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Application and state of development for remote chemical sensors in environmental monitoring: A literature review (open access)

Application and state of development for remote chemical sensors in environmental monitoring: A literature review

A study was performed on chemical sensor technology currently available and under development. The information was compiled into a format wherein information on the sensors is listed in a comparable manner. As introductory section is provided to illustrate the regulatory environment in which such sensor technology will be used. This information should allow corporations or federal agencies ready access to useful information for the potential licensing of sensor technology for commercial development or specific environmental monitoring operations. Although every attempt was made to identify as many chemical sensors as possible, we recognize that some may be missed inadvertently. The accuracy of the information provided by the various sources regarding the state of development for the various sensors was not verified. Judgments or opinions regarding the actual state of development or utility of these devices are not included in this report. However, we feel that this report accurately reflects the state of the art at the present time.
Date: September 1, 1991
Creator: Schabron, J.F.; Niss, N.D. & Hart, B.K.
Object Type: Report
System: The UNT Digital Library
Application and state of development for remote chemical sensors in environmental monitoring: A literature review (open access)

Application and state of development for remote chemical sensors in environmental monitoring: A literature review

A study was performed on chemical sensor technology currently available and under development. The information was compiled into a format wherein information on the sensors is listed in a comparable manner. An introductory section is provided to illustrate the regulatory environment in which such sensor technology will be used. This information should allow corporations or federal agencies ready access to useful information for the potential licensing of sensor technology for commercial development or specific environmental monitoring operations. Although every attempt was made to identify as many chemical sensors as possible, we recognize that some may be missed inadvertently. The accuracy of the information provided by the various sources regarding the state of development for the various sensors was not verified. Judgments or opinions regarding the actual state of development or utility of these devices are not included in this report. However, we feel that this report accurately reflects the state of the art at the present time.
Date: September 1991
Creator: Schabron, J. F.; Niss, N. D. & Hart, B. K.
Object Type: Report
System: The UNT Digital Library
Scouting, Volume 79, Number 4, September 1991 (open access)

Scouting, Volume 79, Number 4, September 1991

Bi-monthly publication of the Boy Scouts of America, written for Boy Scout leaders, officials, and others interested in the work of the Scouts. It includes articles about events and activities, updates from the national headquarters, topical columns and essays, and news from various chapters nationwide.
Date: September 1991
Creator: Boy Scouts of America
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Geothermal direct use engineering and design guidebook (open access)

Geothermal direct use engineering and design guidebook

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.
Date: January 1, 1991
Creator: Lienau, P. J. & Lunis, B. C. (eds.)
Object Type: Report
System: The UNT Digital Library
Mechanical design and development of a high power target system for the SLC Positron Source (open access)

Mechanical design and development of a high power target system for the SLC Positron Source

In order to bring the SLC Positron Source luminosity up to design specifications, the previous (stationary) positron target had to be replaced with a version which could reliably dissipate the higher power levels and cyclic pulsed thermal stresses of the high intensity 33GeV electron beam. In addition to this basic requirement, the new target system had to meet SLAC's specifications for Ultra High Vacuum, be remotely controllable, radiation hard,'' and designed in such a way that it could be removed and replaced quickly and easily with minimum personnel exposure to radiation. It was also desirable to integrate the target and collection components into a compact, easily manufacturable, and easily maintainable module. This paper briefly summarize the mechanical design and development of the new modular target system, its associated controls and software, alignment, and the quick removal system. Operational experience gained with the new system over the first running cycle is also summarized.
Date: December 1, 1991
Creator: Reuter, E.; Mansour, D.; Porter, T.; Sax, W. & Szumillo, A.
Object Type: Article
System: The UNT Digital Library
Catalysis-by-design impacts assessment (open access)

