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Geothermal Materials Development, Annual Report FY 1991 (open access)

Geothermal Materials Development, Annual Report FY 1991

Advances in the development of new materials, the commercial availabilities of which are essential for the attainment of Hydrothermal Category Level I and II Objectives, continue to be made in the Geothermal Materials Development Project. Many successes have already been accrued and the results used commercially. In FY 1991, utility company sponsored full cost'' recovery programs based upon materials technology developed in this project were initiated on topics such as condensing heat exchangers, high temperature composites for utility vaults used in district heating systems, and corrosion resistant coatings for use in oil-fired electric generating processes. In FY 1991 the DOE/GD-sponsored R D project was focused on reducing well drilling, fluid transport and energy conversion costs. Specific activities being performed included lightweight CO{sub 2}- resistant well cements, chemical systems for lost circulation control, thermally conductive and scale resistant protective linear systems, corrosion mitigation in process components at The Geysers, and elastomer-metal bonding systems needed for use in high temperature well drilling and safety related applications.
Date: December 1, 1991
Creator: Kukacka, L. E.
System: The UNT Digital Library
NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts (open access)

NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts

The primary objective of the project is to examine the relations between the catalytic and magnetic properties of the copper-cobalt higher alcohol synthesis catalysts. We have undertaken to investigate the magnetic character by studying the Nuclear Quadrupole resonance of copper and (Zerofield) Nuclear Magnetic Resonance of cobalt in copper cobalt catalysts.
Date: December 17, 1991
Creator: unknown
System: The UNT Digital Library
UNLV Information Science Research Institute quarterly progress report (open access)

UNLV Information Science Research Institute quarterly progress report

This report presents research on information systems, information retrieval, and optical character recognition. (CBS)
Date: December 31, 1991
Creator: Nartker, T.A.
System: The UNT Digital Library
Nitrogen control of chloroplast development and differentiation (open access)

Nitrogen control of chloroplast development and differentiation

The growth and development of plants and photosynthetic microorganisms is commonly limited by the availability of nitrogen. Our work concerns understanding the mechanisms by which plants and algae that are subjected to nitrogen deprivation alter the composition of photosynthetic membranes and enzymes involved in photosynthetic carbon metabolism. Toward these ends, we study biosynthetic and gene expression processes in the unicellular green alga Chlamydomonas reinhardtii which is grown in an ammonium-limited continuous culture system. We have found that the expression of nuclear genes, including those encoding for light-harvesting proteins, are severely repressed in nitrogen-limited cells whereas, in general, chloroplast protein synthesis is attenuated primarily at the level of mRNA translation. Conversely, nitrogen deprivation appears to lead to enhanced synthesis of enzymes that are involved in starch and storage lipid deposition. In addition, as a possible means by which photosynthetic electron transport activities and ATP synthesis is sustained during chronic periods of nitrogen deprivation, thylakoid membranes become enriched with components for chlororespiration. Characterization of the chlororespiratory electron transport constituents, including cytochrome complexes and NAD(P)H dehydrogenase is a major current effort. Also, we are striving to isolate the genes encoding chlororespiration proteins toward determining how they and others that are strongly responsive to …
Date: December 1, 1991
Creator: Schmidt, G.W.
System: The UNT Digital Library
Unusual initial and final state effects in quantum chromodynamics (open access)

Unusual initial and final state effects in quantum chromodynamics

We have constructed a number of fundamental tests which can be used to probe discrete symmetries, and their possible violations, in the required new physics'' beyond the standard model. On-going experiments with unpolarized e{sup {minus}}e{sup +} collisions contain many events for the production-decay sequence e{sup {minus}}e{sup +} {yields} Z{degrees}, {gamma}* {yields} {tau}{sup {minus}}{tau}{sup +} {yields} (A{sup {minus}X}) (B{sup +}X). From the beam referenced spin-correlation function for this sequence, the photon and Z{degrees} boson couplings of the tau lepton can be completely measured. There are four distinct tests for CP/T violation in Z{degrees} {yields} {tau}{sup {minus}}{tau}{sup +}, and in {gamma}* {yields} {tau}{sup {minus}}{tau}{sup +}. The Lorentz structure of the associated helicity amplitudes is very simple. In other research programs, we are (1) continuing to investigate our proposal that partons be identified with nearly degenerate, coherent quark-gluon jet'' states, and are (2) investigating the novel consequences of q-analogue quantization of quantum fields, and of a completeness relation for the q-analogue coherent states.
Date: December 1, 1991
Creator: Nelson, C.A.
System: The UNT Digital Library
Lectures notes for introduction to environmental law (open access)

