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International conference on bone mineral measurement, October 12--13, 1973, Chicago, Illinois (open access)

International conference on bone mineral measurement, October 12--13, 1973, Chicago, Illinois

From international conference on bone mineral measurement; Chicago, Illinois, USA (12 Oct 1973). Abstracts of papers presented at the international conference on bone mineral measurement are presented. The papers were grouped into two sessions: a physical session including papers on measuring techniques, errors, interpretation and correlations, dual photon techniques, and data handling and exchange; a biomedical session including papers on bone disease, osteoporosis, normative data, non-disease influences, renal, and activity and inactivity. (ERB)
Date: December 31, 1973
Creator: unknown
System: The UNT Digital Library
Progress of the LASL dry hot rock geothermal energy project (open access)

Progress of the LASL dry hot rock geothermal energy project

Under sponsorship of the Division of Applied Technology of AEC, Los Alamos Scientific Laboratory is investigating the possibilities and problems of extracting energy from geothermal reservoirs which do not spontaneously yield useful amounts of steam or hot water. The system for accomplishing this which is being developed first is a pressurized-water circulation loop intended for use in relatively impermeable hot rock. It will consist of two holes connected through the hot rock by a very large hydraulic fracture and connected at the surface through the primary heat exchanger of an energy utilization system. Preliminary experiments in a hole 2576 ft (0.7852 km) deep, extending about 470 ft (143 m) into the Precambrian basement rock underlying the Jemez Plateau of north-central New Mexico, revealed no unexpected difficulties in drilling or hydraulically fracturing such rock at a temperature of approximately 100 C, and demonstrated a permeability low enough so that it appeared probable that pressurized water could be contained by the basement rock. Similar experiments are in progress in a second hole, now 6701 ft (2.043 km) deep, about 1.5 miles (2.4km ) south of the first one. Here the bottomhole temperature is about 146 C, and again no unexpected difficulty was …
Date: December 31, 1974
Creator: Smith, M.C.
System: The UNT Digital Library
Analysis of the Genome of a Korean Isolate of the Pieris rapae Granulovirus Enabled by Its Separation from Total Host Genomic DNA by Pulse-Field Electrophoresis (open access)

Analysis of the Genome of a Korean Isolate of the Pieris rapae Granulovirus Enabled by Its Separation from Total Host Genomic DNA by Pulse-Field Electrophoresis

Article on an analysis of the genome of a Korean isolate of the Pieris rapae granulovirus enabled by its separation from total host genomic DNA by pulse-field electrophoresis.
Date: April 8, 2013
Creator: Jo, Yong Hun; Patnaik, Bharat Bhusan; Kang, Se Won; Chae, Sung-Hwa; Oh, Seunghan; Kim, Dong Hyun et al.
System: The UNT Digital Library
STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT - 9114 (open access)

STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT - 9114

Chemical Cleaning is currently in progress for Tanks 5 and 6 at the Savannah River Site. The Chemical Cleaning process is being utilized to remove the residual waste heel remaining after completion of Mechanical Sludge Removal. This work is required to prepare the tanks for closure. Tanks 5 and 6 are 1950s vintage carbon steel waste tanks that do not meet current containment standards. These tanks are 22.9 meters (75 feet) in diameter, 7.5 meters (24.5 feet) in height, and have a capacity of 2.84E+6 liters (750,000 gallons). Chemical Cleaning adds 8 wt % oxalic acid to the carbon steel tank to dissolve the remaining sludge heel. The resulting acidic waste solution is transferred to Tank 7 where it is pH adjusted to minimize corrosion of the carbon steel tank. The Chemical Cleaning flowsheet includes multiple strikes of acid in each tank. Acid is delivered by tanker truck and is added to the tanks through a hose assembly connected to a pipe penetration through the tank top. The flowsheet also includes spray washing with acid and water. This paper includes an overview of the configuration required for Chemical Cleaning, the planned flowsheet, and an overview of technical concerns associated with …
Date: December 31, 2008
Creator: Thaxton, D; Geoff Clendenen, G; Willie Gordon, W; Samuel Fink, S & Michael Poirier, M
System: The UNT Digital Library
RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES (open access)

RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES

The Hypothetical Accident Conditions (HAC) sequential test of radioactive materials packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800 C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate test which provide equivalent total heat input at the 800 C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.
Date: December 31, 2008
Creator: Smith, A
System: The UNT Digital Library
4-D XRD for strain in many grains using triangulation (open access)

4-D XRD for strain in many grains using triangulation

Determination of the strains in a polycrystalline materialusing 4-D XRD reveals sub-grain and grain-to-grain behavior as a functionof stress. Here 4-D XRD involves an experimental procedure usingpolychromatic micro-beam X-radiation (micro-Laue) to characterizepolycrystalline materials in spatial location as well as with increasingstress. The in-situ tensile loading experiment measured strain in a modelaluminum-sapphire metal matrix composite using the Advanced Light Source,Beam-line 7.3.3. Micro-Laue resolves individual grains in thepolycrystalline matrix. Results obtained from a list of grains sorted bycrystallographic orientation depict the strain states within and amongindividual grains. Locating the grain positions in the planeperpendicular to the incident beam is trivial. However, determining theexact location of grains within a 3-D space is challenging. Determiningthe depth of the grains within the matrix (along the beam direction)involved a triangulation method tracing individual rays that producespots on the CCD back to the point of origin. Triangulation wasexperimentally implemented by simulating a 3-D detector capturingmultiple diffraction images while increasing the camera to sampledistance. Hence by observing the intersection of rays from multiple spotsbelonging to the corresponding grain, depth is calculated. Depthresolution is a function of the number of images collected, grain to beamsize ratio, and the pixel resolution of the CCD. The 4DXRD methodprovides grain morphologies, strain …
Date: December 31, 2006
Creator: Bale, Hrishikesh A.; Hanan, Jay C. & Tamura, Nobumichi
System: The UNT Digital Library
ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE (open access)

ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE

Hydrogen storage is one of the greatest challenges for implementing the ever sought hydrogen economy. Here we report a novel cycle to reversibly form high density hydrogen storage materials such as aluminium hydride. Aluminium hydride (AlH{sub 3}, alane) has a hydrogen storage capacity of 10.1 wt% H{sub 2}, 149 kg H{sub 2}/m{sup 3} volumetric density and can be discharged at low temperatures (< 100 C). However, alane has been precluded from use in hydrogen storage systems because of the lack of practical regeneration methods; the direct hydrogenation of aluminium to form AlH{sub 3} requires over 10{sup 5} bars of hydrogen pressure at room temperature and there are no cost effective synthetic means. Here we show an unprecedented reversible cycle to form alane electrochemically, using alkali alanates (e.g. NaAlH{sub 4}, LiAlH{sub 4}) in aprotic solvents. To complete the cycle, the starting alanates can be regenerated by direct hydrogenation of the dehydrided alane and the alkali hydride being the other compound formed in the electrochemical cell. The process of forming NaAlH{sub 4} from NaH and Al is well established in both solid state and solution reactions. The use of adducting Lewis bases is an essential part of this cycle, in the isolation …
Date: December 31, 2008
Creator: Fewox, C; Ragaiy Zidan, R & Brenda Garcia-Diaz, B
System: The UNT Digital Library
Curved mesh generation and mesh refinement using Lagrangian solid mechanics (open access)

Curved mesh generation and mesh refinement using Lagrangian solid mechanics

We propose a method for generating well-shaped curved unstructured meshes using a nonlinear elasticity analogy. The geometry of the domain to be meshed is represented as an elastic solid. The undeformed geometry is the initial mesh of linear triangular or tetrahedral elements. The external loading results from prescribing a boundary displacement to be that of the curved geometry, and the final configuration is determined by solving for the equilibrium configuration. The deformations are represented using piecewise polynomials within each element of the original mesh. When the mesh is sufficiently fine to resolve the solid deformation, this method guarantees non-intersecting elements even for highly distorted or anisotropic initial meshes. We describe the method and the solution procedures, and we show a number of examples of two and three dimensional simplex meshes with curved boundaries. We also demonstrate how to use the technique for local refinement of non-curved meshes in the presence of curved boundaries.
Date: December 31, 2008
Creator: Persson, P.-O. & Peraire, J.
System: The UNT Digital Library
Uncharted Microbial World: Microbes and Their Activities in the Environment (open access)

