Design and Sensor-Based COntrol for Hyper-Redundant Mechanisms (open access)

Design and Sensor-Based COntrol for Hyper-Redundant Mechanisms

Toxic materials in DOE sites pose a significant threat to DOE personnel who must inspect these locations. Working in confined spaces further complicates the situation especially when the workers must wear heavy and cumbersome protective suits.
Date: May 12, 2006
Creator: Choset, Howie
Object Type: Report
System: The UNT Digital Library
The Tariff Analysis Project: A Database and Analysis Platform for Electricity Tariffs (open access)

The Tariff Analysis Project: A Database and Analysis Platform for Electricity Tariffs

Much of the work done in energy research involves ananalysis of the costs and benefits of energy-saving technologies andother measures from the perspective of the consumer. The economic valuein particular depends on the price of energy (electricity, gas or otherfuel), which varies significantly both for different types of consumers,and for different regions of the country. Ideally, to provide accurateinformation about the economic value of energy savings, prices should becomputed directly from real tariffs as defined by utility companies. Alarge number of utility tariffs are now available freely over the web,but the complexity and diversity of tariff structures presents aconsiderable barrier to using them in practice. The goal of the TariffAnalysis Project (TAP) is to collect andarchive a statistically completesample of real utility tariffs, and build a set of database and web toolsthat make this information relatively easy to use in cost-benefitanalysis. This report presentsa detailed picture of the current TAPdatabase structure and web interface. While TAP has been designed tohandle tariffs for any kind of utility service, the focus here is onelectric utilities withinthe United States. Electricity tariffs can bevery complicated, so the database structures that have been built toaccommodate them are quite flexible and can be easily generalized toother …
Date: May 12, 2006
Creator: Coughlin, K.; White, R.; Bolduc, C.; Fisher, D. & Rosenquist, G.
Object Type: Report
System: The UNT Digital Library
Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004. (open access)

Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004.

Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry--specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It is desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The goal is to produce shape-selective catalysts that have the potential to limit the formation of longchain products and yet retain the active metal sites in a protected 'cage'. This cage also restricts their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. This activity report centers upon this first stage of experimentation with particulate FT catalysts. (For reference, a second experimental stage is under way to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes.) To date, experimentation has centered upon the evaluation of a sample of iron-based, spray-dried catalyst prepared by B.H. Davis of the Center of …
Date: May 12, 2006
Creator: Cronauer, D. & Engineering, Chemical
Object Type: Report
System: The UNT Digital Library
Effect of Sled Cavity Temperature Changes on Effective Accelerating Field (open access)

Effect of Sled Cavity Temperature Changes on Effective Accelerating Field

This note discusses the effect of SLED cavity temperature changes and resulting cavity detuning on the effective accelerating field delivered by the linac. This effect is of interest because the power dissipated in the SLED cavities depends on the repetition rate at which the linac operates and there is experimental evidence that the present water cooling system on the cavities is not sufficient to keep the copper temperature constant enough. As a result, for optimum operation of the collider, it may be necessary to adjust the water temperature as a function of repetition rate or to retune the cavities by mechanical means.
Date: May 12, 2006
Creator: Farkas, Z.
Object Type: Report
System: The UNT Digital Library
Localization of Volcanic Activity: Topographic Effects on Dike Propagation, Eruption and COnduit Formation (open access)

Localization of Volcanic Activity: Topographic Effects on Dike Propagation, Eruption and COnduit Formation

Magma flow in a dike rising in a crack whose strike runs from a highland or a ridge to an adjacent lowland has been modeled to determine the effect of topography on the flow. It is found that there is a distinct tendency for the flow to be diverted away from the highland end of the strike toward the lowland. Separation of the geometric effect of the topography from its effect on lateral confining stresses on the crack indicates that both contribute to the effect but that the effect of stress is less important. Although this analysis explains a tendency for volcanic eruptions to occur in low lands, it does not preclude eruptions on highlands. The particular configuration modeled mimics topography around the proposed nuclear waste repository at Yucca Mountain, Nevada, so that the results may indicate some reduction in the volcanic hazard to the site.
Date: May 12, 2006
Creator: Gaffney, E.S. & Damjanac, B.
Object Type: Article
System: The UNT Digital Library
Radiochemical Analysis by High Sensitivity Micro X-Ray Fluorescence Detection (open access)

