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Algebraic calculation of stroboscopic maps of ordinary, nonlinear differential equations
The relation between the parameters of a differential equation and corresponding discrete maps are becoming increasingly important in the study of nonlinear dynamical systems. Maps are well adopted for numerical computation and several universal properties of them are known. Therefore some perturbation methods have been proposed to deduce them for physical systems, which can be modeled by an ordinary differential equation (ODE) with a small nonlinearity. A new iterative, rigorous algebraic method for the calculation of the coefficients of a Taylor expansion of a stroboscopic map from ODE's with not necessarily small nonlinearities is presented. It is shown analytically that most of the coefficients are small for a small integration time and grow slowly in the course of time if the flow vector field of the ODE is polynomial and if the ODE has fixed point in the origin. Approximations of different orders respectively of the rest term are investigated for several nonlinear systems. 31 refs., 16 figs.
Date:
July 25, 1991
Creator:
Wackerbauer, R. (Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany)); Huebler, A. (Illinois Univ., Urbana, IL (United States). Center for Complex Systems Research) & Mayer-Kress, G. (Los Alamos National Lab., NM (United States) California Univ., Santa Cruz, CA (United States). Dept. of Mathematics)
Object Type:
Article
System:
The UNT Digital Library
Substitute safety rods: Physics design and NTG calibration
Under certain assumed accident conditions, an SRS reactor may loose most of its bulk moderator while maintaining flow to fuel assemblies. If this occurs immediately after operation at power, components normally dependent on convective heat transfer to the moderator will heat up with the possibility of melting that component. One component at risk is the safety rod. Tests have shown that the current cadmium safety rod, which contains aluminum as well as cadmium, can fail at temperatures only slightly in excess of 500 deg C. Computations indicate that such temperatures can be reached with operating powers well below the 50% power limit now imposed by other accident scenarios. Safety rod melting would thus establish a new lower operating limit. A substitute safety rod that could tolerate much higher temperatures would eliminate this limit. This memorandum details the physics characteristics of a suitable replacement rod. 7 refs.
Date:
July 1, 1991
Creator:
Baumann, N.P.
Object Type:
Report
System:
The UNT Digital Library
Hanford radiological protection support services annual report for 1990
Various Hanford site-wide radiation protection services provided by the Pacific Northwest Laboratory for the US Department of Energy-Richland Operations Office and Hanford contractors are described in this annual report for calendar year 1990. These activities include internal dosimetry measurements and evaluations, in vivo measurements, external dosimetry measurements and evaluations, instrument calibration and evaluation, radiation source calibration, and radiological records keeping. For each of these activities, the routine program, program changes and enhancements, associated tasks, investigations and studies, and related publications, presentations, and other staff professional activities are discussed as applicable. 22 refs., 10 figs., 19 tabs.
Date:
July 1, 1991
Creator:
Lyon, M; Bihl, D E; Fix, J J; Piper, R K; Freolich, T J; Leonowich, J A et al.
Object Type:
Report
System:
The UNT Digital Library
Modeling long-term collider performance
A model for the SSC arcs is described with multipole lattice field errors agglomerated into 32 lattice points, and with first order lattice errors and modulation provided by discrete transfer elements. Numerical solutions for long term dynamic aperture studies are obtained by multipole kick-drift tracking. The CPU time required to track through one turn is minimal, and comparable to that required to implement a one-turn fifth-order Taylor series map. Comparisons with tracking results using a fine grained representation of the lattice are made, and found to be satisfactory. The effects of tune modulation are studied and can substantially degrade long-term dynamic aperture. The effects of small relativistic momentum corrections, usually neglected for the large momenta at the SSC, are shown to have negligible influence on tracking results. 5 refs., 7 figs.
Date:
July 1, 1991
Creator:
Ritson, D. (Stanford Linear Accelerator Center, Menlo Park, CA (United States) Superconducting Super Collider Lab., Dallas, TX (United States))
Object Type:
Report
System:
The UNT Digital Library
Hanford Environmental Dose Reconstruction Project Monthly Report
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport; environmental monitoring data; demographics, agriculture, food habits; and environmental pathways and dose estimates. 2 figs., 2 tabs.
