Spacecraft active thermal control technology status

Four advanced space radiator concepts that were pursued in an integrated effort to develop multi-mission-use and low cost heat rejection systems which can overcome the limitations of current radiator systems are briefly discussed and described. Also, in order to establish a firm background to compare the advanced space radiator concepts, the Orbiter active thermal control system is also briefly described

Threat perception while viewing single intruder conflicts on a cockpit display of traffic information

Subjective estimates of the threat posed by a single intruder aircraft were determined by showing pilots photographs of a cockpit display of traffic information. The time the intruder was away from the point of minimum separation was found to be the major determinant of the perception of threat. When asked to choose a maneuver to reduce the conflict, pilots selected maneuvers with a bias toward those that would have kept the intruders in sight had they been visible out the cockpit window

Testing Quantum Mechanics in the Neutral Kaon System

The neutral kaon system is a sensitive probe of quantum mechanics. We revive a parametrization of non-quantum-mechanical effects that is motivated by considerations of the nature of space-time foam, and show how it can be constrained by new measurements of $K_L \rightarrow 2\pi$ and $K_{L,S}$ semileptonic decays at LEAR or a $\phi$ factory.Comment: 10 page

An analysis and simulation of landings utilizing stored-energy lift Final report, May 12 - Nov. 30, 1967

Computerized simulation of aircraft landing deceleration with stored energy lif

Impact of Low-Energy Constraints on Lorentz Violation

We extend previous analyses of the violation of Lorentz invariance induced in a non-critical string model of quantum space-time foam, discussing the propagation of low-energy particles through a distribution of non-relativistic D-particles.We argue that nuclear and atomic physics experiments do not constitute sensitive probes of this approach to quantum gravity due to a difference in the dispersion relations for massive probes as compared to those for massless ones, predicted by the model.Comment: 4 pages revte

First-Principles Thermodynamics of Coherent Interfaces in Samarium-Doped Ceria Nanoscale Superlattices

Nanoscale superlattices of samarium-doped ceria layers with varying doping levels have been recently proposed as a novel fuel cell electrolyte. We calculate the equilibrium composition profile across the coherent {100} interfaces present in this system using lattice-gas Monte Carlo simulations with long-range interactions determined from electrostatics and short-range interactions obtained from ab initio calculations. These simulations reveal the formation of a diffuse, nonmonotonic, and surprisingly wide (11 nm at 400 K) interface composition profile, despite the absence of space charge regions

Quantum Decoherence in a Four-Dimensional Black Hole Background

We display a logarithmic divergence in the density matrix of a scalar field in the presence of an Einstein-Yang-Mills black hole in four dimensions. This divergence is related to a previously-found logarithmic divergence in the entropy of the scalar field, which cannot be absorbed into a renormalization of the Hawking-Bekenstein entropy of the black hole. As the latter decays, the logarithmic divergence induces a non-commutator term \nd{\delta H}\rho in the quantum Liouville equation for the density matrix $\rho$ of the scalar field, leading to quantum decoherence. The order of magnitude of \nd{\delta H} is $\mu^2/M_P$, where $\mu$ is the mass of the scalar particle.Comment: 13-pages LATE