Programa de Pós-Graduação em Engenharia Civil - PPGEC/ITEC

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2303

O Programa de Pós-Graduação em Engenharia Civil (PPGEC) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA) foi aprovado pela CAPES em 1999 e teve sua primeira turma iniciada em 2001, sendo o primeiro Curso de Mestrado Engenharia Civil na Região Norte do Brasil, realizando atividades integradas de Ensino, Pesquisa e Extensão nas áreas de Engenharia Civil e Engenharia Sanitária e Ambiental.

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Agora exibindo 1 - 19 de 19

Acesso aberto (Open Access)
Análise experimental de lajes lisas unidirecionais de concreto armado ao puncionamento simétrico ou assimétrico
(Universidade Federal do Pará, 2006-03-02) FERREIRA, Maurício de Pina; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
Punching is normally a critical case in the design of reinforced concrete flat slabs. According to many design codes, punching develops in a more unfavorable way in cases where the load is asymmetrically applied, due to unbalanced bending moments at slab-column connections. In order to evaluate the normative prescriptions in these cases, 12 reinforced concrete oneway flat slabs ( c f ' between 36 and 58 MPa) were submitted to symmetric or asymmetric punching. The slabs dimensions were (1.800 x 1.800 x 110) mm with the load being applied through a metallic plate simulating a square column with (85 x 85 x 50) mm. This research had as variables, in addiction to the load position, the reinforcement rate in transversal direction, in order to evaluate their influence in the punching ultimate resistance of one-way slabs. Results for vertical deflections, concrete surface and flexural reinforcement strains, cracking pattern, observed ultimate loads and failure modes are presented and analyzed. Also were analyzed the estimates of 6 design codes, with 3 European and 1 North-American, beyond the versions from 1978 and 2003 of the Brazilian structural concrete design code. A numerical analysis using the Finite Elements Method to simulate the slabs behavior is presented and its results are compared to the experimentally observed ones. The results showed that, unlike the normative previsions, punching resistance doesnt reduce linearly with the increments in the loads eccentricities, with the flexural effects significantly influencing the ultimate punching resistance. Even in one-way slabs, the transversal reinforcement rate showed significant influence on the slabs force distribution, interfering in the punching resistance.
Acesso aberto (Open Access)
Análise experimental de lajes lisas unidirecionais de concreto armado com pilares retangulares ao puncionamento
(Universidade Federal do Pará, 2007-12-20) DAMASCENO, Lins Sandro Resque; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
They were analyzed 8(eight) experimentally one-way flat slabs of reinforced concrete, without punching shear reinforcement, for that the reinforcement rate in secondary direction and the largest dimension of the pillars (cmax). The flat slab were dimensions of (1.800 x 1.800 x 110) mm, same flexing reinforcement, to smallest dimension of the columns (cmin) constant and equal to 85 mm, resistance to the compression of the concrete around 40 MPa and submitted to the load in the center (symmetrical punching shear), that it simulates an internal column of a pavement. The application of the load was accomplished in passages of columns linked moliticamente to the flat slab with height 150 mm, with retangularidade rate (r = cmax/cmin) varying from 1 to 7. The objective was to evaluate the influence of the retangularidade rate, that contemplated in the increase of the control perimeter in this case, in the behavior of the slabs under flexing, and possibly a more ductile failure. The objective went to also analyze the dear rupture loads starting from the recommendations of six national and international project codes, comparing with the obtained experimental results and evaluating the estimates to the punching shear, once, when the dimensions of the pillars are substantially different can happen the polarization of tensions and the resistance earnings doesn't happen in way directly proportional to the increase of the perimeter of the columns. After analyzing the influences of the retangularidade rate of the columns and the contributions that the reinforcement rate in secondary the last loads of the flats slabs and in the failure modes, it was observed that the experimental results indicated that those varied besides elevating the resistance of the connection can supply certain ductility to the failure of the slabs. It was observed that the rate of growth of the resistances obtained in the rehearsals decreases with increments in the control perimeter. Of the observations regarding the comparison among the values of resistances of the flats slabs, it was verified that the increase of the load of experimental rupture didn't come in a lineal way, indicating that the rate of growth of the load decreases with the increase of the perimeter of the column or of the rate cmax/cmin when stays constant to smallest dimension of the column (cmin).
