Rheological properties of finely dispersed suspensions

The influence exerted by the physical interaction of particles, their Brownian motion, and the fluctuations in porosity on the effective viscosity of suspensions and colloids is evaluated.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 57, No. 6, pp. 923–929, December, 1989.     

Liquid filtration in finely porous capillary structures

A. M. Gor'kii Ural State University, Ekaterinburg. Translated from Inzhenernofizicheskii/Zhurnal, Vol. 62, No. 1, pp. 66–69, January, 1992.     

High-pressure phase transitions and structure of Al–20 at % Si hypereutectic alloy

Phase transformations of an Al–20 at % Si high-silicon hypereutectic alloy have been studied by differential barothermal analysis at temperatures of up to 800°C in argon compressed to 100 MPa. High pressure has been shown to raise the melting point of the alloy by 5°C during heating and to lower the eutectic solidification temperature by 5°C during cooling in comparison with the canonical phase diagram of the Al–Si system. At a temperature of 553°C, heating and cooling lead to silicon dissolution and decomposition of the aluminum-based solid solution, respectively. After high-pressure solidification, the silicon particles in the alloy have a bimodal size distribution. Quantitative porosity characteristics in the alloy after a barothermal scanning cycle are similar to those in the as-prepared alloy. The lattice parameters of the silicon and aluminum remain unchanged. The microhardness of the aluminum matrix of the alloy corresponds to that of pure aluminum.     

Organizational and technological modeling of chemical process systems

A method was suggested for modeling the chemical process systems using the business process models based on SADT, which takes into account the fixed technological structure of chemical process objects.     

The wave collapse analyzed for the nonlinear Klein-Gordon equation with periodic boundary conditions

The integral estimation method is used to study the wave collapse dynamics for the Klein-Gordon equation with a nonlinearity of the general form in the case of periodic boundary conditions. Sufficient integral criteria (generalizing the known ones) for the wave collapse are formulated.     

Stress-strain state and thermal state of rubber-cord casings of highly elastic couplings

A solution of the steady thermoelastic problem is proposed, taking account of the dependence of the elastic and thermophysical constants of the material on the temperature and strain. As an illustration, the stress-strain state and thermal state of rubber-cord casings for highly elastic couplings (of diaphragm and toroidal type) and cylinders for pneumatic-tire couplings are calculated.     

Localization of labile posttranslational modifications by electron capture dissociation: the case of gamma-carboxyglutamic acid.

Tandem mass spectrometry (MS/MS) of 28 residue peptides harboring gamma-carboxylated glutamic acid residues, a posttranslational modification of several proenzymes of the blood coagulation cascade, using either collisions or infrared photons results in complete ejection of the gamma-CO2 moieties (-44 Da) before cleavage of peptide-backbone bonds. However, MS/MS using electron capture dissociation (ECD) in a Fourier transform mass spectrometer cleaves backbone bonds without ejecting CO2, allowing direct localization of this labile modification. Sulfated side chains are also retained in ECD backbone fragmentations of a 21-mer peptide, although CAD causes extensive SO3 loss. ECD thus is a unique complement to conventional methods for MS/MS, causing less undesirable loss of side-chain functionalities as well as more desirable backbone cleavages.     

Curve of calcium deoxidation of iron

The experimental data reflecting the thermodynamic features of deoxidation of liquid iron with metallic calcium are analyzed. A correction technique is proposed for a metallic melt–deoxidizer deoxidation curve according to the standard state by Henry’s law.     

Data recording system of a dispersion interferometer based on a CO<Subscript>2</Subscript> laser

The data recording system of a multichannel double-pass dispersion interferometer based on a CO₂ laser is described. This system has been designed to record the linear density of plasmas in a real-time mode with a time discreteness of 4 μs and resolution 〈N _e L〉 ～ 0.34 × 10¹³ cm^?2 (N _e is the electron component of the plasma density, and L is the plasma size in the wave propagation direction) in the range of linear density variations of up to 10¹⁷ cm^?2. The system is built from unified recording modules that use fast ADCs to record the shape of photodetector and modulator signals and FPGA-based digital units of dataflow processing to form results of measurements. The single-channel recording module of the dispersion interferometer has been tested under actual experimental conditions of the GDL gas-dynamic trap and the TEXTOR tokamak (Julich, Germany).