Programa de Pós-Graduação em Engenharia de Produção

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https://repositorio.ufcat.edu.br/handle/tede/55

Com uma única área de concentração em “Engenharia de Operações e Processos Industriais”, o Programa de Pós-graduação em Engenharia de Produção, em nível de Mestrado, tem por objetivo formar profissionais capazes de atuar no desenvolvimento da pesquisa na área de Engenharia de Operações e Processos Industriais, para tratamento de problemas relacionados ao uso de recursos humanos, físicos e financeiros para geração de bens e serviços de classe mundial. Também é objetivo do curso formar futuros professores e pesquisadores em Engenharia de Produção para atuarem em universidades e institutos de pesquisa e órgãos governamentais para promover a melhoria das condições brasileiras neste campo do conhecimento.

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Agora exibindo 1 - 20 de 22

Uma abordagem não linear ao estudo de modelos de deformação via elementos finitos para viga 2d de concreto protendido com cordoalha aderente
(Universidade Federal de Goiás, 2020-12-16) Silva, Werley Rafael da; Rabelo, Marcos Napoleão; http://lattes.cnpq.br/0067281135180613; Rabelo, Marcos Napoleão; Silva, Wellington Andrade da; Duarte, Carlos Antônio Ribeiro
The purpose of this work is to develop the nonlinear analysis of prestressed beams and obtain their load/displacement curves, the formulation of a finite element of the bar type will be presented for non-linear physical and geometric analysis based on the method of forces. Geometric nonlinearity is considered using the Euler-Bernoulli beam strain theory, with simplification for moderate rotations. In physical non-linearity, non-linear stress / strain relationships provided by the models constituting the materials are allowed. The contribution to concrete in compression uses the model developed by Hognestad (1951), and when subjected to traction the model developed by Bergan and Holand (1973), for the steel of active reinforcement, the model developed by Menegotto and Pinto (1973) and for the passive reinforcement the bi-linear model with perfect elastoplastic behavior is considered. In the coupling between the constituent materials of the structure, perfect adherence between its elements is considered, that is, there is no relative movement between them. The problem is formulated through the balance of nodal forces. For this, the forces and moments are calculated as a function of the stress/strain relationship. To solve the equations, the finite element method is employed. The methodology presented here proposes to achieve the balance of forces directly at the nodal points of the structure using differential equations instead of integral equations. The concept of generalized forces and moments at nodal points is introduced. Finally, numerical simulations are used to compare the results obtained with experimental results. The novelty in the present work resides in the fact that the modeling is done through the coupling between three elements, namely: the displacement of the concrete, the prestressing strand and passive reinforcement. It is also observed that prestressing is responsible for applying axial and shear forces; while the passive reinforcement only contributes to axial displacement. The incorporation of axial displacements is necessary, since the prestressing force is considered to be external, causing, in addition to axial forces, moment reactions due to the eccentricity between the position of the strand and the neutral line of the structure. Using appropriates theory of strain to, concrete, prestressing and reinforcement steel the stiffness matrix is obtained.
Análise do sistema de medição e de fatores do ângulo de repouso em fertilizantes
(Universidade Federal de Goiás, 2019-09-11) Ferreira, Isabel Santana Borges; Fernandes, Nilson José; http://lattes.cnpq.br/4954825505203967; Peruchi, Rogério Santana; http://lattes.cnpq.br/2633968496533807; Guimarães, Marco Paulo; Rotela Junior, Paulo; Peruchi, Rogério Santana; Fernandes, Nilson José
This dissertation presents a statistical study and experimental study to analyze the rest angle measurement system in fertilizers of different particle sizes (1.5 mm
Análise gravimétrica da viabilidade da implantação da coleta seletiva na UFCAT
(Universidade Federal de Goiás, 2018-12-04) Santana, Karine de Jesus Rodrigues; Barbosa, Rommel Melgaço; http://lattes.cnpq.br/6228227125338610; Barbosa, Rommel Melgaço; Guimarães, Marco Paulo; Silva, Leila Roling Scariot da
Selective collection has proved to be a viable and economical alternative for the management of solid waste, among the many technical options developed in the last years because, through the awareness of the individuals involved, it allows the selection and referral of different materials to the recycling process. Through it, recyclable materials are separated from non-recyclable materials, showing that most waste can be recycled, no longer a source of environmental degradation, to become an economic and social opportunity, generating jobs and profit. Exaggerated consumption combined with urban growth has resulted in the generation of large quantities of solid waste. This is one of the major concerns of mankind, which, over the years, is always exposed to pollution and suffers damage from soil, water and air contamination. The greatest difficulty encountered by organizations in implementing selective waste collection is the awareness of people, the need to separate waste, the importance of reducing, reusing and recycling. The aim of the research was to diagnose the current situation and analyze the feasibility of implementing the selective collection of solid waste generated at the Federal University of Catalão (UFCAT). The research methods used were: field research, descriptive and quantitative, using the venn diagram and gravimetry, in order to quantify the data collected and respond to the proposed objectives. From the venn diagrams, it was identified that in blocks I and II, it is where it has the highest concentration of people during the periods, since all the courses have classes in these blocks, and in the morning period 422 people attend it, in the integral 1420 and at night 1118. Therefore during the day, I and II pass through 1,842 people, and in the total 2,960, people attend this block. The results of solid waste gravimetry showed that 51.8% of the solid waste generated is potentially recyclable waste composed of plastic (17.8%), nonferrous metals (17.4%) and paper / cardboard (16.7% %). The mass and volume balance estimated the potential for socioeconomic and environmental reintegration with a reduction of 51.8% of mass and 53.2% of volume of potentially recyclable waste in which separation at source and selective collection will reduce waste overload solid waste that is destined daily and without separation to the sanitary landfill of the municipality, it is still justified the implementation of the selective collection in the UFCAT for the infrastructure already installed, the same account with some own trash cans of the selective collection exposed on campus.
