12,577 research outputs found

    Adaptive tracking notch filter system Patent

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    Adaptive notch filter, using modulation techniques for reversed phase noise signa

    State of New York City's housing and neighborhoods: an overview of recent trends

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    This paper was presented at the conference "Policies to Promote Affordable Housing," cosponsored by the Federal Reserve Bank of New York and New York University's Furman Center for Real Estate and Urban Policy, February 7, 2002. It was part of Session 1: State of New York City's Housing and Neighborhoods.Housing - New York (N.Y.) ; Federal Reserve District, 2nd ; Demography ; Rent ; Metropolitan areas - Statistics

    Preliminary evaluation of a thin organic film coating Final report

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    High temperature and humidity resistance of thin siloxane films on metal substrate

    Protein-Mediated DNA Loops: Effects of Protein Bridge Size and Kinks

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    This paper focuses on the probability that a portion of DNA closes on itself through thermal fluctuations. We investigate the dependence of this probability upon the size r of a protein bridge and/or the presence of a kink at half DNA length. The DNA is modeled by the Worm-Like Chain model, and the probability of loop formation is calculated in two ways: exact numerical evaluation of the constrained path integral and the extension of the Shimada and Yamakawa saddle point approximation. For example, we find that the looping free energy of a 100 base pairs DNA decreases from 24 kT to 13 kT when the loop is closed by a protein of r = 10 nm length. It further decreases to 5 kT when the loop has a kink of 120 degrees at half-length.Comment: corrected typos and figures, references updated; 13 pages, 7 figures, accepted for publication in Phys. Rev.

    Fibers on a graph with local load sharing

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    We study a random fiber bundle model with tips of the fibers placed on a graph having co-ordination number 3. These fibers follow local load sharing with uniformly distributed threshold strengths of the fibers. We have studied the critical behaviour of the model numerically using a finite size scaling method and the mean field critical behaviour is established. The avalanche size distribution is also found to exhibit a mean field nature in the asymptotic limit.Comment: 9 pages, 6 figures, To appear in International Journal of Modern Physics

    A crystallization study of a tetrasilicic fluormica glass

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    The transformation of a synthetic mica composition K₂Mg₅Si₈O₂₀F₄ from amorphous to crystalline structure was studied isothermally at selected temperatures from 560°C to 1150°C. thermal changes associated with the transformation were followed by differential thermal analysis techniques. Structural changes promoted by the isothermal treatments were observed by density measurements, Debye-Scherrer X-ray diffraction techniques, electron replication microscopy, and electron scanning microscopy. Isothermal treatment at 450°C for 9 hours produces structural ordering in quenched K₂Mg₅Si₈O₂₀F₄ glass. Fluorine exerts a significant influence on the transformation temperature; decreasing amounts of fluorine producing increasing transformation temperatures. The crystallizing phase rapidly attains a limiting particle size and morphology at temperatures in the 600°C region. Treatments of quenches K₂Mg₅Si₈O₂₀F₄ glass at 900°C and above promotes a change from spherulitic to blocky crystal habit, accompanied by a more complete development of mica structure during growth --Abstract, page ii

    Preliminary feasibility study of a multi-Phobos encounter experiment during the Viking extended mission

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    The Viking '75 Mission to Mars is reported which permits a truly unique opportunity to explore the natural satellite, Phobos, from distances measured in tens of kilometers. A preliminary feasibility study has been made which shows that a science mission involving a Phobos close encounter is technically feasible and within the capabilities of the current Viking design. For less than 20 m/s, the Viking Orbiter can provide approximately two 40-day periods of close observation of Phobos, with the first encounter period in January and the second in March, 1977. Multi-pass images of the entire satellite from nearly all aspect angles and with resolution on the order of 10 meters are possible. Close encounters will permit mass determinations to an accuracy of tens of percent. These experiments can be performed in series with the nominal mission; thus, providing complementary scientific information without compromising the original mission and science objectives

    An evaluation of certain informal reading tests

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    Thesis (Ed. M.)--Boston University, 194

    Predicted and measured strain responses of isotropic panels to base excitation

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    The accuracy of classical linear theory for predicting acceleration and strain for cantilevered and Clamped-Free-Clamped-Free (C-F-C-F) panels excited through the base is studied. Aluminum, steel and titanium plates of various dimensions and thicknessess were vibration tested, using a broadband random signal applied through a shaker mounting fixture. The strains were measured at 9 locations on the cantilevered panels and at 5 locations on the C-F-C-F panels. Predictions were based on the Ritz method. The measured accelerations of the base were input to the analysis for the forcing function. Comparisons between predicted and measured strain acceleration spectra were within an average error of 20 percent for both the cantilevered and C-F-C-F panels
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