Serial/Series Title
OIT Tip Sheets
10
Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells Quarterly Report
8
Fiscal Year 2004
8
Enhanced Wellbore Stabilization and Reservoir Productivity with Aphron Drilling Fluid Technology
6
Fiscal Year 2003
6
Small Wind Electric Systems Consumers' Guides
6
Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines Progress Report
4
Differential Soil Impedance Obstacle Detection Quarterly Report
4
Field Demonstration of a Membrane Process to Separate Nitrogen From Natural Gas Progress Report
4
Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery From Fractured Reservoirs by Spontaneous Imbibition Quarterly Report
4
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Tracing Geothermal Fluids
Geothermal water must be injected back into the reservoir after it has been used for power production. Injection is critical in maximizing the power production and lifetime of the reservoir. To use injectate effectively the direction and velocity of the injected water must be known or inferred. This information can be obtained by using chemical tracers to track the subsurface flow paths of the injected fluid. Tracers are chemical compounds that are added to the water as it is injected back into the reservoir. The hot production water is monitored for the presence of this tracer using the most sensitive analytic methods that are economically feasible. The amount and concentration pattern of the tracer revealed by this monitoring can be used to evaluate how effective the injection strategy is. However, the tracers must have properties that suite the environment that they will be used in. This requires careful consideration and testing of the tracer properties. In previous and parallel investigations we have developed tracers that are suitable from tracing liquid water. In this investigation, we developed tracers that can be used for steam and mixed water/steam environments. This work will improve the efficiency of injection management in geothermal fields, lowering …
Date:
March 1, 2004
Creator:
Adams, Michael C. & Nash, Greg
Object Type:
Report
System:
The UNT Digital Library
Direct single ion machining of nanopores.
The irradiation of thin insulating films by high-energy ions (374 MeV Au{sup +25} or 241 MeV I{sup +19}) was used to attempt to form nanometer-size pores through the films spontaneously. Such ions deposit a large amount of energy into the target materials ({approx}20 keV/nm), which significantly disrupts their atomic lattice and sputters material from the surfaces, and might produce nanopores for appropriate ion-material combinations. Transmission electron microscopy was used to examine the resulting ion tracks. Tracks were found in the crystalline oxides quartz, sapphire, and mica. Sapphire and mica showed ion tracks that are likely amorphous and exhibit pits 5 nm in diameter on the surface at the ion entrance and exit points. This suggests that nanopores might form in mica if the film thickness is less than {approx}10 nm. Tracks in quartz showed strain in the matrix around them. Tracks were not found in the amorphous thin films examined: 20 nm-SiN{sub x}, deposited SiOx, fused quartz (amorphous SiO{sub 2}), formvar and 3 nm-C. Other promising materials for nanopore formation were identified, including thin Au and SnO{sub 2} layers.
Date:
October 1, 2004
Creator:
Doyle, Barney Lee; Follstaedt, David Martin; Rossi, Paolo & Norman, Adam K.
Object Type:
Report
System:
The UNT Digital Library
NorthAm Fest : fostering a North American continent approach to countering terrorism.
On September 14-16, 2004, the Advanced Concepts Group of Sandia National Laboratories in conjunction with the University of Texas at El Paso and the North American Institute hosted a workshop (fest) designed to explore the concept of a North American continental approach to countering terrorism. The fest began with the basic premise that the successful defense of North America against the threat of terrorism will require close collaboration among the North American allies--Canada, Mexico and the U.S.--as well as a powerful set of information collection and analysis tools and deterrence strategies. The NorthAm Fest recast the notion of ''homeland defense'' as a tri-national effort to protect the North American continent against an evolving threat that respects no borders. This is a report of the event summarizing the ideas explored. The fest examined the uniqueness of dealing with terrorism from a tri-national North American viewpoint, the role and possible features of joint security systems, concepts for ideal continental security systems for North America, and the challenges and opportunities for such systems to become reality. The following issues were identified as most important for the advancement of this concept. (1) The three countries share a set of core values--democracy, prosperity and security--which …
Date:
December 1, 2004
Creator:
Gerdes, Dick (North American Institute, Santa Fe, NM); Moore, Judy Hennessey; Whitley, John B.; Turnley, Jessica Glicken (Galisteo Consulting Group, Inc., Albuquerque, NM) & Oborotova, Marina (Center for International Studies of El Colegio de Mexico)
Object Type:
Report
System:
The UNT Digital Library
Self-assembled ordered carbon-nanotube arrays and membranes.
