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Nadia Vignozzi - One of the best experts on this subject based on the ideXlab platform.
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changes in some physical properties of a clay soil in central italy following the passage of rubber tracked and wheeled Tractors of medium power
Soil & Tillage Research, 2003Co-Authors: M Pagliai, Pieranna Servadio, A Marsili, Nadia Vignozzi, Sergio PellegriniAbstract:Abstract The aim of this study was to evaluate the compacting effect of rubber tracked Tractors in comparison to that of the traditional wheeled Tractors. Macroporosity, pore shape and size distribution, bulk density, penetration resistance and saturated hydraulic conductivity were analysed in a clay soil (Vertic Cambisol) near Rome (Italy) following one and four passes on the same track of rubber tracked and wheeled Tractors of medium power. The soil structure attributes were evaluated by characterising porosity by means of image analysis of soil thin sections prepared from undisturbed samples. Macroporosity decreased in the 0–10 cm layer of compacted soil, particularly after four tractor passes, due to a large reduction in the proportion of elongated pores and in their vertical continuity. The rubber tracked tractor had a more pronounced compaction effect in the surface layer (0–10 cm) than the wheeled tractor both after one and four passes; the latter treatment producing the lowest soil porosity. The same trend was observed for hydraulic conductivity, which showed a highly significant correlation with elongated pores. In the 10–20 cm layer the porosity was significantly decreased following traffic, apart from in the soil under one pass of the rubber tracked tractor. Again in this layer, the lowest values of porosity were found in soil after four passes of the rubber tracked tractor. Single and multiple passes made by the two Tractors induced different effects regarding soil penetration resistance and bulk density. Increment ratio of penetration resistance after tractor passes with respect to the control was: 12.5 and 49.9% with the wheeled and 34.4 and 39.8% with the tracked after one and four passes, respectively. Increment ratio of dry bulk density values after tractor passes with respect to the control was 7.9 and 11.7% with the wheeled and 7.5 and 8.3% with the tracked after one and four passes, respectively. The tractor passes transformed the initial subangular blocky structure into a massive structure with sometimes a platy structure in the upper few centimetres. The results indicated that soil compaction following traffic with the rubber tracked tractor was generally the more pronounced. However the compacting effect of this tractor after one pass seemed to be limited to the surface layer only.
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effects on some clay soil qualities following the passage of rubber tracked and wheeled Tractors in central italy
Soil & Tillage Research, 2001Co-Authors: Pieranna Servadio, A Marsili, M Pagliai, Sergio Pellegrini, Nadia VignozziAbstract:Abstract There is increased use of rubber-tracked Tractors for ploughing on clay soil (Vertic Cambisol) in central, south and insular Italy instead of metal-tracked Tractors, because they allow travel on public roads. Field tests were carried out on arable soil previously ploughed and harrowed to compare two types of Tractors, one rubber-tracked (CAT Challenger Ch 45) and one wheeled (New Holland 8770) in order to establish the compacting effects resulting from 1 and 4 passes of the Tractors in the same track. The following parameters were studied: soil penetration resistance, bulk density and its increment ratio, soil shear strength, soil macroporosity and hydraulic conductivity. Multiple passes made by the two Tractors induced very similar effects on the soil in regards to soil penetration resistance. Mean values of penetration resistance (0–0.20 m depth) were 1.15 MPa for the rubber-tracked tractor and 1.11 MPa for the wheeled tractor; mean values of penetration resistance (0.21–0.40 m depth) were 1.07 MPa for the rubber-tracked tractor and 1.17 MPa for the wheeled tractor. The decrease in macroporosity, in particular that of elongated pores in the soil surface layer (0–0.10 m depth) was greater in treatments involving the rubber-tracked tractor (from 20.2 to 2.7%) than for the wheeled tractor (from 20.2 to 10.3%). Following traffic of the two Tractors, hydraulic conductivity decreased and the following values were found for the five treatments: control, 18.48 mm h−1; wheeled tractor 1 and 4 passes, 11.15 and 7.45 mm h−1, respectively; rubber-tracked tractor 1 and 4 passes, 3.25 and 1.1 mm h−1, respectively. Highly significant correlations between shear strength and dry bulk density, and between hydraulic conductivity and elongated pores and total macroporosity were found. Significant linear relationships between macroporosity and penetration resistance for 1 and 4 passes of both Tractors were found in the soil layers (0–0.10 m). A significant difference was found between Tractors and for correlations of penetration resistance values above control values. However, in the soil layer (0–0.20 m depth), with respect to the higher degree of macroporosity and low values of penetration resistance, treatments involving wheeled tractor (1 pass) showed a lower degree of soil compaction than was observed after 1 pass of the rubber-tracked tractor.
