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Isotope-based medical research in the post genome era: Gene-orchestrated life functions in medicine seen and affected by isotopes. Workshop report (open access)

Isotope-based medical research in the post genome era: Gene-orchestrated life functions in medicine seen and affected by isotopes. Workshop report

The US Department of Energy (DOE) and the National Institutes of Health (NIH) conducted a workshop on Isotope-Based Medical Research in the Post Genome Era at NIH, Bethesda, Maryland, November 12--14, 1997. The workshop aimed at identifying the role of stable and radioisotopes for advanced diagnosis and therapy of a wide range of illnesses using the new information that comes from the human genome program. In this sense, the agenda addressed the challenge of functional genomics in humans. The workshop addressed: functional genomics in clinical medicine; new diagnostic potentials; new therapy potentials; challenge to tracer- and effector-pharmaceutical chemistry; and project plans for joint ventures.
Date: December 31, 1997
Creator: Feinendegen, L. E.
System: The UNT Digital Library
Global climate change mitigation and sustainable forest management--The challenge of monitoring and verification (open access)

Global climate change mitigation and sustainable forest management--The challenge of monitoring and verification

In this paper, sustainable forest management is discussed within the historical and theoretical framework of the sustainable development debate. The various criteria and indicators for sustainable forest management put forth by different institutions are critically explored. Specific types of climate change mitigation policies/projects in the forest sector are identified and examined in the light of the general criteria for sustainable forest management. Areas of compatibility and contradiction between the climate mitigation objectives and the minimum criteria for sustainable forest management are identified and discussed. Emphasis is put on the problems of monitoring and verifying carbon benefits associated with such projects given their impacts on pre-existing policy objectives on sustainable forest management. The implications of such policy interactions on assignment of carbon credits from forest projects under Joint Implementation/Activities Implemented Jointly initiatives are discussed. The paper concludes that a comprehensive monitoring and verification regime must include an impact assessment on the criteria covered under other agreements such as the Biodiversity and/or Desertification Conventions. The actual carbon credit assigned to a specific project should at least take into account the negative impacts on the criteria for sustainable forest management. The value of the impacts and/or the procedure to evaluate them need to …
Date: December 31, 1997
Creator: Makundi, Willy R.
System: The UNT Digital Library
An electromagnetic micro=undulator (open access)

An electromagnetic micro=undulator

Microfabrication technology using the LIGA (a German acronym for Lithography, Electroforming, and Molding) process offers an attractive alternative for fabricating precision devices with micron-sized features. One such device is a mm-sized micro-undulator with potential applications in a table-top synchrotron light source for medical and other industrial uses. The undulator consists of a silver conductor embedded in poles and substrate of nickel-iron. Electromagnetic modeling of the undulator is done using the eddy current computer code ELEKTRA. Computations predict a field pattern of appropriate strength and quality if the current can be prevented from being shunted from silver by the nickel-iron poles either through insulation or through slotted poles. The design of the undulator along with the computational results are discussed.
Date: December 31, 1997
Creator: Nassiri, A. & Turner, L. R.
System: The UNT Digital Library
Second Generation Advanced Reburning for High Efficiency N0x Control (open access)

Second Generation Advanced Reburning for High Efficiency N0x Control

Energy and Environmental Research Corporation is developing a family of high efficiency and low cost NO{sub x} control technologies for coal fired utility boilers based on Advanced Reburning (AR), a synergistic integration of basic reburning with injection of an N-agent. In conventional AR, injection of the reburn fuel is followed by simultaneous N-agent and overfire air injection. The second generation AR systems incorporate several components which can be used in different combinations. These components include: (1) Reburning Injection of the reburn fuel and overfire air. (2) N-agent Injection The N-agent (ammonia or urea) can be injected at different locations: into the reburning zone, along with the overfire air, and downstream of the overfire air injection. (3) N-agent Promotion Several sodium compounds can considerably enhance the NO{sub x} control from N-agent injection. These ''promoters'' can be added to aqueous N-agents. (4) Two Stages of N-agent Injection and Promotion Two N-agents with or without promoters can be injected at different locations for deeper NO{sub x} control. AR systems are intended for post-RACT applications in ozone non-attainment areas where NO{sub x} control in excess of 80% is required. AR will provide flexible installations that allow NO{sub x} levels to be lowered when regulations …
Date: December 31, 1997
Creator: Zamansky, Vladimir M.; Maly, Peter, M.; Sheldon, Mark; Seeker, W. Randall & Folsom, Blair A.
System: The UNT Digital Library
Optical measurement of LIGA milliengine performance (open access)

