36,343 Matching Results

Results open in a new window/tab.

D-0 End Calorimeter Warm Tube/TeV Dry Air Purge (open access)

D-0 End Calorimeter Warm Tube/TeV Dry Air Purge

This Engineering Note studies the design of the Dry Air Purge that is going to flow through the Warm Tube of the End Calorimeter of the D-O Calorimeter. The Tev tubes through the E.C. can be thought of as a cluster of concentric tubes: The Tev tube, the warm (vacuum vessel) tube, 15 layers of superinsulation, the cold (argon vessel) tube, and the Inner Hadronic center support tube. The Dry Air Purge will involve flowing Dry Air through the annular region between the Warm Tube and the Tev Beam Pipe. This air flow is intended to prevent condensation from forming in this region which could turn to ice under cryogenic temperatures. Any ice formed in this gap, could cause serious problems when these tubes are moved. The Air will flow through a Nylon Tube Fitting -1/4-inch I.D. to 1/8-inch male pipe thread (Cole Palmer YB-06465-15) see Drawing MC-295221 (Appendix A). This fitting will be attached to the Nylon 2-inch Tube-Wiper and Seal Assembly which is clamped to the ends of the Warm Tube (Appendix A). This note includes drawings and calculations that explain the setup of the Dry Air Purge and give the required information on the pressure drops through …
Date: August 14, 1991
Creator: Leibfritz, J. R.
Object Type: Report
System: The UNT Digital Library
0-G experiments with advanced ceramic fabric wick structures (open access)

0-G experiments with advanced ceramic fabric wick structures

Both Air Force and NASA future spacecraft thermal management needs span the temperature range from cryogenic to liquid metals. Many of these needs are changing and not well defined and will remain so until goals, technology, and missions converge. Nevertheless, it is certain that high-temperature (> 800 K) and medium-temperature (about 450 K) radiator systems will have to be developed that offer significant improvements over current designs. This paper discusses experiments performed in the lower temperature regime as part of a comprehensive advanced ceramic fabric (ACF) heat pipe development program. These experiments encompassed wicking tests with various ceramic fabric samples, and heat transfer tests with a 1-m long prototype ACF water heat pipe. A prototype ceramic fabric/titanium water heat pipe has been constructed and tested; it transported up to 60 W of power at about 390 K. Startup and operation both with and against gravity examined. Wick testing was begun to aid in the design and construction of an improved prototype heat pipe, with a 38-{mu}m stainless steel linear covered by a biaxially-braided Nextel (trademark of the 3M Co., St. Paul, Minnesota) sleeve that is approximately 300-{mu}m thick. Wick testing took place in 1-g; limited testing in 0-g was initiated, …
Date: July 1991
Creator: Antoniak, Z. I.; Webb, B. J.; Bates, J. M.; Cooper, M. F. & Pauley, K. A.
Object Type: Article
System: The UNT Digital Library
1. Mono((8)annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes (open access)

1. Mono((8)annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

A reproducible, high-yield synthesis of mono((8)annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono((8)annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported.
Date: October 1, 1991
Creator: Boussie, T. R.
Object Type: Report
System: The UNT Digital Library
1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes (open access)

1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

A reproducible, high-yield synthesis of mono([8]annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono([8]annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported.
Date: October 1, 1991
Creator: Boussie, T. R.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
2-D and 3-D computations of curved accelerator magnets (open access)

2-D and 3-D computations of curved accelerator magnets

In order to save computer memory, a long accelerator magnet may be computed by treating the long central region and the end regions separately. The dipole magnets for the injector synchrotron of the Advanced Photon Source (APS), now under construction at Argonne National Laboratory (ANL), employ magnet iron consisting of parallel laminations, stacked with a uniform radius of curvature of 33.379 m. Laplace's equation for the magnetic scalar potential has a different form for a straight magnet (x-y coordinates), a magnet with surfaces curved about a common center (r-{theta} coordinates), and a magnet with parallel laminations like the APS injector dipole. Yet pseudo 2-D computations for the three geometries give basically identical results, even for a much more strongly curved magnet. Hence 2-D (x-y) computations of the central region and 3-D computations of the end regions can be combined to determine the overall magnetic behavior of the magnets. 1 ref., 6 figs.
Date: January 1, 1991
Creator: Turner, L. R.
Object Type: Article
System: The UNT Digital Library
A 2-D imaging heat-flux gauge (open access)

