An Ultrasonic Sensor for Process Modeling and Proces Control of Ceramic Superconductors
This research demonstrates the feasibility of utilizing nondestructive ultrasonic sensors to monitor the effects of oxygen content, processing time and temperature on the resultant mechanical, structural, and electrical properties of high temperature ceramic superconductors. Ultrasonic velocity changes, as a function of processing time and temperature, have clearly been shown to indicate the transformation between orthorhombic and tetragonal phases in Y-Ba-Cu-O.
Eighty consecutive cases of gamete intra-fallopian transfer.
Eighty patients with the main problems of unexplained infertility, oligospermia and endometriosis were treated with gamete intra-Fallopian transfer (GIFT). From 80 treatment cycles, 29 women conceived (36.3%). Of these, four were biochemical pregnancies and therefore the clinical pregnancy rate (25/80) was 31.2%. There were six sets of multiple pregnancies, a multiple pregnancy rate of 24%. Three women (12%) miscarried. The pregnancy rates in the patients with unexplained infertility, oligospermia and endometriosis were 33.3, 16.7 and 38.5%, respectively. The transfer of four oocytes appears to increase the pregnancy rate without increasing the risk of multiple pregnancy. The presence of in-vitro fertilization of excess oocytes after GIFT did not correlate with the final outcome of GIFT.
The electrical conductivity of LiNbO3
Abstract The electrical conductivity of single crystals of LiNbO3 was measured under various pressures of oxygen below 1 atm and up to temperatures of about 1400°K. Experiments yield an exponential slope of σ versus 1/T for constant oxygen pressures, which can be related to an activation energy of 2.15 eV. The dependence of the conductivity on oxygen pressure σ ∝ p o 2 -1 4 may be attributed to singly ionized oxygen vacancies. The activation energy then is half the sum of the heat of formation of vacancies and the ionization energy. Experiments using stoichiometric LiNbO3 yield evidence for a considerable fraction of ionic conductivity.