Resource Type

Non-fusion applications of RF and microwave technology (open access)

Non-fusion applications of RF and microwave technology

The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.
Date: December 1, 1995
Creator: Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C. et al.
System: The UNT Digital Library
Performance and measurements of the AGS and Booster beams (open access)

Performance and measurements of the AGS and Booster beams

Analyses of Hot Gas Stream Cleanup (HGSC) ashes and descriptions of filter performance were made to address the problems with filter operation that are apparently linked to the collected ash. This task is designed to generate data base of the key properties of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters. Activities including initial formatting of the data base and entry, modification of the permeability model, and initial design of a high-temperature test device for measuring uncompacted bulk porosity of ash aggregates (indicator of relative cohesivity of the ash, filter cake porosity/permeability). Chemical analyses of hopper and filter cake ashes from Tidd showed that the consolidation degree could not be accounted for by condensation/adsorption from the flue gas; the mechanism is likely physical rearrangement of the ash particles.
Date: December 31, 1995
Creator: Weng, W. T.
System: The UNT Digital Library
Lattices with minimal space charge effects for crystalline beams (open access)

Lattices with minimal space charge effects for crystalline beams

There are numerous techniques for cooling beams of charged particles including stochastic cooling, electron beam cooling, ionization (foil) cooling (for lepton beams only), and laser cooling which works only with ions with some electrons still attached. The successful implementation of laser cooling at Aarhus, has led to interest in crystalline beams, and it certainly seems that crystallization of small numbers of stored particles should be possible. There are limits, however, that may restrict the total number of charged particles stored; these include the limit on the space-charge tune shift, {vert_bar}{triangle}{nu}{vert_bar} < 0.25 (though the precise number is subject to debate) and intrabeam scattering. In this paper we will be concerned with the possibility of intense crystalline beams; for simplicity we treat only the nonrelativistic case, though the relativistic case is a simple extension of this work. In the next section we review the limits on the number of particles stored and observe that the beam size scaling with beam temperature is the important dependence that determines the limits on the stored current as a function of beam temperature. In section 3 we use a general formalism to determine the beam size scaling and apply it to various kinds of focusing …
Date: December 1995
Creator: Channell, P. J. & Neri, F. R.
System: The UNT Digital Library
Fermilab E687 results and future high statistics charm experiment FOCUS/E831 (open access)

Fermilab E687 results and future high statistics charm experiment FOCUS/E831

Results from the Fermilab charm photoproduction experiment E687 are reviewed. The physics goals and the improvements being made for the next experiment (FOCUS/E831) are described. We expect to accumulate a million fully reconstructed charm decays which represent an order of magnitude improvement over E687.
Date: December 1, 1995
Creator: Cheung, W.K. & Collaboration, The E687
System: The UNT Digital Library
Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production (open access)

Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

Estimating terrestrial net primary production (NPP) using remote- sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Programme`s (IGBP`s) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and …
Date: December 31, 1995
Creator: Olson, R. J.; Turner, R. S.; Scurlock, J. M. O. & Jennings, S. V.
System: The UNT Digital Library
Suppression of Apoptosis by Basement Membrane Requires three-dimensional Tissue Organization and Withdrawal from the Cell Cycle (open access)

Suppression of Apoptosis by Basement Membrane Requires three-dimensional Tissue Organization and Withdrawal from the Cell Cycle

The basement membrane (BM) extracellular matrix induces differentiation and suppresses apoptosis in mammary epithelial cells, whereas cells lacking BM lose their differentiated phenotype and undergo apoptosis. Addition of purified BM components, which are known to induce {beta}-casein expression, did not prevent apoptosis, indicating that a more complex BM was necessary. A comparison of culture conditions where apoptosis would or would not occur allowed us to relate inhibition of apoptosis to a complete withdrawal from the cell cycle, which was observed only when cells acquired a three-dimensional alveolar structure in response to BM. In the absence of this morphology, both the G1 cyclin kinase inhibitor p21/WAF-I and positive proliferative signals including c-myc and cyclin Dl were expressed and the retinoblastoma protein (Rb) continued to be hyperphosphorylated. When we overexpressed either c-myc in quiescent cells or p21 when cells were still cycling, apoptosis was induced. In the absence of three-dimensional alveolar structures, mammary epithelial cells secrete a number of factors including transforming growth factor a and tenascin, which when added exogenously to quiescent cells induced expression of c-myc and interleukin-{beta}1-converting enzyme (ICE) mRNA and led to apoptosis. These experiments demonstrate that a correct tissue architecture is crucial for long-range homeostasis, suppression of …
Date: December 28, 1995
Creator: Boudreau, N.; Werb, Z. & Bissell, M.J.
System: The UNT Digital Library
Applications of neural networks in environmental and energy sciences and engineering. Proceedings of the 1995 workshop on environmental and energy applications of neural networks (open access)

Applications of neural networks in environmental and energy sciences and engineering. Proceedings of the 1995 workshop on environmental and energy applications of neural networks