Acesso aberto (Open Access)
Avaliação da durabilidade de concretos produzidos com agregados graúdos reciclados provenientes de cerâmicas vermelhas com diferentes taxas de pré-saturação
(Universidade Federal do Pará, 2013-09-05) REIS, Felipe José Losada; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
The amount of waste generated by the construction industry has been calling attention lately due to the size with which acts as the environmental impact of using non-renewable natural sources materials and increasing the amounts of waste produced by the urban environment. In Brazil, this estimate is around 90,000 tons generated per day. The proposed use of aggregate from CW ( construction waste ) as part of structural concrete becomes even more interesting from the moment we are seeking a reduction in costs for the production of concrete , carrying environmentalist mentality when sparing use of natural resources which some are already starting to run out. Banks of sand and pebble sources begin to fade due to the wide use of these aggregates in the concrete produced in Belém and inland cities in the state of Pará. The need for new sources of aggregates makes us seek in construction waste likely sources of aggregates responding in a similar fashion to natural. Considering this proposal, this dissertation evaluated the durability of concrete produced with the addition of ceramic CW through trials of water absorption by capillarity, carbonation, chloride ion penetration and electrical resistivity. To that end, we replaced the natural coarse aggregate by ceramic coarse aggregate by 50%, where this percentage of recycled aggregate was subjected to the rates of pre - saturation of 60 %, 80 % and 100 %. According to the results it can be seen that the presence of RCCA (recycled ceramic coarse aggregate), regardless of the degree of pre- saturation was significant in all the results, the fact that the concrete while leaving more susceptible to loss of durability, it showed a pattern of behavior in relation to the reference mixtures. The closest matches conventional concrete mixtures were made by containing pre- saturated with water at a rate of 80 % ceramic aggregates.
Acesso aberto (Open Access)
Avaliação da qualidade da água superficial do canal São Joaquim, Belém - PA
(Universidade Federal do Pará, 2016-03-15) PAREDES, Brenda Melise Morbach; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922
The process of urbanization and illegal occupation of urban channel margins nearby areas generate large impacts on these water bodies, the main one being the discharge of effluents. The channel São Joaquim, Belém Pa, is considered the largest urban channel Bethlehem, and already suffers from such impacts, as well as being affected by the lack of sanitation in its Sub Basin, such a situation can be observed in the results obtained in 12 months sampling over three points from its source to its mouth. This study aimed to analyze the said water quality Canal in physical, chemical and biological parameters through the IQA and application of descriptive statistics, analytical and multivariate analysis, being possible to observe the degradation of this water body caused mainly by organic matter, which was obtained through the OD analysis, BOD, total nitrogen, total phosphorus, and thermotolerant coliforms. The Water Quality Index was calculated for the Channel and was obtained the value of 49 classifying it as quality "acceptable." When performing a seasonal comparison between dry periods and wet, and tide conditions, using the Mann Whitney hypothesis tests and test T Student, it was observed that there was significant variability between the variables, except for the temperature, which It showed a variation between the dry and rainy seasons. The analysis of variance (ANOVA) was applied for the verification of similarity between the points for each variable analisada.Ao perform a temporal assessment of water quality of the channel between the years 1988; 2002; 2005; 2006; 2011 and 2014, it was observed that the degradation of the channel has a history of nearly 30 years, a situation confirmed by the analysis of indicator variables of organic matter. The principal component analysis led to the formation of three components that together represented 67.53% of the variability of the data, and these variables explained by the ACP, anthropic action indicative.
