WorldCat Identities

United States Department of Energy Oak Ridge Operations

Works: 2,025 works in 2,212 publications in 1 language and 8,608 library holdings
Roles: Researcher
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Publications by United States Publications by United States
Most widely held works by United States
Radiation-induced micrencephaly in guinea pigs ( )
3 editions published between 1991 and 1992 in English and held by 12 WorldCat member libraries worldwide
The effect of x rays on brain weight of guinea pig pups at birth was studied for 21-day old embroys exposed in utero to doses of 75 and 100 mGy. When compared to controls and when corrected for body weight, gestation time, litter size, sex, and examiner differences the brains of irradiated pups weighed approximately 46 mg less than those of controls (p<0.001) for the 75-mGy group and about 55 mg less for the 100-mGy group. Brains of females weighed 51 mg less than those of males of the same body weight. Dam weight and caging conditions had no observed effect on brain weight
Development of Technologies for a High Efficiency, Very Low Emission, Diesel Engine for Light Trucks and Sport Utility Vehicles ( )
2 editions published between 1997 and 2005 in English and held by 9 WorldCat member libraries worldwide
Cummins Inc., in partnership with the Department of Energy, has developed technology for a new highly efficient, very low emission, diesel engine for light trucks and sport utility vehicles. This work began in April 1997, and started with very aggressive goals for vehicles in the 5751 to 8500 pound GCW weight class. The primary program goals were as follows: (1) EMISSIONS -- NOx = 0.50 g/mi; PM = 0.05 g/mi; CO = 2.8 g/mi; and NMHC = 0.07 g/mi. California decided to issue new and even tougher LEV II light truck regulations late in 1999. EPA also issued its lower Tier 2 regulations late in 2000. The net result was that the targets for this diesel engine project were lowered, and these goals were eventually modified by the publication of Federal Tier 2 emission standards early in 2000 to the following: NOx = 0.07 g/mi; and PM = 0.01 g/mi. (2) FUEL ECONOMY -- The fuel economy goal was 50 percent MPG improvement (combined city/highway) over the 1997 gasoline powered light truck or sport utility vehicle in the vehicle class for which this diesel engine is being designed to replace. The goal for fuel economy remained at 50 percent MPG improvement, even with the emissions goal revisions. (3) COOPERATIVE DEVELOPMENT -- Regular design reviews of the engine program will be conducted with a vehicle manufacturer to insure that the concepts and design specifics are commercially feasible. (DaimlerChrysler has provided Cummins with this design review input.) Cummins has essentially completed a demonstration of proof-of-principle for a diesel engine platform using advanced combustion and fuel system technologies. Cummins reported very early progress in this project, evidence that new diesel engine technology had been developed that demonstrated the feasibility of the above emissions goals. Emissions levels of NOx = 0.4 g/mi and PM = 0.06 g/mi were demonstrated for a 5250 lb. test weight vehicle with passive aftertreatment only. These results were achieved using the full chassis dynamometer FTP-75 test procedure that allowed compliance with the Tier 2 Interim Bin 10 Standards and would apply to vehicles in MY2004 through MY2007 timeframe. In further technology development with active aftertreatment management, Cummins has been able to report that the emissions goals for the Tier 2 Bin 5 standards were met on an engine running the full FTP-75 test procedure. The fuel economy on the chassis tests was measured at over 59 percent MPG improvement over the gasoline engines that are offered in typical SUVs and light trucks. The above demonstration used only in-cylinder fueling for management of the aftertreatment system
1991 US-Japan workshop on Nuclear Fusion in Dense Plasmas. Proceedings ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
The scientific areas covered at the Workshop may be classified into the following subfields: (1) basic theory of dense plasma physics and its interface with atomic physics and nuclear physics; (2) physics of dense z-pinches, ICF plasmas etc; (3) stellar interior plasmas; (4) cold fusion; and (5) other dense plasmas
Computational and experimental study of a railplug ignitor ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
The plasma plume generated by a new type of high energy Janitor known as the railplug, is examined. The railplug is a miniaturized railgun that has the potential for improving ignition characteristics of combustible mixtures in engines. The objective of the study is to gain an uderstanding of the characteristics of the plasma created by a transparent railplug, and to validate a multidimensional computer simulation of the plasma and shock fronts. The nature of the plume emitted by the railplug was examined for three levels of electrical energy while firing into air at a pressure of 1 atm. The computer model is to be used to predict trends in railplug performance for various railplug designs, energies, and ambient conditions. The velocity of the plasma movement inside a transparent railplug was measured, as well as the velocity of the plume ejected from the cavity. A shock is produced at the initiation point of the arc and propagates down the cavity, eventually exiting the plug. The velocity of the shock was both measured experimentally and simulated by the model. The computer simulation produces a mushroom-shaped plasma plume at the railplug exit similar to that observed in the shadowgraph photos: The simulation also reproduced the toroidal circulation observed at the plug exit in the shadowgraphs, the radial expansion and the penetration depth of the plume. The trend of linearly increasing plasma kinetic energy with stored electrical energy predicted by the simulation was verified by shadowgraph photos. The agreement between the experiments and the simulations suggests that the multidimensional model holds promise is a predictive design tool
