The first step in mining activities is rock excavation in both mine development and production. Constant pressure for cost reduction and creating an improved/safe work environment for personnel has naturally resulted in increased use of mechanical excavation systems in many mining operations. Also, mechanical excavation and mining is more compatible with automation, meaning possibility of reduc...

Skilled action typically requires that individuals guide their activities toward some goal. In skilled action, do so excellently. We not understand well what this capacity to consists in. paper I provide a case study of how shift visual attention. Their attention goal (partly) in an empirically discovered sub-system – the executive system. argue we can explain by appealing operation sub-system....

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A new type of spherical robot, called KisBot, is presented that includes arms and two types of driving mode: rolling and wheeling. In the rolling mode, the robot uses its arms as pendulums and works like a pendulum-driven robot, while in the wheeling mode, it extends its arms to the ground and works like a one-wheel car. The basic design idea of KisBot is introduced and a prototype is implement...

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to incorrect moment-arms if used inappropriately due to its dependency on the choice of joint coordinates. The definition of moment-arms, and the p...

BACKGROUND Submaximal eccentric exertions occur occupationally when rapidly rising tool-generated forces exceed the operator's capacity to react against them. The purpose of this study was to investigate the effects of short duration repetitive submaximal eccentric forearm exertions at levels comparable to industrial power hand tool use on dynamic mechanical properties (stiffness, effective mas...

panies to acquire in-house binding and finishing equipment. However, growth in demand for specialized bindery workers who assist skilled bookbinders will be slowed as binding machinery continues to become more efficient. New technology requires a considerable investment in capital expenditures and employee training; therefore, computer skills and mechanical aptitude are increasingly important. ...

This study measured the changes in moment arm length of thumb motor tendons after simulated ligamentous instability and subsequent reconstruction of the trapeziometacarpal joint. Excursions of thumb motor tendons were measured simultaneously with the trapeziometacarpal joint angulation during flexion to extension and abduction to adduction motion. Tendon moment arms were calculated based on joi...

BACKGROUND The aim of this study is to evaluate the mechanical properties of the screws used for rapid expansion of the upper jaw. METHODS Ten types of expansion screw were assessed, seven with four arms: Lancer Philosophy 1, Dentaurum Hyrax Click Medium, Forestadent Anatomic Expander type "S", Forestadent Anatomic Expander type "S" for narrow palates, Forestadent Memory, Leone A 2620-10 with...