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Measurement of the tau lepton lifetime (open access)

Measurement of the tau lepton lifetime

We report the measurement of the lifetime of the tau lepton. This measurement was made using the HRS spectrometer at PEP, operating at 29 GeV. The 3 prong decay vertices were measured using a four layer tubular cell vertex chamber. The lifetime of the tau was determined to be tau/sub tau/ = .28 +- .02 +- .02 ps. 7 refs., 3 figs.
Date: January 1, 1986
Creator: Abachi, S.; Akerlof, C.; Baringer, P.; Blockus, D.; Brabson, B.; Brom, J.M. et al.
System: The UNT Digital Library
Search for wrong sign D/sup 0/ decays with the HRS detector (open access)

Search for wrong sign D/sup 0/ decays with the HRS detector

Using a data sample corresponding to an integrated luminosity of 300pb/sup -1/ obtained at PEP with the HRS detector we have searched for the wrong sign decay of D/sup 0/ mesons in the decays D* ..-->.. D/sup 0/..pi... We obtain a 90% confidence level limit of 4.0% on the ratio of the wrong sign to the right sign decay rate in the K..pi.. mode. This is the best model independent limit on mixing currently available and constrains the nature of the wrong sign signal recently reported by the MARK III group. 10 refs., 2 figs.
Date: 1986
Creator: Abachi, S.; Akerlof, C.; Barringer, P.; Blockus, D.; Brabson, B.; Brom, J. M. et al.
System: The UNT Digital Library
Consolidation and shear failure leading to subsidence and settlement. Final report (open access)

Consolidation and shear failure leading to subsidence and settlement. Final report

Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. The share of the produced cavities is compared with cavities produced by idealized voids in an idealized environment. Study of root penetration at subsidence sites gives us an indication of the remaining degree of integrity. 30 refs., 24 figs., 19 tabs.
Date: February 1, 1986
Creator: Abeele, W.; Nyhan, J. W.; Hakonson, T. E.; Drennon, B. J.; Lopez, E. A.; Herrera, W. J. et al.
System: The UNT Digital Library
Low-level integrated system test (open access)

Low-level integrated system test

An unusually wet season permitted us to test the integrity of our biobarrier installed in the improved or modified plots in our integrated system. Although the modified plots had a reduced water-holding capacity, they delivered leachate only at the drain installed above the biobarrier, demonstrating once more that the biobarrier is behaving successfully as a capillary barrier in rerouting the subsurface flow around the tuff beneath the biobarrier. As a result of vertical water flow impedance, more water was made available to plot vegetation, enhancing its growth dramatically. The capillary barrier theory was backed up by the tensiometer results showing saturation at the upper biobarrier interface. 11 refs., 19 figs
Date: February 1, 1986
Creator: Abeele, Willy; Nyhan, John; Hakonson, Tom; Drennon, Barry J.; Lopez, Edward A.; Herrera, Wilfred J. et al.
System: The UNT Digital Library
Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments (open access)

Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented.
Date: June 1, 1986
Creator: Abraham, T.; Jain, H. & Soo, P.
System: The UNT Digital Library
User systems guidelines for software projects (open access)

User systems guidelines for software projects

This manual presents guidelines for software standards which were developed so that software project-development teams and management involved in approving the software could have a generalized view of all phases in the software production procedure and the steps involved in completing each phase. Guidelines are presented for six phases of software development: project definition, building a user interface, designing software, writing code, testing code, and preparing software documentation. The discussions for each phase include examples illustrating the recommended guidelines. 45 refs. (DWL)
Date: April 1, 1986
Creator: Abrahamson, L. (ed.)
System: The UNT Digital Library
Transport and Reaction Kinetics at the Glass:Solution Interface Region: Results of Repository-Oriented Leaching Experiments (open access)

Transport and Reaction Kinetics at the Glass:Solution Interface Region: Results of Repository-Oriented Leaching Experiments

Repository-oriented leaching experiments involving Savannah River Laboratory (SRL) 165 type glass under a {gamma}-radiation field (1 = 0.2 x 10{sup 4} R/h) have been performed by the Nevada Nuclear Waste Storage Investigations (NNWSI) project. In this communication, we discuss glass surface analyses obtained by SEM, nuclear resonance profiling, and SIMS together with leachate solution data in relation to a mechanism that couples diffusion, hydrolysis (etching and gelation), and precipitation to qualitatively describe the release of different glass components to the leachant solutions. The release of mobile (e.g., Li) and partly mobile (e.g., B) species is controlled primarily by interdiffusion with water species across the interdiffusion zone. Glass components that are immobile in the interdiffusion zone are released to the solution by etching. For prediction of long-term steady-state concentrations of glass components with low solubility, the relative rates of release from the glass and secondary mineral precipitation must be taken into account.
Date: December 31, 1986
Creator: Abrajano, T. A., Jr. & Bates, J. K.
System: The UNT Digital Library
Effect of gamma radiation on groundwater chemistry and glass leaching as related to the NNWSI repository site (open access)