Lectures notes for introduction to environmental law

This four-hour overview course is designed to briefly describe the environmental law system. The course provides an overview that managers and technical people will find useful as a beginning course or a course that puts formerly taken detailed courses in perspective. The course begins by defining environmental law and describing the legal system that establishes compliance obligations. Then, all the major Environmental Acts such as The Water Pollution Control Act, The National Environmental Policy Act, Resource Conservation and Recovery Act (RCRA), and Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) are briefly described and interrelated. All the environmental DOE Orders, selected books, and other source material are referenced. Radioactive pollutants are not discussed; however, reference material is provided.
Date: December 1, 1991
Creator: Cadwell, J.J.
System: The UNT Digital Library
Conceptual strategy for design, implementation, and validation of a biomarker-based biomonitoring capability (open access)

Conceptual strategy for design, implementation, and validation of a biomarker-based biomonitoring capability

This document describes a strategy for defining specific objectives for biomarker studies and for designing and implementing a biomonitoring study that focuses on these objectives. In researching this subject, it became clear to the authors that the subject of biomarkers created a great deal of interest among scientists and regulators but that general acceptance of biomarkers as a tool for environmental protection was hampered by lack of a clear notion of how to develop and apply this approach. We intend this document to be a user's guide'' that lays out a logical scheme for applying biomarkers in environmental monitoring. In addition, laboratory and field research components needed to develop and validate fundamental understanding and interpretation of biomarker responses are also described, as is a strategy for evolution of a biomarker-based biomonitoring capability. The document is divided into sections intended to lead the reader to an understanding of how biomarkers can be developed and applied.
Date: December 1, 1991
Creator: McCarthy, J.F.; Halbrook, R.S. & Shugart, L.R.
System: The UNT Digital Library
Steam generator secondary pH during a steam generator tube rupture (open access)

Steam generator secondary pH during a steam generator tube rupture

The Nuclear Regulatory Commission requires utilizes to determine the response of a pressurized water reactor to a steam generator tube rupture (SGTR) as part of the safety analysis for the plant. The SGTR analysis includes assumptions regarding the partitioning of iodine between liquid and vapor in steam generator secondary. Experimental studies have determined that the partitioning of iodine in water is very sensitive to the pH. Based on this experimental evidence, the NRC requested the INEL to perform an analytical assessment of secondary coolant system (SCS) pH during an SGTR. Design basis thermal and hydraulic calculations were used together with industry standard chemistry guidelines to determine the SCS chemical concentrations during an SGTR. These were used as input to the Facility for Analysis of Chemical Thermodynamics computer system to calculate the equilibrium pH in the SCS at various discrete time during an SGTR. The results of this analysis indicate that the SCS pH decreases from the initial value of 8.8 to approximately 6.5 by the end of the transient, independent of PWR design.
Date: December 1, 1991
Creator: Adams, J. P. & Peterson, E. S.
System: The UNT Digital Library
Nonlinear evolution of resistive tearing mode instability with shear flow and viscosity (open access)

Nonlinear evolution of resistive tearing mode instability with shear flow and viscosity

