High oxygen conductivities can be achieved in cation ordered LnxZrl_=O2_l x (Ln=Gd, Nd) solid solutions with pyrochlore (P) structure. High values of the pre-exponentlal factor °o are correlated with the degree of anion disorder in the 8b oxygen sublattice (neutron diffraction). The activation energy AH is lowered by cation ordering (F-P transition; effect of x) due to the occurence of a prefer...

Seven-membered lactones undergo selective SmI2 -H2 O-promoted radical cyclization to form substituted cyclooctanols. The products arise from an exo-mode of cyclization rather than the usual endo-attack employed in the few radical syntheses of cyclooctanes. The process is terminated by the quenching of a chiral benzylic samarium. A labeling experiment and neutron diffraction study have been used...

Introduction There is a growing interest in determining the concentration of various elements in food spices. In the present study, the instrumental neutron activation analysis (INAA) was employed to measure the trace elements in 11 commonly food spices consumed in Tehran, Iran. Materials and Methods The levels of K, Mn, Na, Cl, V, Br, Al, and As were determined and their effects on human healt...

The reliability of neutron-induced prompt gamma-ray analysis (PGA) was examined for the determination of Na and Mg in geological and cosmochemical rock samples, because they tend to have been erroneously determined for such samples. JB-1 (basalt standard rock) and Allende (chondritic meteorite) powder samples were repeatedly analyzed by using thermal or cold neutron-guided beams of the JRR-3M r...

Two markers of regional exchange in the Eastern Mediterranean during the first millennium BCE are the White Painted and Bichrome Wares from Cyprus's Cypro-Geometric and Cypro-Archaic periods. Although these ceramics are often assumed to be imports from Cyprus, excavations in southern Turkey at sites such as Tarsus-Gözlükule, Kilise Tepe, Sirkeli Höyük, and Kinet Höyük suggest that at least some...

The particle size and quantity of a plutonium dioxide surrogate escaping an open front hood during routine work was measured. Aerosols were collected using a cascade impactor, and the amount of surrogate on each stage of the impactor was measured using neutron activation analysis. The aerodynamic mass median diameter of particles in the breathing zone of a worker was found to be 0.35 ± 5.1 μm. ...

Sequential measurements of total body calcium by in-vivo neutron activation analysis were made in five patients treated with corticosteroid drugs for severe inflammatory disease. No evidence of osteoporosis was seen to develop during the course of 20-33 months of study. In one case a substantial rise in total body calcium was found.

Ruthenium, silver, rhenium, osmium, iridium, platinum and gold in standard rock samples from Geological Survey of Japan (JB-1, JB-2, JG-1 and JA-1) were determined by thermal neutron activation method with a systematic chemical separation. U.S. Geological Survey standard rocks (BCR-1 and G-2) were also analyzed to obtain an information about the accuracy and precision on the method. Generally a...

Taking the necessary precautions essential for accurate trace element analysis, the zinc concentrations of 227 samples of amniotic fluid taken at term were determined by means of neutron activation analysis. Half of the zinc was found to be bound to the particles present in amniotic fluid. In the control group (123 cases) the zinc concentrations ranged from 25—261 g/l for untreated samples and ...