High-gain antenna with singly-curved reflector

Reflector collects energy over large region of space and focuses it toward small region where antenna feed is located. When incident energy is in form of plane wave, logical choice for shape of reflecting surface is paraboloid which converts plane wave into spherical wave that converges at a point

Dual waveguide mode source having control means for adjusting the relative amplitude of two modes Patent

Dual waveguide mode source for controlling amplitudes of two mode

Prediction of thermal radiation from a rocket's exhaust plume

Data from absorption coefficients and fine-structure parameters measured for water vapor have been incorporated in an analytic program useful in evaluating heating by radiation from the exhaust plume of a large rocket

Some NASA contributions to the use of plasma jet technology in chemical processing

NASA contributions to use of plasma jet technology in chemical processin

Prediction of total emissivity of nitrogen- broadened and self-broadened hot water vapor

Total emissivity predicted for nitrogen-broadened and self-broadened hot water vapo

Combining NLO QCD and Electroweak Radiative Corrections to W boson Production at Hadron Colliders in the POWHEG Framework

The precision measurement of the mass of the $W$ boson is an important goal of the Fermilab Tevatron and the CERN Large Hadron Collider (LHC). It requires accurate theoretical calculations which incorporate both higher-order QCD and electroweak corrections, and also provide an interface to parton-shower Monte Carlo programs which make it possible to realistically simulate experimental data. In this paper, we present a combination of the full ${\cal O}(\alpha)$ electroweak corrections of {\tt WGRAD2}, and the next-to-leading order QCD radiative corrections to $W\to\ell\nu$ production in hadronic collisions in a single event generator based on the {\tt POWHEG} framework, which is able to interface with the parton-shower Monte Carlo programs {\tt Pythia} and {\tt Herwig}. Using this new combined QCD+EW Monte Carlo program for $W$ production we provide numerical results for total cross sections and kinematic distributions of relevance to the $W$ mass measurement at the Tevatron and the LHC for the processes $pp,p\bar p \to W^\pm \to \mu^\pm \nu_\mu$. In particular, we discuss the impact of EW corrections in the presence of QCD effects when including detector resolution effects.Comment: 32 pages, 28 postscript figures, typos fixed, plot on the right-hand side of Fig.12 replaced with results from a higher statistics run, note adde

Composite seal for turbomachinery

A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor protects the rotor blades. A compliant backing surrounds the shroud. The backing may be made of corrugated sheets or the like with adjacent layers having off-set corrugations, with axes of the folds parallel to the rotor axis. The sheets may be bonded together at points of contact by brazing, welding or the like. In another embodiment a compliant material is covered with a thin ductile layer. A mounting fixture surrounds the backing

Low-loss, circularly-polarized dichroic plate

Dichroic plate has orthogonally-disposed, loaded dipole apertures with their orientations arranged so as to cancel cross-coupling effects which would otherwise result in power loss to circularly polarized signal

Low loss dichroic plate

A low loss dichroic plate is disclosed for passing radiation within a particular frequency band and reflecting radiation outside of that frequency band. The dichroic plate is comprised of a configuration of dipole elements defined by slots formed in a conductive plate. The slots are dimensioned so as to pass radiation of a selected frequency and are shaped so as to minimize the relationship between that frequency and the tilt angle of the plate relative to the direction of radiation. The slots are arranged so as to minimize signal power loss due to cross polarization effects