2,997 research outputs found

    Time-domain sensitivity enhancement in pulsed Pb-TDL gas monitors

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    A Pb-salt tunable diode laser (TDL) has found many applications in the field of atmospheric gas analysis. Its continuous tunablility and fine spectral purity in the mid infrared region are outstanding from other lasers. The only shortcoming is that it requires cryogenic operating temperatures, though, it is improved year by year towards the room temperature operation. A repeated pulse operation of Pb salt diode lasers is possible with a thermoelectric cooling device, which allows an instrument a portable geometry disusing a heavy, bulky and power consuming mechanical refrigerator. A derivative spectrometry was exploiting the quick tunability of Pb salt diode lasers, though they are continuous wave (cw) operated with refrigerator or liquid nitrogen so far. A new system for derivative spectrometry with a pulsed diode laser will extend its field of applications because of reduced weights and size of measuring instruments. A preliminary results is shown that demonstrates the feasibility of an attempt to implement the derivative spectrmetry with repeatedly pulse driven diode lasers. Atmospheric methane was measured with 8 ppm/m sensitivity. Further results of parametric optimization for the best signal to noise ratios under any given device characteristics as well as for available real devices is given

    Four-Photon Quantum Interferometry at a Telecom Wavelength

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    We report the experimental demonstration of four-photon quantum interference using telecom-wavelength photons. Realization of multi-photon quantum interference is essential to linear optics quantum information processing and measurement-based quantum computing. We have developed a source that efficiently emits photon pairs in a pure spectrotemporal mode at a telecom wavelength region, and have demonstrated the quantum interference exhibiting the reduced fringe intervals that correspond to the reduced de Broglie wavelength of up to the four photon `NOON' state. Our result should open a path to practical quantum information processing using telecom-wavelength photons.Comment: 4 pages, 4 figure

    Direct Measurement of the Out-of-Plane Spin Texture in the Dirac Cone Surface State of a Topological Insulator

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    We have performed spin- and angle-resolved photoemission spectroscopy of Bi2Te3 and present the first direct evidence for the existence of the out-of-plane spin component on the surface state of a topological insulator. We found that the magnitude of the out-of-plane spin polarization on a hexagonally deformed Fermi surface (FS) of Bi2Te3 reaches maximally 25% of the in-plane counterpart while such a sizable out-of-plane spin component does not exist in the more circular FS of TlBiSe2, indicating that the hexagonal deformation of the FS is responsible for the deviation from the ideal helical spin texture. The observed out-of-plane polarization is much smaller than that expected from existing theory, suggesting that an additional ingredient is necessary for correctly understanding the surface spin polarization in Bi2Te3.Comment: 4 pages, 3 figure

    Absolute negative refraction and imaging of unpolarized electromagnetic waves by two-dimensional photonic crystals

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    Absolute negative refraction regions for both polarizations of electromagnetic wave in two-dimensional photonic crystal have been found through both the analysis and the exact numerical simulation. Especially, absolute all-angle negative refraction for both polarizations has also been demonstrated. Thus, the focusing and image of unpolarized light can be realized by a microsuperlens consisting of the two-dimensional photonic crystals. The absorption and compensation for the losses by introducing optical gain in these systems have also been discussed

    The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus.

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    This is the final version of the article. Available from Hindawi Publishing Corporation via the DOI in this record.This study aims to establish the corneal nerve fiber (CNF) morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV) and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients

    Value Co-creation by Compulsory Facebook-Community in Corporate Culture: A Case Study Malaysian Logistic Company

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    The main purpose of this study was to investigate the value co-creation process using Facebook as compulsory by a company. A new value co-creation model was developed showing how Facebook could be successfully executed as a platform for the value co-creation process with the aim of providing the best possible service to the recipients. This research employed an explanatory case study due to its uniqueness, especially for sufficient and in-depth comprehension of the phenomenon. PKT Logistics Group Sdn Bhd (PKT) was chosen for this study due to its exceptional characteristic of declaring itself as ‘Facebook compulsory’ company in business after Facebook. Data were obtained from interviews, direct observations, and a questionnaire survey of the company’s top management, selected employees, and customers.The proposed model has successfully connected the company’s leader, employees, and customers with each other for attaining the ‘Ba’ in new knowledge creation spirally using Facebook as an effective platform. This has resulted in the achievement of a service-oriented value co-creation process.This research has contributed to create a new model of the value co-creation process involving all the stakeholders via a ‘Facebook community’, which could be useful for other service providers.This study differentiates itself from the restricted application of Facebook in business by focusing on Facebook as compulsory in a corporate culture. The new value co-creation process model thru a ‘Facebook community’ is original and might be first of this type study

    Procedimiento de bioanálisis de moléculas de ácido nucleico en una muestra y biosensor para su implementación

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    Peer reviewedConsejo Superior de investigaciones CientíficasT3 Traducción de patente europe
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