0.5 μm E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant (open access)

0.5 μm E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant

A doped-channel heterostructure field effect transistor (H-FET) technology has been developed with self-aligned refractory gate processing and using both enhancement- and depletion-mode transistors. D-HFET devices are obtained with a threshold voltage adjust implant into material designed for E-HFET operation. Both E- and D-HFETs utilize W/WSi bilayer gates, sidewall spacers, and rapid thermal annealing for controlling short channel effects. The 0.5 {mu}m E- HFETs (D-HFETs) have been demonstrated with transconductance of 425 mS/mm (265-310 mS/mm) and f{sub t} of 45-50 GHz. Ring oscillator gate delays of 19 ps with a power of 0.6 mW have been demonstrated using direct coupled FET logic. These results are comparable to previous doped-channel HFET devices and circuits fabricated by selective reactive ion etching rather than ion implantation for threshold voltage adjustment.
Date: April 1997
Creator: Baca, A. G.; Sherwin, M. E.; Zolper, J. C.; Shul, R. J.; Briggs, R. D.; Heise, J. A. et al.
Object Type: Article
System: The UNT Digital Library
A 3-Axis Force Balanced Accelerometer Using a Single Proof-Mass (open access)

A 3-Axis Force Balanced Accelerometer Using a Single Proof-Mass

This paper presents a new method for wideband force balancing a proof-mass in multiple axes simultaneously. Capacitive position sense and force feedback are accomplished using the same air-gap capacitors through time multiplexing. Proof of concept is experimentally demonstrated with a single-mass monolithic surface micromachined 3-axis accelerometer.
Date: April 1997
Creator: Lemkin, M.A.; Boser, B.E.; Auslander, D. & Smith, J.
Object Type: Article
System: The UNT Digital Library
4. International reservoir characterization technical conference (open access)

4. International reservoir characterization technical conference

This volume contains the Proceedings of the Fourth International Reservoir Characterization Technical Conference held March 2-4, 1997 in Houston, Texas. The theme for the conference was Advances in Reservoir Characterization for Effective Reservoir Management. On March 2, 1997, the DOE Class Workshop kicked off with tutorials by Dr. Steve Begg (BP Exploration) and Dr. Ganesh Thakur (Chevron). Tutorial presentations are not included in these Proceedings but may be available from the authors. The conference consisted of the following topics: data acquisition; reservoir modeling; scaling reservoir properties; and managing uncertainty. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.
Date: April 1997
Creator: unknown
Object Type: Article
System: The UNT Digital Library
100 years of elementary particles [Beam Line, vol. 27, issue 1, Spring 1997] (open access)

100 years of elementary particles [Beam Line, vol. 27, issue 1, Spring 1997]

This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.
Date: April 1, 1997
Creator: Pais, Abraham; Weinberg, Steven; Quigg, Chris; Riordan, Michael; Panofsky, Wolfgang K.H. & Trimble, Virginia
Object Type: Report
System: The UNT Digital Library
1996 Laboratory directed research and development annual report (open access)

1996 Laboratory directed research and development annual report

This report summarizes progress from the Laboratory Directed Research and Development (LDRD) program during fiscal year 1996. In addition to a programmatic and financial overview, the report includes progress reports from 259 individual R&D projects in seventeen categories. The general areas of research include: engineered processes and materials; computational and information sciences; microelectronics and photonics; engineering sciences; pulsed power; advanced manufacturing technologies; biomedical engineering; energy and environmental science and technology; advanced information technologies; counterproliferation; advanced transportation; national security technology; electronics technologies; idea exploration and exploitation; production; and science at the interfaces - engineering with atoms.
Date: April 1, 1997
Creator: Meyers, C. E.; Harvey, C. L.; Lopez-Andreas, L. M.; Chavez, D. L. & Whiddon, C. P.
Object Type: Report
System: The UNT Digital Library
1997 update for the applications guide to vehicle SNM monitors (open access)

1997 update for the applications guide to vehicle SNM monitors

Ten years have elapsed since the publication of the original applications guide to vehicle special nuclear material (SNM) monitors. During that interval, use of automatic vehicle monitors has become more commonplace, and formal procedures for monitor upkeep and evaluation have become available. New concepts for vehicle monitoring are being explored, as well. This update report reviews the basics of vehicle SNM monitoring, discusses what is new in vehicle SNM monitoring, and catalogs the vehicle SNM monitors that are commercial available.
Date: April 1, 1997
Creator: York, R. L. & Fehlau, P. E.
Object Type: Report
System: The UNT Digital Library
3D electromagnetic inversion for environmental site characterization (open access)

