Resource Type
Partner
UNT Libraries Government Documents Department
8,913
UNT College of Arts and Sciences
121
UNT College of Science
63
UNT College of Engineering
49
UNT College of Liberal Arts & Social Sciences
17
UNT Libraries Special Collections
15
UNT College of Education
15
University of North Texas
15
UNT Libraries
9
UNT College of Information
5
21 More
Collection
Office of Scientific & Technical Information Technical Reports
8,913
UNT Scholarly Works
314
LGBT Collections
7
The Society Diaries Collection
7
Dennis Vercher Collection (The Dallas Way)
6
Harris and Eliza Kempner
2
Rescuing Texas History, 2014
2
Texas History Collection
2
UNT Graduate Student Works
2
Abilene Library Consortium
1
12 More
Serial/Series Title
Publicity Articles
7
AIDS: Bill Clinton
4
Harvard Business Review
2
Personal Papers (MS 80-0002)
2
2008 TSDC General Information
1
Education Week
1
Inventory Policy Series
1
National WASP WWII Museum Collection
1
Parkland Lawsuit - Dialog, 1988
1
Sub-Antarctic Biocultural Conservation Program
1
1 More
Degree Department
Degree Discipline
States
Decade
Month
Language
Implementation of logical networks in System 2000 data bases
The need for a means to express general relationships (networks) among entity occurrences (data sets) in System 2000 data bases is established. Integer expression of general path segments is described as a means to meet this need. Operations on the expressions are also described. Two possible implementations are discussed. Either or both of these implementations can be included by the user in System 2000 data bases. They are compatible with the System 2000 hierarchical data model, and could also be internally implemented as an enhancement to System 2000. 4 figures.
Date:
May 1, 1980
Creator:
Hall, R. C.
System:
The UNT Digital Library
Measurement of radiofrequency fields
We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs.
Date:
May 1, 1992
Creator:
Leonowich, J.A.
System:
The UNT Digital Library
Broadband diffractive lens
Significant progress has been made toward solving the century-old problem of chromatic aberrations in diffractive optics. Our approach exploits modern materials and microfabrication technology and is very different from the purely diffractive strategy,'' which is commonly employed and which results in multiple diffractive elements separated by a finite distance. We have developed a Fresnel zone plate lens comprised of a serial stack of patterned minus-filters which allows broadband radiation to be focused (or imaged) without longitudinal or transverse chromatic aberrations. 7 refs., 4 figs.
Date:
May 28, 1991
Creator:
Ceglio, N. M.; Hawryluk, A. M.; London, R. A.; Seppala, L. G. (Lawrence Livermore National Lab., CA (USA)) & Gaines, D. P. (Brigham Young Univ., Provo, UT (USA))
System:
The UNT Digital Library
BRUTE
BRUTE is an algorithm to derive the implied boundary of a piecepart from the part's wireframe representation. BRUTE's input is an IGES file. The geometry is extracted and used to derive the edge-vertex (EV) topology. BRUTE then uses a divide-and-conquer method to derive all reasonable face-edge-vertex (FEV) topologies from the EV topology. The final step is to determine the geometry of each face by using the geometry of its edges. Any FEV topology that contains a face that is not a valid surface type is rejected. Valid surface types are plane, cylinder, cone, and sphere.
Date:
May 1, 1982
Creator:
Christensen, N.C.
System:
The UNT Digital Library
Non-dispersive soft x-ray fluorescence analyses of rocks and waters. [Samples from geothermal areas in north-central Nevada]
None
Date:
May 1, 1975
Creator:
Herbert, A.J. & Bowman, H.R.
System:
The UNT Digital Library
Two-Photon Collisions and QCD
A critical review of the applications of QCD to low- and high-p/sub T/ interactions of two photons is presented. The advantages of the two-photon high-p/sub T/ tests over corresponding hadronic beam and/or target tests of QCD are given particular emphasis.
Date:
May 1, 1980
Creator:
Gunion, J. F.
System:
The UNT Digital Library
Optimal forced-air distribution in new housing
This paper summarizes a system integration approach to residential heating, cooling, and ventilation, embodied in a tight building envelope with precooling and dehumidification of forced ventilation air, and with ducts in the conditioned space.
Date:
May 1, 1992
Creator:
Andrews, J. W.
System:
The UNT Digital Library
Modeling of time dependent mesoscale concentrations
None
Date:
May 1, 1975
Creator:
Pepper, D.W. & Kern, C.D.
