2,334 research outputs found

    Certain Elastic Properties of Phosphor-Bronze Wires

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    The work by Guthe, Guthe and Sieg, and Sieg, on platinumiridium wires when used as suspensions for torsion pendulums, showed some remarkable elastic properties of that alloy. The principal one of these was the variation of the period with the amplitude of vibration. It was these studies that made it seem very desirable to test other alloys commonly used for suspensions, by a similar method

    Glasgow's Stereo Image Database of Garments

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    To provide insight into cloth perception and manipulation with an active binocular robotic vision system, we compiled a database of 80 stereo-pair colour images with corresponding horizontal and vertical disparity maps and mask annotations, for 3D garment point cloud rendering has been created and released. The stereo-image garment database is part of research conducted under the EU-FP7 Clothes Perception and Manipulation (CloPeMa) project and belongs to a wider database collection released through CloPeMa (www.clopema.eu). This database is based on 16 different off-the-shelve garments. Each garment has been imaged in five different pose configurations on the project's binocular robot head. A full copy of the database is made available for scientific research only at https://sites.google.com/site/ugstereodatabase/.Comment: 7 pages, 6 figure, image databas

    Hitzschlag mit Alpha-Koma: Ein Fallbericht

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    Zusammenfassung: Wir berichten über einen 41-jährigen komatösen Patienten, der einen schwer verlaufenden Hitzschlag mit einer Körperkerntemperatur von 41,5°C erlitt. Der klinische Verlauf wurde kompliziert durch eine akute systemische inflammatorische Reaktion und Multiorganversagen. Das EEG zeigte ein prognostisch ungünstiges Alpha-Koma ohne Reaktivität auf externe Stimuli. Der Patient erlangte das Bewusstsein wieder und wurde nach 16Tagen aus der intensivmedizinischen Behandlung entlassen. Im weiteren Verlauf entwickelte sich eine zerebrale Toxoplasmose, die mit einer Kombinationstherapie aus Sulfadiazin und Pyrimethamin behandelt wurde. Nach 65Tagen erfolgte eine Verlegung in eine Neurorehabilitationsklinik mit einem moderaten neurologischen Defizi

    Protein-mediated DNA Loop Formation and Breakdown in a Fluctuating Environment

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    Living cells provide a fluctuating, out-of-equilibrium environment in which genes must coordinate cellular function. DNA looping, which is a common means of regulating transcription, is very much a stochastic process; the loops arise from the thermal motion of the DNA and other fluctuations of the cellular environment. We present single-molecule measurements of DNA loop formation and breakdown when an artificial fluctuating force, applied to mimic a fluctuating cellular environment, is imposed on the DNA. We show that loop formation is greatly enhanced in the presence of noise of only a fraction of kBTk_B T, yet find that hypothetical regulatory schemes that employ mechanical tension in the DNA--as a sensitive switch to control transcription--can be surprisingly robust due to a fortuitous cancellation of noise effects

    Notes on Certain Elastic Peculiarities of Phosphor Bronze Wires

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    Some previous work by one of the authors with wires of an alloy of platinum-iridium, portions of which work were published in these Proceedings, indicated that when the wires were used as suspensions for torsion pendulums, the relations between the period of vibration and the amplitude were exceedingly complicated. The effect of drawing these wires was dealt with in another paper. In all these papers referred to, the statement was made that similar tests should be applied to some of the more common wires in the hope of finding similar, even though smaller effects. Through press of work these experiments have been deferred until the present year. This particular paper will deal with but one feature of the work, namely, the effect of drawing on the elastic nature of phosphor bronze wires. The writers are indebted to the American Electrical Works, of Phillipsdale, Rhode Island, for kindly furnishing them with specimens of the wires

    Composition and luminescence studies of InGaN epilayers grown at different hydrogen flow rates

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    Indium gallium nitride (In(x)Ga(1-x)N) is a technologically important material for many optoelectronic devices, including LEDs and solar cells, but it remains a challenge to incorporate high levels of InN into the alloy while maintaining sample quality. A series of InGaN epilayers was grown with different hydrogen flow rates (0-200 sccm) and growth temperatures (680-750 °C) to obtain various InN fractions and bright emission in the range 390-480 nm. These 160-nm thick epilayers were characterized through several compositional techniques (wavelength dispersive x-ray spectroscopy, x-ray diffraction, Rutherford backscattering spectrometry) and cathodoluminescence hyperspectral imaging. The compositional analysis with the different techniques shows good agreement when taking into account compositional gradients evidenced in these layers. The addition of small amounts of hydrogen to the gas flow at lower growth temperatures is shown to maintain a high surface quality and luminescence homogeneity. This allowed InN fractions of up to ~16% to be incorporated with minimal peak energy variations over a mapped area while keeping a high material quality

    Self-referencable frequency comb from a 170-fs, 1.5-μm solid-state laser oscillator

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    We report measurement of the first carrier-envelope offset (CEO) frequency signal from a spectrally broadened ultrafast solid-state laser oscillator operating in the 1.5μm spectral region. The f-to-2f CEO frequency beat signal is 49 dB above the noise floor (100-kHz resolution bandwidth) and the free-running linewidth of 3.6 kHz is significantly better than typically obtained by ultrafast fiber laser systems. We used a SESAM mode-locked Er:Yb:glass laser generating 170-fs pulses at a 75MHz pulse repetition rate with 110-mW average power. It is pumped by one standard telecom-grade 980-nm diode consuming less than 1.5W of electrical power. Without any further pulse compression and amplification, a coherent octave-spanning frequency comb is generated in a polarization-maintaining highly-nonlinear fiber (PM-HNLF). The fiber length was optimized to yield a strong CEO frequency beat signal between the outer Raman soliton and the spectral peak of the dispersive wave within the supercontinuum. The polarization-maintaining property of the supercontinuum fiber was crucial; comparable octave-spanning supercontinua from two non-PM fibers showed higher intensity noise and poor coherence. Astable CEO-beat was observed even with pulse durations above 200fs. Achieving a strong CEO frequency signal from relatively long pulses with moderate power levels substantially relaxes the demands on the driving laser, which is particularly important for novel gigahertz diode-pumped solid-state and semiconductor laser
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