3D electromagnetic inversion for environmental site characterization

A 3-D non-linear electromagnetic inversion scheme has been developed to produce images of subsurface conductivity structure from electromagnetic geophysical data. The solution is obtained by successive linearized model updates where full forward modeling is employed at each iteration to compute model sensitivities and predicted data. Regularization is applied to the problem to provide stability. Because the inverse part of the problem requires the solution of 10`s to 100`s of thousands of unknowns, and because each inverse iteration requires many forward models to be computed, the code has been implemented on massively parallel computer platforms. The use of the inversion code to image environmental sites is demonstrated on a data set collected with the Apex Parametrics {open_quote}MaxMin I-8S{close_quote} over a section of stacked barrels and metal filled boxes at the Idaho National Laboratory`s {open_quote}Cold Test Pit{close_quote}. The MaxMin is a loop-loop frequency domain system which operates from 440 Hz up to 56 kHz using various coil separations; for this survey coil separations of 15, 30 and 60 feet were employed. The out-of phase data are shown to be of very good quality while the in-phase are rather noisy due to slight mispositioning errors, which cause improper cancellation of the primary free …
Date: April 1, 1997
Creator: Alumbaugh, D.L. & Newman, G.A.
Object Type: Article
System: The UNT Digital Library
Ab-initio calculations of density of states for Ti-oxide (open access)

Ab-initio calculations of density of states for Ti-oxide

Electron energy-loss spectroscopy has been shown to be a powerful tool to determine the chemistry and the electronic structure at grain boundaries by analyzing the energy loss near edge structure (ELNES). This paper describes the ability of ab-initio density of state calculations to perform detailed quantitative analysis at interfaces.
Date: April 1, 1997
Creator: Duscher, G.; Koestlmeier, S. & Elsaesser, C.
Object Type: Article
System: The UNT Digital Library
Accelerated life test of the USDOE OC-OTEC experimental system refurbished with magnetic bearings for the 3rd stage vacuum compressor. Final report (open access)

Accelerated life test of the USDOE OC-OTEC experimental system refurbished with magnetic bearings for the 3rd stage vacuum compressor. Final report

This report documents the accelerated life test (time-to-failure) performed, at the request of DOE, to evaluate the viability of the magnetic bearing system installed in the stage 3 vacuum pump. To this effect the plant was successfully operated for over 500 hours during the period September-November 1996. The first part of this report discusses system performance by deriving subsystem and system performance parameters from a typical record. This is followed by the discussion of the life tests. The instrumentation used to estimate the performance parameters given here is depicted. The third stage pump was operated for 535 hours without incident. It is concluded that magnetic bearings are the preferable choice for the OC-OTEC centrifugal vacuum pumps.
Date: April 1, 1997
Creator: Vega, L.A.
Object Type: Report
System: The UNT Digital Library
Acceleration and collision of ultra-high energy particles using crystal channels (open access)

Acceleration and collision of ultra-high energy particles using crystal channels

We assume that, independent of any near-term discoveries, the continuing goal of experimental high-energy physics (HEP) will be to achieve ultra-high center-of-mass energies early in the next century. To progress to these energies in such a brief span of time will require a radical change in accelerator and collider technology. We review some of our recent theoretical work on high-gradient acceleration of charged particles along crystal channels and the possibility of colliding them in these same strong-focusing atomic channels. An improved understanding of energy and emittance limitations in natural crystal accelerators leads to the suggestion that specially manufactured nano-accelerators may someday enable us to accelerate particles beyond 10{sup 8} eV with emittances limited only by the uncertainty principle of quantum mechanics.
Date: April 1, 1997
Creator: Chen, P. & Noble, R.J.
Object Type: Article
System: The UNT Digital Library
Accuracy estimation for supervised learning algorithms (open access)

