1,457 research outputs found

    Checklist of South American Cenozoic Insects

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    This checklist is a compilation of literature about South American Cenozoic insects. The list include 73 named insects belonging to 11 orders. Records are from the  Oligocene and Pleistocene of south-eastern Brazil, late Paleocene of north-western Argentina and Paleocene-Eocene of southern Argentina

    Analysis of a dry friction problem under small displacements: application to a bolted joint

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    This study presents an analysis of the problem of macroscopic contact of steel upon steel with dry friction, in the specific case of a bolted joint. The configurations of these types of joints result in very small displacements and interface sliding velocities. To understand how the system formed by the two surfaces in contact works, an experiment was carried out. The analysis of the results obtained made it possible to define the behavior of the system and to model the variations of the main parameters by original and continuous laws. These laws accurately correlate to all the results of the tests effectuated

    Field-based models for low speed switched reluctance machine designs

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    Trabalho apresentado na Conferência CPE-POWERENG 2016, 29 junho a 01 de julho 2016, Bydgoszcz, PolóniaThis paper presents a design assistance methodology of low speed Switched Reluctance Machines (SRM) using field-based models. The magnetic properties of the iron, the number of rotor poles, and the number of poles per phase, all play a significant role in the machine design. The proposed comparison procedure uses field-based models along with scale models, based on similarity laws, to compare SRM designs. The field-based models are here applied in dimensional analysis of regular and non-regular topologies distinguished by different characteristics of electric and magnetic circuits. As an added value for this methodology, similarity laws take into account physical phenomena like thermal changes and magnetic saturation. Hypotheses introduced in the methodology formulation were verified by finite element analysis. This work is motivated by the application of SRM to direct drive wind converters and other low speed renewable energy systems. As an application example of this methodology, a non-regular topology with short flux-paths was compared with a regular prototype, 3-phase, 12/16, SRM, designed for a direct drive wind turbine: a gain of power per unit of mass is achieved with the former one

    Darboux-Kadomtsev-Petviashvili system as an integrable Chern-Simons multiform theory in infinite dimensional space

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    The Darboux-Kadomtsev-Petviashvili system is a universal three-dimensional integrable field theory, which is a generating system for the entire Kadomtsev-Petviashvili hierarchy, and at the same time generalizes the Darboux system, describing orthogonal curvilinear coordinates. In this paper, we establish a hierarchy of Lagrangian multiforms for the Darboux-Kadomtsev-Petviashvili system, derived from a hierarchy of Chern-Simons actions in an infinite-dimensional space of Miwa variables. This provides an integrable variational description of this multidimensionally consistent field theory embedded in infinite dimensional space

    Isotopic (Sr-Nd) signatures of the Pedregal Granite and associated migmatite rocks

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    O complexo granito-migmatítico sinorogénico varisco em estudo aflora na Zona Centro Ibérica, noroeste de Portugal. O granito do Pedregal, com idade de 311±5 Ma, é um corpo alongado na direção NW-SE que intrui micaxistos estaurolíticos, rochas gnaisso-migmatíticas bandadas e, localmente, contacta com brechas ígneas. Trata-se de um granito de duas micas, de grão fino a médio, com pequenos nódulos biotíticos (1 a 2 cm). As rochas gnaisso-migmatíticas associadas, de carácter metatexítico estromático, evidenciam bandas leucocratas quartzo-feldspáticas (leucossoma) predominantes e sem foliação, alternando com bandas micáceas (paleossoma) onde ocorre granada em intercrescimento com quartzo (< 1 cm). Os dados isotópicos de Sr-Nd mostram ausência de sobreposição das composições iniciais do granito e das rochas gnaisso-migmatíticas, em aparente contradição com dados geoquímicos apresentados previamente. A inexistência daquela sobreposição é possivelmente resultante quer de desequilíbrio isotópico de Nd durante o processo de fusão parcial, quer de moscovitização tardia, acompanhada de incremento da razão Rb/Sr, no granito.The synorogenic Variscan granite-migmatite complex in study outcrops in the Central Iberian Zone, northern Portugal. The Pedregal granite dated of 311±5 Ma has an NW-SE elongated shape and is intrusive in staurolite-micaschist and banded gneiss-migmatite rocks, with local igneous breccias along the contact. This granite is a fine to medium-grained two mica rock with small biotitic nodules (1 to 2 cm). The associated gneiss-migmatite rocks of stromatic metatexitic character are banded, showing alternating of quartz-feldspathic leucosomes without foliation and subordinated micaceous paleosomes disclosing garnet - quartz intergrowths (< 1 cm). The Sr-Nd isotopic results for the Pedregal granite and associated gneiss-migmatite rocks indicate quite different compositions, in apparent contradiction with geochemical data previously presented. Their isotopic heterogeneity could be explained by Nd isotopic disequilibrium developed both during the melting event and late muscovitization, with Rb/Sr enrichment in the granite

    Geoquímica isotópica Sr-Nd de amostras do CXG da área de Sarnadas do Ródão (Centro de Portugal): contributo para a comparação entre o Grupo do Douro e o Grupo das Beiras

