1,494 research outputs found
Chemical Identification of the Radioelements Produced from Carbon and Boron by Deuteron Bombardment
Chemical experiments were made on the radioactive substances resulting from the bombardment of carbon and boron by deuterons. Carbon is shown to yield an isotope of nitrogen and boron an isotope of carbon. The nitrogen so formed has a half-life of 10.5 minutes while that found by Curie and Joliot on bombardment of boron with alpha-particles has a half-life of 14 minutes. These facts are discussed
The Raman Spectrum of Boron Trifluoride Gas
The Raman spectrum of BF3 was photographed using a purified preparation obtained from the thermal decomposition of C6H5N2BF4. Of the lines observed, that with the frequency 888 cm^—1 is certainly, and the band at 439–513 cm^—1 is probably due to BF3. The Raman frequencies and the infra-red results of Bailey et al. are assigned to the fundamental modes of vibrations
The molecular structure of isocyanic acid from microwave and infra-red absorption spectra
Experimental investigations of the infra-red and microwave spectra of the slightly asymmetric rotor, HNCO, have been made, and the structure of the molecule has been determined
Ramond-Ramond Central Charges in the Supersymmetry Algebra of the Superstring
The free action for the massless sector of the Type II superstring was
recently constructed using closed RNS superstring field theory. The
supersymmetry transformations of this action are shown to satisfy an N=2 D=10
SUSY algebra with Ramond-Ramond central charges.Comment: 10 pages harvmac te
Air-coupled acoustic thermography for in-situ evaluation
Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources
Dipole Moment and Electric Quadrupole Effects in HNCO and HNCS
Interaction of the electric quadrupole moment of the nitrogen nucleus with the molecular electric fields of isocyanic and isothiocyanic acids results in a hyperfine splitting of the rotational trnasitions
The Raman Spectra of Carbon and Silicon Tetrafluorides
We have photographed the Raman spectra for the tetrafluorides of carbon and silicon in both the liquid and gaseous states. The results are presented in Table I together with the Raman frequencies for CCl4 for purposes of comparison
Numerical examples in the investigation of a particular matrix in eigenvector theory.
http://archive.org/details/numericalexample1094512740U.S. Navy (U.S.N.) author
The Raman Spectra of Boron Trifluoride, Trichloride, and Tribromide. The Effect of the Boron Isotopes
The Raman frequencies v1{1}, 2v2{2}, v3{2}, and v4{2} for BF3(g), BCl3(l), and BBr3(l) were found to be 886 and 783, 1394, 1038 and 1105, 440; 471, 924, 958 and 996, 243; 279, 743, 806 and 846, and 151 cm—1, respectively. The assignment of frequencies was determined by polarization experiments on BCl3 and is confirmed for the three compounds by the results of a normal coordinate treatment. The doubling of v1 in BF3 is ascribed to vibrational resonance between v1 and 2v4. The doubling of v3 in all three compounds is shown to be due to the presence of the two isotopes of boron B10 and B11. A satisfactory assignment of the infrared frequencies of BCl3 is made
Role of insulin and IGF1 receptors in proliferation of cultured renal proximal tubule cells
We have used a murine proximal tubule cell line (MCT cells) to determine the presence and binding characteristics of insulin and IGF1 receptors and to correlate these parameters with the concentration-response relationships for ligand-induced cellular proliferation. Separate insulin and IGF1 receptors were identified by equilibrium binding assays. Half-maximal displacement of either peptide occurred at 3-10 nM; crossover binding to the alternate receptor occurred with a 10- to 100-fold lower affinity. Peptide effects on cellular proliferation were determined by measuring [3H]thymidine incorporation. Both insulin and IGF1 stimulate thymidine incorporation in a dose-dependent manner with similar increases above the basal level. The estimated half-maximal stimulation (EC50) occurred at 4 nM for IGF1 and 8 nM for insulin. A comparison of the receptor binding affinities with the dose-response relationships for [3H]thymidine incorporation reveals that each growth factor appears to be exerting its effect via binding to its own receptor. Therefore, in this cell line, physiologic concentrations of either insulin or IGF1 can modulate cellular growth. To our knowledge this is the first demonstration of a mitogenic effect which may be modulated by ligand binding to the insulin receptor in proximal tubule epithelia
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