Acesso aberto (Open Access)
O balanço de massa das unidades componentes de uma estação de tratamento de esgoto e a utilização da estatística multivariada como ferramenta de verificação do comportamento físico, químico, bacteriólogico e de metais no esgoto bruto e tratado. Estudo de caso: estação de tratamento de esgoto doméstico – ETE Sideral - Belém - PA
(Universidade Federal do Pará, 2013-10-04) FARIAS, Flavia da Silva; MENDONÇA, Neyson Martins; http://lattes.cnpq.br/7534816053779593
The mass balance of the component units of a wastewater sewage treatment and use of multivariate statistics as a tool for verifying the behavior of raw sewage and treated, was implemented in ETE Sidereal Municipality of Belem do Para in Brazil. This study observed the entire flowchart constituent of the station that is designed to receive a maximum flow of raw sewage of 73 l / s. and now serves a flow of only 1.7 l / so that decreases in 96% of the station was designed, realizing then that today the Sidereal ETE is oversized. In verifying the constituent physical parts of the station there were not in compliance measures that have been suggested in the executive project and were perceived as "in situ". In the mass held for three types of flows: maximum (73 l / s) averaged 43 l / if current 1.7 l / s realized that the decrease in attendance constituent units of the system decreases somewhere around 97.5% the volume to which the components are designed for and found in the Sewage Treatment Station Sidereal. In the characterization of the metals present in the raw sewage treated and it was found that the Principal Component Analysis of the boron (B) (63.5%) and followed by barium (Ba) with (21.9%) justify 84.48% the coefficient of variation that determine how prevalent metal in the influent. In Effluent Boron (B) showed a coefficient of variation of 73.7% which justifies as the main component in the influent of WWTP. In the characterization of metals in the sludge was observed that with a percentage of 98.8% the Barium (Ba) is the main element found. The results obtained with principal component analysis to characterize the physic-chemical and bacteriological analyzes of raw sewage and treated ETE observed that the variable "total COD" is positively related to component BOD and negatively correlated with the Total Alkalinity . Regarding physic-chemical and bacteriological, high levels of BOD, Fecal coliform, TSS and VSS, from the releases of effluents, making present the highest concentrations of organic load remaining.
Acesso aberto (Open Access)
Desenvolvimento de um sistema de alerta de enchente aplicado aos planos de defesa civil em áreas de risco no estado do Pará utilizando Sistema de Informações Geográficas (SIG), caso: cidade de Marabá
(Universidade Federal do Pará, 2012-03-02) COSTA, Jamer Andrade da; COSTA, Tony Carlos Dias da; http://lattes.cnpq.br/5776447682706171
This dissertation develops a Flood Warning System for the city of Marabá, located at the confluence of Tocantins and Itacaiúnas Rivers, 400 quilometers south from Belém, capital of the State of Pará (Brazil). The Flood Warning System is based on the hydrological model MOD-4B incorporated into a Geographic Information System. This system forecasts changes in the level of the Tocantins River throughout the year. It monitors the initiation of the flood 4 days in advance, resulting in more efficient Civil Defense actions. As reference, the forecasting model used the limnimeter poles located on the Tocantins and Araguaia Rivers, in the towns of Carolina and Conceição do Araguaia, respectively about 225 and 270 quilometers south from the city of Marabá. The system uses the GIS software ArcView 3.3, which was implemented through an interface developed through an object-oriented programming language called Avenue to run the application of the hydrological model. The use of windows and menus adapted to the model grants access to spatial data and relational database tables and / or record database. It also provides modules for spatial analysis and visualization of geographic data in a Geographic Information System (GIS), which forecasts flooding in the form of maps, charts and reports, showing the flooded areas for periods of 4, 3, 2 and 1 day before the occurrence of flooding. The system also identifies the affected streets and buildings, quantifying the affected population and the damages caused. With this, the Civil Defense can execute efficient action plans before, during and after the flooding.
