U N T Established 1890 U N T
University Libraries

Digital Collections

Access

Resource Type

Partner

Collection

Serial/Series Title

Degree Department

Degree Discipline

Degree Level

Country

States

Counties

Decade

Year

Month

Day

Language

75,927 Matching Results

Start Over Access Open Access Day 19th Language English

Results open in a new window/tab.

prev Results: 97 - 120 of 75,927 next
Best Match Title Creator Date Created (Newest) Date Created (Oldest) Date Added (Newest) Date Added (Oldest)
Conceptual design and systems analysis of photovoltaic systems. Volume I. Study summary. Final report (open access)

Conceptual design and systems analysis of photovoltaic systems. Volume I. Study summary. Final report

This investigation of terrestrial PV systems considered the technical and economic feasibility for systems in three size categories: a small system of about 12 kW peak output for on-site residential use; a large 1500 MW central power plant contributing to the bulk energy of a utility system power grid; and an intermediate size system of about 250 kW for use on public or commercial buildings. In each category, conceptual designs were developed, performance was analyzed for a range of climatic regions, economic analyses were performed, and assessments were made of pertinent institutional issues. The report consists of three volumes. This volume contains a Study Summary of the major study results. Volume II contains the detailed results pertaining to on-site residential photovoltaic systems, central power plant photovoltaic systems, and intermediate size systems applied to commercial and public buildings. Volume III contains supporting appendix material. (WHK)
Date: March 19, 1977
Creator: Kirpich, A.
Object Type: Report
System: The UNT Digital Library
SM-1 Reactor Vessel Cover and Flange Stress Analysis (open access)

SM-1 Reactor Vessel Cover and Flange Stress Analysis

The maximum stress calculated for the SMl-1 reactor vessel closure studs occurs during operation at full power. This value is 27,180 psi of which 19,800 psi is tension and 7380 psi bending. This stress does not include a stress concentration factor for effect of threads. It was eonservatively assumed the studs were initially tightened to a code allowable stress of 20,000 psi as specified in the ASME Code rather than the lesser stress obtained by the normal operating procedure. The maximum calculated stress occurs at the outside surface of the cover where the stress ranges from 318 psi in tension to 90,660 psi in compression. The alternating stress is 50,000 psi. According to the Navy Code for a stress range of 50,000 psi, the eover material ean safely undergo a maximum of 1600 cycles. It was estimated that the SM-1 will go through approximately 000 startup and shutdown cycles during a 20-yr life period, so the calculated stress is regarded as safe. For a transient eondition of 30 deg F/hr during heat-up, approximate temperature differences between the inside and outside surfaces of the cover were obtained. Temperature differentials between the inside and outside surfaces of the cover are increased by …
Date: February 19, 1962
Creator: Sayre, M. F.
Object Type: Report
System: The UNT Digital Library
PLUTONIUM OXALATE DISK FILTER AND FILTER MEDIA STUDIES (open access)

PLUTONIUM OXALATE DISK FILTER AND FILTER MEDIA STUDIES

for filtration of plutonium oxalate slurries. A scalpel produces a slit in the filter precoat, leading to increased filtration in this slit, and the oxalate is removed by a doctor knife; this technique results in prolonged blowback cycles and more uniform delivery of filtered oxalate to subsequent processing steps. Several types of filter media were tested, and rigid porous aluminum oxide was found to be the best one. (D.L.C.)
Date: October 19, 1959
Creator: Rey, G.
Object Type: Report
System: The UNT Digital Library
Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np (open access)

Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np

Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.
Date: February 19, 1988
Creator: Hoff, R.W.
Object Type: Article
System: The UNT Digital Library
Free-electron laser using rf-coupled accelerating and decelerating structures (open access)

Free-electron laser using rf-coupled accelerating and decelerating structures

A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is extracted from the electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy extracted from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.
Date: June 19, 1981
Creator: Brau, C.A.; Swenson, D.A. & Boyd, T.J. Jr.
Object Type: Patent
System: The UNT Digital Library
[News Clip: TCJC Lawsuit] captions transcript

[News Clip: TCJC Lawsuit]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: January 19, 1994, 10:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Waco remembered] captions transcript

[News Clip: Waco remembered]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story. This story aired at 6pm.
Date: April 19, 1994, 6:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: King verdict] captions transcript

[News Clip: King verdict]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: April 19, 1994, 10:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: China flood] captions transcript

