The use of high vacuum for the control of insects seems never to have been considered seriously by the commercial world. The recent development and exploitation by private interests of a vacuum chamber intended for the treatment of certain warehoused commodities as a part of the equipment of a modern storage warehouse has aroused much interest in business circles and has given the writers an op...

We prove (under some technical assumptions) that each surface in R3 containing two arcs of parabolas with axes parallel to Oz through point has a parametrization (P(u,v)R(u,v),Q(u,v)R(u,v),Z(u,v)R2(u,v)) for P,Q,R,Z∈R[u,v] such P,Q,R have degree at most 1 u and v, Z 2 v. The proof is based on the observation one can consider parabola vertical axis as an isotropic circle; this allows us use meth...

Thermal conduction in tangled magnetic fields is reduced because heat conducting electrons must travel along the field lines longer distances between hot and cold regions of space than if there were no fields. We consider the case when the tangled magnetic field has a weak homogeneous component. We examine two simple models for temperature in clusters of galaxies: a time-independent model and a...

In this paper, we describe a novel camera calibration method to estimate the extrinsic parameters and the focal length of a camera by using only one single image of two coplanar circles with arbitrary radius. We consider that a method of simple operation to estimate the extrinsic parameters and the focal length of a camera is very important because in many vision based applications, the positio...