1,452,688 research outputs found
NASA-tricot - A lightweight radar reflective, knitted fabric
Fabric knitted on conventional knitting machines uses commercially available yarns, has high aerodynamic drag capability, and is relatively inexpensive. The two yarn components used are 15-denier nylon monofilament and aluminized Mylar tape
Low-cost, portable fire hose tester
Availability of pumping unit permits scheduling and performing required periodic hose tests in proper manner while retaining full fire equipment readiness. Use of pumping unit preserves operating life and capability of pumper truck
High harmonic generation in crystals using Maximally Localized Wannier functions
In this work, the nonlinear optical response, and in particular, the high
harmonic generation of semiconductors is addressed by using the Wannier gauge.
One of the main problems in the time evolution of the Semiconductor Bloch
equations resides in the fact that the dipole couplings between different bands
can diverge and have a random phase along the reciprocal space and this leads
to numerical instability. To address this problem, we propose the use of the
Maximally Localized Wannier functions that provide a framework to map ab-initio
calculations to an effective tight-binding Hamiltonian with great accuracy. We
show that working in the Wannier gauge, the basis set in which the Bloch
functions are constructed directly from the Wannier functions, the dipole
couplings become smooth along the reciprocal space thus avoiding the problem of
random phases. High harmonic generation spectrum is computed for a 2D monolayer
of hBN as a numerical demonstration
Investigation of rock behavior and strength in situ and laboratory techniques adaptability to a lunar exploration program
Rock testing techniques for lunar landing site and for lunar samples returned to earth laborator
Interactions and superconductivity in heavily doped MoS2
We analyze the microscopic origin and the physical properties of the
superconducting phase recently observed in MoS. We show how the combination
of the valley structure of the conduction band, the density dependence of the
screening of the long range Coulomb interactions, the short range electronic
repulsion, and the relative weakness of the electron-phonon interactions, makes
possible the existence of a phase where the superconducting order parameter has
opposite signs in different valleys, resembling the superconductivity found in
the pnictides and cuprates
Study of hot wire techniques in low density flows with high turbulence levels
Prediction of heat, mass, species, and momentum fluxes in a space vehicle and aerodynamic noise production by supersonic jet and rocket exhausts requires a predictability of the associated turbulence fields. The hot wire is a technique that will allow an experimental determination of turbulent properties
Modification of the one-dimensional REKAP program to allow for charring in three material layers Final report
Modified one-dimensional reaction kinetics program to allow for charring in three material layers of rocket nozzle throat insert cas
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