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274,138 Matching Results

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Results: 1 - 24 of 274,138 next
Best Match Title Creator Date Created (Newest) Date Created (Oldest) Date Added (Newest) Date Added (Oldest)
0-2 kv Flash Tube Supplies (open access)

0-2 kv Flash Tube Supplies

The power supplies designed and constructed to power high-intensity flash tubes are described. Three supplies, capable of charging 100 mfd to 2 kv with a repetltion rate of not less than 0.8 sec, are operated remotely from a control panel containing 3 powerstats. The power supplies are full wave center trapped rectifiers employing silicon rectifiers. (M.C.G.)
Date: March 15, 1962
Creator: Miller, D. M.
Object Type: Report
System: The UNT Digital Library
0-2 kv Flash Tube Supplies (open access)

0-2 kv Flash Tube Supplies

In order to perform the various experiments with a bubble chamber, a high intensity flash tube is used. This report briefly describes the power supplies designed and constructed to power these lamps.
Date: March 15, 1962
Creator: Miller, D. M.
Object Type: Report
System: The UNT Digital Library
1.2. & 3 Ranch Headquarters After a Snow

1.2. & 3 Ranch Headquarters After a Snow

Photograph of the 1,2 & 3 ranch after a snowfall. There are several dark wooden buildings and a wooden fence covered in snow. Next to the buildings is a Model T car, a water tower and a windmill. In the foreground is snow-covered ground.
Date: March 17, 1932
Creator: unknown
Object Type: Photograph
System: The Portal to Texas History
1.2 MW klystron for Asymmetric Storage Ring B Factory (open access)

1.2 MW klystron for Asymmetric Storage Ring B Factory

A cw klystron operating at 476 MHz has been developed jointly by SLAC and Varian Associates. The unique set of characteristics of this tube were strongly guided by requirements of the fast feedback necessary to prevent oscillations of the storage ring beams caused by the detuned accelerating cavity. This requires a combination of bandwidth and short group delay within the klystron. The RF feedback stabilization scheme also requires amplitude modulation making it necessary to operate the klystron about 10% below saturation. Performance specifications and initial operating results are presented.
Date: March 1995
Creator: Fowkes, W. R.; Caryotakis, G. & Doyle, E.
Object Type: Article
System: The UNT Digital Library
E-1 (3-7-20)

E-1 (3-7-20)

Photograph of Tuttle FD Engine 1.
Date: March 7, 2020
Creator: unknown
Object Type: Photograph
System: The Gateway to Oklahoma History
1.3 GHz superconducting RF cavity program at Fermilab (open access)

1.3 GHz superconducting RF cavity program at Fermilab

At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.
Date: March 1, 2011
Creator: Ginsburg, C. M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L. et al.
Object Type: Article
System: The UNT Digital Library
1-D Van der Waals Foams Heated by Ion Beam Energy Deposition (open access)

1-D Van der Waals Foams Heated by Ion Beam Energy Deposition

One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of state (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 to 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize.
Date: March 19, 2010
Creator: Zylstra, A; Barnard, J J & More, R M
Object Type: Article
System: The UNT Digital Library
E-1 & E-4 new deliveries (3-24-14)

E-1 & E-4 new deliveries (3-24-14)

Photograph of Norman E-1 and E-4 on the day they were delivered to the NFD.
Date: March 24, 2014
Creator: unknown
Object Type: Photograph
System: The Gateway to Oklahoma History
O(1/M{sup 3}) effects for heavy-light mesons in lattice NRQCD (open access)

O(1/M{sup 3}) effects for heavy-light mesons in lattice NRQCD

The masses of spin-singlet and spin-triplet S-wave mesons containing a single heavy quark are computed in the quenched approximation. The light quark action and gauge field action are both classically-improved and tadpole-improved, and the couplings to the heavy quark are organized by the 1/M expansion of tadpole-improved NRQCD. At each of two lattice spacings, near 0.22fm and 0.26fm, meson masses are obtained for heavy quarks spanning the region between charmed and bottom mesons. Results up to O(1/M), O(1/M{sup 2})and O(1/M{sup 3}) are displayed separately, so that the convergence of the heavy quark expansion can be discussed. Also, the effect of each term in the O(1/M{sup 3}) contribution is computed individually. For bottom mesons the 1/M-expansion appears to be satisfactory, but the situation for charmed mesons is less clear.
Date: March 1998
Creator: Lewis, Randy & Woloshyn, R. M.
Object Type: Article
System: The UNT Digital Library
1/N (open access)

