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Hadron wavefunctions and structure functions in QCD

Description: Theoretical and empirical constraints on the hadron wave function and hadron structure functions are presented. In particular, a new type of low-energy theorem is obtained for the pion wave function from ..pi../sup 0/ ..-->.. ..gamma gamma... Thus the probability of finding the valence vertical bar q anti q > state is obtained. All these constraints allow construction of a possible model that describes hadron wavefunctions, probability amplitudes, and distributions. 3 figures.
Date: January 1, 1980
Creator: Huang, T.
Partner: UNT Libraries Government Documents Department

Aspects of computer control from the human engineering standpoint

Description: A Computer Control System includes data acquisition, information display and output control signals. In order to design such a system effectively we must first determine the required operational mode: automatic control (closed loop), computer assisted (open loop), or hybrid control. The choice of operating mode will depend on the nature of the plant, the complexity of the operation, the funds available, and the technical expertise of the operating staff, among many other factors. Once the mode has been selected, consideration must be given to the method (man/machine interface) by which the operator interacts with this system. The human engineering factors are of prime importance to achieving high operating efficiency and very careful attention must be given to this aspect of the work, if full operator acceptance is to be achieved. This paper will discuss these topics and will draw on experience gained in setting up the computer control system in Main Control Center for Stanford University's Accelerator Center (a high energy physics research facility). (In this complex system both open and closed loop computer controls are used, as well as large numbers of manual functions.)
Date: March 1, 1979
Creator: Huang, T.V.
Partner: UNT Libraries Government Documents Department

Response of secondary containment to presence of sodium and hydrogen

Description: As part of an effort to demonstrate that the risk to the public from extremely low probability events in liquid metal fast breeder reactors is bound within an acceptable envelope, containment pressurization by sodium and hydrogen was evaluated. Temperature and pressure histories are presented for typical sodium spray and pool fires and sodium vapor reactions. A review of mechanisms for hydrogen generation and recombination as well as limit for flammability and autocatalytic recombination is provided, and general containment design options to reduce risk are discussed.
Date: July 1, 1979
Creator: Gleikler, E.L. & Huang, T.C.
Partner: UNT Libraries Government Documents Department

Hadronic wave function in quantum chromodynamics

Description: The underlying link between hadronic phenomena in quantum chromodynamics at large and small distance is the hadronic wavefunction. The theoretical and empirical constraints on the hadronic wave-function and hadronic structure functions; the predictions of perturbative QCD for the large transverse momentum tail of the Fock state infinite momentum wavefunction psi (k/sub perpendicular to i/,x/sub i/,s/sub i/); the valence Fock state meson wavefunctions from the meson decay; the evolution equations of the distribution amplitudes; and a simplified model for the basic wavefunctions are presented. In particular, a new type of low energy theorem is obtained for the pion wavefunction from the ..pi../sup 0/ ..-->.. ..gamma gamma... This result, together with the constraint on the valence wavefunction from the ..pi../sup 0/ ..-->.. ..mu nu.. decay, leads to the probability of finding the valence vertical bar q anti q > state. All these constraints allow construction of a possible model which describes hadronic wavefunctions, probability amplitudes, and distributions. Results are compared with data for form factors and the deep inelastic processes. This work represents a first attempt to construct a model of hadronic structure which is consistent with data and QCD at large and small distances.
Date: January 1, 1980
Creator: Brodsky, S.J.; Huang, T. & Lepage, G.P.
Partner: UNT Libraries Government Documents Department

Quantum chromodynamics and hadronic interactions at short distances

Description: A brief introduction to QCD and asymptotic freedom is given. A new method to avoid scheme and scale ambiguities in perturbative QCD predictions is discussed. A detailed discussion of light-cone perturbation theory and the Fock state expansion of hadronic wavefunctions is given. The QCD equation of motion is also discussed. Measures of the hadronic wavefunction (form factors, magnetic moments, etc.), and the QCD analysis of high momentum transfer exclusive processes are discussed. It is also shown how meson distribution amplitudes can be measured in ..gamma gamma.. ..-->.. M anti M reactions. The connection of the Fock state basis to leading and higher twist contributions to deep inelastic scattering is given. How many different QCD processes are interelated through the hadronic Fock states is discussed, and a novel type of QCD subprocess - direct coupled hadron-induced reactions is considered. A new prediction for the proton form factor is also given. Also, a simple phenomenology of hadron wavefunctions is introduced, and present constraints on the form and normalization of the valence meson and nucleon Fock states are discussed. An important conclusion is that the valence Fock state as defined at equal time or the light cone appears to have a significantly smaller radius than that of the physical hadron; higher Fock states thus play an essential role in low momentum transfer phenomenology. Applications to quark jet diffraction excitation and the hidden heavy quark Fock state structure of hadrons are also discussed. 83 references. (WHK)
Date: January 1, 1981
Creator: Brodsky, S.J.; Huang, T. & Lepage, G.P.
Partner: UNT Libraries Government Documents Department

