Today's Immigrant Woman Entrepreneur

Immigrant women entrepreneurs are rapidly making their mark in the U.S. business sector, in every region of the country and across a large range of industries. Today, immigrant women of the post-1960s wave of immigration comprise one of the fastest growing groups of business owners in the United States. This study examines the rise of immigrant women entrepreneurs and profiles them as a group using data from the 2000 Decennial Census and other sources

Oxygen and carbon impurities and related defects in silicon

Oxygen and carbon are the predominant impurities in Czochralski-grown silicon. The incorporation of oxygen and carbon during crystal growth is reviewed and device effects are discussed. Methods for controlling oxygen and carbon incorporation during crystal growth are discussed and results supporting a segregation coefficient of k=0.5 for oxygen are presented. The nucleation and precipitation behavior of oxygen is complex. Temperature and doping level effects which add insight into the role of point defects in the nucleation process are highlighted. In general, precipitation is found to be retarded in N+ and P+ silicon. The types and quantities of defects resulting from the oxygen precipitates is of interest as they are technologically useful in the process called intrinsic gettering. A comparison is made between the available defect sites and the quantities of metallic impurities present in a typical wafer which need to be gettered. Finally, a discussion of the denuded-zone, intrinsic-gettered (DZ-IG) structure on device properties is presented

The Geometry of Axisymmetric Ideal Fluid Flows with Swirl

The sectional curvature of the volume preserving diffeomorphism group of a Riemannian manifold $M$ can give information about the stability of inviscid, incompressible fluid flows on $M$. We demonstrate that the submanifold of the volumorphism group of the solid flat torus generated by axisymmetric fluid flows with swirl, denoted by $\mathcal{D}_{\mu,E}(M)$, has positive sectional curvature in every section containing the field $X = u(r)\partial_\theta$ iff $\partial_r(ru^2)>0$. This is in sharp contrast to the situation on $\mathcal{D}_{\mu}(M)$, where only Killing fields $X$ have nonnegative sectional curvature in all sections containing it. We also show that this criterion guarantees the existence of conjugate points on $\mathcal{D}_{\mu,E}(M)$ along the geodesic defined by $X$.Comment: 8 page

Some aspects of electro-chemical grid-marking

Introduction The value of fine grids, electromarked (1) on to metal sheets before pressing, so that the type and magnitude of the strain developed in the critical region of the pressing can be assessed, is undisputed. Keeler (2), Meyer and Newby (3), and Goodwin (4), have all discussed practical applications of this technique and Palmer (5) has reviewed the field and introduced the concept of a relative safety factor (MSF). However it may be useful to see what this 'mark' consists of, how the marking affects the subsequent metal performance, what the limitations of the process are and other peripherical issues. It is these aspects of the process which is the concern of this paper

The stability of new transparent polymeric materials: The epoxy trimethoxyboroxine system. Part 1: The preparation, characterization and curing of epoxy resins and their copolymers

The effects of resin composition, curing conditions fillers, and flame retardant additives on the flammability of diglycidyl ether of bisphenol-A (DGEBA) as measured by the oxygen index is examined. The oxygen index of DGEBA cured with various curing agents was between 0.198 to 0.238. Fillers and flame retardant additives can increase the oxygen index dependent on the material and the amount used. Changes in the basic cured resin properties can be anticipated with the addition of noncompatible additives. High flame resistant epoxy resins with good stability and mechanical properties are investigated

Extended plasticity in commercial-purity zinc

90% rolling-reduction of annealed commercial-purity zinc sheet (grain size 100 - 150 μ) results in the fragmentation of the large grains into, finally, stable micro-grains, 1 - 211 in diameter. The stability of the micro-grains is due to the presence of soluble and insoluble impurities which prevent recrystallization. This micro-grain material is strain-rate sensitive, and elongations of 200% have been obtained at room temperature. Although this as-rolled, 90% reduction zinc sheet is not super-plastic according to the current definition, its behaviour has led to the coining of the phase 'extended plasticity'. Evidence of grain-boundary sliding is found on examination of the surface by scanning electron microscopy, while the examination of thin foils and activation energy measurements support the dynamic softening (recovery) theory; thus, both these mechanisms must be operating, to a greater or less extent, to confer on this material the observe mechanical behaviour. It is finally concluded that it is dangerous to draw conclusions regarding the mechanism of plastic deformation from surface observations alone