Date:
July 1, 1991
Creator:
Finch, S.M. (comp.)
Object Type:
Report
System:
The UNT Digital Library
The effect of limiter conditioning on the Tokamak Fusion Test Reactor edge plasma
Measurements by moveable Langmuir probes and edge spectroscopy diagnostics have documented the conditioning effect of low density helium-initiated discharge sequences on the Tokamak Fusion Test Reactor (TFTR) edge plasma. Langmuir probe measurements show in general that the edge electron density n{sub e} decreases by less than a factor of 2 while the edge electron temperature T{sub e} doubles. Radial profiles to the plasma boundary show that the density scrape-off length increases somewhat while the temperature scrape-off length decreases substantially. The particle flux density is unaffected. The spectral emission of C 2 decreases by a factor of 2, a much smaller change than that exhibited by the D{sub {alpha}} signal. These results complement previous accounts of the conditioning technique. Comparisons of these He conditioning measurements are made to edge measurements during a deuterium density scan experiment, showing many similarities, and to an existing edge model of the conditioning process, showing qualitative agreement. 20 refs., 5 figs.
Date:
July 1, 1991
Creator:
Kilpatrick, S. J.; Manos, D. M.; Nyberg, I.; Ramsey, A. T.; Stratton, B. C.; Timberlake, J. et al.
Object Type:
Article
System:
The UNT Digital Library
SERI Solar Radiation Resource Assessment Project: Fiscal Year 1990 Annual Progress Report
The purpose of the Solar Radiation Resource Project is to help meet the needs of the public, government, industry, and utilities for solar radiation data, models, and assessments as required to develop, design, deploy, and operate solar energy conversion systems. The project scientists produce information on the spatial (geographic), temporal (hourly, daily, and seasonal), and spectral (wavelength distribution) variability of solar radiation at different locations in the United States. Resources committed to the project in FY 1990 supported about four staff members, including part-time administrative support. With these resources, the staff must concentrate on solar radiation resource assessment in the United States; funds do not allow for significant efforts to respond to a common need for improved worldwide data. 34 refs., 21 figs., 6 tabs.
Date:
July 1, 1991
Creator:
Riordan, C.; Maxwell, E.; Stoffel, T.; Rymes, M. & Wilcox, S.
Object Type:
Report
System:
The UNT Digital Library
Department management of the Ross Aviation, Inc. , contract aircraft major spare parts inventory, Albuquerque, New Mexico
The purpose of this audit was to determine whether the Department of Energy's (Department) management of its contract with Ross Aviation, Inc. (Ross) provided reasonable assurance that the inventory of aircraft major spare parts at Ross was economical and efficient. The audit disclosed that approximately $447,000 (acquisition and interest carrying costs) of low-use major spare parts was excessive. Internal control deficiencies which fostered the excessive inventory included: (1) Ross had set stock levels without considering such factors as consumption or projected needs; and (2) the Department had not reviewed inventory quantities when appraising Ross' property management. The Albuquerque Operations Office (AL) agreed to take the corrective actions recommended in the report.
Date:
July 26, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Nuclear thermal rocket clustering: 1, A summary of previous work and relevant issues
A general review of the technical merits of nuclear thermal rocket clustering is presented. A summary of previous analyses performed during the Rover program is presented and used to assess clustering in the context of projected Space Exploration Initiative missions. A number of technical issues are discussed including cluster reliability, engine-out operation, neutronic coupling, shutdown core power generation, shutdown reactivity requirements, reactor kinetics, and radiation shielding. 7 refs., 3 figs., 2 tabs.
Date:
July 14, 1991
Creator:
Buksa, J.J. & Houts, M.G.
Object Type:
Article
System:
The UNT Digital Library
Separation of glycols from dilute aqueous solutions via complexation with boronic acids
This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.
Date:
July 1, 1991
Creator:
Randel, L. A. & King, C. J.