Effect of gamma radiation on groundwater chemistry and glass leaching as related to the NNWSI repository site

To address the effect of ionizing radiation on groundwater chemistry and waste form durability, NNWSI is performing an extensive set of experiments as a function of dose rate (2 x 10{sup 5}, 1 x 10{sup 4}, 1 x 10{sup 3}, and 0 rad/h). The results of the tests done at 2 x 10{sup 5} rad/h have been reported, while the 1 x 10{sup 3} and 0 rad/h tests are in progress. This paper presents an overview of the results of the tests done at 1 x 10{sup 4} rad/h and discusses the relevance of these tests to repository conditions. An interpretation of the results relating to the manner by which the glass waste form corrodes is presented elsewhere. A complete discussion of the effect of gamma radiation on groundwater chemistry and waste form durability will be presented when the series of experiments are complete.
Date: May 1986
Creator: Abrajano, T.; Bates, J.; Ebert, W. & Gerding, T.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory (open access)

Micelle-derived catalysts for extended Schulz-Flory

The objective of this program is to develop a synthesis gas conversion catalyst with higher selectivity to liquid fuels, while maintaining catalytic activity and stability at least equivalent relative to state-of-the-art precipitated iron catalysts. Hydrocarbon cutoff hypothesis and developmental needs for a ruthenium catalyst with low light ends selectivity were investigated during this quarter. Hydrocarbon product distribution was Anderson-Schulz-Flory up to a carbon number of 250 and cutoff did not occur with a titania-supported catalyst containing ruthenium particles smaller than 20[Angstrom]. It was found that an alumina-supported catalyst with 1% (by weight) ruthenium in the form of 50[Angstrom] to 100[Angstrom] metal particles was initially about half as active (by catalyst volume) and made one quarter of the amount of C[sub 1][minus]C[sub 4] light end products relative to the Sasol precipitated iron catalyst.
Date: January 1, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory (open access)

Micelle-derived catalysts for extended Schulz-Flory

The objective of this program is to develop a synthesis gas conversion catalyst with higher selectivity to liquid fuels, while maintaining catalytic activity and stability at least equivalent relative to state-of-the-art precipitated iron catalysts. During this quarter, the emphasis in the program has been the investigation of the hydrocarbon cutoff hypothesis with supported ruthenium catalysts. An alumina-supported catalyst with smaller than 20[Angstrom] ruthenium particles was tested under conditions of maximal water gas shift activity. During this test more than 90% of the water made in the Fischer-Tropsch synthesis reaction was converted to H[sub 2]. However, the extent of ruthenium metal agglomeration was not reduced. Accordingly, it was not possible to conclude whether hydrocarbon cutoff occurs with smaller than 20[Angstrom] ruthenium particles on [gamma]-alumina. A ruthenium catalyst prepared on Y-type zeolite had 20[Angstrom] or smaller ruthenium particles according to STEM examination and a 15[Angstrom] average ruthenium metal particle size according to EXAFS examination. The ruthenium metal particle size was stable during the test with this catalyst. The hydrocarbon product distribution was Anderson-Schulz-Flory with no cutoff up to a carbon number of 160. A well-dispersed titania-supported ruthenium catalyst is going to be evaluated during the next quarter in order to determine whether …
Date: January 1, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory (open access)

Micelle-derived catalysts for extended Schulz-Flory

The objective of this program is to develop a synthesis gas conversion catalyst selective to gasoline or diesel range fuel via application of a micelle technique for preparing specific site supported ruthenium particles. The current emphasis is to investigate hydrocarbon cutoff principle and to apply it for developing selective catalysts. During this quarter, micelle technique was further improved and 1 ruthenium particle:l reverse micelle limit was approached by careful control of catalyst synthesis conditions. Accordingly, it became possible to synthesize supported particles that closely meet the size and composition targets originally set. This improved technique was applied to synthesis of chemically modified ruthenium catalysts. Some of the chemically modified ruthenium catalysts will be evaluated later in the program. We previously reported that 40--60 [Angstrom] ruthenium particles prepared on [gamma]-alumina do not result in hydrocarbon cutoff. We could not determine then whether smaller ruthenium particles result in hydrocarbon cutoff because these particles agglomerated via ruthenium carbonyl formation during the course of a 6--10 day test. We have recently evaluated a catalyst with 20--40 [Angstrom] ruthenium particles prepared on [gamma]-alumina by carefully analyzing products initially made during the test prior to substantial ruthenium agglomeration. We concluded that cutoff is not effected by …
Date: January 1, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory (open access)

