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Articles 3361 - 3390 of 3783

Full-Text Articles in Physical Sciences and Mathematics

Reducibility And A New Entropic Term In Multifragment Charge Distribution, A. Ferrero, I. Iori, A. Moroni, F. Petruzelli, R. Scardaoni, L. G. Moretto, D. R. Bowman, M. Bruno, P. Buttazzo, L. Celano, N. Colonna, M. D'Agostino, J. D. Dinius, M. L. Fiandri, E. Fuschini, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, G. J. Kunde, M. A. Lisa, W. G. Lynch, P. F. Mastinu, P. M. Milazzo, G. V. Margagliotti, C. P. Montoya, Graham F. Peaslee, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams Jan 1996

Reducibility And A New Entropic Term In Multifragment Charge Distribution, A. Ferrero, I. Iori, A. Moroni, F. Petruzelli, R. Scardaoni, L. G. Moretto, D. R. Bowman, M. Bruno, P. Buttazzo, L. Celano, N. Colonna, M. D'Agostino, J. D. Dinius, M. L. Fiandri, E. Fuschini, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, G. J. Kunde, M. A. Lisa, W. G. Lynch, P. F. Mastinu, P. M. Milazzo, G. V. Margagliotti, C. P. Montoya, Graham F. Peaslee, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams

Faculty Publications

The charge distributions and their dependence on fragment multiplicity have been studied for the multifragmentation of 30 MeV/nucleon Xe+Au, Cu. For both targets, the charge distributions are approximately independent of the fragment multiplicity n. However, a residual systematic dependence on n is detectable at the largest values of the total charge multiplicity Nc. Such n dependence obeys a simple scaling law and suggests the presence of an entropic term possibly related to the mechanism of multifragmentation. Thermal scaling between the different bins of Nc seems to occur.

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Evaporation Residue, Fission Cross Sections, And Linear Momentum Transfer For 14n Induced Reactions From 35a To 155a Mev, A. A. Sonzogni, A. Elmaani, C. Hyde-Wright, W. Jiang, D. Prindle, R. Vandenbosch, J. Dinius, G. Cron, D. Bowman, C. K. Gelbke, W. Hsi, G. Lynch, C. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang, C. Williams, R. De Souza, D. Fox, T. Moore Jan 1996

Evaporation Residue, Fission Cross Sections, And Linear Momentum Transfer For 14n Induced Reactions From 35a To 155a Mev, A. A. Sonzogni, A. Elmaani, C. Hyde-Wright, W. Jiang, D. Prindle, R. Vandenbosch, J. Dinius, G. Cron, D. Bowman, C. K. Gelbke, W. Hsi, G. Lynch, C. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang, C. Williams, R. De Souza, D. Fox, T. Moore

Faculty Publications

Differential cross sections for evaporation residues and fission fragments for 35A, 100A, 130A and 155A MeV N14 on targets ranging from Sm154 to Au197 have been measured. The angle-integrated cross sections are larger than what might be expected. The fission fragment-fission fragment folding angle correlations for 35A, 100A MeV N14 and 25AMeV O16 on similar targets were also measured. The average linear momentum transfer has been deduced from both the fission angle correlation and from the fore-aft asymmetry of the fission angular distributions in the laboratory system. The data are all consistent with a picture where pre-equilibrium particle emission removes …

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Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin Jan 1996

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …

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Measurement Of The Diffractive Cross Section In Deep Inelastic Scattering, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasinski, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam Jan 1996

Measurement Of The Diffractive Cross Section In Deep Inelastic Scattering, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasinski, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam

