Research Article
Design and Construction
M. Khosravi; M. H. Abbaspour-Fard; M. H. Aghkhani
Abstract
The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has ...
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The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has been designed. Furthermore, it has been assessed after construction. To measure actual and theoretical ground speed, four rotary encoders for sensing the rotation of front and rear wheels have been utilized. Slip and ground speed were measured by means of software which has been developed in an ATmega16PU microprocessor. The measured slip and speed are digitally displayed on tractor dashboard. To evaluate the performance of the system, the measured values of ground speed and slip were compared with their calculated values obtained from conventional method. The Micro-controller has been programmed in such a way that the effect of front wheel sliding on slip is eliminated. In all evaluation conditions (in field and on asphalt), the maximum difference between system measurements for slip and speed and calculated slip and speed via conventional method was 2.4% and 0.2 km h-1, respectively. With slight alteration this system can be fitted on any kind of exiting two wheel drive tractors in the country.
Research Article
M. Younesi Alamouti; A. Sharifi Malvajerdi
Abstract
Using the cropping operations program can significantly save fuel consumption and energy efficiency. Prediction of the accurate amount of fuel requirements for tillage operation of the soil is difficult. Changes in humidity, soil type and tillage depth directly affects on the amount of fuel consumption. ...
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Using the cropping operations program can significantly save fuel consumption and energy efficiency. Prediction of the accurate amount of fuel requirements for tillage operation of the soil is difficult. Changes in humidity, soil type and tillage depth directly affects on the amount of fuel consumption. Bulk density of agricultural soils depends on tillage methods, the value of organic matter, tillage depth and implements. Therefore, in this study, the effects of four types of tillage implements including moldboard plow, heavy duty disk, chisel plow and combinated tillage machine (minimum tillage), on the amount of power required and fuel consumption and some soil physical properties including bulk density, penetration resistance and organic carbon contents in a randomized complete block design was studied. The results showed that minimum tillage with combinated machine, increased the amount of organic matter, reduced fuel consumption and needed less power. The highest fuel consumption of 58.03 liters per hectare and the lowest 8.64 liters per hectare, related to the moldboard plow and heavy disk, respectively. Mean values of soil organic carbon related to the moldboard plow, combinate, chisel plow and heavy disk were 0.31, 0.64, 0.50 and 0.55 percent, respectively. Differences in mean values of the soil organic carbon due to tillage with heavy duty disk and combinate compare to moldboard plow were significant and both were belonging to two separated groups.
Research Article
R. Tabatabaei koloor; A. Kolouri; S. J. Hashemi; R. Hadipour Rokni
Abstract
Apple fruits are subjected to different loading from harvesting to supermarket shelf. Bruising has been attracted many researchers as one of the most important damage criteria. In this research, the effects of some factors such as contact surface material, drop height and linear velocity of apples were ...
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Apple fruits are subjected to different loading from harvesting to supermarket shelf. Bruising has been attracted many researchers as one of the most important damage criteria. In this research, the effects of some factors such as contact surface material, drop height and linear velocity of apples were investigated. Influence of these factors on bruising of “Golden Delicious” variety was analyzed by a Completely Randomized Design (CRD) with factorial test at three level of drop height (10, 20 and 30 cm), linear velocity (0.05, 0.1 and 0.15 ms-1) and four contact surface (wooden, steel, plastic and cardboard). Tests were conducted at three replications with 108 treatments. Analysis of variance results showed that the effects of drop height and contact surface material on bruising area at 1% level was significant while bruising volume only affected by contact surface material (meaningful difference at 1% level). Mean comparison test indicated that there significant difference between levels of drop height on the bruise area. Also, there was a meaningful difference between contact surface of cardboard with steel, wood and plastic. There was a significant difference between surface materials of steel and wooden with cardboard and plastic. Therefore, drop height and contact surface material must be considered in designing the apple processing systems.
Research Article
M. Taki; Y. Ajabshirchi; R. Abdi; M. Akbarpour
Abstract
In this research energy efficiency for greenhouse cucumber production in Shahreza township located in Esfahan province using data envelopment analysis (DEA) technique was studied. In this study, data were obtained from 25 randomize active vegetable greenhouses from 60 greenhouses in Shahreza township ...
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In this research energy efficiency for greenhouse cucumber production in Shahreza township located in Esfahan province using data envelopment analysis (DEA) technique was studied. In this study, data were obtained from 25 randomize active vegetable greenhouses from 60 greenhouses in Shahreza township and villages environs. The results showed that the highest and lowest consumed energy were related to fuel and water inputs with 47% and 1.2% respectively. The results of data envelopment analysis showed in CCR and BCC models 24% and 36% of farmers were efficient and the others were inefficient. Mean technical efficiency, net technical efficiency and scale efficiency were calculated as 90.37, 95.09 94.6 respectively. Also technical efficiency of inefficiency units in CCR model was 87% that shows13% of total energy input could be saved with upgrade efficiency in these units. In this research, total saved and unsaved energy related to fuel consumption.
Research Article
D. Momeni; M. H. Rahmati
Abstract
Temperature and humidity are two important parameters affecting the quality and quantity of greenhouse products so two double greenhouses were manufactured in 3.5, 40 and 11 m in height, length and width respectively in agricultural research center of jiroft and kahnooj to study these effects. Both of ...