Imagine free-standing flexible membranes with highly-aligned arrays of carbon nanotubes (CNTs) running through their thickness. Perhaps with both ends of the CNTs open for highly controlled nanofiltration? Or CNTs at heights uniformly above a polymer membrane for a flexible array of nanoelectrodes or field-emitters? How about CNT films with incredible amounts of accessible surface area for analyte adsorption? These self-assembled crystalline nanotubes consist of multiple layers of graphene sheets rolled into concentric cylinders. Tube diameters (3-300 nm), inner-bore diameters (2-15 nm), and lengths (nanometers - microns) are controlled to tailor physical, mechanical, and chemical properties. We proposed to explore growth and characterize nanotube arrays to help determine their exciting functionality for Sandia applications. Thermal chemical vapor deposition growth in a furnace nucleates from a metal catalyst. Ordered arrays grow using templates from self-assembled hexagonal arrays of nanopores in anodized-aluminum oxide. Polymeric-binders can mechanically hold the CNTs in place for polishing, lift-off, and membrane formation. The stiffness, electrical and thermal conductivities of CNTs make them ideally suited for a wide-variety of possible applications. Large-area, highly-accessible gas-adsorbing carbon surfaces, superb cold-cathode field-emission, and unique nanoscale geometries can lead to advanced microsensors using analyte adsorption, arrays of functionalized nanoelectrodes for enhanced electrochemical detection …
Date:
November 1, 2004
Creator:
Overmyer, Donald L.; Siegal, Michael P. & Yelton, William Graham
Object Type:
Report
System:
The UNT Digital Library
The dihadron fragmentation function and its evolution
Dihadron fragmentation functions and their evolution arestudied in the process of e+e- annihilation. Under the collinearfactorization approximation and facilitated by the cut-vertex technique,the two hadron inclusive cross section at leading order (LO) is shown tofactorize into a short distance parton cross section and a long distancedihadron fragmentation function. We provide the definition of such adihadron fragmentation function in terms of parton matrix elements andderive its DGLAP evolution equation at leading log. The evolutionequation for the non-singlet quark fragmentation function is solvednumerically with a simple ansatz for the initial condition and resultsare presented for cases of physical interest.
Date:
February 24, 2004
Creator:
Majumder, Abhijit & Wang, Xin-Nian
Object Type:
Article
System:
The UNT Digital Library
Evaluation of ingredients for the development of new insensitive munitions.
Several ingredients being considered by the U.S. Army for the development of new insensitive munitions have been examined. One set of ingredients consists of 2,4-dinitrophenylhydrazine (DNPH) and hexahydro-1,3,5-trinitro-s-triazine (RDX). In this set, the decomposition of the mixture was examined to determine whether adding DNPH to RDX would generate a sufficient quantity of gas to rupture the case of a munition prior to the onset of the rapid reaction of RDX, thus mitigating the violence of reaction. The second set of ingredients consists of three different reduced sensitivity RDX (RS-RDX) powders manufactured by SNPE and Dyno-Nobel. In this set, the objective was to determine properties of RS-RDX powders that may distinguish them from normal RDX powder and may account for their reduced shock sensitivity. The decomposition reactions and sublimation properties of these materials were examined using two unique instruments: the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) instrument and the Fourier Transform ion cyclotron resonance (FTICR) mass spectrometry instrument. These instruments provide the capability to examine the details of decomposition reactions in energetic materials. DNPH does not appear to be a good candidate to mitigate the violence of the RDX reaction in a munition. DNPH decomposes between 170 C and 180 …
Date:
December 1, 2004
Creator:
Maharrey, Sean P.; Johnston, Lois A.; Behrens, Richard, Jr. & Wiese-Smith, Deneille
Object Type:
Report
System:
The UNT Digital Library
A set of verification test cases for Eiger : plane wave scattering from a sphere.
