21,030 research outputs found
Mean field baryon magnetic moments and sumrules
New developments have spurred interest in magnetic moments (-s) of
baryons. The measurement of some of the decuplet -s and the findings of
new sumrules from various methods are partly responsible for this renewed
interest. Our model, inspired by large colour approximation, is a relativistic
self consistent mean field description with a modified Richardson potential and
is used to describe the -s and masses of all baryons with up (u), down (d)
and strange (s) quarks. We have also checked the validity of the Franklin
sumrule (referred to as CGSR in the literature) and sumrules of Luty,
March-Russell and White. We found that our result for sumrules matches better
with experiment than the non-relativistic quark model prediction. We have also
seen that quark magnetic moments depend on the baryon in which they belong
while the naive quark model expects them to be constant.Comment: 7 pages, no figure, uses epl.cl
A Note on Complex-Hyperbolic Kleinian Groups
Let Γ be a discrete group of isometries acting on the complex hyperbolic n-space HCn. In this note, we prove that if Γ is convex-cocompact, torsion-free, and the critical exponent δ(Γ) is strictly lesser than 2, then the complex manifold HCn/Γ is Stein. We also discuss several related conjectures
Community-based fish culture in seasonal floodplains
During the rainy season in extensive river floodplains and deltaic lowlands, floods render the land unavailable for crop production for several months each year. These waters are considerably underutilized in terms of managed aquatic productivity. This raises the opportunity to enclose parts of these floodwater areas to produce a crop of specifically stocked aquatic organisms aside from the naturally occurring ‘wild’ species that are traditionally fished and are not affected by the culture activity, resulting in more high-quality, nutrient-dense food production and enhanced farm income for all stakeholders, notably the poor. The WorldFish Center and its national partners recently tested the concurrent rice-fish culture in the shallower flooded areas and the alternating rice-fish culture in the deep-flooded areas of Bangladesh and Viet Nam through a community-based management system. Results indicate that community-based fish culture in rice fields can increase fish production by about 600 kg/ha/year in shallow flooded areas and up to 1.5 t/ha/year in deep-flooded areas, without a reduction in the rice yield or wild fish catch
Thrice weekly nocturnal in-centre haemodiafiltration: a 2-year experience
Background: Adequate control of plasma phosphate without phosphate binders is difficult to achieve on a thrice-weekly haemodialysis schedule. The use of quotidian nocturnal dialysis is effective but not practical in the in-centre setting. This quality improvement project was set up as an exercise allowing the evaluation of small-solute clearance by combining convection with extended-hour dialysis in a thrice-weekly hospital setting. Methods: A single-centred, prospective analysis of patients' electronic records was performed from August 2012 to July 2014. The duration of haemodiafiltration was increased from a median of 4.5 to 8 h. Dialysis adequacy, biochemical parameters and medications were reviewed on a monthly basis. A reduction in plasma phosphate was anticipated, so all phosphate binders were stopped. Results: Since inception, 14 patients have participated with over 2,000 sessions of dialysis. The pre-dialysis phosphate level fell from a mean of 1.52 ± 0.4 to 1.06 ± 0.1 mmol/l (p < 0.05). The average binder intake of 3.26 ± 2.6 tablets was eliminated. A normal plasma phosphate range has been maintained with increased dietary phosphate intake and no requirement for intradialytic phosphate supplementation. Conclusion: Phosphate control can be achieved without the need for binders or supplementation on a thrice-weekly in-centre haemodiafiltration program
Properties of soliton surfaces associated with integrable sigma models
We investigate certain properties of -valued
two-dimensional soliton surfaces associated with the integrable
sigma models constructed by the orthogonal rank-one
Hermitian projectors, which are defined on the two-dimensional Riemann sphere
with finite action functional. Several new properties of the projectors mapping
onto one-dimensional subspaces as well as their relations with three mutually
different immersion formulas, namely, the generalized Weierstrass, Sym-Tafel
and Fokas-Gel'fand have been discussed in detail. Explicit connections among
these three surfaces are also established by purely analytical descriptions
and, it is demonstrated that the three immersion formulas actually correspond
to the single surface parametrized by some specific conditions.Comment: 17 page
Ongoing rehabilitation of coastal communities in Aceh province : a new project
This article presents an overview of the project on Rehabilitation of Fisheries and Aquaculture in Tsunami-affected Coastal Communities in Aceh Province. Building on the research results from the recently completed projects detailed in the previous articles, this project shall synthesize information on coastal fishing communities and resources in order to develop site-specific management options to support rehabilitation of fisheries and aquaculture.Disasters, Coastal zone, ISEW, Indonesia, Aceh,
Strange stars at finite temperature
We calculate strange star properties, using large N_c approximation with
built-in chiral symmetry restoration (CSM). We used a relativistic Hartree Fock
mean field approximation method, using a modified Richardson potential with two
scale parameters \Lambda and \Lambda^\prime, to find a new set of equation of
states for strange quark matter. We take the effect of temperature (T) on gluon
mass, in addition to the usual density dependence, and find that the transition
T from hadronic matter to strange matter is 80 MeV. Therefore formation of
strange stars may be the only signal for formation of QGP with asymptotic
freedom and CSM.Comment: To be published in the proceedings of The Third 21COE Symposium, held
at Department of Physics, Waseda University, Tokyo, Japan, September 1-3,
200
The connection between the nuclear matter mean-field equation of state and the quark and gluon condensates at high density
It is known now that chiral symmetry restoration requires the meson-nucleon
coupling to be density dependent in nuclear-matter mean-field models. We
further show that quite generally, the quark and gluon condensates in medium
are related to the trace of energy-momentum tensor of nuclear matter and in
these models the incompressibility, K, must be less than thrice the chemical
potential, . In the critical density , the gluon condensate is
only reduced by indicating a larger effective nucleon mass.Comment: 10 pages latex file, 3 Postscript figures after being uncompressed.
Submitted to Phys. Rev. Let
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