States

Quantitative Sub-Angstrom Imaging Through ADF STEM (open access)

Quantitative Sub-Angstrom Imaging Through ADF STEM

ORNL/CP-100163 Annular dark-field (ADF) imaging in a scanning transmission electron microscope (STEM) at atomic resolution provides an incoherent image that can be described as the convolution between the intensity of the illuminating STEM probe and an object function consisting of localised sources at the atomic-column positions. It has been shown that the resolution limit of the microscope limits the accuracy to which the object function can be reconstructed [1]. Here we demonstrate how a number of images recorded at various degrees of underfocus can be reconstructed to give sub- angstrom information, and discuss how quantitative physical measurements may be deduced from these images. The conventionally used optimum probe intensity profile for the VG Microscopes HB603U STEM (300 kV, C{sub 5}=l mm), shown in Fig. la, requires an objective aperture radius of 9 mrad and 40 nm of underfocus. However, using a larger aperture and a greater degree of underfocus can give a probe with a much narrower central maximum (Fig 1b), but at the expense of creating side-lobes with increased intensity. Since this probe contains sharper features than the conventionally optimum probe, information at much higher spatial frequencies can be recorded. Figure 2 shows information transfer down to a resolution …
Date: August 31, 1998
Creator: Nellist, P.D. & Pennycook, S.J.
Object Type: Article
System: The UNT Digital Library
Los Alamos National Laboratory environmental restoration program group audit report for underground storage tank removal: Audit ER-92- 04, July 22--August 11, 1992 (open access)

Los Alamos National Laboratory environmental restoration program group audit report for underground storage tank removal: Audit ER-92- 04, July 22--August 11, 1992

Audit ER-92-04 was conducted on activities being performed by Waste Management (EM-7), Environmental Protection (EM-8), and Environmental Restoration (EM-13) groups for the LANL`s underground storage tank removal program. Scope of the audit was limited to an evaluation of the implementation of the State of New Mexico requirements for underground storage-tank removal. Activities were evaluated using requirements specified in the State of New Mexico Environmental Improvement Board Underground Storage Tank Regulations, EIB/USTR. Two recommendations are made: (1) that a single organization be given the responsibility and authority for the implementation of the program, and (2) that the requirements of the NM State environmental improvement board underground storage tank regulations be reviewed and a Los Alamos procedure written to address requirements and interfaces not contained in SOP-EM7-D&D-001.
Date: August 31, 1992
Creator: Gillespie, P.F.
Object Type: Report
System: The UNT Digital Library
Disposal of Fluidized Bed Combustion Ash in an Underground Mine to Control Acid Mine Drainage and Subsidence (open access)

Disposal of Fluidized Bed Combustion Ash in an Underground Mine to Control Acid Mine Drainage and Subsidence

This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion (FBC) ash). Success will be measured in terms of technical feasibility of the approach (i.e. YO void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase Ill the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the spring of 1998 and monitored for following year. The second demonstration involves stowing 2000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during the winter of 1997. This document will report on progress made during Phase Ill. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase Ill tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. …
Date: August 31, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Pulse Combustor CRADA PC91-001 Final Report (open access)

Pulse Combustor CRADA PC91-001 Final Report

As outlined in the Cooperative Research and Development Agreement (CRADA) between BO Technical Developments, Ltd. (BO Tech) and the Pittsburgh Energy Technology Center (PETC) Coal Combustion Division, a BO Tech designed pulse-blade combustor was studied at PETC. Phase 1 involved limited tests of a single-blade pulsed-combustor module to evaluate the suitability of a gas-designed unit for firing coal for use in residential, commercial, or industrial sectors. During the course of the project, three different pulsed blade burners were designed and fabricated by BO Tech and subsequently delivered to PETC for evaluation. These units were designed to allow modification of the furnace dimensions, which would give PETC a means to take simple steps to improve coal firing performance is required. No major furnace design changes were to be included as part of the phase 1 activities.
Date: August 31, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Human Genome Project: Information access, management, and regulation. Final report (open access)

The Human Genome Project: Information access, management, and regulation. Final report

