Venting device for pressurized space suit helmet Patent

Venting device for pressurized space suit helmet to eliminate vomit expelled by crewme

Planar radiation zeros in five-parton QCD amplitudes

We demonstrate the existence of `planar', or `type-II', radiation zeros in 5-parton QCD scattering processes. That is, the Born amplitudes are shown to completely vanish for particular kinematic configurations, when all the particle 3-momenta lie in a plane. This result is shown to follow particularly simply from the known BCJ relations between the colour-ordered tree amplitudes, and the MHV formalism is used to express the additional kinematic constraint as a relatively simple expression in terms of only rapidity differences between the final-state partons. In addition, we find that zeros exist for non-planar configurations of the final-state partons, but for which the normal `type-I' conditions on the particle four-momenta do not generally apply. We present numerical results and comment on the possibility of observing planar radiation zeros in hadronic collisions, via central exclusive three-jet production.Comment: 22 pages, 5 figures. Version accepted for publication in JHE

Locally Adaptive Function Estimation for Binary Regression Models

In this paper we present a nonparametric Bayesian approach for fitting unsmooth or highly oscillating functions in regression models with binary responses. The approach extends previous work by Lang et al. (2002) for Gaussian responses. Nonlinear functions are modelled by first or second order random walk priors with locally varying variances or smoothing parameters. Estimation is fully Bayesian and uses latent utility representations of binary regression models for efficient block sampling from the full conditionals of nonlinear functions

Women, Work, and Motherhood: Changing Employment Penalties for Motherhood in West Germany after 1945 -- A Comparative Analysis of Cohorts Born in 1934-1971

This paper deals with the effects of entry into motherhood on women's employment dynamics. Our analysis is based on the complete lifetime working- and income histories of a 1% sample of all persons born between 1934 and 1971 and employed in West Germany sometime between 1975 and 1995. We use the records of women who were employed before the birth of their first child. We apply a semi-parametric hierarchical Bayesian modeling approach simultaneously including several time scales and further covariates whose effects we estimate by MCMC techniques. We investigate short-term consequences of entry into motherhood and their changes over different birth cohorts and thereby take into account the employment histories before the birth of the first child. We conduct two models differentiating between the simple return to the labor market and the return for at least a certain period in order to measure subsequent employment stability. Our results indicate that a higher extent of employment experience, a stronger attachment to the labor market and an employment in white collar jobs reduces the employment penalty for mothers after the birth of their first child

Elliptic flow of gluon matter in ultrarelativistic heavy-ion collisions

Employing a perturbative QCD based parton cascade we calculate the elliptic flow $v_2$ and its transverse momentum dependence $v_2(p_T)$ for the gluon matter created in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV. To make comparisons with the experimental data at the BNL Relativistic Heavy Ion Collider (RHIC), parton-hadron duality is assumed. We find that whereas the integrated $v_2$ matches the experimental data, the gluon (or pion) $v_2(p_T)$ is about 20-50% smaller than the experimental data. Hadronization via gluon fragmentation and quark recombination seems to be the key to explaining the necessary jump of $v_2(p_T)$ from the partonic to the hadronic phase. We also show that the elliptic flow values moderately depend on the chosen freezeout condition, which will thus constrain the shear viscosity to the entropy density ratio of the quark gluon plasma created at RHIC.Comment: 20 pages, 7 figures, minor corrections, published versio

Lateral coupled cavity semiconductor laser

We report the fabrication and operation of a lateral coupled cavity semiconductor laser that consists of two phase-locked parallel lasers of different lengths and with separate electrical contacts. Mode selectivity that results from the interaction between the two supermodes is investigated experimentally. Frequency selectivity and tunability are obtained by controlling the current to each laser separately. Highly stable single mode operation is also demonstrated

Frequency selectivity in laterally coupled semiconductor laser arrays

A longitudinal-mode analysis of a system of laterally coupled waveguided resonators is presented in the coupled-mode approximation. It is shown that variations in the mirror reflectivity of the individual channels result in coupling between the supermodes of the structure. This may lead to mode suppression by modulation of the threshold gain of different Fabry-Perot modes

Simulation of a new Pressure Swing Batch Distillation System

The operation and performance of a new pressure swing batch distillation configuration is investigated by rigorous simulation calculations. A maximum boiling point azeotrope is separated in a double column batch rectifier. We study the influence of the main operational parameters and determine the optimal value of these parameters. The calculation results are presented for the mixture water (A) – ethylene-diamine (B)