Faculty Publications

© Springer-Verlag 1996. Diffractive scattering of γ∗p → X + N, where N is either a proton or a nucleonic system with MN < 4 GeV has been measured in deep inelastic scattering (DIS) at HERA. The cross section was determined by a novel method as a function of the γ∗p c.m. energy W between 60 and 245 GeV and of the mass MX of the system X up to 15 GeV at average Q2 values of 14 and 31 GeV2. The diffractive cross section dσdi f f /dMX is, within errors, found to rise linearly with W. Parameterizing the W dependence by the form dσdi f f /dMX ∞ (W2)(2αIP - 2) the DIS data yield for the pomeron trajectory αIP = 1.23±0.02(stat)±0.04(syst) averaged over t in the measured kinematic range assuming the longitudinal photon contribution to be zero. This value for the pomeron trajectory is substantially larger than αIP extracted from soft interactions. The value of αIP measured in this analysis suggests that a substantial part of the diffractive DIS cross section originates from processes which can be described by perturbative QCD. From the measured diffractive cross sections the diffractive structure function of the proton F2D(3) (β,Q2, xIP) has been determined, where β is the momentum fraction of the struck quark in the pomeron. The form F2D(3) = constant·(1/xIP)a gives a good fit to the data in all β and Q2 intervals with a = 1.46 ± 0.04(stat) ± 0.08(syst).

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High-Sensitivity Absorption Spectroscopy In Fe Ii, Scott D. Bergeson, K. L. Mullman, J. E. Lawler Jan 1996

High-Sensitivity Absorption Spectroscopy In Fe Ii, Scott D. Bergeson, K. L. Mullman, J. E. Lawler

Faculty Publications

We report the first measurements of UV oscillator strengths (ƒ-values) in Fe II from a high-sensitivity absorption experiment developed at the University of Wisconsin. The accuracy of our measurements is demonstrated by our reproducing well-known ƒ-value ratios in Fe I and Fe II. The first laboratory ƒ-value measurement of the 160.845 nm transition in Fe II is presented and compared to values in the literature. While this paper focuses on Fe II, the high-sensitivity absorption method that we have developed is applicable to essentially every element in the periodic table, for both neutral and ionized species, over a broad range …

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Branching Fractions And Oscillator Strengths For Fe Ii Transitions From The 3d6(5D)4p Subconfiguration, Scott D. Bergeson, K. L. Mullman, M. E. Wickliffe, J. E. Lawler Jan 1996

Branching Fractions And Oscillator Strengths For Fe Ii Transitions From The 3d6(5D)4p Subconfiguration, Scott D. Bergeson, K. L. Mullman, M. E. Wickliffe, J. E. Lawler

Faculty Publications

New experimental branching fractions and transition probabilities are reported for 56 transitions in Fe II. The branching fractions are measured with a Fourier transform spectrometer and also with a high-resolution grating spectrometer on a n optically thin hollow cathode discharge. Highly accurate experimental radiative lifetimes from the recent literature provide the normalization required to convert our branching fractions into absolute transition probabilities. Results are compared with experimental and theoretical values in the literature. Our new transition probabilities will establish the absolute scale for relative absorption oscillator strengths of vacuum ultraviolet lines measured using a new high-sensitivity absorption experiment at the …

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Paracompact Subspaces In The Box Product Topology, Peter Nyikos, Leszek Piatkiwicz Jan 1996

Paracompact Subspaces In The Box Product Topology, Peter Nyikos, Leszek Piatkiwicz

Faculty Publications

No abstract provided.

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A New High Pressure Sapphire Nuclear Magnetic Resonance Cell, Shi Bai, Craig M. Taylor, Charles L. Mayne, Ronald J. Pugmire, David M. Grant Jan 1996

A New High Pressure Sapphire Nuclear Magnetic Resonance Cell, Shi Bai, Craig M. Taylor, Charles L. Mayne, Ronald J. Pugmire, David M. Grant

Faculty Publications

A new version of a single-crystal sapphire high pressure nuclear magnetic resonance (NMR) cell is described that is capable of controlling the sample pressure independent of the temperature. A movable piston inside the cell adjusts and controls the sample pressure from ambient conditions to 200 atm within plus or minus 0.3 atm. The linewidth at half-height for a 13C spectrum of carbon dioxide at 15degrees C and 57.8 atm is found to be 0.5 Hz. The carbon dioxide gas/liquid phase transition is clearly observed by measuring 13C chemical shifts as the sample pressure approaches equilibrium. The time required for this …

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Measurement Of Elastic Ω Photoproduction At Hera, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasiński, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi Jan 1996

Measurement Of Elastic Ω Photoproduction At Hera, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasiński, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi

Faculty Publications

No abstract provided.