The Human Genome Project is a large, internationally coordinated effort in biological research directed at creating a detailed map of human DNA. This report describes the access of information, management, and regulation of the project. The project led to the development of an instructional module titled The Human Genome Project: Biology, Computers, and Privacy, designed for use in high school biology classes. The module consists of print materials and both Macintosh and Windows versions of related computer software-Appendix A contains a copy of the print materials and discs containing the two versions of the software.
Date: August 31, 1996
Creator: McInerney, J.D. & Micikas, L.B.
Object Type: Report
System: The UNT Digital Library
Multiphase Flow Modeling - Validation and Application CRADA MC94-019, Final Report (open access)

Multiphase Flow Modeling - Validation and Application CRADA MC94-019, Final Report

For the development and validation of multiphase flow modeling capability, a cooperative research and development agreement (CRADA) is in effect between Morgantown Energy Technology Center (METC) and Fluent Inc. To validate the Fluent multiphase model, several simulations were conducted at METC and the results were compared with the results of MFIX, a multiphase flow code developed at METC, and with experimental data. The results of these validation studies will be presented. In addition, the application of multiphase flow modeling will be illustrated by presenting the results of simulations of a filter back- flushing and a fluidized bed coal gasifier. These simulations were conducted only with MFIX, since certain features needed in these simulations will be available only in the next release of Fluent.
Date: August 31, 1995
Creator: Syamlal, Madhava & Nicoletti, Philip A.
Object Type: Report
System: The UNT Digital Library
Disposal of Fluidized Bed Combustion Ash in an Underground Mine to Control Acid Drainage and Subsidence. Quarterly report, June 1 - August 31, 1997 (open access)
Nontraditional inheritance: Genetics and the nature of science, now titled, The puzzle of inheritance: Genetics and the methods of science. Final report (open access)

Nontraditional inheritance: Genetics and the nature of science, now titled, The puzzle of inheritance: Genetics and the methods of science. Final report

This project led to the development of an instructional module designed for use in high school biology classes. The module contains two major components. The first is an overview for teachers, which introduces the module, describes the Human Genome Project, and addresses issues in the philosophy of science and some of the ethical, legal, and social implications of research in genetics. It provides a survey of fundamental genetics concepts and of new, nontraditional concepts of inheritance. The second component provides six instructional activities appropriate for high school or introductory college students.
Date: August 31, 1998
Creator: McInerney, J.D.
Object Type: Report
System: The UNT Digital Library
Confined combustion of TNT explosion products in air (open access)

Confined combustion of TNT explosion products in air

Effects of turbulent combustion induced by explosion of a 0.8 kg cylindrical charge of TNT in a 17 m<sup>3</sup> chamber filled with air, are investigated. The detonation wave in the charge transforms the solid explosive (C<sub>7</sub>H<sub>5</sub>N<sub>3</sub>O<sub>6</sub>) to gaseous products, rich (~20% each) in carbon dust and carbon monoxide. The detonation pressure (~210 kb) thereby engendered causes the products to expand rapidly, driving a blast wave into the surrounding air. The interface between the products and air, being essentially unstable as a consequence of strong acceleration to which it is subjected within the blast wave, evolves into a turbulent mixing layer-a process enhanced by shock reflections from the walls. Under such circumstances rapid combustion takes place where the expanded detonation products play the role of fuel. Its dynamic effect is manifested by the experimental measurement of ~3 bar pressure increase in the chamber, in contrast to ~1bar attained by a corresponding TNT explosion in nitrogen. The experiments were modeled as a turbulent combustion in an unmixed system at infinite Reynolds, Peclet and DamkGhler numbers. The CFD solution was obtained by a high-order Godunov scheme using an AMR (Adaptive Mesh Refinement) to trace the turbulent mixing on the computational grid in as …
Date: August 31, 1998
Creator: Chandler, J; Ferguson, R E; Forbes, J; Kuhl, A L; Oppenheim, A K & Spektor, R
Object Type: Article
System: The UNT Digital Library
Co-firing high sulfur coal with refuse derived fuels. Technical progress report No. 8, July 1996--August 1996 (open access)

Co-firing high sulfur coal with refuse derived fuels. Technical progress report No. 8, July 1996--August 1996