Network based high performance concurrent computing ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
The overall objectives of this project are to investigate research issues pertaining to programming tools and efficiency issues in network based concurrent computing systems. The basis for these efforts is the PVM project that evolved during my visits to Oak Ridge Laboratories under the DOE Faculty Research Participation program; I continue to collaborate with researchers at Oak Ridge on some portions of the project
Some simple criteria for gauged R-parity ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
Some simple conditions which are sufficient to guarantee that R- parity survives as an unbroken gauged discrete subgroup of the continuous gauge symmetry in certain supersymmetric extensions of the standard model are presented
Committee on Atomic, Molecular, and Optical Sciences (CAMOS). Technical progress report, [February 1, 1991--January 31, 1992] ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
The Committee on Atomic, Molecular, and Optical Sciences is a standing committee under the auspices of the Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Applications of the National Academy of Sciences -- National Research Council. The atomic, molecular, and optical (AMO) sciences represent a broad and diverse field in which much of the research is carried out by small groups. These groups generally have not operated in concert with each other and, prior to the establishment of CAMOS, there was no single committee or organization that accepted the responsibility of monitoring the continuing development and assessing the general public health of the field as a whole. CAMOS has accepted this responsibility and currently provides a focus for the AMO community that is unique and essential. The membership of CAMOS is drawn from research laboratories in universities, industry, and government. Areas of expertise on the committee include atomic physics, molecular science, and optics. A special effort has been made to include a balanced representation from the three subfields. (A roster is attached.) CAMOS has conducted a number of studies related to the health of atomic and molecular science and is well prepared to response to requests for studies on specific issues. This report brief reviews the committee work of progress
Metastable enhancement of C[sup +] and O[sup +] capture reactions. [10 to 500 eV] ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
The project is devoted to the study of charge transfer neutralization of Carbon and oxygen ions in H and H[sub 2] gases at energies from 10 to 500 eV. A major motivation was to provide cross section data to support analysis of edge plasmas in Tokamak Fusion devices. The first objective was to measure cross sections for metastable excited singly charged ions separately from the cross sections for ground state ions. Previously published values are confusing because the beams used included unknown fractions of metastables and these metastables have cross sections greatly different from the ground states. The program was fully accomplished, metastable cross sections were found to be over an order of magnitude greater than ones for the ground state and existing discrepancies in the literature were resolved. Considerable effort was devoted to the design and operation of ion source configurations were the metastable content of the ion beam was known. Subsequently study progressed to the neutralization of multiply charged C and 0 ions in the same targets. First there has been a need to develop ion sources which can produce useful beams of multiply charged species. This has now been accomplished. The intent is to use these sources for the measurement of cross sections with again an attempt to differentiate between the behavior of ground and metastably excited species
Statistical fluctuations in lasers. Technical progress report ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
A quenched c = 1 critical matrix model ( )
2 editions published in 1990 in English and held by 8 WorldCat member libraries worldwide
We study a variant of the Penner-Distler-Vafa model, proposed as a c = 1 quantum gravity: quenched' matrix model with logarithmic potential. The model is exactly soluble, and exhibits a two-cut branching as observed in multicritical unitary matrix models and multicut Hermitian matrix models. Using analytic continuation of the power in the conventional polynomial potential, we also show that both the Penner-Distler-Vafa model and our quenched' matrix model satisfy Virasoro algebra constraints
Nuclear structure from radioactive decay. [School of Physics, Georgia Inst. of Tech] ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
The most important aspect of the wind-up of UNISOR-based research is completion of student theses. Analysis is proceeding on extensive studies in the neutron-deficient rare earth isotopes with N <82 and the neutron-deficient region below Z = 82. These studies address the onset of deformation in the N <82, Z> 50 open shell region and shape coexistence in the N [approximately] 104, Z [le] 82 region, respectively. The main ongoing topics are shape coexistence in nuclei and the microscopic structure of collective motion in nuclei from a phenomenological point of view. New topics this year focus on the structure of nuclei near the N = Z line. Two topics have been chosen for detailed study: shape coexistence and electric monopole transition strengths
Magnetic surfaces in a steady-state tokamak ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
We study a toroidal plasma in a tokamak with externally given toroidal and poloidal magnetic fields as well as self-consistently interacting internal currents. The unperturbed magnetic surfaces are described by the well-known nonlinear standard map.'' When the magnetic field is allowed to carry an internal current, the self-interaction of these currents disturbs the integrity of the magnetic surfaces. We carry out a computational study of the effects of the interacting internal current filaments, measuring the diffusion of field lines from the unperturbed surfaces, and find the self-interaction to be a significant effect which always serves to increase diffusion. Perfect surfaces are difficult to maintain even when magnetic islands do not overlap. Diffusion from the current interaction dominates when current fluctuations reach (approximately) 10% of the applied field