Micelle-derived catalysts for extended Schulz-Flory

The objective of this program is to develop a synthesis gas conversion catalyst with improved selectivity to gasoline or diesel range fuel via application of a micelle technique for preparing novel supported catalysts with specific size ruthenium particles. The major emphasis is to investigate hydrocarbon cutoff principle and to apply it for developing selective catalysts. We previously reported that cutoff is not effected with 40--60 [Angstrom] and 20--40 [Angstrom] ruthenium particles on [gamma]-Al[sub 2]O[sub 3]. We recently tested a catalyst with <20 [Angstrom] ruthenium particles. Well dispersed ruthenium in that catalyst extensively agglomerated to larger particles even during the course of a short test despite the high H[sub 2]:CO ratio used. Therefore, we could not conclude whether cutoff is effected with <20 [Angstrom] ruthenium particles. We are going to continue to evaluate the effect of operational conditions and also evaluate the effect of modifiers on ruthenium agglomeration. A catalyst with <20 [Angstrom] ruthenium particles will be evaluated to investigate occurrence of cutoff, after no agglomeration conditions are identified. We are now proposing to conduct, parallel to the main approach, a second research approach which will aim at developing a ruthenium catalyst with substantially lower light ends selectivity while maintaining at …
Date: January 1, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory. [Quarterly report], April 1, 1986--June 30, 1986 (open access)

Micelle-derived catalysts for extended Schulz-Flory. [Quarterly report], April 1, 1986--June 30, 1986

The objective of this program is to develop a synthesis gas conversion catalyst with improved selectivity to gasoline or diesel range fuel via application of a micelle technique for preparing novel supported catalysts with specific size ruthenium particles. The major emphasis is to investigate hydrocarbon cutoff principle and to apply it for developing selective catalysts. We previously reported that cutoff is not effected with 40--60 {Angstrom} and 20--40 {Angstrom} ruthenium particles on {gamma}-Al{sub 2}O{sub 3}. We recently tested a catalyst with <20 {Angstrom} ruthenium particles. Well dispersed ruthenium in that catalyst extensively agglomerated to larger particles even during the course of a short test despite the high H{sub 2}:CO ratio used. Therefore, we could not conclude whether cutoff is effected with <20 {Angstrom} ruthenium particles. We are going to continue to evaluate the effect of operational conditions and also evaluate the effect of modifiers on ruthenium agglomeration. A catalyst with <20 {Angstrom} ruthenium particles will be evaluated to investigate occurrence of cutoff, after no agglomeration conditions are identified. We are now proposing to conduct, parallel to the main approach, a second research approach which will aim at developing a ruthenium catalyst with substantially lower light ends selectivity while maintaining at …
Date: December 31, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory. [Quarterly report], January 1, 1986--March 31, 1986 (open access)

Micelle-derived catalysts for extended Schulz-Flory. [Quarterly report], January 1, 1986--March 31, 1986

The objective of this program is to develop a synthesis gas conversion catalyst selective to gasoline or diesel range fuel via application of a micelle technique for preparing specific site supported ruthenium particles. The current emphasis is to investigate hydrocarbon cutoff principle and to apply it for developing selective catalysts. During this quarter, micelle technique was further improved and 1 ruthenium particle:l reverse micelle limit was approached by careful control of catalyst synthesis conditions. Accordingly, it became possible to synthesize supported particles that closely meet the size and composition targets originally set. This improved technique was applied to synthesis of chemically modified ruthenium catalysts. Some of the chemically modified ruthenium catalysts will be evaluated later in the program. We previously reported that 40--60 {Angstrom} ruthenium particles prepared on {gamma}-alumina do not result in hydrocarbon cutoff. We could not determine then whether smaller ruthenium particles result in hydrocarbon cutoff because these particles agglomerated via ruthenium carbonyl formation during the course of a 6--10 day test. We have recently evaluated a catalyst with 20--40 {Angstrom} ruthenium particles prepared on {gamma}-alumina by carefully analyzing products initially made during the test prior to substantial ruthenium agglomeration. We concluded that cutoff is not effected by …
Date: December 31, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory. Technical progress report, July 1, 1986--September 30, 1986 (open access)

Micelle-derived catalysts for extended Schulz-Flory. Technical progress report, July 1, 1986--September 30, 1986

