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Background and Aim: Problems such as less working and aggression in organizations force organizations to reduce these behaviors and increase behaviors that are beneficial such as productivity for organization. One of the elements that create benefits like productivity in organization is Organizational Citizenship Behavior. The purpose of this research is Organizational Citizenship Behavior factor linkage appointment with human resources productivity among selected Hospitals of Tehran Medical Sciences University and Shahid Beheshti Medical Sciences University. Method and material: This research is done in six selected Hospitals of Tehran Medical Sciences University and Shahid Beheshti Medical Sciences University .The data are collected by distributing questionnaires among 429 staff of the hospitals via random 2-stage Sampling method. The research methodology is cross-sectional- descriptive and the type of research is a field study. In order to confirm or reject research hypotheses, we use Spearman Correlations and regression in SPSS software [version 16]. Results: The findings show that in personnels’ point of view, there is a significant correlation between Organizational Citizenship Behavior and staff's productivity in  

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The problem of bone fracture in medicine due to an accident, aging or diseases, has existed from times when humans started to work and activity. The process of bone drilling is an essential part of internal immobilization in orthopaedic and trauma surgery. The force required to chip formation in drilling process, resulting in heat generation in drill site that leads to the occurrence of thermal necrosis. This research experimentally investigates the effect of ultrasonic vibration on thrust force in drilling of bovine femur bone. This method induces high-frequency and law-amplitude vibration in the feed direction during cutting, and has the potential to spread tiny cracks in bone and decrease friction leading to reduce of cutting forces and also increase the speed of chip disposal leading to reduction of machining forces, totally. Experimental results demonstrate that ultrasonic assisted drilling of bone produces fewer thrust force than conventional drilling and rotational speed of 1000 rpm is the optimal speed to achieve at minimum thrust force for all feed rates. Moreover, this method is due to the force independence of the feed rate in the rotational speed of 1000 rpm, is applicable in orthopedic surgery.