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changes of some physical properties of a clay soil following passage of rubber and metal tracked Tractors
Soil & Tillage Research, 1998Co-Authors: A Marsili, Pieranna Servadio, M Pagliai, Nadia VignozziAbstract:Abstract The aim of this research was to evaluate the change in physical properties of an arable clay soil following passage of rubber- and metal-tracked Tractors in view of increased use of tracked Tractors for ploughing on clay soil in centre-south and insular Italy. Field tests were carried out on arable soil cropped to lucerne ( Medicago sativa L.) to compare two types of tracked Tractors, one with rubber tracks (CAT Challenger Ch35) and one with metal tracks (FIAT FA 150) in order to establish the compacting effects resulting from one and four passes of the Tractors on the same track. The following parameters were studied: soil penetration resistance, bulk density and its increment ratio, pressure distribution on soil along the length of the tracks, soil macroporosity and hydraulic conductivity. Multiple passes made by the two Tractors induced very similar effects in the surface soil in regards to soil penetration resistance and dry bulk density. Mean values of penetration resistance (0 to 0.20 m depth), were 2425 kPa for rubber tracked tractor and 2415 kPa for metal-tracked tractor; dry bulk density values were 1.52 and 1.48 Mg m −3 , respectively. The decrease in macroporosity, in particular that of elongated pores in the soil surface layer (0–0.10 m depth) was greater in treatments involving the rubber-tracked tractor (from 10.6% to 4.0%) than for the metal-tracked tractor (from 10.6% to 7.3%). Following traffic of the two Tractors hydraulic conductivity decreased and the lowest values were found after one and four passes of the rubber-tracked tractor (1.5 and 0.08 mm h −1 , respectively). A highly significant correlation between hydraulic conductivity and elongated pores and a significant correlation with total macroporosity were found. Significant exponential relationships between macroporosity and penetration resistance for one and four passes of both Tractors were found in the surface soil. A significant difference was found between Tractors and for correlations of penetration resistance values above control values. However, in the soil surface with respect to the higher degree of porosity, treatments involving the metal-tracked tractor showed better soil structure quality.
Shigeki Inaba - One of the best experts on this subject based on the ideXlab platform.
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CAUSES OF TRACTOR BREAKDOWNS AND REQUISITE SOLUTIONS A CASE STUDY OF SMALL TRACTOR USE IN RIAU PROVINCE, INDONESIA
ASEAN Journal on Science and Technology for Development, 2017Co-Authors: Ujang Paman, Shigeki Inaba, Susumu Uchida, T. KojimaAbstract:A survey has been undertaken to look into the causes of tractor breakdowns on field operations and the main constraints associated with repair and maintenance, and to recommend a solution to the problems in Riau Province. The owners of sixty-two small Tractors were interviewed, from three regencies chosen of the Province in 2003. As a result, the working capacity of the Tractors was relatively high and the average annual use was relatively low compared to the national average. Most tractor operators did not have sufficient skill to operate Tractors. The tractor breakdowns resulted from operators’ mistakes, fuel and oil defilement, rough field conditions, poor maintenance, intense use, and factory design. Inadequate repair shops, a lack of spare parts, and a shortage of mechanics in the local vicinity were the main factors curbing tractor repair. It was also found that inadequate finances led many farmers to ignore tractor maintenance. These suggest that tractor operators should be well trained and tractor-supporting facilities should be provided in rural areas. A mechanical extension officer and credit options should be made available for farmers.