Análise numérica no controle de vibrações
(Universidade Federal de Goiás, 2019-04-15) Leandro, Karla Melissa dos Santos; Guimarães, Marco Paulo; http://lattes.cnpq.br/4547166859048137; Rabelo, Marcos Napoleão; http://lattes.cnpq.br/0067281135180613; Rabelo, Marcos Napoleão; Resende, André Alves de; Borges, Romes Antônio
In micro-structure theory, the equations of motion have their foundations in the relation tension / deformation. Microstructure analysis is focused on the science of preparing, interpreting and studying microstructures in engineering materials to understand the behavior and performance of materials. There is a need to evaluate the methods of manufacturing metallic materials for use in the metal industry, including the aerospace industry, the automotive industry, and parts of the construction industry. From a project point of view, the control of vibrations in micro-structures plays a key role. In this work, a bar of the Euler-Bernoulli type with conditions of the crimping-free type. The aim is to analyze the effects of vibrations in in the crimped end of the frame. For control purposes, a field magnetic field at the free end and the distance from the magnetic field source to the control parameter. It is shown that this control design introduces boundary conditions not linear in the formulation of the equations of motion of the structure. The deformation field, in turn, describes the curvature, which can be obtained through the displacement field in a first and second order nonlinear relationship. Assuming small displacements in the deflection angle, the moment / curvature relationship can be described by means of the second-order derivative of the displacement field. This model allows the analysis of the terms of shear forces and momentum that are present in the theory. Like this using the variational principle, the equations of motion are obtained, which allows to determine the field of displacement. The finite element method is used to discretize the equations of motion. Due to the complexity of equations involved the finite difference method is employed to model the nonlinear problem.
Análise numérica-experimental da força de corte na usinagem de uma liga de alumínio 7075-T6
(Universidade Federal de Goiás, 2019-09-20) Ramaldes, Leandro de Lima; Resende, André Alves de; http://lattes.cnpq.br/3492793149542286; Guimarães, Marco Paulo; http://lattes.cnpq.br/4547166859048137; Guimarães, Marco Paulo; Resende, André Alves de; Moura, Ricardo Ribeiro; Silva, Wellington Andrade da
Chip formation is linked to various machining parameters that directly affect the cutting forces, shear stresses, power and temperatures associated with the machining process. Chip formation mechanisms have been studied for over 100 years and because they involve high temperatures and high deformation rates, there is some difficulty in accurately predicting a mathematical model to describe the formation of this phenomenon, considering the various types of materials available. Efforts during the cutting process are important elements for tool manufacturers and industry consumers. By predicting the stress values during a machining process, you can optimize the manufacture of the consumable, avoiding unexpected stops for tool change, for example. This paper presents the results of experiments in the process of orthogonal bedame turning in a 7075-T6 aluminum alloy with variations in cutting speed and cutting feed rates. The tests were performed using carbide tool MGMN 300-M-H01 - CLASS N and the shear force (Fc) values were collected with a load cell data acquisition system and a data acquisition plate. . Numerical simulations were also performed by the finite element method using Ansys ® software in its explicit dynamic module, simulating the value of the shear force (Fc) during the machining process. Twenty simulations were performed with a fixed hexahedral mesh containing 24021 nodes and 20600 elements. In the numerical simulation by the finiteelement method an increase in the cutting force (Fc) was observed when the cutting speed was reduced, and an increase in the cutting force when there was an increase in the depth of cut and the cutting feed respectively. In the experimental tests obtained the same results trends found in the simulation. These results are important to contribute to the knowledge of the numerical simulation turning process, allowing cost reductions and better performance in the manufacturing process. This enables the definition of a method that will predict the cutting force employed in the process, contributing satisfactorily to the quality, wear and precision of the manufacturing process.