Object Type:
Report
System:
The UNT Digital Library
TAP 2, Performance-Based Training Manual
Training programs at DOE nuclear facilities should provide well- trained, qualified personnel to safely and efficiently operate the facilities in accordance with DOE requirements. A need has been identified for guidance regarding analysis, design, development, implementation, and evaluation of consistent and reliable performance-based training programs. Accreditation of training programs at Category A reactors and high-hazard and selected moderate-hazard nonreactor facilities will assure consistent, appropriate, and cost-effective training of personnel responsible for the operation, maintenance, and technical support of these facilities. Training programs that are designed and based on systematically job requirements, instead of subjective estimation of trainee needs, yield training activities that are consistent and develop or improve knowledge, skills, and abilities that can be directly related to the work setting. Because the training is job-related, the content of these programs more efficiently and effectively meets the needs of the employee. Besides a better trained work force, a greater level of operational reactor safety can be realized. This manual is intended to provide an overview of the accreditation process and a brief description of the elements necessary to construct and maintain training programs that are based on the requirements of the job. Two comparison manuals provide additional information to assist …
Date:
July 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Advanced Neutron Sources: Plant Design Requirements
The Advanced Neutron Source (ANS) is a new, world class facility for research using hot, thermal, cold, and ultra-cold neutrons. At the heart of the facility is a 350-MW{sub th}, heavy water cooled and moderated reactor. The reactor is housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides fans out into a large guide hall, housing about 30 neutron research stations. Office, laboratory, and shop facilities are included to provide a complete users facility. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory at the end of the decade. This Plant Design Requirements document defines the plant-level requirements for the design, construction, and operation of the ANS. This document also defines and provides input to the individual System Design Description (SDD) documents. Together, this Plant Design Requirements document and the set of SDD documents will define and control the baseline configuration of the ANS.
Date:
July 1, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Computer modeling of Y-Ba-Cu-O thin film deposition and growth
The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.
Date:
July 1, 1991
Creator:
Burmester, C.; Gronsky, R. (Lawrence Berkeley Lab., CA (United States)) & Wille, L. (Florida Atlantic Univ., Boca Raton, FL (United States). Dept. of Physics)
Object Type:
Article
System:
The UNT Digital Library
Determining surface profile from sequential interference patterns from a long trace profiler
The Long Trace Profiler (Takacs et al.) is a slope-measuring instrument which was introduced several years ago. Development of this instrument continues at Lawrence Berkeley Laboratory in improving both hardware design and software algorithms for turning the raw interference data (a sequence of intensity patterns) into properly interpreted representations of surface slope and height. This report presents a mathematical model of the interference pattern and methods of extracting the slope and height profile from such patterns. 9 refs.
Date:
July 1, 1991
Creator:
Irick, S.C.
Object Type:
Article
System:
The UNT Digital Library
Investigation of a constant gradient structure with constant iris size
Travelling wave accelerators can be built either with constant impedance or constant gradient structures. Whereas for the constant impedance case the geometry of the cells does not change, the iris size in a constant gradient structure is decreased from cell to cell in order to slow down the power flow of the incoming rf pulse by reducing the group velocity in order to achieve P'(z) = const. Changing the phase advance per cell for the accelerating wave from the beginning towards the end of the structure provides as well a constant power loss per unit length and has the additional advantage of equal iris diameters over the entire length of the travelling wave tube. Concerning short and long range wakefields, dark currents and mechanical demands, this type of constant gradient structure is discussed in comparison to the conventional one. 9 refs., 4 figs., 2 tabs.
Date:
July 1, 1991
Creator:
Holtkamp, N.
Object Type:
Report
System:
The UNT Digital Library
Studies on the development of mossy zinc electrodeposits from flowing alkaline electrolytes
The initiation and characteristics of mossy zinc electrodeposits have been investigated. Batteries with zinc electrodes are candidates for electric vehicle applications; however, this electrode is prone to form non-compact deposits that contribute to capacity loss and battery failure. Moss is deposited when the current density is far from the limiting current. This morphology first appears only after the bulk deposit is approximately 1 {mu}m thick. In this investigation, the effects of flow rate (Re=0--4000), current density (0--50 mA/cm{sup 2}), concentration of the electroactive species (0.25 and 0.5 M), and the concentration of supporting electrolyte (3, 6, and 12 M) on the initiation of moss were examined. The rotating concentric cylinder electrode was employed for most of the experiments; and a flow channel was used to study the development of morphology. After the experiment, the deposit was characterized using microscopic, x-ray diffraction, and profilometric techniques. 94 refs., 72 figs.
