4,810 research outputs found

    Use of MAGSAT anomaly data for crustal structure and mineral resources in the US Midcontinent

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    The analysis and preliminary interpretation of investigator-B MAGSAT data are addressed. The data processing included: (1) removal of spurious data points; (2) statistical smoothing along individual data tracks, to reduce the effect of geomagnetic transient disturbances; (3) comparison of data profiles spatially coincident in track location but acquired at different times; (4) reduction of data by weighted averaging to a grid with 1 deg xl deg latitude/longitude spacing, and with elevations interpolated and weighted to a common datum of 400 km; (5) wavelength filtering; and (6) reduction of the anomaly map to the magnetic pole. Agreement was found between a magnitude data anomaly map and a reduce-to-the-pole map supporting the general assumption that, on a large scale (long wavelength), it is induced crustal magnetization which is responsible for major anamalies. Anomalous features are identified and explanations are suggested with regard to crustal structure, petrologic characteristics, and Curie temperature isotherms

    Use of Magsat anomaly data for crustal structure and mineral resources in the US midcontinent

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    Magnetic profiles on individual satellites tracks were examined to identify bad (nonterrestrially-based) data points r profiles. Anomaly profiles for the same satellite track, but at different passes were compared for parallel tracks and for tracks that cross. The selected and processed data were plotted and contoured to develop a preliminary magnetic anomaly map. The map is similar in general morphology to NASA's Magsat global scalar anomaly map, but has more detail which is related to crustal properties. Efforts have begun to interpret the satellite magnetic anomalies in terms of crustal character. The correlation of magnetics with crustal petrology may have a much larger tectonic implication. Th possibility of there being an ultramafic lower crust along one zone as a consequence of a continental collision/subduction which helped form the midcontinent craton in Precambrian times is being investigated

    Use of MAGSAT anomaly data for crustal structure and mineral resources in the US Midcontinent

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    Personnel matters related to the processing and interpretation of MAGSAT data are reported. Efforts are being initiated to determine the crustal geology, structure, and potential economic consequences to be deduced from the satellite magnetic anomalies in conjuction with correlative data

    Use of MAGSAT anomaly data for crustal structure and mineral resources in the US midcontinent

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    While the preliminary magnetic anomaly map for the centra midcontinent is only in the hand-drawn stage, it agrees in broad aspects with the preliminary global MAGSAT map provided by NASA. Because of data evaluation and finer scale averaging, there are more detailed features which hold promise for eventual geological/crustal interpretation. Some current analysis is directed at examining whether a map data feature such as an elongated anomaly or trend, which seems parallel to satellite data tracks, is likely of crustal origin or is an artifact of the data set

    Use of MAGSAT anomaly data for crustal structure and mineral resources in the US midcontinent

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    Activities concerning the interpretation of processed MAGSAT data and maps are briefly reported. Work involving the identification of long wavelength 'regional' effects that might be associated with varying crustal thickness or Curie temperature depths is processing

    Non-classical photon pair generation in atomic vapours

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    A scheme for the generation of non-classical pairs of photons in atomic vapours is proposed. The scheme exploits the fact that the cross correlation of the emission of photons from the extreme transitions of a four-level cascade system shows anti-bunching which has not been reported earlier and which is unlike the case of the three level cascade emission which shows bunching. The Cauchy-Schwarz inequality which is the ratio of cross-correlation to the auto correlation function in this case is estimated to be 103−10610^3-10^6 for controllable time delay, and is one to four orders of magnitude larger compared to previous experiments. The choice of Doppler free geometry in addition to the fact that at three photon resonance the excitation/deexcitation processes occur in a very narrow frequency band, ensures cleaner signals.Comment: 18 pages, 7 figure

    Petrographic and crystallographic study of silicate minerals in lunar rocks

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    Optical U-stage measurements, chemical microprobe data, and X-ray procession photographs of a bytownite twin group from rock 12032,44 are compared. Sharp but weak b and no c-reflections were observed for this An89 bytownite indicating a partly disordered structure. Euler angles, used to characterize the orientation of the optical indicatrix, compare better with values for plutonic than for volcanic plagioclase. This indicates that structural and optical properties cannot be directly correlated

    Controlling entanglement by direct quantum feedback

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    We discuss the generation of entanglement between electronic states of two atoms in a cavity using direct quantum feedback schemes. We compare the effects of different control Hamiltonians and detection processes in the performance of entanglement production and show that the quantum-jump-based feedback proposed by us in Phys. Rev. A {\bf 76} 010301(R) (2007) can protect highly entangled states against decoherence. We provide analytical results that explain the robustness of jump feedback, and also analyse the perspectives of experimental implementation by scrutinising the effects of imperfections and approximations in our model.Comment: 10 pages, 8 figures. To appear in PR

    Stretchable Ultrasheer Fabrics as Semitransparent Electrodes for Wearable Light-Emitting e-Textiles with Changeable Display Patterns

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    Despite the development throughout human history of a wealth of textile materials and structures, the porous structures and non-planar surfaces of textiles are often viewed as problematic for the fabrication of wearable e-textiles and smart clothing. Here, we demonstrate a new textile-centric design paradigm in which we use the textile structure as an integral part of wearable device design. We coat the open framework structure of an ultrasheer knitted textile with a conformal gold film using solution-based metallization to form gold-coated ultrasheer electrodes that are highly conductive (3.6 ± 0.9 Ω/sq) and retain conductivity to 200% strain with R/R0 \u3c 2. The ultrasheer electrodes produce wearable, highly stretchable light-emitting e-textiles that function to 200% strain. Stencil printing a wax resist provides patterned electrodes for patterned light emission; furthermore, incorporating soft-contact lamination produces light-emitting textiles that exhibit, for the first time, readily changeable patterns of illumination
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