[News Clip: China flood]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: June 19, 1994, 5:30 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will also be investigated.
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
Selective generation and extraction of low emittance electrons from plasmas: A new concept for E-beam cathodes (open access)

Selective generation and extraction of low emittance electrons from plasmas: A new concept for E-beam cathodes

It is shown that hollow cathode discharges can operate in a mode characterized by a two-component electron energy distribution: bulk electrons with a thermal distribution with a temperature of a few electron volts, and a component of fast electrons with an energy of about 30 eV and a thermal spread of about 0.1 eV. Measurements of both parallel and perpendicular energy spreads confirm the existence of fast, low energy spread electrons. Selective extraction of these electrons can form the basis of a high current, high brightness electron gun which could be well suited for EBIS applications. 8 refs., 4 figs., 1 tab.
Date: September 19, 1991
Creator: Hershcovitch, A.
Object Type: Article
System: The UNT Digital Library
[News Clip: Poison murder] captions transcript

[News Clip: Poison murder]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: October 19, 1994, 10:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Lott] captions transcript

[News Clip: Lott]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: September 19, 1994, 6:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: DPD audit] captions transcript

[News Clip: DPD audit]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: August 19, 1994, 6:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading (open access)

High temperature ceramic membrane reactors for coal liquid upgrading

Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.
Date: June 19, 1992
Creator: Tsotsis, T.T.
Object Type: Report
System: The UNT Digital Library
X-ray lines as a density diagnostic in DT plasmas near 100x solid density (open access)

X-ray lines as a density diagnostic in DT plasmas near 100x solid density

The use of electron impact broadened resonance lines to diagnose near-term high density diagnostics is discussed. In particular, the question of how to choose seed and pusher materials to have discernible broadening effects while maintaining line visibility is discussed.
Date: October 19, 1977
Creator: Bailey, D.S.
Object Type: Article
System: The UNT Digital Library
PREPARATION AND FABRICATION OF ThO$sub 2$ FUELS (open access)

PREPARATION AND FABRICATION OF ThO$sub 2$ FUELS

Dense partricles of ThO/sub 2/-UO/sub 2/ were prepared by a sol-gel process and vibratorily compacted into metal tubes to a density approaching 9.0 g/ cc. The steps in this method are all simple and can be carried out behind shielding, which is necessary for refabricating U/sup 233/ fuels. The sol-gel process consists of preparing a hydrous thoria sol, adding the U/sup 233/ as nitrate solution, evaporating to a gel, and finally calcining to almost theoretically dense oxide particles at orly 1150 deg C. The sol-gel-prepared oxide, after being sized, was compacted with a simple, inexpensive pneumatic vibrator. (auth)
Date: June 19, 1962
Creator: Ferguson, D.E.; Arnold, E.D.; Ernst, W.S. Jr. & Dean, O.C.
Object Type: Report
System: The UNT Digital Library
Time-resolved soft-x-ray studies of energy transport in layered and planar laser-driven targets (open access)

Time-resolved soft-x-ray studies of energy transport in layered and planar laser-driven targets

New low-energy x-ray diagnostic techniques are used to explore energy-transport processes in laser heated plasmas. Streak cameras are used to provide 15-psec time-resolution measurements of subkeV x-ray emission. A very thin (50 ..mu..g/cm/sup 2/) carbon substrate provides a low-energy x-ray transparent window to the transmission photocathode of this soft x-ray streak camera. Active differential vacuum pumping of the instrument is required. The use of high-sensitivity, low secondary-electron energy-spread CsI photocathodes in x-ray streak cameras is also described. Significant increases in sensitivity with only a small and intermittant decrease in dynamic range were observed. These coherent, complementary advances in subkeV, time-resolved x-ray diagnostic capability are applied to energy-transport investigations of 1.06-..mu..m laser plasmas. Both solid disk targets of a variety of Z's as well as Be-on-Al layered-disk targets were irradiated with 700-psec laser pulses of selected intensity between 3 x 10/sup 14/ W/cm/sup 2/ and 1 x 10/sup 15/ W/cm/sup 2/.
Date: April 19, 1982
Creator: Stradling, G.L.
Object Type: Report
System: The UNT Digital Library
RADIOISOTOPE AND RADIATION APPLICATIONS. Quarterly Progress Report No. 13 (open access)

