2,046 research outputs found

    T-duality of the Green-Schwarz superstring

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    We study T-duality in the Green-Schwarz formalism to all orders in superspace coordinates. We find two analogs of Buscher rules for the supervielbein and clarify their meaning from the superstring point of view. The transformation rules for the dilaton, spin 1/2 fermions and Ramond-Ramond superfields are also derived.Comment: 21 pages, late

    Polarized neutron channeling as a tool for the investigations of weakly magnetic thin films

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    We present and apply a new method to measure directly weak magnetization in thin films. The polarization of a neutron beam channeling through a thin film structure is measured after exiting the structure edge as a microbeam. We have applied the method to a tri-layer thin film structure acting as a planar waveguide for polarized neutrons. The middle guiding layer is a rare earth based ferrimagnetic material TbCo5 with a low magnetization of about 20 mT. We demonstrate that the channeling method is more sensitive than the specular neutron reflection method

    Awareness of ovarian cancer symptoms and risk factors in a young ethnically diverse British population

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    Background: Ovarian cancer does not cause many symptoms in the early stages, which is why the majority of cases are of advanced disease. Increasing awareness of ovarian cancer symptoms may lead to earlier diagnosis and improved outcomes. Methods: Participants in Britain completed the Ovarian Cancer Awareness Measure by online survey (n = 459). Results: Our participants were 75% female, 25% male and a young (27.89 ± 11.44 years) ethnically diverse population (40.3% White, 29.3% Asian and 18.0% Black). Individuals recalled 1.24 ± 1.30 symptoms, and recognised 5.96 ± 2.4 symptoms. We found higher levels of recall and recognition compared to previous research possibly due to using an online survey. Recognition was lowest for difficulty eating (39.4%) and persistently feeling full (38.7%). Males had slightly lower symptom recall and recognition than females. Participants incorrectly recalled an irregular menstrual cycle (22.4%) as an ovarian cancer symptom and 67% answered the age of incidence question incorrectly. Suggesting that participants incorrectly associate ovarian cancer as a disease of pre‐menopausal women. Individuals recalled 1.47 ± 1.20 risk factors, and recognised 6.1 ± 2.4 risk factors. Family history of ovarian cancer was recalled by 59% of participants. Recognition was lowest for in vitro fertilisation treatment (23.0%) and talcum powder in the genital area (23.0%). The generic cancer risk factors of alcohol (9.3%) and poor diet (8.8%) were recalled as specific ovarian cancer risk factors. 57.9% of participants incorrectly answered that there is an ovarian cancer screening programme. Suggesting confusion between ovarian and cervical cancer as participants also recalled cervical cancer risk factors of sexually transmitted diseases (6.3%) and human papillomavirus (1.5%). 29.7% of female participants would seek help for an ovarian cancer symptom within 1–2 days. Help seeking was higher in the Black and Asian ethnicities (44.4% and 45.0%; p = 0.018). Conclusion: Awareness of ovarian cancer symptoms is low. Ovarian cancer awareness campaigns should include common misconceptions identified in this research

    Charged-rotating black holes and black strings in higher dimensional Einstein-Maxwell theory with a positive cosmological constant

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    We present arguments for the existence of charged, rotating black holes in d=2N+1d=2N+1 dimensions, with d5d\geq 5 with a positive cosmological constant. These solutions posses both, a regular horizon and a cosmological horizon of spherical topology and have NN equal-magnitude angular momenta. They approach asymptotically the de Sitter spacetime background. The counterpart equations for d=2N+2d=2N+2 are investigated, by assuming that the fields are independant of the extra dimension yy, leading to black strings solutions. These solutions are regular at the event horizon. The asymptotic form of the metric is not the de Sitter form and exhibit a naked singularity at finite proper distance.Comment: 21 pages, 9 figure

    Static axially symmetric solutions of Einstein-Yang-Mills equations with a negative cosmological constant: black hole solutions

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    We investigate static axially symmetric black hole solutions in a four-dimensional Einstein-Yang-Mills-SU(2) theory with a negative cosmological constant Λ\Lambda. These solutions approach asymptotically the anti-de Sitter spacetime and possess a regular event horizon. A discussion of the main properties of the solutions and the differences with respect to the asymptotically flat case is presented. The mass of these configurations is computed by using a counterterm method. We note that the Λ=3\Lambda=-3 configurations have an higher dimensional interpretation in context of d=11d=11 supergravity. The existence of axially symmetric monopole and dyon solutions in a fixed Schwarzschild-anti-de Sitter background is also discussed. An exact solution of the Einstein-Yang-Mills equations is presented in Appendix.Comment: 47 pages, 47 figure

    Two-loop world-sheet corrections in AdS_5 x S^5 superstring

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    We initiate the computation of the 2-loop quantum AdS_5 x S^5 string corrections on the example of a certain string configuration in S^5 related by an analytic continuation to a folded rotating string in AdS_5 in the ``long string'' limit. The 2-loop term in the energy of the latter should represent the subleading strong-coupling correction to the cusp anomalous dimension and thus provide a further check of recent conjectures about the exact structure of the Bethe ansatz underlying the AdS/CFT duality. We use the conformal gauge and several choices of the \kappa-symmetry gauge. While we are unable to verify the cancellation of 2d UV divergences we compute the bosonic contribution to the effective action and also determine the non-trivial finite part of the fermionic contribution. Both the bosonic and the fermionic contributions to the string energy happen to be proportional to the Catalan's constant. The resulting value for 2-loop superstring prediction for the subleading coefficient a_2 in the scaling function matches the numerical value found in hep-th/0611135 from the BES equation.Comment: 48 pages, 1 Figure. v3: several mistakes corrected, the finite result for the 2-loop coefficient is found to agree with the numerical value found by Benna et al in hep-th/061113

    Simple, Robust, and Plasticizer-Free Iodide-Selective Sensor Based on Copolymerized Triazole-Based Ionic Liquid

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    Novel solid-contact iodide-selective electrodes based on covalently attached 1,2,3 triazole ionic liquid (IL) were prepared and investigated in this study. Triazole-based IL moieties were synthesized using click chemistry and were further copolymerized with lauryl methacrylate via a simple one-step free radical polymerization to produce a "self-plasticized" copolymer. The mechanical properties of the copolymer are suitable for the fabrication of plasticizer-free ion-selective membrane electrodes. We demonstrate that covalently attached IL moieties provide adequate functionality to the ion-selective membrane, thus achieving a very simple, one-component sensing membrane. We also demonstrate that the presence of iodide as the counterion in the triazole moiety has direct influence on the membrane's functionality. Potentiometric experiments revealed that each electrode displays high selectivity toward iodide anions over a number of inorganic anions. Moreover, the inherent presence of the iodide in the membrane reduces the need for conditioning. The nonconditioned electrodes show strikingly similar response characteristics compared to the conditioned ones. The electrodes exhibited a near Nernstian behavior with a slope of -56.1 mV per decade across a large concentration range with lower detection limits found at approximately 6.3 × 10(-8) M or 8 ppb. These all-solid-state sensors were utilized for the selective potentiometric determination of iodide ions in artificial urine samples in the nanomolar concentration range
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