فهرست مطالب f. khoshnam

A robust numerical analysis was proposed for simulating the rebound velocity pendulum method for melon. For considered varieties (Zard-Eyvanekey and Sousky-Sabz varieties), the change in impact parameters (extracted from excitation by pendulum) was studied for five stages of ripening. With the melon ripeness, the rebound velocity, rebound height, relative rebound height, rebound angle, rebound energy and coefficient of restitution (velocity ratio) increased, while the absorbed energy decreased (from 37.6 to 27.9 MJ for Zard-Eyvanekey and from 38.5 to 27.9 MJ for Sousky-Sabz). The regression analysis showed a highly significant linear relationship (coefficient of determination, R² more than 0.8059) between impact parameters and five stages of ripening. So the results of the analysis are feasible in ripening detection and hence in the classification of the melon maturity.

Evaluating the thermal effects and variations in temperature of rolling pneumatic tires, is a very important factor in safe performance of the vehicles. Normally, the transient thermal investigation of rolling tires is performed by tire test rigs. However, experimental analysis is a very time and cost consuming process and because of technical limitations, the tests cannot be carried out in most severe conditions. In this work, a validated finite element model is proposed for transient thermal investigation of rolling pneumatic tires. Compared with the experimental tests, the current study gives satisfactory results for temperature distribution of the tire.