Catalysis-by-design impacts assessment

Catalyst researchers have always recognized the need to develop a detailed understanding of the mechanisms of catalytic processes, and have hoped that it would lead to developing a theoretical predictive base to guide the search for new catalysts. This understanding allows one to develop a set of hierarchical models, from fundamental atomic-level ab-initio models to detailed engineering simulations of reactor systems, to direct the search for optimized, efficient catalyst systems. During the last two decades, the explosions of advanced surface analysis techniques have helped considerably to develop the building blocks for understanding various catalytic reactions. An effort to couple these theoretical and experimental advances to develop a set of hierarchical models to predict the nature of catalytic materials is a program entitled Catalysis-by-Design (CRD).'' In assessing the potential impacts of CBD on US industry, the key point to remember is that the value of the program lies in developing a novel methodology to search for new catalyst systems. Industrial researchers can then use this methodology to develop proprietary catalysts. Most companies involved in catalyst R D have two types of ongoing projects. The first type, what we call market-driven R D,'' are projects that support and improve upon a company's …
Date: May 1, 1991
Creator: Fassbender, L L; Young, J K & Sen, R K
Object Type: Report
System: The UNT Digital Library
Evaluation of oil shale bitumen as a pavement asphalt additive to reduce moisture damage susceptibility (open access)

Evaluation of oil shale bitumen as a pavement asphalt additive to reduce moisture damage susceptibility

An unrefined shale bitumen was evaluated as an agent to reduce moisture damage susceptibility of asphalt aggregate mixtures. Some activity was observed but less than might have been expected based on the molecular weight and nitrogen content of the bitumen. The counter effects of free carboxylic acids, which are known to be variable in asphalt and which are also present in the unrefined bitumen, appear to diminish the activity of the bitumen to inhibit moisture damage. 5 refs., 1 tab.
Date: January 1, 1991
Creator: Robertson, R. E.; Harnsberger, P. M. & Wolf, J. M.
Object Type: Report
System: The UNT Digital Library
A direct comparison of Ge and Si(Li) detectors in the 2--20 keV range (open access)

A direct comparison of Ge and Si(Li) detectors in the 2--20 keV range

The spectral response of high purity Ge (HPGe) and lithium-drifted Si (Si(Li)) surface barrier detectors of similar geometry has been measured over a range of x-ray energies under identical experimental conditions. Detector characteristics such as spectral background, escape peak intensity, entrance window absorption, and energy resolution are presented and compared. Although these characteristic have been discussed in the literature previously, this paper represents an attempt to consolidate the information by making comparisons under equivalent experimental conditions for the two types of detectors. A primary goal of the study is a comparison of the two types of detectors for use in x-ray fluorescence applications.
Date: October 1, 1991
Creator: Rossington, C. S.; Giauque, R. D. & Jaklevic, J. M.
Object Type: Article
System: The UNT Digital Library
A direct comparison of Ge and Si(Li) detectors in the 2--20 keV range (open access)

A direct comparison of Ge and Si(Li) detectors in the 2--20 keV range

The spectral response of high purity Ge (HPGe) and lithium-drifted Si (Si(Li)) surface barrier detectors of similar geometry has been measured over a range of x-ray energies under identical experimental conditions. Detector characteristics such as spectral background, escape peak intensity, entrance window absorption, and energy resolution are presented and compared. Although these characteristic have been discussed in the literature previously, this paper represents an attempt to consolidate the information by making comparisons under equivalent experimental conditions for the two types of detectors. A primary goal of the study is a comparison of the two types of detectors for use in x-ray fluorescence applications.
Date: October 1, 1991
Creator: Rossington, C.S.; Giauque, R.D. & Jaklevic, J.M.
Object Type: Article
System: The UNT Digital Library
Evaluation of weldments in Type 21-6-9 stainless steel for Compact Ignition Tokamak structural applications: Phase 1 (open access)

Evaluation of weldments in Type 21-6-9 stainless steel for Compact Ignition Tokamak structural applications: Phase 1

