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Item Influência de não linearidades física e geométrica no comportamento de placas retangulares(Universidade Federal de Goiás, 2022-06-28) Aguiar, Daniella Maria Oliveira; Soares, Renata Machado; http://lattes.cnpq.br/1938664529309726; Soares, Renata Machado; Carvalho, Eulher Chaves; Silva, Frederico Martins Alves daThis work studies the influence of physical and geometric nonlinearities on the behavior of simply supported rectangular plates made of hyperelastic, isotropic, homogeneous, and incompressible material. In static analysis, geometrical nonlinearity is accounted for using two different theories to comparison - Novozhilov nonlinear theory and von Kármán nonlinear theory. The plate is under pressure loading that is described in two ways: distributed radial force (dead load) and displacement-dependent pressure (follower load or actual pressure). First the displacement field expansions are considered with three and twelve degrees of freedom, and then the Karhunen-Loève Method is applied to obtain a reduced order model. The pressuredisplacement responses are compared with those of other papers to validate the formulations. And, again using the pressure-displacement responses, the differences depending on the characteristics of the formulation employed are discussed and the solution obtained by the reduced order model is compared with the solution of the original system. In the dynamic analysis, the geometrical nonlinearity is described through von Kármán nonlinear theory, dead load pressure is applied, and the displacement field expansions are derived from the KarhunenLoève Method. The transverse frequency-displacement responses around various initial static configurations are examined. In both static and dynamic analyses, the physical nonlinearity is accounted for by the hyperelastic Neo-Hookean constitutive law, and the equations of motion are derived using Hamilton's Principle, the Rayleigh-Ritz method, and the local model method (MML). The Newton-Raphson method, adapted due to the MML, is used to solve the equations of motion. It is observed that the use of the reduced model gives satisfactory results and that the influence of nonlinearities, both physical and geometrical, are predominant when the plate is subjected to high amplitude displacements.Item Remoção de fluoreto em carvão produzido com borra de café ativada quimicamente com lixívia de cinzas de eucalipto(Universidade Federal de Goiás, 2023-04-25) Bergamini, Mário Henrique Lobo; Oliveira, Sérgio Botelho de; http://lattes.cnpq.br/3447406257464639; Scalize, Paulo Sérgio; http://lattes.cnpq.br/0957896448117207; Scalize, Paulo Sérgio; Costa, Adilson Ben da; Albuquerque, Antonio João Carvalho deThe objective of this research was to produce a biochar from exhausted coffee grounds and chemically activate it with natural lye from eucalyptus ash to subsequently evaluate the fluoride adsorption process in an aqueous medium. The following were determined: moisture content, ash content and thermal analysis of coffee grounds; solubility, alkalinity and calcium content of eucalyptus ashes. Activated biochar was subjected to elemental composition (CHNS), X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS), N2 adsorption and desorption, pH and potential of zero charge (PZC) for characterization. To select the best production condition for activated biochar, a 3² factorial design was performed. Kinetic adsorption studies were fitted to pseudofirst order, pseudo-second order, Elovich and Weber and Moris models. The nature of the process was studied by Langmuir and Freundlich isotherm models. The result of the factorial design indicated as the best scenario the impregnation rate of 5% and the temperature of 650 °C in the carbonization. SEM showed macroporosity. XRD confirmed the amorphous characteristic of cellulosic materials. The following functional groups were identified in coffee grounds and activated biochar: alcohol or phenol, hydroxyl, methyl, methylene, carbonyl, carboxylic acid, ester, chlorogenic acid, ketone, carbonyl, amino, amide and pyranose ring. The pH of the activated biochar was equal to 8.89 and the PZC was 7.17. Preliminary adsorption tests showed that the best dosage of activated biochar was equal to 3.2 g/L and the concentration of adsorbate caused a decrease in resistance to mass transfer due to the fact that there were more active sites of activated biochar in the liquid medium. However, the removal efficiency decreased with increasing adsorbate concentration. It was observed that coffee grounds, when used as an adsorbent, promoted a small reduction in the adsorbate concentration, with an average removal efficiency of 1.35%. The adsorption kinetics revealed that equilibrium is reached around 800 min and that the pseudo-second order model fitted better. The Freundlich model fitted the experimental data with the best quality. Freundlich's constant n allowed inferring that the adsorption is favorable and the isotherm appears to be L-type, with an initial downward curvature, which suggests less availability of active sites when increasing the adsorbent concentration.Item Utilização de solo laterítico, fosfogesso e bentonita em barreiras hidráulicas: uma análise hidromecânica e ambiental(Universidade Federal de Goiás, 2019-02-01) Borges, Yago Isaias da Silva; Mascarenha, Márcia Maria dos Anjos; http://lattes.cnpq.br/5184066802578105; Mascarenha, Márcia Maria dos Anjos; Sales, Maurício Martines; Boscov, Maria Eugênia GimenezThe objective of this study is to evaluate the technical viability of using a sandy lateritic soil chemically stabilized as a liner material, regarding hydromechanical and environmental features. For the chemical stabilization, dehydrated phosphogypsum and sodic bentonite were added to the soil, such six samples were obtained: Soil (S), soil + 10% phosphogypsum (SP), soil + 10% phosphogypsum + 3% bentonite (SPB3), soil + 10% phosphogypsum + 6% bentonite (SPB6), soil + 3% bentonite (SB3) and soil + 6% bentonite (SB6). Since x-ray diffractions tests showed that phosphogypsum shouldn’t be subjected to temperatures above 70˚C, the moisture values of all samples containing this material were determined in this temperature. However, the moisture values obtained in this temperature were corrected, since the soil moisture was determined at 110 ˚C and bentonite’s one at 130 ˚C. It was done through mathematical correlations, obtained comparing samples of this materials in different temperatures. For the hydromechanical tests, specimens were compacted in miniature, in accordance to the Brazilian MCT methodology, in Proctor standard energy. The compaction curves presented similar apparent dry weight values, but the stabilized samples presented higher values of optimum water content than soil. The hydraulic conductivity tests were carried out using the same cylinders used in compaction, with variable hydraulic head and gradient of 10m∕m. Phosphogypsum did not modify the coefficient of hydraulic conductivity of samples, while for the 3% of bentonite addition, these values decreased approximately one order of magnitude. Samples containing 6% of bentonite presented coefficients lower than 1x10-9 m ∕s, therefore, acceptable values for liners. In unconfined compression tests, the samples containing phosphogypsum presented lower strength, while those containing bentonite had an increasing in these values, but all them presented results higher than 200 kPa. The compatibility with contaminants was analyzed through chemical percolation tests, similar to hydraulic conductivity tests, but substituting water with solutions of HNO3, NaOH, NaCl and ethanol. The results showed that the solution of NaOH decreased the coefficients of hydraulic conductivity of samples. On the other hand, the HNO3 increased the coefficients of samples containing bentonite, such all samples presented values higher than 1x10-9 m ∕s. No significant changes were observed for solutions of NaCl and ethanol. The risk of environmental contamination due to the use of phosphogypsum was investigated through chemical analysis of solubilized extracts obtained from samples containing this by-product, taking into account the parameters prescribed by the Brazilian resolution CONAMA 396, for groundwaters. The results obtained indicated excess of iron (attributed to soil) and manganese (attributed to phosphogypsum), but further analysis was recommended for that a precise risk diagnosis was delineated.Item Construção e aplicação de índice de salubridade ambiental em aglomerados rurais(Universidade Federal de Goiás, 2021-02-19) Braga, Débora de Lima; Scalize, Paulo Sérgio; http://lattes.cnpq.br/0957896448117207; Scalize, Paulo Sérgio; Bezerra, Nolan Ribeiro; Cruvine, Karla Alcione da SilvaEnvironmental health is determined through the health status of a population, influenced by the socioeconomic and environmental conditions in which they live. One way to measure and analyze it is through the use of indexes and indicators. In this context, the Environmental Health Index emerged, which has been adapted to the particularities of the studied regions, losing one of the fundamentals of an index, comparability. In view of this scenario, the present study aims to propose a methodology for calculating the Environmental Health Index in rural agglomerates (ISARural) and apply it in rural communities in the state of Goiás. Based on the premise of the concept of environmental health, defined in this paper, and the specificities of rural areas. In order to achieve it, the methodology was carried out in four stages: bibliographic research to support the proposition of the concept and the elaboration of the forms used in this study; prior analysis for the proposition of an ISA Rural, with the participation of seven specialists; proposition of ISARural by the Delphi method, defined by the consensus of specialists in the previous step, starting with 168 specialists from the 27 Federative Units of Brazil; and the application in 43 rural communities (16 settlements, 21 quilombolas and 6 riverside) in the state of Goiás. ISARural was built in three stages: choosing and / or complementing the indicators suggested in the face-to-face discussion, weighting the indicators and selecting and weighting the sub-indicators. The specialists were divided by area of activity, which made it possible to select, adapt and / or create essential sub-indicators with specificity for each indicator. The proposed ISARural resulted in the composition of eight indicators, four related to basic sanitation, and the others, health, socioeconomic conditions, public services offered and housing conditions. The weight attributed to each indicator varied from 22.82%, for the water supply indicator, to 6.35% for the services indicator, and ISARural can be applied in its entirety or for the evaluation of each indicator individually. The application in rural and traditional communities in Goiás showed that 86.05% live in a situation of low health, highlighting the worst conditions for quilombola communities. In addition to identifying that the sewage component is the one that needs the most attention from the government. Finally, this study fulfilled the role of contributing to the proposition of an index in line with the concept of environmental health, which can be used within the scope of public policies as a condition for the application of priority resources, for planning and scenario general diagnosis of rural agglomerates.Item Caracterização experimental de túneis de vento para a análise de potencial eólico(Universidade Federal de Goiás, 2020-08-27) Cardoso, Flávia de Melo Ribeiro; Mariano, Felipe Pamplona; http://lattes.cnpq.br/4538460201961283; Mariano, Felipe Pamplona; Fagundes Neto, Marlipe Garcia; Vasco, Joel Roberto GuimarãesWind tunnel is an equipment used to study aerodynamics, whose main function is to provide high quality air flow in its test section. It