Technology for Producing Schottky Contacts Based on an IrSi–Si Composite

Russian Microelectronics - In this study, in order to obtain Schottky contacts based on an IrSi–Si composite, n- and p-type silicon wafers doped, respectively, with boron and phosphorus with...     

A Method for Analyzing the Domain Structure in Magnetic Powder Microparticles

Technical Physics Letters - A method for analyzing the domain structure in magnetic powder microparticles based on the Mössbauer effect is proposed. This method has been experimentally...     

Graft polymerization of N,N-dimethylaminoethylmethacrylate onto polycarbonates by the preirradiation method

Summary Radiation-induced graft polymerization of N,N-dimethylaminoethylmethacrylate (DMAEMA) from solutions in carbon tetrachloride or in chloroform onto bisphenol A-derived polycarbonate (PC-1) and allyl diglycol carbonate (PC-2), respectively, was carried out by method of preirradiation in air. It has been found essential difference in transparency and durability of the modified PC-1 and PC-2. Effects of preirradiation dose as well as temperature and time of graft polymerization on effectiveness of DMAEMA grafting onto PC-2 were investigated, the optimal values of dose and temperature are 500 kGy and 55°C, respectively. Received: 6 June 1999/Revised version: 9 September 1999/Accepted: 9 September 1999     

Evaluation of convergence rate in the central limit theorem for theKalman filter

State-space models are used for modeling of many physical and economic processes. An asymptotic distribution theory for the state estimate from a Kalman filter in the absence of the usual Gaussian assumption was presented by Spall and Wall (1984). They proved the central limit theorem for state estimators when the random terms in the model have arbitrary distribution. In this study, some convergence rates in the central limit theorem are given. These convergence rates are used for the development of a nonparametric test of the validity of the model     

Thermal transport in MWCNT sheets and yarns

Laser flash and self-heating 3ω techniques were employed to determine the anisotropic thermal conductivity and thermal diffusivity of a highly oriented, free-standing multiwalled carbon nanotube (MWCNT) sheet and a yarn drawn from a sidewall of the MWCNT forest grown by chemical-vapor deposition. Normalized to ideal high density structure the thermal conductivity and the thermal diffusivity along the alignment are 50 ± 5 W/m K and 45 ± 5 mm²/s, respectively, and are mostly limited by dangling terminals of bundles, intrinsic defects of individual nanotubes and phonon scattering within the bundles, which form the supporting matrix of the MWCNT sheet. The high degree of tube–tube overlap substantially decreases the electrical and thermal interconnection resistance, which usually dominates in randomly deposited mat-like nanotube assemblies. The extremely high surface area of the MWCNT sheet leads to excessive radial heat radiation that does not allow transferring the heat energy along the MWCNT sheet by means of phonons to distances >2 mm. On the other hand, the high surface area and negligible heat capacitance make it a perfect material for bolometric sensing (r = 38 V/W) and heat dissipation.     

Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part II – changes in composition of aromatic hydrocarbons

Abstract

This paper discusses aquathermolysis process of heavy crude oil from Boca de Jaruco reservoir, which is developed by CSS method. The catalysts based on cobalt, nickel, iron and cupper are used to intensify the in-situ conversion processes. The active form of catalysts generates after steam injection. In second part of work the conversion of aromatic hydrocarbons depending on thermo-catalytic conditions and composition of catalysts are investigated. The thermo-catalytic treatment destructs resin and asphaltene molecules. The destruction products transform into aromatic fractions. The correlation between the C4-phenanthrene/naphtabenzothiophen ratio and the yields of aromatics and resins are revealed. The increase in high-molecular aromatic hydrocarbon, particularly tetramethyl-phenanthrene content is observed. However, the content of heteroatom compounds such as naphtabenzothiophen is constant. Based on IR-spectroscopy, the changes in composition of aromatic fraction are revealed. The lowest value of aromaticity index is detected for experiments with only hydrogen donor (without catalysts) and for experiments with Ni-, Cu-based catalysts.     

Study of Turbulent Flow in a Long Permeable Channel

Stationary liquid flow in a long (to L/d = 1440) permeable channel was studied for input Reynolds numbers from 28700 to 83000. The distributions of water pressure along the channel were obtained. Experimental data were compared with the numerical solution of equations derived from the energy equation.     

The Phase Relationships in the Sb-S-I System and Thermodynamic Properties of the SbSI

The phase relationships in the Sb-S-I ternary system were determined experimentally over entire concentration range by means of differential thermal analysis (DTA) and x-ray diffraction (XRD) techniques. Two quasi-binary, three isopleth sections, 300 K isothermal section and liquidus surface projection of the system were revised. The primary crystallization fields of all existing phases, the types and coordinates of all invariant and monovariant equilibria were determined. The electromotive force measurements (EMF) method was used to calculate the partial molar functions of antimony in alloys and the standard integral thermodynamic functions of SbSI.     

Technology of calculating robust normalized correlation matrices

It is shown that, under traditional approach, errors caused by noise disappear after normalizing estimates of noisy signals in diagonal elements of correlation matrices and that, on the contrary, such errors arise in other elements. Hence, the expected result of elimination of errors owing to the transition to normalized correlation matrices is not reached. Algorithms and technologies are proposed for correcting this drawback by obtaining robust normalized correlation matrices analogous to matrices of useful signals. Results of numerous computer experiments are presented that testify to the efficiency of the developed technology.