Mechanochemical Synthesis of Hafnium Carbide using Amorphous Carbon from Plant Materials

Metallurgist - The paper presents the results of studying mechanochemical synthesis of hafnium carbide in the process of vibration treatment of the mixture of powders of hafnium and amorphous...     

Mechanical Properties Under Cyclic Loading of Rolled Ordered Materials Produced from Continuous Elastic Fibers. I. Elasticity and Energy Dissipation

Powder Metallurgy and Metal Ceramics - Ribbons with a porosity varying from 22% to conditional 0.5% have been produced by rolling a multilayer knitted-mesh package made of 12Kh18N10T steel wire...     

Intercalation of Porphyrin‐Based SURMOF in Layered Eu(III) Hydroxide: An Approach Toward Symbimetic Hybrid Materials

A strategy for rational design of synergetic hybrid materials exploiting stabilization of intercalated layered matrices via coordination bonding is described. A new hybrid material is assembled through subsequent intercalation of the surface‐anchored metal–organic framework (SURMOF) components, zinc acetate and 5,10,15,20‐tetrakis(4‐carboxyphenyl)‐porphyrin‐zinc(II) (ZnTCPP), into the layered europium(III) hydroxychloride (LEuH). The formation of the SURMOF clusters intercalated in LEuH is confirmed by X‐ray diffraction, FTIR and Raman spectroscopy, and BET nitrogen absorption methods. The catalytic function of the SURMOF/LEuH hybrid and its components in the model reaction of hydrolysis of bis(4‐nitrophenyl) phosphate in the acidic solution is studied by UV–vis and MALDI‐TOF spectroscopy. Both the non‐intercalated matrix and the MOF powder are inactive and unstable in the substrate solution. Unlike its components, the SURMOF/LEuH hybrid exhibits synergetic catalytic activity increasing with the amount of the intercalated compounds because of the mutual stabilization of the components through coordination interactions. The results provide a basis for symbimetic (mimicking the symbiotic behavior in biological systems) hybrid materials, in which stabilization of functional units in the intercalated structure translates into a synergy of useful properties.     

A study into the macrokinetics of heterogeneous oxidation of coked foams of heat-shielding materials

The testing procedure is given, along with the results of investigations of the macrokinetics of heterogeneous oxidation of coked foam residue of heat-shielding and fireproof materials under conditions of their interaction with a high-enthalpy gas flow. Formulations and methods are suggested for solving direct and inverse problems of heat transfer, as well as of the macrokinetics of heterogeneous ignition. The known time dependence of temperature of the sample surface is used to determine the parameters of external heat transfer and the thermokinetic constants of effective heterogeneous reaction. The results of analysis of sensitivity factors are used to find the time intervals at which the experimental data are most suitable for finding the heat-transfer coefficient and the flow temperature. The suggested investigation procedure is used to determine the macrokinetics of heterogeneous oxidation of coked foam of SGK-1 fireproof coating in an oxygen-containing gas medium.     

Investigation of some specific properties of bulk-looped yarns by the acoustical method

Conclusions The principles for change in certain acoustical characteristics of bulk-looped yarns as a function of the load straightening out the yarn have been demonstrated.It has been found that the core yarn is the channel for propagation of ultrasonic waves.The rate of ultrasound damping can characterize certain specific properties of bulk-looped yarns and thereby help optimize the technological process for preparing them.Translated from Khimicheskie Volokna, No. 1, pp. 33–34, January–February, 1986.     

Use of a domestic hydrogel as an occlusive agent of varicose veins of the lower limbs

The authors propose experimental grounds of the method of surgical correction of the pathological blood flow along varicose subcutaneous veins and the endovasal catheter obliteration of them. The method was used in operations on 70 patients with varicosities of the lower extremity veins at the I and II stages of the disease. No complications or recurrences were noted in the following 1-3 years of observation.