Kinetics of saturation of liquid metal flow with gases

An analysis of the kinetics of gas dissolution in a liquid metal flow is performed. It is shown that due to a high pouring rate and specific surface of the flow, the flow in the arc of molten filler metal, as distinct from the flow of liquid metal during its pouring, leads to intense saturation of the melt with gas.Volgograd Branch of the Novocherkassk Polytechnic Institute. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 64, No. 4, pp. 414–420, April, 1993.     

Alpha blockaders--first or second line antihypertensive agents?

Alpha-receptor blockers reduce blood pressure by blocking of the alpha 1-receptors in the smooth muscle cells in the arteriolar walls. The heart pump function is not disturbed. Most studies have shown that the alpha-receptor blockers induce a reduction in plasma-triglycerides and an increase in the ratio between HDL- and LDL-cholesterol. They do not interfere with the metabolism of electrolytes, glucose or uric acid and have no negative effect on pulmonary function. Although long-term use does not induce a permanent increase in heart rate, some patients respond to initial therapy with faster heart rate and palpitations. The alpha-receptor blockers should not be used in patients with coronary heart disease if the patient is not on chronic beta-blockade. When these precautions are followed, the alpha-blockers can be used as first-line treatment--just like ACE-inhibitors and calcium-antagonists.     

Ignition of powder materials under friction

It is shown that ignition may occur under light frictional pressure. In the case of friction applied to a powder, there are two limits of ignition in terms of the frictional pressure. A frictional approach permits a high degree of compaction of powder at low frictional pressure (∼10 kg/cm²). The influence of the material of the frictional body on sample heating and ignition is investigated. Activation of chemically active powder under the action of friction is observed. A discussion of the results is presented. Institute of Structural Macrokinetics, Russian Academy of Sciences, Chernogolovka. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 6, pp. 14–19, November–December, 1995.     

Crystallization mechanism and characteristics of silicomanganese slag melts used to make glass ceramics (Review)

Translated from Steklo i Keramica, No. 3, pp. 2–5, March, 1993.     

Reconstruction of diffusion coefficients in the problem of carbonitriding

The uniqueness of the determination of carbon and nitrogen diffusion coefficients is found for the process of carbonitriding with complete and abbreviated information on the concentration fields.M. V. Lomonosov Moscow State University, Russia. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 4, pp. 480–483, April, 1994.     

Oxidation of boron silicide and materials based on it

Boron silicide and compounds based on it containing titanium, chromium, nickel, and yttrium and scandium oxides are studied for their oxidation in air from room temperature to 1300°C. It is shown that chromium boride markedly improves the heat resistance of B₄Si over a wide temperature range (700–1300°C) probably as a result chromium-oxide dissolution in borosilicate glass and alteration of its structure. A favorable effect of yttrium and scandium oxides as well of nickel silicide appears at above 100°C as a result of forming complex oxide compounds in the scale.     

Bilateral arachnoid cysts, seizures and severe encephalopathy: case report

A case is presented of a 3 1/2-year-old girl with a clinical picture of very severe psychomotor retardation, autistic behavior, and repetitive convulsive episodes starting in the neonatal period and resistant to any pharmacological treatment. Electroencephalography showed generalized abnormalities. Magnetic resonance imaging of the brain disclosed arachnoid cysts in both temporal fossae with marked hypoplasia of both temporal lobes. It is proposed that the severity of symptoms is related to the magnitude of underlying anatomical lesions as well as the associated intractable epilepsy.     

A self‐correction technique for real‐time simulation of regulated rivers

An automatic self‐correction scheme is presented for online adjustment of stream‐flow forecasts during simulation of river systems with regulating structures, when actual flow data for interior points are available in real time. Another scheme is presented which allows for the modelling of channel losses due to physical effects such as evapotranspiration, bank storage and diversions. A previously developed river simulation/reservoir management model has been modified to include both schemes. The model is particularly useful for real‐time, short‐term flood forecasting and reservoir operation. The model application is made to the Lower Colorado River in Texas.