p+-n-p+ BARITT-diode design

p+-n-p+ BARITT diodes have been designed to give maximum output power at X band frequencies. Computed output power against frequency shows good agreement with measured powers. The dominant effect of the maximum n region electric field on output power is demonstrated.     

The turnaround on pornography research: Some implications for psychology and women.

Psychologists have recently attacked the US Attorney General's Commission on Pornography. They have argued that its report overgeneralized from available studies on the harmful consequences of pornographic materials and tended to unfairly single out pornographic materials for their potential to contribute to subsequent violence against women. Yet, when the results of available studies, as well as earlier statements of pornography researchers, are examined, the Commission's basic assumptions about pornography as a factor in violence against women appear substantially correct. Some implications are outlined, including the role that social science should play in this issue. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of thermal imagery in defining frost prone areas in the Niagara fruit belt

Surface temperatures in the Niagara fruit belt measured with a thermal scanner flown at altitudes of 600 m, 2000 m and 5000 m, were utilized to examine the feasibility of using thermal imagery to define frost prone zones during spring radiation frost conditions. Results show that, within a test area in the vicinity of Vineland, Ontario, as well as for the entire Niagara escarpment area from Grimsby to Niagara Falls, a number of zones of different temperature are defineable. It was found that a potential frost prone zone exists below the escarpment in an area considered to be relatively free of such events.     

School psychologists as consultants: Issues in training, practice, and accountability.

From contemporary research and theory in mental health consultation, implications are drawn for the development of an indirect service role for school psychologists. Attention is given to the need for training school psychologists in consultation skills, to the obstacles encountered in the initiation of consultative relationships, and to methods for assessing efficiency and effectiveness of a variety of consultative activities. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fluid flow through a solid-liquid dendritic interface

Fluid flow through a dendritic solid-liquid interfacial zone, during solidification, has been observed in a series of Sn-Pb alloys. It was found that liquid penetrates only a short distance into the zone, relative to the total thickness of the zone. The amount of solid present at the point of maximum penetration varies from 12 to 22 pct, and depends on the alloy concentration. Flow due to volume shrinkage, thermal convection, or solute convection well inside the zone, was not detected. Fluid flow through a wire mesh model of a thin section of the solid-liquid dendritic zone was examined. The results are not in agreement with that predicted for flow through a porous barrier, which had been found applicable to interdendritic fluid flow. Formerly Graduate Student, University of British Columbia, Vancouver, British Columbia, Canada     

Heat capacities of Ar,Ne,4He-Ar,and4He-Ne films adsorbed on Cu at low temperatures

Heat capacities of Ar and Ne monolayers adsorbed on Cu are measurable at 1–4 K. Temperature dependences are similar to the low-temperature law for harmonic oscillators, but the empirical characteristic temperatures of 11–15 K are much lower than can correspond to independent adatoms oscillating in substrate sites. The magnitudes and temperature dependences do not match those predicted for surface modes of an absorbent coated with inert impurities or for the collective modes of epitaxial films. A model involving the excitations in non-epitaxial films appears to offer an explanation of the observed magnitudes and temperature dependences. The heat capacities of⁴He adsorbed on preplated Ar or Ne show little variation with the number of Ar layers, or between Ar and Ne coatings.Research supported by The National Science Foundation.     

Properties of compensated GaAs light-emitting diodes following 60Co irradiation

The effect of gamma radiation on the light-emitting properties of compensated GaAs electroluminescent diodes has been investigated. For gamma doses up to 10⁸ rads(Si), a large exponential reduction in the external quantum efficiency is observed, accompanied by a small reduction in the total carrier lifetime. These results are consistent with a model wherein two different defects are introduced through irradiation. These defects in addition to increasing the number of nonradiative recombination centers can also degrade the radiation process directly. Isochronal annealing data on these irradiated diodes suggest that the defect responsible for degrading the radiative process anneals below 300°C, but that the defect responsible for decreasing the nonradiative lifetime is relatively unaffected. The exponential reduction of efficiency with irradiation, including an observed shift of spectral emission peak, as well as the annealing characteristic seen in these diodes suggests that the defect responsible for degrading the radiative process might be similar to the luminescent killer center associated with an arsenic vacancy.