Desempenho de um veículo flex em bancada dinamométrica de chassi

Flex-fuel vehicles are equipped with Otto Cycle internal combustion engines and have the capability of functioning with more than one type of fuel, mixed at the same tank and burned in the combustion chamber simultaneously. This sort of motorization is a world pattern due to the scarcity of petroleum, the trade of several types of fuels, technology advances and the restriction imposed to gas emissions to the atmosphere. In Brazil, the Flexfuel vehicles are a reality, specially the ones using fuel with 20 to 25% anhydrous alcohol mixed with gasoline and those that use natural gas or original liquid fuel (gasoline or hydrated ethanol). The Brazilian model Fiat Siena, the object of this present scientific investigation, is equipped with a unique electronic central capable of managing the liquid or gaseous fuels. The purpose of this research was to perform a comparative analysis in terms of performance (in terms of both potency and consumption) of a tetra-fuel vehicle - using a chassis dynamometer, operating with different fuels: common gasoline, premium gasoline, Podium gasoline, ethanol or natural gas. It became necessary to develop a bench of tests and trials procedures, as well as to know the functioning of the electronic management of the vehicle under analysis. The experiments were performed at the automotive laboratory in CTGAS-ER (Center of Gas Technologies and Renewable energies) at the light of Brazilian standard ABNT, NBR 7024: Light on-road vehicles - measurement of fuel consumption. The essay results on specific fuel consumption using common gasoline, premium gasoline and Podium gasoline have shown similar results, both for urban and road driving cycles

Estudo da presença de entalhes semicirculares em compósitos poliméricos híbridos

Composite materials have a wide application in various sectors, such as the medical field in the manufacture of prostheses, in automotive and aerospace. Thus it is essential to the development of new composite and a better understanding in the face of various loading conditions and service. Several structural elements are manufactured in the presence of geometric discontinuity (notch, hole, etc ) in their longitudinal sections and/or cross-cutting, and these affect the mechanical response of these elements. The objective is to study the mechanical response of laminated polymer matrix hybrid composites reinforced with glass fiber/jute in a uniaxial tensile test. The mechanical response takes in account both the influence of the presence of a geometric discontinuity (semicircular notches) and the orientation of fibers in the layers (anisotropy). The semicircular notches are located in longitudinal section (with a reduction in cross section) of the same. In this analysis, the anisotropy is characterized by types of configurations (with different orientations of fibers in the outer layers). A comparative study of mechanical properties with and without the presence of notches is developed. Both configurations consist of four layers of woven jute fiber bidirectional and a central layer of bidirectional woven glass fibers. In addition to the mechanical properties was also studied the characteristics of the fracture developed in each composite laminate. The results showed that in the comparative study, the anisotropy and the presence of semicircular notches directly influences the mechanical behavior of laminates composites, mainly in reducing the tensile strength, and well as the final characteristics of the fracture

Desenvolvimento de têxteis técnicos para reforço de compósitos poliméricos

Materials denominated technical textiles can be defined as structures designed and developed with function to fulfill specific functional requirements of various industrial sectors as are the cases of the automotive and aerospace industries. In this aspect the technical textiles are distinguished from conventional textile materials, in which the aesthetic and of comfort needs are of primordial importance. Based on these considerations, the subject of this dissertation was established having as its main focus the study of development of textile structures from aramid and glass fibers and acting in order to develop the manufacture of composite materials that combine properties of two different structures, manufactured in an identical operation, where each structure contributes to improving the properties of the resulting composite material. Therefore were created in laboratory scale, textile structures with low weight and different composition: aramid (100%), glass (100%) and aramid /glass (65/35%), in order to use them as a reinforcing element in composite materials with polyester matrix. These composites were tested in tension and its fracture surface, evaluated by MEV. Based on the analysis of mechanical properties of the developed composites, the efficiency of the structures prepared as reinforcing element were testified by reason of that the resistance values of the composites are far superior to the polyester matrix. It was also observed that hybridization in tissue structure was efficient, since the best results obtained were for hybrid composites, where strength to the rupture was similar to the steel 1020, reaching values on the order of 340 MPa

Caracterização e análise das propriedades da fibra de Macambira (Bromelia Laciniosa)

