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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Semeadura da soja em sistemas de rotação de culturas e integração agricultura-pecuária em um latossolo sob sistema de plantio direto / Seeding of soybean in systems of handling culture and cattle-raising integration in oxisol under no tillage system

Gurgacz, Flavio 17 May 2007 (has links)
Made available in DSpace on 2017-05-12T14:48:21Z (GMT). No. of bitstreams: 1 Flavio_texto.pdf: 2261502 bytes, checksum: 70662acf10f6cee0e3ad7d7d457cd0c3 (MD5) Previous issue date: 2007-05-17 / The no tillage system with cattle-raising integration blunts as an alternative to agricultural activities diversification providing income increase, production risks decrease and optimization of the machinery and inputs. The no tillage seed drill available in the market disposal some components that adapts itselves to different plantation conditions. On the other hand some information are necessary to indicate in which situations the mechanism must be modified and what is its effect in the culture implantion. In this direction it was conducted a research under an oxisol in Cascavel-PR evaluating the performance of a fertilizer and seed drill in the implantation of soybean culture under different systems of soil management. Were used fertilizer coulters cinzel type, double disc and its absence under two rotation systems (wheat/soybean and covering plant/soybean) and cattle-raising integration. For the area characterization were determined the density, macroporosity, microporosity, penetration resistance, humidity and soil vegetal covering. In the tractor were determined the fuel consumption, the drawbar force, pneumatic slip, rotation of the engine and speed. The other evaluated parameters were the depth of ridge and seeds, mobilized soil in the line, index of emergency speed (IVE), plant population and productivity. The results showed a tendency of modification in the soil physics parameters according to management system and a modification in the seeder performance equipped with different coulters under the different soil conditions.The fuel consumption, drawbar force, pneumatic silp and speed were significantly modified by the coulter mechanism. The cinzel coulter showed greater depth of ridge and seeds, soil mobilizing in the line and minor IVE. The soybean productivity was not influenced by the coulter mechanism but was affected by the management system being the major value obtained in the cattle-raising integration system in function of the biggest population of plants gotten. It was concluded that when it works with different management systems it is necessary to modify the coulters of soil preparation in the sowing line to get the desired results. / O sistema plantio direto junto com a integração agricultura-pecuária desponta como alternativa à diversificação das atividades agrícolas, proporcionando aumento de renda, diminuição dos riscos de produção e otimização de máquinas e insumos. As semeadoras para plantio direto, disponíveis no mercado, disponibilizam vários componentes que se adaptam as diferentes condições de implantação da lavoura. Por outro lado, são necessárias informações que indiquem em quais situações deve-se modificar um mecanismo e qual seu efeito na implantação da cultura. Nesse sentido, implantou-se um trabalho sob latossolo no município de Cascavel - PR, avaliando-se o desempenho de uma semeadora adubadora na implantação da cultura da soja sob diferentes sistemas de manejo do solo. Utilizou-se sulcadores de fertilizante tipo haste, disco duplo e sua ausência sob dois sistemas de rotação de cultura (trigo/soja e planta de cobertura/soja) e integração agricultura-pecuária. Para a caracterização da área, mensurou-se a densidade, macroporosidade, microporosidade, resistência à penetração, umidade e cobertura vegetal do solo. No trator, foram mensurados o consumo de combustível, força na barra de tração, patinagem dos rodados, rotação do motor e velocidade. Os outros parâmetros avaliados foram a profundidade de sulco e sementes, revolvimento do solo na linha, índice de velocidade de emergência (IVE), população de plantas e produtividade. Os resultados mostram uma tendência de modificação nos parâmetros físicos do solo de acordo com o sistema de manejo e modificação do desempenho da semeadora equipada com os diferentes mecanismos sob as diferentes condições de solo. O consumo de combustível, requerimento de força, patinagem e velocidade foram significativamente modificados pelo mecanismo sulcador. O mecanismo tipo haste obteve maior profundidade de sulco e sementes, revolvimento do solo na linha e menor IVE. A produtividade de soja não foi influenciada pelo mecanismo sulcador e sim pelo sistema de manejo, sendo o maior valor obtido no sistema integração agricultura-pecuária, em função da maior população de plantas obtida. Concluiu-se que, quando se trabalha com diferentes sistemas de manejo, é necessário modificar os mecanismos de preparo do solo na linha de semeadura, para se obterem os resultados desejados.
132