makes possible to study the effects of air flow around various aerodynamic or non-aerodynamic models (airfoils, blunt bodies, anemometric towers, reduced models of civil structures and others). The qualities to be satisfied when using a wind tunnel are: a low level of turbulent intensity at the entrance of its test section, meaning uniformity in the speed and pressure fields and the height of the boundary layer formed along the length of the test section. The knowledge of both variables for the various ranges of use of the wind tunnel guarantees the appropriate boundary conditions for the experiments and makes it a reliable measuring equipment. For example, a high turbulent intensity can interfere considerably in the transition of the boundary layer, generating undesirable effects. Furnas Centrais Elétricas S.A. acquired two wind tunnels, the purpose of which is the in-depth study of the wind power generation system. To know the characteristics of the tunnels is essential in the exchange of technical and scientific information, in the comparison of experimental results, in the extrapolation of model parameters to the real scale and in the simulation of tests in Computational Fluid Dynamics. Through experimental measures, using Pitot tubes and statistical tools such as experimental planning techniques and analysis of variance (ANOVA), the turbulent intensity of approximately 0.5% was found at wind tunnel (TV1) for speeds above 12.0m/s and for speeds below 12.0m/s, the turbulent intensity increased up to 3.5% for speeds around 5.0m/s. A method of controlling the height of the boundary layer is also presented, in order to be able to study the wind potential of a given terrain.Item Modelagem do escoamento transcrítico sob regime permanente e transiente em canais(Universidade Federal de Goiás, 2021-04-27) Carvalho, Thiago Pires de; Formiga, Klebber Teodomiro Martins; http://lattes.cnpq.br/0787413754235970; Formiga, Klebber Teodomiro Martins; Vasco, Joel Roberto Guimarães; Soares, Alexandre Soares KeplerThe understanding of phenomena related to floods propagation along open channels, especially in artificial urban ones, is becoming increasingly important to avoid flooding and inundation as a result of intense precipitations. In this context, there is still great difficulty in computational modeling certain hydraulic phenomena, such as hydraulic jump, which may occur during a flood wave flow along channels under specific conditions that generate changes in flow regimes. Seeking a better understanding of this phenomenon, this work proposes the development of computational tools that simulate, through physique and mathematical equations, the propagation of flows that occur in the transition from supercritical to subcritical regimes, the so-called transcritical flow. Two computational models were developed for free-surface simulation. The first for the gradually varying permanent regime, through the Standard Step Method, as proposed by Akan (2011). The second one for the transient regime, based on solving the Saint-Venant equations in a hybrid way, where the supercritical curve was defined by the Finite Difference Method (explicit resolution) as proposed by Chaudhry (2007), and the subcritical curve was defined by the Preissmann Method (implicit resolution). Comparisons among the conjugate heights of each flow curve provided the flow transition point determination. These models were validated through laboratory tests, performed in an experimental channel, simulating different scenarios of transcritical flow, allowing the free-surface monitoring and measurement by means of a graduated ruler (experiments in gradually varying permanent regime) and ultrasonic sensors (transient regime). In particular, we aim at computational modeling the hydraulic jump phenomenon, an aproach of extreme importance and relevance for interventions in natural and artificial channels in order to promote controlled energy dissipation, regulating and stabilizing the propagation of floods and mitigating impacts downstream.Item A dinâmica hidrográfica na região sul do estado de Goiás(Universidade Federal de Goiás, 2020-10-23) Castilho, Mayara Paula Silva Franco; Ferreira, Nilson Clementino; http://lattes.cnpq.br/6466969611652630; Ferreira, Nilson Clementino; Teixeira, Denilson; Ribeiro, Hugo JoséBrazil is a world leader concerning water resources, and for its intense agricultural production. In the state of Goiás alone, more than 26 million hectares of land is earmarked for agricultural activities, and water availability is essential for the sustainability of these activities. Because of this, physical changes in hydrography may occur as a result of the increase in agricultural production, since the implementation and maintenance of these activities require interventions such as dams, water abstraction, irrigation, and deforestation. The objective of the research is to map the changes in hydrography in the Water Resources Management Planning Units (UPGRHs) of the affluent Goianos of Baixo Paranaíba and Rio dos Bois in the last three decades and to verify if they are associated with changes in use and coverage from the soil. To identify and map this water dynamics, a computational code was developed in the Java programming language and executed within the Google Earth Engine (GEE) platform, where the classification of the presence of water was carried out using the Landsat satellite images in the years 1987, 2007 and 2017. After mapping the hydrography for the aforementioned years, the data in the form of images were exported to a Geographic Information System (GIS) computer program, for area calculations and comparison of changes about hydrography. It was found that between 1987 and 2007 there were few changes in hydrography, already in 2017, it is possible to notice significant changes mainly to the emergence of large reservoirs. As a basis for calculating the hydrographic areas in this 30-year interval in the UPGRHs in the study area, a