6,569 research outputs found

    A proposed NFC payment application

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    This article has been made available through the Brunel Open Access Publishing Fund. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Near Field Communication (NFC) technology is based on a short range radio communication channel which enables users to exchange data between devices. With NFC technology, mobile services establish a contactless transaction system to make the payment methods easier for people. Although NFC mobile services have great potential for growth, they have raised several issues which have concerned the researches and prevented the adoption of this technology within societies. Reorganizing and describing what is required for the success of this technology have motivated us to extend the current NFC ecosystem models to accelerate the development of this business area. In this paper, we introduce a new NFC payment application, which is based on our previous “NFC Cloud Wallet” model [1] to demonstrate a reliable structure of NFC ecosystem. We also describe the step by step execution of the proposed protocol in order to carefully analyse the payment application and our main focus will be on the Mobile Network Operator (MNO) as the main player within the ecosystem

    Monopoly power and distribution in fragmented markets : the case of groundwater

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    Using data from Pakistan's Punjab, the authors examine monopoly power in the market for groundwater - irrigation water extracted using private tubewells - a market characterized by barriers to entry and spatial fragmentation. Simple theory predicts that tubewell owners should price-discriminate in favor of their own share tenants. And this analysis of individual groundwater transactions over an 18-month period confirms such price discrimination. And among those studied, tubewell owners and their tenants use considerably more groundwater on their plots than do other farmers. The authors also provide evidence that monopoly pricing of groundwater leads to compensating - albeit small - reallocations of canal water, which farmers exchange in a separate informal market. Despite the substantial misallocation of groundwater, a welfare analysis show that monopoly pricing has limited effects on equity and efficiency. In the long run, a policy aimed at eliminating monopoly pricing would do little to help the poorest farmers.Water and Industry,Water Resources Law,Water Conservation,Environmental Economics&Policies,Water Supply and Systems,Water and Industry,Water Conservation,Water Supply and Sanitation Governance and Institutions,Drought Management,Water Use

    A statistical study of the luminosity gap in galaxy groups

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    The luminosity gap between the two brightest members of galaxy groups and clusters is thought to offer a strong test for the models of galaxy formation and evolution. This study focuses on the statistics of the luminosity gap in galaxy groups, in particular fossil groups, e.g. large luminosity gap, in an analogy with the same in a cosmological simulation. We use spectroscopic legacy data of seventh data release (DR7) of SDSS, to extract a volume limited sample of galaxy groups utilizing modified friends-of-friends (mFoF) algorithm. Attention is paid to galaxy groups with the brightest group galaxy (BGG) more luminous than \Mr = -22. An initial sample of 620 groups in which 109 optical fossil groups, where the luminosity gap exceeds 2 magnitude, were identified. We compare the statistics of the luminosity gap in galaxy groups at low mass range from the SDSS with the same in the Millennium simulations where galaxies are modeled semi-analytically. We show that the BGGs residing in galaxy groups with large luminosity gap, i.e. fossil groups, are on average brighter and live in lower mass halos with respect to their counter parts in non-fossil systems. Although low mass galaxy groups are thought to have recently formed, we show that in galaxy groups with 15 galaxies brighter than Mr19.5M_r\ge -19.5, evolutionary process are most likely to be responsible for the large luminosity gap. We also examine a new probe of finding fossil group. In addition we extend the recently introduced observational probe based on the luminosity gap, the butterfly diagram, to galaxy groups and study the probe as a function of halo mass. This probe can, in conjunction with the luminosity function, help to fine tune the semi-analytic models of galaxies employed in the cosmological simulations.Comment: 11 pages, 11 figures, accepted to PASP journa

    Gauge-Invariant Formulation of Spin-Current-Density Functional Theory

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    Spin-currents and non-abelian gauge potentials in electronic systems can be treated by spin-current-density functional theory, whose main input is the exchange-correlation (xc) energy expressed as a functional of spin-currents. Constructing a functional of spin currents that is invariant under U(1)×\timesSU(2) transformations is a long-standing challenge. We solve the problem by expressing the energy as a functional of a new variable we call "invariant vorticity". As an illustration we construct the xc energy functional for a two-dimensional electron gas with linear spin-orbit coupling and show that it is proportional to the fourth power of the spin current.Comment: 8 pages, 3 figures, submitte

    1-(4-Bromo­phen­yl)-1-(4-nitro­benzo­yl)thio­urea

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    The title compound, C14H10BrN3O3S, crystallizes as two concomitant polymorphs that differ in colour (one yellow and one colourless). Only the structure of the colourless form could be determined. The mol­ecule exists in the thio­amide form with an intra­molecular N—H⋯O=C hydrogen bond across the thio­urea system. Mol­ecules are linked into layers parallel to (120) by Br⋯Onitro contacts [3.103 (1) Å], classical hydrogen bonds from the other NH function to the S atom and Nnitro⋯O=C contacts. The layers are linked by weak C—H⋯Onitro hydrogen bonds to produce the observed three-dimensional network

    Going After Lipotoxins to Reduce Inflammation in the Airway of Cystic Fibrosis Patients

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    poster abstractPeople with cystic fibrosis (CF) typically have chronic lung infections, predominantly with Pseudomonas aeruginosa. Lung inflammation, in connection with bacterial colonization, is one of the major factors contributing to the morbidity and mortality of CF patients. Recent studies suggest that a common mutation among CF P. aeruginosa isolates (in the gene mucA) results in high-level expression of lipoproteins which stimulates a pro-inflammatory reaction in cultured CF-derived airways cell (CFBE). Our previous work in this area has revealed that a strain containing a mutation in the putative lipotoxin gene PA4326 is dramatically less toxic to CFBE. We hypothesize that lipotoxins lead to airway structure damage by causing epithelial cell death and tissue destruction, possibly as a downstream effect of immune stimulation. Our results demonstrate that deletion of the PA4326 gene does not affect growth, motility, adhesion, or biofilm development. However, this mutant strain produces 59.1% less pyocyanin compared to the non-mutant strain. Pyocyanin is a bacterial toxin that triggers airway inflammation by stimulating the immune system to produce the signaling molecule IL-8. Thus, our data suggest a possible clue about the decreased toxicity of the PA4325 mutant. The aim of future work is to confirm the role of this lipotoxin gene in the inflammatory process and to elucidate the underlying mechanism of its function. Our long term goal is to characterize other lipotoxins and to develop a novel inhibitor of lspA (a bacterial gene required for lipotoxin production) as an anti-inflammatory strategy to slow down the airway damage and hence improve the longevity and quality of life for people with CF

    Emergence of Wigner molecules in one-dimensional systems of repulsive fermions under harmonic confinement

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    A Bethe-Ansatz spin-density functional approach is developed to evaluate the ground-state density profile in a system of repulsively interacting spin-1/2 fermions inside a quasi-one-dimensional harmonic well. The approach allows for the formation of antiferromagnetic quasi-order with increasing coupling strength and reproduces with high accuracy the exact solution that is available for the two-fermion system.Comment: 3 pages, 2 figures, submitte
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