237 research outputs found
The Bender Visual-Motor Gestalt Test as a Measure of Aggression in Children
The Bender-Gestalt Test has been routinely used for the past two years at the Annie Wittenmyer Home, an institution for dependent and neglected children in Iowa. This simple test was first designed by Bender (1938), as a performance test for young children. Her manual also indicates that the test can be used in the differentiation of organic brain anomolies, schizophrenias and psychoneuroses. This area of research has been covered by Hutt (1945) Swenson and Pascal (1953), Guertin (1954), and others. The observations of the writers have indicated that there is a wide difference in the way apparently normal children respond to these designs. These differences have heretofore been interpreted in the light of Hutt\u27s (1945) findings with an adult population. For example, he indicated that such things as diminution of the figures, conservation of space and the use of light pressure in drawing are indicative of social withdrawal, limited activity and unassertiveness. In another article Hutt (1953) stated that, aggressive and rebellious individuals usually show an excessive use of space. On the other hand an inordinately small amount of space between successive drawings is indicative of repressed hostility, occasionally turned inwards in the form of masochistic strivings or needs. Peek (1953) has shown that the direction of drawing a single line such as the diagonal on the figure 5 (an incomplete circle with an intersecting slanting line both composed of dots) can be indicative of differences in personality adjustment. He found that patients drawing the diagonal toward the half-circle rather than in the popular direction, i.e., away from the halfcircle were significantly more immature and dependent than the control group. Rather than being able to direct their hostility upon the sources of their frustration they were inclined to use less adaptive mechanisms such as headaches and other somatic complaints. They were therefore more apt to build up frustrations which spill over into poorly controlled and indirect forms of aggressive hostility
Locally anisotropic momentum distributions of hadrons at freeze-out in relativistic heavy-ion collisions
A spheroidal anisotropic local momentum distribution is implemented in the
statistical model of hadron production. We show that this form leads to exactly
the same ratios of hadronic abundances as the equilibrium distributions, if the
temperature is identified with a characteristic transverse-momentum scale.
Moreover, to a very good approximation the transverse-momentum spectra of
hadrons are the same for isotropic and anisotropic systems, provided the size
of the system at freeze-out is appropriately adjusted. We further show that
this invariance may be used to improve the agreement between the model and
experimental HBT results.Comment: 7 pages, 4 figure
Flow fluctuations and long-range correlations: elliptic flow and beyond
These proceedings consist of a brief overview of the current understanding of
collective behavior in relativistic heavy-ion collisions. In particular, recent
progress in understanding the implications of event-by-event fluctuations have
solved important puzzles in existing data -- the "ridge" and "shoulder"
phenomena of long-range two-particle correlations -- and have created an
exciting opportunity to tightly constrain theoretical models with many new
observables.Comment: 10 pages, 2 figures, Proceedings for the 22nd International
Conference On Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter
2011), Annecy, France, May 23 - 28, 2011; includes Fig. 2 which was omitted
from journal submission for lack of spac
Jet quenching in a strongly coupled anisotropic plasma
The jet quenching parameter of an anisotropic plasma depends on the relative
orientation between the anisotropic direction, the direction of motion of the
parton, and the direction along which the momentum broadening is measured. We
calculate the jet quenching parameter of an anisotropic, strongly coupled N=4
plasma by means of its gravity dual. We present the results for arbitrary
orientations and arbitrary values of the anisotropy. The anisotropic value can
be larger or smaller than the isotropic one, and this depends on whether the
comparison is made at equal temperatures or at equal entropy densities. We
compare our results to analogous calculations for the real-world quark-gluon
plasma and find agreement in some cases and disagreement in others.Comment: 22 pages, 10 figures; v2: minor changes, added reference. Extends
arXiv:1202.369
Particle Ratios and the QCD Critical Temperature
We show how the measured particle ratios at RHIC can be used to provide
non-trivial information about the critical temperature of the QCD phase
transition. This is obtained by including the effects of highly massive
Hagedorn resonances on statistical models, which are used to describe hadronic
yields. Hagedorn states are relevant close to and have been shown to
decrease to the KSS limit and allow for quick chemical equilibrium
times in dynamical calculations of hadrons. The inclusion of Hagedorn states
creates a dependence of the thermal fits on the Hagedorn temperature, ,
which is assumed to be equal to , and leads to an overall improvement of
thermal fits. We find that for Au+Au collisions at RHIC at
GeV the best square fit measure, , occurs at MeV and
produces a chemical freeze-out temperature of 170.4 MeV and a baryon chemical
potential of 27.8 MeV.Comment: 6 pages, 2 figures, talk presented at the International Conference on
Strangeness in Quark Matter, Buzios, Rio de Janeiro, Brazil, Sept. 27 - oct.
2, 200
Quark-Gluon Plasma at RHIC and the LHC: Perfect Fluid too Perfect?
Relativistic heavy ion collisions have reached energies that enable the
creation of a novel state of matter termed the quark-gluon plasma. Many
observables point to a picture of the medium as rapidly equilibrating and
expanding as a nearly inviscid fluid. In this article, we explore the evolution
of experimental flow observables as a function of collision energy and attempt
to reconcile the observed similarities across a broad energy regime in terms of
the initial conditions and viscous hydrodynamics. If the initial spatial
anisotropies are very similar for all collision energies from 39 GeV to 2.76
TeV, we find that viscous hydrodynamics might be consistent with the level of
agreement for v2 of unidentified hadrons as a function of pT . However, we
predict a strong collision energy dependence for the proton v2(pT). The results
presented in this paper highlight the need for more systematic studies and a
re-evaluation of previously stated sensitivities to the early time dynamics and
properties of the medium.Comment: 11 pages, 9 figures, submitted to the New Journal of Physics focus
issue "Strongly Correlated Quantum Fluids: From Ultracold Quantum Gases to
QCD Plasmas
Parallelization of Kinetic Theory Simulations
Numerical studies of shock waves in large scale systems via kinetic
simulations with millions of particles are too computationally demanding to be
processed in serial. In this work we focus on optimizing the parallel
performance of a kinetic Monte Carlo code for astrophysical simulations such as
core-collapse supernovae. Our goal is to attain a flexible program that scales
well with the architecture of modern supercomputers. This approach requires a
hybrid model of programming that combines a message passing interface (MPI)
with a multithreading model (OpenMP) in C++. We report on our approach to
implement the hybrid design into the kinetic code and show first results which
demonstrate a significant gain in performance when many processors are applied.Comment: 10 pages, 3 figures, conference proceeding
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