In this work, we deal with a classical differential geometry topic in Minkowski space-time. First, we prove that there are no timelike involutes of a time-like evolute. In the light of this result, we observed that involute curve transforms to a time-like curve when evolute is a space-like helix with a time-like principal normal. Then, we investigated relationships among Frenet-Serret apparatus...

This is a geometric approach to spatial involute gearing which has recently been developed by Jack Phillips [4]. Due to Phillips' fundamental theorems helical involute gears for parallel axes (Fig. 2) serve also as tooth flanks for a uniform transmission between skew axes, and the transmission ratio is even independent of the relative position of the axes.

In this study, a transient, non-Newtonian, mixed elastohydrodynamic lubrication (EHL) model of involute spur gear tooth contacts is proposed. Unlike the contact between two cylindrical rollers, spur gear contacts experience a number of time-varying contact parameters including the normal load, radii of curvature, surface velocities, and slide-toroll ratio. The proposed EHL model is designed to ...

metallic nanoparticles can exhibit very large optical extinction in the visible spectrum due to localized surface plasmon resonance. spherical plasmonic nanoparticles have been the subject of numerous studies in recent years due to the fact that the scattering response of spheres can be analytically evaluated using mie theory. however a major disadvantage of metallic spherical nanoparticles is ...

An experiment set-up is used to study wall deposition rate of particles on a rough surface in a turbulent channel flow. Deposition velocities for three classes of particles, namely, spherical glass particles, irregular shape polymer particles, and fibrous silicon particles are studied. The particle concentration at the test section was measured with the aid of an isokinetic probe in conjunction...

In this study, a kind of generalized involute and evolute curve pair is considered in 4 dimensional semi Euclidean space with 2 index. The curvatures the associated Frenet Frame generalized
 involute-evolute are presented.

This paper focuses on the geometric theory of scroll compressor, which includes the determination of the discharge angle, the calculation of the volume in different compression stages, the axial gas force under the condition that the number of scroll turns equals an arbitrary real number. NOMENCLATURE . (J :expanding angle of the involute (rad) a :initial angle of the involute (rad) 6 : orbitin...

purpose: to investigate the effects of surface ablation excimer surgery on higher-order aberrations and to assess the safety and efficacy of wavefront-guided surface ablation excimer surgery in patients with hyperopia and hyperopic astigmatism. methods: in this analytical & descriptive study, wavefront-guided surface ablation excimer surgery was performed in 58 eyes of 31 patients with hyperopi...

BACKGROUND Vascular malformations and hemangiomas, which are endothelial lesions of childhood, may result in considerable morbidity because they can cause discomfort and functional impairment and have a negative affect on the patient's appearance. Although vascular malformations may initially appear very similar to hemangiomas, they have distinct clinical courses. Infantile hemangiomas progress...