Optical measurement of LIGA milliengine performance

Understanding the parameters that affect the performance of milliscale and microscale actuators is essential to the development of optimized designs and fabrication processes, as well as the qualification of devices for commercial applications. This paper discusses the development of optical techniques for motion measurements of LIGA fabricated milliengines. LIGA processing permits the fabrication of precision millimeter-sized machine elements that cannot be fabricated by conventional miniature machining techniques because of their small feature sizes. In addition, tolerances of 1 part in 10{sup 3} to 10{sup 4} may be maintained in millimeter sized components with this processing technique. Optical techniques offer a convenient means for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. Optical techniques can also be used to provide feedback signals needed for control and sensing of the state of the machine. Optical probe concepts and experimental data obtained using a milliengine developed at Sandia National Laboratories are presented.
Date: December 31, 1997
Creator: Dickey, Fred M.; Holswade, Scott C.; Christenson, Todd R.; Garcia, Ernest J. & Polosky, Marc A.
System: The UNT Digital Library
Qualitative risk assessment of Sandia`s rocket preparation and launch facility at Barking Sands, Kauai (open access)

Qualitative risk assessment of Sandia`s rocket preparation and launch facility at Barking Sands, Kauai

This paper demonstrates the application of a qualitative methodology for performing risk assessments using the consequence and probability binning criteria of DOE Order 5481.1B. The particular application that is the subject of this paper is a facility risk assessment conducted for Sandia National Laboratories` Kauai Test Facility (KTF). The KTF is a rocket preparation and launch facility operated by Sandia National Laboratories for the Department of Energy and is located on the US Navy`s Pacific Missile Range Facility (PMRF) at Barking Sands on the western side of the island of Kauai, Hawaii. The KTF consists of an administrative compound and main launch facility located on the north end of the PMRF, as well as the small Kokole Point launch facility located on the south end of the PMRF. It is classified as a moderate hazard facility in accordance with DOE Order 5481.1B. As such, its authorization basis for operations necessitates a safety/risk assessment. This paper briefly addresses the hazards associated with KTF operations and the accidents selected for evaluation, introduces the principal elements of the accident assessment methodology, presents analysis details for two of the selected accidents, and provides a summary of results for all of the accidents evaluated.
Date: December 31, 1997
Creator: Mahn, Jeffrey A.
System: The UNT Digital Library
Kinetics of beneficiated fly ash by carbon burnout (open access)

Kinetics of beneficiated fly ash by carbon burnout

The presence of carbon in fly ash requires an increase in the dosage of the air-entraining admixture for concrete mix, and may cause the admixture to lose efficiency. Specifying authorities for the concrete producers have set maximum allowable levels of residual carbon. These levels are the so called Loss On Ignition (LOI). The concrete producers` day-to-day purchasing decisions sets the LOI at 4%. The objective of the project is to investigate the kinetics of oxidation of residual carbon present in coal fly ash as a possible first step toward producing low-carbon fly ash from high-carbon, low quality fly ash.
Date: December 31, 1997
Creator: Okoh, Joseph M.; Dodoo, Joseph N. D.; Diaz, Adria; Ferguson, William; Udinskey, Joseph R., Jr. & Christiana, Gerald A.
System: The UNT Digital Library
Resonance Interference and Absolute Cross Sections in Near-Threshold Electron-Impact Excitation of Multicharged Ions (open access)

Resonance Interference and Absolute Cross Sections in Near-Threshold Electron-Impact Excitation of Multicharged Ions

