1,788 research outputs found

    A preliminary description of the Chemical Camera

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    Spinning cryostat, or chemical camera, for sampling supersonic gas stream and recording chemical kinetic

    100 Years of Training and Development Research: What We Know and Where We Should Go

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    Training and development research has a long tradition within applied psychology dating back to the early 1900’s. Over the years, not only has interest in the topic grown but there have been dramatic changes in both the science and practice of training and development. In the current article, we examine the evolution of training and development research using articles published in the Journal of Applied Psychology (JAP) as a primary lens to analyze what we have learned and to identify where future research is needed. We begin by reviewing the timeline of training and development research in JAP from 1918 to the present in order to elucidate the critical trends and advances that define each decade. These trends include the emergence of more theory-driven training research, greater consideration of the role of the trainee and training context, examination of learning that occurs outside the classroom, and understanding training’s impact across different levels of analysis. We then examine in greater detail the evolution of four key research themes: training criteria, trainee characteristics, training design and delivery, and the training context. In each area, we describe how the focus of research has shifted over time and highlight important developments. We conclude by offering several ideas for future training and development research

    Propagation of supersymmetric charged sleptons at high energies

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    The potential for neutrino telescopes to discover charged stau production in neutrino-nucleon interactions in Earth depends in part on the stau lifetime and range. In some supersymmetric scenarios, the next lightest supersymmetric particle is a stau with a decay length on the scale of 10 km. We evaluate the electromagnetic energy loss as a function of energy and stau mass. The energy loss parameter ÎČ\beta scales as the inverse stau mass for the dominating electromagnetic processes, photonuclear and e+e−e^+e^- pair production. The range can be parameterized as a function of stau mass, initial energy and minimum final energy. In comparison to earlier estimates of the stau range, our results are as much as a factor of two larger, improving the potential for stau discovery in neutrino telescopes.Comment: 7 pages, 8 figures, version accepted for publication in Astroparticle Physic

    The Error and Repair Catastrophes: A Two-Dimensional Phase Diagram in the Quasispecies Model

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    This paper develops a two gene, single fitness peak model for determining the equilibrium distribution of genotypes in a unicellular population which is capable of genetic damage repair. The first gene, denoted by σvia \sigma_{via} , yields a viable organism with first order growth rate constant k>1 k > 1 if it is equal to some target ``master'' sequence σvia,0 \sigma_{via, 0} . The second gene, denoted by σrep \sigma_{rep} , yields an organism capable of genetic repair if it is equal to some target ``master'' sequence σrep,0 \sigma_{rep, 0} . This model is analytically solvable in the limit of infinite sequence length, and gives an equilibrium distribution which depends on \mu \equiv L\eps , the product of sequence length and per base pair replication error probability, and \eps_r , the probability of repair failure per base pair. The equilibrium distribution is shown to exist in one of three possible ``phases.'' In the first phase, the population is localized about the viability and repairing master sequences. As \eps_r exceeds the fraction of deleterious mutations, the population undergoes a ``repair'' catastrophe, in which the equilibrium distribution is still localized about the viability master sequence, but is spread ergodically over the sequence subspace defined by the repair gene. Below the repair catastrophe, the distribution undergoes the error catastrophe when ÎŒ \mu exceeds \ln k/\eps_r , while above the repair catastrophe, the distribution undergoes the error catastrophe when ÎŒ \mu exceeds ln⁥k/fdel \ln k/f_{del} , where fdel f_{del} denotes the fraction of deleterious mutations.Comment: 14 pages, 3 figures. Submitted to Physical Review

    Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"

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    Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r < 1 fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton-proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.Comment: 62 pages, 39 figures. Review article published in Reports on Progress in Physics on June 23, 2006. In this published version, mistakes, typographical errors, and citations have been corrected and a subsection has been adde

    Offenders' Crime Narratives across Different Types of Crimes

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    The current study explores the roles offenders see themselves playing during an offence and their relationship to different crime types. One hundred and twenty incarcerated offenders indicated the narrative roles they acted out whilst committing a specific crime they remembered well. The data were subjected to Smallest Space Analysis (SSA) and four themes were identified: Hero, Professional, Revenger and Victim in line with the recent theoretical framework posited for Narrative Offence Roles (Youngs & Canter, 2012). Further analysis showed that different subsets of crimes were more like to be associated with different narrative offence roles. Hero and Professional were found to be associated with property offences (theft, burglary and shoplifting), drug offences and robbery and Revenger and Victim were found to be associated with violence, sexual offences and murder. The theoretical implications for understanding crime on the basis of offenders' narrative roles as well as practical implications are discussed

    Event-by-event fluctuations of the mean transverse momentum in 40, 80, and 158 A GeV/c Pb-Au collisions

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    Measurements of event-by-event fluctuations of the mean transverse momentum in Pb-Au collisions at 40, 80, and 158 A GeV/c are presented. A significant excess of mean p_T fluctuations at mid-rapidity is observed over the expectation from statistically independent particle emission. The results are somewhat smaller than recent measurements at RHIC. A possible non-monotonic behaviour of the mean p_T fluctuations as function of collision energy, which may have indicated that the system has passed the critical point of the QCD phase diagram in the range of mu_B under investigation, has not been observed. The centrality dependence of mean p_T fluctuations in Pb-Au is consistent with an extrapolation from pp collisions assuming that the non-statistical fluctuations scale with multiplicity. The results are compared to calculations by the RQMD and UrQMD event generators.Comment: 28 pages, 10 figure

    Event-by-event fluctuations in Mean pTp_T and Mean eTe_T in sqrt(s_NN) = 130 GeV Au+Au Collisions

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    Distributions of event-by-event fluctuations of the mean transverse momentum and mean transverse energy near mid-rapidity have been measured in Au+Au collisions at sqrt(s_NN) = 130 GeV at RHIC. By comparing the distributions to what is expected for statistically independent particle emission, the magnitude of non-statistical fluctuations in mean transverse momentum is determined to be consistent with zero. Also, no significant non-random fluctuations in mean transverse energy are observed. By constructing a fluctuation model with two event classes that preserve the mean and variance of the semi-inclusive p_T or e_T spectra, we exclude a region of fluctuations in sqrt(s_NN) = 130 GeV Au+Au collisions.Comment: 10 pages, RevTeX 3, 7 figures, 4 tables, 307 authors, submitted to Phys. Rev. C on 22 March 2002. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (will be made) publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm
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