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A 3-D numerical study of pinhole diffraction to predict the accuracy of EUV point diffraction interferometry (open access)

A 3-D numerical study of pinhole diffraction to predict the accuracy of EUV point diffraction interferometry

A 3-D electromagnetic field simulation is used to model the propagation of extreme ultraviolet (EUV), 13-nm, light through sub-1500 {Angstrom} dia pinholes in a highly absorptive medium. Deviations of the diffracted wavefront phase from an ideal sphere are studied within 0.1 numerical aperture, to predict the accuracy of EUV point diffraction interferometersused in at-wavelength testing of nearly diffraction-limited EUV optical systems. Aberration magnitudes are studied for various 3-D pinhole models, including cylindrical and conical pinhole bores.
Date: December 1, 1995
Creator: Goldberg, K.A.; Tejnil, E. & Bokor, J.
System: The UNT Digital Library
5. international workshop on the identification of transcribed sequences (open access)

5. international workshop on the identification of transcribed sequences

This workshop was held November 5--8, 1995 in Les Embiez, France. The purpose of this conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on mapping the human genome. Attention is focused on the following topics: transcriptional maps; functional analysis; techniques; model organisms; and tissue specific libraries and genes. Abstracts are included of the papers that were presented.
Date: December 31, 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
A 10-GeV, 5-MW proton source for a muon-muon collider (open access)

A 10-GeV, 5-MW proton source for a muon-muon collider

The performance parameters of a proton source which produces the required flux of muons for a 2-TeV on 2-TeV muon collider are: a beam energy of 10 GeV, a repetition rate of 30 Hz, two bunches per pulse with 5 x 10{sup 13} protons per bunch, and an rms bunch length of 3 nsec (1). Aside from the bunch length requirement, these parameters are identical to those of a 5-MW proton source for a spallation neutron source based on a 10-GeV rapid cycling synchrotron (RCS) (2). The 10-GeV synchrotron uses a 2-GeV accelerator system as its injector, and the 2-GeV RCS is an extension of a feasibility study for a I-MW spallation source described elsewhere (3--9). A study for the 5-MW spallation source was performed for ANL site-specific geometrical requirements. Details are presented for a site-independent proton source suitable for the muon collider utilizing the results of the 5-MW spallation source study.
Date: December 31, 1995
Creator: Cho, Y.; Chae, Y.-C. & Crosbie, E.
System: The UNT Digital Library
A 10-GeV, 5-MW proton source for a pulsed spallation source (open access)

A 10-GeV, 5-MW proton source for a pulsed spallation source

A feasibility study for a pulsed spallation source based on a 5-MW, 10-GeV rapid proton synchrotron (RCS) is in progress. The integrated concept and performance parameters of the facility are discussed. The 10-GeV synchrotron uses as its injector the 2-GeV accelerator system of a 1-MW source described elsewhere. The 1-MW source accelerator system consists of a 400-MeV H{sup {minus}} linac with 2.5 MeV energy spread in the 75% chopped (25% removed) beam and a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV. The time averaged current of the accelerator system is 0.5 mA, equivalent to 1.04 {times} 10{sup 14} protons per pulse. The 10-GeV RCS accepts the 2 GeV beam and accelerates it to 10 GeV. Beam transfer from the 2-GeV synchrotron to the 10-GeV machine u highly efficient bunch-to-bucket injection, so that the transfer can be made without beam loss. The synchrotron lattice uses FODO cells of 90{degrees} phase advance. Dispersion-free straight sections are obtained using a missing magnet scheme. The synchrotron magnets are powered by dual-frequency resonant circuits. The magnets are excited at a 20-Hz rate and de-excited at 60-Hz. resulting in an effective 30-Hz rate. A key feature of the design of this accelerator system …
Date: December 31, 1995
Creator: Cho, Y.; Chae, Y.C. & Crosbie, E.
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
8th International Symposium on Transport Phenomena in Combustion (open access)

