Absence of simulation evidence for critical depletion in slit-pores

Recent Monte Carlo simulation studies of a Lennard-Jones fluid confined to a mesoscopic slit-pore have reported evidence for ``critical depletion'' in the pore local number density near the liquid-vapour critical point. In this note we demonstrate that the observed depletion effect is in fact a simulation artifact arising from small systematic errors associated with the use of long range corrections for the potential truncation. Owing to the large near-critical compressibility, these errors lead to significant changes in the pore local number density. We suggest ways of avoiding similar problems in future studies of confined fluids.Comment: 4 pages Revtex. Submitted to J. Chem. Phy

[Review of] Anzia Yezierska, Red Ribbon on a White Horse

The republication of Anzia Yezierska\u27s Red Ribbon on a White Horse, with an afterword by her daughter, Louise Henriksen, is an important event in two respects: first, it represents another step in the rediscovery of a significant writer whose work deals with the experience of immigrant Jewish women at the turn of the twentieth century. Second, it is a valuable document for information on that period of mass migration. Scholars concerned with ethnic literature, as well as those previously unfamiliar with Yezierska\u27s works, will find here interesting insights into the problems and pressures of the immigrants

[Review of] Ronald H. Bayor. Neighbors in Conflict: The Irish, Germans, Jews and Italians of New York City, 1929-1941

In this study of a seldom-considered period of ethnic interaction, Bayor has provided a well-written and solidly researched appraisal of group conflict in New York City from 1929 to 1941. He has attempted to discover the reasons why conflict erupted between certain groups while others remained quiescent or were resolved

The Jang equation reduction of the spacetime positive energy theorem in dimensions less than eight

We extend the Jang equation proof of the positive energy theorem due to R. Schoen and S.-T. Yau from dimension $n=3$ to dimensions $3 \leq n <8$. This requires us to address several technical difficulties that are not present when $n=3$. The regularity and decay assumptions for the initial data sets to which our argument applies are weaker than those of R. Schoen and S.-T. Yau. In recent joint work with L.-H. Huang, D. Lee, and R. Schoen we have given a different proof of the full positive mass theorem in dimensions $3 \leq n < 8$. We pointed out that this theorem can alternatively be derived from our density argument and the positive energy theorem of the present paper.Comment: All comments welcome! Final version to appear in Comm. Math. Phy

Working Welfare Recipients: A Comparison of the Family Support Act and the Personal Responsibility and Work Opportunity Reconciliation Act

This Note compares the work requirements of the Family Support Act ( FSA ) with those promulgated by the Personal Responsibility and Work Opportunity Reconciliation Act ( PRWORA ) This Note concludes that the fairest and most effective welfare program offers a combination of work, education, and training, and proposes suggestions for implementing the existing work requirements to ensure long-term self sufficiency for welfare recipients

Expandable space frames

Expandable space frames having essentially infinite periodicity limited only by practical considerations, are described. Each expandable space frame comprises a plurality of hinge joint assemblies having arms that extend outwardly in predetermined symmetrically related directions from a central or vertex point. The outer ends of the arms form one part of a hinge point. The outer expandable space frame also comprises a plurality of struts. The outer ends of the struts from the other part of the hinged joint. The struts interconnect the plurality of hinge point in sychronism, the spaceframes can be expanded or collapsed. Three-dimensional as well as two-dimensional spaceframes of this general nature are described

A Generalized Positive Energy Theorem for Spaces with Asymptotic SUSY Compactification

A generalized positive energy theorem for spaces with asymptotic SUSY compactification involving non-symmetric data is proved. This work is motivated by the work of Dai [D1][D2], Hertog-Horowitz-Maeda [HHM], and Zhang [Z].Comment: 13 pages, without figures; Some errors are correcte

Intrinsically dynamic population models

Intrinsically dynamic models (IDMs) depict populations whose cumulative growth rate over a number of intervals equals the product of the long term growth rates (that is the dominant roots or dominant eigenvalues) associated with each of those intervals. Here the focus is on the birth trajectory produced by a sequence of population projection (Leslie) matrices. The elements of a Leslie matrix are represented as straightforward functions of the roots of the matrix, and new relationships are presented linking the roots of a matrix to its Net Reproduction Rate and stable mean age of childbearing. Incorporating mortality changes in the rates of reproduction yields an IDM when the subordinate roots are held constant over time. In IDMs, the birth trajectory generated by any specified sequence of Leslie matrices can be found analytically. In the Leslie model with 15 year age groups, the constant subordinate root assumption leads to reasonable changes in the age pattern of fertility, and equations (27) and (30) provide the population size and structure that result from changing levels of net reproduction. IDMs generalize the fixed rate stable population model. They can characterize any observed population, and can provide new insights into dynamic demographic behavior, including the momentum associated with gradual or irregular paths to zero growth.dynamic models, dynamic population models, eigenvalues, Leslie matrices, population momentum