Accuracy estimation for supervised learning algorithms

This paper illustrates the relative merits of three methods - k-fold Cross Validation, Error Bounds, and Incremental Halting Test - to estimate the accuracy of a supervised learning algorithm. For each of the three methods we point out the problem they address, some of the important assumptions that are based on, and illustrate them through an example. Finally, we discuss the relative advantages and disadvantages of each method.
Date: April 1, 1997
Creator: Glover, C. W.; Oblow, E. M. & Rao, N. S. V.
Object Type: Article
System: The UNT Digital Library
An Adaptive Level Set Approach for Incompressible Two-Phase Flows (open access)

An Adaptive Level Set Approach for Incompressible Two-Phase Flows

In Sussman, Smereka and Osher, a numerical method using the level set approach was formulated for solving incompressible two-phase flow with surface tension. In the level set approach, the interface is represented as the zero level set of a smooth function; this has the effect of replacing the advection of density, which has steep gradients at the interface, with the advection of the level set function, which is smooth. In addition, the interface can merge or break up with no special treatment. The authors maintain the level set function as the signed distance from the interface in order to robustly compute flows with high density ratios and stiff surface tension effects. In this work, they couple the level set scheme to an adaptive projection method for the incompressible Navier-Stokes equations, in order to achieve higher resolution of the interface with a minimum of additional expense. They present two-dimensional axisymmetric and fully three-dimensional results of air bubble and water drop computations.
Date: April 1, 1997
Creator: Sussman, M.; Almgren, A. S. & Bell, J. B.
Object Type: Report
System: The UNT Digital Library
Addressing environmental justice under the National Environment Policy Act at Sandia National Laboratories/New Mexico (open access)

Addressing environmental justice under the National Environment Policy Act at Sandia National Laboratories/New Mexico

Under Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, the Department of Energy (DOE) and Sandia National Laboratories New Mexico (SNL) are required to identify and address, as appropriate, disproportionately high, adverse human health or environmental effects of their activities on minority and low-income populations. The National Environmental Policy Act (NEPA) also requires that environmental justice issues be identified and addressed. This presents a challenge for SNL because it is located in a culturally diverse area. Successfully addressing potential impacts is contingent upon accurately identifying them through objective analysis of demographic information. However, an effective public participation process, which is necessarily subjective, is also needed to understand the subtle nuances of diverse populations that can contribute to a potential impact, yet are not always accounted for in a strict demographic profile. Typically, there is little or no coordination between these two disparate processes. This report proposes a five-step method for reconciling these processes and uses a hypothetical case study to illustrate the method. A demographic analysis and community profile of the population within 50 miles of SNL were developed to support the environmental justice analysis process and enhance SNL`s NEPA and public involvement …
Date: April 1, 1997
Creator: Cohen, Timothy M. & Bleakly, Denise R.
Object Type: Report
System: The UNT Digital Library
Advanced Computational Simulation for Design and Manufacturing of Lightweight Material Components for Automotive Applications (open access)

Advanced Computational Simulation for Design and Manufacturing of Lightweight Material Components for Automotive Applications

Computational vehicle models for the analysis of lightweight material performance in automobiles have been developed through collaboration between Oak Ridge National Laboratory, the National Highway Transportation Safety Administration, and George Washington University. The vehicle models have been verified against experimental data obtained from vehicle collisions. The crashed vehicles were analyzed, and the main impact energy dissipation mechanisms were identified and characterized. Important structural parts were extracted and digitized and directly compared with simulation results. High-performance computing played a key role in the model development because it allowed for rapid computational simulations and model modifications. The deformation of the computational model shows a very good agreement with the experiments. This report documents the modifications made to the computational model and relates them to the observations and findings on the test vehicle. Procedural guidelines are also provided that the authors believe need to be followed to create realistic models of passenger vehicles that could be used to evaluate the performance of lightweight materials in automotive structural components.
Date: April 1, 1997
Creator: Simunovic, S.; Aramayo, G. A.; Zacharia, T.; Toridis, T. G.; Bandak, F. & Ragland, C. L.
Object Type: Report
System: The UNT Digital Library
Advanced Industrial Materials (AIM) program. Compilation of project summaries and significant accomplishments FY 1996 (open access)

Advanced Industrial Materials (AIM) program. Compilation of project summaries and significant accomplishments FY 1996

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven {open_quotes}Vision Industries{close_quotes} that use about 80% of industrial energy and generated about 90% of industrial wastes. These are: (1) Aluminum; (2) Chemical; (3) Forest Products; (4) Glass; (5) Metal Casting; (6) Refineries; and (7) Steel. This report is a compilation of project summaries and significant accomplishments on materials.
Date: April 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advanced photon source low-energy undulator test line (open access)

