Neotectonics of the southern Amargosa Desert, Nye County, Nevada and Inyo County, California (open access)

Neotectonics of the southern Amargosa Desert, Nye County, Nevada and Inyo County, California

A complex pattern of active faults occurs in the southern Amargosa Desert, southern Nye, County, Nevada. These faults can be grouped into three main fault systems: (1) a NE-striking zone of faults that forms the southwest extension of the left-lateral Rock Valley fault zone, in the much larger Spotted Range-Mine Mountain structural zone, (2) a N-striking fault zone coinciding with a NNW-trending alignment of springs that is either a northward continuation of a fault along the west side of the Resting Spring Range or a N-striking branch fault of the Pahrump fault system, and (3) a NW-striking fault zone which is parallel to the Pahrump fault system, but is offset approximately 5 km with a left step in southern Ash Meadows. These three fault zones suggest extension is occurring in an E-W direction, which is compatible with the {approximately}N10W structural grain prevalent in the Death Valley extensional region to the west.
Date: May 1, 1991
Creator: Donovan, D.E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Tritium technology programs in the United States (open access)

Tritium technology programs in the United States

Tritium technology in the United States has advanced considerably since the 1988 Tritium Conferences in Toronto. This advance has come in facilities, processing and safety related technologies and in an ever increasing commitment to compliance related issues. The major laboratories in the US tritium programs continue to be (Westinghouse) Savannah River Site, EG G Mound, Lawrence Livermore National Laboratory, Sandia National Laboratory and the Los Alamos National Laboratory. Each of these Laboratories have made some significant changes in their programs and/or facilities in the past four years. 11 refs, 1 fig.
Date: January 1, 1991
Creator: Anderson, J. L.
Object Type: Article
System: The UNT Digital Library
Effects of Vegetation on Radon Transport Processes in Soil (open access)

Effects of Vegetation on Radon Transport Processes in Soil

A large component of radon entry cannot be explained by pressure differences between the soil and inside the structures. The persistence of this radon entry even when the house is pressurized by 1 Pa indicates that it must be due to molecular diffusion. The radon entry rate as measured by accumulators below ground level (soil + concrete) is roughly 2 times greater than that measured above ground level (concrete alone). The soil permeability is about 10{sup {minus}12} m{sup 2} and does not change dramatically with depth down to 2 m. The diffusion component of radon entry is reduced by about 30% when the floor wall joint is sealed. The Rn3D model is operating on our computer system and is being modified to accommodate the geometrical configurations of the underground test structure.
Date: January 1, 1991
Creator: Borak, T.B.
Object Type: Report
System: The UNT Digital Library
Role of Polycrystallinity in Cdte and Cuinse Sub 2 Photovoltaic Cells (open access)

Role of Polycrystallinity in Cdte and Cuinse Sub 2 Photovoltaic Cells

The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.
Date: January 1, 1991
Creator: Sites, J.R. (Colorado State Univ., Fort Collins, CO (United States))
Object Type: Report
System: The UNT Digital Library
Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter) (open access)

Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter)

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.
Date: January 1, 1991
Creator: Williams, R.M.; Jeffries-Nakamura, B.; Underwood, M.L.; Ryan, M.A.; O'Connor, D. & Kikkert, S.
Object Type: Article
System: The UNT Digital Library
Regional aerosol deposition in human upper airways (open access)

Regional aerosol deposition in human upper airways

During the current report experimental studies of upper respiratory deposition of radon progeny aerosols and stimulant aerosols were carried out in replicate casts of nasal and oral passages of adults and children. Additionally, preliminary studies of nasal passage deposition of unattached Po{sup 218} particles was carried out in four human subjects. Data on nasal inspiratory deposition in replicate models of adults and infants from three collaborating laboratories were compared and a best-fit curve of deposition efficiency for both attached and unattached particles was obtained, showing excellent inter-laboratory agreement. This curve demonstrates that nasal inspiratory deposition of radon progeny is weakly dependent upon flow rate over physiologically realistic ranges of flow, does not show a significant age effect, and is relatively independent of nasal passage dimensions for a given age range. Improved replicate models of the human adult oral passage extending to the mid-trachea were constructed for medium and higher flow mouth breathing states; these models were used to assess the deposition of unattached Po{sup 218} particles during oronasal breathing in the oral passage and demonstrated lower deposition efficiency than the nasal passage. Measurements of both Po{sup 218} particle and attached fraction particle size deposition were performed in replicate nasal passage …
Date: November 1, 1991
Creator: Swift, David L.
Object Type: Report
System: The UNT Digital Library
Spectroscopic diagnostics of high temperature plasmas, January 1, 1991--December 31, 1991 (open access)

Spectroscopic diagnostics of high temperature plasmas, January 1, 1991--December 31, 1991

