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276,479 Matching Results

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(open access)

High-voltage coaxial switch

A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode is described. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure.

Date: June 3, 1981

Creator: Rink, J. P.

Object Type: Patent

System: The UNT Digital Library

(open access)

Power ratings of rf thin film resistive attenuators

Most radio frequency (rf) assemblies built using hybrid microcircuit technology employ thin film attenuators. These attenuators are subject to moderate rf peak power and to moderate average power. Because of intracircuit mismatch, extra considerations of power requirements must be given. To meet these requirements, selected thin film resistive attenuators operated under large rf power conditions were investigated, and the power margin in which these attenuators can be used was defined.

Date: June 1, 1980

Creator: Smith, F.R.

Object Type: Report

System: The UNT Digital Library

(open access)

Preliminary designs for ocean thermal energy conversion (OTEC) stationkeeping subsystems (SKSS). Task I. Design requirements. Final report

The results of Task I, Design Requirements, are presented. Environmental conditions for the Punta Tuna, Puerto Rico site are reviewed and synthesized to provide definition of current, wind and wave severity, direction, and occurrence for service, operational, and extreme sea states. SKSS performance requirements, including design life and watch circle, are followed by interface considerations particularly for the electrical transmission riser cable, and design criteria including safety and load factors. The SKSS concepts will be analyzed to evaluate performance, reliability, and cost. Performance analysis conducted included catenary anchor leg static calculations to size components, as well as drag due to environmental loads in the operational and extreme sea states for both ship and spar platforms. Dynamic analyses and trade studies to be conducted in Task II are presented. A reliability and risk assessment analysis of the three basic SKSS types - single-, multiple-, and tension-anchor-leg moors - was completed, indicating that the multiple-anchor-leg/multiple-point rotary or turret moor has the lowest risk-criticality for the ship, while that for the spar is the multiple-anchor-leg/multiple-point moor. The catenary single-anchor-leg/single-point moor has insufficient reliability for both platforms. The life cycle cost analysis methodology, including work breakdown structure, cost estimating, and cost minimization define the …

Date: June 1, 1979

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

Automated calibrations and dynamic corrections for differential pressure transmitters

A large reprocessing plant is a complex operation with dynamic inventories being required to provide for timely detection of attempted diversion of nuclear materials. The real-time, on-line process measurement capability controls the effectiveness of the dynamic techniques. An economical method to eliminate bias and significantly improve process differential pressure transmitter measurements is evaluated. Errors up to 1.0% have been reduced to less than 0.1%

Date: June 1, 1980

Creator: Crawford, J. M.

Object Type: Article

System: The UNT Digital Library

(open access)

Spectral characteristics and power distribution from insertion devices on a 6 to 7 GeV storage ring

Two different types of insertion devices - undulators and wigglers - are described and compared. Each provides a periodic magnetic field that alters polarity, but whereas the spectral distribution from a wiggler is continuous and wide, the radiation of an undulator has spectrally narrow and discrete peaks. The distinction is determined by the deflection parameter. The energy spread in undulator peaks is calculated. Insertion device magnets and gap are discussed. Undulator tunability from gap variation is considered on a 6-GeV lattice and on a 7-GeV lattice. Also discussed is the angular distribution of power and the polarization from various sources. (LEW)

Date: June 1, 1986

Creator: Shenoy, G. K. & Viccaro, P. J.

Object Type: Article

System: The UNT Digital Library

(open access)

Sodium-fire control by space isolation with nitrogen flooding: FFTF proof test F2

Sodium fire protection by space isolation with nitrogen flooding was evaluated by performing a large-scale sodium fire test within a mockup of an FFTF secondary sodium system pipeway. The full scale (3350 ft/sup 3/) mockup was initially filled with air and its leak tightness set to correspond to that expected in an actual FFTF pipeway. The basis for specifying the rate of nitrogen flood gas is discussed ad the experimental verification provided. Nitrogen flooding was activated 15 minutes after the spill of 770 lb of 1100/sup 0/F sodium into a 32 ft/sup 2/ steel pan. The nitrogen flow was controlled manually at a constant rate of 60 ft/sup 3//min (STP) until the pool temperature had decreased to 370/sup 0/F. After cooldown, 87% of the spilled sodium remained in the unreacted form, demonstrating that sodium fires can be effectively controlled by the method of space isolation with nitrogen flooding.