Primary design considerations for the Compact Ignition Tokamak toroidal field-coil cases are yield strength and toughness in the temperature range from 77 to 300 K. Type 21-6-9 stainless steel, also still known by its original Armco Steel Company trade name Nitronic 40, is the proposed alloy for this application. It has high yield strength and usually adequate base metal toughness, but weldments in thick sections have not been adequately characterized in terms of mechanical properties or hot-cracking propensity. In this study, weldability of the alloy in heavy sections and the mechanical properties of the resultant welds were investigated including tensile yield strength and Charpy V-notch toughness at 77 K and room temperature. Weldments were made in four different base metals using seven different filler metals. None of the weldments showed any indication of hot-cracking problems. All base metals, including weldment heat-affected zones, were found to have adequate strength and impact toughness at both test temperatures. Weld metals, on the other hand, except ERNiCr-3 and ENiCrFe-3 had impact toughnesses of less than 67 J at 77 K. Inconel 82 had an average weld metal impact toughness of over 135 J at 77 K, and although its strength at 77 K is …
Date: June 1, 1991
Creator: Alexander, D. J.; Goodwin, G. M. & Bloom, E. E.
Object Type: Report
System: The UNT Digital Library
A Texas Scrap-Book: Made up of the History, Biography, and Miscellany of Texas and its People (open access)

A Texas Scrap-Book: Made up of the History, Biography, and Miscellany of Texas and its People

Re-print of a historical and biographical account of the earl history of Texas until around 1846; the book is divided into four parts: historical, biography, miscellany, and statistical. Index begins on page 659.
Date: 1991
Creator: Baker, D. W. C. (De Witt Clinton), 1832-1881
Object Type: Book
System: The Portal to Texas History
The changing public sector : shifts in governmental spending and employment (open access)

The changing public sector : shifts in governmental spending and employment

The ACIR Library is composed of publications that study the interactions between different levels of government. This document addresses the changing public sector.
Date: December 1991
Creator: United States. Advisory Commission on Intergovernmental Relations.
Object Type: Book
System: The UNT Digital Library
Isotopic and trace element characteristics of rhyolites from the Valles Caldera, New Mexico. Final technical report (open access)

Isotopic and trace element characteristics of rhyolites from the Valles Caldera, New Mexico. Final technical report

This report is a summary of work supported by DOE grant No. DE-FGO5-87ER13795 that was completed or is still in progress. The stated purpose of this grant was to collect geochemical information (trace element, radiogenic isotope and stable oxygen and hydrogen isotope) on samples from core holes VC-I and VC-2a in the Valles caldera in order to establish a consistent detailed intracaldera stratigraphy and relate this to extracaldera volcanic rock units of the Jemez Mountains. Careful stratigraphic control of the intracaldera units is necessary to evaluate models of caldera formation, ignimbrite deposition, and resurgence. Combined stable and radiogenic isotope and trace element data will also provide major insights to petrogenesis of the Bandelier magma system. The composition of non-hydrothermally altered samples from outflow units of the Bandelier Tuff and related volcanics must be known to assess isotopic variations of intracaldera ignimbrite samples. On detailed examination of the VC-2a core samples, it became apparent that hydrothermal alteration is so extensive that no geochemical information useful for stratigraphic fingerprinting or petrogenesis could be obtained, and that correlation with other intracaldera units and extracaldera units must be made on the basis of stratigraphic position and gross lithologic characteristics. Accordingly, we emphasize geochemical data …
Date: September 1, 1991
Creator: Self, S.; Sykes, M. L.; Wolff, J. A. & Skuba, C. E.
Object Type: Report
System: The UNT Digital Library
Theoretical studies in medium-energy nuclear and hadronic physics. Annual technical progress report, April 1, 1991--March 31, 1992 (open access)

Theoretical studies in medium-energy nuclear and hadronic physics. Annual technical progress report, April 1, 1991--March 31, 1992

In the period covered by this report (April 1, 1991 to March 31, 1992), work focused on six main areas: (1) Relativistic Theories of Nuclear Structure and Saturation, (2) Relativistic Descriptions of Proton-Nucleus and Electron-Nucleus Scattering, (3) Nonrelativistic Theory of Nucleon-Nucleus Reactions, (4) Relativistic Many-Body Theory at Finite Temperature and Density, (5) Neutrino Interactions in Dense Matter, (6) Quark Models of Nuclear and Quark Matter.
Date: December 3, 1991
Creator: Horowitz, C. J.; Macfarlane, M. H.; Matsui, Tetsuo & Serot, B. D.
Object Type: Report
System: The UNT Digital Library
Theoretical studies in medium-energy nuclear and hadronic physics (open access)

