Defense Inventory: Navy Spare Parts Quality Deficiency Reporting Program Needs Improvement (open access)

Defense Inventory: Navy Spare Parts Quality Deficiency Reporting Program Needs Improvement

A letter report issued by the General Accounting Office with an abstract that begins "The Department of Defense (DOD) budgets billions of dollars each year to purchase and repair the spare parts needed to maintain its weapons systems and support equipment. The quality of the spare parts can greatly determine if the Department's investment of funds is effective, efficient, and economical. This report examines the Navy's Product Quality Deficiency Reporting Program and the extent to which the program has gathered the data needed for the analysis, correction, and prevention of deficiencies in spare parts. GAO found that data on parts defects identified at the time of installation were underreported. Data on parts that failed after some operation but before their expected design life were not collected as part of this program. In the quality reports GAO reviewed, some key information was omitted on the cause of the parts' failures and some reports did not identify who was responsible for the defects. To a large extent, the program's ineffectiveness can be attributed to lack of management, limited training and incentives to report deficiencies, and competing priorities for the staff resources needed to carry out the program."
Date: August 8, 2001
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library

Carbon dioxide sequestration: aqueous mineral carbonation studies using olivine and serpentine

None
Date: August 8, 2001
Creator: O'Connor, William K.; Dahlin, David C.; Nilsen, David N.; Rush, Gilbert E.; Walters, Richard P. & Turner, Paul C.
Object Type: Presentation
System: The UNT Digital Library
ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini (open access)

ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini

Both ErbB1 and ErbB2 are overexpressed or amplified in breast tumors. To examine the effects of activating ErbB receptors in a context that mimics polarized epithelial cells in vivo, we activated ErbB1 and ErbB2 homodimers in preformed, growth-arrested mammary acini cultured in three-dimensional basement membrane gels. Activation of ErbB2, but not that of ErbB1, led to a reinitiation of cell proliferation and altered the properties of mammary acinar structures. These altered structures share several properties with early-stage tumors, including a loss of proliferative suppression, an absence of lumen, retention of the basement membrane and a lack of invasive properties. ErbB2 activation also disrupted tight junctions and the cell polarity of polarized epithelia, whereas ErbB1 activation did not have any effect. Our results indicate that ErbB receptors differ in their ability to induce early stages of mammary carcinogenesis in vitro and this three-dimensional model system can reveal biological activities of oncogenes that cannot be examined in vitro in standard transformation assays.
Date: August 8, 2001
Creator: Muthuswamy, Senthil K; Li, Dongmei; Lelievre, Sophie; Bissell, Mina J & Brugge, Joan S
Object Type: Article
System: The UNT Digital Library
Final report on Effects of Water in Synthetic Lubricant Systems and Clathrate Formation: A Literature Search and Review (open access)

Final report on Effects of Water in Synthetic Lubricant Systems and Clathrate Formation: A Literature Search and Review

An extensive literature search and a confidential survey were critically analyzed to determine the effects of water on the stability of hydrofluorocarbon/synthetic lubricant systems and to identify key areas requiring further investigation. Following are highlights from the analysis: Clathrate hydrates are solid solutions formed when water molecules are linked through hydrogen bonding creating cavities that can enclose various guest molecules from hydrate formers, such as hydrofluorocarbons R-32, R-125, R-134a, R-407C and R-410A. The four methods for preventing clathrate formation were drying the gas, heating it, reducing its pressure, or using inhibitors. The hydrolysis of polyolester lubricants was mostly acid-catalyzed and its reaction rate constant typically followed the Arrhenius equation of an activated process. Hydrolytic stability improved with hindered molecular structures, and with the presence of acid catcher additives and desiccants. Water vapor can effect the adsorption of long-chain fatty acids and the chemistry of formation of protective oxide film. However, these effects on lubrication can be either positive or negative. Fifty to sixty percent of the moisture injected into an air-conditioning system remained in the refrigerant and the rest mixed with the compressor oil. In an automotive air-conditioning system using R-134a, ice would form at 0 C evaporating temperature when …
Date: August 8, 2001
Creator: Rohatgi, Ngoc Dung T.
Object Type: Report
System: The UNT Digital Library
New limit on the electron electric dipole moment (open access)

New limit on the electron electric dipole moment

We present the result of our most recent search for T-violation in 205Tl, which is interpreted in terms of an electric dipole moment of the electron de. We find de = (6.9 plus/minus 7.4) times 10{sup -28} e cm. The present apparatus is a major upgrade of the atomic beam magnetic resonance device used to set the previous limit on de.
Date: August 8, 2001
Creator: Regan, B.C.; Commins, Eugene D.; Schmidt, Christian J. & DeMille, David
Object Type: Article
System: The UNT Digital Library
Almost Optimal Interior Penalty Discontinuous Approximations of Symmetric Elliptic Problems on Non-Matching Grids (open access)