Acesso aberto (Open Access)
Desenvolvimento de uma metodologia para implantação de centrais maremotrizes: aplicação na costa atlântica do Pará
(Universidade Federal do Pará, 2014-10-06) OLIVEIRA, Luciana Leal Pimentel; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
It presents a methodology for deploying tidal plants, which were modeled phenomena and parameters needed for basic studies project. The chosen study area was the Atlantic Coast Pará. Thus, a simplified model is proposed to represent the reservoir. This model was validated with the results obtained from the bathymetry held in the estuary of Bacanga in São Luís, Maranhão, Brazil. In addition to the reservoir modeling, tidal heights were shaped by the Hermitian interpolation process. The diameter of the turbine was determined by correlations available in literature. The flow resulting from the height of variation between the sea and the reservoir caused by tidal variations, was determined by Hazen-Williams formula. The modeling of the reservoir and the tide high, more methods of determining the diameter of the turbine and the flow, allowed the determination of the installed capacity and energy generated at each site studied, which were classified as small, medium and large size. Subsequently, the cost analysis was performed for each location, including investment cost, operation, maintenance and unit energy cost. The investment cost of tidal power in comparison with other energy sources, is high. However, the unit cost of energy is much lower than the unit cost of energy of its main competitor in the region, the diesel generators. The modeling of the three cases mentioned above and your energy costs and generated results show that tidal power has the potential to be exploited in the Atlantic Coast of Pará.
Acesso aberto (Open Access)
Estudo comparativo entre reatores UASB e tanque séptico, em escala unifamiliar, no tratamento de esgoto de comunidade quilombola amazônica
(Universidade Federal do Pará, 2012-08-28) FREITAS, Elenilce Monteiro de; COELHO, André Luiz da Silva Salgado; http://lattes.cnpq.br/0853586340257273
This research presents a comparative study of reactors upflow anaerobic sludge blanket (UASB) and septic tank (ST) in order to investigate the use of these reactors scale single-family home in sewage treatment. The research was conducted in quilombola community near the city of Belém-PA. For this, were used eight UASB reactors (in the form of “Y”) and a septic tank prismatic single camera. The UASB reactors had volume of 0,42 m3, while the septic tank volume of 4,20 m3. Each reactor was installed in a home, with powered exclusively by sewage black (water, feces and urine) come from the toilets of the bathrooms. Was analyzed the technical feasibility of the use of the first replacement in the second, with a view that the ST is widely used in places of Brazil devoid of sewage collecting system. The operations were carried out simultaneously for approximately 90 weeks, being monitored parameters that allowed the analysis of operating stability and performance of each reactor. At the end of the research was observed that the UASB reactors showed performance as satisfactory as or better than that of the ST in the treatment of organic matter and suspended solids. Therefore, was demonstrated the feasibility of application of the UASB reactor used in the treatment of sewage from single-family small rural communities.
Acesso aberto (Open Access)
Estudo de aproveitamento do resíduo do beneficiamento de caulim como matéria prima na produção de pozolanas para cimentos compostos e pozolânicos
(Universidade Federal do Pará, 2004-01-16) LIMA, Jefferson Maia; CARNEIRO, Arnaldo Manoel Pereira; http://lattes.cnpq.br/9191655335324358
The use of residue in civil construction can to become a activity of extreme important and more frequent, mainly due to amount available with potential of recycling, possible reduction of environments impacts. The kaolin industries produces two type of residue. The residue contain clay mineral kaulinite show potentially of is to employ by pozzolanas at the construction civil industry. This research evaluates the technical viability to production of pozzolanas from mixtures in various percentagens of kaulinitic residue with limestone, wanting increase the reactivity. The contents of replacement of cement for pozzolanas is of 10%, 20%, 30%, 40%, 50% e 60% was studied. The cement employed was CP I S 32 and the pozolanas was made in the laboratory. The following tests in the experiment cements were carried out: specific gravity, specific surface area, water of normal consistency, setting time and compressive strength. Also, were carried out mineralogical tests in the pozolanas. The incorporation of pozzolanas allowed to mortar obtain compressive strengths more than it reference even though in high contents. Due to the pozzolanas show a considerable hydraulic characteristic this it occurred. It waits of residue burned becomes a higher pozzolana to employ at the civil construction, mainly along with cement, mortars and concretes in the substitution of burning clays from natural deposits despite necessity of adding tests for confirmation and complementation of effects was observed.
