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Sample records for accelerated exclusion process

  1. Mass transport perspective on an accelerated exclusion process: Analysis of augmented current and unit-velocity phases

    NASA Astrophysics Data System (ADS)

    Dong, Jiajia; Klumpp, Stefan; Zia, R. K. P.

    2013-02-01

    In an accelerated exclusion process (AEP), each particle can “hop” to its adjacent site if empty as well as “kick” the frontmost particle when joining a cluster of size ℓ⩽ℓmax. With various choices of the interaction range, ℓmax, we find that the steady state of AEP can be found in a homogeneous phase with augmented currents (AC) or a segregated phase with holes moving at unit velocity (UV). Here we present a detailed study on the emergence of the novel phases, from two perspectives: the AEP and a mass transport process (MTP). In the latter picture, the system in the UV phase is composed of a condensate in coexistence with a fluid, while the transition from AC to UV can be regarded as condensation. Using Monte Carlo simulations, exact results for special cases, and analytic methods in a mean field approach (within the MTP), we focus on steady state currents and cluster sizes. Excellent agreement between data and theory is found, providing an insightful picture for understanding this model system.

  2. Exclusive processes in quantum chromodynamics

    SciTech Connect

    Brodsky, S.J.; Lepage, G.P.

    1981-06-01

    Large momentum transfer exclusive processes and the short distance structure of hadronic wave functions can be systematically analyzed within the context of perturbative QCD. Predictions for meson form factors, two-photon processes ..gamma gamma.. ..-->.. M anti M, hadronic decays of heavy quark systems, and a number of other related QCD phenomena are reviewed.

  3. Exclusive photon-photon processes

    SciTech Connect

    Brodsky, S.J.

    1997-07-01

    Exclusive gamma gamma right arrow hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain (s, t, large, Theta cm for t/s fixed), these processes can be computed from first principles in QCD, yielding important information on the nature of the QCD coupling data and the form of hadron distribution amplitudes. Similarly, the transition form factors gamma star gamma, gamma star gamma right arrow pi(o), Eta (0), Eta`, Eta(c)... provide rigorous tests of QCD and definitive determinations of the meson distribution amplitudes Phi H(x,Q). We show that the assumption of a frozen coupling at low momentum transfers can explain the observed scaling of two-photon exclusive processes.

  4. Intrapersonal and interpersonal processes of social exclusion

    PubMed Central

    Kawamoto, Taishi; Ura, Mitsuhiro; Nittono, Hiroshi

    2015-01-01

    People have a fundamental need to belong with others. Social exclusion impairs this need and has various effects on cognition, affect, and the behavior of excluded individuals. We have previously reported that activity in the dorsal anterior cingulate cortex (dACC) and right ventrolateral prefrontal cortex (rVLPFC) could be a neurocognitive index of social exclusion (Kawamoto et al., 2012). In this article, we provide an integrative framework for understanding occurrences during and after social exclusion, by reviewing neuroimaging, electrophysiological, and behavioral studies of dACC and rVLPFC, within the framework of intrapersonal and interpersonal processes of social exclusion. As a result, we have indicated directions for future studies to further clarify the phenomenon of social exclusion from the following perspectives: (1) constructional elements of social exclusion, (2) detection sensitivity and interpretation bias in social exclusion, (3) development of new methods to assess the reactivity to social exclusion, and (4) sources of social exclusion. PMID:25798081

  5. Accelerator simulation of astrophysical processes

    NASA Technical Reports Server (NTRS)

    Tombrello, T. A.

    1983-01-01

    Phenomena that involve accelerated ions in stellar processes that can be simulated with laboratory accelerators are described. Stellar evolutionary phases, such as the CNO cycle, have been partially explored with accelerators, up to the consumption of He by alpha particle radiative capture reactions. Further experimentation is indicated on reactions featuring N-13(p,gamma)O-14, O-15(alpha, gamma)Ne-19, and O-14(alpha,p)F-17. Accelerated beams interacting with thin foils produce reaction products that permit a determination of possible elemental abundances in stellar objects. Additionally, isotopic ratios observed in chondrites can be duplicated with accelerator beam interactions and thus constraints can be set on the conditions producing the meteorites. Data from isotopic fractionation from sputtering, i.e., blasting surface atoms from a material using a low energy ion beam, leads to possible models for processes occurring in supernova explosions. Finally, molecules can be synthesized with accelerators and compared with spectroscopic observations of stellar winds.

  6. Diffusive Shock Acceleration and Reconnection Acceleration Processes

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; Hunana, P.; Mostafavi, P.; Le Roux, J. A.; Li, Gang; Webb, G. M.; Khabarova, O.; Cummings, A.; Stone, E.; Decker, R.

    2015-12-01

    Shock waves, as shown by simulations and observations, can generate high levels of downstream vortical turbulence, including magnetic islands. We consider a combination of diffusive shock acceleration (DSA) and downstream magnetic-island-reconnection-related processes as an energization mechanism for charged particles. Observations of electron and ion distributions downstream of interplanetary shocks and the heliospheric termination shock (HTS) are frequently inconsistent with the predictions of classical DSA. We utilize a recently developed transport theory for charged particles propagating diffusively in a turbulent region filled with contracting and reconnecting plasmoids and small-scale current sheets. Particle energization associated with the anti-reconnection electric field, a consequence of magnetic island merging, and magnetic island contraction, are considered. For the former only, we find that (i) the spectrum is a hard power law in particle speed, and (ii) the downstream solution is constant. For downstream plasmoid contraction only, (i) the accelerated spectrum is a hard power law in particle speed; (ii) the particle intensity for a given energy peaks downstream of the shock, and the distance to the peak location increases with increasing particle energy, and (iii) the particle intensity amplification for a particular particle energy, f(x,c/{c}0)/f(0,c/{c}0), is not 1, as predicted by DSA, but increases with increasing particle energy. The general solution combines both the reconnection-induced electric field and plasmoid contraction. The observed energetic particle intensity profile observed by Voyager 2 downstream of the HTS appears to support a particle acceleration mechanism that combines both DSA and magnetic-island-reconnection-related processes.

  7. Accelerated stochastic diffusion processes

    NASA Astrophysics Data System (ADS)

    Garbaczewski, Piotr

    1990-07-01

    We give a purely probabilistic demonstration that all effects of non-random (external, conservative) forces on the diffusion process can be encoded in the Nelson ansatz for the second Newton law. Each random path of the process together with a probabilistic weight carries a phase accumulation (complex valued) weight. Random path summation (integration) of these weights leads to the transition probability density and transition amplitude respectively between two spatial points in a given time interval. The Bohm-Vigier, Fenyes-Nelson-Guerra and Feynman descriptions of the quantum particle behaviours are in fact equivalent.

  8. Exclusive hadronic and nuclear processes in QCD

    SciTech Connect

    Brodsky, S.J.

    1985-12-01

    Hadronic and nuclear processes are covered, in which all final particles are measured at large invariant masses compared with each other, i.e., large momentum transfer exclusive reactions. Hadronic wave functions in QCD and QCD sum rule constraints on hadron wave functions are discussed. The question of the range of applicability of the factorization formula and perturbation theory for exclusive processes is considered. Some consequences of quark and gluon degrees of freedom in nuclei are discussed which are outside the usual domain of traditional nuclear physics. 44 refs., 7 figs. (LEW)

  9. Overview of HERMES Results on Exclusive Processes

    NASA Astrophysics Data System (ADS)

    Movsisyan, Aram

    2015-01-01

    An overview of HERMES results on measurements of hard exclusive electroproduction of real photons and mesons on hydrogen and deuterium targets is presented. Experimental measurements of hard exclusive processes are commonly described within the formalism of generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The HERMES experiment at DESY Hamburg studies hard exclusive processes using polarized electron or positron beams from HERA and internal gas targets. Information about GPDs is gained from the measurements of asymmetries that appear in the azimuthal distributions of produced mesons and photons, together with studies of the azimuthal distribution of the decay products via spin-density matrix elements.

  10. ESS Accelerator Cryoplant Process Design

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Arnold, P.; Hees, W.; Hildenbeutel, J.; Weisend, J. G., II

    2015-12-01

    The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The ESS accelerator will deliver protons with 5 MW of power to the target at 2.0 GeV, with a nominal current of 62.5 mA. The superconducting part of the accelerator is about 300 meters long and contains 43 cryomodules. The ESS accelerator cryoplant (ACCP) will provide the cooling for the cryomodules and the cryogenic distribution system that delivers the helium to the cryomodules. The ACCP will cover three cryogenic circuits: Bath cooling for the cavities at 2 K, the thermal shields at around 40 K and the power couplers thermalisation with 4.5 K forced helium cooling. The open competitive bid for the ACCP took place in 2014 with Linde Kryotechnik AG being selected as the vendor. This paper summarizes the progress in the ACCP development and engineering. Current status including final cooling requirements, preliminary process design, system configuration, machine concept and layout, main parameters and features, solution for the acceptance tests, exergy analysis and efficiency is presented.

  11. An exclusion process with dynamic roadblocks

    NASA Astrophysics Data System (ADS)

    Ning, Guo; Jin-Yong, Chen; Mao-Bin, Hu; Rui, Jiang

    2016-06-01

    We study an exclusion process with multiple dynamic roadblocks. Each roadblock can move diffusively forward or backward with different rates, as well as unbind from/rebind to a free site. By Monte Carlo simulations, the two moving types are investigated in combination of roadblock number. The case of only diffusive roadblocks shows an asymmetric current-density relation. The case of only long-range jumping roadblocks presents that flux decreases with increasing roadblock number. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11422221, 71171185, and 71371175).

  12. Death to perturbative QCD in exclusive processes?

    SciTech Connect

    Eckardt, R.; Hansper, J.; Gari, M.F.

    1994-04-01

    The authors discuss the question of whether perturbative QCD is applicable in calculations of exclusive processes at available momentum transfers. They show that the currently used method of determining hadronic quark distribution amplitudes from QCD sum rules yields wave functions which are completely undetermined because the polynomial expansion diverges. Because of the indeterminacy of the wave functions no statement can be made at present as to whether perturbative QCD is valid. The authors emphasize the necessity of a rigorous discussion of the subject and the importance of experimental data in the range of interest.

  13. Maximal acceleration and radiative processes

    NASA Astrophysics Data System (ADS)

    Papini, Giorgio

    2015-08-01

    We derive the radiation characteristics of an accelerated, charged particle in a model due to Caianiello in which the proper acceleration of a particle of mass m has the upper limit 𝒜m = 2mc3/ℏ. We find two power laws, one applicable to lower accelerations, the other more suitable for accelerations closer to 𝒜m and to the related physical singularity in the Ricci scalar. Geometrical constraints and power spectra are also discussed. By comparing the power laws due to the maximal acceleration (MA) with that for particles in gravitational fields, we find that the model of Caianiello allows, in principle, the use of charged particles as tools to distinguish inertial from gravitational fields locally.

  14. Critical behavior of the exclusive queueing process

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Schadschneider, Andreas

    2013-11-01

    The exclusive queueing process (EQP) is a generalization of the classical M/M/1 queue. It is equivalent to a totally asymmetric exclusion process (TASEP) of varying length. Here we consider two discrete-time versions of the EQP with parallel and backward-sequential update rules. The phase diagram (with respect to the arrival probability α and the service probability β) is divided into two phases corresponding to divergence and convergence of the system length. We investigate the behavior on the critical line separating these phases. For both update rules, we find diffusive behavior for small service probability (\\beta < \\beta_c) . However, for \\beta>\\beta_c it becomes sub-diffusive and nonuniversal: the critical exponents characterizing the divergence of the system length and the number of customers are found to depend on the update rule. For the backward-update case, they also depend on the hopping parameter p, and remain finite when p is large, indicating a first-order transition.

  15. Deeply exclusive processes and generalized parton distributions

    SciTech Connect

    Marc Vanderhaegen

    2005-02-01

    We discuss how generalized parton distributions (GPDs) enter into hard exclusive processes, and focuses on the links between GPDs and elastic nucleon form factors. These links, in the form of sum rules, represent powerful constraints on parameterizations of GPDs. A Regge parameterization for the GPDs at small momentum transfer -t is extended to the large-t region and it is found to catch the basic features of proton and neutron electromagnetic form factor data. This parameterization allows to estimate the quark contribution to the nucleon spin. It is furthermore discussed how these GPDs at large-t enter into two-photon exchange processes and resolve the discrepancy between Rosenbluth and polarization experiments of elastic electron nucleon scattering.

  16. Generalized parton distributions and exclusive processes

    SciTech Connect

    Guzey, Vadim

    2013-10-01

    In last fifteen years, GPDs have emerged as a powerful tool to reveal such aspects of the QCD structure of the nucleon as: - 3D parton correlations and distributions; - spin content of the nucleon. Further advances in the field of GPDs and hard exclusive processes rely on: - developments in theory and new methods in phenomenology such as new flexible parameterizations, neural networks, global QCD fits - new high-precision data covering unexplored kinematics: JLab at 6 and 12 GeV, Hermes with recoil detector, Compass, EIC. This slide-show presents: Nucleon structure in QCD, particularly hard processes, factorization and parton distributions; and a brief overview of GPD phenomenology, including basic properties of GPDs, GPDs and QCD structure of the nucleon, and constraining GPDs from experiments.

  17. Auroral plasma acceleration processes at Mars

    NASA Astrophysics Data System (ADS)

    Lundin, R.; Barabash, S.; Winningham, D.

    2012-09-01

    Following the first Mars Express (MEX) findings of auroral plasma acceleration above Martian magnetic anomalies[1, 2], a more detailed analysis is carried out regarding the physical processes that leads to plasma acceleration, and how they connect to the dynamo-, and energy source regions. The ultimate energy source for Martian plasma acceleration is the solar wind. The question is, by what mechanisms is solar wind energy and momentum transferred into the magnetic flux tubes that connect to Martian magnetic anomalies? What are the key plasma acceleration processes that lead to aurora and the associated ionospheric plasma outflow from Mars? The experimental setup on MEX limits our capability to carry out "auroral physics" at Mars. However, with knowledge acquired from the Earth, we may draw some analogies with terrestrial auroral physics. Using the limited data set available, consisting of primarily ASPERA and MARSIS data, an interesting picture of aurora at Mars emerges. There are some strong similarities between accelerated/heated electrons and ions in the nightside high altitude region above Mars and the electron/ion acceleration above Terrestrial discrete aurora. Nearly monoenergetic downgoing electrons are observed in conjunction with nearly monoenergetic upgoing ions. Monoenergetic counterstreaming ions and electrons is the signature of plasma acceleration in quasi-static electric fields. However, compared to the Earth's aurora, with auroral process guided by a dipole field, aurora at Mars is expected to form complex patterns in the multipole environment governed by the Martian crustal magnetic field regions. Moreover, temporal/spatial scales are different at Mars. It is therefore of interest to mention another common characteristics that exist for Earth and Mars, plasma acceleration by waves. Low-frequency, Alfvén, waves is a very powerful means of plasma acceleration in the Earth's magnetosphere. Low-frequency waves associated with plasma acceleration

  18. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  19. Dissociable Brain Mechanisms for Processing Social Exclusion and Rule Violation

    PubMed Central

    Bolling, Danielle Z.; Pitskel, Naomi B.; Deen, Ben; Crowley, Michael J.; McPartland, James C.; Mayes, Linda C.; Pelphrey, Kevin A.

    2010-01-01

    Social exclusion inherently involves an element of expectancy violation, in that we expect other people to follow the unwritten rule to include us in social interactions. In this functional magnetic resonance imaging (fMRI) study, we employed a unique modification of an interactive virtual ball-tossing game called “Cyberball” (Williams et al., 2000) and a novel paradigm called “Cybershape”, in which rules are broken in the absence of social exclusion, to dissociate brain regions that process social exclusion from rule violations more generally. Our Cyberball game employed an alternating block design and removed evoked responses to events when the participant was throwing the ball in inclusion to make this condition comparable to exclusion, where participants did not throw. With these modifications, we replicated prior findings of ventral anterior cingulate cortex (vACC), insula, and posterior cingulate cortex activity evoked by social exclusion relative to inclusion. We also identified exclusion-evoked activity in the hippocampi, left ventrolateral prefrontal cortex, and left middle temporal gyrus. Comparing social exclusion and rule violation revealed a functional dissociation in the active neural systems as well as differential functional connectivity with vACC. Some overlap was observed in regions differentially modulated by social exclusion and rule violation, including the vACC and lateral parietal cortex. These overlapping brain regions showed different activation during social exclusion compared to rule violation, each relative to fair play. Comparing activation patterns to social exclusion and rule violation allowed for the dissociation of brain regions involved in the experience of exclusion versus expectancy violation. PMID:20974272

  20. Dissociable brain mechanisms for processing social exclusion and rule violation.

    PubMed

    Bolling, Danielle Z; Pitskel, Naomi B; Deen, Ben; Crowley, Michael J; McPartland, James C; Mayes, Linda C; Pelphrey, Kevin A

    2011-02-01

    Social exclusion inherently involves an element of expectancy violation, in that we expect other people to follow the unwritten rule to include us in social interactions. In this functional magnetic resonance imaging (fMRI) study, we employed a unique modification of an interactive virtual ball-tossing game called "Cyberball" (Williams et al., 2000) and a novel paradigm called "Cybershape," in which rules are broken in the absence of social exclusion, to dissociate brain regions that process social exclusion from rule violations more generally. Our Cyberball game employed an alternating block design and removed evoked responses to events when the participant was throwing the ball in inclusion to make this condition comparable to exclusion, where participants did not throw. With these modifications, we replicated prior findings of ventral anterior cingulate cortex (vACC), insula, and posterior cingulate cortex activity evoked by social exclusion relative to inclusion. We also identified exclusion-evoked activity in the hippocampi, left ventrolateral prefrontal cortex, and left middle temporal gyrus. Comparing social exclusion and rule violation revealed a functional dissociation in the active neural systems as well as differential functional connectivity with vACC. Some overlap was observed in regions differentially modulated by social exclusion and rule violation, including the vACC and lateral parietal cortex. These overlapping brain regions showed different activation during social exclusion compared to rule violation, each relative to fair play. Comparing activation patterns to social exclusion and rule violation allowed for the dissociation of brain regions involved in the experience of exclusion versus expectancy violation. PMID:20974272

  1. Asymmetric exclusion process and extremal statistics of random sequences.

    PubMed

    Bundschuh, R

    2002-03-01

    A mapping is established between sequence alignment, one of the most commonly used tools of computational biology, at a certain choice of scoring parameters and the asymmetric exclusion process, one of the few exactly solvable models of nonequilibrium physics. The statistical significance of sequence alignments is characterized through studying the total hopping current of the discrete time and space version of the asymmetric exclusion process. PMID:11909113

  2. Exclusive processes and the fundamental structure of hadrons

    DOE PAGESBeta

    Brodsky, Stanley J.

    2015-01-20

    I review the historical development of QCD predictions for exclusive hadronic processes, beginning with constituent counting rules and the quark interchange mechanism, phenomena which gave early validation for the quark structure of hadrons. The subsequent development of pQCD factorization theorems for hard exclusive amplitudes and the development of evolution equations for the hadron distribution amplitudes provided a rigorous framework for calculating hadronic form factors and hard scattering exclusive scattering processes at high momentum transfer. I also give a brief introduction to the field of "light-front holography" and the insights it brings to quark confinement, the behavior of the QCD couplingmore » in the nonperturbative domain, as well as hadron spectroscopy and the dynamics of exclusive processes.« less

  3. Exclusive processes and the fundamental structure of hadrons

    SciTech Connect

    Brodsky, Stanley J.

    2015-01-20

    I review the historical development of QCD predictions for exclusive hadronic processes, beginning with constituent counting rules and the quark interchange mechanism, phenomena which gave early validation for the quark structure of hadrons. The subsequent development of pQCD factorization theorems for hard exclusive amplitudes and the development of evolution equations for the hadron distribution amplitudes provided a rigorous framework for calculating hadronic form factors and hard scattering exclusive scattering processes at high momentum transfer. I also give a brief introduction to the field of "light-front holography" and the insights it brings to quark confinement, the behavior of the QCD coupling in the nonperturbative domain, as well as hadron spectroscopy and the dynamics of exclusive processes.

  4. Radiative processes of uniformly accelerated entangled atoms

    NASA Astrophysics Data System (ADS)

    Menezes, G.; Svaiter, N. F.

    2016-05-01

    We study radiative processes of uniformly accelerated entangled atoms, interacting with an electromagnetic field prepared in the Minkowski vacuum state. We discuss the structure of the rate of variation of the atomic energy for two atoms traveling in different hyperbolic world lines. We identify the contributions of vacuum fluctuations and radiation reaction to the generation of entanglement as well as to the decay of entangled states. Our results resemble the situation in which two inertial atoms are coupled individually to two spatially separated cavities at different temperatures. In addition, for equal accelerations we obtain that one of the maximally entangled antisymmetric Bell state is a decoherence-free state.

  5. Accelerated erosion: Process, problems, and prognosis

    NASA Astrophysics Data System (ADS)

    Toy, Terrence J.

    1982-10-01

    Soil erosion may well be the world's most serious environmental problem. A variety of human activities accelerates the rate of this geomorphie process by altering the natural characteristics of a site. The problems arising from accelerated erosion and subsequent deposition provide numerous research opportunities to both physical and social scientists whose cooperation will be necessary in our search for solutions. Factors of demography, economics, geography, and historical inertia to change suggest that man-induced erosion is likely to continue into the future unless this trend is abated by timely and forceful action.

  6. Process in high energy heavy ion acceleration

    NASA Astrophysics Data System (ADS)

    Dinev, D.

    2009-03-01

    A review of processes that occur in high energy heavy ion acceleration by synchrotrons and colliders and that are essential for the accelerator performance is presented. Interactions of ions with the residual gas molecules/atoms and with stripping foils that deliberately intercept the ion trajectories are described in details. These interactions limit both the beam intensity and the beam quality. The processes of electron loss and capture lie at the root of heavy ion charge exchange injection. The review pays special attention to the ion induced vacuum pressure instability which is one of the main factors limiting the beam intensity. The intrabeam scattering phenomena which restricts the average luminosity of ion colliders is discussed. Some processes in nuclear interactions of ultra-relativistic heavy ions that could be dangerous for the performance of ion colliders are represented in the last chapter.

  7. Quark Orbital Angular Momentum and Exclusive Processes at HERMES

    SciTech Connect

    Ellinghaus, F.

    2006-11-17

    A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum.

  8. When push comes to shove: Exclusion processes with nonlocal consequences

    NASA Astrophysics Data System (ADS)

    Almet, Axel A.; Pan, Michael; Hughes, Barry D.; Landman, Kerry A.

    2015-11-01

    Stochastic agent-based models are useful for modelling collective movement of biological cells. Lattice-based random walk models of interacting agents where each site can be occupied by at most one agent are called simple exclusion processes. An alternative motility mechanism to simple exclusion is formulated, in which agents are granted more freedom to move under the compromise that interactions are no longer necessarily local. This mechanism is termed shoving. A nonlinear diffusion equation is derived for a single population of shoving agents using mean-field continuum approximations. A continuum model is also derived for a multispecies problem with interacting subpopulations, which either obey the shoving rules or the simple exclusion rules. Numerical solutions of the derived partial differential equations compare well with averaged simulation results for both the single species and multispecies processes in two dimensions, while some issues arise in one dimension for the multispecies case.

  9. Reply to "Comment on `Generalized exclusion processes: Transport coefficients' "

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Krapivsky, P. L.; Mallick, Kirone

    2016-07-01

    We reply to the Comment of Becker, Nelissen, Cleuren, Partoens, and Van den Broeck [Phys. Rev. E 93, 046101 (2016), 10.1103/PhysRevE.93.046101] on our article [Arita, Krapivsky, and Mallick, Phys. Rev. E 90, 052108 (2014), 10.1103/PhysRevE.90.052108] about the transport properties of a class of generalized exclusion processes.

  10. Accelerating an iterative process by explicit annihilation

    NASA Technical Reports Server (NTRS)

    Jespersen, D. C.; Buning, P. G.

    1983-01-01

    A slowly convergent stationary iterative process can be accelerated by explicitly annihilating (i.e., eliminating) the dominant eigenvector component of the error. The dominant eigenvalue or complex pair of eigenvalues can be estimated from the solution during the iteration. The corresponding eigenvector or complex pair of eigenvectors can then be annihilated by applying an explicit Richardson process over the basic iterative method. This can be done entirely in real arithmetic by analytically combining the complex conjugate annihilation steps. The technique is applied to an implicit algorithm for the calculation of two dimensional steady transonic flow over a circular cylinder using the equations of compressible inviscid gas dynamics. This demonstrates the use of explicit annihilation on a nonlinear problem.

  11. Accelerating an iterative process by explicit annihilation

    NASA Technical Reports Server (NTRS)

    Jespersen, D. C.; Buning, P. G.

    1985-01-01

    A slowly convergent stationary iterative process can be accelerated by explicitly annihilating (i.e., eliminating) the dominant eigenvector component of the error. The dominant eigenvalue or complex pair of eigenvalues can be estimated from the solution during the iteration. The corresponding eigenvector or complex pair of eigenvectors can then be annihilated by applying an explicit Richardson process over the basic iterative method. This can be done entirely in real arithmetic by analytically combining the complex conjugate annihilation steps. The technique is applied to an implicit algorithm for the calculation of two dimensional steady transonic flow over a circular cylinder using the equations of compressible inviscid gas dynamics. This demonstrates the use of explicit annihilation on a nonlinear problem.

  12. Particle acceleration processes in the solar corona

    NASA Astrophysics Data System (ADS)

    Melrose, D. B.

    A review is presented of some theoretical ideas on particle acceleration associated with solar flares. Various acceleration mechanisms are discussed, including forms of stochastic acceleration, shock drift acceleration, resonant acceleration, diffusive acceleration at shock fronts, acceleration during magnetic reconnection, and acceleration by parallel electric fields in double layers or electrostatic shocks. Particular attention is given to first phase acceleration of electrons in solar flares, which is usually attributed to bulk energization of electrons. It is proposed that the dissipation cannot be due to classical resistivity and entails anomalous resistivity or hyperresistivity, such as in multiple double layers. A model is developed for bulk energization due to the continual formation and decay of weak double layers.

  13. Inclusive and Exclusive Compton Processes in Quantum Chromodynamics

    SciTech Connect

    Ales Psaker

    2005-12-31

    In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.

  14. Recent progress in some exclusive and semi-exclusive processes in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Szczurek, Antoni; Cisek, Anna; Łuszczak, Marta; Schäfer, Wolfgang

    2016-07-01

    We present the main results of our recent analyses of exclusive production of vector charmonia (J/ψ and ψ') in kt-factorization approach and for γγ production of charged dilepton pairs in exclusive and semiinclusive processes in a new approach, similar in spirit to kt-factorization. The results for charmonia are compared with recent results of the LHCb collaboration. We include some helicity flip contributions and quantify the effect of absorption correction. The effect of cc̅ wave function is illustrated. We present uncertainties related to F2 structure function which are the main ingredient of the approach. Our results are compared with recent CMS data for dilepton production with lepton isolation cuts imposed.

  15. Studies of semi-inclusive and hard exclusive processes at Jlab

    SciTech Connect

    Harutyun Avagyan

    2008-06-19

    The main goal of experiments proposed for the {\\tt CLAS12} detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and {\\tt CLAS12}.

  16. The ADS/QCD correspondence and exclusive processes

    SciTech Connect

    Stanley J. Brodsky, Guy F. De Teramond, Alexandre Deur

    2011-05-01

    The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling alpha^AdS/s (Q) and its Beta-function which agrees with the effective coupling alphag1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable zeta, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.

  17. The AdS/QCD Correspondence and Exclusive Processes

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; Deur, Alexandre; /Jefferson Lab

    2010-08-25

    The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS}(q) and its {beta}-function which agrees with the effective coupling {alpha}{sub ga} extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta}, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.

  18. Exclusion-type spatially heterogeneous processes in continua

    NASA Astrophysics Data System (ADS)

    Blank, Michael

    2011-06-01

    We study deterministic discrete time exclusion-type spatially heterogeneous particle processes in continua. A typical example of this sort is a traffic flow model with obstacles: traffic lights, speed bumps, spatially varying local velocities etc. Ergodic averages of particle velocities are obtained and their connections to other statistical quantities, in particular to particle and obstacle densities (the so-called fundamental diagram), are analyzed rigorously. The main technical tool is a 'dynamical' coupling construction applied in a nonstandard fashion: instead of proving the existence of the successful coupling (which might even fail to hold) we use its presence/absence as an important diagnostic tool.

  19. Symmetric exclusion processes on a ring with moving defects

    NASA Astrophysics Data System (ADS)

    Chatterjee, Rakesh; Chatterjee, Sakuntala; Pradhan, Punyabrata

    2016-06-01

    We study symmetric simple exclusion processes (SSEP) on a ring in the presence of uniformly moving multiple defects or disorders—a generalization of the model we proposed earlier [Phys. Rev. E 89, 022138 (2014), 10.1103/PhysRevE.89.022138]. The defects move with uniform velocity and change the particle hopping rates locally. We explore the collective effects of the defects on the spatial structure and transport properties of the system. We also introduce an SSEP with ordered sequential (sitewise) update and elucidate the close connection with our model.

  20. Tests of quantum chromodynamics in exclusive e sup + e sup minus and. gamma. gamma. processes

    SciTech Connect

    Brodsky, S.J.

    1989-09-01

    This paper discusses the following topics: Factorization theorem for exclusive processes; Electromagnetic form factors of baryons; Suppression of final state interactions; The {gamma}{pi}{sub 0} Transition form factor; Exclusive charmonium decays; The {pi}-{rho} puzzle; Time-like compton processes; Multi-hadron production; Heavy Quark exclusive states and form factor zeros in QCD; Exclusive {gamma}{gamma} reactions; Higher twist effects; and Tauonium and threshold {tau}{sup +}{tau}{sup {minus}} production. 41 refs., 15 figs. (LSP)

  1. Spatiotemporally Complete Condensation in a Non-Poissonian Exclusion Process

    NASA Astrophysics Data System (ADS)

    Concannon, Robert J.; Blythe, Richard A.

    2014-02-01

    We investigate a non-Poissonian version of the asymmetric simple exclusion process, motivated by the observation that coarse graining the interactions between particles in complex systems generically leads to a stochastic process with a non-Markovian (history-dependent) character. We characterize a large family of one-dimensional hopping processes using a waiting-time distribution for individual particle hops. We find that when its variance is infinite, a real-space condensate forms that is complete in space (involves all particles) and time (exists at almost any given instant) in the thermodynamic limit. The mechanism for the onset and stability of the condensate is rather subtle and depends on the microscopic dynamics subsequent to a failed particle hop attempt.

  2. Finite-Time Fluctuations for the Totally Asymmetric Exclusion Process

    NASA Astrophysics Data System (ADS)

    Prolhac, Sylvain

    2016-03-01

    The one-dimensional totally asymmetric simple exclusion process, a Markov process describing classical hard-core particles hopping in the same direction, is considered on a periodic lattice of L sites. The relaxation to the nonequilibrium steady state, which occurs on the time scale t ˜L3 /2 for large L , is studied for the half-filled system with N =L /2 particles. Using large L asymptotics of Bethe ansatz formulas for the eigenstates, exact expressions depending explicitly on the rescaled time t /L3 /2 are obtained for the average and two-point function of the local density, and for the current fluctuations for simple (stationary, flat and step) initial conditions, relating previous results for the infinite system to stationary large deviations. The final formulas have a nice interpretation in terms of a functional integral with the action of a scalar field in a linear potential.

  3. Finite-Time Fluctuations for the Totally Asymmetric Exclusion Process.

    PubMed

    Prolhac, Sylvain

    2016-03-01

    The one-dimensional totally asymmetric simple exclusion process, a Markov process describing classical hard-core particles hopping in the same direction, is considered on a periodic lattice of L sites. The relaxation to the nonequilibrium steady state, which occurs on the time scale t∼L^{3/2} for large L, is studied for the half-filled system with N=L/2 particles. Using large L asymptotics of Bethe ansatz formulas for the eigenstates, exact expressions depending explicitly on the rescaled time t/L^{3/2} are obtained for the average and two-point function of the local density, and for the current fluctuations for simple (stationary, flat and step) initial conditions, relating previous results for the infinite system to stationary large deviations. The final formulas have a nice interpretation in terms of a functional integral with the action of a scalar field in a linear potential. PMID:26991165

  4. Power spectra of a constrained totally asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Cook, L. Jonathan; Zia, R. K. P.

    2010-07-01

    In nature, all biological systems function in a far-from-equilibrium state. Here, we study the process of translation in protein synthesis, using the totally asymmetric simple exclusion process (TASEP) as a model. In particular, we explore the effects of a finite supply of particles for the TASEP, as in a living cell with a finite pool of ribosomes. Specifically, we investigate the power spectrum associated with total occupancy, utilizing both Monte Carlo simulations and theoretical analysis. New features arise, such as large suppressions at low frequencies, due to the added constraint. A theory is formulated based on a Langevin approach with discrete space and time. With good agreement between the simulation and theory, we gain some insights into the effects of finite resources on the TASEP.

  5. From generalized directed animals to the asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Haug, N.; Nechaev, S.; Tamm, M.

    2014-10-01

    Using the generalized normally ordered form of words in a locally-free group of n generators, we show that in the limit n → ∞, the partition function of weighted directed lattice animals on a semi-infinite strip coincides with the partition function of stationary configurations of the asymmetric simple exclusion process (ASEP) with arbitrary entry/escape rates through open boundaries. We relate the features of the ASEP in the different regimes of the phase diagram to the geometric features of the associated generalized directed animals by showing the results of numerical simulations. In particular, we show how the presence of shocks at the first order transition line translates into the directed animal picture. Using the evolution equation for generalized, weighted Lukasiewicz paths, we also provide a straightforward calculation of the known ASEP generating function.

  6. The wiper model: avalanche dynamics in an exclusion process

    NASA Astrophysics Data System (ADS)

    Politi, Antonio; Romano, M. Carmen

    2013-10-01

    The exclusion-process model (Ciandrini et al 2010 Phys. Rev. E 81 051904) describing traffic of particles with internal stepping dynamics reveals the presence of strong correlations in realistic regimes. Here we study such a model in the limit of an infinitely fast translocation time, where the evolution can be interpreted as a ‘wiper’ that moves to dry neighbouring sites. We trace back the existence of long-range correlations to the existence of avalanches, where many sites are dried at once. At variance with self-organized criticality, in the wiper model avalanches have a typical size equal to the logarithm of the lattice size. In the thermodynamic limit, we find that the hydrodynamic behaviour is a mixture of stochastic (diffusive) fluctuations and increasingly coherent periodic oscillations that are reminiscent of a collective dynamics.

  7. Ultrasonic acceleration of enzymatic processing of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. It has been found that the intr...

  8. Computational Tools for Accelerating Carbon Capture Process Development

    SciTech Connect

    Miller, David; Sahinidis, N V; Cozad, A; Lee, A; Kim, H; Morinelly, J; Eslick, J; Yuan, Z

    2013-06-04

    This presentation reports development of advanced computational tools to accelerate next generation technology development. These tools are to develop an optimized process using rigorous models. They include: Process Models; Simulation-Based Optimization; Optimized Process; Uncertainty Quantification; Algebraic Surrogate Models; and Superstructure Optimization (Determine Configuration).

  9. Theoretical analysis and simulation for a facilitated asymmetric exclusion process.

    PubMed

    Hao, Qing-Yi; Chen, Zhe; Sun, Xiao-Yan; Liu, Bing-Bing; Wu, Chao-Yun

    2016-08-01

    Driven diffusive systems are important models in nonequilibrium state statistical mechanics. This paper studies an asymmetric exclusion process model with nearest rear neighbor interactions associated with energy. The exact flux expression of the model is obtained by a cluster mean-field method. Based on the flux expression, the properties of the fundamental diagram have been investigated in detail. To probe the energy's influence on the coarsening process of the system, Monte Carlo simulations are carried out to acquire the monotonic phase boundary in energy-density space. Above the phase boundary, the system is inhomogeneous and the normalized residence distribution p(s) is nonmonotonically decreasing. Under the phase boundary, the system is homogeneous and p(s) is monotonically decreasing. Further study comparatively shows that the system has turned into a microscopic inhomogeneous state from a homogeneous state before the system current arrives at maximum, if nearest rear neighbor interactions are strong. Our findings offer insights to deeply understand the dynamic features of nonequilibrium state systems. PMID:27627252

  10. Asymmetric exclusion process with a dynamic roadblock and open boundaries

    NASA Astrophysics Data System (ADS)

    Sahoo, Mamata; Klumpp, Stefan

    2016-08-01

    Motivated by complex transport processes occurring in nature, we study a totally asymmetric simple exclusion process (TASEP) with a dynamic ‘roadblock’ particle. The roadblock particle blocks the traffic of moving particles while bound to the lattice, but can stochastically unbind or switch off, thus enabling the traffic to pass. We use simulations to study the dependence of the particle flux on the on/off switching dynamics of the roadblock, which exhibits a surprisingly rich dynamic behaviour. In particular, unlike in other studied TASEP variants with defects, here we observe that the particle flux is affected by the roadblock even in the initiation-limited or low density phase if the roadblock dynamics is slow. Rapid switching off the roadblock results in the typical behaviour of a TASEP with a defect/pause with reduced maximal current, but no effect of the roadblock on the flux in the initiation-limited phase. Moreover, in an intermediate range of roadblock rates, the particle current is found to be system-size dependent.

  11. Theoretical analysis and simulation for a facilitated asymmetric exclusion process

    NASA Astrophysics Data System (ADS)

    Hao, Qing-Yi; Chen, Zhe; Sun, Xiao-Yan; Liu, Bing-Bing; Wu, Chao-Yun

    2016-08-01

    Driven diffusive systems are important models in nonequilibrium state statistical mechanics. This paper studies an asymmetric exclusion process model with nearest rear neighbor interactions associated with energy. The exact flux expression of the model is obtained by a cluster mean-field method. Based on the flux expression, the properties of the fundamental diagram have been investigated in detail. To probe the energy's influence on the coarsening process of the system, Monte Carlo simulations are carried out to acquire the monotonic phase boundary in energy-density space. Above the phase boundary, the system is inhomogeneous and the normalized residence distribution p (s ) is nonmonotonically decreasing. Under the phase boundary, the system is homogeneous and p (s ) is monotonically decreasing. Further study comparatively shows that the system has turned into a microscopic inhomogeneous state from a homogeneous state before the system current arrives at maximum, if nearest rear neighbor interactions are strong. Our findings offer insights to deeply understand the dynamic features of nonequilibrium state systems.

  12. A CLASSIFICATION SCHEME FOR TURBULENT ACCELERATION PROCESSES IN SOLAR FLARES

    SciTech Connect

    Bian, Nicolas; Kontar, Eduard P.; Emslie, A. Gordon E-mail: eduard@astro.gla.ac.uk

    2012-08-01

    We establish a classification scheme for stochastic acceleration models involving low-frequency plasma turbulence in a strongly magnetized plasma. This classification takes into account both the properties of the accelerating electromagnetic field, and the nature of the transport of charged particles in the acceleration region. We group the acceleration processes as either resonant, non-resonant, or resonant-broadened, depending on whether the particle motion is free-streaming along the magnetic field, diffusive, or a combination of the two. Stochastic acceleration by moving magnetic mirrors and adiabatic compressions are addressed as illustrative examples. We obtain expressions for the momentum-dependent diffusion coefficient D(p), both for general forms of the accelerating force and for the situation when the electromagnetic force is wave-like, with a specified dispersion relation {omega} = {omega}(k). Finally, for models considered, we calculate the energy-dependent acceleration time, a quantity that can be directly compared with observations of the time profile of the radiation field produced by the accelerated particles, such as those occuring during solar flares.

  13. Adaptive control technique for accelerators using digital signal processing

    SciTech Connect

    Eaton, L.; Jachim, S.; Natter, E.

    1987-01-01

    The use of present Digital Signal Processing (DSP) techniques can drastically reduce the residual rf amplitude and phase error in an accelerating rf cavity. Accelerator beam loading contributes greatly to this residual error, and the low-level rf field control loops cannot completely absorb the fast transient of the error. A feedforward technique using DSP is required to maintain the very stringent rf field amplitude and phase specifications. 7 refs.

  14. Myopic random walkers and exclusion processes: Single and multispecies

    NASA Astrophysics Data System (ADS)

    Landman, Kerry A.; Fernando, Anthony E.

    2011-10-01

    A motility mechanism based on a simple exclusion process, where the probability of movement of an agent depends on the number of unoccupied nearest-neighbor sites is considered. Such interacting agents are termed myopic. This problem is an extension of the famous blind or myopic ant in a labyrinth problem. For the interacting agent models considered here, each agent plays the role of an ant in a labyrinth, where the paths of allowed sites though the labyrinth consist of sites not occupied by other agents. We derive a nonlinear diffusion equation for the average occupancy of the discrete agent-based model for myopic agents. In contrast, interacting blind agents have a constant probability of movement to each of their nearest-neighbor sites, giving rise to a linear diffusion equation. Insight into the various terms in the nonlinear diffusion coefficient is obtained from a study of multiple subpopulations of interacting myopic agents, where an advection-diffusion equation for each subpopulation is derived, and from tracking an individual agent within the crowd, where a motility coefficient is extracted. Averaged discrete simulation data compares very well with the solution to the continuum models. We also compare the behavior of myopic and blind agents. The myopic motility mechanism is biologically motivated to emulate information an individual cell gathers from environment cues. The multispecies model developed and investigated here assists with the interpretation of experimental data involving the tracking subpopulations of cells within a total cell population.

  15. QED Radiative Corrections in Processes of Exclusive Pion Electroproduction

    SciTech Connect

    Andrei Afanasev; I. Akushevich; Volker Burkert; K. Joo

    2002-03-01

    Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.

  16. QED radiative corrections in processes of exclusive pion electroproduction

    NASA Astrophysics Data System (ADS)

    Afanasev, A.; Akushevich, I.; Burkert, V.; Joo, K.

    2002-10-01

    A formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.

  17. Graphics Processing Unit Acceleration of Gyrokinetic Turbulence Simulations

    NASA Astrophysics Data System (ADS)

    Hause, Benjamin; Parker, Scott

    2012-10-01

    We find a substantial increase in on-node performance using Graphics Processing Unit (GPU) acceleration in gyrokinetic delta-f particle-in-cell simulation. Optimization is performed on a two-dimensional slab gyrokinetic particle simulation using the Portland Group Fortran compiler with the GPU accelerator compiler directives. We have implemented the GPU acceleration on a Core I7 gaming PC with a NVIDIA GTX 580 GPU. We find comparable, or better, acceleration relative to the NERSC DIRAC cluster with the NVIDIA Tesla C2050 computing processor. The Tesla C 2050 is about 2.6 times more expensive than the GTX 580 gaming GPU. Optimization strategies and comparisons between DIRAC and the gaming PC will be presented. We will also discuss progress on optimizing the comprehensive three dimensional general geometry GEM code.

  18. Plasma acceleration processes in an ablative pulsed plasma thruster

    SciTech Connect

    Koizumi, Hiroyuki; Noji, Ryosuke; Komurasaki, Kimiya; Arakawa, Yoshihiro

    2007-03-15

    Plasma acceleration processes in an ablative pulsed plasma thruster (APPT) were investigated. APPTs are space propulsion options suitable for microspacecraft, and have recently attracted much attention because of their low electric power requirements and simple, compact propellant system. The plasma acceleration mechanism, however, has not been well understood. In the present work, emission spectroscopy, high speed photography, and magnetic field measurements are conducted inside the electrode channel of an APPT with rectangular geometry. The successive images of neutral particles and ions give us a comprehensive understanding of their behavior under electromagnetic acceleration. The magnetic field profile clarifies the location where the electromagnetic force takes effect. As a result, it is shown that high density, ablated neutral gas stays near the propellant surface, and only a fraction of the neutrals is converted into plasma and electromagnetically accelerated, leaving the residual neutrals behind.

  19. Asymmetric simple exclusion process on chains with a shortcut

    NASA Astrophysics Data System (ADS)

    Bunzarova, Nadezhda; Pesheva, Nina; Brankov, Jordan

    2014-03-01

    We consider the asymmetric simple exclusion process (TASEP) on an open network consisting of three consecutively coupled macroscopic chain segments with a shortcut between the tail of the first segment and the head of the third one. The model was introduced by Y.-M. Yuan et al. [J. Phys. A 40, 12351 (2007), 10.1088/1751-8113/40/41/006] to describe directed motion of molecular motors along twisted filaments. We report here unexpected results which revise the previous findings in the case of maximum current through the network. Our theoretical analysis, based on the effective rates' approximation, shows that the second (shunted) segment can exist in both low- and high-density phases, as well as in the coexistence (shock) phase. Numerical simulations demonstrate that the last option takes place in finite-size networks with head and tail chains of equal length, provided the injection and ejection rates at their external ends are equal and greater than one-half. Then the local density distribution and the nearest-neighbor correlations in the middle chain correspond to a shock phase with completely delocalized domain wall. Upon moving the shortcut to the head or tail of the network, the density profile takes a shape typical of a high- or low-density phase, respectively. Surprisingly, the main quantitative parameters of that shock phase are governed by a positive root of a cubic equation, the coefficients of which linearly depend on the probability of choosing the shortcut. Alternatively, they can be expressed in a universal way through the shortcut current. The unexpected conclusion is that a shortcut in the bulk of a single lane may create traffic jams.

  20. Asymmetric simple exclusion process on chains with a shortcut.

    PubMed

    Bunzarova, Nadezhda; Pesheva, Nina; Brankov, Jordan

    2014-03-01

    We consider the asymmetric simple exclusion process (TASEP) on an open network consisting of three consecutively coupled macroscopic chain segments with a shortcut between the tail of the first segment and the head of the third one. The model was introduced by Y.-M. Yuan et al. [J. Phys. A 40, 12351 (2007)] to describe directed motion of molecular motors along twisted filaments. We report here unexpected results which revise the previous findings in the case of maximum current through the network. Our theoretical analysis, based on the effective rates' approximation, shows that the second (shunted) segment can exist in both low- and high-density phases, as well as in the coexistence (shock) phase. Numerical simulations demonstrate that the last option takes place in finite-size networks with head and tail chains of equal length, provided the injection and ejection rates at their external ends are equal and greater than one-half. Then the local density distribution and the nearest-neighbor correlations in the middle chain correspond to a shock phase with completely delocalized domain wall. Upon moving the shortcut to the head or tail of the network, the density profile takes a shape typical of a high- or low-density phase, respectively. Surprisingly, the main quantitative parameters of that shock phase are governed by a positive root of a cubic equation, the coefficients of which linearly depend on the probability of choosing the shortcut. Alternatively, they can be expressed in a universal way through the shortcut current. The unexpected conclusion is that a shortcut in the bulk of a single lane may create traffic jams. PMID:24730808

  1. Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

    SciTech Connect

    Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2013-11-15

    The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA.

  2. QCD mechanisms of (semi)exclusive Drell-Yan processes

    SciTech Connect

    Pivovarov, A.A.; Teryaev, O.V.

    2015-04-10

    Two mechanisms for the lepton pair production in exclusive proton-meson collisions are considered and compared. Amplitudes and differential cross sections are calculated. The interference of these mechanisms is taken into account. The skewness dependence of the result is discussed.

  3. Secondary electron emission from plasma processed accelerating cavity grade niobium

    NASA Astrophysics Data System (ADS)

    Basovic, Milos

    Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier. Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher energy upgrades of existing accelerators and more compact designs of new accelerators. Each new and improved technology was faced with ever emerging limiting factors. With the standard high accelerating gradients of more than 25 MV/m, free electrons inside the cavities get accelerated by the field, gaining enough energy to produce more electrons in their interactions with the walls of the cavity. The electron production is exponential and the electron energy transfer to the walls of a cavity can trigger detrimental processes, limiting the performance of the cavity. The root cause of the free electron number gain is a phenomenon called Secondary Electron Emission (SEE). Even though the phenomenon has been known and studied over a century, there are still no effective means of controlling it. The ratio between the electrons emitted from the surface and the impacting electrons is defined as the Secondary Electron Yield (SEY). A SEY ratio larger than 1 designates an increase in the total number of electrons. In the design of accelerator cavities, the goal is to reduce the SEY to be as low as possible using any form of surface manipulation. In this dissertation, an experimental setup was developed and used to study the SEY of various sample surfaces that were treated

  4. Measurement of diffractive and exclusive processes with the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Gach, Grzegorz

    2016-07-01

    The ATLAS Collaboration has carried out a study of diffractive dijet production in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.

  5. 78 FR 37242 - Request for Public Comments: Interagency Review of Exclusion Order Enforcement Process

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... exclusion order. IPEC will chair a new interagency effort directed at strengthening the processes that CBP..., 19 CFR part 177, an importer may seek a prospective ruling on whether a redesigned or new...

  6. Experimental review of exclusive processes in two photon reactions

    SciTech Connect

    Ronan, M.T.

    1986-07-01

    Recent experimental results on exclusive final stated produced in photon-photon interactions are reviewed. Comparisons between experiments and with perturbative QCD calculations are made for meson and baryon pair production. New results on vector meson pair (rho/sup 0/rho/sup 0/,rho/sup 0/omega,rho/sup 0/phi,...) production and production of multiparticle (KK..pi pi..,K*K..pi..,...) final states are summarized. 34 refs.

  7. Exclusive processes at JLab at 6 GeV

    SciTech Connect

    Kim, Andrey

    2015-01-01

    Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and -t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.

  8. Induction linear accelerators for commercial photon irradiation processing

    SciTech Connect

    Matthews, S.M.

    1989-01-13

    A number of proposed irradiation processes requires bulk rather than surface exposure with intense applications of ionizing radiation. Typical examples are irradiation of food packaged into pallet size containers, processing of sewer sludge for recycling as landfill and fertilizer, sterilization of prepackaged medical disposals, treatment of municipal water supplies for pathogen reduction, etc. Volumetric processing of dense, bulky products with ionizing radiation requires high energy photon sources because electrons are not penetrating enough to provide uniform bulk dose deposition in thick, dense samples. Induction Linear Accelerator (ILA) technology developed at the Lawrence Livermore National Laboratory promises to play a key role in providing solutions to this problem. This is discussed in this paper.

