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Construction Report
56
Texas Department of Transportation Contract Reports
56
Texas Register
34
San Antonio Monthly Reports
28
Space Nuclear Safety and Fuels Program Progress Report
27
San Antonio Board of Adjustment Monthly Report
26
San Antonio Board of Review for Historic Districts and Landmarks Monthly Report
26
San Antonio Monthly Permit Report
26
San Antonio Monthly Minimum Housing Report
23
San Antonio Monthly Report of Demolitions
23
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1987 calibration of the TFTR neutron spectrometers
The {sup 3}He neutron spectrometer used for measuring ion temperatures and the NE213 proton recoil spectrometer used for triton burnup measurements were absolutely calibrated with DT and DD neutron generators placed inside the TFTR vacuum vessel. The details of the detector response and calibration are presented. Comparisons are made to the neutron source strengths measured from other calibrated systems. 23 refs., 19 figs., 6 tabs.
Date:
December 1, 1989
Creator:
Barnes, C.W.; Strachan, J.D. (Los Alamos National Lab., NM (USA) & Princeton Univ., NJ (USA). Plasma Physics Lab.)
Object Type:
Report
System:
The UNT Digital Library
Activation of methane by transition metal-substituted aluminophosphate molecular sieves
Recent experiments in our laboratory have demonstrated that aluminophosphate molecular sieves substituted with cobalt and cobalt/silicon combinations and having the AlPO{sub 4}-34 or AlPO{sub 4}-5 structure activate methane starting at {approximately}350{degree}C. Between 400 and 500{degree}C the rate of methane conversion increases steadily with typical conversion efficiencies at 500{degree}C ranging from 15 to 60%. The cobalt and silicon substituted AlPO{sub 4}-34 structure (CoAPSO-34) produces ethylene, ethane, propylene, and propane in varying proportions, depending on reactions conditions. The cobalt-substituted AlPO{sub 4}-5 (CoAPSO-5) produces propylene in very high yield with ethane, ethylene, and propane also seen. Analogous aluminophosphate molecular sieves substituted with magnesium or silicon, but containing no transition metal (e.g., SAPO-34, MAPO-5), do not activate methane under the conditions described above. The activation mechanism is based on reduction of the cobalt(III) form of the molecular sieve to the cobalt(II) form with accompanying oxidative dehydrogenation of the methane. Reoxidation of the cobalt(II) for to the cobalt(III) form can be done either chemically (e.g., using O{sub 2}) or electrochemically. 7 refs., 2 figs., 1 tab.
Date:
December 1, 1989
Creator:
Maroni, V A; Willms, K A; Nguyen, Hiephoa & Iton, L E
Object Type:
Article
System:
The UNT Digital Library
AEROPLT: A versatile general purpose plot program
AEROPLT is an interactive, user-friendly, general purpose plot code for plotting tabular data from multiple files. This DISSPLA-based code is convenient and easy to use while permitting great flexibility for users who want to customize their plots. A series of questions leads the user through the program and permits a return to specific portions of the code for plot refinement. Multidevice capability permits the user to plot on the terminal, write to a file for hardcopy plots, or do both simultaneously. An easily modified Setup File is used to store the terminal and hardcopy type codes, plot and text dimensions, and default plot specifications. Parameters for individual plots are written to a Restart File which can easily be edited to change subsequent plots. Additional capabilities are: color plots; a convenient method (similar to TEX) to implement all DISSPLA fonts, character sets, and math alphabets; superscripts, subscripts, underline, and italicize; and plots of the results of mathematical functions of the input data. 12 figs., 21 tabs.
Date:
December 1, 1989
Creator:
Larson, D. E. & Fuentes, M. K.