During 1991, the activities of the John Hopkins University Plasma Spectroscopy Group have covered several areas of research, in the domain of XUV spectroscopy of magnetically confined fusion plasmas. While the main effort concentrated on the development of novel diagnostics which utilize Layered Synthetic Microstructures (LSMs) as the dispersive/filtering elements, work has been done in the area of detector development and the physics of the tokamak edge plasma. An XUV monochromator for the 20--200{Angstrom} range, which uses flat LSMs, has been built and is currently operated on the D3-D tokamak at General Atomics in San Diego. A design for a follow-up experiment at D3-D is now in progress. As a preliminary step toward tokamak plasma imaging in the XUV wavelength range using curved LSM coated substrates, a prototype XUV camera was built and operated in our laboratory in image the A1 3 emission at {lambda}-175{Angstrom} from a Penning Ionization Discharge plasma. Based on these laboratory results, the design of the XUV camera, which will image plasma in the Phaedrus T tokamak O VI emission (150{Angstrom}), has been completed. This instrument is presently under construction. Also a detailed design of a system composed of four LSM based imaging devices for N{sub …
Date: December 31, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter) (open access)

Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter)

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double_prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.
Date: December 31, 1991
Creator: Williams, R. M.; Jeffries-Nakamura, B.; Underwood, M. L.; Ryan, M. A.; O`Connor, D. & Kikkert, S.
Object Type: Article
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. Technical Progress Report, April 1, 1991--June 30, 1991 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. Technical Progress Report, April 1, 1991--June 30, 1991

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain data useful to develop a process more economic than existing processes and to report all findings. Quarter summary: all modifications previously planned where completed and a reaction experiment was run. A couple design flaws were discovered, improvements were designed, and all parts are expected in the first week of July. Experiment {number_sign}6 is expected to run the following Monday. Barring further mishap, experiments will be run one each week thereafter. The project is behind schedule, but the project is well positioned to make significant and considerable progress.
Date: December 1, 1991
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991 (open access)

Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.
Date: December 31, 1991
Creator: Sites, J. R.
Object Type: Report
System: The UNT Digital Library
Disposal of chemical agents and munitions stored at Pine Bluff Arsenal, Pine Bluff, Arkansas. Final phase 1, Environmental report (open access)

Disposal of chemical agents and munitions stored at Pine Bluff Arsenal, Pine Bluff, Arkansas. Final phase 1, Environmental report

The Pine Bluff Arsenal (PBA) near Pine Bluff, Arkansas, is one of eight continental United States (CONUS) Army installations where lethal unitary chemical agents and munitions are stored and where destruction of agents and munitions is proposed under the Chemical Stockpile Disposal Program (CSDP). The chemical agent inventory at PBA consists of approximately 12%, by weight, of the total US stockpile. The destruction of the stockpile is necessary to eliminate the risk to the public from continued storage and to dispose of obsolete and leaking munitions. In 1988 the US Army issued a Final Programmatic Environmental Impact Statement (FPEIS) for the CSDP that identified on-site disposal of agents and munitions as the environmentally preferred alternative (i.e., the alternative with the least potential to cause significant adverse impacts). The purpose of this report is to examine the proposed implementation of on-site disposal at PBA in light of more recent and more detailed data than those on which the FPEIS is based. New population data were used to compute fatalities using the same computation methods and values for all other parameters as in the FPEIS. Results indicate that all alternatives are indistinguishable when the potential health impacts to the PBA community are …
Date: September 1, 1991
Creator: Ensminger, J. T.; Hillsman, E. L.; Johnson, R. D.; Morrisey, J. A.; Staub, W. P.; Boston, C. R. et al.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain data useful to develop a process more economic than existing processes and to report all findings. The technical progress of the project is reported. The project status is that the solutions to the problems discussed in the third quarter status, were found to function satisfactorily. Future needs have been considered, and appropriate equipment and instrumentation changes have been designed. Only one experiment was performed this quarter, with some improvement over the previous experiments. The increase in shale oil recovery followed directly from the changes discussed last quarter, but the improvement could have been larger with wider-spread implementation of the changes. Equipment was purchased to rectify the need, and will be installed shortly. Further, a minor change in the design was necessary to account for the brittleness of high temperature electrical resistance heating tapes. The focus of the work this quarter has been on the development of computer software to enable the use of on-line parameter identification, the design of the instrumentation necessary to adequately …
Date: December 31, 1991
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Escarpment seeps at Shiprock, New Mexico. [Risk posed by seep water to human health and the environment] (open access)

Escarpment seeps at Shiprock, New Mexico. [Risk posed by seep water to human health and the environment]

The purpose of this report is to characterize the seeps identified at the Shiprock UMTRA Project site during the prelicensing custodial care inspection conducted in December of 1990, to evaluate the relationship between the seeps and uranium processing activities or tailings disposal, and to evaluate the risk posed by the seep water to human health and the environment. The report provides a brief description of the geology, groundwater hydrology, and surface water hydrology. The locations of the seeps and monitor wells are identified, and the water quality of the seeps and groundwater is discussed in the context of past activities at the site. The water quality records for the site are presented in tables and appendices; this information was used in the risk assessment of seep water.
Date: October 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library