  9. Enzyme clustering accelerates processing of intermediates through metabolic channeling.

    PubMed

    Castellana, Michele; Wilson, Maxwell Z; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M; Rabinowitz, Joshua D; Gitai, Zemer; Wingreen, Ned S

    2014-10-01

    We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

  10. Enzyme clustering accelerates processing of intermediates through metabolic channeling

    PubMed Central

    Castellana, Michele; Wilson, Maxwell Z.; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M.; Rabinowitz, Joshua D.; Gitai, Zemer; Wingreen, Ned S.

    2015-01-01

    We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

  11. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  12. Modeling the Acceleration Process of Dust in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Jia, Y. D.; Lai, H.; Russell, C. T.; Wei, H.

    2015-12-01

    In previous studies we have identified structures created by nano-dust in the solar wind, and we have observed the expected draping and diverting signatures of such structures using well-spaced multi-spacecraft observations. In this study, we reproduce such an interaction event with our multi-fluid MHD model, modeling the dust particles as a fluid. When the number density of dust particles is comparable to the solar wind ions, a significant draping in the IMF is created, with amplitude larger than the ambient fluctuations. We note that such a density is well above several nano dust particles per Debye sphere and a dusty fluid is appropriate for modeling the dust-solar wind interaction. We assume a spherical cloud of dust travelling with 90% solar wind speed. In addition to reproducing the IMF response to the nano-dust at the end-stage of dust acceleration, we model the entire process of such acceleration in the gravity field of the inner heliosphere. It takes hours for the smallest dust with 3000 amu per proton charge to reach the solar wind speed. We find the dust cloud stretched along the solar wind flow. Such stretching enhances the draping of IMF, compared to the spherical cloud we used in an earlier stage of this study. This model will be further used to examine magnetic perturbations at an earlier stage of dust cloud acceleration, and then determine the size, density, and total mass of dust cloud, as well as its creation and acceleration.

  13. Deeply Virtual Exclusive Processes and Generalized Parton Distributions

    SciTech Connect

    ,

    2011-06-01

    The goal of the comprehensive program in Deeply Virtual Exclusive Scattering at Jefferson Laboratory is to create transverse spatial images of quarks and gluons as a function of their longitudinal momentum fraction in the proton, the neutron, and in nuclei. These functions are the Generalized Parton Distributions (GPDs) of the target nucleus. Cross section measurements of the Deeply Virtual Compton Scattering (DVCS) reaction ep {yields} ep{gamma} in Hall A support the QCD factorization of the scattering amplitude for Q^2 {>=} 2 GeV^2. Quasi-free neutron-DVCS measurements on the Deuteron indicate sensitivity to the quark angular momentum sum rule. Fully exclusive H(e, e'p{gamma} ) measurements have been made in a wide kinematic range in CLAS with polarized beam, and with both unpolarized and longitudinally polarized targets. Existing models are qualitatively consistent with the JLab data, but there is a clear need for less constrained models. Deeply virtual vector meson production is studied in CLAS. The 12 GeV upgrade will be essential for for these channels. The {rho} and {omega} channels reactions offer the prospect of flavor sensitivity to the quark GPDs, while the {phi}-production channel is dominated by the gluon distribution.

  14. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P. ); Elliott, A. )

    1992-01-01

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  15. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P.; Elliott, A.

    1992-12-31

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  16. Accelerating sino-atrium computer simulations with graphic processing units.

    PubMed

    Zhang, Hong; Xiao, Zheng; Lin, Shien-fong

    2015-01-01

    Sino-atrial node cells (SANCs) play a significant role in rhythmic firing. To investigate their role in arrhythmia and interactions with the atrium, computer simulations based on cellular dynamic mathematical models are generally used. However, the large-scale computation usually makes research difficult, given the limited computational power of Central Processing Units (CPUs). In this paper, an accelerating approach with Graphic Processing Units (GPUs) is proposed in a simulation consisting of the SAN tissue and the adjoining atrium. By using the operator splitting method, the computational task was made parallel. Three parallelization strategies were then put forward. The strategy with the shortest running time was further optimized by considering block size, data transfer and partition. The results showed that for a simulation with 500 SANCs and 30 atrial cells, the execution time taken by the non-optimized program decreased 62% with respect to a serial program running on CPU. The execution time decreased by 80% after the program was optimized. The larger the tissue was, the more significant the acceleration became. The results demonstrated the effectiveness of the proposed GPU-accelerating methods and their promising applications in more complicated biological simulations. PMID:26406070

  17. Polymer processing by a low energy ion accelerator

    NASA Astrophysics Data System (ADS)

    Lorusso, A.; Velardi, L.; Nassisi, V.; Paladini, F.; Visco, A. M.; Campo, N.; Torrisi, L.; Margarone, D.; Giuffrida, L.; Rainò, A.

    2008-05-01

    Ion implantation is a process in which ions are accelerated toward a substrate at energies high enough to bury them just below the surface substrate in order to modify the surface characteristics. Laser-produced plasma is a very suitable and low cost technique in the production of ion sources. In this work, a laser ion source is developed by a UV pulsed laser of about 108 W/cm2 power density, employing a C target and a post ion acceleration of 40 kV to increase the ion energy. In this work, we implanted C ions on ultra-high-molecular-weight-polyethylene (UHMWPE) and low-density polyethylene (LDPE). We present the preliminary results of surface property modifications for both samples. In particular, we have studied the modifications of the surface micro-hardness of the polymers by applying the "scratch test" method as well as the hydrophilicity modifications by the contact angle measurements.

  18. Ads/cft and Exclusive Processes in QCD

    NASA Astrophysics Data System (ADS)

    Brodsky, Stanley J.; de Téramond, Guy F.

    2008-03-01

    The AdS/CFT correspondence between string theory in AdS space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. One can use holography to map the amplitude describing the hadronic state in the fifth dimension of Anti-de Sitter space AdS5 to the light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons in QCD at the amplitude level. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable ζ which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. New relativistic light-front equations in ordinary space-time can then be derived which reproduce the results obtained using the 5-dimensional theory. The effective light-front equations possess elegant algebraic structures and integrability properties. This connection between the AdS and the light-front representations allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties and allow the computation of decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. As specific examples we compute the pion coupling constant fπ and study the behavior of the pion form factor Fπ(q2) in the space and time-like regions. We also determine the Dirac nucleon form factors Fp1(q^2) and Fn1(q^2) in the space-like region.

  19. Graphics Processing Unit Acceleration of Gyrokinetic Turbulence Simulations

    NASA Astrophysics Data System (ADS)

    Hause, Benjamin; Parker, Scott; Chen, Yang

    2013-10-01

    We find a substantial increase in on-node performance using Graphics Processing Unit (GPU) acceleration in gyrokinetic delta-f particle-in-cell simulation. Optimization is performed on a two-dimensional slab gyrokinetic particle simulation using the Portland Group Fortran compiler with the OpenACC compiler directives and Fortran CUDA. Mixed implementation of both Open-ACC and CUDA is demonstrated. CUDA is required for optimizing the particle deposition algorithm. We have implemented the GPU acceleration on a third generation Core I7 gaming PC with two NVIDIA GTX 680 GPUs. We find comparable, or better, acceleration relative to the NERSC DIRAC cluster with the NVIDIA Tesla C2050 computing processor. The Tesla C 2050 is about 2.6 times more expensive than the GTX 580 gaming GPU. We also see enormous speedups (10 or more) on the Titan supercomputer at Oak Ridge with Kepler K20 GPUs. Results show speed-ups comparable or better than that of OpenMP models utilizing multiple cores. The use of hybrid OpenACC, CUDA Fortran, and MPI models across many nodes will also be discussed. Optimization strategies will be presented. We will discuss progress on optimizing the comprehensive three dimensional general geometry GEM code.

  20. Radiative And Electroweak Penguin Processes in Exclusive B Decays

    SciTech Connect

    Kovalskyi, Dmytro; /UC, Santa Barbara

    2011-06-14

    A review of recent BABAR results on exclusive B {yields} ({rho}/{Omega}){gamma}, B {yields} {pi}l{sup +}l{sup -} and B {yields} K(*) l{sup +}l{sup -} decays is presented. It was found that {bar {Beta}}[B {yields} ({rho}/{omega}){gamma}] = (1.01 {+-} 0.21 {+-} 0.08) x 10{sup -6}, {bar {Beta}}[B{sup +} {yields} {pi}l{sup +}l{sup -}] < 7.9 x 10{sup -8} at 90% C.L., {bar {Beta}}[B {yields} Kl{sup +}l{sup -}] = (0.84 {+-} 0.07 {+-} 0.02) x 10{sup -6} and {bar {Beta}}[B {yields} K*l{sup +}l{sup -}] = (0.78{sub -0.17}{sup +0.19} {+-} 0.11) x 10{sup -6}. it was also found that different asymmetry measurements are consistent with Standard Model expectations. Based on these results an independent estimate of the |V{sub td}/V{sub ts}| matrix element of the CKM matrix is derived to be |V{sub td}/V{sub ts}| = 0.171{sub -0.021-0.014}{sup +0.018+0.017}. A first evidence of B{sup +} {yields} {rho}{sup +}{gamma} decays was found and last year's observation of B{sup 0} {yields} {rho}{sup 0}{gamma} was confirmed.

  1. Exact dynamical state of the exclusive queueing process with deterministic hopping

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Schadschneider, Andreas

    2011-11-01

    The exclusive queueing process (EQP) has recently been introduced as a model for the dynamics of queues that takes into account the spatial structure of the queue. It can be interpreted as a totally asymmetric exclusion process of varying length. Here we investigate the case of deterministic bulk hopping p=1 that turns out to be one of the rare cases where exact nontrivial results for the dynamical properties can be obtained. Using a time-dependent matrix product form we calculate several dynamical properties, e.g., the density profile of the system.

  2. Particle acceleration via reconnection processes in the supersonic solar wind

    SciTech Connect

    Zank, G. P.; Le Roux, J. A.; Webb, G. M.; Dosch, A.; Khabarova, O.

    2014-12-10

    An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We derive a gyrophase-averaged transport equation for particles experiencing pitch-angle scattering and energization in a super-Alfvénic flowing plasma experiencing multiple small-scale reconnection events. A simpler advection-diffusion transport equation for a nearly isotropic particle distribution is derived. The dominant charged particle energization processes are (1) the electric field induced by quasi-2D magnetic island merging and (2) magnetic island contraction. The magnetic island topology ensures that charged particles are trapped in regions where they experience repeated interactions with the induced electric field or contracting magnetic islands. Steady-state solutions of the isotropic transport equation with only the induced electric field and a fixed source yield a power-law spectrum for the accelerated particles with index α = –(3 + M{sub A} )/2, where M{sub A} is the Alfvén Mach number. Considering only magnetic island contraction yields power-law-like solutions with index –3(1 + τ {sub c}/(8τ{sub diff})), where τ {sub c}/τ{sub diff} is the ratio of timescales between magnetic island contraction and charged particle diffusion. The general solution is a power-law-like solution with an index that depends on the Alfvén Mach number and the timescale ratio τ{sub diff}/τ {sub c}. Observed power-law distributions of energetic particles observed in the quiet supersonic solar wind at 1 AU may be a consequence of particle acceleration associated with dissipative small-scale reconnection processes in a turbulent plasma, including the widely reported c {sup –5} (c particle

  3. Full current statistics for a disordered open exclusion process

    NASA Astrophysics Data System (ADS)

    Ayyer, Arvind

    2016-04-01

    We consider the nonabelian sandpile model defined on directed trees by Ayyer et al (2015 Commun. Math. Phys. 335 1065) and restrict it to the special case of a one-dimensional lattice of n sites which has open boundaries and disordered hopping rates. We focus on the joint distribution of the integrated currents across each bond simultaneously, and calculate its cumulant generating function exactly. Surprisingly, the process conditioned on seeing specified currents across each bond turns out to be a renormalised version of the same process. We also remark on a duality property of the large deviation function. Lastly, all eigenvalues and both Perron eigenvectors of the tilted generator are determined.

  4. The application of a linear electron accelerator in radiation processing

    NASA Astrophysics Data System (ADS)

    Ruiying, Zhou; Binglin, Wang; Wenxiu, Chen; Yongbao, Gu; Yinfen, Zhang; Simin, Qian; Andong, Liu; Peide, Wang

    A 3-5 MeV electron beam generated by a BF-5 type linear electron accelerator has been used in some radiation processing works, such as, (1) The cross-linking technology by radiation for the polyethylene foaming processing --- the correlation between the cross-linkage and the absorbed dose, the relation between the elongation of foaming polyethylene and the dose, the relation between the size of the cavities and the gelatin rate and the optimum range of dosage for foaming have been found. (2) The research work on the fast switch thyristor irradiated by electron beam --- The relation between the absorbed dose and the life-time of minority carriers has been studied and the optimum condition for radiation processing was determined. This process is much better than the conventional gold diffusion in raising the quality and end-product rate of these devices. Besides, we have made some testing works on the hereditary mutation of plant seeds and microorganism mutation induced by electron radiation and radiation sterilization for some medical instruments and foods.

  5. Entropy of Stationary Nonequilibrium Measures of Boundary Driven Symmetric Simple Exclusion Processes

    NASA Astrophysics Data System (ADS)

    Bernardin, Cédric; Landim, Claudio

    2010-12-01

    We examine the entropy of stationary nonequilibrium measures of boundary driven symmetric simple exclusion processes. In contrast with the Gibbs-Shannon entropy (Bahadoran in J. Stat. Phys. 126(4-5):1069-1082, 2007; Derrida et al. in J. Stat. Phys. 126(4-5):1083-1108, 2007), the entropy of nonequilibrium stationary states differs from the entropy of local equilibrium states.

  6. Shocks induced by junctions in totally asymmetric simple exclusion processes under periodic boundary condition

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoyan; Xie, Yanbo; He, Zhiwei; Wang, Binghong

    2011-07-01

    This Letter investigates a totally asymmetric simple exclusion process (TASEP) with junctions in a one-dimensional transport system. Parallel update rules and periodic boundary condition are adopted. Two cases corresponding to different update rules are studied. The results show that the stationary states of system mainly depend on the selection behavior of particle at the bifurcation point.

  7. Comment on ``Steady-state properties of a totally asymmetric exclusion process with periodic structure''

    NASA Astrophysics Data System (ADS)

    Jiang, Rui; Hu, Mao-Bin; Wu, Qing-Song

    2008-07-01

    Lakatos [Phys. Rev. E 71, 011103 (2005)] have studied a totally asymmetric exclusion process that contains periodically varying movement rates. They have presented a cluster mean-field theory for the problem. We show that their cluster mean-field theory leads to redundant equations. We present a mean-field analysis in which there is no redundant equation.

  8. Exclusive processes: Tests of coherent QCD phenomena and nucleon substructure at CEBAF

    SciTech Connect

    Brodsky, S.J.

    1994-07-01

    Measurements of exclusive processes such as electroproduction, photoproduction, and Compton scattering are among the most sensitive probes of proton structure and coherent phenomena in quantum chromodynamics. The continuous electron beam at CEBAF, upgraded in laboratory energy to 10--12 GeV, will allow a systematic study of exclusive, semi-inclusive, and inclusive reactions in a kinematic range well-tuned to the study of fundamental nucleon and nuclear substructure. I also discuss the potential at CEBAF for studying novel QCD phenomena at the charm production threshold, including the possible production of nuclear-bound quarkonium.

  9. [Female students in internships in Parisian hospitals (1871-1910). Exclusion and inclusion processes].

    PubMed

    José, María; Somavilla, Ruiz

    2016-01-01

    This study addresses the explicit and implicit exclusion mechanisms that limited the access of women to internships in Paris hospitals during the last decades of the 19th century through examination of the documentation generated in the admission process and the texts of female physicians who supported their access. In response to the applications of female medical students to register for the admission tests, the Conseil de Surveillance de l'Assistance Publique delayed their entry for some years until their registration was finally permitted. However, their inclusion in the institution did not produce integration because of the multiple dimensions of the exclusion mechanisms. PMID:27363249

  10. Effects of social exclusion on cognitive processes: anticipated aloneness reduces intelligent thought.

    PubMed

    Baumeister, Roy F; Twenge, Jean M; Nuss, Christopher K

    2002-10-01

    Three studies examined the effects of randomly assigned messages of social exclusion. In all 3 studies, significant and large decrements in intelligent thought (including IQ and Graduate Record Examination test performance) were found among people told they were likely to end up alone in life. The decline in cognitive performance was found in complex cognitive tasks such as effortful logic and reasoning; simple information processing remained intact despite the social exclusion. The effects were specific to social exclusion, as participants who received predictions of future nonsocial misfortunes (accidents and injuries) performed well on the cognitive tests. The cognitive impairments appeared to involve reductions in both speed (effort) and accuracy. The effect was not mediated by mood. PMID:12374437

  11. Spatiotemporal processing of linear acceleration: primary afferent and central vestibular neuron responses

    NASA Technical Reports Server (NTRS)

    Angelaki, D. E.; Dickman, J. D.

    2000-01-01

    Spatiotemporal convergence and two-dimensional (2-D) neural tuning have been proposed as a major neural mechanism in the signal processing of linear acceleration. To examine this hypothesis, we studied the firing properties of primary otolith afferents and central otolith neurons that respond exclusively to horizontal linear accelerations of the head (0.16-10 Hz) in alert rhesus monkeys. Unlike primary afferents, the majority of central otolith neurons exhibited 2-D spatial tuning to linear acceleration. As a result, central otolith dynamics vary as a function of movement direction. During movement along the maximum sensitivity direction, the dynamics of all central otolith neurons differed significantly from those observed for the primary afferent population. Specifically at low frequencies (acceleration. At least three different groups of central response dynamics were described according to the properties observed for motion along the maximum sensitivity direction. "High-pass" neurons exhibited increasing gains and phase values as a function of frequency. "Flat" neurons were characterized by relatively flat gains and constant phase lags (approximately 20-55 degrees ). A few neurons ("low-pass") were characterized by decreasing gain and phase as a function of frequency. The response dynamics of central otolith neurons suggest that the approximately 90 degrees phase lags observed at low frequencies are not the result of a neural integration but rather the effect of nonminimum phase behavior, which could arise at least partly through spatiotemporal convergence. Neither afferent nor central otolith neurons discriminated between gravitational and inertial components of linear acceleration. Thus response sensitivity was indistinguishable during 0.5-Hz pitch oscillations and fore-aft movements

  12. GPU accelerated processing of astronomical high frame-rate videosequences

    NASA Astrophysics Data System (ADS)

    Vítek, Stanislav; Švihlík, Jan; Krasula, Lukáš; Fliegel, Karel; Páta, Petr

    2015-09-01

    Astronomical instruments located around the world are producing an incredibly large amount of possibly interesting scientific data. Astronomical research is expanding into large and highly sensitive telescopes. Total volume of data rates per night of operations also increases with the quality and resolution of state-of-the-art CCD/CMOS detectors. Since many of the ground-based astronomical experiments are placed in remote locations with limited access to the Internet, it is necessary to solve the problem of the data storage. It mostly means that current data acquistion, processing and analyses algorithm require review. Decision about importance of the data has to be taken in very short time. This work deals with GPU accelerated processing of high frame-rate astronomical video-sequences, mostly originating from experiment MAIA (Meteor Automatic Imager and Analyser), an instrument primarily focused to observing of faint meteoric events with a high time resolution. The instrument with price bellow 2000 euro consists of image intensifier and gigabite ethernet camera running at 61 fps. With resolution better than VGA the system produces up to 2TB of scientifically valuable video data per night. Main goal of the paper is not to optimize any GPU algorithm, but to propose and evaluate parallel GPU algorithms able to process huge amount of video-sequences in order to delete all uninteresting data.

  13. Accelerating sparse linear algebra using graphics processing units

    NASA Astrophysics Data System (ADS)

    Spagnoli, Kyle E.; Humphrey, John R.; Price, Daniel K.; Kelmelis, Eric J.

    2011-06-01

    The modern graphics processing unit (GPU) found in many standard personal computers is a highly parallel math processor capable of over 1 TFLOPS of peak computational throughput at a cost similar to a high-end CPU with excellent FLOPS-to-watt ratio. High-level sparse linear algebra operations are computationally intense, often requiring large amounts of parallel operations and would seem a natural fit for the processing power of the GPU. Our work is on a GPU accelerated implementation of sparse linear algebra routines. We present results from both direct and iterative sparse system solvers. The GPU execution model featured by NVIDIA GPUs based on CUDA demands very strong parallelism, requiring between hundreds and thousands of simultaneous operations to achieve high performance. Some constructs from linear algebra map extremely well to the GPU and others map poorly. CPUs, on the other hand, do well at smaller order parallelism and perform acceptably during low-parallelism code segments. Our work addresses this via hybrid a processing model, in which the CPU and GPU work simultaneously to produce results. In many cases, this is accomplished by allowing each platform to do the work it performs most naturally. For example, the CPU is responsible for graph theory portion of the direct solvers while the GPU simultaneously performs the low level linear algebra routines.

  14. The Impact of Social Class on Parent-Professional Interaction in School Exclusion Processes: Deficit or Disadvantage?

    ERIC Educational Resources Information Center

    Gazeley, Louise

    2012-01-01

    Although a great deal of previous literature has explored the ways in which social class affects parental engagement in educational processes, there has been surprisingly little discussion of the way in which social class shapes the parent-professional interaction that occurs in school exclusion processes specifically. School exclusion processes…

  15. Effective ergodicity breaking in an exclusion process with varying system length

    NASA Astrophysics Data System (ADS)

    Schultens, Christoph; Schadschneider, Andreas; Arita, Chikashi

    2015-09-01

    Stochastic processes of interacting particles in systems with varying length are relevant e.g. for several biological applications. We try to explore what kind of new physical effects one can expect in such systems. As an example, we extend the exclusive queueing process that can be viewed as a one-dimensional exclusion process with varying length, by introducing Langmuir kinetics. This process can be interpreted as an effective model for a queue that interacts with other queues by allowing incoming and leaving of customers in the bulk. We find surprising indications for breaking of ergodicity in a certain parameter regime, where the asymptotic growth behavior depends on the initial length. We show that a random walk with site-dependent hopping probabilities exhibits qualitatively the same behavior.

  16. Scaling Limits of a Tagged Particle in the Exclusion Process with Variable Diffusion Coefficient

    NASA Astrophysics Data System (ADS)

    Gonçalves, Patrícia; Jara, Milton

    2008-09-01

    We prove a law of large numbers and a central limit theorem for a tagged particle in a symmetric simple exclusion process in ℤ with variable diffusion coefficient. The scaling limits are obtained from a similar result for the current through -1/2 for a zero-range process with bond disorder. For the CLT, we prove convergence to a fractional Brownian motion of Hurst exponent 1/4.

  17. A new microwave EB accelerator for radiation processing

    NASA Astrophysics Data System (ADS)

    Cracknell, P. J.

    1995-02-01

    A new high beam power microwave electron linear accelerator, LINTEC 1020, has been built and installed for the AEA, EBIS (Harwell) Limited medical sterilisation irradiation facility. LINTEC microwave electron beam accelerator designs are based upon travelling wave RF structures working at 1300 MHz, with beam powers from 10 to 45 k Watts at 5 to 12 MeV. The accelerator design, installation and operating details are described together with performance characteristics of alternative equipments.

  18. Effects of serotonin 2A/1A receptor stimulation on social exclusion processing.

    PubMed

    Preller, Katrin H; Pokorny, Thomas; Hock, Andreas; Kraehenmann, Rainer; Stämpfli, Philipp; Seifritz, Erich; Scheidegger, Milan; Vollenweider, Franz X

    2016-05-01

    Social ties are crucial for physical and mental health. However, psychiatric patients frequently encounter social rejection. Moreover, an increased reactivity to social exclusion influences the development, progression, and treatment of various psychiatric disorders. Nevertheless, the neuromodulatory substrates of rejection experiences are largely unknown. The preferential serotonin (5-HT) 2A/1A receptor agonist, psilocybin (Psi), reduces the processing of negative stimuli, but whether 5-HT2A/1A receptor stimulation modulates the processing of negative social interactions remains unclear. Therefore, this double-blind, randomized, counterbalanced, cross-over study assessed the neural response to social exclusion after the acute administration of Psi (0.215 mg/kg) or placebo (Pla) in 21 healthy volunteers by using functional magnetic resonance imaging (fMRI) and resting-state magnetic resonance spectroscopy (MRS). Participants reported a reduced feeling of social exclusion after Psi vs. Pla administration, and the neural response to social exclusion was decreased in the dorsal anterior cingulate cortex (dACC) and the middle frontal gyrus, key regions for social pain processing. The reduced neural response in the dACC was significantly correlated with Psi-induced changes in self-processing and decreased aspartate (Asp) content. In conclusion, 5-HT2A/1A receptor stimulation with psilocybin seems to reduce social pain processing in association with changes in self-experience. These findings may be relevant to the normalization of negative social interaction processing in psychiatric disorders characterized by increased rejection sensitivity. The current results also emphasize the importance of 5-HT2A/1A receptor subtypes and the Asp system in the control of social functioning, and as prospective targets in the treatment of sociocognitive impairments in psychiatric illnesses. PMID:27091970

  19. An Unusual Process of Accelerated Weathering of a Marly Limestone

    NASA Astrophysics Data System (ADS)

    Ercoli, L.; Rizzo, G.; Algozzini, G.

    2003-04-01

    This work deals with a singular case of stone deterioration, which occurred during the restoration of the Cathedral of Cefalù. In particular, a significant process of stone decohesion started after a consolidation treatment on ashlars of the external face of the cloister portico. A study was carried out to characterize the stone and to investigate the deterioration process. Petrographical, chemical and physical analyses were performed on samples taken from the wall. The results indicate that the medieval monument was built using a Pliocene marly limestone, called "trubo", quarried from outcrops of the environs of Cefalù. The rock is soft and uniformely cemented. The carbonatic fraction of the rock is due to foraminifera shells; the rock also contains detritic quartz, feldspate and glauconite. The clay minerals, mainly illite and montmorillonite, are widespread in the rock in the form of thin layers. The use of such a stone in a building of relevant artistic value is definitely unusual. In fact, the "trubo" is a rock subjected to natural decay because of its mineralogical composition and fabric; as effect of natural weathering, in the outcrops the rock disaggregates uniformely, producing silt. In the cloister this effect was magnified by extreme environmental conditions (marine spray, severe excursions of both relative humidity and temperature). Furthermore, after soluble salts removing and subsequent consolidation with ethyl silicate, a significant acceleration of the decay process was observed, producing friable scales detach for a depth of about 3 cm into the ashlars. The stone appeared corroded and uneven. Experimental tests were performed in laboratory in order to evidence any origin of incompatibility between such stone composition and the treatments carried out, which on the other hand are the most generally adopted in restoration interventions.

  20. Analyzing Collision Processes with the Smartphone Acceleration Sensor

    ERIC Educational Resources Information Center

    Vogt, Patrik; Kuhn, Jochen

    2014-01-01

    It has been illustrated several times how the built-in acceleration sensors of smartphones can be used gainfully for quantitative experiments in school and university settings (see the overview in Ref. 1 ). The physical issues in that case are manifold and apply, for example, to free fall, radial acceleration, several pendula, or the exploitation…

  1. Analyzing collision processes with the smartphone acceleration sensor

    NASA Astrophysics Data System (ADS)

    Vogt, Patrik; Kuhn, Jochen

    2014-02-01

    It has been illustrated several times how the built-in acceleration sensors of smartphones can be used gainfully for quantitative experiments in school and university settings (see the overview in Ref. 1). The physical issues in that case are manifold and apply, for example, to free fall,2 radial acceleration,3 several pendula, or the exploitation of everyday contexts.6 This paper supplements these applications and presents an experiment to study elastic and inelastic collisions. In addition to the masses of the two impact partners, their velocities before and after the collision are of importance, and these velocities can be determined by numerical integration of the measured acceleration profile.

  2. Anomalous/Fractional Diffusion in Particle Acceleration Processes.

    NASA Astrophysics Data System (ADS)

    Bian, Nicolas

    2016-07-01

    This talk is aimed at reviewing a certain number of theoretical aspects concerning the relation between stochastic acceleration and anomalous/fractional transport of particles. As a matter of fact, anomalous velocity-space diffusion is required within any stochastic acceleration scenario to explain the formation of the ubiquitous power-law tail of non-thermal particles, as observed e.g. in the accelerated distribution of electrons during solar flares. I will establish a classification scheme for stochastic acceleration models involving turbulence in magnetized plasmas. This classification takes into account both the properties of the accelerating electromagnetic field, and the nature of the spatial transport (possibly fractional) of charged particles in the acceleration region. I will also discuss recent attempts to obtain spatially non-local and fractional diffusion equations directly from first principles, starting either from the Fokker-Planck equation in the large mean free-path regime or the Boltzmann equation involving velocity-space relaxation toward the kappa distribution instead of the standard Maxwellian distribution.

  3. Accelerating Cardiac Bidomain Simulations Using Graphics Processing Units

    PubMed Central

    Neic, Aurel; Liebmann, Manfred; Hoetzl, Elena; Mitchell, Lawrence; Vigmond, Edward J.; Haase, Gundolf

    2013-01-01

    Anatomically realistic and biophysically detailed multiscale computer models of the heart are playing an increasingly important role in advancing our understanding of integrated cardiac function in health and disease. Such detailed simulations, however, are computationally vastly demanding, which is a limiting factor for a wider adoption of in-silico modeling. While current trends in high-performance computing (HPC) hardware promise to alleviate this problem, exploiting the potential of such architectures remains challenging since strongly scalable algorithms are necessitated to reduce execution times. Alternatively, acceleration technologies such as graphics processing units (GPUs) are being considered. While the potential of GPUs has been demonstrated in various applications, benefits in the context of bidomain simulations where large sparse linear systems have to be solved in parallel with advanced numerical techniques are less clear. In this study, the feasibility of multi-GPU bidomain simulations is demonstrated by running strong scalability benchmarks using a state-of-the-art model of rabbit ventricles. The model is spatially discretized using the finite element methods (FEM) on fully unstructured grids. The GPU code is directly derived from a large pre-existing code, the Cardiac Arrhythmia Research Package (CARP), with very minor perturbation of the code base. Overall, bidomain simulations were sped up by a factor of 11.8 to 16.3 in benchmarks running on 6–20 GPUs compared to the same number of CPU cores. To match the fastest GPU simulation which engaged 20GPUs, 476 CPU cores were required on a national supercomputing facility. PMID:22692867

  4. Accelerating molecular docking calculations using graphics processing units.

    PubMed

    Korb, Oliver; Stützle, Thomas; Exner, Thomas E

    2011-04-25

    The generation of molecular conformations and the evaluation of interaction potentials are common tasks in molecular modeling applications, particularly in protein-ligand or protein-protein docking programs. In this work, we present a GPU-accelerated approach capable of speeding up these tasks considerably. For the evaluation of interaction potentials in the context of rigid protein-protein docking, the GPU-accelerated approach reached speedup factors of up to over 50 compared to an optimized CPU-based implementation. Treating the ligand and donor groups in the protein binding site as flexible, speedup factors of up to 16 can be observed in the evaluation of protein-ligand interaction potentials. Additionally, we introduce a parallel version of our protein-ligand docking algorithm PLANTS that can take advantage of this GPU-accelerated scoring function evaluation. We compared the GPU-accelerated parallel version to the same algorithm running on the CPU and also to the highly optimized sequential CPU-based version. In terms of dependence of the ligand size and the number of rotatable bonds, speedup factors of up to 10 and 7, respectively, can be observed. Finally, a fitness landscape analysis in the context of rigid protein-protein docking was performed. Using a systematic grid-based search methodology, the GPU-accelerated version outperformed the CPU-based version with speedup factors of up to 60. PMID:21434638

  5. Pain Processing after Social Exclusion and Its Relation to Rejection Sensitivity in Borderline Personality Disorder

    PubMed Central

    Bungert, Melanie; Koppe, Georgia; Niedtfeld, Inga; Vollstädt-Klein, Sabine; Schmahl, Christian

    2015-01-01

    Objective There is a general agreement that physical pain serves as an alarm signal for the prevention of and reaction to physical harm. It has recently been hypothesized that “social pain,” as induced by social rejection or abandonment, may rely on comparable, phylogenetically old brain structures. As plausible as this theory may sound, scientific evidence for this idea is sparse. This study therefore attempts to link both types of pain directly. We studied patients with borderline personality disorder (BPD) because BPD is characterized by opposing alterations in physical and social pain; hyposensitivity to physical pain is associated with hypersensitivity to social pain, as indicated by an enhanced rejection sensitivity. Method Twenty unmedicated female BPD patients and 20 healthy participants (HC, matched for age and education) played a virtual ball-tossing game (cyberball), with the conditions for exclusion, inclusion, and a control condition with predefined game rules. Each cyberball block was followed by a temperature stimulus (with a subjective pain intensity of 60% in half the cases). The cerebral responses were measured by functional magnetic resonance imaging. The Adult Rejection Sensitivity Questionnaire was used to assess rejection sensitivity. Results Higher temperature heat stimuli had to be applied to BPD patients relative to HCs to reach a comparable subjective experience of painfulness in both groups, which suggested a general hyposensitivity to pain in BPD patients. Social exclusion led to a subjectively reported hypersensitivity to physical pain in both groups that was accompanied by an enhanced activation in the anterior insula and the thalamus. In BPD, physical pain processing after exclusion was additionally linked to enhanced posterior insula activation. After inclusion, BPD patients showed reduced amygdala activation during pain in comparison with HC. In BPD patients, higher rejection sensitivity was associated with lower activation

  6. Competition between multiple totally asymmetric simple exclusion processes for a finite pool of resources.

    PubMed

    Cook, L Jonathan; Zia, R K P; Schmittmann, B

    2009-09-01

    Using Monte Carlo simulations and a domain-wall theory, we discuss the effect of coupling several totally asymmetric simple exclusion processes (TASEPs) to a finite reservoir of particles. This simple model mimics directed biological transport processes in the presence of finite resources such as protein synthesis limited by a finite pool of ribosomes. If all TASEPs have equal length, we find behavior which is analogous to a single TASEP coupled to a finite pool. For the more generic case of chains with different lengths, several unanticipated regimes emerge. A generalized domain-wall theory captures our findings in good agreement with simulation results. PMID:19905097

  7. Competition between multiple totally asymmetric simple exclusion processes for a finite pool of resources

    NASA Astrophysics Data System (ADS)

    Cook, L. Jonathan; Zia, R. K. P.; Schmittmann, B.

    2009-09-01

    Using Monte Carlo simulations and a domain-wall theory, we discuss the effect of coupling several totally asymmetric simple exclusion processes (TASEPs) to a finite reservoir of particles. This simple model mimics directed biological transport processes in the presence of finite resources such as protein synthesis limited by a finite pool of ribosomes. If all TASEPs have equal length, we find behavior which is analogous to a single TASEP coupled to a finite pool. For the more generic case of chains with different lengths, several unanticipated regimes emerge. A generalized domain-wall theory captures our findings in good agreement with simulation results.

  8. Self-duality for the two-component asymmetric simple exclusion process

    SciTech Connect

    Belitsky, V.; Schütz, G. M.

    2015-08-15

    We study a two-component asymmetric simple exclusion process (ASEP) that is equivalent to the ASEP with second-class particles. We prove self-duality with respect to a family of duality functions which are shown to arise from the reversible measures of the process and the symmetry of the generator under the quantum algebra U{sub q}[gl{sub 3}]. We construct all invariant measures in explicit form and discuss some of their properties. We also prove a sum rule for the duality functions.

  9. Accelerated Schools: The Inquiry Process and the Prospects for School Change.

    ERIC Educational Resources Information Center

    Polkinghorn, Robert, Jr.; And Others

    An assessment of two pilot accelerated schools using the inquiry process model for the transformation of school culture and classroom practices in serving at-risk students is presented in this report. The inquiry process is a central feature of the accelerated school, a comprehensive school renewal initiative. The traditional approach to changing…

  10. 77 FR 21991 - Federal Housing Administration (FHA): Multifamily Accelerated Processing (MAP)-Lender and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... URBAN DEVELOPMENT Federal Housing Administration (FHA): Multifamily Accelerated Processing (MAP)--Lender and Underwriter Eligibility Criteria and Credit Watch for MAP Lenders AGENCY: Office of the Assistant... processes for determining lender and underwriter eligibility and tier qualification for MAP...

  11. Accelerators for E-beam and X-ray processing

    NASA Astrophysics Data System (ADS)

    Auslender, V. L.; Bryazgin, A. A.; Faktorovich, B. L.; Gorbunov, V. A.; Kokin, E. N.; Korobeinikov, M. V.; Krainov, G. S.; Lukin, A. N.; Maximov, S. A.; Nekhaev, V. E.; Panfilov, A. D.; Radchenko, V. N.; Tkachenko, V. O.; Tuvik, A. A.; Voronin, L. A.

    2002-03-01

    During last years the demand for pasteurization and desinsection of various food products (meat, chicken, sea products, vegetables, fruits, etc.) had increased. The treatment of these products in industrial scale requires the usage of powerful electron accelerators with energy 5-10 MeV and beam power at least 50 kW or more. The report describes the ILU accelerators with energy range up to 10 MeV and beam power up to 150 kW.The different irradiation schemes in electron beam and X-ray modes for various products are described. The design of the X-ray converter and 90° beam bending system are also given.

  12. Microscopic Processes On Radiation from Accelerated Particles in Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Hardee, P. E.; Mizuno, Y.; Medvedev, M.; Zhang, B.; Sol, H.; Niemiec, J.; Pohl, M.; Nordlund, A.; Fredriksen, J.; Lyubarsky, Y.; Hartmann, D. H.; Fishman, G. J.

    2009-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electro-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the collisionless relativistic shock particle acceleration is due to plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The jitter'' radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  13. A co-design method for parallel image processing accelerator based on DSP and FPGA

    NASA Astrophysics Data System (ADS)

    Wang, Ze; Weng, Kaijian; Cheng, Zhao; Yan, Luxin; Guan, Jing

    2011-11-01

    In this paper, we present a co-design method for parallel image processing accelerator based on DSP and FPGA. DSP is used as application and operation subsystem to execute the complex operations, and in which the algorithms are resolving into commands. FPGA is used as co-processing subsystem for regular data-parallel processing, and operation commands and image data are transmitted to FPGA for processing acceleration. A series of experiments have been carried out, and up to a half or three quarter time is saved which supports that the proposed accelerator will consume less time and get better performance than the traditional systems.

  14. Exclusive two-photon processes: Tests of QCD at the amplitude level

    SciTech Connect

    Brodsky, S.J.

    1992-07-01

    Exclusive two-photon processes at large momentum transfer, particularly Compton scattering {gamma}p{yields}{gamma}p and its crossed-channel reactions {gamma}{gamma}{yields}{bar p}p and {bar p}p{yields}{gamma}{gamma}, can provide definitive information on the bound-state distributions of quarks in hadrons at the amplitude level. Recent theoretical work has shown that QCD predictions based on the factorization of long and short distance physics are already applicable at momentum transfers of order of a few GeV.

  15. Asymmetric Exclusion Process with Constrained Hopping and Parallel Dynamics at a Junction

    NASA Astrophysics Data System (ADS)

    Liu, Mingzhe; Tuo, Xianguo; Li, Zhe; Yang, Jianbo

    In this article totally asymmetric simple exclusion process (TASEP) with constrained hopping and parallel dynamics at a junction is investigated using a mean-field approximation and Monte Carlo simulations. The constrained particle hopping probability r (r ≤ 1) at a junction may correspond to a delay caused by a driver choosing the right direction or a delay waiting for green traffic light in the real world. There are six stationary phases in the system, which can reflect free flow and congested traffic situations. Correlations at the junction point are investigated via simulations. It is observed that small r leads to stronger correlations. The theoretical results are agreement with computer simulations well.

  16. Power Spectra of a Totally Asymmetric Simple Exclusion Process with Finite Resources

    NASA Astrophysics Data System (ADS)

    Cook, L. Jonathan; Zia, Royce K. P.

    2010-03-01

    In a cell, a mRNA has only a finite number of ribosomes to use during protein synthesis. We take this constraint into account in the modeling of translation by a totally asymmetric simple exclusion process (TASEP). Through Monte Carlo simulations and analytical methods, we study the power spectrum of the total particle occupancy of the TASEP. New features are found, such as a severe suppression at low frequencies. We formulate a theory based on a linearized Langevin equation with discrete space and time. With good agreement between the theoretical approach and the simulations, we gain some insight in how finite resources affect a TASEP.

  17. Origin and dynamics of a bottleneck-induced shock in a two-channel exclusion process

    NASA Astrophysics Data System (ADS)

    Dhiman, Isha; Gupta, Arvind Kumar

    2016-05-01

    We analyze the origin and characteristics of the bottleneck-induced shock in a two-channel totally asymmetric simple exclusion process with Langmuir kinetics under symmetric coupling conditions. The variation in height of the spike, which has been found to be a precursor to the bottleneck-induced shock, is analyzed with respect to lane-changing rate Ω and bottleneck rate q. The critical value of q (qc), below which the effect of bottleneck turns from local to global, has been identified. A non-monotonic variation of qc with respect to Ω is observed. The bottleneck-induced shock exhibits turning effect with respect to an increase in Ω.

  18. Strong Asymmetric Coupling of Two Parallel Exclusion Processes: Effect of Unequal Injection Rates

    NASA Astrophysics Data System (ADS)

    Xiao, Song; Dong, Peng; Zhang, Yingjie; Liu, Yanna

    2016-03-01

    In this letter, strong asymmetric coupling of two parallel exclusion processes: effect of unequal injection rates will be investigated. It is a generalization of the work of Xiao et al. (Phys. Lett. A 8, 374 (2009)), in which the particles only move on two lanes with rate 1 toward right. We can obtain the diverse phase diagram and density profiles of the system. The vertical cluster mean-field approach and extensively Monte Carlo simulations are used to study the system, and theoretical predictions are in excellent agreement with simulation results.

  19. A computation using mutually exclusive processing is sufficient to identify specific Hedgehog signaling components

    PubMed Central

    Spratt, Spencer J.

    2013-01-01

    A system of more than one part can be deciphered by observing differences between the parts. A simple way to do this is by recording something absolute displaying a trait in one part and not in another: in other words, mutually exclusive computation. Conditional directed expression in vivo offers processing in more than one part of the system giving increased computation power for biological systems analysis. Here, I report the consideration of these aspects in the development of an in vivo screening assay that appears sufficient to identify components specific to a system. PMID:24391661

  20. Exclusive QCD processes, quark-hadron duality, and the transition to perturbative QCD

    NASA Astrophysics Data System (ADS)

    Corianò, Claudio; Li, Hsiang-nan; Savkli, Cetin

    1998-07-01

    Experiments at CEBAF will scan the intermediate-energy region of the QCD dynamics for the nucleon form factors and for Compton Scattering. These experiments will definitely clarify the role of resummed perturbation theory and of quark-hadron duality (QCD sum rules) in this regime. With this perspective in mind, we review the factorization theorem of perturbative QCD for exclusive processes at intermediate energy scales, which embodies the transverse degrees of freedom of a parton and the Sudakov resummation of the corresponding large logarithms. We concentrate on the pion and proton electromagnetic form factors and on pion Compton scattering. New ingredients, such as the evolution of the pion wave function and the complete two-loop expression of the Sudakov factor, are included. The sensitivity of our predictions to the infrared cutoff for the Sudakov evolution is discussed. We also elaborate on QCD sum rule methods for Compton Scattering, which provide an alternative description of this process. We show that, by comparing the local duality analysis to resummed perturbation theory, it is possible to describe the transition of exclusive processes to perturbative QCD.

  1. Next generation tools to accelerate the synthetic biology process.

    PubMed

    Shih, Steve C C; Moraes, Christopher

    2016-05-16

    Synthetic biology follows the traditional engineering paradigm of designing, building, testing and learning to create new biological systems. While such approaches have enormous potential, major challenges still exist in this field including increasing the speed at which this workflow can be performed. Here, we present recently developed microfluidic tools that can be used to automate the synthetic biology workflow with the goal of advancing the likelihood of producing desired functionalities. With the potential for programmability, automation, and robustness, the integration of microfluidics and synthetic biology has the potential to accelerate advances in areas such as bioenergy, health, and biomaterials. PMID:27146265

  2. Accelerated conformational entropy calculations using graphic processing units.

    PubMed

    Zhang, Qian; Wang, Junmei; Guerrero, Ginés D; Cecilia, José M; García, José M; Li, Youyong; Pérez-Sánchez, Horacio; Hou, Tingjun

    2013-08-26

    Conformational entropy calculation, usually computed by normal-mode analysis (NMA) or quasi harmonic analysis (QHA), is extremely time-consuming. Here, instead of NMA or QHA, a solvent accessible surface area (SASA) based model was employed to compute the conformational entropy, and a new fast GPU-based method called MURCIA (Molecular Unburied Rapid Calculation of Individual Areas) was implemented to accelerate the calculation of SASA for each atom. MURCIA employs two different kernels to determine the neighbors of each atom. The first kernel (K1) uses brute force for the calculation of the neighbors of atoms, while the second one (K2) uses an advanced algorithm involving hardware interpolations via GPU texture memory unit for such purpose. These two kernels yield very similar results. Each kernel has its own advantages depending on the protein size. K1 performs better than K2 when the size is small and vice versa. The algorithm was extensively evaluated for four protein data sets and achieves good results for all of them. This GPU-accelerated version is ∼600 times faster than the former sequential algorithm when the number of the atoms in a protein is up to 10⁵. PMID:23862733

  3. Bidirectional transport in a multispecies totally asymmetric exclusion-process model

    NASA Astrophysics Data System (ADS)

    Muhuri, Sudipto; Shagolsem, Lenin; Rao, Madan

    2011-09-01

    We study a minimal lattice model which describes bidirectional transport of “particles” driven along a one-dimensional track, as is observed in microtubule based, motor protein driven bidirectional transport of cargo vesicles, lipid bodies, and organelles such as mitochondria. This minimal model, a multispecies totally asymmetric exclusion process (TASEP) with directional switching, can provide a framework for understanding the interplay between the switching dynamics of individual particles and the collective movement of particles in one dimension. When switching is much faster than translocation, the steady-state density and current profiles of the particles are homogeneous in the bulk and are well described by mean-field (MF) theory, as determined by comparison to a Monte Carlo simulation. In this limit, we can map this model to the exactly solvable partially asymmetric exclusion-process (PASEP) model. Away from this fast switching regime the MF theory fails, although the average bulk density profile still remains homogeneous. We study the steady-state behavior as a function of the ratio of the translocation and net switching rates Q and find a unique first-order phase transition at a finite Q associated with a discontinuous change of the bulk density. When the switching rate is decreased further (keeping translocation rate fixed), the system approaches a jammed phase with a net current that tends to zero as J˜1/Q. We numerically construct the phase diagram for finite Q.

  4. Polymeric flocculants processing by accelerated electron beams and microwave heating

    NASA Astrophysics Data System (ADS)

    Martin, Diana I.; Mateescu, Elena; Craciun, Gabriela; Ighigeanu, Daniel; Ighigeanu, Adelina

    2002-08-01

    Results obtained by accelerated electron beam, microwave and simultaneous microwave and electron beam application in the chemistry of acrylamide and acrylic acid copolymers (polymeric flocculants used for wastewater treatment) are presented. Comparative results concerning the molecular weight and Huggins' constant for the acrylamide and acrylic acid copolymers obtained by classical heating, microwave heating, electron beam irradiation and simultaneous microwave and electron beam treatment are reported. Microwave heating produces high water solubility of the polymeric flocculants but median molecular weight values. Electron beam irradiation gives high molecular weight values but associated with a cross-linked structure (poor water solubility) while microwave energy addition to electron beam energy gives simultaneously high molecular weight values and high water solubility.

  5. A process for separating acid-sugar mixtures using ion exclusion chromatography

    SciTech Connect

    Hester, R.D.; Hartfield, S.W.; Farina, G.E.

    1994-10-01

    Work using a low-temperature concentrated sulfuric acid hydrolysis process to convert the cellulosic fraction of corn stover to monomeric sugars demonstrated the high conversion efficiencies possible with that process. The TVA work also confirmed the need for a cost-effective acid-sugar separation process. A preparative-scale ion-exclusion chromatography (IEC) system was designed, constructed, and tested with a variety of synthetic solutions and actual hydrolyzates. Although significant dispersion was observed initially, design changes were effective in minimizing this phenomenon. Data collected during the operation of the preparative-scale system were used in the design and construction of an IEC miniplant capable of processing larger volumes of synthetic solutions or hydrolyzates and in the design of an extraction-assisted IEC system. The data were also used to assess the viability of a continuous feed IEC system. This paper includes a discussion of the IEC process, provides overall material balances for various IEC process scenarios, and presents a discussion on process economics.

  6. Emotional, Cognitive and Self-Enhancement Processes in Aggressive Behavior After Interpersonal Rejection and Exclusion

    PubMed Central

    Rajchert, Joanna

    2015-01-01

    The relationship between exclusion or rejection and aggression is already well documented, but there is still a debate about the mechanisms that underlie this effect. In two studies we focused on the propensity to react aggressively (readiness for aggression) on the bases of emotional, cognitive or self-enhancement (personality-immanent) processes. In both studies we first measured readiness for aggression and then ego-depleted participants. Next, in Study 1 we excluded participants (n = 96) using an online ball throwing game and measured displaced aggressive behavior - intensity and duration of an unpleasant noise administrated to a stranger. In Study 2 participants (n = 140) were rejected by a peer on the basis of an interview that they gave and then could retaliate by reducing peer's chance for getting a job. The results show that exclusion effect on displaced aggression was moderated by cognitive readiness for aggression, while rejection effect on retaliatory aggression was shaped by emotional and personality-immanent readiness for aggression as well as ego-depletion. The results were discussed in light of the strength model of self-control by Baumeister, Vohs, and Tice (2007). PMID:27247687

  7. Hard Exclusive Vector Meson Leptoproduction At HERMES

    SciTech Connect

    Golembiovskaya, M.

    2011-07-15

    The HERMES experiment at DESY, Hamburg collected a set of data on hard exclusive vector meson ({rho}{sup 0}{phi},{omega}) leptoproduction using the 27.6 GeV longitudinally polarized lepton beam of HERA accelerator and longitudinally or transversely polarized or unpolarized gas targets. Measurements of exclusive vector meson production provide access to the structure of the nucleon since the process can be described in terms of Generalized Parton Distributions (GPDs). An overview of the HERMES results on exclusive vector mesons production is presented.