The development of an integrated routing and carbon dioxide emissions model for goods vehicles

Palmer, Andrew 11 1900 (has links)
The issues of global warming and climate change are a worldwide concern and the UK government has committed itself to major reductions in CO2 emissions, the most significant of the six greenhouse gases. Road transport currently accounts for about 22% of total UK emissions of CO2, and has been steadily rising. Therefore, initiatives are required to try and reduce the gas emissions in this sector. The aim of this research has been to develop a computer based vehicle routing model that calculates the overall amount of CO2 emitted from road journeys, as well as time and distance. The model has been used to examine a number of delivery strategies to assess how CO2 emissions vary. The aim has not been to produce new mathematical theories, but to produce an innovative basis for routing which will provide new information and knowledge about how CO2 emissions vary for different minimisation and congestion criteria. The approach used in this research brings together elements from transportation planning and environmental modelling combined with logistics based vehicle routing techniques. The model uses a digitised road network containing predicted traffic volumes, to which speed flow formulae are applied so that a good representation of speed can be generated on each of the roads. This means that the model is uniquely able to address the issue of congestion in the context of freight vehicle routing. It uses driving cycle data to apply variability to the generated speeds to reflect acceleration and deceleration so that fuel consumption, and therefore CO2, can be estimated. Integrated within the model are vehicle routing heuristics to enable routes to be produced which minimise the specified criterion of time, distance or CO2. The results produced by the model show that there is a potential to reduce CO2 emissions by about 5%. However, when other transport externalities are considered overall benefits are dependent on road traffic volumes.
133

Įsiurbiamo oro parametrų įtakos dyzelinio variklio rodikliams tyrimas / Influence of Air Intake Parameters on Diesel Engine Performance

Kurkauskas, Vaclovas 28 May 2012 (has links)
Šiuo metu vis gausėjantis transporto priemonių skaičius ir didėjantys išmetamų teršalų kiekiai atmosferoje, skatina vyriausybes griežtinti reikalavimus VDV deginių emisijai. Vieni iš kenksmingiausių elementų deginiuose yra azoto oksidai NOX, kurie sąveikaudami atmosferoje sudaro rūgštinius junginius. Vandens dalyvavimas degimo procese taip pat mažina šių teršalų koncentraciją deginiuose. VDV maitinant vandens ir degalų emulsijomis gaunama mažesnė NOX koncentraciją deginiuose, bet tai neigiamai veikia visą variklio maitinimo sistemą. Šiame tiriamajame darbe nagrinėjamas vandens poveikis dyzelinio VDV deginių emisijai. Siekiant išvengti galimo neigiamo poveikio variklio maitinimo sistemai bei dėl paprastesnio dozavimo, vanduo įvedamas į variklio įsiurbimo traktą garų pavidalu. Tyrimai atlikti varikliui dirbant be vandens garų bei įvedant vandens garus į variklio įsiurbimo traktą trimis skirtingomis koncentracijomis. Tyrimais nustatyta 12 % didesnės lyginamosios efektyviosios degalų sąnaudos vidutinių apkrovų zonoje bei 5 % mažesnės maksimalių apkrovų zonoje, iki 8 % didesnė CO koncentracija, taip pat nustatyta iki 26 % mažesnė bendra NOX koncentracija deginiuose įvedant maksimalų 13,0 g/min vandens garų kiekį VDV vidutinių apkrovų zonoje. / Recently growing number of vehicles increases the amount of emitted pollutants into the atmosphere. This fact rushes the governments to tighten requirements for the ICE exhaust emissions. Some of the most harmful elements in the exhaust gases are nitrogen oxides NOX, which interact in the atmosphere and compose acidic compounds. However, presence of water in the combustion process reduces the concentration of pollutants in the exhaust gases. ICE fueled by water and fuel emulsions produces less NOX in the exhaust gases, but it adversely affects the fuel supply system. This study examined the effect of water on ICE diesel exhaust emissions. In order to avoid possible negative effects on fuel supply system and to simplify dosing, water is infused into the engine inlet tract in the form of vapor. Investigations were carried the engine operating without water vapor and with the introduction of water vapor into the engine inlet tract in three different concentrations. The research revealed that basic fuel consumption was 12 % higher in the average load area and 5% lower at the maximum load area. CO concentration was found to be up to 8 % higher, moreover total concentration of NOX was revealed to be 26 % lower in the exhaust gases entering the maximum 13,0 g/min of water vapor in the average load area.
134

