937 resultados para DISK REFINING
Resumo:
Forage sorghum can be grown in areas presenting dry and hot environmental situations where the yield of other grasses can often be uneconomical. The objective of this study was to analyze the operating performance of agricultural machines in the deployment of sorghum forage in four tillage systems, as follows: no-tillage system, disk harrow + seeding, disk harrow + two light disking + seeding, minimum tillage + seeding and four seeding different speeds, as follows: 3, 5, 6 and 9 km h(-1). The study was performed under field conditions in FCA/UNESP, Botucatu County, SP, Brazil. The data were subjected to variance analysis in a simple factorial 4 x 4, and a random block design with split plots. Operational performance of the agricultural machinery, physical characteristics the soil, its water content and the yield of dry matter and green sorghum were determined. The operational performance of agricultural machines in the deployment of sorghum forage is influenced by the sowing speed and the soil tillage system used. Chisel plow was the equipment that required the highest mean traction force, mean traction and slip, as well as the lowest mean speed for the studied tillage system. Forage sorghum showed higher yields in no-tillage systems at a seeding speed of 5 km h(-1).
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As informações da avaliação de mecanismos de abertura de sulco de semeadoras de plantio direto auxiliam as empresas no dimensionamento de ferramentas rompedoras do solo, que buscam menor requerimento energético. Este trabalho foi realizado num solo classificado como Latossolo Vermelho com o objetivo de avaliar tridimensionalmente os esforços dos mecanismos de abertura de sulco de semeadoras adubadoras de plantio direto. O delineamento experimental utilizado foi o de blocos ao acaso com cinco tratamentos, sendo cinco mecanismos de abertura de sulco (disco liso - DL, disco corrugado - DC, disco ondulado - DO, disco duplo - DD e haste sulcadora - H). Para mensurar os esforços dos mecanismos de abertura de sulco, foi utilizado um dinamômetro com sensibilidade nas direções horizontal, transversal e vertical e no momento fletor e torsor. A avaliação mostrou que a interação entre mecanismos de abertura de sulco e carga vertical não foi significativa, entretanto os fatores foram significativos quando analisados individualmente. O resultado individual dos mecanismos de abertura de sulco mostrou que o disco ondulado proporcionou maior área de mobilização do solo, a haste sulcadora apresentou o menor valor de força vertical e o disco duplo e a haste sulcadora obtiveram o menor esforço horizontal.
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The individual evaluation of mechanisms for opening furrows to drop the seeds in a no-tillage seeders cultivation assists the companies in the sizing of opening tools of the ground, that search for minor energy petition and for diminishing the ground area mobilized. Therefore this work had the aim of evaluate the efforts of five different mechanisms of opening of ridge of seeding of direct plantation varyng the vertical load. The experiment was installed in one ground classified as Dystroferric Red Nitosol. The used experimental delineation was of the one randomized blocks in a factorial project 5 x 4, constituted a the following factors: five mechanisms of furrow opening (even disk - DL, corrugated disk - DC, ondulated disk - DO, double disk - DD and furrow rod - F) and four vertical loads (750, 1500, 2250 and 3000 N). To measure the forces in the studied treatments a dynamometer with sensitivity in the directions was used horizontal, lateral and vertical direction. The evaluation showed that the interaction between mechanisms of opening of ridge and vertical load was not significant, however the factors were significant when analyzed individually. The connecting rod promoted mobilization of the ground with smaller draft of horizontal effort reaching depths of work. The work showed that the vertical load influenced the depth of work of the mechanisms of ridge opening. The mechanisms of ridge opening of record type need vertical force to penetrate into the ground.
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Both the inadequate use and the ignorance of the different soil tillage implements available in the home market has become one of the leading motives of failures, related to soil and water conservation. The periodical tillage is traditionally utilized after subsoiling for soil clod breaking, leveling and residue incorporation. This work aimed to evaluate the energy requirement for different periodical soil tillage systems performed before and after subsoiling in a soil classified as Distroferric Red Nitosol. The periodic tillage systems were: disk plowing; disk plowing plus one leveling harrowing; disk harrow; disk harrow plus leveling harrowing stirring. The experimental design was a 5x2 factorial scheme with 5 completely randomized blocks. The results show that the periodic soil preparation systems based on disks have better energy efficiency when performed before the operation of subsoiling. The system of soil preparation with harrowing obtained the lower energy demand, in relation to other periodic soil preparation systems, when done after subsoiling.
