The 1995 NRC Ratings of Doctoral Programs: A Hedonic Model

We describe how one can use multivariate regression models and data collected by the National Research Council as part of its recent ranking of doctoral programs (Research-Doctorate Programs in the United States: Continuity and Change) to analyze how measures of program size, faculty seniority, faculty research productivity, and faculty productivity in producing doctoral degrees influence subjective ratings of doctoral programs in 35 academic fields. Using data for one of the fields, economics, we illustrate how university administrators can use the models to compute the impact of changing the number of faculty positions they allocate to the field on the ranking of their programs. Finally, we illustrate how administrators can decompose the differences between a department\u27s rating and the ratings of a group of higher ranked departments in the field into difference due to faculty size, faculty seniority, faculty research productivity, and faculty productivity in producing doctoral students. This decomposition suggests the types of questions that a department and a university should be addressing if they are serious about wanting to improve the department\u27s ranking

Diagnostic system design for the Ion Auxiliary Propulsion System (IAPS). Flight tests of two 8 cm mercury ion

The mechanical, thermal, electrical design and the ground test results of four types of detectors are explained. The DSS is designed to measure the thruster efflux material deposition and S/C potential relative to the local plasma in the vicinity of two 8 cm mercury ion thrusters. The DSS consists of two quartz crystal microbalance (QCM) detectors, one potential probe, nine solar cell arrays, seven ion collectors and two electronic packages

Some studies on the behavior of W-RE thermocouple materials at high temperatures

Bare 0.25 mm diameter W-Re alloy thermoelements (W, W-3% Re, W-5% Re and W-25%) and BeO-insulated W-3% Re and W-25% Re thermoelements were examined for metallurgical, chemical and thermal emf changes after testing for periods up to 1000 hours at temperatures principally in the range 2000 to 2400 K. Environments for the tests consisted of high purity argon, hydrogen, helium or nitrogen gases. Commercially obtained bare-wire thermoelements typically exhibited a shift in their emf-temperature relationship upon initial exposure. The shift was completed by thermally aging the W-3% Re thermoelement for 1 hour and the W-25% Re thermoelement for 2 minutes at 2400 K in argon or hydrogen. Aged thermoelements experienced no appreciable drift with subsequent exposure at 2400 K in the gaseous environments. The chemically doped W3% Re thermoelement retained a small-grained structure for exposure in excess of 50 hours at 2400 K. BeO-insulated thermoelement assemblies showed varied behavior that depended upon the method of exposure. However, when the assemblies were heated in a furnace, no serious material incompatibility problems were found if the materials were given prior thermal treatments. Thermocouples, assembled from aged W-3% Re and W-25% Re thermoelements and degassed sintered BeO insulators, exhibited a drift of only 2 to 3 K during exposure in argon at 2070 K for 1029 hours

An investigation of W-3% Re and W-25% Re thermoelements in vacuum, argon and hydrogen Final report

High vacuum, argon, and hydrogen effects on bare wire rhenium thermoelements at high temperature

High reliability sheathed, beryllia insulated, tungsten-rhenium alloy thermocouple assemblies; their fabrication and EMF stability

Tantalum sheathed, BeO insulated, W-3% Re/W-25% Re thermocouple assemblies were fabricated and their emf drift determined during 2059 hours of exposure at 2073 K in a gaseous helium environment. The sheathed thermocouple assemblies were constructed from aged thermoelements, specially heat-treated BeO insulators, and specially cleaned and etched tantalum sheaths. Their thermal emf drifts ranged from the equivalent of only -0.3 to -0.8 K drift per 1000 hours of exposure at 2073 K. No evidence of any gross chemical attack or degradation of the component materials was found. The emf drift and material behavior of some unsheathed, BeO insulated, W-3% Re/W-25% Re thermocouples at 2250 and 2400 K were also determined. Unsheathed thermocouples tested in an argon environment at 2250 K for 1100 hours and at 2400 K for 307 hours exhibited changes in thermal emf that typically ranged from the equivalent of a few degrees K to as much as +11 K. Post-test examinations of these thermocouples revealed some undesirable material degradation and interaction which included erosion of the BeO insulators and contamination of the thermoelements by tantalum from the tantalum blackbody enclosure in which the thermocouples were contained

Unity And Ministry Through the Massification Of Adventism

The Seventh-day Adventist Church has a history of ministering to people groups who have been fractured from their original congregations or social norms (demassification) and then renew their identity in Adventism (remassification). The unique needs of today’s generations are a rapid remassification of youth groups who need to be discipled. The uniqueness of these youth, their need for parental influence, peer affirmation, and a horizontal leadership structure to enable future mentoring and ministry at minimal cost are a vital part of the cycle of ministry which appears to be currently nonexistent in many Adventist congregations

Emplacement of sandstone intrusions during contractional tectonics

Acknowledgments We acknowledge the support of sponsoring companies of Phase 3 of the Sand Injection Research Group (SIRG). We are very grateful to John Waldron and Jessica Ross for the constructive reviews of the manuscript. We also wish to thank and acknowledge the continuing help and access provided by the Bureau of Land Management.Peer reviewedPostprin

Abradable compressor and turbine seals, volume 1

The application and advantages of abradable coatings as gas-path seals in a general aviation turbine engine were evaluated for use on the high-pressure compressor, the high-pressure turbine, and the low-pressure turbine shrouds. Topics covered include: (1) the initial selection of candidate materials for interim full-scale engine testing; (2) interim engine testing of the initially selected materials and additional candidate materials; (3) the design of the component required to adapt the hardware to permit full-scale engine testing of the most promising materials; (4) finalization of the fabrication methods used in the manufacture of engine test hardware; and (5) the manufacture of the hardware necessary to support the final full-scale engine tests

Abradable compressor and turbine seals, volume 2

The applications and advantages of abradable coatings as gas path seals in a general aviation turbofan engine were investigated. Abradable materials were evaluated for the high pressure radial compressor and the axial high and low pressure turbine shrouds