Almost Optimal Interior Penalty Discontinuous Approximations of Symmetric Elliptic Problems on Non-Matching Grids

We consider an interior penalty discontinuous approximation for symmetric elliptic problems of second order on non-matching grids in this paper. The main result is an almost optimal error estimate for the interior penalty approximation of the original problem based on the partition of the domain into a finite number of subdomains. Further, an error analysis for the finite element approximation of the penalty formulation is given. Finally, numerical experiments on a series of model second order problems are presented.
Date: August 8, 2001
Creator: Lazarov, R D; Pasciak, J E; Schoberl, J & Vassilevski, P S
Object Type: Report
System: The UNT Digital Library
Implementation of Deterministically-Derived Hydrostatigraphic Units into a 3D Finite Element Model at the Lawrence Livermore Laboratory Superfund Site (open access)

Implementation of Deterministically-Derived Hydrostatigraphic Units into a 3D Finite Element Model at the Lawrence Livermore Laboratory Superfund Site

Lawrence Livermore National Laboratory (LLNL) is a large Superfund site in California that is implementing an extensive ground water remediation program. The site is underlain by a thick sequence of heterogeneous alluvial sediments. Defining ground-water flow pathways in this complex geologic setting is difficult. To better evaluate these pathways, a deterministic approach was applied to define hydrostratigraphic units (HSUS) on the basis of identifiable hydraulic behavior and contaminant migration trends. The conceptual model based on this approach indicates that groundwater flow and contaminant transport occurs within packages of sediments bounded by thin, low-permeability confining layers. To aid in the development of the remediation program, a three-dimensional finite-element model was developed for two of the HSUS at LLNL. The primary objectives of this model are to test the conceptual model with a numerical model, and provide well field management support for the large ground-water remediation system. The model was successfully calibrated to 12 years of ground water flow and contaminant transport data. These results confirm that the thin, low-permeability confining layers within the heterogeneous alluvial sediments are the dominant hydraulic control to flow and transport. This calibrated model is currently being applied to better manage the large site-wide ground water extraction …
Date: August 8, 2001
Creator: Mansoor, K; Maley, M; Demir, Z & Hoffman, F
Object Type: Article
System: The UNT Digital Library
Detonation Product EOS Studies: Using ISLS to Refine Cheetah (open access)

Detonation Product EOS Studies: Using ISLS to Refine Cheetah

Knowledge of an effective interatomic potential function underlies any effort to predict or rationalize the properties of solids and liquids. The experiments we undertake are directed towards determination of equilibrium and dynamic properties of simple fluids at densities sufficiently high that traditional computational methods and semi-empirical forms successful at ambient conditions may require reconsideration. In this paper we present high-pressure and temperature experimental sound speed data on a simple fluid, methanol. Impulsive Stimulated Light Scattering (ISLS) conducted on diamond-anvil cell (DAC) encapsulated samples offers an experimental approach to determine cross-pair potential interactions through equation of state determinations. In addition the kinetics of structural relaxation in fluids can be studied. We compare our experimental results with our thermochemical computational model Cheetah. Computational models are systematically improved with each addition of experimental data.
Date: August 8, 2001
Creator: Zaug, J M; Howard, W M; Fried, L E & Hansen, D W
Object Type: Article
System: The UNT Digital Library
WUFI-ORNL/IBP Hygrothermal Model (open access)

WUFI-ORNL/IBP Hygrothermal Model

Moisture engineering is becoming an important task in the overall design of building enclosures in both North America and Europe. Several methods may be used to design wall systems, and modeling is definitively the most flexible approach. There is an increasing demand for calculation methods to assess the moisture behavior of building components. In North America alone, the estimated cost in increased energy consumption due to the presence of moisture is approximately $1 billion dollars annually. Current tasks, such as preserving historical buildings or restoring and insulating existing buildings are closely related to the moisture tolerance in a building structure. Calculative analyses are becoming increasingly important due to the expensive and time-consuming experimental investigations and the limited transferability to real situations. The Oak Ridge National Laboratory (Building Technology Center) and the Fraunhofer Institute for Building Physics in an international collaboration h ave jointly developed a moisture engineering assessment model that predicts the transient transport of heat and moisture. This model, WUFI-ORNL/IBP is now available in North America free of charge, and can be downloaded via the Internet at: www.ornl.gov/btc/moisture. The unique features of this particular model are that it incorporates vapor and diffusion transport mechanism, along with realistic boundary conditions …
Date: August 8, 2001
Creator: Karagiozis, A.N.
Object Type: Article
System: The UNT Digital Library
Dual-Fiberoptic Microcantilever Proximity Sensor (open access)