Acesso aberto (Open Access)
Implementação de células móveis de produção alinhadas com a técnica de linha de balanço para melhorias dos processos produtivos
(Universidade Federal do Pará, 2011-12-21) UGULINO, Janilton Maciel; LIMA, Adalberto da Cruz; http://lattes.cnpq.br/7803369097132222
In this work we presented the result of an exploratory study investigating the insert in a horizontal work the application of the concept of "production mobile cell" for the Civil Construction. This research was conducted in an evolutionary process between a work of vertical and horizontal features; The study was addressed for production mobile cells, that is to say, cells that retains all the characteristics of the cell of traditional manufacture, even so with the characteristic of the mobility through the product, the work compares like this and it illustrates the results obtained with this form of the workers' organization before the productivity data and cost originating from of works executed previously.
Acesso aberto (Open Access)
Influência da protensão na resistência ao cisalhamento de vigas de concreto protendido
(Universidade Federal do Pará, 2014-11-21) SOUZA JUNIOR, Orivaldo de Azevedo; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
With the increase of the construction industry, the prestressed concrete has advanced beyond of the stages of evolution, being consolidated as a structural material, evolving and bringing reliable technical and technologies for many different structures, ranging from conventional buildings, with applications in bridges and stadiums, and on to more complex structures such as offshore platforms. The study of shear in reinforced concrete beams and prestressed concrete beams always had many controversies because of the many variables that involve the study of shear. In the case of prestressed beams, which are adopted profiles with different inclinations together with shear reinforcement, there is need for improved theoretical methods and practical, this research may contribute materially to the understanding of these variables. Thus, to determine the influence of the inclination of prestressing strands in the shear strength of prestressed concrete beams, oriented the focus this research to study of six prestressed concrete beams with alternating tracing cable straight and parabolic and transverse reinforcement, in order to observe the structural behavior of these beams, mainly observations about the influence of the stress generated by varying the inclination of the cables and varying the rate of transverse mode rupture, the load capacity, the surfaces of rupture and other factors in order to understand the shear in prestressed concrete beams.
Acesso aberto (Open Access)
Modelo cognitivo informacional de suporte a decisão aplicado à gestão de bacias urbanas
(Universidade Federal do Pará, 2005-01-19) BAGANHA JÚNIOR, Luiz Gonzaga; BARP, Ana Rosa Baganha; http://lattes.cnpq.br/0286183914646934
The research was carried through from the choice of the corresponding area to the basin of the Tucunduba narrow river, in the urban zone of Belém, capital of the State of Pará, and is come back toward the development of a computational causal structure cognitive capable to identify and to characterize the potential indicating processes conflicts generated for the multiple uses of the water in this urban basin, and with this to make possible decisions in the scope of the structural and not structural measures. The use of a qualitative model, using informacionais methodologies, as software Decision Explorer, in the area of water resources, aims at to not only understand the aspects hydrologics, but also the social, indispensable aspects in the taking of decision ahead of a scene of conflitualidade how much to the use of these resources. This software is a tool for the development of the cognitive mapping, through which representative causes and effect by means of visualization codified of the same ones will be grouped the concepts joining. The identification and qualification of the decurrent conflicts of the multiple uses of the water had been carried through from interviews with specialists in the area of management and sanitation, being later generated the cognitives maps thus making possible the description of the chosen system and the identification of the possible mediating solutions for the conflicts identified there. The result gotten from the interviews was added in an only map with intention to prove the hypothesis formulated in the research, by means of the analysis tools, or either, to assist in the identification of the conflicts for the multiple use of the water, from existing the structural and not structural measures (or proposals), in order to provide to the manager the borrower of decision of more efficient form in the solution of these conflicts. In this in case that, we could say that this group of constructs illustrates the main ones measured to be observed for the decision borrower, in order to solve the conflicts for the multiple use in the basin of the Tucunduba, evidenced for the facilitator through the interviews and individual cognitives maps. The conclusions and recommendations are contained in the final chapter are gotten not only through the extracted results of used software, but mainly by means of the intervention and interpretation of the data for the researcher, that it gets to break of these analyses the agreement of the functioning of the system, the identification of the potential conflicts, its causes and effect, as well as the mitigates measures to be suggested the decision borrower. They are enclosed in this chapter suggestions aiming at the improvement of the model bred.
