Structural characteristics of a sormatt type alloy powder produced by electroerosion disintegration in water

Conclusions The electroerosion disintegration of a manganese-containing Sormait type alloy in water yields powders of spherical particle shape. A coarse (>40-m) fraction of such a powder consists mainly of hollow particles, which are the most suitable for the flame-spray deposition of coatings. The particles of the powder have a homogeneous fine-grained structure differing radically from that of the starting alloy, and surpass the latter in microhardness. The powder is passivated by Fe₃O₄ films which increase its resistance to attack by corrosive environments. EE powders may find application for the deposition of protective coatings.A group of Fe-base C-Mn-Si-Cr-Ni hard-facing alloys-Publisher.Translated from Poroshkovaya Metallurgiya, No. 10(274), pp. 66–71, October, 1985.     

Linear hexane isomerization over the natural zeolite based catalysts depending on the zeolite phase composition

A range of Pd-containing catalysts on the basis of mordenite–clinoptilolite rocks of different starting phase compositions is synthesized. Final phase composition and acidity of rocks change as the conditions of their dealumination are changed. The efficiency of catalysts synthesized is weakly influenced by change of mordenite component contents within 50–80%, and it is not inferior to the efficiency of the catalysts on the synthetic mordenite basis. The nature of active sites as trifunction ones and isomerization mechanism are proposed.     

Normative design of organizations. I. Mission planning

This paper presents a design methodology for synthesizing organizations to execute complex missions efficiently. It focuses on devising mission planning strategies to optimally achieve mission goals while optimally utilizing organization's resources. Effective planning is often the key to successful completion of the mission, and conversely, mission failure can often be traced back to poor planning. Details on subsequent phases of the design process to construct the mission-driven human organizations are discussed in a companion paper.     

On an inverse thermo-elasticity problem for an infinite medium containing a cavity of unknown shape

The static inverse thermoelastic problem for an infinite elastic isotropic medium containing a cavity of unknown shape, under three-axes tension and given constant values of the pressure and the temperature on the cavity surface, is considered. The shape of a cavity is sought subject to the condition that certain stress components are uniform on the cavity surface. It is shown that ellipsoidal shapes furnish a solution of this inverse thermo-elasticity problem. Nonlinear equations for determining the geometric cavity parameters, which lead to an equal-stress state along the cavity surface, are obtained. Results of other authors for force loading only are obtained as special cases. Numerical investigations have been carried out and correlations between values of the force and temperature loadings and geometrical parameters for an equal-stress cavity surface are studied. The stress values on the equal-stress cavity surface under force and temperature loadings are investigated.     

Generation of neutrons in a long lead target

Translated from Atomnaya Énergiya, Vol. 68, No. 6, pp. 449–452, June, 1990.     

Paenibacillus polymyxa purified bacteriocin to control Campylobacter jejuni in chickens

Campylobacter spp. cause numerous foodborne diseases. Poultry is thought to be a significant source of this zoonosis. Although many interventions designed to control this agent have been researched, none have succeeded. We evaluated a bacteriocin-based treatment to reduce Campylobacter jejuni colonization in poultry. A previously described purified bacteriocin (class IIa; molecular mass, 3,864 Da), secreted by Paenibacillus polymyxa NRRL-B-30509, was microencapsulated in polyvinylpyrrolidone, and 0.25 g of the purified bacteriocin was incorporated into 1 kg of chicken feed. One-day-old chickens were orally challenged and colonized with one of four isolates of C. jejuni, then reared in isolation facilities. Birds were provided ad libitum access to standard broiler starter feed and water for 7 days until 3 days before sampling, when only the treated groups of birds were provided the bacteriocin-emended feed described. In each of the eight (four by two replicates) trials, significant reductions in colonization by C. jejuni were observed (P < or = 0.05). As an example of this highly consistent data, in the first trial, 10 untreated 10-day-old chickens were colonized at a mean log 7.2 + 0.3 CFU/g of feces, whereas none of the 10 bacteriocin-treated 10-day-old chickens were colonized with detectable numbers of C. jejuni. Bacteriocin treatment dramatically reduced both intestinal levels and frequency of chicken colonization by C. jejuni. Feeding bacteriocins before poultry slaughter appears to provide control of C. jejuni to effectively reduce human exposure. This advance is directed toward on-farm control of pathogens, as opposed to the currently used chemical disinfection of contaminated carcasses.     

Al-Cr-O thin films as an efficient hydrogen barrier

Thin Al-Cr-O films are proposed as hydrogen permeation barriers. Layers of a few microns in thickness are able to suppress hydrogen permeability by a factor of 2000 to 3500 at temperatures of 700 °C, as has been found in our gas phase permeation experiments. We attribute this excellent efficiency to a dense layer morphology and the possible (pre)-formation of solid solutions in corundum-type structure. These films are deposited by pulsed arc evaporation in a batch-type production system at substrate temperatures of 550 °C.     

Complex electrochemical processing of the metallic wastes from a rhenium-containing nickel superalloy in sulfuric acid electrolytes

A principal technological scheme for the complex electrochemical processing of the wastes from a rhenium-containing nickel superalloy in sulfuric acid electrolytes is developed on the basis of physicochemical studies. The process according to the technological scheme produces potassium perrhenate, calcium tungstate, nickel sulfate, and a tantalum concentrate as marketable products.