Controlled Source Electromagnetic (CSEM) is an important technique in hydrocarbon exploration, because it uses the large contrast in electrical resistivity to distinguishes between water and hydrocarbons. In a shallow sea environment, the airwave that is refracted from the air-water interface dominates the recorded signal at large offsets. Therefore, the hydrocarbon detection ability of the CSE...

A phase integral (WKBJ) theory of damped modes in a resistive cylindrical plasma column is developed. The theory predicts several phenomena observed previously in numerical studies: (i) the complex frequency w has a point spectrum lying on a locus which is approximately independent of the resistivity, and which intersects the ideal continuum only at its end points (at angles of 45° and 30°); (i...

The lack of X-ray pulsars with spin periods > 12 s raises the question about where the population of evolved high magnetic field neutron stars has gone. Unlike canonical radio-pulsars, X-ray pulsars are not subject to physical limits to the emission mechanism nor observational biases against the detection of sources with longer periods. Here we show that a highly resistive layer in the innermos...

We report a high-pressure single crystal study of the superconducting ferromagnet UCoGe. Measurements of the ac susceptibility and resistivity under pressures up to 2.2 GPa show ferromagnetism is smoothly depressed and vanishes at a critical pressure p(c) = 1.4 GPa. Near the ferromagnetic critical point superconductivity is enhanced. Upper-critical field measurements under pressure show B(c2)(0...

The crystal structure and numerous normal and superconducting state properties of layered tetragonal (P4/nmm) LaFeAsO, with F-doping of  11 %, are reported. Resistivity measurements give an onset transition temperature Tc = 28.2 K, and low field magnetic susceptibility data indicate bulk superconductivity. In applied magnetic field, analysis of the resistive transition results in a critical fi...

The crystal structure and numerous normal and superconducting state properties of layered tetragonal P4 /nmm LaFeAsO, with F doping of 11%, are reported. Resistivity measurements give an onset transition temperature Tc=28.2 K, and low field magnetic susceptibility data indicate bulk superconductivity. In applied magnetic field, analysis of the resistive transition results in a critical field Hc...

Two 2-D aeroelastic models are presented here to determine instability boundary (flutter speed) and gust response of a typical section airfoil with degrees of freedom in pitch and plunge directions. To build these 2-D aeroelastic models, two different aerodynamic theories including Indicial Aerodynamic Theory and Vortex Lattice Method (VLM) have been employed. Also, a 3-D aeroelastic framework ...

Magnetic island equilibria resulting from reconnection in magnetohydrodynamic (MHD) simulations are explored in a two-dimensional slab geometry. Magnetic islands are evolved to finite amplitude with a nonzero resistivity. The resistivity and flows are then set to zero and the system is allowed to relax toward equilibrium. A y-type singular current layer in the equilibrium state is identified fo...

A new fuzzy maximum power point tracker (MPPT) for photovoltaic systems is proposed. Fuzzy controller input parameters dI dP , ) dI dP ( D and variation of duty cycle ( DC D ) are used to generate the optimal MPPT converter duty cycle, such that solar panel maximum power is generated under different operating conditions. A photovoltaic system including a solar panel, a fuzzy MPP tracker and...

Nanocrystalline silicon microwires are self-heated through single, large amplitude, and microsecond voltage pulses. Scanning electron micrographs show very smooth wire surfaces after the voltage pulse compared to as-fabricated nanocrystalline texture. Voltage-pulse induced self-heating leads to significant conductance improvement, suggesting crystallization of the wires. The minimum resistivity...