WorldCat Identities

United States Department of Energy Oakland Operations Office

Works: 3,820 works in 4,032 publications in 1 language and 15,117 library holdings
Roles: Researcher
Publication Timeline
Most widely held works by United States
Experiences with remote collaborations in fusion research ( )
18 editions published between 1997 and 1998 in English and held by 68 WorldCat member libraries worldwide
DIII-D's ECH upgrade with 1 MW, 110 GHz gyrotrons is ongoing, and with it, an upgrade of the control system. The ECH Multiple Gyrotron Control System uses software distributed among networked computers, interfaced to a programmable logic controller (PLC), the timing and pulse system, power supplies, vacuum and wave guide controls, and instrumentation. During DIII-D operations, the system will allow a chief and a co-operator to control and monitor a number of gyrotrons from different manufacturers. The software, written using LabVIEW, allows for remote and multiple operator control. Thus any supported computer can become a control station and multiple projects can be simultaneously accommodated. Each operator can be given access to the controls of all gyrotrons or to a subset of controls. Status information is also remotely available. The use of a PLC simplifies the hardware and software design. It reduces interlock and control circuitry, includes monitoring for slow analog signals, and allows one software driver to efficiently interface to a number of systems. In addition, the interlock logic can be easily changed and control points can be forced as needed. The pulse system is designed around arbitrary function generators. Various modulation schemes can be accommodated, including real-time control of the modulation. This discussion will include the hardware and software design of the control system and its current implementation
[Restriction of virus infection by plants Annual report, 1986] ( )
2 editions published in 1986 in English and held by 42 WorldCat member libraries worldwide
This research concerns the strong resistance, or even immunity, against a specific virus that is exhibited by one or a few lines of a plant species, in contrast to the general susceptibility of most lines of that species. The contrast between the reactions to virus inoculation of different lines of one species implies that a single gene or a very few genes may mediate the resistance or immunity. The prospects for isolating, studying and transferring such a gene should be good for a system with these characteristics. Seedlings of a line Arlington of the cowpea (Vigna unguiculata) fail to support the replication of cowpea mosaic virus strain SB (CPMV-SB). Genetic crosses of Arlington cowpea to the systemic host Blackeye 5 cowpea show that the immunity is inherited as a simple dominant gene. In contrast to the seedlings, the protoplasts of the Arlington cowpea support CPMV-SB replication, but only to a very low level compared to protoplasts of Blackeye 5 cowpeas. From evidence reported earlier we concluded that Arlington cowpea protoplasts restrict the production of CPMV-SB proteins. We postulated, and obtained evidence for, a proteinase inhibitor that is specific for a CPMV-SB proteinase. This proteinase inhibitor is our prime candidate for the mediator of the resistance of Arlington protoplasts to CPMV-SB. Progress to date is described
Final Report ( )
6 editions published between 1998 and 2004 in English and held by 22 WorldCat member libraries worldwide
OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves
Nuclear research with electromagnetic probe. Progress report ( )
4 editions published between 1988 and 1994 in English and held by 16 WorldCat member libraries worldwide
This is the final report on the research carried at Stanford University under contract DE-FG03-88ER40439. All the work accomplished under this grant is reported in the publications listed as part of the Principal Investigator bibliography at the end of this report. In the last few years our research was directed at some of the forefront questions in nuclear physics. We investigated the nuclear medium effects on the intrinsic properties of bound nucleons, specifically the ectromagnetic form factors. For these studies we performed a number of specialized electron scattering experiments with specific sensitivity to nuclear medium effects. At the next level of structure, elementary constituents of matter are quarks and gluons. Defining the energy regime where the quark-gluon description of nuclear systems becomes more relevant than the nucleon-meson description is of great importance in thoroughly understanding the nuclear structure. To explore this transition region, we studied the scaling region in the disintegration of the deuteron, the simplest nuclear system with high energy photons. Finally we focused on the investigation of the nucleon internal spin structure along with the test of the Bjoerken sum rule a fundamental sum rule of QCD
3 editions published between 1992 and 2005 in English and held by 13 WorldCat member libraries worldwide