The new Metals and Alloys Indexes -- Search Manual: A phase diagram research tool

Description: A new Metals and Alloys (M&A) Indexes to the Powder Diffraction File (PDF) has been developed. These indexes will be immediately useful to material scientists because the indexes share many features with references such as Hansen, Elliot, Shunk, Pearson, and Villars and Calvert. These indexes, as contained in the Search Manual, may be used independently or in conjunction with the Powder Diffraction File. The book contains four indexes: two contain data for all materials in the M&A PDF, and two contain supporting data. The permuted-sort Alphabetical Formula Index brings together all entries containing a given element in alphabetical formula order. It has n entries for an n-component material and a straight-line format for the element being sorted to simplify reading the index. Thus, chemical knowledge can make identifications easier. Further, within binary and ternary phase diagrams, phases are listed in compositional order to facilitate direct use in phase diagram research. The Pearson Symbol Code Index has entries arranged in order of the Pearson Symbol Code, hence one can find all the materials with a given structure, and if desired, compare their atomic contents and lattice parameters. The latter are in the standard Crystal Data setting to aid in structural comparisons. The Common Names Index cross-references common metallurgical names, such as austenite or cementite, to the appropriate PDF data. The Strukturbericht Symbol Index cross-references Strukturbericht Symbols and the equivalent Pearson Symbols and Structure Prototypes. Examples of the uses of this index in phase diagram research are given.
Date: December 31, 1993
Creator: Mueller, M. H.; Wallace, P. L.; Huang, T. C. & Dann, J. N.
Partner: UNT Libraries Government Documents Department

Post-implementation review of inadequate core cooling instrumentation

Description: Studies of Three Mile Island (TMI) accident identified the need for additional instrumentation to detect inadequate core cooling (ICC) in nuclear power plants. Industry studies by plant owners and reactor vendors supported the conclusion that improvements were needed to help operators diagnose the approach to or existence of ICC and to provide more complete information for operator control of safety injection, flow to minimize the consequences of such an accident. In 1980, the US Nuclear Regulatory Commission (NRC) required further studies by the industry and described ICC instrumentation design requirements that included human factors and environmental considerations. On December 10, 1982, NRC issued to Babcock and Wilcox (BandW) licensees' orders for Modification of License and transmitted to all pressurized water reactor (PWR) licensees Generic Letter 82-28 to inform them of the revised NRC requirements. The instrumentation requirements for detection of ICC include upgraded subcooling margin monitors (SMMs), upgraded core exit thermocouples (CETs), and installation of a reactor coolant inventory tracking system (RCITS).
Date: January 1, 1988
Creator: Anderson, J.L.; Anderson, R.L.; Hagen, E.W.; Morelock, T.C.; Huang, T.L. & Phillips, L.E.
Partner: UNT Libraries Government Documents Department

GRI methane chemistry program review meeting

Description: Methane is an important greenhouse gas which affects the atmosphere directly by the absorption and re-emission of infrared radiation as well as indirectly, through chemical interactions. Emissions of several important greenhouse gases (GHGS) including methane are increasing, mainly due to human activity. Higher concentrations of these gases in the atmosphere are projected to cause a decrease in the amount of infrared radiation escaping to space, and a subsequent warming of global climate. It is therefore vital to understand not only the causes of increased production of methane and other GHGS, but the effect of higher GHG concentrations on climate, and the possibilities for reductions of these emissions. In GRI-UIUC methane project, the role of methane in climate change and greenhouse gas abatement strategies is being studied using several distinct approaches. First, a detailed treatment of the mechanisms controlling each important methane source and sink, and hence the atmospheric concentration of methane, is being developed for use with the UIUC Integrated Science Assessment Model. The focus of this study is to resolve the factors which determine methane emissions and removal, including human population, land use, energy demand, global temperature, and regional concentrations of the hydroxyl radical, carbon monoxide, nitrous oxides, non-methane hydrocarbons, water vapor, tropospheric and stratospheric ozone.
Date: February 1, 1997
Creator: Dignon, J.; Grant, K.; Grossman, A.; Wuebles, D.; Brasseur, G.; Madronich, S. et al.
Partner: UNT Libraries Government Documents Department

The new metals and alloys compilation, a powerful materials analysis tool

Description: A new compilation of Metals and Alloys indexes of powder diffraction and structural data has been completed. This compilation is designed to make characterization of metallic and related nonmetallic materialsl easier and more accurate. To achieve these goals, the existing Metals and Alloys Powder Diffraction File (M A PDF) contents were greatly increased to make the M A PDF contents similar to standard metallurgical references. Then six new indexes based on the M A PDF were developed.
Date: January 1, 1991
Creator: Wallace, P.L. (Los Alamos National Lab., NM (United States)); Calvert, L.D. (Calvert (L.D.), Lakes Entrance (Australia)) & Huang, T.C. (IBM Research Div., San Jose, CA (United States). Almaden Research Center)
Partner: UNT Libraries Government Documents Department