A Vortex Contactor for Carbon Dioxide Separations (open access)

A Vortex Contactor for Carbon Dioxide Separations

Many analysts identify carbon dioxide (CO2) capture and separation as a major roadblock in efforts to cost effectively mitigate greenhouse gas emissions via sequestration. An assessment 4 conducted by the International Energy Agency (IEA) Greenhouse Gas Research and Development Programme cited separation costs from $35 to $264 per tonne of CO2 avoided for a conventional coal fired power plant utilizing existing capture technologies. Because these costs equate to a greater than 40% increase in current power generation rates, it appears obvious that a significant improvement in CO2 separation technology is required if a negative impact on the world economy is to be avoided.
Date: May 1, 2001
Creator: Raterman, Kevin Thomas; Mc Kellar, Michael George; Turner, Terry Donald; Podgorney, Anna Kristine; Stacey, Douglas Edwin; Stokes, B. et al.
Object Type: Article
System: The UNT Digital Library
Electrical Sitchgear Building No. 5010-ESF Fire Hazards Technical Report (open access)

Electrical Sitchgear Building No. 5010-ESF Fire Hazards Technical Report

The purpose of this Fire Hazards Analysis Technical Report (hereinafter referred to as Technical Report) is to assess the risk from fire within individual fire areas to ascertain whether the U.S. Department of Energy (DOE) fire safety objectives are met. The objectives, identified in DOE Order 420.1, Change 2, Fire Safety, Section 4.2, establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: (1) The occurrence of a fire or related event; (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of the employees, the public, and the environment; (3) Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards; (4) Property losses from a fire and related events exceeding defined limits established by DOE; and (5) Critical process controls and safety class systems being damaged as a result of a fire and related event.
Date: May 8, 2001
Creator: Ruonavaara, N.M.
Object Type: Report
System: The UNT Digital Library
Contribution of the Three-Dimensional Image Analysis to the Study of Breast Cancer (open access)

Contribution of the Three-Dimensional Image Analysis to the Study of Breast Cancer

None
Date: May 2, 2001
Creator: Ortiz de Solorzano, Carlos
Object Type: Article
System: The UNT Digital Library
Requirements Analysis in the Value Methodology (open access)

Requirements Analysis in the Value Methodology

The Value Methodology (VM) study brings together a multidisciplinary team of people who own the problem and have the expertise to identify and solve it. With the varied backgrounds and experiences the team brings to the study, come different perspectives on the problem and the requirements of the project. A requirements analysis step can be added to the Information and Function Analysis Phases of a VM study to validate whether the functions being performed are required, either regulatory or customer prescribed. This paper will provide insight to the level of rigor applied to a requirements analysis step and give some examples of tools and techniques utilized to ease the management of the requirements and functions those requirements support for highly complex problems.
Date: May 1, 2001
Creator: Conner, Alison Marie
Object Type: Article
System: The UNT Digital Library
Multiple Peaks in the Angular Power Spectrum of the CosmicMicrowave Background: Significance and Consequences for Cosmology (open access)

Multiple Peaks in the Angular Power Spectrum of the CosmicMicrowave Background: Significance and Consequences for Cosmology

Three peaks and two dips have been detected in the power spectrum of the cosmic microwave background from the BOOMERANG experiment, at {ell} {approx} 210, 540, 840 and {ell} {approx} 420, 750, respectively. Using model-independent analyses, we find that all five features are statistically significant and we measure their location and amplitude. These are consistent with the adiabatic inflationary model. We also calculate the mean and variance of the peak and dip locations and amplitudes in a large 7-dimensional parameter space of such models, which gives good agreement with the model-independent estimates, and forecast where the next few peaks and dips should be found if the basic paradigm is correct. We test the robustness of our results by comparing Bayesian marginalization techniques on this space with likelihood maximization techniques applied to a second 7-dimensional cosmological parameter space, using an independent computational pipeline, and find excellent agreement: {Omega}{sub tot} = 1.02{sub -0.05}{sup +0.06} vs. 1.04 {+-} 0.05, {Omega}{sub b}h{sup 2} = 0.022{sub -0.003}{sup +0.004} vs. 0.019{sub -0.004}{sup +0.005}, and n{sub s} = 0.96{sub -0.09}{sup +0.10} vs. 0.90 {+-} 0.08. The deviation in primordial spectral index n{sub s} is a consequence of the strong correlation with the optical depth.
Date: May 17, 2001
Creator: de Bernardis, P.; Ade, P. A. R.; Bock, J. J.; Bond, J. R.; Borrill, J.; Boscaleri, A. et al.
Object Type: Article
System: The UNT Digital Library
Swing-Down of 21-PWR Waste Package (open access)