The objective of this study was to investigate the role of oceanic carbon chemistry in modulating the atmospheric levels of CO[sub 2]. It is well known that the oceans are the primary sink of the excess carbon pumped into the atmosphere since the beginning of the industrial period. The suspended particulate and the dissolved organic matters in the deep ocean play important roles as carriers of carbon and other elements critical to the fate of CO[sub 2]. In addition, the suspended particulate matter provides sites for oxidation-reduction reactions and microbial activities. The problem is of an intricate system with complex chemical, physical and biological processes. This report describes a methodology to describe the interconversions of different forms of the organic and inorganic nutrients, that may be incorporated in the ocean circulation models. Our approach includes the driving force behind the transfers in addition to balancing the elements. Such thermodynamic considerations of describing the imbalance in the chemical potentials is a new and unique feature of our approach
Culturally relevant science an approach to math science education for hispanics. Final technical report ( )
3 editions published in 1996 in English and held by 12 WorldCat member libraries worldwide
This progress report summarizes results of a teacher workshop. A letter sent to 17 teachers who had participated in the workshop requested a report of any activities undertaken and copies of lesson plans and materials developed. Only nine responses were received, and not all of them demonstrated a satisfactory level of activity. Teachers who submitted materials showing the most promise were invited to participate in the Summer Writing Workshop. A partial first draft of a companion volume for the teacher's manual was written which provides a rationale for culturally relevant science and presents the cultural and scientific background needed. The outline of the book is presented in Appendix 1. Appendix 2 is a sample chapter from the book
Current driven due to localized electron power deposition in DIII-D ( )
3 editions published in 1999 in English and held by 12 WorldCat member libraries worldwide
The power deposition profiles for different poloidal and toroidal launch angles have been determined by modulating the ECH power and measuring the electron temperature response. The peak of the measured power density follows the poloidal steering of the ECH launcher, and perpendicular launch gives a narrower deposition profile than does oblique (current drive) launch. The difference in wave refraction between X-mode and O-mode allows positive identification of an unwanted O-mode component of the launched beam
Lied Animal Shelter Animal campus Renewable Energy Demonstration Project ( )
3 editions published between 1999 and 2001 in English and held by 12 WorldCat member libraries worldwide
(B204) The meeting will bring together observers and theorists in a highly interactive format, to further connect the local and cosmological star formation communities. Forward looking talks, aimed at the other communities, will survey terminology, achievements, problems and aspirations. Discussion will focus on the definition of the key questions, how the different communities can help each other, and preparations for the incorporation of realistic star formation into cosmological simulations
H-mode pedestal characteristics, ELMs, and energy confinement in ITER shape discharges on DIII-D ( )
3 editions published in 1997 in English and held by 11 WorldCat member libraries worldwide
The edge pressure gradient (H-mode pedestal) for computed equilibria in which the current density profile is consistent with the bootstrap current may not be limited by the first regime ballooning limit. The transition to second stability is easier for: higher elongation, intermediate triangularity, larger ratio, pedestal at larger radius, narrower pedestal width, higher q₉₅, and lower collisionality
An algorithm to provide real time neutral beam substitution in the DIII-D tokamak ( )
3 editions published in 1999 in English and held by 11 WorldCat member libraries worldwide
The DIII-D tokamak fusion research experiment's real-time digital plasma control system (PCS) is a complex and ever evolving system. During a plasma experiment, it is tasked with some of the most crucial functions at DIII-D. Key responsibilities of the PCS involve sub-system control, data acquisition/storage, and user interface. To accomplish these functions, the PCS is broken down into individual components (both software and hardware), each capable of handling a specific duty set. Constant interaction between these components is necessary prior, during and after a standard plasma cycle. Complicating the matter even more is that some components, mostly those which deal with user interaction, may exist remotely, that is to say they are not part of the immediate hardware which makes up the bulk of the PCS. The four main objectives of this paper are to (1) present a brief outline of the PCS hardware/software and how they relate to each other; (2) present a brief overview of a standard DIII-D plasma cycle (a shot); (3) using three sets of PCS sub-systems, describe in more detail the communication processes; and (4) evaluate the benefits and drawbacks of said systems
3 editions published in 1996 in English and held by 11 WorldCat member libraries worldwide