Date:
July 1, 1991
Creator:
Mc Vay, L.
Object Type:
Report
System:
The UNT Digital Library
Comparative sodium void effects for different advanced liquid metal reactor fuel and core designs
An analysis of metal-, oxide, and nitride-fueled advanced liquid metal reactor cores was performed to investigate the calculated differences in sodium void reactivity, and to determine the relationship between sodium void reactivity and burnup reactivity swing using the three fuel types. The results of this analysis indicate that nitride fuel has the least positive sodium void reactivity for any given burnup reactivity swing. Thus, it appears that a good design compromise between transient overpower and loss of flow response is obtained using nitride fuel. Additional studies were made to understand these and other nitride advantages. 8 refs., 5 figs., 3 tabs.
Date:
July 1, 1991
Creator:
Dobbin, K. D.; Kessler, S. F.; Nelson, J. V.; Gedeon, S. R. & Omberg, R. P.
Object Type:
Article
System:
The UNT Digital Library
Update to the RHIC Letter of Intent for an experiment on particle and jet production at midrapidity
This document is an Update to the Letter of Intent (LOI) submitted by this collaboration in September 1990 proposing a large acceptance solenoidal tracking experiment. Since that time the collaboration has chosen the name STAR, representing Solenoidal Tracker At RHIC. The physics interests of the STAR collaboration and the goals of the experiment are described in the original LOI. Since submission of the LOI, several changes have been made in the design of the experiment motivated by the desire to expand pseudorapidity coverage for complete event characterization and by the necessity to achieve cost reduction. The major changes are: Expansion of pseudorapidity coverage to {vert bar}{eta}{vert bar} < 4.5 by the addition of tracking chambers external to the magnet; reduction in the number of time-of-flight channels from 100K to 10K; staging implementation of hadronic calorimetry while using tracking and electromagnetic calorimetry to extract parton physics in the initial configuration; reduction in the cost per channel of Time Projection Chamber (TPC) electronics through continued TPC electronics R D supported from RHIC funds; and a change in the Silicon Vertex Tracker (SVT) technique to the use of silicon drift chambers. These changes and the status of ongoing R D programs to optimize …
Date:
July 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Electron energies in metals
The modern era of electron-electron interactions began a decade ago. Plummer's group initiated a program of using angular resolved photoemission to examine the band structure of the simple metals. Beginning with aluminum, and carrying on to sodium and potassium, they always found that the occupied energy bands were much narrower than expected. For example, the compressed energy bands for metallic potassium suggest a band effective mass of m* = 1.33m{sub e}. This should be compared to the band mass found from optical conductivity m*/m{sub e} = 1.01 {plus minus} 0.01. The discrepancy between these results is startling. It was this great difference which started my group doing calculations. Our program was two-fold. On one hand, we reanalyzed the experimental data, in order to see if Plummer's result was an experimental artifact. On the other hand, we completely redid the electron-electron self-energy calculations for simple metals, using the most modern choices of local-field corrections and vertex corrections. Our results will be reported in these lectures. They can be summarized as following: Our calculations give the same effective masses as the older calculations, so the theory is relatively unchanged; Our analysis of the experiments suggests that the recent measurements of band narrowing …
Date:
July 10, 1991
Creator:
Mahan, G.D. (Oak Ridge National Lab., TN (United States) Tennessee Univ., Knoxville, TN (United States). Dept. of Physics and Astronomy)
Object Type:
Article
System:
The UNT Digital Library
Photovoltaics: New opportunities for utilities
This publication presents information on photovoltaics. The following topics are discussed: Residential Photovoltaics: The New England Experience Builds Confidence in PV; Austin's 300-kW Photovoltaic Power Station: Evaluating the Breakeven Costs; Residential Photovoltaics: The Lessons Learned; Photovoltaics for Electric Utility Use; Least-Cost Planning: The Environmental Link; Photovoltaics in the Distribution System; Photovoltaic Systems for the Rural Consumer; The Issues of Utility-Intertied Photovoltaics; and Photovoltaics for Large-Scale Use: Costs Ready to Drop Again.
