Assessing Risk of Innovation (open access)

Assessing Risk of Innovation

Today's manufacturing systems and equipment must perform at levels thought impossible a decade ago. Companies must push operations, quality, and efficiencies to unprecedented levels while holding down costs. In this new economy, companies must be concerned with market shares, equity growth, market saturation, and profit. U.S. manufacturing is no exception and is a prime example of businesses forced to adapt to constant and rapid changes in customer needs and product mixes, giving rise to the term ''Agile Manufacturing''. The survival and ultimate success of the American Manufacturing economy may depend upon its ability to create, innovate, and quickly assess the impact that new innovations will have on its business practices. Given the need for flexibility, companies need proven methods to predict and measure the impact that new technologies and strategies will have on overall plant performance from an enterprise perspective. The Value-Derivative Model provides a methodology and approach to assess such impacts in terms of energy savings, production increases, quality impacts, emission reduction, and maintenance and operating costs as they relate to enabling and emerging technologies. This is realized by calculating a set of first order sensitivity parameters obtained from expanding a Taylor Series about the system's operating point. These …
Date: August 15, 2001
Creator: Allgood, GO
System: The UNT Digital Library
Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis (open access)

Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis

The central goal of the National Ignition Facility (NIF) is demonstration of controlled thermonuclear ignition. The mainline ignition target is a low-Z, single-shell cryogenic capsule designed to have weakly nonlinear Rayleigh-Taylor growth of surface perturbations. Double-shell targets are an alternative design concept that avoids the complexity of cryogenic preparation but has greater physics uncertainties associated with performance-degrading mix. A typical double-shell design involves a high-Z inner capsule filled with DT gas and supported within a low-Z ablator shell. The largest source of uncertainty for this target is the degree of highly evolved nonlinear mix on the inner surface of the high-Z shell. High Atwood numbers and feed-through of strong outer surface perturbation growth to the inner surface promote high levels of instability. The main challenge of the double-shell target designs is controlling the resulting nonlinear mix to levels that allow ignition to occur. Design and analysis of a suite of indirect-drive NIF double-shell targets with hohlraum temperatures of 200 eV and 250 eV are presented. Analysis of these targets includes assessment of two-dimensional radiation asymmetry as well as nonlinear mix. Two-dimensional integrated hohlraum simulations indicate that the x-ray illumination can be adjusted to provide adequate symmetry control in hohlraums specially …
Date: October 15, 2001
Creator: Amendt, P.; Colvin, J.; Tipton, R. E.; Hinkel, D.; Edwards, M. J.; Landen, O. L. et al.
System: The UNT Digital Library
Industrial Applications of Low Temperature Plasmas (open access)

Industrial Applications of Low Temperature Plasmas

The use of low temperature plasmas in industry is illustrated by the discussion of four applications, to lighting, displays, semiconductor manufacturing and pollution control. The type of plasma required for each application is described and typical materials are identified. The need to understand radical formation, ionization and metastable excitation within the discharge and the importance of surface reactions are stressed.
Date: March 15, 2001
Creator: Bardsley, J N
System: The UNT Digital Library
Proposed Multiconjugate Adaptive Optics Experiment at Lick Observatory (open access)

Proposed Multiconjugate Adaptive Optics Experiment at Lick Observatory

While the theory behind design of multiconjugate adaptive optics (MCAO) systems is growing, there is still a paucity of experience building and testing such instruments. We propose using the Lick adaptive optics (AO) system as a basis for demonstrating the feasibility/workability of MCAO systems, testing underlying assumptions, and experimenting with different approaches to solving MCAO system issues.
Date: August 15, 2001
Creator: Bauman, B. J.; Gavel, D. T.; Flath, L. M.; Hurd, R. L.; Max, C. E. & Olivier, S. S.
System: The UNT Digital Library
Preparation and Properties of Nitrate-Deficient Gadolinium Nitrate Solutions (open access)