RADIOISOTOPE AND RADIATION APPLICATIONS. Quarterly Progress Report No. 13

Research was continued during the report period on the use of isotope neutron sources for producing short-lived radioisotopes. Experiments with a newly constructed betacounting cell are reported in which a 50-curie Be--Po neutron source was used. Study of the radiation chemistry of polymers was continued concerning the effects of polymer structure on free-radical formation. Free-radical formation in several additional polymers was studied. Preliminary work is also reported in an investigation of internal irradiation effects on the chemical activity of catalysts. (J.R.D.)
Date: July 19, 1962
Creator: Sunderman, D.N. ed.
Object Type: Report
System: The UNT Digital Library
Research and Development Studies on Waste Storage Process (open access)

Research and Development Studies on Waste Storage Process

The basic objectives of this program were the determination of the thermal stability of various fission product oxides and nitrates, and an investigation of the gas phase decomposition of ruthenium tetroxide. To accomplish these objectives, a literature survey was flrst made of available physical and chemical data for the oxides and nitrates of Cs, Sr, Ru, Zr, Nb, and Ce. The data were supplemented by a calculation of thermodynamic functions for RuO/sub 4/ vapor from the experimentally determined infrared spectrum and the theoretically calculated raman-active fundamentals. Data are presented graphically. (C.H.)
Date: May 19, 1961
Creator: Ortner, M. H.; Anderson, C. J. & Campbell, P. F.
Object Type: Report
System: The UNT Digital Library
Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense (open access)

Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense

Twenty-seven papers are presented on beryllium supply, production, fabrication, safe handling, analysis, powder technology, and coatings. Separate abstracts have been prepared for the individual papers. (DLC)
Date: February 19, 1988
Creator: Hanafee, J.E. (ed.)
Object Type: Article
System: The UNT Digital Library
Conceptual design and systems analysis of photovoltaic systems. Volume II. Study results. Final report (open access)

Conceptual design and systems analysis of photovoltaic systems. Volume II. Study results. Final report

This investigation of terrestrial PV systems considered the technical and economic feasibility for systems in three size categories: a small system of about 12 kW peak output for on-site residential use; a large 1500 MW central power plant contributing to the bulk energy of a utility system power grid; and an intermediate size system of about 250 kW for use on public or commercial buildings. In each category, conceptual designs were developed, performance was analyzed for a range of climatic regions, economic analyses were performed, and assessments were made of pertinent institutional issues. The report consists of three volumes. Volume I contains a Study Summary of the major study results. This volume contains the detailed results pertaining to on-site residential photovoltaic systems, central power plant photovoltaic systems, and intermediate size systems applied to commercial and public buildings. Volume III contains supporting appendix material. (WHK)
Date: March 19, 1977
Creator: Kirpich, A.
Object Type: Report
System: The UNT Digital Library
Accelerometer and strain gage evaluation (open access)

Accelerometer and strain gage evaluation

This document describes the method developed by Sandia National Laboratories (SNL) to evaluate transducer used in the design certification testing of nuclear material shipping packages. This testing project was performed by SNL for the Office of Civilian Radioactive Waste Management (OCRWM). This evaluation is based on the results of tests conducted to measure ruggedness, failure frequency, repeatability, and manufacturers' calibration data under both field and laboratory conditions. The results of these tests are provided and discussed. The transducer were selected for testing by surveying cask contractors and testing facilities. Important insights relating to operational characteristics of accelerometer types were gained during field testing. 11 refs., 105 figs., 16 tabs.
Date: June 19, 1991
Creator: Ammerman, D. J.; Madsen, M. M.; Uncapher, W. L.; Stenberg, D. R. & Bronowski, D. R.
Object Type: Report
System: The UNT Digital Library
Discrete-event simulation of nuclear-waste transport in geologic sites subject to disruptive events. Final report (open access)

Discrete-event simulation of nuclear-waste transport in geologic sites subject to disruptive events. Final report

This report outlines a methodology to study the effects of disruptive events on nuclear waste material in stable geologic sites. The methodology is based upon developing a discrete events model that can be simulated on the computer. This methodology allows a natural development of simulation models that use computer resources in an efficient manner. Accurate modeling in this area depends in large part upon accurate modeling of ion transport behavior in the storage media. Unfortunately, developments in this area are not at a stage where there is any consensus on proper models for such transport. Consequently, our work is directed primarily towards showing how disruptive events can be properly incorporated in such a model, rather than as a predictive tool at this stage. When and if proper geologic parameters can be determined, then it would be possible to use this as a predictive model. Assumptions and their bases are discussed, and the mathematical and computer model are described.
Date: June 19, 1980
Creator: Aggarwal, S.; Ryland, S. & Peck, R.
Object Type: Report
System: The UNT Digital Library