57,787 research outputs found
Dielectrophoresis in the microgravity environment
Microgravity and vacuum, singly or combined, are uniquely advantageous media for the use of dielectrophoresis as a mmaterial s separation technology. In order to assess these advantages, a free-fall vacuum dielectrophoretic separator was designed and constructed for use at the earth's surface
Educational assortative mating in Italy: what can Gini’s homogamy index still say?
The homogamy index proposed by Gini is applied to describe the changes occurred in marital choice - across time and regions in Italy. The relevant increase in education by women has provoked an increase in the number of homogamous couples and in an increasing proportion of women who marry downward. Relevant differences are observed in the case of informal unions and mixed marriages
Novel application of query-based qualitative predictors for characterization of solvent accessible residues in conjunction with protein sequence homology. Proceedings of the 22nd International Workshop on Database and Expert Systems Applications
Effectiveness of a Rigid Grate for Excluding Pacific Halibut, Hippoglossus stenolepis, From Groundfish Trawl Catches
A rigid grate was installed in a groundfish trawl to test its effectiveness in excluding Pacific halibut, Hippoglossus stenolepis, from commercial flatfish catches in the Gulf of Alaska. The grate was located ahead of the trawl codend to direct halibut toward an escape opening while allowing target species to pass through toward the codend. In an experimental fishery, the escape rate of halibut was estimated at 94%, while 72% of the Dover sole, Microstomas pacificus, 67% of the rex sole, Glyptocephalus zachirus, and 79% of the flathead sole, Hippoglossoides elassodon, were retained
Leak test system
System for quantitative determination of leak rates in large pressurized compartments is described. Method uses pressure reference cylinder placed in thermal contact with internal environment of compartment. Construction of equipment and details of operational procedure are reported. Illustration of equipment is included
Controlling the second-harmonic in a phase matched negative-index metamaterial
Nonlinear metamaterials (NLMMs) have been predicted to support new and
exciting domains in the manipulation of light, including novel phase matching
schemes for wave mixing. Most notable is the so-called nonlinear-optical
mirror, in which a nonlinear negative-index medium emits the generated
frequency towards the source of the pump. For the first time, we experimentally
demonstrate the nonlinear-optical mirror effect in a bulk negative-index NLMM,
along with two other novel phase matching configurations, utilizing periodic
poling to switch between the three phase matching domains.Comment: 5 pages, 7 figure
Three-Nucleon Bound State in a Spin-Isospin Dependent Three Dimensional Approach
A spin-isospin dependent Three-Dimensional approach based on momentum vectors
for formulation of the three-nucleon bound state is presented in this paper.
The three-nucleon Faddeev equations with two-nucleon interactions are
formulated as a function of vector Jacobi momenta, specifically the magnitudes
of the momenta and the angle between them with the inclusion of the
spin-isospin quantum numbers, without employing a partial wave decomposition.
As an application the spin-isospin dependent Faddeev integral equations are
solved with Bonn-B potential. Our result for the Triton binding energy with the
value of -8.152 MeV is in good agreement with the achievements of the other
partial wave based methods.Comment: 24 pages, 1 figure, 7 tables. Major changes; version to appear in
Physical Review
Numerical methods for incompressible viscous flows with engineering applications
A numerical scheme has been developed to solve the incompressible, 3-D Navier-Stokes equations using velocity-vorticity variables. This report summarizes the development of the numerical approximation schemes for the divergence and curl of the velocity vector fields and the development of compact schemes for handling boundary and initial boundary value problems
Endurance testing of downstream cathodes on a low-power MPD thruster
A low-power MPD thruster with downstream cathode was tested for endurance with a series of hollow cathode designs. Failure modes and failure mechanisms were identified. A new hollow cathode (with rod inserts) has emerged which shows promise for long life. The downstream positioning of the cathode was also changed from an on-axis location to an off-axis location. Data are presented for a 1332-hour life test of this new hollow cathode located at the new off-axis location. Xenon propellant was used
- …