  8. Computational Tools for Accelerating Carbon Capture Process Development

    SciTech Connect

    Miller, David

    2013-01-01

    The goals of the work reported are: to develop new computational tools and models to enable industry to more rapidly develop and deploy new advanced energy technologies; to demonstrate the capabilities of the CCSI Toolset on non-proprietary case studies; and to deploy the CCSI Toolset to industry. Challenges of simulating carbon capture (and other) processes include: dealing with multiple scales (particle, device, and whole process scales); integration across scales; verification, validation, and uncertainty; and decision support. The tools cover: risk analysis and decision making; validated, high-fidelity CFD; high-resolution filtered sub-models; process design and optimization tools; advanced process control and dynamics; process models; basic data sub-models; and cross-cutting integration tools.

  9. Accelerate!

    PubMed

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves. PMID:23155997

  10. Stepping and Crowding of Molecular Motors: Statistical Kinetics from an Exclusion Process Perspective

    PubMed Central

    Ciandrini, Luca; Romano, M. Carmen; Parmeggiani, Andrea

    2014-01-01

    Motor enzymes are remarkable molecular machines that use the energy derived from the hydrolysis of a nucleoside triphosphate to generate mechanical movement, achieved through different steps that constitute their kinetic cycle. These macromolecules, nowadays investigated with advanced experimental techniques to unveil their molecular mechanisms and the properties of their kinetic cycles, are implicated in many biological processes, ranging from biopolymerization (e.g., RNA polymerases and ribosomes) to intracellular transport (motor proteins such as kinesins or dyneins). Although the kinetics of individual motors is well studied on both theoretical and experimental grounds, the repercussions of their stepping cycle on the collective dynamics still remains unclear. Advances in this direction will improve our comprehension of transport process in the natural intracellular medium, where processive motor enzymes might operate in crowded conditions. In this work, we therefore extend contemporary statistical kinetic analysis to study collective transport phenomena of motors in terms of lattice gas models belonging to the exclusion process class. Via numerical simulations, we show how to interpret and use the randomness calculated from single particle trajectories in crowded conditions. Importantly, we also show that time fluctuations and non-Poissonian behavior are intrinsically related to spatial correlations and the emergence of large, but finite, clusters of comoving motors. The properties unveiled by our analysis have important biological implications on the collective transport characteristics of processive motor enzymes in crowded conditions. PMID:25185553

  11. Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

    PubMed

    Vandevivere, Eva; Braet, Caroline; Bosmans, Guy; Mueller, Sven C; De Raedt, Rudi

    2014-01-01

    Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years) completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information. PMID:25061662

  12. Acceleration of the GAMESS-UK electronic structure package on graphical processing units.

    PubMed

    Wilkinson, Karl A; Sherwood, Paul; Guest, Martyn F; Naidoo, Kevin J

    2011-07-30

    The approach used to calculate the two-electron integral by many electronic structure packages including generalized atomic and molecular electronic structure system-UK has been designed for CPU-based compute units. We redesigned the two-electron compute algorithm for acceleration on a graphical processing unit (GPU). We report the acceleration strategy and illustrate it on the (ss|ss) type integrals. This strategy is general for Fortran-based codes and uses the Accelerator compiler from Portland Group International and GPU-based accelerators from Nvidia. The evaluation of (ss|ss) type integrals within calculations using Hartree Fock ab initio methods and density functional theory are accelerated by single and quad GPU hardware systems by factors of 43 and 153, respectively. The overall speedup for a single self consistent field cycle is at least a factor of eight times faster on a single GPU compared with that of a single CPU. PMID:21541963

  13. Using pattern enumeration to accelerate process development and ramp yield

    NASA Astrophysics Data System (ADS)

    Zhuang, Linda; Pang, Jenny; Xu, Jessy; Tsai, Mengfeng; Wang, Amy; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

    2016-03-01

    During a new technology node process setup phase, foundries do not initially have enough product chip designs to conduct exhaustive process development. Different operational teams use manually designed simple test keys to set up their process flows and recipes. When the very first version of the design rule manual (DRM) is ready, foundries enter the process development phase where new experiment design data is manually created based on these design rules. However, these IP/test keys contain very uniform or simple design structures. This kind of design normally does not contain critical design structures or process unfriendly design patterns that pass design rule checks but are found to be less manufacturable. It is desired to have a method to generate exhaustive test patterns allowed by design rules at development stage to verify the gap of design rule and process. This paper presents a novel method of how to generate test key patterns which contain known problematic patterns as well as any constructs which designers could possibly draw based on current design rules. The enumerated test key patterns will contain the most critical design structures which are allowed by any particular design rule. A layout profiling method is used to do design chip analysis in order to find potential weak points on new incoming products so fab can take preemptive action to avoid yield loss. It can be achieved by comparing different products and leveraging the knowledge learned from previous manufactured chips to find possible yield detractors.

  14. Searching for Processes Violating the Pauli Exclusion Principle in na and i with Dama/libra

    NASA Astrophysics Data System (ADS)

    Bernabei, R.; Belli, P.; Montecchia, F.; Nozzoli, F.; Cappella, F.; D'Angelo, A.; Incicchitti, A.; Prosperi, D.; Cerulli, R.; Dai, C. J.; He, H. L.; Kuang, H. H.; Ma, X. H.; Sheng, X. D.; Ye, Z. P.

    2011-10-01

    A search for processes normally forbidden by the Pauli-Exclusion-Principle (PEP) has been carried out at LNGS by means of the DAMA/LIBRA set-up. The obtained upper limit for the spontaneous non-paulian emission rate of protons with energy Ep ≥ 10 MeV in 23Na and 127I is 1.63 × 10-33 s-1 (90%C.L.). The corresponding limit on the relative strength (δ2) for the transition is δ2 ≲ (3 - 4)×10-55 (90%C.L.). PEP violating electron transitions in Iodine atoms have also been investigated. Lifetimes shorter than 4.7 × 1030 s are excluded at 90%C.L. and a limit δ e2 < 1.28 × 10{ - 47} has been derived.

  15. Translation with secondary structure: Dynamic blockages in totally asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Shaw, Leah

    2011-03-01

    The totally asymmetric simple exclusion process (TASEP) is often used as a model for protein synthesis, with the lattice and particles representing the mRNA and ribosomes, respectively. Here we model the effect of secondary structure (folding) of the mRNA by introducing a dynamic blockage region in the lattice. If the region is unoccupied by particles, the blockage can close and prevent upstream particles from moving into it, representing the folding of that section of mRNA. Reopening of the blockage, allowing particles to pass, represents unfolding. We study the effects of the blockage size, closing/opening probabilities, and TASEP parameters on the particle current and blockage switching rates.

  16. Collective dynamics of an inhomogeneous two-channel exclusion process: Theory and Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Dhiman, Isha; Gupta, Arvind Kumar

    2016-03-01

    This work is devoted to the development of a novel theoretical approach, named hybrid approach, to handle a localized bottleneck in a symmetrically coupled two-channel totally asymmetric simple exclusion process with Langmuir kinetics. The hybrid approach is combined with singular perturbation technique to get steady-state phase diagrams and density profiles. We have thoroughly examined the role played by the strength of bottleneck, binding constant and lane-changing rate in the system dynamics. The appearances of bottleneck-induced shock, a bottleneck phase and Meissner phase are explained. Further, the critical values of bottleneck rate are identified, which signify the changes in the topology of phase diagram. It is also found that an increase in lane-changing rate as well as unequal attachment, detachment rates weaken the bottleneck effect. Our theoretical arguments are in good agreement with extensively performed Monte Carlo simulations.

  17. Defect-induced phase transition in the asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Schmidt, Johannes; Popkov, Vladislav; Schadschneider, Andreas

    2015-04-01

    We reconsider the long-standing question of the critical defect hopping rate r c in the one-dimensional totally asymmetric exclusion process (TASEP) with a slow bond (defect). For r < r c a phase-separated state is observed due to queuing at the defect site, whereas for r≥ rc the defect site, has only local effects on the stationary state of the homogeneous system. Mean-field theory predicts r_c=1 (when hopping rates outside the defect bond are equal to 1) but numerical investigations seem to indicate rc ≈ 0.80 (2) . Here we improve the numerics to show that r c > 0.99 and give strong evidence that indeed r_c=1 as predicted by mean-field theory, and anticipated by recent theoretical findings.

  18. Time-headway distribution for periodic totally asymmetric exclusion process with various updates

    NASA Astrophysics Data System (ADS)

    Hrabák, P.; Krbálek, M.

    2016-03-01

    The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.

  19. Development of neural systems for processing social exclusion from childhood to adolescence.

    PubMed

    Bolling, Danielle Z; Pitskel, Naomi B; Deen, Ben; Crowley, Michael J; Mayes, Linda C; Pelphrey, Kevin A

    2011-11-01

    Adolescence is a period of development in which peer relationships become especially important. A computer-based game (Cyberball) has been used to explore the effects of social exclusion in adolescents and adults. The current functional magnetic resonance imaging (fMRI) study used Cyberball to extend prior work to the cross-sectional study of younger children and adolescents (7 to 17 years), identifying age-related changes in the neural correlates of social exclusion across the important transition from middle childhood into adolescence. Additionally, a control task illustrated the specificity of these age-related changes for social exclusion as distinct from expectancy violation more generally. During exclusion, activation in and functional connectivity between ventrolateral prefrontal cortex and ventral anterior cingulate cortex increased with age. These effects were specific to social exclusion and did not exist for expectancy violation. Our results illustrate developmental changes from middle childhood through adolescence in both affective and regulatory brain regions during social exclusion. PMID:22010901

  20. Accelerating COTS Middleware Acquisition: The i-Mate Process

    SciTech Connect

    Liu, Anna; Gorton, Ian

    2003-03-05

    Most major organizations now use some commercial-off-the-shelf middleware components to run their businesses. Key drivers behind this growth include ever-increasing Internet usage and the ongoing need to integrate heterogeneous legacy systems to streamline business processes. As organizations do more business online, they need scalable, high-performance software infrastructures to handle transactions and provide access to core systems.

  1. Emergence of jams in the generalized totally asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Derbyshev, A. E.; Povolotsky, A. M.; Priezzhev, V. B.

    2015-02-01

    The generalized totally asymmetric exclusion process (TASEP) [J. Stat. Mech. (2012) P05014, 10.1088/1742-5468/2012/05/P05014] is an integrable generalization of the TASEP equipped with an interaction, which enhances the clustering of particles. The process interpolates between two extremal cases: the TASEP with parallel update and the process with all particles irreversibly merging into a single cluster moving as an isolated particle. We are interested in the large time behavior of this process on a ring in the whole range of the parameter λ controlling the interaction. We study the stationary state correlations, the cluster size distribution, and the large-time fluctuations of integrated particle current. When λ is finite, we find the usual TASEP-like behavior: The correlation length is finite; there are only clusters of finite size in the stationary state and current fluctuations belong to the Kardar-Parisi-Zhang universality class. When λ grows with the system size, so does the correlation length. We find a nontrivial transition regime with clusters of all sizes on the lattice. We identify a crossover parameter and derive the large deviation function for particle current, which interpolates between the case considered by Derrida-Lebowitz and a single-particle diffusion.

  2. The IBA Rhodotron: an industrial high-voltage high-powered electron beam accelerator for polymers radiation processing

    NASA Astrophysics Data System (ADS)

    Van Lancker, Marc; Herer, Arnold; Cleland, Marshall R.; Jongen, Yves; Abs, Michel

    1999-05-01

    The Rhodotron is a high-voltage, high-power electron beam accelerator based on a design concept first proposed in 1989 by J. Pottier of the French Atomic Agency, Commissariat à l'Energie Atomique (CEA). In December 1991, the Belgian particle accelerator manufacturer, Ion Beam Applications s.a. (IBA) entered into an exclusive agreement with the CEA to develop and industrialize the Rhodotron. Electron beams have long been used as the preferential method to cross-link a variety of polymers, either in their bulk state or in their final form. Used extensively in the wire and cable industry to toughen insulating jackets, electron beam-treated plastics can demonstrate improved tensile and impact strength, greater abrasion resistance, increased temperature resistance and dramatically improved fire retardation. Electron beams are used to selectively cross-link or degrade a wide range of polymers in resin pellets form. Electron beams are also used for rapid curing of advanced composites, for cross-linking of floor-heating and sanitary pipes and for cross-linking of formed plastic parts. Other applications include: in-house and contract medical device sterilization, food irradiation in both electron and X-ray modes, pulp processing, electron beam doping of semi-conductors, gemstone coloration and general irradiation research. IBA currently markets three models of the Rhodotron, all capable of 10 MeV and alternate beam energies from 3 MeV upwards. The Rhodotron models TT100, TT200 and TT300 are typically specified with guaranteed beam powers of 35, 80 and 150 kW, respectively. Founded in 1986, IBA, a spin-off of the Cyclotron Research Center at the University of Louvain (UCL) in Belgium, is a pioneer in accelerator design for industrial-scale production.

  3. The STIRAP-based unitary decelerating and accelerating processes of a single free atom

    NASA Astrophysics Data System (ADS)

    Miao, Xijia

    2008-05-01

    The STIRAP-based unitary decelerating and accelerating processes have been constructed for the physical system of a single free atom. The present theoretical work is focused on investigating analytically how the momentum distribution of a momentum superposition state of a quantum system such as a momentum Gaussian wave-packet state of a single freely moving atom affects the STIRAP state transfer in these decelerating and accelerating processes. The complete STIRAP state transfer and the unitarity of these processes are stressed highly in the investigation. It has been shown that the momentum distribution has an important influence upon the STIRAP state-transfer efficiency. In the ideal adiabatic condition these unitary decelerating and accelerating processes are studied in detail for a freely moving atom. A general adiabatic condition for the basic STIRAP unitary decelerating and accelerating processes is also derived analytically. The unitary decelerating and accelerating processes may be used to manipulate and control in time and space a Gaussian wave-packet motional state of a free atom. The detail work see: Xijia Miao, http://arxiv.org/abs/quant-ph/0707.0063.

  4. Accelerating radio astronomy cross-correlation with graphics processing units

    NASA Astrophysics Data System (ADS)

    Clark, M. A.; LaPlante, P. C.; Greenhill, L. J.

    2013-05-01

    We present a highly parallel implementation of the cross-correlation of time-series data using graphics processing units (GPUs), which is scalable to hundreds of independent inputs and suitable for the processing of signals from 'large-Formula' arrays of many radio antennas. The computational part of the algorithm, the X-engine, is implemented efficiently on NVIDIA's Fermi architecture, sustaining up to 79% of the peak single-precision floating-point throughput. We compare performance obtained for hardware- and software-managed caches, observing significantly better performance for the latter. The high performance reported involves use of a multi-level data tiling strategy in memory and use of a pipelined algorithm with simultaneous computation and transfer of data from host to device memory. The speed of code development, flexibility, and low cost of the GPU implementations compared with application-specific integrated circuit (ASIC) and field programmable gate array (FPGA) implementations have the potential to greatly shorten the cycle of correlator development and deployment, for cases where some power-consumption penalty can be tolerated.

  5. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    NASA Astrophysics Data System (ADS)

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-01

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly.

  6. Graphics processing units accelerated semiclassical initial value representation molecular dynamics.

    PubMed

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-01

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly. PMID:24811627

  7. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    SciTech Connect

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-07

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly.

  8. Accelerating chemical database searching using graphics processing units.

    PubMed

    Liu, Pu; Agrafiotis, Dimitris K; Rassokhin, Dmitrii N; Yang, Eric

    2011-08-22

    The utility of chemoinformatics systems depends on the accurate computer representation and efficient manipulation of chemical compounds. In such systems, a small molecule is often digitized as a large fingerprint vector, where each element indicates the presence/absence or the number of occurrences of a particular structural feature. Since in theory the number of unique features can be exceedingly large, these fingerprint vectors are usually folded into much shorter ones using hashing and modulo operations, allowing fast "in-memory" manipulation and comparison of molecules. There is increasing evidence that lossless fingerprints can substantially improve retrieval performance in chemical database searching (substructure or similarity), which have led to the development of several lossless fingerprint compression algorithms. However, any gains in storage and retrieval afforded by compression need to be weighed against the extra computational burden required for decompression before these fingerprints can be compared. Here we demonstrate that graphics processing units (GPU) can greatly alleviate this problem, enabling the practical application of lossless fingerprints on large databases. More specifically, we show that, with the help of a ~$500 ordinary video card, the entire PubChem database of ~32 million compounds can be searched in ~0.2-2 s on average, which is 2 orders of magnitude faster than a conventional CPU. If multiple query patterns are processed in batch, the speedup is even more dramatic (less than 0.02-0.2 s/query for 1000 queries). In the present study, we use the Elias gamma compression algorithm, which results in a compression ratio as high as 0.097. PMID:21696144

  9. Using Qualitative Observation To Document Group Processes in Accelerated Schools Training: Techniques and Results.

    ERIC Educational Resources Information Center

    McFarland, Katherine; Batten, Constance

    This paper describes the use of qualitative observation techniques for gathering and analyzing data related to group processes during an Accelerated Schools Model training session. The purposes for this research were to observe the training process in order better to facilitate present continuation and future training, to develop questions for…

  10. Accelerator Production of Tritium project process waste assessment

    SciTech Connect

    Carson, S.D.; Peterson, P.K.

    1995-09-01

    DOE has made a commitment to compliance with all applicable environmental regulatory requirements. In this respect, it is important to consider and design all tritium supply alternatives so that they can comply with these requirements. The management of waste is an integral part of this activity and it is therefore necessary to estimate the quantities and specific wastes that will be generated by all tritium supply alternatives. A thorough assessment of waste streams includes waste characterization, quantification, and the identification of treatment and disposal options. The waste assessment for APT has been covered in two reports. The first report was a process waste assessment (PWA) that identified and quantified waste streams associated with both target designs and fulfilled the requirements of APT Work Breakdown Structure (WBS) Item 5.5.2.1. This second report is an expanded version of the first that includes all of the data of the first report, plus an assessment of treatment and disposal options for each waste stream identified in the initial report. The latter information was initially planned to be issued as a separate Waste Treatment and Disposal Options Assessment Report (WBS Item 5.5.2.2).

  11. Accelerating compartmental modeling on a graphical processing unit.

    PubMed

    Ben-Shalom, Roy; Liberman, Gilad; Korngreen, Alon

    2013-01-01

    Compartmental modeling is a widely used tool in neurophysiology but the detail and scope of such models is frequently limited by lack of computational resources. Here we implement compartmental modeling on low cost Graphical Processing Units (GPUs), which significantly increases simulation speed compared to NEURON. Testing two methods for solving the current diffusion equation system revealed which method is more useful for specific neuron morphologies. Regions of applicability were investigated using a range of simulations from a single membrane potential trace simulated in a simple fork morphology to multiple traces on multiple realistic cells. A runtime peak 150-fold faster than the CPU was achieved. This application can be used for statistical analysis and data fitting optimizations of compartmental models and may be used for simultaneously simulating large populations of neurons. Since GPUs are forging ahead and proving to be more cost-effective than CPUs, this may significantly decrease the cost of computation power and open new computational possibilities for laboratories with limited budgets. PMID:23508232

  12. Graphics processing unit acceleration of computational electromagnetic methods

    NASA Astrophysics Data System (ADS)

    Inman, Matthew

    The use of Graphical Processing Units (GPU's) for scientific applications has been evolving and expanding for the decade. GPU's provide an alternative to the CPU in the creation and execution of the numerical codes that are often relied upon in to perform simulations in computational electromagnetics. While originally designed purely to display graphics on the users monitor, GPU's today are essentially powerful floating point co-processors that can be programmed not only to render complex graphics, but also perform the complex mathematical calculations often encountered in scientific computing. Currently the GPU's being produced often contain hundreds of separate cores able to access large amounts of high-speed dedicated memory. By utilizing the power offered by such a specialized processor, it is possible to drastically speed up the calculations required in computational electromagnetics. This increase in speed allows for the use of GPU based simulations in a variety of situations that the computational time has heretofore been a limiting factor in, such as in educational courses. Many situations in teaching electromagnetics often rely upon simple examples of problems due to the simulation times needed to analyze more complex problems. The use of GPU based simulations will be shown to allow demonstrations of more advanced problems than previously allowed by adapting the methods for use on the GPU. Modules will be developed for a wide variety of teaching situations utilizing the speed of the GPU to demonstrate various techniques and ideas previously unrealizable.

  13. 75 FR 77624 - Intent To Grant an Exclusive License for U.S. Army Owned Inventions to Polymer Processing Institute

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Army Intent To Grant an Exclusive License for U.S. Army Owned Inventions to Polymer... Polymer Processing Institute, a not-for-profit corporation having a place of business in the New...

  14. Swarm accelerometer data processing from raw accelerations to thermospheric neutral densities

    NASA Astrophysics Data System (ADS)

    Siemes, Christian; de Teixeira da Encarnação, João; Doornbos, Eelco; van den IJssel, Jose; Kraus, Jiří; Pereštý, Radek; Grunwaldt, Ludwig; Apelbaum, Guy; Flury, Jakob; Holmdahl Olsen, Poul Erik

    2016-05-01

    The Swarm satellites were launched on November 22, 2013, and carry accelerometers and GPS receivers as part of their scientific payload. The GPS receivers do not only provide the position and time for the magnetic field measurements, but are also used for determining non-gravitational forces like drag and radiation pressure acting on the spacecraft. The accelerometers measure these forces directly, at much finer resolution than the GPS receivers, from which thermospheric neutral densities can be derived. Unfortunately, the acceleration measurements suffer from a variety of disturbances, the most prominent being slow temperature-induced bias variations and sudden bias changes. In this paper, we describe the new, improved four-stage processing that is applied for transforming the disturbed acceleration measurements into scientifically valuable thermospheric neutral densities. In the first stage, the sudden bias changes in the acceleration measurements are manually removed using a dedicated software tool. The second stage is the calibration of the accelerometer measurements against the non-gravitational accelerations derived from the GPS receiver, which includes the correction for the slow temperature-induced bias variations. The identification of validity periods for calibration and correction parameters is part of the second stage. In the third stage, the calibrated and corrected accelerations are merged with the non-gravitational accelerations derived from the observations of the GPS receiver by a weighted average in the spectral domain, where the weights depend on the frequency. The fourth stage consists of transforming the corrected and calibrated accelerations into thermospheric neutral densities. We present the first results of the processing of Swarm C acceleration measurements from June 2014 to May 2015. We started with Swarm C because its acceleration measurements contain much less disturbances than those of Swarm A and have a higher signal-to-noise ratio

  15. Quasi-steady stages in the process of premixed flame acceleration in narrow channels

    NASA Astrophysics Data System (ADS)

    Valiev, D. M.; Bychkov, V.; Akkerman, V.; Eriksson, L.-E.; Law, C. K.

    2013-09-01

    The present paper addresses the phenomenon of spontaneous acceleration of a premixed flame front propagating in micro-channels, with subsequent deflagration-to-detonation transition. It has recently been shown experimentally [M. Wu, M. Burke, S. Son, and R. Yetter, Proc. Combust. Inst. 31, 2429 (2007)], 10.1016/j.proci.2006.08.098, computationally [D. Valiev, V. Bychkov, V. Akkerman, and L.-E. Eriksson, Phys. Rev. E 80, 036317 (2009)], 10.1103/PhysRevE.80.036317, and analytically [V. Bychkov, V. Akkerman, D. Valiev, and C. K. Law, Phys. Rev. E 81, 026309 (2010)], 10.1103/PhysRevE.81.026309 that the flame acceleration undergoes different stages, from an initial exponential regime to quasi-steady fast deflagration with saturated velocity. The present work focuses on the final saturation stages in the process of flame acceleration, when the flame propagates with supersonic velocity with respect to the channel walls. It is shown that an intermediate stage may occur during acceleration with quasi-steady velocity, noticeably below the Chapman-Jouguet deflagration speed. The intermediate stage is followed by additional flame acceleration and subsequent saturation to the Chapman-Jouguet deflagration regime. We elucidate the intermediate stage by the joint effect of gas pre-compression ahead of the flame front and the hydraulic resistance. The additional acceleration is related to viscous heating at the channel walls, being of key importance at the final stages. The possibility of explosion triggering is also demonstrated.

  16. FAST Observations of Acceleration Processes in the Cusp--Evidence for Parallel Electric Fields

    NASA Technical Reports Server (NTRS)

    Pfaff, R. F.. Jr.; Carlson, C.; McFadden, J.; Ergun, R.; Clemmons, J.; Klumpar D.; Strangeway, R.

    1999-01-01

    The existence of precipitating keV ions in the Earth's cusp originating at the magnetosheath provide unique means to test our understanding of particle acceleration and parallel electric fields in the lower altitude acceleration region. On numerous occasions, the FAST (The Fast Auroral Snapshot) spacecraft has encountered the Earth's cusp regions near its apogee of 4175 km which are characterized by their signatures of dispersed keV ion injections. The FAST instruments also reveal a complex microphysics inherent to many, but not all, of the cusp regions encountered by the spacecraft, that include upgoing ion beams and conics, inverted-V electrons, upgoing electron beams, and spikey DC-coupled electric fields and plasma waves. Detailed inspection of the FAST data often show clear modulation of the precipitating magnetosheath ions that indicate that they are affected by local electric potentials. For example, the magnetosheath ion precipitation is sometimes abruptly shut off precisely in regions where downgoing localized inverted-V electrons are observed. Such observations support the existence of a localized process, such as parallel electric fields, above the spacecraft which accelerate the electrons downward and consequently impede the precipitating ion precipitation. Other acceleration events in the cusp are sometimes organized with an apparent cellular structure that suggests Alfven waves or other large-scale phenomena are controlling the localized potentials. We examine several cusp encounters by the FAST satellite where the modulation of energetic session on acceleration particle populations reveals evidence of localized acceleration, most likely by parallel electric fields.

  17. Power spectra of totally asymmetric exclusion processes on lattices with a junction

    NASA Astrophysics Data System (ADS)

    Wang, Dong-Xiang; Jiang, Rui; Hu, Mao-Bin; Wu, Qing-Song

    2016-07-01

    In this paper, we have studied the power spectra of the entire particle occupancy in the totally asymmetric exclusion processes on lattices with a junction, at which two lanes I and II merge into lane III. We have performed the investigations, utilizing both Monte Carlo simulations and theoretical analysis based on linearized Langevin equations. The effect of lane length, particle entry rates at lanes I and II, and particle exit rate at lane III have been discussed. The transition from damped periodic oscillation to irregular oscillation as well as disappearance of oscillation has been observed. In particular, when lanes I, II, III are simultaneously in low density (LD) state or high density (HD) state, and the length L1 of lane I is not remarkably different from the length L2 of lane II, the damped periodic oscillations could be observed and the minima of the power spectra could be calculated via weighted average. However, when L1 is notably different from L2, the oscillation becomes irregular.

  18. Bi-orthogonal polynomial sequences and the asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Brak, R.; Moore, W.

    2015-08-01

    We state the diffusion algebra equations of the stationary state of the three parameter (α, β and q) asymmetric simple exclusion Process as a linear functional {L}, acting on a tensor algebra. From {L} we construct a pair of sequences, \\{{P}n\\} and \\{{Q}m\\}, of monic polynomials which are bi-orthogonal, that is, they satisfy {L}({P}n{Q}m)={Λ }n{δ }n,m(where {Λ }n is a scalar). The uniqueness and existence of the pair of sequences arises from the determinant of the bi-moment matrix whose elements satisfy a pair of q-recurrence relations. The determinant is evaluated using an LDU-decomposition. If the linear functional is represented as an inner product, {L}(\\cdot )=< W| \\cdot | V> then the action of the polynomials Qn on the boundary vector | V> generate a basis | {V}n> ={Q}n| V> whose orthogonal dual vectors are given by the action of Pn on the dual boundary vector < W| , that is < {W}n| =< W| {P}n. This basis gives the representation of the algebra which is associated with the Al-Salam-Chihara polynomials obtained by Sasamoto.

  19. Estimating currents in totally asymmetric simple exclusion process with extended particles and inhomogeneous hopping rates.

    NASA Astrophysics Data System (ADS)

    Zia, R. K. P.; Dong, Jiajia; Schmittmann, B.

    2009-03-01

    Motivated by translation in protein synthesis, we study the totally asymmetric simple exclusion process with extended particles transported along a 1-D lattice with (quenched) inhomogeneous hopping rates. The particles model ribosomes, the lattice models sequences of codons, and the hopping rates reflect the aa-tRNA concentrations. Taking the latter from data for real E.Coli genes, Monte Carlo simulations allow us to find the steady state currents, associated with protein production rates. An application would be to predict the effects of ``silent mutations'' in biological systems. In such mutations, one or more codons are replaced by others which code for the same amino-acid, so that the same protein (amino-acid chain) is synthesized by a different sequence of codons. However, the rate of production (the overall current), which depends on the details of sequence, will differ. We aim to predict the changes in these currents for all possible silent mutations. Beyond this application, this study of ``quenched distribution of distributions'' is expected to have far reaching implications in other areas of physics.

  20. Translation by Ribosomes with mRNA Degradation: Exclusion Processes on Aging Tracks

    NASA Astrophysics Data System (ADS)

    Nagar, Apoorva; Valleriani, Angelo; Lipowsky, Reinhard

    2011-12-01

    We investigate the role of degradation of mRNA on protein synthesis using the totally asymmetric simple exclusion process (TASEP) as the underlying model for ribosome dynamics. mRNA degradation has a strong effect on the lifetime distribution of the mRNA, which in turn affects polysome statistics such as the number of ribosomes present on an mRNA strand of a given size. An average over mRNA of all ages is equivalent to an average over possible configurations of the corresponding TASEP—both before steady state and in steady state. To evaluate the relevant quantities for the translation problem, we first study the approach towards steady state of the TASEP, starting with an empty lattice representing an unloaded mRNA. When approaching the high density phase, the system shows two distinct phases with the entry and exit boundaries taking control of the density at their respective ends in the second phase. The approach towards the maximal current phase exhibits the surprising property that the ribosome entry flux can exceed the maximum possible steady state value. In all phases, the averaging over the mRNA age distribution shows a decrease in the average ribosome density profile as a function of distance from the entry boundary. For entry/exit parameters corresponding to the high density phase of TASEP, the average ribosome density profile also has a maximum near the exit end.

  1. Totally Asymmetric Simple Exclusion Process with Langmuir Kinetics depending on the Occupancy of the Neighboring Sites

    NASA Astrophysics Data System (ADS)

    Ichiki, Shingo; Sato, Jun; Nishinari, Katsuhiro

    2016-04-01

    We generalize the totally asymmetric simple exclusion process with Langmuir kinetics (TASEP-LK). In the original TASEP-LK, when a site on the lattice is empty, a particle is attached at a certain rate, whereas the particle is detached at a certain rate when the site is occupied. In the extended TASEP-LK, the rates of attachment and detachment depend on the occupancy of the neighboring sites. In particular, we consider the case where the attachment rate and detachment rate are equal in each state of the neighboring sites. We analytically study a density profile using a mean-field approximation. Then, the results are compared with Monte Carlo simulations. We find in detail that the characteristic of the density profile is changed by manipulating each attachment and detachment parameter. It is showed that the position of a domain wall, which is fixed in the original model, changes depending on the inflow and outflow rates when the rates at the right and left boundaries are the same.

  2. Mixed population of competing totally asymmetric simple exclusion processes with a shared reservoir of particles.

    PubMed

    Greulich, Philip; Ciandrini, Luca; Allen, Rosalind J; Romano, M Carmen

    2012-01-01

    We introduce a mean-field theoretical framework to describe multiple totally asymmetric simple exclusion processes (TASEPs) with different lattice lengths and entry and exit rates, competing for a finite reservoir of particles. We present relations for the partitioning of particles between the reservoir and the lattices: These relations allow us to show that competition for particles can have nontrivial effects on the phase behavior of individual lattices. For a system with nonidentical lattices, we find that when a subset of lattices undergoes a phase transition from low to high density, the entire set of lattice currents becomes independent of total particle number. We generalize our approach to systems with a continuous distribution of lattice parameters, for which we demonstrate that measurements of the current carried by a single lattice type can be used to extract the entire distribution of lattice parameters. Our approach applies to populations of TASEPs with any distribution of lattice parameters and could easily be extended beyond the mean-field case. PMID:22400547

  3. Acceleration of Early-Photon Fluorescence Molecular Tomography with Graphics Processing Units

    PubMed Central

    Wang, Xin; Zhang, Bin; Cao, Xu; Liu, Fei; Luo, Jianwen; Bai, Jing

    2013-01-01

    Fluorescence molecular tomography (FMT) with early-photons can improve the spatial resolution and fidelity of the reconstructed results. However, its computing scale is always large which limits its applications. In this paper, we introduced an acceleration strategy for the early-photon FMT with graphics processing units (GPUs). According to the procedure, the whole solution of FMT was divided into several modules and the time consumption for each module is studied. In this strategy, two most time consuming modules (Gd and W modules) were accelerated with GPU, respectively, while the other modules remained coded in the Matlab. Several simulation studies with a heterogeneous digital mouse atlas were performed to confirm the performance of the acceleration strategy. The results confirmed the feasibility of the strategy and showed that the processing speed was improved significantly. PMID:23606899

  4. Nanomanufacturing Portfolio: Manufacturing Processes and Applications to Accelerate Commercial Use of Nanomaterials

    SciTech Connect

    Industrial Technologies Program

    2011-01-05

    This brochure describes the 31 R&D projects that AMO supports to accelerate the commercial manufacture and use of nanomaterials for enhanced energy efficiency. These cost-shared projects seek to exploit the unique properties of nanomaterials to improve the functionality of industrial processes and products.

  5. Sampling frequency affects the processing of Actigraph raw acceleration data to activity counts.

    PubMed

    Brønd, Jan Christian; Arvidsson, Daniel

    2016-02-01

    ActiGraph acceleration data are processed through several steps (including band-pass filtering to attenuate unwanted signal frequencies) to generate the activity counts commonly used in physical activity research. We performed three experiments to investigate the effect of sampling frequency on the generation of activity counts. Ideal acceleration signals were produced in the MATLAB software. Thereafter, ActiGraph GT3X+ monitors were spun in a mechanical setup. Finally, 20 subjects performed walking and running wearing GT3X+ monitors. Acceleration data from all experiments were collected with different sampling frequencies, and activity counts were generated with the ActiLife software. With the default 30-Hz (or 60-Hz, 90-Hz) sampling frequency, the generation of activity counts was performed as intended with 50% attenuation of acceleration signals with a frequency of 2.5 Hz by the signal frequency band-pass filter. Frequencies above 5 Hz were eliminated totally. However, with other sampling frequencies, acceleration signals above 5 Hz escaped the band-pass filter to a varied degree and contributed to additional activity counts. Similar results were found for the spinning of the GT3X+ monitors, although the amount of activity counts generated was less, indicating that raw data stored in the GT3X+ monitor is processed. Between 600 and 1,600 more counts per minute were generated with the sampling frequencies 40 and 100 Hz compared with 30 Hz during running. Sampling frequency affects the processing of ActiGraph acceleration data to activity counts. Researchers need to be aware of this error when selecting sampling frequencies other than the default 30 Hz. PMID:26635347

  6. Graphics processing unit-accelerated double random phase encoding for fast image encryption

    NASA Astrophysics Data System (ADS)

    Lee, Jieun; Yi, Faliu; Saifullah, Rao; Moon, Inkyu

    2014-11-01

    We propose a fast double random phase encoding (DRPE) algorithm using a graphics processing unit (GPU)-based stream-processing model. A performance analysis of the accelerated DRPE implementation that employs the Compute Unified Device Architecture programming environment is presented. We show that the proposed methodology executed on a GPU can dramatically increase encryption speed compared with central processing unit sequential computing. Our experimental results demonstrate that in encryption data of an image with a pixel size of 1000×1000, where one pixel has a 32-bit depth, our GPU version of the DRPE scheme can be approximately two times faster than the advanced encryption standard algorithm implemented on a GPU. In addition, the quality of parallel processing on the presented DRPE acceleration method is evaluated with performance parameters, such as speedup, efficiency, and redundancy.

  7. Acceleration and transport processes - Verification and observations. [of particles in interstellar medium

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.

    1983-01-01

    The general problem of diffusive transport and acceleration of energetic charged particles is considered. The transport of solar-flare particles, solar modulation of galactic cosmic rays and shock acceleration processes on the solar wind are examined and observational tests are summarized. It is concluded that the basic diffusive transport equation is a useful approximation in situations like the solar wind, where turbulent scattering by magnetic irregularities is sufficient to maintain near isotropy. The application of this equation to the interstellar medium andd other, more distant astrophysical regimes is then discussed and implications for gamma-ray astrophysics are outlined. Finally the evidence for interstellar turbulence is reviewed and its consequences briefly discussed.

  8. Risk-Based Decision Process for Accelerated Closure of a Nuclear Weapons Facility

    SciTech Connect

    Butler, L.; Norland, R. L.; DiSalvo, R.; Anderson, M.

    2003-02-25

    Nearly 40 years of nuclear weapons production at the Rocky Flats Environmental Technology Site (RFETS or Site) resulted in contamination of soil and underground systems and structures with hazardous substances, including plutonium, uranium and hazardous waste constituents. The Site was placed on the National Priority List in 1989. There are more than 370 Individual Hazardous Substance Sites (IHSSs) at RFETS. Accelerated cleanup and closure of RFETS is being achieved through implementation and refinement of a regulatory framework that fosters programmatic and technical innovations: (1) extensive use of ''accelerated actions'' to remediate IHSSs, (2) development of a risk-based screening process that triggers and helps define the scope of accelerated actions consistent with the final remedial action objectives for the Site, (3) use of field instrumentation for real time data collection, (4) a data management system that renders near real time field data assessment, and (5) a regulatory agency consultative process to facilitate timely decisions. This paper presents the process and interim results for these aspects of the accelerated closure program applied to Environmental Restoration activities at the Site.

  9. Recent developments in the application of electron accelerators for polymer processing

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Al-Sheikhly, M.; Berejka, A. J.; Cleland, M. R.; Antoniak, M.

    2014-01-01

    There are now over 1700 high current, electron beam (EB) accelerators being used world-wide in industrial applications, most of which involve polymer processing. In contrast to the use of heat, which transfers only about 5-10% of input energy into energy useful for materials modification, radiation processing is very energy efficient, with 60% or more of the input energy to an accelerator being available for affecting materials. Historic markets, such as the crosslinking of wire and cable jacketing, of heat shrinkable tubings and films, of partial crosslinking of tire components and of low-energy EB to cure or dry inks and coatings remain strong. Accelerator manufacturers have made equipment more affordable by down-sizing units while maintaining high beam currents. Very powerful accelerators with 700 kW output have made X-ray conversion a practical alternative to the historic use of radioisotopes, mainly cobalt-60, for applications as medical device sterilization. New EB end-uses are emerging, such as the development of nano-composites and nano-gels and the use of EB processing to facilitate biofuel production. These present opportunities for future research and development.

  10. Acceleration processes in the quasi-steady magnetoplasmadynamic discharge. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Boyle, M. J.

    1974-01-01

    The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

  11. General description of electromagnetic radiation processes based on instantaneous charge acceleration in ''endpoints''

    SciTech Connect

    James, Clancy W.; Falcke, Heino; Huege, Tim; Ludwig, Marianne

    2011-11-15

    We present a methodology for calculating the electromagnetic radiation from accelerated charged particles. Our formulation - the 'endpoint formulation' - combines numerous results developed in the literature in relation to radiation arising from particle acceleration using a complete, and completely general, treatment. We do this by describing particle motion via a series of discrete, instantaneous acceleration events, or 'endpoints', with each such event being treated as a source of emission. This method implicitly allows for particle creation and destruction, and is suited to direct numerical implementation in either the time or frequency domains. In this paper we demonstrate the complete generality of our method for calculating the radiated field from charged particle acceleration, and show how it reduces to the classical named radiation processes such as synchrotron, Tamm's description of Vavilov-Cherenkov, and transition radiation under appropriate limits. Using this formulation, we are immediately able to answer outstanding questions regarding the phenomenology of radio emission from ultra-high-energy particle interactions in both the earth's atmosphere and the moon. In particular, our formulation makes it apparent that the dominant emission component of the Askaryan effect (coherent radio-wave radiation from high-energy particle cascades in dense media) comes from coherent 'bremsstrahlung' from particle acceleration, rather than coherent Vavilov-Cherenkov radiation.

  12. Competitive Exclusion and Axiomatic Set-Theory: De Morgan's Laws, Ecological Virtual Processes, Symmetries and Frozen Diversity.

    PubMed

    Flores, J C

    2016-03-01

    This work applies the competitive exclusion principle and the concept of potential competitors as simple axiomatic tools to generalized situations in ecology. These tools enable apparent competition and its dual counterpart to be explicitly evaluated in poorly understood ecological systems. Within this set-theory framework we explore theoretical symmetries and invariances, De Morgan's laws, frozen evolutionary diversity and virtual processes. In particular, we find that the exclusion principle compromises the geometrical growth of the number of species. By theoretical extending this principle, we can describe interspecific depredation in the dual case. This study also briefly considers the debated situation of intraspecific competition. The ecological consequences of our findings are discussed; particularly, the use of our framework to reinterpret coupled mathematical differential equations describing certain ecological processes. PMID:26801920

  13. Development of Neural Systems for Processing Social Exclusion from Childhood to Adolescence

    ERIC Educational Resources Information Center

    Bolling, Danielle Z.; Pitskel, Naomi B.; Deen, Ben; Crowley, Michael J.; Mayes, Linda C.; Pelphrey, Kevin A.

    2011-01-01

    Adolescence is a period of development in which peer relationships become especially important. A computer-based game (Cyberball) has been used to explore the effects of social exclusion in adolescents and adults. The current functional magnetic resonance imaging (fMRI) study used Cyberball to extend prior work to the cross-sectional study of…

  14. Getting into Teams in Physical Education and Exclusion Processes among Students

    ERIC Educational Resources Information Center

    Grimminger, Elke

    2014-01-01

    Although splitting up a class into teams is a consistent didactical element in physical education (PE), it is under-investigated in terms of how students handle the social dynamics in these situations. Therefore, the present study examines the strategies of exclusion as markers for non-recognition when students are split up into teams/pairs. The…

  15. Challenges Encountered during the Processing of the BNL ERL 5 Cell Accelerating Cavity

    SciTech Connect

    A. Burrill; I. Ben-Zvi; R. Calaga; H. Hahn; V. Litvinenko; G. T. McIntyre; P. Kneisel; J. Mammosser; J. P. Preble; C. E. Reece; R. A. Rimmer; J. Saunders

    2007-08-01

    One of the key components for the Energy Recovery Linac being built by the Electron cooling group in the Collider Accelerator Department is the 5 cell accelerating cavity which is designed to accelerate 2 MeV electrons from the gun up to 15-20 MeV, allow them to make one pass through the ring and then decelerate them back down to 2 MeV prior to sending them to the dump. This cavity was designed by BNL and fabricated by AES in Medford, NY. Following fabrication it was sent to Thomas Jefferson Lab in VA for chemical processing, testing and assembly into a string assembly suitable for shipment back to BNL and integration into the ERL. The steps involved in this processing sequence will be reviewed and the deviations from processing of similar SRF cavities will be discussed. The lessons learned from this process are documented to help future projects where the scope is different from that normally encountered.

  16. Distinguishing Between Quasi-static and Alfvénic Auroral Acceleration Processes

    NASA Astrophysics Data System (ADS)

    Lysak, R. L.; Song, Y.

    2013-12-01

    Models for the acceleration of auroral particles fall into two general classes. Quasi-static processes, such as double layers or magnetic mirror supported potential drops, produce a nearly monoenergetic beam of precipitating electrons and upward flowing ion beams. Time-dependent acceleration processes, often associated with kinetic Alfvén waves, can produce a broader range of energies and often have a strongly field-aligned pitch angle distribution. Both processes are associated with strong perpendicular electric fields as well as the parallel electric fields that are largely responsible for the particle acceleration. These electric fields and the related magnetic perturbations can be characterized by the ratio of the electric field to a perpendicular magnetic perturbation, which is related to the Pedersen conductivity in the static case and the Alfvén velocity in the time-dependent case. However, these considerations can be complicated by the interaction between upward and downward propagating waves. The relevant time and space scales of these processes will be assessed and the consequences for observation by orbiting spacecraft and ground-based instrumentation will be determined. These features will be illustrated by numerical simulations of the magnetosphere-ionosphere coupling with emphasis on what a virtual spacecraft passing through the simulation would be expected to observe.

  17. CHALLENGES ENCOUNTERED DURING THE PROCESSING OF THE BNL ERL 5 CELL ACCELERATING CAVITY

    SciTech Connect

    BURRILL,A.

    2007-06-25

    One of the key components for the Energy Recovery Linac being built by the Electron cooling group in the Collider Accelerator Department is the 5 cell accelerating cavity which is designed to accelerate 2 MeV electrons from the gun up to 15-20 MeV, allow them to make one pass through the ring and then decelerate them back down to 2 MeV prior to sending them to the dump. This cavity was designed by BNL and fabricated by AES in Medford, NY. Following fabrication it was sent to Thomas Jefferson Lab in VA for chemical processing, testing and assembly into a string assembly suitable for shipment back to BNL for integration into the ERL. The steps involved in this processing sequence will be reviewed and the deviations from processing of similar SRF cavities will be discussed. The lessons learned from this process are documented to help future projects where the scope is different from that normally encountered.

  18. Small scale particle acceleration processes in the auroral region: Remote sensing and "in situ" measurements

    NASA Astrophysics Data System (ADS)

    Pottelette, R.; Berthomier, M.; Pickett, J.

    2012-04-01

    Among the many problems in auroral physics that are barely understood the microphysical problems occupy a majority position. Thanks to high sampling and telemetry rates implemented on spacecraft devoted to the study of the auroral regions such as POLAR, FAST, CLUSTER 2…, it has become possible to determine the role of transient nonlinear structures in the basic microscopic processes regulating the Magnetosphere-Ionosphere interactions. Great progress has been achieved in probing the nonlinear turbulent plasma processes which accelerate energetic particles and generate radiation such as the Auroral Kilometric Radiation (AKR) in the auroral upward current region. Narrow-in-altitude acceleration layers (double layers) can be identified by using both particles and waves measurements. Double layers once immersed in the plasma necessarily accelerate particles along the magnetic field, thereby generating locally strong turbulent processes leading to the formation of phase-space holes. As predicted by numerical simulations, we will emphasize the asymmetric character of the turbulence generated in the regions located upstream (low-potential side) or downstream (high-potential side) of a double layer. We will also point out that monitoring the time variation of the frequency drift of the elementary AKR radiators allows to qualitatively infer about the dynamics and the spatial extension of the field-aligned potential drops.

  19. An anti-symmetric exclusion process for two particles on an infinite 1D lattice

    NASA Astrophysics Data System (ADS)

    Potts, J. R.; Harris, S.; Giuggioli, L.

    2011-12-01

    A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propagator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system’s behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed.

  20. Real-time reprogrammable low-level image processing: edge detection and edge tracking accelerator

    NASA Astrophysics Data System (ADS)

    Meribout, M.; Hou, Kun M.

    1993-10-01

    Currently, in image processing, segmentation algorithms comprise between real time video rate processing and accurate results. In this paper, we present an efficient and not recursive algorithm filter originated from Deriche filter. This algorithm is implemented in hardware by using FPGA technology. Thus, it permits video rate edge detection. In addition, the FPGA board is used as an edge tracking accelerator, it allows us to greatly reduce execution time by avoiding scanning the whole image. We also present the architecture of our vision system dedicated to build 3D scene every 200 ms.

  1. Measurement of the velocities in the transient acceleration process using all-fiber photonic Doppler velocimetry

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Wu, Chong-qing; Song, Hong-wei; Yu, Tao; Xu, Jing-jing

    2011-05-01

    Based on analysis of basic photonic Doppler velocimetry (PDV), a formula to measure velocity variation in a single cycle is put forward. PDV has been improved in three aspects, namely, the laser, the detector and the data processing. A measurement system for velocity of the initial stage of a shock motion has been demonstrated. Instantaneous velocity measurements have been performed. The experimental results have a good agreement with the values obtained from the accelerometer. Compared with the traditional fringe method, the proposed method in this paper can identify instantaneous velocity variation. So it is particularly suitable for measuring the velocity in the transient acceleration process of shock waves and detonation waves.

  2. An accelerated method of computing nonlinear processes in instruments with longitudinal interaction

    NASA Astrophysics Data System (ADS)

    Pikunov, V. M.; Prokopev, V. E.; Sandalov, A. N.

    1985-04-01

    The use of the reference particle method for investigating nonlinear processes in instruments with longitudinal interaction is considered in an attempt to accelerate the computation of the processes. It is demonstrated that, coupled with interpolation formulas based on Kotelnikov series, the method yields effective numerical algorithms in the framework of discrete models of electron flux. A comparison of the method with a disk model of an electron flux for the case of multiresonator clistron was performed for clistron bunchers with 50 to 80-percent efficiency. It is concluded that the computation time was reduced by a factor of 3-10 while maintaining satisfactory accuracy.

  3. In-situ plasma processing to increase the accelerating gradients of SRF cavities

    SciTech Connect

    Doleans, Marc; Afanador, Ralph; Barnhart, Debra L.; Degraff, Brian D.; Gold, Steven W.; Hannah, Brian S.; Howell, Matthew P.; Kim, Sang-Ho; Mammosser, John; McMahan, Christopher J.; Neustadt, Thomas S.; Saunders, Jeffrey W.; Tyagi, Puneet V.; Vandygriff, Daniel J.; Vandygriff, David M.; Ball, Jeffrey Allen; Blokland, Willem; Crofford, Mark T.; Lee, Sung-Woo; Stewart, Stephen; Strong, William Herb

    2015-12-31

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.