Radiochemical Analysis by High Sensitivity Micro X-Ray Fluorescence Detection

The primary objective of the project was to develop a novel dual-optic x-ray fluorescence instrument capable of doing radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford Site.
Date: May 12, 2006
Creator: Gao, Ning
Object Type: Report
System: The UNT Digital Library
Uranium Detection Using Small Scintillators in a Maritime Environment (open access)

Uranium Detection Using Small Scintillators in a Maritime Environment

The performance of several commercially available portable radiation spectrometers containing small NaI(Tl) scintillation detectors has been studied at the Savannah River National Laboratory (SRNL). These hand-held radioisotope identifiers are used by field personnel to detect and identify the illegal transport of uranium as a deterrent to undeclared nuclear proliferation or nuclear terrorism. The detection of uranium in a variety of chemical forms and isotopic enrichments presents some unique challenges in the maritime environment. This study was conducted using a variety of shielded and unshielded uranium sources in a simulated maritime environment. The results include estimates of the detection sensitivity for various isotopic enrichments and configurations using the manufacturer's spectral analysis firmware. More sophisticated methods for analyzing the spectra off-line are also evaluated to determine the detection limits and enrichment sensitivities from the field measurements.
Date: May 12, 2006
Creator: Hofstetter, K.; Donna Beals, D. & Ken Odell, K.
Object Type: Article
System: The UNT Digital Library
Multi-Point Radiation Monitor (open access)

Multi-Point Radiation Monitor

A unique radiation monitor has been developed for performing wide-area field surveys for radiation sources. This device integrates the real-time output of multiple radiation detectors into a hand-held personal computer (e.g., a PDA) containing an intuitive graphical user interface. An independent hardware module supplies high voltage to the detectors and contains a rapid sampling system for transferring the detector count rates through an interface to the PDA. The imbedded firmware can be changed for various applications using a programmable memory card. As presently configured, the instrument contains a series of Geiger-Mueller (GM) tubes in a flexible detector string. This linear array of multiple sensors can be used by US Coast Guard and Customs container inspection personnel to measure radiation intensity in stacks of transport containers where physical access is impeded.
Date: May 12, 2006
Creator: Hofstetter, K.; Donna Beals, D.; Ken Odell, K.; Robert Eakle, R.; Russell Huffman, R. & Larry Harpring, L.
Object Type: Article
System: The UNT Digital Library
Not All Large Customers are Made Alike: Disaggregating Response toDefault-Service Day-Ahead Market Pricing (open access)

Not All Large Customers are Made Alike: Disaggregating Response toDefault-Service Day-Ahead Market Pricing

For decades, policymakers and program designers have gone onthe assumption that large customers, particularly industrial facilities,are the best candidates for realtime pricing (RTP). This assumption isbased partly on practical considerations (large customers can providepotentially large load reductions) but also on the premise thatbusinesses focused on production cost minimization are most likely toparticipate and respond to opportunities for bill savings. Yet fewstudies have examined the actual price response of large industrial andcommercial customers in a disaggregated fashion, nor have factors such asthe impacts of demand response (DR) enabling technologies, simultaneousemergency DR program participation and price response barriers been fullyelucidated. This second-phase case study of Niagara Mohawk PowerCorporation (NMPC)'s large customer RTP tariff addresses theseinformation needs. The results demonstrate the extreme diversity of largecustomers' response to hourly varying prices. While two-thirdsexhibitsome price response, about 20 percent of customers provide 75-80 percentof the aggregate load reductions. Manufacturing customers are mostprice-responsive as a group, followed by government/education customers,while other sectors are largely unresponsive. However, individualcustomer response varies widely. Currently, enabling technologies do notappear to enhance hourly price response; customers report using them forother purposes. The New York Independent System Operator (NYISO)'semergency DR programs enhance price response, in part by signaling tocustomers that day-ahead prices …
Date: May 12, 2006
Creator: Hopper, Nicole; Goldman, Charles & Neenan, Bernie
Object Type: Article
System: The UNT Digital Library
Crevice Corrosion on Ni-Cr-Mo Alloys (open access)