Uncharted Microbial World: Microbes and Their Activities in the Environment

Microbes are the foundation for all of life. From the air we breathe to the soil we rely on for farming to the water we drink, everything humans need to survive is intimately coupled with the activities of microbes. Major advances have been made in the understanding of disease and the use of microorganisms in the industrial production of drugs, food products and wastewater treatment. However, our understanding of many complicated microbial environments (the gut and teeth), soil fertility, and biogeochemical cycles of the elements is lagging behind due to their enormous complexity. Inadequate technology and limited resources have stymied many lines of investigation. Today, most environmental microorganisms have yet to be isolated and identified, let alone rigorously studied. The American Academy of Microbiology convened a colloquium in Seattle, Washington, in February 2007, to deliberate the way forward in the study of microorganisms and microbial activities in the environment. Researchers in microbiology, marine science, pathobiology, evolutionary biology, medicine, engineering, and other fields discussed ways to build on and extend recent successes in microbiology. The participants made specific recommendations for targeting future research, improving methodologies and techniques, and enhancing training and collaboration in the field. Microbiology has made a great deal …
Date: December 31, 2007
Creator: Harwood, Caroline & Buckley, Merry.
System: The UNT Digital Library
MEASUREMENT AND CALCULATION OF RADIONUCLIDE ACTIVITIES IN SAVANNAH RIVER SITE HIGH LEVEL WASTE SLUDGE FOR ACCEPTANCE OF DEFENSE WASTE PROCESSING FACILITY GLASS IN A FEDERAL REPOSITORY (open access)

MEASUREMENT AND CALCULATION OF RADIONUCLIDE ACTIVITIES IN SAVANNAH RIVER SITE HIGH LEVEL WASTE SLUDGE FOR ACCEPTANCE OF DEFENSE WASTE PROCESSING FACILITY GLASS IN A FEDERAL REPOSITORY

This paper describes the results of the analyses of High Level Waste (HLW) sludge slurry samples and of the calculations necessary to decay the radionuclides to meet the reporting requirement in the Waste Acceptance Product Specifications (WAPS) [1]. The concentrations of 45 radionuclides were measured. The results of these analyses provide input for radioactive decay calculations used to project the radionuclide inventory at the specified index years, 2015 and 3115. This information is necessary to complete the Production Records at Savannah River Site's Defense Waste Processing Facility (DWPF) so that the final glass product resulting from Macrobatch 5 (MB5) can eventually be submitted to a Federal Repository. Five of the necessary input radionuclides for the decay calculations could not be measured directly due to their low concentrations and/or analytical interferences. These isotopes are Nb-93m, Pd-107, Cd-113m, Cs-135, and Cm-248. Methods for calculating these species from concentrations of appropriate other radionuclides will be discussed. Also the average age of the MB5 HLW had to be calculated from decay of Sr-90 in order to predict the initial concentration of Nb-93m. As a result of the measurements and calculations, thirty-one WAPS reportable radioactive isotopes were identified for MB5. The total activity of MB5 …
Date: December 31, 2008
Creator: Bannochie, C; David Diprete, D & Ned Bibler, N
System: The UNT Digital Library
The Genomes On Line Database (GOLD) in 2007: status of genomic and metagenomic projects and their associated metadata (open access)

The Genomes On Line Database (GOLD) in 2007: status of genomic and metagenomic projects and their associated metadata

