35,633 research outputs found

    Spectrum of the non-commutative spherical well

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    We give precise meaning to piecewise constant potentials in non-commutative quantum mechanics. In particular we discuss the infinite and finite non-commutative spherical well in two dimensions. Using this, bound-states and scattering can be discussed unambiguously. Here we focus on the infinite well and solve for the eigenvalues and eigenfunctions. We find that time reversal symmetry is broken by the non-commutativity. We show that in the commutative and thermodynamic limits the eigenstates and eigenfunctions of the commutative spherical well are recovered and time reversal symmetry is restored

    Pharmacokinetic Studies on Metoprolol - Eudragit Matrix Tablets and Bioequivalence Consideration with Mepressor®

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    Purpose: To investigate the pharmacokinetics of of a developed metoprolol and a reference standard (Mepressor®).Methods: Metoprolol tartrate-loaded Eudragit® FS microparticles were formulated and compressed into tablets. The tablets were tested for their physicochemical properties according to United States Pharmacopoeia (USP) criteria. In vivo studies of the formulations were carried out in 28 young healthy fasting male volunteers based on a randomized open label 4×4 crossover study design with a washout period of 7 days.Results: In vitro tests showed that the developed and reference standard of metoprolol tablets met compendia (USP) requirements. Zero order release of drug was observed from all the tablets. In vivo data demonstrated that there were significant (p < 0.05) differences in tmax, Cmax, MRT, AUC0−t, and AUC0–∞ between the reference and test (developed) formulations. However, the 90 % class interval for the mean ratios of the ln-transformed Cmax, AUC0-t and AUC0-α for the reference, T1, T2, and T3 lied in the bioequivalence range (80 to 125 %) indicating bioequivalence between the compared formulations.                  Conclusion: It can be concluded from this single-dose study that the reference and test (developed) formulations met the predetermined criteria for bioequivalence in young healthy fasting male human subjects as the bioequivalence factor lie in the pre-determined limits for bioequivalence. Thus, the two formulations can be considered bioequivalent.Keywords: Metoprolol tartrate, Eudragit® FS, Microparticles, Bioavailability, Pharmacokinetics

    Fast track children's hearing pilot: final report of the evaluation of the pilot

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    This report presents key findings of the evaluation of the Fast Track children’s hearings pilot in Scotland1. The research was undertaken by staff at the Universities of Glasgow, Stirling and Strathclyde between February 2003 and January 2005

    An optical model description of momentum transfer in heavy ion collisions

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    An optical model description of momentum transfer in relativistic heavy ion collisions, based upon composite particle multiple scattering theory, is presented. The imaginary component of the complex momentum transfer, which comes from the absorptive part of the optical potential, is identified as the longitudinal momentum downshift of the projectile. Predictions of fragment momentum distribution observables are made and compared with experimental data. Use of the model as a tool for estimating collision impact parameters is discussed

    Infinite hierarchies of exact solutions of the Einstein and Einstein-Maxwell equations for interacting waves and inhomogeneous cosmologies

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    For space-times with two spacelike isometries, we present infinite hierarchies of exact solutions of the Einstein and Einstein--Maxwell equations as represented by their Ernst potentials. This hierarchy contains three arbitrary rational functions of an auxiliary complex parameter. They are constructed using the so called `monodromy transform' approach and our new method for the solution of the linear singular integral equation form of the reduced Einstein equations. The solutions presented, which describe inhomogeneous cosmological models or gravitational and electromagnetic waves and their interactions, include a number of important known solutions as particular cases.Comment: 7 pages, minor correction and reduction to conform with published versio

    Blockchain-based DDoS attack mitigation protocol for device-to-device interaction in smart homes

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    Smart home devices are vulnerable to a variety of attacks. The matter gets more complicated when a number of devices collaborate to launch a colluding attack (e.g. Distributed-Denial-of-Service (DDoS)) in a network (e.g., Smart home). To handle these attacks, most studies have hitherto proposed authentication protocols that cannot necessarily be implemented in devices, especially during Device-to-Device (D2D) interactions. Tapping into the potential of Ethereum blockchain and smart contracts, this work proposes a lightweight authentication mechanism that enables safe D2D interactions in a smart home. The Ethereum blockchain enables the implementation of a decentralized prototype as well as a peer-to-peer distributed ledger system. The work also uses a single server queuing system model and the authentication mechanism to curtail DDoS attacks by controlling the number of service requests in the system. The simulation was conducted twenty times, each with varying number of devices chosen at random (ranging from 1 to 30). Each requester device sends an arbitrary request with a unique resource requirement at a time. This is done to measure the system’s consistency across a variety of device capabilities. The experimental results show that the proposed protocol not only prevents colluding attacks, but also outperforms the benchmark protocols in terms of computational cost, message processing, and response time

    MAC for Networks with Multipacket Reception Capability and Spatially Distributed Nodes

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    Search for a Signal on QCD Critical Point in Central Nucleus-Nucleus Collisions

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    We discuss that the QCD critical point could appear in central collisions in percolation cluster. We suggest using the nuclear transparency effect and the one of the light nuclear production to identify the critical point.Comment: To appear in the proceedings of the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2008), Jaipur, India, February 4-10, 200

    Continuum quasiparticle random phase approximation and the time dependent Hartree-Fock-Bogoliubov approach

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    Quadrupole excitations of neutron-rich nuclei are analyzed by using the linear response method in the Quasiparticle Random Phase Approximation (QRPA). The QRPA response is derived starting from the time-dependent Hartree-Fock-Bogoliubov (HFB) equations. The residual interaction between the quasiparticles is determined consistently from the two-body force used in the HFB equations, and the continuum coupling is treated exactly. Calculations are done for the neutron-rich oxygen isotopes. It is found that pairing correlations affect the low-lying states, and that a full treatment of the continuum can change the structure of the states in the giant resonance region.Comment: 17 pages, 7 figures. Revised version with comments and references adde
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