This report discusses a set of verification test cases for the frequency-domain, boundary-element, electromagnetics code Eiger based on the analytical solution of plane wave scattering from a sphere. Three cases will be considered: when the sphere is made of perfect electric conductor, when the sphere is made of lossless dielectric and when the sphere is made of lossy dielectric. We outline the procedures that must be followed in order to carefully compare the numerical solution to the analytical solution. We define an error criterion and demonstrate convergence behavior for both the analytical and numerical cases. These problems test the code's ability to calculate the surface current density and secondary quantities, such as near fields and far fields.
Date:
October 1, 2004
Creator:
Jorgenson, Roy Eberhardt & Kotulski, Joseph Daniel
Object Type:
Report
System:
The UNT Digital Library
A fast algorithm for three-dimensional interpretations ofsingle-well electromagnetic data
An efficient inversion algorithm has been developed forthree-dimensional (3D) interpretations for single-hole electromagnetic(EM) logging data based on a modified extended Born approximation (MEBA)scheme. The single-hole data was collected at an oil field undergoing CO2injection in southern California using a tool, Geo-BILT, developed byElectromagnetic Instruments, Inc (EMI). The tool is equipped with amulti-component source, and an array of multi-component receivers atdifferent separations. The inversion result provides a reasonableelectrical conductivity image to a distance of 10 m from the well, andillustrates several zones with lateral conductivity variations that couldnot be resolved with traditional induction logging tools. The computercost of the inversion processes can be further reduced using a trivialmulti-grid methodology.
Date:
September 17, 2004
Creator:
Tseng, Hung-Wen & Lee, Ki Ha
Object Type:
Report
System:
The UNT Digital Library
Development of the augmented musculature device.
We developed an Augmented Musculature Device (AMD) that assists the movements of its wearer. It has direct application to aiding military and law enforcement personnel, the neurologically impaired, or those requiring any type of cybernetic assistance. The AMD consists of a collection of artificial muscles, each individually actuated, strategically placed along the surface of the human body. The actuators employed by the AMD are known as 'air muscles' and operate pneumatically. They are commercially available from several vendors and are relatively inexpensive. They have a remarkably high force-to-weight ratio--as high as 400:1 (as compared with 16:1 typical of DC motors). They are flexible and elastic, even when powered, making them ideal for interaction with humans.
Date:
December 1, 2004
Creator:
Rohrer, Brandon Robinson & Pankretz, Ty
Object Type:
Report
System:
The UNT Digital Library
Autofocus correction of excessive migration in synthetic aperture radar images.
When residual range migration due to either real or apparent motion errors exceeds the range resolution, conventional autofocus algorithms fail. A new migration-correction autofocus algorithm has been developed that estimates the migration and applies phase and frequency corrections to properly focus the image.
Date:
September 1, 2004
Creator:
Doerry, Armin Walter
Object Type:
Report
System:
The UNT Digital Library
Annual Change Report 2003/2004
As part of continuing compliance, the U.S. Environmental Protection Agency (EPA) requires the U.S. Department of Energy (DOE) to provide any change in information since the most recent compliance application. This requirement is identified in Title 40 Code of Federal Regulations (CFR), Section 194.4(b)(4), which states: “No later than six months after the administrator issues a certification, and at least annually thereafter, the Department shall report to the Administrator, in writing, any changes in conditions or activities pertaining to the disposal system that were not required to be reported by paragraph (b)(3) of this section and that differ from information contained in the most recent compliance application.” In meeting the requirement, the DOE provides an annual report of all changes applicable under the above requirement each November. This annual report informs the EPA of changes to information in the most recent compliance application, or for this report the 1996 Compliance Certification Application (CCA). Significant planned changes must be reported to the EPA prior to implementation by the DOE. In addition, Title 40 CFR, Section 194.4(b)(3) requires that significant unplanned changes be reported to the EPA within 24 hours or ten days, depending on the severity of the activity or condition. …
Date:
November 10, 2004
Creator:
Washington Regulatory and Environmental Services
Object Type:
Report
System:
The UNT Digital Library
Coho Salmon Master Plan, Clearwater River Basin.