Theoretical studies in medium-energy nuclear and hadronic physics

In the period covered by this report (April 1, 1991 to March 31, 1992), work focused on six main areas: (1) Relativistic Theories of Nuclear Structure and Saturation, (2) Relativistic Descriptions of Proton-Nucleus and Electron-Nucleus Scattering, (3) Nonrelativistic Theory of Nucleon-Nucleus Reactions, (4) Relativistic Many-Body Theory at Finite Temperature and Density, (5) Neutrino Interactions in Dense Matter, (6) Quark Models of Nuclear and Quark Matter.
Date: December 3, 1991
Creator: Horowitz, Charles J.; Macfarlane, Malcolm H.; Matsui, Tetsuo & Serot, Brian D.
Object Type: Report
System: The UNT Digital Library
Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films (open access)

Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Amorphous TiO{sub 2} sol-gel films are irreversibly transformed to a crystalline anatase phase when heated to temperatures in excess of 575 K or subjected to intense pulsed or CW laser irradiation. The laser-induced transformation is initiated as a result of impurity absorption and subsequent heating, and results in densification and relative changes in compressive stress of the film. Isothermally annealed films exhibit a decrease in compressive stress as crystallization proceeds while an increase in compressive stress followed by a decrease in stress is observed when crystallization is laser-induced. Raman spectroscopy has been used to characterize the crystallization ingrowth kinetics and is used in this work as a real time probe of both film temperature and localized stress which can be evaluated from shifts in lattice phonon frequencies measured in real time during laser irradiation. The laser not only induces the phase transformation but excites inelastic Raman scattering from which film stress and temperature can be estimated. A second approach for the determination of these parameters requires incorporation of a thin ruby film between the titania and silica substrate. Here, the wavelength shift of the laser-induced ruby fluorescence can be used to quantify interfacial stress; the fluorescence lifetime measurements are used …
Date: October 1, 1991
Creator: Exarhos, G.J.; Hess, N.J. (Pacific Northwest Lab., Richland, WA (United States)) & Wood, S. (Washington State Univ., Pullman, WA (United States). Dept. of Physics)
Object Type: Article
System: The UNT Digital Library
A carbon monoxide passive sampler: Research and development needs (open access)

A carbon monoxide passive sampler: Research and development needs

In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a CO-quantifying technique suitable for affordable field research. A CO passive sampler, if developed, could fulfill these requirements. Existing CO monitoring techniques are discussed as well as three potential CO-detection methods for use in a CO passive sampler. Laboratory and field research needed for the development and validation of an effective and cost-efficient CO passive sampler are also discussed.
Date: November 1, 1991
Creator: Traynor, G. W.; Apte, M. G.; Diamond, R. C. & Woods, A. L.
Object Type: Report
System: The UNT Digital Library
A carbon monoxide passive sampler: Research and development needs (open access)

A carbon monoxide passive sampler: Research and development needs

In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a CO-quantifying technique suitable for affordable field research. A CO passive sampler, if developed, could fulfill these requirements. Existing CO monitoring techniques are discussed as well as three potential CO-detection methods for use in a CO passive sampler. Laboratory and field research needed for the development and validation of an effective and cost-efficient CO passive sampler are also discussed.
Date: November 1, 1991
Creator: Traynor, G. W.; Apte, M. G.; Diamond, R. C. & Woods, A. L.
Object Type: Report
System: The UNT Digital Library
Texas Almanac, 1992-1993 (open access)

Texas Almanac, 1992-1993

The almanac covers general topics about the state of Texas including statistics for individual counties, history, wildlife, science, agriculture, expenditures, and weather, as well as discussions of legal and social issues of the time. The general index and advertisers index begin on page 626.
Date: 1991
Creator: Kingston, Mike
Object Type: Book
System: The Portal to Texas History
HEMP emergency planning and operating procedures for electric power systems (open access)