Swing-Down of 21-PWR Waste Package

The objective of this calculation is to determine the structural response of the waste package (WP) swinging down from a horizontally suspended height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in terms of stress intensities. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 13). AP-3.12Q, ''Calculations'' (Ref. 18) is used to perform the calculation and develop the document. The information provided by the sketches attached to this calculation is that of the potential design of the type of 21-PWR WP design considered in this calculation and provides the potential dimensions and materials for the 21-PWR WP design.
Date: May 4, 2001
Creator: Scheider, A.K.
Object Type: Report
System: The UNT Digital Library
Midwest Transmission Workshop I Summary (open access)

Midwest Transmission Workshop I Summary

OAK-B135 The meeting was opened with a review of the purposes of the workshop: (1) Present and discuss key studies and assessments of transmission upgrades, additions and related issues for the upper Midwest, including work that addresses the full range of views on these topics; (2) Understand the various transmission issues in the upper Midwest and discuss options for addressing the issues; and (3) Identify the decision makers and entities that need to play an active role if transmission issues are to be resolved, and agree on next steps for engaging these individuals and organizations through education, outreach, and information dissemination.
Date: May 1, 2001
Creator: Bryan, Kevin
Object Type: Report
System: The UNT Digital Library
Microstructural and Microchemical Characterization of Dual Step Aged Alloy X-750 and its Relationship to Environmentally Assisted Cracking (open access)

Microstructural and Microchemical Characterization of Dual Step Aged Alloy X-750 and its Relationship to Environmentally Assisted Cracking

When exposed to deaerated high purity water, Alloy X-750 is susceptible to both high temperature (> 249 C) intergranular stress corrosion cracking (IGSCC) and intergranular low temperature (< 149 C) fracture (LTF). However, the microstructural and microchemical factors that govern environmentally assisted cracking (EAC) susceptibility are poorly understood. The present study seeks to characterize the grain boundary microstructure and microchemistry in order to gain a better mechanistic understanding of stress corrosion crack initiation, crack growth rate, and low temperature fracture. Light microscopy, scanning electron microscopy, transmission electron microscopy, orientation imaging microscopy, scanning Auger microscopy, and thermal desorption spectroscopy were performed on selected heats of Alloy X-750 AH. These data were correlated to EAC tests performed in 338 C deaerated water. Results show that grain boundary MC-type [(Ti,Nb)C] carbides and increased levels of grain boundary phosphorus correlate with an increase in LTF susceptibility but have little effect on the number of initiation sites or the SCC crack growth rate. Thermal desorption data show that multiple hydrogen trapping states exist in Alloy X-750 condition AH. Moreover, it appears that exposure to high temperature (> 249 C), hydrogen deaerated water increases the hydrogen concentration in strong hydrogen trap states and degrades the resistance …
Date: May 8, 2001
Creator: Young, G.A.; Lewis, N.; Hanson, M.; Matuszyk, W.; Wiersma, B. & Gonzalez, S.
Object Type: Report
System: The UNT Digital Library
An Investigation of Model Catalyzed Hydrocarbon Formation Reactions (open access)