Analysis and optimization of the tig-mig/mag process variables on the welding bead geometry parameters
(2021-11-30) Correia, Evanielly Guimarães
Estudos sobre o processo hibrido TIG-MIG/MAG (Tungsten Inert Gas - Metal Inert Gas/Metal Active Gas) tem crescido significativamente. Este crescimento se dá principalmente em decorrência de novas exigências de mercado. O objetivo deste estudo é examinar os parâmetros operacionais do processo hibrido TIG-MIG/MAG (Altura do eletrodo TIG, extensão do arame MIG/MAG, distância entre os eletrodos TIG e MIG/MAG, ângulos das tochas e a corrente TIG) com relação aos aspectos referente a geometria do cordão de solda (largura da solda, altura do reforço, profundidade da zona fundida da solda, ângulo de convexidade e taxa de diluição). Analise estatística foi utilizada pra examinar as variáveis e seus relacionamentos. CCD (Central Composite Design), RSM (Response Surface Analysis), análise de efeitos principais e ANOVA são algumas das técnicas utilizadas. Neste estudo é proposto um modelo de otimização aplicado para uma aplicação especifica de solda de revestimento. Os resultados do modelo de otimização mostram que para atingir soldas com maiores larguras é necessário aumentar a distância entre eletrodos e aumentar a altura do eletrodo TIG. Para obter maior altura de reforço é preciso diminuir a distância entre os eletrodos, diminuir a corrente TIG, a altura do eletrodo TIG deve ser ajustada em cerca de 4.5 mm e o ângulo da tocha MIG/MAG deve ser por volta de 35o. Para obter menor profundidade da zona fundida de solda é necessário diminuir a corrente TIG, diminuir a altura do eletrodo TIG e diminuir a distância entre eletrodos, além de aumentar o ângulo da tocha MIG/MAG. Menores ângulos de convecção são obtidos com o aumento da distância entre eletrodos, aumento da altura do eletrodo TIG e o ângulo da tocha MIG/MAG deve ser ajustado para cerca de 30o. Para minimizar a diluição deve-se diminuir a distância entre eletrodos, diminuir a corrente do TIG, o ângulo MIG/MAG deve ser ajustado para cerca de 35o. Os resultados mostram que a é possível influenciar os resultados da geometria do cordão de solda através da variação dos parâmetros analisados neste estudo. O modelo estatístico proposto provou ser efetivo e os resultados previstos foram experimentalmente confirmados.
Automação do processo de compostagem: uso de sensores para monitoramento e controle de parâmetros de um processo sustentável
(Universidade Federal de Goiás, 2019-09-18) Silva, Janice Rodrigues da; Paiva, Ed Carlo Rosa; http://lattes.cnpq.br/8015791628495184; Espinosa, José Waldo Martínez; http://lattes.cnpq.br/5055033961082674; Espinosa, José Waldo Martínez; Guimarães, Marco Paulo; Paula, Heber Martins de; Sarnento, Antover Panazzolo; Silva, Leila Roling Scariot da
The growing production and disposal of organic waste generates an environmental, economic and social concern, which pressures, the responsible, the resolution of the problems caused by this factor. Thus, the creation of Law No. 12,305 / 10 and Decree No. 7,404, of December 23, 2010, the National Solid Waste Policy (PNRS), helps in the proper disposal of waste and sustainable consumption, providing the possibility of realization. waste treatment and reuse. Organic composting of waste is a form of treatment that requires the completion of a process that involves factors to be analyzed, technologies and equipment to be defined according to the capacity of each agent. Thus, the objective of this work is to monitor, in an automated way, a composting process, using sensors capable of real time data acquisition and control of the presented parameters. The materials for assembling the composting system were established according to the availability of waste and the determination of the process based on the capacity of the facilities and the tools required for analysis and process monitoring. The results showed that there is a need to monitor the parameters of composting processes, thus contributing to the acquisition of reliable data and providing real-time decision making; the windrow has points with different parameters at the same composting time; the center of the windrow does not behave the same as the outermost points; Automated monitoring can be applied to any composting process as long as there is daily monitoring of the entire system. Based on the results obtained, it can be concluded that the composting system is a sustainable alternative to waste disposal problems and the process automation allows the analysis of the parameters that influence the optimized compost treatment.
