Effect of photoaligning azo dye structure on liquid crystal anchoring energy

A method of controlling anchoring energy of surface interaction of liquid crystal photoaligning substances is considered to enhance the liquid crystal display performances. An important parameter of the dye's molecular structure that determines the ratio of polar and azimuthal anchoring energy is the ability to form dimers. The values of dimerization thermodynamic potentials have been found. The probability of the formation of dye molecules dimers is evaluated. The bonds conjugation transfer via intermolecular hydrogen bond is revealed, and anisotropy of polarizability of the hydrogen bond is evaluated. The effect of dimerization on polar and azimuthal anchoring energy of liquid crystal — azo dye system — is shown.     

LLVM-based static analysis tool using type and effect systems

The intent of this paper is to describe a static analysis tool under development. The main idea behind the design of this tool is to use type and effect systems for static analysis of real programs. The tool uses LLVM bitcode files as input, thus extending the set of analyzed languages to those supported by LLVM compiler infrastructure. It uses its own parser of bitcode files and a program model similar to that of LLVM. The approach taken is to research feasibility of designing instruments for static analysis by applying known type and effect system based algorithms for detecting defects to LLVM bitcode language and effectively to original source code.     

An acoustic study of the relaxation properties of ZhK-1282 nematic liquid crystals in the vicinity of the nematic-isotropic phase transition

The viscous and elastic properties of a ZhK-1282 nematic liquid crystal (NLC) were studied in a temperature interval from 290 to 360 K by method of ultrasonic spectroscopy in the 3–63 MHz frequency range. The temperature dependences of the NLC density and shear viscosity are presented. The results of measurements of the velocity and attenuation of ultrasound and the shear viscosity were used to calculate the volume viscosity coefficient, the moduli of dilatation and isothermal compressibility, the relaxation times of the elastic and viscous properties, and the corresponding critical characteristics of the given NLC.     

The СПРУТ-VI Instrument Complex for the Mir Orbital Station

The basic elements of the instrument package program for orbital stations are presented. The characteristics of the -VI equipment developed for the Mir orbital station within the framework of this program are described. This equipment allows the simultaneous recording of the characteristics of near-earth space (electron, proton, and nucleus fluxes, magnetic fields, and low-frequency electromagnetic waves) and their effect on the elements of spaceborne equipment and systems. The mass of the equipment is 16 kg; the power consumption is no more than 20 W.     

Current flow through metal shunts in ohmic contacts to n +-Si

It is experimentally found that an ohmic contact based on Au-Pt-Ti-Pd-n ⁺-Si metallization is formed due to nanoscale metal shunts containing Si, Au, and Pt in the region of the interface with n ⁺-Si, which appears during heat treatment at T = 450°C for 10 min in a vacuum chamber with a residual pressure of 10^?6 Torr. The high density of shunts adjoining dislocations and other imperfections is confirmed by the temperature dependence of the specific contact resistance ρ _c (T). The density of conductive dislocations, calculated from the temperature dependence of ρ _c is ～5 × 10⁹ cm^?2 which correlates with the density of structural defects, determined by the etch pits after removal of the metallization layers.     

Adjustable synchronous electric drives of shaft fans with vector-based control oriented in the field

A special algorithm is developed that provides satisfactory control for mass high-power electric drives. Results of an experimental study and tests of drives are presented that are performed when they are being put into use.     

Accumulation of Residual Strain in TiNi Alloy During Thermal Cycling

Residual strain accumulation during thermal cycling of the Ti₅₀Ni₅₀ alloy under a constant stress of 200 MPa through the temperature range of complete and incomplete forward martensitic transformation was studied. The temperature range of the forward martensitic transformation during thermal cycling was chosen as 25, 50, 75, or 100% of the M _s-M _f interval measured in the first cycle. It was shown that intensive accumulation of residual strain took place in the last stage of the forward transformation. It was observed that resistivity increased more rapidly with an increase of the fraction of the temperature range of forward martensitic transformation.     

Effect of the cooling rate on the phase composition and structure of copper matte converting slags

The effect of the cooling rate on the phase composition and microstructure of copper matte converting slags is studied by X-ray diffraction, combined thermogravimetry and calorimetry, mineragraphy, and electron-probe microanalysis. The compositions of oxide and sulfide phases are determined, and the forms of nonferrous metals in slags cooled at a rate of 0.3 and 900°C/s are revealed. At high cooling rates of the slags, iron silicate glass is shown to form apart from sulfide phases. Repeated heating of the slags leads to the development of devitrification, “cold” crystallization, and melting. A decrease in the cooling rate favors an increase in the grain sizes in oxides (magnetite, iron silicates) and sulfides (bornite-, sphalerite, and galena-based solid solutions).