System:
The UNT Digital Library
Fabrication development of full-sized components for GCFR core assemblies
This paper presents the status of the development of full-sized components for gas-cooled fast reactor (GCFR) core assemblies. Methods for ribbing of the fuel rod cladding, fabrication of grid spacers of two different designs, drawing of assembly flow ducts, and fabrication of fission gas collection manifolds by several methods are discussed.
Date:
May 1980
Creator:
Lindgren, J. R.; Flynn, P. W. & Foster, L. C.
System:
The UNT Digital Library
Writing audit findings: Be reasonable
A customary approach to auditing and reporting deficiencies is to keep a running list of those that are found, evaluate the severity of each, and based on the evidence, document findings or observations or concerns in an audit report. The report is issued and the auditee is normally requested to address root cause'' as part of their corrective action. This paper describes a root problems'' approach to documenting audit findings that is designed not only to put the QA auditor in a more favorable light, but to more effectively enable the auditee to identify root cause and meaningful corrective action. The positive results of this approach are considerable. You will have fewer findings but those you do have will be substantial. You will cite requirements that sound reasonable and make arguments difficult. If some of the supporting deficiencies (examples) prove to be incorrect, you will still have ample support for the original finding. You will be seen as reasonable individual who can help lead the auditee towards identification of root cause without taking away part of the responsibility. You even have a fair chance of fostering a sense of commitment to quality improvement on the auditee's part. This in itself, …
Date:
May 1, 1992
Creator:
Girvin, N.W.
System:
The UNT Digital Library
Electron ray tracing programs for gun design and beam transport. [None]
Computer simulation of electron and ion sources is made by using a class of computer codes known as gun design programs. In this paper, we shall first list most of the necessary and some optional capabilities of such programs. Then we will briefly note specific codes and/or authors of codes with attention to specialized applications if any. There may be many more such programs in use than are treated here; we are only trying to cover a range of examples, not perform a comprehensive survey.
Date:
May 1, 1988
Creator:
Herrmannsfeldt, W.B.
System:
The UNT Digital Library
New rf power system for SuperHILAC
The upgraded rf system for the SuperHILAC is now operational using 9 new tetrode amplifiers. Each amplifier can produce in excess of 1MW of 70 Mhz pulsed rf power. Ferrite is used to decouple the screen grid circuit and to absorb parasitic oscillations. This results in a very stable amplifier with reasonable gain. This system uses a common 8 MW anode power supply and crowbar system. Overall system efficiency has been increased significantly. We project a 3 year payback on the equipment cost, realized from the power savings alone. 2 refs., 5 figs.
Date:
May 1, 1985
Creator:
Fugitt, J.; Lancaster, H. & Sorensen, R.
System:
The UNT Digital Library
High-temperature borate liquids: physical properties of glass-forming compositions
Several experimental routes can be used to develop a better understanding of the polymeric constitution (polyanionic and/or polyhedral distribution) of borate, germanate, and silicate glasses. Spectral, chemical, physical-chemical, and mechanical property information can be determined directly for the glass compositions of interest. Generally, only physical-chemical information is readily accessible for the corresponding high temperature liquids. It will be shown that information on each state of matter has its own particular merits. Most of the evidence thus far published suggests an excellent agreement between polyhedral distributions in an oxide glass and its corresponding high temperature liquid state. There is no well known oxide glass forming system for which such a state of affairs does not exist. In spite of this, occasional efforts are put forth which ignore some of what is known for oxide liquids, glasses, and crystals. Such attempts therefore invariably imply, if only indirectly, that significant changes occur in the polyhedral distributions close to the glass transition temperature region. Specific examples to be discussed will include efforts that avoid well known coordination change equilibria such as BO/sub 3/ reversible BO/sub 4/ and GeO/sub 4/ reversible GeO/sub 6/.
Date:
May 6, 1977
Creator:
Riebling, E.F.
System:
The UNT Digital Library
Attack of stainless steel type 2169 by decomposition products of TATB studied by Auger spectroscopy and ESCA
None
Date:
May 19, 1975
Creator:
Colmenares, C.; Meisenheimer, R.; Smith, R.L. & Fischer, J.W.