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Model Equations From Gyrokinetic Theory For A Non-Neutral Plasma To Include Temperature Effects And Applications To A Plasma Of Infinite Length, S. Neil Rasband Jan 1996

Model Equations From Gyrokinetic Theory For A Non-Neutral Plasma To Include Temperature Effects And Applications To A Plasma Of Infinite Length, S. Neil Rasband

Faculty Publications

Gyrokinetic equations are derived for applications to non-neutral plasmas in constant, straight magnetic fields wherein E X B drift velocities are of the same order as thermal velocities. The ratio of the E X B rotation frequency to the cyclotron frequency and the ratio of the gyroradius to a plasma scale length are assumed to be of order epsilon and terms are retained in the gyrokinetic expansion to second order to include finite-Larmor-radius (FLR) effects. A mode equation is obtained for a non-neutral plasma in the infinite-length approximation. The singularities of this equation are compared and contrasted with the familiar …

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The Implications Of Turbidite-Driven Redox Changes In Sediments Of The Iberia Abyssal Plain, Timothy J. Shaw, P. A. Meyers Jan 1996

The Implications Of Turbidite-Driven Redox Changes In Sediments Of The Iberia Abyssal Plain, Timothy J. Shaw, P. A. Meyers

Faculty Publications

No abstract provided.

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Measurement Of The F2 Structure Function In Deep Inelastic E+P Scattering Using 1994 Data From The Zeus Detector At Hera, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasinski, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi Jan 1996

Measurement Of The F2 Structure Function In Deep Inelastic E+P Scattering Using 1994 Data From The Zeus Detector At Hera, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. R. Okrasinski, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi

Faculty Publications

We present measurements of the structure function F2 in e+p scattering at HERA in the range 3.5 GeV2 < Q2 < 5000 GeV2. A new reconstruction method has allowed a significant improvement in the resolution of the kinematic variables and an extension of the kinematic region covered by the experiment. At Q2 < 35 GeV2 the range in x now spans 6.3 · 10-5 < x < 0.08 providing overlap with measurements from fixed target experiments. At values of Q2 above 1000 GeV2 the x range extends to 0.5. Systematic errors below 5% have been achieved for most of the kinematic region. The structure function rises as x decreases; the rise becomes more pronounced as Q2 increases. The behaviour of the structure function data is well described by next-to-leading order perturbative QCD as implemented in the DGLAP evolution equations. © Springer-Verlag 1996.

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Seismogeological Features Of The Crust In Romania, V Mocanu, C Dinu, F Radulescu, M Diaconescu, Camelia C. Diaconescu, A Pompilian Jan 1996

Seismogeological Features Of The Crust In Romania, V Mocanu, C Dinu, F Radulescu, M Diaconescu, Camelia C. Diaconescu, A Pompilian

Faculty Publications

The Romanian area consists of old consolidated units of pre-Alpine age (the Moesian, Moldavian and Scythian platforms) and Alpine orogenic units (the Carpathian arc and North-Dobrudjan orogen). General seismogeological peculiarities of the pre-Alpine tectonic units are presented, as well as some structural characteristics of the Transylvanian Basin and the Pannonian Depression. Both shallow and deep seismic reflection/refraction data as well as log information and some potential field data were used for the investigation of the crustal structure. The varibility in the seismogeological pattern and crustal thickness shown by the different tectonic units is due to the differences in structure and …

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Multifragmentation In E/A=35 Mev Collisions: Evidence For A Coulomb Driven Breakup?, M. D'Agostino, G. J. Kunde, P. M. Milazzo, J. D. Diniu, M. Bruno, N. Colonna, M. L. Fiandri, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, W. C. Hsi, M. Huang, M. A. Lisa, W. G. Lynch, P. F. Mastinu, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams Dec 1995