The nonlinear evolution of the tearing mode instability with equilibrium shear flow is investigated via numerical solutions of the resistive magnetohydrodynamic equations. The two-dimensional simulations are in slab geometry, are periodic in the x-direction, and are initiated with solutions of the linearized MHD equations. The magnetic Reynolds number S was varied from 10{sup 2} to 10{sup 5}, a parameter V that measures the strength of the flow in units of the average Alfven speed was varied, and the viscosity as measured by the Reynolds number of S{sub v} satisfied S{sub v} > 10{sup 3}. When the shear flow is small (V < 0.3) the tearing mode saturates within one resistive time, while for larger flows the nonlinear saturation develops on a longer time scale. The two-dimensional spatial structure of both the flux function and the steam function distort in the direction of the equilibrium flow. The magnetic energy release decreased and the saturation time increased with V, for both small and large resistivity. The validity of the numerical solutions was tested by verifying that the total energy and the magnetic helicity were conserved. Total energy dissipation rate dE/dt decreases as the tearing mode approached its saturated state.
Date: December 1, 1991
Creator: Ofman, L.; Morrison, P.J. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies) & Steinolfson, R.S. (Southwest Research Inst., San Antonio, TX (United States). Dept. of Space Sciences)
System: The UNT Digital Library
Studies of Coupled Chemical and Catalytic Coal Conversion Methods (open access)

Studies of Coupled Chemical and Catalytic Coal Conversion Methods

The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.
Date: December 1, 1991
Creator: Stock, L. M.; Chatterjee, K.; Cheng, C.; Ettinger, M.; Flores, F.; Jiralerspong, S. et al.
System: The UNT Digital Library
The production of fuels and chemicals from food processing wastes using a novel fermenter separator (open access)

The production of fuels and chemicals from food processing wastes using a novel fermenter separator

During 1991, considerable progress was made on the waste utilization project. Two small Wisconsin companies have expressed an interest in promoting and developing the ICRS technology. Pilot plant sites at (1) Hopkinton, IA, for a sweet whey plant, and Beaver Dam WI, for an acid whey site have been under development siting ICRS operations. The Hopkinton, IA site is owned and operated by Permeate Refining Inc., who have built a batch ethanol plant across the street from Swiss Valley Farms cheddar cheese operations. Permeate from Swiss Valley is piped across to PRI. PRI has signed a contract to site a 300--500,000 gallon/yr to ICRS pilot plant. They feel that the lower labor, lower energy, continuous process offered by the ICRS will substantially improve their profitability. Catalytics, Inc, is involved with converting whey from a Kraft cream cheese operation to ethanol and yeast. A complete project including whey concentration, sterilization, and yeast growth has been designed for this site. Process design improvements with the ICRS focussed on ethanol recovery techniques during this year's project. A solvent absorption/extractive distillation (SAED) process has been developed which offers the capability of obtaining an anhydrous ethanol product from vapors off 3 to 9% ethanol solutions …
Date: December 1, 1991
Creator: Dale, M.C.; Venkatesh, K.V.; Choi, Hojoon; Moelhman, M.; Saliceti, L.; Okos, M.R. et al.
System: The UNT Digital Library
A comparison of dose and dose-rate conversion factors from the Soviet Union, United Kingdom, US Department of Energy, and the Idaho National Engineering Laboratory Fusion Safety Program (open access)

A comparison of dose and dose-rate conversion factors from the Soviet Union, United Kingdom, US Department of Energy, and the Idaho National Engineering Laboratory Fusion Safety Program

Several independent data sets of radiological dose and dose-rate conversion factors (DCF/DRCF) have been tabulated or developed by the international community both for fission and fusion safety purposes. This report compares sets from the US Department of Energy, the Soviet Union, and the United Kingdom with those calculated by the Idaho National Engineering Laboratory Fusion Safety Program. The objectives were to identify trends and potential outlying values for specific radionuclides and contribute to a future benchmark evaluation of the CARR computer code. Fifty-year committed effective dose equivalent factors were compared for the inhalation and ingestion pathways. External effective dose equivalent rates were compared for the air immersion and ground surface exposure pathways. Comparisons were made by dividing dose factors in the different data bases by the values in the FSP data base. Differences in DCF/DRCF values less than a factor of 2 were considered to be in good agreement and are likely due to the use of slightly different decay data, variations in the number of organs considered for calculating CEDE, and rounding errors. DCF/DRCF values that differed by greater than a factor of 10 were considered to be significant. These differences are attributed primarily to the use of different …
Date: December 1, 1991
Creator: Rood, A.S. & Abbott, M.L.
System: The UNT Digital Library
Buried Waste Integrated Demonstration Plan (open access)

