544 research outputs found
Excited states nonlinear integral equations for an integrable anisotropic spin 1 chain
We propose a set of nonlinear integral equations to describe on the excited
states of an integrable the spin 1 chain with anisotropy. The scaling
dimensions, evaluated numerically in previous studies, are recovered
analytically by using the equations. This result may be relevant to the study
on the supersymmetric sine-Gordon model.Comment: 15 pages, 2 Figures, typos correcte
Stability and structure of two coupled boson systems in an external field
The lowest adiabatic potential expressed in hyperspherical coordinates is
estimated for two boson systems in an external harmonic trap. Corresponding
conditions for stability are investigated and the related structures are
extracted for zero-range interactions. Strong repulsion between non-identical
particles leads to two new features, respectively when identical particles
attract or repel each other. For repulsion new stable structures arise with
displaced center of masses. For attraction the mean-field stability region is
restricted due to motion of the center of masses
Density matrix renormalization group for the Berezinskii-Kosterlitz-Thouless transition of the 19-vertex model
We embody the density matrix renormalization group (DMRG) method for the
19-vertex model on a square lattice in order to investigate the
Berezinskii-Kosterlitz-Thouless transition. Elements of the transfer matrix of
the 19-vertex model are classified in terms of the total value of arrows in one
layer of the square lattice. By using this classification, we succeed to reduce
enormously the dimension of the matrix which has to be diagonalized in the DMRG
method. We apply our method to the 19-vertex model with the interaction
and obtain for the conformal anomaly. PACS. 05.90.+m,
02.70.-cComment: RevTeX style, 20 pages, 12 figure
Effect of Biological and Chemical Ripening Agents on the Nutritional and Metal Composition of Banana (Musa spp)
The use of potentially toxic ripening agents is common in developing countries. Four ripening agents namely calcium carbide, potash, African mango and jathropha curcas leaf were used and compared with a control with no ripening agent. Result showed that RB1 and RB2 were the first to ripen at 3days with RB5 at 6th day. Protein content reduced in the ripened samples in the order of 4.12>3.68>3.04>2.52>1.99>1.77%. Protein value was lowest when calcium carbide was used. Fat ash and fiber contents range between 0.28-1.72, 0.75-2.75and 0.50-1.75% respectively. The moisture content increased from 65.50 to 74.0%, while carbohydrate content range is 17.49-29.29%. Pb, Cu, Zn and Mn values of 0.22, 0.87, 1.96 and 0.67ppm was highest in calcium carbide ripened banana and lowest in the control 0.09, 0.26, 0.37 and 0.19 ppm.Keywords: Banana; ripening; ripening agents; postharvest losses; metal contaminatio
Spontaneous generation of spin-orbit coupling in magnetic dipolar Fermi gases
The stability of an unpolarized two-component dipolar Fermi gas is studied
within mean-field theory. Besides the known instability towards spontaneous
magnetization with Fermi sphere deformation, another instability towards
spontaneous formation of a spin-orbit coupled phase with a Rashba-like spin
texture is found. A phase diagram is presented and consequences are briefly
discussed
Spinons in Magnetic Chains of Arbitrary Spins at Finite Temperatures
The thermodynamics of solvable isotropic chains with arbitrary spins is
addressed by the recently developed quantum transfer matrix (QTM) approach. The
set of nonlinear equations which exactly characterize the free energy is
derived by respecting the physical excitations at T=0, spinons and RSOS kinks.
We argue the implication of the present formulation to spinon character formula
of level k=2S SU(2) WZWN model .Comment: 25 pages, 8 Postscript figures, Latex 2e,uses graphicx, added figures
and detailed discussion
From the quantum Jacobi-Trudi and Giambelli formula to a nonlinear integral equation for thermodynamics of the higher spin Heisenberg model
We propose a nonlinear integral equation (NLIE) with only one unknown
function, which gives the free energy of the integrable one dimensional
Heisenberg model with arbitrary spin. In deriving the NLIE, the quantum
Jacobi-Trudi and Giambelli formula (Bazhanov-Reshetikhin formula), which gives
the solution of the T-system, plays an important role. In addition, we also
calculate the high temperature expansion of the specific heat and the magnetic
susceptibility.Comment: 18 pages, LaTeX; some explanations, 2 figures, one reference added;
typos corrected; to appear in J. Phys. A: Math. Ge
PHYSICOCHEMICAL PROPERTIES OF PRO-VITAMIN A CASSAVA-WHEAT COMPOSITE FLOUR BISCUIT
In this research work, the physicochemical properties of biscuit made from wheat flour and pro-vitamin A cassava flour mixed in different ratios of 100:0, 90:10, 80:20, 70:30 and 60:40 (w/w) was investigated. The addition of pro-vitamin A flour to wheat flour influenced the functional properties such as water absorption, swelling and pasting properties. Peak, trough, breakdown and final viscosities of 100% wheat flour was generally lower than the mixes. However, the setback viscosity of the mixes were lower than that of wheat flour. This was attributed to possible complex formation between the starch components of the flours and the carotenoid. Protein (10.80-15.45%), fat (11.87-21.35%) and carbohydrate (60.08-70.99%) were the major components of the biscuits. The protein and fat contents of the biscuit decreased with increasing proportions of pro-vitamin A cassava flour. But, the carotenoid contents of the biscuits increased. Sensory results showed that biscuit prepared from wheat flour and pro-vitamin A cassava flour in ratio 90 to 10 had similar overall acceptability rating (6.50) and total rating score (31.8) to the control (Overall acceptability rating; 6.50 and total rating score; 32.5). The research has established that acceptable biscuits which could be potentially used to address protein, energy and vitamin A challenges in developing nations of the world
Finite-dimensional analogs of string s <-> t duality and pentagon equation
We put forward one of the forms of functional pentagon equation (FPE), known
from the theory of integrable models, as an algebraic explanation to the
phenomenon known in physics as st duality. We present two simple geometrical
examples of FPE solutions, one of them yielding in a particular case the
well-known Veneziano expression for 4-particle amplitude. Finally, we interpret
our solutions of FPE in terms of relations in Lie groups.Comment: LaTeX, 12 pages, 6 eps figure
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