Avaliação de aspectos operacionais do processo de soldagem TIG-MIG/MAG
(Universidade Federal de Goiás, 2019-03-12) Azevedo, Sarah Cristina; Resende, André Alves de; http://lattes.cnpq.br/3492793149542286; Resende, André Alves de; Duarte, Carlos Antônio Ribeiro; Reis, Ruham Pablo
In the search for productivity gains and cost reduction, the optimization of welding processes has been presented as an opportunity for the industries of the metal-mechanic sector. In this context, the so-called "Hybrid Welding Processes", in which two or more conventional processes are combined, have gained prominence. Among these, TIG-MIG / MAG has shown itself to be an alternative, mainly because it associates processes already traditionally known and used in the market. Thus, the general objective of the present work is to analyze the influence of the TIG-MIG / MAG process variables on the weld bead geometry obtained. For this purpose, welds of simple deposition on sheet were performed, varying the TIG current, the TIG torch angle, the MIG / MAG torch angle and the distance between the electrodes. Then, tests were performed by varying the current circuit of the TIG and MIG / MAG process. As main results, for the set of evaluated parameters, it was verified that it is possible to act on the weld bead geometry, varying the positioning parameters and the TIG and MIG / MAG current. Greater melt and penetration area achieved with TIG torch angle and MIG / MAG torch angle, maximum values and the distance between the electrodes in the minimum value. Inserting the current into the TIG circuit contributes to a greater melt area and greater penetration. A greater width is obtained by using the TIG torch angle and the MIG / MAG torch angle in the minimum values and the distance between electrodes, in the maximum values, in this sense, the insertion of the current in the TIG circuit increases the width. The greatest reinforcement is obtained by using the TIG torch angle and the MIG / MAG torch angle at the maximum values and the minimum electrode distance. Already when the current is inserted in the TIG circuit, there is a decrease in the values of the reinforcement. Finally, a greater angle of convexity was achieved by using the torch angles at the maximum values, and with the insertion of the current in the TIG circuit, there was a decrease in the convexity angle values.
Avaliação de parâmetros de desempenho térmico para Blocos de EPS revestidos por concreto na zona bioclimática 6
(Universidade Federal de Goiás, 2021-06-01) Silva, Alessandro Oliveira da; Sarmento, Antover Panazzolo; https://orcid.org/0000-0002-8533-1575; http://lattes.cnpq.br/4025685702530313; Sarmento, Antover Panazzolo; Rezende, André Alves de; Paiva, Ed Carlo Rosa
The purpose of this work was to analyze the application of thermal efficiency principles for sealing masonry, made for the city of Itumbiara-GO; and the thermal performance evaluation of a building can be done both in the design phase and after construction. Using the regulations and specifications that guide the methods for investigating thermal performance and Energy efficiency for buildings, Brazilian standards are consulted that present specific guidelines for the various regions of the country and their respective Bioclimatic Zones, which stand out as NBR 15.220 (ABNT, 2005) and NBR 15.575 (ABNT, 2013); The Casa Azul Seal of Caixa Econômica Federal and Ordinance No. 18 of 2012 (RTQ-R: Technical Quality Regulation for the Level of Efficiency in Residential Buildings) are also attested. In the research we have the implementation of the EPS block (styrofoam) coated with concrete as an alternative to replacement for conventional bricks, with the application of specific thermal criteria; which demonstrated the implementation of new construction methods for the city of Itumbiara-GO, which is inserted in the Brazilian Bioclimatic Zone 6; aiming for better architectural designs for popular class buildings. The development of an alternative fence block for civil construction provides diversification in the use of materials encompassing the concept of sustainability in this field. Based on the results obtained, it is verified that the EPS block coated with concrete provides better thermal performance than ceramic blocks, evidenced by the calculated physical quantities that are standardized by current standards and that measure this concept: the thermal resistance is about 205% higher than the conventional ceramic block, the termal transmittance is 67.28% lower, the total thermal capacity is about 38% lower, the thermal delay is about 53% higher than the ceramic block, and finally, the solar factor is about 67 % lower than ceramic block. Where such comparative results prove the efficiency of the EPS block in relation to the ceramic block in terms of thermal performance.
Avaliação de potencialidades do processo de soldagem TIG-MIG/MAG com variação de polaridade no eletrodo MIG/MAG
(Universidade Federal de Goiás, 2019-07-15) Costa, Gabriella Cristina da Silva; Resende, André Alves de; http://lattes.cnpq.br/3492793149542286; Resende, André Alves de; Duarte, Carlos Antonio Ribeiro; Ferreira Filho, Demostenes
This study proposes a contribution to the improvement of production processes through the study of hybrid welding processes. It aims to evaluate the effects provided by the association of two conventional welding processes on the behavior of the welding voltage and current signals, on the production capacity and on the geometry of the weld obtained. In this case, the arc welding processes TIG (Tungsten Inert Gas) and MIG/MAG (Metal Inert Gas / Metal Active Gas) are associated and give rise to the TIG-MIG/MAG process. The tests were performed following a factorial planning, through simple deposition in SAE 1020 steel plates of 6.35 mm thickness. Experiments were performed varying the polarity of the MIG/MAG part of the process and the current of the TIG part of the process. The data of the voltage and current signals of the TIG-MIG/MAG process demonstrated that at the moment of insertion of the MIG/MAG arc in the process, the signals realigned their intensities in order to stabilize the process. The productive capacity analysis showed that the TIG-MIG/MAG process with the MIG/MAG electrode in direct polarity has better rates of deposition and fusion, if compared with the results obtained for conventional polarity. Through the analysis of variance it was identified that MIG/MAG polarity is the most influential factor in the results of weld bead geometry. The TIG-MIG/MAG process with theMIG/MAG electrode in direct polarity can generate larger widths, penetrations and molten areas and smaller reinforcements when compared to the conventional MIG/MAG process in direct polarity, opening the possibility of welding in this polarity. And finally, the presence of the TIG arc was able to reduce the convexity of the weld beads, regardless of the polarity.