Vidutinės galios traktorių variklių apkrovos, degalų sąnaudų ir deginių emisijos racionali sąveika / Engine load, fuel consumption and exhaust gas emissions retional interaction of the medium power tractors

Juostas, Antanas 03 January 2013 (has links)
Pirmą kartą Lietuvoje traktorių variklių darbo ir degalų sąnaudų efektyvumo bei deginių emisijos vertinimui panaudota šiuolaikiškų traktorių variklių valdymo elektroninės sistemos mikroprocesoriuose sukaupta eksploatacinių darbo parametrų duomenų bazė. Traktorių valdymo ir kontrolės mikroprocesoriuose kaupiamos duomenų bazės pagrindu nustatyti daugumoje žemės ūkyje naudojami traktorių variklių darbo režimai. Sudaryta traktorių variklių darbo režimų, degalų naudojimo efektyvumo ir oro taršos variklio išmetamomis dujomis vertinimo metodika, panaudojant mikroprocesoriuose kaupiamų duomenų bazę. Ištirtos traktorių mikroprocesoriuose kaupiamų darbo parametrų pritaikymo traktorių variklio darbo režimų, degalų naudojimo efektyvumo ir oro taršos variklio išmetamomis dujomis vertinimo galimybės. Ištirtas degalų naudojimo efektyvumas ir deginių emisija traktorių eksploatacijos laikotarpiu bei sėjos ir arimo darbuose. Eksploatacijos laikotarpiu bei atliekant lauko darbus nustatytas apskaičiuotos deginių emisijos vertinimo tinkamumas šiuo metu traktorių varikliams taikomiems deginių emisijos kontrolės standartams. Siūloma metodika gali būti panaudota žemės ūkyje dirbančių traktorių deginių emisijos bei degalų sąnaudų vertinimui realiu darbo metu. Taip pat, gauti rezultatai bei taikomi metodai gali būti panaudoti traktorių darbo kokybės rodiklių tokių kaip degalų sąnaudų, deginių emisijos, įdirbimo gylio ir pan., lauko žemėlapių sudarymui. / First time in Lithuania tractors’ engine, fuel efficiency and exhaust gas emission estimated by using data base collected in the modern tractor engine management electronic microprocessors. The majority of agricultural tractors engine operating modes was determined by using data base collected in tractor management and control microprocessors. The evaluation methodology of the tractor engine operating modes, fuel efficiency and exhaust gas emissions was made. Investigated tractor engine operating modes, fuel efficiency and exhaust gas emissions assessment possibilities by using tractor operating parameters stored in their microprocessors. Fuel efficiency and exhaust emissions during tractor operation period, sowing and plowing jobs were investigated. Evaluated adequacy of calculated investigated tractors engine exhaust emission during operation period and field work with applicable exhaust emission control standards. The proposed methodology can be used for evaluation of the agriculture tractor exhaust emissions and fuel consumption during operation in real time. Also, the obtained results and methods can be used for the tractor work quality indicators such as fuel consumption, exhaust emissions, tillage depth, and so etc. field mapping creation.
135

Porovnání automobilového a traktorového zemědělského dopravního systému s výměnnými nástavbami v podniku zemědělské prvovýroby / Comparing automotive and tractor agricultuar transport system with swap bodies in agriculture business

HRACH, Milan January 2016 (has links)
This thesis deals with the collation of the automotive and wheel tractor transport system with interchangeable superstructures and their use in the business of primary agricultural production in terms of technical parameters, analysis of the use of individual bodies, analysis of investment and operating costs and by comparing the two systems on the basis of the identified parameters. Comparasion was the truck Tatra Phoenix 158 with the superstructures for the transport of powdery and bulky materials, spreaders, manure spreaders and superstructure designed for the transport of heavy materials with tractors transport system John Deere 8320 and tandem semi-trailer Fliegl with manure and conveyor superstructure ASW 268 in the Agricultural cooperative Cizova. In the performance collation of both systems when transporting silage and achieve the highest mass performance at the tractors transport system and it 14,39 t.h-1 which is aganist automotive system less about 5.94 t.h-1. On the other hand fuel consumption to distance traveled, weight and the cycle was recorded the lowest consumption of the lorry Tatra. The economic collation showed that the truck Tatra Phoenix 158 has a lower cost on the distance travelled, the transported amount of cargo and per tonne-kilometre compared to tractors transport system. The cost of the distance travelled makes 90,24 CZK.km-1 which is beside tractor system lower of 100 CZK.km-1. The value of the cost of the transported amount of cargo by lorry moves on 92,10 CZK.t-1 but tractor system has this value lower of 24.83 CZK.t-1.The lowest difference between the costs experienced in the evaluation of the cost per tonne-kilometre where the truck Tatra reached the cost of 9.42 CZK.tkm1 which is compared with tractors transport system, the lower of 3.28 CZK.tkm-1.
136