Date: June 1, 1974

Creator: Hilliard, R.K. & Muhlestein, L.D.

Object Type: Report

System: The UNT Digital Library

(open access)

Actinide partitioning-transmutation program. V. Preconceptual designs and costs of partitioning facilities and shipping casks, Appendix 4. Final report

This Appendix contains cost estimate documents for the Fuels Fabrication Plant Waste Treatment Facility. Plant costs are summarized by Code of Accounts and by Process Function. Costs contributing to each account are detailed. Process equipment costs are detailed for each Waste Treatment Process. Service utility costs are also summarized and detailed. Shipping cask costs are provided.

Date: June 1, 1980

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

Gauge invariant actions for string models

String models of unified interactions are elegant sets of Feynman rules for the scattering of gravitons, gauge bosons, and a host of massive excitations. The purpose of these lectures is to describe the progress towards a nonperturbative formulation of the theory. Such a formulation should make the geometrical meaning of string theory manifest and explain the many ''miracles'' exhibited by the string Feynman rules. There are some new results on gauge invariant observables, on the cosmological constant, and on the symmetries of interacting string field theory. 49 refs.

Date: June 1, 1986

Creator: Banks, T.

Object Type: Article

System: The UNT Digital Library

(open access)

Technical study for the chemical cleaning of Dresden-1. Volume I, Section 1 and 2

A feasibility study has been completed to decontaminate the primary system of the Dresden-1 Nuclear Power Unit operated by Commonwealth Edison Company of Illinois. Available data initially were searched to determine the state of the art. Solvents based on organic acids and chelates gave unsatisfactory deontamination factors or unacceptable corrosion rates when evaluated for cleaning of specimens from the Dresden-1 primary system, under static and dynamic conditions. A new proprietary cleaning solution, Dow Solvent NS-1, was successfully applied in these laboratory studies.

Date: June 15, 1977

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

Measurement of the analyzing power for pion proton elastic scattering between 471 and 687 MeV/c

The analyzing power, A/sub N/, has been measured for ..pi../sup + -/p..--> pi../sup + -/p at 471, 547, 625, and 687 MeV/c in an angular range corresponding to -0.9 less than or equal to cos theta/sub cm/ less than or equal to 0.8. A polarized proton target with polarization axis normal to the scattering plane was used. The scattered pion and recoil proton were detected in coincidence, using a magnetic spectrometer and a wire chamber/scintillator array, except in cases where one of the particles was kinematically inaccessible. Statistical uncertainties in the data are as low as 0.02; systematic uncertainties are estimated to be less than 3%. The ..pi../sup -/p data are characterized by large values of analyzing power, and rapid variations in the angular distribution with incident momentum. The measurements are compared with the results of existing partial wave analysis.

Date: June 1, 1985

Creator: Mokhtari-Amirmajdi, A.

Object Type: Report

System: The UNT Digital Library

(open access)

UPS UNIX product support

The need to provide central support an distribution of many software packages across a variety of UNIX platforms at Fermilab has led to development of a methodology, UPS, for the packaging, maintenance, and distribution of our software. UPS has now been implemented and in use for almost a year on four different UNIX platforms. This paper discusses the goals of the software, implementation of the product, and experiences in its use. 8 refs., 3 figs.

Date: June 1, 1991

Creator: Votava, M.; Bliss, W.; Cutts-Bone, S.; Debaun, C.; Donno-Raffaelli, F.; Herber, R. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Gas evolution from geopressured brines

The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.

Date: June 1, 1980

Creator: Matthews, C.S.

Object Type: Report

System: The UNT Digital Library

(open access)

Transport of intense ion beams. [HIBALL II]

The maximum transportable current for an ion beam is determined by considerations of focal strength, space charge equilibrium and stability, structural practically and emittance. These factors are described within the context of a heavy ion driver for Inertial Confinement Fusion. Recent supporting results from particle-in-cell simulations and transport experiments will be described.