Avaliação do comportamento no torneamento do aço SAE 8640 em diferentes condições de lubri-refrigeração
(Universidade Federal de Goiás, 2020-03-30) Leandro, Gustavo Henrique Correia Rosa; Resende, André Alves de; http://lattes.cnpq.br/3492793149542286; Resende, André Alves de; Moura, Ricardo Ribeiro; Sales, Wisley Falco
During machining processes, methods and parameters are sought that enable low roughness values of the machined surface, due to their influence on the final quality of the part. Thus, it is necessary to associate machining parameters with the cutting tool and more suitable lubrication and cooling conditions, as they are directly or indirectly linked to the final quality of the machined surface. In this sense, this work presents a study on the solid lubricant in the SAE 8640 steel turning process. The tests were dry, with Minimum Amount of Lubrication - MQL and MQL, containing in the solution 10% by weight of solid lubricant, with cemented Carbide GR 20 (cemented Carbide with particle size of 20 μm). For the MQL system, two nebulizer nozzles were used with a pressure of 6 bar and a flow rate of 4 ml / min. Cutting speed - Vc (360 m / min, 290 m / min, 220 m / min and 150 m / min), feed - f (0.01 mm / rev and 0.06 mm / rot) and the depth of cut - constant ap (0.5 mm), for the three lubricationcooling conditions mentioned. The parameters evaluated in the tests were: finishing of the machined surface (Ra and Rt), wear of the cutting tool and chip analysis and degree of repression (Rc). The results of the tests showed that when adding graphite, the roughness decreases, considering that using the same volume of fluid, temperature was not a decisive factor in this reduction (from MQL to MQL + graphite). This is evidence that, in fact, MQL has an important action as a lubricant, so much so that the graphite showed lower values of Ra and Rt roughness - less wear of the cutting tool, as well as a reduction in the degree of repression. Thus, flank wear was prevalent in the tests for all lubrication and cooling conditions. Therefore, it is possible to conclude that the application of graphite in the turning of SAE 8640 steel can offer greater productivity in the machining process and better finishing of the workpiece.
Como o controle de torque, integrado ao sistema MES XGAAT e torquímetros wireless, controladoras e ponteiras, contribuirão para a diminuição do FPM, no chão de fábrica? Um estudo de caso à luz da indústria 4.0
(Universidade Federal de Goiás, 2019-09-13) Costa, Rodrigo Pereira da; Duarte, Márcio Antônio; http://lattes.cnpq.br/9907691146700229; Carvalho, Luciana; Duarte, Márcio Antônio; Guimarães, Núbia Rosa da Silva
Industrial manufacturing companies are constantly faced with the challenge of increasing productivity, reducing rework costs and achieving rapid increases in production. The pressure, to keep production costs under control, is intense. Failure and poor quality in the production process is extremely dangerous to the competitiveness of manufacturing industries. According this context, it was purposed a Quantitative and a Qualitative case study at XGreen S/A assembly line of sprayers self-propelled. The study has got the proposal to verify the feasibility and the possibility to stablish a distinguished Quality in this product line, through the implementation of the intelligent tools: wireless torque wrenches, toolings (devices) and MES XGAAT (Manufacturing Execution System - X Green Assembly Assist Tool), which correspond to the materialization of Industry 4.0 concepts, within the scope of XGreen S/A. In short, it is expected through this study can itself to promote a reduction of Failure Per Machines (FPM), to improve the process traceability, the torque control as well as the Distinct Quality, in the assembly line of the sprayers from XGreen company. Although the implementation of the MES XGAAT system and the intelligent tools have been done into a conservative way, the quarterly reports from the Quality team suggest a considerable improvement regarding the Production indicators. The quarterly reports from Quality team have showed an improvement related to the Production´s indicators and a reduction of 27% in the Failures Per Machine (FPM), which was the main goal of this research project.