8th International Symposium on Transport Phenomena in Combustion

The 8th International Symposium on Transport Phenomena in Combustion will be held in San Francisco, California, U.S.A., July 16-20, 1995, under the auspices of the Pacific Center of Thermal-Fluids Engineering. The purpose of the Symposium is to provide a forum for researchers and practitioners from around the world to present new developments and discuss the state of the art and future directions and priorities in the areas of transport phenomena in combustion. The Symposium is the eighth in a series; previous venues were Honolulu 1985, Tokyo 1987, Taipei 1988, Sydney 1991, Beijing 1992, Seoul 1993 and Acapulco 1994, with emphasis on various aspects of transport phenomena. The current Symposium theme is combustion. The Symposium has assembled a balanced program with topics ranging from fundamental research to contemporary applications of combustion theory. Invited keynote lecturers will provide extensive reviews of topics of great interest in combustion. Colloquia will stress recent advances and innovations in fire spread and suppression, and in low NO{sub x} burners, furnaces, boilers, internal combustion engines, and other practical combustion systems. Finally, numerous papers will contribute to the fundamental understanding of complex processes in combustion. This document contains abstracts of papers to be presented at the Symposium.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
AC 95 - selected readings (open access)

AC 95 - selected readings

Reports are presented on energy efficiency and conservation in residential buildings. Topics include housing and energy linkages; the people factor; low-income initiatives; green visions; utility programs; affordable comfort; housing as a system; and pressures and air flow in buildings.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
Accelerated Characterization of Metal Fuel Stored in the Hanford K Basins (open access)

Accelerated Characterization of Metal Fuel Stored in the Hanford K Basins

Efforts are under way to gather data on the condition of the metal fuel and associated sludge stored in the water-filled Hanford K Basins. Most of the current data gathering activities are being performed in the basins without fuel movement. These techniques include a video survey of open storage canisters, determination of water/gas levels in sealed canisters, sampling of gas and water from sealed canisters (for chemical analysis) and measurement of sludge depth and sludge volume.
Date: December 31, 1995
Creator: Makenas, B. J.; Omberg, R. P.; Lawrence, L. A.; Marschman, S. C. & Abrefah, J.
System: The UNT Digital Library
Accelerating polarized beams at the AGS (open access)

Accelerating polarized beams at the AGS

The acceleration of polarized beams in circular accelerators is complicated by the presence of numerous depolarizing resonances. During acceleration, a depolarizing resonance is crossed whenever the spin precession frequency equals the frequency with which spin-perturbing magnetic fields are encountered. There are two main types of depolarizing resonances corresponding to the possible sources of such fields: imperfection resonances, which are driven by magnet errors and misalignments, and intrinsic resonances, driven by the focusing fields. The resonance conditions are usually expressed in terms of the spin tune {nu}{sub s}, which is defined as the number of spin precessions per revolution. For an ideal planar accelerator, where orbiting particles experience only the vertical guide field, the spin tune is equal to G{gamma}, where G = 1.7928 is the anomalous magnetic moment of the proton and {gamma} is the relativistic Lorentz factor. The resonance condition for imperfection depolarizing resonances arise when {nu}{sub s} = G{gamma} = n, where n is an integer. Imperfection resonances are therefore separated by only 523 MeV energy steps. The condition for intrinsic resonances is {nu}{sub s} = G{gamma} = kP {+-} {nu}{sub y}, where k is an integer, {nu}{sub y} is the vertical betatron tune and P is the …
Date: December 1, 1995
Creator: Roser, T.
System: The UNT Digital Library
Acceleration and storage of polarized proton beams (open access)

Acceleration and storage of polarized proton beams

High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10{sup 32} cm{sup -2} s{sup -1}.
Date: December 31, 1995
Creator: Roser, T.
System: The UNT Digital Library
Accelerator design for the high-power industrial FEL (open access)

Accelerator design for the high-power industrial FEL

We have developed a conceptual design for an industrial-use kilowatt UV and IR FEL driven by a recirculating, energy-recovering 200 MeV, 1- 5 mA superconducting rf (SRF) electron accelerator. In this paper we describe the accelerator design of this FEL. The accelerator consists of a 10 MeV injector, a 96 MeV SRF linac with a two-pass transport which accelerates the beam to 200 MeV, followed by energy-recovery deceleration through two passes to the dump. Technical challenges include high-intensity injector development, multi-pass energy- recovery operation, SRF modifications and control for FEL operation, development of tuneable, nearly-isochronous, large-acceptance transports, and matching of the beam to the FEL wiggler. An overview of the accelerator design is presented. 9 refs., 1 fig., 1 tab.
Date: December 31, 1995
Creator: Neuffer, D. V.; Benson, S. & Bisognano, J.
System: The UNT Digital Library
Accelerators for high energy physics research (open access)