Strong resonance features were observed in near-threshold excitation of {sup 1}S right arrow {sup 3}P intercombination transitions in Si(2+), Ar(6+), and Kr(6+). Such resonances are predicted to dominate over direct excitation by more than an order of magnitude in the threshold region. Absolute cross sections were measured by using the merged electron-ion beams energy loss technique. The results are compared with R-matrix close-coupling (CCR) theory for all of the ions. Several discrepancies in resonance positions and magnitudes exist between experiment and theory for these spin forbidden transitions.
Date: December 31, 1997
Creator: Bannister, M. E.; Chung, Y. S.; Djuric, N.; Wallbank, B.; Woitke, O.; Zhou, S. et al.
System: The UNT Digital Library
Chemical kinetics models for semiconductor processing (open access)

Chemical kinetics models for semiconductor processing

Chemical reactions in the gas-phase and on surfaces are important in the deposition and etching of materials for microelectronic applications. A general software framework for describing homogeneous and heterogeneous reaction kinetics utilizing the Chemkin suite of codes is presented. Experimental, theoretical and modeling approaches to developing chemical reaction mechanisms are discussed. A number of TCAD application modules for simulating the chemically reacting flow in deposition and etching reactors have been developed and are also described.
Date: December 31, 1997
Creator: Coltrin, Michael E.; Creighton, J. Randall; Meeks, Ellen; Grcar, Joseph F.; Houf, William G. & Kee, Robert J.
System: The UNT Digital Library
Analyses of the Grain Boundary Misorientation and Oxygen Content of Bulk Processed YBA(2)CU(3)O(7-D). (open access)

Analyses of the Grain Boundary Misorientation and Oxygen Content of Bulk Processed YBA(2)CU(3)O(7-D).

None
Date: March 31, 1997
Creator: Wang, J. Y.; King, A. H.; Zhu, Y.; Wang, Y. L. & Suenaga,M.
System: The UNT Digital Library
LLW Forum meeting report, May 7--9, 1997 (open access)

LLW Forum meeting report, May 7--9, 1997

The Low-Level Radioactive Waste Forum met in Chicago, Illinois, on may 7--9, 1997. Twenty-three Forum Participants, Alternate Forum Participants, and meeting designees representing 20 compacts and states participated. A report on the meeting is given under the following subtitles: New developments in states and compacts; Upgrading an existing disposal facility; Revisions to DOE Order 5820 re DOE waste management; Conference of radiation control program directors: Recent and upcoming activities; National Conference of State Legislatures` (NCSL) low-level radioactive waste working group: Recent and upcoming activities; Executive session; LLW forum business session; Public involvement and risk communication: Success at West Valley, New York; DOE low-level waste management program; impact of the International Atomic Energy Agency`s convention on waste; Panel discussion: The environmental justice concept--Past, present and future; New technologies for processing and disposal of LLRW; High-level and low-level radioactive waste: A dialogue on parallels and intersections; Draft agreement re uniform application of manifesting procedures; Regulatory issues focus; LLW forum October 1997 agenda planning; Resolutions; LLW forum regulatory issues discussion group meets; and Attendance.
Date: December 31, 1997
Creator: Norris, Cynthia; Brown, Holmes; Lovinger, Todd; Scheele, Laura & Shaker, M. A.
System: The UNT Digital Library
LLW Forum meeting report, October 20--22, 1997 (open access)

LLW Forum meeting report, October 20--22, 1997

The Low-Level Radioactive Waste Forum met in Annapolis, Maryland, on October 20--22, 1997. Twenty-six Forum Participants, Alternate Forum Participants, and meeting designees representing 22 compacts and states participated. A report on the meeting is given under the following subtitles: New developments in states and compacts; Discussion with NRC Commissioner McGaffigan; Regulatory issues session; Executive session; LLW forum business session; DOE low-level waste management program; Transportation of radioactive waste; Environmental equity: Title VI; Congressional studies on Ward Valley Site; Implementation of DOE`s strategy for waste management; Relicensing Envirocare; Draft agreement for uniform application of manifesting procedures; CRCPD report; Panel: Future of low-level radioactive waste management; Agenda planning: February 1998; Resolutions; and Attendance.
Date: December 31, 1997
Creator: Norris, Cynthia; Brown, Holmes; Lovinger, Todd; Scheele, Laura & Shaker, M. A.
System: The UNT Digital Library
Automatic tuning of the reinforcement function (open access)

