الفهرس 
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Abstract
This research aimed to apply a vibration mechanism for seeding crops, to avoid the mechanical damage in the seeds. br The vibration mechanism consists of an eccentric mass fixed on an AC electric motor which was attached to the out side of the bottom of the galvanized cylindrical seed box, to avoid the direct contact between the mechanism and the seeds. br The seed rate could be adjusted through either changing: the seven vibration frequencies used in the research, or the four gate opening dimensions ( the geometry group ), or by the three seed levels of the barrier which was fixed inside the seed box above the bottom of the hopper. br Also some physical and mechanical seed properties were determined through the study. br The obtained results indicated that: br •The lowest values of static coefficient of friction for the metal surfaces were on galvanized iron followed by mild – steel, and the highest on plywood. br •The lowest values of static coefficient of friction for the painted surfaces were on oven - baked enamel paint followed by untreated (mild steel), then the mutt paint and the highest on polish paint. br •The effect of vibration frequency was in decreasing the static coefficient of friction for all treatments (metal and painted surfaces) in the research. br •Increasing frequency group ( ) increases the seed group ( ), till the maximum of at (12.2 Hz), further increase in frequency group decreases seed group. br •Increasing vibration frequency increases the seed spacing, the highest frequent percent (66.9 %) was -#102;-#114;-#111;-#109; the vibration frequency 4.27 Hz at seed spacing ( 20 – 29 cm ). br •The vibration frequency did not affect the germination (%) or the emergence (day) needed for germination, which give a good evidence that there was no damage for the seeds -#102;-#114;-#111;-#109; the vibration mechanism. br The conclusions of this study are as follows: br 1. The lowest values of static coefficient of friction for the painted surfaces were on oven - baked enamel paint followed by untreated (mild steel), then the mutt paint and the highest on polish paint. br 2. The effect of vibration frequency for all treatments in the investigation was in decreasing the static coefficient of friction, the highest decrease was at the Polish paint surface (23%), and the lowest decrease was at the mild – steel surface (11.47%). br 3. The vibration metering device did not show any visible or invisible damage on the seeds through determining the seed: germination and emergence.