Preparation and Properties of Nitrate-Deficient Gadolinium Nitrate Solutions

Because of the high neutron absorption cross sections of some gadolinium isotopes, gadolinium salts in solution are used to control nuclear reactivity in aqueous systems. The present studies concern the preparation and analysis of nitrate-deficient solutions, the effect of time and gamma radiation on their stability, and the determination of the solubility of gadolinium hydroxide in H2O and D2O.
Date: March 15, 2001
Creator: Baumann, E. W.
System: The UNT Digital Library
Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet (open access)

Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet

The LBNL Superconducting Magnet Program is extending accelerator magnet technology to the highest possible fields. A 1 meter long, racetrack dipole magnet, utilizing state-of-the-art Nb{sub 3}Sn superconductor, has been built and tested. A record dipole filed of 14.7 Tesla has been achieved. Relevant features of the final assembly and tested results are discussed.
Date: June 15, 2001
Creator: Benjegerdes, R.; Bish, P.; Byford, D.; Caspi, S.; Dietderich, D.R.; Gourlay, S.A. et al.
System: The UNT Digital Library
A new support structure for high field magnets (open access)

A new support structure for high field magnets

Pre-stress of superconducting magnets can be applied directly through the magnet yoke structure. We have replaced the collar functionality in our 14 Tesla R and D Nb{sub 3}Sn dipole magnets with an assembly procedure based on an aluminum shell and bladders. Bladders, placed between the coil pack and surrounding yoke inside the shell, are pressurized up to 10 ksi [70 MPa] to create an interference gap. Keys placed into the interference gap replace the bladder functionality. Following the assembly, the bladders are deflated and removed. Strain gauges mounted directly on the shell are used to monitor the stress of the entire magnet structure, thereby providing a high degree of pre-stress control without the need for high tolerances. During assembly, a force of 8.2 x 10{sup 5} lbs/ft [12 MN/m] is generated by the bladders and the stress in the 1.57 inch [40mm] aluminum shell reaches 20.3 ksi [140 MPa]. During cool-down the thermal expansion difference between shell and yoke generates an additional compressive force of 6.85 x 10{sup 5} lbs/ft [10 MN/m], corresponding to a final stress in the shell of 39.2 ksi [270 MPa]. Pre-stress conditions are sufficient for 16 T before the coils separate at the bore. Bladders …
Date: June 15, 2001
Creator: Bish, P. S.; Caspi, S.; Dietderich, D. R.; Gourlay, S. A.; Hafalia, R. R.; Hannaford, R. et al.
System: The UNT Digital Library
Searches for supersymmetry at the Tevatron (open access)

Searches for supersymmetry at the Tevatron

We review current experimental results of searches for Supersymmetry (SUSY) at the Fermilab Tevatron Collider using the Run I data collected during 1992-1996. New results from the CDF detector in the jets + missing E{sub t} and lepton-photon channels are presented. Recent results from model independent searches at D0 using the SLEUTH algorithm are reviewed. We discuss the prospects for supersymmetry searches at Run II of the Tevatron, scheduled to start in March, 2001.
Date: May 15, 2001
Creator: Bishai, Mary R. M.
System: The UNT Digital Library
FAST{_}AD Code Verification: A Comparison to ADAMS (open access)

FAST{_}AD Code Verification: A Comparison to ADAMS

The National Renewable Energy Laboratory's National Wind Technology Center (NWTC) has refocused its wind turbine design-code comparison effort to verify FAST{_}AD with ADAMS. FAST{_}AD is a wind turbine structural-response code developed by Oregon State University for the NWTC. ADAMS is a commercial, general-purpose, multibody-dynamics code developed by Mechanical Dynamics, Inc. ADAMS, which is used in many industries, has been rigorously tested. Both ADAMS and FAST{_}AD use the AeroDyn subroutine package for calculating aerodynamic forces. The University of Utah developed AeroDyn for the NWTC. To compare FAST{_}AD to ADAMS, we modeled a rough approximation of the AWT-27 P4 turbine, using the same properties for both simulators. The AWT-27 is a 275-kilowatt (kW), two-bladed wind turbine. We also created three-bladed versions of the turbine models to verify FAST{_}AD for three-bladed turbines. In this paper, we list the aerodynamic features used in the comparison. We also explain how the programs model the turbine structure, describe the degrees of freedom (DOFs) used for this study, and present simulation comparisons that show very good agreement.
Date: February 15, 2001
Creator: Buhl, M. L.; Wright, A. D. & Pierce, K. G.
System: The UNT Digital Library
Structural aspects of the fivefold quasicrystalline Al-Cu-Fe surface from STM and dynamical LEED Studies (open access)