Accelerators for high energy physics research

A brief survey of particle accelerators as research tools for high energy physics is given. The survey includes existing accelerators, as well as those envisioned for the future.
Date: December 1, 1995
Creator: Chao, A.
System: The UNT Digital Library
Accident sequence precursor events with age-related contributors (open access)

Accident sequence precursor events with age-related contributors

The Accident Sequence Precursor (ASP) Program at ORNL analyzed about 14.000 Licensee Event Reports (LERs) filed by US nuclear power plants 1987--1993. There were 193 events identified as precursors to potential severe core accident sequences. These are reported in G/CR-4674. Volumes 7 through 20. Under the NRC Nuclear Plant Aging Research program, the authors evaluated these events to determine the extent to which component aging played a role. Events were selected that involved age-related equipment degradation that initiated an event or contributed to an event sequence. For the 7-year period, ORNL identified 36 events that involved aging degradation as a contributor to an ASP event. Except for 1992, the percentage of age-related events within the total number of ASP events over the 7-year period ({approximately}19%) appears fairly consistent up to 1991. No correlation between plant ape and number of precursor events was found. A summary list of the age-related events is presented in the report.
Date: December 31, 1995
Creator: Murphy, G.A. & Kohn, W.E.
System: The UNT Digital Library
The accident site portable integrated video system (open access)

The accident site portable integrated video system

This paper presents a high bandwidth fiber-optic communication system intended for post accident recovery of weapons. The system provides bi-directional multichannel, and multi-media communications. Two smaller systems that were developed as direct spin-offs of the larger system are also briefly discussed.
Date: December 31, 1995
Creator: Jones, D. P.; Shirey, D. L. & Amai, W. A.
System: The UNT Digital Library
Accurate and portable weigh-in-motion system for manifesting air cargo (open access)

Accurate and portable weigh-in-motion system for manifesting air cargo

An automated and portable weigh-in-motion system has been developed at Oak Ridge National Laboratory for the purpose of manifesting cargo onto aircraft. The system has an accuracv range of {plus_minus} 3.0% to {plus_minus} 6.0% measuring gross vehicle weight and locating the center of balance of moving vehicles at speeds of 1 to 5 mph. This paper reviews the control/user interface system and weight determination algorithm developed to acquire, process, and interpret multiple sensor inputs. The development effort resulted in a self-zeroing, user-friendly system capable of weighing a wide range of vehicles in any random order. The control system is based on the STANDARD (STD) bus and incorporates custom-designed data acquisition and sensor fusion hardware controlled by a personal computer (PC) based single-board computer. The user interface is written in the ``C`` language to display number of axles, axle weight, axle spacing, gross weight, and center of balance. The weighing algorithm developed will function with any linear weight sensor and a set of four axle switches per sensor.
Date: December 1, 1995
Creator: Nodine, R. N.; Scudiere, M. B. & Jordan, J. K.
System: The UNT Digital Library
Actinides at the Crossroads: ICP-MS or Alpha Spectrometry? (open access)

Actinides at the Crossroads: ICP-MS or Alpha Spectrometry?

The report contains viewgraphs only that summarize the following: Why turn to mass spectrometry for radiochemical measurements; What might be some advantages of using ICP mass spectrometry; Sensitivity of ETV-ICP-MS relative to decay counting (versus half-life); ICP-MS instrument detection limits for dissolved actinide isotopes; Effect of dissolved solids on USN-ICP-MS analysis; Polyatomic ion interferences in ICP-MS actinide measurements; Effect of operating conditions on uranium and protonated uranium signal; ICP mass spectrometry performance in actinide determinations; Determination of actinide elements in soil; Leachable Th-230 and Pu-239 in soil as determined by ICP-MS and alpha spectrometry; Leachable U-234 and U-238 in soil by ICP-MS and alpha spectrometry; Determination of uranium isotopic composition on smears; Activity ratios (U-234/U-238) as determined by mass spectrometry and alpha spectrometry; Uranium isotopic abundances as determined by TIMS and ICP-MS; and Comparison of uranium atom percentages determined by TIMS and ICP-MS. It is concluded that isotope dilution and radiochemical preparative techniques work well in radioanalytical applications of ICP-MS; radioanalytical ICP-MS data are equivalent to data from standard methods (TIMS, alpha spectrometry); and applications in radiation protection and earth sciences are certain to expand further.
Date: December 31, 1995
Creator: Crain, J. S.; Yaeger, J. S.; Smith, F. P.; Alvarado, J. A.; Smith, L. L.; Kiely, J. T. et al.
System: The UNT Digital Library
Adaptive, predictive controller for optimal process control (open access)

