Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.     

Cryoscopic studies in molten salts. Dissociation state of some alkali isopolymolybdates and some related molybdenum(VI) compounds in molten K2Cr2O7and KNO3

The dissociation state of the solutes M₂MoO₄, M₂Mo₃O₁₀, M₂Mo₄O₁₃, M₂Mo₅O₁₆ (MRb or Cs), Na₂CrO₄·MoO₃, K₂CrO₄·2 MoO₃, Cr₂Mo₃O₁₂ and V₂MoO₈ was studied cryoscopically in molten K₂ Cr₂O₇ and KNO₃ solvents. The freezing point depression, ΔT, of the solvents was obtained by measuring the cooling curves of the binary salt mixtures over unlimited range of solute concentration. The number of foreign ions obtained ν, showed that the solutes were either simply dissociated in the melt into the probable stable species (MoO₄)^2?, (Mo₃O₁₀)^2?, (Mo₄O₁₃)^2? and (Mo₅O₁₆)^2? or, in some cases after reactions and rearrangements, into (CrMo₂O₁₀)^2? heteropolyions. The solute V₂MoO₈, on the other hand, was found to dissolve without any apparent dissociation. An agreement between the experimental and calculated values of activity, a, based on the Temkin and Random Mixing models and that of Van't Hoff's equation support the proposed simple dissocia- tion scheme for K₂Cr₂O₇Cs₂MoO₄ system.     

Solid Reactions of Egyptian Kaolin towards Ni(II). II

The solid reactions between Kaolin of particle size 37 and 74μ and NiO in different mole ratios were performed at two temperatures, viz., 900 and 1100°C. The effect of the three parameters: concentration, particle size and temperature was studied spectrophotometrically and by x-ray diffractometry. The identified resulting phases are mainly the green spinel NiAl₂O₄, together with free SiO₂ and mullite Al₆Si₂O₁₃.     

On right G-semilocal rings

The notion of semilocal ring is extended to the classes of right G-semilocal and right N-semilocal rings. We explore the algebraic properties of such classes and study their relations with many other rings such as clean, exchange and I-finite rings. Localization of right G-semilocal rings is considered.     

Causal loop diagrams as a de-escalation technique

Escalation of commitment, the tendency of decision makers to keep on investing in losing courses of action, has been shown to be a costly decision bias that affects many areas of decision making. Even though escalation is a widely studied phenomenon, there has been comparatively little research on how to avoid this bias. The present study focuses on de-escalation of commitment and proposes that causal loop diagrams (CLDs) can help to decrease escalating commitment to a failing course of action. By means of an experiment, this study shows that using a CLD decreases escalation tendencies.     

Separation of carrier-free 64,67Cu radionuclides from irradiated zinc targets using 6-tungstocerate(IV) gel matrix

Summary A procedure for the separation of ^64,67Cu radioisotopes from irradiated natural zinc targets was developed. Production of ^64,67Cu was carried out using ^64,67Zn(n,p)^64,67Cu reactions by fast neutron bombardment of natural zinc targets at The Second Egyptian Research Reactor (ETRR-2). The sorption behavior of ⁶⁵Zn and ^64,67Cu ions in HCl acid solutions showed high affinity of Cu ions towards 6-tungstocerate(IV) gel matrix compared with Zn ions. Carrier-free ^64,67Cu radionuclides were separated from ⁶⁵Zn on 6-tungstocerate(IV) column matrix by eluting the column with 10 ml 0.001 and 1M HCl acid solutions. The separated ^64,67Cu radionuclides were of high chemical, radiochemical and radionuclidic purity.