiber reinforced concrete can be obtained from direct shear tests associated to computational modeling. A concrete matrix with compressive strength of 60 MPa, to which 1% and 2% content of steel fibers were added, was used for the shear tests. The stress-slip relationship was obtained from these tests, and the shear retention factor of the steel fiber reinforced concrete was determined from inverse analysis using the Finite Element Method software DIANA© 8.1.2. Finally, the shear retention factor and the influence of steel fibers on the cracks were validated from the computational modeling of steel fiber reinforced concrete beams subjected to shear available in the literature.Item Remoção de coliformes totais e escherichia coli utilizando a filtração em múltiplas etapas (fime) em períodos de alta turbidez da água bruta(Ricardo Prado Abreu Reis, 2010-12) Camplesi, Daniela Cristina Fonseca; Perez, Wanderlei Elias; Siqueira, Eduardo QueijaItem Avaliação do desempenho de sistema de reúso de água de uma edificação unifamiliar em Goiânia‐Go(Ricardo Prado Abreu Reis, 2010-12) Nirenberg, Larissa Paranhos; Reis, Ricardo Prado AbreuItem Parametric instability and snap-through of partially fluid-filled cylindrical shells(2011) Silva, Frederico Martins Alves da; Gonçalves, Paulo Batista; Guzmán del Prado, Zenón JoséThe aim of the present paper is to study the parametric instability and snap-through buckling of an axially pre-loaded, partially fluid-filled cylindrical shell. The Donnell non-linear shallow shell theory is used to study the nonlinear vibrations of the shell. For this, the Galerkin method is used, together with a suitable expansion that takes into account the main nonlinear interactions, to discretize the shell. The resulting nonlinear equations of motion are solved by numerical integration. The fluid is assumed to be non-viscous and incompressible and its inertial effects on the shell surface are obtained by the potential flow theory. A detailed parametric analysis is carried out to demonstrate the influence of the fluid height within the shell on the parametric instability load and on the snap-through buckling load in the main parametric resonance region. Using bifurcations diagrams, the main bifurcation events associated with these stability boundaries are identified. The influence of the different types of bifurcation and fluid height on the safety is also discussed.Item Denitrification coupled with methane anoxic oxidation and microbial community involved identification(2011-02) Cuba, Renata Medici Frayne; Duarte, Iolanda Cristina; Hoffmann, Nora Katia Saavedra del Aguila; Varesche, Maria Bernadete Amâncio; Foresti, EugenioIn this work, the biological denitrification associated with anoxic oxidation of methane and the microbial diversity involved were studied. Kinetic tests for nitrate (NO3 -) and nitrite (NO2 -) removal and methane uptake were carried out in 100 mL batch reactors incubated in a shaker (40 rpm) at 30 oC. Denitrificant/methanotrophic biomass was taken from a laboratory scale reactor fed with synthetic nitrified substrates (40 mgN L-1 of NO3 - and subsequently NO2 -) and methane as carbon source. Results obtained from nitrate removal followed a first order reaction, presenting a kinetic apparent constant (kNO3)) of 0.0577±0.0057d-1. Two notable points of the denitrification rate (0.12gNO3 --N g-1 AVS d-1 and 0.07gNO3 --N g-1 AVS d-1) were observed in the beginning and on the seventh day of operation. When nitrite was added as an electron acceptor, denitrification rates were improved, presenting an apparent kinetic constant (kNO2) of 0.0722±0.0044d-1, a maximum denitrification rate of 0.6gNO2 --N g-1AVS d-1, and minimum denitrification rate of 0.1gNO2 --N g-1AVS d-1 at the beginning and end of the test, respectively. Endogenous material supporting denitrification and methane concentration dissolved in the substrate was discarded from the control experiments in the absence of methane and seed, respectively. Methylomonas sp. was identified in the reactors fed with nitrate and nitrite as well as uncultured bacterium.Item Padrões de distribuições espaciais e temporais de temperaturas associados ao bioma Cerrado(2011-04) Santos, Nicali Bleyer Ferreira dos; Ferreira Júnior, Laerte Guimarães; Ferreira, Nilson ClementinoThe occurrence of vegetation is an important factor regarding the maintainance of natural biogeochemical processes. In the Cerrado, the conversion of the vegetative cover into crop fi elds and areas of cultivated pastures has induced severe modifi cations in biophysical variables such as land surface temperatures, highly sensitive to land cover / land use changes. Thus, and aiming at a more thorough understanding of the land conversion impacts on the Cerrado biophysical variables, in this study we assessed, through orbital data (MOD 11 product - Land Surface Temperature), the correlation between land occupation and thermal variability, considering 2003 imagery obtained at the beginning and end of the dry season. Data analysis showed signifi cant differences in surface temperature between natural and converted classes and revealed the spatial patterns and dependency of this variable in relation to seasonality.Item Disposição de resíduos gerados em ETAs no decantador primário de ETEs(2011-05) Scalize, Paulo Sérgio; Bernardo, Luiz Di