63,856 research outputs found

    Radiation Induced Fermion Resonance

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    The Dirac equation is solved for two novel terms which describe the interaction energy between the half integral spin of a fermion and the classical, circularly polarized, electromagnetic field. A simple experiment is suggested to test the new terms and the existence of radiation induced fermion resonance.Comment: latex, 4 pages, no figure

    Boundary layer integral matrix procedure: Verification of models

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    The three turbulent models currently available in the JANNAF version of the Aerotherm Boundary Layer Integral Matrix Procedure (BLIMP-J) code were studied. The BLIMP-J program is the standard prediction method for boundary layer effects in liquid rocket engine thrust chambers. Experimental data from flow fields with large edge-to-wall temperature ratios are compared to the predictions of the three turbulence models contained in BLIMP-J. In addition, test conditions necessary to generate additional data on a flat plate or in a nozzle are given. It is concluded that the Cebeci-Smith turbulence model be the recommended model for the prediction of boundary layer effects in liquid rocket engines. In addition, the effects of homogeneous chemical reaction kinetics were examined for a hydrogen/oxygen system. Results show that for most flows, kinetics are probably only significant for stoichiometric mixture ratios

    Construction of ATS Cloud Console Final Report

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    ATS cloud console for rapid analysis of cloud image sequence

    Making a national atlas of population by computer

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    This paper describes the conceptual and practical problems encountered and solved in producing a multi-colour atlas of population characteristics in Great Britain. The atlas itself is in A4 format; it consists of some thirty-four maps of Great Britain in four colours and the same number of regional maps, together with descriptive text. All maps were plotted on a laser plotter with a resolution of 127 microns. The paper describes how mapping of ratios, such as percentages, was found to be highly misleading and describes the novel probability mapping solution adopted, based on the signed chi-square statistic. In addition, the rationale for selecting the class intervals and for selecting colour schemes is described

    Analysis of ERTS imagery using special electronic viewing/measuring equipment

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    An electronic satellite image analysis console (ESIAC) is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. Quantitative measurements of distances, areas, and brightness profiles can be extracted digitally under operator supervision. Initial results are presented for the display and measurement of snowfield extent, glacier development, sediment plumes from estuary discharge, playa inventory, phreatophyte and other vegetative changes

    Task Persistence: A Potential Mediator of the Income-Achievement Gap

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    Background: The pervasive gap in achievement among impoverished children has been investigated primarily in terms of parental investments, specifically parent to child speech and other forms of cognitive stimulation (e.g., toys, print materials). This research extends that literature by considering the role of a non-cognitive factor, namely task persistence, in the income-achievement gap. Using task persistence as the hypothesized mediator, duration of childhood in poverty is used to predict two educational variables - perceived academic competence and educational attainment. Although bivariate relationships between each of the variables have been demonstrated in past research, a full model linking task persistence with the income-achievement gap has not been investigated thus far. Methods: Using multiple waves of longitudinal data, duration of childhood poverty (ages 0-9) is used to predict both perceived academic competence (age 17) and educational attainment (age 23) with task persistence (average of ages 9, 13, 17) as a mediator. Results: With task persistence included in each model, the relationships between duration of childhood in poverty and both perceived academic competence and educational attainment are significantly reduced, confirming a mediational influence of task persistence. Conclusions: As hypothesized, task persistence statistically mediates the relationship between duration of childhood in poverty and educational outcomes. The implications of these findings on school success and intergenerational poverty are addressed, as well as suggestions for future research

    A Note on the Relativistic Covariance of the BB- Cyclic Relations

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    It is shown that the Evans-Vigier modified electrodynamics is compatible with the Relativity Theory.Comment: ReVTeX file, 14pp., no figure

    Wick's Theorem for non-symmetric normal ordered products and contractions

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    We consider arbitrary splits of field operators into two parts, and use the corresponding definition of normal ordering introduced by Evans and Steer. In this case the normal ordered products and contractions have none of the special symmetry properties assumed in existing proofs of Wick's theorem. Despite this, we prove that Wick's theorem still holds in its usual form as long as the contraction is a c-number. Wick's theorem is thus shown to be much more general than existing derivations suggest, and we discuss possible simplifying applications of this result.Comment: 17 page

    Kinetic pathways of multi-phase surfactant systems

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    The relaxation following a temperature quench of two-phase (lamellar and sponge phase) and three-phase (lamellar, sponge and micellar phase) samples, has been studied in an SDS/octanol/brine system. In the three-phase case we have observed samples that are initially mainly sponge phase with lamellar and micellar phase on the top and bottom respectively. Upon decreasing temperature most of the volume of the sponge phase is replaced by lamellar phase. During the equilibriation we have observed three regimes of behaviour within the sponge phase: (i) disruption in the sponge texture, then (ii) after the sponge phase homogenises there is a lamellar nucleation regime and finally (iii) a bizarre plume connects the lamellar phase with the micellar phase. The relaxation of the two-phase sample proceeds instead in two stages. First lamellar drops nucleate in the sponge phase forming a onion `gel' structure. Over time the lamellar structure compacts while equilibriating into a two phase lamellar/sponge phase sample. We offer possible explanatioins for some of these observations in the context of a general theory for phase kinetics in systems with one fast and one slow variable.Comment: 1 textfile, 20 figures (jpg), to appear in PR
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