Object Type:
Report
System:
The UNT Digital Library
The Age of the Universe: Concordance
Arguments on the Age of the Universe, t{sub u}, are reviewed. The four independent age determination techniques are: dynamics (Hubble Age and deceleration); oldest stars (globular clusters); radioactive dating (nucleocosmochronology); and white dwarf cooling (age of the disk). While discussing all four, this review will concentrate more on nucleocosmochronology due in part to recent possible controversies there. It is shown that all four techniques are in general agreement, which is an independent argument in support of a catastrophic creation event such as the Big Bang. It is shown that the most consistent range of cosmological ages is for 12 {approx lt} t{sub u} {approx lt} 17Gyr. It is argued that the upper bound from white dwarf cooling is only {approximately}10Gyr due to the disk of the Galaxy probably forming several Gyr after the Big Bang itself. Only values of the Hubble constant, H{sub 0} {approx lt} 60km/sec/Mpc, are consistent with the other age arguments if the universe is at its critical density. An interesting exception to this limit is noted for the case of a domain wall dominated universe where ages as large as 2/H{sub 0} are possible. 42 refs., 1 fig., 1 tab.
Date:
December 1, 1989
Creator:
Schramm, D. N.
Object Type:
Article
System:
The UNT Digital Library
Amorphous silicon detectors in positron emission tomography
The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list …
Date:
December 1, 1989
Creator:
Conti, M. & Perez-Mendez, V.
Object Type:
Report
System:
The UNT Digital Library
Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum
On March 6, 1980, the US Department of Energy (DOE) and the Ministry of Energy and Mines of Venezuela (MEMV) entered into a joint agreement which included analysis of heavy crude oils from the Venezuelan Orinoco oil belt.The purpose of this report is to present compositional data and describe new analytical methods obtained from work on the Cerro Negro Orinoco belt crude oil since 1980. Most of the chapters focus on the methods rather than the resulting data on Cerro Negro oil, and results from other oils obtained during the verification of the method are included. In addition, published work on analysis of heavy oils, tar sand bitumens, and like materials is reviewed, and the overall state of the art in analytical methodology for heavy fossil liquids is assessed. The various phases of the work included: distillation and determination of routine'' physical/chemical properties (Chapter 1); preliminary separation of >200{degree}C distillates and the residue into acid, base, neutral, saturated hydrocarbon and neutral-aromatic concentrates (Chapter 2); further separation of acid, base, and neutral concentrates into subtypes (Chapters 3-5); and determination of the distribution of metal-containing compounds in all fractions (Chapter 6).
Date:
December 1, 1989
Creator:
Carbognani, L.; Hazos, M.; Sanchez, V.; Green, J. A.; Green, J. B.; Grigsby, R. D. et al.
Object Type:
Report
System:
The UNT Digital Library
Analytical Chemistry Laboratory progress report for FY 1989
The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1989 (October 1988 through September 1989). The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques.
Date:
December 1, 1989
Creator:
Green, D. W.; Heinrich, R. R.; Graczyk, D. G.; Lindahl, P. C. & Erickson, M. D.
Object Type:
Report
System:
The UNT Digital Library
Annual status report on the Uranium Mill Tailings Remedial Action Program
This eleventh annual status report summarizes activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project undertaken during Fiscal Year (FY) 1989 by the US Department of Energy (DOE) and other agencies. Project goals for FY 1990 are also presented. An annual report of this type was a statutory requirement through January 1, 1986, pursuant to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95--604. The DOE will continue to submit an annual report through project completion in order to inform the public of yearly project status. Title I of the UMTRCA authorizes the DOE, in cooperation with affected states and Indian tribes within whose boundaries designated uranium processing sites are located, to provide a program of assessment and remedial action at such sites. The purpose of the remedial action is to stabilize and control the tailings and other residual radioactive materials located on the inactive uranium processing sites in a safe and environmentally sound manner and to minimize or eliminate potential radiation health hazards. Commercial and residential properties in the vicinity of designated processing sites that are contaminated with material from the sites, herein referred to as vicinity properties,'' are also eligible for remedial …
Date:
December 1, 1989
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Aspects of incompressibility
The nuclear matter incompressibility K{sub {infinity}} (usually called the compressibility'' for some reason lost in antiquity) has been receiving an increasing amount of attention lately. Quite a spirited discussion is underway between groups who favor rather low values for use in simulations of supernova explosions, those who favor much higher values for the explanation of certain measurements in high-energy nuclear collisions, and many others who favor various intermediate values. The purpose of this paper is to present some preliminary results concerning the value of K{sub {infinity}} arising from a statistical model of macroscopic nuclear properties that is currently under development by Wladek Swiatecki and myself. This model, which is described in the next section, is meant to serve as a replacement for the traditional Liquid Drop Model and Droplet Model and their various extensions. It is itself an extension of the Thomas-Fermi approach of Seyler and Blanchard. However, it is important to note that we do not regard this approach as a poor approximation to Hartree-Fock, but rather as a vast improvement over the traditional LDM type approaches with their obvious limitations for light nuclei, at the drip lines, for large deformations, and other extreme situations such as large amounts …
Date:
December 1, 1989
Creator:
Myers, W.D.