Desenvolvimento de um aplicativo colaborativo para compartilhamento de preços de produtos de supermercados
(Universidade Federal de Goiás, 2020-09-03) Vaz, Lucas Fagundes; Duarte, Carlos Antonio Ribeiro; http://lattes.cnpq.br/3533635470069420; Duarte, Carlos Antonio Ribeiro; Resende, André Alves de; Andrade, João Rodrigo
Over the years, the constant integration of mobile technologies between suppliers and customers has become a strong ally in the dissemination and sharing of prices quickly and safely. In this context, the present work has as objective, the elaboration of an app for sharing prices of supermarket products. The app was planned and implemented to run on the Android platform. For its preparation, a management and product development planning was initially carried out based on renowned reference models available in the literature. Subsequently, a set of technical tools in the field of computer programming, such as: Android Studio, Java, Jsoup, Zxing and Firebase, were widely used in the development of a functional prototype of the app. As main assumptions, an app was developed with a friendly interface, ease of use, good execution performance and that was able to perform treatments for systemic errors. As a main result, an app was obtained as close as possible to an information system to be put into production. Among the main characteristics obtained from the development of the app, the possibility of reading the Nota Fiscal do Consumidor Eletrônica (NFC-e) through the Quick Response Code (QR Code) and the export of products, prices and other relevant information to the database stands out in order to allow the real-time sharing of information from each NFC-e sent. Additionally, the ability to search for specific products was implemented through key terms to be inserted in a search screen and the option to manage notes sent, with the possibility of verifying monthly expenses for the current year in list and graph format. It is concluded that the tools studied and used in the conception of the app are capable of meeting the established objective and a functional prototype was conceived.
Desenvolvimento de um disco pelotizador em escala laboratorial utilizando controle em malha aberta
(Universidade Federal de Goiás, 2019-09-19) Garcia, Eloisa Angélica Silva; Guimarães, Marco Paulo; http://lattes.cnpq.br/4547166859048137; Guimarães, Marco Paulo; Fernandes, Nilson José; Santos, Andrea Cristina dos
Pelletizing was created with the purpose of using ores with particle size less than 0.15 mm, obtaining the agglomerates by rolling the material in drums or discs. This work aimed to develop an automated ore pelletizing equipment, in laboratory scale, with open loop control of the inclination, the angular velocity of the equipment and the amount of water added to the material, generating a product according to the selected size on the machine panel. All tests were performed for thirty minutes, in batch, with five kilograms of material, using limestone as the test mineral. The raw pellets were characterized in size by bench top vibratory screening assays. Initially, the quantities were manually varied to infer their effect on the dimensions of the generated product. Then the appropriate parameters were selected for the generation of a small, medium and large product, according to the smallest variability obtained in the tests. These parameters were later used in open-loop PLC programming, automatically controlling the inclination, angular velocity, and amount of water fed to the agglomeration parameters according to the size selected by the operator. The final tests were performed with automated equipment confirming the efficiency of open loop control in the generation of the three product sizes, affirmed by the approximation of the d 50 of each test before and after automation.
Modelos de programação linear inteira para variantes do problema de programação de projetos com restrição de recursos
(Universidade Federal de Goiás, 2018-11-23) Melo, Luciana Vieira de; Queiroz, Thiago Alves de; http://lattes.cnpq.br/8041183668335400; Queiroz, Thiago Alves de; Mundim, Leandro Resende; Bachega, Stella Jacyszyn
The resource-constrained project scheduling problem has its importance both in the theoretical part, as in the field of operational research, and in practice, with project management in corporate environments and other applications. In this context, some integer linear programming models, solved with the help of an optimization library, were studied for the resource-constrained project scheduling problem. This problem aims at minimizing the makespan, namely, the total completion time of the project, given the scheduling of activities. In order to achieve this objective, a quantitative approach is used, and the research is classified as descriptive with regard to its objective, and bibliographical and experimental with regard to the technical procedures used. The first model has two types of decision variables, while in the second model there is only one type of variable. When considering the insertion of real constraints, in particular, the multi-skill, the multi-mode and time lags, the third, fourth and fifth models are obtained, respectively, from the second model with the addition of such constraints. The models are analyzed with regard to the runtime and the amount of instances solved in optimality. The results of the computational experiments indicate that the second model is a bit more competitive in comparison with the first one, since it was able to solve a larger number of instances, present solutions with a smaller gap and require less computational time. Therefore, the other models started from the second with the addition of practical constraints. The results of the computational experiments indicate that the models with practical constraints can have better performance (that is, related to the number of instances solved, gap value and computational time) when smaller instances are considered. Therefore, developing models that are capable of solving medium and large size instances is a challenge, but, it can bring great advantages for the corporate environment, helping managers in making decisions, reducing waste, improving costs and thus bringing personal well-being.