The Nez Perce Tribe has a desire and a goal to reintroduce and restore coho salmon to the Clearwater River Subbasin at levels of abundance and productivity sufficient to support sustainable runs and annual harvest. Consistent with the Clearwater Subbasin Plan (EcoVista 2003), the Nez Perce Tribe envisions developing an annual escapement of 14,000 coho salmon to the Clearwater River Subbasin. In 1994, the Nez Perce Tribe began coho reintroduction by securing eggs through U.S. v. Oregon; by 1998 this agreement provided an annual transfer of 550,000 coho salmon smolts from lower Columbia River hatchery facilities for release in the Clearwater River Subbasin. In 1998, the Northwest Power and Conservation Council authorized the Bonneville Power Administration to fund the development of a Master Plan to guide this reintroduction effort. This Master Plan describes the results of experimental releases of coho salmon in the Clearwater River Subbasin, which have been ongoing since 1995. These data are combined with results of recent coho reintroduction efforts by the Yakama Nation, general coho life history information, and historical information regarding the distribution and life history of Snake River coho salmon. This information is used to assess a number of alternative strategies aimed at restoring …
Date:
October 1, 2004
Creator:
Tribe, Nez Perce & FishPro
Object Type:
Report
System:
The UNT Digital Library
Scheduling in Heterogeneous Grid Environments: The Effects of DataMigration
Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this goal can be fully realized. One problem critical to the effective utilization of computational grids is efficient job scheduling. Our prior work addressed this challenge by defining a grid scheduling architecture and several job migration strategies. The focus of this study is to explore the impact of data migration under a variety of demanding grid conditions. We evaluate our grid scheduling algorithms by simulating compute servers, various groupings of servers into sites, and inter-server networks, using real workloads obtained from leading supercomputing centers. Several key performance metrics are used to compare the behavior of our algorithms against reference local and centralized scheduling schemes. Results show the tremendous benefits of grid scheduling, even in the presence of input/output data migration - while highlighting the importance of utilizing communication-aware scheduling schemes.
Date:
January 1, 2004
Creator:
Oliker, Leonid; Biswas, Rupak; Shan, Hongzhang & Smith, Warren
Object Type:
Article
System:
The UNT Digital Library
Dynamic vulnerability assessment.
With increased terrorist threats in the past few years, it is no longer feasible to feel confident that a facility is well protected with a static security system. Potential adversaries often research their targets, examining procedural and system changes, in order to attack at a vulnerable time. Such system changes may include scheduled sensor maintenance, scheduled or unscheduled changes in the guard force, facility alert level changes, sensor failures or degradation, etc. All of these changes impact the system effectiveness and can make a facility more vulnerable. Currently, a standard analysis of system effectiveness is performed approximately every six months using a vulnerability assessment tool called ASSESS (Analytical Systems and Software for Evaluating Safeguards and Systems). New standards for determining a facility's system effectiveness will be defined by tools that are currently under development, such as ATLAS (Adversary Time-line Analysis System) and NextGen (Next Generation Security Simulation). Although these tools are useful to model analyses at different spatial resolutions and can support some sensor dynamics using statistical models, they are limited in that they require a static system state as input. They cannot account for the dynamics of the system through day-to-day operations. The emphasis of this project was to …
Date:
September 1, 2004
Creator:
Nelson, Cynthia Lee
Object Type:
Report
System:
The UNT Digital Library
Understanding communication in counterterrorism crisis management.