Object Type:
Article
System:
The UNT Digital Library
Assessment of susceptibility of Type 304 stainless steel to intergranular stress corrosion cracking in simulated Savannah River Reactor environments
Intergranular stress corrosion cracking (IGSCC) of Type 304 stainless steel rate tests (CERT) of specimens machined was evaluated by constant extension from Savannah River Plant (SRP) decontaminated process water piping. Results from 12 preliminary CERT tests verified that IGSCC occurred over a wide range of simulated SRP envirorments. 73 specimens were tested in two statistical experimental designs of the central composite class. In one design, testing was done in environments containing hydrogen peroxide; in the other design, hydrogen peroxide was omitted but oxygen was added to the environment. Prediction equations relating IGSCC to temperature and environmental variables were formulated. Temperature was the most important independent variable. IGSCC was severe at 100 to 120C and a threshold temperature between 40C and 55C was identified below which IGSCC did not occur. In environments containing hydrogen peroxide, as in SRP operation, a reduction in chloride concentration from 30 to 2 ppB also significantly reduced IGSCC. Reduction in sulfate concentration from 50 to 7 ppB was effective in reducing IGSCC provided the chloride concentration was 30 ppB or less and temperature was 95C or higher. Presence of hydrogen peroxide in the environment increased IGSCC except when chloride concentration was 11 ppB or less. Actual …
Date:
December 1, 1989
Creator:
Ondrejcin, R.S. & Caskey, C.R. Jr.
Object Type:
Report
System:
The UNT Digital Library
Assessment of susceptibility of Type 304 stainless steel to intergranular stress corrosion cracking in simulated Savannah River Reactor environments
Intergranular stress corrosion cracking (IGSCC) of Type 304 stainless steel rate tests (CERT) of specimens machined was evaluated by constant extension from Savannah River Plant (SRP) decontaminated process water piping. Results from 12 preliminary CERT tests verified that IGSCC occurred over a wide range of simulated SRP envirorments. 73 specimens were tested in two statistical experimental designs of the central composite class. In one design, testing was done in environments containing hydrogen peroxide; in the other design, hydrogen peroxide was omitted but oxygen was added to the environment. Prediction equations relating IGSCC to temperature and environmental variables were formulated. Temperature was the most important independent variable. IGSCC was severe at 100 to 120C and a threshold temperature between 40C and 55C was identified below which IGSCC did not occur. In environments containing hydrogen peroxide, as in SRP operation, a reduction in chloride concentration from 30 to 2 ppB also significantly reduced IGSCC. Reduction in sulfate concentration from 50 to 7 ppB was effective in reducing IGSCC provided the chloride concentration was 30 ppB or less and temperature was 95C or higher. Presence of hydrogen peroxide in the environment increased IGSCC except when chloride concentration was 11 ppB or less. Actual …
Date:
December 1, 1989
Creator:
Ondrejcin, R. S. & Caskey, C. R. Jr.
