34,996 research outputs found

    A characterization of quasi-rational polygons

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    The aim of this paper is to study quasi-rational polygons related to the outer billiard. We compare different notions introduced, and make a synthesis of those.Comment: 15 pages, 9 figure

    Solar energy conversion through the interaction of plasmons with tunnel junctions. Part A: Solar cell analysis. Part B: Photoconductor analysis

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    A solar cell utilizing guided optical waves and tunnel junctions was analyzed to determine its feasibility. From this analysis, it appears that the limits imposed upon conventional multiple cell systems also limit this solar cell. Due to this limitation, it appears that the relative simplicity of the conventional multiple cell systems over the solar cell make the conventional multiple cell systems the more promising candidate for improvement. It was discovered that some superlattice structures studied could be incorporated into an infrared photodetector. This photoconductor appears to be promising as a high speed, sensitive (high D sup star sub BLIP) detector in the wavelength range from 15 to over 100 micrometers

    Golabi-Ito-Hall syndrome results from a missense mutation in the WW domain of the PQBP1 gene

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    Background: Golabi, Ito, and Hall reported a family with X linked mental retardation (XLMR), microcephaly, postnatal growth deficiency, and other anomalies, including atrial septal defect, in 1984.Methods: This family was restudied as part of our ongoing study of XLMR, but significant linkage to X chromosome markers could not be found. Extreme short stature and microcephaly as well as other new clinical findings were observed. Mutations in the polyglutamine tract binding protein 1 gene (PQBP1) have recently been reported in four XLMR disorders (Renpenning, Hamel cerebro-palato-cardiac, Sutherland-Haan, and Porteous syndromes) as well as in several other families. The clinical similarity of our family to these patients with mutations in PQBP1, particularly the presence of microcephaly, short stature, and atrial septal defect, prompted examination of this gene.Results: A missense mutation in PQBP1 was identified which changed the conserved tyrosine residue in the WW domain at position 65 to a cysteine (p.Y65C).Conclusions: This is the first missense mutation identified in PQBP1 and the first mutation in the WW domain of the gene. The WW domain has been shown to play an important role in the regulation of transcription by interacting with the PPxY motif found in transcription factors. The p.Y65C mutation may affect the proper functioning of the PQBP1 protein as a transcriptional co-activator

    Lost City meteorite: Its recovery and a comparison with other fireballs

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    Lost City meteoroid trajectory analysis and determination of original mas

    Final Report on NASA Grant NAG 3-433. Solar Energy Conversion Through the Interaction of Plasmons with Tunnel Junctions. Part A Solar Cell Analysis. Part B Photoconductor Analysis

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    A novel solar cell utilizing guided optical waves and tunnel junctions has been analyzed to determine its feasibility. From this analysis, it appears that the limits imposed upon conventional multiple cell systems also limit this novel solar cell. Due to this limitation, it appears that the relative simplicity of the conventional multiple cell systems over the novel solar cell make the conventional multiple cell systems the more promising candidate for improvement. In the course of this investigation, it was discovered that some superlattice structures studied could be incorporated into an infrared photodetector. This photoconductor appears to be promising as a high speed, sensitive (high DBLip) detector in the wavelength range from 15 μm to over 100 μm

    Lost City meteorite - It's recovery and a comparison with other fireballs

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    Photographic and trajectory data for Lost City meteor and establishment of calibration of mass scale of other meteor

    Determinisitic Writing and Control of the Dark Exciton Spin using Short Single Optical Pulses

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    We demonstrate that the quantum dot-confined dark exciton forms a long-lived integer spin solid state qubit which can be deterministically on-demand initiated in a pure state by one optical pulse. Moreover, we show that this qubit can be fully controlled using short optical pulses, which are several orders of magnitude shorter than the life and coherence times of the qubit. Our demonstrations do not require an externally applied magnetic field and they establish that the quantum dot-confined dark exciton forms an excellent solid state matter qubit with some advantages over the half-integer spin qubits such as the confined electron and hole, separately. Since quantum dots are semiconductor nanostructures that allow integration of electronic and photonic components, the dark exciton may have important implications on implementations of quantum technologies consisting of semiconductor qubits.Comment: Added two authors, minor edits to figure captions, expanded discussion of dark exciton eigenstate
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