hoseinali shamsabadi

In this research, draft requirement of subsoiler tine plus fuel consumption, slippage, drawbar power, traction efficiency and overall energy efficiency of MF399 and JD3140 tractors at four speeds of 1.8, 2.3, 2.9 and 3.5 km/h and two depths of 40 and 50 cm were compared. Tractor type, speed and depth plus interaction effects had a significant effect on all parameters other than draft and drawbar power. Generally, JD3140 showed a better performance as the increase in speed from 1.8 to 3.5 km/h caused the increase of draft, fuel consumption, slippage, drawbar power and overall energy efficiency in two depths of 40 and 50 cm of 7, 4, 23, 108.3 and 89%, respectively but caused the decrease of traction efficiency of 13.8%. Furthermore, 10 cm increase in depth caused the increase in draft, fuel consumption, slippage and drawbar power of 21.3, 31.6, 20.6 and 21.4%, respectively but caused the decrease in traction efficiency and overall energy efficiency of 9.7 and 25%, respectively. The results of optimization of studied parameters using response surface methodology (RSM) show that depth of 42.9 cm and speed of 2.4 km/h resulted in the optimized condition about the performance of the tractor-subsoiler set.

Drying is one of the most common techniques for agricultural production processing which improves shelf life of the final product. Corn (Zea mayz) is a high nutritional value food and is an essential source of minerals and vitamins; thus it makes a substantial contribution to human nutrition. In this study the effects of hot air drying temperature (35, 50, 65 and 80°C), drum rotation speed (2, 6 and 10 rpm) and final moisture content of kernels (13 and 17 %) at constant air velocity (0.8 m/s) on drying time, percentage of broken kernels of corn, and percentage of crack of corn kernels were investigated. For this propose, the laboratory batch rotary dryer is designed. The results showed that increasing the temperature form 35 °C to 80°C, the percentage of broken grains and percentage of cracked grains increased and the drying time was decreased. Increasing the rotating cylinder rotation speed increased the drying time and the percentage of broken grains, but not significant effect in percentage of cracked grains.. The drying time, percentage of broken grains and percentage of cracked grains is lower in grain with 17 % db than the sample with 13 % db To obtain the desired quality parameter, the optimum drying for production of dried corn was determined as 65°C for 2 rpm and 17 % db.