Buried Waste Integrated Demonstration Plan

This document presents the plan of activities for the Buried Waste Integrated Demonstration (BWID) program which supports the environmental restoration (ER) objectives of the Department of Energy (DOE) Complex. Discussed in this plan are the objectives, organization, roles and responsibilities, and the process for implementing and managing BWID. BWID is hosted at the Idaho National Engineering Laboratory (INEL), but involves participants from throughout the DOE Complex, private industry, universities, and the international community. These participants will support, demonstrate, and evaluate a suite of advanced technologies representing a comprehensive remediation system for the effective and efficient remediation of buried waste. The processes for identifying technological needs, screening candidate technologies for applicability and maturity, selecting appropriate technologies for demonstration, field demonstrating, evaluation of results and transferring technologies to environmental restoration programs are also presented. This document further describes the elements of project planning and control that apply to BWID. It addresses the management processes, operating procedures, programmatic and technical objectives, and schedules. Key functions in support of each demonstration such as regulatory coordination, safety analyses, risk evaluations, facility requirements, and data management are presented.
Date: December 1, 1991
Creator: Kostelnik, K.M.
System: The UNT Digital Library
Publications on maglev technologies (open access)

Publications on maglev technologies

Magnetically levitated passenger-transportation vehicles, using attractive and repulsive magnetic forces, are currently in the development or prototype-revenue stages in Japan and Germany. The basic principles of these technologies have been understood for several decades, but their practical applications awaited advances in high-power electronic devices, modern controls, superconducting magnets, and improvements in our transportation infrastructures. A considerable amount of work was devoted to magnetic-levitation (maglev) transportation system in the late 1960s and the 1970s. Detailed development was sustained primarily in Germany and Japan. This listing of publications was begun as the initial phase of a design study for a maglev development facility sponsored by the State of Illinois. The listing has been continually updated under programs sponsored by the Federal Railroad Administration and the US Army Corps of Engineers. In 1991, the National Maglev Initiative issued 27 contracts for the study of technical issues related to maglev and four contracts for the definition of maglev systems. In December 1991, the Intermodal Surface Transportation Efficiency Act was enacted, mandating the development of a US-designed maglev system in a six-year period. This listing is offered as an aid to those working on these projects, to help them locate technical papers on relevant technologies. …
Date: December 1, 1991
Creator: He, J. L.; Coffey, H. T.; Rote, D. M. & Wang, Z.
System: The UNT Digital Library
US Photovoltaic Patents, 1988--1990 (open access)

US Photovoltaic Patents, 1988--1990

This document contains US patents on terrestrial photovoltaic (PV) power applications, including systems, components, and materials, as well as manufacturing and support functions. The patent entries in this document were issued from 1988 through 1990. The entries were located by searching USPA, the data base of the US Patent Office. The final search retrieved all patents under the class Batteries, Thermoelectric and Photoelectric'' and the subclasses Photoelectric,'' Testing,'' and Applications.'' The search also located patents that contained the words photovoltaic(s)'' or solar cell(s)'' and their derivatives. A manual search of the patents in the Solar Energy Research Institute (SERI) patent file augmented the data base search. After the initial list was compiled, most of the patents on the following subjects were excluded: space photovoltaic technology, use of the photovoltaic effect for detectors and subjects only peripherally concerned with photovoltaics. Some patents on these three subjects were included when it appeared that those inventions might be of use in terrestrial PV power technologies.
Date: December 1, 1991
Creator: unknown
System: The UNT Digital Library
Augmented Fish Health Monitoring; Volume 2. Completion Report. (open access)

Augmented Fish Health Monitoring; Volume 2. Completion Report.