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Operators’ Capability and Facilities Availability for Repair and Maintenance of Small Tractors in Riau Province, Indonesia: A Case Study
The Journal of Agricultural Science, 2011Co-Authors: Ujang Paman, Susumu Uchida, Shigeki InabaAbstract:This paper presents the capability of tractor operators in performing repair and maintenance of small Tractors, the availability of service and repair facilities at the farm level, and the manner of the operators in maintaining their Tractors. Data are based on field visits and interviews with 65 tractor operators from 6 villages collected in three regencies of Riau Province. The results show that most operators lack the technical skill to service and repair Tractors due to insufficient training, specific education, and work experience. Inadequate repair and maintenance facilities, such as workshops, mechanics, and spare part depots cause delays in repair work and raise the price of spare parts in the survey areas. Farmers do not keep accurate service records and most of them disregard proper maintenance and service of their Tractors, such as changing engine oil without following the manufacturer’s recommendations. Provincial governments should provide training facilities and a program to improve the technical knowledge and skills of the operators and local mechanics. Repair and maintenance facilities should be established in village areas to guarantee timely repair in case of breakdowns and to make spare parts available at low price. The operators should keep service records accurately and adhere to maintenance and service schedules according to the manufacturer’s instructions. They should also be encouraged to properly service and maintain their Tractors.
Nicolae Ispas - One of the best experts on this subject based on the ideXlab platform.
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Potential performance characteristics for different types of Tractors: two-wheel-drive tractor, four-wheel-drive Tractors and crawler Tractors
Proceedings of the 4th International Congress of Automotive and Transport Engineering (AMMA 2018), 2018Co-Authors: Mircea Nastasoiu, Nicolae IspasAbstract:The paper addresses a very important criterion for the evaluation of the tractive and economical performances of agricultural Tractors, namely the potential performance characteristics, which represents the drawbar power curve depending on the drawbar pull. At a large scale, this curve coincides with the tractive efficiency of the tractor taking account of the drawbar pull. We herein present the mathematical modelling of the potential performance characteristics which is particularized for three types of Tractors: two-wheel-drive tractor, four-wheel-drive tractor and caterpillar Tractors. The mathematical modeling has a high degree of generalization: the final mathematical functions comprise only dimensionless parameters. Related graphs are subsequently presented and the three types of Tractors are comparatively analyzed taking into account the tractive and economical performances. Considering the potential performance characteristics, we put forward proposals for an accurate design of a tractor transmission when establishing the number and structure of gears.
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Simultaneous Influences of Tyre Pressure and Steering Geometry upon the Theoretical Speed Ratio in the Running Gear System of Four-Wheel Drive Tractors
CONAT 2016 International Congress of Automotive and Transport Engineering, 2016Co-Authors: Mircea Nastasoiu, Nicolae IspasAbstract:The paper develops a mathematical model in order to evaluate the theoretical speed ratio in the running gear system of four-wheel drive Tractors, taking account of both the tyre pressure and the turning radius. In using this model, we may emphasize situations when the recirculating power (parasitic losses power) occurs in tractor’s transmission due to inequality of wheels’ theoretical speeds on the two axles. The paper presents applications of the mathematical model developed for the tractor MAT 81, manufactured in Craiova, Romania.
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Influence of Tyre Pressure and Weight Distribution on Axles on the Theoretical Speed Ratio in the Running Gear System of Four-Wheel Drive Tractors
Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015Co-Authors: Mircea Nastasoiu, Nicolae IspasAbstract:The paper presents a mathematical model used to evaluate the theoretical speed ratio in the running gear system of four-wheel drive Tractors, taking account of tyres pressure. This model emphasizes situations when the parasite power phenomenon occurs in tractor’s transmission, the criterion being the negative slip of wheels on one axle. Likewise, the paper addresses the influence of redistributing the tractor’s weight on the two axles upon the theoretical speed ratio. The authors present applications of the mathematical model elaborated for the tractor MAT 81, manufactured by MAT Craiova, Romania.
Ujang Paman - One of the best experts on this subject based on the ideXlab platform.
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CAUSES OF TRACTOR BREAKDOWNS AND REQUISITE SOLUTIONS A CASE STUDY OF SMALL TRACTOR USE IN RIAU PROVINCE, INDONESIA
ASEAN Journal on Science and Technology for Development, 2017Co-Authors: Ujang Paman, Shigeki Inaba, Susumu Uchida, T. KojimaAbstract:A survey has been undertaken to look into the causes of tractor breakdowns on field operations and the main constraints associated with repair and maintenance, and to recommend a solution to the problems in Riau Province. The owners of sixty-two small Tractors were interviewed, from three regencies chosen of the Province in 2003. As a result, the working capacity of the Tractors was relatively high and the average annual use was relatively low compared to the national average. Most tractor operators did not have sufficient skill to operate Tractors. The tractor breakdowns resulted from operators’ mistakes, fuel and oil defilement, rough field conditions, poor maintenance, intense use, and factory design. Inadequate repair shops, a lack of spare parts, and a shortage of mechanics in the local vicinity were the main factors curbing tractor repair. It was also found that inadequate finances led many farmers to ignore tractor maintenance. These suggest that tractor operators should be well trained and tractor-supporting facilities should be provided in rural areas. A mechanical extension officer and credit options should be made available for farmers.