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Avaliou-se o desempenho operacional de campo de uma semeadora-adubadora de precisão, equipada com seis linhas espaçadas de 550 mm, em um solo muito argiloso, classificado como Nitossolo Vermelho Distrófico Latossólico, na semeadura do feijoeiro (Phaseolus vulgaris L.). Os tratamentos consistiram de três métodos de preparo do solo: a) convencional (uma aração com arado de discos e duas gradagens niveladoras); b) escarificação (uma passagem de escarificador conjugado com rolo destorroador), e c) semeadura direta. Esses procedimentos foram combinados com quatro condições de cobertura do solo no inverno (consórcio aveia-preta + nabo forrageiro manejados com rolo-faca, triturador de palhas, herbicida e solo em pousio). Os métodos de preparo do solo e os manejos da cobertura foram repetidos por três anos consecutivos. Os valores de força e pico de força de tração na barra, patinagem dos rodados motrizes e consumo de combustível foram maiores no preparo com escarificador em relação aos obtidos no preparo convencional e na semeadura direta. A capacidade de campo efetiva foi maior na semeadura direta em relação aos outros tratamentos. Os manejos efetuados nas coberturas vegetais e o solo mantido em pousio não influenciaram em nenhuma das variáveis.
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This paper analyzes the performance of a parallel implementation of Coupled Simulated Annealing (CSA) for the unconstrained optimization of continuous variables problems. Parallel processing is an efficient form of information processing with emphasis on exploration of simultaneous events in the execution of software. It arises primarily due to high computational performance demands, and the difficulty in increasing the speed of a single processing core. Despite multicore processors being easily found nowadays, several algorithms are not yet suitable for running on parallel architectures. The algorithm is characterized by a group of Simulated Annealing (SA) optimizers working together on refining the solution. Each SA optimizer runs on a single thread executed by different processors. In the analysis of parallel performance and scalability, these metrics were investigated: the execution time; the speedup of the algorithm with respect to increasing the number of processors; and the efficient use of processing elements with respect to the increasing size of the treated problem. Furthermore, the quality of the final solution was verified. For the study, this paper proposes a parallel version of CSA and its equivalent serial version. Both algorithms were analysed on 14 benchmark functions. For each of these functions, the CSA is evaluated using 2-24 optimizers. The results obtained are shown and discussed observing the analysis of the metrics. The conclusions of the paper characterize the CSA as a good parallel algorithm, both in the quality of the solutions and the parallel scalability and parallel efficiency
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Hard metals are the composite developed in 1923 by Karl Schröter, with wide application because high hardness, wear resistance and toughness. It is compound by a brittle phase WC and a ductile phase Co. Mechanical properties of hardmetals are strongly dependent on the microstructure of the WC Co, and additionally affected by the microstructure of WC powders before sintering. An important feature is that the toughness and the hardness increase simultaneously with the refining of WC. Therefore, development of nanostructured WC Co hardmetal has been extensively studied. There are many methods to manufacture WC-Co hard metals, including spraying conversion process, co-precipitation, displacement reaction process, mechanochemical synthesis and high energy ball milling. High energy ball milling is a simple and efficient way of manufacturing the fine powder with nanostructure. In this process, the continuous impacts on the powders promote pronounced changes and the brittle phase is refined until nanometric scale, bring into ductile matrix, and this ductile phase is deformed, re-welded and hardened. The goal of this work was investigate the effects of highenergy milling time in the micro structural changes in the WC-Co particulate composite, particularly in the refinement of the crystallite size and lattice strain. The starting powders were WC (average particle size D50 0.87 μm) supplied by Wolfram, Berglau-u. Hutten - GMBH and Co (average particle size D50 0.93 μm) supplied by H.C.Starck. Mixing 90% WC