Crevice Corrosion on Ni-Cr-Mo Alloys

Ni-Cr-Mo alloys were developed for their exceptional corrosion resistance in a variety of extreme corrosive environments. An alloy from this series, Alloy-22, has been selected as the reference material for the fabrication of nuclear waste containers in the proposed Yucca Mountain repository located in Nevada (US). A possible localized corrosion process under the anticipated conditions at this location is crevice corrosion. therefore, it is necessary to assess how this process may, or may not, propagate if the use of this alloy is to be justified. Consequently, the primary objective is the development of a crevice corrosion damage function that can be used to assess the evolution of material penetration rates. They have been using various electrochemical methods such as potentiostatic, galvanostatic and galvanic coupling techniques. Corrosion damage patterns have been investigated using surface analysis techniques such as scanning electron microscopy (SEM) and optical microscopy. All crevice corrosion experiments were performed at 120 C in 5M NaCl solution. Initiating crevice corrosion on these alloys has proven to be difficult; therefore, they have forced it to occur under either potentiostatic or galvanostatic conditions.
Date: May 12, 2006
Creator: Jakupi, P.; Zagidulin, D.; Noel, J. J. & Shoesmith, D. W.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS (open access)

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale.
Date: May 12, 2006
Creator: Kennel, Elliot B.; Bergen, R. Michael; Carpenter, Stephen P.; Dadyburjor, Dady; Katakdaunde, Manoj; Magean, Liviu et al.
Object Type: Report
System: The UNT Digital Library
Comparison of Kinetic and Equilibrium Reaction Models inSimulating the Behavior of Gas Hydrates in Porous Media (open access)

Comparison of Kinetic and Equilibrium Reaction Models inSimulating the Behavior of Gas Hydrates in Porous Media

In this study we compare the use of kinetic and equilibrium reaction models in the simulation of gas (methane) hydrates in porous media. Our objective is to evaluate through numerical simulation the importance of employing kinetic versus equilibrium reaction models for predicting the response of hydrate-bearing systems to external stimuli, such as changes in pressure and temperature. Specifically, we (1) analyze and compare the responses simulated using both reaction models for production in various geological settings and for the case of depressurization in a core during extraction; and (2) examine the sensitivity to factors such as initial hydrate saturation, hydrate reaction surface area, and numerical discretization. We find that for systems undergoing thermal stimulation and depressurization, the calculated responses for both reaction models are remarkably similar, though some differences are observed at early times. Given these observations, and since the computational demands for the kinetic reaction model far exceed those for the equilibrium reaction model, the use of the equilibrium reaction model often appears to be justified and preferred for simulating the behavior of gas hydrates.
Date: May 12, 2006
Creator: Kowalsky, Michael B. & Moridis, George J.
Object Type: Article
System: The UNT Digital Library
Residential Two-Stage Gas Furnaces - Do They Save Energy? (open access)

Residential Two-Stage Gas Furnaces - Do They Save Energy?

Residential two-stage gas furnaces account for almost a quarter of the total number of models listed in the March 2005 GAMA directory of equipment certified for sale in the United States. Two-stage furnaces are expanding their presence in the market mostly because they meet consumer expectations for improved comfort. Currently, the U.S. Department of Energy (DOE) test procedure serves as the method for reporting furnace total fuel and electricity consumption under laboratory conditions. In 2006, American Society of Heating Refrigeration and Air-conditioning Engineers (ASHRAE) proposed an update to its test procedure which corrects some of the discrepancies found in the DOE test procedure and provides an improved methodology for calculating the energy consumption of two-stage furnaces. The objectives of this paper are to explore the differences in the methods for calculating two-stage residential gas furnace energy consumption in the DOE test procedure and in the 2006 ASHRAE test procedure and to compare test results to research results from field tests. Overall, the DOE test procedure shows a reduction in the total site energy consumption of about 3 percent for two-stage compared to single-stage furnaces at the same efficiency level. In contrast, the 2006 ASHRAE test procedure shows almost no difference …
Date: May 12, 2006
Creator: Lekov, Alex; Franco, Victor & Lutz, James
Object Type: Article
System: The UNT Digital Library
BPM Motors in Residential Gas Furnaces: What are theSavings? (open access)

BPM Motors in Residential Gas Furnaces: What are theSavings?

Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This paper examines both types of blower motors in non-condensing non-weatherized gas furnaces at a range of static pressures. Fan performance data is based on manufacturer product literature and laboratory tests. We use field-measured static pressure in ducts to get typical system curves to calculate how furnaces would operate in the field. We contrast this with the electricity consumption of a furnace blower operating under the DOE test procedure and manufacturer rated conditions. Furnace electricity use is also affected by operating modes that happen at the beginning and end of each furnace firing cycle. These operating modes are the pre-purge and post-purge by the draft inducer, the on-delay and off-delay of the blower, and the hot surface ignitor operation. To accurately calculate this effect, we use the number of firing cycles in a typical California …
Date: May 12, 2006
Creator: Lutz, James; Franco, Victor; Lekov, Alex & Wong-Parodi, Gabrielle
Object Type: Article
System: The UNT Digital Library
"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study" (open access)

"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study"

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Date: May 12, 2006
Creator: McConnell, S
Object Type: Article
System: The UNT Digital Library
High Pressure Scanning Tunneling Microscopy and High PressureX-ray Photoemission Spectroscopy Studies of Adsorbate Structure,Composition and Mobility during Catalytic Reactions on A Model SingleCrystal (open access)

High Pressure Scanning Tunneling Microscopy and High PressureX-ray Photoemission Spectroscopy Studies of Adsorbate Structure,Composition and Mobility during Catalytic Reactions on A Model SingleCrystal

Our research focuses on taking advantage of the ability of scanning tunneling microscopy (STM) to operate at high-temperatures and high-pressures while still providing real-time atomic resolution images. We also utilize high-pressure x-ray photoelectron spectroscopy (HPXPS) to monitor systems under identical conditions thus giving us chemical information to compare and contrast with the structural and dynamic data provided by STM.
Date: May 12, 2006
Creator: Montano, M. O.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Depressurization-induced gas production from Class 1 and Class 2hydrate deposits (open access)

Depressurization-induced gas production from Class 1 and Class 2hydrate deposits

Class 1 hydrate deposits are characterized by a Hydrate-Bearing Layer (HBL) underlain by a two-phase zone involving mobile gas. Such deposits are further divided to Class 1W (involving water and hydrate in the HBL) and Class 1G (involving gas and hydrate in the HBL). In Class 2 deposits, a mobile water zone underlies the hydrate zone. Methane is the main hydrate-forming gas in natural accumulations. Using TOUGH-FX/HYDRATE to study the depressurization-induced gas production from such deposits, we determine that large volumes of gas could be readily produced at high rates for long times using conventional technology. Dissociation in Class 1W deposits proceeds in distinct stages, but is continuous in Class 1G deposits. Hydrates are shown to contribute significantly to the production rate (up to 65 percent and 75 percent in Class 1W and 1G, respectively) and to the cumulative volume of produced gas (up to 45 percent and 54 percent in Class 1W and 1G, respectively). Large volumes of hydrate-originating CH4 could be produced from Class 2 hydrates, but a relatively long lead time would be needed before gas production (which continuously increases over time) attains a substantial level. The permeability of the confining boundaries plays a significant role in …
Date: May 12, 2006
Creator: Moridis, George J. & Kowalsky, Michael
Object Type: Article
System: The UNT Digital Library
TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost (open access)

TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost

We use TOUGH+/GasH2O to study the effects of a heat sourceburied in the Martian permafrost to evaluate the possibility ofestablishing a wet zone of liquid water, in which terrestrialmicroorganisms could survive and multiply. Analysis of the problemindicates that (1) only a limited permafrost volume (not exceeding 0.35 min radius) is affected, (2) a "wet" zone with limited amounts of liquidwater de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 Wsource, respectively), (3) the wet zone per-sists for a long time,becomes practically stationary after t = 20 sols because of venting intothe Martian atmosphere, and its thickness is limited and decreases slowlyover time, (4) a "dry" zone (where SG>0.9) evolves, continues toexpand (albeit slowly) with time, but its extent remains limited, and (5)the ice front surrounding the wet zone is self-sharpening. For a range ofinitial conditions investigated, evolution of the liquid water massoccurs at approximately the same rate, reaches roughly the same maximum,and occurs at about the same time (10 to 20 sols; 1 sol = 24.39hours).
Date: May 12, 2006
Creator: Moridis, George J. & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Deformable Nanolaminate Optics (open access)