This report describes the purpose and results of the two-year, Sandia-sponsored Laboratory Directed Research and Development (LDRD) project entitled Understanding Communication in Counterterrorism Crisis Management The purpose of this project was to facilitate the capture of key communications among team members in simulated training exercises, and to learn how to improve communication in that domain. The first section of this document details the scenario development aspects of the simulation. The second section covers the new communication technologies that were developed and incorporated into the Weapons of Mass Destruction Decision Analysis Center (WMD-DAC) suite of decision support tools. The third section provides an overview of the features of the simulation and highlights its communication aspects. The fourth section describes the Team Communication Study processes and methodologies. The fifth section discusses future directions and areas in which to apply the new technologies and study results obtained as a result of this LDRD.
Date:
October 1, 2004
Creator:
Djordjevich, Donna D.; Barr, Pamela K.; Arnold, Jason Darrel; Johnson, Michael M.; Sa, Timothy J.; Hawley, Marilyn F. et al.
Object Type:
Report
System:
The UNT Digital Library
Habitat Evaluation Procedures (HEP) Report : Oleson Tracts of the Tualatin River National Wildlife Refuge, 2001-2002 Technical Report.
Located in the northern Willamette River basin, Tualatin River National Wildlife Refuge (Refuge) was established in 1992 with an approved acquisition boundary to accommodate willing sellers with potentially restorable holdings within the Tualatin River floodplain. The Refuge's floodplain of seasonal and emergent wetlands, Oregon ash riparian hardwood, riparian shrub, coniferous forest, and Garry oak communities are representative of remnant plant communities historically common in the Willamette River valley and offer an opportunity to compensate for wildlife habitat losses associated with the Willamette River basin federal hydroelectric projects. The purchase of the Oleson Units as additions to the Refuge using Bonneville Power Administration (BPA) funds will partially mitigate for wildlife habitat and target species losses incurred as a result of construction and inundation activities at Dexter and Detroit Dams. Lands acquired for mitigation of Federal Columbia River Power System (FCRPS) impacts to wildlife are evaluated using the Habitat Evaluation Procedures (HEP) methodology, which quantifies how many Habitat Units (HUs) are to be credited to BPA. HUs or credits gained lessen BPA's debt, which was formally tabulated in the FCRPS Loss Assessments and adopted as part of the Northwest Power and Conservation Council's Fish and Wildlife Program as a BPA obligation (NWPCC, …
Date:
September 1, 2004
Creator:
Allard, Donna; Smith, maureen & Schmidt, Peter
Object Type:
Report
System:
The UNT Digital Library
Initial cost analysis of a desalination process utilizing hydrotalcite and permutite for ion sequestration.
An initial cost analysis of a proposed desalination process was performed. The proposed process utilizes tailored inorganic ion exchangers, hydrotalcite and permutite, to sequester anions and cations from a brackish water solution. Three different process scenarios were considered: (1) disposal of the spent exchangers as dry waste (2) conventional chemical regeneration, and (3) acid regeneration of permutite coupled with thermal (550 C) regeneration of hydrotalcite. Disposal of the resin and conventional regeneration are not viable options from an economic standpoint. Applying limited data and optimistic assumptions to the third scenario yielded an estimate of $2.34/kgal of product water. Published values for applying conventional reverse osmosis to similar water streams range from $0.70 to $2.65/kgal. Consistent with these baseline values, the Water Treatment Estimation Routine, WaTER, developed by the United States Department of the Interior, Bureau of Reclamation produced a cost estimate of $1.16/kgal for brackish water reverse osmosis.
Date:
December 1, 2004
Creator:
Miller, James Edward & Evans, Lindsey R.