Desempenho operacional de semeadora-adubadorae perdas na colheita do milho em sistema de plantio direto

Grotta, Danilo Cesar Checchio [UNESP] 29 May 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-29Bitstream added on 2014-06-13T18:45:40Z : No. of bitstreams: 1 grotta_dcc_dr_jabo.pdf: 473302 bytes, checksum: f8cdc0255abc578da01bc3a223137e5e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo buscado com o desenvolvimento do trabalho foi obter informações quanto às melhores alternativas para o sistema de semeadura direta em regiões com características semelhantes às de Jaboticabal/SP, na cultura do milho, em diferentes manejos de culturas de cobertura do solo. O experimento foi conduzido na área experimental do Laboratório de Máquinas e Mecanização Agrícola (LAMMA) da UNESP/Jaboticabal. Avaliou-se o desempenho do conjunto trator-semeadora-adubadora, o desenvolvimento de um híbrido simples de milho (DKB 390), e as perdas na colheita mecanizada em função de 2 culturas de cobertura crotalária (Crotalária juncea L.) e mucuna preta (Mucuna aterrina L.), manejadas de 3 formas, sendo duas mecânicas (triturador de palhas e rolo-faca) e uma química (herbicida via pulverizador) com a cultura do milho semeada a 5 cm de profundidade e deposição de adubo em 3 profundidades (11, 14 e 17 cm) totalizando 18 tratamentos com 4 repetições com delineamento em blocos ao acaso, em esquema fatorial. Os resultados evidenciaram que a força de tração na barra foi menor nas profundidades 11 e 14 cm do sulcador de adubo, e o mesmo ocorreu para a força de tração na barra por fileira de semeadura, força de pico na barra de tração, potência na barra de tração, potência na barra por fileira de semeadura, consumos volumétrico e ponderal. O consumo específico foi maior na profundidade de 11 cm do sulcador de adubo. A distribuição longitudinal de plantas não foi influenciada pelos fatores. Os fatores cultura, manejo e profundidade não influenciaram as variáveis, fluxo de grãos, fluxo de material não grão, fluxo total e perdas totais. As perdas totais não foram influenciadas por nenhum dos fatores estudados. / The objective sought with the development of the work was to obtain information on the best alternatives to the no-tillage system sowing in regions with similar characteristics to those of Jaboticabal / SP, in the corn crop in different management cultures of soil cover. The experiment was conducted in the experimental area of the Laboratory of Machinery and Agricultural Mechanization (LAMMA) of São Paulo University State. It was evaluated the performance of all tractor-seeder-fertilizer, the development of a simple hybrid maize (DKB 390), and losses in mechanized harvesting crops in function of 2 coverage cultures (Crotalária juncea L.) and black mucuna ( Mucuna aterrina L.), managed in 3 ways, two mechanical (crusher of straw and roll-knife) and a chemical (herbicide spray route) with the corn crop sown to 5 cm deep and deposition of fertilizer in 3 depths ( 11, 14 and 17 cm) totaling 18 treatments with 4 repetitions with design in randomized blocks in factorial plots. The results showed that the force of traction in the bar was lower at depths of 11 to 14 cm stem of fertilizer, and the same occurred for the traction force on the bar by row of sowing, the power peak in the bar of traction, potency on the traction bar, potency on the traction bar by the row of sowing, consumption volumetric and weight. The specific consumption was higher in the depth of 11 cm from steam of fertilizer. The longitudinal distribution of plants was not influenced by factors. The factors culture, management and depth did not influence the variables of grain flow, flow of material non-grain, total flow and total losses. The total losses were not affected by any of the factors studied.
137

