997 resultados para Plasma (Ionized gases)
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1. Respiratory alkalosis accompanies the clinical syndrome of tetany, precipitates cardiac arrhythmias and predisposes to coronary vasoconstriction. Magnesium plays a critical role in the maintenance of membrane function, and magnesium depletion is often associated with cardiac arrhythmias or vasoconstriction. 2. As technology for detecting circulating ionized magnesium (the most interesting form with respect to physiological and biological properties) is now available in the form of new magnesium-selective electrodes, the effect of respiratory alkalosis induced by voluntary overbreathing for 30 min on circulating ionized magnesium was studied in eight healthy subjects. 3. The total plasma magnesium concentration was not modified by hyperventilation. On the contrary, hyperventilation was associated with a significant reduction in the ionized magnesium concentration of 0.05 (0.02-0.15) mmol/l (median and range) and in the free magnesium fraction of 0.06 (0.01-0.19). During hyperventilation the relative intravascular magnesium mass, calculated from changes in total plasma magnesium concentration and haematocrit, decreased significantly. 4. It is concluded that acute overbreathing reduces the circulating ionized magnesium concentration and the intravascular magnesium mass. It is therefore conceivable that extracellular magnesium deficiency is at least a subsidiary cause of the syndrome of tetany and the cardiac complications that are precipitated by hyperventilation.
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Experimental and theoretical investigations for growth of silicon nanoparticles (4 to 14 nm) in radio frequency discharge were carried out. Growth processes were performed with gas mixtures of SiH4 and Ar in a plasma chemical reactor at low pressure. A distinctive feature of presented kinetic model of generation and growth of nanoparticles (compared to our earlier model) is its ability to investigate small"critical" dimensions of clusters, determining the rate of particle production and taking into account the influence of SiH2 and Si2Hm dimer radicals. The experiments in the present study were extended to high pressure (≥20 Pa) and discharge power (≥40 W). Model calculations were compared to experimental measurements, investigating the dimension of silicon nanoparticles as a function of time, discharge power, gas mixture, total pressure, and gas flow.
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Includes index.
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"These notes are the result of the author's lectures [sic] on plasma physics in the spring term of 1961 at the University of Miami."
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Includes index.
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Includes bibliographical references (p. 24).
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"Prepared for the Air Force Ballistic Missile Division, Headquarters Air Research and Development Command, under contract AF 04 (647)-309, Thermonuclear Propulsion Research."
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"This report was prepared in connection with Space Technology Laboratories Program of General Research."
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"This work was supported by the Air Research and Development Center, Griffis Air Force Base, New York."
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"Prepared for the United States Atomic Energy Commission, under AEC Contract AT (04-3)-321, Plasma Turbulence Research."
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"Prepared for the Air Force Ballistic Missile Division, Headquarters Air Research and Development Command, under contract AF 04(647)-309, Thermonuclear Propulsion Research."
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At head of title: PRL-9-23.
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"RADC TN 61-150.
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"Prepared for the Air Force Ballistic Missile Division, Headquarters Air Research and Development Command, under Contract AF 04(647)-309, Thermonuclear Propulsion Research."