Structural aspects of the fivefold quasicrystalline Al-Cu-Fe surface from STM and dynamical LEED Studies

We investigate the atomic structure of the fivefold surface of an icosahedral Al-Cu-Fe alloy, using scanning tunneling microscopy (STM) imaging and a special dynamical low energy-electron diffraction (LEED) method. STM indicates that the step heights adopt (primarily) two values in the ratio of tau, but the spatial distribution of these two values does not follow a Fibonacci sequence, thus breaking the ideal bulk-like quasicrystalline layer stacking order perpendicular to the surface. The appearance of screw dislocations in the STM images is another indication of imperfect quasicrystallinity. On the other hand, the LEED analysis, which was successfully applied to Al-Pd-Mn in a previous study, is equally successful for Al-Cu-Fe. Similar structural features are found for both materials, in particular for interlayer relaxations and surface terminations. Although there is no structural periodicity, there are clear atomic planes in the bulk of the quasicrystal, some of which can be grouped in recurring patterns. The surface tends to form between these grouped layers in both alloys. For Al-Cu-Fe, the step heights measured by STM are consistent with the thicknesses of the grouped layers favored in LEED. These results suggest that the fivefold Al-Cu-Fe surface exhibits a quasicrystalline layering structure, but with stacking defects.
Date: April 15, 2001
Creator: Cai, T.; Shi, F.; Shen, Z.; Gierer, M.; Goldman, A. I.; Kramer, M. J. et al.
System: The UNT Digital Library
Towards the Standardization of a MATLAB-Based Control Systems Laboratory Experience for Undergraduate Students (open access)

Towards the Standardization of a MATLAB-Based Control Systems Laboratory Experience for Undergraduate Students

This paper seeks to begin a discussion with regard to developing standardized Computer Aided Control System Design (CACSD) tools that are typically utilized in an undergraduate controls laboratory. The advocated CACSD design tools are based on the popular, commercially available MATLAB environment, the Simulink toolbox, and the Real-Time Workshop toolbox. The primary advantages of the proposed approach are as follows: (1) the required computer hardware is low cost, (2) commercially available plants from different manufacturers can be supported under the same CACSD environment with no hardware modifications, (3) both the Windows and Linux operating systems can be supported via the MATLAB based Real-Time Windows Target and the Quality Real Time Systems (QRTS) based Real-Time Linux Target, and (4) the Simulink block diagram approach can be utilized to prototype control strategies; thereby, eliminating the need for low level programming skills. It is believed that the above advantages related to standardization of the CACSD design tools will facilitate: (1) the sharing of laboratory resources within each university (i.e., between departments) and (2) the development of Internet laboratory experiences for students (i.e., between universities).
Date: March 15, 2001
Creator: Dixon, W.E.
System: The UNT Digital Library
Preliminary Results on Luminaire Designs for Hybrid Solar Lighting Systems (open access)

Preliminary Results on Luminaire Designs for Hybrid Solar Lighting Systems

We report on the design of two hybrid lighting luminaires that blend light from a fiber optic end-emitted solar source with electric T8 fluorescent lamps. Both designs involve the retrofit of a commercially-available recessed fluorescent luminaire with minimal reductions in the original luminaire's optical efficiency. Two methods for high-angle dispersion of fiber optic end-emitted solar light are described and the resulting spatial intensity distributions, simulated using ZEMAX, are compared with standard cylindrical fluorescent tubes. Differences in spatial intensity distribution are qualitatively characterized and potential design improvements discussed.
Date: June 15, 2001
Creator: Earl, D.D.
System: The UNT Digital Library
Simulating the operation of photosensor-based lighting controls (open access)

