1,553 research outputs found
An Analysis of a Need-Based Student Aid Program for Georgia - Brief
This report explores issues associated with establishing a need-based student aid program in Georgia. FRC Brief 17
An Analysis of a Need-Based Student Aid Program for Georgia
This report explores issues associated with establishing a need-based student aid program in Georgia. FRC Report 17
Jet-fluid string formation and decay in high-energy heavy-ion collisions
We propose a new hadronization mechanism, jet-fluid string (JFS) formation
and decay, to understand observables in intermediate to high- regions
comprehensively. In the JFS model, hard partons produced in jet lose their
energy in traversing the QGP fluid, which is described by fully
three-dimensional hydrodynamic simulations. When a jet parton escapes from the
QGP fluid, it picks up a partner parton from a fluid and forms a color singlet
string, then it decays to hadrons. We find that high- values in JFS
are about two times larger than in the independent fragmentation model.Comment: 6 pages, 2 figures; Proceeding for poster sessions at Quark Matter
2006, Shanghai, China, 14-20 November 2006; to appear in Int. J. of Mod.
Phys.
Ultraviolet avalanche in anisotropic non-Abelian plasmas
We present solutions of coupled particle-field evolution in classical U(1)
and SU(2) gauge theories in real time on three-dimensional lattices. For
strongly anisotropic particle momentum distributions, we find qualitatively
different behavior for the two theories when the field strength is high enough
that non-Abelian self-interactions matter for SU(2). It appears that the energy
drained by a Weibel-like plasma instability from the particles does not build
up exponentially in transverse magnetic fields but instead returns,
isotropically, to the hard scale via a rapid avalanche into the ultraviolet.Comment: 22 pages, 10 figures; v3: small textual changes; updated to
correspond with version to appear in publicatio
Forward particle productions at RHIC and the LHC from CGC within local rcBK evolution
In order to describe forward hadron productions in high-energy nuclear
collisions, we propose a Monte-Carlo implementation of
Dumitru-Hayashigaki-Jalilian-Marian formula with the unintegrated gluon
distribution obtained numerically from the running-coupling BK equation. We
discuss influence of initial conditions for the BK equation by comparing a
model constrained by global fit of small-x HERA data and a newly proposed one
from the running coupling MV model.Comment: Talk given at conference Quark Matter 2011, 4 page
Functional outcome of small and long bone lengthening by distraction osteogenesis
Background: Upper limb lengthening has limited indications because of the predominant non weight bearing nature. However, lengthening does have specific indications where the functional outcomes improve in selected patients. The aim of the study was to compare the clinical and radiological outcomes of upper limb long and short bone lengthening by distraction osteogenesis.Methods: A total of twenty four lengthenings were done in 21 patients, three cases being bilateral. The study group included cases of club hand, symbrachydactyly, multiple hereditary osteocondramatosis, traumatic amputations and congenital defects. Operative technique involved gradual mechanical distraction by orthofix external fixator after osteotomy. Clinical and radiological evaluation was done on follow up. The functional outcome for daily activities was assessed. The Healing index, Percentage healing index and Consolidation time were calculated.Results: The mean age of patients was 11.6 years. The percentage healing index of long bones was higher compared to short bones but the consolidation time was almost similar. Complications were seen in 35% patients. The satisfaction rates were higher in small bone lengthening and the complication rates were almost same as for long bones. Grasp, pinch strength and range of motion improved in cases of short bone lengthening.Conclusions: Distraction osteogenesis is reliable and predictable method of correction of osseous defects with vascular bone without sacrificing any adjacent digits or toes. It also gains soft tissue that is sensate with good blood supply
Diurnal changes in shoot water dynamics are synchronized with hypocotyl elongation in Arabidopsis thaliana
We recently demonstrated the circadian clock modulated water dynamics in the roots of a small model plant, Arabidopsis thaliana, by the Nuclear Magnetic Resonance (NMR) microimaging technique. Our developed technique was able to visualize the water distribution that depended on differences in the 1H signal among region in the shoot, such as the shoot apex, the hypocotyl and the root shoot junction. Water content in the shoot increased during periods of light in comparison with dark periods, and continued through the early stage of seedling growth until the dark period. When the water content changed, elongation and/or movement occurred in the hypocotyl, and these events were synchronized. The water dynamics of the shoot also displayed an opposite phase with the root water dynamics
Status of ECR ion sources at JAERI
At the Takasaki site of Japan Atomic Energy Research Institute, four ECR ion sources were purchased or developed so far. This paper will report their performance, modification and status. The outlines for each source are as follows; 1. OCTOPUS purchased from IBA s.a. has been in use with a cyclotron since 1990. The gas feed system was modified to change gas species within 10 minutes to avoid impurity ions in the cocktail beam acceleration technique of the cyclotron. 2. ECR-18 with 18-GHz microwave has a solenoid coil between a pair of mirror coils to change mirror ratio in a wide range. A bump between mirror peaks in the original axial field distribution was removed by halving the solenoid length. The performance in generating high charge state ions was significantly improved as a result. 3. HYPERNANOGAN was purchased from PANTECHNIK s.a. and installed in the cyclotron system this year. Test operation was successfully made with generation of Ar, Pb and Ta ions. 4. MINI ECR is a full permanent magnet source with 10 GHz microwave. As a result of modifications for vacuum and the application of a bias probe, 40 microA of Ar4+ beam was obtained, for example. Using this source, a new technique was developed to vaporize very refractory materials into plasma by fluorinating them with SF6 plasma. The source is in use for a 400 kV ion implantor since last year
Thermalization and the chromo-Weibel instability
Despite the apparent success of ideal hydrodynamics in describing the
elliptic flow data which have been produced at Brookhaven National Lab's
Relativistic Heavy Ion Collider, one lingering question remains: is the use of
ideal hydrodynamics at times t < 1 fm/c justified? In order to justify its use
a method for rapidly producing isotropic thermal matter at RHIC energies is
required. One of the chief obstacles to early isotropization/thermalization is
the rapid longitudinal expansion of the matter during the earliest times after
the initial nuclear impact. As a result of this expansion the parton
distribution functions become locally anisotropic in momentum space. In
contrast to locally isotropic plasmas anisotropic plasmas have a spectrum of
soft unstable modes which are characterized by exponential growth of transverse
chromo-magnetic/-electric fields at short times. This instability is the QCD
analogue of the Weibel instability of QED. Parametrically the chromo-Weibel
instability provides the fastest method for generation of soft background
fields and dominates the short-time dynamics of the system.Comment: 8 pages, 4 figures, Invited plenary talk given at the 19th
International Conference on Ultrarelativistic Nucleus-Nucleus Collisions:
Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 200
Re-Hardening of Hadron Transverse Mass Spectra in Relativistic Heavy-Ion Collisions
We analyze the spectra of pions and protons in heavy-ion collisions at
relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented
hadron-string cascade model. In this energy region, hadron transverse mass
spectra first show softening until SPS energies, and re-hardening may emerge at
RHIC energies. Since hadronic matter is expected to show only softening at
higher energy densities, this re-hardening of spectra can be interpreted as a
good signature of the quark-gluon plasma formation.Comment: 10 pages, 3 figures, 1 table, Poster presentation at QM2001, Revised
to correct latex error in citation on April 6, 200
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