Advanced photon source low-energy undulator test line

The injector system of the Advanced Photon Source (APS) consists of a linac capable of producing 450-MeV positrons or > 650-MeV electrons, a positron accumulator ring (PAR), and a booster synchrotron designed to accelerate particles to 7 GeV. There are long periods of time when these machines are not required for filling the main storage ring and instead can be used for synchrotron radiation research. We describe here an extension of the linac beam transport called the Low-Energy Undulator Test Line (LEUTL). The LEUTL will have a twofold purpose. The first is to fully characterize innovative, future generation undulators, some of which may prove difficult or impossible to measure by traditional techniques. These might include small-gap and superconducting undulators, very long undulators, undulators with designed-in internal focusing, and helical undulators. This technique also holds the promise of extending the magnetic measurement sensitivity beyond that presently attainable. This line will provide the capability to directly test undulators before their possible insertion into operating storage rings. A second use for the test line will be to investigate the generation of coherent radiation at wavelengths down to a few tens of nanometers.
Date: April 1, 1997
Creator: Milton, S. V.
Object Type: Article
System: The UNT Digital Library
Advanced temperature measurement system for the US glass industry melt tanks and delivery system. Phase 1 [final] report (open access)

Advanced temperature measurement system for the US glass industry melt tanks and delivery system. Phase 1 [final] report

Improved temperature measurement in the melting and delivery systems of the glass making process will aid in energy conservation. The ``Needs Analysis`` survey found the greatest problem was the inability to identify in situ decalibration (drift). Phase I objectives are: a more rugged reliable sensor; high quality inner protective sheath; improved data transmission hardened to the melt tank environs; a system that reduces or eliminates drift; and an improved outer protection sheath. Results show that 4 of the 5 problem areas have been resolved; with the help of the Univ. of Missouri-Rolla`s materials group, the fifth may be solvable. The major identified problem, the inability to identify in-situ drift has been solved.
Date: April 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advanced zinc phosphate conversion coatings. Final report, June 1996--December 1996 (open access)

Advanced zinc phosphate conversion coatings. Final report, June 1996--December 1996

A SERDP-sponsored program aims at developing environmentally benign zinc phosphate conversion coatings and their process technologies for the electrogalvanized steel (EGS). We succeeded in formulating an environmentally acceptable phosphate solution without Co- and Ni-related additives, and also in replacing a hexavalent Cr acid sealant applied over the zinc phosphate (Zh-Ph) layers with a water-based polysiloxane sealers. The specific advantages of the newly developed Zn-Ph coatings were as follows: (1) there was rapid growth of uniform, dense embryonic Zn-Ph crystals on the EGS surfaces due to the creation of short-circuited cells with Mn acting as the cathode and the galvanized (zinc) coatings as the anode, (2) an excellent protection layer against corrosion was formed, extending the service life of zinc layers as galvanic sacrifice barriers, and (3) adhesion to the electro-deposited polymeric primer coating was improved because of the interaction between the siloxane sealer and primer. A full-scale demonstration to evaluate the reproducibility of this new coating technology on mini-sized automotive door panels made from EGS was carried out in collaboration with the Palnut Company (as industrial coating applicator) in New Jersey. All of the 150 mini-door panels were successfully coated with Zn-Ph.
Date: April 1997
Creator: Handsy, C. I. & Sugama, T.
Object Type: Report
System: The UNT Digital Library
Advantages of Traveling Wave Resonant Antennas for Fast Wave Heating Systems (open access)

Advantages of Traveling Wave Resonant Antennas for Fast Wave Heating Systems

The resilience of a maximally flat externally coupled traveling wave antenna (TWA) is contrasted with the sensitivity of a simple directly driven resonant loop array to vacuum and plasma conditions in DIII-D. We find a unique synergy between standing and traveling wave resonant TWA components. This synergy extends TWA operation to several passbands between 60 and 120 MHZ, provides 60{degrees}- 120{degrees} tunability between elements within a 1-2 MHZ bandwidth and permits efficient and continuous operation during ELMing H-mode.
Date: April 1, 1997
Creator: Phelps, D. A.; Callis, R. W. & deGrassie, J. S.
Object Type: Article
System: The UNT Digital Library
An aerial radiological survey of the Fernald Environmental Management Project and surrounding area, Fernald, Ohio (open access)

