52 resultados para Crawler tractors.


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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Esta pesquisa analisou as diversas soluções para atenuar os níveis de ruído dos tratores e propor um projeto de redução do ruído na sua fonte. Para tal, se propôs projetar, executar e testar alterações em componentes mecânicos causadores de ruído nos tratores, fazendo com que esses níveis se enquadrem em valores considerados salubres. Todas alterações e ensaios foram executados num trator Massey Ferguson MF 290. Para a redução do ruído foram atacados as 3 fontes principais de ruído do trator : o sistema de exaustão de gases, a hélice do sistema de arrefecimento e o sistema de admissão de ar. Como conclusão final pode-se afirmar que é possível atenuar o ruído de tratores agrícolas até níveis salubres (que não causem perda de audição a seus operadores), atuando-se exclusivamente nas fontes de ruído (motor e seus acessórios).

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Bacterial cellulose (BC) has become established as a remarkably versatile biomaterial and can be used in a wide variety of scientific applications, especially for medical devices. In this work, the bacterial cellulose fermentation process is modified by the addition of chondroitin sulfate and hyaluronic acid (1% w/w) to the culture medium before the bacteria is inoculated. Besides, biomimetic precipitation of calcium phosphate of biological interest from simulated body fluid on bacterial cellulose was studied. Chondroitin sulfate and hyaluronic acid influences in bacterial cellulose were analyzed using transmission infrared spectroscopy (FTIR), XRD (X-ray diffraction) and scanning electron microscopy (SEM). FTIR analysis showed interaction between bacterial cellulose nanobiocomposites and calcium phosphate and XRD demonstrated amorphous calcium phosphate and calcium chloride on bacterial cellulose nanobiocomposites. SEM images confirmed incorporation of calcium phosphate in bacterial cellulose nanobiocomposites surface with different calcium phosphate particles morphology.

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O desempenho de tratores agrícolas em condições de campo resulta da interação entre pneu e rodado, influenciado pela velocidade de deslocamento. O objetivo deste trabalho foi avaliar o desempenho de um trator agrícola sob diferentes pressões de inflação dos pneus da semeadora (518, 483, and 414kPa) e em duas marchas que proporcionaram velocidades de 3,0 e 6,0km h-1. O experimento foi realizado no campus de Jaboticabal da Universidade Estadual Paulista (UNESP). O delineamento experimental utilizado foi fatorial inteiramente casualizado (3x2), com quatro repetições. A força de tração foi influenciada pela marcha e pela potência exigida; no entanto, a pressão de inflação do pneu da semeadora não alterou esses parâmetros. Além disso, o consumo de combustível foi influenciado apenas pela marcha do trator. O consumo de energia foi maior com o aumento da velocidade, ocasionada pela mudança de marcha. A velocidade de deslocamento foi maior para a pressão de 518kPa, em razão da menor patinagem da semeadora promovida por essa pressão. A patinagem do trator não foi alterada pelos fatores testados.

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With the search for treatments faster and aesthetic improvement of materials and surgical techniques, immediate implants have become a clinical reality increasingly practiced. Thus, based on literature the specific purpose of this study was to address critically the concepts of immediate implants, discussing issues related to dental extraction, milling technique, care of the periodontal tissues support and protection, prosthetic replacement, benefits, indications and contraindications. To this end, from Pubmed electronic crawler Medline, 54 articles published between 1990 and 2009, over 4 items classics, all in English were selected. The Studies have shown success rates for this technique Conventional techniques like two-stage surgery, many different techniques and planning are present among these techniques, and implants more immediate subject to failures.

