Journal of Researches in Mechanics of Agricultural Machinery

Abstract The present research was carried out to measure sound levels of John Deere harvesting combine and evaluate the effective factors of combine sound. The Experiments were done based on OSHA standards rules in different levels of engine revolution speed, transmission gear ratio at different distances from operator ear. The sound signals in different conditions were recorded by sound level meter unit and analyzed based on completely random block design in factorial experiment. Results showed that the different levels of transmission ratio had a significant effect on means of sound levels (p

Abstract White mulberry (Moraceae group and the genus Morus), is from soft fruit group and sensitive to mold, yeast and impact. Drying white mulberry is one of the oldest methods used to protect the white mulberry. Microwave is a rapid method of drying food and their energy can be compared with hot air drying. Microwave drying system significantly reduced drying times without any negative effect on product quality. Drying time for white mulberry samples reduced 30.72%. The effective moisture diffusivity for white mulberry samples changed from 3.19 ×10-8 to 8-10 × 11.91×10-8 m2 / s. The activation energy and moisture diffusion constant for white mulberry samples were calculated as -10.8 (W/g) and 3×10-8, respectively.

Abstract Potato as one of the most important agricultural products around the world is cultured in about 170,000 hectares that is produced 5.7 million tons per year. Colorado potato beetles “CPB” are the main problem of the culture which damages all the production in the field and makes serious losses economically. Use of chemicals on CPB control as routine method has made some problems from health care and environmental and agricultural points. The procedure of this research is related to the desig and fabrication a four-row prototype machine (Burner) for mechanical CPB control which can be used behind a tractor in the field .This is a kind of pneumatic thermal machine. First the fans send the compressed air to the rows to fly the insect pests, and then the cpb’s is burnt immediately by special burners

Abstract In this research bulk and frictional properties of four Safflower seed varieties typically cultivated in Iran (Goldasht, Padideh, PS and Esfahan 28) at 5.5% moisture content level ( ) were studied. Results showed that Goldasht var. has max actual density (997.7 ) and porosity percent (42.2%) and Esfahan 28 var. has min actual density (911 ) and porosity percent (38%). Bulk density of seeds is in range of 30.8-35.2 . Emptying and filling angle of repose and hull thickness of seeds is in range of 23.2-26 degree, 30.8-35.2 degree and 0.4-0.46 mm, respectively. Between vars., Goldasht has max weight of 1000 seeds (44.39gr). Measuring static coefficient of friction of seeds on five surfaces (glass, steel, wood, ceramic and MDF) stated that effect of variety, surface and interplay effect on coefficient of friction is significant ( ). At all frictional surfaces under the experiment, the coefficients of Goldasht var. (0.253) and Padideh var. (0.255) are the most and coefficient of PS var. (0.244) is the least values and at all vars., the coefficient on wood surface (0.31) is the most and coefficient on ceramic surface (0.21) is the least values.

Abstract The objective of this study is the estimation of energy consumption during various stages of broiler production and analysis the effects of numbers of chick and ventilation system type on energy efficiency of these units. Data for this study were collected from 44 growers by using a face to face questionnaire method during January–February 2010. Collected data were classified into three groups according to the numbers of chicks and two groups according to type of ventilation system. The effects of numbers of chicks at three levels (less 10000 bird, 10000 to 20000 bird and more 20000 bird) and ventilation system type at two levels (tunnel and cross ventilation) were analyzed on energy efficiency. The results indicated energy ratio, energy productivity and specific energy as 0.15, 0.014 kg MJ-1 and 71.95 MJ kg-1, respectively. The results of ANOVA presented that the number of chicks had significant effect on energy efficiency (P

Abstract A‎ field study was conducted to compare the effects of four primary tillage implements (moldboard (MB), disk (DP), improved disk (IDP) and chisel (CH) ‎plows) and two vine killing methods (vine killed (VK) and without vine killing (NVK)) on some physical and hardness properties of potato tuber. The study was conducted using a 4‎‏×‏‎2 factorial experiment (strip plots) ‎with a randomized complete block design. Eight ‎treatments representing four primary tillage implement levels and two levels of ‎vine killing were replicated three ‎times. The results showed that tuber dry matter content in "MB.NVK" and "DP.NVK" treatment was significantly higher than that of "IDP.VK" at 5%‏ level. The multiple linear regression analysis with stepwise method showed that there was a linear regression model between tuber dry matter content and wet weight, moisture content, maximum diameter and spherisity.

Abstract The use of biodiesel compared to current fuels could reduce greenhouse gas emissions. Different properties of biodiesel in comparison with standard Ddiesel fuel have some effects on engine performance. To achieve optimum performance, engine conditions should be modified based on the fuel or fuel blends. In this study, performance of a diesel engine using biodiesel was investigated in injection timings 10, 15 and 20 degrees before top dead center. The experiments were carried out in different speeds of engine. The results of torque, power, exhaust gas temperature and brake specific fuel consumption for fuel blends of B20, B40, and B100 in different engine speeds and injection timing were recorded and analyzed by regression equations. The predicted results with these equations had acceptable correlation with experimental results. The results showed that advancing the injection timing increases the brake torque, power and thermal efficiency and decreases the brake specific fuel consumption.