The stability of an air-maintained cavity behind a stationary object in flowing water

In studies made in the Free Surface Water Tunnel of a projectile running in an air-maintained cavity, the experimental relation between air entrainment rate and cavitation number was determined. The entrainment-rate coefficient CQ = Q/V0d^2, where Q is the air rate in cfs, V0 the free-stream velocity, and d the disk nose diameter, was plotted against cavitation parameter, K = (p0 - pk)/q0 where p0 is the free-stream pressure at the disk center line, pk the cavity pressure, and q0 the free-stream dynamic pressure. This experimental relationship for one single disc is shown for three different velocities in Fig. 1. The curves are similar in shape and each has a minimum value of entrainment coefficient which is designated by CQ^* at a value of K as designated as K^*

What Do Wage Differentials Tell Us about Labor Market Discrimination?

We examine the extent to which non-discriminatory factors can explain observed wage gaps between racial and ethnic minorities and whites, and between women and men. In general we find that differences in productivity-related factors account for most of the between group wage differences in the year 2000. Determinants of wage gaps differ by group. Differences in schooling and in skills developed in the home and in school, as measured by test scores, are of central importance in explaining black/white and Hispanic/white wage gaps among both women and men. Immigrant assimilation is an additional factor for Asians and workers from Central and South America. The sources of the gender gap are quite different, however. Gender differences in schooling and cognitive skills as measured by the AFQT are quite small and explain little of the pay gap. Instead the gender gap largely stems from choices made by women and men concerning the amount of time and energy devoted to a career, as reflected in years of work experience, utilization of part-time work, and other workplace and job characteristics.

Remarks on the Reeh-Schlieder property for higher spin free fields on curved spacetimes

The existence of states enjoying a weak form of the Reeh-Schlieder property has been recently established on curved backgrounds and in the framework of locally covariant quantum field theory. Since only the example of a real scalar field has been discussed, we extend the analysis to the case of massive and massless free fields either of spin 1/2 or of spin 1. In the process, it is also shown that both the vector potential and the Proca field can be described as a locally covariant quantum field theory.Comment: 28 pages, references and remarks added, typos correcte

Monte Carlo Simulation of Spacecraft Particle Detectors to Assess the True Human Risk

Particle detectors (DOSTEL, CPDS, and TEPC) measure the energy deposition spectrum inside earth orbiting - manned spacecraft (shuttle, space station). These instruments attempt to emulate the deposition of energy in human tissue to evaluate the health risk. However, the measurements are often difficult to relate to tissue equivalent because nuclear fragmentation (internuclear cascade/evaporation), energy-loss straggling, heavy ions, spacecraft shielding and detector geometry/orientation, and coincidence thresholds significantly affect the measured spectrum. 'A le have developed a high fidelity Monte Carlo model addressing each of these effects that significantly improves interpretation of these instruments and the resulting assessment of radiation risk to humans