Particle line shape after γ-ray emission in flight

Line shapes broadened by theγ-ray emission are described in the coordinate frame, in which a quantization axis is chosen to be the direction of the center of mass scattering angle of a decaying nucleus. In this coordinate frame the line shapes can be described only by diagonal density matrix elements for finite values of kinematic factork. The method of this analysis has been applied to the single and mutual excitations of the first 2⁺ state of¹²C in the¹²C+¹²C inelastic scattering.     

Arsenobetaine as the major arsenic compound in the muscle of two species of freshwater fish

The chemical form of arsenic contained in the muscle of certain freshwater fish was examined using cultured specimens of rainbow trout (Salmo gairdneri) and wild specimens of Japanese smelt (Hypomesus nipponensis). More than 95% of the total arsenic of both species was extracted with methanol and recovered in the water-soluble fraction. The major arsenic compound of both species was purified by cation-exchange chromatography on Dowex 50, gel filtration on Bio-Gel P-2 and HPLC on Asahipak GS-220H. Behavior in the above purification procedure and analyses of the purified compounds by HPLC–ICP and TLC confirmed that the major arsenic compound of both species was arsenobetaine. Arsenobetaine found in cultured rainbow trout seems to be derived from the commercial assorted feed containing arsenobetaine as the major arsenical. On the other hand, the result with wild Japanese smelt suggested that arsenobetaine is a naturally occurring compound in the freshwater environment.     

Core-excited states of Fe from the Fe(p, t)Fe reaction at 52 MeV

The perturbation theory for projected states is applied to the two-level pairing force model. Both approximate and exact forms of number projection are considered. The results are compared with the exact ones and with ordinary perturbation theory based on BCS wave functions without projection.     

Interdependence of Anion and Cation Exchanges in Calcium Hydroxyapatite: Pb(2+) and Cl(-)

The ion exchange of Pb(2+) and Cl(-) into calcium hydroxyapatite from aqueous solutions is studied at 293 K. Although the exchange of Cl(-) into CaHAp and PbHAp was not observed, in the presence of both Pb(2+) and Cl(-) in aqueous solution the exchange of both Pb(2+) and Cl(-) into CaHAp occurred, and, at least at intermediate concentrations of HCl, a proportionality between the sorbed quantities of these two ions was observed. The dissolution of CaHAp is shown to be dependent upon the pH, while the quantity of Pb(2+) exchanged into the solid is not a function of the proton content; consequently, the exchange is not primarily a dissolution-precipitation process. Copyright 1999 Academic Press.     

The oxidation of ethane in the presence and absence of tetrachloromethane on calcium hydroxyapatites with incorporated lead

The oxidative dehydrogenation of ethane has been investigated on various lead-added calcium hydroxyapatites and the effect of the addition of tetrachloromethane (TCM) into the feedstream has been examined. The catalysts are stable up to 873 K but are converted to the corresponding phosphates at approximately 973 K. The conversions of ethane and the selectivities to C₁ and C₂ compounds were found to be dependent on the lead contents of the catalysts, both the pretreatment and reaction temperatures, the presence of TCM and the times-on-stream as well as the structural forms of the catalysts. In the absence of TCM the conversion of ethane and the various selectivities show a dependence on the lead content of the catalysts which is similar at 773 and 873 K, but dissimilar at 973 K due, at least in part to the formation of the phosphates at the latter temperature. With TCM in the process feedstream the influence of the chlorapatites which are formed overrides that of the added lead.