Functional understanding of the carbon cycle from the molecular to the global level is a high scientific priority requiring explanation of the relationship between fluxes at different spatial and temporal scales. We describe methods used to convert an open top chamber into both closed and open flow gas exchange systems utilized to measure such fluxes. The systems described consist of temporary modifications to an open top chamber, and are put in place for several days on one or several open top chambers. In the closed system approach, a chamber is quickly sealed for a short, predetermined time interval, the change in gas concentrations is measured, then the chamber is unsealed and ventilated. In the open flow system approach, airflow into the open top chamber is measured by trace gas injection, and the air stream concentration of CO₂ and water vapor is measured before and after injection into the chamber. The closed chamber approach can resolve smaller fluxes, but causes transient increases in chamber air temperature, and has a high labor requirement. The open flow approach reduces the deviation of measuring conditions from ambient, may be semi-automated (requiring less labor), allows a more frequent sampling interval, but cannot resolve low fluxes well. Data demonstrating the capabilities of these systems show that, in open canopies of ponderosa pine, scaling fluxes from leaves to whole canopies is well approximated from summation of leaf P{sub s} rates. Flux measurements obtained from these systems can be a valuable contribution to our understanding whole system material fluxes, and challenge our understanding of ecosystem carbon budgets
[Studies of supported molybdenum and tungsten]. Progress report ( )
3 editions published between 1991 and 1994 in English and held by 11 WorldCat member libraries worldwide
The effective starting date of this grant was May 15. In the first three months of this project we focused primarily on organizational and technical aspects of our research which included: organization of the database of repeats in primates; preparation of software for rapid and sensitive search of novel repetitive elements in GenBank; purchase and installation of the Sun workstation; and research on the mammal-specific MAR1 family of repetitive elements (to be communicated in October)
3 editions published between 1996 and 2000 in English and held by 11 WorldCat member libraries worldwide
The goal of the Castle project was to provide a parallel programming environment that enables the construction of high performance applications that run portably across many platforms. The authors approach was to design and implement a multilayered architecture, with higher levels building on lower ones to ensure portability, but with care taken not to introduce abstractions that sacrifice performance
Final Report on Grant DE-FG03-02ER63470 ( )
2 editions published between 2006 and 2011 in English and held by 9 WorldCat member libraries worldwide
The goal of this project is to provide critical information to characterize the qualitative and quantitative similarities and difference in repair characteristics between clustered damage sites formed by ionizing radiation and singly damaged sites produced by endogenous processes. The premise is that base pairing and base stacking interactions are qualitatively and quantitatively different for singly and multiply damaged DNA sites. State-of-the-art computational chemistry model were used to characterize the structure, energetics, and spectroscopy of singly and multiply damaged (clustered) DNA sites
Final Technical Report ( )
2 editions published between 1998 and 2003 in English and held by 9 WorldCat member libraries worldwide
OAK B202 Final Technical Report. The present generation of reactor analysis methods uses few-group nodal diffusion approximations to calculate full-core eigenvalues and power distributions. The cross sections, diffusion coefficients, and discontinuity factors (collectively called ''group constants'') in the nodal diffusion equations are parameterized as functions of many variables, ranging from the obvious (temperature, boron concentration, etc.) to the more obscure (spectral index, moderator temperature history, etc.). These group constants, and their variations as functions of the many variables, are calculated by assembly-level transport codes. The current methodology has two main weaknesses that this project addressed. The first weakness is the diffusion approximation in the full-core calculation; this can be significantly inaccurate at interfaces between different assemblies. This project used the nodal diffusion framework to implement nodal quasidiffusion equations, which can capture transport effects to an arbitrary degree of accuracy. The second weakness is in the parameterization of the group constants; current models do not always perform well, especially at interfaces between unlike assemblies. The project developed a theoretical foundation for parameterization and homogenization models and used that theory to devise improved models. The new models were extended to tabulate information that the nodal quasidiffusion equations can use to capture transport effects in full-core calculations
A New Layering Method for Indirect Drive IFE Targets Progress Report for the Periods August 15, 2000 through December 14, 2001 ( )
2 editions published in 2001 in English and held by 8 WorldCat member libraries worldwide
