9,671 research outputs found

    Effect of the chemical state of pyrolysis gases on heat-shield mass

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    Effect of chemical properties of pyrolysis gases on heat shield mass required for lifting reentry vehicle in typical reentry trajector

    Mineral exploration potential of ERTS-1 data

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    The author has identified the following significant results. Preliminary analysis of a mosaic composing eight individual ERTS frames (1:1,000,000) extending well beyond the test site has revealed a number of tectonic structural trends that are controlled by regional lineations. So far most of the regional lineations fall into three general directions: east by northeast, northwest, and north-south. From preliminary examination, it appears that the older Precambrian basement predominates in the NE-bearing structural trends, whereas the predominate NW trend is most likely associated with the Texas Structural Zone, and the north-south trend being the Utah-Arizona belt and/or part of the southern Basin and Range Province. One major lineation, made up of many parallel lineations, is noticeable just north of Lake Pleasant which extends for approximately 100 miles in a northern direction out of the target area. This feature corresponds to a Precambrian schist formation shown on the USGS geologic map of Arizona

    Survey and monitoring of opium poppy and wheat in Afghanistan: 2003-2009

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    An integrated application of remote-sensing technology was devised and applied in Afghanistan during 2003–2009 providing critical information on cereal and poppy cultivation and poppy eradication. The results influenced UK and international policy and counter-narcotics actions in Afghanistan

    1st, 2nd and 3rd Generation Implementations of an eLearning Deign: Re-use from Postgraduate Law to Block/online Engineering Course

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    In order to meet the demands of postgraduate students who were time poor and unable to regularly attend face-to-face classes, one lecturer in the Faculty Law at the University of Wollongong (UOW) sought the assistance of a Learning Designer to redesign the Postgraduate Practical Legal Training (PLT) program into a flexible blended learning format, using a block/online approach. The program used an authentic workplace-simulated model that took advantage of emerging technologies to enable effective online teaching and learning. This learning design was reused to redesign two subjects within the Postgraduate Engineering Management course. To monitor the effectiveness of this approach and to ensure quality in teaching and learning the Engineering program was evaluated, with positive results

    Kinetics and mechanism of proton transport across membrane nanopores

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    We use computer simulations to study the kinetics and mechanism of proton passage through a narrow-pore carbon-nanotube membrane separating reservoirs of liquid water. Free energy and rate constant calculations show that protons move across the membrane diffusively in single-file chains of hydrogen-bonded water molecules. Proton passage through the membrane is opposed by a high barrier along the effective potential, reflecting the large electrostatic penalty for desolvation and reminiscent of charge exclusion in biological water channels. At neutral pH, we estimate a translocation rate of about 1 proton per hour and tube.Comment: 4 pages, 4 figure

    Mineral exploration potential of ERTS-1 data

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    The author has identified the following significant results. ERTS-1 imagery of an area approximately 15,000 square miles in Arizona was interpreted for regional structure and tectonic units. Eight fault systems were identified by trend, of which two, northeast and northwest, are considered to be related to porphyry copper mineralization. Nine tectonic units can be identified on the imagery as distinct geological identities. The boundaries between these units can be correlated with theoretical shear directions related to the San Andreas stress system. Fourier analysis of the N 50 W fault trend indicates a fundamental spacing between Fourier energy maxima that can be related to distances between copper deposits

    Train of high-power femtosecond pulses: Probe wave in a gas of prepared atoms

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    We present a new method for generating a regular train of ultrashort optical pulses in a prepared two-level medium. The train develops from incident monochromatic probe radiation travelling in a medium of atoms, which are in a quantum mechanical superposition of dressed internal states. In the frame of used linear theory for the probe radiation, the energy of individual pulses is an exponentially growing function of atom density and of interaction cross section. Pulse repetition rate is determined by the generalized Rabi frequency and can be around 1 THz and greater. We also show that the terms, extra to the dipole approximation, endow the gas by a new property: non-saturating dependence of refractive index on the dressing monochromatic field intensity. Contribution of these nonsaturating terms can be compatible with the main dipole approximation in the wavelength region of about ten micrometers (the range of CO_2 laser) or larger

    Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

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    Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards
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