The Genomes On Line Database (GOLD) is a comprehensive resource of information for genome and metagenome projects world-wide. GOLD provides access to complete and ongoing projects and their associated metadata through pre-computed lists and a search page. The database currently incorporates information for more than 2900 sequencing projects, of which 639 have been completed and the data deposited in the public databases. GOLD is constantly expanding to provide metadata information related to the project and the organism and is compliant with the Minimum Information about a Genome Sequence (MIGS) specifications.
Date: December 31, 2007
Creator: Fenner, Marsha W; Liolios, Konstantinos; Mavromatis, Konstantinos; Tavernarakis, Nektarios & Kyrpides, Nikos C.
System: The UNT Digital Library
A Strong Hot Spot Theorem (open access)

A Strong Hot Spot Theorem

A real number alpha is said to be b-normal if every m-long string of digits appears in the base-b expansion of alpha with limiting frequency b-m. We prove that alpha is b-normal if and only if it possesses no base-b ''hot spot''. In other words, alpha is b-normal if and only if there is no real number y such that smaller and smaller neighborhoods of y are visited by the successive shifts of the base-b expansion of alpha with larger and larger frequencies, relative to the lengths of these neighborhoods
Date: December 31, 2005
Creator: Bailey, David H. & Misiurewicz, Michal
System: The UNT Digital Library
Scalable parallel Newton-Krylov solvers for discontinuous Galerkin discretizations (open access)

Scalable parallel Newton-Krylov solvers for discontinuous Galerkin discretizations

We present techniques for implicit solution of discontinuous Galerkin discretizations of the Navier-Stokes equations on parallel computers. While a block-Jacobi method is simple and straight-forward to parallelize, its convergence properties are poor except for simple problems. Therefore, we consider Newton-GMRES methods preconditioned with block-incomplete LU factorizations, with optimized element orderings based on a minimum discarded fill (MDF) approach. We discuss the difficulties with the parallelization of these methods, but also show that with a simple domain decomposition approach, most of the advantages of the block-ILU over the block-Jacobi preconditioner are still retained. The convergence is further improved by incorporating the matrix connectivities into the mesh partitioning process, which aims at minimizing the errors introduced from separating the partitions. We demonstrate the performance of the schemes for realistic two- and three-dimensional flow problems.
Date: December 31, 2008
Creator: Persson, P.-O.
System: The UNT Digital Library
Advanced turbine cooling, heat transfer, and aerodynamic studies (open access)

Advanced turbine cooling, heat transfer, and aerodynamic studies

The contractual work is in three parts: Part I - Effect of rotation on enhanced cooling passage heat transfer, Part II - Effect of Thermal Barrier Coating (TBC) spallation on surface heat transfer, and Part III - Effect of surface roughness and trailing edge ejection on turbine efficiency under unsteady flow conditions. Each section of this paper has been divided into three parts to individually accommodate each part. Part III is further divided into Parts IIIa and IIIb.
Date: December 31, 1995
Creator: Han, Je-Chin & Schobeiri, Meinhard T.
System: The UNT Digital Library
Disilene Addition to C{sub 70} (open access)

Disilene Addition to C{sub 70}

Semiempirical and ab initio Hartree Fock computational results indicate that the highly reactive dienophile tetramethyldisilene, Me{sub 2}Si=SiMe{sub 2}, is an excellent candidate for a novel functionalization of the equator of C{sub 70} via a [2+4] cycloaddition to the 21, 22, 23, 42 carbons. Thermal or photochemical generation of tetramethyldisilene in the presence of C{sub 70} results in similar complex mixtures in which the major product appears to be that of [2+2] cycloaddition to the 7,8 carbons of C{sub 70}. A minor product clearly results from [2+2] cycloaddition to the 1,9 carbons. Both of these products are hydrolytically unstable and are converted nonspecifically to mixtures of 1,9- and 7,8-C{sub 70}H{sub 2} which are also present in HPLC traces of the reaction mixtures.
Date: December 31, 1994
Creator: Jacobs, S. J.; Cahill, P. A. & Rohlfing, C. M.
System: The UNT Digital Library
Pilot gasification and hot gas cleanup operations (open access)