A 2-D imaging heat-flux gauge

This report describes a new leadless two-dimensional imaging optical heat-flux gauge. The gauge is made by depositing arrays of thermorgraphic-phosphor (TP) spots onto the faces of a polymethylpentene is insulator. In the first section of the report, we describe several gauge configurations and their prototype realizations. A satisfactory configuration is an array of right triangles on each face that overlay to form squares when the gauge is viewed normal to the surface. The next section of the report treats the thermal conductivity of TPs. We set up an experiment using a comparative longitudinal heat-flow apparatus to measure the previously unknown thermal conductivity of these materials. The thermal conductivity of one TP, Y{sub 2}O{sub 3}:Eu, is 0.0137 W/cm{center dot}K over the temperature range from about 300 to 360 K. The theories underlying the time response of TP gauges and the imaging characteristics are discussed in the next section. Then we discuss several laboratory experiments to (1) demonstrate that the TP heat-flux gauge can be used in imaging applications; (2) obtain a quantum yield that enumerates what typical optical output signal amplitudes can be obtained from TP heat-flux gauges; and (3) determine whether LANL-designed intensified video cameras have sufficient sensitivity to acquire …
Date: July 1, 1991
Creator: Noel, B.W.; Borella, H.M. (Los Alamos National Lab., NM (United States)); Beshears, D.L.; Sartory, W.K.; Tobin, K.W.; Williams, R.K. (Oak Ridge National Lab., TN (United States)) et al.
Object Type: Report
System: The UNT Digital Library
A 2-GHz Rectangular Corrugated Horn (open access)

A 2-GHz Rectangular Corrugated Horn

We have designed, constructed and tested a large, rectangular horn antenna with a center frequency of 2.0 GHz, corrugated on the E-plane walls, made out of aluminum sheet. A new technique has been developed to solder thin aluminum strips onto the back plane to form the corrugations. The radiation beam pattern shows half-power beamwidths of 12{sup 0} and 14{sup 0} in the H and E planes respectively, and side lobe response below -40 dB at angles greater than 50{sup 0} from horn axis. The measured return loss is less than -20 dB (VSWR < 1.22) between 1.7 and 2.3 GHz; insertion loss is less than 0.15 dB.
Date: October 1, 1991
Creator: Bersanelli, M.; Bensadoun, M.; De Amici, Giovanni; Limon, M.; Smoot, George F.; Tanaka, S. et al.
Object Type: Article
System: The UNT Digital Library
A 3-D adaptive mesh refinement algorithm for multimaterial gas dynamics (open access)

A 3-D adaptive mesh refinement algorithm for multimaterial gas dynamics

Adaptive Mesh Refinement (AMR) in conjunction with high order upwind finite difference methods has been used effectively on a variety of problems. In this paper we discuss an implementation of an AMR finite difference method that solves the equations of gas dynamics with two material species in three dimensions. An equation for the evolution of volume fractions augments the gas dynamics system. The material interface is preserved and tracked from the volume fractions using a piecewise linear reconstruction technique. 14 refs., 4 figs.
Date: August 12, 1991
Creator: Puckett, E. G. & Saltzman, J. S.
Object Type: Article
System: The UNT Digital Library
3-D turbulent particle dispersion submodel development. Quarterly progress report No. 1, 5 April--5 July 1991 (open access)

3-D turbulent particle dispersion submodel development. Quarterly progress report No. 1, 5 April--5 July 1991

The lack of a mathematical description of the interactions of fluid turbulence with other physics-chemical processes is a major obstacle in modeling many industrial program. Turbulent two-phase flow is a phenomenon that is of significant practical importance to coal combustion as well as other disciplines. The interactions of fluid turbulence with the particulate phase has yet to be accurately and efficiently modeled for these industrial applications. On 15 May 1991 work was initiated to cover four major tasks toward the development of a computational submodel for turbulent particle dispersion that would be applicable to coal combustion simulations. Those four tasks are: 1. A critical evaluation of the 2-D Lagrangian particle dispersion submodel, 2. Development of a 3-D submodel for turbulent particle dispersion, 3. Evaluation of the 3-D submodel for turbulent particle dispersion, 4.Exploration of extensions of the Lagrangian dispersion theory to other applications including chemistry-turbulence interactions.
Date: December 31, 1991
Creator: Smith, P. J.
Object Type: Report
System: The UNT Digital Library
3-D turbulent particle dispersion submodel development. Quarterly progress report No. 2, 15 July--15 October 1991 (open access)

3-D turbulent particle dispersion submodel development. Quarterly progress report No. 2, 15 July--15 October 1991