Date:
July 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
ITER divertor sputtering erosion -- recent analysis for carbon, beryllium, tungsten, and niobium surfaces
ITER divertor plate sputtering erosion has been analyzed using current design information and updated impurity transport models. The REDEP erosion/redeposition code was used to compute erosion for a very low plasma divertor temperature (T{sub e{sub 0}} {approx} 12 eV) physics phase reference'' case, and for other plasma conditions. A high surface temperature case (T{sub s{sub 0}} = 1800{degree}C) is analyzed for a carbon surface. Niobium is analyzed using WBC near-surface transport code results for the redeposited charge state. The REDEP results show high net erosion rates ({approx gt} 20 cm/burn{sm bullet}yr) for beryllium and carbon, even at low plasma temperatures. Net erosion rates are low to moderate for niobium ({approximately}0-3 cm/burn{sm bullet}yr), depending on plasma conditions, and low for tungsten ({approximately}0-0.2 cm/burn{sm bullet}yr). 9 refs., 2 figs.
Date:
July 1, 1991
Creator:
Brooks, J. N.
Object Type:
Report
System:
The UNT Digital Library
Overview of the first workshop on alpha particle physics in TFTR
The First Workshop on Alpha Physics in TFTR'' was held at the Princeton Plasma Physics Lab March 28--29, 1991. The motivation for this meeting was to clarify and strengthen the TFTR alpha physics program, and to increase the involvement of the fusion community outside PPPL in the TFTR D-T experiments. Therefore the meeting was sharply focused on alpha physics relevant to the upcoming TFTR D-T simulation, and was asked to devote half of his talk to specific TFTR issues. The Workshop consisted of 27 talks on: (1) experimental possibilities; (2) theoretical possibilities; (3) diagnostic possibilities; (4) relevance for future machines; and (5) discussion/summary session. This summary contains a brief sampling of the new results and ideas brought out by these talks, followed by two more general overviews of the status of experiment and theory.
Date:
July 1, 1991
Creator:
Zweben, S. J. & Biglari, H.
Object Type:
Article
System:
The UNT Digital Library
Electromagnetic field effects on cells of the immune system: The role of calcium signalling
During the past decade considerable evidence has accumulated demonstrating the exposures of cells of the immune system to relatively weak extremely-low-frequency (ELF) electromagnetic fields (< 300 Hz) can elicit cellular changes which might be relevant to in-vivo immune activity. However, knowledge about the underlying biological mechanisms by which weak fields induce cellular changes is still very limited. It is generally believed that the cell membrane and Ca{sup 2+} regulated activity is involved in bioactive ELF field-coupling to living systems. This article begins with a short review of the current state of knowledge concerning the effects of nonthermal levels of ELF electromagnetic fields on the biochemistry and activity of immune cells, and then closely examines new results which suggest a role for Ca{sup 2+} in the induction of these cellular field effects. Based on these findings it is proposed that membrane-mediated Ca{sup 2+} signalling processes are involved in the mediation of field effects on the immune system. 64 refs., 2 tabs.
Date:
July 1, 1991
Creator:
Walleczek, J.
Object Type:
Article
System:
The UNT Digital Library
Automatic network analyzer procedures for 5045 klystron cavities
This Note describes the results of using Automatic Network Analyzers in measuring SLAC 5045 klystron cavities. Two different analyzers were compared; the HP8753 and HP8510. Both analyzers have frequency synthesizer accuracy and stability to perform the measurement without the need for a frequency counter. The klystron has six cavities which can be put into three categories; input, gain and output. The input and output cavities require an external Q measurement (Qe) to determine coupling ({beta}) and center frequency (f{sub o}). The gain cavities require a resonant frequency measurement only.
Date:
July 1, 1991
Creator:
Judkins, J.G.
Object Type:
Report
System:
The UNT Digital Library