1,523 research outputs found

    Prospects for cosmic neutrino detection in tritium experiments in the case of hierarchical neutrino masses

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    We discuss the effects of neutrino mixing and the neutrino mass hierarchy when considering the capture of the cosmic neutrino background (CNB) on radioactive nuclei. The implications of mixing and hierarchy at future generations of tritium decay experiments are considered. We find that the CNB should be detectable at these experiments provided that the resolution for the kinetic energy of the outgoing electron can be pushed to a few 0.01 eV for the scenario with inverted neutrino mass hierarchy, about an order of magnitude better than that of the upcoming KATRIN experiment. Another order of magnitude improvement is needed in the case of normal neutrino mass hierarchy. We also note that mixing effects generally make the prospects for CNB detection worse due to an increased maximum energy of the normal beta decay background.Comment: 12 pages, 4 figures, REVTeX4, minor updates, final version, to be published in Phys. Rev.

    Design and testing of an experiment to measure self-filtration in particulate suspensions

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    Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 24).An experiment for measuring self-filtration in terms of change in volume fraction downstream of a constriction compared to volume fraction upstream of said constriction was designed and tested. The user has the ability to control a variety of parameters including constriction geometry, flow rate, and initial volume fraction in order to evaluate their impact on downstream volume fraction. The relative uncertainty in measured downstream volume fraction was found to be 1.31%. Experimental data was collected to show the effect of changing initial volume fraction and flow rate on downstream volume fraction.by Mattias S. Flander.S.B

    Proton acceleration by circularly polarized traveling electromagnetic wave

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    The acceleration of charged particles, producing collimated mono-energetic beams, over short distances holds the promise to offer new tools in medicine and diagnostics. Here, we consider a possible mechanism for accelerating protons to high energies by using a phase-modulated circularly polarized electromagnetic wave propagating along a constant magnetic field. It is observed that a plane wave with dimensionless amplitude of 0.1 is capable to accelerate a 1 KeV proton to 386 MeV under optimum conditions. Finally we discuss possible limitations of the acceleration scheme.Comment: 6 pages, 9 figure

    Approximative two-flavor framework for neutrino oscillations with nonstandard interactions

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    In this paper, we develop approximative two-flavor neutrino oscillation formulas including subleading nonstandard interaction effects. Especially, the limit when the small mass-squared difference approaches zero is investigated. The approximate formulas are also tested against numerical simulations in order to determine their accuracy and they will probably be most useful in the GeV energy region, which is the energy region where most upcoming neutrino oscillation experiments will be operating. Naturally, it is important to have analytical formulas in order to interpret the physics behind the degeneracies between standard and nonstandard parameters.Comment: 21 pages, 7 figures, REVTeX4. Final version published in Phys. Rev.

    Stability of a jet in crossflow

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    We have produced a fluid dynamics video with data from Direct Numerical Simulation (DNS) of a jet in crossflow at several low values of the velocity inflow ratio R. We show that, as the velocity ratio R increases, the flow evolves from simple periodic vortex shedding (a limit cycle) to more complicated quasi-periodic behavior, before finally exhibiting asymmetric chaotic motion. We also perform a stability analysis just above the first bifurcation, where R is the bifurcation parameter. Using the overlap of the direct and the adjoint eigenmodes, we confirm that the first instability arises in the shear layer downstream of the jet orifice on the boundary of the backflow region just behind the jet.Comment: Two fluid dynamics videos, high-resolution 1024x768 (~80MB), and low resolution 320x240 (~10MB), included in the ancillary file

    Response to ``Comment on `Primordial magnetic seed field amplification by gravitational waves' "

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    Here we respond to the comment by Tsagas (gr-qc/0503042) on our paper gr-qc/0503006. We show that the results in that comment are flawed and cannot be used for drawing conclusion about the nature of magnetic field amplification by gravitational waves, and give further support that the results of gr-qc/0503006 are correct.Comment: 4 pages, 2 figures, to appear in Physical Review

    Kinetic theory of electromagnetic ion waves in relativistic plasmas

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    A kinetic theory for electromagnetic ion waves in a cold relativistic plasma is derived. The kinetic equation for the broadband electromagnetic ion waves is coupled to the slow density response via an acoustic equation driven by ponderomotive force like term linear in the electromagnetic field amplitude. The modulational instability growth rate is derived for an arbitrary spectrum of waves. The monochromatic and random phase cases are studied.Comment: 7 pages, 4 figures, to appear in Physics of Plasma

    The Promise of Patent-Backed Finance for Smes and Universities, and Shifting Patent Eligible Subject Matter

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    This Article reviews and addresses some of the problems concerning adequate capital to develop patented inventions and products, and inhibiting the widespread use of patents to raise financing. The Article divides the IP finance market into three separate, but interrelated markets and analyzes problems, including U.S. patent-eligible subject matter doctrine, within those markets impeding patent backed financing. The Article provides numerous proposals, some of which are in the literature, and calls for additional research for addressing the issues

    Applicability of molding procedures in laboratory mix tests for quality control and assurance of the deep mixing method

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    The deep mixing method (DMM) has been applied in many construction projects. The laboratory mix test is essential to the quality control and quality assurance (QC/QA) of deep mixing methods. The procedures used for the preparation of specimens in the laboratory mix test greatly affect the physical and mechanical properties of the stabilized soils. Different procedures are applied in different countries/regions. With the increasingly globalized DMM market, it is desirable that a common understanding of the nature of the laboratory mix test and internationally accepted guidelines to conduct it be established in order to guarantee the QC/QA of DMMs. As part of an international collaborative study, the influence of different molding techniques for the laboratory preparation of specimens was studied. Five different molding techniques were tested in four organizations. The results showed that the molding techniques considerably influenced the magnitude and variation of the unconfined compressive strength and the wet unit weight of the stabilized specimens. The applicability of the molding techniques was discussed in terms of their undrained shear strength and the liquidity index of the soil and binder mixture, and the usefulness of the techniques was demonstrated. (C) 2015 The Japanese Geotechnical Societ
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