System:
The UNT Digital Library
Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics
Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction of component performance and the development of process technology. Knowledge of the degradation extent of fiber tows or monofilament degradation after processing, extent of open porosity before densification, and filament/fiber alignments before and after processing are also examples of important variables to be measured. Work in this program has emphasized continuous fiber ceramic matrix composites (CFCCs) that use chemical vapor infiltration (CVI)-infiltrated SiC/SiC materials, primarily those made of Nicalon satin or plain weave with 16 {times} 16 tows/in. in 2-D layups. All studied samples were provided by Oak Ridge National Laboratory and were made using 100 layers per inch. CVI specimens with 0/30/60, 0/90, and 0/45 were examined by 3-D X-ray microtomography to characterize in-plane fiber orientations. Current information suggests that for Nicalon-type fiber architecture, a {plus minus}2--1/2{degrees} misalignment may not affect mechanical properties. Thus the near-term goal has been to establish a detection capability for angular orientation. By using 512 {times} 512 images from 3-D X-ray CT data with pixel sizes of < 140 {mu}m and …
Date:
May 1, 1992
Creator:
Ellingson, W.A.; Singh, J.P.; Holloway, D.L.; Dieckman, S.L.; Singh, D.; Sivers, E.A. et al.
System:
The UNT Digital Library
Thyratron characteristics under high di/dt and high-repetition-rate operation
Power conditioning systems for high peak and average power, high repetition rate discharge excited lasers involve operation of modulator components in unconventional regimes. Reliable operation of switches and energy storage elements under high voltage and high di/dt conditions is a pacing item for laser development at the present time. To test and evaluate these components a Modulator Component Test Facility (MCTF) was constructed. The MCTF consists of a command charge system, energy storage capacitors, thyratron switch with inverse thyratron protection, and a resistive load. The modulator has initially been operated at voltages up to 60 kV at 600 Hz. Voltage, current, and calorimetric diagnostics are provided for major modulator components. Measurements of thyratron characteristics under high di/dt operation are presented. Commutation energy loss and di/dt have been measured as functions of the tube hydrogen pressure.
Date:
May 11, 1981
Creator:
Ball, D.; Hill, J. & Kan, T.
System:
The UNT Digital Library
Some physical aspects of higher twist
A brief description of some of the physical origins of higher twist terms and their possible relevance to data is given. 13 references, 7 figures.
Date:
May 1, 1980
Creator:
Blankenbecler, R.
System:
The UNT Digital Library
Thick Target Neutron Yields and Spectra From the Li(d,xn) Reaction at 35 Mev
Measurements were performed using a 35 MeV deuteron beam from the isochronous cyclotron at the University of California at Davis. Data were obtained using the time-of-flight technique with an NE213 liquid scintillator. One set of measurements was used to observe the neutron spectrum from approx. 1 MeV to approx. 50 MeV, the maximum kinematically allowed energy. Observation angles were from 0/sup 0/ to 150/sup 0/ with emphasis on forward angles. Spectral data below approx. 1.5 MeV had poor accuracy. It was felt that a significant fraction of the neutron yield might lie at still lower energies, therefore a second set of measurements was performed to investigate the spectra to as low an energy as possible. Additional measurements were performed with a target enriched in the isotope /sup 6/Li replacing the natural lithium target used in previous measurements. The main advantage of a /sup 6/Li target is that the maximum kinematically allowed neutron energy is only about 38 MeV, hence reducing shielding requirements. The experiments, preliminary results, and future needs will be described.
Date:
May 1, 1980
Creator:
Johnson, D. L.; Mann, F. M.; Watson, J. W.; Brady, F. P.; Ullmann, J. L.; Romero, J. L. et al.
System:
The UNT Digital Library
Frank loop unfaulting mechanism in fcc metals during neutron irradiation
The unfaulting mechanism whereby sessile Frank dislocation loops evolve into a complex tangle of glissile dislocations during irradiation of face centered cubic metals is not well understood. It is presumed that such loops grow by absorption of point defects until interactions develop which provide sufficient impetus for nucleation of an unfaulting event. The loops then become glissile, interact and form a dislocation network. An alternate mechanism which has been observed to occur in an austenitic precipitation-strengthened commercial alloy irradiated in the EBR-II fast reactor. The mechanism requires an interaction between the sessile a/3 <111> Frank loop and a moving glissile a/2 <110> perfect dislocation. An unfaulting a/6 <112> dislocation is created which, as it moves, eliminates the Frank loop and leaves only a perfect dislocation with the original a/2 <110> Burgers vector. This process is demonstrated. This alternate mechanism can have significant impact on the development of the dislocation microstructure in a metal undergoing irradiation creep. This impact will be discussed in relation to relevant irradiation creep models.
