Investigation of the Effect of Ultrasonication on the Properties of Feedstock for Production of Compounded Road Asphalts

The influence of ultrasound on the physicochemical and rheological properties of bituminous feedstocks (vacuum residues of West Siberian and heavy Arlan oils, heavy vacuum gas oil, distillate oil fraction, black oil fraction) for the manufacturing of road asphalt by compounding a blown product with unoxidized feedstock has been studied. It has been shown that ultrasonication leads to a change in the chemical group composition and decreases the kinematic viscosity and density of the feedstock components. The homogeneity of the compounded asphalts obtained has been assessed by studying dynamic viscosity with a rotational rheometer under conditions of a multiple change (from 1.5 to 30 s^-1) of shear rate. For an asphalt sample obtained by conventional mixing of components, the relative change in dynamic viscosity after the shear load was 58.5%. An asphalt sample obtained by compounding with ultrasonic treatment has shown a smaller change in dynamic viscosity by 32.2% and, hence, better resistance to shear loads during use as part of asphalt concrete.     

Optimization of circuits of compositional microprogram control units implemented on FPGA

Two methods are proposed for microinstruction addressing in interpreting a control algorithm by a compositional microprogram control unit (CMCU). The method of refined addressing allows one to uniquely identify outputs of operational linear chains (OLCs) using a minimal number of address bits. The method of optimal addressing makes it possible to represent classes of pseudoequivalent OLCs using a minimal number of generalized intervals of the code space. The proposed methods are illustrated by examples. Both methods make it possible to reduce the number of look-up table (LUT) elements in a CMCU logic circuit in comparison with its base structure. In the majority of cases, the clock period decreases with decreasing the amount of hardware     

Thermal stability of MoSi2-TiB2-CrB2 composites at 900–1400°C

Slip casting procedure with subsequent firing in air is used to synthesize composites (100 ? x)MoSi₂?x MB₂, where M = Ti, Cr, (Ti, Cr) and x = 10, 20, and 30 mol % at 900–1400°C. The MoSi₂-CrB₂ and MoSi₂-(Ti, Cr)B₂ composites containing 20 and 30 mol % of borides are found to possess the highest protective properties. The optimum temperature range for sintering is 1100–1400°C.