Acesso aberto (Open Access)
Modelo de simulação computacional para balanceamento de linhas de produção das empresas cerâmicas de São Miguel do Guamá: um estudo de caso
(Universidade Federal do Pará, 2013-10-16) SILVA, Denilson Costa da; ICHIHARA, Jorge de Araújo; http://lattes.cnpq.br/5726366418302065
This work is to present a computer simulation model for the purpose of solving the problem of balancing production lines of a factory belonging to the polo red ceramic potter-ceramic São Miguel of Guama. In this sense, it is initially performed a literature search on the discrete event systems, the methods of solution for line balancing and concepts involving the modeling and simulation. The methodology addresses the case study, which is conducted by the method proposed by Chwif (1999) in which covers three (03) macros stages in conducting a simulation project, whether the stage of design, implementation and analysis stage. With the computational model developed based on the current characteristics of the production line, one can describe the current state of the process, identify the problem operation as well as forward proposals for improvements from the construction of 03 scenarios. Where the third scenario presented the best results and, therefore, being the representative model of the balancing. At the end, it is understood as the main contributions of this work even bringing into the university experience of the practical application of simulation involving a ceramic industry of São Miguel of Guama and offer the industry of this region a potential tool for improving their processes productive.
Acesso aberto (Open Access)
Modelo WEPP para estimativa da produção de sedimentos em uma pequena bacia hidrográfica da Amazônia
(Universidade Federal do Pará, 2017-12-06) SAMPAIO, Liliane da Cruz; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
Erosive processes produce several economic and environmental damages. The development of mathematical models has made it possible to quantify these processes, allowing estimating the magnitude of the problem, in order to minimize it. In this sense, this work uses the WEPP (Water Erosion Prediction Project) model to simulate the sediment yield in an Amazon small catchment, igarapé da Prata catchment, located in the Municipality of Capitão Poço-PA. The calibrated main parameters of the WEPP model were: initial soil saturation (Si), erosion by runoff (Ki), erosion by channel or groove flow (Kr) and saturated hydraulic conductivity (Ke). After the calibration, it was verified that most of the sediment yield is in the plans. And as is to be expected, this production is higher in areas with predominance of agriculture and livestock. The results of the estimated sediment yield calculated by the model were compared to the observed data for the year 2012. The model presented a value of 131.99 t / km², close to the observed value, which was 121.64 t / km2. This result leads to the conclusion that the values calculated by the model are consistent with the reality of the sediment yield of the small catchment in question.
Acesso aberto (Open Access)
Punção em lajes lisas unidirecionais de concreto armado com diferentes taxas de armadura secundária e pilares retangulares.
(Universidade Federal do Pará, 2022-09-29) BRANCO, Vitor Hugo Lopes; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
Symmetric punching tests and experimental analyses were conducted to evaluate the behavior of nine one-way reinforced concrete flat slabs. The slabs measured (1800 x 1800 x 120) mm, and loads were applied through three types of columns: A (85 × 85) mm, B (85 × 255) mm and C (85 × 425) mm. All slabs were made with constant longitudinal reinforcement ratio at around 1% (ρx) and different secondary flexural reinforcement ratios (ρy), namely type 1 (0.5%), type 2 (1%) and type 3 (2%), approximately. Concrete compressive strength of 28 MPa and elasticity modulus of 27 GPa. Reinforcement yield stress of 573 MPa and elasticity modulus of 244 GPa. Column rectangularity index (cmax/cmín) and secondary reinforcement ratio were the main research variables, and the present study evaluated their influence on the ultimate punching strength of the sampled one way reinforced concrete flat slabs. The experimental results were compared with four current international standards: ACI 318 (2019), EC2 (2004), MC 2010 (2011) and NBR 6118 (2014). They were also compared with the findings from a nonlinear numerical analysis made with the software ABAQUS CAE 6.14, based on the Finite Element Method (FEM) and on the Concrete Damage Plasticity (CDP) model. The results indicated that the standards need to be updated, and that there is a proportional increase of up to 50% approximately in slab punching strength when the secondary reinforcement ratio is increased by up to 2%.