An Investigation of Model Catalyzed Hydrocarbon Formation Reactions

Work was focused on two areas aimed at understanding the chemistry of realistic catalytic systems: (1) The synthesis and characterization of model supported olefin metathesis catalysts. (2) Understanding the role of the carbonaceous layer present on Pd(111) single crystal model catalysts during reaction.
Date: May 2, 2001
Creator: Tysoe, W. T.
Object Type: Report
System: The UNT Digital Library
PRODUCTION AND SCREENING OF CARBON PRODUCTS PRECURSORS FROM COAL (open access)

PRODUCTION AND SCREENING OF CARBON PRODUCTS PRECURSORS FROM COAL

The authors have examined effects of blending a raw coal extract (EXT) with an extracted coal-tar pitch (ECTP). Previous reports were concerned with the addition of 15 wt% EXT, or less, on the physical characteristics of the blend and on the development of optical texture following carbonization. Two additional blends of ECTP and EXT were prepared at the 30 and 50 wt% EXT content using a procedure already described. The characteristics of the blends are presented. The density for these blended materials is not much different than the density for the blends reported earlier. The softening point temperature for the 30 wt% EXT increased to over 200 C while the softening point temperature for the 50 wt% EXT blend was too high to be determined by the Mettler method. Coke yields approximately follow the law of mixtures. The optical texture of the green cokes for the 30 and 50 wt% EXT blends is shown. Though the optical texture of the green cokes was not significantly affected where the level of EXT is 15 wt% or less, larger proportions of EXT exert a marked reduction in anisotropy. The co-processing of coal with petroleum residues or other heavy hydrocarbons at elevated temperature …
Date: May 31, 2001
Creator: Irwin, Caulton L.
Object Type: Report
System: The UNT Digital Library
Measurement of the Nickel/Nickel Oxide Phase Transition in High Temperature Hydrogenated Water Using the Contact Electric Resistance (CER) Technique (open access)

Measurement of the Nickel/Nickel Oxide Phase Transition in High Temperature Hydrogenated Water Using the Contact Electric Resistance (CER) Technique

Prior studies of Alloy 600 and Alloy X-750 have shown the existence of a maximum in stress corrosion cracking (SCC) susceptibility in high temperature water (e.g., at 360 C), when testing is conducted over a range of dissolved (i.e., aqueous) hydrogen (H{sub 2}) concentrations. It has also been shown that this maximum in SCC susceptibility tends to occur in proximity to the nickel/nickel oxide (Ni/NiO) phase transition, suggesting that oxide phase stability may affect primary water SCC (PWSCC) resistance. Previous studies have estimated the Ni/NiO transition using thermodynamic calculations based on free energies of formation for NiO and H{sub 2}O. The present study reports experimental measurements of the Ni/NiO transition performed using a contact electric resistance (CER) instrument. The CER is capable of measuring the surface resistance of a metal to determine whether it is oxide-covered or oxide-free at a given condition. The transition aqueous hydrogen (H{sub 2}) concentration corresponding to the Ni/NiO equilibrium was measured at 288, 316, 338 and 360 C using high purity Ni specimens. The results showed an appreciable deviation (i.e., 7 to 58 scc H{sub 2}/kg H{sub 2}O) between the measured Ni/NiO transition and the theoretical Ni/NiO transition previously calculated using free energy data from …
Date: May 8, 2001
Creator: Attanasio, S. A.; Morton, D. S.; Ando, M. A.; Panayotou, N. F. & Thompson, C. D.
Object Type: Report
System: The UNT Digital Library
Fast methods for static Hamilton-Jacobi Partial Differential Equations (open access)

Fast methods for static Hamilton-Jacobi Partial Differential Equations

The authors develop a family of fast methods approximating the solution to a wide class of static Hamilton-Jacobi partial differential equations. These partial differential equations are considered in the context of control-theoretic and front-propagation problems. In general, to produce a numerical solution to such a problem, one has to solve a large system of coupled non-linear discretized equations. The techniques use partial information about the characteristic directions to de-couple the system. Previously known fast methods, available for isotropic problems, are discussed in detail. They introduce a family of new Ordered Upwinding Methods (OUM) for general (anisotropic) problems and prove convergence to the viscosity solution of the corresponding Hamilton-Jacobi partial differential equation. The hybrid methods introduced here are based on the analysis of the role played by anisotropy in the context of front propagation and optimal trajectory problems. The performance of the methods is analyzed and compared to that of several other numerical approaches to these problems. Computational experiments are performed using test problems from control theory, computational geometry and seismology.
Date: May 1, 2001
Creator: Vladimirsky, Alexander Boris
Object Type: Thesis or Dissertation
System: The UNT Digital Library
THERM Simulations of Window Indoor Surface Temperatures for Predicting Condensation (open access)