Automatic tuning of the reinforcement function

The aim of this work is to present a method that helps tuning the reinforcement function parameters in a reinforcement learning approach. Since the proposal of neural based implementations for the reinforcement learning paradigm (which reduced learning time and memory requirements to realistic values) reinforcement functions have become the critical components. Using a general definition for reinforcement functions, the authors solve, in a particular case, the so called exploration versus exploitation dilemma through the careful computation of the RF parameter values. They propose an algorithm to compute, during the exploration part of the learning phase, an estimate for the parameter values. Experiments with the mobile robot Nomad 200 validate their proposals.
Date: December 31, 1997
Creator: Touzet, Claude & Santos, Juan Miguel
System: The UNT Digital Library
Field experience with a new performance characterization procedure for photovoltaic arrays (open access)

Field experience with a new performance characterization procedure for photovoltaic arrays

As photovoltaic systems become larger and more numerous, improved methods are needed for testing and modeling their performance. Test methods that successfully separate the interacting, time-of-day dependent influences of solar irradiance, operating temperature, solar spectrum, and solar angle-of-incidence have now been developed. These test methods have resulted in a new array performance model that is reasonably simple, yet accurately predicts performance for all operating conditions. This paper describes the new model, outdoor tests required to implement it, results of field tests for five arrays of different technologies, and the evolution of the model into a numerical tool for designing and sizing photovoltaic arrays based on annual energy production.
Date: December 31, 1997
Creator: King, David L.; Kratochvil, Jay A. & Boyson, William E.
System: The UNT Digital Library
Alpha-Driven Alfven Instabilities and Velocity Shear Effects (open access)

Alpha-Driven Alfven Instabilities and Velocity Shear Effects

Energetic particle populations such as fusion alphas, beams and RF tails can drive a wide variety of shear Alfven instabilities in toroidal confinement systems. These instabilities lead to enhanced loss of fast ions and decreased heating efficiencies. Our gyrofluid stability model has recently been extended to include sheared plasma flow velocities. We also discuss recent results from applying this model to ITER, TFTR, and W7-AS.
Date: December 31, 1997
Creator: Spong, D. A.; Carreras, B. A.; Jeboeuf, J-N.; Weller, A.; Nazikian, R. & Zweben, S. J.
System: The UNT Digital Library
Recent progress in tubular solid oxide fuel cell technology (open access)

Recent progress in tubular solid oxide fuel cell technology

The tubular design of solid oxide fuel cells (SOFCs) and the materials used therein have been validated by successful, continuous electrical testing over 69,000 h of early technology cells built on a calcia-stabilized zirconia porous support tube (PST). In the latest technology cells, the PST has been eliminated and replaced by a doped lanthanum manganite air electrode tube. These air electrode supported (AES) cells have shown a power density increase of about 33% with a significantly improved performance stability over the previously used PST type cells. These cells have also demonstrated the ability to thermally cycle over 100 times without any mechanical damage or performance loss. In addition, recent changes in processes used to fabricate these cells have resulted in significant cost reduction. This paper reviews the fabrication and performance of the state-of-the-art AES tubular cells. It also describes the materials and processing studies that are underway to further reduce the cell cost, and summarizes the recently built power generation systems that employed state-of-the-art AES cells.
Date: December 31, 1997
Creator: Singhal, S.C.
System: The UNT Digital Library
Comparison of Materials for Use in the Precision Grinding of Optical Components (open access)

Comparison of Materials for Use in the Precision Grinding of Optical Components

Precision grinding of optical components is becoming an accepted practice for rapidly and deterministically fabrication optical surfaces to final or near-final surface finish and figure. In this paper, a comparison of grinding techniques and materials is performed. Flat and spherical surfaces were ground in three different substrate materials: BK7 glass, chemical vapor deposited (CVD) silicon carbide ceramic, and sapphire. Spherical surfaces were used to determine the contouring capacity of the process, and flat surfaces were used for surface finish measurements. The recently developed Precitech Optimum 2800 diamond turning and grinding platform was used to grind surfaces in 40mm diameter substrates sapphire and silicon carbide substrates and 200 mm BK7 glass substrates using diamond grinding wheels. The results of this study compare the surface finish and figure for the three materials.
Date: December 31, 1997
Creator: Evans, Boyd M. III; Miller, Arthur C. Jr. & Egert, Charles M.
System: The UNT Digital Library
Prediction of strongly-heated internal gas flows (open access)