and 10% Co in planetary ball milling at 2, 10, 20, 50, 70, 100 and 150 hours, BPR 15:1, 400 rpm. The starting powders and the milled particulate composite samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to identify phases and morphology. The crystallite size and lattice strain were measured by Rietveld s method. This procedure allowed obtaining more precise information about the influence of each one in the microstructure. The results show that high energy milling is efficient manufacturing process of WC-Co composite, and the milling time have great influence in the microstructure of the final particles, crushing and dispersing the finely WC nanometric order in the Co particles
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Due to advances in the manufacturing process of orthopedic prostheses, the need for better quality shape reading techniques (i.e. with less uncertainty) of the residual limb of amputees became a challenge. To overcome these problems means to be able in obtaining accurate geometry information of the limb and, consequently, better manufacturing processes of both transfemural and transtibial prosthetic sockets. The key point for this task is to customize these readings trying to be as faithful as possible to the real profile of each patient. Within this context, firstly two prototype versions (α and β) of a 3D mechanical scanner for reading residual limbs shape based on reverse engineering techniques were designed. Prototype β is an improved version of prototype α, despite remaining working in analogical mode. Both prototypes are capable of producing a CAD representation of the limb via appropriated graphical sheets and were conceived to work purely by mechanical means. The first results were encouraging as they were able to achieve a great decrease concerning the degree of uncertainty of measurements when compared to traditional methods that are very inaccurate and outdated. For instance, it's not unusual to see these archaic methods in action by making use of ordinary home kind measure-tapes for exploring the limb's shape. Although prototype β improved the readings, it still required someone to input the plotted points (i.e. those marked in disk shape graphical sheets) to an academic CAD software called OrtoCAD. This task is performed by manual typing which is time consuming and carries very limited reliability. Furthermore, the number of coordinates obtained from the purely mechanical system is limited to sub-divisions of the graphical sheet (it records a point every 10 degrees with a resolution of one millimeter). These drawbacks were overcome by designing the second release of prototype β in which it was developed an electronic variation of the reading table components now capable of performing an automatic reading (i.e. no human intervention in digital mode). An interface software (i.e. drive) was built to facilitate data transfer. Much better results were obtained meaning less degree of uncertainty (it records a point every 2 degrees with a resolution of 1/10 mm). Additionally, it was proposed an algorithm to convert the CAD geometry, used by OrtoCAD, to an appropriate format and enabling the use of rapid prototyping equipment aiming future automation of the manufacturing process of prosthetic sockets.
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Thermal insulation is used to protect the heated or cooled surfaces by the low thermal conductivity materials. The rigid ricin polyurethane foams (PURM) are used for thermal insulation and depend on the type and concentration of blowing agent. Obtaining PURM occurs by the use of polyol, silicone, catalyst and blowing agent are pre -mixed, reacting with the isocyanate. The glass is reusable, returnable and recyclable heat insulating material, whose time of heat dissipation determines the degree of relaxation of its structure; and viscosity determines the conditions for fusion, operating temperatures, annealing, etc. The production of PURM composites with waste glass powder (PV) represents economical and renewable actions of manufacturing of thermal insulating materials. Based on these aspects, the study aimed to produce and characterize the PURM composites with PV, whose the mass percentages were 5, 10, 20, 30, 40 and 50 wt%. PURM was obtained commercially, while the PV was recycled from the tailings of the stoning process of a glassmaking; when the refining process was applied to obtain micrometer particles. The PURM + PV composites were studied taking into account the standard sample of pure PURM