The development of an integrated routing and carbon dioxide emissions model for goods vehicles

Palmer, Andrew January 2007 (has links)
The issues of global warming and climate change are a worldwide concern and the UK government has committed itself to major reductions in CO2 emissions, the most significant of the six greenhouse gases. Road transport currently accounts for about 22% of total UK emissions of CO2, and has been steadily rising. Therefore, initiatives are required to try and reduce the gas emissions in this sector. The aim of this research has been to develop a computer based vehicle routing model that calculates the overall amount of CO2 emitted from road journeys, as well as time and distance. The model has been used to examine a number of delivery strategies to assess how CO2 emissions vary. The aim has not been to produce new mathematical theories, but to produce an innovative basis for routing which will provide new information and knowledge about how CO2 emissions vary for different minimisation and congestion criteria. The approach used in this research brings together elements from transportation planning and environmental modelling combined with logistics based vehicle routing techniques. The model uses a digitised road network containing predicted traffic volumes, to which speed flow formulae are applied so that a good representation of speed can be generated on each of the roads. This means that the model is uniquely able to address the issue of congestion in the context of freight vehicle routing. It uses driving cycle data to apply variability to the generated speeds to reflect acceleration and deceleration so that fuel consumption, and therefore CO2, can be estimated. Integrated within the model are vehicle routing heuristics to enable routes to be produced which minimise the specified criterion of time, distance or CO2. The results produced by the model show that there is a potential to reduce CO2 emissions by about 5%. However, when other transport externalities are considered overall benefits are dependent on road traffic volumes.
138

Economia de combustível de tratores agrícolas utilizando diferentes transmissões e estratégia de condução / Fuel economy of agricultural tractors using diferent transmissions and driving strategy

Farias, Marcelo Silveira de 19 August 2016 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Due to Diesel oil s mineral origin and marketing price, the consumption of this fuel by a tractor becomes one of the most important aspects at the time of its acquisition and use. Knowledge of the appropriate strategies in driving combined with correct selection of modern power transmissions can help farmers to reduce production costs. When driving the tractor of different ways with different types of power transmissions, more efficiently and cost-effectively, the fuel consumption changes. The following research aimed to evaluate the effects of different types of power transmission and driving strategies on fuel consumption of agricultural tractors. For this, two experiments were conducted at the Agricultural Mechanics Station, Madrid, Spain, using two tractors, one equipped with Powershift transmission and the other with Continuously Variable Transmission (CVT). Standard procedure has been applied considering six load levels (30; 40; 50; 60; 70 and 80%) by means of breaking with a dynamometer car instrumented in a concrete test track, at three travel speeds (5.16; 7.29 and 10.48 km.h-1). Furthermore, the tractor equipped with Powershift transmission was conducted in two ways: Full throttle; Gear up - throttle down. Already the tractor equipped with Continuously Variable Transmission was conducted using the automatic mode. The responses evaluated variables were speed and thermal efficiency of the engine and hourly and specific fuel consumption. Analysis of variance was performed and that presented difference the data were subjected to the Tukey s test (≤0.05) for comparison of averages. The results indicate that the Gear up - throttle down mode (Powershift transmission) can be recommended as a strategy of agricultural tractor driving, since savings may be obtained up to 29.39% of fuel in relation to the Full throttle, typically recommended by manufacturers. The specific fuel consumption of tractor equipped with Continuously Variable Transmission decreases as the load levels and travel speeds are incremented. / Por ser um combustível de origem mineral e devido ao preço de comercialização, o consumo de óleo Diesel de um trator torna-se um dos aspectos mais importantes a considerar no momento da sua aquisição e utilização. O conhecimento de estratégias adequadas na condução, aliado à escolha correta de modernas transmissões de potência podem auxiliar os agricultores a diminuírem os custos de produção. Quando se conduz o trator de distintas maneiras, com diferentes tipos de transmissão de potência, de forma mais eficiente e econômica, o consumo de combustível se altera. O objetivo deste trabalho de pesquisa foi avaliar o efeito de diferentes tipos de transmissão de potência e estratégias de condução no consumo de combustível de tratores agrícolas. Para isto, foram conduzidos dois experimentos na Estação de Mecânica Agrícola, Madrid, Espanha, utilizando dois tratores, sendo um equipado com transmissão Powershift e o outro com Transmissão Continuamente Variável. Para a avaliação utilizou-se procedimento normalizado, com aplicação de seis cargas parciais (30; 40; 50; 60; 70 e 80%), por meio da frenagem com um carro dinamométrico instrumentado, em pista de concreto, em três velocidades de deslocamento (5,16; 7,29 e 10,58 km.h-1). O trator equipado com transmissão Powershift foi conduzido de duas maneiras: Aceleração Máxima e Marcha Longa - Aceleração Reduzida. Já o trator equipado com Transmissão Continuamente Variável foi conduzido utilizando-se o modo automático. As variáveis respostas avaliadas foram a rotação e a eficiência térmica do motor, os consumos horário e específico de combustível. Foi realizada a análise de variância e os dados que apresentaram diferença foram submetidos ao teste de Tukey (≤0,05), para comparação de médias. Os resultados indicaram que o modo Marcha Longa - Aceleração Reduzida (transmissão Powershift) pode ser recomendado como uma estratégia de condução do trator agrícola, visto que podem ser obtidas economias de até 29,39% de combustível em relação ao modo Aceleração Máxima, normalmente recomendado pelos fabricantes. O consumo específico de combustível do trator equipado com transmissão Continuamente Variável diminui à medida que as cargas parciais e as velocidades de deslocamento são incrementadas.
139