significant increase was observed from 505.16km² to 630.46km², in water depth, corresponding to an increase of 24.80%. Likewise, changes in land use and coverage were observed. The quality of the hydrography mapping elaborated in this research was evaluated in comparison with the mapping carried out for the same years by the MapBiomas project. By comparing the areas found by the two mappings, hydrographic omissions were identified in the MapBiomas data, ranging from 41% to 63%. This discrepancy does not invalidate the data provided by MapBiomas, since the classification methodology and area of coverage of the mapping is for the entire Brazilian territory, however, this comparison found the good quality of the mappings carried out within the scope of the research. Thus, the results obtained demonstrate that there is a relationship between changes in land use and hydrography and that these changes can be identified from images with a special resolution of tens of meters.Item Influência da sucção na perda de massa de um solo arenoso laterítico submetido ao efeito de ondas(Universidade Federal de Goiás, 2020-10-29) Castro, Marcus Divino de; Gitirana Júnior, Gilson de Farias Neves; http://lattes.cnpq.br/4710728908810849; Mascarenha, Márcia Maria dos Anjos; http://lattes.cnpq.br/5184066802578105; Mascarenha, Márcia Maria dos Anjos; Gitirana Júnior, Gilson de Farias Neves; Sales, Maurício Martines; Santos Júnior, Olavo Francisco dosAmong the causes of silting up in large reservoirs, the sediments deposition at bottom them, resulting from the erosion on its margins, is one those causes the decrease the useful volume these water bodies. Recent studies indicate that soil erodibility is significantly affected by its initial suction, with relative differences between initially saturated and relatively dry soil in order of 300%. Given the above, this study aims to evaluate the sandy lateritic soil mass loss of reservoir’s edge Itumbiara hydroelectric power plant, located on Paranaíba River, on border the states of Goiás and Minas Gerais, Brazil, due the waves impact, considering the suction influence. To simulate the phenomenon in question, erodibility tests were carried out on undeformed and deformed specimen the referred soil, statically compacted in differents water contents, subjecting its to the waves impact generated in a wave flume, at a pre-established frequency and inclination, which were 0.56 Hz and 30°, respectively, thus triggering hydraulic erosion on the exposed soil surface. The water contents used in the specimens moulding were defined from the samples soil-water characteristic curves, obtained through the following equipments: tempe cell, pressure plate and WP4. Mass losses from hidraulic erosion were determined after the tests and along the distance of wave flume, including the sediments granulometry determination. The soil mass loss results were compared with the initial specimens suctions, indicating an increase in soil erodibility rates with the growth of initial suction, while that the sediment distribution along the wave flume followed the general trend of sediment deposition observed in water reservoirs.Item Avaliação de soluções de manejo de águas pluviais baseadas na natureza em loteamento urbano(Universidade Federal de Goiás, 2023-10-25) Chagas, Isabela Moura; Basso, Raviel Eurico; http://lattes.cnpq.br/2827247646651873; Basso, Raviel Eurico; Formiga, Klebber Teodomiro Martins; Swarowsky, AlexandreWorldwide urban growth is continuous, accompanied by an increase in impermeable areas. This results in a reduction of evapotranspiration and water infiltration capacity into the soil, leading to increased surface runoff and negatively impacting the environment and public health. Currently, nature-based stormwater management solutions seek to mitigate these negative impacts of urbanization. This study aimed to determine, through a hydrological model, the performance of these solutions in an urban development with a high percentage of impermeable area. Considering the literature review, municipal regulations, and design criteria, green roofs and cisterns were selected as nature-based solutions to be modeled using the SWMM software. The research was conducted in five stages, including literature review and selection of nature-based solutions, selection of the study area, acquisition of secondary data, evaluation of the hydrological performance of the proposed scenarios, and assessment of the impact on the conventional drainage system. The performance evaluation included selecting SWMM variables, designing the drainage network, analyzing input data, scenario development (isolated and combined techniques), SWMM application, and analysis and comparison of results. Ten simulations were carried out with different scenarios, including the implementation of isolated and combined techniques and variations in the degree of soil impermeability. The research investigated the behavior of green roofs and found that their implementation alone reduced surface runoff by 15.5% and peak runoff by 19.7%. The isolated cistern also contributed, but to a lesser extent, with a reduction of 8.5% in surface runoff and 4.3% in peak runoff. However, the combination of the two solutions showed a more effective synergy, achieving a reduction of 20.2% in surface runoff and 22.2% in peak runoff. The results also confirmed that the degree of impermeability of the soil is inversely related to its capacity to infiltrate rainwater.Item Análise de estimativas de precipitação por satélite e de diferentes métodos de preenchimento de falhas para a região do Sudeste Goiano(Universidade Federal de Goiás, 2018-12-19) Duarte, Luíza Virgínia; Formiga, Klebber Teodomiro Martins; http://lattes.cnpq.br/0787413754235970; Formiga, Klebber Teodomiro Martins; Souza, Saulo Bruno Silveira e; Ferreira, Nilson ClementinoPrecise estimation and monitoring of rainfall occurrence patterns are essential for the modeling of hydrological systems and the planning