14,739 research outputs found

    Variational Principle in the Algebra of Asymptotic Fields

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    This paper proposes a variational principle for the solutions of quantum field theories in which the ``trial functions'' are chosen from the algebra of asymptotic fields, and illustrates this variational principle in simple cases.Comment: 15 pages, Latex, no figure

    Reaction of O/1D/ with N2O

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    Reaction of excited oxygen with nitrous oxide 1 yielding nitrogen and oxyge

    Interactive color display of 3-D engineering analysis results

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    A general approach to three-dimensional postprocessing of engineering analyses is presented. The approach is versatile and may handle the results from a wide range of engineering analysis methods which involve the discretization of continua. To facilitate the understanding of complex three-dimensional numerical models, advanced interactive color postprocessing techniques are introduced. Finite element, finite difference, and boundary element models are evaluated with the prototype postprocessor. The existing color graphics program (POSTPRO3D) was ported to a high-resolution device. Interactive graphic tools were implemented to facilitate qualitative mesh evaluation from a single analysis. A postprocessing environment was design for workstation technology

    Virtual Transfer Price Negotiations:Unintended Interactions with Incentive Systems

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    Despite decades of research concerning the impact of computer-mediated communication (CMC) on decision-making, the potential interaction with the organization\u27s management control system has just recently received attention. Media naturalness theory is used to develop hypotheses concerning the interactions of communication medium with the incentive pay scheme, a ubiquitous aspect of management control systems. A laboratory experiment was used to examine the interactions between two treatments: face-to-face negotiations versus virtual (computer-mediated) negotiations and cooperative versus competitive incentive pay schemes. Buyer-seller dyads negotiated the price and quantity of the transferred goods. Results indicate that while virtual negotiations are more efficient in terms of time than face-to-face negotiations, there is not a significant interaction with the incentive pay scheme for efficiency. However. results also indicate that virtual negotiations are less effective in terms of optimal quantity (organizational profit) than face-to-face, and that there is a significant interaction with the incentive pay scheme. Virtual negotiations have the unintended consequence of reducing the effectiveness (organizational profitability) of the negotiations

    Non-Pauli Effects from Noncommutative Spacetimes

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    Noncommutative spacetimes lead to nonlocal quantum field theories (qft's) where spin-statistics theorems cannot be proved. For this reason, and also backed by detailed arguments, it has been suggested that they get corrected on such spacetimes leading to small violations of the Pauli principle. In a recent paper \cite{Pauli}, Pauli-forbidden transitions from spacetime noncommutativity were calculated and confronted with experiments. Here we give details of the computation missing from this paper. The latter was based on a spacetime Bχn⃗\mathcal{B}_{\chi\vec{n}} different from the Moyal plane. We argue that it quantizes time in units of χ\chi. Energy is then conserved only mod 2πχ\frac{2\pi}{\chi}. Issues related to superselection rules raised by non-Pauli effects are also discussed in a preliminary manner.Comment: 15 Pages, 1 Table, Full details and further developments of arXiv:1003.2250. This version is close to the one accepted by JHE

    A model of ballistic aggregation and fragmentation

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    A simple model of ballistic aggregation and fragmentation is proposed. The model is characterized by two energy thresholds, Eagg and Efrag, which demarcate different types of impacts: If the kinetic energy of the relative motion of a colliding pair is smaller than Eagg or larger than Efrag, particles respectively merge or break; otherwise they rebound. We assume that particles are formed from monomers which cannot split any further and that in a collision-induced fragmentation the larger particle splits into two fragments. We start from the Boltzmann equation for the mass-velocity distribution function and derive Smoluchowski-like equations for concentrations of particles of different mass. We analyze these equations analytically, solve them numerically and perform Monte Carlo simulations. When aggregation and fragmentation energy thresholds do not depend on the masses of the colliding particles, the model becomes analytically tractable. In this case we show the emergence of the two types of behavior: the regime of unlimited cluster growth arises when fragmentation is (relatively) weak and the relaxation towards a steady state occurs when fragmentation prevails. In a model with mass-dependent Eagg and Efrag the evolution with a cross-over from one of the regimes to another has been detected

    Genetic mapping of retinitis pigmentosa implications for South African patients

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