Photoreceiver efficiency measurements

The efficiency and other related parameters of Smithsonian Astrophysical Observatory's four laser receivers were measured at the observing stations by oscilloscope photography. If the efficiency is defined as the number of photoelectrons generated by the photomultiplier tube divided by the number of photons entering the aperture of the receiver, its measured value is about 1% for the laser wavelength of 694 nm. This value is consistent with the efficiency computed from the specified characteristics of the photoreceiver's optical components

Investigation of continental drift, phase 1 effort Progress report, 1 Apr. - 30 Sep. 1968

Feasibility of using ultrashort pulse laser ranging and independent clock radio interferometry distance measurement methods to test for existence of continental drif

A foam model highlights the differences of the macro- and microrheology of respiratory horse mucus

Native horse mucus is characterized with micro- and macrorheology and compared to hydroxyethylcellulose (HEC) gel as a model. Both systems show comparable viscoelastic properties on the microscale and for the HEC the macrorheology is in good agreement with the microrheology. For the mucus, the viscoelastic moduli on the macroscale are several orders of magnitude larger than on the microscale. Large amplitude oscillatory shear experiments show that the mucus responds nonlinearly at much smaller deformations than HEC. This behavior fosters the assumption that the mucus has a foam like structure on the microscale compared to the typical mesh like structure of the HEC, a model that is supported by cryogenic-scanning-electron-microscopy (CSEM) images. These images allow also to determine the relative amount of volume that is occupied by the pores and the scaffold. Consequently, we can estimate the elastic modulus of the scaffold. We conclude that this particular foam like microstructure should be considered as a key factor for the transport of particulate matter which plays a central role in mucus function with respect to particle penetration. The mesh properties composed of very different components are responsible for macroscopic and microscopic behavior being part of particles fate after landing.Comment: Accepted for publication in the Journal of the Mechanical Behavior of Biomedical Material

Satellite tracking with a laser

Satellite tracking with laser - range equation, detection at night and in daylight, noncooperative satellites, and comparison of of laser and radar system

The statistics of laser returns from cube-corner arrays on satellite

A method first presented by Goodman is used to derive an equation for the statistical effects associated with laser returns from satellites having retroreflecting arrays of cube corners. The effect of the distribution on the returns of a satellite-tracking system is illustrated by a computation based on randomly generated numbers

Laser pulse analysis

Methods are presented for locating threshold points by using laser pulse analysis. It was found that there are errors involved in the determination of each of these quantities, and an attempt was made to separate their effects on the overall range correction. Several series of corrected range measurements for fixed reflectors and satellites were obtained. Residuals were computed by fitting the range measurements to either fixed-reflector distances or short arcs of satellite orbits. Root mean square values of these residuals are presented

Novel approaches in professional education to foster innovation in the chemical industry

Fostering innovation in the chemical industry demands a new approach to the competencies required by employees. To succeed in innovation processes, competencies are needed that transcend the mere scientific knowledge in chemistry: skills are needed to work in teams in a transdisciplinary manner in order to generate new ideas. Moreover, these skills will enable employees to exploit innovations that exist at the interface with other disciplines and industries. However, how can such competencies be trained and fostered? This article addresses competencies that are crucial to cross-industry and interdisciplinary innovation processes. Furthermore, it outlines principles for developing competencies through professional educational activities and provides both practical examples and domains for further researc

The procurement and evaluation of a prototype laser satellite-tracking system Final report, 1 Jan. 1967 - 30 Sep. 1968

Pulsed ruby laser satellite tracking syste

The 67 Hz Feature in the Black Hole Candidate GRS 1915+105 as a Possible ``Diskoseismic'' Mode

The Rossi X-ray Timing Explorer (RXTE) has made feasible for the first time the search for high-frequency (~ 100 Hz) periodic features in black hole candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This feature is weak (rms variability ~0.3%-1.6%), stable in frequency (to within ~2 Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ~ 20). Several of these properties are what one expects for a ``diskoseismic'' g-mode in an accretion disk about a 10.6 M_sun (nonrotating) - 36.3 M_sun (maximally rotating) black hole (if we are observing the fundamental mode frequency). We explore this possibility by considering the expected luminosity modulation, as well as possible excitation and growth mechanisms---including turbulent excitation, damping, and ``negative'' radiation damping. We conclude that a diskoseismic interpretation of the observations is viable.Comment: 4 Pages, Latex (emulateapj.sty included), to Appear in ApJ Letters, Vol. 477, Final Version with Updated Reference