  4. In-situ plasma processing to increase the accelerating gradients of SRF cavities

    DOE PAGESBeta

    Doleans, Marc; Afanador, Ralph; Barnhart, Debra L.; Degraff, Brian D.; Gold, Steven W.; Hannah, Brian S.; Howell, Matthew P.; Kim, Sang-Ho; Mammosser, John; McMahan, Christopher J.; et al

    2015-12-31

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipactingmore » issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.« less

  5. In-situ plasma processing to increase the accelerating gradients of superconducting radio-frequency cavities

    NASA Astrophysics Data System (ADS)

    Doleans, M.; Tyagi, P. V.; Afanador, R.; McMahan, C. J.; Ball, J. A.; Barnhart, D. L.; Blokland, W.; Crofford, M. T.; Degraff, B. D.; Gold, S. W.; Hannah, B. S.; Howell, M. P.; Kim, S.-H.; Lee, S.-W.; Mammosser, J.; Neustadt, T. S.; Saunders, J. W.; Stewart, S.; Strong, W. H.; Vandygriff, D. J.; Vandygriff, D. M.

    2016-03-01

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. In this article, the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus are discussed.

  6. Investigation of physico-chemical processes in hypervelocity MHD-gas acceleration wind tunnels

    SciTech Connect

    Alfyorov, V.I.; Dmitriev, L.M.; Yegorov, B.V.; Markachev, Yu.E.

    1995-12-31

    The calculation results for nonequilibrium physicochemical processes in the circuit of the hypersonic MHD-gas acceleration wind tunnel are presented. The flow in the primary nozzle is shown to be in thermodynamic equilibrium at To=3400 K, Po=(2{approximately}3)x10{sup 5} Pa, M=2 used in the plenum chamber. Variations in the static pressure due to oxidation reaction of Na, K are pointed out. The channels of energy transfer from the electric field to different degrees of freedom of an accelerated gas with Na, K seeds are considered. The calculation procedure for gas dynamic and kinetic processes in the MHD-channel using measured parameters is suggested. The calculated results are compared with the data obtained in a thermodynamic gas equilibrium assumption. The flow in the secondary nozzle is calculated under the same assumptions and the gas parameters at its exit are evaluated. Particular attention is given to the influence of seeds on flows over bodies. It is shown that the seeds exert a very small influence on the flow behind a normal shock wave. The seeds behind an oblique shock wave accelerate deactivation of vibrations of N{sub 2}, but this effect is insignificant.

  7. Status of development of actinide blanket processing flowsheets for accelerator transmutation of nuclear waste

    SciTech Connect

    Dewey, H.J.; Jarvinen, G.D.; Marsh, S.F.; Schroeder, N.C.; Smith, B.F.; Villarreal, R.; Walker, R.B.; Yarbro, S.L.; Yates, M.A.

    1993-09-01

    An accelerator-driven subcritical nuclear system is briefly described that transmutes actinides and selected long-lived fission products. An application of this accelerator transmutation of nuclear waste (ATW) concept to spent fuel from a commercial nuclear power plant is presented as an example. The emphasis here is on a possible aqueous processing flowsheet to separate the actinides and selected long-lived fission products from the remaining fission products within the transmutation system. In the proposed system the actinides circulate through the thermal neutron flux as a slurry of oxide particles in heavy water in two loops with different average residence times: one loop for neptunium and plutonium and one for americium and curium. Material from the Np/Pu loop is processed with a short cooling time (5-10 days) because of the need to keep the total actinide inventory, low for this particular ATW application. The high radiation and thermal load from the irradiated material places severe constraints on the separation processes that can be used. The oxide particles are dissolved in nitric acid and a quarternary, ammonium anion exchanger is used to extract neptunium, plutonium, technetium, and palladium. After further cooling (about 90 days), the Am, Cm and higher actinides are extracted using a TALSPEAK-type process. The proposed operations were chosen because they have been successfully tested for processing high-level radioactive fuels or wastes in gram to kilogram quantities.

  8. Plasma Processing of SRF Cavities for the next Generation Of Particle Accelerators

    SciTech Connect

    Vuskovic, Leposava

    2015-11-23

    The cost-effective production of high frequency accelerating fields are the foundation for the next generation of particle accelerators. The Ar/Cl2 plasma etching technology holds the promise to yield a major reduction in cavity preparation costs. Plasma-based dry niobium surface treatment provides an excellent opportunity to remove bulk niobium, eliminate surface imperfections, increase cavity quality factor, and bring accelerating fields to higher levels. At the same time, the developed technology will be more environmentally friendly than the hydrogen fluoride-based wet etching technology. Plasma etching of inner surfaces of standard multi-cell SRF cavities is the main goal of this research in order to eliminate contaminants, including niobium oxides, in the penetration depth region. Successful plasma processing of multi-cell cavities will establish this method as a viable technique in the quest for more efficient components of next generation particle accelerators. In this project the single-cell pill box cavity plasma etching system is developed and etching conditions are determined. An actual single cell SRF cavity (1497 MHz) is plasma etched based on the pill box cavity results. The first RF test of this plasma etched cavity at cryogenic temperature is obtained. The system can also be used for other surface modifications, including tailoring niobium surface properties, surface passivation or nitriding for better performance of SRF cavities. The results of this plasma processing technology may be applied to most of the current SRF cavity fabrication projects. In the course of this project it has been demonstrated that a capacitively coupled radio-frequency discharge can be successfully used for etching curved niobium surfaces, in particular the inner walls of SRF cavities. The results could also be applicable to the inner or concave surfaces of any 3D structure other than an SRF cavity.

  9. ACCELERATED PROCESSING OF SB4 AND PREPARATION FOR SB5 PROCESSING AT DWPF

    SciTech Connect

    Herman, C

    2008-12-01

    The Defense Waste Processing Facility (DWPF) initiated processing of Sludge Batch 4 (SB4) in May 2007. SB4 was the first DWPF sludge batch to contain significant quantities of HM or high Al sludge. Initial testing with SB4 simulants showed potential negative impacts to DWPF processing; therefore, Savannah River National Laboratory (SRNL) performed extensive testing in an attempt to optimize processing. SRNL's testing has resulted in the highest DWPF production rates since start-up. During SB4 processing, DWPF also began incorporating waste streams from the interim salt processing facilities to initiate coupled operations. While DWPF has been processing SB4, the Liquid Waste Organization (LWO) and the SRNL have been preparing Sludge Batch 5 (SB5). SB5 has undergone low-temperature aluminum dissolution to reduce the mass of sludge for vitrification and will contain a small fraction of Purex sludge. A high-level review of SB4 processing and the SB5 preparation studies will be provided.

  10. Accessing proton generalized parton distributions and pion distribution amplitudes with the exclusive pion-induced Drell-Yan process at J-PARC

    NASA Astrophysics Data System (ADS)

    Sawada, Takahiro; Chang, Wen-Chen; Kumano, Shunzo; Peng, Jen-Chieh; Sawada, Shinya; Tanaka, Kazuhiro

    2016-06-01

    Generalized parton distributions (GPDs) encoding multidimensional information of hadron partonic structure appear as the building blocks in a factorized description of hard exclusive reactions. The nucleon GPDs have been accessed by deeply virtual Compton scattering and deeply virtual meson production with lepton beam. A complementary probe with hadron beam is the exclusive pion-induced Drell-Yan process. In this paper, we discuss recent theoretical advances on describing this process in terms of nucleon GPDs and pion distribution amplitudes. Furthermore, we address the feasibility of measuring the exclusive pion-induced Drell-Yan process π-p →μ+μ-n via a spectrometer at the High Momentum Beamline being constructed at J-PARC in Japan. Realization of such measurement at J-PARC will provide a new test of perturbative QCD descriptions of a novel class of hard exclusive reactions. It will also offer the possibility of experimentally accessing nucleon GPDs at large timelike virtuality.

  11. A Correction to the Hydrodynamic Limit of Boundary Driven Weakly Asymmetric Exclusion Processes in a Quasi-Static Time Scale

    NASA Astrophysics Data System (ADS)

    Chavez, E.; Landim, C.

    2016-06-01

    We consider a one-dimensional, weakly asymmetric, boundary driven exclusion process on the interval [0,N]\\cap Z in the quasi-static time scale N^2 ɛ ^{-1}_N, where 1≪ ɛ ^{-1}_N ≪ N^{1/4}. We assume that the external field and the chemical potentials, which fix the density at the boundaries, evolve smoothly in the macroscopic time scale. We derive an equation which describes the evolution of the density up to the order ɛ _N.

  12. A Correction to the Hydrodynamic Limit of Boundary Driven Weakly Asymmetric Exclusion Processes in a Quasi-Static Time Scale

    NASA Astrophysics Data System (ADS)

    Chavez, E.; Landim, C.

    2016-06-01

    We consider a one-dimensional, weakly asymmetric, boundary driven exclusion process on the interval [0,N]\\cap {Z} in the quasi-static time scale N^2 ɛ ^{-1}_N, where 1≪ ɛ ^{-1}_N ≪ N^{1/4}. We assume that the external field and the chemical potentials, which fix the density at the boundaries, evolve smoothly in the macroscopic time scale. We derive an equation which describes the evolution of the density up to the order ɛ _N.

  13. Open-source graphics processing unit-accelerated ray tracer for optical simulation

    NASA Astrophysics Data System (ADS)

    Mauch, Florian; Gronle, Marc; Lyda, Wolfram; Osten, Wolfgang

    2013-05-01

    Ray tracing still is the workhorse in optical design and simulation. Its basic principle, propagating light as a set of mutually independent rays, implies a linear dependency of the computational effort and the number of rays involved in the problem. At the same time, the mutual independence of the light rays bears a huge potential for parallelization of the computational load. This potential has recently been recognized in the visualization community, where graphics processing unit (GPU)-accelerated ray tracing is used to render photorealistic images. However, precision requirements in optical simulation are substantially higher than in visualization, and therefore performance results known from visualization cannot be expected to transfer to optical simulation one-to-one. In this contribution, we present an open-source implementation of a GPU-accelerated ray tracer, based on nVidias acceleration engine OptiX, that traces in double precision and exploits the massively parallel architecture of modern graphics cards. We compare its performance to a CPU-based tracer that has been developed in parallel.

  14. Successes and lessons learned: How to accelerate the base closure process

    SciTech Connect

    Larkin, V.C.; Stoll, R.

    1994-12-31

    Naval Station Puget Sound, Seattle, was nominated for closure by the Base Closure Commission in 1991 (BRAC II) and will be transferred in September of 1995. Historic activities have resulted in petroleum-related environmental issues. Unlike many bases being closed, the politically sensitive issues are not the economics of job losses. Because homeless housing is expected to be included in the selected reuse plan, the primary concerns of the public are reduced real estate values and public safety. In addition to a reuse plan adopted by the Seattle City Council, the Muckleshoot Indian tribe has also submitted an alternative reuse plan to the Navy. Acceleration methods described in this paper include methods for beginning the environmental impact statement (EIS) process before reuse plans are finalized; tracking development of engineering alternatives in parallel with environmental investigations; using field screening data to begin developing plans and specifications for remediation, instead of waiting 6 weeks for analytical results and data validation; using efficient communication techniques to facilitate accelerated review of technical documents by the BCT; expediting removal actions and performing ``cleanups incidental to investigation``; and effectively facilitating members of the Restoration Advisory Board with divergent points of view. This paper will describe acceleration methods that proved to be effective and methods that could be modified to be more effective at other sites.

  15. BioThreads: a novel VLIW-based chip multiprocessor for accelerating biomedical image processing applications.

    PubMed

    Stevens, David; Chouliaras, Vassilios; Azorin-Peris, Vicente; Zheng, Jia; Echiadis, Angelos; Hu, Sijung

    2012-06-01

    We discuss BioThreads, a novel, configurable, extensible system-on-chip multiprocessor and its use in accelerating biomedical signal processing applications such as imaging photoplethysmography (IPPG). BioThreads is derived from the LE1 open-source VLIW chip multiprocessor and efficiently handles instruction, data and thread-level parallelism. In addition, it supports a novel mechanism for the dynamic creation, and allocation of software threads to uncommitted processor cores by implementing key POSIX Threads primitives directly in hardware, as custom instructions. In this study, the BioThreads core is used to accelerate the calculation of the oxygen saturation map of living tissue in an experimental setup consisting of a high speed image acquisition system, connected to an FPGA board and to a host system. Results demonstrate near-linear acceleration of the core kernels of the target blood perfusion assessment with increasing number of hardware threads. The BioThreads processor was implemented on both standard-cell and FPGA technologies; in the first case and for an issue width of two, full real-time performance is achieved with 4 cores whereas on a mid-range Xilinx Virtex6 device this is achieved with 10 dual-issue cores. An 8-core LE1 VLIW FPGA prototype of the system achieved 240 times faster execution time than the scalar Microblaze processor demonstrating the scalability of the proposed solution to a state-of-the-art FPGA vendor provided soft CPU core. PMID:23853147

  16. Investigation of acceleration processes of the 14th july 2005 flare series occurred in ar 10786

    NASA Astrophysics Data System (ADS)

    Sizykh, Tatyana; Kashapova, Larisa

    We present the results of acceleration process study in the flare series occurred 14th July 2005 on the western limb of the Sun. Our investigation is based on HXR data obtained by RHESSI. It was observed increasing of solar flare activity with X1.2 class flare at its culmination. The presence of accelerated electrons (the power-law component of HXR spectrum for energies more than 25 keV) was clearly signified only in the first (C3.8) and the last of studied flares. We applied lgT-1/2lgEM diagrams ( Jakimiec et al,1986) for quantitative study of HXR spectrums for all flares. For analysis of the flares showed presence of significant flux of accelerated electrons we also used diagrams made on base of parameters obtained from non-thermal part of the spectrum (flux, spectral index, spectral curvature, Grigis Benz 2009). The possible scenario of evolution of this active region is discussed.

  17. Using Graphical Processing Units to Accelerate Orthorectification, Atmospheric Correction and Transformations for Big Data

    NASA Astrophysics Data System (ADS)

    O'Connor, A. S.; Justice, B.; Harris, A. T.

    2013-12-01

    Graphics Processing Units (GPUs) are high-performance multiple-core processors capable of very high computational speeds and large data throughput. Modern GPUs are inexpensive and widely available commercially. These are general-purpose parallel processors with support for a variety of programming interfaces, including industry standard languages such as C. GPU implementations of algorithms that are well suited for parallel processing can often achieve speedups of several orders of magnitude over optimized CPU codes. Significant improvements in speeds for imagery orthorectification, atmospheric correction, target detection and image transformations like Independent Components Analsyis (ICA) have been achieved using GPU-based implementations. Additional optimizations, when factored in with GPU processing capabilities, can provide 50x - 100x reduction in the time required to process large imagery. Exelis Visual Information Solutions (VIS) has implemented a CUDA based GPU processing frame work for accelerating ENVI and IDL processes that can best take advantage of parallelization. Testing Exelis VIS has performed shows that orthorectification can take as long as two hours with a WorldView1 35,0000 x 35,000 pixel image. With GPU orthorecification, the same orthorectification process takes three minutes. By speeding up image processing, imagery can successfully be used by first responders, scientists making rapid discoveries with near real time data, and provides an operational component to data centers needing to quickly process and disseminate data.

  18. Monitoring oil displacement processes with k-t accelerated spin echo SPI.

    PubMed

    Li, Ming; Xiao, Dan; Romero-Zerón, Laura; Balcom, Bruce J

    2016-03-01

    Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time-dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T2 signal lifetime distribution. In this work, a pure phase-encoding MRI technique, spin echo SPI (SE-SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k-t acceleration method, with low-rank matrix completion, was employed to improve the temporal resolution of the SE-SPI MRI measurements. Comparison to conventional SE-SPI T2 mapping measurements revealed that the k-t accelerated measurement was more sensitive and provided higher-quality results. It was demonstrated that the k-t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no (1) H, and H2 O brine were employed to distinguish oil and water phases in model flooding experiments. High-quality 1D water saturation profiles were acquired from the k-t accelerated SE-SPI measurements. Spatially and temporally resolved T2 distributions were extracted from the profile data. The shift in the (1) H T2 distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26626141

  19. Ground Test of the Urine Processing Assembly for Accelerations and Transfer Functions

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Almond, Deborah F. (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of the ground test of the urine processing assembly for accelerations and transfer functions. Details are given on the test setup, test data, data analysis, analytical results, and microgravity assessment. The conclusions of the tests include the following: (1) the single input/multiple output method is useful if the data is acquired by tri-axial accelerometers and inputs can be considered uncorrelated; (2) tying coherence with the matrix yields higher confidence in results; (3) the WRS#2 rack ORUs need to be isolated; (4) and future work includes a plan for characterizing performance of isolation materials.

  20. Turbulent Magnetohydrodynamic Acceleration Processes: Theory SSX Experiments and Connections to Space and Astrophysics

    SciTech Connect

    W Matthaeus; M Brown

    2006-07-15

    This is the final technical report for a funded program to provide theoretical support to the Swarthmore Spheromak Experiment. We examined mhd relaxation, reconnecton between two spheromaks, particle acceleration by these processes, and collisonless effects, e.g., Hall effect near the reconnection zone,. Throughout the project, applications to space plasma physics and astrophysics were included. Towards the end ofthe project we were examining a more fully turbulent relaxation associated with unconstrained dynamics in SSX. We employed experimental, spacecraft observations, analytical and numerical methods.

  1. Study of the near-electrode processes in quasi-steady plasma accelerators with impenetrable electrodes

    NASA Astrophysics Data System (ADS)

    Kozlov, A. N.

    2012-01-01

    Near-electrode processes in a coaxial plasma accelerator with equipotential impenetrable electrodes are simulated using a two-dimensional (generally, time-dependent) two-fluid MHD model with allowance for the Hall effect and the plasma conductivity tensor. The simulations confirm the theoretically predicted mechanism of the so-called "crisis of current" caused by the Hall effect. The simulation results are compared with available experimental data. The influence of both the method of plasma supply to the channel and an additional longitudinal magnetic field on the development of near-electrode instabilities preceding the crisis of current is studied.

  2. Segregating metabolic processes into different microbial cells accelerates the consumption of inhibitory substrates.

    PubMed

    Lilja, Elin E; Johnson, David R

    2016-07-01

    Different microbial cell types typically specialize at performing different metabolic processes. A canonical example is substrate cross-feeding, where one cell type consumes a primary substrate into an intermediate and another cell type consumes the intermediate. While substrate cross-feeding is widely observed, its consequences on ecosystem processes is often unclear. How does substrate cross-feeding affect the rate or extent of substrate consumption? We hypothesized that substrate cross-feeding eliminates competition between different enzymes and reduces the accumulation of growth-inhibiting intermediates, thus accelerating substrate consumption. We tested this hypothesis using isogenic mutants of the bacterium Pseudomonas stutzeri that either completely consume nitrate to dinitrogen gas or cross-feed the intermediate nitrite. We demonstrate that nitrite cross-feeding eliminates inter-enzyme competition and, in turn, reduces nitrite accumulation. We further demonstrate that nitrite cross-feeding accelerates substrate consumption, but only when nitrite has growth-inhibiting effects. Knowledge about inter-enzyme competition and the inhibitory effects of intermediates could therefore be important for deciding how to best segregate different metabolic processes into different microbial cell types to optimize a desired biotransformation. PMID:26771930

  3. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    NASA Astrophysics Data System (ADS)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  4. Large scale neural circuit mapping data analysis accelerated with the graphical processing unit (GPU)

    PubMed Central

    Shi, Yulin; Veidenbaum, Alexander V.; Nicolau, Alex; Xu, Xiangmin

    2014-01-01

    Background Modern neuroscience research demands computing power. Neural circuit mapping studies such as those using laser scanning photostimulation (LSPS) produce large amounts of data and require intensive computation for post-hoc processing and analysis. New Method Here we report on the design and implementation of a cost-effective desktop computer system for accelerated experimental data processing with recent GPU computing technology. A new version of Matlab software with GPU enabled functions is used to develop programs that run on Nvidia GPUs to harness their parallel computing power. Results We evaluated both the central processing unit (CPU) and GPU-enabled computational performance of our system in benchmark testing and practical applications. The experimental results show that the GPU-CPU co-processing of simulated data and actual LSPS experimental data clearly outperformed the multi-core CPU with up to a 22x speedup, depending on computational tasks. Further, we present a comparison of numerical accuracy between GPU and CPU computation to verify the precision of GPU computation. In addition, we show how GPUs can be effectively adapted to improve the performance of commercial image processing software such as Adobe Photoshop. Comparison with Existing Method(s) To our best knowledge, this is the first demonstration of GPU application in neural circuit mapping and electrophysiology-based data processing. Conclusions Together, GPU enabled computation enhances our ability to process large-scale data sets derived from neural circuit mapping studies, allowing for increased processing speeds while retaining data precision. PMID:25277633

  5. New Applications of Ultraviolet Spectroscopy to the Identification of Coronal Heating and Solar Wind Acceleration Processes

    NASA Astrophysics Data System (ADS)

    Cranmer, S. R.

    2001-05-01

    The Ultraviolet Coronagraph Spectrometer (UVCS) aboard SOHO has revealed surprisingly extreme plasma conditions in the extended solar corona. This presentation reviews several new ways that UVCS and future spectroscopic instruments can be used to identify the physical processes responsible for producing the various components of the solar wind. The most promising mechanism for heating and accelerating heavy ions remains the dissipation of ion cyclotron waves, but the origin of these waves---as well as the dominant direction of propagation relative to the background magnetic field---is not yet known. Ultraviolet spectroscopy of a sufficient number of ions would be able to pinpoint the precise magnetohydrodynamic modes and the relative amounts of damping, turbulent cascade, and local plasma instability in the corona. (A simple graphical comparison of line-width ratios will be presented as a first step in this direction.) Spectroscopic observations with sufficient sensitivity can also detect departures from Gaussian line shapes that are unique identifiers of non-Maxwellian velocity distributions arising from cyclotron (or other) processes. Even without these next-generation diagnostics, UVCS data are continuing to put constraints on how the heating and acceleration mechanisms respond to changes in the ``background'' properties of coronal holes and streamers; i.e., geometry, latitude, and density. These provide crucial scaling relations in the acceleration region of the fast and slow solar wind that must be reproduced by any candidate theory. This work is supported by the National Aeronautics and Space Administration under grant NAG5-10093 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the Swiss contribution to the ESA PRODEX program.

  6. UV Irradiation Accelerates Amyloid Precursor Protein (APP) Processing and Disrupts APP Axonal Transport

    PubMed Central

    Almenar-Queralt, Angels; Falzone, Tomas L.; Shen, Zhouxin; Lillo, Concepcion; Killian, Rhiannon L.; Arreola, Angela S.; Niederst, Emily D.; Ng, Kheng S.; Kim, Sonia N.; Briggs, Steven P.; Williams, David S.

    2014-01-01

    Overexpression and/or abnormal cleavage of amyloid precursor protein (APP) are linked to Alzheimer's disease (AD) development and progression. However, the molecular mechanisms regulating cellular levels of APP or its processing, and the physiological and pathological consequences of altered processing are not well understood. Here, using mouse and human cells, we found that neuronal damage induced by UV irradiation leads to specific APP, APLP1, and APLP2 decline by accelerating their secretase-dependent processing. Pharmacological inhibition of endosomal/lysosomal activity partially protects UV-induced APP processing implying contribution of the endosomal and/or lysosomal compartments in this process. We found that a biological consequence of UV-induced γ-secretase processing of APP is impairment of APP axonal transport. To probe the functional consequences of impaired APP axonal transport, we isolated and analyzed presumptive APP-containing axonal transport vesicles from mouse cortical synaptosomes using electron microscopy, biochemical, and mass spectrometry analyses. We identified a population of morphologically heterogeneous organelles that contains APP, the secretase machinery, molecular motors, and previously proposed and new residents of APP vesicles. These possible cargoes are enriched in proteins whose dysfunction could contribute to neuronal malfunction and diseases of the nervous system including AD. Together, these results suggest that damage-induced APP processing might impair APP axonal transport, which could result in failure of synaptic maintenance and neuronal dysfunction. PMID:24573290

  7. Accelerated rescaling of single Monte Carlo simulation runs with the Graphics Processing Unit (GPU).

    PubMed

    Yang, Owen; Choi, Bernard

    2013-01-01

    To interpret fiber-based and camera-based measurements of remitted light from biological tissues, researchers typically use analytical models, such as the diffusion approximation to light transport theory, or stochastic models, such as Monte Carlo modeling. To achieve rapid (ideally real-time) measurement of tissue optical properties, especially in clinical situations, there is a critical need to accelerate Monte Carlo simulation runs. In this manuscript, we report on our approach using the Graphics Processing Unit (GPU) to accelerate rescaling of single Monte Carlo runs to calculate rapidly diffuse reflectance values for different sets of tissue optical properties. We selected MATLAB to enable non-specialists in C and CUDA-based programming to use the generated open-source code. We developed a software package with four abstraction layers. To calculate a set of diffuse reflectance values from a simulated tissue with homogeneous optical properties, our rescaling GPU-based approach achieves a reduction in computation time of several orders of magnitude as compared to other GPU-based approaches. Specifically, our GPU-based approach generated a diffuse reflectance value in 0.08ms. The transfer time from CPU to GPU memory currently is a limiting factor with GPU-based calculations. However, for calculation of multiple diffuse reflectance values, our GPU-based approach still can lead to processing that is ~3400 times faster than other GPU-based approaches. PMID:24298424

  8. Accelerating the performance of a novel meshless method based on collocation with radial basis functions by employing a graphical processing unit as a parallel coprocessor

    NASA Astrophysics Data System (ADS)

    Owusu-Banson, Derek

    In recent times, a variety of industries, applications and numerical methods including the meshless method have enjoyed a great deal of success by utilizing the graphical processing unit (GPU) as a parallel coprocessor. These benefits often include performance improvement over the previous implementations. Furthermore, applications running on graphics processors enjoy superior performance per dollar and performance per watt than implementations built exclusively on traditional central processing technologies. The GPU was originally designed for graphics acceleration but the modern GPU, known as the General Purpose Graphical Processing Unit (GPGPU) can be used for scientific and engineering calculations. The GPGPU consists of massively parallel array of integer and floating point processors. There are typically hundreds of processors per graphics card with dedicated high-speed memory. This work describes an application written by the author, titled GaussianRBF to show the implementation and results of a novel meshless method that in-cooperates the collocation of the Gaussian radial basis function by utilizing the GPU as a parallel co-processor. Key phases of the proposed meshless method have been executed on the GPU using the NVIDIA CUDA software development kit. Especially, the matrix fill and solution phases have been carried out on the GPU, along with some post processing. This approach resulted in a decreased processing time compared to similar algorithm implemented on the CPU while maintaining the same accuracy.

  9. He-Ne laser irradiation acceleration of healing process of open gingival wounds in cats

    NASA Astrophysics Data System (ADS)

    Abramovici, Armand; Roisman, P.; Hirsch, A.; Segal, S.; Fischer, J.

    1994-09-01

    A histopathological study on the effect of He-Ne laser treatment on the evolution of cat gingiva open wounds is presented. The irradiation initiates first a massive inflammatory cell exudate together with an antiedematic effect after the second postoperative day. A substantial acceleration of the healing process is noted on the sixth day among irradiated tissues as compared to the operated gingiva which still shows, at this period of time, inflammatory exudate and isolated fibroblasts. The persistence of inflammatory exudate and edema among the untreated gingiva seemed to have a delaying effect upon the healing process. The biostimulatory effect of soft laser seems to act photodynamically both at the intracellular level and extracellular millieu, thus promoting the proliferative capacity of fibroblasts and capillary buds formation necessary for a rapid differentiation of connective tissue. The controlled application of He-Ne laser treatment is suggested in dental healing procedures.

  10. Modified Anderson Method for Accelerating 3D-RISM Calculations Using Graphics Processing Unit.

    PubMed

    Maruyama, Yutaka; Hirata, Fumio

    2012-09-11

    A fast algorithm is proposed to solve the three-dimensional reference interaction site model (3D-RISM) theory on a graphics processing unit (GPU). 3D-RISM theory is a powerful tool for investigating biomolecular processes in solution; however, such calculations are often both memory-intensive and time-consuming. We sought to accelerate these calculations using GPUs, but to work around the problem of limited memory size in GPUs, we modified the less memory-intensive "Anderson method" to give faster convergence to 3D-RISM calculations. Using this method on a Tesla C2070 GPU, we reduced the total computational time by a factor of 8, 1.4 times by the modified Andersen method and 5.7 times by GPU, compared to calculations on an Intel Xeon machine (eight cores, 3.33 GHz) with the conventional method. PMID:26605714

  11. ATCOM: accelerated image processing for terrestrial long-range imaging through atmospheric effects

    NASA Astrophysics Data System (ADS)

    Curt, Petersen F.; Paolini, Aaron

    2013-05-01

    Long-range video surveillance performance is often severely diminished due to atmospheric turbulence. The larger apertures typically used for video-rate operation at long-range are particularly susceptible to scintillation and blurring effects that limit the overall diffraction efficiency and resolution. In this paper, we present research progress made toward a digital signal processing technique which aims to mitigate the effects of turbulence in real-time. Our previous work in this area focused on an embedded implementation for portable applications. Our more recent research has focused on functional enhancements to the same algorithm using general-purpose hardware. We present some techniques that were successfully employed to accelerate processing of high-definition color video streams and study performance under nonideal conditions involving moving objects and panning cameras. Finally, we compare the real-time performance of two implementations using a CPU and a GPU.

  12. Arsenite exposure accelerates aging process regulated by the transcription factor DAF-16/FOXO in Caenorhabditis elegans.

    PubMed

    Yu, Chan-Wei; How, Chun Ming; Liao, Vivian Hsiu-Chuan

    2016-05-01

    Arsenic is a known human carcinogen and high levels of arsenic contamination in food, soils, water, and air are of toxicology concerns. Nowadays, arsenic is still a contaminant of emerging interest, yet the effects of arsenic on aging process have received little attention. In this study, we investigated the effects and the underlying mechanisms of chronic arsenite exposure on the aging process in Caenorhabditis elegans. The results showed that prolonged arsenite exposure caused significantly decreased lifespan compared to non-exposed ones. In addition, arsenite exposure (100 μM) caused significant changes of age-dependent biomarkers, including a decrease of defecation frequency, accumulations of intestinal lipofuscin and lipid peroxidation in an age-dependent manner in C. elegans. Further evidence revealed that intracellular reactive oxygen species (ROS) level was significantly increased in an age-dependent manner upon 100 μM arsenite exposure. Moreover, the mRNA levels of transcriptional makers of aging (hsp-16.1, hsp-16.49, and hsp-70) were increased in aged worms under arsenite exposure (100 μM). Finally, we showed that daf-16 mutant worms were more sensitive to arsenite exposure (100 μM) on lifespan and failed to induce the expression of its target gene sod-3 in aged daf-16 mutant under arsenite exposure (100 μM). Our study demonstrated that chronic arsenite exposure resulted in accelerated aging process in C. elegans. The overproduction of intracellular ROS and the transcription factor DAF-16/FOXO play roles in mediating the accelerated aging process by arsenite exposure in C. elegans. This study implicates a potential ecotoxicological and health risk of arsenic in the environment. PMID:26796881

  13. Initial investigation using statistical process control for quality control of accelerator beam steering

    PubMed Central

    2011-01-01

    Background This study seeks to increase clinical operational efficiency and accelerator beam consistency by retrospectively investigating the application of statistical process control (SPC) to linear accelerator beam steering parameters to determine the utility of such a methodology in detecting changes prior to equipment failure (interlocks actuated). Methods Steering coil currents (SCC) for the transverse and radial planes are set such that a reproducibly useful photon or electron beam is available. SCC are sampled and stored in the control console computer each day during the morning warm-up. The transverse and radial - positioning and angle SCC for photon beam energies were evaluated using average and range (Xbar-R) process control charts (PCC). The weekly average and range values (subgroup n = 5) for each steering coil were used to develop the PCC. SCC from September 2009 (annual calibration) until two weeks following a beam steering failure in June 2010 were evaluated. PCC limits were calculated using the first twenty subgroups. Appropriate action limits were developed using conventional SPC guidelines. Results PCC high-alarm action limit was set at 6 standard deviations from the mean. A value exceeding this limit would require beam scanning and evaluation by the physicist and engineer. Two low alarms were used to indicate negative trends. Alarms received following establishment of limits (week 20) are indicative of a non-random cause for deviation (Xbar chart) and/or an uncontrolled process (R chart). Transverse angle SCC for 6 MV and 15 MV indicated a high-alarm 90 and 108 days prior to equipment failure respectively. A downward trend in this parameter continued, with high-alarm, until failure. Transverse position and radial angle SCC for 6 and 15 MV indicated low-alarms starting as early as 124 and 116 days prior to failure, respectively. Conclusion Radiotherapy clinical efficiency and accelerator beam consistency may be improved by instituting SPC

  14. A polarization-based frequency scanning interferometer and the signal processing acceleration method based on parallel processing architecture

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Kim, Min Young

    FSI system, one of the most promising optical surface measurement techniques, generally results in superior optical performance comparing with other 3-dimensional measuring methods as its hardware structure is fixed in operation and only the light frequency is scanned in a specific spectral band without vertical scanning of the target surface or the objective lens. FSI system collects a set of images of interference fringe by changing the frequency of light source. After that, it transforms intensity data of acquired image into frequency information, and calculates the height profile of target objects with the help of frequency analysis based on FFT. However, it still suffers from optical noise from target surface and relatively long processing time due to the number of images acquired in frequency scanning phase. First, a polarization-based frequency scanning interferometry (PFSI) is proposed for optical noise robustness. It consists of tunable laser for light source, λ/4 plate in front of reference mirror, λ/4 plate in front of target object, polarizing beam splitter, polarizer in front of image sensor, polarizer in front of the fiber coupled light source, λ/2 plate between PBS and polarizer of the light source. Using the proposed system, we can solve the problem low contrast of acquired fringe image by using polarization technique. Also, we can control light distribution of object beam and reference beam. Second, the signal processing acceleration method is proposed for PFSI, based on parallel processing architecture, which consists of parallel processing hardware and software such as GPU (Graphic Processing Unit) and CUDA (Compute Unified Device Architecture). As a result, the processing time reaches into tact time level of real-time processing. Finally, the proposed system is evaluated in terms of accuracy and processing speed through a series of experiment and the obtained results show the effectiveness of the proposed system and method.

  15. Surface damage correction, and atomic level smoothing of optics by Accelerated Neutral Atom Beam (ANAB) Processing

    NASA Astrophysics Data System (ADS)

    Walsh, M.; Chau, K.; Kirkpatrick, S.; Svrluga, R.

    2014-10-01

    Surface damage and surface contamination of optics has long been a source of problems for laser, lithography and other industries. Nano-sized surface defects may present significant performance issues in optical materials for deep UV and EUV applications. The effects of nanometer sized surface damage (scratches, pits, and organics) on the surface of optics made of traditional materials and new more exotic materials is a limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, zinc sulfide, BK7 and others presents a unique set of challenges. Exogenesis Corporation, using its proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and contamination and leaves many material surfaces with roughness typically around one angstrom. This process technology has been demonstrated on nonlinear crystals, and various other high-end optical materials. This paper describes the ANAB technology and summarizes smoothing results for various materials that have been processed with ANAB. All surface measurement data for the paper was produced via AFM analysis. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply normal forces associated with traditional polishing techniques. ANAB efficiently removes surface contaminants, nano-scale scratches, bumps and other asperities under low energy physical sputtering conditions as the removal action proceeds. ANAB may be used to remove a precisely controlled, uniform thickness of material without any increase of surface roughness, regardless of the total amount of material removed. The ANAB process does not

  16. Accelerated Molecular Dynamics Simulations with the AMOEBA Polarizable Force Field on Graphics Processing Units

    PubMed Central

    2013-01-01

    The accelerated molecular dynamics (aMD) method has recently been shown to enhance the sampling of biomolecules in molecular dynamics (MD) simulations, often by several orders of magnitude. Here, we describe an implementation of the aMD method for the OpenMM application layer that takes full advantage of graphics processing units (GPUs) computing. The aMD method is shown to work in combination with the AMOEBA polarizable force field (AMOEBA-aMD), allowing the simulation of long time-scale events with a polarizable force field. Benchmarks are provided to show that the AMOEBA-aMD method is efficiently implemented and produces accurate results in its standard parametrization. For the BPTI protein, we demonstrate that the protein structure described with AMOEBA remains stable even on the extended time scales accessed at high levels of accelerations. For the DNA repair metalloenzyme endonuclease IV, we show that the use of the AMOEBA force field is a significant improvement over fixed charged models for describing the enzyme active-site. The new AMOEBA-aMD method is publicly available (http://wiki.simtk.org/openmm/VirtualRepository) and promises to be interesting for studying complex systems that can benefit from both the use of a polarizable force field and enhanced sampling. PMID:24634618

  17. Accelerating image reconstruction in three-dimensional optoacoustic tomography on graphics processing units

    PubMed Central

    Wang, Kun; Huang, Chao; Kao, Yu-Jiun; Chou, Cheng-Ying; Oraevsky, Alexander A.; Anastasio, Mark A.

    2013-01-01

    Purpose: Optoacoustic tomography (OAT) is inherently a three-dimensional (3D) inverse problem. However, most studies of OAT image reconstruction still employ two-dimensional imaging models. One important reason is because 3D image reconstruction is computationally burdensome. The aim of this work is to accelerate existing image reconstruction algorithms for 3D OAT by use of parallel programming techniques. Methods: Parallelization strategies are proposed to accelerate a filtered backprojection (FBP) algorithm and two different pairs of projection/backprojection operations that correspond to two different numerical imaging models. The algorithms are designed to fully exploit the parallel computing power of graphics processing units (GPUs). In order to evaluate the parallelization strategies for the projection/backprojection pairs, an iterative image reconstruction algorithm is implemented. Computer simulation and experimental studies are conducted to investigate the computational efficiency and numerical accuracy of the developed algorithms. Results: The GPU implementations improve the computational efficiency by factors of 1000, 125, and 250 for the FBP algorithm and the two pairs of projection/backprojection operators, respectively. Accurate images are reconstructed by use of the FBP and iterative image reconstruction algorithms from both computer-simulated and experimental data. Conclusions: Parallelization strategies for 3D OAT image reconstruction are proposed for the first time. These GPU-based implementations significantly reduce the computational time for 3D image reconstruction, complementing our earlier work on 3D OAT iterative image reconstruction. PMID:23387778

  18. On-site installation and shielding of a mobile electron accelerator for radiation processing

    NASA Astrophysics Data System (ADS)

    Catana, Dumitru; Panaitescu, Julian; Axinescu, Silviu; Manolache, Dumitru; Matei, Constantin; Corcodel, Calin; Ulmeanu, Magdalena; Bestea, Virgil

    1995-05-01

    The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account.

  19. Graphics processing unit (GPU)-accelerated particle filter framework for positron emission tomography image reconstruction.

    PubMed

    Yu, Fengchao; Liu, Huafeng; Hu, Zhenghui; Shi, Pengcheng

    2012-04-01

    As a consequence of the random nature of photon emissions and detections, the data collected by a positron emission tomography (PET) imaging system can be shown to be Poisson distributed. Meanwhile, there have been considerable efforts within the tracer kinetic modeling communities aimed at establishing the relationship between the PET data and physiological parameters that affect the uptake and metabolism of the tracer. Both statistical and physiological models are important to PET reconstruction. The majority of previous efforts are based on simplified, nonphysical mathematical expression, such as Poisson modeling of the measured data, which is, on the whole, completed without consideration of the underlying physiology. In this paper, we proposed a graphics processing unit (GPU)-accelerated reconstruction strategy that can take both statistical model and physiological model into consideration with the aid of state-space evolution equations. The proposed strategy formulates the organ activity distribution through tracer kinetics models and the photon-counting measurements through observation equations, thus making it possible to unify these two constraints into a general framework. In order to accelerate reconstruction, GPU-based parallel computing is introduced. Experiments of Zubal-thorax-phantom data, Monte Carlo simulated phantom data, and real phantom data show the power of the method. Furthermore, thanks to the computing power of the GPU, the reconstruction time is practical for clinical application. PMID:22472843

  20. High-Speed Digital Signal Processing Method for Detection of Repeating Earthquakes Using GPGPU-Acceleration

    NASA Astrophysics Data System (ADS)

    Kawakami, Taiki; Okubo, Kan; Uchida, Naoki; Takeuchi, Nobunao; Matsuzawa, Toru

    2013-04-01

    Repeating earthquakes are occurring on the similar asperity at the plate boundary. These earthquakes have an important property; the seismic waveforms observed at the identical observation site are very similar regardless of their occurrence time. The slip histories of repeating earthquakes could reveal the existence of asperities: The Analysis of repeating earthquakes can detect the characteristics of the asperities and realize the temporal and spatial monitoring of the slip in the plate boundary. Moreover, we are expecting the medium-term predictions of earthquake at the plate boundary by means of analysis of repeating earthquakes. Although the previous works mostly clarified the existence of asperity and repeating earthquake, and relationship between asperity and quasi-static slip area, the stable and robust method for automatic detection of repeating earthquakes has not been established yet. Furthermore, in order to process the enormous data (so-called big data) the speedup of the signal processing is an important issue. Recently, GPU (Graphic Processing Unit) is used as an acceleration tool for the signal processing in various study fields. This movement is called GPGPU (General Purpose computing on GPUs). In the last few years the performance of GPU keeps on improving rapidly. That is, a PC (personal computer) with GPUs might be a personal supercomputer. GPU computing gives us the high-performance computing environment at a lower cost than before. Therefore, the use of GPUs contributes to a significant reduction of the execution time in signal processing of the huge seismic data. In this study, first, we applied the band-limited Fourier phase correlation as a fast method of detecting repeating earthquake. This method utilizes only band-limited phase information and yields the correlation values between two seismic signals. Secondly, we employ coherence function using three orthogonal components (East-West, North-South, and Up-Down) of seismic data as a

  1. Image processing and computer controls for video profile diagnostic system in the ground test accelerator (GTA)

    SciTech Connect

    Wright, R.M.; Zander, M.E.; Brown, S.K.; Sandoval, D.P.; Gilpatrick, J.D.; Gibson, H.E.

    1992-09-01

    This paper describes the application of video image processing to beam profile measurements on the Ground Test Accelerator (GTA). A diagnostic was needed to measure beam profiles in the intermediate matching section (IMS) between the radio-frequency quadrupole (RFQ) and the drift tube linac (DTL). Beam profiles are measured by injecting puffs of gas into the beam. The light emitted from the beam-gas interaction is captured and processed by a video image processing system, generating the beam profile data. A general purpose, modular and flexible video image processing system, imagetool, was used for the GTA image profile measurement. The development of both software and hardware for imagetool and its integration with the GTA control system (GTACS) will be discussed. The software includes specialized algorithms for analyzing data and calibrating the system. The underlying design philosophy of imagetool was tested by the experience of building and using the system, pointing the way for future improvements. The current status of the system will be illustrated by samples of experimental data.

  2. Image processing and computer controls for video profile diagnostic system in the ground test accelerator (GTA)

    SciTech Connect

    Wright, R.M.; Zander, M.E.; Brown, S.K.; Sandoval, D.P.; Gilpatrick, J.D.; Gibson, H.E.

    1992-01-01

    This paper describes the application of video image processing to beam profile measurements on the Ground Test Accelerator (GTA). A diagnostic was needed to measure beam profiles in the intermediate matching section (IMS) between the radio-frequency quadrupole (RFQ) and the drift tube linac (DTL). Beam profiles are measured by injecting puffs of gas into the beam. The light emitted from the beam-gas interaction is captured and processed by a video image processing system, generating the beam profile data. A general purpose, modular and flexible video image processing system, imagetool, was used for the GTA image profile measurement. The development of both software and hardware for imagetool and its integration with the GTA control system (GTACS) will be discussed. The software includes specialized algorithms for analyzing data and calibrating the system. The underlying design philosophy of imagetool was tested by the experience of building and using the system, pointing the way for future improvements. The current status of the system will be illustrated by samples of experimental data.

  3. Acceleration of Electron Repulsion Integral Evaluation on Graphics Processing Units via Use of Recurrence Relations.

    PubMed

    Miao, Yipu; Merz, Kenneth M

    2013-02-12

    Electron repulsion integral (ERI) calculation on graphical processing units (GPUs) can significantly accelerate quantum chemical calculations. Herein, the ab initio self-consistent-field (SCF) calculation is implemented on GPUs using recurrence relations, which is one of the fastest ERI evaluation algorithms currently available. A direct-SCF scheme to assemble the Fock matrix efficiently is presented, wherein ERIs are evaluated on-the-fly to avoid CPU-GPU data transfer, a well-known architectural bottleneck in GPU specific computation. Realized speedups on GPUs reach 10-100 times relative to traditional CPU nodes, with accuracies of better than 1 × 10(-7) for systems with more than 4000 basis functions. PMID:26588740

  4. Totally asymmetric simple exclusion process with a time-dependent boundary: Interaction between vehicles and pedestrians at intersections

    NASA Astrophysics Data System (ADS)

    Ito, Hidetaka; Nishinari, Katsuhiro

    2014-04-01

    Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: extended two-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right-turn lane.

  5. Totally asymmetric simple exclusion process simulations of molecular motor transport on random networks with asymmetric exit rates

    NASA Astrophysics Data System (ADS)

    Denisov, D. V.; Miedema, D. M.; Nienhuis, B.; Schall, P.

    2015-11-01

    Using the totally asymmetric simple-exclusion-process and mean-field transport theory, we investigate the transport in closed random networks with simple crossing topology—two incoming, two outgoing segments, as a model for molecular motor motion along biopolymer networks. Inspired by in vitro observation of molecular motor motion, we model the motor behavior at the intersections by introducing different exit rates for the two outgoing segments. Our simulations of this simple network reveal surprisingly rich behavior of the transport current with respect to the global density and exit rate ratio. For asymmetric exit rates, we find a broad current plateau at intermediate motor densities resulting from the competition of two subnetwork populations. This current plateau leads to stabilization of transport properties within such networks.

  6. Totally asymmetric simple exclusion process with a time-dependent boundary: interaction between vehicles and pedestrians at intersections.

    PubMed

    Ito, Hidetaka; Nishinari, Katsuhiro

    2014-04-01

    Interaction between vehicles and pedestrians is seen in many areas such as crosswalks and intersections. In this paper, we study a totally asymmetric simple exclusion process with a bottleneck at a boundary caused by an interaction. Due to the time-dependent effect originating from the speed of pedestrians, the flow of the model varies even if the average hopping probability at the last site is the same. We analyze the phenomenon by using two types of approximations: extended two-cluster approximation and isolated rarefaction wave approximation. The approximate results capture intriguing features of the model. Moreover, we discuss the situation where vehicles turn right at the intersection by adding a traffic light at the boundary condition. The result suggests that pedestrian scrambles are valid to eliminate traffic congestion in the right-turn lane. PMID:24827299

  7. Accelerated transport and growth with symmetrized dynamics

    NASA Astrophysics Data System (ADS)

    Merikoski, Juha

    2013-12-01

    In this paper we consider a model of accelerated dynamics with the rules modified from those of the recently proposed [Dong et al., Phys. Rev. Lett. 109, 130602 (2012), 10.1103/PhysRevLett.109.130602] accelerated exclusion process (AEP) such that particle-vacancy symmetry is restored to facilitate a mapping to a solid-on-solid growth model in 1+1 dimensions. In addition to kicking a particle ahead of the moving particle, as in the AEP, in our model another particle from behind is drawn, provided it is within the "distance of interaction" denoted by ℓmax. We call our model the doubly accelerated exclusion process (DAEP). We observe accelerated transport and interface growth and widening of the cluster size distribution for cluster sizes above ℓmax, when compared with the ordinary totally asymmetric exclusion process (TASEP). We also characterize the difference between the TASEP, AEP, and DAEP by computing a "staggered" order parameter, which reveals the local order in the steady state. This order in part explains the behavior of the particle current as a function of density. The differences of the steady states are also reflected by the behavior of the temporal and spatial correlation functions in the interface picture.

  8. Variability of Mass Dependence of Auroral Acceleration Processes with Solar Activity

    NASA Technical Reports Server (NTRS)

    Ghielmetti, Arthur G.

    1997-01-01

    The objectives of this investigation are to improve understanding of the mass dependent variability of the auroral acceleration processes and so to clarify apparent discrepancies regarding the altitude and local time variations with solar cycle by investigating: (1) the global morphological relationships between auroral electric field structures and the related particle signatures under varying conditions of solar activity, and (2) the relationships between the electric field structures and particle signatures in selected events that are representative of the different conditions occurring during a solar cycle. The investigation is based in part on the Lockheed UFI data base of UpFlowing Ion (UFI) events in the 5OO eV to 16keV energy range and associated electrons in the energy range 7O eV to 24 keV. This data base was constructed from data acquired by the ion mass spectrometer on the S3-3 satellite in the altitude range of I to 1.3 Re. The launch of the POLAR spacecraft in early 1996 and successful operation of its TIMAS ion mass spectrometer has provided us with data from within the auroral acceleration regions during the current solar minimum. The perigee of POLAR is at about 1 Re, comparable to that of S3-3. The higher sensitivity and time resolution of TIMAS compared to the ion mass spectrometer on S3-3 together with its wider energy range, 15 eV to 33 keV, facilitate more detailed studies of upflowing ions.

  9. The influence of acceleration forces on nucleation, solidification, and deformation processes in tin single crystals

    NASA Technical Reports Server (NTRS)

    Johnston, M. H.; Baldwin, D. H.

    1974-01-01

    An apparatus was designed and assembled to directionally solidify single crystals under the influence of acceleration forces of various magnitudes. The investigation conducted showed that acceleration gradients produce a preferred growth orientation effect not previously observed for tin. Convection currents at approximately 5-g encourage multiple nucleation and subsequent random orientation of growth direction. Deformation effects such as recrystallization and twinning are observed at acceleration levels greater than 2-g.