and management of water resources in various sectors of society. Failures in data series records may compromise studies in practical applications. Advances in precipitation physics are imperative to improve numerical models and rely heavily on testing new hypotheses for actual precipitation measurements, and improved predictions are deeply intertwined with the ability to measure precipitation. In this sense, the quality of satellite precipitation products has been significantly improved in the last decades, especially with the emergence of the missions: Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) that comes as a successor to the TRMM mission in order to provide better global estimates of high quality and precipitation resolution. The objective of this study was to compare precipitation estimates generated by the GPM satellite with data observed on land in order to test the effectiveness of these rainfall estimates in relation to temporal and spatial patterns and to compare these data with traditional methods of filling data for the generation of complete series of data. The methods of comparison were applied for mean rainfall in the Meia Ponte and Rio dos Bois basins of the State of Goiás for daily, monthly and annual scales, and the failure completion methods were analyzed for the same region in daily and monthly data. The results were satisfactory for the monthly and annual analyzes in the region of the two basins and the daily precipitation data, due to their greater variability, they require more studies to refine the techniques in order to obtain better results.Item Estudo de ensaios e parâmetros de transporte de cloretos no concreto para aplicação em modelos preditivos de vida útil(Universidade Federal de Goiás, 2022-03-31) Fagundes, Rayane Campos Lopes; Matos, Oswaldo Cascudo; http://lattes.cnpq.br/3336749062812376; Oliveira, Andrielli Morais de; http://lattes.cnpq.br/9590390602101344; Oliveira, Andrielli Morais de; Faria, Tulio Honorio de; Cascudo, Helena Carasek; Matos, Oswaldo CascudoIn a contemporary engineering context, a performance approach and the design of more durable, sustainable and efficient structures are required. Corrosion of reinforcement is one of the main mechanisms of degradation of reinforced concrete structures, especially in the marine environment, and can lead to its collapse if there is no intervention. To meet this approach, predictive models have been developed, with the objective of predicting the useful life of structures, considering different degradation mechanisms; among them, the corrosion of the reinforcements. Thus, the objective of this work is to study different parameters of chloride transport in concrete with three water/cement – w/c ratios (0.40; 0.55 and 0.70) for application in prediction models of service life. For that, four different test methodologies were used to evaluate the transport of chlorides, over four months. Two migration tests were then considered – NT Build 492: 1999 (in non-steady state); LMDC test (steady state) – and a nonsteady state diffusion test: NT Build 443: 1995, carried out in two different ways, according to the standard (exclusive diffusion mechanism, with the concrete continuously submerged) and by means of weekly cycles of wetting and drying (hybrid mechanism, containing capillary absorption in the convection layer and diffusion in the deeper saturated layers). The results of the experimental program, as expected, showed a tendency for the coefficients to increase with increasing w/c ratio and a decrease in these parameters with increasing maturity of the cement matrix (age effect). Despite having different principles, the coefficients obtained by different methods showed good correlations: with the results of the NT Build 492 and NT Build 443 standards being close to each other and about 10 to 16 times greater than the effective coefficient (steady state) obtained by the LMDC test. The application of prediction models indicated the importance of a more assertive definition of the input parameters of these models, especially the diffusion coefficient used. Among the methods studied, the use of the effective diffusion coefficient (LMDC test) as an input parameter resulted in service lives more in line with reality. Among the models applied, Life-365 stood out for considering different influential factors and getting closer to reality. Regardless of the model applied or the coefficient considered as an input parameter, the w/c ratio strongly influenced the calculated service life: it reduced, on average, 40% of concrete with w/c ratio 0.40 for concrete with w/c ratio c 0.55, reduced by 50% when the w/c ratio increased from 0.55 to 0.70 and 70% from 0.40 to 0.70.Item Análise da influência do alquilbenzeno sulfonato linear (las) na agregação, sedimentação e coagulação química das nanopartículas de óxido de zinco em matriz aquosa(Universidade Federal de Goiás, 2020-10-30) Guimarães, Dáfnis Barsanulfa Vieira; Teran, Francisco Xavier Cuba; http://lattes.cnpq.br/3433455726987770; Teran, Francisco Xavier Cuba; Cuba, Renata Medici Frayne; Santiago, Mariangela FontesWith the widespread use of anionic surfactant alkylbezene linear sulfonate (LAS) and nanoparticles of zinc oxide (NP ZnO) it becomes probable the coexistence of both compounds in the aquatic environment, showning the importance of the present work in studying the effect of LAS in nanoparticles ZnO. This study was divided into 3 stages that consisted of analyzing the influence of LAS on aggregation, sedimentation, zero charge point (PCZ) and removal of nanoparticles in the coagulation process. The induced results that LAS influence the aggregation and sedimentation of nano-ZnO, mainly in LAS practices above 100mg / L. Sedimentation data were adjusted (R² without 0.85-0.99 interval) with a kinetic equation of first order with residual. The surfactant did not interfere significantly in the pHPCZ of the nano-ZnO, but both coagulants, ferric chloride and tannin, showed