An?lise da sensibilidade do biodiesel B5 em frotas de transporte coletivo com motoriza??o diesel

Oliveira Filho, Manoel Fernandes de 31 January 2011 (has links)
Made available in DSpace on 2014-12-17T14:58:06Z (GMT). No. of bitstreams: 1 ManoelFOF_DISSERTCP.pdf: 4342544 bytes, checksum: aea44959b05b87d14d463b3b07cde70c (MD5) Previous issue date: 2011-01-31 / The aim of this study was investigate the consolidation of the biodiesel fuel used in (a) engines of urban and intercity bus companies, (b) a stationary engine. It was necessary to investigate and analyze, technologically, if the biodiesel fuels were presenting troubleshooting relative to wear of parts lied to fuel and to evaluate the consumption fluctuations of this fuel. The urban and intercity bus companies, localized in Natal, Rio Grande do Norte state, Brazil, had 41 and 12 vehicles, respectively. It were analyzed datasheet of each one vehicle during three years, since 2008 until 2010 and were interviewed the management of the maintenance team of bus companies relative to aspects concerning the substitution of the diesel fuel by the B5 biodiesel. The second aim of this study was visually inspect the wear of the parts directly lied to combustion process. For this reason, it was investigated a stationary engine, manufactured by Branco BD5, 5 HP of power, fueled by (a) diesel, (b) biodiesel B5, (c) biodiesel B20 and (d) diesel or biodiesel, both contaminated by distilled water. In this engine, its power utilizing biodiesel B5 versus diesel was lower about 5.2% and, in the investigated case of B20 versus diesel, it was lower around 11.5% / Investigou-se a consolida??o do uso do biodiesel em (a) motores de duas frotas de ?nibus, uma urbana e uma intermunicipal e (b) um motor estacion?rio. Entende-se serem necess?rios estudos para se observar, do ponto de vista tecnol?gico, se o uso do biodiesel apresenta problemas quanto ao desgaste das pe?as diretamente envolvidas com o combust?vel e tamb?m observar as flutua??es, para mais ou para menos, do consumo espec?fico desse combust?vel. As frotas de ?nibus urbana e intermunicipal, sediadas em Natal RN - Brasil, possu?am 41 e 13 ve?culos, respectivamente. Foram analisadas as planilhas de cada ve?culo no per?odo de tr?s anos, de 2008 a 2010 e entrevistados os respons?veis pela manuten??o e condu??o da frota para observar os relatos dos mesmos quanto aos aspectos resultantes da substitui??o do ?leo diesel pelo B5. O segundo objetivo deste estudo foi inspecionar visualmente o desgaste das pe?as diretamente envolvidas no processo da combust?o. Para isso, utilizou-se um motor estacion?rio da marca Branco BD5, pot?ncia de 5 CV, abastecido por (a) diesel, (b) biodiesel B5, (c) biodiesel B20 e (d) diesel ou biodiesel contaminado com ?gua destilada. Nesse motor, sua pot?ncia utilizando B5 versus diesel demonstrou ser inferior em 5,2% e, no caso investigado de B20 versus diesel, inferior em 11,5%
140