1/N

There exist families of field theories with symmetry group SO(N) (or SU(N)) that become simpler as N becomes larger. More precisely, the solutions to these theories possess an expansion in powers of 1/N. This expansion is the subject of these lectures. The 1/N expansion can be used to analyze model field theories. The 1/N expansion is developed for phi/sup 4/ theory and applied to two two-dimensional models with similar combinatoric structures, the Gross-Neveu model and the CP/sup N-1/ model. These models display (in the leading 1/N approximation) such interesting phenomena as asymptotic freedom, dynamical symmetry breaking, dimensional transmutation, and non-perturbative confinement. It is possible that the 1/N expansion, with N the number of colors, might fruitfully be applied to quantum chromodynamics. Unfortunately, it is not possible to make a decisive test of the approximation, because no one knows how to compute even the first term in the expansion in closed form. However, it is possible to argue that this first term, whatever its detailed form, has many properties that are also shared by the real world, and which are otherwise underived from field theory. These include the saturation of scattering amplitudes by an infinite number of narrow resonances, the essential …
Date: March 1, 1980
Creator: Coleman, S.
Object Type: Report
System: The UNT Digital Library
1 Outreach, Education and Domestic Market Enhancement 2 Export Promotion and Assistance (open access)

1 Outreach, Education and Domestic Market Enhancement 2 Export Promotion and Assistance

Geothermal Energy Association supports the US geothermal industry in its efforts to bring more clean geothermal energy on-line throughout the world. Activities designed to accomplish this goal include: (1) developing and maintaining data bases, web pages, (2) commissioning of special studies and reports, (3) preparing, printing and distributing brochures and newsletters, (4) developing exhibits and displays, and participating in trade shows, (5) designing, producing and disseminating audio-video materials, (6) monitoring and coordinating programs carried out by US DOE and other Federal agencies, (7) holding workshops to facilitate communication between researchers and industry and to encourage their recognition of emerging markets for geothermal technology, (8) attending conferences, making speeches and presentation, and otherwise interacting with environmental and other renewable energy organizations and coalitions, (9) hosting events in Washington, DC and other appropriate locations to educate Federal, State and local representatives, environmental groups, the news media, and other about the status and potential of geothermal energy, (10) conducting member services such as the preparation and distribution of a member newsletter related to operating and maintaining s useful and viable association, and (11) performing similar kinds of activities designed to inform others about geothermal energy. The activities of the export promotion aim to …
Date: March 15, 2004
Creator: Geothermal Energy Association
Object Type: Report
System: The UNT Digital Library
2-1/2-dimensional numerical solution for the electromagnetic scattering using a hybrid technique (open access)

2-1/2-dimensional numerical solution for the electromagnetic scattering using a hybrid technique

The use of the electromagnetic method for geothermal reservoir exploration and delineation was studied. A number of techniques were developed to provide high quality field data. The remaining problem of interpreting these data in regions of complex geologic structure was overcome by the development of a numerical solution based on the hybrid technique, making use of both the finite element and the integral equation techniques. The major improvement is in the computing speed. (ACR)
Date: March 1, 1983
Creator: Lee, K. H. & Morrison, H. F.
Object Type: Article
System: The UNT Digital Library
A 2.53 NEF 8-bit 10 kS/s 0.5 µm CMOS Neural Recording Read-Out Circuit with High Linearity for Neuromodulation Implants (open access)

A 2.53 NEF 8-bit 10 kS/s 0.5 µm CMOS Neural Recording Read-Out Circuit with High Linearity for Neuromodulation Implants

This article presents a power-efficient complementary metal-oxide-semiconductor (CMOS) neural signal-recording read-out circuit for multichannel neuromodulation implants.
Date: March 3, 2021
Creator: Tasneem, Nishat Tarannum & Mahbub, Ifana
Object Type: Article
System: The UNT Digital Library
2-mm microwave interferometer (open access)