better results when the coagulation process with pH was close to the pHPCZ calculated. The presence of LAS in the suspension significantly influenced the efficiency of the coagulation process, in application of 300mg / L the removal efficiency was below the 5% evaluated at different pH and with two different coagulants. This study can contribute to demonstrate that the presence of LAS can alter the behavior of nano-ZnO and significantly reduce the efficiency of the coagulation process.Item Estudo do precondicionamento para o ensaio de carbonatação acelerada do concreto(Universidade Federal de Goiás, 2019-12-18) Jungblut, Mônica Engel; Cascudo, Oswaldo; http://lattes.cnpq.br/3336749062812376; Cascudo, Helena Carasek; http://lattes.cnpq.br/3023241186996790; Cacudo, Helena Carasek; Possan, Edna; Oliveira, Andrielli Morais deDurability indicators are indispensable parameters for assessing and predicting the durability of the element and structure as a whole and must be easily quantifiable by laboratory testing. However, in Brazil there is not yet a standard to standardize the accelerated carbonation test and, therefore, the tests are performed based on international standards or literature data. The accelerated carbonation test is used to obtain the durability indicator for carbonation. One of the important steps for the accelerated carbonation test is preconditioning, which must occur after curing and prior to the onset of accelerated carbonation and aims to achieve an appropriate degree of saturation of the specimen so that the carbonation reactions can occur accelerated form. Due to the lack of standardization and the variety of methodologies found in the literature to perform this step, it was proposed to study the influence of different preconditioning methods on the carbonation results with a view to proposing a methodology. For this, four types of concrete were molded: three of them being without mineral addition, with water/binder of 0,40; 0,55 and 0,70; and onde concrete with replacement of 10% by weight of cement with metakaolin with 0,55 water/binder. The concretes were preconditioned by four different methods, following the recommendations of the ISO 1920-12 (2015), NF EN 13295 (2004), XP P 18-458 (2008) e RILEM TC 116-PDC (1999). Subsequently, the accelerated carbonation test was performed with 3% of CO2, 22°C and 65% of relative humidity. The results showed that the preconditioning type had a significant influence on the carbonation depths, and for the methods of ISO 1920-12 (2015) and NF EN 13295 (2004) the measured depths were smaller, while for the methods according to XP P 18-458 (2008) and RILEM TC 116- PDC (1999) were higher, considering the same type of concrete. In addition, it was observed that concretes with lower carbonation depths presented higher surface humidity at the beginning of the test, and this humidity was reduced at the end of the test, indicating that, for these concretes, the balance between internal humidity and ambient humidity had not yet been established during preconditioning ; this had a significant influence on the carbonation depth results. Thus, the simplest preconditioning method with the least influence of internal humidity in the accelerated carbonation test was XP P 18-458 (2008).Item Envoltória de resistência do Concreto Compactado com Rolo (CCR), incluindo o efeito escala(Universidade Federal de Goiás, 2010-08-31) Junqueira, Pedro João Barbosa; Cascudo, Oswaldo; http://lattes.cnpq.br/3336749062812376; Vargas, Carlos Alberto Lauro; http://lattes.cnpq.br/3816106720170772; Vargas, Carlos Alberto Lauro; Cascudo, Oswaldo; Bittencourt, Túlio NogueiraThe dam construction tecnology with roller compacted concrete has undergone noticeable improvements in the areas of concrete technology and enforcement procedure. One can cite the enrichment of roller compacted concrete dam face and the whole sequence leading to obtaining such enrichment, in a short-term enforcement, by the least cost and with the guarantee of the security needed, as one of those remarkable improvements. This work, however, tries to contribute with the theme of the properties of concrete and incorporates basic issues of materials science to set a failure criterion to the results of combined loadings tests performed in RCC specimens of varied sizes, made with the same dosage of Junqueira et al. (2008). The goal is to predict the real strength of the roller compacted concrete dam. Therefore, tests of diametral compression, uniaxial compression, triaxial compression and direct shear tests were performed in RCC specimens of different sizes. The results of such tests were presented using tables and graphs which showed a fall of resistance with increasing the size of the specimen tested face of such loadings. Finally, the data from all trials of this work and of Junqueira et al. (2008) were gathered and studied, so as to increase the precision of the strength envelope of Hoek and Brown set.Item Estudo das técnicas de tomografia ultrassônica e radar de penetração com contribuição em metodologia de inspeção de obras de concreto(Universidade Federal de Goiás, 2022-12-21) Leonel, Antônio Carlos Assis; Matos, Oswaldo Cascudo; http://lattes.cnpq.br/3336749062812376; Oliveira, Andrielli Morais de; http://lattes.cnpq.br/9590390602101344; Oliveira, Andrielli Morais de; Cascudo, Helena Carasek; Vieira, Janine Domingos; Matos, Oswaldo CascudoPeriodic inspection programs are essential for planning preventive and corrective maintenance in a timely manner, making financial contributions and hiring technical and engineering staff, and avoiding structure collapses, huge monetary losses and social disturbances. Allied to these needs for maintenance actions, modern non-destructive testing methods are important tools for monitoring the integrity of these structures, offering quantitative and qualitative parameters that help the inspector's analysis. Given this context, this work proposes to evaluate the applicability