THERM Simulations of Window Indoor Surface Temperatures for Predicting Condensation

As part of a ''round robin'' project, the performance of two wood windows and a Calibrated Transfer Standard was modeled using the THERM heat-transfer simulation program. The resulting interior surface temperatures can be used as input to condensation resistance rating procedures. The Radiation and Condensation Index features within THERM were used to refine the accuracy of simulation results. Differences in surface temperatures between the ''Basic'' calculations and those incorporating the Radiation and/or Condensation Index features are demonstrated and explained.
Date: May 18, 2001
Creator: Kohler, Christian; Arasteh, Dariush & Mitchell, Robin
Object Type: Article
System: The UNT Digital Library
Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils Semi-Annual Report: November 2000-April 2001 (open access)

Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils Semi-Annual Report: November 2000-April 2001

The overall program objective is to develop and evaluate integrated biological/physical/chemical co-treatment strategies for the remediation of wastes associated with the exploration and production of fossil energy. The specific objectives of this project are: chemical accelerated biotreatment (CAB) technology development for enhanced site remediation, application of the risk based analyses to define and support the rationale for environmental acceptable endpoints (EAE) for exploration and production wastes, and evaluate both the technological technologies in conjugation for effective remediation of hydrocarbon contaminated soils from E&P sites in the USA.
Date: May 1, 2001
Creator: Paterek, J. R.; Bogan, W. W.; Lahner, L. M.; Trbovic, V. & Korach, E.
Object Type: Report
System: The UNT Digital Library
Obtaining the nuclear gluon distribution from heavy quark decaysto lepton pairs in pA collisions (open access)

Obtaining the nuclear gluon distribution from heavy quark decaysto lepton pairs in pA collisions

We have studied how lepton pairs from decays of heavy-flavoured mesons produced in pA collisions can be used to determine the modifications of the gluon distribution in the nucleus. Since heavyquark production is dominated by the gg channel, the ratio of correlated lepton pair cross sections from DD-bar and BB-bar decays in pA and pp collisions directly reflects the ratio R{sub g}A= f{sub g}A/f{sub g}p. We have numerically calculated the lepton pair cross sections from these decays in pp and pA collisions at SPS, RHIC and LHC energies. We find that ratio of the pA to pp cross sections agrees quite well with the input R{sub g}A. Thus, sufficiently accurate measurements could be used to determine the nuclear modification of the gluon distribution over a greater range of x and Q2 than presently available, putting strong constraints on models.
Date: May 10, 2001
Creator: Eskola, K.J.; Kolhinen, V.J. & Vogt, R.
Object Type: Article
System: The UNT Digital Library
The China Motor Systems Energy Conservation Program: A major national initiative to reduce motor system energy use in China (open access)

The China Motor Systems Energy Conservation Program: A major national initiative to reduce motor system energy use in China

Electric motor systems are widely used in China to power fans, pumps, blowers, air compressors, refrigeration compressors, conveyers, machinery, and many other types of equipment. Overall, electric motor systems consume more than 600 billion kWh annually, accounting for more than 50 percent of China's electricity use. There are large opportunities to improve the efficiency of motor systems. Electric motors in China are approximately 2-4 percent less efficient on average than motors in the U.S. and Canada. Fans and pumps in China are approximately 3-5 percent less efficient than in developed countries. Even more importantly, motors, fans, pumps, air compressors and other motor-driven equipment are frequently applied with little attention to system efficiency. More optimized design, including appropriate sizing and use of speed control strategies, can reduce energy use by 20 percent or more in many applications. Unfortunately, few Chinese enterprises use or even know about these energy-saving practices. Opportunities for motor system improvements are probably greater in China than in the U.S. In order to begin capturing these savings, China is establishing a China Motor Systems Energy Conservation Program. Elements of this program include work to develop minimum efficiency standards for motors, a voluntary ''green motor'' labeling program for high-efficiency …
Date: May 31, 2001
Creator: Nadel, Steven; Wang, Wanxing; Liu, Peter & McKane, Aimee T.
Object Type: Article
System: The UNT Digital Library
A physically-based abrasive wear model for composite materials (open access)