Previsão do lead time de processos usando mineração de dados
(Universidade Federal de Goiás, 2021-03-09) Oliveira, Maíza Biazon de; Cordeiro, Douglas Farias; http://lattes.cnpq.br/5269312530540199; Silva, Núbia Rosa da; http://lattes.cnpq.br/8448585265537772; Silva, Núbia Rosa da; Duarte, Carlos Antonio Ribeiro; Silva, Sergio Francisco da; Cordeiro, Douglas Farias
The era of Industry 4.0 leads to constant adaptations of production processes and generates a significant amount of information. In this way, information management becomes a crucial factor to guarantee the competitive strategy in the industries. One of the information to be managed is textit lead time, time between the customer requesting an order and it being available. Usually, it can be estimated using expensive measurements or traditional methods that do not normally reflect the actual behavior of the data or do not support the significant amount of information generated in Industry 4.0. In addition, there are gaps in the literature on textit lead time forecasting, such as the use of smart methods to predict textit lead time across the supply chain. In this context, the objective of this research is to use data mining using machine learning algorithms to predict the textit lead time in real processes. The proposed methodology made use of the textit Knowledge Discovery in Databases (KDD) cycle structured in the selection, pre-processing, transformation, data mining and knowledge discovery phases. The learning algorithms for textit Linear Regression (LR), textit Random Forest (RF), textit Support Vector Machine (SVM), textit K-Nearest Neighbors (KNN) were tested and textit Multilayers Perceptron (MLP). To validate the experiments, three databases from the Electronic Information System (SEI), a supply chain from a pharmaceutical logistics sector and from the industrial automation sector for the ceramic sector, were used. The results showed that data mining is an effective tool for analyzing data generated in the fourth industrial revolution for forecasting textit Lead time and decision making on production planning and control.
Produção de adubos de liberação lenta utilizando a briquetagem de finos de calcário e melado de cana: estudos iniciais
(Universidade Federal de Goiás, 2019-03-12) Marinho, Douglas Yusuf; Espinosa, José Waldo Martínez; http://lattes.cnpq.br/5055033961082674; Espinosa, José Waldo Martínez; Guimarães, Marco Paulo; Godinho Júnior, Mário
Mineral agglomeration is a technique used to join mineral particles of fine granulometry. It aims to improve the conditions of application, storage and transport. The limestone, in turn, is a rock composed mainly of calcium and widely used as soil corrective, since it has the capacity to raise the pH of acid soils, besides providing Ca and Mg to the plants. Acidic soils are harmful to the full development of plants, since they negatively interfere with the absorption of nutrients. Brazil is the largest producer of sugarcane in the world, presenting great potential in the production of sugarcane molasses. On the other hand, the molasses, besides being an efficient agglomerant, also presents capacity of fertilization, since it has in its composition minerals essential to the plants, as it is the case of Fe, Ca, K, Na, P, Mg and Cl. Slow release fertilizers are those that gradually make nutrients available to plants. These fertilizers are proven to be more efficient than traditional ones because they are less susceptible to nutrient leaching, avoiding losses and contamination. In addition, large deforestation caused in our biomes, whether by agricultural exploration or urban growth, together with greater control of the environmental preservation areas generated by law 12.727 of 2012, create a potential growth in the demand for seedlings of native plants, the main niche application of slow release fertilizers. Thus, this work aims to propose, through preliminary tests, the creation of a slow - release fertilizer, composed of limestone (<400 #) and cane molasses, generated from mineral agglomeration by briquetting. For this, the generated briquettes were submitted to tests of mechanical resistance, such as tests of resistance to fall, compression and water action. The technical parameters of briquetting were used that presented better results in the resistance tests, according to existing works. The pressure used for briquetting is 3 tons for a time of 50 seconds. The briquettes were made in two different sizes, depending on the mass of limestone used, of 5 and 7.5 g. The percentage of cane molasses used was 8.5% of the limestone mass. The effect of curing time on the resistance of these briquettes was also analyzed, ranging from zero, five and ten days. The results showed that there is an increase in resistance of the briquettes with the curing process. The loss of moisture generated with the cure allows the crystallization of the sucrose, which contributes to the greater hardening of the briquettes. The higher resistance is reflected in the increase of degradation time under the action of the water, which would allow its use as slow release fertilizers. It should be emphasized that field trials would be important to prove their efficacy by conducting experiments involving one or more plant species, although this is not the objective of this study.
Proposta de melhoria da gestão hospitalar com uso da lean healthcare
(2021-09-28) Cechin, Débora Paula Borges De Oliveira; Bachega, Stella Jacyszyn; Tavares, Dalton Matsuo; Fernandes, Nilson José; Queiroz José Antonio de,
Evidências e pesquisas demonstram a necessidade de mudanças no setor de saúde, caracterizando os desafios enfrentados na gestão hospitalar. Aplicações do lean, conhecido como Lean Healthcare, vêm ocorrendo em diversas partes do mundo e inúmeros têm sido seus resultados. Apesar das melhorias que a Lean Healthcare tem proporcionado, pouco tem sido a percepção dos benefícios gerados aos olhos dos clientes. Além disso, nota-se que há um grande interesse em relação a integração da Lean Healthcare com outras técnicas. Assim, para contribuir com a melhoria da perspectiva de valor aos olhos dos clientes e integração da Lean Healthcare com outras técnicas, o presente trabalho tem o objetivo de propor o uso de ferramentas afins a Lean Healthcare para melhoria de processos na gestão de um hospital. Ressalta-se que o foco da melhoria é a redução do lead time do processo. Para isso, foi realizada uma pesquisa aplicada, por meio de uma abordagem qualitativa, com a realização de uma pesquisa bibliográfica e um estudo de caso no setor de exames de imagem de um hospital. As principais técnicas da Lean Healthcare utilizadas no estudo foram o mapeamento do fluxo de valor e a análise dos sete desperdícios, que em conjunto com uma pesquisa aplicada aos clientes do hospital de estudo e a revisão teórica foi construída uma proposta de melhoria. Dentre as melhorias que foram geradas a partir da aplicabilidade da proposta estão a redução do lead time em 22,95%, do tempo de espera em aproximadamente 22,97%, do deslocamento tanto aos clientes quanto dos colaboradores em 13,18%, a diminuição de desperdícios que impactarão diretamente na melhoria da qualidade no atendimento, menor tempo de exposição no ambiente hospitalar e maior satisfação na entrega dos serviços de saúde. Desse modo, o estudo pode contribuir no desenvolvimento científico da área de Lean Healthcare, com propostas para uma melhora nos processos do setor de exames de imagem, maior identificação e definição de valor aos olhos dos clientes e a contribuição para a comunidade acadêmica referente a pesquisas que utilizem ferramentas da Lean Healthcare em conjunto com outras técnicas. Ademais, a pesquisa contribuiu também para que outras instituições de saúde possam enxergar alguns obstáculos referentes ao setor de exames de imagem e apresenta a proposta da inclusão de um sistema (app) para contribuir com a agilidade do processo do agendamento até o resultado do exame, com o foco na diminuição do tempo de espera do paciente.