of non-destructive tests for detecting damage in concrete structures, mainly ultrasonic tomography and GPR radar tests and, based on quali-quantitative parameters, propose the improvement of a methodology pre-existing infrastructure dedicated to large Brazilian infrastructure works such as dams, hydroelectric plants and wind farms, considering their degree of deterioration. The proposed experimental program foresees the laboratory production and molding of two structural concretes used in infrastructure works, with strength classes C25 and C45, under two curing conditions: air and humid. In these concretes, the basic characterization of the constituent materials and physical and mechanical characterization were carried out with the use of tests of compressive strength, modulus ofelasticity, water absorption by immersion and voids index and non-destructive tests (rebound hammer, ultrasonic wave velocity and surface electrical resistivity and volumetric) from 1 to 28 days. The potential use of ultrasonic tomography and GPR radar tests was also verified to identify bars and tubes inside blocks, analysis of defects generated in plates and cracking in slabs. As a result, it was possible to obtain good correlations between destructive and non- destructive tests, with coefficients of determination R 2 , mostly above 0.9. The smallest correlations obtained (on the order of 0.7 to 0.79) refer to the results of electrical resistivity of concrete submitted to dry curing in air. Regarding the verification of defects and damages in the C25 and C45 concretes, the GPR radar proved to be efficient to locate reinforcement and defects of greater magnitude. The use of ultrasonic tomography, on the other hand, proved to be useful to analyze different homogeneities, detect internal voids in small and medium-sized concrete structures, in addition to being able to act in the detection of reinforcement. However, none of the techniques could be able to accurately identify concrete cold joints. Thus, each situation in which these cutting-edge techniques are used must be precisely analyzed, depending on the test conditions and the expected results, since on many occasions it is up to the operator to interpret what is presented to him by the images generated by the radar and tomography. Finally, a proposal has been presented to change the GDE UNB methodology, with the recommendation of inserting some non-destructive tests, as well as the addition of new weighting and intensity factors to be considered, in order to compose a methodology focused on the damage analysis adapted to the situations of large infrastructure works.Item Estudo dos mecanismos de transferência de tensões de cisalhamento em concreto reforçado com fibras de aço: análise do intertravamento de agregados(Universidade Federal de Goiás, 2017-06-30) Lobo, Fausto Arantes; Araújo, Daniel de Lima; http://lattes.cnpq.br/8801080897723883; Araújo, Daniel de Lima; Pituba, José Julio de Cerqueira; Bittencourt, Túlio NogueiraIt was performed an experimental analysis in order to evaluate the contribution of the steel fibers and the aggregate size in the shear strength of the concrete. This paper describes tests to evaluate the shear strength and a test method for evaluation of shear stress transfer by aggregates interlock. In the experimental development, it was used concrete with a mean strength of 60 MPa, with 9.50 mm and 12.50 mm coarse aggregate, varying the volume of steel fibers in 0%, 0.5% and 1.5%. The results showed that the methodology developed to evaluate the direct shear test with two planes worked well until the maximum force for all the models. The direct shear testing results for pre-cracked (push-off test) attested that the fibers contribute to the effect of the aggregates interlock by reducing the crack opening and the sliding of the interface for a given shear stress. Moreover, the aggregate size contributes to the increasing of the interface roughness and consequently in the increasing of shear stress transfer. In addition, it was proposed the modification in one of the empirical models used to evaluate the interlocking aggregate phenomenon in the concrete by considering the experimental value of shear strength concrete. This modified empirical model demonstrated good correlation with the shear stress versus dilatancy that was obtained experimentally.Item Estimativa do potencial eólico a partir de experimento em túnel de vento utilizando placa plana de camada limite(Universidade Federal de Goiás, 2023-12-21) Maia, Cássia Silva de Azevedo; Fagundes Neto, Marlipe Garcia; http://lattes.cnpq.br/6303674803792521; Mariano, Felipe Pamplona; http://lattes.cnpq.br/4538460201961283; Mariano, Felipe Pamplona; Vasco, Joel Roberto Guimarães; Moreira, Leonardo de QueirozConcern about environmental imbalances is frequent throughout the world and investment in clean and renewable energy is increasing progressively. The assessment of wind resources becomes increasingly challenging, as it takes into account environmental parameters, such as climate fluctuations, in addition to financial expenses in feasibility studies for the construction of wind farms. For these studies, the estimation of wind potential uses numerical and experimental models as a complement to field measurements. This work refers to the experimental study in a wind tunnel made, available by FURNAS of the atmospheric boundary layer variation from an apparatus known as a flat boundary layer plate, which contains installed pressure probes and a flap mechanism installed on the trailing edge. Different combinations of angles (-10°, +10°, 0°, -20°, +20°) and velocities (6, 13, 20, 26 and 33 m.s-1 ) were made. The results obtained show that, when modifying the flap positioning angle, the boundary layer generated on the plate undergoes significant changes. When analyzing the angle separately for each speed, the boundary layer generated is significantly different for all speeds studied. The wind potential was better