Simulating the operation of photosensor-based lighting controls

Energy savings from the use of daylighting in commercial buildings are realized through implementation of photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate workplane illumination. The dimming level of electric lighting is based on the signal of a photosensor. Current simulation approaches for such systems are based on the questionable assumption that the signal of the photosensor is proportional to the task illuminance. This paper presents a method that simulates the performance of photosensor controls considering the acceptance angle, angular sensitivity, placement of the photosensor within a space, and color correction filter. The method is based on the multiplication of two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180- or 360-degree fisheye image of the space as ''seen'' by the photosensor. The paper includes a detailed description of the method and its implementation, example applications, and validation results based on comparison with measurements in an actual office space.
Date: February 15, 2001
Creator: Ehrlich, Charles; Papamichael, Konstantinos; Lai, Judy & Revzan, Kenneth
System: The UNT Digital Library
Magnetic bead purification of labeled DNA fragments forhigh-throughput capillary electrophoresis sequencing (open access)

Magnetic bead purification of labeled DNA fragments forhigh-throughput capillary electrophoresis sequencing

We have developed an automated purification method for terminator sequencing products based on a magnetic bead technology. This 384-well protocol generates labeled DNA fragments that are essentially free of contaminates for less than $0.005 per reaction. In comparison to laborious ethanol precipitation protocols, this method increases the phred20 read length by forty bases with various DNA templates such as PCR fragments, Plasmids, Cosmids and RCA products. Our method eliminates centrifugation and is compatible with both the MegaBACE 1000 and ABIPrism 3700 capillary instruments. As of September 2001, this method has produced over 1.6 million samples with 93 percent averaging 620 phred20 bases as part of Joint Genome Institutes Production Process.
Date: September 15, 2001
Creator: Elkin, Christopher; Kapur, Hitesh; Smith, Troy; Humphries, David; Pollard, Martin; Hammon, Nancy et al.
System: The UNT Digital Library
Nuclear Proliferation Using Laser Isotope Separation -- Verification Options (open access)

Nuclear Proliferation Using Laser Isotope Separation -- Verification Options

Two levels of nonproliferation verification exist. Signatories of the basic agreements under the Nuclear Non-proliferation Treaty (NPT) agree to open their nuclear sites to inspection by the IAEA. A more detailed and intrusive level was developed following the determination that Iraq had begun a nuclear weapons development program that was not detected by the original level of verification methods. This level, referred to as 93+2 and detailed in model protocol INFCIRC/540, allows the IAEA to do environmental monitoring of non-declared facilities that are suspected of containing proliferation activity, and possibly further inspections, as well as allowing more detailed inspections of declared sites. 56 countries have signed a Strengthened Safeguards Systems Additional Protocol as of 16 July 2001. These additional inspections can be done on the instigation of the IAEA itself, or after requests by other parties to the NPT, based on information that they have collected. Since information able to cause suspicion of proliferation could arrive at any country, it is important that countries have procedures in place that will assist them in making decisions related to these inspections. Furthermore, IAEA inspection resources are limited, and therefore care needs to be taken to make best use of these resources. Most …
Date: October 15, 2001
Creator: Erickson, S A
System: The UNT Digital Library
First Results of Reaction Propagation Rates in HMX at High Pressure (open access)

First Results of Reaction Propagation Rates in HMX at High Pressure

The authors have measured the reaction propagation rate (RPR) in weapons-grade, ultrafine octahydro-1,3,57-tetranitro-1,3,5,7-tetrazocine (HMX) powder in a diamond anvil cell over the pressure range 0.7-35 GPa. In order to have a cross-comparison of their experiments, they carried out a series of experiments on nitromethane (NM) up to 15 GPa. The results on NM are indistinguishable from previous measurements of Rice and Folz. In comparison to high-pressure, NM, the burn process for solid HMX is not spatially uniform.
Date: June 15, 2001
Creator: Farber, D L; Esposito, A; Zaug, J M & Aracne-Ruddle, C
System: The UNT Digital Library
First Results of Reaction Propagation Rates in HMX at High Pressure (open access)