Concern for the environment and the exploitation of natural resources has motivated the development of research in lignocellulosic materials, mainly from plant fibers. The major attraction of these materials include the fact that the fibers are biodegradable, they are a renewable natural resource, low cost and they usually produce less wear on equipment manufacturing when compared with synthetic fibers. Its applications are focused on the areas of technology, including automotive, aerospace, marine, civil, among others, due to the advantageous use in economic and ecological terms. Therefore, this study aims to characterize and analyze the properties of plant fiber macambira (bromelia laciniosa), which were obtained in the municipality of Ielmo Marino, in the state of Rio Grande do Norte, located in the region of the Wasteland Potiguar. The characterization of the fiber is given by SEM analysis, tensile test, TG, FTIR, chemical analysis, in addition to obtaining his title and density. The results showed that the extraction of the fibers, only 0.5% of the material is converted into fibers. The results for title and density were satisfactory when compared with other fibers of the same nature. Its structure is composed of microfibrils and its surface is roughened. The cross section has a non-uniform geometry, therefore, it is understood that its diameter is variable along the entire fiber. Values for tensile strength were lower than those of sisal fibers and curauá. The degradation temperature remained equivalent to the degradation temperatures of other vegetable fibers. In FTIR analysis showed that the heat treatment may be an alternative to making the fiber hydrophobic, since, at high temperature can remove the hemicellulose layer, responsible for moisture absorption. Its chemical constitution is endowed with elements of polar nature, so their moisture is around 8.5% which is equivalent to the percentage of moisture content of hydrophilic fibers. It can be concluded that the fiber macambira stands as an alternative materials from renewable sources and depending on the actual application and purpose, it may achieve satisfactory results

Avaliação da estrutura de tecidos técnicos como elemento reforçante em compósitos poliméricos sistema poliéster isoftálico

Materials known as technical textiles can be defined as structures designed and developed to meet specific functional requirements of various industry sectors, which is the case in automotive and aerospace industries, and other specific applications. Therefore, the purpose of this work presents the development and manufacture of polymer composite with isophthalic polyester resin. The reinforcement of the composite structure is a technical textile fabric made from high performance fibers, aramid (Kevlar 49) and glass fiber E. The fabrics are manufactured by the same method, with the aim of improving the tensile strength of the resulting polymer composite material. The fabrics, we developed some low grammage technical textile structures in laboratory scale and differentiated-composition type aramid (100%), hybrid 1 aramid fiber / glass (65/35%) and hybrid 2 aramid fiber / glass (85/15% ) for use as a reinforcing element in composite materials with unsaturated isophthalic polyester matrix. The polymer composites produced were tested in uniaxial tensile fracture surface and it´s evaluated by SEM. The purpose of this work characterize the performance of polymer composites prepared, identifying changes and based on resistance to strain corresponding to the mechanical behavior. The objectives are to verify the capability of using this reinforcement structure, along with the use of high performance fibers and resin in terms of workability and mechanical strength; verify the adherence of the fiber to the matrix and the fracture surface by electron microscopy scanning and determination of tensile strength by tensile test. The results indicate that, in a comparative study to the response of uniaxial tensile test for tensile strength of the composites and the efficiency of the low percentage of reinforcement element, being a technical textile fabric structure that features characteristic of lightness and low weight added in polymer composites

Biossorção utilizando alga marinha (sargassum sp.) aplicada em meio orgânico

In this work, biosorption process was used to remove heavy metals from used automotive lubricating oils by a bus fleet from Natal-RN-Brazil. This oil was characterized to determine the physical-chemistry properties. It was also characterized the used oil with the aim of determining and quantifying the heavy metal concentration. Fe and Cu were the metals existent in large concentration and these metals were choused to be studied in solubilization process. For the biosorption process was used the seaweed Sargassum sp for the study of influencing of the metals presents separately and with other metals. It was also studied the effect of the protonation treatment of alga with the objective to know the best efficiency of heavy metals removal. The study of the solubilization showed that the presence of more than a metal favors the solubilization of the metals presents in the oil and consequently, it favors the biosorption process, what becomes interesting the perspective application in the heavy metals removal in lubricating oils used, because the presence of more than a heavy metal favors the solubility of all metals present. It was observed that the iron and copper metals, which are present in large concentration, the protonated biosorbtent was more effective. In this study we used as biomass the marine alga Sargassum sp to study the influence of agitation velocity, temperature and initial biomass concentration on the removal of iron and copper from used lubricant oils. We performed an experimental design and a kinetic study. The experiments were carried out with samples of used lubricant oil and predetermined amounts of algae, allowing sufficient time for the mixture to obtain equilibrium under controlled conditions. The results showed that, under the conditions studied, the larger the amount of biomass present, the lower the adsorption capacity of the iron and of the copper, likely due to a decrease in interface contact area. The experimental design led us to conclude that a function can be obtained that shows the degree of influence of each one of the system variables

State-of-the-art for extrusion and injection moulding FPC: natural Fibre Plastics Composites in Brazil

Environmental and economical concerns are stimulating research of new materials for construction, furniture, packaging and automotive industries. Particularly attractive are the new materials. This paper presents results about the properties of composites of polyhydroxybutyrate (PHB), polypropylene (PP) and High Density Polyethylene (HDPE) reinforced with natural fibres. The composites were prepared through the extrusion with natural fibres, in an ratio of 30% by weight. The quality of samples was tested utilising injection moulded samples, according to ASTM standards. Results showed that natural fibres can act as an excellent reinforcing material, resulting in low cost composites and improving economical and ecological interests.

