An experimental assessment of the dependence of the normal flame velocity of methane-hydrogen fuel with air using the Gouy-Michelson method has been carried out. The concentration of hydrogen varied from 0% to 70% by volume.

Keywords: burning rate, normal flame propagation speed, flame front, methane-hydrogen fuel, Gouy-Michelson method

The article presents the local type of logistic centers in urban environment as an essential part of freight network and its place in hierarchic logistic system of a country. Transport, compositional, ecologic and other aspects that have impact on spacial concept of local logistic centers are under examination. Thus generalized models of local logistic centers are put forward. They are developed by the authors with large volume of handled cargo, turnover capacity, and are space-saving. The main concepts of such models are following:  vertical development of storage volume due to construction of several floor and shelf storage levels with different ramps as well as provision of comfort one-way transport of minimum maneuvers and without crossing and conflicting traffic.

Keywords: architectural spatial concepts, logistic centers, warehousing types , generalized spacial model

In this paper, based on Darcy equations that govern the lubricant in porous layers , and the modified Reynolds equation in the framework of a short bearing solve the problem of unsteady motion of a viscous incompressible lubricant in the bearing clearance double-layer porous . Here we consider the case when the permeability in porous layers in the axial direction is changed by the normal law , and the combined feed lubrication is performed simultaneously in the axial and perpendicular to the bearing axis directions. As a result, the pressure field found in porous layers and in the lubricating layer and analytical dependences for the efforts of the oil film . Compiled by the equation of motion tongue and solved the problem of the stability of the unsteady motion of a pin bearing , found that in the case of a combined bearing lubrication working more steadily compared with the cases or axial directions perpendicular to the axis lubrication . The results obtained can be offered for the development of cylindrical dampers with double-layer porous collar , effectively attenuating transmitted force imbalance in the combined feed lubrication.

Keywords: two-layer porous plug; permeability porous layers, load capacity; equation of motion of the stud; stability

Considers and researches dimensional stability advanced base polyimide materials for high-density PCB.

Keywords: Printed circuit boards, flexible printed circuit boards, flex-rigid printed circuit boards, foil dielectric materials, polyimide foil materials

Information about authors of issue №4 (2011)

Keywords: authors