Computation at the edge of chaos: Phase transition and emergent computation (open access)

Computation at the edge of chaos: Phase transition and emergent computation

In order for computation to emerge spontaneously and become an important factor in the dynamics of a system, the material substrate must support the primitive functions required for computation: the transmission, storage, and modification of information. Under what conditions might we expect physical systems to support such computational primitives This paper presents research on Cellular Automata which suggests that the optimal conditions for the support of information transmission, storage, and modification, are achieved in the vicinity of a phase transition. We observe surprising similarities between the behaviors of computations and systems near phase-transitions, finding analogs of computational complexity classes and the Halting problem within the phenomenology of phase-transitions. We conclude that there is a fundamental connection between computation and phase-transitions, and discuss some of the implications for our understanding of nature if such a connection is borne out. 31 refs., 16 figs.
Date: January 25, 1990
Creator: Langton, C.
Object Type: Article
System: The UNT Digital Library
HFBR: Review of the technical specifications against the FSAR (open access)

HFBR: Review of the technical specifications against the FSAR

The purpose of this review is to determine the adequacy of the High Flux Beam Reactor (HFBR) Technical Specifications for 40 MW operation by comparison with the HFBR Final Safety Analysis Report, particularly the accident analyses chapter. Specifically, the Technical Specifications were compared against the Design Basis Accident (DBA) Analyses presented in the Addendum to the HFBR FSAR for 60 MW Operation. The 60 MW DBA analyses was used since it is more current and complete than the analyses presented in the original FSAR which is considered obsolete. A listing of the required systems and equipment was made for each of the accidents analyzed. Additionally, the Technical Specification instrument setpoints were compared to the DBA analyses parametric values. Also included in this review was a comparison of the Technical Specification Bases against the FSAR and the identification of any differences. The HFBR Operations Procedures Manual (OPM) was also reviewed for any inconsistencies between the FSAR or the Technical Specifications. Upon completion of this review it was determined that the Technical Specifications are well written and the items commented on should not delay the low power restart (40 MW). Additionally, the OPM is also well written and does not require further …
Date: January 25, 1990
Creator: Rao, D. V.; Ross, S. B.; Claiborne, E. R.; Darby, J. L. & Clark, R. A.
Object Type: Report
System: The UNT Digital Library
Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys (open access)

Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys

This health and safety guide was written to satisfy two objectives: to summarize the toxicity of metals and alloys used in superconductivity for the benefit of those who work with these materials, and to summarize and describes the basic principles of a highly technical field from a health and safety point-of-view for the benefit of health professionals. The guide begins with a profile of the superconductivity industry, including a list of current and potential applications, a literature review of the market potential, and summary of the current industry status. The body of the paper provides a toxicity and hazard summary for 50 metals, alloys and metal oxides used in superconductivity. The toxicity and hazard summary for all 50 compounds includes: occupational exposure limits, explosiveness and flammability potential, LD{sub 50}'s, chemical and physical properties, incompatibilities and reactivities, recommended personal protective equipment, symptoms of acute and chronic exposure, target organs and toxic effects, and steps for emergency first aid. Finally, a discussion of general occupational hygiene principles is provided, with emphasis on how these principles apply to the unique field of superconductivity. 41 refs.
Date: April 25, 1990
Creator: Arnold, S. D. & Talley, G. M.
Object Type: Article
System: The UNT Digital Library
Status of the Relativistic Heavy Ion Collider (open access)

Status of the Relativistic Heavy Ion Collider

Accelerator Physics issues, such as the dynamical aperture, the beam lifetime and the current--intensity limitation are carefully studied for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The single layer superconducting magnets, of 8 cm coil inner diameter, satisfying the beam stability requirements have also been successfully tested. The proposal has generated wide spread interest in the particle and nuclear physics. 1 ref., 4 figs., 3 tabs.
Date: April 25, 1990
Creator: Lee, S. Y.
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: JM-1166 (open access)

Texas Attorney General Opinion: JM-1166

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Use of controlled substances as "bait" in a sting operation (RQ-1928)
Date: April 25, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1167 (open access)

Texas Attorney General Opinion: JM-1167

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Status of insurance programs in which applicants are referred, for a fee, to a single health care provider (RQ-1867)
Date: April 25, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
EMPACT: Electrons Muons Partons with Air Core Toroids (open access)