The lack of a mathematical description of the interactions of fluid turbulence with other physics-chemical processes is a major obstacle in modeling many industrial program. Turbulent two-phase flow is a phenomenon that is of significant practical importance to coal combustion as well as other disciplines. The interactions of fluid turbulence with the particulate phase has yet to be accurately and efficiently modeled for these industrial applications. On 15 May 1991 work was initiated to cover four major tasks toward the development of a computational submodel for turbulent particle dispersion that would be applicable to coal combustion simulations. Those four tasks are: 1. A critical evaluation of the 2-D Lagrangian particle dispersion submodel, 2. Development of a 3-D submodel for turbulent particle dispersion, 3. Evaluation of the 3-D submodel for turbulent particle dispersion, 4. Exploration of extensions of the Lagrangian dispersion theory to other applications including chemistry-turbulence interactions.
Date: December 31, 1991
Creator: Smith, P. J.
Object Type: Report
System: The UNT Digital Library
5-Year Plan for Independent Living in Texas (open access)

5-Year Plan for Independent Living in Texas

Report that includes the progress of he plan, purpose of the revised plan, and outlines the goals and strategies of the 5 year plan for independent living in Texas.
Date: August 1991
Creator: Texas. State Living Council.
Object Type: Report
System: The Portal to Texas History

6 regards sur L.

Access: Use of this item is restricted to the UNT Community
Recording of Xavier Garcia's 6 regards sur L. This piece uses voice and manipulates the sound to create unsettling and technical passages. There is a wide use of the music technique of spatialisation.
Date: 1991
Creator: Garcia, Xavier, 1959-
Object Type: Sound
System: The UNT Digital Library

7 L Ranch Quadrangle

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24,000
Date: 1991
Creator: Geological Survey (U.S.)
Object Type: Map
System: The Portal to Texas History
9-1-1 Caller, Volume 3, Number 1, January/February 1991 (open access)

9-1-1 Caller, Volume 3, Number 1, January/February 1991

Bimonthly newsletter of the Texas Advisory Commission on State Emergency Communications discussing news and activities of the organization as well as other information related to 9-1-1 services and other emergency communication within Texas.
Date: January 1991
Creator: Texas. Advisory Commission on State Emergency Communications.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
9-1-1 Caller, Volume 3, Number 2, May/June 1991 (open access)

9-1-1 Caller, Volume 3, Number 2, May/June 1991

Bimonthly newsletter of the Texas Advisory Commission on State Emergency Communications discussing news and activities of the organization as well as other information related to 9-1-1 services and other emergency communication within Texas.
Date: May 1991
Creator: Texas. Advisory Commission on State Emergency Communications.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
9-1-1 Caller, Volume 3, Number 3, July/August 1991 (open access)

9-1-1 Caller, Volume 3, Number 3, July/August 1991

Bimonthly newsletter of the Texas Advisory Commission on State Emergency Communications discussing news and activities of the organization as well as other information related to 9-1-1 services and other emergency communication within Texas.
Date: July 1991
Creator: Texas. Advisory Commission on State Emergency Communications.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
9-1-1 Caller, Volume 3, Number 4, September/October 1991 (open access)

9-1-1 Caller, Volume 3, Number 4, September/October 1991

Bimonthly newsletter of the Texas Advisory Commission on State Emergency Communications discussing news and activities of the organization as well as other information related to 9-1-1 services and other emergency communication within Texas.
Date: September 1991
Creator: Texas. Advisory Commission on State Emergency Communications.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
A 10,000 A 1000 VDC solid state dump switch (open access)

A 10,000 A 1000 VDC solid state dump switch

The superconducting magnet test program at Fermilab requires a switch, called a dump switch, rated 10,000 A, 1000 Vdc, which must be able to continuously carry rated current. A dump resistor rated 2 MJoules, is connected in parallel with the switch contacts and dissipates the stored energy from a magnet when the switch opens. The required switch opening time is 250 {mu}sec maximum after detection of a fault or a trip command. A successful switch can be constructed from six parallel inverter type Silicon Controlled Rectifiers (SCR's) which each carry their share of the load current. These run SCR's are mounted at watercooled heatsinks and are commutated off from stored energy in capacitors. Each parallel SCR is connected in series with a 1 m{Omega} watercooled resistor to assure dc current sharing and turn on. A description of the control and construction of the switch is presented. 6 figs.
Date: May 1, 1991
Creator: Visser, A.
Object Type: Article
System: The UNT Digital Library
23 to 300{degrees}C demagnetization resistance of samarium-cobalt permanent magnets (open access)

23 to 300{degrees}C demagnetization resistance of samarium-cobalt permanent magnets

The influence of temperature on the knee point and squareness of the M-H demagnetization characteristic of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperatures in demagnetization-resistant permanent magnet devices. Composite plots of the knee field and the demagnetizing field required to produce a given magnetic induction swing below remanence were obtained for several commercial Sm{sub 2}Co{sub 17}-type magnet samples in the temperature range of 23 to 300{degrees}C. The knee point was used to define the limits of operation safe against irreversible demagnetization, and the resulting plots are interpreted to show the temperature-induction swing limits of safe magnet operation. The observed second quadrant M-H characteristic squareness is shown, by two measures, to increase gradually with temperature and to peak in the interval 200 to 300{degrees}C.
Date: October 1, 1991
Creator: Niedra, J. M. & Overton, E.
Object Type: Report
System: The UNT Digital Library
30-60 MHz FWCD system on DIII-D: Power division, phase control and tuning for a four-element antenna array (open access)