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The tractors are the main potency source, for the traction of tillage equipments and their use are increasing more and more in Brazilian agriculture. In spite of the great technological progress the increase of the number of agricultural tractors brought positive aspects and some negative, among these last ones it stands out the appearance of a new source of work accidents, which importance is given by the physical damages caused to the operator. Therefore the objective of this work was to project and develop an inclinometer, which indicates the inclination of the land, as safety sensor for agricultural tractors to avoid lateral hollovers, through a resonant sign, for the operator and the machine preservation. The built and evaluated inclinometer showed to be efficient for inclination indication of different areas during field operations with agricultural tractors, small angle oscillation and enough answer time to help operators to take decisions in imminence situation of lateral machine hollovers.

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Regardless its power rate, the tractors are the most used source in operations of tillage. Thus, due to the expansion of cultivated areas and the need of striking application of technologies to meet the advance of agribusiness, it has been shown that these machines are concentrated during the work periods, the physical and mechanical actions to perform the activity. So, it's possible to realize that the time of physical exposures and the operational decision-making are related with the job station comfort. In regard to what was mentioned, this paper's main objective is to design an ergonomically viable seat to furnish the operational requirements of the tractor driver, using the new CAD / CAE technologies in order to provide optimal comfort to the relationship between human being and machines.

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This article discusses an ergonomic analysis of the controls used by tractor operators, covering their positions in relation to the casing of your job. Was performed an assessment of the controls of the job of a model NH 7630 tractor average power of 74 kW (100 CV), using the norms of the ABNT. With this screening could detect the positive and negative. Then was accomplished an analytical study of the controls. Evaluation results show that some controls of tractors have errors evaluated in relation to NBR/ ISO 6682.

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This research aimed to the comparison between two methods for obtaining three-dimensional coordinates of the controls of the upper limbs of the job of the tractor operator. The methods used were based on NBR / NM / ISO 5353 - Road machines, tractors and agricultural and forestry machinery – Reference point of the seat. The first method used follows the principles recommended by the standard NBR/NM/ISO/5353 The second method is an adaptation of this standard with the introduction of a laser measuring equipment developed by Silva (2009). The results were compared statistically to evaluate differences between the methodological processes involved. In this research, data was collected thought a brand new tractor Massey Ferguson model MF 292, awarded by the dealership from Londrina. The results have shown a considerable variation between the traditional measurement process and the laser measuring. It must be considered that this variation can be used to calibrate the tractor controls positioning, therefore the tractor is not in accordance to ABNT.

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This paper has two main objective the study of the productive space circuit of fertilizers in Brazil. For this, we study the company's operations Vale Fertilizers SA More specifically, the production and consumption of fertilizers in Brazil. In the current globalization the Brazilian countryside know new ways of doing (SANTOS, 1994). This, with less roughness, adopts the Green Revolution package, and introduces inputs to the soil, such as seeders, combines, tractors, herbicides, fungicides and fertilizers (Santos & Silveira, 2001). The examination of the Brazilian case as the agricultural modernization reveals the great vulnerability of modern agricultural regions in the face of globalizing modernization (Santos, 2000: 92). The places that receive capital reproduction of imperatives gain a new medium, is the formation of informational scientific technical means, are the bright spots corresponding to other places (Santos, 1994). Thus, the productive circuits are no longer confined to the environment, but establish connections with distant places (Santos, 1986; Frederick & CASTILLO, 2004). What's more, the policy is now made in the market (Santos, 2000, p.67) and the adoption by the Brazilian government's neoliberal policies, the Brazilian state-owned companies related to fertilizer production circuit are privatized, thereby Brazil makes It is further more dependent on inputs used in the field, including fertilizers

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Agricultural mechanization improved the efficiency of field operations by providing an increase in crop production. The intensified mechanization, however, has led to higher energy use mainly in the area of fuel consumption. The objective of this study was to compare the fuel consumption of tractors using two different tire pressures for two different types of soil during tillage with irrigated cotton in semi-arid regions. These tests were performed at the Maricopa Agricultural Center (MAC), an experimental farm belonging to The University of Arizona with a Case 4x2 TDA 88kW equipped with an autopilot system. The results showed lower fuel consumption using a tire pressure of 124 kPa on sandy clay loan soil.