24,379 research outputs found

    Electric-arc heater Patent

    Get PDF
    Magnetically diffused radial electric arc heate

    Computer aids for worst case electronic circuit design

    Get PDF
    Computer aids for worst case electronic circuit desig

    A magnetically rotated electric arc air heater employing a strong magnetic field and copper electrodes

    Get PDF
    Magnetically rotated electric arc air heater using strong magnetic field and copper electrode

    Dielectric properties and lattice dynamics of alpha-PbO2-type TiO2: The role of soft phonon modes in pressure-induced phase transition to baddeleyite-type TiO2

    Full text link
    Dielectric tensor and lattice dynamics of alpha-PbO2-type TiO2 have been investigated using the density functional perturbation theory, with a focus on responses of the vibrational frequencies to pressure. The calculated Raman spectra under different pressures are in good agreement with available experimental results and the symmetry assignments of the Raman peaks of alpha-PbO2-type TiO2 are given for the first time. In addition, we identified two anomalously IR-active soft phonon modes, B1u and B3u, respectively, around 200 cm-1 which have not been observed in high pressure experiments. Comparison of the phonon dispersions at 0 and 10 GPa reveals that softening of phonon modes also occurs for the zone-boundary modes. The B1u and B3u modes play an important role in transformation from the alpha-PbO2-type phase to baddeleyite phase. The significant relaxations of the oxygen atoms from the Ti4 plane in the Ti2O2Ti2 complex of the baddeleyite phase are directly correlated to the oxygen displacements along the directions given by the eigenvectors of the soft B1u and B3u modes in the alpha-PbO2-type phase.Comment: 8 pages, 9 figure

    Epidermal growth factor (EGF)-like repeats of human tenascin-C as ligands for EGF receptor.

    Get PDF
    Signaling through growth factor receptors controls such diverse cell functions as proliferation, migration, and differentiation. A critical question has been how the activation of these receptors is regulated. Most, if not all, of the known ligands for these receptors are soluble factors. However, as matrix components are highly tissue-specific and change during development and pathology, it has been suggested that select growth factor receptors might be stimulated by binding to matrix components. Herein, we describe a new class of ligand for the epidermal growth factor (EGF) receptor (EGFR) found within the EGF-like repeats of tenascin-C, an antiadhesive matrix component present during organogenesis, development, and wound repair. Select EGF-like repeats of tenascin-C elicited mitogenesis and EGFR autophosphorylation in an EGFR-dependent manner. Micromolar concentrations of EGF-like repeats induced EGFR autophosphorylation and activated extracellular signal-regulated, mitogen-activated protein kinase to levels comparable to those induced by subsaturating levels of known EGFR ligands. EGFR-dependent adhesion was noted when the ligands were tethered to inert beads, simulating the physiologically relevant presentation of tenascin-C as hexabrachion, and suggesting an increase in avidity similar to that seen for integrin ligands upon surface binding. Specific binding to EGFR was further established by immunofluorescence detection of EGF-like repeats bound to cells and cross-linking of EGFR with the repeats. Both of these interactions were abolished upon competition by EGF and enhanced by dimerization of the EGF-like repeat. Such low affinity behavior would be expected for a matrix-tethered ligand; i.e., a ligand which acts from the matrix, presented continuously to cell surface EGF receptors, because it can neither diffuse away nor be internalized and degraded. These data identify a new class of insoluble growth factor ligands and a novel mode of activation for growth factor receptors

    Photon signature analysis using template matching

    Get PDF
    We describe an approach to detect improvised explosive devices (IEDs) by using a template matching procedure. This approach relies on the signature due to backstreaming ? photons from various targets. In this work we have simulated cylindrical targets of aluminum, iron, copper, water and ammonium nitrate (nitrogen-rich fertilizer). We simulate 3.5 MeV source photons distributed on a plane inside a shielded area using Monte Carlo N-Particle (MCNP TM) code version 5 (V5). The 3.5 MeV source gamma rays yield 511 keV peaks due to pair production and scattered gamma rays. In this work, we simulate capture of those photons that backstream, after impinging on the target element, toward a NaI detector. The captured backstreamed photons are expected to produce a unique spectrum that will become part of a simple signal processing recognition system based on the template matching method. Different elements were simulated using different sets of random numbers in the Monte Carlo simulation. To date, the sum of absolute differences (SAD) method has been used to match the template. In the examples investigated, template matching was found to detect all elements correctly

    Explaining Crime in Metropolitan and Non-Metropolitan Communities

    Get PDF
    Traditional urban theories of community crime development increasingly are being adapted and evaluated for their relevance to the crime problems of smaller and less urban settings. Most notable of these have been social disorganization theory and civic community theory. This paper compares these two major theoretical frameworks for explaining community-level variations in crime, using county-level data on crime rates merged with data on the economic, geographic, population, and ecological features of counties in the U.S. The study finds that both traditional social disorganization and civic community theories are good predictors of some, but not all, types of crime, in the largest metropolitan areas. However, their predictive power declines substantially when applied to the most rural communities

    Solar radiation observation stations with complete listing of data archived by the National Climatic Center, Asheville, North Carolina and initial listing of data not currently archived

    Get PDF
    A listing is provided of organizations taking solar radiation data, the 166 stations where observations are made, the type of equipment used, the form of the recorded data, and the period of operation of each station. Included is a listing of the data from 150 solar radiation stations collected over the past 25 years and stored by the National Climatic Center

    The association between busy directors and acquisition performance

    Full text link
    This paper addresses the question of whether independent directors of the bidding firm are effective monitors during acquisitions and whether this effectiveness is impaired when the independent directors serve on multiple boards. The choice of the acquisition setting, where the board of directors is known to be engaged in active decision-making, facilitates a direct test of the role of independent directors as effective, external monitors of the boards activities. We employ three indicators of the bidding boards performance in making optimal acquisition decisions: the acquisition premium (benchmarked against subsequent performance), a new indicator comprising the conflicts of interest associated with the acquisitions (conflicted acquisitions), and the post-acquisition stock performance. The results suggest that more independent boards and busy independent directors on the bidding firms board are associated with more effective acquisition decisions by the board. However, busy independent directors are associated with less effective acquisition decisions when the bidding firm has higher free cash flows consistent with Jensen (1986). We also find that busy executive directors on the bidding firms board have no implications for the effectiveness of acquisition decisions unless the director is a busy chairperson or busy CEO both of whom are associated with less effective acquisition decisions. This paper contributes direct evidence on the effectiveness of bidding firm independent directors in their role as monitors and decision-makers
    corecore