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The Levi problem on mixed manifolds

Description: Article discussing the Levi problem on mixed manifolds. This article gives a new proof that the problem of Levi, to mixed varieties have a solution in the sense that every pseudoconvex closely mixed variety, with enough real global morphisms, is a variety of Cartan.
Date: 1984
Creator: Anghel, Nicolae
Partner: UNT College of Arts and Sciences

Determination of absolute rate data for the reaction of atomic sodium, Na (3²S(1/2)), with CF₃Cl, CF₂Cl₂, CFCl₃, CF₃Br and SF₆ as a Function of Temperature by Time-resolved Atomic Resonance-absorption Spectroscopy at λ = 589 nm [Na(3²Pᴊ) ← Na(3²S(1/2))

Description: Article on a kinetic study of the reactions of ground-state sodium atoms with the molecules CF₃Cl, CF₂Cl₂, CFCl₃, CF₃Br and SF₆ over the temperature range 644-918 K.
Date: 1985
Creator: Husain, David & Marshall, Paul
Partner: UNT College of Arts and Sciences

High-Temperature Fast-Flow Reactor Kinetics Studies of the Reactions of Al with Cl₂, Al with HCl, and AlCl, with Cl₂ over Wide Temperature Ranges

Description: Article on high-temperature fast-flow reactor kinetics studies of the reactions of aluminum with chlorine, aluminum with hydrogen chloride and aluminum monochloride with chlorine over wide temperature ranges.
Date: April 12, 1988
Creator: Rogowski, Donald F.; Marshall, Paul & Fontijn, A. (Arthur)
Partner: UNT College of Arts and Sciences

Temperature Dependence of the Absolute Third-order Rate Constant for the Reaction between Na + O₂ + N₂ over the Range 571 - 1016 K Studied by Time-resolved Atomic Resonance Absorption Spectroscopy

Description: Article on temperature dependence of the absolute third-order rate constant for the reaction between Na + O₂ + N₂ over the range 571-1016 K studied by time-resolved atomic resonance absorption spectroscopy.
Date: 1985
Creator: Husain, David; Marshall, Paul & Plane, John M. C.
Partner: UNT College of Arts and Sciences

Laboratory studies of radionuclide migration in tuff

Description: The movement of selected radionuclides has been observed in crushed tuff, intact tuff, and fractured tuff columns. Retardation factors and dispersivities were determined from the elution profiles. Retardation factors have been compared with those predicted on the basis of batch sorption studies. This comparison forms a basis for either validating distribution coefficients or providing evidence of speciation, including colloid formation. Dispersivities measured as a function of velocity provide a means of determining the effect of sorption kinetics or mass transfer on radionuclide migration. Dispersion is also being studied in the context of scaling symmetry to develop a basis for extrapolating from the laboratory scale to the field. 21 refs., 6 figs., 2 tabs.
Date: October 1, 1989
Creator: Rundberg, R.S.; Mitchell, A.J.; Ott, M.A.; Thompson, J.L. & Triay, I.R.
Partner: UNT Libraries Government Documents Department

NRL capillary Z-pinch experiment

Description: The current renewed interest in the dense linear z-pinch is due in large part to a recent Los Alamos Study which concluded that a z- pinch based reactor could produce 4.4 KJ of fusion energy per pulse for the modest input of 140 kJ per pulse, if a straight pinch could be maintained for 2 {mu}sec. Early attempts to achieve suitable high density z-pinches were of the implosion type which produced hollow pressure profiles that quickly resulted in disruptive m = 0 instabilities. These instabilities are not found in the gas embedded pinch in which an initially small diameter plasma is kept in radial equilibrium by following a prescribed current waveform. Unfortunately, these pinches are prone to a rapid accretion of the surrounding gas during the early stages of formation. Our approach is to form the pinch inside small diameter quartz capillaries filled with neutral hydrogen. This fixes the line density. By driving currents through the pinch at a rate that exceeds that necessary for radial equilibrium, we expect the pinch to contract away from the walls and be subject to compressional, as well as ohmic heating. This contraction will, of course, produce a plasma between the pinch and the capillary wall, but we anticipate this ``corona`` will be kept at a low temperature (i.e., high resistance) by radiation and hence shunt only a small fraction of the pinch current. We also expect negligible impurities in the pinch as the classical mixing time will be much longer than the pinch duration at the densities (10{sup 21}- 10{sup 22} ions/cm{sup 3}) and magnetic fields (1 - 10 MG) involved. However, we do expect the presence of the dense corona to reduce the growth rate of the m = 1 instability. Our results demonstrate that a z-pinch can be formed inside a ...
Date: December 31, 1984
Creator: Sethian, J.D.; Gerber, K.A.; Robson, A.E. & DeSilva, A.W.
Partner: UNT Libraries Government Documents Department

MCNP photon transport benchmarking calculations performed at SRP. Revision 1

Description: Monte Carlo methods have long been used at the Savannah River Laboratory (SRL) to perform criticality calculations for many different processes. To perform transport analyses (both neutron and photon) a two-dimensional infinite lattice integral transport code (GLASS) has been used. The neutron transport portion of the code has been benchmarked against other codes and experimental data. The photon transport portion of the code, which is used to calculate gamma redistribution in the event of a loss of moderator and/or coolant, had not been benchmarked against either. For this reason, the Monte Carlo code MCNP was used to benchmark the photon transport portion of the GLASS code. Preceding this, a brief description of the geometry of the Savannah River Plant`s (SRP) reactor cores and how they were modeled using MCNP will be given.
Date: 1989-06~
Creator: White, A. M.
Partner: UNT Libraries Government Documents Department

