5,744 research outputs found

    The Gap Function Phi(k,w) for a Two-leg t-J Ladder and the Pairing Interaction

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    The gap function phi(k,omega), determined from a Lanczos calculation for a doped 2-leg t-J ladder, is used to provide insight into the spatial and temporal structure of the pairing interaction. It implies that this interaction is a local near-neighbor coupling which is retarded. The onset frequency of the interaction is set by the energy of an S=1 magnon-hole-pair and it is spread out over a frequency region of order the bandwith

    Commercial hospitality : a vehicle for the sustainable empowerment of Nepali women

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    To illustrate how commercial hospitality has catalysed sustainable social change in Nepal through empowering women. Utilising a new framework, developed by combining existing theories, empowerment of women Tea House owners/ managers is assessed. Within a critical feminist paradigm, primary research consisting of interviews and participant observation was undertaken in Nepal over a three month period in the central region of Nepal. Involvement in the hospitality industry improved the livelihoods of the women Tea House owners/ managers, it also has the potential to facilitate sustainable empowerment for future generations, providing them with education, choice, control and opportunities. Although steps were taken to limit rhetorical issues, language barriers could have influenced the findings of the interviews. To fully investigate the potential for hospitality to act as a vehicle for the sustainable empowerment of women, it is suggested that this study be replicated again in another region or that a detailed ethnographic study be carried out. Demonstrates how the commercial hospitality industry can be a force for good; women working in the industry are agents of change, actively improving their levels of empowerment in their immediate environment. The commercial hospitality industry has pioneered the empowerment of women and this could lay the foundation for the further emancipation of women. To date, there has been limited research into the relationship between involvement in the commercial hospitality sector and the empowerment of women; this paper begins to fill this gap by investigating a tourist region of Nepal

    Complexing additives to reduce the immiscible phase formed in the hybrid ZnBr2 flow battery

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    The zinc-bromine redox flow battery (RFB) is one of a very few commercially viable RFB energy storage system capable of integration with intermittent renewable energy sources to deliver improved energy management. However, due to the volatility of the electrogenerated bromine and potential for its crossover from positive to negative electrolytes, this system requires the use of quaternary ammonium complexes (N-methyl-N-ethylpyrrolidinium, (MEP)) to capture this bromine. This produces an immiscible phase with the Br2 which requires a complex network of pipes, pumps and automated controls to ensure access to the electroactive material during discharge. In this work, the use of novel quaternary ammonium complexes to capture the electrogenerated bromine but to keep it in the aqueous phase is examined. Three compounds, 1-(carboxymethyl) pyridine-1-ium, 1-(2-carboxymethyl)-1-methylmorpholin-1-ium and 1-(2-carboxymethyl)-1-methylpyrrolidin-1-ium, were found to successfully reduce the volume of the immiscible phase formed on complexing with the polybromide (Brx-) whilst displaying similar enthalpy of vaporisation values as that of MEP. Electrochemical analysis also revealed that these compounds did not impact on the electrode kinetics of the Br-/Brx- reaction indicating that the resulting surface film formed with these compounds behaved as a chemically modified electrode, in contrast to the surface film formed with MEP

    Finite-Size Scaling of the Domain Wall Entropy Distributions for the 2D ±J\pm J Ising Spin Glass

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    The statistics of domain walls for ground states of the 2D Ising spin glass with +1 and -1 bonds are studied for L×LL \times L square lattices with L48L \le 48, and pp = 0.5, where pp is the fraction of negative bonds, using periodic and/or antiperiodic boundary conditions. When LL is even, almost all domain walls have energy EdwE_{dw} = 0 or 4. When LL is odd, most domain walls have EdwE_{dw} = 2. The probability distribution of the entropy, SdwS_{dw}, is found to depend strongly on EdwE_{dw}. When Edw=0E_{dw} = 0, the probability distribution of Sdw|S_{dw}| is approximately exponential. The variance of this distribution is proportional to LL, in agreement with the results of Saul and Kardar. For Edw=k>0E_{dw} = k > 0 the distribution of SdwS_{dw} is not symmetric about zero. In these cases the variance still appears to be linear in LL, but the average of SdwS_{dw} grows faster than L\sqrt{L}. This suggests a one-parameter scaling form for the LL-dependence of the distributions of SdwS_{dw} for k>0k > 0.Comment: 13 page

    Discovery of near-Earth asteroids by CCD scanning

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    The found near-Earth asteroid are different objects with peculiar orbits. With the new technique of CCD scanning we entered the domain of the smallest, the fastest, and the closest near-Earth asteroids. The results are presented

    Non-Universal Fractional Quantum Hall States in a Quantum wire

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    The ground state as well as low-lying excitations in a 2D electron system in strong magnetic fields and a parabolic potential is investigated by the variational Monte Calro method. Trial wave functions analogous to the Laughlin state are used with the power-law exponent as the variational parameter. Finite size scaling of the excitation energy shows that the correlation function at long distance is characterized by anon-universal exponent in sharp contrast to the standard Laughlin state.The Laughlin-type state becomes unstable depending on strength of the confining potential.Comment: 10 pages, REVTE

    Planets in triple star systems--the case of HD188753

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    We consider the formation of the recently discovered ``hot Jupiter'' planet orbiting the primary component of the triple star system HD188753. Although the current outer orbit of the triple is too tight for a Jupiter-like planet to have formed and migrated to its current location, the binary may have been much wider in the past. We assume here that the planetary system formed in an open star cluster, the dynamical evolution of which subsequently led to changes in the system's orbital parameters and binary configuration. We calculate cross sections for various scenarios that could have led to the multiple system currently observed, and conclude that component A of HD188753 with its planet were most likely formed in isolation to be swapped in a triple star system by a dynamical encounter in an open star cluster. We estimate that within 500pc of the Sun there are about 1200 planetary systems which, like Hd188753, have orbital parameters unfavorable for forming planets but still having a planet, making it quite possible that the HD188753 system was indeed formed by a dynamical encounter in an open star cluster.Comment: ApJ Letters in pres

    Preoperative systemic inflammation predicts postoperative infectious complications in patients undergoing curative resection for colorectal cancer

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    The presence of systemic inflammation before surgery, as evidenced by the glasgow prognostic score (mGPS), predicts poor long-term survival in colorectal cancer. The aim was to examine the relationship between the preoperative mGPS and the development of postoperative complications in patients undergoing potentially curative resection for colorectal cancer. Patients (n=455) who underwent potentially curative resections between 2003 and 2007 were assessed consecutively, and details were recorded in a database. The majority of patients presented for elective surgery (85%) were over the age of 65 years (70%), were male (58%), were deprived (53%), and had TNM stage I/II disease (61%), had preoperative haemoglobin (56%), white cell count (87%) and mGPS 0 (58%) in the normal range. After surgery, 86 (19%) patients developed a postoperative complication; 70 (81%) of which were infectious complications. On multivariate analysis, peritoneal soiling (P<0.01), elevated preoperative white cell count (P<0.05) and mGPS (P<0.01) were independently associated with increased risk of developing a postoperative infection. In elective patients, only the mGPS (OR=1.75, 95% CI=1.17-2.63, P=0.007) was significantly associated with increased risk of developing a postoperative infection. Preoperative elevated mGPS predicts increased postoperative infectious complications in patients undergoing potentially curative resection for colorectal cancer
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