Pilot gasification and hot gas cleanup operations

The Morgantown Energy Technology Center (METC) has an integrated gasification hot gas cleanup facility to develop gasification, hot particulate and desulfurization process performance data for IGCC systems. The objective of our program is to develop fluidized-bed process performance data for hot gas desulfurization and to further test promising sorbents from lab-scale screening studies at highpressure (300 psia), and temperatures (1,200{degrees}F) using coal-derived fuel gases from a fluid-bed gasifier. The 10-inch inside diameter (ID), nominal 80 lb/hr, air blown gasifier is capable of providing about 300 lb/hr of low BTU gas at 1,000{degrees}F and 425 psig to downstream cleanup devices. The system includes several particle removal stages, which provide the capability to tailor the particle loading to the cleanup section. The gas pressure is reduced to approximately 300 psia and filtered by a candle filter vessel containing up to four filter cartridges. For batch-mode desulfurization test operations, the filtered coal gas is fed to a 6-inch ID, fluid-bed reactor that is preloaded with desulfurization sorbent. Over 400 hours of gasifier operation was logged in 1993 including 384 hours of integration with the cleanup rig. System baseline studies without desulfurization sorbent and repeatability checks with zinc ferrite sorbent were conducted before testing …
Date: December 31, 1995
Creator: Rockey, John M.; Galloway, Edwin; Thomson, Teresa A.; Rutten, Jay & Lui, Alain
System: The UNT Digital Library
Heavy duty gas turbine combustion tests with simulated low BTU coal gas (open access)

Heavy duty gas turbine combustion tests with simulated low BTU coal gas

There is an increasing industry interest in integrated gas turbine combined cycle plants in which coal gasifiers provide the fuel for the gas turbines. Some gasifier plant designs, including the air-blown processes, some integrated oxygen blown processes and some oxygen-blown processes followed by heavy moisturization, produce fuel gases which have lower heating values ranging from 130 to below 100 BTU/scf for which there is little gas turbine combustion experience. This program has the objectives to: Parametrically determine the effects of moisture, nitrogen and carbon dioxide as diluents so that the combustion characteristics of many varieties of gasification product gases can be reasonably predicted without physically testing each specific gas composition; determine emissions characteristics including NO{sub x}, CO, levels etc. associated with each of the diluents; operate with two syngas compositions; DOE chosen air-blown and integrated oxygen-blown, to confirm that the combustion characteristics are in line with predictions; determine if ``logical`` refinements to the fuel nozzle will yield improved performance for LBTU fuels; determine the conversion rate of ammonia to NO{sub x}; determine the effects of methane inclusion in the fuel.
Date: December 31, 1992
Creator: Ekstrom, T. E.; Battista, R. A. & Maxwell, G. P.
System: The UNT Digital Library
An improvement in the modified finite element procedure for underwater shock analysis (open access)

An improvement in the modified finite element procedure for underwater shock analysis

The modified finite element procedure for underwater shock analysis decomposes the total pressure field into the incident, reflected and radiated pressure. The incident pressure is calculated by using a closed form solution. The reflected and radiated pressure are calculated in two separate finite element analyses. Artificial damping is added in the finite element analyses. Since these two pressures are generated from the fluid-structure interface and mostly propagate away from the interface, the artificial damping has no significant effect on the result. The modified finite element procedure was developed using a displacement formulated finite element to model the fluid region. In the paper, a pressure formulated finite element is used to model the fluid region which has a potential of saving 90 percent of the computer time. In doing so, the reflected and radiated pressure are calculated in one analysis which greatly simplifies the analysis procedure and saves more computer time. Two verification examples are given.
Date: December 31, 1992
Creator: Chan, S. K.
System: The UNT Digital Library
FLASH predictions of the MB-2 steam line break tests (open access)