Prediction of strongly-heated internal gas flows

The purposes of the present article are to remind practitioners why the usual textbook approaches may not be appropriate for treating gas flows heated from the surface with large heat fluxes and to review the successes of some recent applications of turbulence models to this case. Simulations from various turbulence models have been assessed by comparison to the measurements of internal mean velocity and temperature distributions by Shehata for turbulent, laminarizing and intermediate flows with significant gas property variation. Of about fifteen models considered, five were judged to provide adequate predictions.
Date: December 31, 1997
Creator: McEligot, D. M.; Shehata, A. M. & Kunugi, Tomoaki
System: The UNT Digital Library
Progress on the study of self-interaction of a bunch in a bend (open access)

Progress on the study of self-interaction of a bunch in a bend

When a short (mm-length) bunch with high (nC-regime) charge is transported through a magnetic bending system, self-interaction via coherent synchrotron radiation and space charge may cause emittance growth. Earlier the authors studied analytically the shielded transient self-interaction of a rigid-line bunch entering from a straight path to a circular orbit, and estimated the concomitant emittance degradation in parts of Jefferson Lab`s infrared free-electron laser (IR-FEL). In this paper, they generalize their earlier results by calculating the curvature-induced steady-state longitudinal wakefield on particles with transverse offsets from the design orbit. Recent progress in developing a self-consistent simulation are also presented.
Date: December 31, 1997
Creator: Li, R.; Bohm, C.L. & Bisognano, J.J.
System: The UNT Digital Library
Real-time, automated characterization of surfaces for alpha and beta radiation (open access)

Real-time, automated characterization of surfaces for alpha and beta radiation

A new data collection system, called ABACUS{trademark}, has been developed that automates and expedites the collection, conversion, and reporting of radiological survey data of surfaces. Field testing of the system by Oak Ridge National Laboratory/Environmental Technology Section is currently underway. Preliminary results are presented. The system detects, discriminates, and separately displays the results for alpha and beta contamination scans on floors and walls with a single pass. Fixed-position static counting is also possible for quantitative measuring. The system is currently configured with five 100 cm{sup 2} dual-phosphor plastic scintillation detectors mounted in a lightweight aluminum fixture that holds the detectors in a fixed array. ABACUS{trademark} can be configured with other detectors if desired. Ratemeter/scalars traditionally coupled to individual detectors have been replaced by a single unit that houses the power supply and discriminator circuit boards to support up to five detectors. The system is designed to be used by a single operator. Each detector`s position and data are transmitted once per second and recorded on a nearby laptop computer. The data are converted to appropriate units, color-coded, and mapped to display graphically the findings for each detector in real-time. Reports can be generated immediately following the survey. Survey data can …
Date: December 31, 1997
Creator: Egidi, P.V.; Flynn, C.R.; Blair, M.S. & Selfridge, R.J.
System: The UNT Digital Library
Neutron Radiography and Computed Tomography at Oak Ridge National Laboratory (open access)

Neutron Radiography and Computed Tomography at Oak Ridge National Laboratory

The capability to perform neutron radiography and computed tomography is being developed at Oak Ridge National Laboratory. The facility will be located at the High Flux Isotope Reactor (HFIR), which has the highest steady state neutron flux of any reactor in the world. The Monte Carlo N-Particle transport code (MCNP), versions 4A and 4B, has been used extensively in the design phase of the facility to predict and optimize the operating characteristics, and to ensure the safety of personnel working in and around the blockhouse. Neutrons are quite penetrating in most engineering materials and can be useful to detect internal flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant or a metal hydride, are relatively opaque to neutron transmission. Thus, neutron based tomography or radiography is ideal to image their presence. The source flux also provides unparalleled flexibility for future upgrades, including real time radiography where dynamic processes can be observed. A novel tomography detector has been designed using optical fibers and digital technology to provide a large dynamic range for reconstructions. Film radiography is also available for high resolution imaging applications. This paper summarizes the results of the design phase of this facility and the potential …
Date: December 31, 1997
Creator: Raine, Dudley A. III; Hubbard, Camden R.; Whaley, Paul M.; Wright, Michael C. & Hutchinson, Donald P.
System: The UNT Digital Library
Anticipating Potential Waste Acceptance Criteria for Defense Spent Nuclear Fuel (open access)