2-mm microwave interferometer

A 2-mm microwave interferometer has been developed, and phase shift measurements have been made on the Baseball II experiment. The interferometer system employs a 140-GHz receiver for double down conversion of the plasma signal to a 60-MHz, IF frequency. The 140-GHz references signal is also down-converted and compared with the plasma signal to provide the desired phase change of the signal passing through the plasma. A feedback voltage from a 60-MHz discriminator to a voltage-controlled oscillator in the receiver provides frequency stability of the 60-MHz IF signals.
Date: March 1, 1977
Creator: Futch, A. H. & Mortensen, W. K.
Object Type: Report
System: The UNT Digital Library
2-Page Summary for Neptunium solubility in the Near-field Environment of A Proposed Yucca Mountain Repository (open access)

2-Page Summary for Neptunium solubility in the Near-field Environment of A Proposed Yucca Mountain Repository

The total system performance assessment (TSPA) for the proposed repository at Yucca Mountain, NV, includes a wide variety of processes to evaluate the potential release of radionuclides from the Engineered Barrier System into the unsaturated zone of the geosphere. The principal processes controlling radionuclide release and mobilization from the waste forms are captured in the model to assess the dissolved concentrations of radionuclides in the source-term. The TSPA model of the source-term incorporates the far-from-equilibrium dissolution of, for example, spent nuclear fuel (SNF) to capture bounding rates of radionuclide availability as the SNF degrades. In addition, for individual radionuclides, the source-term model evaluates solubility constraints that are more indicative of longer-term, equilibrium processes that can limit the potential mass transport from the source term in those cases. These solubility limits represent phase saturation and precipitation processes that can occur either at the waste form as it alters, or at other locations in the near-field environment (e.g., within the invert) if chemical conditions are different. Identification and selection of applicable constraints for solubility-limited radionuclide concentrations is a primary focus in formulating the source-term model for the TSPA. Neptunium is a long-lived radionuclide that becomes a larger fraction of the potential dose …
Date: March 29, 2005
Creator: Sassani, D.; van Luik, A. & Summerson, J.
Object Type: Report
System: The UNT Digital Library
2" Sea Chest Discharge

2" Sea Chest Discharge

Blueprint depicting technical details of Battleship Texas.
Date: March 28, 1917
Creator: unknown
Object Type: Technical Drawing
System: The Portal to Texas History
2"siren whistle 8c 10" plain whistle

2"siren whistle 8c 10" plain whistle

Blueprint depicting technical details of Battleship Texas.
Date: March 12, 1912
Creator: unknown
Object Type: Technical Drawing
System: The Portal to Texas History
E-3 (3-7-20)

E-3 (3-7-20)

Photograph of Tuttle FD E-3.
Date: March 7, 2020
Creator: unknown
Object Type: Photograph
System: The Gateway to Oklahoma History
A 3.3 MJ, Rb + 1 driver design based on an integrated systems analysis (open access)

A 3.3 MJ, Rb + 1 driver design based on an integrated systems analysis

A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.
Date: March 7, 2000
Creator: Meier, W. R.; Barnard, J. J. & Bangerter, R. O.
Object Type: Article
System: The UNT Digital Library
3-D Cavern Enlargement Analyses (open access)

3-D Cavern Enlargement Analyses

Three-dimensional finite element analyses simulate the mechanical response of enlarging existing caverns at the Strategic Petroleum Reserve (SPR). The caverns are located in Gulf Coast salt domes and are enlarged by leaching during oil drawdowns as fresh water is injected to displace the crude oil from the caverns. The current criteria adopted by the SPR limits cavern usage to 5 drawdowns (leaches). As a base case, 5 leaches were modeled over a 25 year period to roughly double the volume of a 19 cavern field. Thirteen additional leaches where then simulated until caverns approached coalescence. The cavern field approximated the geometries and geologic properties found at the West Hackberry site. This enabled comparisons are data collected over nearly 20 years to analysis predictions. The analyses closely predicted the measured surface subsidence and cavern closure rates as inferred from historic well head pressures. This provided the necessary assurance that the model displacements, strains, and stresses are accurate. However, the cavern field has not yet experienced the large scale drawdowns being simulated. Should they occur in the future, code predictions should be validated with actual field behavior at that time. The simulations were performed using JAS3D, a three dimensional finite element analysis …
Date: March 1, 2002
Creator: EHGARTNER, BRIAN L. & SOBOLIK, STEVEN R.
Object Type: Report
System: The UNT Digital Library
3-d finite element model development for biomechanics: a software demonstration (open access)