Acesso aberto (Open Access)
Regionalização de precipitações via fuzzy C-means
(Universidade Federal do Pará, 2017-04-05) GOMES, Evanice Pinheiro; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The knowledge of the precipitation behavior is indispensable, since any change in its quantity and spatial and temporal distributions have an important impact on nature and consequently on the various human activities. However, in precipitation studies, the lack of rainfall monitoring, generating the lack of information over time and spatially in the river basins is a problem for the understanding of this variable. In order to overcome this problem, the rainfall regionalization method was proposed. The main idea was to divide the Tocantins Araguaia - RHTA hydrographic region into homogeneous regions, defined by the Fuzzy C-means method. The Euclidean distance was adopted as a measure of similarity and the fuzzification parameter, ranging from 1.2 to 2.0, and the explanatory variables of rainfall (altitude, latitude and longitude) were used as input data. Three homogeneous regions were obtained, which were validated by the PBM index and the heterogeneity test. The frequencies of observed rainfall events were generated for the 83 rain gauge stations, distributed in their respective regions, and calibrated by the Normal, Log-Normal, Gama, Gumbel, Exponential, Logarithmic and Weibull probability functions. With the application of the chi-square test, we defined the best probability function in the occurrence of rainfall in each homogeneous region. The validation of the probabilities functions was performed in 9 target stations, using the chi-square test. In this stage, it was observed that for annual average precipitation, data adherence occurred to all the rain gauge stations, since they presented results of the chi-square test of less than 5.99 (for Log-normal distribution functions). It was also observed that for monthly average precipitation, data were adhered to all the rainfall stations with the Gama and Weibull functions. For the simulation of rain depth, Linear, Potential, Exponential and Logarithm models were tested through the multiple regression method, using as independent variables, altitude, latitude and longitude. As performance criterion of the models, the R², R²_a, E%, ε%, NASH and RMSE were used. In the simulation of annual averages, the Linear model presented the best performance indices. In the estimation ofviii monthly averages, all multiple regression models did not perform well, with errors above 50%, which motivated the estimation of monthly rainfall for rainy and dry periods. In this new approach the regression models presented excellent performance criteria with errors below 10%. The performance indexes allowed us to conclude that the regional models developed for the homogeneous regions of rainfall, defined by the Fuzzy C-Means method, are a good option in the estimation of annual and monthly average rainfall and are important for a better understanding of the rainfall regime in RHTA, and can serve as a tool for better planning of water resources in the region.
Acesso aberto (Open Access)
Uso de geotêxtil para a desidratação de lodo da ETE Vila da Barca-PA
(Universidade Federal do Pará, 2016-04-15) SOUZA, Luciana Otoni de; MENDONÇA, Neyson Martins; http://lattes.cnpq.br/7534816053779593
Checks the sludge dewatering performance of ETE Barca Village with use of geotextile. Sludge conditioning was done with the aid of chemical coagulant PAC (polyaluminium chloride - Polyvinyl aluminum- 10%) and the cationic flocculant polymer of the type FLONEX 4400 SH 0.1%, which allowed the formation of well-defined and larger flakes short stirring time interval approximately 9 jar test ". For the evaluation and selection of the ideal situation for dosages on conditioning were performed 25 trials with varying the concentrations of the raw sludge and polymer and PAC. Among the tests, which was stood the test 3, the second dosing with 95 mg / L and 8 mg polymer / L of PAC and concentration of sludge 24,106 mg / L. For these dosages showed a dewatering filtrate with satisfactory quality and the physical and chemical characteristics and a pie with high concentrations of ST and low moisture content. In the mass balance in the cake, it was possible to obtain the geotextile dewatering efficiency in the first 3 doses of the test results 3 with 90%, 91% and 91% showing good performance of geotextile. In the statistical analysis, the formation of two main components forming the set of all physical and chemical variables of 3 filtrates from the 3 trial demonstrated homogeneity, inter-relationship and similarity between them, because they can define with a high degree of significance the filtrate characteristics.