Deformable Nanolaminate Optics

We are developing a new class of deformable optic based on electrostatic actuation of nanolaminate foils. These foils are engineered at the atomic level to provide optimal opto-mechanical properties, including surface quality, strength and stiffness, for a wide range of deformable optics. We are combining these foils, developed at Lawrence Livermore National Laboratory (LLNL), with commercial metal processing techniques to produce prototype deformable optics with aperture sizes up to 10 cm and actuator spacing from 1 mm to 1 cm and with a range of surface deformation designed to be as much as 10 microns. The existing capability for producing nanolaminate foils at LLNL, coupled with the commercial metal processing techniques being used, enable the potential production of these deformable optics with aperture sizes of over 1 m, and much larger deformable optics could potentially be produced by tiling multiple deformable segments. In addition, based on the fabrication processes being used, deformable nanolaminate optics could potentially be produced with areal densities of less than 1 kg per square m for applications in which lightweight deformable optics are desirable, and deformable nanolaminate optics could potentially be fabricated with intrinsically curved surfaces, including aspheric shapes. We will describe the basic principles of …
Date: May 12, 2006
Creator: Olivier, S. S.; Papavasiliou, A. P.; Barbee, T. W.; Miles, R. R.; Walton, C. C.; Cohn, M. B. et al.
Object Type: Article
System: The UNT Digital Library
The Commercial Energy Consumer: About Whom Are We Speaking? (open access)

The Commercial Energy Consumer: About Whom Are We Speaking?

Who are commercial sector customers, and how do they make decisions about energy consumption and energy efficiency investment? The energy policy field has not done a thorough job of describing energy consumption in the commercial sector. First, the discussion of the commercial sector itself is dominated by discussion of large businesses/buildings. Second, discussion of this portion of the commercial sectors consumption behavior is driven primarily by theory, with very little field data collected on the way commercial sector decision-makers describe their own options, choices, and reasons for taking action. These limitations artificially constrain energy policy options. This paper reviews the extant literature on commercial sector energy consumption behavior and identifies gaps in our knowledge. In particular, it argues that the primary energy policy model of commercial sector energy consumption is a top-down model that uses macro-level investment data to make conclusions about commercial behavior. Missing from the discussion is a model of consumption behavior that builds up to a theoretical framework informed by the micro-level data provided by commercial decision-makers themselves. Such a bottom-up model could enhance the effectiveness of commercial sector energy policy. In particular, translation of some behavioral models from the residential sector to the commercial sector may …
Date: May 12, 2006
Creator: Payne, Christopher
Object Type: Article
System: The UNT Digital Library
Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash (open access)

Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

During this reporting period, efforts focused on improving our understanding of the basic operating principles of the lamella classifier. It was determined from testing that product grade is primarily a function of the classifier configuration and operation and the feed grade has relatively minor influence. Additionally, within the range of the testing conducted, the feed density did not seem to have an impact of the yield. Thus, the product composition will not be strongly influenced by the variability of the feed, an important consideration for heterogeneous ponded fly ash. Three types of chemically and functionally different thermoplastic polymers have been chosen for evaluation with the fly ash derived filler: high density polyethylene, thermoplastic elastomer, and polyethylene terphthalate. The selections were based on volumes consumed in commercial and recycled products. The reference filler selected for comparison was 3 {micro}m calcium carbonate, a material which is commonly used with all three types of polymers. A procedure to prepare filled polymers has been developed and most ({approx}80%) of the polymer/filler blends have been prepared. Selected samples of filled polymers were subjected to SEM analysis to verify that the fly ash derived filler and the calcium carbonate were well dispersed. A stainless steel mold …
Date: May 12, 2006
Creator: Robl, T.L.; Groppo, J.G. & Rathbone, Robert
Object Type: Report
System: The UNT Digital Library
Development and analysis of a compact low-conversion ratio fast burner reactor. (open access)

Development and analysis of a compact low-conversion ratio fast burner reactor.

This report explores design options for compact fast burner reactors that can achieve low conversion ratios. Operational characteristics and whole-core reactivity coefficients are generated and contrasted with low conversion ratio designs of previous studies. A compact core point design is then selected and detailed reactivity coefficients are displayed and discussed. The effectiveness of fast spectrum systems for actinide transmutation has been well documented. The key advantage of the fast spectrum resides in the severely reduced capture/fission ratios. this inhibits the production of the higher actinides that dominate the long-term radiotoxicity of nuclear waste. In conventional fast burner studies, the transmutation rate was limited by constraints placed on the fuel composition. In an earlier phase of this study the entire range of fuel compositions (including non-uranium fuel) was explored to assess the performance and safety limits of fast burner reactor systems. In this report, similar fuel compositions are utilized for application in compact configurations to achieve conversion ratios below 0.5.
Date: May 12, 2006
Creator: Smith, M. A. & Hill, R. N.
Object Type: Report
System: The UNT Digital Library