Object Type:
Report
System:
The UNT Digital Library
An automated procedure for covariation-based detection of RNA structure
This paper summarizes our investigations into the computational detection of secondary and tertiary structure of ribosomal RNA. We have developed a new automated procedure that not only identifies potential bondings of secondary and tertiary structure, but also provides the covariation evidence that supports the proposed bondings, and any counter-evidence that can be detected in the known sequences. A small number of previously unknown bondings have been detected in individual RNA molecules (16S rRNA and 7S RNA) through the use of our automated procedure. Currently, we are systematically studying mitochondrial rRNA. Our goal is to detect tertiary structure within 16S rRNA and quaternary structure between 16S and 23S rRNA. Our ultimate hope is that automated covariation analysis will contribute significantly to a refined picture of ribosome structure. Our colleagues in biology have begun experiments to test certain hypotheses suggested by an examination of our program's output. These experiments involve sequencing key portions of the 23S ribosomal RNA for species in which the known 16S ribosomal RNA exhibits variation (from the dominant pattern) at the site of a proposed bonding. The hope is that the 23S ribosomal RNA of these species will exhibit corresponding complementary variation or generalized covariation. 24 refs.
Date:
December 1, 1989
Creator:
Winker, S.; Overbeek, R.; Woese, C. R.; Olsen, G. J. & Pfluger, N.
Object Type:
Report
System:
The UNT Digital Library
B physics theory
The status of the theoretical predictions for loop decays, strategy for precise determination of Vub and the issue of symmetric versus asymmetric machine for a B factory were discussed in the working group. While from our present perspective observation of CP violation appears as the most prominent goal for a B factory, the importance and richness of other B physics was stressed. 23 refs.
Date:
December 1, 1989
Creator:
Soni, A. (Brookhaven National Lab., Upton, NY (USA). Physics Dept.)
Object Type:
Article
System:
The UNT Digital Library
Camas Creek (Meyers Cove) Anadromous Species Habitat Improvement: Annual Report 1989.
Historical agricultural practices and natural events contributed to severe degradation of riparian zones and instream fish habitat in the Meyers Cove area of Camas Creek. In 1984, Salmon National Forest personnel began implementing specific management activities in riparian areas and the stream channel to accelerate habitat recovery. In 1987--88, 4.3 miles of fence was constructed establishing a riparian livestock exclosure in the Meyers Cove area of Camas Creek. One end-gap and two water-crossing corridors were constructed in 1989 to complete the fence system. The riparian exclosure has been fertilized with phosphorous-rich fertilizer to promote root growth. A stream crossing ford was stabilized with angular cobble. Streambank stabilization/habitat cover work was completed at three sites and three additional habitat structures were placed. Extensive habitat inventories were completed to identify quality/quantity of habitat available to anadromous fish. The work accomplished was designed to promote natural revegetation of the riparian area to improve rearing habitat cover and streambank stability. Streambank work was limited to extremely unstable sites. Enhancement activities will improve spawning, incubation, and rearing habitat for wild populations of steelhead trout and chinook salmon. Anadromous species population increases resulting from these enhancement activities will provide partial compensation for downstream losses resulting from …
Date:
December 1, 1989
Creator:
Hardy, Terry
Object Type:
Report
System:
The UNT Digital Library
Cesium capsule thermal analysis
Double-walled stainless steel capsules, produced by the Hanford Waste Encapsulation and Storage Facility (WESF), were designed to facilitate storage of radioactive cesium chloride (CsCl). The capsules were later determined to be a useful resource for irradiation facilities (IFs), and are currently being used at several commercial IFs. A capsule at one of these facilities recently failed, resulting in a release of the CsCl. A thermal analysis of a WESF capsule was performed by Pacific Northwest Laboratory (PNL) at the request of Westinghouse Hanford Company. In this analysis, parametric calculations demonstrates the impact that various parameters have on the temperature distribution within a capsule in a commercial irradiation facility. Specifically, the effect of varying the gas gap conductivity, the exterior heat sink temperatures, the exterior heat transfer distribution, the stainless steel emissivity, and the gamma heating rate were addressed. In addition, a calculation was performed to estimate the highest temperatures likely to have been encountered in one of these capsules. 8 refs., 17 figs., 4 tabs.