  10. Retrospective analysis of linear accelerator output constancy checks using process control techniques.

    PubMed

    Sanghangthum, Taweap; Suriyapee, Sivalee; Srisatit, Somyot; Pawlicki, Todd

    2013-01-01

    Shewhart control charts have previously been suggested as a process control tool for use in routine linear accelerator (linac) output verifications. However, a comprehensive approach to process control has not been investigated for linac output verifications. The purpose of this work is to investigate a comprehensive process control approach to linac output constancy quality assurance (QA). The RBA-3 dose constancy check was used to verify outputs of photon beams and electron beams delivered by a Varian Clinac 21EX linac. The data were collected during 2009 to 2010. Shewhart-type control charts, exponentially weighted moving average (EWMA) charts, and capability indices were applied to these processes. The Shewhart-type individuals chart (X-chart) was used and the number of data points used to calculate the control limits was varied. The parameters tested for the EWMA charts (smoothing parameter (λ) and the control limit width (L)) were λ = 0.05, L = 2.492; λ = 0.10, L = 2.703; and λ = 0.20, L = 2.860, as well as the number of points used to estimate the initial process mean and variation. Lastly, the number of in-control data points used to determine process capability (C(p)) and acceptability (C(pk)) were investigated, comparing the first in-control run to the longest in-control run of the process data. C(p) and C(pk) values greater than 1.0 were considered acceptable. The 95% confidence intervals were reported. The X-charts detected systematic errors (e.g., device setup errors). In-control run lengths on the X-charts varied from 5 to 30 output measurements (about one to seven months). EWMA charts showed in-control runs ranging from 9 to 33 output measurements (about two to eight months). The C(p) and C(pk) ratios are higher than 1.0 for all energies, except 12 and 20 MeV. However, 10 MV and 6, 9, and 16 MeV were in question when considering the 95% confidence limits. The X-chart should be calculated using 8-12 data points. For EWMA chart, using 4 data points

  11. Graphics Processing Unit (GPU) Acceleration of the Goddard Earth Observing System Atmospheric Model

    NASA Technical Reports Server (NTRS)

    Putnam, Williama

    2011-01-01

    The Goddard Earth Observing System 5 (GEOS-5) is the atmospheric model used by the Global Modeling and Assimilation Office (GMAO) for a variety of applications, from long-term climate prediction at relatively coarse resolution, to data assimilation and numerical weather prediction, to very high-resolution cloud-resolving simulations. GEOS-5 is being ported to a graphics processing unit (GPU) cluster at the NASA Center for Climate Simulation (NCCS). By utilizing GPU co-processor technology, we expect to increase the throughput of GEOS-5 by at least an order of magnitude, and accelerate the process of scientific exploration across all scales of global modeling, including: The large-scale, high-end application of non-hydrostatic, global, cloud-resolving modeling at 10- to I-kilometer (km) global resolutions Intermediate-resolution seasonal climate and weather prediction at 50- to 25-km on small clusters of GPUs Long-range, coarse-resolution climate modeling, enabled on a small box of GPUs for the individual researcher After being ported to the GPU cluster, the primary physics components and the dynamical core of GEOS-5 have demonstrated a potential speedup of 15-40 times over conventional processor cores. Performance improvements of this magnitude reduce the required scalability of 1-km, global, cloud-resolving models from an unfathomable 6 million cores to an attainable 200,000 GPU-enabled cores.

  12. Click chemistry approach to conventional vegetable tanning process: accelerated method with improved organoleptic properties.

    PubMed

    Krishnamoorthy, Ganesan; Ramamurthy, Govindaswamy; Sadulla, Sayeed; Sastry, Thotapalli Parvathaleswara; Mandal, Asit Baran

    2014-09-01

    Click chemistry approaches are tailored to generate molecular building blocks quickly and reliably by joining small units together selectively and covalently, stably and irreversibly. The vegetable tannins such as hydrolyzable and condensed tannins are capable to produce rather stable radicals or inhibit the progress of radicals and are prone to oxidations such as photo and auto-oxidation, and their anti-oxidant nature is well known. A lot remains to be done to understand the extent of the variation of leather stability, color variation (lightening and darkening reaction of leather), and poor resistance to water uptake for prolonged periods. In the present study, we have reported click chemistry approaches to accelerated vegetable tanning processes based on periodates catalyzed formation of oxidized hydrolysable and condensed tannins for high exhaustion with improved properties. The distribution of oxidized vegetable tannin, the thermal stability such as shrinkage temperature (T s) and denaturation temperature (T d), resistance to collagenolytic activities, and organoleptic properties of tanned leather as well as the evaluations of eco-friendly characteristics were investigated. Scanning electron microscopic analysis indicates the cross section of tightness of the leather. Differential scanning calorimetric analysis shows that the T d of leather is more than that of vegetable tanned or equal to aldehyde tanned one. The leathers exhibited fullness, softness, good color, and general appearance when compared to non-oxidized vegetable tannin. The developed process benefits from significant reduction in total solids and better biodegradability in the effluent, compared to non-oxidized vegetable tannins. PMID:24888617

  13. An Accelerated Analytical Process for the Development of STR Profiles for Casework Samples.

    PubMed

    Laurin, Nancy; Frégeau, Chantal J

    2015-07-01

    Significant efforts are being devoted to the development of methods enabling rapid generation of short tandem repeat (STR) profiles in order to reduce turnaround times for the delivery of human identification results from biological evidence. Some of the proposed solutions are still costly and low throughput. This study describes the optimization of an analytical process enabling the generation of complete STR profiles (single-source or mixed profiles) for human identification in approximately 5 h. This accelerated process uses currently available reagents and standard laboratory equipment. It includes a 30-min lysis step, a 27-min DNA extraction using the Promega Maxwell(®) 16 System, DNA quantification in <1 h using the Qiagen Investigator(®) Quantiplex HYres kit, fast amplification (<26 min) of the loci included in AmpFℓSTR(®) Identifiler(®), and analysis of the profiles on the 3500-series Genetic Analyzer. This combination of fast individual steps produces high-quality profiling results and offers a cost-effective alternative approach to rapid DNA analysis. PMID:25782346

  14. Incipient fault detection and identification in process systems using accelerating neural network learning

    SciTech Connect

    Parlos, A.G.; Muthusami, J.; Atiya, A.F. . Dept. of Nuclear Engineering)

    1994-02-01

    The objective of this paper is to present the development and numerical testing of a robust fault detection and identification (FDI) system using artificial neural networks (ANNs), for incipient (slowly developing) faults occurring in process systems. The challenge in using ANNs in FDI systems arises because of one's desire to detect faults of varying severity, faults from noisy sensors, and multiple simultaneous faults. To address these issues, it becomes essential to have a learning algorithm that ensures quick convergence to a high level of accuracy. A recently developed accelerated learning algorithm, namely a form of an adaptive back propagation (ABP) algorithm, is used for this purpose. The ABP algorithm is used for the development of an FDI system for a process composed of a direct current motor, a centrifugal pump, and the associated piping system. Simulation studies indicate that the FDI system has significantly high sensitivity to incipient fault severity, while exhibiting insensitivity to sensor noise. For multiple simultaneous faults, the FDI system detects the fault with the predominant signature. The major limitation of the developed FDI system is encountered when it is subjected to simultaneous faults with similar signatures. During such faults, the inherent limitation of pattern-recognition-based FDI methods becomes apparent. Thus, alternate, more sophisticated FDI methods become necessary to address such problems. Even though the effectiveness of pattern-recognition-based FDI methods using ANNs has been demonstrated, further testing using real-world data is necessary.

  15. Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind Braille readers

    PubMed Central

    Bhattacharjee, Arindam; Ye, Amanda J.; Lisak, Joy A.; Vargas, Maria G.; Goldreich, Daniel

    2010-01-01

    Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at about 100-ms intervals, and adjacent raised dots within a character at 50-ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25-ms target tap) and amplitude discrimination (compared to 100-micron reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker: 50-Hz, 50-micron; target-masker delays ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged, but that perceptual processing is accelerated in congenitally blind Braille readers. PMID:20980584

  16. In Vivo Hypobaric Hypoxia Performed During the Remodeling Process Accelerates Bone Healing in Mice

    PubMed Central

    Durand, Marjorie; Collombet, Jean-Marc; Frasca, Sophie; Begot, Laurent; Lataillade, Jean-Jacques; Le Bousse-Kerdilès, Marie-Caroline

    2014-01-01

    We investigated the effects of respiratory hypobaric hypoxia on femoral bone-defect repair in mice because hypoxia is believed to influence both mesenchymal stromal cell (MSC) and hematopoietic stem cell mobilization, a process involved in the bone-healing mechanism. To mimic conditions of non-weight-bearing limb immobilization in patients suffering from bone trauma, our hypoxic mouse model was further subjected to hind-limb unloading. A hole was drilled in the right femur of adult male C57/BL6J mice. Four days after surgery, mice were subjected to hind-limb unloading for 1 week. Seven days after surgery, mice were either housed for 4 days in a hypobaric room (FiO2 at 10%) or kept under normoxic conditions. Unsuspended control mice were housed in either hypobaric or normoxic conditions. Animals were sacrificed on postsurgery day 11 to allow for collection of both contralateral and lesioned femurs, blood, and spleen. As assessed by microtomography, delayed hypoxia enhanced bone-healing efficiency by increasing the closing of the cortical defect and the newly synthesized bone volume in the cavity by +55% and +35%, respectively. Proteome analysis and histomorphometric data suggested that bone-repair improvement likely results from the acceleration of the natural bone-healing process rather than from extended mobilization of MSC-derived osteoprogenitors. Hind-limb unloading had hardly any effect beyond delayed hypoxia-enhanced bone-healing efficiency. PMID:24944208

  17. Project Zero Delay: a process for accelerating the activation of cancer clinical trials.

    PubMed

    Kurzrock, Razelle; Pilat, Susan; Bartolazzi, Marcel; Sanders, Dwana; Van Wart Hood, Jill; Tucker, Stanley D; Webster, Kevin; Mallamaci, Michael A; Strand, Steven; Babcock, Eileen; Bast, Robert C

    2009-09-10

    Drug development in cancer research is lengthy and expensive. One of the rate-limiting steps is the initiation of first-in-human (phase I) trials. Three to 6 months can elapse between investigational new drug (IND) approval by the US Food and Drug Administration and the entry of a first patient. Issues related to patient participation have been well analyzed, but the administrative processes relevant to implementing clinical trials have received less attention. While industry and academia often partner for the performance of phase I studies, their administrative processes are generally performed independently, and their timelines driven by different priorities: safety reviews, clinical operations, regulatory submissions, and contracting of clinical delivery vendors for industry; contracts, budgets, and institutional review board approval for academia. Both processes converge on US Food and Drug Administration approval of an IND. In the context of a strategic alliance between M. D. Anderson Cancer Center and AstraZeneca Pharmaceuticals LP, a concerted effort has been made to eliminate delays in implementing clinical trials. These efforts focused on close communications, identifying and matching key timelines, alignment of priorities, and tackling administrative processes in parallel, rather than sequentially. In a recent, first-in-human trial, the study was activated and the first patient identified in 46 days from completion of the final study protocol and about 48 hours after final US Food and Drug Administration IND approval, reducing the overall timeline by about 3 months, while meeting all clinical good practice guidelines. Eliminating administrative delays can accelerate the evaluation of new drugs without compromising patient safety or the quality of clinical research. PMID:19652061

  18. Reproducing Visible-Minority Exclusion from the Ontario School Curriculum: An Ethnography of Educational Processes.

    ERIC Educational Resources Information Center

    Haughton, Harry S.

    This study examines how the Ontario (Canada) educational system serves Southeast Asians and West Indians. This is the most recent stage of a longitudinal study started about 16 years ago. The main purpose of the larger study is to examine the notion of curriculum as a social process of cultural selection engaged in by schools operating as the…

  19. The Transition Process: Towards Exclusion or Financial Sufficiency. A French-Irish Comparison.

    ERIC Educational Resources Information Center

    Grelet, Yvette; Mansuy, Michele; Thomas, Gwenaelle

    Data from longitudinal school leavers' surveys in France and Ireland were compared to determine types of transition pathways leading to unsuccessful conclusions. Focus was on outcomes of the transition process for school leavers unemployed five years after leaving and for employed young people whose earnings did not allow them to be financially…

  20. Role of the particle's stepping cycle in an asymmetric exclusion process: A model of mRNA translation

    NASA Astrophysics Data System (ADS)

    Ciandrini, L.; Stansfield, I.; Romano, M. C.

    2010-05-01

    Messenger RNA translation is often studied by means of statistical-mechanical models based on the asymmetric simple exclusion process (ASEP), which considers hopping particles (the ribosomes) on a lattice (the polynucleotide chain). In this work we extend this class of models and consider the two fundamental steps of the ribosome’s biochemical cycle following a coarse-grained perspective. In order to achieve a better understanding of the underlying biological processes and compare the theoretical predictions with experimental results, we provide a description lying between the minimal ASEP-like models and the more detailed models, which are analytically hard to treat. We use a mean-field approach to study the dynamics of particles associated with an internal stepping cycle. In this framework it is possible to characterize analytically different phases of the system (high density, low density or maximal current phase). Crucially, we show that the transitions between these different phases occur at different parameter values than the equivalent transitions in a standard ASEP, indicating the importance of including the two fundamental steps of the ribosome’s biochemical cycle into the model.

  1. Role of the particle's stepping cycle in an asymmetric exclusion process: a model of mRNA translation.

    PubMed

    Ciandrini, L; Stansfield, I; Romano, M C

    2010-05-01

    Messenger RNA translation is often studied by means of statistical-mechanical models based on the asymmetric simple exclusion process (ASEP), which considers hopping particles (the ribosomes) on a lattice (the polynucleotide chain). In this work we extend this class of models and consider the two fundamental steps of the ribosome's biochemical cycle following a coarse-grained perspective. In order to achieve a better understanding of the underlying biological processes and compare the theoretical predictions with experimental results, we provide a description lying between the minimal ASEP-like models and the more detailed models, which are analytically hard to treat. We use a mean-field approach to study the dynamics of particles associated with an internal stepping cycle. In this framework it is possible to characterize analytically different phases of the system (high density, low density or maximal current phase). Crucially, we show that the transitions between these different phases occur at different parameter values than the equivalent transitions in a standard ASEP, indicating the importance of including the two fundamental steps of the ribosome's biochemical cycle into the model. PMID:20866258

  2. A remediation contractor`s view of accelerating the cleanup process

    SciTech Connect

    Librizzi, W.J.; Phelps, G.S.

    1994-12-31

    Superfund, since its passage in December, 1980, has been under continual evaluation and change. Progress has been made over the past 13 years. To date, EPA under Superfund has completed 220 long term cleanups with 1,100 in various stages of completion. In addition, Superfund has been a catalyst for the development of new innovative cleanup technologies. In this regard, EPA has identified more than 150 innovative technologies now being used to treat contaminated soil, groundwater, sludge and sediments. Despite these noted accomplishments, continued criticisms of the program focus on Superfund weaknesses. They include: inconsistent cleanups; high transactional costs; perceived unfairness in liability; overlapping federal/state relationship; Inadequate community involvement; impediments to economic development. Techniques that can accelerate the hazardous waste cleanup process are discussed further in this paper. They include: strengthened interrelationships between the design and remediation contractors; role of the remediation contractor in the implementation of presumptive remedies; a proactive community relations program, partnering and early and frequent interface with regulatory agencies.

  3. Graphics processing unit accelerated one-dimensional blood flow computation in the human arterial tree.

    PubMed

    Itu, Lucian; Sharma, Puneet; Kamen, Ali; Suciu, Constantin; Comaniciu, Dorin

    2013-12-01

    One-dimensional blood flow models have been used extensively for computing pressure and flow waveforms in the human arterial circulation. We propose an improved numerical implementation based on a graphics processing unit (GPU) for the acceleration of the execution time of one-dimensional model. A novel parallel hybrid CPU-GPU algorithm with compact copy operations (PHCGCC) and a parallel GPU only (PGO) algorithm are developed, which are compared against previously introduced PHCG versions, a single-threaded CPU only algorithm and a multi-threaded CPU only algorithm. Different second-order numerical schemes (Lax-Wendroff and Taylor series) are evaluated for the numerical solution of one-dimensional model, and the computational setups include physiologically motivated non-periodic (Windkessel) and periodic boundary conditions (BC) (structured tree) and elastic and viscoelastic wall laws. Both the PHCGCC and the PGO implementations improved the execution time significantly. The speed-up values over the single-threaded CPU only implementation range from 5.26 to 8.10 × , whereas the speed-up values over the multi-threaded CPU only implementation range from 1.84 to 4.02 × . The PHCGCC algorithm performs best for an elastic wall law with non-periodic BC and for viscoelastic wall laws, whereas the PGO algorithm performs best for an elastic wall law with periodic BC. PMID:24009129

  4. Closing the gap: accelerating the translational process in nanomedicine by proposing standardized characterization techniques

    PubMed Central

    Khorasani, Ali A; Weaver, James L; Salvador-Morales, Carolina

    2014-01-01

    On the cusp of widespread permeation of nanomedicine, academia, industry, and government have invested substantial financial resources in developing new ways to better treat diseases. Materials have unique physical and chemical properties at the nanoscale compared with their bulk or small-molecule analogs. These unique properties have been greatly advantageous in providing innovative solutions for medical treatments at the bench level. However, nanomedicine research has not yet fully permeated the clinical setting because of several limitations. Among these limitations are the lack of universal standards for characterizing nanomaterials and the limited knowledge that we possess regarding the interactions between nanomaterials and biological entities such as proteins. In this review, we report on recent developments in the characterization of nanomaterials as well as the newest information about the interactions between nanomaterials and proteins in the human body. We propose a standard set of techniques for universal characterization of nanomaterials. We also address relevant regulatory issues involved in the translational process for the development of drug molecules and drug delivery systems. Adherence and refinement of a universal standard in nanomaterial characterization as well as the acquisition of a deeper understanding of nanomaterials and proteins will likely accelerate the use of nanomedicine in common practice to a great extent. PMID:25525356

  5. Acceleration of High Angular Momentum Electron Repulsion Integrals and Integral Derivatives on Graphics Processing Units.

    PubMed

    Miao, Yipu; Merz, Kenneth M

    2015-04-14

    We present an efficient implementation of ab initio self-consistent field (SCF) energy and gradient calculations that run on Compute Unified Device Architecture (CUDA) enabled graphical processing units (GPUs) using recurrence relations. We first discuss the machine-generated code that calculates the electron-repulsion integrals (ERIs) for different ERI types. Next we describe the porting of the SCF gradient calculation to GPUs, which results in an acceleration of the computation of the first-order derivative of the ERIs. However, only s, p, and d ERIs and s and p derivatives could be executed simultaneously on GPUs using the current version of CUDA and generation of NVidia GPUs using a previously described algorithm [Miao and Merz J. Chem. Theory Comput. 2013, 9, 965-976.]. Hence, we developed an algorithm to compute f type ERIs and d type ERI derivatives on GPUs. Our benchmarks shows the performance GPU enable ERI and ERI derivative computation yielded speedups of 10-18 times relative to traditional CPU execution. An accuracy analysis using double-precision calculations demonstrates that the overall accuracy is satisfactory for most applications. PMID:26574356

  6. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway.

    PubMed

    Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L; Turteltaub, Kenneth W; Newman, Lee S

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) than HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ. PMID:24932923

  7. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    SciTech Connect

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  8. Accelerator Mass Spectrometry Detection of Beryllium Ions in the Antigen Processing and Presentation Pathway

    PubMed Central

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ. PMID:24932923

  9. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    DOE PAGESBeta

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstratemore » that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.« less

  10. Power spectra in totally asymmetric simple exclusion process (TASEP) with local inhomogeneity

    NASA Astrophysics Data System (ADS)

    Dong, Jiajia; Zia, Royce K. P.

    2010-03-01

    As a paradigmatic system in non-equilibrium statistical mechanics, TASEP has been extensively studied in the abstract and also applied to model many complex phenomena such as traffic flow and protein synthesis. We focus on a rather less studied aspect of TASEP: the total number of particles on a one-dimension open TASEP at time t, N(t), and its power spectra I(φ), especially when there are local inhomogeneities. Motivated by the protein synthesis process where messenger RNA, codons and ribosomes are associated with the underlying lattice, sites and particles transported in TASEP, we investigate the effect on the power spectrum due to one defect (slower hopping rate) at different positions along the lattice. Using Monte Carlo simulation, we measure I(φ) for both the entire system and the subsystems separated by the defect. As in previous studies, oscillations are found. Here, however, more interesting characteristics emerge, depending on the location and the ``strength'' of the slow site. The biological implication of these results is also discussed.

  11. SHAPE OF PION DISTRIBUTION AMPLITUDE AND TRANSVERSE MOMENTUM IN HARD EXCLUSIVE PROCESSES

    SciTech Connect

    Anatoly Radyushkin

    2011-11-01

    The problem is discussed of including transverse momentum effects into the description of the pion-photon transition form factor. It is argued that at low k{sub {perp}}, a consistent description may be obtained within the light-front formalism. On the other hand, the large-k{sub {perp}} limit is most conveniently treated within the Sudakov parameterization framework. It is stressed that these two approaches correspond to different definitions of transverse momentum, with no evident connection between them in the region of intermediate and small k{sub {perp}}. The third way of introducing k{sub {perp}} for the description of the photon-pion transition form factor is based on the "local duality" approach motivated by QCD sum rules. It is observed that for large photon virtualities Q{sup 2}, the local duality expressions look similar to those obtained within the modified perturbative factorization scheme. It is shown that, while the local duality gives a correct (coinciding with the axial anomaly based prediction) result for the real photon point, a straightforward extension of the formulas of the modified factorization approach into the small virtualities domain produces a divergent result. It is pointed out that such lessons should be taken into account while constructing transverse-momentum-dependent schemes for inclusive processes.

  12. Phase-plane analysis of the totally asymmetric simple exclusion process with binding kinetics and switching between antiparallel lanes.

    PubMed

    Kuan, Hui-Shun; Betterton, Meredith D

    2016-08-01

    Motor protein motion on biopolymers can be described by models related to the totally asymmetric simple exclusion process (TASEP). Inspired by experiments on the motion of kinesin-4 motors on antiparallel microtubule overlaps, we analyze a model incorporating the TASEP on two antiparallel lanes with binding kinetics and lane switching. We determine the steady-state motor density profiles using phase-plane analysis of the steady-state mean field equations and kinetic Monte Carlo simulations. We focus on the density-density phase plane, where we find an analytic solution to the mean field model. By studying the phase-space flows, we determine the model's fixed points and their changes with parameters. Phases previously identified for the single-lane model occur for low switching rate between lanes. We predict a multiple coexistence phase due to additional fixed points that appear as the switching rate increases: switching moves motors from the higher-density to the lower-density lane, causing local jamming and creating multiple domain walls. We determine the phase diagram of the model for both symmetric and general boundary conditions. PMID:27627345

  13. Matrix-product ansatz for the totally asymmetric simple exclusion process with a generalized update on a ring.

    PubMed

    Aneva, B L; Brankov, J G

    2016-08-01

    We apply the matrix-product ansatz to study the totally asymmetric simple exclusion process on a ring with a generalized discrete-time dynamics depending on two hopping probabilities, p and p[over ̃]. The model contains as special cases the TASEP with parallel update, when p[over ̃]=0, and with sequential backward-ordered update, when p[over ̃]=p. We construct a quadratic algebra and its two-dimensional matrix-product representation to obtain exact finite-size expressions for the partition function, the current of particles, and the two-point correlation function. Our main new result is the derivation of the finite-size pair correlation function. Its behavior is analyzed in different regimes of effective attraction and repulsion between the particles, depending on whether p[over ̃]>p or p[over ̃]

  14. Comparison of Diafiltration and Size-Exclusion Chromatography to Recover Hemicelluloses From Process Water From Thermomechanical Pulping of Spruce

    NASA Astrophysics Data System (ADS)

    Andersson, Alexandra; Persson, Tobias; Zacchi, Guido; Stålbrand, Henrik; Jönsson, Ann-Sofi

    Hemicelluloses constitute one of the most abundant renewable resources on earth. To increase their utilization, the isolation of hemicelluloses from industrial biomass side-streams would be beneficial. A method was investigated to isolate hemicelluloses from process water from a thermomechanical pulp mill. The method consists of three steps: removal of solids by microfiltration, preconcentration of the hemicelluloses by ultrafiltration, and purification by either size-exclusion chromatography (SEC) or diafiltration. The purpose of the final purification step is to separate hemicelluloses from small oligosaccharides, monosaccharides, and salts. The ratio between galactose, glucose, and mannose in oligo- and polysaccharides after preconcentration was 0.8∶1∶2.8, which is similar to that found in galactoglucomannan. Continuous diafiltration was performed using a composite fluoro polymer membrane with cutoff of 1000 Da. After diafiltration with four diavolumes the purity of the hemicelluloses was 77% (gram oligo- and polysaccharides/ gram total dissolved solids) and the recovery was 87%. Purification by SEC was performed with 5, 20, and 40% sample loadings, respectively and a flow rate of 12 or 25 mL/min (9 or 19 cm/h). The purity of hemicelluloses after SEC was approx 82%, and the recovery was above 99%. The optimal sample load and flow rate were 20% and 25 mL/min, respectively. The process water from thermomechanical pulping of spruce is inexpensive. Thus, the recovery of hemicelluloses is not of main importance. If the purity of 77%, obtained with diafiltration, is sufficient for the utilization of the hemicelluloses, diafiltration probably offers a less expensive alternative in this application.

  15. Electron bunching in a Penning trap and accelerating process for CO2 gas mixture active medium

    NASA Astrophysics Data System (ADS)

    Tian, Xiu-Fang; Wu, Cong-Feng; Jia, Qi-Ka

    2015-12-01

    In PASER (particle acceleration by stimulated emission of radiation), in the presence of an active medium incorporated in a Penning trap, moving electrons can become bunched, and as they get enough energy, they escape the trap forming an optical injector. These bunched electrons can enter the next PASER section filled with the same active medium to be accelerated. In this paper, electron dynamics in the presence of a gas mixture active medium incorporated in a Penning trap is analyzed by developing an idealized 1D model. We evaluate the energy exchange occurring as the train of electrons traverses into the next PASER section. The results show that the oscillating electrons can be bunched at the resonant frequency of the active medium. The influence of the trapped time and population inversion are analyzed, showing that the longer the electrons are trapped, the more energy from the medium the accelerated electrons get, and with the increase of population inversion, the decelerated electrons are virtually unchanged but the accelerated electrons more than double their peak energy values. The simulation results show that the gas active medium needs a lower population inversion to bunch the electrons compared to a solid active medium, so the experimental conditions can easily be achieved. Supported by National Natural Science Foundation of China (10675116) and Major State Basic Research Development Programme of China (2011CB808301)

  16. Control of Listeria spp. by Competitive-Exclusion Bacteria in Floor Drains of a Poultry Processing Plant

    PubMed Central

    Zhao, Tong; Podtburg, Teresa C.; Zhao, Ping; Schmidt, Bruce E.; Baker, David A.; Cords, Bruce; Doyle, Michael P.

    2006-01-01

    In previous studies workers determined that two lactic acid bacterium isolates, Lactococcus lactis subsp. lactis C-1-92 and Enterococcus durans 152 (competitive-exclusion bacteria [CE]), which were originally obtained from biofilms in floor drains, are bactericidal to Listeria monocytogenes or inhibit the growth of L. monocytogenes both in vitro and in biofilms at 4 to 37°C. We evaluated the efficacy of these isolates for reducing Listeria spp. contamination of floor drains of a plant in which fresh poultry is processed. Baseline assays revealed that the mean numbers of Listeria sp. cells in floor drains sampled on six different dates (at approximately biweekly intervals) were 7.5 log10 CFU/100 cm2 for drain 8, 4.9 log10 CFU/100 cm2 for drain 3, 4.4 log10 CFU/100 cm2 for drain 2, 4.1 log10 CFU/100 cm2 for drain 4, 3.7 log10 CFU/100 cm2 for drain 1, and 3.6 log10 CFU/100 cm2 for drain 6. The drains were then treated with 107 CE/ml in an enzyme-foam-based cleaning agent four times in 1 week and twice a week for the following 3 weeks. In samples collected 1 week after CE treatments were applied Listeria sp. cells were not detectable (samples were negative as determined by selective enrichment culture) for drains 4 and 6 (reductions of 4.1 and 3.6 log10 CFU/100 cm2, respectively), and the mean numbers of Listeria sp. cells were 3.7 log10 CFU/100 cm2 for drain 8 (a reduction of 3.8 log10 CFU/100 cm2), <1.7 log10 CFU/100 cm2 for drain 1 (detectable only by selective enrichment culture; a reduction of 3.3 log10 CFU/100 cm2), and 2.6 log10 CFU/100 cm2 for drain 3 (a reduction of 2.3 log10 CFU/100 cm2). However, the aerobic plate counts for samples collected from floor drains before, during, and after CE treatment remained approximately the same. The results indicate that application of the two CE can greatly reduce the number of Listeria sp. cells in floor drains at 3 to 26°C in a facility in which fresh poultry is processed. PMID:16672472

  17. The effects of partial throughfall exclusion on canopy processes, aboveground production, and biogeochemistry of an Amazon forest

    NASA Astrophysics Data System (ADS)

    Nepstad, D. C.; Moutinho, P.; Dias-Filho, M. B.; Davidson, E.; Cardinot, G.; Markewitz, D.; Figueiredo, R.; Vianna, N.; Chambers, J.; Ray, D.; Guerreiros, J. B.; Lefebvre, P.; Sternberg, L.; Moreira, M.; Barros, L.; Ishida, F. Y.; Tohlver, I.; Belk, E.; Kalif, K.; Schwalbe, K.

    2002-10-01

    Moist tropical forests in Amazonia and elsewhere are subjected to increasingly severe drought episodes through the El Niño-Southern Oscillation (ENSO) and possibly through deforestation-driven reductions in rainfall. The effects of this trend on tropical forest canopy dynamics, emissions of greenhouse gases, and other ecological functions are potentially large but poorly understood. We established a throughfall exclusion experiment in an east-central Amazon forest (Tapajós National Forest, Brazil) to help understand these effects. After 1-year intercalibration period of two 1-ha forest plots, we installed plastic panels and wooden gutters in the understory of one of the plots, thereby excluding ˜890 mm of throughfall during the exclusion period of 2000 (late January to early August) and ˜680 mm thus far in the exclusion period of 2001 (early January to late May). Average daily throughfall reaching the soil during the exclusion period in 2000 was 4.9 and 8.3 mm in the treatment and control plots and was 4.8 and 8.1 mm in 2001, respectively. During the first exclusion period, surface soil water content (0-2 m) declined by ˜100 mm, while deep soil water (2-11 m) was unaffected. During the second exclusion period, which began shortly after the dry season when soil water content was low, surface and deep soil water content declined by ˜140 and 160 mm, respectively. Although this depletion of soil water provoked no detectable increase in leaf drought stress (i.e., no reduction in predawn leaf water potential), photosynthetic capacity declined for some species, the canopy thinned (greater canopy openness and lower leaf area index) during the second exclusion period, stem radial growth of trees <15 m tall declined, and fine litterfall declined in the treatment plot, as did tree fruiting. Aboveground net primary productivity (NPP) (stemwood increment and fine litter production) declined by one fourth, from 15.1 to 11.4 Mg ha-1 yr-1, in the treatment plot and decreased

  18. Determination of some aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography with conductimetric detection on a weakly acidic cation-exchange resin column.

    PubMed

    Ito, Kazuaki; Takayama, Yohichi; Ikedo, Mikaru; Mori, Masanobu; Taoda, Hiroshi; Xu, Qun; Hu, Wenzhi; Sunahara, Hiroshi; Hayashi, Tsuneo; Sato, Shinji; Hirokawa, Takeshi; Tanaka, Kazuhiko

    2004-06-11

    The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences. PMID:15250416

  19. Optimization of the accelerated curing process of concrete using a fibre Bragg grating-based control system and microwave technology

    NASA Astrophysics Data System (ADS)

    Fabian, Matthias; Jia, Yaodong; Shi, Shi; McCague, Colum; Bai, Yun; Sun, Tong; Grattan, Kenneth T. V.

    2016-05-01

    In this paper, an investigation into the suitability of using fibre Bragg gratings (FBGs) for monitoring the accelerated curing process of concrete in a microwave heating environment is presented. In this approach, the temperature data provided by the FBGs are used to regulate automatically the microwave power so that a pre-defined temperature profile is maintained to optimize the curing process, achieving early strength values comparable to those of conventional heat-curing techniques but with significantly reduced energy consumption. The immunity of the FBGs to interference from the microwave radiation used ensures stable readings in the targeted environment, unlike conventional electronic sensor probes.

  20. Observations of energetic water-group ions at Comet Giacobini-Zinner - Implications for ion acceleration processes

    NASA Astrophysics Data System (ADS)

    Richardson, I. G.; Cowley, S. W. H.; Hynds, R. J.; Tranquille, C.; Sanderson, T. R.; Wenzel, K.-P.

    1987-10-01

    Observations of energetic water-group pick-up ions made by the EPAS instrument during ICE fly-by of Comet P/Giacobini-Zinner are investigated for evidence concerning the processes which accelerate the ions from initial pick-up energies of around 10 keV to energies of a few hundred keV. The form of the ion spectrum in the ion rest frame is investigated and compared with theoretical suggestions that exponential energy distributions might be produced by either first- or second-order Fermi acceleration in the cometary environment. It is shown that such distributions do not fit the data at all well, but that rather the observed distribution functions closely approximate an exponential in ion speed. The variations of ion intensity and spectral hardness which occur during the comet encounter are investigated, and an indication of the degree of isotropy of the ion distribution in the rest frame of the flow is obtained.

  1. What can we learn from inverse methods regarding the processes behind the acceleration and retreat of Helheim glacier (Greenland)?

    NASA Astrophysics Data System (ADS)

    Gagliardini, O.; Gillet-chaulet, F.; Martin, N.; Monnier, J.; Singh, J.

    2011-12-01

    Greenland outlet glaciers control the ice discharge toward the sea and the resulting contribution to sea level rise. Physical processes at the root of the observed acceleration and retreat, - decrease of the back force at the calving terminus, increase of basal lubrication and decrease of the lateral friction -, are still not well understood. All these three processes certainly play a role but their relative contributions have not yet been quantified. Helheim glacier, located on the east coast of Greenland, has undergone an enhanced retreat since 2003, and this retreat was concurrent with accelerated ice flow. In this study, the flowline dataset including surface elevation, surface velocity and front position of Helheim from 2001 to 2006 is used to quantify the sensitivity of each of these processes. For that, we used the full-Stokes finite element ice flow model DassFlow/Ice, including adjoint code and full 4d-var data assimilation process in which the control variables are the basal and lateral friction parameters as well as the calving front pressure. For each available date, the sensitivity of each processes is first studied and an optimal distribution is then inferred from the surface measurements. Using this optimal distribution of these parameters, a transient simulation is performed over the whole dataset period. The relative contributions of the basal friction, lateral friction and front back force are then discussed under the light of these new results.

  2. Measurements of exclusive photoproduction processes at large values of t and u from 4 to 7.5 GeV

    USGS Publications Warehouse

    Anderson, R.L.; Gustavson, D.B.; Ritson, D.M.; Weitsch, G.A.; Halpern, H.J.; Prepost, R.; Tompkins, D.H.; Wiser, D.E.

    1976-01-01

    Exclusive photoproduction cross sections have been measured for the processes p+n, p0p, p-++, p0p, pK+, and pK+0 at large t and u values at several energies for each process between 4 and 7.5 GeV. These measurements taken together with past data taken at small values of t and u provide complete angular distributions. The data show the usual small t and u peaks and a central region in which the cross section decreases approximately as s-7. The results are discussed within the context of parton or constituent models. ?? 1976 The American Physical Society.

  3. Accelerating the commercialization of university technologies for military healthcare applications: the role of the proof of concept process

    NASA Astrophysics Data System (ADS)

    Ochoa, Rosibel; DeLong, Hal; Kenyon, Jessica; Wilson, Eli

    2011-06-01

    The von Liebig Center for Entrepreneurism and Technology Advancement at UC San Diego (vonliebig.ucsd.edu) is focused on accelerating technology transfer and commercialization through programs and education on entrepreneurism. Technology Acceleration Projects (TAPs) that offer pre-venture grants and extensive mentoring on technology commercialization are a key component of its model which has been developed over the past ten years with the support of a grant from the von Liebig Foundation. In 2010, the von Liebig Entrepreneurism Center partnered with the U.S. Army Telemedicine and Advanced Technology Research Center (TATRC), to develop a regional model of Technology Acceleration Program initially focused on military research to be deployed across the nation to increase awareness of military medical needs and to accelerate the commercialization of novel technologies to treat the patient. Participants to these challenges are multi-disciplinary teams of graduate students and faculty in engineering, medicine and business representing universities and research institutes in a region, selected via a competitive process, who receive commercialization assistance and funding grants to support translation of their research discoveries into products or services. To validate this model, a pilot program focused on commercialization of wireless healthcare technologies targeting campuses in Southern California has been conducted with the additional support of Qualcomm, Inc. Three projects representing three different universities in Southern California were selected out of forty five applications from ten different universities and research institutes. Over the next twelve months, these teams will conduct proof of concept studies, technology development and preliminary market research to determine the commercial feasibility of their technologies. This first regional program will help build the needed tools and processes to adapt and replicate this model across other regions in the

  4. Molecular Mechanisms and Evolutionary Processes Contributing to Accelerated Divergence of Gene Expression on the Drosophila X Chromosome.

    PubMed

    Coolon, Joseph D; Stevenson, Kraig R; McManus, C Joel; Yang, Bing; Graveley, Brenton R; Wittkopp, Patricia J

    2015-10-01

    In species with a heterogametic sex, population genetics theory predicts that DNA sequences on the X chromosome can evolve faster than comparable sequences on autosomes. Both neutral and nonneutral evolutionary processes can generate this pattern. Complex traits like gene expression are not predicted to have accelerated evolution by these theories, yet a "faster-X" pattern of gene expression divergence has recently been reported for both Drosophila and mammals. Here, we test the hypothesis that accelerated adaptive evolution of cis-regulatory sequences on the X chromosome is responsible for this pattern by comparing the relative contributions of cis- and trans-regulatory changes to patterns of faster-X expression divergence observed between strains and species of Drosophila with a range of divergence times. We find support for this hypothesis, especially among male-biased genes, when comparing different species. However, we also find evidence that trans-regulatory differences contribute to a faster-X pattern of expression divergence both within and between species. This contribution is surprising because trans-acting regulators of X-linked genes are generally assumed to be randomly distributed throughout the genome. We found, however, that X-linked transcription factors appear to preferentially regulate expression of X-linked genes, providing a potential mechanistic explanation for this result. The contribution of trans-regulatory variation to faster-X expression divergence was larger within than between species, suggesting that it is more likely to result from neutral processes than positive selection. These data show how accelerated evolution of both coding and noncoding sequences on the X chromosome can lead to accelerated expression divergence on the X chromosome relative to autosomes. PMID:26041937

  5. Laser Processing on the Surface of Niobium Superconducting Radio-Frequency Accelerator Cavities

    NASA Astrophysics Data System (ADS)

    Singaravelu, Senthilraja; Klopf, Michael; Krafft, Geoffrey; Kelley, Michael

    2011-03-01

    Superconducting Radio frequency (SRF) niobium cavities are at the heart of an increasing number of particle accelerators.~ Their performance is dominated by a several nm thick layer at the interior surface. ~Maximizing its smoothness is found to be critical and aggressive chemical treatments are employed to this end.~ We describe laser-induced surface melting as an alternative ``greener'' approach.~ Modeling guided selection of parameters for irradiation with a Q-switched Nd:YAG laser.~ The resulting topography was examined by SEM, AFM and Stylus Profilometry.

  6. Processive acceleration of actin barbed-end assembly by N-WASP

    PubMed Central

    Khanduja, Nimisha; Kuhn, Jeffrey R.

    2014-01-01

    Neuronal Wiskott–Aldrich syndrome protein (N-WASP)–activated actin polymerization drives extension of invadopodia and podosomes into the basement layer. In addition to activating Arp2/3, N-WASP binds actin-filament barbed ends, and both N-WASP and barbed ends are tightly clustered in these invasive structures. We use nanofibers coated with N-WASP WWCA domains as model cell surfaces and single-actin-filament imaging to determine how clustered N-WASP affects Arp2/3-independent barbed-end assembly. Individual barbed ends captured by WWCA domains grow at or below their diffusion-limited assembly rate. At high filament densities, however, overlapping filaments form buckles between their nanofiber tethers and myosin attachment points. These buckles grew ∼3.4-fold faster than the diffusion-limited rate of unattached barbed ends. N-WASP constructs with and without the native polyproline (PP) region show similar rate enhancements in the absence of profilin, but profilin slows barbed-end acceleration from constructs containing the PP region. Increasing Mg2+ to enhance filament bundling increases the frequency of filament buckle formation, consistent with a requirement of accelerated assembly on barbed-end bundling. We propose that this novel N-WASP assembly activity provides an Arp2/3-independent force that drives nascent filament bundles into the basement layer during cell invasion. PMID:24227886

  7. Improved laser damage threshold performance of calcium fluoride optical surfaces via Accelerated Neutral Atom Beam (ANAB) processing

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, S.; Walsh, M.; Svrluga, R.; Thomas, M.

    2015-11-01

    Optics are not keeping up with the pace of laser advancements. The laser industry is rapidly increasing its power capabilities and reducing wavelengths which have exposed the optics as a weak link in lifetime failures for these advanced systems. Nanometer sized surface defects (scratches, pits, bumps and residual particles) on the surface of optics are a significant limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, magnesium fluoride, zinc sulfide, LBO and others presents a unique challenge for traditional polishing techniques. Exogenesis Corporation, using its new and proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and particle contamination leaving many material surfaces with roughness typically around one Angstrom. This surface defect mitigation via ANAB processing can be shown to increase performance properties of high intensity optical materials. This paper describes the ANAB technology and summarizes smoothing results for calcium fluoride laser windows. It further correlates laser damage threshold improvements with the smoothing produced by ANAB surface treatment. All ANAB processing was performed at Exogenesis Corporation using an nAccel100TM Accelerated Particle Beam processing tool. All surface measurement data for the paper was produced via AFM analysis on a Park Model XE70 AFM, and all laser damage testing was performed at Spica Technologies, Inc. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply mechanical forces associated with traditional polishing techniques. ANAB efficiently removes surface

  8. Real-time dual-mode standard/complex Fourier-domain OCT system using graphics processing unit accelerated 4D signal processing and visualization

    NASA Astrophysics Data System (ADS)

    Zhang, Kang; Kang, Jin U.

    2011-03-01

    We realized a real-time dual-mode standard/complex Fourier-domain optical coherence tomography (FD-OCT) system using graphics processing unit (GPU) accelerated 4D (3D+time) signal processing and visualization. For both standard and complex FD-OCT modes, the signal processing tasks were implemented on a dual-GPUs architecture that included λ-to-k spectral re-sampling, fast Fourier transform (FFT), modified Hilbert transform, logarithmic-scaling, and volume rendering. The maximum A-scan processing speeds achieved are >3,000,000 line/s for the standard 1024-pixel-FD-OCT, and >500,000 line/s for the complex 1024-pixel-FD-OCT. Multiple volumerendering of the same 3D data set were preformed and displayed with different view angles. The GPU-acceleration technique is highly cost-effective and can be easily integrated into most ultrahigh speed FD-OCT systems to overcome the 3D data processing and visualization bottlenecks.

  9. 24 CFR 58.35 - Categorical exclusions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL RESPONSIBILITIES Environmental Review Process: Documentation, Range of Activities, Project Aggregation and Classification § 58.35 Categorical exclusions. Categorical exclusion refers to a category of activities for which no...

  10. 24 CFR 58.35 - Categorical exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL RESPONSIBILITIES Environmental Review Process: Documentation, Range of Activities, Project Aggregation and Classification § 58.35 Categorical exclusions. Categorical exclusion refers to a category of activities for which no...

  11. Studies of $${\\rm Nb}_{3}{\\rm Sn}$$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

    DOE PAGESBeta

    Barzi, E.; Bossert, M.; Gallo, G.; Lombardo, V.; Turrioni, D.; Yamada, R.; Zlobin, A. V.

    2011-12-21

    A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

  12. Impact absorption of four processed soft denture liners as influenced by accelerated aging.

    PubMed

    Kawano, F; Koran, A; Nuryanti, A; Inoue, S

    1997-01-01

    The cushioning effect of soft denture liners was evaluated by using a free drop test with an accelerometer. Materials tested included SuperSoft (Coe Laboratories, Chicago, IL), Kurepeet-Dough (Kreha Chemical, Tokyo), Molteno Soft (Molten, Hiroshima, Japan), and Molloplast-B (Molloplast Regneri, Karlsruhe, Germany). All materials were found to reduce the impact force when compared to acrylic denture base resin. A 2.4-mm layer of soft denture material demonstrated good impact absorption, and Molloplast-B and Molteno had excellent impact absorption. When the soft denture liner was kept in an accelerated aging chamber for 900 hours, the damping effect recorded increased for all materials tested. Aging of all materials also affected the cushioning effect. PMID:9484071

  13. Young coconut juice can accelerate the healing process of cutaneous wounds

    PubMed Central

    2012-01-01

    Background Estrogen has been reported to accelerate cutaneous wound healing. This research studies the effect of young coconut juice (YCJ), presumably containing estrogen-like substances, on cutaneous wound healing in ovairectomized rats. Methods Four groups of female rats (6 in each group) were included in this study. These included sham-operated, ovariectomized (ovx), ovx receiving estradiol benzoate (EB) injections intraperitoneally, and ovx receiving YCJ orally. Two equidistant 1-cm full-thickness skin incisional wounds were made two weeks after ovariectomy. The rats were sacrificed at the end of the third and the fourth week of the study, and their serum estradiol (E2) level was measured by chemiluminescent immunoassay. The skin was excised and examined in histological sections stained with H&E, and immunostained using anti-estrogen receptor (ER-α an ER-β) antibodies. Results Wound healing was accelerated in ovx rats receiving YCJ, as compared to controls. This was associated with significantly higher density of immunostaining for ER-α an ER-β in keratinocytes, fibroblasts, white blood cells, fat cells, sebaceous gland, skeletal muscles, and hair shafts and follicles. This was also associated with thicker epidermis and dermis, but with thinner hypodermis. In addition, the number and size of immunoreactive hair follicles for both ER-α and ER-β were the highest in the ovx+YCJ group, as compared to the ovx+EB group. Conclusions This study demonstrates that YCJ has estrogen-like characteristics, which in turn seem to have beneficial effects on cutaneous wound healing. PMID:23234369

  14. Developmental Changes in Processing Speed: Influence of Accelerated Education for Gifted Children

    ERIC Educational Resources Information Center

    Duan, Xiaoju; Shi, Jiannong; Zhou, Dan

    2010-01-01

    There are two major hypotheses concerning the developmental trends of processing speeds. These hypotheses explore both local and global trends. The study presented here investigates the effects of people's different knowledge on the speed with which they are able to process information. The participants in this study are gifted children aged 9,…

  15. Application of Low Level, Uniform Ultrasound Field for Acceleration of Enzymatic Bio-processing of Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. Our research has found that th...

  16. Implications of acceleration environments on scaling materials processing in space to production

    NASA Technical Reports Server (NTRS)

    Demel, Ken

    1990-01-01

    Some considerations regarding materials processing in space are covered from a commercial perspective. Key areas include power, proprietary data, operational requirements (including logistics), and also the center of gravity location, and control of that location with respect to materials processing payloads.

  17. Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

    SciTech Connect

    Charles Reece, Hui Tian, Michael Kelley, Chen Xu

    2012-04-01

    Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

  18. Evaluation of an accelerated mineral carbonation process using Class F fly ash to sequester flue gas CO2

    NASA Astrophysics Data System (ADS)

    Erikson, Lisa N.

    Accelerated mineral carbonation (AMC) processes have been recommended as a mitigation technique to reduce coal-fired flue gas carbon dioxide (CO 2) emissions. This research concerns an AMC process which reacts humid flue gas with fly ash in a fluidized bed reactor (FBR). In theory the alkaline products in the fly ash will react with the CO2 in the flue gas, producing stable mineral carbonates. Although the original goal of the current testing was to optimize an AMC process, recent testing revealed no significant mineralization taking place over the duration of the tests. Further evaluation of the AMC process indicated that small amounts of available alkalinity in the fly ash and limited amounts of water in the flue gas compromised the mineralization reactions. The use of a FBR coupled with an elemental analyzer for carbon measurement may have resulted in quantifying movement of unburned carbon as opposed to changes in carbonation. A subsequent review of previous testing regarding this AMC process indicated less than 1% CO2 uptake by the fly ash with past claims of mineralization based on incorrect data reduction. In general, AMC processes prove to be impractical for the reduction of large quantities of CO2 emissions produced by coal-fired power plants.

  19. Tests of an environmental and personnel safe cleaning process for BNL accelerator and storage ring components

    SciTech Connect

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1996-10-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10{sup 22} and 10{sup 23} photons per meter for a PSD measurement. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4} and H{sub 2}O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories.

  20. Accelerating solidification process simulation for large-sized system of liquid metal atoms using GPU with CUDA

    NASA Astrophysics Data System (ADS)

    Jie, Liang; Li, KenLi; Shi, Lin; Liu, RangSu; Mei, Jing

    2014-01-01

    Molecular dynamics simulation is a powerful tool to simulate and analyze complex physical processes and phenomena at atomic characteristic for predicting the natural time-evolution of a system of atoms. Precise simulation of physical processes has strong requirements both in the simulation size and computing timescale. Therefore, finding available computing resources is crucial to accelerate computation. However, a tremendous computational resource (GPGPU) are recently being utilized for general purpose computing due to its high performance of floating-point arithmetic operation, wide memory bandwidth and enhanced programmability. As for the most time-consuming component in MD simulation calculation during the case of studying liquid metal solidification processes, this paper presents a fine-grained spatial decomposition method to accelerate the computation of update of neighbor lists and interaction force calculation by take advantage of modern graphics processors units (GPU), enlarging the scale of the simulation system to a simulation system involving 10 000 000 atoms. In addition, a number of evaluations and tests, ranging from executions on different precision enabled-CUDA versions, over various types of GPU (NVIDIA 480GTX, 580GTX and M2050) to CPU clusters with different number of CPU cores are discussed. The experimental results demonstrate that GPU-based calculations are typically 9∼11 times faster than the corresponding sequential execution and approximately 1.5∼2 times faster than 16 CPU cores clusters implementations. On the basis of the simulated results, the comparisons between the theoretical results and the experimental ones are executed, and the good agreement between the two and more complete and larger cluster structures in the actual macroscopic materials are observed. Moreover, different nucleation and evolution mechanism of nano-clusters and nano-crystals formed in the processes of metal solidification is observed with large-sized system.