Date: June 1, 1986

Creator: Lee, Edward P.

Object Type: Article

System: The UNT Digital Library

(open access)

Ferrules seals

A device is provided for sealing an inner tube and an outer tube without excessively deforming the tubes. The device includes two ferrules which cooperate to form a vacuum-tight seal between the inner tube and outer tube and having mating surfaces such that overtightening is not possible.

Date: June 19, 1981

Creator: Smith, J.L.

Object Type: Patent

System: The UNT Digital Library

(open access)

Surface density representation of critical configurations of U(5)O/sub 2/ planar and linear arrays

A criticality data base for planar and linear arrays of low enriched damp uranium dioxide powder contained in cylindrical units is generated with the Monte Carlo criticality program KENO-IV. This information is correlated with the Limiting Surface Density model, sigma(m) = c/sub 2/(m/sub 0/-m), refining the bulky KENO data base into a simple table of correlation constants c/sub 2/ and m/sub 0/. A solid angle representation of the KENO data base is provided. The solid angles were analytically determined by the SNAKE code and these are compared to an approximate formulation of the total solid angle associated with a critical array.

Date: June 1, 1980

Creator: Maudlin, P.J. & Thomas, J.T.

Object Type: Report

System: The UNT Digital Library

(open access)

Safety analysis of thorium-based fuels in the General Electric Standard BWR

A denatured (U-233/Th)O/sub 2/ fuel assembly has been designed which is energy equivalent to and hardware interchangeable with a modern boiling water reactor (BWR) reference reload assembly. Relative to the reference UO/sub 2/ fuel, the thorium fuel design shows better performance during normal and transient reactor operation for the BWR/6 product line and will meet or exceed current safety and licensing criteria. Power distributions are flattened and thermal operating margins are increased by reduced steam void reactivity coefficients caused by U-233. However, a (U-233/Th)O/sub 2/-fueled BWR will likely have reduced operating flexibility. A (U-235/Th)O/sub 2/-fueled BWR should perform similar to a UO/sub 2/-fueled BWR under all operating conditions. A (Pu/Th)O/sub 2/-fueled BWR may have reduced thermal margins and similar accident response and be less stable than a UO/sub 2/-fueled BWR. The assessment is based on comparisions of point model and infinite lattice predictions of various nuclear reactivity parameters, including void reactivity coefficients, Doppler reactivity coefficients, and control blade worths.

Date: June 1, 1980

Creator: Colby, M.J.; Townsend, D.B. & Kunz, C.L.

Object Type: Report

System: The UNT Digital Library

(open access)

KMC unitarity and K/sup +/ yields. pi. /sup +/. nu. anti. nu

Experimental constraints on the Kobayashi-MaskawaCabibbo (KMC) matrix are surveyed and shown to provide a test of the standard model at the level of its O (..cap alpha..) radioactive corrections. The three generation prediction BR (K/sup +/ ..-->.. ..pi../sup +/..nu..) approx. = (0.35 approx. 3) x 10/sup 10/ is reviewed and the potential for enhancement up to approx. = 3 x 10/sup -9/ due to the fourth generation mixing is described. 19 refs.

Date: June 1, 1986

Creator: Marciano, William J.

Object Type: Article

System: The UNT Digital Library

(open access)

Mechanical structure of the Mirror Hybrid Reactor Power Plant

The mechanical structure of the LLL/GA Mirror Hybrid Reactor vessel is briefly discussed. Functional requirements and over-all design considerations leading to selection of a post-tensioned concrete reactor vessel and a modular blanket approach are indicated. Module design life of four years, module replacement, capability and remote fueling are provided by the chosen structural design. (RME)

Date: June 6, 1977

Creator: Culver, D.W. & Neef, W.S.

Object Type: Article

System: The UNT Digital Library

(open access)

Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells

None

Date: June 30, 1999

Creator: Muschler, J.; Lochter, A.; Roskelley, C. D.; Yurchenco, P. & Bissell, M. J.