These proceedings contain edited versions of the technical presentations of the Workshop on Environmental and Energy Applications of Neural Networks, held on March 30--31, 1995, in Richland, Washington. The purpose of the workshop was to provide a forum for discussing environmental, energy, and biomedical applications of neural networks. Panels were held to discuss various research and development issues relating to real-world applications in each of the three areas. The applications covered in the workshop were: Environmental applications -- modeling and predicting soil, air and water pollution, environmental sensing, spectroscopy, hazardous waste handling and cleanup; Energy applications -- process monitoring and optimization of power systems, modeling and control of power plants, environmental monitoring for power systems, power load forecasting, fault location and diagnosis of power systems; and Biomedical applications -- medical image and signal analysis, medical diagnosis, analysis of environmental health effects, and modeling biological systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
Date: December 31, 1995
Creator: Hashem, S.; Keller, P. E.; Kouzes, R. T. & Kangas, L. J.
System: The UNT Digital Library
BNL feasibility studies of spallation neutron sources (open access)

BNL feasibility studies of spallation neutron sources

This paper is the summary of conceptual design studies of a 5 MW Pulsed Spallation Neutron Source (PSNS) conducted by an interdepartmental study group at Brookhaven National Laboratory. The study was made of two periods. First, a scenario based on the use of a 600 MeV Linac followed by two fast-cycling 3.6 GeV Synchrotrons was investigated. Then, in a subsequent period, the attention of the study was directed toward an Accumulator scenario with two options: (1) a 1.25 GeV normal conducting Linac followed by two Accumulator Rings, and (2) a 2.4 GeV superconducting Linac followed by a single Accumulator Ring. The study did not make any reference to a specific site.
Date: December 1, 1995
Creator: Lee, Y. Y.; Ruggiero, A. G.; van Steenbergen, A. & Weng, W. T.
System: The UNT Digital Library
DOE-sponsored cable aging research at Sandia National Laboratories (open access)

DOE-sponsored cable aging research at Sandia National Laboratories

Cables have been identified as critical components requiring detailed technical evaluation for extending the lifetime of Light Water Reactors beyond 40 years. This paper highlights some of the DOE-sponsored cable aging studies currently underway at Sandia. These studies are focused on two important issues: the validity of the often-used Arrhenius thermal aging prediction method and methods for predicting lifetimes in combined thermal-radiation environments. Accelerated thermal aging results are presented for three cable jacket and insulation materials, which indicate that hardening of the outside surface has an Arrhenius temperature dependence and correlates well with reductions in ultimate tensile elongation. This suggests that the indentor approach is a promising NDE technique for cable jacket and unjacketed insulation materials installed in thermally-dominated regions of nuclear power plants.
Date: December 1, 1995
Creator: Gillen, K. T.; Clough, R. L.; Celina, M.; Wise, J. & Malone, G. M.
System: The UNT Digital Library
Recent developments in ecological theory: hierarchy and scale (open access)

Recent developments in ecological theory: hierarchy and scale

Over the past decade, hierarchy and scale have been adopted as an ecological paradigm. Beyond this new awareness, however, a number of studies have attempted to test the underlying hierarchy theory and developed new analytical applications. The purpose of the present paper is to review these recent developments. Tests of the theory have focused on the prediction that ecological systems should not be uniformly distributed across scale, but grouped or lumped into discrete levels. The predicted breaks in spatial distribution have been found in vegetation transects. Vertebrate weight distributions are also distinctly aggregated, corresponding to the spatial scale at which each species operates. An important development of hierarchy theory has considered extrapolating information upscale. Simply stated, the dynamics of the higher level cannot be represented by the same functional form as its components. One cannot insert the mean parameter value for the components and predict higher level effects. Analytical methods, derived from hierarchy theory, have been developed deal with the problem.
Date: December 31, 1995
Creator: O`Neill, R.V.
System: The UNT Digital Library
Low-level waste forum meeting reports (open access)

Low-level waste forum meeting reports

This paper provides highlights from the 1995 summer meeting of the Low Level radioactive Waste Forum. Topics included: new developments in state and compacts; federal waste management; DOE plans for Greater-Than-Class C waste management; mixed wastes; commercial mixed waste management; international export of rad wastes for disposal; scintillation cocktails; license termination; pending legislation; federal radiation protection standards.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
Recent improvements to the SOURCE1 and SOURCE2 computer codes (open access)

Recent improvements to the SOURCE1 and SOURCE2 computer codes

Performance assessments of low-level radioactive waste (LLW) disposal facilities often involve the use of computer codes to describe radionuclide releases from a waste form and the subsequent transport of radionuclides through the environment. The SOURCE1 and SOURCE2 computer codes are used to calculate radionuclide release rates (i.e., source terms) for LLW disposal facilities. These codes have been used to evaluate the source terms for Oak Ridge National Laboratory performance assessments. SOURCE1 is applicable to tumulus-type facilities, while SOURCE2 can be applied to silo, well-in-silo, well, and trench-type facilities. In addition to the calculation of radionuclide release rates, both SOURCE1 and SOURCE2 calculate the degradation of engineered barriers. This paper provides an overview of these codes and a description of recent improvements to the codes. Major improvements include incorporation of a new advective transport model into SOURCE1 and SOURCE2, development of a new model for SOURCE1 that calculates the degradation and failure of the tumulus pad and leachate collection system, improvement of routines for controlling water infiltration inputs, expansion of options for obtaining output summaries, and restructuring of SOURCE1 and SOURCE2 for sensitivity and uncertainty analyses. The status of code verification efforts is also presented.
Date: December 31, 1995
Creator: Icenhour, A.S. & Tharp, M.L.
System: The UNT Digital Library
Nonequilibrium multiphase mixture modeling of energetic material response (open access)