Object Type:
Report
System:
The UNT Digital Library
Proc. Agent 2004 Conf. on Social Dynamics : Interaction, Reflexivity and Emergence
I'd like to welcome you to the Agent 2004 conference. As most of you are aware, this conference is the fifth in a series of meetings that began in 1999. A conference followed the next year in 2000. The 2001 conference was skipped because of some conflicts with other conferences, and the conferences have proceeded annually since then. We have the proceedings of the previous conferences available here on CDs. One CD has the proceedings from 1999, 2000, and 2002; the other contains last year's proceedings. The purpose of these conferences is to advance the state of the computational social sciences and to integrate the social sciences with the decision sciences and something that is traditionally known as the management sciences. Those of you in the operations/research area are familiar with the traditional school of modeling simulation that emerged from that scientific area. This conference will bring together a different group of people to talk about the topic of agent-based theories and simulations. This fifth agent conference is one of a group of conferences held annually around the country. Most of you are probably aware of the CASOS Conference held at Carnegie Mellon University, usually in July. UCLA holds the …
Date:
January 1, 2004
Creator:
C. M. Macal, D. Sallach, M. J. North, eds.
Object Type:
Article
System:
The UNT Digital Library
LDRD final report on nanovehicle light-driven propulsion.
Having demonstrated the possibility of constructing nanoscale metallic vehicular bodies as described in last year's proposal, our goals have been to make uniform preparations of the metallized lipid assemblies and to determine the feasibility of powering these nanostructures with biological motors that are activated and driven by visible light. We desired that the propulsion system be constructed entirely by self-assembly and powered by a photocatalytic process partially already built into the nanovehicle. The nanovehicle we desire to build is composed of both natural biological components (ATPase, kinesin-microtubules) and biomimetic components (platinized liposomes, photosynthetic membrane) as functional units. The vehicle's body was originally envisioned to be composed of a surfactant liposomal bilayer coated with platinum nanoparticles, but instead of the expected nanoparticles we were able to grow dendritic 2-nm thick platinum sheets on the liposomes. Now, we have shown that it is possible to completely enclose the liposomes with sheeting to form porous platinum spheres, which show good structural stability as evidenced by their ability to survive the stresses of electron-microscopy sample preparation. Our goals were to control the synthesis of the platinized liposomes well enough to make uniform preparations of the coated individual liposomes and to develop the propulsion system …
Date:
December 1, 2004
Creator:
Singh, Anup K.; van Swol, Frank B.; Shelnutt, John Allen; Medforth, Craig J. & Song, Yujiang
Object Type:
Report
System:
The UNT Digital Library
ASIC Development for Three-Dimensional Silicon Imaging Array for Cold Neutrons
An Integrated Circuit (IC) readout chip with four channels arranged so as to receive input charge from the corners of the chip was designed for use with 5- to 7-mm pixel detectors. This Application Specific IC (ASIC) can be used for cold neutron imaging, for study of structural order in materials using cold neutron scattering or for particle physics experiments. The ASIC is fabricated in a 0.5-{micro}m n-well AMI process. The design of the ASIC and the test measurements made is reported. Noise measurements are also reported.
Date:
May 19, 2004
Creator:
Britton, C.L.; Jagadish, U. & Bryan, W.L.
Object Type:
Report
System:
The UNT Digital Library
Two Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA
Multidimensional hydrodynamic properties of high-adiabat direct-drive plastic-shell implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] are investigated using the multidimensional hydrodynamic code, DRACO. Multimode simulations including the effects of nonuniform illumination and target roughness indicate that shell stability during the acceleration phase plays a critical role in determining target performance. For thick shells that remain integral during the acceleration phase, target yields are significantly reduced by the combination of the long-wavelength ({ell} < 10) modes due to surface roughness and beam imbalance and the intermediate modes (20 {le} {ell} {le} 50) due to single-beam nonuniformities. The neutron-production rate for these thick shells truncates relative to one-dimensional (1-D) predictions. The yield degradation in the thin shells is mainly due to shell breakup at short wavelengths ({lambda} {approx} {Delta}, where {Delta} is the in-flight shell thickness). The neutron-rate curves for the thinner shells have significantly lower amplitudes and a fall-off that is less steep than 1-D rates. DRACO simulation results are consistent with experimental observations.