Date:
December 1, 1989
Creator:
Eyler, L.L. & Dodge, R.E.
Object Type:
Report
System:
The UNT Digital Library
Characterization and supply of coal-based fuels. Quarterly report, August 1, 1989--October 31, 1989
Under the Department of Energy`s Combustor Technology Program, combustor contractors are developing combustor systems for use in residential, commercial, light industrial and industrial retrofit markets. Well-characterized coal based fuels possessing appropriate specifications are required by the contractors for their developmental test programs. Fuels may be dry pulverized or micronized coal or coal-water fuels. In support of these equipment development efforts, Energy International is providing such fuels. A complete list of all of the delivered fuels,the quantities and users are provided in the Appendix. Their fuel needs ranged from small sample quantities (e.g. 5 to 500 lbs.) up to 15 tons per delivery; by now most no longer need fuel. During the twelfth quarter of this contract (August 1, 1989 through October 31, 1989) the primary activities were involved with: (1) Continuation of the procurement, preparation and delivery of coal-based fuels for the combustor contractors. (2) Continuation of the interaction with combustor contractors in order to update their fuel specifications, fuel requirements and delivery schedules. (3) Continuation of the quality control activities to insure that fuel specifications are being met and to determine the cause of any problem which might occur. (4) Issuance of a request-for-bid (Procurement {number_sign}MN-01-2003) for deep cleaning …
Date:
December 1, 1989
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Characterization of U. S. energy resources and reserves
This report provides a comprehensive overview of the best available estimates of the total domestic energy potential within the United States. The array of energy sources include those appropriate for power generation, liquid fuels, and direct heat applications. The energy sources examined are: geothermal energy, solar energy, biomass energy, wind energy, shale oil, coal, petroleum, natural gas, peat, uranium, and hydropower. 37 refs., 7 figs., 59 tabs.
Date:
December 1, 1989
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Characterizing source regions with signal subspace methods: Theory and computational methods
A mathematical approach is developed for empirically characterizing a given source region using waveforms from a collection of calibration events. A region is considered to be adequately characterized if the waveforms from any event in the source region can be represented as a linear combination of calibration event waveforms. The purpose of such characterizations is to build waveform recognizers'' for specific regions for precision location applications, and to provide a means of separating superimposed waveforms from multiple events in different source regions. The particular form of characterization used is insensitive to variations in the source time function and to anything but changes from the normal range of source mechanisms encountered in the source region. The standard waveform correlation coefficient used to estimate event clustering is generalized to estimate separation between single events and event clusters, and between two clusters of events. The generalized correlation coefficient is insensitive to variations in source time function and, to some extent, mechanism. The statistics of waveform correlation coefficients are developed, and show that conventional estimates made from single station data are often developed for network or array data removes the ambiguity. 23 refs., 4 figs.
Date:
December 1, 1989
Creator:
Harris, D. B.
Object Type:
Report
System:
The UNT Digital Library
Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations
Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfactory health outcomes. However, several categories of delayed sequelae of stereotactic radiosurgery have been identified, involving the vascular structures essential for the integrity of the brain tissue and the brain parenchyma directly. These categories reflect both reaction to injury and to alterations in regional hemodynamic status, and include vasogenic edema, occlusion of functional vasculature, radiation necrosis, and local or remote effects on cerebral arterial aneurysms. 10 refs., 7 figs., 1 tab.
Date:
December 1, 1989
Creator:
Levy, R. P.; Fabrikant, J. I.; Frankel, K. A.; Phillips, M. H.; Steinberg, G. K.; Marks, M. P. et al.
