4,385 research outputs found

    Heat Conduction in two-dimensional harmonic crystal with disorder

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    We study the problem of heat conduction in a mass-disordered two-dimensional harmonic crystal. Using two different stochastic heat baths, we perform simulations to determine the system size (L) dependence of the heat current (J). For white noise heat baths we find that J ~ 1/L^a with a0.59 a \approx 0.59 while correlated noise heat baths gives a0.51 a \approx 0.51 . A special case with correlated disorder is studied analytically and gives a=3/2 which agrees also with results from exact numerics.Comment: Revised version. 4 pages, 3 figure

    Teleportation and Dense Coding with Genuine Multipartite Entanglement

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    We present an explicit protocol E0{\cal E}_0 for faithfully teleporting an arbitrary two-qubit state via a genunie four-qubit entangled state. By construction, our four-partite state is not reducible to a pair of Bell states. Its properties are compared and contrasted with those of the four-party GHZ and W states. We also give a dense coding scheme D0{\cal D}_0 involving our state as a shared resource of entanglement. Both D0{\cal D}_0 and E0{\cal E}_0 indicate that our four-qubit state is a likely candidate for the genunine four-partite analogue to a Bell state.Comment: 9 pages, 0 figur

    Are Asians comfortable with discussing death in health valuation studies? A study in multi-ethnic Singapore

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    BACKGROUND To characterize ease in discussing death (EID) and its influence on health valuation in a multi-ethnic Asian population and to determine the acceptability of various descriptors of death and "pits"/"all-worst" in health valuation. METHODS In-depth interviews (English or mother-tongue) among adult Chinese, Malay and Indian Singaporeans selected to represent both genders and a wide range of ages/educational levels. Subjects rated using 0–10 visual analogue scales (VAS): (1) EID, (2) acceptability of 8 descriptors for death, and (3) appropriateness of "pits" and "all-worst" as descriptors for the worst possible health state. Subjects also valued 3 health states using VAS followed by time trade-off (TTO). The influence of sociocultural variables on EID and these descriptors was studied using univariable analyses and multiple linear regression (MLR). The influence of EID on VAS/TTO utilities with adjustment for sociocultural variables was assessed using MLR. RESULTS Subjects (n = 63, 35% Chinese, 32% Malay, median age 44 years) were generally comfortable with discussing death (median EID: 8.0). Only education significantly influenced EID (p = 0.045). EID correlated weakly with VAS/TTO scores (range: VAS: -0.23 to 0.07; TTO: -0.14 to 0.11). All subjects felt "passed away", "departed" and "deceased" were most acceptable (median acceptability: 8.0) while "sudden death" and "immediate death" were least acceptable (median acceptability: 5.0). Subjects clearly preferred "all-worst" to "pits" (63% vs. 19%, p < 0.001). CONCLUSION Singaporeans were generally comfortable with discussing death and had clear preferences for several descriptors of death and for "all-worst". EID is unlikely to influence health preference measurement in health valuation studies

    How asynchronous video interviews are used in practice:A study of an Australian‐based AVI vendor

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    With an archival data set from an Australian-based asynchronous video interview (AVI) vendor, we examined how employers implemented AVI features as a step toward understanding how AVIs can be more optimally designed. The multilevel data contained information about 2,550,105 responses from 627,999 candidates to 52,623 questions, nested within 12,105 interview templates. We found that AVIs were often used for small applicant pools (Mdn = 10 candidates per AVI) and that a majority of the AVIs comprised four to five questions, with candidates typically given 30 seconds to prepare a response, and 2 minutes to record it. Only rarely were candidates permitted to preview questions or re-record responses. Finally, we noted that the settings typically applied were highly consistent with platform's default settings