AvaliaÃÃo do ruÃdo e do desempenho energÃtico de um trator de rabiÃas com um arado de disco acoplado. / Evalution of noise and the energy performance of a tractor with plow disc attached

Silvia Ferreira da Silva 24 August 2012 (has links)
O preparo inicial do solo tem grande importÃncia para a produÃÃo agrÃcola, essa atividade à geralmente realizada por traÃÃo animal na agricultura familiar. Nesse trabalho estudou-se a utilizaÃÃo de tratores de rabiÃas como fonte de otimizaÃÃo do trabalho no campo. O experimento foi desenvolvido com um trator de rabiÃas com um arado acoplado na Universidade Federal do Cearà com o objetivo de avaliar a eficiÃncia energÃtica do trator de rabiÃas acoplado ao arado de disco utilizando trÃs marchas (1Â, 2 e 3Â) em um Argissolo Vermelho Amarelo, avaliou-se tambÃm o empolamento do solo e os nÃveis de ruÃdo com a mÃquina parada em diferentes raios de afastamento (1, 2, 5 e 10 m), e com o trator de rabiÃas em movimento utilizando trÃs rotaÃÃes (810, 1.040 e 1.360 rpm). Para obtenÃÃo de dados sobre a eficiÃncia energÃtica utilizou-se um trator de rabiÃas, instrumentado com sensores indutivos nas rodas para medir a patinagem dos rodados, fluxÃmetro para medida do consumo de combustÃvel e cÃlula de carga para obtenÃÃo da forÃa de trabalho na barra de traÃÃo. Para instalar a cÃlula de carga e obter estabilidade do implemento foi necessÃrio utilizar um comboio, onde o conjunto percorria um espaÃo 25 m com trÃs repetiÃÃes em cada marcha para as coletas dos dados. O empolamento do solo foi calculado atravÃs de dados obtidos com o perfilometro no campo e os nÃveis de ruÃdo foram medidos com dosÃmetro e decibelimetro. As variÃveis estudadas foram consumo horÃrio de combustÃvel (L.h-1), consumo especÃfico de combustÃvel (g.kW.h-1), patinagem dos rodados (%), forÃa de traÃÃo na barra (kN), velocidade de trabalho (m.s-1) e potÃncia disponÃvel (kW). Esses dados foram avaliados com o arado realizando trabalho e com o implemento erguido para ser feito de comparaÃÃo calculou-se as diferenÃa (resultados com o implemento arando, menos os resultados com o arado sem realizar trabalho), para estudo das mÃdias obtidas. A anÃlise dos dados foi realizada utilizando estatÃstica descritiva utilizando o programa computacional Assistat 7.6 beta. Os resultados mostraram que os valores mÃdios da patinagem foram de 10 % (1 marcha), 12 % (2 marcha) e 18 % (3 marcha). Os valores mÃdios encontrados para o arado realizando trabalho para o consumo horÃrio de combustÃvel foi de 5,45 L.h-1 (1 marcha), 4,22 L.h-1 (2 marcha) e 2,54 L.h-1 (3 marcha); o consumo especÃfico de combustÃvel foi de 3004,98 g.kW.h-1 (1 marcha), 4343,88 g.kW.h-1 (2 marcha) e 5787,91 g.kW.h-1 (3 marcha); a potÃncia foi de 1,54; 0,83 e 0,38 kW para a 1Â, 2 e 3 marcha respectivamente e as mÃdias da velocidade de deslocamento foram de 0,32 m.s-1 (1 marcha), 0,41 m.s-1 (2 marcha) e 0,44 m.s-1 (3 marcha). Os valores mÃdios encontrados para o momento em que o arado nÃo realizava trabalho, ou seja, o implemento estava erguido foi para o consumo horÃrio de combustÃvel de 6,58 L.h-1 (1 marcha), 5,98 L.h-1 (2 marcha) e 4,20 L.h-1 (3 marcha); o consumo especÃfico de combustÃvel apresentou valores de 3514,09 g.kW.h-1 (1 marcha), 4728,22 g.kW.h-1 (2 marcha) e 5787,91 g.kW.h-1 (3 marcha); a potÃncia foi de 1,54 kW (1 marcha), 0,83 kW (2 marcha) e 0,38 kW (3 marcha) e as mÃdias da velocidade de deslocamento foram de 0,27; 0,33 e 0,40 m.s-1 para a 1Â, 2 e 3 marchas respectivamente. O empolamento do solo chegou a 75 % (2 marcha) e obteve valores de aproximadamente 64 % para a 1 e 3 marcha. E os nÃveis de ruÃdo encontrados utilizando o dosimetro foram de 95,7 dB(A) (1 marcha), de 98,2 dB(A) (2 marcha) e 98,8 dB(A) (3 marcha). Os nÃveis mÃdios de ruÃdo encontrados com o auxilio do decibelimetro foi de 76,71; 77,38 e 80,80 dB(A) para as rotaÃÃes de 