674 research outputs found

    Two-dimensional Rydberg gases and the quantum hard squares model

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    We study a two-dimensional lattice gas of atoms that are photo-excited to high-lying Rydberg states in which they interact via the van-der-Waals interaction. We explore the regime of dominant nearest neighbor interaction where this system is intimately connected to a quantum version of Baxter's hard squares model. We show that the strongly correlated ground state of the Rydberg gas can be analytically described by a projected entangled pair state that constitutes the ground state of the quantum hard squares model. This correspondence allows us to identify a first order phase boundary where the Rydberg gas undergoes a transition from a disordered (liquid) phase to an ordered (solid) phase

    Pulp and paper production from Spruce wood with kraft and modified kraft methods

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    In this study, kraft and modified kraft pulping methods were applied for spruce (Picea orientalis) wood collected from the Black Sea Region of Turkey. Fiber properties, carbohydrate contents, strength and optical properties of resultant paper were included to determine the properties of these pulp samples. Optimum kraft, kraft-borohydride (NaBH4), kraft- anthraquinone (AQ) and kraft-ethanol pulping conditions were determined. After determining screened yield, kappa number, viscosity, fiber length, fiber coarseness, α-cellulose, holocellulose, lignin and ash content, breaking length, tear indexes and burst indexes of the obtained pulp samples, the differences of SEM image of each pulp sample were captured and evaluated. The results indicated that kraft-AQ pulps from spruce wood exhibited better characteristics than the other pulp samples with lower kappa number, higher paper strength properties and optical properties. However, kraft-NaBH4 method gave pulps with closer characteristics to kraft-AQ and also gave a higher screened yield and α-cellulose ratio than the others

    Case report: A Stauffer’s syndrome variant associated with renal cell carcinoma and thrombocytopenia

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    Stauffer’s syndrome is a rare paraneoplastic manifestation of renal cell carcinoma which is characterized by elevated alkaline phosphatase, erythrocyte  sedimentation rate, -2-globulin, -glutamyl transferase,  thrombocytosis, prolongation of prothrombin time and hepatosplenomegaly, in the absence of hepatic  metastasis and jaundice. In this case report, we report a patient who was admitted with fever, fatigue,  abdominal pain, weight loss and pruritus in whom renal cell carcinoma was incidentally found in the right kidney during an initial workup.KEYWORDS: Cholestasis; Paraneoplastic syndrome; RCC; Stauffer’s syndrome; Thrombocytopeni

    Efficient out-coupling of high-purity single photons from a coherent quantum dot in a photonic-crystal cavity

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    We demonstrate a single-photon collection efficiency of (44.3±2.1)%(44.3\pm2.1)\% from a quantum dot in a low-Q mode of a photonic-crystal cavity with a single-photon purity of g(2)(0)=(4±5)%g^{(2)}(0)=(4\pm5)\% recorded above the saturation power. The high efficiency is directly confirmed by detecting up to 962±46962\pm46 kilocounts per second on a single-photon detector on another quantum dot coupled to the cavity mode. The high collection efficiency is found to be broadband, as is explained by detailed numerical simulations. Cavity-enhanced efficient excitation of quantum dots is obtained through phonon-mediated excitation and under these conditions, single-photon indistinguishability measurements reveal long coherence times reaching 0.77±0.190.77\pm0.19 ns in a weak-excitation regime. Our work demonstrates that photonic crystals provide a very promising platform for highly integrated generation of coherent single photons including the efficient out-coupling of the photons from the photonic chip.Comment: 13 pages, 8 figures, submitte
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