Anticipating Potential Waste Acceptance Criteria for Defense Spent Nuclear Fuel

The Office of Environmental Management of the U.S. Department of Energy is responsible for the safe management and disposal of DOE owned defense spent nuclear fuel and high level waste (DSNF/DHLW). A desirable option, direct disposal of the waste in the potential repository at Yucca Mountain, depends on the final waste acceptance criteria, which will be set by DOE`s Office of Civilian Radioactive Waste Management (OCRWM). However, evolving regulations make it difficult to determine what the final acceptance criteria will be. A method of anticipating waste acceptance criteria is to gain an understanding of the DOE owned waste types and their behavior in a disposal system through a performance assessment and contrast such behavior with characteristics of commercial spent fuel. Preliminary results from such an analysis indicate that releases of 99Tc and 237Np from commercial spent fuel exceed those of the DSNF/DHLW; thus, if commercial spent fuel can meet the waste acceptance criteria, then DSNF can also meet the criteria. In large part, these results are caused by the small percentage of total activity of the DSNF in the repository (1.5%) and regulatory mass (4%), and also because commercial fuel cladding was assumed to provide no protection.
Date: December 31, 1997
Creator: Rechard, R. P.; Lord, M. E.; Stockman, C. T. & McCurley, R. D.
System: The UNT Digital Library
Influence of Neutron Energy Spectrum on Primary Damage Formation (open access)

Influence of Neutron Energy Spectrum on Primary Damage Formation

Displacement cascade formation in iron has been investigated by the method of molecular dynamics (MD) for cascade energies up to 40 keV. The results of these simulations have been used to obtain effective, energy-dependent cross sections for two measures of primary damage production: (1) the number of surviving point defects expressed as a fraction of the those predicted by the standard secondary displacement model by Norgett, Robinson, and Torrens (NRT),and (2) the fraction of the surviving interstitials contained in clusters that formed during the cascade event. The primary knockon atom spectra for iron obtained from the SPECTER code have been used to weight these MD-based damage production cross sections in order to obtain spectrally-averaged values for several locations in commercial fission reactors, materials test reactors, a DT fusion reactor first wall, and a pulsed spallation neutron source. An evaluation of these results indicates that neutron energy spectrum differences between the various environments do not lead to significant differences between the average primary damage formation parameters. This conclusion implies that the displacement damage component of radiation damage produced in a high energy spallation neutron source should be well simulated by irradiation in a fission reactor neutron spectrum, and that differences in …
Date: December 31, 1997
Creator: Stoller, R. E.
System: The UNT Digital Library
Variable White Dwarf Data Tables (open access)

Variable White Dwarf Data Tables

Below, I give a brief explanation of the information in these tables. In all cases, I list the WD {number_sign}, either from the catalog of McCook {ampersand} Sion (1987) or determined by me from the epoch 1950 coordinates. Next, I list the most commonly used name (or alias), then I list the variable star designation if it is available. If not, I list the constellation name and a V** or?? depending on what the last designated variable star for that constellation is. I present epoch 2000 coordinates for all of the stars, which I precessed from the 1950 ones in most cases. I do not include proper motion effects; this is negligible for all except the largest proper motion DAV stars, such as L 19-2, BPM 37093, B 808, and G 29-38. Even in these cases, the error is no more than 30` in declination and 2 s in right ascension. I culled effective temperatures from the latest work (listed under each table); they are now much more homogeneous than before. I pulled the magnitude estimates from the appropriate paper, and they are mean values integrated over several cycles. The amplitude given is for the height of a typical pulse …
Date: December 31, 1997
Creator: Bradley, P. A.
System: The UNT Digital Library