The objective of this program is to develop a synthesis gas conversion catalyst with higher selectivity to liquid fuels, while maintaining catalytic activity and stability at least equivalent relative to state-of-the-art precipitated iron catalysts. During this quarter, the emphasis in the program has been the investigation of the hydrocarbon cutoff hypothesis with supported ruthenium catalysts. An alumina-supported catalyst with smaller than 20{Angstrom} ruthenium particles was tested under conditions of maximal water gas shift activity. During this test more than 90% of the water made in the Fischer-Tropsch synthesis reaction was converted to H{sub 2}. However, the extent of ruthenium metal agglomeration was not reduced. Accordingly, it was not possible to conclude whether hydrocarbon cutoff occurs with smaller than 20{Angstrom} ruthenium particles on {gamma}-alumina. A ruthenium catalyst prepared on Y-type zeolite had 20{Angstrom} or smaller ruthenium particles according to STEM examination and a 15{Angstrom} average ruthenium metal particle size according to EXAFS examination. The ruthenium metal particle size was stable during the test with this catalyst. The hydrocarbon product distribution was Anderson-Schulz-Flory with no cutoff up to a carbon number of 160. A well-dispersed titania-supported ruthenium catalyst is going to be evaluated during the next quarter in order to determine whether …
Date: December 31, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Micelle-derived catalysts for extended Schulz-Flory. Technical progress report, October 1, 1986--December 31, 1986 (open access)

Micelle-derived catalysts for extended Schulz-Flory. Technical progress report, October 1, 1986--December 31, 1986

The objective of this program is to develop a synthesis gas conversion catalyst with higher selectivity to liquid fuels, while maintaining catalytic activity and stability at least equivalent relative to state-of-the-art precipitated iron catalysts. Hydrocarbon cutoff hypothesis and developmental needs for a ruthenium catalyst with low light ends selectivity were investigated during this quarter. Hydrocarbon product distribution was Anderson-Schulz-Flory up to a carbon number of 250 and cutoff did not occur with a titania-supported catalyst containing ruthenium particles smaller than 20{Angstrom}. It was found that an alumina-supported catalyst with 1% (by weight) ruthenium in the form of 50{Angstrom} to 100{Angstrom} metal particles was initially about half as active (by catalyst volume) and made one quarter of the amount of C{sub 1}{minus}C{sub 4} light end products relative to the Sasol precipitated iron catalyst.
Date: December 31, 1986
Creator: Abrevaya, H.
System: The UNT Digital Library
Finite Temperature Instability for Compactification (open access)

Finite Temperature Instability for Compactification

We consider finite temperature effects upon theories with extra dimensions compactified via vacuum stress energy (Casimir) effects. For sufficiently high temperature, a static configuration for the internal space is impossible. At somewhat lower temperatures, there is an instability due to thermal fluctuations of radius of the compact dimensions. For both cases, the Universe can evolve to a de Sitter-like expansion of all dimensions. Stability to late times constrains the initial entropy of the universe. 28 refs., 1 fig., 2 tabs.
Date: March 1, 1986
Creator: Accetta, F. S. & Kolb, E. W.
System: The UNT Digital Library
Stable Compactifications (open access)

Stable Compactifications

We show that compactifications of theories with extra dimensions are unstable if due to monopole configurations of an antisymmetric tensor field balanced against one-loop Casimir corrections. In the case of ten dimensional supergravity, it is possible, at least for a portion of the phase space, to achieve a stable compactification without fine-tuning by including the contribution of fermionic condensates to the monopole configurations. 23 refs., 2 figs.
Date: March 1, 1986
Creator: Accetta, F. S.; Gleiser, M.; Holman, R. & Kolb, E. W.
System: The UNT Digital Library
Thermodynamics of higher dimensional black holes (open access)

Thermodynamics of higher dimensional black holes

We discuss the thermodynamics of higher dimensional black holes with particular emphasis on a new class of spinning black holes which, due to the increased number of Casimir invariants, have additional spin degrees of freedom. In suitable limits, analytic solutions in arbitrary dimensions are presented for their temperature, entropy, and specific heat. In 5 + 1 and 9 + 1 dimensions, more general forms for these quantities are given. It is shown that the specific heat for a higher dimensional black hole is negative definite if it has only one non-zero spin parameter, regardless of the value of this parameter. We also consider equilibrium configurations with both massless particles and massive string modes. 16 refs., 3 figs.
Date: May 1, 1986
Creator: Accetta, F.S. & Gleiser, M.
System: The UNT Digital Library
Feasibility assessment of copper-base waste package container materials in a tuff repository (open access)

Feasibility assessment of copper-base waste package container materials in a tuff repository