Dual-Fiberoptic Microcantilever Proximity Sensor

Microcantilevers are key components of many Micro-Electro-Mechanical Systems (MEMS) and Micro-Optical-Electro-Mechanical Systems (MOEMS) because slight changes to them physically or chemically lead to changes in mechanical characteristics. An inexpensive dual-fiberoptic microcantilever proximity sensor and model to predict its performance are reported here. Motion of a magnetic-material-coated cantilever is the basis of a system under development for measuring magnetic fields. The dual fiber proximity sensor will be used to monitor the motion of the cantilever. The specific goal is to sense induction fields produced by a current carrying conductor. The proximity sensor consists of two fibers side by side with claddings in contact. The fiber core diameter, 50 microns, and cladding thickness, 10 microns, are as small as routinely available commercially with the exception of single mode fiber. Light is launched into one fiber from a light-emitting diode (LED). It emerges from that fiber and reflects from the cantilever into the adjacent receiving fiber connected to a detector. The sensing end is cast molded with a diameter of 3-mm over the last 20-mm, yielding a low profile sensor. This reflective triangulation approach is probably the oldest and simplest fiber proximity sensing approach, yet the novelty here is in demonstrating high sensitivity …
Date: August 8, 2001
Creator: Goedeke, S.M.
Object Type: Article
System: The UNT Digital Library
Thermoelastic response of suddenly heated liquid targets in high-power colliders. (open access)

Thermoelastic response of suddenly heated liquid targets in high-power colliders.

Thermoelastic response of liquid metal targets exposed to high-volumetric-energy deposition in times shorter than the target hydrodynamic response time (i.e., sound travel time) is of interest to several research areas, including targets for high-power accelerators such as the Spallation Neutron Source, muon collider targets, etc. Sudden energy deposition causes shock and rarefaction waves of magnitude {+-} {Delta}P that corresponds to an initial thermal pressure of tens of katm. Nevertheless a liquid subjected to a negative pressure is metastable. The problem of liquid target oscillations in the presence of large negative pressure, and the mechanism of fragmentation and its consequences, are considered in this paper.
Date: August 8, 2001
Creator: Hassanein, A.; Konkashbaev, I. & Norem, J.
Object Type: Article
System: The UNT Digital Library
The program in muon and neutrino physics: Superbeams, cold muon beams, neutrino factory and the muon collider (open access)

The program in muon and neutrino physics: Superbeams, cold muon beams, neutrino factory and the muon collider

The concept of a Muon Collider was first proposed by Budker [10] and by Skrinsky [11] in the 60s and early 70s. However, there was little substance to the concept until the idea of ionization cooling was developed by Skrinsky and Parkhomchuk [12]. The ionization cooling approach was expanded by Neufer [13] and then by Palmer [14], whose work led to the formation of the Neutrino Factory and Muon Collider Collaboration (MC) [3] in 1995. The concept of a neutrino source based on a pion storage ring was originally considered by Koshkarev [18]. However, the intensity of the muons created within the ring from pion decay was too low to provide a useful neutrino source. The Muon Collider concept provided a way to produce a very intense muon source. The physics potential of neutrino beams produced by muon storage rings was investigated by Geer in 1997 at a Fermilab workshop [19, 20] where it became evident that the neutrino beams produced by muon storage rings needed for the muon collider were exciting on their own merit. The neutrino factory concept quickly captured the imagination of the particle physics community, driven in large part by the exciting atmospheric neutrino deficit results …
Date: August 8, 2001
Creator: al., R. Raja et
Object Type: Article
System: The UNT Digital Library
Production of Radioactive Iodine. (open access)

Production of Radioactive Iodine.

Probably the most widely used cyclotron produced radiohalogen is I-123. It has gradually replaced I-131 as the isotope of choice for diagnostic radiopharmaceuticals containing radioiodine. It gives a much lower radiation dose to the patient and the gamma ray energy of 159 keV is ideally suited for use in a gamma camera. The gamma ray will penetrate tissue very effectively without excessive radiation dose. For this reason, it has in many instances replaced the reactor produced iodine-131 (Lambrecht and Wolf 1973). A great number of radiopharmaceuticals have been labeled using I-123 and the number is increasing. One of the most promising uses of I-123 is in the imaging of monoclonal antibodies to localize and visualize tumors. However, preclinical and clinical experiences with radiolabeled antibodies have not realized the expectations regarding specificity and sensitivity of tumor localization with these agents. It appears that much of the administered activity is not associated with the tumor site and only a small fraction actually accumulates there. Work continues in this area and tumor-associated antigens can be targets for specific antibody reagents.
Date: August 8, 2001
Creator: Schlyer, D. J.
Object Type: Article
System: The UNT Digital Library
The Oak Ridge Isochronous Cyclotron: Enhancements to ORNL's HRIBF Driver Accelerator (open access)

The Oak Ridge Isochronous Cyclotron: Enhancements to ORNL's HRIBF Driver Accelerator

None
Date: August 8, 2001
Creator: Tatum, BA
Object Type: Article
System: The UNT Digital Library
INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES (open access)

INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California, through the testing and application of advanced reservoir characterization and thermal production technologies. The hope is that successful application of these technologies will result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs, …
Date: August 8, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library