597 research outputs found

    Combinatorial Topology Of Multipartite Entangled States

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    With any state of a multipartite quantum system its separability polytope is associated. This is an algebro-topological object (non-trivial only for mixed states) which captures the localisation of entanglement of the state. Particular examples of separability polytopes for 3-partite systems are explicitly provided. It turns out that this characterisation of entanglement is associated with simulation of arbitrary unitary operations by 1- and 2-qubit gates. A topological description of how entanglement changes in course of such simulation is provided.Comment: 14 pages, LaTeX2e. Slightly revised version of the poster resented on the International Conference on Quantum Information, Oviedo, Spain, 13-18 July, 2002. To appear in the special issue of Journal of Modern Optic

    A Dodecalogue of Basic Didactics from Applications of Abstract Differential Geometry to Quantum Gravity

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    We summarize the twelve most important in our view novel concepts that have arisen, based on results that have been obtained, from various applications of Abstract Differential Geometry (ADG) to Quantum Gravity (QG). The present document may be used as a concise, yet informal, discursive and peripatetic conceptual guide-cum-terminological glossary to the voluminous technical research literature on the subject. In a bonus section at the end, we dwell on the significance of introducing new conceptual terminology in future QG research by means of `poetic language'Comment: 16 pages, preliminary versio

    Loop quantum black hole

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    In this paper we consider the Kantowski-Sachs space-time in Ashtekar variables and the quantization of this space-time starting from the complete loop quantum gravity theory. The Kanthowski-Sachs space-time coincides with the Schwarzschild black hole solution inside the horizon. By studying this model we can obtain information about the black hole singularity and about the dynamics across the point r=0. We studied this space-time in ADM variables in two previous papers where we showed that the classical black hole singularity disappears in quantum theory. In this work we study the same model in Ashtekar variables and we obtain a regular space-time inside the horizon region and that the dynamics can be extend further the classical singularity.Comment: 12 pages, latex. We introduce and we calculate the spectrum of the operator 1/|E

    Experimental study of the turbulent structure of the surface marine Atmospheric Boundary Layer over the Aegean Pelagos under etesian winds

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    In order to study the physical processes of the turbulent transportation of mass and energy within the surface Marine Atmospheric Boundary Layer over the Aegean Pelagos, field measurements were conducted on the island of Skyros, mainly under the etesian winds, during summer 2011. Α meteorological mast was installed close to the shoreline, instrumented with fast anemometer (sonic) and hydrometer measuring the three components of the wind, the virtual temperature and water vapor at 10m height with a sampling frequency of 20Hz. At the same mast slow response sensors were measuring wind speed and direction, temperature and humidity at three levels (2, 6 and 10 m). Weak stable to near neutral flows were recorded during the experimental period. The eddy correlation analysis re-vealed the momentum and heat fluxes values which are presented and discussed. The estimated values are related both with stability and wind speed variations

    Abdominoperineal Resection for Rectal Cancer: Is the Pelvic Drain Externalization Site an Independent Risk Factor for Perineal Wound Healing?

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    Aim. The aim of this paper is to investigate if the insertion of the pelvic drainage tube via the perineal wound could be considered as an independent risk factor for perineal healing disorders, after abdominoperineal resection for rectal malignancy. Patients and Methods. The last two decades, 75 patients underwent elective abdominoperineal resection for malignancy. In 42 patients (56%), the pelvic drain catheter was inserted through the perineal wound (PW group), while in the remaining 33 (44%) through a puncture skin wound of the perineum (SW group). Patients' data with respect to age (P = 0.136), stage (P > 0.05), sex (P = 0.188) and comorbidity (P = 0.128) were similar in both groups. 25 patients (PW versus SW: 8 versus 17, P = 0.0026) underwent neoadjuvant radio/chemotherapy. Results. The overall morbidity rate was 36%, but a significant increase was revealed in PW group (52.4% versus 9%, P = 0.0007). In 33.3% of the patients in the PW group, perineal healing was delayed, while in the SW group, no delay was noted. Perineal healing disorders were revealed as the main source of increased morbidity in this group. Conclusion. The insertion of the pelvic drain tube through the perineal wound should be considered as an independent risk factor predisposing to perineal healing disorders

    rac-5-Acetyl-6-hy­droxy-3,6-dimethyl-4-phenyl-2H-4,5,6,7-tetra­hydro­indazol-1-ium chloride

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    The structure of the title compound, C17H21N2O2 +·Cl−, is of inter­est with respect to its biological activity. The title compound comprises an organic cation and a chloride anion in the asymmetric unit. The positive charge is localized in a pyrazole moiety forming a pyrazolium cation. The structure displays inter­molecular O—H⋯Cl and N—H⋯Cl hydrogen bonding
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