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Temperature and humidity are two important parameters affecting the quality and quantity of greenhouse products so two double greenhouses were manufactured in 3.5, 40 and 11 m in height, length and width respectively in agricultural research center of jiroft and kahnooj to study these effects. Both of greenhouses are similar in materials, final height, gutter height, covering and field operation but in one of them one heating system, two ventilation fans and one wooden pad were assembled and temperature and humidity besides yield were registered in both of them. The results showed that temperature changing trend inside and outside of the unheated greenhouse were in same phase and this isn't suitable in cold night so the greenhouse with heating system had more yield and picking cucumber fruit numbers than another. Therefore it is necessary to be heated by artificial systems. Because of rapid relative humidity changing in outside of greenhouse in the end of the season, the efficiency of fan and pads cooling system is so low then using of evaporating cooling systems such as fans and pad wasn't proposed and recommend to optimize the temperature by ventilation and shading the greenhouse and in hot days production will be cut.
Research Article
J. Habibi Asl; E. Dehghan
Abstract
This study was conducted during two years (2007-2009) in Shawoor Agricultural Research Station on a silty-clay soil. Experiment conducted in split plots in a Randomized Complete Blocks Design in three replications. Main plots were planting methods including centrifugal broadcaster (P1), centrifugal broadcaster ...
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This study was conducted during two years (2007-2009) in Shawoor Agricultural Research Station on a silty-clay soil. Experiment conducted in split plots in a Randomized Complete Blocks Design in three replications. Main plots were planting methods including centrifugal broadcaster (P1), centrifugal broadcaster + furrower (P2), seed drill (P3), seed drill + furrower (P4), three lines bed drilling (P5) and four lines bed drilling (P6). Subplots were included seed rates of 120, 160, 200 and 240 kg.ha-1. The results showed that P2 method with 14.91 litter.ha-1 and P3 method with 5.02 litter.ha-1 had the highest and lowest fuel consumption respectively. P3 method with 1.462 h.ha-1 and P5 method with 0.620 h.ha-1 required maximum and minimum total operation time respectively. P2 method with 0.684 ha.h-1 had minimum field capacity. Field capacity of P5 and P6 with averagely 1.67 ha.h-1 was maximum. Field capacity of all drilling methods (P3, P4, P5 and P6) was significantly more than that of broadcasting methods (P1 and P2). The highest seed spacing uniformity (87.2%) was belonged to P6 method and the lowest value (54.7%) was for P1 method. By using drilling methods of P3 and P5 (or P6) instead of P1 method total cost was reduced 41% and 29% respectively. The results of variance analysis of data showed that the difference between planting methods in case of wheat grain yield and yield components was not significant. However, the seed rate had significant effect on some yield components. Suggestion for cropping of wheat Chamran variety in silty-clay soil in Khuzestan province, used P5, P6 and P3 methods are recommended respectively with seed rate of 120 - 160 kg.ha-1.
Research Article
I. Alahdadi; H. Oraki; F. Parhizkar Khajani
Abstract
In order to investigate the water deficit impact on physical characteristics of seed in four sunflower hybrids (Azargol, Allstar, Hysun 33 and Hysun25), under three irrigation regimes (irrigation after 50, 100 and 150 mm cumulative evaporation from class A evaporation pan, respectively) and experiment ...
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In order to investigate the water deficit impact on physical characteristics of seed in four sunflower hybrids (Azargol, Allstar, Hysun 33 and Hysun25), under three irrigation regimes (irrigation after 50, 100 and 150 mm cumulative evaporation from class A evaporation pan, respectively) and experiment was conducted. Sampling was done at the end of growing period (season) when the moisture content of the seed was reached to 13%. The results showed that the maximum length, width and seed thickness were obtained from irrigation after 50 mm cumulative evaporation from pan, while irrigations after 100 and 150 mm evaporation caused to decrease the length by 15% and 24%, width by 18% and 35% and seed diameter by 17% and 30%, respectively. Also, the seed width in comparison with length and seed thickness had the most susceptive to water deficit stress levels. The maximum length, width and seed thickness were seen in Allstar variety. Also, Allstar had the highest seed weight for all levels of irrigation. There was no significant difference between Allstar and Hysun 25 in 50mm evaporation. Therefore, the Allstar hybrid had most tolerance to water deficit stress condition under all levels of irrigation in aspect of seed weight and physical properties of seed.
Short Paper
M. Rasouli; S. S. Seiiedlou Heris
Abstract
Garlic (Allium sativumL.) is one of the most important Allium spice. From an economic point of view, the dried garlic slices are valuable products. In this research, garlic slices as a thin layer were dried in a laboratory scale hot-air dryer, under air flow of 1.5 m/s, air temperatures of 50, 60 and ...
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Garlic (Allium sativumL.) is one of the most important Allium spice. From an economic point of view, the dried garlic slices are valuable products. In this research, garlic slices as a thin layer were dried in a laboratory scale hot-air dryer, under air flow of 1.5 m/s, air temperatures of 50, 60 and 70˚C and slice thicknesses of 2, 3 and 4 mm. The mean values of shrinkage of garlic slices obtained 69.8%. In addition, the effects of the drying variables on the shrinkage of dried garlic were evaluated. The ANOVA results indicated that the air temperature and slice thickness had no significant effect on final shrinkage of dried garlic slices. In order to derive and select the appropriate shrinkage model, four mathematical models were fitted to the experimental data. According to the statistical criteria (R2, SSE & RMSE) the best model was found to describe the shrinkage behavior of garlic slice.
