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PROCESSING OF SODIUM--POTASSIUM NIOBATE CERAMICS.

Description: Sintering studies of undoped (Na{sub 0.5}K{sub 0.5})NbO{sub 3} and the same material doped with 1/2, 1, 2, and 4 mole percent BaO and 2 mole % B{sub 2}O{sub 3} were made. The persistence of a second phase after calcining to form the compound led to a study of reactions occurring during calcination. The calcining of sodium-potassium niobates involves the formation of an intermediate compound (the second phase) and its subsequent reaction with sodium oxide and potassium oxide to form (Na{sub 0.5}K{sub 0.5})NbO{sub 3}. Sintering data show that up to 1/2 mole % BaO added to the system increases the initial densification. However, the sintered bodies then exhibit densification and form sharp cubic grains and large voids. Indications are that a liquid phase is the major contributor to densification of this system through the mechanism of particle rearrangement, and that the contribution of any sintering mechanism to densification is negligible.
Date: January 1, 1971
Creator: Powell, B.R. Jr.
Partner: UNT Libraries Government Documents Department

Rubidium-81 used as a myocardium imaging agent

Description: From 11th international annual meeting of the German Society of Nuclear Medicine; Athens, Greece (24 Sep 1973). Rubidium-81 is a new myocardial imaging agent with an ideal T/sub 1/2 of 4.6 hr and energies acceptable for gamma-camera viewing. The target-to-nontarget ratio for heart image to background in the projection images is usually less than 2: 1, thus good statistics are necessary to delineate lesions. The low radiation dose and availability of this isotope allow one to obtain 6 to 10 times the data, and /sup 81/Rb is probably superior to /sup 129/Cs and /sup 43/K for myoca rdial imaging if adequate collimation is present. (auth)
Date: September 1, 1973
Creator: Budinger, T.F.; Yano, Y. & McRae, J.
Partner: UNT Libraries Government Documents Department

Search for Pomeron--Pomeron-2$pi$ events in 205 GeV/c $pi$$sup -$p interactions

Description: Pomeron- pomeron-2 pi vertices were sought in the reaction pi /sup -/p yields pi /sup -/ pi /sup +/ pi /sup -/p at 205 GeV/c. From a sample of 1 86 of these events, about 2/3 were extracted for which the rapidity ordering of the four outgoing particles makes them candidates for the double-Pomeron exchange process (i.e., the fastest and the slowest particle are respectively a pi /sup -/ and a proton). A separation from single-Pomeron processes was attempted with the help of a rapidity triangle plot. The number of possible double-Pomeron-type events was also estimated from a Regge-propagator fit to the nonhomogeneous distribution of the events within this triangle. The number of such events obtained by either method gives a cross section upper limit of 85 mu b for double-Pomeron exchange, consistent with the predictions of a pion-pole dominance model. (auth)
Date: August 1, 1973
Creator: Chew, D.M.; Abrams, G.S. & Bingham, H.H.
Partner: UNT Libraries Government Documents Department

Comparison of elementary geothermal-brine power-production processes

Description: From applied technology geothermal committee meeting; Idaho Falls, Idaho, USA (7 Aug 1973). A comparison of three simple geothermal power- production systems shows that the flashed steam and the compound systems are favored for use with high-temperature brines. The binary system becomes economically competitive only when used on low-temperature brines (enthalpies less than 350 Btu/lb). Geothermal power appears to be economically attractive even when low-temperature brines are used. (auth)
Date: August 1, 1973
Creator: Green, M.A. & Laird, A.D.K.
Partner: UNT Libraries Government Documents Department