Dynamic response analysis of mechanical structures is usually performed by adopting numerical/analytical models. Finite element (FE) modeling as a numerical approach plays an important role in dynamic response analysis of complex structures. The calculated dynamic responses from FE analysis are only reliable if accurate FE models are used. There are many elements in real mechanical structures w...

the repetitious nature of propelling a wheelchair has been associated with the high incidence of injury among manual wheelchair users (mwus), mainly in the shoulder, elbow and wrist. recent literature has found a link between handrim biomechanics and risk of injury to the upper extremity. the valid measurement of three‑dimensional net joint forces and torques, however, can lead to a better unde...

Photofission enables a unique capability for the domain of non-chemical space propulsion. An ultra-intense laser enables the capacity to induce nuclear fission through the development of bremsstrahlung photons. A fundamental architecture and performance analysis of a photofission pulsed space propulsion system through the operation of an ultra-intense laser is presented. A historical perspectiv...

Design of high-performance electric propulsion systems requires thorough dynamic analysis of both the electric power and propulsion systems. This paper presents a simple but effective method to model the relevant components in the electric and propulsion plants to facilitate the integration and analysis of the entire system for the purpose of predicting the overall system performance. The objec...

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Mathematics requires three markers to define a local coordinate system to calculate rotations in three dimensions (3D), as three coordinates are necessary to specify the orientation of a rigid body with respect to a fixed set of space axes. However, it is not uncommon in wheelchair literature to find papers (Veeger, et al., 1991) that used only two markers to define segment rotation in three di...

Rehabilitation scientists and biomedical engineers have been investigating wheelchair propulsion biomechanics in order to prevent musculoskeletal injuries. Several studies have investigated wheelchair propulsion biomechanics; however, few have examined wheelchair propulsion stroke patterns. The purpose of this study was to characterize wheelchair propulsion stroke patterns by investigating join...

objectives: wheelchairs are the prime mobility aid of persons with spinal cord injuries. manual wheelchair propulsion puts a lot of demand on the cardiopulmonary as well as the skeletal system. the main purpose of the study was to compare the effects of both arm ergometry training and progressive resistance exercise training of upper limbs on resting heart rate and distance covered during wheel...