EMPACT: Electrons Muons Partons with Air Core Toroids

The EMPACT experiment utilizes a broad approach to maximize its discovery potential for new phenomena accessible at the SSC. The high resolution detector has a balances emphasis on, and large acceptance for, electrons, muons, jets, and noninteracting particles, and is capable of utilizing the ultimate luminosity of the SSC. The detector emphasizes excellent calorimetry augmented by TRD tracking, and employs an innovative system of superconducting air core toroids for muon measurements. Significant engineering effort has established the feasibility of a baseline detector concept and has addressed the related issues of support facilities, assembly, and detector integration. The design has been tested against the challenges of predicted phenomena, with the expectation that this will optimize the capacity for observing the unexpected. EMPACT's international collaboration has unprecedented support from major aerospace industries who are providing tools and expertise for project design and integration, which will assure that a detector optimized for performance and cost will be available for the first collisions at the new laboratory.
Date: May 25, 1990
Creator: Marx, M. D.
Object Type: Report
System: The UNT Digital Library
An expression of interest in a Super Fixed Target Beauty Facility (SFT) at the Superconducting Super Collider (open access)

An expression of interest in a Super Fixed Target Beauty Facility (SFT) at the Superconducting Super Collider

The concept of a Super Fixed Target Beauty Facility (SFT) which uses a relatively low intensity 20 TeV proton beam as a generator of very high momenta B's is an exciting prospect which is very competitive with other B factory ideas. The yields of B's in such a facility are quite high (3 {times} 10{sup 10} {yields} 10{sup 11} B's per year). At this level of statistics, CP violation measurements will be possible in many modes. In addition, the fixed target configuration, because of the high momenta of the produced B's and the resulting long decay lengths, facilitates the detection and reconstruction of B's and offers unique opportunities for observation of the B decays. The limited solid angle coverage required for the fixed target spectrometer makes the cost of the facility much cheaper than other e{sup +}e{sup {minus}} or hadron collider options under consideration. The relatively low intensity 20 TeV beam (1 {yields} 2 {times} 10{sup 8} protons/second) needed for the SFT makes it possible to consider an extraction system which operates concurrently and in a non-interfering manner with the other collider experiments. One possible method for generating such a beam, crystal channeling, is discussed.
Date: May 25, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A pipelined IC architecture for radon transform computations in a multiprocessor array (open access)

A pipelined IC architecture for radon transform computations in a multiprocessor array

The amount of data generated by CT scanners is enormous, making the reconstruction operation slow, especially for 3-D and limited-data scans requiring iterative algorithms. The Radon transform and its inverse, commonly used for CT image reconstruction from projections, are computationally burdensome for today's single-processor computer architectures. If the processing times for the forward and inverse Radon transforms were comparatively small, a large set of new CT algorithms would become feasible, especially those for 3-D and iterative tomographic image reconstructions. In addition to image reconstruction, a fast Radon Transform Computer'' could be naturally applied in other areas of multidimensional signal processing including 2-D power spectrum estimation, modeling of human perception, Hough transforms, image representation, synthetic aperture radar processing, and others. A high speed processor for this operation is likely to motivate new algorithms for general multidimensional signal processing using the Radon transform. In the proposed workshop paper, we will first describe interpolation schemes useful in computation of the discrete Radon transform and backprojection and compare their errors and hardware complexities. We then will evaluate through statistical means the fixed-point number system required to accept and generate 12-bit input and output data with acceptable error using the linear interpolation scheme selected. These …
Date: May 25, 1990
Creator: Agi, I.; Hurst, P.J. & Current, K.W. (California Univ., Davis, CA (USA). Dept. of Electrical Engineering and Computer Science)
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: LO90-29 (open access)

Texas Attorney General Opinion: LO90-29

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether the parties to a collective bargaining agreement entered into pursuant to the Fire and Police Employee Relations Act, article 5154c-1, V.T.C.S. (hereinafter, the act), may agree to the following provision: Each party for the term of this Agreement specifically waives the right to demand or petition for charges herein, whether or not the subjects were known to the parties at the time of execution hereof as proper subjects for Collective Bargaining.
Date: May 25, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Register, Volume 15, Number 40, Pages 2871-2935, May 25, 1990 (open access)

Texas Register, Volume 15, Number 40, Pages 2871-2935, May 25, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: May 25, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Workshop on heavy ion physics at the AGS: Outlook (open access)

