2,218 research outputs found

    The effect of the spacing of background elements upon optomotor memory responses in the crab: the influence of adding or deleting features during darkness

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    1. Study was made of the effect of separation between stripes in the visual field upon responses which indicate memory of those stripes. 2. The amount of separation between white stripes had very little effect, whereas response strength and the amount of separation between black stripes were directly proportional. 3. The presence of extra, non-displaced black stripes prior to or following displacement reduced the size of the memory responses. 4. The effects of the amount of separation in the two cases were comparable. In both situations the separation affected only the responses to displacement of the stripe borders nearest to the extra stripe. 5. The effect of extra stripes present prior to displacement was in turn affected by the duration of the dark period, whilst the effect of those present during the post-displacement period was not. This accounts for the larger effect of extra stripes present during the psot-displacement period. 6. By expanding stripe width during darkness it was possible to distinguish between the effects of distance between stripes and the amount of white space separating them. Reducing white space while distance remains constant causes reductions in response strength, whereas reducing the distance between a memory zone and the white space between it and the neighboring stripe increased the size of the memory response

    A Mechanical Analysis of the Oriskany Sandstone in Northwestern Virginia

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    The primary purpose of this paper is to present specific data as a means of explaining the sedimentation conditions at the time of deposition of the Oriskany Sandstone. The data were obtained through the use of laboratory methods upon specimens taken from several outcrops in the vicinity of Monterey, Virginia (see Darton\u27s U.S.G.S. folio No. 51). In addition to the presentation of objective results, the author has attempted to make tentative interpretations of them, based primarily upon textural and shape analysis of the sediment. The writer realizes that the investigation is inadequate in many respects, due to lack of time available for field study and collection, and the little experience with similar types of problems. It is to be hoped, however, that a more complete report may be forthcoming in the near future

    A Mechanical Analysis of the Oriskany Sandstone in Northwestern Virginia

    Get PDF
    The primary purpose of this paper is to present specific data as a means of explaining the sedimentation conditions at the time of deposition of the Oriskany Sandstone. The data were obtained through the use of laboratory methods upon specimens taken from several outcrops in the vicinity of Monterey, Virginia (see Darton\u27s U.S.G.S. folio No. 51). In addition to the presentation of objective results, the author has attempted to make tentative interpretations of them, based primarily upon textural and shape analysis of the sediment. The writer realizes that the investigation is inadequate in many respects, due to lack of time available for field study and collection, and the little experience with similar types of problems. It is to be hoped, however, that a more complete report may be forthcoming in the near future

    To what extent do the Classical Equations of Motion Determine the Quantization Scheme?

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    A simple example of one particle moving in a (1+1) space-time is considered. As an example we take the harmonic oscillator. We confirm the statement that the classical Equations of Motion do not determine at all the quantization scheme. To this aim we use two inequivalent Lagrange functions, yielding Euler-Lagrange Equations, having the same set of solutions. We present in detail the calculations of both cases to emphasize the differences occuring between them.Comment: LaTeX 20 page

    Gender Differences in Personality across the Ten Aspects of the Big Five

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    This paper investigates gender differences in personality traits, both at the level of the Big Five and at the sublevel of two aspects within each Big Five domain. Replicating previous findings, women reported higher Big Five Extraversion, Agreeableness, and Neuroticism scores than men. However, more extensive gender differences were found at the level of the aspects, with significant gender differences appearing in both aspects of every Big Five trait. For Extraversion, Openness, and Conscientiousness, the gender differences were found to diverge at the aspect level, rendering them either small or undetectable at the Big Five level. These findings clarify the nature of gender differences in personality and highlight the utility of measuring personality at the aspect level

    Magnon-Paramagnon Effective Theory of Itinerant Ferromagnets

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    The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of localized spins. For small magnetization the effective model describes the physics of weak ferromagnets in accordance with the experimental results. It is written in a way which keeps O(3) symmetry manifest,and describes both the order and disordered phases of the system. Analytical expression for the Curie temperature,which takes the magnon fluctuations into account exactly, is obtained. For weak ferromagnets TcT_c is well below the Stoner's critical temperature and the critical temperature obtained within Moriya's theory.Comment: 14 pages, changed content,new result

    Cost performance and risk in the construction of offshore and onshore wind farms

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    This article investigates the risk of cost overruns and underruns occurring in the construction of 51 onshore and offshore wind farms commissioned between 2000 and 2015 in 13 countries. In total, these projects required about 39billionininvestmentandreachedabout11GWofinstalledcapacity.Weusethisoriginaldatasettotestsixhypothesesaboutconstructioncostoverrunsrelatedto(i)technologicallearning,(ii)fiscalcontrol,(iii)economiesofscale,(iv)configuration,(v)regulationandmarketsand(vi)manufacturingexperience.Wefindthatacrosstheentiredataset,themeancostescalationperprojectis6.539 billion in investment and reached about 11 GW of installed capacity. We use this original dataset to test six hypotheses about construction cost overruns related to (i) technological learning, (ii) fiscal control, (iii) economies of scale, (iv) configuration, (v) regulation and markets and (vi) manufacturing experience. We find that across the entire dataset, the mean cost escalation per project is 6.5% or about 63 million per windfarm, although 20 projects within the sample (39%) did not exhibit cost overruns. The majority of onshore wind farms exhibit cost underruns while for offshore wind farms the results have a larger spread. Interestingly, no significant relationship exists between the size (in total MWor per individual turbine capacity) of a windfarm and the severity of a cost overrun. Nonetheless, there is an indication that the risk increases for larger wind farms at greater distances offshore using new types of turbines and foundations. Overall, the mean cost escalation for onshore projects is 1.7% and 9.6% for offshore projects, amounts much lower than those for other energy infrastructure

    C-axis Optical Sum Rule in Josephson Coupled Vortex State

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    Observed violations of the cc-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is considerably modified in the presence of the cc-axis magnetic field. Interlayer correlation of pancake vortices is involved in the sum rule modification; however, details of the vortex distribution in the plane are less important.Comment: one figure. To be published in PRB (Sep. 20001
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