Studies of fluctuation processes in nuclear collisions. [Dept. of Physics, Tennessee Technological Univ., Cookeville, Tennessee] ( )
2 editions published between 1992 and 1993 in English and held by 8 WorldCat member libraries worldwide
This report discusses the following topics: Relativistic Boltzmann-Langevin model for heavy-ion collision; K+ production far below free neucleon-nucleon threshold and damping of collective vibrations in a memory-dependent transport model
Manipulating the chloroplast genome of Chlamydomonas Present realities and future prospects ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
Biotechnology is being applied in vitro modification and stable reintroduction of chloroplast genes in Chlamydomonas reinhardtii and Nicotiana tabacum by homologous recombination. We are attempting the function analyses of plastid encoded proteins involved in photosynthesis, characterization of sequences which regulate expression of plastid genes at the transcriptional and translational levels, targeted disruption of chloroplast genes and molecular analysis of processes involved in chloroplast recombination
Fermilab E791 ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
Fermilab E791, a very high statistics charm particle experiment, recently completed its data taking at Fermilab's Tagged Photon Laboratory. Over 20 billionevents were recorded through a loose transverse energy trigger and written to 8mm tape in the 1991--92 fixed target run at Fermilab. This unprecedented data sample containing charm is being analysis on many-thousand MIP RISC computing farms set up at sites in the collaboration. A glimpse of the data taking and analysis effort is presented. We also show some preliminary results for common charm decay modes. Our present analysis indicates a very rich yield of over 200K reconstructed charm decays
Self shielding of surfaces irradiated by intense energy fluxes ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
This dissertation will outline a direct methods of temperature, density, composition, and velocity measurement which should be widely applicable to railgun systems. The measurements demonstrated here should prove usefull basis for further studies of plasma/target interaction
Kinetics and mechanisms of key elementary processes of importance to high temperature combustion chemistry ( )
2 editions published in 1989 in English and held by 8 WorldCat member libraries worldwide
We have investigated the kinetics and mechanisms numerous reactions involving many key reactive combustion species: CH[sub 2]O, CH[sub 3]O, CH, NO, NO[sub 2], CH[sub 3]OH, C[sub 2]H[sub 5]OH, i-C[sub 3]H[sub 7]OH, t-C[sub 4]H[sub 9]OH, C[sub 6]H[sub 5], C[sub 5]O and C[sub 6]H[sub 5]O and C[sub 6]H[sub 6], among others. A total of 24 reactive systems have been studied
Zircons and fluids An experimental investigation with applications for radioactive waste disposal ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
The long-term stability of nuclear waste forms or barriers is related to changes in physical properties of the material induced through radiation damage and subsequent changes in solubility. Investigations conducted by us on natural zircons (ZrSiO₄) supports a positive correlation between level of alpha damage and fluid composition to enhanced levels of corrosion. New data are presented on the nature and rate of the solution process. We also present data on our continuing efforts to synthesize and characterize both pure ZrSiO₄ and doped with U, Th, Hf, Dy and P
Magnetic reconnection at stressed x-type neutral points ( )
2 editions published in 1992 in English and held by 8 WorldCat member libraries worldwide
The reconnection and relaxation of two-dimensional stressed (non-potential) x-type neutral point magnetic fields are studied via solution of the nonlinear resistive 2-D MHD equations and by analytical solution of the linear eigenvalue problem. The linear dispersion relation was generalized for azimuthally nonsymmetric perturbations, and have found that for modes with azimuthal mode numbers m> 0, the relaxation can occur at a rate faster than that for n = m = 0, where n is the radial quantum'' number. One finds that for nearly azimuthally symmetric magnetic perturbations that are zero at the boundary; i.e. the frozen-in'' (sometimes called fine-tied'') boundary conditions, the fields relax incompressibly and nonlinearly to the unstressed x-type neutral point at a rate close to that predicted by linear theory. Also, fully compressible nonlinear MHD simulations have been performed, which show that the interaction between the plasma flow velocity and the magnetic field is the important physical effect, while the inclusion of thermodynamics does not affect the evolution considerably. A Lyapunov functional for the nonlinear incompressible 2-D resistive MHD equations is derived to show that the current-free x-point configuration is a global equilibrium to which general initial conditions relax
Activity composition relationships in silicate melts ( )
2 editions published in 1990 in English and held by 8 WorldCat member libraries worldwide
Equipment progress include furnace construction and electron microprobe installation. The following studies are underway: phase equilibria along basalt-rhyolite mixing line (olivine crystallization from natural silicic andensites, distribution of Fe and Mg between olivine and liquid, dist. of Ca and Na between plagioclase and liquid), enthalpy-composition relations in magmas (bulk heat capacity of alkali basalt), density model for magma ascent and contamination, thermobarometry in igneous systems (olivine/plagioclase phenocryst growth in Quat. basalt), high-pressure phase equilibria of alkali basalt, basalt-quartz mixing experiments, phase equilibria of East African basalts, and granitic minerals in mafic magma. (DLC)
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English (44)