Date:
September 27, 2004
Creator:
Radha, P. B.; Goncharov, V. N.; Collins, T. B.; Delettrez, J. A.; Elbaz, Y.; Glebov, V. Y. et al.
Object Type:
Article
System:
The UNT Digital Library
Nanoporous-carbon adsorbers for chemical microsensors.
Chemical microsensors rely on partitioning of airborne chemicals into films to collect and measure trace quantities of hazardous vapors. Polymer sensor coatings used today are typically slow to respond and difficult to apply reproducibly. The objective of this project was to produce a durable sensor coating material based on graphitic nanoporous-carbon (NPC), a new material first studied at Sandia, for collection and detection of volatile organic compounds (VOC), toxic industrial chemicals (TIC), chemical warfare agents (CWA) and nuclear processing precursors (NPP). Preliminary studies using NPC films on exploratory surface-acoustic-wave (SAW) devices and as a {micro}ChemLab membrane preconcentrator suggested that NPC may outperform existing, irreproducible coatings for SAW sensor and {micro}ChemLab preconcentrator applications. Success of this project will provide a strategic advantage to the development of a robust, manufacturable, highly-sensitive chemical microsensor for public health, industrial, and national security needs. We use pulsed-laser deposition to grow NPC films at room-temperature with negligible residual stress, and hence, can be deposited onto nearly any substrate material to any thickness. Controlled deposition yields reproducible NPC density, morphology, and porosity, without any discernable variation in surface chemistry. NPC coatings > 20 {micro}m thick with density < 5% that of graphite have been demonstrated. NPC can …
Date:
November 1, 2004
Creator:
Overmyer, Donald L.; Siegal, Michael P.; Staton, Alan W.; Provencio, Paula Polyak & Yelton, William Graham
Object Type:
Report
System:
The UNT Digital Library
Human error mitigation initiative (HEMI) : summary report.
Despite continuing efforts to apply existing hazard analysis methods and comply with requirements, human errors persist across the nuclear weapons complex. Due to a number of factors, current retroactive and proactive methods to understand and minimize human error are highly subjective, inconsistent in numerous dimensions, and are cumbersome to characterize as thorough. An alternative and proposed method begins with leveraging historical data to understand what the systemic issues are and where resources need to be brought to bear proactively to minimize the risk of future occurrences. An illustrative analysis was performed using existing incident databases specific to Pantex weapons operations indicating systemic issues associated with operating procedures that undergo notably less development rigor relative to other task elements such as tooling and process flow. Future recommended steps to improve the objectivity, consistency, and thoroughness of hazard analysis and mitigation were delineated.
Date:
November 1, 2004
Creator:
Stevens, Susan M.; Ramos, M. Victoria; Wenner, Caren A. & Brannon, Nathan Gregory
Object Type:
Report
System:
The UNT Digital Library
Laboratory evaluation of damage criteria and permeability of Big Hill salt.
To establish strength criteria of Big Hill salt, a series of quasi-static triaxial compression tests have been completed. This report summarizes the test methods, set-up, relevant observations, and results. The triaxial compression tests established dilatant damage criteria for Big Hill salt in terms of stress invariants (I{sub 1} and J{sub 2}) and principal stresses ({sigma}{sub a,d} and {sigma}{sub 3}), respectively: {radical}J{sub 2}(psi) = 1746-1320.5 exp{sup -0.00034I{sub 1}(psi)}; {sigma}{sub a,d}(psi) = 2248 + 1.25 {sigma}{sub 3} (psi). For the confining pressure of 1,000 psi, the dilatant damage strength of Big Hill salt is identical to the typical salt strength ({radical}J{sub 2} = 0.27 I{sub 1}). However, for higher confining pressure, the typical strength criterion overestimates the damage strength of Big Hill salt.
Date:
November 1, 2004
Creator:
Ehgartner, Brian L.; Park, Byoung Yoon; Lee, Moo Yul & Bronowski, David R.
Object Type:
Report
System:
The UNT Digital Library