  1. Accelerating solidification process simulation for large-sized system of liquid metal atoms using GPU with CUDA

    SciTech Connect

    Jie, Liang; Li, KenLi; Shi, Lin; Liu, RangSu; Mei, Jing

    2014-01-15

    Molecular dynamics simulation is a powerful tool to simulate and analyze complex physical processes and phenomena at atomic characteristic for predicting the natural time-evolution of a system of atoms. Precise simulation of physical processes has strong requirements both in the simulation size and computing timescale. Therefore, finding available computing resources is crucial to accelerate computation. However, a tremendous computational resource (GPGPU) are recently being utilized for general purpose computing due to its high performance of floating-point arithmetic operation, wide memory bandwidth and enhanced programmability. As for the most time-consuming component in MD simulation calculation during the case of studying liquid metal solidification processes, this paper presents a fine-grained spatial decomposition method to accelerate the computation of update of neighbor lists and interaction force calculation by take advantage of modern graphics processors units (GPU), enlarging the scale of the simulation system to a simulation system involving 10 000 000 atoms. In addition, a number of evaluations and tests, ranging from executions on different precision enabled-CUDA versions, over various types of GPU (NVIDIA 480GTX, 580GTX and M2050) to CPU clusters with different number of CPU cores are discussed. The experimental results demonstrate that GPU-based calculations are typically 9∼11 times faster than the corresponding sequential execution and approximately 1.5∼2 times faster than 16 CPU cores clusters implementations. On the basis of the simulated results, the comparisons between the theoretical results and the experimental ones are executed, and the good agreement between the two and more complete and larger cluster structures in the actual macroscopic materials are observed. Moreover, different nucleation and evolution mechanism of nano-clusters and nano-crystals formed in the processes of metal solidification is observed with large

  2. Accelerated process development for protease production in continuous multi-stage cultures.

    PubMed

    Raninger, A; Steiner, W

    2003-06-01

    A fermentation process was developed and optimized for the production of a specific protease from Bacillus licheniformis PWD-1. Media formulations were constructed and crucial environmental parameters were optimized to enhance growth and product formation. Process dynamics of substrate consumption, biomass-, product-, as well as by-product formation were determined under controlled conditions in a bioreactor. Using kinetic data from batch- and continuous-culture experiments, a fed-batch process was developed producing proteolytic activities 10 times those found during regular batch culture. In one stage continuous stirred tank culture protease formation was completely decoupled from sporulation. Shift experiments in one-stage continuous cultures led to the development of a two-stage continuous stirred tank fermentation process using optimized conditions for growth in the first stage and protease formation in the second stage. Accordingly, the basis for a continuous production of the enzyme on a pilot scale was accomplished. PMID:12652475

  3. Brightest Fermi-LAT flares of PKS 1222+216: implications on emission and acceleration processes

    SciTech Connect

    Kushwaha, Pankaj; Singh, K. P.; Sahayanathan, Sunder

    2014-11-20

    We present a high time resolution study of the two brightest γ-ray outbursts from a blazar PKS 1222+216 observed by the Fermi Large Area Telescope (LAT) in 2010. The γ-ray light curves obtained in four different energy bands, 0.1-3, 0.1-0.3, 0.3-1, and 1-3 GeV, with time bins of six hours, show asymmetric profiles with similar rise times in all the bands but a rapid decline during the April flare and a gradual one during the June flare. The light curves during the April flare show an ∼2 day long plateau in 0.1-0.3 GeV emission, erratic variations in 0.3-1 GeV emission, and a daily recurring feature in 1-3 GeV emission until the rapid rise and decline within a day. The June flare shows a monotonic rise until the peak, followed by a gradual decline powered mainly by the multi-peak 0.1-0.3 GeV emission. The peak fluxes during both the flares are similar except in the 1-3 GeV band in April, which is twice the corresponding flux during the June flare. Hardness ratios during the April flare indicate spectral hardening in the rising phase followed by softening during the decay. We attribute this behavior to the development of a shock associated with an increase in acceleration efficiency followed by its decay leading to spectral softening. The June flare suggests hardening during the rise followed by a complicated energy dependent behavior during the decay. Observed features during the June flare favor multiple emission regions while the overall flaring episode can be related to jet dynamics.

  4. Dynamical phase transitions in totally asymmetric simple exclusion processes with two types of particles under periodically driven boundary conditions

    NASA Astrophysics Data System (ADS)

    Yeşil, Ayşe Ferhan; Yalabik, M. Cemal

    2016-01-01

    Driven diffusive systems have provided simple models for nonequilibrium systems with nontrivial structures. Steady-state behavior of these systems with constant boundary conditions have been studied extensively. Comparatively less work has been carried out on the responses of these systems to time-dependent parameters. We report the modifications to the probability density function of a two-particle exclusion model in response to a periodically changing perturbation to its boundary conditions. The changes in the shape of the distribution as a function of the frequency of the perturbation contains considerable structure. A dynamical phase transition in which the system response changes abruptly as a function of perturbation frequency was observed. We interpret this structure to be a consequence of the existence of a typical time scale associated with the dynamics of density shock profiles within the system.

  5. Hardware acceleration of lucky-region fusion (LRF) algorithm for image acquisition and processing

    NASA Astrophysics Data System (ADS)

    Maignan, William; Koeplinger, David; Carhart, Gary W.; Aubailly, Mathieu; Kiamilev, Fouad; Liu, J. Jiang

    2013-05-01

    "Lucky-region fusion" (LRF) is an image processing technique that has proven successful in enhancing the quality of images distorted by atmospheric turbulence. The LRF algorithm extracts sharp regions of an image obtained from a series of short exposure frames, and "fuses" them into a final image with improved quality. In previous research, the LRF algorithm had been implemented on a PC using a compiled programming language. However, the PC usually does not have sufficient processing power to handle real-time extraction, processing and reduction required when the LRF algorithm is applied not to single picture images but rather to real-time video from fast, high-resolution image sensors. This paper describes a hardware implementation of the LRF algorithm on a Virtex 6 field programmable gate array (FPGA) to achieve real-time video processing. The novelty in our approach is the creation of a "black box" LRF video processing system with a standard camera link input, a user controller interface, and a standard camera link output.

  6. Monte Carlo-based fluorescence molecular tomography reconstruction method accelerated by a cluster of graphic processing units

    NASA Astrophysics Data System (ADS)

    Quan, Guotao; Gong, Hui; Deng, Yong; Fu, Jianwei; Luo, Qingming

    2011-02-01

    High-speed fluorescence molecular tomography (FMT) reconstruction for 3-D heterogeneous media is still one of the most challenging problems in diffusive optical fluorescence imaging. In this paper, we propose a fast FMT reconstruction method that is based on Monte Carlo (MC) simulation and accelerated by a cluster of graphics processing units (GPUs). Based on the Message Passing Interface standard, we modified the MC code for fast FMT reconstruction, and different Green's functions representing the flux distribution in media are calculated simultaneously by different GPUs in the cluster. A load-balancing method was also developed to increase the computational efficiency. By applying the Fréchet derivative, a Jacobian matrix is formed to reconstruct the distribution of the fluorochromes using the calculated Green's functions. Phantom experiments have shown that only 10 min are required to get reconstruction results with a cluster of 6 GPUs, rather than 6 h with a cluster of multiple dual opteron CPU nodes. Because of the advantages of high accuracy and suitability for 3-D heterogeneity media with refractive-index-unmatched boundaries from the MC simulation, the GPU cluster-accelerated method provides a reliable approach to high-speed reconstruction for FMT imaging.

  7. NREL Develops Accelerated Sample Activation Process for Hydrogen Storage Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-12-01

    This fact sheet describes NREL's accomplishments in developing a new sample activation process that reduces the time to prepare samples for measurement of hydrogen storage from several days to five minutes and provides more uniform samples. Work was performed by NREL's Chemical and Materials Science Center.

  8. [Acceleration of osmotic dehydration process through ohmic heating of foods: raspberries (Rubus idaeus)].

    PubMed

    Simpson, Ricardo R; Jiménez, Maite P; Carevic, Erica G; Grancelli, Romina M

    2007-06-01

    Raspberries (Rubus idaeus) were osmotically dehydrated by applying a conventional method under the supposition of a homogeneous solution, all in a 62% glucose solution at 50 degrees C. Raspberries (Rubus idaeus) were also osmotically dehydrated by using ohmic heating in a 57% glucose solution at a variable voltage (to maintain temperature between 40 and 50 degrees C) and an electric field intensity <100 V/cm. When comparing the results from both experiments it was evident that processing time is reduced when ohmic heating technique was used. In some cases this reduction reached even 50%. This is explained by the additional effect to the thermal damage that is generated in an ohmic process, denominated electroporation. PMID:17992985

  9. Basic Electropolishing Process Research and Development in Support of Improved Reliable Performance SRF Cavities for the Future Accelerator

    SciTech Connect

    H. Tian, C.E. Reece,M.J. Kelley

    2009-05-01

    Future accelerators require unprecedented cavity performance, which is strongly influenced by interior surface nanosmoothness. Electropolishing is the technique of choice to be developed for high-field superconducting radiofrequency cavities. Electrochemical impedance spectroscopy (EIS) and related techniques point to the electropolishing mechanism of Nb in a sulfuric and hydrofluoric acid electrolyte of controlled by a compact surface salt film under F- diffusion-limited mass transport control. These and other findings are currently guiding a systematic characterization to form the basis for cavity process optimization, such as flowrate, electrolyte composition and temperature. This integrated analysis is expected to provide optimum EP parameter sets for a controlled, reproducible and uniform surface leveling for Nb SRF cavities.

  10. Exclusive Dijet production from CDF2LHC

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U.

    2005-04-01

    Exclusive dijet production at the Tevatron can be used as a benchmark to establish predictions on exclusive diffractive Higgs production, a process with a much smaller cross section. Exclusive dijet production in Double Pomeron Exchange processes, including diffractive Higgs production with measurements at the Tevatron and predictions for the Large Hadron Collider are presented. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Upper limits on the exclusive dijet production cross section are presented and compared to current theoretical predictions.

  11. Audit Report on "Waste Processing and Recovery Act Acceleration Efforts for Contact-Handled Transuranic Waste at the Hanford Site"

    SciTech Connect

    2010-05-01

    The Department of Energy's Office of Environmental Management's (EM), Richland Operations Office (Richland), is responsible for disposing of the Hanford Site's (Hanford) transuranic (TRU) waste, including nearly 12,000 cubic meters of radioactive contact-handled TRU wastes. Prior to disposing of this waste at the Department's Waste Isolation Pilot Plant (WIPP), Richland must certify that it meets WIPP's waste acceptance criteria. To be certified, the waste must be characterized, screened for prohibited items, treated (if necessary) and placed into a satisfactory disposal container. In a February 2008 amendment to an existing Record of Decision (Decision), the Department announced its plan to ship up to 8,764 cubic meters of contact-handled TRU waste from Hanford and other waste generator sites to the Advanced Mixed Waste Treatment Project (AMWTP) at Idaho's National Laboratory (INL) for processing and certification prior to disposal at WIPP. The Department decided to maximize the use of the AMWTP's automated waste processing capabilities to compact and, thereby, reduce the volume of contact-handled TRU waste. Compaction reduces the number of shipments and permits WIPP to more efficiently use its limited TRU waste disposal capacity. The Decision noted that the use of AMWTP would avoid the time and expense of establishing a processing capability at other sites. In May 2009, EM allocated $229 million of American Recovery and Reinvestment Act of 2009 (Recovery Act) funds to support Hanford's Solid Waste Program, including Hanford's contact-handled TRU waste. Besides providing jobs, these funds were intended to accelerate cleanup in the short term. We initiated this audit to determine whether the Department was effectively using Recovery Act funds to accelerate processing of Hanford's contact-handled TRU waste. Relying on the availability of Recovery Act funds, the Department changed course and approved an alternative plan that could increase costs by about $25 million

  12. Influence of processing procedure on the quality of Radix Scrophulariae: a quantitative evaluation of the main compounds obtained by accelerated solvent extraction and high-performance liquid chromatography.

    PubMed

    Cao, Gang; Wu, Xin; Li, Qinglin; Cai, Hao; Cai, Baochang; Zhu, Xuemei

    2015-02-01

    An improved high-performance liquid chromatography with diode array detection combined with accelerated solvent extraction method was used to simultaneously determine six compounds in crude and processed Radix Scrophulariae samples. Accelerated solvent extraction parameters such as extraction solvent, temperature, number of cycles, and analysis procedure were systematically optimized. The results indicated that compared with crude Radix Scrophulariae samples, the processed samples had lower contents of harpagide and harpagoside but higher contents of catalpol, acteoside, angoroside C, and cinnamic acid. The established method was sufficiently rapid and reliable for the global quality evaluation of crude and processed herbal medicines. PMID:25431110

  13. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  14. Linear Accelerators

    SciTech Connect

    Sidorin, Anatoly

    2010-01-05

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  15. Accelerated evaluation of the robustness of treatment plans against geometric uncertainties by Gaussian processes

    NASA Astrophysics Data System (ADS)

    Sobotta, B.; Söhn, M.; Alber, M.

    2012-12-01

    In order to provide a consistently high quality treatment, it is of great interest to assess the robustness of a treatment plan under the influence of geometric uncertainties. One possible method to implement this is to run treatment simulations for all scenarios that may arise from these uncertainties. These simulations may be evaluated in terms of the statistical distribution of the outcomes (as given by various dosimetric quality metrics) or statistical moments thereof, e.g. mean and/or variance. This paper introduces a method to compute the outcome distribution and all associated values of interest in a very efficient manner. This is accomplished by substituting the original patient model with a surrogate provided by a machine learning algorithm. This Gaussian process (GP) is trained to mimic the behavior of the patient model based on only very few samples. Once trained, the GP surrogate takes the place of the patient model in all subsequent calculations.The approach is demonstrated on two examples. The achieved computational speedup is more than one order of magnitude.

  16. Rock varnish in New York: An accelerated snapshot of accretionary processes

    NASA Astrophysics Data System (ADS)

    Krinsley, David H.; Dorn, Ronald I.; DiGregorio, Barry E.; Langworthy, Kurt A.; Ditto, Jeffrey

    2012-02-01

    Samples of manganiferous rock varnish collected from fluvial, bedrock outcrop and Erie Barge Canal settings in New York state host a variety of diatom, fungal and bacterial microbial forms that are enhanced in manganese and iron. Use of a Dual-Beam Focused Ion Beam Scanning Electron Microscope to manipulate the varnish in situ reveals microbial forms that would not have otherwise been identified. The relative abundance of Mn-Fe-enriched biotic forms in New York samples is far greater than varnishes collected from warm deserts. Moisture availability has long been noted as a possible control on varnish growth rates, a hypothesis consistent with the greater abundance of Mn-enhancing bioforms. Sub-micron images of incipient varnish formation reveal that varnishing in New York probably starts with the mortality of microorganisms that enhanced Mn on bare mineral surfaces; microbial death results in the adsorption of the Mn-rich sheath onto the rock in the form of filamentous networks. Clay minerals are then cemented by remobilization of the Mn-rich material. Thus, the previously unanswered question of what comes first - clay mineral deposition or enhancement of Mn - can be answered in New York because of the faster rate of varnish growth. In contrast, very slow rates of varnishing seen in warm deserts, of microns per thousand years, make it less likely that collected samples will reveal varnish accretionary processes than samples collected from fast-accreting moist settings.

  17. Graphic processing unit accelerated real-time partially coherent beam generator

    NASA Astrophysics Data System (ADS)

    Ni, Xiaolong; Liu, Zhi; Chen, Chunyi; Jiang, Huilin; Fang, Hanhan; Song, Lujun; Zhang, Su

    2016-07-01

    A method of using liquid-crystals (LCs) to generate a partially coherent beam in real-time is described. An expression for generating a partially coherent beam is given and calculated using a graphic processing unit (GPU), i.e., the GeForce GTX 680. A liquid-crystal on silicon (LCOS) with 256 × 256 pixels is used as the partially coherent beam generator (PCBG). An optimizing method with partition convolution is used to improve the generating speed of our LC PCBG. The total time needed to generate a random phase map with a coherence width range from 0.015 mm to 1.5 mm is less than 2.4 ms for calculation and readout with the GPU; adding the time needed for the CPU to read and send to LCOS with the response time of the LC PCBG, the real-time partially coherent beam (PCB) generation frequency of our LC PCBG is up to 312 Hz. To our knowledge, it is the first real-time partially coherent beam generator. A series of experiments based on double pinhole interference are performed. The result shows that to generate a laser beam with a coherence width of 0.9 mm and 1.5 mm, with a mean error of approximately 1%, the RMS values needed 0.021306 and 0.020883 and the PV values required 0.073576 and 0.072998, respectively.

  18. Grid-based algorithm to search critical points, in the electron density, accelerated by graphics processing units.

    PubMed

    Hernández-Esparza, Raymundo; Mejía-Chica, Sol-Milena; Zapata-Escobar, Andy D; Guevara-García, Alfredo; Martínez-Melchor, Apolinar; Hernández-Pérez, Julio-M; Vargas, Rubicelia; Garza, Jorge

    2014-12-01

    Using a grid-based method to search the critical points in electron density, we show how to accelerate such a method with graphics processing units (GPUs). When the GPU implementation is contrasted with that used on central processing units (CPUs), we found a large difference between the time elapsed by both implementations: the smallest time is observed when GPUs are used. We tested two GPUs, one related with video games and other used for high-performance computing (HPC). By the side of the CPUs, two processors were tested, one used in common personal computers and other used for HPC, both of last generation. Although our parallel algorithm scales quite well on CPUs, the same implementation on GPUs runs around 10× faster than 16 CPUs, with any of the tested GPUs and CPUs. We have found what one GPU dedicated for video games can be used without any problem for our application, delivering a remarkable performance, in fact; this GPU competes against one HPC GPU, in particular when single-precision is used. PMID:25345784

  19. Accelerating Monte Carlo simulations of photon transport in a voxelized geometry using a massively parallel graphics processing unit

    SciTech Connect

    Badal, Andreu; Badano, Aldo

    2009-11-15

    Purpose: It is a known fact that Monte Carlo simulations of radiation transport are computationally intensive and may require long computing times. The authors introduce a new paradigm for the acceleration of Monte Carlo simulations: The use of a graphics processing unit (GPU) as the main computing device instead of a central processing unit (CPU). Methods: A GPU-based Monte Carlo code that simulates photon transport in a voxelized geometry with the accurate physics models from PENELOPE has been developed using the CUDA programming model (NVIDIA Corporation, Santa Clara, CA). Results: An outline of the new code and a sample x-ray imaging simulation with an anthropomorphic phantom are presented. A remarkable 27-fold speed up factor was obtained using a GPU compared to a single core CPU. Conclusions: The reported results show that GPUs are currently a good alternative to CPUs for the simulation of radiation transport. Since the performance of GPUs is currently increasing at a faster pace than that of CPUs, the advantages of GPU-based software are likely to be more pronounced in the future.

  20. Accelerators and the Accelerator Community

    SciTech Connect

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  1. Monitoring of pigmented and wooden surfaces in accelerated ageing processes by FT-Raman spectroscopy and multivariate control charts.

    PubMed

    Marengo, Emilio; Robotti, Elisa; Liparota, Maria Cristina; Gennaro, Maria Carla

    2004-07-01

    Two of the most suitable analytical techniques used in the field of cultural heritage are NIR (near-infrared) and Raman spectroscopy. FT-Raman spectroscopy coupled to multivariate control charts is applied here for the development of a new method for monitoring the conservation state of pigmented and wooden surfaces. These materials were exposed to different accelerated ageing processes in order to evaluate the effect of the applied treatments on the goods surfaces. In this work, a new approach based on the principles of statistical process control (SPC) to the monitoring of cultural heritage, has been developed: the conservation state of samples simulating works-of-art has been treated like an industrial process, monitored with multivariate control charts, owing to the complexity of the spectroscopic data collected. The Raman spectra were analysed by principal component analysis (PCA) and the relevant principal components (PCs) were used for constructing multivariate Shewhart and cumulative sum (CUSUM) control charts. These tools were successfully applied for the identification of the presence of relevant modifications occurring on the surfaces. CUSUM charts however proved to be more effective in the identification of the exact beginning of the applied treatment. In the case of wooden boards, where a sufficient number of PCs were available, simultaneous scores monitoring and residuals tracking (SMART) charts were also investigated. The exposure to a basic attack and to high temperatures produced deep changes on the wooden samples, clearly identified by the multivariate Shewhart, CUSUM and SMART charts. A change on the pigment surface was detected after exposure to an acidic solution and to the UV light, while no effect was identified on the painted surface after the exposure to natural atmospheric events. PMID:18969526

  2. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  3. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

  4. EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE

    SciTech Connect

    Yan Dahai; Zhang Li; Fan Zhonghui; Zeng Houdun; Yuan Qiang

    2013-03-10

    We investigate the electron energy distributions (EEDs) and the acceleration processes in the jet of Mrk 421 through fitting the spectral energy distributions (SEDs) in different active states in the frame of a one-zone synchrotron self-Compton model. After assuming two possible EEDs formed in different acceleration models: the shock-accelerated power law with exponential cut-off (PLC) EED and the stochastic-turbulence-accelerated log-parabolic (LP) EED, we fit the observed SEDs of Mrk 421 in both low and giant flare states using the Markov Chain Monte Carlo method which constrains the model parameters in a more efficient way. The results from our calculations indicate that (1) the PLC and LP models give comparably good fits for the SED in the low state, but the variations of model parameters from low state to flaring can be reasonably explained only in the case of the PLC in the low state; and (2) the LP model gives better fits compared to the PLC model for the SED in the flare state, and the intra-day/night variability observed at GeV-TeV bands can be accommodated only in the LP model. The giant flare may be attributed to the stochastic turbulence re-acceleration of the shock-accelerated electrons in the low state. Therefore, we may conclude that shock acceleration is dominant in the low state, while stochastic turbulence acceleration is dominant in the flare state. Moreover, our result shows that the extrapolated TeV spectra from the best-fit SEDs from optical through GeV with the two EEDs are different. It should be considered with caution when such extrapolated TeV spectra are used to constrain extragalactic background light models.

  5. Evaluation of acceleration and deceleration cardiac processes using phase-rectified signal averaging in healthy and idiopathic dilated cardiomyopathy subjects.

    PubMed

    Bas, Rosana; Vallverdú, Montserrat; Valencia, Jose F; Voss, Andreas; de Luna, Antonio Bayés; Caminal, Pere

    2015-02-01

    The aim of the present study was to investigate the suitability of the Phase-Rectified Signal Averaging (PRSA) method for improved risk prediction in cardiac patients. Moreover, this technique, which separately evaluates acceleration and deceleration processes of cardiac rhythm, allows the effect of sympathetic and vagal modulations of beat-to-beat intervals to be characterized. Holter recordings of idiopathic dilated cardiomyopathy (IDC) patients were analyzed: high-risk (HR), who suffered sudden cardiac death (SCD) during the follow-up; and low-risk (LR), without any kind of cardiac-related death. Moreover, a control group of healthy subjects was analyzed. PRSA indexes were analyzed, for different time scales T and wavelet scales s, from RR series of 24 h-ECG recordings, awake periods and sleep periods. Also, the behavior of these indexes from simulated data was analyzed and compared with real data results. Outcomes demonstrated the PRSA capacity to significantly discriminate healthy subjects from IDC patients and HR from LR patients on a higher level than traditional temporal and spectral measures. The behavior of PRSA indexes agrees with experimental evidences related to cardiac autonomic modulations. Also, these parameters reflect more regularity of the autonomic nervous system (ANS) in HR patients. PMID:25585858

  6. 40 CFR 261.39 - Conditional Exclusion for Used, Broken Cathode Ray Tubes (CRTs) and Processed CRT Glass...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs is... CFR part 266, subpart C instead of the requirements of this section. ... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection...

  7. 40 CFR 261.39 - Conditional Exclusion for Used, Broken Cathode Ray Tubes (CRTs) and Processed CRT Glass...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs is... CFR part 266, subpart C instead of the requirements of this section. § 261.39, Nt. Effective Date Note... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection...

  8. 40 CFR 261.39 - Conditional Exclusion for Used, Broken Cathode Ray Tubes (CRTs) and Processed CRT Glass...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs is... CFR part 266, subpart C instead of the requirements of this section. ... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection...

  9. 40 CFR 261.39 - Conditional Exclusion for Used, Broken Cathode Ray Tubes (CRTs) and Processed CRT Glass...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs is... CFR part 266, subpart C instead of the requirements of this section. ... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection...

  10. 40 CFR 261.39 - Conditional Exclusion for Used, Broken Cathode Ray Tubes (CRTs) and Processed CRT Glass...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... complete until any such claim is resolved in accordance with 40 CFR 260.2. (v) The export of CRTs is... CFR part 266, subpart C instead of the requirements of this section. ... Cathode Ray Tubes (CRTs) and Processed CRT Glass Undergoing Recycling. 261.39 Section 261.39 Protection...

  11. Position dependence of the particle density in a double-chain section of a linear network in a totally asymmetric simple exclusion process

    NASA Astrophysics Data System (ADS)

    Pesheva, N. C.; Brankov, J. G.

    2013-06-01

    We report here results on the study of the totally asymmetric simple exclusion process, defined on an open network, consisting of head and tail simple-chain segments with a double-chain section inserted in between. Results of numerical simulations for relatively short chains reveal an interesting feature of the network. When the current through the system takes its maximum value, a simple translation of the double-chain section forward or backward along the network leads to a sharp change in the shape of the density profiles in the parallel chains, thus affecting the total number of particles in that part of the network. In the symmetric case of equal injection and ejection rates α=β>1/2 and equal lengths of the head and tail sections, the density profiles in the two parallel chains are almost linear, characteristic of the coexistence line (shock phase). Upon moving the section forward (backward), their shape changes to the one typical for the high- (low-) density phases of a simple chain. The total bulk density of particles in a section with a large number of parallel chains is evaluated too. The observed effect might have interesting implications for the traffic flow control as well as for biological transport processes in living cells. An explanation of this phenomenon is offered in terms of a finite-size dependence of the effective injection and ejection rates at the ends of the double-chain section.

  12. Compact Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness, this accelerator could be nearly ideal for primary or station-keeping propulsion for spacecraft having masses between 1 and 20 kg. Because this accelerator is designed to generate beams of ions having energies between 50 and 200 eV, it could also be used for surface modification or activation of thin films.

  13. Graphics processing unit-accelerated non-rigid registration of MR images to CT images during CT-guided percutaneous liver tumor ablations

    PubMed Central

    Tokuda, Junichi; Plishker, William; Torabi, Meysam; Olubiyi, Olutayo I; Zaki, George; Tatli, Servet; Silverman, Stuart G.; Shekhar, Raj; Hata, Nobuhiko

    2015-01-01

    Rationale and Objectives Accuracy and speed are essential for the intraprocedural nonrigid MR-to-CT image registration in the assessment of tumor margins during CT-guided liver tumor ablations. While both accuracy and speed can be improved by limiting the registration to a region of interest (ROI), manual contouring of the ROI prolongs the registration process substantially. To achieve accurate and fast registration without the use of an ROI, we combined a nonrigid registration technique based on volume subdivision with hardware acceleration using a graphical processing unit (GPU). We compared the registration accuracy and processing time of GPU-accelerated volume subdivision-based nonrigid registration technique to the conventional nonrigid B-spline registration technique. Materials and Methods Fourteen image data sets of preprocedural MR and intraprocedural CT images for percutaneous CT-guided liver tumor ablations were obtained. Each set of images was registered using the GPU-accelerated volume subdivision technique and the B-spline technique. Manual contouring of ROI was used only for the B-spline technique. Registration accuracies (Dice Similarity Coefficient (DSC) and 95% Hausdorff Distance (HD)), and total processing time including contouring of ROIs and computation were compared using a paired Student’s t-test. Results Accuracy of the GPU-accelerated registrations and B-spline registrations, respectively were 88.3 ± 3.7% vs 89.3 ± 4.9% (p = 0.41) for DSC and 13.1 ± 5.2 mm vs 11.4 ± 6.3 mm (p = 0.15) for HD. Total processing time of the GPU-accelerated registration and B-spline registration techniques was 88 ± 14 s vs 557 ± 116 s (p < 0.000000002), respectively; there was no significant difference in computation time despite the difference in the complexity of the algorithms (p = 0.71). Conclusion The GPU-accelerated volume subdivision technique was as accurate as the B-spline technique and required significantly less processing time. The GPU-accelerated

  14. CMS results on exclusive and diffractive production

    SciTech Connect

    Alves, Gilvan A.

    2015-04-10

    We present recent CMS measurements of diffractive and exclusive processes, using data collected at 7 TeV at the LHC. Measurements of soft single- and double-diffractive cross sections are presented, as well as measurements of photon-induced processes including studies of exclusive WW production via photon-photon exchange.

  15. Effect of the Drying Process on the Intensification of Phenolic Compounds Recovery from Grape Pomace Using Accelerated Solvent Extraction

    PubMed Central

    Rajha, Hiba N.; Ziegler, Walter; Louka, Nicolas; Hobaika, Zeina; Vorobiev, Eugene; Boechzelt, Herbert G.; Maroun, Richard G.

    2014-01-01

    In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications. PMID:25322155

  16. Effect of the drying process on the intensification of phenolic compounds recovery from grape pomace using accelerated solvent extraction.

    PubMed

    Rajha, Hiba N; Ziegler, Walter; Louka, Nicolas; Hobaika, Zeina; Vorobiev, Eugene; Boechzelt, Herbert G; Maroun, Richard G

    2014-01-01

    In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications. PMID:25322155

  17. QED radiative effects in the processes of exclusive photon electroproduction from polarized protons with the next-to-leading accuracy

    SciTech Connect

    Akushevich, Igor V.; Ilyichev, Alexander; Shumeiko, Nikolai M

    2014-08-01

    Radiative effects in the electroproduction of photons in polarized ep-scattering are calculated with the next-to-leading (NLO) accuracy. The contributions of loops and two photon emission were presented in analytical form. The covariant approach of Bardin and Shumeiko was used to extract the infrared divergence. All contributions to the radiative correction were presented in the form of the correction to the leptonic tensor thus allowing for further applications in other experiments, e.g., deep inelastic scattering. The radiative corrections (RC) to the cross sections and polarization asymmetries were analyzed numerically for kinematical conditions of the current measurement at Jefferson Lab. Specific attention was paid on analyzing kinematical conditions for the process with large radiative effect when momenta of two photons in the final state are collinear to momenta of initial and final electrons, respectively.

  18. Formation of hexagonal boron nitride nanoscrolls induced by inclusion and exclusion of self-assembling molecules in solution process

    NASA Astrophysics Data System (ADS)

    Hwang, Da Young; Suh, Dong Hack

    2014-05-01

    Unlike nanoscrolls of 2D graphene, those of 2D h-BN have not been demonstrated, except for only a few experimental reports. Nanoscrolls of h-BN with high yields and reproducibility are first synthesized by a simple solution process. Inner-tube diameters of BNSs including LCAs, N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide, a bile acid derivative and self-assembling material, can be controlled by adjusting the diameter of the LCA fiber which is grown by self-assembly. TEM and SEM images show that BNSs have a tube-like morphology and the inner-tube diameter of BNSs can be controlled in the range from 20 to 60 nm for a smaller diameter, up to 300 nm for a larger diameter by LCA fiber growth inside the BNSs. Finally, open cylindrical BNSs with hollow cores were obtained by dissolving LCAs inside BNSs.Unlike nanoscrolls of 2D graphene, those of 2D h-BN have not been demonstrated, except for only a few experimental reports. Nanoscrolls of h-BN with high yields and reproducibility are first synthesized by a simple solution process. Inner-tube diameters of BNSs including LCAs, N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide, a bile acid derivative and self-assembling material, can be controlled by adjusting the diameter of the LCA fiber which is grown by self-assembly. TEM and SEM images show that BNSs have a tube-like morphology and the inner-tube diameter of BNSs can be controlled in the range from 20 to 60 nm for a smaller diameter, up to 300 nm for a larger diameter by LCA fiber growth inside the BNSs. Finally, open cylindrical BNSs with hollow cores were obtained by dissolving LCAs inside BNSs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00897a

  19. Listening to an Audio Drama Activates Two Processing Networks, One for All Sounds, Another Exclusively for Speech

    PubMed Central

    Boldt, Robert; Malinen, Sanna; Seppä, Mika; Tikka, Pia; Savolainen, Petri; Hari, Riitta; Carlson, Synnöve

    2013-01-01

    Earlier studies have shown considerable intersubject synchronization of brain activity when subjects watch the same movie or listen to the same story. Here we investigated the across-subjects similarity of brain responses to speech and non-speech sounds in a continuous audio drama designed for blind people. Thirteen healthy adults listened for ∼19 min to the audio drama while their brain activity was measured with 3 T functional magnetic resonance imaging (fMRI). An intersubject-correlation (ISC) map, computed across the whole experiment to assess the stimulus-driven extrinsic brain network, indicated statistically significant ISC in temporal, frontal and parietal cortices, cingulate cortex, and amygdala. Group-level independent component (IC) analysis was used to parcel out the brain signals into functionally coupled networks, and the dependence of the ICs on external stimuli was tested by comparing them with the ISC map. This procedure revealed four extrinsic ICs of which two–covering non-overlapping areas of the auditory cortex–were modulated by both speech and non-speech sounds. The two other extrinsic ICs, one left-hemisphere-lateralized and the other right-hemisphere-lateralized, were speech-related and comprised the superior and middle temporal gyri, temporal poles, and the left angular and inferior orbital gyri. In areas of low ISC four ICs that were defined intrinsic fluctuated similarly as the time-courses of either the speech-sound-related or all-sounds-related extrinsic ICs. These ICs included the superior temporal gyrus, the anterior insula, and the frontal, parietal and midline occipital cortices. Taken together, substantial intersubject synchronization of cortical activity was observed in subjects listening to an audio drama, with results suggesting that speech is processed in two separate networks, one dedicated to the processing of speech sounds and the other to both speech and non-speech sounds. PMID:23734202

  20. Plasma inverse transition acceleration

    SciTech Connect

    Xie, Ming

    2001-06-18

    It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood, and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several realizations of the new principle.

  1. Nano-fabricated size exclusion chromatograph

    NASA Technical Reports Server (NTRS)

    Svehla, D.; Feldman, S.; Feldman, J.; Grunthaner, F.; Shakkottai, P.; Castillo, L. del; White, V.

    2002-01-01

    This paper describes the development of a nano-fabricated size exclusion chromatograph (nSEC) based on the principle that molecules traveling through amicrocolumn containing nano-fabricated features will have characteristic elution times that directly correlate to molecular weight. Compared to conventional size exclusion chromatography, the nSEC offers greater control over the size exclusion process; mass fabrication; integration of the separation column with associated valves, pumps, and detectors; and dramatic reductions in instrument mass and power requirements.

  2. Towards the effect of transverse inhomogeneity of electromagnetic pulse on the process of ion acceleration in the RPDA regime

    NASA Astrophysics Data System (ADS)

    Lezhnin, K. V.; Kamenets, F. F.; Beskin, V. S.; Kando, M.; Esirkepov, T. Z.; Bulanov, S. V.

    2015-05-01

    The stability of accleration of ions in the RPDA regime against transversal shift of the cluster target relative to gaussian and supergaussian laser pulses is considered. It is shown that the maximum energy of ions decreases while the shift increases, as the target escapes the acceleration domain. The effect of self-focusing for the supergaussian pulse profile is found and interpreted. An analytical approach based on the relativistic mirror model is developed. We also conduct PIC simulations that prove our theoretical estimations. The results obtained can be applied to the optimization of ion acceleration by the laser radiation pressure with mass-limited targets.

  3. Plasma accelerators

    SciTech Connect

    Ruth, R.D.; Chen, P.

    1986-03-01

    In this paper we discuss plasma accelerators which might provide high gradient accelerating fields suitable for TeV linear colliders. In particular we discuss two types of plasma accelerators which have been proposed, the Plasma Beat Wave Accelerator and the Plasma Wake Field Accelerator. We show that the electric fields in the plasma for both schemes are very similar, and thus the dynamics of the driven beams are very similar. The differences appear in the parameters associated with the driving beams. In particular to obtain a given accelerating gradient, the Plasma Wake Field Accelerator has a higher efficiency and a lower total energy for the driving beam. Finally, we show for the Plasma Wake Field Accelerator that one can accelerate high quality low emittance beams and, in principle, obtain efficiencies and energy spreads comparable to those obtained with conventional techniques.

  4. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  5. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  6. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  7. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  8. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  9. 5 CFR 581.105 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Exclusions. 581.105 Section 581.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROCESSING GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Purpose and Definitions § 581.105 Exclusions. In determining...

  10. 40 CFR 503.6 - Exclusions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Exclusions. 503.6 Section 503.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.6 Exclusions. (a) Treatment processes. This part does not establish requirements for...

  11. Recombinant growth factor mixtures induce cell cycle progression and the upregulation of type I collagen in human skin fibroblasts, resulting in the acceleration of wound healing processes.

    PubMed

    Lee, Do Hyun; Choi, Kyung-Ha; Cho, Jae-We; Kim, So Young; Kwon, Tae Rin; Choi, Sun Young; Choi, Yoo Mi; Lee, Jay; Yoon, Ho Sang; Kim, Beom Joon

    2014-05-01

    Application of growth factor mixtures has been used for wound healing and anti-wrinkles agents. The aim of this study was to evaluate the effect of recombinant growth factor mixtures (RGFM) on the expression of cell cycle regulatory proteins, type I collagen, and wound healing processes of acute animal wound models. The results showed that RGFM induced increased rates of cell proliferation and cell migration of human skin fibroblasts (HSF). In addition, expression of cyclin D1, cyclin E, cyclin-dependent kinase (Cdk)4, and Cdk2 proteins was markedly increased with a growth factor mixtures treatment in fibroblasts. Expression of type I collagen was also increased in growth factor mixtures-treated HSF. Moreover, growth factor mixtures-induced the upregulation of type I collagen was associated with the activation of Smad2/3. In the animal model, RGFM-treated mice showed accelerated wound closure, with the closure rate increasing as early as on day 7, as well as re-epithelization and reduced inflammatory cell infiltration than phosphate-buffered saline (PBS)-treated mice. In conclusion, the results indicated that RGFM has the potential to accelerate wound healing through the upregulation of type I collagen, which is partly mediated by activation of Smad2/3-dependent signaling pathway as well as cell cycle progression in HSF. The topical application of growth factor mixtures to acute and chronic skin wound may accelerate the epithelization process through these molecular mechanisms. PMID:24626875

  12. On the retention of high-energy protons and nuclei with charges Z or equal to 2 in large solar flares after the process of their acceleration

    NASA Technical Reports Server (NTRS)

    Volodichev, N. N.; Kuzhevsky, B. M.; Nechaev, O. Y.; Savenko, I. A.

    1985-01-01

    Data which suggest that the protons with energies of up to several GeV should be retained on the Sun after the process of their acceleration are presented. The protons are on the average retained for 15 min, irrespectively of the solar flare heliolatitude and of the accelerated particle energy ranging from 100 MeV to several GeV. It is suggested that the particles are retained in a magnetic trap formed in a solar active region. No Z or = 2 nuclei of solar origin during large solar flares. The absence of the 500 MeV/nucleon nuclei with Z or = 2 may be due to their retention in the magnetic trap which also retains the high-energy protons. During the trapping time the approx. 500 MeV/nucleon nuclei with Z or = 2 may escape due to nuclear interactions and ionization loss.

  13. Conclusive exclusion of quantum states

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Somshubhro; Jain, Rahul; Oppenheim, Jonathan; Perry, Christopher

    2014-02-01

    In the task of quantum state exclusion, we consider a quantum system prepared in a state chosen from a known set. The aim is to perform a measurement on the system which can conclusively rule that a subset of the possible preparation procedures cannot have taken place. We ask what conditions the set of states must obey in order for this to be possible and how well we can complete the task when it is not. The task of quantum state discrimination forms a subclass of this set of problems. Within this paper, we formulate the general problem as a semidefinite program (SDP), enabling us to derive sufficient and necessary conditions for a measurement to be optimal. Furthermore, we obtain a necessary condition on the set of states for exclusion to be achievable with certainty, and we give a construction for a lower bound on the probability of error. This task of conclusively excluding states has gained importance in the context of the foundations of quantum mechanics due to a result from Pusey, Barrett, and Rudolph (PBR). Motivated by this, we use our SDP to derive a bound on how well a class of hidden variable models can perform at a particular task, proving an analog of Tsirelson's bound for the PBR experiment and the optimality of a measurement given by PBR in the process. We also introduce variations of conclusive exclusion, including unambiguous state exclusion, and state exclusion with worst-case error.

  14. Access to Institutional Resources as a Measure of Social Exclusion: Relations with Family Process and Cognitive Development in the Context of Immigration

    ERIC Educational Resources Information Center

    Yoshikawa, Hirokazu; Godfrey, Erin B.; Rivera, Ann C.

    2008-01-01

    Few studies have examined how experiences associated with being an undocumented immigrant parent affects children's development. In this article, the authors apply social exclusion theory to examine how access to institutional resources that require identification may matter for parents and children in immigrant families. As hypothesized, groups…

  15. 29 CFR 780.610 - Workweek exclusively in exempt work.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Workweek exclusively in exempt work. 780.610 Section 780... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... for Exemption § 780.610 Workweek exclusively in exempt work. An employee who engages exclusively in...

  16. A data processing method for determining instantaneous angular speed and acceleration of crankshaft in an aircraft engine-propeller system using a magnetic encoder

    NASA Astrophysics Data System (ADS)

    Yu, S. D.; Zhang, X.

    2010-05-01

    This paper presents a method for determining the instantaneous angular speed and instantaneous angular acceleration of the crankshaft in a reciprocating engine and propeller dynamical system from electrical pulse signals generated by a magnetic encoder. The method is based on accurate determination of the measured global mean angular speed and precise values of times when leading edges of individual magnetic teeth pass through the magnetic sensor. Under a steady-state operating condition, a discrete deviation time vs. shaft rotational angle series of uniform interval is obtained and used for accurate determination of the crankshaft speed and acceleration. The proposed method for identifying sub- and super-harmonic oscillations in the instantaneous angular speeds and accelerations is new and efficient. Experiments were carried out on a three-cylinder four-stroke Saito 450R model aircraft engine and a Solo propeller in connection with a 64-teeth Admotec KL2202 magnetic encoder and an HS-4 data acquisition system. Comparisons with an independent data processing scheme indicate that the proposed method yields noise-free instantaneous angular speeds and is superior to the finite difference based methods commonly used in the literature.

  17. Direct Particle Acceleration in Astroplasmas

    NASA Astrophysics Data System (ADS)

    Hoshino, M.

    2002-10-01

    The high energy particle acceleration mechanisms are discussed by focusing on the direct acceleration in the astrophysical context. We specifically argue that the relativistic magnetic reconnection and the shock surfing/surfatron processes can efficiently accelerate charged particles to a relativistic energy, and that those mechanisms may produce a non-thermal, power-law energy spectrum. [copyright] 2002 American Institute of Physics

  18. Using compute unified device architecture-enabled graphic processing unit to accelerate fast Fourier transform-based regression Kriging interpolation on a MODIS land surface temperature image

    NASA Astrophysics Data System (ADS)

    Hu, Hongda; Shu, Hong; Hu, Zhiyong; Xu, Jianhui

    2016-04-01

    Kriging interpolation provides the best linear unbiased estimation for unobserved locations, but its heavy computation limits the manageable problem size in practice. To address this issue, an efficient interpolation procedure incorporating the fast Fourier transform (FFT) was developed. Extending this efficient approach, we propose an FFT-based parallel algorithm to accelerate regression Kriging interpolation on an NVIDIA® compute unified device architecture (CUDA)-enabled graphic processing unit (GPU). A high-performance cuFFT library in the CUDA toolkit was introduced to execute computation-intensive FFTs on the GPU, and three time-consuming processes were redesigned as kernel functions and executed on the CUDA cores. A MODIS land surface temperature 8-day image tile at a resolution of 1 km was resampled to create experimental datasets at eight different output resolutions. These datasets were used as the interpolation grids with different sizes in a comparative experiment. Experimental results show that speedup of the FFT-based regression Kriging interpolation accelerated by GPU can exceed 1000 when processing datasets with large grid sizes, as compared to the traditional Kriging interpolation running on the CPU. These results demonstrate that the combination of FFT methods and GPU-based parallel computing techniques greatly improves the computational performance without loss of precision.

  19. Remote sensing of the energy of Jovian auroral electrons with STIS: a clue to unveil plasma acceleration processes

    NASA Astrophysics Data System (ADS)

    Gerard, Jean-Claude

    2013-10-01

    The polar aurora, an important energy source for the Earth's upper atmosphere, is about two orders of magnitude more intense at Jupiter where it releases approximately 10 GW in Jupiter's thermosphere. So far, HST observations of Jupiter's aurora have concentrated on the morphology and the relationship between the solar wind and the brightness distribution. While STIS-MAMA is still operational, time is now critical to move into a new era where FUV long-slit spectroscopy and the spatial scanning capabilities of HST are combined. We propose to use this powerful tool to remotely sense the characteristics of the precipitated electrons by slewing the spectral slit over the different auroral components. It will then be possible to associate electron energies with spatial auroral components and constrain acceleration mechanisms {field-aligned acceleration, magnetic field reconnection, pitch angle electron scattering} associated with specific emission regions. For this, a combination of FUV imaging with STIS long slit spectroscopy will map the spatial variations of the auroral depth and thus the energy of the precipitated electrons. These results will be compared with current models of the Jovian magnetosphere-ionosphere interactions and will provide key inputs to a 3-D model of the Jupiter's atmosphere global heat budget and dynamics currently under development. This compact timely program is designed to provide a major step forward for a better understanding of the physical interactions taking place in Jupiter's magnetosphere and their effects on giant planets' atmospheres, a likely paradigm for many giant fast spinning planets with massive magnetic field in the universe.

  20. Accelerated Reader.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO.

    This paper provides an overview of Accelerated Reader, a system of computerized testing and record-keeping that supplements the regular classroom reading program. Accelerated Reader's primary goal is to increase literature-based reading practice. The program offers a computer-aided reading comprehension and management program intended to motivate…

  1. 10 CFR 781.52 - Exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Exclusive and partially exclusive licenses. 781.52 Section 781.52 Energy DEPARTMENT OF ENERGY DOE PATENT LICENSING REGULATIONS Types of Licenses and Conditions for Licensing § 781.52 Exclusive and partially exclusive licenses. (a) Availability of licenses. The Department may grant exclusive or...

  2. Higgs central exclusive production

    NASA Astrophysics Data System (ADS)

    Cudell, J. R.; Dechambre, A.; Hernández, O. F.

    2012-01-01

    Using the CHIDe model, we tune the calculation of central exclusive Higgs production to the recent CDF central exclusive dijet data, and predict the cross section for the exclusive production of Higgs boson at the LHC. In this model, due to different choices of the scale in the Sudakov form factor for dijet and Higgs production, it is always below 1 fb, and below 0.3 fb after experimental cuts.

  3. Application of a low level, uniform ultrasound field for the acceleration of enzymatic bio-processing of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. Our research has found that th...

  4. Production-passage-time approximation: a new approximation method to accelerate the simulation process of enzymatic reactions.

    PubMed

    Kuwahara, Hiroyuki; Myers, Chris J

    2008-09-01

    Given the substantial computational requirements of stochastic simulation, approximation is essential for efficient analysis of any realistic biochemical system. This paper introduces a new approximation method to reduce the computational cost of stochastic simulations of an enzymatic reaction scheme which in biochemical systems often includes rapidly changing fast reactions with enzyme and enzyme-substrate complex molecules present in very small counts. Our new method removes the substrate dissociation reaction by approximating the passage time of the formation of each enzyme-substrate complex molecule which is destined to a production reaction. This approach skips the firings of unimportant yet expensive reaction events, resulting in a substantial acceleration in the stochastic simulations of enzymatic reactions. Additionally, since all the parameters used in our new approach can be derived by the Michaelis-Menten parameters which can actually be measured from experimental data, applications of this approximation can be practical even without having full knowledge of the underlying enzymatic reaction. Here, we apply this new method to various enzymatic reaction systems, resulting in a speedup of orders of magnitude in temporal behavior analysis without any significant loss in accuracy. Furthermore, we show that our new method can perform better than some of the best existing approximation methods for enzymatic reactions in terms of accuracy and efficiency. PMID:18662102

  5. Tests of an environmental and personnel safe cleaning process for Brookhaven National Laboratory accelerator and storage ring components

    SciTech Connect

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1997-05-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its ultrahigh vacuum (UHV) components during and after construction. A new UHV cleaning process, which has to be environmentally and personnel safe, is needed to replace the harsh, unfriendly process which is still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on photon stimulated desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel, and oxygen-free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 eV. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils, and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10{sup 22} and 10{sup 23} photons per meter for a PSD measurement. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4}, and H{sub 2}O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories. After modification, the new UHV cleaning process was accepted by BNL.

  6. Breakthrough: Fermilab Accelerator Technology

    ScienceCinema

    None

    2014-08-12

    There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

  7. Breakthrough: Fermilab Accelerator Technology

    SciTech Connect

    2012-04-23

    There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

  8. LHCb GPU acceleration project

    NASA Astrophysics Data System (ADS)

    Badalov, A.; Cámpora, D.; Neufeld, N.; Vilasís-Cardona, X.

    2016-01-01

    The LHCb detector is due to be upgraded for processing high-luminosity collisions, which will increase data bandwidth to the event filter farm from 100 GB/s to 4 TB/s, encouraging us to look for new ways of accelerating Online reconstruction. The Coprocessor Manager is a new framework for integrating LHCb's existing computation pipelines with massively parallel algorithms running on GPUs and other accelerators. This paper describes the system and analyzes its performance.

  9. LINEAR ACCELERATOR

    DOEpatents

    Colgate, S.A.

    1958-05-27

    An improvement is presented in linear accelerators for charged particles with respect to the stable focusing of the particle beam. The improvement consists of providing a radial electric field transverse to the accelerating electric fields and angularly introducing the beam of particles in the field. The results of the foregoing is to achieve a beam which spirals about the axis of the acceleration path. The combination of the electric fields and angular motion of the particles cooperate to provide a stable and focused particle beam.

  10. Acceleration switch

    DOEpatents

    Abbin, J.P. Jr.; Devaney, H.F.; Hake, L.W.

    1979-08-29

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  11. Acceleration switch

    DOEpatents

    Abbin, Jr., Joseph P.; Devaney, Howard F.; Hake, Lewis W.

