RETSCP-A computer program for analysis of rocket engine thermal strains with cyclic plasticity

Finite element program employs three-dimensional isoparametric element for analysis of rocket engine thermal strains with cyclic plasticity

Biaxial prestressing of brittle materials

Strengthening of chemically consolidated zirconia with tungsten fibers, graphite fibers, sapphire whiskers, and silicon carbide whiskers is investigated. Addition of silicon carbide whiskers gives the highest increase in strength of zirconia at room and elevated temperatures. Prestressing with tungsten cables increases tensile strength and ductilit

Negative and Positive Assimilation, Skill Transferability, and Linguistic Distance

There are two complementary models of immigrants' economic and social adjustment -- the positive assimilation model of Chiswick (1978, 1979), and the negative assimilation model of Chiswick and Miller (2011). The negative assimilation model is applicable for immigrants from countries that are very similar in terms of the transferability of skills, culture, and labor market institutions to the host country, and has been tested previously primarily using migration among the English-speaking developed countries. This paper generalizes the negative/positive assimilation models through analyzing the post-arrival learnings profiles of immigrants in the US from non-English-speaking countries according to the linguistic distance of their mother tongue from English. Using data on adult male immigrants from the 2000 US Census, it is shown that all groups of immigrants from non English-speaking countries are characterized by positive assimilation. Earnings in the immediate post-arrival period are lowest for the language groups furthest from English, and the increase in earnings with duration is steeper the further the immigrant's mother tongue is from English. The linguistic distance of the immigrants' mother tongue from the destination language appears, therefore, to play a crucial role in generating the inverse relationship between post-arrival earnings growth and the initial earnings disadvantage documented in most studies of immigrant earnings

A New S-S' Pair Creation Rate Expression Improving Upon Zener Curves for I-E Plots

To simplify phenomenology modeling used for charge density wave (CDW)transport, we apply a wavefunctional formulation of tunneling Hamiltonians to a physical transport problem characterized by a perturbed washboard potential. To do so, we consider tunneing between states that are wavefunctionals of a scalar quantum field. I-E curves that match Zener curves - used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. This has a very strong convergence with electron-positron pair production representations.The similarities in plot behavior of the current values after the threshold electric field values argue in favor of the Bardeen pinning gap paradigm proposed for quasi-one-dimensional metallic transport problems.Comment: 22 pages,6 figures, and extensive editing of certain segments.Paper has been revised due to acceptance by World press scientific MPLB journal. This is word version of file which has been submitted to MPLBs editor for final proofing. Due for publication perhaps in mid spring to early summer 200

The Hilbert Action in Regge Calculus

The Hilbert action is derived for a simplicial geometry. I recover the usual Regge calculus action by way of a decomposition of the simplicial geometry into 4-dimensional cells defined by the simplicial (Delaunay) lattice as well as its dual (Voronoi) lattice. Within the simplicial geometry, the Riemann scalar curvature, the proper 4-volume, and hence, the Regge action is shown to be exact, in the sense that the definition of the action does not require one to introduce an averaging procedure, or a sequence of continuum metrics which were common in all previous derivations. It appears that the unity of these two dual lattice geometries is a salient feature of Regge calculus.Comment: 6 pages, Plain TeX, no figure

The "Negative" Assimilation of Immigrants: A Special Case

Research on the economic or labor market assimilation of immigrants has to date focused on the degree of improvement in their economic status with duration in the destination. This pattern has been found for all the immigrant receiving countries, time periods and data sets that have been studied. The theoretical underpinning for this finding is the international transferability of skills. This paper addresses whether positive assimilation will be found if skills are very highly transferable internationally. It outlines the conditions for “negative” assimilation in the context of the traditional immigration assimilation model, and examines the empirical relevance of the hypothesis using data on immigrants from the English-speaking developed countries (i.e., the UK, Ireland, Canada and Australia/New Zealand) to the United States. Comparisons with the native born are also presented to test whether the findings are sensitive to immigrant cohort quality effects. Even after controlling for cohort effects, “negative” assimilation (a decline in earnings with duration) is found for immigrants in the US from the English-speaking developed countries.immigrants, earnings, assimilation