Object Type: Article

System: The UNT Digital Library

(open access)

Finite element and node point generation computer programs used for the design of toroidal field coils in tokamak fusion devices

The structural analysis of toroidal field coils in Tokamak fusion machines can be performed with the finite element method. This technique has been employed for design evaluations of toroidal field coils on the Princeton Large Torus (PLT), the Poloidal Diverter Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). The application of the finite element method can be simplified with computer programs that are used to generate the input data for the finite element code. There are three areas of data input where significant automation can be provided by supplementary computer codes. These concern the definition of geometry by a node point mesh, the definition of the finite elements from the geometric node points, and the definition of the node point force/displacement boundary conditions. The node point forces in a model of a toroidal field coil are computed from the vector cross product of the coil current and the magnetic field. The computer programs named PDXNODE and ELEMENT are described. The program PDXNODE generates the geometric node points of a finite element model for a toroidal field coil. The program ELEMENT defines the finite elements of the model from the node points and from material property considerations. The program descriptions …

Date: June 1, 1975

Creator: Smith, R. A.

Object Type: Report

System: The UNT Digital Library

(open access)

Neutral beam source commercialization study. Final report

The basic tasks of this Phase II project were to: generate a set of design drawings suitable for quantity production of sources of this design; fabricate a functional neutral beam source incorporating as many of the proposed design changes as proved feasible; and document the procedures and findings developed during the contract. These tasks have been accomplished and represent a demonstrated milestone in the industrialization of this complete device.

Date: June 1, 1980

Creator: King, H. J.

Object Type: Report

System: The UNT Digital Library

(open access)

Recovery of cesium, technetium, rhodium and palladium from stored waste supernates

The results of our assessment of the processing methods and costs for the recovery of cesium, techneium, rhodium, and palladium from aged waste supernates are presented. Guidelines for the assessment of costs are given. Cesium can be readily absorbed from alkaline waste supernates without prior treatment using Linde AW-500, a synthetic zolite. Technetium, present in the supernate as the pertechnetate anion, together with rhodium and palladium, probably present as anionic nitrite complexes, can be absorbed from untreated waste supernates using Dowex 1-X4 or similar anion resins. Although the behavior of cesium and technetium is reasonably well understood, the behavior of the anionic complex that accounts for the presence of rhodium and palladium in this strongly alkaline solution is not well understood. Further work is required before a process can be outlined for the clean separation of rhodium and palladium from the technetium-rhodium-palladium crude fraction sorbed on the anion resin. An assessment of capital and operating costs for the recovery of cesium only, technetium only, or both cesium and technetium are tabulated. No costs are shown for rhodium and palladium, since the technology for their separation is not sufficiently advanced. However, the incremental cost for their separation from technetium is expected …

Date: June 22, 1966

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

Numerical solutions for steady thermal convection from a concentrated source in a porous medium

Solutions for the steady, axisymmetric velocity and temperature fields associated with a point source of thermal energy in a fluid-saturated porous medium are obtained numerically through use of similarity transformations. The two cases considered are those of a point source located on the lower, insulated boundary of a semi-infinite region and a point source embedded in an infinite region. Numerical results are presented from which complete descriptions of the velocity and temperature fields can be constructed for Rayleigh numbers ranging from 10/sup -3/ to 10/sup 2/.

Date: June 1, 1980

Creator: Hickox, C.E. & Watts, H.A.

Object Type: Report

System: The UNT Digital Library

(open access)

Numerical accuracy of linear triangular finite elements in modeling multi-holed structures

A study has been performed to quantify the accuracy of linear triangular finite elements for modeling temperature and stress fields in structures with multiple holes. The purpose of the study was to evaluate the use of these elements for the analysis of HTGR fuel blocks, which may contain up to 325 holes. Since an accurate full scale analysis was not feasible with existing methods, a representative small scale benchmark problem containing only seven holes was selected. The finite element codes used in this study were TEPC-2D for thermal analysis and SAFIRE for stress analysis. It was concluded that linear triangular finite elements are too inefficient for this application. An accurate analysis of stresses in HTGR fuel blocks will require the use of higher order elements, such as the 8-node quadrilaterals in the new TWOD code.

Date: June 1, 1980

Creator: Sullivan, R.M. & Griffen, J.E.

Object Type: Report

System: The UNT Digital Library

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