Acesso aberto (Open Access)
Utilização de escória produzida em alto-forno a carvão vegetal como agregado graúdo e miúdo para concreto
(Universidade Federal do Pará, 2014-01-29) ALMEIDA, Gyselle Maciel de; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
The steel production requires many stages and generates large quantities of slag, these rising stocks are worrying metallurgists and environmentalists aiming the rational use of this industrial byproduct, in order to minimize possibles environmental problems. In this sense, the civil construction presents a quite fit sector to the use of reuse techniques, of wastes and byproducts, from different industries. Besides the environmental benefits, like the reduction of non-renewable natural resources, the emergence alternative construction materials enables the reduction in the cost of construction, important factor when is evaluated the deficiency existing housing in Brazil. In this research is studied a possible recycling of blast furnace slag, from of hypothesis that is viable its utilization as coarse aggregate and fine aggregate for concretes. Its influence is studied on the characteristic of concrete in fresh state (workability) and in hardened state (axial compressive strength, tensile strength by diametral compression and elastic modulus). In this work the content of substitutions of blast furnace slag was diversified, the water-to-cement ratio and the ages of breaking of the specimens. The used methodology was based on lab rehearsals and in the use of statistical tools to validate the results. With the results obtained in this study, it was found that the use of large amounts of blast furnace slag as coarse and kid aggregate for concrete, in general, had no influence or not exerted a positive influence in the studied properties. We conclude that the findings pointed to the non-technical viability of using this waste as aggregates for concrete.
Acesso aberto (Open Access)
Verificação da tratabilidade de água residuária oriunda de beneficiamento do açaí por processo físico-químico
(Universidade Federal do Pará, 2016-04-15) FEIO, Vanessa Farias; MENDONÇA, Neyson Martins; http://lattes.cnpq.br/7534816053779593
This work aims to study the wastewater treatability coming from açaí processing plant, trougth jar test assay to get the best conditions for the physical-chemical wastewater treatment. For this, two experimental steps was done:1) Quantitative and qualitative characterization of raw wastewater to elaborate flow hydrograph and hydric balance. 2) Assay coagulation/flocculation/oxidation on jar test using hydrated lime, tannin, sodium hypochlorite, polyaluminium cloride and polymer. In treatability test dosage was varied for each product and analyzed in the clarified effluent variables: pH, apparent color, turbidity and COD. It was also determined the treated effluent quality index and the qualitative characterization of effluent of the proposed treatment, beyond the physical characterization of the sludge. Furthermore, it was estimated monthly cost of chemicals products for proposed treatment. By the results for wastewater quantitative characterization were obtained flow of Qméd = 305 L/h; Qmax = 521 L/h and Qmin = 183 L/h and qesp. of 0.51 L/kg.d. To the water balance was found that weight of water used is 112.4 ton/d, generating 7.30 ton/d of wastewater, water in the pulp mass equal to 49.36 ton/d and water loss of 55.81 ton/d. For treatability tests the best result was obtained for the combination polyaluminium (18mg/L) and polymer (30 mg/l) at pH 8.0, resulting in apparent color removal 98.5%; 99.8% of turbidity and COD equal to 90% . In the physical characterization of sludge was found values: density of 1.002 and specific mass equal to 1001.8 kg/m³, moisture content of 98.9%, and the SV/ST equal to 73%. In the cost estimate with chemical products was obtained R$4,77/month, representing R$0,022/m³ of treated effluent. We conclude that this effluent treatment is viable for physical-chemical treatment process.