Stress Concentration and Shape Optimization for a Fillet Surface of a Step-Shaped Shaft

Journal of Machinery Manufacture and Reliability - An analytical solution to the direct boundary-value problem and the two-dimensional problem concerning the stressed condition in the median...     

Limiting Ignition Conditions and Time Characteritics of Combustion of Liquid Biofuel Drops

Chemical and Petroleum Engineering - The results of experimental research on ignition and liquid biofuel drops combustion characteristics are presented. The main fuel components used are rapeseed...     

Calibration of an image-tube picosecond dissector

This paper describes a new image-tube dissector based on a PIF-01 chronographic image-tube device developed and manufactured at the Prokhorov General Physics Institute of the Russian Academy of Sciences (PGPI RAS). The results of the static measurements of the instrumental function of the dissector showing that its temporal resolution can be higher than 4 ps are given. These data are confirmed by direct measurements on the bench of the PGPI RAS with the use of a femtosecond titanium-sapphire laser.     

Proton-conducting sorption-active cyclam-based layers on chemically modified PVC surfaces of cellulose fabric

At different concentrations of hydrochloric, sulfuric, and phosphoric acids, the conductivity of the following electrochemical cell was measured: anode-acid solution-in-air bridge-acid solution-cathode. Cellulose fabric, the fibers of which are encapsulated in polyvinyl chloride, the surface of which is chemically modified with porous layers of aggregates formed by acid molecules and salt groups of ethanol and acetate cyclams, served as the bridge. The range where the logarithmic conductivity is proportional to the acid concentration is found. In this range, the molar contents of acids and water in the layers are estimated, the presence of aggregates composed of acid hydrates and cyclam salt groups is determined, the structure of layer is studied, and the similarity between the H⁺ conductivity of the layers on fabric and the conductivity of membranes based on polymers involving the skeleton ammonia salt groups is followed. For the aggregate layers, the specific surface; the limiting volume of pores; and the adsorption capacities for water, alcohol, benzene, and hexane vapors are measured. The formation of aggregates is shown to produce an insubstantial effect on the adsorption characteristics of the surface. During migration of H⁺ ions in the fabric and on its surface, the following process was carried out in the electrochemical cell: adsorption of NH₃, formation of NH ₄ ⁺ ions, and transfer of NH ₄ ⁺ ions to the catholyte. The migration velocity of H⁺ ions is shown to correspond to the measured current in the circuit, and NH ₄ ⁺ ions formed are found to be accumulated in the catholyte.     

Spectral measurement of frequency modulation index

A method is proposed of measuring the frequency modulation index based on the evaluation of the amplitudes of four spectral lines. The method does not require a priori knowledge of the harmonic numbers of spectral components of frequency-modulated signals. The accuracy of the proposed method is evaluated. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 37–40, September, 1998.     

Calculations of thermodynamic cycles via internet

Information is provided regarding a website where calculations of thermodynamic cycles can be carried out in an interactive mode.     

Toxic components in diesel exhaust fumes

To control diesel-engine toxicity, a computation method is proposed for the concentration of toxic components in diesel exhaust fumes, on the basis of external engine characteristics such as the crankshaft speed and the compression ratio.