The Bonneville Power Administration (BPA) initiated the Augmented Fish Health Monitoring project in 1986. This project was a five year interagency project involving fish rearing agencies in the Columbia Basin. Participating agencies included: Washington Department of Fisheries (WDF), Oregon Department of Fish and Wildlife, Idaho Department of Fish and Game, and the US Fish and Wildlife Service (USFWS). This is the final data report for the Augmented Fish Health Monitoring project. Data collected and sampling results for 1990 and 1991 are presented within this report. An evaluation of this project can be found in Augmented Fish Health Monitoring, Volume 1, Completion Report.'' May, 1991. Pathogen detection methods remained the same from methods described in Augmented Fish Health Monitoring, Annual Report 1989,'' May, 1990. From January 1, 1990 to June 30, 1991 fish health monitoring sampling was conducted. In 1990 21 returning adult stocks were sampled. Juvenile pre-release exams were completed on 20 yearling releases, and 13 sub-yearling releases in 1990. In 1991 17 yearling releases and 11 sub-yearling releases were examined. Midterm sampling was completed on 19 stocks in 1990. Organosomatic analysis was performed at release on index station stocks; Cowlitz spring and fall chinook, Lewis river early coho and …
Date: December 1, 1991
Creator: Michak, Patty
System: The UNT Digital Library
Development of advanced secondary zinc cells for power-source applications (open access)

Development of advanced secondary zinc cells for power-source applications

The general advantages of Zn/AgO batteries are high specific energy, high discharge rate capability, good charge acceptance, and low self-discharge rate. However, the principal disadvantages of high cost and short cycle life have limited the use of this battery to applications where high specific energy is the prime requisite, such as military and flight applications, portable electronic equipment, etc. The major objectives of this research project are to improve the Zn/AgO cell cycle life and increases its performance. The redistribution of Zn active material (shape change) and the growth of Zn dendrites (which leads to cell shorting) have been identified as primary factors that limit the cycle-life performance of Zn/AgO cells. These phenomena can be largely overcome by improvements in separator materials, and by additives to the electrode and electrolyte. Recent development work on Zn/AgO cells has been concentrated in the area of Zn electrode and separator improvements to extend the lifetimes of cells.
Date: December 1, 1991
Creator: Chen, Jenn-Shing; McLarnon, F. R. & Cairns, E. J.
System: The UNT Digital Library
Reviews of computing technology: Fiber distributed data interface (open access)

Reviews of computing technology: Fiber distributed data interface

Fiber Distributed Data Interface, more commonly known as FDDI, is the name of the standard that describes a new local area network (LAN) technology for the 90's. This technology is based on fiber optics communications and, at a data transmission rate of 100 million bits per second (mbps), provides a full order of magnitude improvement over previous LAN standards such as Ethernet and Token Ring. FDDI as a standard has been accepted by all major computer manufacturers and is a national standard as defined by the American National Standards Institute (ANSI). FDDI will become part of the US Government Open Systems Interconnection Profile (GOSIP) under Version 3 GOSIP and will become an international standard promoted by the International Standards Organization (ISO). It is important to note that there are no competing standards for high performance LAN's so that FDDI acceptance is nearly universal. This technology report describes FDDI as a technology, looks at the applications of this technology, examine the current economics of using it, and describe activities and plans by the Information Resource Management (IRM) department to implement this technology at the Savannah River Site.
Date: December 1, 1991
Creator: Johnson, A.J.
System: The UNT Digital Library
Pacific Northwest Non-Residential/Commercial Energy Survey (PNNonRES) Final : Phases I and II, Descriptive Data Analysis Report. (open access)

Pacific Northwest Non-Residential/Commercial Energy Survey (PNNonRES) Final : Phases I and II, Descriptive Data Analysis Report.

The Pacific Northwest Nonresidential Energy Survey (PNNonRES) was a two-phase survey of nonresidential buildings in Idaho, Oregon, Washington, and Western Montana. In Phase 1, 15,250 nonresidential buildings, comprising a statistical sample of the population of nonresidential buildings in the Pacific Northwest, were enumerated. Phase 2, on-site surveys were conducted of a sample of 621 of the commercial buildings enumerated in Phase 1. In Phase 1, each building had a walk-by'' survey. In addition, the utility type (public, private) of each building was determined. In Phase 2, the Phase 1 information (except for type of development) was recollected. Information about the following additional characteristics was also collected for each building. Predominate fuel and equipment type used for heating, cooling, and water heating; heated, cooled, and refrigerated floor area; indoor and outdoor lighting capacity; and, wall, door, window, roof, and skylight area and material. In addition, partial surveys were conducted of the buildings sharing electric or gas service with each of the sampled buildings, and the electric and natural gas bills for each of the shared service areas'' were collected.
Date: December 1, 1991
Creator: BR Associates, Inc. & Administration., United States. Bonneville Power
System: The UNT Digital Library
The limnology of L Lake: Results of the L-Lake monitoring program, 1986--1989 (open access)