Adaptive, predictive controller for optimal process control

One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some …
Date: December 1, 1995
Creator: Brown, S. K.; Baum, C. C.; Bowling, P. S.; Buescher, K. L.; Hanagandi, V. M.; Hinde, Jr., R. F. et al.
System: The UNT Digital Library
Additive synthesis with DIASS-M4C on Argonne National Laboratory`s IBM POWERparallel System (SP) (open access)

Additive synthesis with DIASS-M4C on Argonne National Laboratory`s IBM POWERparallel System (SP)

DIASS-M4C, a digital additive instrument was implemented on the Argonne National Laboratory`s IBM POWER parallel System (SP). This paper discusses the need for a massively parallel supercomputer and shows how the code was parallelized. The resulting sounds and the degree of control the user can have justify the effort and the use of such a large computer.
Date: December 31, 1995
Creator: Kaper, H.; Ralley, D.; Restrepo, J. & Tiepei, S.
System: The UNT Digital Library
Advanced 3D inverse method for designing turbomachine blades (open access)

Advanced 3D inverse method for designing turbomachine blades

To meet the goal of 60% plant-cycle efficiency or better set in the ATS Program for baseload utility scale power generation, several critical technologies need to be developed. One such need is the improvement of component efficiencies. This work addresses the issue of improving the performance of turbo-machine components in gas turbines through the development of an advanced three-dimensional and viscous blade design system. This technology is needed to replace some elements in current design systems that are based on outdated technology.
Date: December 31, 1995
Creator: Dang, T.
System: The UNT Digital Library
Advanced combustion technologies for gas turbine power plants (open access)

Advanced combustion technologies for gas turbine power plants

Objectives are to develop actuators for enhancing the mixing between gas streams, increase combustion stability, and develop hgih-temperature materials for actuators and sensors in combustors. Turbulent kinetic energy maps of an excited jet with co-flow in a cavity with a partially closed exhaust end are given with and without a longitudinal or a transverse acoustic field. Dielectric constants and piezoelectric coefficients were determined for Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} ceramics.
Date: December 1995
Creator: Vandsburger, U.; Roe, L. A. & Desu, S. B.
System: The UNT Digital Library
Advanced low-temperature sorbents (open access)

Advanced low-temperature sorbents

A number of promising technologies are currently being optimized for coal-based power generation, including the Integrated-Gasification Combined Cycle (IGCC) system. If IGCC is to be used successfully for power generation, an economic and efficient way must be found to remove the contaminants, particularly sulfur species, found in coal gas. Except for the hot gas desulfurization system, all major components of IGCC are commercially available or have been shown to meet system requirements. Over the last two decades, the U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) has sponsored development of various configurations of high-temperature desulfurization systems including fixed-bed, moving-bed, transport-bed, and fluidized-bed systems. Because of their mode of operation and requirements for sorbent manufacturing, the fixed-bed systems can generally use the same materials as moving-bed configurations, i.e., pelletized or extruded sorbents, while fluidized-bed (circulating or bubbling configurations) and transport reactor configurations use materials generally described as agglomerated or granulated.The objective of this program is to remove hydrogen sulfides from coal gas using sorbent materials.
Date: December 1, 1995
Creator: Ayala, R.E.; Venkataramani, V.S.; Abbasian, J. & Hill, A.H.
System: The UNT Digital Library
Advanced materials for solid oxide fuel cells (open access)

Advanced materials for solid oxide fuel cells

The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs.
Date: December 31, 1995
Creator: Armstrong, T. & Stevenson, J.
System: The UNT Digital Library
Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer (open access)

Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer

The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage …
Date: December 31, 1995
Creator: Fleeter, S. & Lawless, P.B.
System: The UNT Digital Library