Nonequilibrium multiphase mixture modeling of energetic material response

To model the shock-induced behavior of porous or damaged energetic materials, a nonequilibrium mixture theory has been developed and incorporated into the shock physics code, CTH. Foundation for this multiphase model is based on a continuum mixture formulation given by Baer and Nunziato. In this nonequilibrium approach, multiple thermodynamic and mechanics fields are resolved including the effects of material relative motion, rate-dependent compaction, drag and heat transfer interphase effects and multiple-step combustion. Benchmark calculations are presented which simulate low-velocity piston impact on a propellant porous bed and experimentally-measured wave features are well replicated with this model. This mixture model introduces micromechanical models for the initiation and growth of reactive multicomponent flow which are key features to describe shock initiation and self-accelerated deflagration-to-detonation combustion behavior. To complement one-dimensional simulation, two dimensional numerical simulations are presented which indicate wave curvature effects due to the loss of wall confinement.
Date: December 31, 1995
Creator: Baer, M. R.; Hertel, E. & Bell, R.
System: The UNT Digital Library
Pulsed spallation neutron source with an induction linac and a fixed-field alternating-gradient accelerator (open access)

Pulsed spallation neutron source with an induction linac and a fixed-field alternating-gradient accelerator

The paper describes an accelerator scenario of a Pulsed Spallation Neutron Source made of an Induction Linac injecting into a Fixed-Field Alternating-Gradient Accelerator (FFAG). The motivations underlying the proposal deal with the concern of removing technical risks peculiar to other scenarios involving RF Linacs, Synchrotrons and Accumulator Rings, which originate, for example, from the need of developing intense negative-ion sources and of multi-turn injection into the Compressor Rings. The system proposed here makes use of a positive-ion source of very short pulse duration, and of single-turn transfer into the circular accelerator.
Date: December 1, 1995
Creator: Ruggiero, A. G.; Bauer, G. & Faltens, A.
System: The UNT Digital Library
15. International Conference on Plant Growth Substances: Program -- Abstracts (open access)

15. International Conference on Plant Growth Substances: Program -- Abstracts

Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ``classical`` plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joined by a number of new signal molecules, e.g., systemin, jasmonic acid, salicylic acid, whose biosynthesis and functions are being understood in ever greater detail. Molecular genetics has opened new vistas in an understanding of transduction pathways that regulate developmental processes in response to hormonal and environmental signals. The program of the 15th Conference includes accounts of this progress and brings together scientists whose work focuses on physiological, biochemical, and chemical aspects of plant growth regulation. This volume contains the abstracts of papers presented at this conference.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
Intelligent systems for the molecular biologist (open access)

Intelligent systems for the molecular biologist

This tutorial was one of eight tutorials selected to be presented at the Third International Conference on Intelligent Systems for Molecular Biology which was held in the United Kingdom from July 16 to 19, 1995. In this paper, one objective is to identify properties of DNA sequences that determine their function, by computer-aided statistical analysis and to accurately predict its function, given a new sequence. A related problem is to predict protein structure and function from the sequence.
Date: December 31, 1995
Creator: Brutlag, D.L.
System: The UNT Digital Library
Proceedings: pellet fuels conference (open access)

Proceedings: pellet fuels conference

The conference brought together professionals from the process- engineered-fuels (PEF), utility, paper, plastics, and boiler industries. Although the last two decades have produced technical breakthroughs, efforts to advance PEF must now focus on increasing commercial breakthroughs. Successful commercialization will depend on increasing supplier, consumer, and regulator confidence and support by demonstrating the performance and value of PEF products. Speakers provided updates on how PEF technology is evolving with respect to technical, economic, and regulatory challenges. Actions critical toward full commercialization of PEF were then considered. Discussion groups addressed materials sourcing, fuel processing and transportation, combustion, and ash handling.
Date: December 1995
Creator: unknown
System: The UNT Digital Library
9. international mouse genome conference (open access)

9. international mouse genome conference

This conference was held November 12--16, 1995 in Ann Arbor, Michigan. The purpose of this conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on genetic mapping in mice. This report contains abstracts of presentations, focusing on the following areas: mutation identification; comparative mapping; informatics and complex traits; mutagenesis; gene identification and new technology; and genetic and physical mapping.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
Proceedings: 17th annual US Department of Energy low-level radioactive waste management conference (open access)

Proceedings: 17th annual US Department of Energy low-level radioactive waste management conference

Selected papers have been processed separately for inclusion in the Energy Science and Technology database. Also included are four 3.5` discs that are to accompany the report.
Date: December 31, 1995
Creator: Lake, D.
System: The UNT Digital Library