The mathematical model of many physical problems takes the form of the well-known Abel integral equation. This equation was applied by Niels Abel in 1823 to describe a sliding point mass in a vertical plane on a unknown curve under gravitational force. The point mass starts its motion without initial velocity from a point which has a vertical distance x from the lowest point of the curve [1]. U...

The Poynting-Robertson (P-R) effect has been applied to meteoroids – interplanetary dust particles – for several decades. It is well known that the P-R effect produces only changes in the orbital plane of the particle. Provided the initial orbits are not near circular, the differential equations governing the secular changes in both eccentricity and semimajor axis have been known since the time...

Background: Balance disorder is one of the most-studied fields in low-back pain patients (LBP). However, there isinsufficient information regarding the effect of LBP subgrouping on postural control. The purpose of the present studywas to compare postural control between subgroups of chronic nonspecific LBP and healthy subjects during lifting.Methods: A total of 35 men with chronic LBP (19 activ...

Slab method of analysis has been used for solving metal forming problems for a long time. However it has been restricted to plane strain and axisymmetric problems due to limitations in its formulations. In this paper a new formulation has been proposed so that it could be applied to three dimensional problems in metal forming. A parametric slab has been considered in this analysis and the force...

Crouch gait decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. Crouch gait is generally considered to be disadvantageous for children with cerebral palsy; however, a crouched posture may allow biomechanical advantages that lead some children to adopt a crouch gait. To investigate one possible advantage of crouch gait, a musculoskeletal model ...

This paper aims to maximize optical force or torque on arbitrary micro- and nanoscale objects using numerically optimized structured illumination. By developing a numerical framework for computer-automated design of 3d vector-field illumination, we demonstrate a 20-fold enhancement in optical torque per intensity over circularly polarized plane wave on a model plasmonic particle. The nonconvex ...

For general plane contact of elastically similar materials, including cases where there are multiple regions of contact, general properties of the partial slip solution for conditions of constant normal force and monotonically increasing shearing force have been found recently by the first author. An extension is given here to cover the unloading and cyclic loading cases. Further, it is shown t...

One of the most important fluid phenomena observed in the left ventricle during diastole is the presence of vortex rings that develop with a strong jet entering through the mitral valve. The present study is focused on the rapid filling phase of diastole, during which the left ventricle expands and receives blood through the fully open mitral valve. The atrioventricular system during the rapid ...