Workshop on heavy ion physics at the AGS: Outlook

This report presents the closing talk of the workshop on AGS heavy ion program held at BNL March 5--7, 1990. The emphasis is on new questions posed by the new data presented at this meeting with emphasis on the pion-proton puzzle. 10 refs., 1 fig., 1 tab.
Date: May 25, 1990
Creator: Gyulassy, M.
Object Type: Article
System: The UNT Digital Library
Heavy metal contamination in TIMS Branch sediments (open access)

Heavy metal contamination in TIMS Branch sediments

The objective of this memorandum is to summarize results of previous sediment studies on Tims Branch and Steed's Pond conducted by Health Protection (HP) and by the Savannah River Laboratory (SRL) in conjunction with Reactor Materials Engineering Technology (RMET). The results for other heavy metals, such as lead, nickel, copper, mercury, chromium, cadmium, zinc, and thorium are also summarized.
Date: June 25, 1990
Creator: Pickett, J.B.
Object Type: Report
System: The UNT Digital Library
Heavy metal contamination in TIMS Branch sediments (open access)

Heavy metal contamination in TIMS Branch sediments

The objective of this memorandum is to summarize results of previous sediment studies on Tims Branch and Steed`s Pond conducted by Health Protection (HP) and by the Savannah River Laboratory (SRL) in conjunction with Reactor Materials Engineering & Technology (RMET). The results for other heavy metals, such as lead, nickel, copper, mercury, chromium, cadmium, zinc, and thorium are also summarized.
Date: June 25, 1990
Creator: Pickett, J. B.
Object Type: Report
System: The UNT Digital Library
Molecular iodine absolute frequencies. Final report (open access)

Molecular iodine absolute frequencies. Final report

Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was determined, hyperfine components were identified, and one well-resolved component was selected for precise determination of its absolute frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. Absolute frequency determinations were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the absolute measurement, the line classification, and a Doppler-free spectrum are given.
Date: June 25, 1990
Creator: Sansonetti, C. J.
Object Type: Report
System: The UNT Digital Library
Technical publication transfer test with McDonnell Aircraft Company: MIL-M-28001 (SGML) and MIL-D-28000 Class 1 (IGES) (open access)

Technical publication transfer test with McDonnell Aircraft Company: MIL-M-28001 (SGML) and MIL-D-28000 Class 1 (IGES)

The CALS Test Network (CTN) conducted a CTN Planned Test (CPT) of several CALS standards related to the transfer of technical publication data: MIL-STD-1840A (1840A), MIL-D-28000 Class I (28000), MIL-M-28001 (28001), and MIL-D-28003 (28003). The test was conducted with the McDonnell Aircraft Company (CMAIR) of St. Louis, Missouri in accordance with part one of CTN Test Plan CTN89-TM-06 and using material from an F-15E technical manual. One focus of the test was the transfer of a moderately large volume of technical publication data. There were 9 text files, 74 Initial Graphics Exchange Specification (IGES) files, and 74 Computer Graphics Metafile (CGM) files in the exchange package. A noteworthy feature of the test was its early attempt to exchange CGM data. Part one of CTN89-TM-06 called for technical publication data to be output from MCAIR's Xyvision system on 9-track magnetic tape. The data was to be in accordance with the 28001 subset of the Standard Generalized Mark-up Language (SGML) and the 28001 Document Type Definition (DTD) that conformed to MIL-M-38784B, the general style and format requirements for technical manuals. Technical illustrations in the manual were to be done in accordance with 28000 Class I (IGES) and 28003 (CGM). Part two of …
Date: June 25, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
(Fuel, fission product, and graphite technology) (open access)

(Fuel, fission product, and graphite technology)

Travel to the Forschungszentrum (KFA) -- Juelich described in this report was for the purpose of participating in the annual meeting of subprogram managers for the US/DOE Umbrella Agreement for Fuel, Fission Product, and Graphite Technology. At this meeting the highlights of the cooperative exchange were reviewed for the time period June 1989 through June 1990. The program continues to contribute technology in an effective way for both countries. Revision 15 of the Subprogram Plan will be issued as a result of the meeting. There was interest expressed by KFA management in the level of support received from the NPR program and in potential participation in the COMEDIE loop experiment being conducted at the CEA.
Date: July 25, 1990
Creator: Stansfield, O.M.
Object Type: Report
System: The UNT Digital Library
Real-space multiple scattering theory calculations of LEED (low-energy electron diffraction) intensities for stepped surfaces (open access)