First Results of Reaction Propagation Rates in HMX at High Pressure

The authors have measured the reaction propagation rate (RPR) in weapons-grade, ultrafine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) powder in a diamond anvil cell over the pressure range 0.7-35 GPa. In order to have a cross-comparison of their experiments, they carried out a series of experiments on nitromethane (NM) up to 15 GPa. The results on NM are indistinguishable from previous measurements of Rice and Folz. In comparison to high-pressure NM, the burn process for solid HMX is between 5-10 times faster at pressures above 10 GPa.
Date: June 15, 2001
Creator: Farber, D L; Esposito, A; Zaug, J M & Aracne-Ruddle, C
System: The UNT Digital Library
Operation of a Four-Cylinder 1.9L Propane Fueled HCCI Engine (open access)

Operation of a Four-Cylinder 1.9L Propane Fueled HCCI Engine

A four-cylinder 1.9 Volkswagen TDI Engine has been converted to run in Homogeneous Charge Compression Ignition (HCCI) mode. The stock configuration is a turbocharged direct injection Diesel engine. The combustion chamber has been modified by discarding the in-cylinder Diesel fuel injectors and replacing them with blank inserts (which contain pressure transducers). The stock pistons contain a reentrant bowl and have been retained for the tests reported here. The intake and exhaust manifolds have also been retained, but the turbocharger has been removed. A heater has been installed upstream of the intake manifold and fuel is added just downstream of this heater. The performance of this engine in naturally aspirated HCCI operation, subject to variable intake temperature and fuel flow rate, has been studied. The engine has been run with propane fuel at a constant speed of 1800 rpm. This work is intended to characterize the HCCI operation of the engine in this configuration that has been minimally modified from the base Diesel engine. The performance (BMEP, IMEP, efficiency, etc) and emissions (THC, CO, NOx) of the engine are presented, as are combustion process results based on heat release analysis of the pressure traces from each cylinder.
Date: March 15, 2001
Creator: Flowers, D.; Aceves, S. M.; Martinez-Frias, J.; Smith, J. R.; Au, M.; Girard, J. et al.
System: The UNT Digital Library
Promising X-ray fluorescence tests for superconducting tunneljunction detector (open access)

Promising X-ray fluorescence tests for superconducting tunneljunction detector

Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal centers are present in very dilute concentrations so that their weak fluorescence is often obscured by strong background signals carbon and oxygen. To solve this problem, the Berkeley group has been working with researchers from the Advanced Detector Group at the Lawrence Livermore National Laboratory on an energy-dispersive superconducting tunnel junction x-ray detector. These devices in principle have the energy resolution needed to reveal the metal signal. The most recent results with the latest version of the detector on Beamline 4.0.1-2 at the Advanced Light Source (ALS) illustrate the promise of the cryogenic detector strategy not only for this application but also for spectroscopy of other types of dilute samples. Transition-metal complexes are key elements in many biologically important processes that are catalyzed by proteins (enzymes), photosynthesis being a prime example. The changes in that occur in electronic structure throughout a catalytic cycle are the subject of much research aimed at understanding the mechanisms of these processes. L-edge x-ray spectroscopy offers …
Date: May 15, 2001
Creator: Friedrich, Stephan & Robinson, Arthur L.
System: The UNT Digital Library
Combining Semi-Classical and Quantum Mechanical Methodologies for Nuclear Cross-section Calculations Between 1 Mev and 5 Gev (open access)

Combining Semi-Classical and Quantum Mechanical Methodologies for Nuclear Cross-section Calculations Between 1 Mev and 5 Gev

With a goal to develop a nuclear cross-section code usable over the wide energy range of 1 MeV to 5 GeV, one option is to combine intranuclear cascade, pre-equilibrium, and Hauser-Feshbach models in existing codes. However, the first two models are semi-classical while the third one is quantum mechanical, and combining them is not straightforward because the third model requires spin and parity distributions for all excited states that cannot be supplied by either one of the first two models. Approximations to overcome this difficulty are described in this paper. Success of this combined model will allow nuclear data evaluations for a large number of materials whose cross sections are needed in a wide range of applications, including the design, operation, and future upgrades of the SNS (1 GeV proton). The incident particles may be neutrons, protons, charged pions, or photons. Though only partially completed at this time, the new model compares well with experimental radionuclide production cross sections from thresholds to 2.6 GeV for proton-induced reactions on Fe.
Date: August 15, 2001
Creator: Fu, C.Y.
System: The UNT Digital Library
An Ultra-Compact Marx-Type High-Voltage Generator (open access)

