Vibrational Protection by Pneumatic Suspension with Hybrid Damping

Russian Engineering Research - A pneumatic suspension with a hybrid damping system is investigated. The system includes a hydraulic shock absorber, a pneumatic damper, an inertial–frictional...     

Carbon‐Nanotube–Polymer Nanocomposites for Field‐Emission Cathodes

The electron field‐emission (FE) characteristics of functionalized single‐walled carbon‐nanotube (CNT)–polymer composites produced by solution processing are reported. It is shown that excellent electron emission can be obtained by using as little as 0.7% volume fraction of nanotubes in the composite. Furthermore by tailoring the nanotube concentration and type of polymer, improvements in the charge transfer through the composite can be obtained. The synthesis of well‐dispersed randomly oriented nanotube–polymer composites by solution processing allows the development of CNT‐based large area cathodes produced using a scalable technology. The relative insensitivity of the cathode's FE characteristics to the electrical conductivity of the composite is also discussed.     

Structure and properties of strengthening layer on Hardox 450 steel

The microstructure and microhardness distribution in the surface of low-carbon Hardox 450 steel coated with alloyed powder wires of different chemical compositions are studied. It is shown that the microhardness of 6–8?mm-thick surfaced layer exceeds that of base metal by more than two times. The increased mechanical properties of surfaced layer are caused by the submicro and nanoscale dispersed martensite, containing the niobium carbides Nb₂C, NbC and iron borides Fe₂B. In the bulk plates, a dislocation substructure of the net-like type with scalar dislocation density of 10¹¹?cm^?2 is observed. The layer surfaced with the wire containing B possesses highest hardness. The possible mechanisms and temperature regimes of niobium and boron carbides in surfacing are discussed.     

Rapid group analysis of straight-run petroleum cuts by liquid-adsorption chromatography (LAC) with automatic recording

Summary A method of quantitative group analysis has been developed for bicyclic aromatic hydrocarbons with a minimum content of these hydrocarbons (down to 0.2%) in kerosine and kerosine-gas oil distillates, and also for the analysis of monocyclic aromatic hydrocarbons in naphtha cuts, by a recording method of column liquid-adsorption chromatography (LAC) on-Al₂O₃ in a stream of n-hexane or petroleum ether. The analysis requires 20–25 min, and the chromatographic column can be used repeatedly.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 51–53, April, 1974.     

A Parallel-Plate Chamber as a Detector for Time-of-Flight Measurements

The possibility of measuring the time of flight of minimum-ionizing particles with high accuracy and efficiency using a gaseous parallel-plate detector operating in avalanche gas-amplification mode is demonstrated in principle.     

Binding of aroma compounds with legumin. III. Thermodynamics of competitive binding of aroma compounds with 11S globulin depending on the structure of aroma compounds

This paper considers the prominent features in competitive binding of aroma esters from their mixtures to 11S globulin of broad beans (legumin) in aqueous medium at pH 7.2 and ionic strength of 0.05 mol dm⁻³. Series of alkyl acetates (C₄–C₈) and methyl esters of carbonic acids (C₅–C₉), differing in the length of hydrocarbon chain, have been under our studying. To accomplish the ends of the study, a combination of ultrafiltration and gas–liquid chromatography (GC) has been used. An increase in the length of hydrocarbon chain of the aroma esters brought about greater binding affinity for the protein, the occurrence of some structural restrictions in the interior of the protein molecule, preventing binding, and the change in the binding mechanism of the aroma compounds at the specific critical length of hydrocarbon chain. Differential scanning microcalorimetry data suggested that the revealed changes in the binding mechanism of the studied aroma compounds were attributable to the conformational modification of the protein globule as a result of binding with the aroma compounds. A distinguishing feature in binding of methyl esters of carbonic acids with legumin was their greater binding affinity for the protein as compared with alkyl acetates. The mutual effect of aroma compounds on binding from their equimolar mixtures to the protein made itself evident, firstly, as a drastic increase in the binding extent of aroma esters, having rather long hydrocarbon chain and, secondly, as a dramatic change in the binding mechanism of the aroma esters with relatively short hydrocarbon chain.     

Wettability of Calcium Fluoride by V-, Nb-, and Cr-Containing Liquid Alloys

The wetting of calcium fluoride by liquid metal alloys containing 10-50 mass% of chemically active metals (vanadium, niobium, and chromium) was studied by the sessile drop method in vacuum at 700-1350°C. At temperatures above 900°C these alloys did not wet calcium fluoride. The wetting angle was above 90deg;. This is explained by the formation of volatile reaction products at the interface between calcium fluoride and the liquid metal alloys.