Multifragmentation In E/A=35 Mev Collisions: Evidence For A Coulomb Driven Breakup?, M. D'Agostino, G. J. Kunde, P. M. Milazzo, J. D. Diniu, M. Bruno, N. Colonna, M. L. Fiandri, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, W. C. Hsi, M. Huang, M. A. Lisa, W. G. Lynch, P. F. Mastinu, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams

Faculty Publications

Multifragment disintegrations have been measured for central Au+Au collisions at EA=35 MeV. Fragment emission occurs predominantly at low center of mass energies of about EA≈5 MeV, consistent with a Coulomb dominated breakup of a single source. Mean fragment multiplicities of ⟨NIMF⟩≈10.8 are extracted after correction for the detection efficiency. The fragment charge distributions decrease much more gradually than expected from scaling laws recently applied to the extraction of critical exponents for the nuclear liquid-gas phase transition from nuclear collisions.

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Prompt And Sequential Decay Processes In The Fragmentation Of 40 Mev/A 20ne Projectiles, R. J. Charity, L. G. Sobotka, N. J. Robertson, D. G. Sarantites, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, W. C. Hsi, M. J. Huang, W. G. Lynch, C. P. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang Dec 1995

Prompt And Sequential Decay Processes In The Fragmentation Of 40 Mev/A 20ne Projectiles, R. J. Charity, L. G. Sobotka, N. J. Robertson, D. G. Sarantites, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, W. C. Hsi, M. J. Huang, W. G. Lynch, C. P. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang

Faculty Publications

The fragmentation of E/A=40 MeV Ne20 projectiles into exit channels containing only p, d, t, He3, α, He6, Li6, and Li7fragments has been investigated. Relative shifts between the average longitudinal velocity of each fragment type were measured with Sn120 and Au197 targets. A post-breakup Coulomb acceleration component of these shifts was isolated. Its magnitude indicates that the projectile broke up while in near contact with the target. On the other hand, correlations between projectile fragments indicate that a significant fraction of these fragments are produced by the sequential decay of long- and short-lived unstable intermediates. A fully sequential decay process, …

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Dynamics Of Binary Liquids In Pores, J.C. Lee Dec 1995

Dynamics Of Binary Liquids In Pores, J.C. Lee

Faculty Publications

A computer simulation is performed to study the dynamics of binary liquids in the pores of Vycor glasses. The pores are modeled with glass walls that form randomly interconnected tunnels. When the relaxation is probed with a particular wavelength, the time autocorrelation function depends on whether or not there is a significant periodic or quasiperiodic structure in the distribution of the walls with that wavelength. If there is not, the relaxation may be fitted as the sum of an exponential term and a nonexponential activated term. If there is, the relaxation shows a long-lasting tail that can be fitted by …

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Observation Of Beam-Induced Changes In The Polarization Of Balmer-Α Radiation Emitted Following Beam--Tilted-Foil Transmission, Wang Qi, David D. Allred, Larry V. Knight, Douglas L. Harper, Royal G. Albridge, Norman H. Tolk Dec 1995

Observation Of Beam-Induced Changes In The Polarization Of Balmer-Α Radiation Emitted Following Beam--Tilted-Foil Transmission, Wang Qi, David D. Allred, Larry V. Knight, Douglas L. Harper, Royal G. Albridge, Norman H. Tolk

Faculty Publications

Measurements of the circular polarization of Balmer-α radiation emitted by excited hydrogen atoms, following the transmission of (20-50)-keV protons through thin, tilted amorphous carbon foils, exhibit markedly unexpected behavior as a function of exposure of the foil to the proton beam. Specifically, the circular polarization changes from an initially well understood tilt-angle dependence to a behavior which, for low tilt angles, gives the opposite handedness of circular polarization from that predicted. In addition, the degree of alignment, indicated by the linear Stokes parameter M/I, is enhanced also as a function of dose. These changes in the tilt-angle dependence of the …