Date:
May 1980
Creator:
Gelles, D. S.
System:
The UNT Digital Library
Ripple burn control
The ripple contribution to the ion thermal conductivity is ideally suited in magnitude, temperature dependence, and spatial dependence to serve as a burn control mechanism. Furthermore, a considerable measure of automatic burn control results because of the radial shift of the plasma to a region of higher ripple. Unfortunately, the window in ripple values consistent with both ignition and a burn equilibrium is uncomfortably narrow, given the current lack of contact between the theoretical models of ripple transport and experimental observations. A survey is made of the techniques to vary the ripple and thus broaden the design window. One new technique is discussed in some detail: the use of ferromagnetic materials in the shield with magnetic properties which are sensitive functions of the operating temperature.
Date:
May 1, 1980
Creator:
Bhadra, D. K.; Petrie, T. W.; Peuron, U. A. & Rawls, J. M.
System:
The UNT Digital Library
W mass and W asymmetry at CDF
The lepton charge asymmetry from W decaying into a lepton and a neutrino is discussed (preliminary result). This measurement gives information on parton distribution functions at low x values. The derivation of the recently published W mass value of 79.91 {plus minus} 0.39 GeV/c{sup 2} is also presented. M{sub W} is used to set an upper limit on the top quark mass. 13 refs., 4 figs., 1 tab.
Date:
May 1, 1991
Creator:
Leone, S. (Pisa Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Pisa (Italy))
System:
The UNT Digital Library
Determination of the composition of ordered Pt/sub 3/Co by atom-probe field-ion microscopy: intrinsic problems
Atom-probe field-ion microscope (FIM) analyses were performed on specimens of fully ordered Pt/sub 3/Co. The purpose of the investigation was to study the effects of different important experimental variables on the composition measured by the atom probe technique. The dependence of the alloy's composition on the following variables was determined: (1) pulse fraction (f); (2) specimen temperature; (3) crystal plane; and (4) field-evaporation rate. It was demonstrated that the composition determined by atom probe analyses of Pt/sub 3/Co was very sensitive to the above four variables. The observations were discussed in terms of possible field-evaporation mechanisms.
Date:
May 1, 1980
Creator:
Yamamoto, M. & Seidman, D. N.
System:
The UNT Digital Library
High-intensity photoionization of H sub 2
A tunable, high-intensity picosecond dye laser system has been employed with electron energy analysis to investigate the dynamics of (3+1) resonance-enhanced multiphoton ionization of H{sub 2} via different vibrational levels of its B{sub 1}{Sigma}{sub u}{sup +} and C{sup 1}{Pi}{sub u} electronic states. We observe production of molecular ions in various vibrational levels, with a shift to increased population of lower vibrational states of H{sub 2}{sup +} consistent with the a.c. Stark shift of the correspondingly lower vibrational levels of the C state into resonance with the three- photon energy of the laser. Clear evidence of direct dissociation of H{sub 2} followed by single-photon ionization of the excited H atom is observed as well. Above threshold ionization of these two processes occurs readily. We also find that dissociative ionization is an increasingly important ionization pathway as the wavelength is increased. Finally, we see evidence of a new ionization pathway, which we assign to photoionization into a transient bound state created by the avoided crossing of the first repulsive electronic state of H{sub 2}{sup +}, {vert bar}2p{sigma}{sub u}, n{r angle}, with the single-photon-dressed ground state of H{sub 2}{sup +}, {vert bar}1s{sigma}{sub g},n + 1{r angle}. 6 refs., 2 figs.
Date:
May 1, 1991
Creator:
Allendorf, S.W. & Szoeke, A.
System:
The UNT Digital Library
Whole facility energy use monitoring
Pacific Northwest Laboratory (PNL) is conducting numerous field monitoring studies of the induces of energy in buildings. Energy use monitoring techniques have been developed to provide reliable empirical measurements of energy consumption according to enduse and time of day. These measurements are analyzed in conjunction with climate and site characteristics data to determine energy use efficiencies and identify energy conservation and load management opportunities. This paper draws upon this experience to advance an approach to minimize the cost and maximize the benefits of field data collection projects for entire facilities.
Date:
May 1, 1989
Creator:
Mazzucchi, R.P. & Jo, J.
System:
The UNT Digital Library