3,049 research outputs found

    Uniaxial magnetocrystalline anisotropy in CaRuO3{\rm CaRuO_3}

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    CaRuO3{\rm CaRuO_3} is a paramagnetic metal and since its low temperature resistivity is described by ρ=ρ0+ATγ\rho=\rho_0+AT^\gamma with γ1.5\gamma \sim 1.5, it is also considered a non-Fermi liquid (NFL) metal. We have performed extensive magnetoresistance and Hall effect measurements of untwinned epitaxial films of CaRuO3{\rm CaRuO_3}. These measurements reveal that CaRuO3{\rm CaRuO_3} exhibits uniaxial magnetocrystalline anisotropy. In addition, the low-temperature NFL behavior is most effectively suppressed when a magnetic field is applied along the easy axis, suggesting that critical spin fluctuations, possibly due to proximity of a quantum critical phase transition, are related to the NFL behavior.Comment: 7 figure

    Geophysical characteristics and crustal structure of greenstone terranes: Canadian Shield

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    Geophysical studies in the Canadian Shield have provided some insights into the tectonic setting of greenstone belts. Greenstone belts are not rooted in deep crustal structures. Geophysical techniques consistently indicate that greenstones are restricted to the uppermost 10 km or so of crust and are underlain by geophysically normal crust. Gravity models suggest that granitic elements are similarly restricted, although magnetic modelling suggests possible downward extension to the intermediate discontinuity around approx. 18 km. Seismic evidence demonstrates that steeply-dipping structure, which can be associated with the belts in the upper crust, is not present in the lower crust. Horizontal intermediate discontinuities mapped under adjacent greenstone and granitic components are not noticeably disrupted in the boundary zone. Geophysical evidence points to the presence of discontinuities between greenhouse-granite and adjacent metasedimentary erranes. Measured stratigraphic thicknesses of greenstone belts are often twice or more the vertical thicknesses determined from gravity modelling. Explantations advanced for the discrepancy include stratigraphy repeated by thrust faulting and/or listric normal faulting, mechanisms which are consistent with certain aspects of conceptual models of greenstone development. Where repetition is not a factor the gravity evidence points to removal of the root zones of greenstone belts. For one region, this has been attributed to magmatic stopping during resurgent caldera activity

    Chemistry in Evaporating Ices: Unexplored Territory

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    We suggest that three-body chemistry may occur in warm high density gas evaporating in transient co\textendash desorption events on interstellar ices. Using a highly idealised computational model we explore the chemical conversion from simple species of the ice to more complex species containing several heavy atoms, as a function of density and of adopted three body rate coefficients. We predict that there is a wide range of densities and rate coefficients in which a significant chemical conversion may occur. We discuss the implications of this idea for the astrochemistry of hot cores.Comment: Accepted in Ap

    Trophic polymorphism and behavioral differences decrease intraspecific competition in a cichlid, Herichthys minckleyi

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    Resource polymorphisms, or morphological variations related to resource use, are common in fishes and are thought to be a possible step in speciation. This study experimentally tests the hypothesis that fitness (as estimated by growth rates) is increased by the presence of multiple trophic morphotypes (or morphs) within a population. Cage experiments were used to quantify the intraspecific competitive interactions between morphs of the polymorphic cichlid Herichthys minckleyi in Cuatro Cienegas, Mexico. Results suggest that competition is reduced between morphs in mixed-morph treatments relative to equal-density single-morph treatments. Field studies revealed that the morphs feed in different microhabitats and use different feeding behaviors within these microhabitats. These results suggest that the polymorphism is maintained in the population because it decreases competition between the morphs, and that differences in feeding behavior facilitate resource partitioning

    Programming Protocol-Independent Packet Processors

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    P4 is a high-level language for programming protocol-independent packet processors. P4 works in conjunction with SDN control protocols like OpenFlow. In its current form, OpenFlow explicitly specifies protocol headers on which it operates. This set has grown from 12 to 41 fields in a few years, increasing the complexity of the specification while still not providing the flexibility to add new headers. In this paper we propose P4 as a strawman proposal for how OpenFlow should evolve in the future. We have three goals: (1) Reconfigurability in the field: Programmers should be able to change the way switches process packets once they are deployed. (2) Protocol independence: Switches should not be tied to any specific network protocols. (3) Target independence: Programmers should be able to describe packet-processing functionality independently of the specifics of the underlying hardware. As an example, we describe how to use P4 to configure a switch to add a new hierarchical label

    Bunk attendance of feedlot cattle monitored with radio frequency technology

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    Bunk attendance of 72 feedlot cattle (412 ± 23.6 kg) was monitored for 86 d using radio frequency technology. Late morning and late afternoon were confirmed as primary ad libitum feeding periods. The system detected differences (P \u3c 0.005) in feeding behaviour in response to level of feeding and frequency of meals

    Law Libraries and Laboratories: The Legacies of Langdell and His Metaphor

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    Law Librarians and others have often referred to Harvard Law School Dean C.C. Langdell’s statements that the law library is the lawyer’s laboratory. Professor Danner examines the context of what Langdell through his other writings, the educational environment at Harvard in the late nineteenth century, and the changing perceptions of university libraries generally. He then considers how the “laboratory metaphor” has been applied by librarians and legal scholars during the twentieth century and into the twenty-first. The article closes with thoughts on Langdell’s legacy for law librarians and the usefulness of the laboratory metaphor

    Logics, rhetoric and 'the blob': populist logic in the Conservative reforms to English schooling

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    A lot has been written about the lasting implications of the Conservative reforms to English schooling, particularly changes made by Michael Gove as Education Secretary (2010–2014). There is a lot less work, however, on studying the role that language, strategy and the broader political framework played in the process of instituting and winning consent for these reforms. Studying these factors is important for ensuring that any changes to education and schooling are not read in isolation from their political context. Speeches particularly capture moments where intellectual and strategic political traditions meet, helping us to form a richer understanding of the motives behind specific reform goals and where they fit into a political landscape. This article analyses speeches and policy documents from prominent politicians who led the Conservative education agenda between 2010–2014 to illustrate how politicians mobilised a deliberate populist strategy and argumentation to achieve specific educational goals, but which have had broader social and political implications. Concepts from interpretive political studies are used to develop a case analysis of changes to teacher training provision and curriculum reform, illustrating how politicians constructed a frontier between ‘the people’ (commonly teachers or parents) and an illegitimate ‘elite’ (an educational establishment) that opposed change. This anti‐elite populist rhetoric, arguably first tested in the Department for Education, has now become instituted more widely in our current British politics

    Analysis of construction accidents in Spain, 2003-2008

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    The research objective for this paper is to obtain a new extended and updated insight to the likely causes of construction accidents in Spain, in order to identify suitable mitigating actions. Method: The paper analyzes all construction sector accidents in Spain between 2003 and 2008. Ten variables were chosen and the influence of each variable is evaluated with respect to the severity of the accident. The descriptive analysis is based on a total of 1,163,178 accidents. Results: Results showed that the severity of accidents was related to variables including age, CNAE (National Classification of Economic Activities) code, size of company, length of service, location of accident, day of the week, days of absence, deviation, injury, and climatic zones. Conclusions: According to data analyzed, a large company is not always necessarily safer than a small company in the aspect of fatal accidents, experienced workers do not have the best accident fatality rates, and accidents occurring away from the usual workplace had more severe consequences. Impact on the industry: Results obtained in this paper can be used by companies in their occupational safety strategies, and in their safety training programs
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