A physically-based abrasive wear model for composite materials

A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of the reinforcement is estimated by modeling the three primary wear mechanisms, specifically plowing, interfacial cracking and particle removal. Critical variables describing the role of the reinforcement, such as its relative size and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy matrix composite material.
Date: May 1, 2001
Creator: Lee, Gun Y.; Dharan, C. K. H. & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
Solubility and Surface Adsorption Characteristics of Metal Oxides to High Temperature (open access)

Solubility and Surface Adsorption Characteristics of Metal Oxides to High Temperature

The interaction of high temperature aqueous solutions with mineral surfaces plays a key role in many aspects of fossil, geothermal and nuclear energy production. This is an area of study in which the subsurface geochemical processes that determine brine composition, porosity and permeability changes, reservoir integrity, and fluid flow rates overlap with the industrial processes associated with corrosion of metal parts and deposition of solids in pipes and on heat exchanger surfaces. The sorption of ions on mineral surfaces is also of great interest in both the subsurface and ''above ground'' regimes of power production, playing a key role in subsurface migration of contaminants (nuclear waste disposal, geothermal brine re-injection, etc.) and in plant operations (corrosion mitigation, migration of radioactive metals from reactor core to heat exchanger, etc.). In this paper, results of the solubility and surface chemistry of metal oxides relevant to both regimes are summarized.
Date: May 4, 2001
Creator: Wesolowski, D. J.; Machesky, M. L.; Ziemniak, S. E.; Xiao, C.; Palmer, D. A.; Anovitz, L. M. et al.
Object Type: Report
System: The UNT Digital Library
Proceedings of National Avian-Wind Power Planning Meeting IV (open access)

Proceedings of National Avian-Wind Power Planning Meeting IV

OAK-B135 The purpose of the fourth meeting was to (1) share research and update research conducted on avian wind interactions (2) identify questions and issues related to the research results, (3) develop conclusions about some avian/wind power issues, and (4) identify questions and issues for future avian research.
Date: May 1, 2001
Creator: Subcommittee, NWCC Avian
Object Type: Article
System: The UNT Digital Library
Probability Distribution for Flowing Interval Spacing (open access)

Probability Distribution for Flowing Interval Spacing

The purpose of this analysis is to develop a probability distribution for flowing interval spacing. A flowing interval is defined as a fractured zone that transmits flow in the Saturated Zone (SZ), as identified through borehole flow meter surveys (Figure 1). This analysis uses the term ''flowing interval spacing'' as opposed to fractured spacing, which is typically used in the literature. The term fracture spacing was not used in this analysis because the data used identify a zone (or a flowing interval) that contains fluid-conducting fractures but does not distinguish how many or which fractures comprise the flowing interval. The flowing interval spacing is measured between the midpoints of each flowing interval. Fracture spacing within the SZ is defined as the spacing between fractures, with no regard to which fractures are carrying flow. The Development Plan associated with this analysis is entitled, ''Probability Distribution for Flowing Interval Spacing'', (CRWMS M&O 2000a). The parameter from this analysis may be used in the TSPA SR/LA Saturated Zone Flow and Transport Work Direction and Planning Documents: (1) ''Abstraction of Matrix Diffusion for SZ Flow and Transport Analyses'' (CRWMS M&O 1999a) and (2) ''Incorporation of Heterogeneity in SZ Flow and Transport Analyses'', (CRWMS M&O …
Date: May 16, 2001
Creator: Kuzio, S.
Object Type: Report
System: The UNT Digital Library
Integrated simulation environment for lighting design (open access)