Experimental Aspects of Hypernuclear Physics at CEBAF

Description: The general features of the electromagnetic excitation of hypernuclei are outlined. Experimental aspects of investigating these reactions at CEBAF are discussed. Two specific experimental set-ups are compared.
Date: September 1, 1986
Creator: Mecking, Bernhard
Partner: UNT Libraries Government Documents Department

Performance criteria testing

Description: Savannah River Plant (SRP) has initiated an aggressive program aimed at improving their shipper/receiver (S/R) posture. The site is routinely involved in 800 nuclear material transfers/year. This many transactions between facilities provides many opportunities for resolving S/R differences. Resolution of S/R differences requires considerable effort from both DOE offices and contractors, presents legitimate safeguards concerns if the receiving quantity is less than the quantity shipped, and must be resolved for shipments to continue. This paper will discuss the programs in place at SRP to improve their position versus shipments and receipts of nuclear materials including: S/R agreements, which provide a method of communicating between the shipping and receiving facility and protects both facilities by eliminating misunderstandings; nondestructive assay (NDA) instrumentation, which allows the facility to obtain an accountability quality value for receipt before the material is processed; more accurate and precise analytical techniques in use wherever SRP does not have the capability to measure a shipment or receipt by NDA; S/R values are graphed to identify trends and/or biases that may not have exceeded any error limits; and the central Material Control and Accountability (MC and A) division has become more involved in analyzing the data from shipments and receipts including the calculation of limits of error (LOE`s), instrument biases, and analyzing trends.
Date: 1988-06~
Creator: Davis, F. B.
Partner: UNT Libraries Government Documents Department

Sensitivity of SRP LOCA power limit to break size and location

Description: SRP reactors are low pressure, heavy water reactors with six external process water loops that drive the coolant into an upper plenum and then downward through the assemblies. Assembly LOCA power limits are currently set in these reactors to prevent Ledinegg flow instability (FI) in any assembly flow channel. These limits are based on a postulated break area and location. This study determined the sensitivity of the power limit to the break area and location.
Date: 1989-06~
Creator: White, A. M.; Pevey, R. E. & Smith, F. G.
Partner: UNT Libraries Government Documents Department

Data acquisition with Masscomp

Description: Applications and products for data acquisition and control are abundant. Systems and boards for Apple or IBM products collect, store, and manipulate data up to rates in the 10`s of thousands. These systems may suit your application; if so, it would be good for you to obtain one of these systems. However, if you need speed in the hundreds of thousands of samples per second and you want to store, process, and display data in real time, data acquisition becomes much more complex. Operating system code has to be sufficient to handle the load. A company known as Massachusetts Computer Corporation has modified UNIX operating system code to allow real time data acquisition and control. They call this operating system Real Time Unix, or RTU. They have built a family of computer systems around this operating system with specialized hardware to handle multiple processes and quick communications, which a real time operating system needs to function. This paper covers the basics of an application using a Masscomp 5520 computer. The application is for the KYLE Project Cold Tests in SRL. KYLE is a classified weapons program. The data flow from source to Masscomp, the generic features of Masscomp systems, and the specifics of the Masscomp computer related to this application will be presented.
Date: October 1988
Creator: Collins, A. J.
Partner: UNT Libraries Government Documents Department

Evaluation of automated emergency response systems

Description: Automated Emergency Response (ER) systems are playing a greater role in providing prompt and reliable predictions of the impact of inadvertent releases of hazardous materials to the environment. Observed and forecast environmental and accident source term data are input into environmental transport and dispersion models to provide dosimetry estimates used as decision making aids for responding to emergencies. Several automated ER systems have been developed for US Federal Government facilities and many are available commercially. For such systems to be useful, they must reliably and consistently deliver a timely product to the decision makers. Evaluation of the entire ER system is essential to determine the performance that can be expected from the system during an emergency. Unfortunately, seldom are ER systems evaluated as a whole. Usually Quality Assurance programs evaluate the performance of individual components of the system. Most atmospheric pollution model evaluation methods usually involve an evaluation of the predictive performance of the transport and dispersion model when compared either with experimental tracer results or results from other models. Rarely, however, is the ability of the ER system to provide timely, reliable and consistent information evaluated. Such an evaluation is vital to determine the system performance during an emergency and to provide valuable information to aid in improving the system.
Date: 1988-09~
Creator: Addis, R. P.
Partner: UNT Libraries Government Documents Department

Automated dimensional analysis using a light-sectioning microscope

Description: A computer vision system has been integrated with a modified light-sectioning microscope for quality control and inspection of a machined part whose critical dimensions are 30 to 300 {mu}m. Height measurements were determined by analysis of the projected light-section line. Transverse measurements were made using the microscope in a traditional configuration with illumination from selected elements of an external LED ring array. The light section irradiance was under computer control to accommodate the spatial variations in surface reflectance whose dynamic range exceeded that of the vision system. Part features are located by the vision system. Edges and line centers are then measured to sub-pixel resolution with a gray-level analysis algorithm. This paper describes the design and operation of this system. Details of the measurement process and analysis algorithms are provided.
Date: December 31, 1988
Creator: Loomis, J.; Lightman, A.; Poe, A. & Caldwell, R.
Partner: UNT Libraries Government Documents Department