    1982-08-17

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  12. ION ACCELERATOR

    DOEpatents

    Bell, J.S.

    1959-09-15

    An arrangement for the drift tubes in a linear accelerator is described whereby each drift tube acts to shield the particles from the influence of the accelerating field and focuses the particles passing through the tube. In one embodiment the drift tube is splii longitudinally into quadrants supported along the axis of the accelerator by webs from a yoke, the quadrants. webs, and yoke being of magnetic material. A magnetic focusing action is produced by energizing a winding on each web to set up a magnetic field between adjacent quadrants. In the other embodiment the quadrants are electrically insulated from each other and have opposite polarity voltages on adjacent quadrants to provide an electric focusing fleld for the particles, with the quadrants spaced sufficienily close enough to shield the particles within the tube from the accelerating electric field.

  13. Selective and simultaneous determination of phosphate and silicate ions in leaching process waters for ceramics glaze raw materials of narutal origin by ion-exclusion chromatography coupled with UV-detection after postcolumn derivatization.

    PubMed

    Ikedo, Mikaru; Mori, Masanobu; Kurachi, Kazumasa; Hu, Wenzhi; Tanaka, Kazuhiko

    2006-01-01

    The selective and simultaneous ion-exclusion chromatography (IEC) with UV-detection on a weakly acidic cation-exchange resin column in the H+ -form (TSKgel Super IC-A/C) was developed and applied for the simultaneous determination of phosphate and silicate ions as the water quality parameters required for optimizing the water-leaching process for ceramics glaze raw materials of natural origin including feldspar, woods-ash, and straw-ash. Phosphate and silicate ions in these water-leaching process water samples were separated selectively from the coexisting anions such as sulfate, chloride, nitrate and carbonate ions, based on the ion-exclusion separation mechanism. They were detected selectively and simultaneously by a postcolumn derivatization with molybdenum-yellow using the UV-detector. Under the optimized separation and detection conditions (eluent, 0-1 mM sulfuric acid; reactant, 10 mM sodium molybdate-25 mM sulfuric acid; detector, UV at 370 nm; temperature, 45 degrees C), the linearity of calibration was in the range 0.1 - 10 ppm for both phosphate and silicate ions, and the detection limits at S/N = 3 were 2.58 ppb for silicate ions and 4.75 ppb for phosphate ions. The effectiveness of this method was demonstrated in practical applications to the water-leaching process for some ceramics glaze raw materials. PMID:16429785

  14. LINEAR ACCELERATOR

    DOEpatents

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  15. Central Exclusive Dijet Production

    SciTech Connect

    Dechambre, A.; Cudell, J. R.; Ivanov, I. P.; Hernandez, O.

    2008-08-29

    The ingredients of central exclusive production cross section include large perturbative corrections and soft quantities that must be parametrized and fitted to data. In this talk, we summarize the results of a study of the uncertainties coming from these ingredients, in the case of exclusive dijet production.

  16. Enhanced Information Exclusion Relations

    NASA Astrophysics Data System (ADS)

    Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing

    2016-07-01

    In Hall’s reformulation of the uncertainty principle, the entropic uncertainty relation occupies a core position and provides the first nontrivial bound for the information exclusion principle. Based upon recent developments on the uncertainty relation, we present new bounds for the information exclusion relation using majorization theory and combinatoric techniques, which reveal further characteristic properties of the overlap matrix between the measurements.

  17. Enhanced Information Exclusion Relations.

    PubMed

    Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing

    2016-01-01

    In Hall's reformulation of the uncertainty principle, the entropic uncertainty relation occupies a core position and provides the first nontrivial bound for the information exclusion principle. Based upon recent developments on the uncertainty relation, we present new bounds for the information exclusion relation using majorization theory and combinatoric techniques, which reveal further characteristic properties of the overlap matrix between the measurements. PMID:27460975

  18. Exclusive Reactions Involving Pions and Nucleons

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Blattnig, Steve R.; Tripathi, R. K.

    2002-01-01

    The HZETRN code requires inclusive cross sections as input. One of the methods used to calculate these cross sections requires knowledge of all exclusive processes contributing to the inclusive reaction. Conservation laws are used to determine all possible exclusive reactions involving strong interactions between pions and nucleons. Inclusive particle masses are subsequently determined and are needed in cross-section calculations for inclusive pion production.

  19. Real-time atmospheric imaging and processing with hybrid adaptive optics and hardware accelerated lucky-region fusion (LRF) algorithm

    NASA Astrophysics Data System (ADS)

    Liu, Jony Jiang; Carhart, Gary W.; Beresnev, Leonid A.; Aubailly, Mathieu; Jackson, Christopher R.; Ejzak, Garrett; Kiamilev, Fouad E.

    2014-09-01

    Atmospheric turbulences can significantly deteriorate the performance of long-range conventional imaging systems and create difficulties for target identification and recognition. Our in-house developed adaptive optics (AO) system, which contains high-performance deformable mirrors (DMs) and the fast stochastic parallel gradient decent (SPGD) control mechanism, allows effective compensation of such turbulence-induced wavefront aberrations and result in significant improvement on the image quality. In addition, we developed advanced digital synthetic imaging and processing technique, "lucky-region" fusion (LRF), to mitigate the image degradation over large field-of-view (FOV). The LRF algorithm extracts sharp regions from each image obtained from a series of short exposure frames and fuses them into a final improved image. We further implemented such algorithm into a VIRTEX-7 field programmable gate array (FPGA) and achieved real-time video processing. Experiments were performed by combining both AO and hardware implemented LRF processing technique over a near-horizontal 2.3km atmospheric propagation path. Our approach can also generate a universal real-time imaging and processing system with a general camera link input, a user controller interface, and a DVI video output.

  20. Principles of Induction Accelerators

    NASA Astrophysics Data System (ADS)

    Briggs*, Richard J.

    The basic concepts involved in induction accelerators are introduced in this chapter. The objective is to provide a foundation for the more detailed coverage of key technology elements and specific applications in the following chapters. A wide variety of induction accelerators are discussed in the following chapters, from the high current linear electron accelerator configurations that have been the main focus of the original developments, to circular configurations like the ion synchrotrons that are the subject of more recent research. The main focus in the present chapter is on the induction module containing the magnetic core that plays the role of a transformer in coupling the pulsed power from the modulator to the charged particle beam. This is the essential common element in all these induction accelerators, and an understanding of the basic processes involved in its operation is the main objective of this chapter. (See [1] for a useful and complementary presentation of the basic principles in induction linacs.)

  1. Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy Studies on Processed Tooth Graft Material by Vacuum-ultrasonic Acceleration

    PubMed Central

    Lee, Eun-Young; Kim, Eun-Suk; Kim, Kyung-Won

    2014-01-01

    Purpose: The current gold standard for clinical jawbone formation involves autogenous bone as a graft material. In addition, demineralized dentin can be an effective graft material. Although demineralized dentin readily induces heterotopic bone formation, conventional decalcification takes three to five days, so, immediate bone grafting after extraction is impossible. This study evaluated the effect of vacuum ultrasonic power on the demineralization and processing of autogenous tooth material and documented the clinical results of rapidly processed autogenous demineralized dentin (ADD) in an alveolar defects patient. Methods: The method involves the demineralization of extracted teeth with detached soft tissues and pulp in 0.6 N HCl for 90 minutes using a heat controlled vacuum-ultrasonic accelerator. The characteristics of processed teeth were evaluated by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Bone grafting using ADD was performed for narrow ridges augmentation in the mandibular area. Results: The new processing method was completed within two hours regardless of form (powder or block). EDS and SEM uniformly demineralized autotooth biomaterial. After six months, bone remodeling was observed in augmented sites and histological examination showed that ADD particles were well united with new bone. No unusual complications were encountered. Conclusion: This study demonstrates the possibility of preparing autogenous tooth graft materials within two hours, allowing immediate one-day grafting after extraction. PMID:27489819

  2. Hardware acceleration of lucky-region fusion (LRF) algorithm for high-performance real-time video processing

    NASA Astrophysics Data System (ADS)

    Browning, Tyler; Jackson, Christopher; Cayci, Furkan; Carhart, Gary W.; Liu, J. J.; Kiamilev, Fouad

    2015-06-01

    "Lucky-region" fusion (LRF) is a synthetic imaging technique that has proven successful in enhancing the quality of images distorted by atmospheric turbulence. The LRF algorithm extracts sharp regions of an image obtained from a series of short exposure frames from fast, high-resolution image sensors, and fuses the sharp regions into a final, improved image. In our previous research, the LRF algorithm had been implemented on CPU and field programmable gate array (FPGA) platforms. The CPU did not have sufficient processing power to handle real-time processing of video. Last year, we presented a real-time LRF implementation using an FPGA. However, due to the slow register-transfer level (RTL) development and simulation time, it was difficult to adjust and discover optimal LRF settings such as Gaussian kernel radius and synthetic frame buffer size. To overcome this limitation, we implemented the LRF algorithm on an off-the-shelf graphical processing unit (GPU) in order to take advantage of built-in parallelization and significantly faster development time. Our initial results show that the unoptimized GPU implementation has almost comparable turbulence mitigation to the FPGA version. In our presentation, we will explore optimization of the LRF algorithm on the GPU to achieve higher performance results, and adding new performance capabilities such as image stabilization.

  3. Accelerating the culture change!

    PubMed

    Klunk, S W; Panetta, J; Wooten, J

    1996-11-01

    Exide Electronics, a major supplier of uninterruptible power system equipment, embarked on a journey of changing a culture to improve quality, enhance customer responsiveness, and reduce costs. This case study examines the evolution of change over a period of seven years, with particular emphasis on the most recent years, 1992 through 1995. The article focuses on the Raleigh plant operations and describes how each succeeding year built on the successes and fixed the shortcomings of the prior years to accelerate the culture change, including corrective action and continuous improvement processes, organizational structures, expectations, goals, achievements, and pitfalls. The real challenge to changing the culture was structuring a dynamic approach to accelerate change! The presentation also examines how the evolutionary process itself can be created and accelerated through ongoing communication, regular feedback of progress and goals, constant evaluation and direction of the process, and measuring and paying for performance. PMID:10162360

  4. From Cleanup to Stewardship. A companion report to Accelerating Cleanup: Paths to Closure and background information to support the scoping process required for the 1998 PEIS Settlement Study

    SciTech Connect

    1999-10-01

    Long-term stewardship is expected to be needed at more than 100 DOE sites after DOE's Environmental Management program completes disposal, stabilization, and restoration operations to address waste and contamination resulting from nuclear research and nuclear weapons production conducted over the past 50 years. From Cleanup to stewardship provides background information on the Department of Energy (DOE) long-term stewardship obligations and activities. This document begins to examine the transition from cleanup to long-term stewardship, and it fulfills the Secretary's commitment to the President in the 1999 Performance Agreement to provide a companion report to the Department's Accelerating Cleanup: Paths to Closure report. It also provides background information to support the scoping process required for a study on long-term stewardship required by a 1998 Settlement Agreement.

  5. Analysis of accelerated failure process before the 1999 Mw7.1 Düzce earthquake based on near-fault seismograms

    NASA Astrophysics Data System (ADS)

    Wu, C.; Peng, Z.; Ben-Zion, Y.

    2011-12-01

    Laboratory and theoretical studies imply that accelerated local failure should occur at the transition from locked or slowly creeping fault to dynamic rupture. However, observing this process in natural tectonic setting has been illusive. Bouchon et al. (2011) found recently tantalizing evidence for accelerated local failure before the 1999 Mw7.4 Izmit event, by detecting in data of a near-fault instrument a family of small foreshocks that were buried in the noise. Here we use the recently developed match-filter technique to examine immediate foreshocks before the Mw7.1 Düzce earthquake, which occurred ~3 month after the Izmit event. We employ extensive waveform data set recorded by a 10-station fault zone array deployed a week after the Izmit mainshock. The data set contains many events recorded in close proximity to the hypocenter of the Düzce mainshock, over a time interval of ~3 months before and after the Düzce earthquake. Our preliminary match-filter analysis identified ~1600 small seismic events within ~2.5 days before the Düzce mainshock, although there are only 248 earthquakes listed in the catalog for the same time period. In the analysis done so far, such extensive seismic signals can only be identified both visually and by cross-correlation at a near-fault station FP (~20 km west the Düzce earthquake epicenter and ~400 m off the surface rupture of the Izmit earthquake). This is likely due to the fact that FP is the closest off-fault station to the Düzce earthquake epicenter, and the higher attenuation at nearby on-fault stations. The continuing studies will attempt to establish whether the detected seismic events are from the Düzce source region or generated locally near the station FP, and to perform more comprehensive search for immediate foreshocks using all the recorded data. Uncovering additional small events buried in the noise of the recorded waveforms can increase the available data significantly. This will offer unprecedented

  6. Graphics processing unit accelerated three-dimensional model for the simulation of pulsed low-temperature plasmas

    SciTech Connect

    Fierro, Andrew Dickens, James; Neuber, Andreas

    2014-12-15

    A 3-dimensional particle-in-cell/Monte Carlo collision simulation that is fully implemented on a graphics processing unit (GPU) is described and used to determine low-temperature plasma characteristics at high reduced electric field, E/n, in nitrogen gas. Details of implementation on the GPU using the NVIDIA Compute Unified Device Architecture framework are discussed with respect to efficient code execution. The software is capable of tracking around 10 × 10{sup 6} particles with dynamic weighting and a total mesh size larger than 10{sup 8} cells. Verification of the simulation is performed by comparing the electron energy distribution function and plasma transport parameters to known Boltzmann Equation (BE) solvers. Under the assumption of a uniform electric field and neglecting the build-up of positive ion space charge, the simulation agrees well with the BE solvers. The model is utilized to calculate plasma characteristics of a pulsed, parallel plate discharge. A photoionization model provides the simulation with additional electrons after the initial seeded electron density has drifted towards the anode. Comparison of the performance benefits between the GPU-implementation versus a CPU-implementation is considered, and a speed-up factor of 13 for a 3D relaxation Poisson solver is obtained. Furthermore, a factor 60 speed-up is realized for parallelization of the electron processes.

  7. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, E.J.; Wijesinghe, A.M.; Viani, B.E.

    1997-01-14

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculants and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude. 8 figs.

  8. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, Edward J.; Wijesinghe, Ananda M.; Viani, Brian E.

    1997-01-01

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculents and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude.

  9. In Vitro High-Throughput RNAi Screening to Accelerate the Process of Target Identification and Drug Development.

    PubMed

    Yin, Hongwei; Kassner, Michelle

    2016-01-01

    High-throughput RNA interference (HT-RNAi) is a powerful tool that can be used to knock down gene expression in order to identify novel genes and pathways involved in many cellular processes. It is a systematic, yet unbiased, approach to identify essential or synthetic lethal genes that promote cell survival in diseased cells as well as genes that confer resistance or sensitivity to drug treatment. This information serves as a foundation for enhancing current treatments for cancer and other diseases by identifying new drug targets, uncovering potential combination therapies, and helping clinicians match patients with the most effective treatment based on genetic information. Here, we describe the method of performing an in vitro HT-RNAi screen using chemically synthesized siRNA. PMID:27581290

  10. Acceleration Studies

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.

    1993-01-01

    Work to support the NASA MSFC Acceleration Characterization and Analysis Project (ACAP) was performed. Four tasks (analysis development, analysis research, analysis documentation, and acceleration analysis) were addressed by parallel projects. Work concentrated on preparation for and implementation of near real-time SAMS data analysis during the USMP-1 mission. User support documents and case specific software documentation and tutorials were developed. Information and results were presented to microgravity users. ACAP computer facilities need to be fully implemented and networked, data resources must be cataloged and accessible, future microgravity missions must be coordinated, and continued Orbiter characterization is necessary.

  11. Model of reversible vesicular transport with exclusion

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Karamched, Bhargav R.

    2016-08-01

    A major question in neurobiology concerns the mechanics behind the motor-driven transport and delivery of vesicles to synaptic targets along the axon of a neuron. Experimental evidence suggests that the distribution of vesicles along the axon is relatively uniform and that vesicular delivery to synapses is reversible. A recent modeling study has made explicit the crucial role that reversibility in vesicular delivery to synapses plays in achieving uniformity in vesicle distribution, so called synaptic democracy (Bressloff et al 2015 Phys. Rev. Lett. 114 168101). In this paper we generalize the previous model by accounting for exclusion effects (hard-core repulsion) that may occur between molecular motor-cargo complexes (particles) moving along the same microtubule track. The resulting model takes the form of an exclusion process with four internal states, which distinguish between motile and stationary particles, and whether or not a particle is carrying vesicles. By applying a mean field approximation and an adiabatic approximation we reduce the system of ODEs describing the evolution of occupation numbers of the sites on a 1D lattice to a system of hydrodynamic equations in the continuum limit. We find that reversibility in vesicular delivery allows for synaptic democracy even in the presence of exclusion effects, although exclusion does exacerbate nonuniform distributions of vesicles in an axon when compared with a model without exclusion. We also uncover the relationship between our model and other models of exclusion processes with internal states.

  12. k-t acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems. PMID:24809307

  13. k-t Acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs

    NASA Astrophysics Data System (ADS)

    Xiao, Dan; Balcom, Bruce J.

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

  14. Plasma accelerator

    DOEpatents

    Wang, Zhehui; Barnes, Cris W.

    2002-01-01

    There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.

  15. Accelerated Achievement

    ERIC Educational Resources Information Center

    Ford, William J.

    2010-01-01

    This article focuses on the accelerated associate degree program at Ivy Tech Community College (Indiana) in which low-income students will receive an associate degree in one year. The three-year pilot program is funded by a $2.3 million grant from the Lumina Foundation for Education in Indianapolis and a $270,000 grant from the Indiana Commission…

  16. ACCELERATION INTEGRATOR

    DOEpatents

    Pope, K.E.

    1958-01-01

    This patent relates to an improved acceleration integrator and more particularly to apparatus of this nature which is gyrostabilized. The device may be used to sense the attainment by an airborne vehicle of a predetermined velocitv or distance along a given vector path. In its broad aspects, the acceleration integrator utilizes a magnetized element rotatable driven by a synchronous motor and having a cylin drical flux gap and a restrained eddy- current drag cap deposed to move into the gap. The angular velocity imparted to the rotatable cap shaft is transmitted in a positive manner to the magnetized element through a servo feedback loop. The resultant angular velocity of tae cap is proportional to the acceleration of the housing in this manner and means may be used to measure the velocity and operate switches at a pre-set magnitude. To make the above-described dcvice sensitive to acceleration in only one direction the magnetized element forms the spinning inertia element of a free gyroscope, and the outer housing functions as a gimbal of a gyroscope.

  17. Particle acceleration

    NASA Technical Reports Server (NTRS)

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  18. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    PubMed Central

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-01-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys. PMID:27535800

  19. Acceleration of atmospheric Cherenkov telescope signal processing to real-time speed with the Auto-Pipe design system

    NASA Astrophysics Data System (ADS)

    Tyson, Eric J.; Buckley, James; Franklin, Mark A.; Chamberlain, Roger D.

    2008-10-01

    The imaging atmospheric Cherenkov technique for high-energy gamma-ray astronomy is emerging as an important new technique for studying the high energy universe. Current experiments have data rates of ≈20TB/year and duty cycles of about 10%. In the future, more sensitive experiments may produce up to 1000 TB/year. The data analysis task for these experiments requires keeping up with this data rate in close to real-time. Such data analysis is a classic example of a streaming application with very high performance requirements. This class of application often benefits greatly from the use of non-traditional approaches for computation including using special purpose hardware (FPGAs and ASICs), or sophisticated parallel processing techniques. However, designing, debugging, and deploying to these architectures is difficult and thus they are not widely used by the astrophysics community. This paper presents the Auto-Pipe design toolset that has been developed to address many of the difficulties in taking advantage of complex streaming computer architectures for such applications. Auto-Pipe incorporates a high-level coordination language, functional and performance simulation tools, and the ability to deploy applications to sophisticated architectures. Using the Auto-Pipe toolset, we have implemented the front-end portion of an imaging Cherenkov data analysis application, suitable for real-time or offline analysis. The application operates on data from the VERITAS experiment, and shows how Auto-Pipe can greatly ease performance optimization and application deployment of a wide variety of platforms. We demonstrate a performance improvement over a traditional software approach of 32x using an FPGA solution and 3.6x using a multiprocessor based solution.

  20. Structural, dynamic, and electrostatic properties of fully hydrated DMPC bilayers from molecular dynamics simulations accelerated with graphical processing units (GPUs).

    PubMed

    Ganesan, Narayan; Bauer, Brad A; Lucas, Timothy R; Patel, Sandeep; Taufer, Michela

    2011-11-15

    We present results of molecular dynamics simulations of fully hydrated DMPC bilayers performed on graphics processing units (GPUs) using current state-of-the-art non-polarizable force fields and a local GPU-enabled molecular dynamics code named FEN ZI. We treat the conditionally convergent electrostatic interaction energy exactly using the particle mesh Ewald method (PME) for solution of Poisson's Equation for the electrostatic potential under periodic boundary conditions. We discuss elements of our implementation of the PME algorithm on GPUs as well as pertinent performance issues. We proceed to show results of simulations of extended lipid bilayer systems using our program, FEN ZI. We performed simulations of DMPC bilayer systems consisting of 17,004, 68,484, and 273,936 atoms in explicit solvent. We present bilayer structural properties (atomic number densities, electron density profiles), deuterium order parameters (S(CD)), electrostatic properties (dipole potential, water dipole moments), and orientational properties of water. Predicted properties demonstrate excellent agreement with experiment and previous all-atom molecular dynamics simulations. We observe no statistically significant differences in calculated structural or electrostatic properties for different system sizes, suggesting the small bilayer simulations (less than 100 lipid molecules) provide equivalent representation of structural and electrostatic properties associated with significantly larger systems (over 1000 lipid molecules). We stress that the three system size representations will have differences in other properties such as surface capillary wave dynamics or surface tension related effects that are not probed in the current study. The latter properties are inherently dependent on system size. This contribution suggests the suitability of applying emerging GPU technologies to studies of an important class of biological environments, that of lipid bilayers and their associated integral

  1. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance.

    PubMed

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-01-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys. PMID:27535800

  2. Size exclusion chromatography to gain insight into the complex formation of carrot pectin methylesterase and its inhibitor from kiwi fruit as influenced by thermal and high-pressure processing.

    PubMed

    Jolie, Ruben P; Duvetter, Thomas; Verlinde, Philippe H C J; Van Buggenhout, Sandy; Van Loey, Ann M; Hendrickx, Marc E

    2009-12-01

    A size exclusion chromatography (HPSEC) method was implemented to study complex formation between carrot pectin methylesterase (PME) and its inhibitor (PMEI) from kiwi fruit in the context of traditional thermal and novel high-pressure processing. Evidence was gained that both thermal and high-pressure treatments of PME give rise to two distinct enzyme subpopulations: a catalytically active population, eluting from the size exclusion column, and an inactive population, aggregated and excluded from the column. When mixing a partly denatured PME sample with a fixed amount of PMEI, a PME-PMEI complex peak was observed on HPSEC, of which the peak area was highly correlated with the residual enzyme activity of the corresponding PME sample. This observation indicates complex formation to be restricted to the active PME fraction. When an equimolar mixture of PME and PMEI was subjected to either a thermal or a high-pressure treatment, marked differences were observed. At elevated temperature, enzyme and inhibitor remained united and aggregated as a whole, thus gradually disappearing from the elution profile. Conversely, elevated pressure caused the dissociation of the PME-PMEI complexes, followed by a separate action of pressure on enzyme and inhibitor. Remarkably, PMEI appeared to be pressure-resistant when compressed at acidic pH (ca. 4). PMID:19908835

  3. Enhanced Information Exclusion Relations

    PubMed Central

    Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing

    2016-01-01

    In Hall’s reformulation of the uncertainty principle, the entropic uncertainty relation occupies a core position and provides the first nontrivial bound for the information exclusion principle. Based upon recent developments on the uncertainty relation, we present new bounds for the information exclusion relation using majorization theory and combinatoric techniques, which reveal further characteristic properties of the overlap matrix between the measurements. PMID:27460975

  4. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M.; Sampayan, Stephen; Slenes, Kirk; Stoller, H. M.

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  5. High energy plasma accelerators

    SciTech Connect

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ..omega../sub 0/, kappa/sub 0/ and ..omega../sub 1/, kappa/sub 1/ shone on a plasma with frequency separation equal to the electron plasma frequency ..omega../sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ..omega../sub pe//e of the order of 1GeV/cm for a plasma density of 10/sup 18/ cm/sup -3/ through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed.

  6. Resuspension and redistribution of radionuclides during grassland and forest fires in the Chernobyl exclusion zone: part II. Modeling the transport process.

    PubMed

    Yoschenko, V I; Kashparov, V A; Levchuk, S E; Glukhovskiy, A S; Khomutinin, Yu V; Protsak, V P; Lundin, S M; Tschiersch, J

    2006-01-01

    To predict parameters of radionuclide resuspension, transport and deposition during forest and grassland fires, several model modules were developed and adapted. Experimental data of controlled burning of prepared experimental plots in the Chernobyl exclusion zone have been used to evaluate the prognostic power of the models. The predicted trajectories and elevations of the plume match with those visually observed during the fire experiments in the grassland and forest sites. Experimentally determined parameters could be successfully used for the calculation of the initial plume parameters which provide the tools for the description of various fire scenarios and enable prognostic calculations. In summary, the model predicts a release of some per thousand from the radionuclide inventory of the fuel material by the grassland fires. During the forest fire, up to 4% of (137)Cs and (90)Sr and up to 1% of the Pu isotopes can be released from the forest litter according to the model calculations. However, these results depend on the parameters of the fire events. In general, the modeling results are in good accordance with the experimental data. Therefore, the considered models were successfully validated and can be recommended for the assessment of the resuspension and redistribution of radionuclides during grassland and forest fires in contaminated territories. PMID:16476511

  7. FPGA Verification Accelerator (FVAX)

    NASA Technical Reports Server (NTRS)

    Oh, Jane; Burke, Gary

    2008-01-01

    Is Verification Acceleration Possible? - Increasing the visibility of the internal nodes of the FPGA results in much faster debug time - Forcing internal signals directly allows a problem condition to be setup very quickly center dot Is this all? - No, this is part of a comprehensive effort to improve the JPL FPGA design and V&V process.

  8. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  9. BICEP's acceleration

    SciTech Connect

    Contaldi, Carlo R.

    2014-10-01

    The recent Bicep2 [1] detection of, what is claimed to be primordial B-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential V(φ) for the first time — if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles ε(N) as a function of e-fold N and derived posterior distributions of the primordial power spectrum P(k) and potential V(φ). We find that the Bicep2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales k∼ 10{sup -3} Mpc {sup -1}. This is in agreement with a previous detection of a suppression in the scalar power [2].

  10. Interfacing to accelerator instrumentation

    SciTech Connect

    Shea, T.J.

    1995-12-31

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed.

  11. Accelerated molecular dynamics methods

    SciTech Connect

    Perez, Danny

    2011-01-04

    The molecular dynamics method, although extremely powerful for materials simulations, is limited to times scales of roughly one microsecond or less. On longer time scales, dynamical evolution typically consists of infrequent events, which are usually activated processes. This course is focused on understanding infrequent-event dynamics, on methods for characterizing infrequent-event mechanisms and rate constants, and on methods for simulating long time scales in infrequent-event systems, emphasizing the recently developed accelerated molecular dynamics methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics). Some familiarity with basic statistical mechanics and molecular dynamics methods will be assumed.

  12. Exclusive process [sup 2]H([ital e],[ital e][prime][ital p])[ital N][sup *] as a tool for investigation of the quark structure of the deuteron

    SciTech Connect

    Glozman, L.Y. ); Neudatchin, V.G.; Obukhovsky, I.T. )

    1993-07-01

    The exclusive [sup 2]H([ital e],[ital e][prime][ital p])[ital N][sup *] process at CEBAF energies, with the missing mass coincidence technique, offers the opportunity to reveal the baryon-baryon (BB) composition of the deuteron and to reconstruct the deuteron six-quark wave function. As an example, we project out two different kinds of currently discussed six-quark functions into various BB channels including such baryons as [ital n], [ital p], [Delta], [ital N](1440), [ital N](1520), and [ital N](1535). Spectroscopic factors and momentum distributions are calculated using the nonrelativistic quark model. The results are that the [Delta][Delta] component in the deuteron is almost entirely connected with the six-quark configuration [ital s][sup 6] while the channels with [ital N](1440), [ital N](1520), and [ital N](1535) display the configuration [ital s][sup 4][ital p2].

  13. Accelerators for research and applications

    SciTech Connect

    Alonso, J.R.

    1990-06-01

    The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

  14. Accelerated oxidation processes is biodiesel

    SciTech Connect

    Canakci, M.; Monyem, A.; Van Gerpen, J.

    1999-12-01

    Biodiesel is an alternative fuel for diesel engines that can be produced from renewable feedstocks such as vegetable oil and animal fats. These feedstocks are reacted with an alcohol to produce alkyl monoesters that can be used in conventional diesel engines with little or no modification. Biodiesel, especially if produced from highly unsaturated oils, oxidizes more rapidly than diesel fuel. This article reports the results of experiments to track the chemical and physical changes that occur in biodiesel as it oxidizes. These results show the impact of time, oxygen flow rate, temperature, metals, and feedstock type on the rate of oxidation. Blending with diesel fuel and the addition of antioxidants are explored also. The data indicate that without antioxidants, biodiesel will oxidize very quickly at temperatures typical of diesel engines. This oxidation results in increases in peroxide value, acid value, and viscosity. While the peroxide value generally reaches a plateau of about 350 meq/kg ester, the acid value and viscosity increase monotonically as oxidation proceeds.

  15. Accelerated image processing on FPGAs.

    PubMed

    Draper, Bruce A; Beveridge, J Ross; Böhm, A P Willem; Ross, Charles; Chawathe, Monica

    2003-01-01

    The Cameron project has developed a language called single assignment C (SA-C), and a compiler for mapping image-based applications written in SA-C to field programmable gate arrays (FPGAs). The paper tests this technology by implementing several applications in SA-C and compiling them to an Annapolis Microsystems (AMS) WildStar board with a Xilinx XV2000E FPGA. The performance of these applications on the FPGA is compared to the performance of the same applications written in assembly code or C for an 800 MHz Pentium III. (Although no comparison across processors is perfect, these chips were the first of their respective classes fabricated at 0.18 microns, and are therefore of comparable ages.) We find that applications written in SA-C and compiled to FPGAs are between 8 and 800 times faster than the equivalent program run on the Pentium III. PMID:18244709

  16. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  17. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  18. Magnetic Insulation for Electrostatic Accelerators

    SciTech Connect

    Grisham, L. R.

    2011-09-26

    The voltage gradient which can be sustained between electrodes without electrical breakdowns is usually one of the most important parameters in determining the performance which can be obtained in an electrostatic accelerator. We have recently proposed a technique which might permit reliable operation of electrostatic accelerators at higher electric field gradients, perhaps also with less time required for the conditioning process in such accelerators. The idea is to run an electric current through each accelerator stage so as to produce a magnetic field which envelopes each electrode and its electrically conducting support structures. Having the magnetic field everywhere parallel to the conducting surfaces in the accelerator should impede the emission of electrons, and inhibit their ability to acquire energy from the electric field, thus reducing the chance that local electron emission will initiate an arc. A relatively simple experiment to assess this technique is being planned. If successful, this technique might eventually find applicability in electrostatic accelerators for fusion and other applications.

  19. Laser acceleration and its future.

    PubMed

    Tajima, Toshiki

    2010-01-01

    Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators. PMID:20228616

  20. Laser acceleration and its future

    PubMed Central

    Tajima, Toshiki

    2010-01-01

    Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators. PMID:20228616

  1. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  2. Advanced accelerator theory development

    SciTech Connect

    Sampayan, S.E.; Houck, T.L.; Poole, B.; Tishchenko, N.; Vitello, P.A.; Wang, I.

    1998-02-09

    A new accelerator technology, the dielectric wall accelerator (DWA), is potentially an ultra compact accelerator/pulsed power driver. This new accelerator relies on three new components: the ultra-high gradient insulator, the asymmetric Blumlein and low jitter switches. In this report, we focused our attention on the first two components of the DWA system the insulators and the asymmetric Blumlein. First, we sought to develop the necessary design tools to model and scale the behavior of the high gradient insulator. To perform this task we concentrated on modeling the discharge processes (i.e., initiation and creation of the surface discharge). In addition, because these high gradient structures exhibit favorable microwave properties in certain accelerator configurations, we performed experiments and calculations to determine the relevant electromagnetic properties. Second, we performed circuit modeling to understand energy coupling to dynamic loads by the asymmetric Blumlein. Further, we have experimentally observed a non-linear coupling effect in certain asymmetric Blumlein configurations. That is, as these structures are stacked into a complete module, the output voltage does not sum linearly and a lower than expected output voltage results. Although we solved this effect experimentally, we performed calculations to understand this effect more fully to allow better optimization of this DWA pulse-forming line system.

  3. Accelerating electrostatic interaction calculations with graphical processing units based on new developments of Ewald method using non-uniform fast Fourier transform.

    PubMed

    Yang, Sheng-Chun; Wang, Yong-Lei; Jiao, Gui-Sheng; Qian, Hu-Jun; Lu, Zhong-Yuan

    2016-01-30

    We present new algorithms to improve the performance of ENUF method (F. Hedman, A. Laaksonen, Chem. Phys. Lett. 425, 2006, 142) which is essentially Ewald summation using Non-Uniform FFT (NFFT) technique. A NearDistance algorithm is developed to extensively reduce the neighbor list size in real-space computation. In reciprocal-space computation, a new algorithm is developed for NFFT for the evaluations of electrostatic interaction energies and forces. Both real-space and reciprocal-space computations are further accelerated by using graphical processing units (GPU) with CUDA technology. Especially, the use of CUNFFT (NFFT based on CUDA) very much reduces the reciprocal-space computation. In order to reach the best performance of this method, we propose a procedure for the selection of optimal parameters with controlled accuracies. With the choice of suitable parameters, we show that our method is a good alternative to the standard Ewald method with the same computational precision but a dramatically higher computational efficiency. PMID:26584145

  4. Quasi-steady plasma acceleration.

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Von Jaskowsky, W. F.; Clark, K. E.

    1973-01-01

    A coaxial plasma accelerator driven by protracted pulses of current in the range of 10,000 to 100,000 A and synchronized mass flows from 1.0 to 36 g/sec argon attains, after some tens of microseconds, a stable magnetoplasmadynamic acceleration mode. This 'quasi-steady' discharge form is characterized by constant terminal voltage and current, a diffuse, fixed current distribution within the discharge, and a steady plasma efflux at velocities of approximately 20 km/sec. Measured potential distributions reveal that the bulk of the arc voltage gradient, exclusive of the electrode falls, occurs within two diameters of the cathode, and is normal to it. The anode fall voltage varies inversely with local current density, implying substantially lower anode losses at higher power arc operation. Spectroscopic, potential, and velocity measurements indicate the existence of a characteristic mass flow rate for a given current, below which arc operation becomes erratic.

  5. Increase in presenilin 1 (PS1) levels in senescence-accelerated mice (SAMP8) may indirectly impair memory by affecting amyloid precursor protein (APP) processing.

    PubMed

    Kumar, Vijaya B; Franko, Mark; Banks, William A; Kasinadhuni, Pranav; Farr, Susan A; Vyas, Kamlesh; Choudhuri, Veena; Morley, John E

    2009-02-01

    Senescence-accelerated mice (SAMP8) serve as a model for Alzheimer's disease (AD) as they exhibit early loss of memory and increased amyloid precursor protein (APP) expression. APP is a ubiquitous membrane protein that is physiologically processed by site-specific proteolysis firstly by alpha- or beta-secretases, releasing a large fragment called APP(S) that contains most of the extracellular sequences of APP, a small extracellular stub, the transmembrane region and the cytoplasmic tail of APP (;AICD'-APP intracellular domain). These are subsequently cleaved by gamma-secretase at multiple sites in the transmembrane region, releasing small peptides, Abeta(1-40) and Abeta(1-42), the major components of AD-associated amyloid fibrils. gamma-secretase is a high-molecular-mass complex composed of presenilin-1 (PS1), nicastrin, APH-1 and Pen-2. As PS1 has been shown to play a critical role in facilitating gamma-secretase activity, and mutations in this protein are associated with familial AD (FAD), we have cloned it from SAMP8 mouse hippocampus and compared its sequence with those of other species. Furthermore, changes in the expression of PS1 with age in the hippocampal tissue of SAMP8 were studied. The results showed that the SAMP8 PS1 cDNA sequence is identical to that of normal mice. However, its expression in the hippocampus of SAMP8 exhibited an increase, while CD-1 mice, a strain that does not exhibit premature memory loss, showed no change with age. An increased amount or mutation(s) in PS1, which alters the stoichiometric balance of the gamma-secretase complex, may be the cause of aberrant or increased processing of APP, resulting in Abeta accumulation leading to loss of memory. PMID:19181896

  6. Long-term variation of the polar wind velocity and its implication for the ion acceleration process: Akebono/suprathermal ion mass spectrometer observations

    NASA Astrophysics Data System (ADS)

    Abe, Takumi; Yau, Andrew W.; Watanabe, Shigeto; Yamada, Manabu; Sagawa, Eiichi

    2004-09-01

    We present the solar activity dependence and seasonal variation of H+ and O+ polar wind velocity profiles observed by the suprathermal ion mass spectrometer (SMS) on Akebono. These observations spanned a solar cycle and covered a wide range of altitudes and invariant latitudes (ILAT) in the polar ionosphere and a variety of geomagnetic activity conditions from 1500 km to 8500 km altitude and from the poleward edge of the ionospheric trough (˜60° ILAT) to the polar cap (>85° ILAT). At low (high) altitudes below (above) 4000 km, the increase of the averaged H+ and O+ ion velocities with altitude was larger (smaller) at solar minimum than at solar maximum. For example, the averaged H+ velocity on the dayside at 4000 km altitude was approximately 8 km s-1 at low solar activity but ˜5 km s-1 at high activity. This suggests that the averaged polar wind velocity correlates differently with solar activity and the dominant acceleration process may be different at low and high altitudes, respectively. For both H+ and O+ the observed ion velocity at high altitude was largest in the summer under essentially all magnetic and solar activity conditions. The O+ velocity at high altitude (>4000 km) was significant and largest in the summer at solar maximum, when the solar energy input into the polar cap was largest; theoretically, the velocity of O+ ions in the polar wind is expected to be negligible below 10,000 km. We consider geophysical processes that may contribute to the observed velocities and their solar activity and seasonal dependences, including the possible contributions of photoelectrons and elevated electron temperatures to the ambipolar electric field that drives the polar wind.

  7. Monolithic Composite “Pressure + Acceleration + Temperature + Infrared” Sensor Using a Versatile Single-Sided “SiN/Poly-Si/Al” Process-Module

    PubMed Central

    Ni, Zao; Yang, Chen; Xu, Dehui; Zhou, Hong; Zhou, Wei; Li, Tie; Xiong, Bin; Li, Xinxin

    2013-01-01

    We report a newly developed design/fabrication module with low-cost single-sided “low-stress-silicon-nitride (LS-SiN)/polysilicon (poly-Si)/Al” process for monolithic integration of composite sensors for sensing-network-node applications. A front-side surface-/bulk-micromachining process on a conventional Si-substrate is developed, featuring a multifunctional SiN/poly-Si/Al layer design for diverse sensing functions. The first “pressure + acceleration + temperature + infrared” (PATIR) composite sensor with the chip size of 2.5 mm × 2.5 mm is demonstrated. Systematic theoretical design and analysis methods are developed. The diverse sensing components include a piezoresistive absolute-pressure sensor (up to 700 kPa, with a sensitivity of 49 mV/MPa under 3.3 V supplied voltage), a piezoresistive accelerometer (±10 g, with a sensitivity of 66 μV/g under 3.3 V and a −3 dB bandwidth of 780 Hz), a thermoelectric infrared detector (with a responsivity of 45 V/W and detectivity of 3.6 × 107 cm·Hz1/2/W) and a thermistor (−25–120 °C). This design/fabrication module concept enables a low-cost monolithically-integrated “multifunctional-library” technique. It can be utilized as a customizable tool for versatile application-specific requirements, which is very useful for small-size, low-cost, large-scale sensing-network node developments. PMID:23325169

  8. 43 CFR 46.215 - Categorical exclusions: Extraordinary circumstances.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Categorical exclusions: Extraordinary circumstances. 46.215 Section 46.215 Public Lands: Interior Office of the Secretary of the Interior IMPLEMENTATION OF THE NATIONAL ENVIRONMENTAL POLICY ACT OF 1969 Initiating the NEPA Process § 46.215 Categorical exclusions: Extraordinary...

  9. 43 CFR 46.210 - Listing of Departmental categorical exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Listing of Departmental categorical exclusions. 46.210 Section 46.210 Public Lands: Interior Office of the Secretary of the Interior IMPLEMENTATION OF THE NATIONAL ENVIRONMENTAL POLICY ACT OF 1969 Initiating the NEPA Process § 46.210 Listing of Departmental categorical exclusions....

  10. 43 CFR 46.215 - Categorical exclusions: Extraordinary circumstances.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Categorical exclusions: Extraordinary circumstances. 46.215 Section 46.215 Public Lands: Interior Office of the Secretary of the Interior IMPLEMENTATION OF THE NATIONAL ENVIRONMENTAL POLICY ACT OF 1969 Initiating the NEPA Process § 46.215 Categorical exclusions: Extraordinary...

  11. 43 CFR 46.215 - Categorical exclusions: Extraordinary circumstances.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Categorical exclusions: Extraordinary circumstances. 46.215 Section 46.215 Public Lands: Interior Office of the Secretary of the Interior IMPLEMENTATION OF THE NATIONAL ENVIRONMENTAL POLICY ACT OF 1969 Initiating the NEPA Process § 46.215 Categorical exclusions: Extraordinary...

  12. Contrasting Stories of Inclusion/Exclusion in the Chemistry Classroom

    ERIC Educational Resources Information Center

    Gomes, Maria de Fatima Cardoso; Mortimer, Eduardo F.; Kelly, Gregory J.

    2011-01-01

    This article reports on the construction process of inclusion/exclusion for high school chemistry students in two schools in Belo Horizonte, the capital of Minas Gerais State, Brazil. We examined the interactional accomplishment of inclusion/exclusion of four students, two from a private school and two from a public school. The aim of this article…

  13. Tests of quantum chromodynamics in exclusive and inclusive electroproduction

    SciTech Connect

    Brodsky, S.J.

    1989-06-01

    This paper discusses the following topics: overview of electroproduction phenomenology; hadronization of the quark and spectator systems; hadronization in nuclei; shadowing and anti- shadowing; color transparency; exclusive channels in electroproduction; hadronic wavefunction phenomenology; diffractive electroproduction; exclusive nuclear processes in QCD; and relation of electroproduction to QCD wavefunctions. 58 refs., 22 figs. (LSP)

  14. Pulsed electromagnetic gas acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1974-01-01

    Detailed measurements of the axial velocity profile and electromagnetic structure of a high power, quasi-steady MPD discharge are used to formulate a gasdynamic model of the acceleration process. Conceptually dividing the accelerated plasma into an inner flow and an outer flow, it is found that more than two-thirds of the total power in the plasma is deposited in the inner flow, accelerating it to an exhaust velocity of 12.5 km/sec. The outer flow, which is accelerated to a velocity of only 6.2 km/sec, appears to provide a current conduction path between the inner flow and the anode. Related cathode studies have shown that the critical current for the onset of terminal voltage fluctuations, which was recently shown to be a function of the cathode area, appears to reach an asymptote for cathodes of very large surface area. Detailed floating potential measurements show that the fluctuations are confined to the vicinity of the cathode and hence reflect a cathode emission process rather than a fundamental limit on MPD performance.

  15. Diffusive Shock Acceleration

    NASA Astrophysics Data System (ADS)

    Baring, Matthew

    2003-04-01

    The process of diffusive acceleration of charged particles in shocked plasmas is widely invoked in astrophysics to account for the ubiquitous presence of signatures of non-thermal relativistic electrons and ions in the universe. This statistical energization mechanism, manifested in turbulent media, was first posited by Enrico Fermi in 1949 to explain the observed cosmic ray population, which exhibits an almost power-law distribution in rigidity. The absence of a momentum scale is a key characteristic of diffusive shock acceleration, and astrophysical systems generally only impose scales at the injection (low energy) and loss (high energy) ends of the particle spectrum. The existence of structure in the cosmic ray spectrum (the "knee") at around 3000 TeV has promoted contentions that there are at least two origins for cosmic rays, a galactic one supplying those up to the knee, and perhaps an extragalactic one that can explain even the ultra-high energy cosmic rays (UHECRs) seen at 1-300 EeV. Accounting for the UHECRs with familiar astrophysical sites of acceleration has historically proven difficult due to the need to assume high magnetic fields in order to reduce the shortest diffusive acceleration timescale, the ion gyroperiod, to meaningful values. Yet active galaxies and gamma-ray bursts remain strong and interesting candidate sources for UHECRs, turning the theoretical focus to relativistic shocks. This review summarizes properties of diffusive shock acceleration that are salient to the issue of UHECR generation. These include spectral indices, anisotropies, acceleration efficencies and timescales, as functions of the shock speed and mean field orientation, and also the degree of field turbulence. Astrophysical sites for UHECR production are also critiqued.

  16. Inclusive and Exclusive |Vub|

    SciTech Connect

    Petrella, Antonio; /Ferrara U. /INFN, Ferrara

    2011-11-17

    The current status of the determinations of CKM matrix element |V{sub ub}| via exclusive and inclusive charmless semileptonic B decays is reviewed. The large datasets collected at the B-Factories, and the increased precision of theoretical calculations have allowed an improvement in the determination of |V{sub ub}|. However, there are still significant uncertainties. In the exclusive approach, the most precise measurement of the pion channel branching ratio is obtained by an untagged analysis. This very good precision can be reached by tagged analyses with more data. The problem with exclusive decays is that the strong hadron dynamics can not be calculated from first principles and the determination of the form factor has to rely on light-cone sum rules or lattice QCD calculations. The current data samples allow a comparison of different FF models with data distributions. With further developments on lattice calculations, the theoretical error should shrink to reach the experimental one. The inclusive approach still provides the most precise |V{sub ub}| determinations. With new theoretical calculations, the mild (2.5{sigma}) discrepancy with respect to the |V{sub ub}| value determined from the global UT fit has been reduced. As in the exclusive approach, theoretical uncertainties represent the limiting factor to the precision of the measurement. Reducing the theoretical uncertainties to a level comparable with the statistical error is challenging. New measurements in semileptonic decays of charm mesons could increase the confidence in theoretical calculations and related uncertainties.

  17. Mutually Exclusive, Complementary, or . . .

    ERIC Educational Resources Information Center

    Schloemer, Cathy G.

    2016-01-01

    Whether students are beginning their study of probability or are well into it, distinctions between complementary sets and mutually exclusive sets can be confusing. Cathy Schloemer writes in this article that for years she used typical classroom examples but was not happy with the student engagement or the level of understanding they produced.…

  18. 24 CFR 58.35 - Categorical exclusions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Categorical exclusions. 58.35 Section 58.35 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL RESPONSIBILITIES Environmental Review Process: Documentation, Range...

  19. 24 CFR 58.35 - Categorical exclusions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Categorical exclusions. 58.35 Section 58.35 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL RESPONSIBILITIES Environmental Review Process: Documentation, Range...

  20. 24 CFR 58.35 - Categorical exclusions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Categorical exclusions. 58.35 Section 58.35 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL RESPONSIBILITIES Environmental Review Process: Documentation, Range...

  1. Accelerator system and method of accelerating particles

    NASA Technical Reports Server (NTRS)

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  2. Modelling multi-phase liquid-sediment scour and resuspension induced by rapid flows using Smoothed Particle Hydrodynamics (SPH) accelerated with a Graphics Processing Unit (GPU)

    NASA Astrophysics Data System (ADS)

    Fourtakas, G.; Rogers, B. D.

    2016-06-01

    A two-phase numerical model using Smoothed Particle Hydrodynamics (SPH) is applied to two-phase liquid-sediments flows. The absence of a mesh in SPH is ideal for interfacial and highly non-linear flows with changing fragmentation of the interface, mixing and resuspension. The rheology of sediment induced under rapid flows undergoes several states which are only partially described by previous research in SPH. This paper attempts to bridge the gap between the geotechnics, non-Newtonian and Newtonian flows by proposing a model that combines the yielding, shear and suspension layer which are needed to predict accurately the global erosion phenomena, from a hydrodynamics prospective. The numerical SPH scheme is based on the explicit treatment of both phases using Newtonian and the non-Newtonian Bingham-type Herschel-Bulkley-Papanastasiou constitutive model. This is supplemented by the Drucker-Prager yield criterion to predict the onset of yielding of the sediment surface and a concentration suspension model. The multi-phase model has been compared with experimental and 2-D reference numerical models for scour following a dry-bed dam break yielding satisfactory results and improvements over well-known SPH multi-phase models. With 3-D simulations requiring a large number of particles, the code is accelerated with a graphics processing unit (GPU) in the open-source DualSPHysics code. The implementation and optimisation of the code achieved a speed up of x58 over an optimised single thread serial code. A 3-D dam break over a non-cohesive erodible bed simulation with over 4 million particles yields close agreement with experimental scour and water surface profiles.

