The Certification of Standard Reference Material 1979: Powder Diffraction Line Profile Standard for Crystallite Size Analysis
Abstract not provided
Engineering topics
Publications and source records attributed to Black, David.
Abstract not provided
This report includes the results of monthly inspections and monitoring for January, February, and March 2020. Monthly inspections and monitoring were conducted on January 15, February 12, and March 17, 2020. Inspections include a visual assessment of the berms, ponding, water levels relative to the overflow pipes, tunneling or burrowing into the berms, soil conditions on and around the berms, erosion or sloughing of the slopes of the berms, seeps at the toe of the berms, deep-rooting botanicals on the berms, and fencing. Monthly monitoring includes measurements of the instantaneous flow rate, hydrogen ion activity (pH), and specific conductance of the E-Tunnel Wastewater Disposal System discharge.
This report includes the results of monthly inspections and monitoring for October, November, and December 2019. Monthly inspections and monitoring were conducted on October 15, November 26, and December 18, 2019. Inspections include a visual assessment of the berms, ponding, water levels relative to the overflow pipes, tunneling or burrowing into the berms, soil conditions on and around the berms, erosion or sloughing of the slopes of the berms, seeps at the toe of the berms, deep-rooting botanicals on the berms, and fencing. Monthly monitoring includes measurements of the instantaneous flow rate, hydrogen ion activity (pH), and specific conductance of the E-Tunnel Wastewater Disposal System (ETDS) discharge. Annual sample results of the effluent water from the ETDS are also included in this report. The effluent sample was collected on September 11, 2019, and analyzed for the parameters listed in Table 1-B of Permit NEV 96021. In addition, Permit NEV 96021 requires the collection and analysis of representative groundwater samples from Well ER 12-1 every 24 months. This summary report provides the information pertaining to the sampling and analysis of groundwater samples collected on April 10, 2019.
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Environmental monitoring data are collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) within the Nevada National Security Site. This report summarizes the 2018 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment activities.
This report describes research undertaken by USRA scientists working in the NASA Space Science Directorate laboratories at Goddard Space Flight Center.
The mission of this activity, know as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, USRA recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members.
The mission of this activity, known as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, the Universities Space Research Association (USRA) recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members. This paper is the final report from this now completed Cooperative Agreement.
The Universities Space Research Association received an award of Cooperative Agreement NCC5-356 on September 29, 1998. The mission of this activity, known as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, USRA recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members.
High resolution X-ray diffraction images of two directly comparable crystals of lead tin telluride, one Bridgman-grown on Space Shuttle STS 61A and the other terrestrially Bridgman-grown under similar conditions from identical material, present different subgrain structure. In the terrestrial, sample 1 the appearance of an elaborate array of subgrains is closely associated with the intrusion of regions that are out of diffraction in all of the various images. The formation of this elaborate subgrain structure is inhibited by growth in microgravity.
Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non-diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space.
The evolution of the Astrometric Telescope Facility (ATF) proposed for use on NASA's Space Station is traced and its design characteristics are presented. With a focal plane scale of 12.7 arcsec/mm, the strawman design has a field size of 10 sq arcmin and a limiting visual magnitude fainter than 16. Output from an observation includes the X and Y coordinates of each star and its relative brightness.
The authors profile the field of astronomy, identify some of the key scientific questions that can be addressed during the decade of the 1990's, and recommend several facilities that are critically important for answering these questions. Scientific opportunities for the 1990' are discussed. Areas discussed include protoplanetary disks, an inventory of the solar system, primitive material in the solar system, the dynamics of planetary atmospheres, planetary rings and ring dynamics, the composition and structure of the atmospheres of giant planets, the volcanoes of IO, and the mineralogy of the Martian surface. Critical technology developments, proposed projects and facilities, and recommendations for research and facilities are discussed.