HEMP emergency planning and operating procedures for electric power systems

Investigations of the impact of high-altitude electromagnetic pulse (HEMP) on electric power systems and electrical equipment have revealed that HEMP creates both misoperation and failures. These events result from both the early time E[sub 1] (steep-front pulse) component and the late time E[sub 3] (geomagnetic perturbations) component of HEMP. In this report a HEMP event is viewed in terms of its marginal impact over classical power system disturbances by considering the unique properties and consequences of HEMP. This report focuses on system-wide electrical component failures and their potential consequences from HEMP. In particular, the effectiveness of planning and operating procedures for electric systems is evaluated while under the influence of HEMP. This assessment relies on published data and characterizes utilities using the North American Electric Reliability Council's regions and guidelines to model electric power system planning and operations. Key issues addressed by the report include how electric power systems are affected by HEMP and what actions electric utilities can initiate to reduce the consequences of HEMP. The report also reviews the salient features of earlier HEMP studies and projects, examines technology trends in the electric power industry which are affected by HEMP, characterizes the vulnerability of power systems to HEMP, …
Date: January 1, 1991
Creator: Reddoch, T. W. & Markel, L. C. (Electrotek Concepts, Inc., Knoxville, TN (United States))
Object Type: Report
System: The UNT Digital Library
Determination of ideal-gas enthalpies of formation for key compounds: (open access)

Determination of ideal-gas enthalpies of formation for key compounds:

The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of ({plus minus})-butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene-2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group-additivity parameters useful in the application of group- contribution correlations are derived. 112 refs., 13 figs., 19 tabs.
Date: October 1, 1991
Creator: Steele, W. V.; Chirico, R. D.; Nguyen, A.; Hossenlopp, I. A. & Smith, N. K.
Object Type: Report
System: The UNT Digital Library
Research on stable, high-efficiency amorphous silicon multijunction modules (open access)

Research on stable, high-efficiency amorphous silicon multijunction modules

This report discusses the progress made from May to October 1990 on the development of solar cell modules by the Solar Energy Research Institute. Topics include the preparation and performance of semiconductor junctions. Research work in non-semiconductor materials is presented, and the design and testing of triple stacked solar cells are presented, too. 21 refs., 30 figs., 6 tabs. (GHH)
Date: April 1, 1991
Creator: Catalano, A.; Arya, R.; Bennett, M.; Fieselmann, B.; Li, Y.; Morris, J. et al.
Object Type: Report
System: The UNT Digital Library
Biological (molecular and cellular) markers of toxicity. Final report, September 15, 1988--September 14, 1991 (open access)

Biological (molecular and cellular) markers of toxicity. Final report, September 15, 1988--September 14, 1991

Several molecular and cellular markers of genotoxicity were adapted for measurement in the Medaka (Oryzias latipes), and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). NO{sup 6}-ethyl guanine adducts were detected, and a slight statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O{sup 6}-ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA. Following a five week continuous DEN exposure with 100 percent renewal of DEN-water every third day, the F values (DNA double strandedness) increased considerably and to similar extent in fish exposed to 25, 50, and 100 ppM DEN. This has been observed also in medaka exposed to BaP.
Date: December 15, 1991
Creator: Shugart, L. R.; D`Surney, S. J.; Gettys-Hull, C. & Greeley, M. S. Jr.
Object Type: Report
System: The UNT Digital Library
Biological (molecular and cellular) markers of toxicity (open access)

Biological (molecular and cellular) markers of toxicity

Several molecular and cellular markers of genotoxicity were adapted for measurement in the Medaka (Oryzias latipes), and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). NO{sup 6}-ethyl guanine adducts were detected, and a slight statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O{sup 6}-ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA. Following a five week continuous DEN exposure with 100 percent renewal of DEN-water every third day, the F values (DNA double strandedness) increased considerably and to similar extent in fish exposed to 25, 50, and 100 ppM DEN. This has been observed also in medaka exposed to BaP.
Date: December 15, 1991
Creator: Shugart, L. R.; D'Surney, S. J.; Gettys-Hull, C. & Greeley, M. S., Jr.
Object Type: Report
System: The UNT Digital Library