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Coincidence Correlations Between Light Charged Particles In The Matched Reactions 905 And 1030 Mev121sb + 27al And 550 And 750 Mev 86kr + 63cu, Winifred E. Parker, Morton Kaplan, David J. Moses, John M. Alexander, Roy B. Lacey, Dalva M. De Castro Rizzo, J. Bolger, A. Narayanan, Graham F. Peaslee, D. G. Popescu Nov 1995

Coincidence Correlations Between Light Charged Particles In The Matched Reactions 905 And 1030 Mev121sb + 27al And 550 And 750 Mev 86kr + 63cu, Winifred E. Parker, Morton Kaplan, David J. Moses, John M. Alexander, Roy B. Lacey, Dalva M. De Castro Rizzo, J. Bolger, A. Narayanan, Graham F. Peaslee, D. G. Popescu

Faculty Publications

Coincidence measurements have been made between and a second particle () produced in the reactions 905 and 1030 MeV and 550 and 750 MeV . All four of the reactions lead to composite systems of 149Tb∗ or 148Gd∗ which facilitates comparisons of matched reactions. In the two reactions and the 550 MeV reaction, the particle-particle coincidences are dominated by processes that lead to evaporation residues. In the 750 MeV reaction, about half of the 1H and 4He are associated with evaporation residue production. These particle-particle coincidences arise from cross sections that are subsets of the total evaporation residue cross sections. …

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Evidence For The Reducibility Of Multifragment Emission To An Elementary Binary Emission In Xe-Induced Reactions, K. Tso, L. Phair, A. Colonna, W. Skulski, G. J. Wozniak, L. G. Moretto, D. R. Bowman, M. Chartiet, C. K. Gelbke, W. G. Gong, W. C. Hsi, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, C. Schwarz, R. T. De Souza, M. B. Tsang, F. Zhu Nov 1995

Evidence For The Reducibility Of Multifragment Emission To An Elementary Binary Emission In Xe-Induced Reactions, K. Tso, L. Phair, A. Colonna, W. Skulski, G. J. Wozniak, L. G. Moretto, D. R. Bowman, M. Chartiet, C. K. Gelbke, W. G. Gong, W. C. Hsi, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, C. Schwarz, R. T. De Souza, M. B. Tsang, F. Zhu

Faculty Publications

Multifragmentation for 129Xe-induced reactions on several targets (natCu, 89Y, 165Ho, 197Au) has been studied at . The probability of emitting n intermediate mass fragments is shown to be binomial at each transversal energy and reducible to an elementary binary probability p. For each target and at each bombarding energy, p shows a thermal behavior as demonstrated by linear Arrhenius plots. A nearly universal linear Arrhenius plot is observed at each bombarding energy, independent of target. The sensitivity of p to the Zthreshold points to its physical significance and rules out auto-correlation effects.

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Understanding Proton Emission In Central Heavy-Ion Collisions, D. O. Handzy, W. Bauer, F. C. Daffin, S. J. Gaff, C. K. Gelbke, T. Glasmacher, E. Gualtieri, S. Hannuschke, M. J. Huang, G. J. Kunde, R. Lacey, T. Li, M. A. Lisa, W. J. Llope, W. G. Lynch, L. Martin, C. P. Montoya, R. Pak, Graham F. Peaslee, S. Pratt, C. Schwarz, N. Stone, M. B. Tsang, A. M. Vander Molen, G. D. Westfall, J. Yee, S. J. Yennello Oct 1995

Understanding Proton Emission In Central Heavy-Ion Collisions, D. O. Handzy, W. Bauer, F. C. Daffin, S. J. Gaff, C. K. Gelbke, T. Glasmacher, E. Gualtieri, S. Hannuschke, M. J. Huang, G. J. Kunde, R. Lacey, T. Li, M. A. Lisa, W. J. Llope, W. G. Lynch, L. Martin, C. P. Montoya, R. Pak, Graham F. Peaslee, S. Pratt, C. Schwarz, N. Stone, M. B. Tsang, A. M. Vander Molen, G. D. Westfall, J. Yee, S. J. Yennello

Faculty Publications

Two-proton correlation functions for central collisions of 36Ar+45Sc at E/A=80, 120, and 160 MeV are compared to calculations with the Boltzmann-Uehling-Uhlenbeck (BUU) transport model. Agreement is found at E/A=80MeV, but the model predicts too large correlations at E/A=120 and 160 MeV. The discrepancy may be due to delayed emission of protons from particle-unstable states not modeled in BUU.

