Today, preserving the quality and reducing the losses of agricultural products is an important topic and has attracted the attention of many scholars in the field. This study aims at investigating the engineering properties (physical, mechanical, and hydrodynamic properties) of cantaloupe in order to manage and reduce the losses that is produced postharvest. The results show that the mean values physical properties measured for the geometric mean diameter, arithmetic mean diameter, sphericity, surface area, volume, and true density of the cantaloupes were 130.13 mm, 130.26 mm, 0.94%, 53,367.59 mm 2 , 633.30 cm 3 , and 0.83 g/cm 3 , respectively. Maximum force required for bruising and shearing cantaloupes in the investigation of their mechanical properties were 248.20 and 108.30 N. The hydrodynamic properties of cantaloupes such as the terminal velocity, the cantaloupes' rise time in the water column, the buoyance force and the drag force were obtained to be equal to 0.12 m/s, 4.10 S, 6.21 N, and 0.11 N, respectively. The results obtained through this study can be used in designing harvest machines, optimization, processing, transport, separation of impurities, and grading equipment for the purpose of reducing cantaloupe waste. Practical applicationsOf the 67 million tons of agricultural production in Iran, 20 million tons of it are turned into waste in the postharvest stage. That is the equivalent of food of 20 million people. Fruits are among the most important horticultural products that play an important role in supplying human nutrition and human health. Failure to review the engineering properties of agricultural products (physical, mechanical, and hydrodynamic properties) are the most important factors in increasing the agricultural waste at the postharvest stage. The physical properties of agricultural products are essential for the design and optimization of harvesting and postharvesting machinery, separating, transferring, grading, and drying processes. Mechanical properties can be useful in designing machinery and equipment for transportation and displacement of the product. Hydrodynamic properties can be useful for transfer, separation and grading by water in order to reduce processing costs and reduce cantaloupe waste.

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Agricultural machineries as one of the main inputs in producing agricultural materials are associated with some problems on occupational health such as vibrations. At the lowest level, vibrations cause different diseases such as those affecting blood vessels, nerves, muscles, etc. The aim of this study was to determine and investigate the seat vibrations in John Deere 1055I combine harvester at different conditions. The experiments were carried out based on ISO 2631 and the Iranian standard number 14133. The tests were done at different engine revolutions and gear ratios with three replications. The collected data were analyzed considering factorial experiments based on completely randomized design. The results of variance analysis related to the effect of the main factors on combine seat vibrations showed a significant difference at the probability level of 1%. Effect of engine revolutions on vibration of the combine seat was higher than that of shifting gears. By calculating the allowable exposure time, there was concluded that for the first and second gears at the engine revolution of 1800 rpm and the first gear at the revolution of 2500 rpm, operators can easily drive the combine harvester for eight hours every day without any problems. The results of this study can be used to optimize the components affecting the vibration of the combine seat.

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