The objective of this study was to examine the possible formation of chlorinated organic compounds during the combustion of blends of refuse derived fuels (RDF) and coal under conditions similar to those of an atmospheric fluidized bed combustion (AFBC) system. A series of experiments were conducted using a TGA interfaced to FTIR. Additional experiments using a tube furnace preheated to AFBC operating temperatures were also conducted. The combustion products were cryogenically trapped and analyzed with a GC/MS system. The chlorination of phenols and the condensation reactions of chlorophenols were investigated in this study. A possible mechanism for the formation of chlorinated organic compounds such as dibenzodioxins and dibenzofurans, by chlorination and condensation reactions involving phenols, was proposed.
Date: August 31, 1996
Creator: Pan, Wei-Ping; Riley, J. T. & Lloyd, W. G.
Object Type: Report
System: The UNT Digital Library
Corrective Action Plan for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range, Nevada (open access)

Corrective Action Plan for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range, Nevada

This corrective action plan provides the closure implementation methods for the Area 3 Landfill Complex, Corrective Action Unit (CAU) 424, located at the Tonopah Test Range. The Area 3 Landfill Complex consists of 8 landfill sites, each designated as a separate corrective action site.
Date: August 31, 1998
Creator: Bechtel Nevada
Object Type: Report
System: The UNT Digital Library
Subgrid-scale model for the scalar dissipation rate in nonpremixed combustion (open access)

Subgrid-scale model for the scalar dissipation rate in nonpremixed combustion

A subgrid-scale model is presented for the scalar dissipation rate in nonpremixed turbulent reacting flows. Inputs to the model are the filtered density, the Favre- filtered temperature and the Favre-filtered misture-fraction. The model contains a coefficient which is determined by assuming a form for the scalar energy spectrum. Inputs to the presumed spectrum are the integral and dissipation length scales of the scalar field. These quantities are estimated locally from the Favre-filtered velocity field, resulting in a model coefficient which is spatially and temporally dependent. The model is tested a priori using data from a Direct Numerical Simulation (DXS) of a temporal reacting mixing layer. Estimated values of the dissipation rate are found in good agreement with dissipation rates computed directly from the DXS data. Furthermore, the presumed spectrum methodology is found to accurately predict the mean value of the model coefficient as well as its spatial and temporal variations.
Date: August 31, 1998
Creator: Bushe, W. K. & Cook, A. W.
Object Type: Article
System: The UNT Digital Library
Coal/Polymer Coprocessing with Efficient Use of Hydrogen. (open access)

Coal/Polymer Coprocessing with Efficient Use of Hydrogen.

The objective of the current research is to investigate the feasibility of coprocessing coal with waste polymers, with particular interest in employing the polymers as an alternate hydrogen source for coal upgrading and simultaneously recovering high valued fuels and chemicals from plastic waste. A chemical modeling approach was employed in which real and model feedstocks were used to identify the underlying reaction pathways, kinetics, and mechanisms controlling coal liquefaction in the presence of plastics and catalysts. Simple model systems were employed to facilitate product analysis and obtain information about the intrinsic reactivity. When reacted in binary mixtures, the conversion of tetradecane, a model compound of polyethylene, increased while the selectivities to primary products of 4-(naphthylmethyl) bibenzyl were enhanced. Experiments in the last six months in which the relative concentrations of the components were varied revealed that the effect was indeed a chemical one and not simply a result of dilution. An experimental protocol was developed to conduct experiments at elevated pressures more representative of coal liquefaction conditions. Preliminary experiments with real feedstocks allowed the extrinsic factors (i.e., diffusion limitations, solvent effects) to be identified. The combination of these two sets of experiments will ultimately be used to carry out process …
Date: August 31, 1997
Creator: Broadbelt, Linda J.
Object Type: Report
System: The UNT Digital Library
A probabilistic risk assessment of the LLNL Plutonium facility`s evaluation basis fire operational accident (open access)

A probabilistic risk assessment of the LLNL Plutonium facility`s evaluation basis fire operational accident

The Lawrence Livermore National Laboratory (LLNL) Plutonium Facility conducts numerous involving plutonium to include device fabrication, development of fabrication techniques, metallurgy research, and laser isotope separation. A Safety Analysis Report (SAR) for the building 332 Plutonium Facility was completed rational safety and acceptable risk to employees, the public, government property, and the environment. This paper outlines the PRA analysis of the Evaluation Basis Fire (EDF) operational accident. The EBF postulates the worst-case programmatic impact event for the Plutonium Facility.
Date: August 31, 1994
Creator: Brumburgh, G.
Object Type: Article
System: The UNT Digital Library
DOE Research Set-Aside Areas of the Savannah River Site (open access)