Proposta de processo para desenvolvimento de um centro de descarte e reuso de lixo eletrônico na Universidade Federal de Goiás
(Universidade Federal de Goiás, 2020-03-10) Silva, Edvaldo Capingote Serafim da; Tavares, Dalton Matsuo; http://lattes.cnpq.br/2307520004470578; Bachega, Stella Jacyszyn; http://lattes.cnpq.br/6057931770645811; Fernandes, Nilson José; Paula, Heber Martins de; Bachega, Stella Jacyszyn
In an attempt to promote awareness of the destination of electronic waste in universities, it is necessary to adopt sustainable practices that can achieve social, economic and environmental benefits. It has to be said that activities such as recycling or even reusing electronic waste (Green IT actions) considered outdated or useless in IEs, can be an important initiative to reduce the need for raw materials and, thus, contribute positively to reducing pollution in the planet. From this approach, the research problem is defined: how to implement an electronic waste disposal and reuse center in a university? To guide the execution of the study, the hypothesis formulated for the research problem is: a disposal and reuse center ensures that electronic waste is not dispersed in university departments. Thus, the general objective is to propose a center for the disposal and reuse of electronic waste at a university. The specific objectives contribute: in the analysis of legislation (environmental and patrimonial) aimed at the disposal of electronic waste, in public institutions; identification of forms / models for the development of electronic waste disposal and reuse centers; and, development of a scenario for the disposal and reuse of electronic waste in a university via simulation. For this, the literature review was performed with the aid of the CiteSpace® software, using the Web of Science and Scopus databases. The sampling technique was used to find the number of disassembly timings for computer equipment, in order to compose some parameters needed in the simulation. It is also noteworthy that semi-structured scripts were applied in areas of interest, such as CEDIR-USP and UFG bodies, such as CERCOMP and DPAME. It is concluded that the execution of the project stimulates sustainable development, as well as local remanufacturing, recycling or reuse; the increase in the rates of waste collection and the pioneering nature of the disposal of material in a higher education institution in the state of Goiás.
Proposta de uso de simulação computacional para incorporação de conceitos e atividades de green it em uma universidade
(Universidade Federal de Goiás, 2019-03-15) Marques, Carulina; Bachega, Stella Jacyszyn; http://lattes.cnpq.br/6057931770645811; Bachega, Stella Jacyszyn; Fernandes, Nilson José; Tavares, Dalton Matsuo
The concept of Green IT refers to sustainable technologies and information systems, as well as environmentally correct practices in the field of Information Technology. Universities, which have the role of propagating and applying knowledge, play an important role as disseminators of ideas related to Green IT. Therefore, it is necessary to study ways to achieve sustainable measures in these educational institutions. Based on this assumption, the main objective of the present research is to evaluate, through computer simulation, the environmental impact of a university's computer laboratories in terms of energy consumption and CO2 emission. Through these metrics, it was possible to calculate the value of the eco-efficiency indicator. A review of the literature on the integrated approach of green it and sustainable university themes was also carried out. The method of analysis of cocitations in multiple perspectives was used, which allowed the evaluation of which authors are most frequent in research on the themes , most commonly used keywords, and which topics are best covered when themes are studied together. The novelty is that the integration of the concepts of Sustainable University and Green IT have not yet been approached together in the Campus that will be the target of the research. Therefore the results generated with the research are of importance for the scientific development of the university. The results obtained by joining these approaches will contribute to the achievement of some approaches to sustainable universities, and may be used by national and international universities. In addition, it becomes possible to strengthen scientific researches that have interdisciplinary / transversal traits.

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