  3. Nodes and biological processes identified on the basis of network analysis in the brain of the senescence accelerated mice as an Alzheimer's disease animal model

    PubMed Central

    Cheng, Xiao-rui; Cui, Xiu-liang; Zheng, Yue; Zhang, Gui-rong; Li, Peng; Huang, Huang; Zhao, Yue-ying; Bo, Xiao-chen; Wang, Sheng-qi; Zhou, Wen-xia; Zhang, Yong-xiang

    2013-01-01

    Harboring the behavioral and histopathological signatures of Alzheimer's disease (AD), senescence accelerated mouse-prone 8 (SAMP8) mice are currently considered a robust model for studying AD. However, the underlying mechanisms, prioritized pathways and genes in SAMP8 mice linked to AD remain unclear. In this study, we provide a biological interpretation of the molecular underpinnings of SAMP8 mice. Our results were derived from differentially expressed genes in the hippocampus and cerebral cortex of SAMP8 mice compared to age-matched SAMR1 mice at 2, 6, and 12 months of age using cDNA microarray analysis. On the basis of PPI, MetaCore and the co-expression network, we constructed a distinct genetic sub-network in the brains of SAMP8 mice. Next, we determined that the regulation of synaptic transmission and apoptosis were disrupted in the brains of SAMP8 mice. We found abnormal gene expression of RAF1, MAPT, PTGS2, CDKN2A, CAMK2A, NTRK2, AGER, ADRBK1, MCM3AP, and STUB1, which may have initiated the dysfunction of biological processes in the brains of SAMP8 mice. Specifically, we found microRNAs, including miR-20a, miR-17, miR-34a, miR-155, miR-18a, miR-22, miR-26a, miR-101, miR-106b, and miR-125b, that might regulate the expression of nodes in the sub-network. Taken together, these results provide new insights into the biological and genetic mechanisms of SAMP8 mice and add an important dimension to our understanding of the neuro-pathogenesis in SAMP8 mice from a systems perspective. PMID:24194717

  4. Attention's Accelerator.

    PubMed

    Reinhart, Robert M G; McClenahan, Laura J; Woodman, Geoffrey F

    2016-06-01

    How do people get attention to operate at peak efficiency in high-pressure situations? We tested the hypothesis that the general mechanism that allows this is the maintenance of multiple target representations in working and long-term memory. We recorded subjects' event-related potentials (ERPs) indexing the working memory and long-term memory representations used to control attention while performing visual search. We found that subjects used both types of memories to control attention when they performed the visual search task with a large reward at stake, or when they were cued to respond as fast as possible. However, under normal circumstances, one type of target memory was sufficient for slower task performance. The use of multiple types of memory representations appears to provide converging top-down control of attention, allowing people to step on the attentional accelerator in a variety of high-pressure situations. PMID:27056975

  5. "She Didn't Ask Me about My Grandma": Using Process Drama to Explore Issues of Cultural Exclusion and Educational Leadership

    ERIC Educational Resources Information Center

    Kana, Pare; Aitken, Viv

    2007-01-01

    Purpose: This purpose of this paper is to describe a collaborative project from the University of Waikato, Hamilton New Zealand, in which the authors used process drama to engage final year teaching students with complex issues of cultural diversity, enabling them to "grow into" different kinds of leadership positions in an imagined educational…

  6. The Mechanisms of Interpersonal Privacy in Social Networking Websites: A Study of Subconscious Processes, Social Network Analysis, and Fear of Social Exclusion

    ERIC Educational Resources Information Center

    Hammer, Bryan

    2013-01-01

    With increasing usage of social networking sites like Facebook there is a need to study privacy. Previous research has placed more emphasis on outcome-oriented contexts, such as e-commerce sites. In process-oriented contexts, like Facebook, privacy has become a source of conflict for users. The majority of architectural privacy (e.g. privacy…

  7. Stochastic acceleration of solar protons in the transrelativistic region

    NASA Astrophysics Data System (ADS)

    Steinacker, J.; Schlickeiser, R.

    1989-10-01

    A model for the stochastic proton acceleration in solar flares with solutions valid for all energies is presented. A comparison with measured proton spectra supplies excellent agreement for shock dominated events and deviations in the nonrelativistic range for spectra of curved shape in contradiction to the conclusions of McGuire and v. Rosenvinge 1984, who used exclusively the non- and ultrarelativistic approximation. The deviations are discussed in detail with regard to a more accurate consideration of the spatial conditions. In the case of a constant escape time we obtain a theoretical spectrum that can be used for calculating the gamma ray radiation with energies greater than 10 MeV, reproducing the data in the transrelativistic region, where the relevant cross sections of the radiation producing processes are maximal.

  8. Central exclusive production at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek

    2014-11-01

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment's Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at √ {s} = 200 GeV. The preliminary spectra of two-pion mass reconstructed by STAR TPC in central region of pseudorapidity |η| < 1, are presented. Near future plans to take data with the current system at center-of-mass energy √ {s} = 200 GeV and plans to upgrade the forward proton tagging system are presented. Also a possible addition of the RPs to the sPHENIX detector is discussed.

  9. Central exclusive production at RHIC

    SciTech Connect

    Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity | | < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.

  10. GPU accelerated dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Ferroni, Francesco; Tarleton, Edmund; Fitzgerald, Steven

    2014-09-01

    In this paper we analyze the computational bottlenecks in discrete dislocation dynamics modeling (associated with segment-segment interactions as well as the treatment of free surfaces), discuss the parallelization and optimization strategies, and demonstrate the effectiveness of Graphical Processing Unit (GPU) computation in accelerating dislocation dynamics simulations and expanding their scope. Individual algorithmic benchmark tests as well as an example large simulation of a thin film are presented.

  11. Hugoniot analysis of the ram accelerator

    NASA Astrophysics Data System (ADS)

    Knowlen, C.; Bruckner, A. P.

    The thermodynamic properties of a combustible propellant gas, after it has been processed by a ram accelerator propulsive mode, are related by a 'ram accelerator Hugoniot' expression. These end states are determined from the 1-D conservation equations in a manner similar to that used for detonation waves, but with the addition of a force term in the momentum equation. Establishment of a region of potentially accessible thermodynamic end states that are consistent with ram accelerator operation at and above the Chapman-Jouguet detonation speed indicates that there are no fundamental constraints on accelerating projectiles over a wide range of Mach numbers in a single propellant mixture. Interpreting experimental data in the context of a generalized ram accelerator process leads to relatively simple propulsive models which can predict the projectile acceleration of any propulsive mode. The projectile velocity and acceleration histories determined by the Hugoniot analysis for the thermally choked ram accelerator mode are in excellent agreement with experiments.

  12. Observations of particle acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.

    1979-01-01

    Solar flares provide several examples of nonthermal particle acceleration. The paper reviews the information gained about these processes via X-ray and gamma-ray astronomy, which can presently distinguish among three separate particle-acceleration processes at the sun: an impulsive accelerator of more than 20 keV electrons, a gradual accelerator of more than 20 keV electrons, and a gradual accelerator of more than 10 MeV ions. The acceleration energy efficiency (total particle energy divided by total flare energy) of any of these mechanisms cannot be less than about 0.1%, although the gradual acceleration does not occur in every flare. The observational material suggests that both the impulsive and gradual accelerations take place preferentially in closed magnetic-field structures, but that the electrons decay in these traps before they can escape. The ions escape very efficiently.

  13. Robust Visual Tracking via Exclusive Context Modeling.

    PubMed

    Zhang, Tianzhu; Ghanem, Bernard; Liu, Si; Xu, Changsheng; Ahuja, Narendra

    2016-01-01

    In this paper, we formulate particle filter-based object tracking as an exclusive sparse learning problem that exploits contextual information. To achieve this goal, we propose the context-aware exclusive sparse tracker (CEST) to model particle appearances as linear combinations of dictionary templates that are updated dynamically. Learning the representation of each particle is formulated as an exclusive sparse representation problem, where the overall dictionary is composed of multiple group dictionaries that can contain contextual information. With context, CEST is less prone to tracker drift. Interestingly, we show that the popular L1 tracker is a special case of our CEST formulation. The proposed learning problem is efficiently solved using an accelerated proximal gradient method that yields a sequence of closed form updates. To make the tracker much faster, we reduce the number of learning problems to be solved by using the dual problem to quickly and systematically rank and prune particles in each frame. We test our CEST tracker on challenging benchmark sequences that involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that CEST consistently outperforms state-of-the-art trackers. PMID:25680224

  14. Prospects for Accelerator Technology

    NASA Astrophysics Data System (ADS)

    Todd, Alan

    2011-02-01

    Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

  15. Superdiffusive shock acceleration and short acceleration times at interplanetary shocks

    NASA Astrophysics Data System (ADS)

    Perri, Silvia; Zimbardo, Gaetano

    2016-04-01

    The analysis of time profiles of particles accelerated at interplanetary shock waves has shown evidence for superdiffusive transport in the upstream region. Superdiffusive transport is characterized by a mean square displacement that grows faster than linearly in time and by non Gaussian statistics for the distribution of the particle jump lengths. In the superdiffusive framework it has been shown that particle time profiles upstream of a planar shock decay as power laws, at variance with exponential particle time profiles predicted in the case of diffusive transport. A large number of interplanetary shocks, including coronal mass ejection driven shocks, exhibit energetic particle time profiles that decay as power laws far upstream. In order to take this evidence into account, we have extended the standard theory of diffusive shock acceleration to the case of particle superdiffusive transport (superdiffusive shock acceleration). This has allowed us to derive both hard energy spectral indices and short acceleration times. This new theory has been tested for a number of interplanetary shock waves, observed by the Ulysses and the ACE spacecraft, and for the termination shock. The superdiffusive shock acceleration leads to a strong reduction of the acceleration times (even of about one order of magnitude) with respect to the diffusive shock acceleration. Thus, this new framework provides a substantial advancement in the understanding of the processes of particle acceleration and particle transport, which are among the main objectives of the new Solar Probe and Solar Orbiter space missions.

  16. Disrupting the Pipeline: The Role of School Leadership in Mitigating Exclusion and Criminalization of Students

    ERIC Educational Resources Information Center

    Wilson, Michael G.

    2013-01-01

    Recently, the effects of school exclusion and criminalization of youth misbehavior has garnered much attention from the research community. The process associated with school exclusion and criminalization has been described popularly as a school to prison pipeline (STPP). Studies of school exclusion and criminalization repeatedly report evidence…

  17. Efficient particle acceleration in shocks

    NASA Astrophysics Data System (ADS)

    Heavens, A. F.

    1984-10-01

    A self-consistent non-linear theory of acceleration of particles by shock waves is developed, using an extension of the two-fluid hydrodynamical model by Drury and Völk. The transport of the accelerated particles is governed by a diffusion coefficient which is initially assumed to be independent of particle momentum, to obtain exact solutions for the spectrum. It is found that steady-state shock structures with high acceleration efficiency are only possible for shocks with Mach numbers less than about 12. A more realistic diffusion coefficient is then considered, and this maximum Mach number is reduced to about 6. The efficiency of the acceleration process determines the relative importance of the non-relativistic and relativistic particles in the distribution of accelerated particles, and this determines the effective specific heat ratio.

  18. 37 CFR 404.7 - Exclusive, co-exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Exclusive, co-exclusive and partially exclusive licenses. 404.7 Section 404.7 Patents, Trademarks, and Copyrights NATIONAL INSTITUTE OF... applicants, on reasonable terms, when necessary to fulfill health or safety needs. (iii) The license shall...

  19. Plant growth promoting rhizobacteria and endophytes accelerate phytoremediation of metalliferous soils.

    PubMed

    Ma, Y; Prasad, M N V; Rajkumar, M; Freitas, H

    2011-01-01

    Technogenic activities (industrial-plastic, textiles, microelectronics, wood preservatives; mining-mine refuse, tailings, smelting; agrochemicals-chemical fertilizers, farm yard manure, pesticides; aerosols-pyrometallurgical and automobile exhausts; biosolids-sewage sludge, domestic waste; fly ash-coal combustion products) are the primary sources of heavy metal contamination and pollution in the environment in addition to geogenic sources. During the last two decades, bioremediation has emerged as a potential tool to clean up the metal-contaminated/polluted environment. Exclusively derived processes by plants alone (phytoremediation) are time-consuming. Further, high levels of pollutants pose toxicity to the remediating plants. This situation could be ameliorated and accelerated by exploring the partnership of plant-microbe, which would improve the plant growth by facilitating the sequestration of toxic heavy metals. Plants can bioconcentrate (phytoextraction) as well as bioimmobilize or inactivate (phytostabilization) toxic heavy metals through in situ rhizospheric processes. The mobility and bioavailability of heavy metal in the soil, particularly at the rhizosphere where root uptake or exclusion takes place, are critical factors that affect phytoextraction and phytostabilization. Developing new methods for either enhancing (phytoextraction) or reducing the bioavailability of metal contaminants in the rhizosphere (phytostabilization) as well as improving plant establishment, growth, and health could significantly speed up the process of bioremediation techniques. In this review, we have highlighted the role of plant growth promoting rhizo- and/or endophytic bacteria in accelerating phytoremediation derived benefits in extensive tables and elaborate schematic sketches. PMID:21147211

  20. Development of a preliminary design of a method to measure the effectiveness of virus exclusion during water process reclamation at zero-G

    NASA Technical Reports Server (NTRS)

    Fraser, A. S.; Wells, A. F.; Tenoso, H. J.; Linnecke, C. B.

    1976-01-01

    Organon Diagnostics has developed, under NASA sponsorship, a monitoring system to test the capability of a water recovery system to reject the passage of viruses into the recovered water. In this system, a non-pathogenic marker virus, bacteriophage F2, is fed into the process stream before the recovery unit and the reclaimed water is assayed for its presence. An engineering preliminary design has been performed as a parallel effort to the laboratory development of the marker virus test system. Engineering schematics and drawings present a preliminary instrument design of a fully functional laboratory prototype capable of zero-G operation.

  1. Acceleration modules in linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Wang, Shao-Heng; Deng, Jian-Jun

    2014-05-01

    The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

  2. Social exclusion in finite populations

    NASA Astrophysics Data System (ADS)

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.

  3. Social exclusion in finite populations.

    PubMed

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation. PMID:25974550

  4. Introduction to Particle Acceleration in the Cosmos

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Horwitz, J. L.; Perez, J.; Quenby, J.

    2005-01-01

    Accelerated charged particles have been used on Earth since 1930 to explore the very essence of matter, for industrial applications, and for medical treatments. Throughout the universe nature employs a dizzying array of acceleration processes to produce particles spanning twenty orders of magnitude in energy range, while shaping our cosmic environment. Here, we introduce and review the basic physical processes causing particle acceleration, in astrophysical plasmas from geospace to the outer reaches of the cosmos. These processes are chiefly divided into four categories: adiabatic and other forms of non-stochastic acceleration, magnetic energy storage and stochastic acceleration, shock acceleration, and plasma wave and turbulent acceleration. The purpose of this introduction is to set the stage and context for the individual papers comprising this monograph.

  5. Mineralization by Inhibitor Exclusion

    PubMed Central

    Price, Paul A.; Toroian, Damon; Lim, Joo Eun

    2009-01-01

    One of our goals is to understand the mechanisms that deposit mineral within collagen fibrils, and as a first step we recently determined the size exclusion characteristics of the fibril. This study revealed that apatite crystals up to 12 unit cells in size can access the water within the fibril, whereas molecules larger than a 40-kDa protein are excluded. Based on these observations, we proposed a novel mechanism for fibril mineralization: that macromolecular inhibitors of apatite growth favor fibril mineralization by selectively inhibiting crystal growth in the solution outside of the fibril. To test this mechanism, we developed a system in which crystal formation is driven by homogeneous nucleation at high calcium phosphate concentration and the only macromolecule in solution is fetuin, a 48-kDa inhibitor of apatite growth. Our experiments with this system demonstrated that fetuin determines the location of mineral growth; in the presence of fetuin mineral grows exclusively within the fibril, whereas in its absence mineral grows in solution outside the fibril. Additional experiments showed that fetuin is also able to localize calcification to the interior of synthetic matrices that have size exclusion characteristics similar to those of collagen and that it does so by selectively inhibiting mineral growth outside of these matrices. We termed this new calcification mechanism “mineralization by inhibitor exclusion,” the selective mineralization of a matrix using a macromolecular inhibitor of mineral growth that is excluded from that matrix. Future studies will be needed to evaluate the possible role of this mechanism in bone mineralization. PMID:19414589

  6. Menopause accelerates biological aging.

    PubMed

    Levine, Morgan E; Lu, Ake T; Chen, Brian H; Hernandez, Dena G; Singleton, Andrew B; Ferrucci, Luigi; Bandinelli, Stefania; Salfati, Elias; Manson, JoAnn E; Quach, Austin; Kusters, Cynthia D J; Kuh, Diana; Wong, Andrew; Teschendorff, Andrew E; Widschwendter, Martin; Ritz, Beate R; Absher, Devin; Assimes, Themistocles L; Horvath, Steve

    2016-08-16

    Although epigenetic processes have been linked to aging and disease in other systems, it is not yet known whether they relate to reproductive aging. Recently, we developed a highly accurate epigenetic biomarker of age (known as the "epigenetic clock"), which is based on DNA methylation levels. Here we carry out an epigenetic clock analysis of blood, saliva, and buccal epithelium using data from four large studies: the Women's Health Initiative (n = 1,864); Invecchiare nel Chianti (n = 200); Parkinson's disease, Environment, and Genes (n = 256); and the United Kingdom Medical Research Council National Survey of Health and Development (n = 790). We find that increased epigenetic age acceleration in blood is significantly associated with earlier menopause (P = 0.00091), bilateral oophorectomy (P = 0.0018), and a longer time since menopause (P = 0.017). Conversely, epigenetic age acceleration in buccal epithelium and saliva do not relate to age at menopause; however, a higher epigenetic age in saliva is exhibited in women who undergo bilateral oophorectomy (P = 0.0079), while a lower epigenetic age in buccal epithelium was found for women who underwent menopausal hormone therapy (P = 0.00078). Using genetic data, we find evidence of coheritability between age at menopause and epigenetic age acceleration in blood. Using Mendelian randomization analysis, we find that two SNPs that are highly associated with age at menopause exhibit a significant association with epigenetic age acceleration. Overall, our Mendelian randomization approach and other lines of evidence suggest that menopause accelerates epigenetic aging of blood, but mechanistic studies will be needed to dissect cause-and-effect relationships further. PMID:27457926

  7. Network acceleration techniques

    NASA Technical Reports Server (NTRS)

    Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

    2012-01-01

    Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

  8. Progress on plasma accelerators

    SciTech Connect

    Chen, P.

    1986-05-01

    Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

  9. Cascaded target normal sheath acceleration

    SciTech Connect

    Wang, W. P.; Shen, B. F.; Zhang, X. M.; Wang, X. F.; Xu, J. C.; Zhao, X. Y.; Yu, Y. H.; Yi, L. Q.; Shi, Y.; Zhang, L. G.; Xu, T. J.; Xu, Z. Z.

    2013-11-15

    A cascaded target normal sheath acceleration (TNSA) scheme is proposed to simultaneously increase energy and improve energy spread of a laser-produced mono-energetic proton beam. An optimum condition that uses the maximum sheath field to accelerate the center of the proton beam is theoretically found and verified by two-dimensional particle-in-cell simulations. An initial 10 MeV proton beam is accelerated to 21 MeV with energy spread decreased from 5% to 2% under the optimum condition during the process of the cascaded TNSA. The scheme opens a way to scale proton energy lineally with laser energy.

  10. SUPERDIFFUSIVE SHOCK ACCELERATION

    SciTech Connect

    Perri, S.; Zimbardo, G.

    2012-05-10

    The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

  11. EM Structure Based and Vacuum Acceleration

    SciTech Connect

    Colby, E.R.; /SLAC

    2005-09-27

    The importance of particle acceleration may be judged from the number of applications which require some sort of accelerated beam. In addition to accelerator-based high energy physics research, non-academic applications include medical imaging and treatment, structural biology by x-ray diffraction, pulse radiography, cargo inspection, material processing, food and medical instrument sterilization, and so on. Many of these applications are already well served by existing technologies and will profit only marginally from developments in accelerator technology. Other applications are poorly served, such as structural biology, which is conducted at synchrotron radiation facilities, and medical treatment using proton accelerators, the machines for which are rare because they are complex and costly. Developments in very compact, high brightness and high gradient accelerators will change how accelerators are used for such applications, and potentially enable new ones. Physical and technical issues governing structure-based and vacuum acceleration of charged particles are reviewed, with emphasis on practical aspects.

  12. Exclusive interactions in p anti-p collisions at s**(1/2) = 1.96 TeV

    SciTech Connect

    Hamilton, Andrew

    2006-05-01

    This thesis presents two exclusive production processes in p{bar p} collisions at {radical}s = 1.96 TeV, using the Collider Detector Facility at Fermi National Accelerator Laboratory. An observation of exclusive e{sup +}e{sup -} production through {gamma}{gamma} {yields} e{sup +}e{sup -} is presented, as well as evidence for exclusive production of {gamma}{gamma} through gg {yields} {gamma}{gamma} (via a quark loop). The exclusive e{sup +}e{sup -} production observation is based on 16 candidate events, with a background estimate of 2.1{sub -0.3}{sup +0.7}. Each event has an e{sup +}e{sup -} pair (E{sub T} (e) > 5 GeV, |{eta}(e)| < 2) and nothing else observable in the CDF detector. The measured cross section is 1.6{sub -0.3}{sup +0.5}(stat) {+-} 0.3(sys) pb, while the predicted cross section is 1.711 {+-} 0.008 pb. The kinematic properties of the events are consistent with the predictions of the LPAIR Monte Carlo. The evidence for exclusive {gamma}{gamma} production consists of 3 candidate events, with a background estimate of 0.0{sub -0.0}{sup +0.2} events. Each event has two photons (E{sub T}{gamma}) > 5 GeV, |{eta}({gamma})| < 1 and nothing else observable in the CDF detector. The measured cross section for these events is 0.14{sub -0.04}{sup +0.14}(stat) {+-} (sys) pb. It agrees with the theoretical prediction of 0.04 pb with a factor 3 to 5 theoretical uncertainty.

  13. Vacuum Brazing of Accelerator Components

    NASA Astrophysics Data System (ADS)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  14. Mutual exclusivity and exclusion: Converging evidence from two contrasting traditions

    PubMed Central

    Huntley, Kenneth R.; Ghezzi, Patrick M.

    1993-01-01

    Mutual exclusivity and exclusion are two terms used by cognitive psychologists and behavior analysts, respectively, to identify essentially the same phenomenon. While cognitive psychologists view mutual exclusivity in terms of a hypothesis that individuals use intuitively while acquiring language, behavior analysts regard exclusion as a derived stimulus relation that bears upon the acquisition and elaboration of verbal behavior. Each research tradition, though at odds with respect to accounting for the phenomenon, employs similar procedures to answer comparable questions. Insofar as both cognitive and behavioral psychologists are studying the same phenomenon, the ground work is established for collaboration between them. PMID:22477081

  15. Electron Acceleration by Transient Ion Foreshock Phenomena

    NASA Astrophysics Data System (ADS)

    Wilson, L. B., III; Turner, D. L.

    2015-12-01

    Particle acceleration is a topic of considerable interest in space, laboratory, and astrophysical plasmas as it is a fundamental physical process to all areas of physics. Recent THEMIS [e.g., Turner et al., 2014] and Wind [e.g., Wilson et al., 2013] observations have found evidence for strong particle acceleration at macro- and meso-scale structures and/or pulsations called transient ion foreshock phenomena (TIFP). Ion acceleration has been extensively studied, but electron acceleration has received less attention. Electron acceleration can arise from fundamentally different processes than those affecting ions due to differences in their gyroradii. Electron acceleration is ubiquitous, occurring in the solar corona (e.g., solar flares), magnetic reconnection, at shocks, astrophysical plasmas, etc. We present new results analyzing the dependencies of electron acceleration on the properties of TIFP observed by the THEMIS spacecraft.

  16. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Roberts, W. T.

    1985-01-01

    The space experiments with particle accelerators (SEPAC) instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  17. Tandem betatron accelerator

    NASA Astrophysics Data System (ADS)

    Keinigs, Rhon K.

    1991-04-01

    1407_50The tandem betatron is a compact, high-current induction accelerator that has the capability to accelerate electrons to an energy of order one gigavolt. Based upon the operating principle of a conventional betatron, the tandem betatron employs two synchronized induction cores operating 180 degrees out of phase. Embedded within the cores are the vacuum chambers, and these are connected by linear transport sections to allow for moving the beam back and forth between the two betatrons. The 180 degree phase shift between the core fluxes permits the circumvention of the flux swing constraint that limits the maximum energy gain of a conventional betatron. By transporting the beam between the synchronized cores, an electron can access more than one acceleration cycle, and thereby continue to gain energy. This added degree of freedom also permits a significant decrease in the size of the magnet system. Biasing coils provide independent control of the confining magnetic field. Provided that efficient beam switching can be performed, it appears feasible that a one gigavolt electron beam can be generated and confined. At this energy, a high current electron beam circulating in a one meter radius orbit could provide a very intense source of short wavelength ((lambda) < 10 nm) synchrotron radiation. This has direct application to the emerging field of x-ray lithography. At more modest energies (10 MeV-30 MeV) a compact tandem betatron could be employed in the fields of medical radiation therapy, industrial radiography, and materials processing.

  18. Acceleration during magnetic reconnection

    SciTech Connect

    Beresnyak, Andrey; Li, Hui

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  19. A single pass electron accelerator

    NASA Astrophysics Data System (ADS)

    Schuetz, Marlin N.; Vroom, David A.

    1995-02-01

    Higher volumes, increasing competition and the need to improve quality have led us to re-examine the process for irradiation of tubing and wire. Traditionallyin Raychem, product irradiation has involved the use of large multi-purpose facilities that were designed to handle relatively small volumes of a large variety of products as a separate process. Today, with larger volumes of certain products, there is an interest in combining processes to improve quality and reduce cost. We have recently designed and constructed a small, low voltage accelerator system that can be placed in-line with another manufacturing process and can uniformly irradiate a tube or wire product in a single pass. The system is comprised of two conventional accelerator systems having elongated filaments and placed on opposite sides of a linear product path. The ribbon shaped electron beams from these two accelerators are scanned, after acceleration toward the product path, in a conventional manner and 180 degrees out of phase from each other. The two accelerated electron beams then enter a third magnetic field that is synchronous with the scanning magnets and whose oscillating polarity is such that the ribbon beams are converged onto a tubular shaped window close to and around a segment of the product path. Trials with a prototype system have produced tubing having a dose concentricity of better than ± 10 percent on a single pass through the system.

  20. 10 CFR 781.52 - Exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Exclusive and partially exclusive licenses. 781.52 Section 781.52 Energy DEPARTMENT OF ENERGY DOE PATENT LICENSING REGULATIONS Types of Licenses and Conditions... to sublicense the licensed invention to any foreign government pursuant to any existing or...

  1. Particle acceleration by the sun

    SciTech Connect

    Lin, R. P.

    2008-08-25

    Observations of hard X-ray/{gamma}-ray continuum and {gamma}-ray line emission show that electrons are accelerated to >{approx}100 s of MeV and ions up to GeV energies, respectively, in large solar flares. The flare-accelerated electrons above {approx}20 keV and ions above a few MeV often contain >{approx}10-50% or more of the total energy released, indicating that the particle acceleration is intimately related to the energy release mechanism. RHESSI observations show strong evidence that both the ion and electron acceleration are associated with the process of magnetic reconnection. Direct in situ observations of solar energetic particles (SEPs) near 1 AU indicate that shock waves driven by fast (>{approx}1000 km/s) coronal mass ejections (CMEs) accelerate ions and electrons to similarly high energies, at altitudes of {approx}2-40 solar radii. Both CMEs and large flares involve the transient release of up to {approx}10{sup 32}-10{sup 33} ergs. Frequent acceleration of electrons to {approx}10 keV is observed in smaller flares and even in microflares. Radio type III bursts indicate that electron acceleration can occur high in the corona, often without flare signatures at lower altitude. At 1 AU, hundreds of small impulsive SEP events are detected per year near solar maximum. These are dominated by <{approx}1 to {approx}100 keV electrons and often accompanied by tens of keV to MeV/nuc ions, strongly enriched in 3He and heavies. Here I review the recent RHESSI and related in situ observations as they bear on the fundamental acceleration processes that are occurring.

  2. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2006-04-18

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  3. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2005-06-14

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  4. Self-mode-transition from laser wakefield accelerator to plasma wakefield accelerator of laser-driven plasma-based electron acceleration

    SciTech Connect

    Pae, K. H.; Choi, I. W.; Lee, J.

    2010-12-15

    Via three-dimensional particle-in-cell simulations, the self-mode-transition of a laser-driven electron acceleration from laser wakefield to plasma-wakefield acceleration is studied. In laser wakefield accelerator (LWFA) mode, an intense laser pulse creates a large amplitude wakefield resulting in high-energy electrons. Along with the laser pulse depletion, the electron bunch accelerated in the LWFA mode drives a plasma wakefield. Then, after the plasma wakefield accelerator mode is established, electrons are trapped and accelerated in the plasma wakefield. The mode transition process and the characteristics of the accelerated electron beam are presented.

  5. Development of PUNDA (Parametric Universal Nonlinear Dynamics Approximator) Models for Self-Validating Knowledge-Guided Modelling of Nonlinear Processes in Particle Accelerators \\& Industry

    SciTech Connect

    Sayyar-Rodsari, Bijan; Schweiger, Carl; Hartman, Eric

    2007-10-07

    The difficult problems being tackled in the accelerator community are those that are nonlinear, substantially unmodeled, and vary over time. Such problems are ideal candidates for model-based optimization and control if representative models of the problem can be developed that capture the necessary mathematical relations and remain valid throughout the operation region of the system, and through variations in system dynamics. The goal of this proposal is to develop the methodology and the algorithms for building high-fidelity mathematical representations of complex nonlinear systems via constrained training of combined first-principles and neural network models.

  6. Exclusive Breastfeeding Experiences among Mexican American Women

    PubMed Central

    Wambach, Karen; Domian, Elaine Williams; Page-Goertz, Sallie; Wurtz, Heather; Hoffman, Kelli

    2016-01-01

    Background According to the Centers for Disease Control and Prevention, Hispanic breastfeeding mothers begin early formula supplementation at higher rates than other ethnic groups, which can lead to shorter breastfeeding duration and decreased exclusive breastfeeding. Acculturation, the process of adopting beliefs and behaviors of another culture, appears to influence breastfeeding practices of Hispanic women in the United States. Little is known about Mexican American mothers’ formula use and exclusive breastfeeding within the context of acculturation. Objective Our study identified perceived benefits and barriers to exclusive breastfeeding and levels of acculturation among Mexican American women living in a Midwestern city. Methods We used a qualitative descriptive design integrating Pender’s Health Promotion Model concepts. Individual interviews were conducted in English or Spanish (N = 21). The revised Acculturation Rating Scale for Mexican Americans was used to examine acculturation levels. Results Acculturation scores indicated that the majority (66%) of the sample was “very Mexican oriented.” Most women exclusively breastfed, with a few using early supplementation for “insufficient milk production.” Three themes emerged: (1) It is natural that a woman give life and also provide the best food for her baby; (2) Breastfeeding is ultimately a woman’s decision but is influenced by tradition, guidance, and encouragement; and (3) Breast milk is superior but life circumstances can challenge one’s ability to breastfeed. Conclusion Strong familial/cultural traditions supported and normalized breastfeeding. Barriers to exclusive breastfeeding were similar to breastfeeding women in general, in the United States. Findings support the need for culturally competent and individualized lactation care. PMID:26289059

  7. Accelerating deactivation

    SciTech Connect

    FISHBACK, K.M.

    1999-02-01

    In recent years, the focus of the U.S. Department of Energy (DOE) complex has shifted from defense production to facility stabilization, decommissioning, and environmental restoration. This shift from production to cleanup requires a parallel shift from operations-focused management to project-focused management for an efficient facility deactivation. In the operation-focused management organization, activities are planned and executed based on production goals and are typically repetitive and cyclic. In the project-focused management environment, activities are based on a defined scope/end objective, start date, and completion date. Since the workforce used to perform production operations is also usually relied onto perform facility deactivation, it is important to shift from an operations management approach to a project management approach. It is best if the transition is accomplished quickly so the project can move forward and workers don't spend a lot of energy anticipating change. Therefore, it is essential that managers, planners, and other workers understand the key elements associated with planning a deactivation project. This paper describes a planning approach that has been used successfully to plan deactivation projects consistent with the requirements provided in DOE Order 430.1A Life Cycle Asset Management and the companion Deactivation Implementation Guide, G430. 1A-3, while exceeding schedule expectations and reducing costs. Although the planning of a deactivation project closely mirrors the classic project planning for construction projects, there are unique variations associated with facility deactivation. The key elements of planning a deactivation project are discussed relative to scope, schedule, and cost. Management tools such as project metrics and histograms are discussed as desired outputs from the planning process. In addition, lessons learned from planning deactivation projects across the DOE complex are discussed relative to making the

  8. Central exclusive production at RHIC

    DOE PAGESBeta

    Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity | |more » < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.« less

  9. 37 CFR 404.7 - Exclusive, co-exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... subject to any licenses in force at the time of the grant of the exclusive, co-exclusive or partially... or United States industry in foreign commerce will be enhanced; and (iii) The Federal agency has not... with the United States. (ii) The license shall be subject to any licenses in force at the time of...

  10. Seed rain dynamics following disturbance exclusion in a secondary tropical dry forest in Morelos, Mexico.

    PubMed

    Ceccon, Eliane; Hernández, Patricia

    2009-01-01

    In most of the legally protected areas in Mexico local inhabitants use natural resources, such as fire wood or cattle grazing. These frequent but low-intensity disturbances have consequences at various levels of the tropical ecosystems and strongly impact forest structure and its regeneration capacity. Despite their importance, the effects of these perturbations in many aspects of tropical forest ecology and in the forest's capacity to recover after disturbance exclusion remain poorly understood. Understanding the impact of these processes on tropical forests is necessary for rehabilitating these forests and enhancing their productivity. In this study, we evaluate the impact of twelve years of exclusion (E) of cattle grazing and fire wood extraction in the composition and dynamics of seed rain, and compare this assessment to a similar analysis in an area where these perturbations continued (without exclusion, WE). We found a strong seasonality in seed rain (96% of seeds fell in the dry season) in both areas. There were no significant differences between E and WE sites in relation to overall seed density, species richness and diversity. However, the distribution along the year of seed species density was significantly different among the E and WE sites. The Jaccard's similarity index between E and WE sites was relatively low (0.57). Barochory was the most common dispersal mode observed among the 23 species in terms of seed species density (48%), followed by anemochory (39%) and zoochory (13%). In relation to seed density, anemochory was the most frequent dispersal mode (88%). Most species in the zone were categorized as small seeds (92%), and there were no significant differences in the distribution of seed size between E and WE. The spatial pattern of dispersal of the four species with the highest relative importance value index, in both areas, was aggregated. Twelve years of disturbance exclusion were not enough to fully restore the seed rain of the area; some

  11. Studies of ${\\rm Nb}_{3}{\\rm Sn}$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

    SciTech Connect

    Barzi, E.; Bossert, M.; Gallo, G.; Lombardo, V.; Turrioni, D.; Yamada, R.; Zlobin, A. V.

    2011-12-21

    A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

  12. Exclusive vector meson production at HERMES

    NASA Astrophysics Data System (ADS)

    Movsisyan, Aram

    2014-06-01

    Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.

  13. A study of Central Exclusive Production

    SciTech Connect

    Monk, James; /Manchester U.

    2008-09-01

    Central exclusive production of a system X in a collision between two hadrons h is defined as hh {yields} h + X + h with no other activity apart from the decay products of X. This thesis presents predictions for the production cross section of a CP violating supersymmetric Higgs boson and the radion of the Randall-Sundrum model. The ExHuME Monte Carlo generator was written to simulate central exclusive processes and is described and explored. A comparison to di-jet observations made by the D0 detector at the Tevatron, Fermilab between January and June 2004 is made and the distributions found support the predictions of ExHuME.

  14. The direction of acceleration

    NASA Astrophysics Data System (ADS)

    Wilhelm, Thomas; Burde, Jan-Philipp; Lück, Stephan

    2015-11-01

    Acceleration is a physical quantity that is difficult to understand and hence its complexity is often erroneously simplified. Many students think of acceleration as equivalent to velocity, a ˜ v. For others, acceleration is a scalar quantity, which describes the change in speed Δ|v| or Δ|v|/Δt (as opposed to the change in velocity). The main difficulty with the concept of acceleration therefore lies in developing a correct understanding of its direction. The free iOS app AccelVisu supports students in acquiring a correct conception of acceleration by showing acceleration arrows directly at moving objects.

  15. TURBULENT SHEAR ACCELERATION

    SciTech Connect

    Ohira, Yutaka

    2013-04-10

    We consider particle acceleration by large-scale incompressible turbulence with a length scale larger than the particle mean free path. We derive an ensemble-averaged transport equation of energetic charged particles from an extended transport equation that contains the shear acceleration. The ensemble-averaged transport equation describes particle acceleration by incompressible turbulence (turbulent shear acceleration). We find that for Kolmogorov turbulence, the turbulent shear acceleration becomes important on small scales. Moreover, using Monte Carlo simulations, we confirm that the ensemble-averaged transport equation describes the turbulent shear acceleration.

  16. Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect

    Spentzouris, P.; Cary, J.; McInnes, L.C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.; /LBL, Berkeley

    2011-11-14

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization

  17. Contrasting Stories of Inclusion/Exclusion in the Chemistry Classroom

    NASA Astrophysics Data System (ADS)

    de Fátima Cardoso Gomes, Maria; Mortimer, Eduardo F.; Kelly, Gregory J.

    2011-04-01

    This article reports on the construction process of inclusion/exclusion for high school chemistry students in two schools in Belo Horizonte, the capital of Minas Gerais State, Brazil. We examined the interactional accomplishment of inclusion/exclusion of four students, two from a private school and two from a public school. The aim of this article is to describe these students' stories of inclusion/exclusion and to discuss what motivated them to learn chemistry in the classrooms investigated. To learn chemistry, students need to develop an individual understanding of the social language of the discipline. Inclusion/exclusion is accomplished interactively as members of different communities make choices about how to participate, involve others, and direct their actions. Such interactions are mediated by the teacher, and thus, through discourse, the collective group establishes certain learning opportunities.

  18. Tomography of injection and acceleration of monoenergetic electrons in a laser-wakefield accelerator.

    PubMed

    Hsieh, C-T; Huang, C-M; Chang, C-L; Ho, Y-C; Chen, Y-S; Lin, J-Y; Wang, J; Chen, S-Y

    2006-03-10

    A tomographic diagnosis method was developed to systematically resolve the injection and acceleration processes of a monoenergetic electron beam in a laser-wakefield accelerator. It was found that all the monoenergetic electrons are injected at the same location in the plasma column and accelerated from 5 to 55 MeV energy in 200 microm distance. This is a direct measurement of the real acceleration gradient in a laser-wakefield accelerator, and the experimental data are consistent with the model of transverse wave breaking and beam loading for monoenergetic electron injection. PMID:16606269

  19. Accelerating Particles with Plasma

    SciTech Connect

    Litos, Michael; Hogan, Mark

    2014-11-05

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  20. Improved plasma accelerator

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  1. Commnity Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect

    Spentzouris, Panagiotis; Cary, John; Mcinnes, Lois Curfman; Mori, Warren; Ng, Cho; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2008-07-01

    The design and performance optimization of particle accelerators is essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC1 Accelerator Science and Technology project, the SciDAC2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modeling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multi-physics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  2. Community petascale project for accelerator science and simulation : Advancing computational science for future accelerators and accelerator technologies.

    SciTech Connect

    Spentzouris, P.; Cary, J.; McInnes, L. C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.

    2008-01-01

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R & D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  3. Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

    SciTech Connect

    Spentzouris, Panagiotis; Cary, John; Mcinnes, Lois Curfman; Mori, Warren; Ng, Cho; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2011-10-21

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  4. Reading Instruction in the Accelerated School.

    ERIC Educational Resources Information Center

    Barton, Jim

    Disadvantaged elementary school students can be taught to think critically as part of the process of learning to read. The key to student change is teacher knowledge. The purpose of this paper is to inform the development of powerful teaching strategies for reading instruction as used in Accelerated Schools. The Accelerated School is a…

  5. 10 CFR 820.34 - Accelerated decision.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Accelerated decision. 820.34 Section 820.34 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES Enforcement Process § 820.34 Accelerated... facie case or other grounds that show no right to relief on the part of the Director. (b) Effect...

  6. Inverse Cerenkov acceleration using an IFEL prebuncher

    SciTech Connect

    Kimura, W.D.; Pogorelsky, I.V.; Liu, Y.; Kusche, K.P.; van Steenbergen, A.; Gallardo, J.C.; Sandweiss, J.; Cline, D.B.; Quimby, D.C.; Babzien, M.

    1997-03-01

    The BNL IFEL will be used to optically prebunch the e-beam before sending it into an inverse Cerenkov acceleration (ICA) stage. Prebunching the beam will greatly improve the efficiency of the ICA process. The basic experimental design and preliminary model predictions for the combined ICA/IFEL experiment are discussed. Near-term goals are to demonstrate optical prebunching, rephasing of the prebunched beam with the optical field, and more efficient acceleration. Long-term goals are to demonstrate 100 MeV net acceleration using an ICA accelerator. {copyright} {ital 1997 American Institute of Physics.}

  7. Acceleration gradient of a plasma wakefield accelerator

    SciTech Connect

    Uhm, Han S.

    2008-02-25

    The phase velocity of the wakefield waves is identical to the electron beam velocity. A theoretical analysis indicates that the acceleration gradient of the wakefield accelerator normalized by the wave breaking amplitude is K{sub 0}({xi})/K{sub 1}({xi}), where K{sub 0}({xi}) and K{sub 1}({xi}) are the modified Bessel functions of the second kind of order zero and one, respectively and {xi} is the beam parameter representing the beam intensity. It is also shown that the beam density must be considerably higher than the diffuse plasma density for the large radial velocity of plasma electrons that are required for a high acceleration gradient.

  8. Far field acceleration

    SciTech Connect

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

  9. Angular Acceleration Without Torque?

    NASA Astrophysics Data System (ADS)

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.2

  10. Sustained linear acceleration

    NASA Technical Reports Server (NTRS)

    Fraser, T. M.

    1973-01-01

    The subjective effects of sustained acceleration are discussed, including positive, negative, forward, backward, and lateral acceleration effects. Physiological effects, such as retinal and visual response, unconsciousness and cerebral function, pulmonary response, and renal output, are studied. Human tolerance and performance under sustained acceleration are ascertained.

  11. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  12. Acceleration: It's Elementary

    ERIC Educational Resources Information Center

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  13. Accelerating the discontinuous Galerkin method for seismic wave propagation simulations using the graphic processing unit (GPU)—single-GPU implementation

    NASA Astrophysics Data System (ADS)

    Mu, Dawei; Chen, Po; Wang, Liqiang

    2013-02-01

    We have successfully ported an arbitrary high-order discontinuous Galerkin (ADER-DG) method for solving the three-dimensional elastic seismic wave equation on unstructured tetrahedral meshes to an Nvidia Tesla C2075 GPU using the Nvidia CUDA programming model. On average our implementation obtained a speedup factor of about 24.3 for the single-precision version of our GPU code and a speedup factor of about 12.8 for the double-precision version of our GPU code when compared with the double precision serial CPU code running on one Intel Xeon W5880 core. When compared with the parallel CPU code running on two, four and eight cores, the speedup factor of our single-precision GPU code is around 12.9, 6.8 and 3.6, respectively. In this article, we give a brief summary of the ADER-DG method, a short introduction to the CUDA programming model and a description of our CUDA implementation and optimization of the ADER-DG method on the GPU. To our knowledge, this is the first study that explores the potential of accelerating the ADER-DG method for seismic wave-propagation simulations using a GPU.

  14. Charged Particle Acceleration by Lasers in Plasmas

    SciTech Connect

    Liu, C. S.; Tripathi, V. K.

    2007-07-11

    Several physical processes of laser electron acceleration in plasmas are revisited. A laser beam can drive plasma waves which in turn can accelerate resonant electrons. If these plasma waves can reach amplitude limited only by wave breaking alone, then the corresponding accelerating gradient in the plasma wave is of the order of electron rest mass energy per plasma skin depth, typically about GEV per centimeter. This is several orders of magnitudes higher than the conventional RF field gradient, giving rise to the possibility of compact accelerators needed for high energy physics research as well as medical and other applications. The chirped short pulse laser, with intensity exceeding the threshold for relativistic self focusing, can generate ion bubble in its wake by expelling electrons. The electrons at the bubble boundary, surge toward the stagnation point and pile up there. As the pile acquires a critical size, these electrons are injected into the bubble and accelerated by the combined fields of ion space charge and the plasma wave to Gev in energy. Most remarkably these electrons are bunched in phase space while being accelerated to high energy, resulting in near mono-energetic electron beam of high beam quality, with narrow energy spread. We review also other processes related to laser electron acceleration, such as acceleration in plasma wave assisted by ponderomotive force and betatron acceleration.

  15. Real-time GPU-accelerated processing and volumetric display for wide-field laser-scanning optical-resolution photoacoustic microscopy.

    PubMed

    Kang, Heesung; Lee, Sang-Won; Lee, Eun-Soo; Kim, Se-Hwa; Lee, Tae Geol

    2015-12-01

    Fast signal processing and real-time displays are essential for practical imaging modality in various fields of applications. However, the imaging speed in optical-resolution photoacoustic microscopy (OR-PAM), in particular, depends on factors such as the pulse repetition rate of the laser, scanning method, field of view (FOV), and signal processing time. In the past, efforts to increase acquisition speed either focused on developing new scanning methods or using lasers with higher pulse repetition rates. However, high-speed signal processing is also important for real-time volumetric display in OR-PAM. In this study, we carried out parallel signal processing using a graphics processing unit (GPU) to enable fast signal processing and wide-field real-time displays in laser-scanning OR-PAM. The average total GPU processing time for a B-mode PAM image was approximately 1.35 ms at a display speed of 480 fps when the data samples were acquired with 736 (axial) × 500 (lateral) points/B-mode-frame at a pulse repetition rate of 300 kHz. In addition, we successfully displayed maximum amplitude projection images of a mouse's ear as volumetric images with an FOV of 3 mm × 3 mm (500 × 500 pixels) at 1.02 s, corresponding to 0.98 fps. PMID:26713184

  16. Real-time GPU-accelerated processing and volumetric display for wide-field laser-scanning optical-resolution photoacoustic microscopy

    PubMed Central

    Kang, Heesung; Lee, Sang-Won; Lee, Eun-Soo; Kim, Se-Hwa; Lee, Tae Geol

    2015-01-01

    Fast signal processing and real-time displays are essential for practical imaging modality in various fields of applications. However, the imaging speed in optical-resolution photoacoustic microscopy (OR-PAM), in particular, depends on factors such as the pulse repetition rate of the laser, scanning method, field of view (FOV), and signal processing time. In the past, efforts to increase acquisition speed either focused on developing new scanning methods or using lasers with higher pulse repetition rates. However, high-speed signal processing is also important for real-time volumetric display in OR-PAM. In this study, we carried out parallel signal processing using a graphics processing unit (GPU) to enable fast signal processing and wide-field real-time displays in laser-scanning OR-PAM. The average total GPU processing time for a B-mode PAM image was approximately 1.35 ms at a display speed of 480 fps when the data samples were acquired with 736 (axial) × 500 (lateral) points/B-mode-frame at a pulse repetition rate of 300 kHz. In addition, we successfully displayed maximum amplitude projection images of a mouse’s ear as volumetric images with an FOV of 3 mm × 3 mm (500 × 500 pixels) at 1.02 s, corresponding to 0.98 fps. PMID:26713184

  17. Lectures in accelerator theory

    SciTech Connect

    Month, M

    1980-01-01

    Lecture I deals with the behavior of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. The case treated, that of counter-rotating proton beams crossing each other at a non-zero angle, has the simple feature that the force between the beam is one dimensional. In lecture II, an analysis of the development of traveling waves on particle beams is presented. The situation studied is that of a uniform beam current in a circular accelerator and the excitation for the coherent motion is induced by the resistivity of the vacuum chamber wall. Finally, in lecture III, a description of the current accumulation process used at the proton storage rings at CERN (The ISR) is given. Particle pulses of rather low average current are injected and stored along the length and width of the vacuum chamber. The efficiency is very high and large currents (over 40 amperes) have been achieved.

  18. Laser acceleration in novel media

    NASA Astrophysics Data System (ADS)

    Tajima, T.

    2014-05-01

    With newly available compact laser technology [1] we are capable of producing 100 PW-class laser pulses with a single-cycle duration on the femtosecond timescale. With this fs intense laser we can produce a coherent X-ray pulse that is also compressed, well into the hard X-ray regime (˜10 keV) and with a power up to as much as 10 Exawatts. We suggest utilizing these coherent X-rays to drive the acceleration of particles. Such X-rays are focusable far beyond the diffraction limit of the original laser wavelength and when injected into a crystal it forms a metallic-density electron plasma ideally suited for laser wakefield acceleration. If the X-ray field is limited by the Schwinger field at the focal size of ˜100 nm, the achievable energy is 1 PeV over 50 m. (If the X-rays are focused further, much higher energies beyond this are possible). These processes are not limited to only electron acceleration, and if ions are pre-accelerated to beyond GeV they are capable of being further accelerated using a LWFA scheme [2] to similar energies as electrons over the same distance-scales. Such high energy proton (and ion) beams can induce copious neutrons, which can also give rise to intense compact muon beams and neutrino beams that may be portable. High-energy gamma rays can also be efficiently emitted with a bril- liance many orders of magnitude above the brightest X-ray sources by this accelerating process, from both the betatron radiation as well as the dominant radiative-damping dynamics. With the exceptional conditions enabled by this technology we envision a whole scope of new physical phenomena, including: the possibility of laser self-focus in the vacuum, neutron manipulation by the beat of such lasers, zeptosecond spectroscopy of nuclei, etc. Further, we now introduce along with the idea of vacuum as a nonlinear medium, the Schwinger Fiber Accelerator. This is a self-organized vacuum fiber acceleration concept, in which the repeated process of self-focusing and

  19. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  20. Fiber Accelerating Structures

    SciTech Connect

    Hammond, Andrew P.; /Reed Coll. /SLAC

    2010-08-25

    One of the options for future particle accelerators are photonic band gap (PBG) fiber accelerators. PBG fibers are specially designed optical fibers that use lasers to excite an electric field that is used to accelerate electrons. To improve PBG accelerators, the basic parameters of the fiber were tested to maximize defect size and acceleration. Using the program CUDOS, several accelerating modes were found that maximized these parameters for several wavelengths. The design of multiple defects, similar to having closely bound fibers, was studied to find possible coupling or the change of modes. The amount of coupling was found to be dependent on distance separated. For certain distances accelerating coupled modes were found and examined. In addition, several non-periodic fiber structures were examined using CUDOS. The non-periodic fibers produced several interesting results and promised more modes given time to study them in more detail.