DOE Research Set-Aside Areas of the Savannah River Site

Designated as the first of seven National Environmental Research Parks (NERPs) by the Atomic Energy Commission (now the Department of Energy), the Savannah River Site (SRS) is an important ecological component of the Southeastern Mixed Forest Ecoregion located along the Savannah River south of Aiken, South Carolina. Integral to the Savannah River Site NERP are the DOE Research Set-Aside Areas. Scattered across the SRS, these thirty tracts of land have been set aside for ecological research and are protected from public access and most routine Site maintenance and forest management activities. Ranging in size from 8.5 acres (3.44 ha) to 7,364 acres (2,980 ha), the thirty Set-Aside Areas total 14,005 acres (5,668 ha) and comprise approximately 7% of the Site`s total area. This system of Set-Aside Areas originally was established to represent the major plant communities and habitat types indigenous to the SRS (old-fields, sandhills, upland hardwood, mixed pine/hardwood, bottomland forests, swamp forests, Carolina bays, and fresh water streams and impoundments), as well as to preserve habitats for endangered, threatened, or rare plant and animal populations. Many long-term ecological studies are conducted in the Set-Asides, which also serve as control areas in evaluations of the potential impacts of SRS operations …
Date: August 31, 1997
Creator: Davis, C. E. & Janecek, L. L.
Object Type: Report
System: The UNT Digital Library
Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical report, January 14, 1997--August 14, 1997 (open access)

Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical report, January 14, 1997--August 14, 1997

Research is presently being conducted to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The research will be accomplished by producing model cermet composites using powder metallurgy and electrodeposition methods in which the effect of ceramic/metal combination for the erosion and corrosion resistance will be determined. These results will provide the basis for determining the optimum hard phase constituent size and volume percent in thermal spray coatings. Thermal spray coatings will be applied by our industrial sponsor and tested in our erosion and corrosion laboratories. Bulk powder processed Ni-Al{sub 2}O{sub 3} composites were produced at Idaho National Engineering Laboratory. The composite samples contained 0, 21, 27, 37, and 45 volume percent Al{sub 2}O{sub 3} with an average particle size of 12 um. Also, to deposit model Ni-Al{sub 2}O{sub 3} coatings, an electrodeposition technique was developed and coatings with various volume fractions (0-35%) of Al{sub 2}O{sub 3} were produced. The powder and electrodeposition processing of Ni-Al{sub 2}O{sub 3} Composites provide the ability to produce two phase microstructure without changing the microstructure of the matrix material. Therefore, the effect of hard second phase particles size and volume fraction on …
Date: August 31, 1997
Creator: Schorr, B. S.; Levin, B. F.; DuPont, J. N. & Marder, A. R.
Object Type: Report
System: The UNT Digital Library
Economic Recovery of Oil Trapped at Fan Margins Using High Angle Wells and Multiple Hydraulic fractures. (open access)

Economic Recovery of Oil Trapped at Fan Margins Using High Angle Wells and Multiple Hydraulic fractures.

The long radius, near-horizontal well has been drilled and completion operations are in progress. Upon initial review of log data, two hydraulic fracture treatments were planned. However, the probability of the lower frac growing into thick sands previously swept by waterflood has called for additional information to be obtained prior to proceeding with hydraulic fracture treatments. Should permeabilities prove to be as favorable as some data indicate, produced water volumes could be excessively high. Prior to pumping the first frac, the well will be perforated and produced from lower pay intervals. These perfs will not impact future frac work. Rate data and pressure transient analysis will dictate the need for the lower frac.
Date: August 31, 1997
Creator: Laue, M.L.
Object Type: Report
System: The UNT Digital Library
A scoping study on the costs of indoor air quality illnesses:an insurance loss reduction perspective (open access)

A scoping study on the costs of indoor air quality illnesses:an insurance loss reduction perspective

