Subnanometer Analysis and Modeling of MBE Grown InP Based MODFETs

InGaAs/InAlAs double-doped double-strained modulation-doped field-effect transistors OD-SMODFETs)1 were grown by solid source molecular beam epitaxy. The structures were characterized using high resolution x-ray diffraction, Hall effect, and cross-sectional scanning tunneling microscopy. A record two-dimensional electron gas (2DEG) sheet density of 8.5 × 10¹²/cm² and 8.1 × 10¹²/cm² for 300 and 77K, respectively, was achieved. The mobility was 6500 and 12000 cm²/ Vs for 300 and 77K, respectively. To the author’s knowledge,² the previous record 2DEG result was 6.58 × 10¹²/cm². The electron mobility was limited by alloy scattering and interface roughness caused by the presence of “clustering.” Using cross-sectional scanning tunneling microscopy to verify the presence of these clusters, we have the first images of the lattice matched InAlAs (spacer)-InGaAs (quantum well) interface. These images reveal clusters that have approximate spherical or cylindrical shapes with equivalent cubic dimensions ranging from 25 to 45Å.     

Desalination of brackish water by electrodialysis

The performance of an electrodialysis unit comprising interpolymer type cation and anion-exchange membranes developed in this institute in single-stage and two-stage operation for desalting of brackish waters having different total dissolved solids has been studied highlighting the energy requirement and pressure drop under different conditions. For higher salinity waters, a two-stage reduction is advantageous with lower power requirements and power index. The results will be useful for design and installation of ED plants in brackish water sectors.     

Providing mental health care services to Americans.

Summarizes legislation introduced or cosponsored by the author, a US Senator from Minnesota, to respond to Americans' need for mental health services. This legislation included the Medicare Ambulatory Mental Health Services Access Amendments of 1987; S.123, a bill that would amend Part B of the Medicare program to recognize and reimburse psychologists as independent mental health providers; S.763, the Services for Homeless Mentally Ill Individuals Act of 1987; S.809, the Urgent Relief for the Homeless Act; and S.1663, the Child Abuse Prevention Act of 1987. The author encourages mental health professionals to promote public policies that expand Americans' access to public health services through research, effective communication of this research, and preventive mental health efforts (such as programs aimed at preventing teen suicide). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effective parent consultation in play therapy.

Effective communication with caregivers can contribute to successful play therapy outcomes. This article examines the structure of parent consultation in play therapy. The components of effective parent consultation are outlined, from the initial phone interview through termination, to provide guidance to play therapists for communicating with caregivers throughout the therapy process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of terrain orientation and solar position on satellite-level luminance observations

Changes in the luminance of a terrain along the local nadir direction are studied as a function of terrain slope, and the solar azimuth and elevation angles. The digital terrain data for the Santa Clara valley-Mt. Hamilton region of California, available from the U.S. National Cartographic Information Center, are used for this purpose. The elevation above mean sea-level of this selected region varies between 24 and 1,282 m. Luminance computations are performed by assuming the Lommel-Seeliger law of reflection, and the terrain reflectance to be a constant and independent of its geographic location. The atmospheric effects and contributions due to multiple reflections are neglected. It is shown that the ratio of the actual terrain luminance to that for the corresponding flat surface for 64 equal-size (～ 4 km²) finite subregions, changes by a very significant amount over the selected region, and also with changes in the solar position. Selected Landsat MSS band 7 data of the same region are presented for validation purposes.     

Latency–probability functions: A reply to Pike and Dalgleish.

Evaluated A. R. Pike and L. Dalgleish's (see record 1982-11178-001) assertion that certain constraints exist that mitigate D. Weatherburn's (see record 1979-25180-001) arguments against the latency–probability function (LPF) as a basis for evaluating theories of RT. It is concluded that although not every use of the LPF may be inappropriate, its use in evaluating certain theories that are often compared remains of dubious value. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)