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    Foram analisadas, para isótopos de Sr e Nd, cinco amostras de metassedimentos pertencentes ao Complexo Xisto-Grauváquico (CXG), ou Supergrupo Dúrico-Beirão, de idade ante-ordovícica, mais precisamente ediacarana. Quatro das amostras são de litologias pertencentes ao Grupo das Beiras do CXG, tendo sido colhidas na área de Sarnadas do Ródão, região da Beira-Baixa, ao longo das margens do Rio Ocreza, a NE do sinclinal ordovícico das Portas de Ródão. Para comparação, analisou-se também uma amostra do Grupo do Douro do CXG, proveniente do vale do Rio Távora, a SE de Tabuaço, na região do Alto Douro. Os resultados obtidos apontam para uma heterogeneidade nas litologias analisadas, destacando-se principalmente: a) a diferença na assinatura de isotópica de Nd entre as amostras do Grupo das Beiras e a do Grupo do Douro, sendo esta última a mais empobrecida em Nd radiogénico (εNd310Ma = -8.6; enquanto as do Grupo das Beiras têm -4.1 ≤ εNd310Ma ≤ -6.1); b) a individualização da amostra Alv55, do Grupo das Beiras, com valores claramente mais baixo de (87Sr/86Sr)310Ma (= 0.7117) e mais alto de εNd310Ma (= -4.1) relativamente às restantes amostras do mesmo grupo (de 0.7173 a 0.7207 e de -4.8 a -6.1, respetivamente). Tendo em conta que os últimos importantes reequilíbrios isotópicos terão ocorrido durante o metamorfismo varisco, foi feito o cálculo das razões isotópicas para uma idade de 310 Ma, tendo-se verificado uma concordância dos resultados obtidos com dados disponíveis na bibliografia. As amostras que em termos de geoquímica elementar revelam um protólito essencialmente detrítico projetam-se nos campos que podem ser definidos, com base em trabalhos anteriores, para os dois grupos do CXG, havendo total concordância entre a unidade em que cada amostra foi colhida e o campo em que se projeta. Quanto à amostra Alv55, a sua assinatura isotópica, distinta de todas as outras obtidas neste trabalho, deverá relacionar-se com um protólito sedimentar com material detrítico com menor maturidade e/ou em que terá ocorrido mistura com componente químico, como parece ser revelado pela geoquímica elementar, em que esta amostra apresenta teores de CaO muito mais elevados do que os das outras amostras da mesma área. Quanto às idades-modelo TDM, elas variam entre 1.2 e 1.6 Ga, o que está de acordo com o obtido em materiais análogos ao longo da cadeia varisca europeia. Neste parâmetro, a amostra do Grupo do Douro não se distingue das restantes. O valor mais baixo de TDM é o da amostra Alv55, o que reforça a interpretação apresentada acima. Tendo em conta que as idades-modelo podem ser vistas como a idade média da extração do manto dos materiais que originaram os metassedimentos analisados, poder-se-á concluir que as rochas estudadas são produtos de retrabalhamento de crosta continental cujos componentes mais antigos teriam, no mínimo, uma idade mesoproterozoica. Os dados obtidos confirmam resultados de trabalhos anteriores que apontavam para que as litologias metadetríticas dos dois grupos do CXG teriam assinaturas isotópicas de Nd distintas, sendo a do Grupo das Beiras mais radiogénica do que a do Grupo do Douro

    Analecta Indica

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    説話の流伝を考える上でユダヤの貢献を無視することはできないが、今日まで語学力の貧困さのためと、資料を閲覧する努力を怠っていたので、インドと西洋の間が欠落していて、いつも情けない思いをしていた。幸いにも平成17年度は大妻学院からスタディリーヴを許可され、その前半はSOASに籍を置いてその図書館に毎日出入りする機会に恵まれた(ロンドン大学内の他図書館、大英図書館も随時訪れた)。本来の仕事の合間にその方面の書架も覗いてみると、見るべくして見ずにいたビン・ゴリオンやギンズバーグの膨大な集成本もあり、これまでどうして勉強しなかったのかと悔やむこと頻りであった(それでもこれまで我が国では全く無視されていたベレキア・ハ・ナクダンの寓話集のヘブライ語からの和訳は秘かに計画し、毎日就寝前の数分を利用して一日一話を励行している)。それとは別にこれまで論究した説話で、そのパラレルとしてユダヤのものを抜かしたことの補いをここで雑録風に果たして(その他のことがらも備忘用に込めてあるが)、リーヴ中の主目的は別途発表のこととし、ここでは副産物の一端の報告ともしたい。The present paper is a part of result of my research carried out during my study leave from April 2005 to March 2006. Although this is a byproduct in course of doing a main project, i.e. compiling a critical edition of the Civaravastu, it was also needed to make some amendments to my previous works. In XXXVII I add some Jewish material to the transmission line of the Everyman story and provide a supplement to my bibliography of the first and secondary sources on the Everyman. In XXXVIII also some additions are made from Jewish material having connection to Le lai de Voiselet. Some studies on this lai are reviewed and criticized. Out of my indications the most important fact is that there is a parallel story in the Southern tradition of the Pancatantra, of which I was completely ignorant at the time when I wrote my previous article. The Southern tradition of it has not been fully treated so far except a few scholars, but I would like to make emphasis on the significance of this tradition in various aspects. A parable "a man in the well" has been discussed by many scholars up to now, but it seems that the final work is still desideratum. XXXIX treats of related material which have not been discussed fully by former studies. Because this parable was incorporated into the Kalilah and Dimnah and the Barlaam and Josaphat, further additions may be still possible from some versions of these texts which were circulated most widely in the medieval world. A story "a tortoise and two geese" formed a favourite theme for both Eastern and Western scholars. It seems that nothing has been left unsaid about the literature on it. In XL necessity of an examination into relationship between art objects and the literature is advocated. A critical review of Grey\u27s Concordance of the Jataka is given in the Excursus. XLI is no more than mere reference to Schiefner\u27s article on a story of Rhampsinit. In XLII a Japanese translation of "Ants" of Theobaldus\u27s Physiologus is provided
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