and the influence of the percentage of PV in this PURM matrix. The results of the chemical, physical and morphological characterization were discussed taking into account the difference in the microstructural morphology of the PURM+PV composites and the pure PURM, as well the results of the physicochemical, mechanical e thermophysical tests by values obtained of density, hardness, compressive strength, specific heat, thermal conductivity and diffusivity. In general, the structure of pure PURM showed large, elongated and regular pores, while PURM+PV composites showed irregular, small and rounded pores with shapeless cells. This may have contributed to reducing their mechanical strength, especially for PURM - PV50. The hardness and density were found to have a proportional relationship with the PV content on PURM matrix. The specific heat, thermal diffusivity and thermal conductivity showed proportional relationship to each other. So, this has been realized that the increasing the PV content on PURM matrix resulted in the rise of diffusivity and thermal conductivity and the decrease of the specific heat. However, the values obtained by the PURM composites were similar the values of pure PURM, mainly the PURM-PV5 and PURM-PV10. Therefore, these composites can be applied like thermal insulator; furthermore, their use could reduce the production costs and to preserve the environment
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The petroleum industry, in consequence of an intense activity of exploration and production, is responsible by great part of the generation of residues, which are considered toxic and pollutants to the environment. Among these, the oil sludge is found produced during the production, transportation and refine phases. This work had the purpose to develop a process to recovery the oil present in oil sludge, in order to use the recovered oil as fuel or return it to the refining plant. From the preliminary tests, were identified the most important independent variables, like: temperature, contact time, solvents and acid volumes. Initially, a series of parameters to characterize the oil sludge was determined to characterize its. A special extractor was projected to work with oily waste. Two experimental designs were applied: fractional factorial and Doehlert. The tests were carried out in batch process to the conditions of the experimental designs applied. The efficiency obtained in the oil extraction process was 70%, in average. Oil sludge is composed of 36,2% of oil, 16,8% of ash, 40% of water and 7% of volatile constituents. However, the statistical analysis showed that the quadratic model was not well fitted to the process with a relative low determination coefficient (60,6%). This occurred due to the complexity of the oil sludge. To obtain a model able to represent the experiments, the mathematical model was used, the so called artificial neural networks (RNA), which was generated, initially, with 2, 4, 5, 6, 7 and 8 neurons in the hidden layer, 64 experimental results and 10000 presentations (interactions). Lesser dispersions were verified between the experimental and calculated values using 4 neurons, regarding the proportion of experimental points and estimated parameters. The analysis of the average deviations of the test divided by the respective training showed up that 2150 presentations resulted in the best value parameters. For the new model, the determination coefficient was 87,5%, which is quite satisfactory for the studied system
Resumo:
In the oil industry the mixture oil/water occurs in the operations of production, transportation and refining, as well as during the use of its derivatives. The amount of water produced associated with the oil varies and can reach values of 90% in volume in the case of mature phase of the production fields. The present work deals with the development of new design of the Mixer Settler based on Phase Inversion (MDIF) in a laboratory scale. We envisage this application in industrial scale so the phases of project, construction and operation are considered. The modifications most significant, in comparison with the original prototype, include the materials of construction and the substitution of the equipment used in the mixing stage of the process. It was tested the viability of substitution of the original system of mechanical mixing by a static mixer. A statistical treatment by means of an experimental design of composed central type was used in order to evaluate the behavior of the main variables of the separation