Integrated simulation environment for lighting design

Lighting design involves the consideration of multiple performance criteria, from the earliest stages of conceptual design, through various stages of controls and operation in a project's life cycle. These criteria include: (1) the quantitative analysis of illuminance and luminance distribution due to daylighting and electric lighting; (2) qualitative analysis of the lighting design with photometrically accurate renderings of the designed environment; (3) analysis of energy implications of daylighting and electric lighting design and operation;, and (4) analysis of control strategies and sensor placement for maximizing energy savings from lighting control while providing visual comfort. In this paper we describe the development of an integrated decision-making environment that brings together several different tools, and provides the data management and process control required for a multi-criterion support of the design and operation of daylighting and electric lighting systems. The result is a powerful design and decision-making environment to meet the diverse and evolving needs of lighting designers and operators.
Date: May 24, 2001
Creator: Pal, Vineeta & Papamichael, Konstantinos
Object Type: Article
System: The UNT Digital Library
A comparison of three programming models for adaptive applications on the Origin2000 (open access)

A comparison of three programming models for adaptive applications on the Origin2000

Adaptive applications have computational workloads and communication patterns which change unpredictably at runtime, requiring dynamic load balancing to achieve scalable performance on parallel machines. Efficient parallel implementations of such adaptive applications is therefore a challenging task. In this paper, we compare the performance of and the programming effort required for two major classes of adaptive applications under three leading parallel programming models on an SGI Origin2000 system, a machine which supports all three models efficiently. Results indicate that the three models deliver comparable performance; however, the implementations differ significantly beyond merely using explicit messages versus implicit loads/stores even though the basic parallel algorithms are similar. Compared with the message-passing (using MPI) and SHMEM programming models, the cache-coherent shared address space (CC-SAS) model provides substantial ease of programming at both the conceptual and program orchestration levels, often accompanied by performance gains. However, CC-SAS currently has portability limitations and may suffer from poor spatial locality of physically distributed shared data on large numbers of processors.
Date: May 30, 2001
Creator: Shan, Hongzhang; Singh, Jaswinder Pal; Oliker, Leonid & Biswas, Rupak
Object Type: Article
System: The UNT Digital Library
Speciation, Mobility and Fate of Actinides in the Groundwater at the Hanford Site (Sept. 1999-Sept. 2002) (open access)

Speciation, Mobility and Fate of Actinides in the Groundwater at the Hanford Site (Sept. 1999-Sept. 2002)

The objectives of this project are: (1) the determination of the speciation of plutonium and other actinides (Np, U) in groundwater at the 100 and 200 areas at the Hanford Site. This includes the separation of Pu into particulate, colloidal and <1 kilo-Dalton dissolved phases and the determination of redox states and isotopic composition in each fraction; (2) the characterization of groundwater colloids, which includes submicron-sized inorganic particles and organic macromolecules (3) the prediction of the rate of transport and fate of actinides in the groundwater of the Hanford Site using a three-phase (dissolved-colloid-particulate) model.
Date: May 31, 2001
Creator: Buesseler, K. O.; Dai, M. & Repeta, D. J.
Object Type: Report
System: The UNT Digital Library
Research on electric utility regulatory and policy matters relating to state and federal jurisdiction. Final report for period September 1, 1994 - February 28, 2001 (open access)

Research on electric utility regulatory and policy matters relating to state and federal jurisdiction. Final report for period September 1, 1994 - February 28, 2001

The projects funded by the above referenced grant, are based on the October 1992 proposal to the FERC, which outlined the need for closer dialogue between Federal and State energy officials. The project is designed to assist State commissioners in responding to outreach initiatives that were already forthcoming from the FERC and to further develop and refine proposals that were still outstanding.
Date: May 1, 2001
Creator: Spahn, Andrew & Dwyer, Alix
Object Type: Report
System: The UNT Digital Library