Test complex for the onboard navigation system of an airport ground vehicle

An experimental model of the onboard integrated navigation system for airport ground vehicles designed for use as part of an advanced surface movement guidance and control system is considered. The technique and the results of field tests of the system are presented. The composition and design of the mobile test stand are described.     

Controlling the microporosity of SBA-15 silicate material by background salt solution

The structure of silicate material of the SBA-15 type has been studied under variable composition of a salt solution in synthesis. Ammonium and sodium chlorides, as well as ammonium fluoride, introduced into the composition of the reaction mixture both at the first stage of precipitation and at the second stage of the thermal treatment (TT), have been used as the salt additives. The mesostructure was controlled by X-ray diffraction, gas adsorption and transmission electron microscopy. It was found that the multiple increase of the ionic strength of the solutions in the presence of chloride salts disrupt the stoichiometry of the silicate-surfactant interaction at the first stage of formation of mesostructure and leads to the formation of an impurity of irregular structure. The ions of ammonium promote an increase in the microporosity of the silicate wall. The presence of sodium ions reduces microporosity. Small quantities of fluoride ions (F^?: Si = 0.032) improve the ordering of the product at the stage of primary precipitation. At the ratio F^?: Si = 0.16, the hexagonal mesostructure is not formed. The introduction of fluorides at the TT stage leads to a decrease of the silicate pore wall thickness, microporosity and hexagonality of the pore.     

Microstructural Features of Low-Alloy Pipeline Steels that Determine Impact Strength of Welded Joint Heat-Affected Zone

Metallurgist - Microstructural mechanisms reducing the impact strength values of a coarse grained heat-affected zone are studied for two K60 microalloyed steels. Research is conducted on specimens...     

Application of the microwave technique for burning-rate measurement in high-energy composite materials

A facility designed to determine the current burning rate of high-energy composite materials is described. Methodical aspects of processing the measured information are considered. Results on the effect of humidity of the samples on their burning rate are presented. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 1, pp. 79–82, January–February, 2000.     

Relaxation Processes in Fe – Al Alloys

Metal Science and Heat Treatment -     

Ribamidyl (ribavirin) as a modulator of the biological action of arabinosylcytosine and methotrexate

Administration of ribamidyl (Rb) prior to Ara-C to intact mice or mice with implanted tumours enhanced Ara-C toxicity. The growth of tumours (plasmacytoma MOPC-21, adenocarcinoma of the small intestine (strain AKATON), mammary adenocarcinoma 755 (Ca 755) resistant to Ara-C or Rb was inhibited after coadministration of these drugs. The augmentation of toxic and antitumour effects of Ara-C by Rb is similar to the described effect of high doses of thymidine. This is in accordance with the enhancement of the intracellular pool of thymidine phosphates under the action of Rb. The toxicity of methotrexate in vivo was increased by coadministration with Rb. This effect may be connected with a decrease in purine precursors pool under the action of Rb.