The incidence of commercial buildings with poor indoor air quality (IAQ), and the frequency of litigation over the effects of poor IAQ is increasing. If so, these increases have ramifications for insurance carriers, which pay for many of the costs of health care and general commercial liability. However, little is known about the actual costs to insurance companies from poor IAQ in buildings. This paper reports on the results of a literature search of buildings-related, business and legal databases, and interviews with insurance and risk management representatives aimed at finding information on the direct costs to the insurance industry of poor building IAQ, as well as the costs of litigation. The literature search and discussions with insurance and risk management professionals reported in this paper turned up little specific information about the costs of IAQ-related problems to insurance companies. However, those discussions and certain articles in the insurance industry press indicate that there is a strong awareness and growing concern over the "silent crisis" of IAQ and its potential to cause large industry losses, and that a few companies are taking steps to address this issue. The source of these losses include both direct costs to insurers from paying health …
Date: August 31, 1998
Creator: Chen, Allan & Vine, Edward L.
Object Type: Report
System: The UNT Digital Library
Coal-fired high performance power generating system. Final report (open access)

Coal-fired high performance power generating system. Final report

As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved …
Date: August 31, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advanced Turbine Systems (ATS) program conceptual design and product development (open access)

Advanced Turbine Systems (ATS) program conceptual design and product development

Achieving the Advanced Turbine Systems (ATS) goals of 60% efficiency, single-digit NO{sub x}, and 10% electric power cost reduction imposes competing characteristics on the gas turbine system. Two basic technical issues arise from this. The turbine inlet temperature of the gas turbine must increase to achieve both efficiency and cost goals. However, higher temperatures move in the direction of increased NO{sub x} emission. Improved coatings and materials technologies along with creative combustor design can result in solutions to achieve the ultimate goal. GE`s view of the market, in conjunction with the industrial and utility objectives, requires the development of Advanced Gas Turbine Systems which encompass two potential products: a new aeroderivative combined-cycle system for the industrial market, and a combined-cycle system for the utility sector that is based on an advanced frame machine. The GE Advanced Gas Turbine Development program is focused on two specific products: (1) a 70 MW class industrial gas turbine based on the GE90 core technology utilizing an innovative air cooling methodology; (2) a 200 MW class utility gas turbine based on an advanced Ge heavy-duty machine utilizing advanced cooling and enhancement in component efficiency. Both of these activities required the identification and resolution of technical …
Date: August 31, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
An indirect sensing technique for diesel fuel quantity control. Progress report, April 1--June 30, 1998 (open access)

An indirect sensing technique for diesel fuel quantity control. Progress report, April 1--June 30, 1998

This reports on a project to develop an indirect sensing technique for diesel fuel quantity control. Development has continued on a vehicle-installed prototype for EPA certification and demonstration. Focus of development is on the use of this technology for retrofitting existing diesel vehicles to reduce emissions rather than exclusively upon deployment in the OEM market. Technical obstacles that have been encountered and their solutions and remaining project tasks are described.
Date: August 31, 1998
Creator: MacCarley, C. Arthur
Object Type: Report
System: The UNT Digital Library
Novel Explosively Driven Flying Plate System (open access)

Novel Explosively Driven Flying Plate System

The authors describe a new technique for driving thick flying plates to high velocities without spall and with excellent flatness over a uniformly large area.
Date: August 31, 1998
Creator: Forest, C. A.; Rabie, R. L.; Bennett, L. & Vorthman, J.
Object Type: Article
System: The UNT Digital Library
Dehydration project report (open access)

Dehydration project report

Catalytic Industrial Group became interested in the ability to use its catalytic infrared technology for the removal of moisture in substances after having had very positive experience in removing moisture from water-based coatings which are becoming increasingly popular as industry strives to comply with clean air mandates. The first attempts were crude but showed that the moisture could be removed, and intriguing enough that they started to think about a conveying-based system that would remove moisture from products. The initial tests were designed around sawdust. The authors felt that the market in particleboard and in the MDF board by itself justified the research into this concept. The Kansas Department of Health and Environment has been kept apprised of the on-going development of the infrared drying system by Catalytic Industrial Group. There were some early delays in the delivery of equipment needed to build the prototype machine. The design changes identified during the experimental phase of the development of the infrared dryer have been resolved and a process-testing device has been developed. This technical report outlines the progress made to date.
Date: August 31, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library