OAK B202 A New Layering for Indirect Drive IFE Targets Progress report for the periods August 15, 2000 through December 14, 2001 Layering is the process whereby condensed deuterium tritium (DT) fusion fuel at 18-19 K is very uniformly distributed on the inside wall of an Inertial Fusion Energy (IFE) target. The quality and uniformity of the DT layer has a profound effect on the performance (gain) of the target. It would be a great advantage for indirect drive targets to carry out layering with the capsule already assembled in the hohlraum. One concept to accomplish this is to layer targets in controlled temperature, cryogenic tubes while they are being staged for feeding to the injection system. In this report we have demonstrated through extensive analysis that in-hohlraum layering is possible, but that variations in dimensions, alignments and material properties can easily cause the capsule temperature nonuniformity to exceed values needed to assure proper fuel layering. The concept shows sufficient promise to warrant continued investigation. Analysis alone cannot demonstrate the feasibility of in-hohlraum layering. One of the most basic and important experiments is the measurement of the properties of hohlraum materials. Such measurements must be performed with sufficient accuracy to demonstrate predictability and repeatability to the level of precision needed to maintain thermal control. Continued close interaction between target designers and target fabricators is needed to ensure development of a cost-effective target design
Laser-driven ICF experiments Laboratory Report No. 223 ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
Laser irradiation uniformity is a key issue and is treated in some detail. The basic irradiation uniformity requirements and practical ways of achieving these requirements are both discussed, along with two beam-smoothing techniques: induced spatial incoherence (ISI), and smoothing by spectral dispersion (SSD). Experiments to measure and control the irradiation uniformity are also highlighted. Following the discussion of irradiation uniformity, a brief review of coronal physics is given, including the basic physical processes and their experimental signatures, together with a summary of pertinent diagnostics and results from experiments. Methods of determining ablation rates and thermal transport are also described. The hydrodynamics of laser-driven targets must be fully understood on the basis of experiments. Results from implosion experiments, including a brief description of the diagnostics, are presented. Future experiments aimed at determining ignition scaling and demonstrating hydrodynamically equivalent physics applicable to high-gain designs
An assessment of the base blanket for ITER ( )
2 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
Ideally, the ITER base blanket would provide the necessary tritium for the reactor to be self-sufficient during operation, while having minimal impact on the overall reactor cost, reliability and safety. A solid breeder blanket has been developed in CDA phase in an attempt to achieve such objectives. The reference solid breeder base blanket configurations at the end of the CDA phase has many attractive features such as a tritium breeding ratio (TBR) of 0.8--0.9 and a reasonably low tritium inventory. However, some concerns regarding the risk, cost and benefit of the base blanket have been raised. These include uncertainties associated with the solid breeder thermal control and the potentially high cost of the amount of Be used to achieve high TBR and to provide the necessary thermal barrier between the high temperature solid breeder and low temperature coolant. This work addresses these concerns. The basis for the selection of a breeding blanket is first discussed in light of the incremental risk, cost and benefits relative to a non-breeding blanket. Key issues associated with the CDA breeding blanket configurations are then analyzed. Finally, alternative schemes that could enhance the attractiveness and flexibility of a breeding blanket are explored
Classification theorem for principal fibre bundles, Berry's phase, and exact cycle evolution ( )
2 editions published in 1993 in English and held by 8 WorldCat member libraries worldwide
The relation between the two mathematical interpretations of the geometric (Berry) phase is discussed, using either the fibre bundle over parameter space or over projective Hilbert space. It turns out that these two geometric constructions are linked by the classification theorem for vector bundles. The classification theorem provides the means to classify the parameter space bundles for adiabatic evolution and for non-adiabatic cyclic evolution of the statevectors
Burning of a spherical fuel droplet in a uniform subsonic flowfield ( )
2 editions published in 1989 in English and held by 8 WorldCat member libraries worldwide
An analytical/numerical model is described for the evaporation and burning of a spherical fuel droplet in a subsonic crossflow. The external gaseous flowfield is represented using an approximate compressible potential solution, while the internal flowfield of the droplet is represented by the classical Hill's spherical vortex. This allows numerical solution for the external boundary layer and diffusion flame characteristics to be made, from which the droplet's effective drag coefficient, rate of mass loss, size, and flame shape are determined. Comparison with experimental data indicate good agreement, and thus the potential for such simplified models in performing parametric studies
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English (73)