30-60 MHz FWCD system on DIII-D: Power division, phase control and tuning for a four-element antenna array

The 2 MW Fast Wave Current Drive system on DIII-D is intended to provide a near-term demonstration of up to 0.3 MA of current driven by the fast wave. The system used to drive the four element phased antenna array which produces the required directional spectrum is presented. This system must be able to cope with strong coupling between antenna elements and the time-varying plasma load seen by the antennas. Computer modelling shows that this system should be able to maintain a directional spectrum at full power under most anticipated load conditions. 5 refs., 1 fig.
Date: November 1, 1991
Creator: Pinsker, R. I.; Mayberry, M. J.; Petty, C. C.; Cary, W. P.; Pusl, J.; Remsen, D. (General Atomics, San Diego, CA (United States)) et al.
Object Type: Article
System: The UNT Digital Library
30-60 MHz FWCD system on DIII-D: Power division, phase control and tuning for a four-element antenna array (open access)

30-60 MHz FWCD system on DIII-D: Power division, phase control and tuning for a four-element antenna array

The 2 MW Fast Wave Current Drive system on DIII-D is intended to provide a near-term demonstration of up to 0.3 MA of current driven by the fast wave. The system used to drive the four element phased antenna array which produces the required directional spectrum is presented. This system must be able to cope with strong coupling between antenna elements and the time-varying plasma load seen by the antennas. Computer modelling shows that this system should be able to maintain a directional spectrum at full power under most anticipated load conditions. 5 refs., 1 fig.
Date: November 1, 1991
Creator: Pinsker, R. I.; Mayberry, M. J.; Petty, C. C.; Cary, W. P.; Pusl, J.; Remsen, D. et al.
Object Type: Article
System: The UNT Digital Library

34 With Scars

Access: Use of this item is restricted to the UNT Community
The artwork consists of a piece of white fabric with dark stitching around the edges and some stitching in the center and the number 34.
Date: 1991
Creator: Leonilson Bezerra Dias, José
Object Type: Artwork
System: The UNT Digital Library
40- angstrom FEL designs for the PEP storage ring (open access)

40- angstrom FEL designs for the PEP storage ring

We explore the use of the 2.2-km PEP storage ring at SLAC to drive a 40-{Angstrom} free-electron laser in the self-amplified spontaneous emission configuration. Various combinations for electron-beam and undulator parameters, as well as special undulator designs, are discussed. Saturation and high peak, in-band, coherent power (460 MW) are possible with a 67-m, hybrid permanent-magnet undulator in a ring bypass. A 100-m, cusp-field undulator can achieve high average, in-band, coherent power (0.25 W) in the main ring. The existing, 25.6-m, Paladin undulator at LLNL, with the addition of optical-klystron dispersive sections, is considered for both peak and average power. 35 refs., 4 figs., 1 tab.
Date: January 1, 1991
Creator: Fisher, A. S.; Gallardo, J. C. (Brookhaven National Lab., Upton, NY (United States)); Nuhn, H. D.; Tatchyn, R.; Winick, H. (Stanford Univ., CA (United States). Stanford Synchrotron Radiation Lab.) & Pellegrini, C. (California Univ., Los Angeles, CA (United States). Dept. of Physics)
Object Type: Article
System: The UNT Digital Library
40-{angstrom} FEL designs for the PEP storage ring (open access)

40-{angstrom} FEL designs for the PEP storage ring

We explore the use of the 2.2-km PEP storage ring at SLAC to drive a 40-{Angstrom} free-electron laser in the self-amplified spontaneous emission configuration. Various combinations for electron-beam and undulator parameters, as well as special undulator designs, are discussed. Saturation and high peak, in-band, coherent power (460 MW) are possible with a 67-m, hybrid permanent-magnet undulator in a ring bypass. A 100-m, cusp-field undulator can achieve high average, in-band, coherent power (0.25 W) in the main ring. The existing, 25.6-m, Paladin undulator at LLNL, with the addition of optical-klystron dispersive sections, is considered for both peak and average power. 35 refs., 4 figs., 1 tab.
Date: December 31, 1991
Creator: Fisher, A. S.; Gallardo, J. C.; Nuhn, H. D.; Tatchyn, R.; Winick, H. & Pellegrini, C.
Object Type: Article
System: The UNT Digital Library