3-d finite element model development for biomechanics: a software demonstration

Finite element analysis is becoming an increasingly important part of biomechanics and orthopedic research, as computational resources become more powerful, and data handling algorithms become more sophisticated. Until recently, tools with sufficient power did not exist or were not accessible to adequately model complicated, three-dimensional, nonlinear biomechanical systems. In the past, finite element analyses in biomechanics have often been limited to two-dimensional approaches, linear analyses, or simulations of single tissue types. Today, we have the resources to model fully three-dimensional, nonlinear, multi-tissue, and even multi-joint systems. The authors will present the process of developing these kinds of finite element models, using human hand and knee examples, and will demonstrate their software tools.
Date: March 1, 1997
Creator: Hollerbach, K.; Hollister, A.M. & Ashby, E.
Object Type: Article
System: The UNT Digital Library
3-D Nonlinear Calculations of Resistive Tearing Modes (open access)

3-D Nonlinear Calculations of Resistive Tearing Modes

Recent numerical calculations of the evolution of resistive tearing modes have been central to the understanding of magnetohydrodynamic activity and disruptions in tokamaks. The nonlinear, 3-D, initial-value computer code RSF has provided many of these results. This code assumes cylindrical geometry with a Fourier series representation in the two periodic coordinates and a finite-difference representation in the radial direction. This choice makes RSF considerably more accurate and efficient than previous codes.
Date: March 1, 1981
Creator: Hicks, H. R.; Holmes, J. A.; Lee, D. K.; Carreras, B. & Waddell, B. V.
Object Type: Report
System: The UNT Digital Library
3-D nonlinear evolution of MHD instabilities (open access)

3-D nonlinear evolution of MHD instabilities

The nonlinear evolution of ideal MHD internal instabilities is investigated in straight cylindrical geometry by means of a 3-D initial-value computer code. These instabilities are characterized by pairs of velocity vortex cells rolling off each other and helically twisted down the plasma column. The cells persist until the poloidal velocity saturates at a few tenths of the Alfven velocity. The nonlinear phase is characterized by convection around these essentially fixed vortex cells. For example, the initially centrally peaked temperature profile is convected out and around to form an annulus of high temperature surrounding a small region of lower temperature. Weak, centrally localized instabilities do not alter the edge of the plasma. Strong, large-scale instabilities, resulting from a stronger longitudinal equilibrium current, drive the plasma against the wall. After three examples of instability are analyzed in detail, the numerical methods and their verification are discussed.
Date: March 1, 1977
Creator: Bateman, G.; Hicks, H. R. & Wooten, J. W.
Object Type: Report
System: The UNT Digital Library
A 3-D SAR approach to IFSAR processing (open access)

A 3-D SAR approach to IFSAR processing

Interferometric SAR (IFSAR) can be shown to be a special case of 3-D SAR image formation. In fact, traditional IFSAR processing results in the equivalent of merely a super-resolved, under-sampled, 3-D SAR image. However, when approached as a 3-D SAR problem, a number of IFSAR properties and anomalies are easily explained. For example, IFSAR decorrelation with height is merely ordinary migration in 3-D SAR. Consequently, treating IFSAR as a 3-D SAR problem allows insight and development of proper motion compensation techniques and image formation operations to facilitate optimal height estimation. Furthermore, multiple antenna phase centers and baselines are easily incorporated into this formulation, providing essentially a sparse array in the elevation dimension. This paper shows the Polar Format image formation algorithm extended to 3 dimensions, and then proceeds to apply it to the IFSAR collection geometry. This suggests a more optimal reordering of the traditional IFSAR processing steps.
Date: March 1, 2000
Creator: Doerry, Armin W. & Bickel, Doug L.
Object Type: Article
System: The UNT Digital Library