810, 1.040 e 1.360 rpm respectivamente. Recomenda-se o uso de protetores auriculares ou a diminuiÃÃo da carga horÃria de trabalho para o operador que esteja trabalhando diretamente com o trator de rabiÃas. / The initial tillage has great importance for agricultural production. This activity is usually performed by animal traction in family farming. In this paper, we studied the use of handlebar tractors as a source for field work optimization. The experiment was conducted with a handlebar tractor with a plow attached to it at the Federal University of CearÃ. The goal was to evaluate the energetic efficiency of the handlebar traitor attached to the disc plow, using three gears (1st, 2nd, 3rd) in a red, yellow argisoil. It was also evaluated the soil shoaling and the noise levels with the machine both stopped in different rays of distances (1, 2, 5 and 10 meters), and with handlebar traitor in movement, using three different number of turns (810, 1040 and 1360 rpm). To obtain data about energetic efficiency, it was used a handlebar traitor, an instrument with inductive sensors on wheels to measure the wheelsets slippage, a flowmeter to measure the fuel consumption and a loading cell to obtain the workforce in the drawbar. To install the loading cell and obtain the implement stability, it was necessary to use a train, in which the set traveled 25m with three repetitions in each gear to the collecting of the data. The soil shoaling was calculated through the data obtained in the field by a profilometer, and the levels of noise were measured with a dosimeter and a decibelimeter. The studied variables were the hourly fuel consumption (L.h-1), the specific fuel consumption, (g.kW.h-1), the wheelsets slippage (%), traction force in the bar (kN), work speed (m.s-1) and available power (kW). These data were evaluated with the plow working and with the implement raised to be compared. We calculated the difference (results with the implement plowing minus the results with the plow not working) to study the obtained averages. Data analysis was performed using descriptive statistics using the computer program Assistat 7.6 beta. The results showed that the average rates of slippage were 10% (1st gear), 12 % (2nd gear) and 18% (3rd gear). The average rates for the plow while it was working for the hourly fuel consumption were 5,45 L.h-1 (1st gear), 4,22 L.h-1 (2nd gear) and 2,54 L.h-1 (3rd gear); the specific fuel consumption was 3004,98 g.kW.h-1 (1st gear), 4343,88 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54; 0,83 and 0,38 kW for 1st, 2nd and 3rd gear respectively, and the movement speed averages were 0,32 m.s-1 (1st gear), 0,41 m.s-1 (2nd gear) and 0,44 m.s-1 (3rd gear). The average rates for the hourly fuel consumption that were found for the moment when the plow was not working, that is, the implement was raised, were 6,58 L.h-1 (1st gear), 5,98 L.h-1 (2nd gear) and 4,20 L.h-1 (3rd gear); the rates for the specific fuel consumption were 3514,09 g.kW.h-1 (1st gear), 4728,22 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54 kW (1st gear), 0,83 kW (2nd gear) and 0,38 kW (3rd gear), and the movement speed averages were 0,27; 0,33 and 0,40 m.s-1 for 1st , 2nd and 3rd gears respectively. The soil shoaling achieved the rates 75 % (2nd gear) and, approximately, 64 % for the 1st and 3rd gears. And the levels of noise that were found by the usage of the dosimeter were 95,7dB(A) (1st gear), 98,2dB(A) (2nd gear) and 98,8 dB(A) (3rd gear). The average levels of noise that were found by the usage of the decibelimeter were 76,71; 77,38 and 80,80 dB(A) for the turns 810, 1.040 e 1.360 rpm respectively. It is advised the use of headphones or the decreasing of the working hours for the operator who is working directly with the tractor handlebars.

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