An Ultra-Compact Marx-Type High-Voltage Generator

This paper discusses the design of an ultra-compact, Marx-type, high-voltage generator. This system incorporates high-performance components that are closely coupled and integrated into an extremely compact assembly. Low profile, custom ceramic capacitors with coplanar extended electrodes provide primary energy storage. Low-inductance, spark-gap switches incorporate miniature gas cavities imbedded within the central region of the annular shaped capacitors, with very thin dielectric sections separating the energy storage capacitors. Carefully shaped electrodes and insulator surfaces are used throughout to minimize field enhancements, reduce fields at triple-point regions, and enable operation at stress levels closer to the intrinsic breakdown limits of the dielectric materials. Specially shaped resistors and inductors are used for charging and isolation during operation. Forward-coupling ceramic capacitors are connected across successive switch-capacitor-switch stages to assist in switching. Pressurized SF, gas is used for electrical insulation in the spark-gap switches and throughout the unit. The pressure housing is constructed entirely of dielectric materials, with segments that interlock with the low-profile switch bodies to provide an integrated support structure for all of the components. This ultra-compact Marx generator employs a modular design that can be sized as needed for a particular application. Units have been assembled with 4, 10, and 30 stages …
Date: June 15, 2001
Creator: Goerz, D.; Ferriera, T.; Nelson, D.; Speer, R. & Wilson, M.
System: The UNT Digital Library
D0 calorimeter upgrades for Tevatron Run II (open access)

D0 calorimeter upgrades for Tevatron Run II

The electronic readout system for the D0 liquid argon calorimeter has been upgraded to take advantage of the upcoming Tevatron Run II. New scintillation preshower detectors have been installed as well as replacements for scintillation detectors in the intercryostat regions. These upgrades and preliminary testing and calibration results are described.
Date: August 15, 2001
Creator: Groer, Leslie S.
System: The UNT Digital Library
Plutonium Immobilization Project - Can-In-Canister Hardware Development/Selection (open access)

Plutonium Immobilization Project - Can-In-Canister Hardware Development/Selection

This paper covers the design, development and testing of the magazines (cylinders containing cans of plutonium-ceramic pucks) and the rack that holds them in place inside the waste glass canister. Several magazine and rack concepts were evaluated to produce a design that gives the optimal balance between resistance to thermal degradation and facilitation of remote handling. This paper also reviews the effort to develop a jointed robotic arm that can remotely load seven magazines into defined locations inside a stationary canister working only through the 4 inch (102mm) diameter canister throat.
Date: February 15, 2001
Creator: Hamilton, L.
System: The UNT Digital Library
Plutonium Immobilization Project - Cold Pour Phase 2 Test Results (open access)

Plutonium Immobilization Project - Cold Pour Phase 2 Test Results

The U.S. Department of Energy will immobilize excess plutonium in the proposed Plutonium Immobilization Plant (PIP) at the Savannah River site (SRS) as part of a two-track approach for dispositioning weapons-usable plutonium. The Department of Energy is funding the development and testing effort for the PIP being conducted by Lawrence Livermore National Laboratory and Argonne National Laboratory. PIP is developing the ''Can-in Canister'' (CIC) technology that immobilizes plutonium by encapsulating it in ceramic forms (or pucks) and ultimately surrounding the forms with high-level waste glass to provide a deterrent to recovery. A cold (non-radioactive) test program was conducted to develop and verify the baseline design for the canister and internal hardware. Tests were conducted in two phases. Phase 1 Cold Pour Tests, conducted in 1999, were scoping tests. This paper describes the Phase 2 tests conducted in 2000 that verified the adequacy of the baseline and demonstrated compliance with repository requirements.
Date: February 15, 2001
Creator: Hamilton, L.
System: The UNT Digital Library