We study the possibilities of direct (using one intersection with each light ray) stigmatic imaging with a curved surface that can change ray directions in an arbitrary way. By purely geometric arguments we show that the only possible case of such imaging is the trivial one where the image of any point is identical to the point itself and the surface does not perform any change of the ray direc...

In this review we discuss the fundamental role of surface forces, with a particular emphasis on the effect of the disjoining pressure, in establishing the wetting regime in the three phase systems with both plane and curved geometry. The special attention is given to the conditions of the formation of wetting/adsorption liquid films on the surface of poorly wetted substrate and the possibility ...

The high-field permanent magnetic circuits of 1.2 T and 1.5 T with novel magnetic focusing and curved-surface correction are developed. The permanent magnetic circuit comprises a magnetic yoke, main magnetic steel, nonspherical curved-surface magnetic poles, plugging magnetic steel, and side magnetic steel. In this work, a novel shimming method is proposed for the effective correction of base m...

None (Members of Erysiphales cause powdery mildew diseases on wide host rang and produce whitish primary mycelium on surface of infected parts. Based on microscopic study of one specimen on Jasminum sp., structures of fungus including conidiophores and conidia were observed. Foot cells of conidiophores were cylindrical or curved in basal part, followed by 1-2 shorter cells. Conidia were ellipso...

members of erysiphales cause powdery mildew diseases on wide host rang and produce whitish primary mycelium on surface of infected parts. based on microscopic study of one specimen on jasminum sp., structures of fungus including conidiophores and conidia were observed. foot cells of conidiophores were cylindrical or curved in basal part, followed by 1-2 shorter cells. conidia were ellipsoid to ...

Typically flank milling is used to machine ruled surfaces. In this paper, a method of designing doubly curved NURBS surfaces for flank milling using the least squares method is given. In this method, grazing points generated by the Bedi et al. [4] tool positioning method are used as sample points. The user defines the degree and the number of control points along two parametric directions of th...