A practical application of the spherical involute surface to the forged straight bevel gears is provided and demonstrated in this work. Conjugate (pure involute) theoretical surfaces are developed from the input design parameters. The surfaces are modified to suit the actual application (automotive differential). The unloaded (or low load) tooth contact analysis of modified surfaces is performe...

Background and Objectives: Investigating the risk factors in osteoporosis elderly to prevent falls and fractures is of high importance. Therefore, this study assesses the effect of different surfaces on postural stability and gait variations in the osteoporosis elderly. Methods: 22 elderlies participated (11 with severe osteoporosis & 11 healthy elderly) in this study in two static and dynam...

In this paper, we define X-slant helix in Euclidean 3-space and we obtain helix, slant helix, clad and g-clad helix as special case of the X-slant helix. Then we study Darboux, tangential darboux developable surfaces and their singular points. Especially we show that the striction lines of these surfaces are singular locus of the surfaces.

In this paper, we show that an $L_1$-2-type surface in the three-dimensional hyperbolic space $H^3subset R^4_1$ either is an open piece of a standard Riemannian product $ H^1(-sqrt{1+r^2})times S^{1}(r)$, or it has non constant mean curvature, non constant Gaussian curvature, and non constant principal curvatures.

In this paper a Frequency Selective Surface (FSS) as a UWB electromagnetic shield is introduced. The proposed FSS comprises a quasi-J.C-Jerusalem Cross- and a copper ring, which are located at both sides of a FR4 substrate and can represent a S.E -Shielding Effectiveness- better than 20dB in 90% bandwidth of Ultra Wide Band frequency. This structure is compact and thin. Each cell comprises J.C ...

an investigation was made to study the residual activity and air- borne effect of pirimiphos- methyl, at 2g a.i./m2 in hut scale trials on different surfaces in kazeroun, and bandar-abbas, south of iran. in kazeroun area, bio-assay contact mortality test with pirimiphos methyl on mud, wood, cement and plaster surfaces, 54 days after hut spraying, decreased from 100% to 46.7%, 61.25%, 36.6% and ...