THE EFFECTS OF SHOT WEIGHT ON THROWING POWER OUTPUT IN ELITE FEMALE SHOT PUTTTERS

INTRODUCTION: Sport specific strength development is one of the key factors of the efficient training for throwing athletes (Liu, 1996). Little research has been conducted to examine the appropriate weight of shot that could develop specific strength and promote maximum power output in shot put. The purpose of this study was to compare the power and strength output induced by different weight selected for shot-put exercise in elite female shot putters

A Comparison Study on the Orientation Capability and Parasitic Motions of Two Novel Articulated Tool Heads with Parallel Kinematics

This paper proposes two novel articulated tool heads based on three degree-of-freedom (DoF) parallel kinematic mechanisms (PKMs). They can realize one translation and the A/B-axis (rotations about the x - and y -axes) linkage movements. Both of the proposed tool heads can be used as modular machining units in five-axis machine centers. Based on the proposed configurations, the performance comparison on orientation capability and parasitic motions is carried out to provide theoretical foundation for the design of a five-axis hybrid machine. In this process, the motion/force transmissibility is taken into consideration and the orientation capability is investigated by using local transmission index (LTI) as the evaluation criterion. To get better orientation performance of the selected configuration, kinematic optimization is carried out and a geometric deviation parameter is brought into the already established configuration. Consequently, the orientation capability of more than fifty degrees is achieved. The proposition of the tool heads and the corresponding comparison and optimization are very helpful for the development of the new hybrid machine tool

Research Progress of Food Freshness Indicator Packaging Based on Natural Pigment

As awareness of food safety grows, consumers want to know the quality of the food they buy in a quicker and more intuitive way. Food freshness indicator packaging, which offers information about the quality of food throughout transport and storage, has become more common as a result of this. Considering the safety of food, more and more researchers are using natural pigments derived from plants as indicators. This paper reviews the current status of research on food freshness indicator films using anthocyanins, curcumin, alizarin and shikonin as dyes in recent years. The principles of the application of natural pigment-based food freshness indicator films in raw meat, aquatic products, milk and fruits and the progress of their research are analysed, and the prospects of research and application of food freshness indicator packaging are also prospected