The limnology of L Lake: Results of the L-Lake monitoring program, 1986--1989

L Lake was constructed in 1985 on the upper regions of Steel Creek, SRS to mitigate the heated effluents from L Reactor. In addition to the NPDES permit specifications (Outfall L-007) for the L-Reactor outfall, DOE-SR executed an agreement with the South Carolina Department of Health and Environmental Control (SCDHEC), that thermal effluents from L-Reactor will not substantially alter ecosystem components in the approximate lower half of L Lake. This region should be inhabited by Balanced (Indigenous) Biological Communities (BBCs) in accordance with Section 316(a) of the Pollution Control (Clean Water) Act (Public Law 92-500). In response to this requirement the Environmental Sciences Section/Ecology Group initiated a comprehensive biomonitoring program which documented the development of BBCs in L Lake from January 1986 through December 1989. This report summarizes the principal results of the program with regards to BBC compliance issues and community succession in L Lake. The results are divided into six sections: water quality, macronutrients, and phytoplankton, aquatic macrophytes, zooplankton, benthic macroinvertebrates, fish, and community succession. One of the prime goals of the program was to detect potential reactor impacts on L Lake.
Date: December 15, 1991
Creator: Bowers, J.A.
System: The UNT Digital Library
Coal-fueled high-speed diesel engine development: Task 2, Market assessment and economic analysis (open access)

Coal-fueled high-speed diesel engine development: Task 2, Market assessment and economic analysis

Based on the preliminary coal engine design developed, this task was conducted to identify the best opportunity(s) to enter the market with the future coal-fueled, high-speed diesel engine. The results of this market and economic feasibility assessment will be used to determine what specific heavy duty engine application(s) are most attractive for coal fuel, and also define basic economic targets for the engine to be competitive.
Date: December 1, 1991
Creator: unknown
System: The UNT Digital Library
Development of an advanced continuous mild gasification process for the production of coproducts (open access)

Development of an advanced continuous mild gasification process for the production of coproducts

This document describes the results of Task 4 under which a 50 pound/hour char-to-carbon (CTC) process research unit (PRU) was designed in the second half of 1989, with construction completed in June 1990. The CTC PRU at Golden was operated for nearly one year during which 35 runs were completed for a total of nearly 800 hours of operation. Char methanation and carbon production reactor development activities are detailed in this report, as well as the results of integrated runs of the CTC process. Evaluation of the process and the carbon product produced is also included. It was concluded that carbon could be produced from mild gasification char utilizing the CTC process. Char methanation and membrane separation steps performed reasonably well and can scaled up with confidence. However, the novel directly heated reactor system for methane cracking did not work satisfactorily due to materials of construction and heat transfer problems, which adversely affected the quantity and quality of the carbon product. Alternative reactor designs are recommended.
Date: December 1, 1991
Creator: Jha, M. C.; McCormick, R. L.; Hogsett, R. F.; Rowe, R. M. & Anast, K. R.
System: The UNT Digital Library
Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers (open access)

Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a mud,'' sludge,'' or slurry''). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids).
Date: December 1, 1991
Creator: Shaw, M.E.
System: The UNT Digital Library
Intrinsic-surface-tag image authentication (open access)

Intrinsic-surface-tag image authentication

The objective of this work is to further the development of a unique treaty limited item (TLI) intrinsic surface tag for arms control applications. This tag's unique feature is the ability to capture the sub-micron scale topography of the TLI surface. The surface topography is captured by plastic castings of the surface as digitally imaged by an electron microscope. Tag authentication is accomplished by comparing digital castings images obtained in two different inspections. Surface replication experiments are described, as these experiments from the basis for the authentication algorithm. Both the experiments and the authentication algorithm are analyzed using the modulation transfer function. Recommendations for future improvements in tag authentication are also suggested by the modulation transfer function analysis. 4 refs.
Date: December 1, 1991
Creator: Palm, R.G. & DeVolpi, A.
System: The UNT Digital Library