Deep space monitor communication satellite system Patent

Elimination of tracking occultation problems occurring during continuous monitoring of interplanetary missions by using Earth orbiting communications satellit

Levels of Complexity in the Microstructure of Mammalian Enamel and Their Application in Studies of Systematics

Description and analysis of the complex structure of enamel can be facilitated through the application of a system of hierarchical levels of structural complexity. Five interdependent levels are distinguished. These are the levels of: 1) crystallites, 2) prisms, 3) enamel types, 4) schmelzmuster, and 5) dentition. This system provides a basis for analysis of both variation of particular structures and variation of structural types throughout a mammal\u27s dentition. Optimally, in wide ranging systematic and biomechanical studies, all levels of structural complexity should be considered, but lack of information about one level does not prevent significant analyses at other levels

Ion mixing to produce amorphous Mo-Ru superconducting films

Amorphous Mo55Ru45 alloy films were formed by ion mixing of multilayered samples. The ion mixed films, which contain no metalloid element, show excellent superconducting properties. The measured properties are correlated with the microstructure obtained by both x-ray diffraction and transmission electron microscopy

A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars

In an earlier paper, we introduced a model for pulsars in which non-radial oscillations of high spherical degree (\el) aligned to the magnetic axis of a spinning neutron star were able to reproduce subpulses like those observed in single-pulse measurements of pulsar intensity. The model did not address polarization, which is an integral part of pulsar emission. Observations show that many pulsars emit radio waves that appear to be the superposition of two linearly polarized emission modes with orthogonal polarization angles. In this paper, we extend our model to incorporate linear polarization. As before, we propose that pulsational displacements of stellar material modulate the pulsar emission, but now we apply this modulation to a linearly-polarized mode of emission, as might be produced by curvature radiation. We further introduce a second polarization mode, orthogonal to the first, that is modulated by pulsational velocities. We combine these modes in superposition to model the observed Stokes parameters in radio pulsars.Comment: 19 pages, 4 figures accepted Ap

Dynamics of precipitation pattern formation at geothermal hot springs

We formulate and model the dynamics of spatial patterns arising during the precipitation of calcium carbonate from a supersaturated shallow water flow. The model describes the formation of travertine deposits at geothermal hot springs and rimstone dams of calcite in caves. We find explicit solutions for travertine domes at low flow rates, identify the linear instabilities which generate dam and pond formation on sloped substrates, and present simulations of statistical landscape evolution

U.S. Marine Corps Equipment Readiness Information Tool: usage and decision-support for performance based logistics

MBA Professional ReportThe Marine Corps is transforming its automated logistics programs to meet the increasingly complex operational requirements of the 21st Century. One program that is part of this transformation is the Marine Corps Equipment Readiness Information Tool (MERIT). Our research analyzed: how can MERIT be used as a decision support tool for performance based logistics (PBL) and what areas of MERIT are recommended for improvement. Included in the analysis is a description of current readiness procedures used in the Marine Corps, providing a point of comparison for how well MERIT enables the logistics transformation. The basis of our analysis was user perceptions, assessed by a user survey and focus groups. The conclusions of our analysis determined: MERIT has not received official Marine Corps endorsement for its continued use; MERIT is a valuable material readiness information tool used by the Marine Corps; there is a general lack of understanding by users regarding MERIT's logical architecture and operation; and there is a lack of training on MERIT throughout the Marine Corps.http://archive.org/details/usmarinecorpsequ109459891Major, United States Marine CorpsCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

Inverse characterization of plates using zero group velocity Lamb modes

AbstractIn the presented work, the characterization of plates using zero group velocity Lamb modes is discussed. First, analytical expressions are shown for the determination of the k–ω location of the zero group velocity Lamb modes as a function of the Poisson’s ratio. The analytical expressions are solved numerically and an inverse problem is formulated to determine the unknown wave velocities in plates of known thickness. The analysis is applied to determine the elastic properties of tungsten and aluminum plates based on the experimentally measured frequency spectra

High Resolution Spectroscopy of the Pulsating White Dwarf G29-38

We present the analysis of time-resolved, high resolution spectra of the cool white dwarf pulsator, G29-38. From measuring the Doppler shifts of the H-alpha core, we detect velocity changes as large as 16.5 km/s and conclude that they are due to the horizontal motions associated with the g-mode pulsations on the star. We detect seven pulsation modes from the velocity time-series and identify the same modes in the flux variations. We discuss the properties of these modes and use the advantage of having both velocity and flux measurements of the pulsations to test the convective driving theory proposed for DAV stars. Our data show limited agreement with the expected relationships between the amplitude and phases of the velocity and flux modes. Unexpectedly, the velocity curve shows evidence for harmonic distortion, in the form of a peak in the Fourier transform whose frequency is the exact sum of the two largest frequencies. Combination frequencies are a characteristic feature of the Fourier transforms of light curves of G29-38, but before now have not been detected in the velocities, nor does published theory predict that they should exist. We compare our velocity combination frequency to combination frequencies found in the analysis of light curves of G29-38, and discuss what might account for the existence of velocity combinations with the properties we observe. We also use our high-resolution spectra to determine if either rotation or pulsation can explain the truncated shape observed for the DAV star's line core. We are able to eliminate both mechanisms: the average spectrum does not fit the rotationally broadened model and the time-series of spectra provides proof that the pulsations do not significantly truncate the line.Comment: 24 pages, 9 figures, Accepted for publication in ApJ (June