Real-space multiple scattering theory calculations of LEED (low-energy electron diffraction) intensities for stepped surfaces

We use a newly developed real-space multiple scattering theory (RS-MST) to calculate low-energy electron diffraction (LEED) intensities from stepped surfaces. In this calculation the electron wavefunctions are expanded in terms of an angular momentum basis, utilizing the property of removal invariance of systems with semi-infinite periodicity. This strongly reduces the dependence of the calculation on the interlayer spacing and thus opens up the possibility of treating more open surfaces. This includes in particular stepped surfaces, to which conventional methods cannot be applied. Applications of the formalism to various stepped surfaces are presented. In particular, the results for Cu(311) and (331) surfaces obtained from both the layer doubling and RS-MST methods are compared. In addition, numerical techniques which can improve the convergence as well as the speed of the RS-MST approach are discussed. 6 refs., 3 figs.
Date: July 25, 1990
Creator: Zhang, X.-G.; Rous, P.J.; Van Hove, M.A. (Lawrence Berkeley Lab., CA (USA)); MacLaren, J.M. (Los Alamos National Lab., NM (USA)); Gonis, A. (Lawrence Livermore National Lab., CA (USA)) & Somorjai, G.A. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Chemistry)
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: JM-1190 (open access)

Texas Attorney General Opinion: JM-1190

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Exemption of lessees of the General Land Office from the permitting requirements for removal of sand, shell, gravel, or marl within state tidewater limits (RQ-1910)
Date: July 25, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1191 (open access)

Texas Attorney General Opinion: JM-1191

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Whether section 2(g) of article 6252-17, V. T. C. S., authorizes the school principal and school district superintendent to require a teacher's grievance to be heard in executive session (RQ- 2027)
Date: July 25, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Thermal analysis of the FSP-1 fuel pin irradiation test (open access)

Thermal analysis of the FSP-1 fuel pin irradiation test

Thermal analysis of a pin from the FSP-1 fuels irradiation test has been completed. The purpose of the analysis was to provide predictions of fuel pin temperatures, determine the flow regime within the lithium annulus of the test assembly, and provide a standardized model for a consistent basis of comparison between pins within the test assembly. The calculations have predicted that the pin is operating at slightly above the test design temperatures and that the flow regime within the lithium annulus is a laminar buoyancy driven flow. 7 refs., 5 figs.
Date: July 25, 1990
Creator: Lyon, W. F., III
Object Type: Article
System: The UNT Digital Library
Report of Foreign Travel of Environmental Sciences Research Staff, August-September 1990 (open access)

Report of Foreign Travel of Environmental Sciences Research Staff, August-September 1990

the travelers attended the Fifth International Congress of Ecology (INTECOL) in Yokohama, Japan, and two presented invited papers and chaired symposia. One traveler also attended the OJI International Seminar in Gifu, Japan and the Fukuoka Symposium on Theoretical Ecology in Fukuoka, Japan and presented invited papers. At these scientific gatherings, a large number of symposia and specific presentations were relevant to current research at Oak Ridge National Laboratory (ORNL), especially in the areas of landscape dynamics, plant physiology, and aquatic ecosystems.
Date: September 25, 1990
Creator: DeAngelis, Donald L.; Garten, Charles T., Jr. & Turner, Monica G.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 15, Number 73, Pages 5527-5625, September 25, 1990 (open access)

Texas Register, Volume 15, Number 73, Pages 5527-5625, September 25, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: September 25, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
(Biotechnology for the conversion of lignocellulosics) (open access)

(Biotechnology for the conversion of lignocellulosics)

This report summarizes the results of the traveler's participation in the International Energy Agency (IEA) Network planning meeting for Biotechnology for the Conversion of Lignocellulosics,'' held at the Institut Francais du Petrole (IFP), Rueil-Malmaison, France. It also summarizes the results of discussions held at Aston University, Birmingham, UK, with Dr. Martin Beevers with whom the traveler is attempting to initiate a collaborative research project that will be beneficial to ongoing research programs at Oak Ridge National Laboratory (ORNL). The itinerary for the trip is given in Appendix A; the names of the people contacted are listed in Appendix B. Also, pertinent information about the Institut Francais du Petrole is attached (Appendix C). 1 tab.
Date: October 25, 1990
Creator: Woodward, J.
Object Type: Report
System: The UNT Digital Library