Refractories for the slide gates for molten steel

Conclusions A variety of refractories were subjected to testing in the slide gate of a 3-ton ladle. Nonoxygenous refractories are unsuitable for steel casting either because their thermal conductivity is too high or because they are not strong enough. Oxygen-containing materials developed cracks during the pouring operation so that they could be used only once.The refractories recommended for testing in a large-capacity ladle were periclase. corundum, and zircon types.The best results were obtained with periclase plates which permitted an entire melt to be poured within 1.5 h, during which the jet of molten steel was shut off 23 times.Translated from Ogneupory, No. 7, pp. 34–38, July, 1976.     

Preparation of composite fibres based on fluoroplastic and graphitic carbon fillers,and their electrical properties

Institute of Synthetic Polymeric Materials, Moscow. Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 3, pp. 48–50, May–June, 1992.     

Wounds of the heart

The frequency of wounds of the heart as the cause of lethal outcomes on the battle-field practically has not changed during the recent 50 years and is equal to 80%. At the same time, the danger of such complications as infectious endocarditis has increased. The author's experience with surgical treatment of gunshot wounds of the heart makes 85 cases. Symptoms of intracardiac infection were detected in 74% of the wounded, 52 of them having the septic form. Operations were performed under artificial circulation. They included the extraction of foreign bodies, complex sanitation of the heart chambers and recovery of intracardiac hemodynamics. There were no lethal outcomes in the nearest postoperative period. Success of the treatment depends on terms of delivery of the patient to the hospital, quickness of surgical intervention and adequate intensive therapy.     

Unusual photoelectric properties of polymeric composites containing heteropolynuclear complexes of transition metals

Composites based on acrylonitrilebutadienestyrene and poly-N-epoxypropylcarbazole doped with heteropolynuclear copper complexes were synthesized. The electric and photoconductive properties of films of these composites are studied. The absorption and internal photoelectric effect in the visible region of the spectrum are controlled by the d-d transitions of Cu (II) ions. Positive and anomalous negative photoconductivity effects were detected in films of these composites. Unusual photoelectric properties can be caused by nonequilibrium-carrier capture by deep traps near the boundaries of the associations of structurally different complexes. The negative photoconductivity effect is leveled, and film photosensitivity increases as an additional channel of excess hole transport is formed using poly-N-epoxypropylcarbazole. A phenomenological model of the photo-conductivity kinetics that explains the experimental results, is suggested.