Object Type:
Article
System:
The UNT Digital Library
Clinical Results of Stereotactic Heavy-Charged-Particle Radiosurgery for Intracranial Angiographically Occult Vascular Malformations
Angiographically occult vascular malformations (AOVMs) of the brain have been recognized for many years to cause neurologic morbidity and mortality. They generally become symptomatic due to intracranial hemorrhage, focal mass effect, seizures or headaches. The true incidence of AOVMs is unknown, but autopsy studies suggest that they are more common than high-flow angiographically demonstrable arteriovenous malformations (AVMs). We have developed stereotactic heavy-charged-particle Bragg peak radiosurgery for the treatment of inoperable intracranial vascular malformations, using the helium ion beams at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron and Bevatron. This report describes the protocol for patient selection, radiosurgical treatment planning method, clinical and neuroradiologic results and complications encountered, and discusses the strengths and limitations of the method. 10 refs., 1 fig.
Date:
December 1, 1989
Creator:
Levy, R. P.; Fabrikant, J. I.; Phillips, M. H.; Frankel, K. A.; Steinberg, G. K.; Marks, M. P. et al.
Object Type:
Article
System:
The UNT Digital Library
Clinical results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory
The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. Since then, over 800 patients have received stereotactically-directed plateau-beam heavy-charged particle pituitary irradiation at this institution. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of these treatments. 11 refs.
Date:
December 1, 1989
Creator:
Levy, R. P.; Fabrikant, J. I.; Lyman, J. T.; Frankel, K. A.; Phillips, M. H.; Lawrence, J. H. et al.
Object Type:
Article
System:
The UNT Digital Library
Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory
The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory. 11 refs.
Date:
December 1, 1989
Creator:
Levy, R. P.; Fabrikant, Jacob I.; Lyman, J. T.; Frankel, K. A.; Phillips, M. H.; Lawrence, J. H. et al.
Object Type:
Article
System:
The UNT Digital Library
The Collective Vector method in nuclear and atomic physics
We present a brief review of the method of the Collective Vector (CV) and its use in conjunction with the Lanczos algorithm (LA). The combination of these two ideas produces a method for contracting super-large hamiltonians (up to 10{sup 6} {times} 10{sup 6}) by factors of 1000 or more. The contracted hamiltonians, which we call quasi-hamiltonians, typically have dimensions of the order of 10{sup 2} {times} 10{sup 2} and produce corresponding quasi-spectra with associated quasi-eigenfunctions which reproduce the features of the full microscopic spectrum thru the conservation of the spectral moments. Examples of applications to both nuclear and atomic physics are given demonstrating the convergence properties of the method. The application of the LA/CV approach to the problem of modelling nuclear level densities is described and finally we discuss the possibility of conjoining new collective models of nuclear structure with the LA/CV method. 13 refs., 4 figs.
Date:
December 1, 1989
Creator:
Bloom, S.D.
Object Type:
Article
System:
The UNT Digital Library
Combustion characterization of beneficiated coal-based fuels
This three-year research project at Combustion Engineering, Inc. (CE) will assess the potential economic and environmental benefits derived from coal beneficiation by various advanced cleaning processes. The objectives of this program include the development of a detailed generic engineering database, comprised of fuel combustion and ash performance data on beneficiated coal-based fuels (BCFs), which is needed to permit broad application. This technical database will provide detailed information on fundamental fuel properties influencing combustion and mineral matter behavior as well as quantitative performance data on combustion, ash deposition, ash erosion, particulate collection, and gaseous and particulate emissions. Program objectives also address the application of this technical database to predict performance impacts associated with firing BCFs in various commercial boiler designs as well as assessment of the economic implications of BCF utilization. Additionally, demonstration of this technology, with respect to large-scale fuel preparation, firing equipment operation, fuel performance, environmental impacts, and verification of prediction methodology, will be provided during field testing. Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for the field test. Approximately nine BCFs will be in dry ultra fine coal (DUC) form, and six BCFs will be …
Date:
December 1, 1989
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library