An aerial radiological survey of the Fernald Environmental Management Project and surrounding area, Fernald, Ohio

An aerial radiological survey was conducted from May 17--22, 1994, over a 36 square mile (93 square kilometer) area centered on the Fernald Environmental Management Project located in Fernald, Ohio. The purpose of the survey was to detect anomalous gamma radiation in the environment surrounding the plant. The survey was conducted at a nominal altitude of 150 feet (46 meters) with a line spacing of 250 feet (76 meters). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter (3.3 feet) above ground was prepared and overlaid on an aerial photograph of the area. Analysis of the data for man made sources showed five sites within the boundaries of the Fernald Environmental Management Project having elevated readings. The exposure rates outside the plant boundary were typical of naturally occurring background radiation. Soil samples and pressurized ion chamber measurements were obtained at four locations within the survey boundaries to supplement the aerial data. It was concluded that although the radionuclides identified in the high-exposure-rate areas are naturally occurring, the levels encountered are greatly enhanced due to industrial activities at the plant.
Date: April 1, 1997
Creator: Phoenix, K.A.
Object Type: Report
System: The UNT Digital Library
Air Monitoring Report: 1995 (open access)

Air Monitoring Report: 1995

Annual report documenting air quality measurements throughout the state of Texas for calendar year 1995, including a summary and information about specific pollutants.
Date: April 1997
Creator: Texas Natural Resource Conservation Commission. Monitoring Operations Division.
Object Type: Report
System: The Portal to Texas History
Los Alamos Plutonium Facility newly generated tru waste certification. Final revised version 3/97 (open access)

Los Alamos Plutonium Facility newly generated tru waste certification. Final revised version 3/97

This paper presents an overview of the activities being planned and implemented to certify newly generated contact handled transuranic (TRU) waste produced by Los Alamos National Laboratory`s (LANL`s) Plutonium Facility. Certifying waste at the point of generation is the most important cost and labor saving step in the WIPP certification process. The pedigree of a waste item is best known by the originator of the waste and frees a site from many of the expensive characterization activities associated with legacy waste. Through a cooperative agreement with LANLs Waste Management Facility and under the umbrella of LANLs WIPP-related certification and quality assurance documents, the Plutonium Facility will be certifying most of its own newly generated waste. Some of the challenges faced by the Plutonium Facility in preparing to certify TRU waste include the modification and addition of procedures to meet WIPP requirements, standardizing packaging for TRU waste, collecting processing documentation from operations which produce TRU waste, and developing ways to modify waste streams which are not certifiable in their present form.
Date: April 1, 1997
Creator: Gruetzmacher, K.; Montoya, A.; Sinkule, B. & Maez, M.
Object Type: Article
System: The UNT Digital Library
Alaska Power Administration combined financial statements, schedules and supplemental reports, September 30, 1996 and 1995 (open access)

Alaska Power Administration combined financial statements, schedules and supplemental reports, September 30, 1996 and 1995

This report presents the results of the independent certified public accountants` audit of the Department of Energy`s Alaska Power Administration`s (Alaska) financial statements as of September 30, 1996. The auditors have expressed an unqualified opinion on the 1996 combined statements of assets, Federal investment and liabilities, and the related combined statements of revenues, expenses and accumulated net revenues, and cash flows. The auditors` report on Alaska`s internal control structure disclosed no reportable conditions that could have a material effect on the financial statements. The auditors also considered the overview and performance measure data for completeness and material consistency with the basic financial statements, as noted in the internal control report. The auditor`s report on compliance with laws and regulations disclosed no instances of noncompliance by Alaska.
Date: April 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Alkaline cleaner replacement for printed wiring board fabrication (open access)

Alkaline cleaner replacement for printed wiring board fabrication

A replacement alkaline cleaning chemistry was qualified for the copper cleaning process used to support printed wiring board fabrication. The copper cleaning process was used to prepare copper surfaces for enhancing the adhesion of dry film photopolymers (photoresists and solder masks) and acrylic adhesives. The alkaline chemistry was used to remove organic contaminates such as fingerprints.
Date: April 1, 1997
Creator: Goldammer, S. E.; Pemberton, S. E. & Tucker, D. R.
Object Type: Report
System: The UNT Digital Library