62,689 research outputs found

    Programmed multiplexing system simultaneously monitors several voltages

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    System consists of digital voltmeter with binary coded decimal output, programmer, multiplexer, and two to six gated digital displays. Maximum number of circuits monitored is determined by digital voltmeter, rate of change of parameter being measured and complexity of multiplexer design

    Modelling nominal debt contracts and fixed rate debt

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    We provide a simple model of sticky nominal debt contracts and fixed rate debt that can easily be embedded in a dynamic general equilibrium framework. Once linearized, the debt process increases the order of autoregressive dynamics in the system by one; thus potentially introducing more complex adjustment processes

    Approximate Coulomb distortion effects in (e,e'p) reactions

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    In this paper we apply a well-tested approximation of electron Coulomb distortion effects to the exclusive reaction (e,e'p) in the quasielastic region. We compare the approximate treatment of Coulomb distortion effects to the exact distorted wave Born approximation evaluated by means of partial wave analysis to gauge the quality of our approximate treatment. We show that the approximate M\"oller potential has a plane-wave-like structure and hence permits the separation of the cross section into five terms which depend on bilinear products of transforms of the transition four current elements. These transforms reduce to Fourier transforms when Coulomb distortion is not present, but become modified with the inclusion of Coulomb distortion. We investigate the application of the approximate formalism to a model of 208Pb(e,e'p) using Dirac-Hartree single particle wave functions for the ground state and relativistic optical model wave functions for the continuum proton. We show that it is still possible to extract, albeit with some approximation, the various structure functions from the experimentally measured data even for heavy nuclei.Comment: 32 pages, 11 figures, 19 reference

    Transitivity for height versus speed: To what extent do the under-7s really have a transitive capacity?

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Psychology Press.Transitive inference underpins many human reasoning competencies. The dominant task (the “extensive training paradigm”) employs many items and large amounts of training, instilling an ordered series in the reasoner's mind. But findings from an alternative “three-term paradigm” suggest transitivity is not present until 7 + years. Interestingly, a second alternative paradigm (the “spatial task”), using simultaneously displayed height relationships to form premise pairs, can uphold the 4-year estimate. However, this paradigm risks cueing children and hence is problematic. We investigated whether a height-task variant might correspond to a more ecologically valid three-term task. A total of 222 4–6-year-olds either completed a modified height task, including an increased familiarisation phase, or a computer-animated task about cartoon characters running a race in pairs. Findings confirmed that both tasks were functionally identical. Crucially, 4-year-olds were at chance on both, whereas 6-year-olds performed competently. These findings contrast with estimates from all three paradigms considered. A theoretical evaluation of our tasks and procedures against previous ones, leads us to two conclusions. First, our estimate slightly amends the 7-year estimate offered by the three-term paradigm, with the difference explained in terms of its greater relevance to child experiences. Second, our estimate can coexist alongside the 4-year estimate from the extensive training paradigm. This is because, applying a recently developed “dual-process” conception of reasoning, anticipates that extensive training benefits a species-general associative system, while the spatial paradigm and three-term paradigm can potentially index a genuinely deductive system, which has always been the target of transitive research

    Extraction of Structure Functions from Quasielastic Electron Scattering (e,e') from Medium and Heavy Nuclei

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    Using a relativistic mean-field single particle knock-out model for (e,e') reactions on nuclei, we investigate approximate treatments of Coulomb distortion effects and the extraction of longitudinal and transverse structure functions. We show that an effective momentum approximation (EMA) when coupled with a focusing factor provides a good description of the transverse contributions to the (e,e') cross sections for electron energies above 300 MeV on 208Pb. This approximation is not as good for the longitudinal contributions even for incident electron eneriges above 1 GeV and if one requires very precise extraction of longitudinal and transverse structure functions in the quasielastic region it is necessary to utilize distortion factors based on a nuclear model and a more accurate inclusion of Coulomb distortion effects.Comment: 5 pages, 7 figures, submitted to Phys. Rev.

    Attraction of Acorn-Infesting \u3ci\u3eCydia Latiferreana\u3c/i\u3e (Lepidoptera: Tortricidae) to Pheromone-Baited Traps

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    Males of acorn-infesting Cydia latiferreana are attracted to an equilibrium mixture of the four isomers of 8, 10-dodecadien-l-ol acetate, the virgin female-produced pheromone. Trap height relative to the height of trees in which traps are placed seems to be a significant factor influencing moth catches at attractant-baited traps. In an oak woodlot and in an oak nursery, catches of male moths were greater in traps placed near the upper periphery of the canopy than at traps deployed at lower levels in the tree. Practical application of pheromone-baited traps in a forest situation will require further study on lure formulation and on trap deployment under forest conditions

    Coulomb Distortion Effects for Electron or Positron Induced (e,e)(e,e') Reactions in the Quasielastic Region

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    In response to recent experimental studies we investigate Coulomb distortion effects on (e,e)(e,e') reactions from medium and heavy nuclei for the case of electrons and positrons. We extend our previously reported full DWBA treatment of Coulomb distortions to the case of positrons for the 208Pb(e,e)^{208}Pb(e,e') reaction in the quasielastic region for a particular nuclear model. In addition, we use previously reported successful approaches to treating Coulomb corrections in an approximate way to calculate the Coulomb distortion effects for (e,e)(e,e') reactions for both electrons and positrons for the case of a simple nuclear model for quasielastic knock-out of nucleons. With these results in hand we develop a simple {\em ad-hoc} approximation for use in analyzing experiments, and discuss methods of extracting the ``longitudinal structure function" which enters into evaluation of the Coulomb sum rule. These techniques are generally valid for lepton induced reactions on nuclei with momentum transfers greater than approximately 300 MeV/cMeV/c.Comment: 18 pages, 6 figure

    y-scaling in Quasielastic Electron Scattering from Nuclei

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    A relativistic single particle model is used to calculate the inclusive (e,e)(e,e') reaction from A=A=12, 40, 56, 197, and 208 nuclei in the quasielastic region. We have shown that this model provides a very good description of the available experimental cross sections when they are dominated by the quasielastic process. In this paper we use this model to investigate the dependence of yy-scaling on electron kinematics, particularly the electron scattering angle, for a range of squared four momentum transfer 0.200.800.20-0.80 (GeV/c)2^2. In this kinematic domain, Coulomb distortion of the electron does not significantly affect scaling, but final state interactions of the knocked out nucleon do affect scaling particularly when the nucleons have lower energies. In general, we find that scaling works for this reaction, but at lower values of the four momentum transfer, the scaling function does have some dependence on the electron scattering angle. We also consider a modification of y-scaling to include small binding energy effects as a function of Z and A and show that there is some improvement in scaling.Comment: 21 pages, 11 figure
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