1,616 research outputs found

    Earth resources evaluation for New Mexico by LANDSAT-2

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    The author has identified the following significant results. The Middle Rio Grande project has not yet progressed to the point where mineral exploration sites can be chosen; however, there does appear to be some correlation between the known structure and mineral deposits and the LANDSAT lineament map. A circular feature identified in the southern Magdalena Mountains on LANDSAT-1 imagery agrees well with the location of a newly proposed caldron complex. Several recognized and unrecognized circular features were identified on imagery of the Mogollon-Datil volcanic field. A check of aeromagnetic maps for New Mexico found that the circular features on the LANDSAT imagery showed up as areas of generally high magnetic intensity

    Geologic analysis of ERTS-1 imagery for the State of New Mexico

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    There are no author-identified significant results in this report

    Excavations and the afterlife of a professional football stadium, Peel Park, Accrington, Lancashire: towards an archaeology of football

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    Association football is now a multi-billion dollar global industry whose emergence spans the post-medieval to the modern world. With its professional roots in late 19th-century industrial Lancashire, stadiums built for the professionalization of football first appear in frequency in the North of England. While many historians of sport focus on consumerism and ‘topophilia’ (attachment to place) regarding these local football grounds, archaeological research that has been conducted on the spectator experience suggests status differentiation within them. Our excavations at Peel Park confirm this impression while also showing a significant afterlife to this stadium, particularly through children’s play

    Why 'scaffolding' is the wrong metaphor : the cognitive usefulness of mathematical representations.

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    The metaphor of scaffolding has become current in discussions of the cognitive help we get from artefacts, environmental affordances and each other. Consideration of mathematical tools and representations indicates that in these cases at least (and plausibly for others), scaffolding is the wrong picture, because scaffolding in good order is immobile, temporary and crude. Mathematical representations can be manipulated, are not temporary structures to aid development, and are refined. Reflection on examples from elementary algebra indicates that Menary is on the right track with his ‘enculturation’ view of mathematical cognition. Moreover, these examples allow us to elaborate his remarks on the uniqueness of mathematical representations and their role in the emergence of new thoughts.Peer reviewe

    ASCA observations of type-2 Seyfert Galaxies. III. Orientation and X-ray Absorption

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    We discuss the spectral properties of a sample of type-2 Seyfert galaxies based upon the analysis of \asca data. In this paper we consider the sources for which the X-ray spectra appear to be dominated by the nuclear continuum, transmitted through a large column of absorbing material. We find that both Seyfert-2 galaxies and NELGs show iron Kα\alpha line profiles indicative of reprocessing of nuclear X-rays in a face-on accretion disk. Such line profiles are also observed in Seyfert-1 galaxies. This result is contrary to unification models, which would predict the inner regions of Seyfert-2 galaxies to be observed edge-on. This raises some questions as to the orientation of the circumnuclear absorber. If the observed differences between Seyfert type-1 and type-2 galaxies, and NELGs are not due to differences in the orientation of the absorbing material, then we suggest that differences in dust composition and grain size, and in the density of the circumnuclear gas could be of primary importance.Comment: 28 pages, 3 figures. LaTeX with encapsulated postscript. To appear in the Astrophysical Journa

    Foundations of self-consistent particle-rotor models and of self-consistent cranking models

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    The Kerman-Klein formulation of the equations of motion for a nuclear shell model and its associated variational principle are reviewed briefly. It is then applied to the derivation of the self-consistent particle-rotor model and of the self-consistent cranking model, for both axially symmetric and triaxial nuclei. Two derivations of the particle-rotor model are given. One of these is of a form that lends itself to an expansion of the result in powers of the ratio of single-particle angular momentum to collective angular momentum, that is essentual to reach the cranking limit. The derivation also requires a distinct, angular-momentum violating, step. The structure of the result implies the possibility of tilted-axis cranking for the axial case and full three-dimensional cranking for the triaxial one. The final equations remain number conserving. In an appendix, the Kerman-Klein method is developed in more detail, and the outlines of several algorithms for obtaining solutions of the associated non-linear formalism are suggested.Comment: 29 page

    Investigating on the nuclear obscuration in two types of Seyfert 2 galaxies

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    We build a large sample of Seyfert 2 galaxies (Sy2s) with both optical spectropolarimetric and X-ray data available, in which 29 Sy2s with the detection of polarized broad emission line (PBL) and 25 without. We find that for luminous Sy2s with L_[OIII] > 10^41 erg/s, sources with PBL have smaller X-ray absorption column density comparing with those without PBL (at 92.3% confidence level): most of the Sy2s with N_H<10^23.8 cm^-2 show PBL (86%, 12 out 14), while the fraction is much smaller for sources with heavier obscuration (54%, 15 out 28). The confidence level of the difference in absorption bounces up to 99.1% while using the "T" ratio (F_2-10keV/F_[O III]) as an indicator. We rule out observation or selection bias as the origin for the difference. Our results, for the first time with high statistical confidence, show that, in additional to the nuclei activity, the nuclear obscuration also plays an important role in the visibility of PBL in Sy2s. These results can be interpreted in the framework of the unified model. We can reach these results in the unified model if: a) the absorption column density is higher at large inclinations and b) the scattering region is obscured at large inclinations.Comment: 28 pages, including 7 figures and 3 tables, ApJ accepte

    Trichoderma from Brazilian garlic and onion crop soils and description of two new species: Trichoderma azevedoi and Trichoderma peberdyi.

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    Fifty four Trichoderma strains were isolated from soil samples collected from garlic and onion crops in eight different sites in Brazil and were identified using phylogenetic analysis based on combined ITS region, tef1-α, cal, act and rpb2 sequences. The genetic variability of the recovered Trichoderma species was analysed by AFLP and their phenotypic variability determined using MALDI-TOF. The strain clusters from both typing techniques coincided with the taxonomic determinations made from phylogenetic analysis. The phylogenetic analysis showed the occurrence of Trichoderma asperellum, Trichoderma asperelloides, Trichoderma afroharzianum, Trichoderma hamatum, Trichoderma lentiforme, Trichoderma koningiopsis, Trichoderma longibrachiatum and Trichoderma erinaceum, in the soil samples. We also identified and describe two new Trichoderma species, both in the harzianum clade of section Pachybasium, which we have named Trichoderma azevedoi sp. nov. and Trichoderma peberdyi sp. nov. The examined strains of both T. azevedoi (three strains) and T. peberdyi (12 strains) display significant genotypic and phenotypic variability, but form monophyletic clades with strong bootstrap and posterior probability support and are morphologically distinct from their respective most closely related species
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