Zinc-and aluminum-based protective coatings obtained in a fluidized bed

Sherardizing and zinc-aluminizing Ct3 steel in a fluidized bed are considered. Microhardness, microbrittleness, porosity, and corrosion resistance of zinc coatings are analyzed. Original Russian Text ? Yu.A. Balandin, A.S. Kolpakov, E.V. Zharkov, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 4, pp. 379–382.     

Synthesis of controllers on the basis of a solution of linear matrix inequalities and a search algorithm for reciprocal matrices

It is shown how the synthesis of stabilizing, H-optimal, and robust controllers of the prescribed order in the output for linear continuous and discrete systems reduces to a solution of linear matrix inequalities relative to two reciprocal matrices. To verify the solvability of such inequalities and to find their solutions, an algorithm realizable in the MATLAB package is proposed. An example of stabilization of an inverted pendulum with the aid of a controller of the reduced order in the output is given.Translated from Avtomatika i Telemekhanika, No. 1, 2005, pp. 82–99.Original Russian Text Copyright © 2005 by Balandin, Kogan.This work was supported by the Russian Foundation for Basic Research, project nos. 04-01-0022, 02-01-00230, the Universities of Russia Program, project no. UR.03.01.013, and INTAS, project no. 03-51-5547.This paper was recommended for publication by A.P. Kurdyukov, a member of the Editorial Board     

Multicriteria Robust Generalized <Emphasis Type="Italic">H</Emphasis><Subscript>2</Subscript> and γ<Subscript>0</Subscript> Controllers with Application to Stabilization of a Rotor in Electromagnetic Bearings

For linear plants with unstructured or structured uncertainty of bounded norm, this paper designs Pareto optimal robust controllers in terms of linear matrix inequalities in multicriteria control problems with the generalized H₂ or γ₀ norms. The controller design procedure is based on optimization of a scalar objective function (Germeier convolution) and semi-definite programming. The developed theory is used to design multicriteria robust controllers in the stabilization problem for a rotor in electromagnetic bearings.     

Pareto optimal generalized <Emphasis Type="Italic">H</Emphasis><Subscript>2</Subscript>-control and vibroprotection problems

We consider a novel multi-objective control problem where the criteria are generalized H ₂-norms of transfer matrices of individual channels from the disturbance input to various objective outputs. We obtain necessary conditions for Pareto optimality. We show that synthesis of Pareto optimal controls can be done in terms of linear matrix inequalities based on optimizing Germeier’s convolution, which also turns out to be the generalized H ₂-norm of the closed-loop system with output composed of the objective outputs multiplied by scalars. As applications we consider multi-objective problems of vibration isolation and oscillation suppression with new types of criteria.     

Towards ultrathick battery electrodes: aligned carbon nanotube-enabled architecture

Vapor deposition techniques were utilized to synthesize very thick (～1 mm) Li-ion battery anodes consisting of vertically aligned carbon nanotubes coated with silicon and carbon. The produced anode demonstrated ultrahigh thermal (>400 W·m(-1) ·K(-1)) and high electrical (>20 S·m(-1)) conductivities, high cycle stability, and high average capacity (>3000 mAh·g(Si) (-1)). The processes utilized allow for the conformal deposition of other materials, thus making it a promising architecture for the development of Li-ion anodes and cathodes with greatly enhanced electrical and thermal conductivities.     

Thermal properties of graphene and nanostructured carbon materials

Recent years have seen a rapid growth of interest by the scientific and engineering communities in the thermal properties of materials. Heat removal has become a crucial issue for continuing progress in the electronic industry, and thermal conduction in low-dimensional structures has revealed truly intriguing features. Carbon allotropes and their derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range--of over five orders of magnitude--from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. Here, I review the thermal properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. Special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe the prospects of applications of graphene and carbon materials for thermal management of electronics.     

Effect of neutron irradiation on the long-term thermal cycling resistance of austenitic steels

Strength of Materials -