12,289 research outputs found
Monte Carlo Study of Ordering and Domain Growth in a Class of fcc-Alloy Models
Ordering processes in fcc-alloys with composition A_3B (like Cu_3Au, Cu_3Pd,
CoPt_3 etc.) are investigated by Monte Carlo simulation within a class of
lattice models based on nearest-neighbor (NN) and second-neighbor (NNN)
interactions. Using an atom-vacancy exchange algorithm, we study the growth of
ordered domains following a temperature quench below the ordering spinodal. For
zero NNN-interactions we observe an anomalously slow growth of the domain size
L(t) \sim t^\alpha, where \alpha \sim 1/4 within our accessible timescales.
With increasing NNN-interactions domain growth becomes faster and \alpha
gradually approaches the value 1/2 as predicted by the conventional
Lifshitz-Allen-Cahn theory.Comment: 6 pages, 4 figure
Application of wavelets to singular integral scattering equations
The use of orthonormal wavelet basis functions for solving singular integral
scattering equations is investigated. It is shown that these basis functions
lead to sparse matrix equations which can be solved by iterative techniques.
The scaling properties of wavelets are used to derive an efficient method for
evaluating the singular integrals. The accuracy and efficiency of the wavelet
transforms is demonstrated by solving the two-body T-matrix equation without
partial wave projection. The resulting matrix equation which is characteristic
of multiparticle integral scattering equations is found to provide an efficient
method for obtaining accurate approximate solutions to the integral equation.
These results indicate that wavelet transforms may provide a useful tool for
studying few-body systems.Comment: 11 pages, 4 figure
Scattering Calculations with Wavelets
We show that the use of wavelet bases for solving the momentum-space
scattering integral equation leads to sparse matrices which can simplify the
solution. Wavelet bases are applied to calculate the K-matrix for
nucleon-nucleon scattering with the s-wave Malfliet-Tjon V potential. We
introduce a new method, which uses special properties of the wavelets, for
evaluating the singular part of the integral. Analysis of this test problem
indicates that a significant reduction in computational size can be achieved
for realistic few-body scattering problems.Comment: 26 pages, Latex, 6 eps figure
Equation-free Dynamic Renormalization of a KPZ-type Equation
In the context of equation-free computation, we devise and implement a
procedure for using short-time direct simulations of a KPZ type equation to
calculate the self-similar solution for its ensemble averaged correlation
function. The method involves "lifting" from candidate pair-correlation
functions to consistent realization ensembles, short bursts of KPZ-type
evolution, and appropriate rescaling of the resulting averaged pair correlation
functions. Both the self-similar shapes and their similarity exponents are
obtained at a computational cost significantly reduced to that required to
reach saturation in such systems
Alternative Liability in Litigation Malpractice Actions: Eradicating the Last Resort of Scoundrels
The legal malpractice tort, however, has managed to withstand the winds of legal change. Particularly crucial has been the refusal to apply alternative causation doctrines. The refusal to apply causation doctrines that have been embraced in other areas has significant social effects. As a result, the consumers of legal services receive less protection from the courts than do the consumers of products or medical services
Expression of the insulin-like growth factor-II/mannose-6-phosphate receptor in multiple human tissues during fetal life and early infancy
The insulin like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor has been detected in many cells and tissues. In the rat, there is a dramatic developmental regulation of IGF-II/M6P receptor expression, the receptor being high in fetal and neonatal tissues and declining thereafter. We have systematically studied the expression of the human IGF-II/M6P receptor protein in tissues from 10 human fetuses and infants (age 23 weeks gestation to 24 months postnatal). We have asked 1) whether there is differential expression among different organs, and 2) whether or not the human IGF-II/M6P receptor is developmentally regulated from 23 weeks gestation to 24 months postnatal. Protein was extracted from human tissues using a buffer containing 2% sodium dodecyl sulfate and 2% Triton X-100. Aliquots of the protein extracts were analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis and immunoblotting using an anti-IGF- II/M6P receptor antiserum (no. 66416) and 125I-protein A or an immunoperoxidase stain. IGF-II/M6P receptor immunoreactivity was detected in all tissues studied with the highest amount of receptor being expressed in heart, thymus, and kidney and the lowest receptor content being measured in brain and muscle. The receptor content in ovary, testis, lung, and spleen was intermediate. The apparent molecular weight of the IGF-II/M6P receptor (220,000 kilos without reduction of disulfide bonds) varied among the different tissues: in brain the receptor was of lower molecular weight than in other organs. Immunoquantitation experiments employing 125I-protein A and protein extracts from human kidney at different ages revealed a small, albeit not significant, difference of the receptor content between fetal and postnatal tissues: as in other species, larger amounts of receptor seemed to be present in fetal than in postnatal organs. In addition, no significant difference of the receptor content between human fetal liver and early postnatal liver was measured employing 125I-protein A- immunoquantitation in three fetal and five postnatal liver tissue samples. The distribution of IGF-binding protein (IGEBP) species, another abundant and major class of IGF binding principles, was also measured in human fetal and early postnatal lung, liver, kidney, muscle, and brain using Western ligand blotting with 125I-IGF-II: as with IGF-II/M6P receptor immunoreactivity there was differential expression of the different classes of IGFBPs in the various organs
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