Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z > 5 AGN in the 2 Ms X-ray exposure of the Chandra Deep Field-North. Of the 423 X-ray sources bright enough (z < 25.2) for a color-color analysis, at most one lies at z = 5 − 6 and none at z > 6. The z > 5 object ...

Abstract. We study the density of the roots of the derivative of the characteristic polynomial Z(U, z) of an N × N random unitary matrix with distribution given by Haar measure on the unitary group. Based on previous random matrix theory models of the Riemann zeta function ζ(s), this is expected to be an accurate description for the horizontal distribution of the zeros of ζ (s) to the right of ...

High-resolution global ocean models forced by atmospheric fields and tides are beginning to display realistic internal gravity wave spectra, especially as model resolution increases. This paper examines internal waves in global simulations with 0.08° and 0.04° (~8 and 4 km) horizontal resolutions, respectively. Frequency spectra of internal wave horizontal kinetic energy in the North Pacific li...

Coastally trapped wind reversals (CTWRs) occur periodically in the marine boundary layer off the western coast of the United States and dramatically change the low-level wind regime and coastal weather. Southerly flow becomes established with the passage of a CTWR along with cooler temperatures and a low stratus deck in a narrow band along the coast. CTWRs can propagate northward along the coas...

A model for the tectonic evolution of the Eastern Mediterranean region from Mesozoic to Present is developed from geological, geophysical, and seismological data on and surrounding the island of Cyprus. This model emphasizes the role of major transform structures in accommodating horizontal plate motions, driven from the west by spreading along the Atlantic-Arctic mid-ocean-ridge system and fro...

We show that if an orientable Seifert fibered space M with an orientable genus g base space admits a strongly irreducible horizontal Heegaard splitting then there is a one-to-one correspondence between isotopy classes of strongly irreducible horizontal Heegaard splittings and elements of Z. The correspondence is determined by the slopes of intersection of each Heegaard splitting with a collecti...

This paper presents the results of laboratory experiment concerned with perception thresholds for whole-body vibration on recumbent subjects. Thresholds of subjects exposed to x-, yand z-axis sinusoidal vibration were determined for supine, prone, lying on the left side and lying on the right side subjects (from 1 to 80 Hz). It was clear that the threshold curves, as a function of frequency, ha...

An idealized electostatically actuated microelectromechanical system (MEMS) consists of a fixed horizontal ground plate held at zero potential above which an elastic membrane held at potential V is suspended. A Coulomb force is generated by the potential difference across the device and results in a deformation of the membrane, thereby converting electrostatic energy into mechanical energy, see...