Organochlorine pesticides and polychlorinated biphenyls in soil and water samples in the northeastern part of São Paulo State, Brazil

Detailed analyses of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs) and congeners of polychlorinated biphenyls (PCBs) in soil and surface water from the northeastern São Paulo, Brazil allowed the evaluation of the contamination status, distribution and possible pollution sources. The pesticides and PCBs demonstrated markedly different distributions, reflecting different agricultural, domestic and industrial usage in each region studied. The ranges of HCH, DDT, and PCBs concentrations in the soil samples were 0.05-0.92, 0.12-11.01, 0.02-0.25 ng g(-1) dry wt, respectively, and in the surface water samples were 0.02-0.6, 0.02-0.58 and 0.02-0.5 ng l(-1), respectively. Overall elevated levels of DDT and PCB were recorded in region 2, a site very close to melting, automotive batteries industries, and agricultural practice regions. High ratios of metabolites of DDT to DDT isomers revealed the recent use of DDT in this environment. The sources of contamination are closely related to human activities, such as domestic and industrial discharge, street runoff, agricultural pesticides and soil erosion, due to deforestation as well as atmospheric transport. (c) 2006 Elsevier Ltd. All rights reserved.

Gestão da segurança e saúde no trabalho em empresas produtoras de baterias automotivas: um estudo para identificar boas práticas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diretrizes para implantação de sistemas de segurança e saúde do trabalho em empresas produtoras de baterias automotivas

O desenvolvimento de Sistemas de Gestão da Segurança e Saúde no Trabalho (SGSST) ganha um significado cada vez mais importante no desempenho das empresas, pois, por meio deles, é possível obter a promoção da saúde e satisfação dos trabalhadores e a redução dos riscos de acidentes. No entanto, para que um SGSST obtenha bons resultados, as empresas precisam estar atentas às dificuldades comumente encontradas durante o seu processo de implantação, procurando solucioná-las de maneira antecipada e estruturada. Pelo exposto, este trabalho tem como principal objetivo apresentar diretrizes, baseadas no referencial teórico e nos resultados dos estudos de caso realizados, para implantação de SGSSTs em empresas fabricantes de baterias automotivas. Para o seu desenvolvimento adotou-se o método de pesquisa qualitativa a partir da realização de dois estudos de caso em empresas fabricantes de baterias automotivas localizadas na cidade de Bauru. Os instrumentos de coleta de dados foram entrevistas semiestruturadas, análise de documentos e observação in loco. Ao final do artigo, são propostas diretrizes relacionadas aos seguintes elementos: alta direção, estratégia organizacional, cultura organizacional, departamento de Segurança e Saúde do Trabalho (SST), técnicos de SST, recursos humanos, treinamento, equipes multidisciplinares, comunicação interna, resistência à mudança, indicadores de desempenho, ferramentas gerenciais para solução de problemas de SST, gestão de projetos, recompensas e incentivos, e integração do sistema.

A study of reverse logistics flow management in vehicle battery industries in the midwest of the state of São Paulo (Brazil)

Having the objective of minimizing costs and improving their image in the consumer and export market, car battery industries began to seek environmental alternatives geared towards sustainable development. Reverse logistics flow represents an unprecedented tool for the economic and operational development of company activities, as well as a differential in the search for competitive advantages through environmentally correct practices. The aim of this paper is to describe the reverse logistics chain adopted by automotive battery industries in the midwest of the state of São Paulo, proposing a reverse logistics framework for small manufacturers that creates actions aimed at not harming the environment. (C) 2010 Elsevier Ltd. All rights reserved.