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Operators’ Capability and Facilities Availability for Repair and Maintenance of Small Tractors in Riau Province, Indonesia: A Case Study
The Journal of Agricultural Science, 2011Co-Authors: Ujang Paman, Susumu Uchida, Shigeki InabaAbstract:This paper presents the capability of tractor operators in performing repair and maintenance of small Tractors, the availability of service and repair facilities at the farm level, and the manner of the operators in maintaining their Tractors. Data are based on field visits and interviews with 65 tractor operators from 6 villages collected in three regencies of Riau Province. The results show that most operators lack the technical skill to service and repair Tractors due to insufficient training, specific education, and work experience. Inadequate repair and maintenance facilities, such as workshops, mechanics, and spare part depots cause delays in repair work and raise the price of spare parts in the survey areas. Farmers do not keep accurate service records and most of them disregard proper maintenance and service of their Tractors, such as changing engine oil without following the manufacturer’s recommendations. Provincial governments should provide training facilities and a program to improve the technical knowledge and skills of the operators and local mechanics. Repair and maintenance facilities should be established in village areas to guarantee timely repair in case of breakdowns and to make spare parts available at low price. The operators should keep service records accurately and adhere to maintenance and service schedules according to the manufacturer’s instructions. They should also be encouraged to properly service and maintain their Tractors.
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A Survey on Causes of Tractor Breakdowns in Riau Province, Indonesia A Case Study of Small Tractor Operations
Applied Engineering in Agriculture, 2007Co-Authors: Ujang Paman, Susumu Uchida, S. Inaba, T. KojimaAbstract:A survey was undertaken to look into the causes of tractor breakdowns on field operations, to identify the main constraints associated with repair and maintenance, and to recommend a solution to the problems in Riau Province, Indonesia. The owners of 62 small Tractors were interviewed from three regencies chosen of the P rovince in 2003. As a result, the working capacity of the Tractors was relatively high and the average annual use was relatively low compared to the national average. Most tractor operators did not have sufficient skill to operate Tractors due to inadequate training programs. The tractor breakdowns resulted from operator error, the use of inferior fuel and oil, rough field conditions, poor maintenance, intense use, and factory design. Inadequate repair shops, a lack of spare parts, and a shortage of mechanics in the local vicinity were the main factors curbing tractor repair. It was also found that inadequate finances led many farmers to ignore tractor maintenance. These results suggest that tractor operators should be well trained and tractor-supporting facilities should be provided in rural areas. A mechanical extension officer and credit options should be made available for farmers.
Shamsolla Abdolahpour - One of the best experts on this subject based on the ideXlab platform.
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prediction of tractor repair and maintenance costs using artificial neural network
Expert Systems With Applications, 2011Co-Authors: Abbas Rohani, Mohammad Hossein Abbaspourfard, Shamsolla AbdolahpourAbstract:The prediction of repair and maintenance costs has significant impacts on proper economical decisions making of machinery managers, such as machine's replacement and substitution. In this article the potential of Artificial Neural Network (ANN) technique has evaluated as an alternative method for the prediction of machinery (specifically tractor) repair and maintenance costs. The study was conducted using empirical data on 60 two-wheel drive Tractors from Astan Ghodse Razavi agro-industry in Iran. Optimal parameters for the network were selected via a trial and error procedure on the available data. In this paper, the performance of Basic Back-propagation (BB) training algorithm was also compared with Back-propagation with Declining Learning-Rate Factor algorithm (BDLRF). It was found that BDLRF has a better performance for the prediction of tractor's costs. The prediction of repair and maintenance cost components of Tractors with a single network produced a better result than using separate networks for prediction of each cost component. It has been concluded that ANN represents a promising tool for predicting repair and maintenance costs.