at high speeds and had a slight increase at negative flap angles.Item Análise do comportamento de sistemas dinâmicos com absorsores de vibração não-lineares sintonizados(Universidade Federal de Goiás, 2022-05-13) Marques Filho, Marcello Gomes; Nuñez del Prado, Zenón José Guzmán; http://lattes.cnpq.br/7703344458057759; Nuñez del Prado, Zenón José Guzmán; Avila, Suzana Moreira; Soares, Renata MachadoSlender and flexible structures, such as buildings or long span bridges, have become more susceptible to dynamic loads effects and an increment of their oscillation amplitudes can be noticed. Hence, the effect of large-amplitude vibrations and the consideration of nonlinearities become a relevant factor on the analysis, and, in a lot of cases, an intervention is necessary, by using vibration control mechanisms. First, in this work, the performance of a nonlinear tuned mass damper is evaluated when applied to a nonlinear Duffing equation considering nonlinear stiffness parameters with both softening and hardening behavior for the main system and the damper. For this, damped and undamped Duffing nonlinear oscillators are studied when subjected to a harmonic load or free vibration and attached to a nonlinear damper. First, the optimal linear control parameters were obtained by using Den Hartog’s criteria and these parameters are used to evaluate its performance on the nonlinear vibration regime. Then, the performance of a nonlinear tuned mass damper is evaluated when applied to a simply supported nonlinear 2D Euler-Bernoulli beam, subjected to a harmonic load or an aerodynamic follower load. For this case, the optimization process is also performed. A parametrical analysis is performance to evaluate the quality of the nonlinear tuned mass damper on the resonance curves, basin of attraction, time responses, phase planes and Poincaré sections for both the discrete and the continuous systems.Item Controle das vibrações não lineares do sistema acoplado torre eólica-pás(Universidade Federal de Goiás, 2021-04-08) Martins, Yuri Luiz Dias; Ávila, Suzana Moreira; http://lattes.cnpq.br/3770883410480180; Prado, Zenón José Guzmán Núñez del; http://lattes.cnpq.br/7703344458057759; Prado, Zenón José Guzmán Núñez del; Ávila, Suzana Moreira; Soares, Renata Machado; Morais, Marcus Vinicius Girão deSlender structures, such as wind towers, are very flexible and can undergo large displacements when subjected to external loads, considering the occurrence of coupling between tower and blades. An important way to reduce these excessive vibrations is to apply structural control. In this work, the structural control of a coupled wind tower–blade system subjected to external lateral loads and rotating blade is studied. To model the tower and blade, the nonlinear Euler-Bernoulli beam theory and the linear Euler-Bernoulli beam, respectively, are considered, and the structural control device considered is an inverted pendulum tuned mass damper, located at the top of the tower. The Rayleigh-Ritz method, together with Hamilton principle, is applied to obtain a set of nonlinear ordinary differential equations of motion which are, in turn, solved by the Runge-Kutta method. First, the dynamic instability is studied from the variation of the natural frequency with respect to the speed of rotation of the blade, where it is possible to observe the phenomenon of veering. In addition, the time response in resonance situations is obtained, as well as the optimum parameters of the mass damper tuned as an inverted pendulum. Next, a nonlinear dynamic analysis is performed to evaluate the influence of the tuned mass damper in the nonlinear regime, by obtaining the resonance curves, Poincaré sections and basins of attraction. The results demonstrate a good performance of the structural control in the dynamic behavior of the system.Item Determinação de áreas impermeáveis por meio de ferramentas de geoprocessamento(Universidade Federal de Goiás, 2021-08-18) Moreira, Pedro Augusto Gonzaga; Mendes, Thiago Augusto; http://lattes.cnpq.br/7064953575888122; Ferreira, Nilson Clementino; http://lattes.cnpq.br/6466969611652630; Ferreira, Nilson Clementino; Formiga, Klebber Teodoro Martins; Barberi, MaíraThe accelerated urbanization process associated with the government’s lack of planning generates environmental, social and economic impacts. Inherent in the urbanization process, impervious surface coverage appears as one of the main factors that generate these impacts, even becoming an indicator not only of the degree of urbanization, but also of environmental quality. goiânia was planned for 50 thousand inhabitants, however, today it has more than 1.2 million inhabitants. Therefore, it is justifiable to determine the percentage of impermeable areas in the urban perimeter of the city of Goiânia, state of Goiás, Brazil, as well as to determine the quality of drainage in the census sectors, generating a product that supports decision-making by of public managers. For that, we used the object-oriented classification technique implemented in the free InterImage software. The drainage quality map was generated by crossing the impermeable areas, Topographic Wetness Index (TWI) map and access to micro-drainage equipment. The result of the final classification was Kappa index 85%, considered excellent. The regions of the study area with the highest waterproofing rates were: central and south with 73 and 71%, respectively. The other regions had waterproofing rates close to 50%. However, it should be noted that the northern region is 35% urbanized, and according to the Goiânia risk map, this region should be preserved. In relation to the InterImage software, one should point out its limitation in relation to the maximum amount of pixel it can process. The urban drainage quality map generated identified that approximately 70% of the study area is found to be very unfavorable and unfavorable, a fact directly related to the current high degree of waterproofing of the study area