Influência de defeitos e diferentes processos de fabricação nas propriedades mecânicas finais de cerâmicas

Os materiais cerâmicos são atualmente cada vez utilizados como opção na engenharia mundial. Por se tratar de materiais com alta resistência mecânica, possuem muitas aplicações em diversas áreas, como por exemplo a de mancais, a automotiva (sensores, isoladores, catalisadores, pistões, válvulas, revestimentos), a de implantes biocompatíveis (dentário, substituição óssea, válvulas cardíacas), a de produtos sujeitos ao desgaste (guias), a de refratários (revestimento de equipamento bélico, componentes de fornos), a eletrônica, e outras. Nos processos de fabricação da cerâmica há uma gama de fatores que contribuem para as características do produto final. Devido a isso, muitos pesquisadores têm trabalhado no estudo da influência de determinados defeitos e técnicas de produção de cerâmicas nas características do produto final. Este trabalho tem como objetivo fazer uma revisão bibliográfica de recentes artigos que analisam a influência de fatores como velocidade de queima, surgimento de trincas, porosidade, fases cristalinas, e tamanho de partículas, nas propriedades mecânicas finais das cerâmicas. Pode-se concluir que é possível aperfeiçoar o processo de fabricação da cerâmica a fim de promover as melhores propriedades mecânicas possíveis, conhecendo-se fatores prejudiciais e métodos adequados para se obter o melhor produto final.

Biodiesel CO2 emissions: A comparison with the main fuels in the Brazilian market

The use of biodiesel is increasing as an attractive fuel due to the depleting fossil fuel resources and environmental degradation. This paper presents results of an investigation on the potentials of biodiesel as an alternative fuel and main substitute of diesel oil, comparing the CO2 emissions of the main fuels in the Brazilian market with those of biodiesel, in pure form or blended in different proportions with diesel oil (2%, 5%, and 20%, called B2, B5, and B20, respectively). The results of the study are shown in ton CO2 per m(3) and ton CO2 per year of fuel. The fuels were analyzed considering their chemical composition, stoichiometric combustion parameters and mean consumption for a single vehicle. The fuels studied were: gasoline, diesel oil, anhydrous ethyl alcohol (anhydrous ethanol), and biodiesel from used frying oil and from soybean oil. For the case of biodiesel, its complete life cycle and the closed carbon cycle (photosynthesis) were considered. With data provided by the Brazilian Association of Automotive Vehicle Manufacturers (ANFAVEA) for the number of vehicles produced in Brazil, the emissions of CO2 for the national fleet in 2007 were obtained per type of fuel. With data provided by the Brazilian Department of Transit (DENATRAN) concerning the number of diesel vehicles in the last five years in Brazil, the total CO2 emissions and the percentage that they would decrease in the case of use of pure biodiesel, B100, or several mixtures, B2, B5 and B20, were calculated. Estimates of CO2 emissions for a future scenario considering the mixtures B5 and B20 are also included in this article. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm(-1)), C-H (3000-2900cm(-1)), C=O (1730-1650cm(-1)), C-O and C-O-C bonds at 1200-1600cm(-1). The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85(0) to 22(0). Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

STUDY of THE TURNING NICKEL BASE ALLOY PYROMET (R) 31V (SAE HEV8)

Considering the constant technological developments in the aeronautical, space, automotive, shipbuilding, nuclear and petrochemical fields, among others, the use of materials with high strength mechanical capabilities at high temperatures has been increasingly used. Among the materials that meet the mechanical strength and corrosion properties at temperatures around 815 degrees C one can find the nickel base alloy Pyromet 31V (SAE HEV8). This alloy is commonly applied in the manufacturing of high power diesel engines exhaust valves where it is required high resistance to sulphide, corrosion and good resistance to creep. However, due to its high mechanical strength and low thermal conductivity its machinability is made difficult, creating major challenges in the analysis of the best combinations among machining parameters and cutting tools to be used. Its low thermal conductivity results in a concentration of heat at high temperatures in the interfaces of workpiece-tool and tool-chip, consequently accelerating the tools wearing and increasing production costs. This work aimed to study the machinability, using the carbide coated and uncoated tools, of the hot-rolled Pyromet 31V alloy with hardness between 41.5 and 42.5 HRC. The nickel base alloy used consists essentially of the following components: 56.5% Ni, 22.5% Cr, 2,2% Ti, 0,04% C, 1,2% Al, 0.85% Nb and the rest of iron. Through the turning of this alloy we able to analyze the working mechanisms of wear on tools and evaluate the roughness provided on the cutting parameters used. The tests were performed on a CNC lathe machine using the coated carbide tool TNMG 160408-23 Class 1005 (ISO S15) and uncoated tools TNMG 160408-23 Class H13A (ISO S15). Cutting fluid was used so abundantly and cutting speeds were fixed in 75 and 90 m/min. to feed rates that ranged from 0.12, 0.15, 0.18 and 0.21 mm/rev, and cutting depth of 0.8mm. The results of the comparison between uncoated tools and coated ones presented a machined length of just 30% to the first in relation to the performance of the second. The coated tools has obtained its best result for both 75 and 90 m/min. with feed rate of 0.15 mm/rev, unlike the uncoated tool which obtained its better results to 0.12 mm/rev.