process as function of the efficiency of separation for the new device. This procedure is useful to delimit an optimal region of operation with the equipment. The variables of process considered on the experimental design were: oil concentration in the feeding water (mg/L); Total volumetric flow rate (L/h); Ratio organic/water on volumetric basis (O/A). The separation efficiency is calculated by comparison of the content of oil and greases in the inlet and outlet of the equipment. For determination of TOG (Total Oil and Grease), the method used was based in the absorption of radiation in the infra-red region. The equipment used for these determinations was InfraCal® TOG/TPH Model HATR-T2 of the Wilks Enterprise, Incorporation. It´s important to stand out that this method of measure has being used by PETROBRAS S.A. Results of global efficiency of separation oil/water varied from 75.3 to 97.7% for contaminated waters containing up to 1664,1 mg/L of oil. By means of tests carried out with a real sample of contaminated water supplied by PETROBRAS we have got an effluent specified in terms of the legal standards required for discharging. Thus, the new design of equipment constitutes a real alternative for the conventional systems of treatment of produced water in the oil industry
Resumo:
A seca de ponteiros é uma doença que vem acarretando danos severos em plantas de eucalipto, causando cancros ao longo do ramo principal. O objetivo deste trabalho foi avaliar o efeito de fungicidas e extratos vegetais no controle de Botryosphaeria ribis. O teste in vitro dos fungicidas foi inteiramente casualizado com oito tratamentos: carbendazim, clorotalonil, difenoconazole, picoxystrobin + ciproconazole, ciproconazole, azoxystrobin, picoxystrobin e testemunha, quatro doses: 1 µg/mL, 10 µg/mL, 100 µg/mL e 1000 µg/mL; com cinco repetições. Após homogeneização do meio foram vertidas para as placas, repicado um disco de meio de cultura contendo o patógeno para estas placas e mantidas em BOD a 25°C por cinco dias. A avaliação foi feita através de medição diária do crescimento radial do micélio em centímetros. O delineamento experimental do controle químico a campo foi em fatorial 5x3, com cinco fungicidas e três métodos de aplicação (poda, pincelado e pulverizado), com quatro repetições. Foram feitas quatro aplicações, com intervalo de quinze dias. Os tratamentos foram: 1. azoxystrobin, 2. carbendazim, 3. clorotalonil + tiofanato-metílico, 4. difenoconazole e 5. testemunha. Simultaneamente foram feitas avaliações seguindo uma escala de notas de 1 a 6. O delineamento experimental do teste in vitro dos extratos vegetais foi em fatorial 5x4, com três repetições. Os tratamentos avaliados foram os extratos de: mil folhas, melão de são caetano, eucalipto , álcool e testemunha, nas concentrações de 5, 10, 15 e 20%. Os extratos e o álcool foram misturados ao meio de cultura previamente autoclavado, sendo estes colocados em placas de Petri. A avaliação foi feita através de medição diária do crescimento radial do micélio em centímetros. No teste com mudas o delineamento experimental foi em fatorial 2 x 2 x 4, sendo utilizado no experimento de duas procedências, dois modos de tratamento (preventivo e convencional) e quatro produtos para o controle (extrato de melão de são caetano, extrato de Corymbia citriodora, álcool e água). A inoculação do patógeno foi feita no caule das mudas. Foram feitas aplicações dos produtos e avaliações semanais. A avaliação foi feita através da contagem de plantas doentes. O ingrediente ativo carbendazin foi o que mostrou os melhores resultados in vitro diferindo estatísticamente dos outros tratamentos pelo teste Tukey a 1% de probabilidade; seguido pelo clorotalonil e difenoconazole. Todos os ingredientes ativos avaliados mostraram-se superiores a testemunha. A campo, azoxystrobin foi superior aos demais tratamentos e não houve diferença significativa entre os métodos de aplicação. In vitro, os extratos de mil folhas, melão e eucalipto não diferiram entre si pelo teste de Tukey a 5% de probabilidade. O álcool proporcionou a maior inibição do crescimento micelial e diferiu estatisticamente dos outros tratamentos utilizados. As concentrações de 10, 15 e 20% dos extratos não diferiram entre si, mas foram superiores a concentração de 5%. No teste em mudas, a aplicação preventiva mostrou-se superior a aplicação curativa, sendo que o álcool e o extrato de C. citriodora não diferiram entre si, mas foram superiores ao extrato de melão-de-são-caetano. Todos os produtos foram superiores a testemunha.