FLASH predictions of the MB-2 steam line break tests

If a main steam line from a pressurized water reactor (PWR) steam generator were to rupture, the effect would be a depressurization of the secondary side and a consequential overcooling transient on the primary side. Analyses must accurately predict the effects of the rapid cooldown of the reactor vessel coolant on positive nuclear-kinetic reactivity feedback to the core plus thermal shock to the reactor vessel and other primary system components. Many early studies of the steam line break (SLB) transient made extremely conservative assumptions to maximize the primary to secondary heat transfer which in turn maximized the reactor vessel cooldown rate. Among the more significant of these assumptions was that flow from the break was pure steam and that the tube bundle remained covered until the secondary mass inventory was significantly reduced. The Model F commercial PWR steam generator testing performed in the Model Boiler No. 2 (MB-2) facility located at the Westinghouse Engineering Test Facility in Tampa, Florida provided data to better qualify the actual variation in these key parameters. A conclusion of this analysis is that the MB-2 steam line break data base is accurate and of sufficient detail to provide a valuable basis for making comparisons relative …
Date: December 31, 1992
Creator: Lincoln, F. W.; Coffield, R. D. & Johnson, E. G.
System: The UNT Digital Library
Polarized protons in large center of mass collisions (open access)

Polarized protons in large center of mass collisions

We present a scheme for polarized proton operation in the RHIC collider complex. For low energies the partial siberian snake project in the AGS is reviewed. As the energy is increased the difficulties of preserving the polarization also increases. A plan for preserving the polarization at high energies in RHIC using two Siberian Snakes is discussed. Spin rotators will be used around the collision points so that the helicity can be varied.
Date: December 31, 1992
Creator: Tepikian, S.
System: The UNT Digital Library
Some Measurements for Determining Strangeness Matrix Elements in the Nucleon (open access)

Some Measurements for Determining Strangeness Matrix Elements in the Nucleon

Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.
Date: December 31, 1991
Creator: Henley, Ernest M.; Pollock, S. J.; Ying, S.; Frederico, T.; Krein, & Williams, A. G.
System: The UNT Digital Library
Logistics for the implementation of lead-free solders on electronic assemblies (open access)

Logistics for the implementation of lead-free solders on electronic assemblies

The prospects of legislative and regulatory action aimed at taxing, restricting or banning lead-bearing materials from manufactured products has prompted the electronics community to examine the implementation of lead-free solders to replace currently used lead-containing alloys in the manufacture of electronic devices and assemblies. The logistics for changing the well established ``tin-lead solder technology`` require not only the selection of new compositions but also the qualification of different surface finishes and manufacturing processes. The meniscometer/wetting balance technique was used to evaluate the wettability of several candidate lead-free solders as well as to establish windows on processing parameters so as to facilitate prototype manufacturing. Electroplated and electroless 100Sn coatings, as well as organic preservatives, were also examined as potential alternative finishes for device leads and terminations as well as circuit board conductor surfaces to replace traditional tin-lead layers. Sandia National Laboratories and AT&T have implemented a program to qualify the manufacturing feasibility of surface mount prototype circuit boards using several commercial lead-free solders by infrared reflow technology.
Date: December 31, 1993
Creator: Vianco, P. T. & Artaki, I.
System: The UNT Digital Library
Efficient data transmission from silicon wafer strip detectors (open access)

Efficient data transmission from silicon wafer strip detectors

An architecture for on-wafer processing is proposed for central silicon-strip tracker systems as they are currently designed for high energy physics experiments at the SSC, and for heavy ion experiments at RHIC. The data compression achievable with on-wafer processing would make it possible to transmit all data generated to the outside of the detector system. A set of data which completely describes the state of the wafer for low occupancy events and which contains important statistical information for more complex events can be transmitted immediately. This information could be used in early trigger decisions. Additional data packages which complete the description of the state of the wafer vary in size and are sent through a second channel. By buffering this channel the required bandwidth can be kept far below the peak data rates which occur in rate but interesting events. 18 refs.
Date: December 31, 1991
Creator: Cooke, B. J.; Lackner, K. S.; Palounek, A. P. T.; Sharp, D. H.; Winter, L. & Ziock, H. J.
System: The UNT Digital Library