    Endoscopic orbital decompression for Graves' ophthalmopathy

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    Graves’ disease may occasionally result in significant proptosis that is either cosmetically unacceptable or causes visual loss. This has traditionally been managed surgically by external decompression of the orbital bony skeleton. Trans-nasal endoscopic orbital decompression is emerging as a new minimally-invasive technique, that avoids the need for cutaneous or gingival incisions. Decompression of the medial orbital wall can be performed up to the anterior wall of the sphenoid sinus. This can be combined with resection of the medial and posterior portion of the orbital floor (preserving the infra-orbital nerve). This technique produces decompression which is comparable to external techniques. We present a series of 10 endoscopic orbital decompressions with an average improvement of 4.4 mm in orbital proptosis. There was an improvement in visual acuity in all patients with visual impairment. Endoscopic orbital decompression is recommended as an alternative to traditional decompression techniques.Desmond T. H. Wee, A. Simon Carney, Mark Thorpe and Peter J. Wormal

    Foreign exchange exposure: Evidence from the U.S. insurance industry

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    We study the foreign exchange exposure of U.S. insurers. The evidence shows that no systematic difference exists in the currency risk profiles of life and non-life segments within the insurance industry. This suggests that life and non-life insurers have similar risk exposure management strategies arising from similar risk pooling and financial intermediary functions. The empirical results reveal that a sizable proportion of U.S. insurers are exposed to foreign exchange movements against the seven largest U.S. trade partners in insurance services (U.K., Japan, Switzerland, Netherlands, France, Germany and Canada). Significant operational and size effects are also documented and we find that the frequency of foreign exchange exposure increases with time horizon

    One-dimensional collision carts computer model and its design ideas for productive experiential learning

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    We develop an Easy Java Simulation (EJS) model for students to experience the physics of idealized one-dimensional collision carts. The physics model is described and simulated by both continuous dynamics and discrete transition during collision. In the field of designing computer simulations, we discuss briefly three pedagogical considerations such as 1) consistent simulation world view with pen paper representation, 2) data table, scientific graphs and symbolic mathematical representations for ease of data collection and multiple representational visualizations and 3) game for simple concept testing that can further support learning. We also suggest using physical world setup to be augmented complimentary with simulation while highlighting three advantages of real collision carts equipment like tacit 3D experience, random errors in measurement and conceptual significance of conservation of momentum applied to just before and after collision. General feedback from the students has been relatively positive, and we hope teachers will find the simulation useful in their own classes. 2015 Resources added: http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/46-one-dimension-collision-js-model http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/195-elastic-collisionComment: 6 pages, 8 figures, 1 table, 1 L. K. Wee, Physics Education 47 (3), 301 (2012); ISSN 0031-912

    Enhanced self-field critical current density of nano-composite YBa(2)Cu(3)O(7) thin films grown by pulsed-laser deposition

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ EPLA, 2008.Enhanced self-field critical current density Jc of novel, high-temperature superconducting thin films is reported. Layers are deposited on (001) MgO substrates by laser ablation of YBa2Cu3O7−δ(Y-123) ceramics containing Y2Ba4CuMOx (M-2411, M=Ag, Nb, Ru, Zr) nano-particles. The Jc of films depends on the secondary-phase content of the ceramic targets, which was varied between 0 and 15 mol%. Composite layers (2 mol% of Ag-2411 and Nb-2411) exhibit Jc values at 77 K of up to 5.1 MA/cm2, which is 3 to 4 times higher than those observed in films deposited from phase pure Y-123 ceramics. Nb-2411 grows epitaxially in the composite layers and the estimated crystallite size is ~10 nm.The Austrian Science Fund, the Austrian Federal Ministry of Economics and Labour, the European Science Foundation and the Higher Education Commission of Pakistan

    Studies on Silica-Scaled Chrysophytes from Iowa

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    References in the literature to the silica-scaled chrysophytes of Iowa are few and, since the advent of the electron microscope, identifications of taxa in this group are no longer considered valid without accompanying electron micrographs. Using scanning electron microscopy for critical identifications, eight taxa genera of the Synuraceae are reported here including the first known report of the genus Paraphysomonas from Iowa. From the other two genera, Mallomonas and Synura, only one of the taxa in this paper, Mallomonas pseudocoronata, has been reported from Iowa previously. Mallomonas acaroides var. striatula, M. tonsurata, M. tonsurata var. alpina, M. teilingii, M. pseudocorcnata, Mallomonas sp., Synura petersenii, and Paraphysomonas imperforata are the taxa reported
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