12,742 research outputs found

    Fuse and switch functions combined within a single housing

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    Fuswitch provides both switch and fuse functions within a single housing. A mercury capillary is used to alternately vaporize and condense the mercury within a reservoir. The housing is impervious to mercury and the fuse portion of the device operates on the principle of the self-healing mercury fuse

    Global Classical Solutions of the Boltzmann Equation with Long-Range Interactions and Soft Potentials

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    In this work we prove global stability for the Boltzmann equation (1872) with the physical collision kernels derived by Maxwell in 1866 for the full range of inverse power intermolecular potentials, r−(p−1)r^{-(p-1)} with p>2p>2. This completes the work which we began in (arXiv:0912.0888v1). We more generally cover collision kernels with parameters s∈(0,1)s\in (0,1) and γ\gamma satisfying γ>−(n−2)−2s\gamma > -(n-2)-2s in arbitrary dimensions Tn×Rn\mathbb{T}^n \times \mathbb{R}^n with n≥2n\ge 2. Moreover, we prove rapid convergence as predicted by the Boltzmann H-Theorem. When γ+2s≥0\gamma + 2s \ge 0, we have exponential time decay to the Maxwellian equilibrium states. When γ+2s<0\gamma + 2s < 0, our solutions decay polynomially fast in time with any rate. These results are constructive. Additionally, we prove sharp constructive upper and lower bounds for the linearized collision operator in terms of a geometric fractional Sobolev norm; we thus observe that a spectral gap exists only when γ+2s≥0\gamma + 2s \ge 0, as conjectured in Mouhot-Strain (2007).Comment: This file has not changed, but this work has been combined with (arXiv:0912.0888v1), simplified and extended into a new preprint, please see the updated version: arXiv:1011.5441v

    Fault detection and accommodation testing on an F100 engine in an F-15 airplane

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    The fault detection and accommodation (FDA) methodology for digital engine-control systems may range from simple comparisons of redundant parameters to the more complex and sophisticated observer models of the entire engine system. Evaluations of the various FDA schemes are done using analytical methods, simulation, and limited-altitude-facility testing. Flight testing of the FDA logic has been minimal because of the difficulty of inducing realistic faults in flight. A flight program was conducted to evaluate the fault detection and accommodation capability of a digital electronic engine control in an F-15 aircraft. The objective of the flight program was to induce selected faults and evaluate the resulting actions of the digital engine controller. Comparisons were made between the flight results and predictions. Several anomalies were found in flight and during the ground test. Simulation results showed that the inducement of dual pressure failures was not feasible since the FDA logic was not designed to accommodate these types of failures

    Transport and Helfand moments in the Lennard-Jones fluid. I. Shear viscosity

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    We propose a new method, the Helfand-moment method, to compute the shear viscosity by equilibrium molecular dynamics in periodic systems. In this method, the shear viscosity is written as an Einstein-like relation in terms of the variance of the so-called Helfand moment. This quantity, is modified in order to satisfy systems with periodic boundary conditions usually considered in molecular dynamics. We calculate the shear viscosity in the Lennard-Jones fluid near the triple point thanks to this new technique. We show that the results of the Helfand-moment method are in excellent agreement with the results of the standard Green-Kubo method.Comment: Submitted to the Journal of Chemical Physic

    Programmable telemetry system Patent

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    Time division multiplexed telemetry transmitting system controlled by programmed memor

    Self-organized criticality in the intermediate phase of rigidity percolation

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    Experimental results for covalent glasses have highlighted the existence of a new self-organized phase due to the tendency of glass networks to minimize internal stress. Recently, we have shown that an equilibrated self-organized two-dimensional lattice-based model also possesses an intermediate phase in which a percolating rigid cluster exists with a probability between zero and one, depending on the average coordination of the network. In this paper, we study the properties of this intermediate phase in more detail. We find that microscopic perturbations, such as the addition or removal of a single bond, can affect the rigidity of macroscopic regions of the network, in particular, creating or destroying percolation. This, together with a power-law distribution of rigid cluster sizes, suggests that the system is maintained in a critical state on the rigid/floppy boundary throughout the intermediate phase, a behavior similar to self-organized criticality, but, remarkably, in a thermodynamically equilibrated state. The distinction between percolating and non-percolating networks appears physically meaningless, even though the percolating cluster, when it exists, takes up a finite fraction of the network. We point out both similarities and differences between the intermediate phase and the critical point of ordinary percolation models without self-organization. Our results are consistent with an interpretation of recent experiments on the pressure dependence of Raman frequencies in chalcogenide glasses in terms of network homogeneity.Comment: 20 pages, 18 figure

    Antiangiogenic Cancer Therapy

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