Resumo:
Algumas culturas têm pouca adaptação ao sistema plantio direto (SPD), em vista da alta compactação da camada superficial do solo. Nesse caso, o mecanismo utilizado na semeadora para a abertura dos sulcos para deposição do fertilizante pode ter grande importância no sentido de facilitar a penetração das raízes. Avaliouse a influência do mecanismo de distribuição de fertilizante e da adubação nitrogenada na cultura do arroz de terras altas (Oryza sativa) no sistema plantio direto. O experimento foi conduzido nos anos agrícolas 2001/2002 e 2002/2003, em Botucatu-SP, Brasil. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por dois mecanismos de distribuição de fertilizantes (haste sulcadora e disco duplo). Nas subparcelas, quatro níveis de N foram aplicados em cobertura (0, 40, 80 e 120 kg ha-1). Avaliou-se a profundidade de abertura do sulco e de deposição das sementes, a população de plantas, a altura de plantas, o número de colmos e de panículas m-2, o número total de espiguetas por panícula, a fertilidade das espiguetas, a massa de 1.000 grãos, a matéria seca da parte aérea, a produtividade e o teor de N na folha bandeira. O sucesso no estabelecimento da cultura do arroz de terras altas no SPD nas regiões de inverno seco do Brasil está diretamente ligado ao mecanismo de distribuição das semeadoras-adubadoras. A haste sulcadora promoveu maior profundidade de deposição de sementes, conseqüentemente reduzindo o estande, o número de panículas por área e a produtividade. A aplicação de N em cobertura no arroz de terras altas em SPD proporciona maiores produtividades quando a semeadura é realizada com mecanismo de disco duplo.
Resumo:
Crude oil is a complex liquid mixture of organic and inorganic compounds that are dominated by hydrocarbons. It is a mixture of alkanes from the simplest to more complex aromatic compounds that are present derivatives such as gasoline, diesel, alcohol, kerosene, naphtha, etc.. These derivatives are extracted from any oil, however, only with a very high quality, in other words, when the content of hydrocarbons of low molecular weight is high means that production of these compounds is feasible. The American Petroleum Institute (API) developed a classification system for the various types of oil. In Brazil, the quality of most of the oil taken from wells is very low, so it is necessary to generate new technology to develop best practices for refining in order to produce petroleum products of higher commercial value. Therefore, it is necessary to study the thermodynamic equilibrium properties of its derivative compounds of interest. This dissertation aims to determine vapor-liquid equilibrium (VLE) data for the systems Phenilcyclohexane - CO2, and Cyclohexane - Phenilcyclohexane - CO2 at high pressure and temperatures between 30 to 70oC. Furthermore, comparisons between measured VLE experimental data from this work and from the literature in relation to the Peng- Robinson molecular thermodynamic model, using a simulation program SPECS IVCSEP v5.60 and two adjustable interaction parameters, have been performed for modeling and simulation purposes. Finally, the developed apparatus for determination of phase equilibrium data at high pressures is presented
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The composition of petroleum may change from well to well and its resulting characteristics influence significantly the refine products. Therefore, it is important to characterize the oil in order to know its properties and send it adequately for processing. Since petroleum is a multicomponent mixture, the use of synthetic mixtures that are representative of oil fractions provides a better understand of the real mixture behavior. One way for characterization is usually obtained through correlation of physico-chemical properties of easy measurement, such as density, specific gravity, viscosity, and refractive index. In this work new measurements were obtained for density, specific gravity, viscosity, and refractive index of the following binary mixtures: n-heptane + hexadecane, cyclohexane + hexadecane, and benzene + hexadecane. These measurements were accomplished at low pressure and temperatures in the range 288.15 K to 310.95 K. These data were applied in the development of a new method of oil characterization. Furthermore, a series of measurements of density at high pressure and temperature of the binary mixture cyclohexane + n-hexadecane were performed. The ranges of pressure and temperature were 6.895 to 62.053 MPa and 318.15 to 413.15 K, respectively. Based on these experimental data of compressed liquid mixtures, a thermodynamic modeling was proposed using the Peng-Robinson equation of state (EOS). The EOS was modified with scaling of volume and a relatively reduced number of parameters were employed. The results were satisfactory demonstrating accuracy not only for density data, but also for isobaric thermal expansion and isothermal compressibility coefficients. This thesis aims to contribute in a scientific manner to the technological problem of refining heavy fractions of oil. This problem was treated in two steps, i.e., characterization and search of the processes that can produce streams with economical interest, such as solvent extraction at high pressure and temperature. In order to determine phase equilibrium data in these conditions, conceptual projects of two new experimental apparatus were developed. These devices consist of cells of variable volume together with a analytical static device. Therefore, this thesis contributed with the subject of characterization of hydrocarbons mixtures and with development of equilibrium cells operating at high pressure and temperature. These contributions are focused on the technological problem of refining heavy oil fractions