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Structure Factors Of Binary Fluids In A Dilute Gel, J.C. Lee Oct 1995

Structure Factors Of Binary Fluids In A Dilute Gel, J.C. Lee

Faculty Publications

The statio and dynamic structure factors of binary fluids in a dilute gel are computed using a two-dimensional kinetic Ising model. The wetting effect of the gel strands is modeled with ''gel atoms'' which are distributed randomly among the spins and impose a field on their neighboring spins, all in the same direction. The result for the static structure factor shows the presence of adsorption clusters which mask the gel atoms. The result for the dynamic Structure factor shows an extremely slow relaxation-at late times which cannot be fitted in the form of the activated dynamic scaling known for random-field …

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A Provably Convergent Dynamic Training Method For Multi-Layer Perceptron Networks, Timothy L. Andersen, Tony R. Martinez Sep 1995

A Provably Convergent Dynamic Training Method For Multi-Layer Perceptron Networks, Timothy L. Andersen, Tony R. Martinez

Faculty Publications

This paper presents a new method for training multi-layer perceptron networks called DMP1 (Dynamic Multilayer Perceptron 1). The method is based upon a divide and conquer approach which builds networks in the form of binary trees, dynamically allocating nodes and layers as needed. The individual nodes of the network are trained using a genetic algorithm. The method is capable of handling real-valued inputs and a proof is given concerning its convergence properties of the basic model. Simulation results show that DMP1 performs favorably in comparison with other learning algorithms.

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Assessing The Evolutionary Nature Of Multifragment Decay, E. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman Aug 1995

Assessing The Evolutionary Nature Of Multifragment Decay, E. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman

Faculty Publications

Multifragment decays of central collisions in 84Kr+197Au at E/A=35, 55, and 70 MeV are studied. The dependence of the extracted emission time on the velocity of the fragment pair is investigated. More energetic pairs manifest a stronger Coulomb interaction, indicating emission from a source of smaller spatial-temporal extent than less energetic pairs. This trend can be understood in the context of a statistical model that allows the source characteristics to evolve as the fragments are emitted.

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Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen Aug 1995

Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen

Faculty Publications

The histones H2B, H3 and H4, the transition protein TP1 and protamine were localised using ultrastructural immunocytochemistry in nuclei of rabbit spermatids and spermatozoa. Histones are present in round spermatid nuclei and are lost during the elongation of nuclei. TP1 and protamine appear simultaneously in all nuclei during this period. TP1 is located at the periphery of chromatin cords, while protamine seems to be located at random in the same cords. TP1 is lost in most elongated sprematids during step 13 of spermiogenesis, and the protamine stays in all sperm nuclei. TP1 remains persent in some old spermatids and ejaculated …

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Space-Time Characteristics Of Fragment Emission In The E/A=30 Mev 129xe + Natcu Reaction, D. R. Bowman, N. Colonna, W. A. Friedman, L. Celano, M. D'Agostino, J. D. Dinius, A. Ferrero, C. K. Gelbke, T. Glasmacher, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, I. Iori, M. A. Lisa, W. G. Lynch, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Scardaoni, C. Schwarz, M. B. Tsang, C. Williams Aug 1995

Space-Time Characteristics Of Fragment Emission In The E/A=30 Mev 129xe + Natcu Reaction, D. R. Bowman, N. Colonna, W. A. Friedman, L. Celano, M. D'Agostino, J. D. Dinius, A. Ferrero, C. K. Gelbke, T. Glasmacher, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, I. Iori, M. A. Lisa, W. G. Lynch, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Scardaoni, C. Schwarz, M. B. Tsang, C. Williams

