It is shown that for a class of position dependent mass Schrödinger equation the shape invariance condition is equivalent to a potential symmetry algebra. Explicit realization of such algebras have been obtained for some shape invariant potentials. PACS: 03.65.Ca; 03.65.Fd; 03.65.Ge 1e-mail : [email protected] 2e-mail : [email protected]

Introduction: Microdosimeters are helpful for dose equivalent measurement in unknown radiation fields. The favorable physical and mechanical properties of the detector-grade chemical vapor deposition diamond materials have made the diamond microdosimeters suitable candidate for radioprotection applications in space. The purpose of this work is the investigation of the dose equivalent response o...

In this paper, the stress intensity factor (SIF) expression for defected butt welds containing undercut and inclined lack of penetration (LOP) subject to far-field tensile stress is derived. Some of the standards such as ISO 5817 and BS EN 25817 have specified allowable limits for the length of the undercut and LOP defects and for the height of the weld. In addition, EN 29692 standard has deter...

Dimensionless coefficient () in convergence confinement method shows the relaxation of stress in the wall of the tunnel at different excavation movements. This factor is considered a constant number in previous studies and tunnel geometric characteristics (such as depth, cross-section shape, radius, soil material, etc.) are not included in its determination; however, ignoring these effects can...

Avoiding toxicities in radiotherapy requires the knowledge of tolerable organ doses. For new, experimental fractionation schemes (e.g. hypofractionation) these are typically derived from traditional schedules using the biologically effective dose (BED) model. In this report we investigate the difficulties of establishing mean dose tolerances that arise since the mean BED depends on the entire s...

A module $M$ is said to be coretractable if there exists a nonzero homomorphism of every nonzero factor of $M$ into $M$. We prove that all right (left) modules over a ring are coretractable if and only if the ring is Morita equivalent to a finite product of local right and left perfect rings.