12,549 research outputs found

    Simple temperature sensor with direct readout

    Get PDF
    Sensor is easy to construct, requires only one operational amplifier, and has very fast response. It provides direct readout of temperature on digital voltmeter

    Nondestructive measurement of capillary tube internal diameter

    Get PDF
    Technique provides nondestructive method of making quick, accurate determination by measuring electrical resistance of capillary tube when it is filled with electrolyte of known conductivity. Apparatus consists of conductivity cell and equipment for measuring resistance and for monitoring and controlling temperature

    Modular Symmetries, Threshold Corrections And Moduli For Z2×Z2Z_2 \times Z_2 Orbifolds

    Full text link
    Z2×Z2{\bf Z}_2\times {\bf Z}_2 Coxeter orbifolds are constructed with the property that some twisted sectors have fixed planes for which the six-torus can not be decomposed into a direct sum T2T4{\bf T}^2\bigoplus{\bf T}^4 with the fixed plane lying in T2{\bf T}^2. The string loop threshold corrections to the gauge coupling constants are derived, and display symmetry groups for the TT and UU moduli that are subgroups of the full modular group PSL(2,Z)PSL(2,Z). The effective potential for duality invariant gaugino condensate in the presence of hidden sector matter is constructed and minimized for the values of the moduli. The effect of Wilson lines on the modular symmetries is also studied.Comment: QMW--TH--94/18, 12 page

    Duality Symmetries in Orbifold Models

    Full text link
    We derive the duality symmetries relevant to moduli dependent gauge coupling constant threshold corrections, in Coxeter ZN {\bf Z_N} orbifolds. We consider those orbifolds for which the point group leaves fixed a 2-dimensional sublattice Λ2\Lambda_2, of the six dimensional torus lattice Λ6\Lambda_6, where Λ6\Lambda_6 cannot be decomposed as Λ2Λ4.\Lambda_2 \bigoplus{\Lambda_4}.Comment: 13 pages, QMW--TH--93/21, SUSX--TH--93/1

    Measurements of the dielectric properties of sea water at 1.43 GHz

    Get PDF
    Salinity and temperature of water surfaces of estuaries and bay regions are determined to accuracies of 1 ppt salinity and 0.3 kelvin surface temperature. L-band and S-band radiometers are used in combination as brightness temperature detectors. The determination of the brightness temperature versus salinity, with the water surface temperature as a parameter for 1.4 GHz, is performed with a capillary tube inserted into a resonance cavity. Detailed analysis of the results indicates that the measured values are accurate to better than 0.2 percent in the electric property epsilon' and 0.4 percent in epsilon''. The calculated brightness temperature as a function of temperature and salinity is better than 0.2 kelvin. Thus it is possible to reduce the measured data obtained with the two-frequency radiometer system with 1 ppt accuracy to values in the salinity range 5 to 40 ppt

    Anisotropic Solutions For Orbifold Moduli From Duality Invariant Gaugino Condensates

    Full text link
    The values of the TT and UU moduli are studied for those ZN{\bf Z}_N Coxeter orbifolds with the property that some of the twisted sectors have fixed planes for which the six-torus T6{\bf T}^6 can not be decomposed into a direct sum T2T4{\bf T}^2\bigoplus {\bf T}^4 with the fixed plane lying in T2{\bf T}^2 . Such moduli in general transform under a subgroup of the modular group SL(2,Z).SL(2,Z). The moduli are determined by minimizing the effective potential derived from a duality invariant gaugino condensate.Comment: QMW--TH--94/11, SUSX--TH--94/11, 16 page

    Establishing an energy scale for pulse-height distributions from gamma-ray spectrometers based on inorganic scintillators

    Get PDF
    Energy scale for pulse height distributions from gamma ray spectrometers based on inorganic scintillator

    Plasma tests of sprayed coatings for rocket thrust chambers

    Get PDF
    Several plasma-sprayed coating systems were evaluated for structural stability in hydrogen plasma and in oxygen plasma mixed with hydrogen plasma. The principal test heat flux was 15 Btu per inch squared seconds. The system consisted of a number of thin 0.002 to 0.020 in. layers of metal oxides and/or metals. The principal materials included are molybdenum nichrome, alumina, and zirconia. The study identifies important factors in coating system fabrication and describes the durability of the coating systems in the test environments. Values of effective thermal conductivity for some of the systems are indicated

    Modular Symmetries in ZNZ_N Orbifold Compactified String Theories with Wilson lines

    Full text link
    Target space modular symmetries relevant to string loop threshold corrections are studied for ZNZ_N orbifold compactified string theories containing Wilson line background fields.Comment: SUSX--TH--93/17, QMW--TH--93/31, 12 page
    corecore