This report discussed progress made during the second year of a two-year study on the feasibility of using copper or a copper-base alloy as a container material for a waste package in a potential repository in tuff rock at the Yucca Mountain site in Nevada. Corrosion testing in potentially corrosive irradiated environments received emphasis during the feasibility study. Results of experiments to evaluate the effect of a radiation field on the uniform corrosion rate of the copper-base materials in repository-relevant aqueous environments are given as well as results of an electrochemical study of the copper-base materials in normal and concentrated J-13 water. Results of tests on the irradiation of J-13 water and on the subsequent formation of hydrogen peroxide are given. A theoretical study was initiated to predict the long-term corrosion behavior of copper in the repository. Tests were conducted to determine whether copper would adversely affect release rates of radionuclides to the environment because of degradation of the Zircaloy cladding. A manufacturing survey to determine the feasibility of producing copper containers utilizing existing equipment and processes was completed. The cost and availability of copper was also evaluated and predicted to the year 2000. Results of this feasibility assessment are …
Date: September 30, 1986
Creator: Acton, C. F. & McCright, R. D.
System: The UNT Digital Library
Defect fractions for fissile and fertile TRISO-coated fuel (open access)

Defect fractions for fissile and fertile TRISO-coated fuel

High quality TRISCO-coated UCO and ThO{sub 2} particles with reference MHTGR dimensions were produced in a coating campaign in August and September 1986 for irradiation tests. The heavy metal contamination and the defect levels were below the limits established for the MHTGR fuel. Over 9 kg of uranium in UCO and 30 kg of thorium in ThO{sub 2} were TRISCO-coated in 4 fissile and 3 fertile batches in the 240mm Development Coater. These coated fuel particles will be used to produce fuel rods for testing in the irradiation validation tests to be conducted in capsules HRB-19, -20 and -21 on the DOE Fuel and Fission Product Technology Program. 3 refs., 6 figs., 6 tabs.
Date: September 1, 1986
Creator: Adams, C.C.
System: The UNT Digital Library
Analyzing powers and proton spin transfer coefficients in the elastic scattering of 800 MeV polarized protons from an L-type polarized deuteron target at small momentum transfers (open access)

Analyzing powers and proton spin transfer coefficients in the elastic scattering of 800 MeV polarized protons from an L-type polarized deuteron target at small momentum transfers

Analyzing powers and spin transfer coefficients which describe the elastic scattering of polarized protons from a polarized deuteron target have been measured. The energy of the proton beam was 800 MeV and data were taken at laboratory scattering angles of 7, 11, 14, and 16.5 degrees. One analyzing power was also measured at 180 degrees. Three linearly independent orientations of the beam polarization were used and the target was polarized parallel and antiparallel to the direction of the beam momentum. The data were taken with the high resolution spectrometer at the Los Alamos Meson Physics Facility (experiment 685). The results are compared with multiple scattering predictions based on Dirac representations of the nucleon-nucleon scattering matrices. 27 refs., 28 figs., 4 tabs.
Date: October 1, 1986
Creator: Adams, D.L.
System: The UNT Digital Library
Subsurface marker emplacement test plan (open access)

Subsurface marker emplacement test plan

Current plans propose placing subsurface markers within protective barriers to deter potential human intrusion into disposed radioactive wastes. The subsurface markers would provide warning to the digging intruder should surface markers be removed, destroyed, or ignored. This plan sets forth procedures for testing the survivability of the subsurface markers during construction of the barrier. After the tests described herein are concluded, a decision can be made as to whether subsurface markers will require protection during barrier construction. If protection is required, additional tests will be needed to test the effectiveness of various protective approaches.
Date: May 30, 1986
Creator: Adams, M. R. & Carlson, R. A.
System: The UNT Digital Library
Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984 (open access)

Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984

March 1, 1984, was the 30th anniversary of the Bravo thermonuclear test that resulted in the accidental exposure of the populations of Rongelap and Utirik atolls to radioactive fallout. The chronicling of the medical events resulting from that exposure is continued in this report, which covers the period from January 1983 through December 1984. An updated listing of all relevant publications from the Medical Department Brookhaven National Laboratory, is presented in the Reference Section. Thirty years of observation continue to show no detectable increase in mortality in the exposed population as a result of that exposure. The survival curves of the high-exposure Rongelap group, the low-exposure Utirik population, and an unexposed group of Rongelap people matched by age and sex to the exposed Rongelap group in 1957 continue to be similar. 89 refs., 2 figs., 6 tabs.
Date: January 1, 1986
Creator: Adams, W. H.; Engle, J. R.; Harper, J. A.; Heotis, P. M. & Scott, W. A.
System: The UNT Digital Library