Faculty Publications

Intermediate-mass-fragment emission has been studied in central E/A=30 MeV Xe129+natCu reactions. The measured fragment multiplicities, reduced-velocity correlation functions, and emission velocities have been compared with schematic three-body trajectory calculations and with three statistical models with input based upon a dynamical BNV code. The statistical models which include expansion either explicitly or implicitly are able to generate a sufficient number of fragments. The three-body trajectory calculations indicate a mean emission time of ≊200 fm/c, consistent with sequential decay. Dynamical expanding-emitting source calculations predict a similar time scale for fragment emission and give satisfactory agreement with the experimental correlation functions if the …

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An Integrated Framework For Learning And Reasoning, Christophe G. Giraud-Carrier, Tony R. Martinez Aug 1995

An Integrated Framework For Learning And Reasoning, Christophe G. Giraud-Carrier, Tony R. Martinez

Faculty Publications

Learning and reasoning are both aspects of what is considered to be intelligence. Their studies within AI have been separated historically, learning being the topic of machine learning and neural networks, and reasoning falling under classical (or symbolic) AI. However, learning and reasoning are in many ways interdependent. This paper discusses the nature of some of these interdependencies and proposes a general framework called FLARE, that combines inductive learning using prior knowledge together with reasoning in a propositional setting. Several examples that test the framework are presented, including classical induction, many important reasoning protocols and two simple expert systems.

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Surface Intersection Loop Destruction, Thomas W. Sederberg, Alan K. Zundel Jul 1995

Surface Intersection Loop Destruction, Thomas W. Sederberg, Alan K. Zundel

Faculty Publications

The intersection curve between two surface patches consists of one or more connected components or branches. Each component can be classified as either an open branch, with endpoints on at least one patch boundary, or as a closed loop.

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Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu Jul 1995

Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu

Faculty Publications

A strong thermal signature is found in the charge distributions associated with multifragmentation from the reaction 36Ar+197Au at E/A=110 MeV. The n-fold charge distributions are reducible to the onefold charge distributions through a simple scaling that is dictated by fold number and charge conservation.

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Numerical Calculation Of Axisymmetric Electrostatic Modes For Cold Finite-Length Non-Neutral Plasmas, Johnny K. Jennings, Ross L. Spencer, K. C. Hansen Jul 1995

Numerical Calculation Of Axisymmetric Electrostatic Modes For Cold Finite-Length Non-Neutral Plasmas, Johnny K. Jennings, Ross L. Spencer, K. C. Hansen

Faculty Publications

A numerical calculation of mode frequencies for cold, non-neutral plasmas is reported. The numerical method can be applied to any axisymmetric plasma shape in a trap. Here, it is used to study axisymmetric electrostatic modes in a long conducting cylinder. These modes were previously studied by Prasad and O'Neil [Phys. Fluids 26, 665 (1983)] and by Dubin [Phys. Rev. Lett. 66, 2076 (1991)]. In contrast to Dubin's calculation, the effects of a nearby cylindrical wall, including its influence on the shape of the plasma equilibrium, are considered. It is found that for plasmas with aspect ratios (length divided by diameter) …

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Space-Time Ambiguity Of Two- And Three-Fragment Reduced Velocity Correlation Functions, T. Glasmacher, L. Phair, D. R. Bowman, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, R. T. De Souza, M. B. Tsang, F. Zhu Jun 1995

Space-Time Ambiguity Of Two- And Three-Fragment Reduced Velocity Correlation Functions, T. Glasmacher, L. Phair, D. R. Bowman, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, R. T. De Souza, M. B. Tsang, F. Zhu

Faculty Publications

Reduced-velocity correlation functions between two and three intermediate mass fragments are compared for central Ar36+197Ar collisions at E/A=50 MeV. Previously published N-body Coulomb-trajectory calculations, capable of reproducing the measured two-fragment reduced velocity-correlation function, describe the measured three-fragment correlation function equally well. Moreover, ambiguities between source size and lifetime observed in the analysis of two-fragment correlations remain unresolved in the three-fragment correlation function.

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