4,682 research outputs found

    Steady state thermal radiometers

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    A radiometer is described operating in a vacuum under steady state conditions. The front element is an aluminum sheet painted on the outer side with black or other absorptive material of selected characteristics. A thermocouple is bonded to the inner side of the aluminum sheet. That is backed by highly insulative layers of glass fiber and crinkled, aluminized Mylar polyester. Those layers are backed with a sturdy, polyester sheet, and the entire lamination is laced together by nylon cords. The device is highly reliable in that it does not drift out of calibration, and is significantly inexpensive

    Gemini Planet Imager Observational Calibrations II: Detector Performance and Calibration

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    The Gemini Planet Imager is a newly commissioned facility instrument designed to measure the near-infrared spectra of young extrasolar planets in the solar neighborhood and obtain imaging polarimetry of circumstellar disks. GPI's science instrument is an integral field spectrograph that utilizes a HAWAII-2RG detector with a SIDECAR ASIC readout system. This paper describes the detector characterization and calibrations performed by the GPI Data Reduction Pipeline to compensate for effects including bad/hot/cold pixels, persistence, non-linearity, vibration induced microphonics and correlated read noise.Comment: 11 pages, 6 figures. Proceedings of the SPIE, 9147-28

    Constitution and the Falling Elevator: The Continuing Incompatibility of Materialism and Resurrection Belief

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    Ontological dualism is energetically resisted by a range of Christian scholars including philosophers such as Baker and Corcoran who defend accounts of human persons based on material constitution. Whilst Baker’s view fails to account for diachronic identity, Corcoran’s account of life after death makes use of Zimmerman’s problematic “Falling Elevator Model.” It is argued that Zimmerman’s recent reassessment of the model overestimates its value for materialists. In fact, the model generates either a fatal encounter with the nature of identity, or absurdity. A lack of alternatives is illustrated by anticriterialist proposals. Thus it seems materialism and resurrection belief remain incompatible

    A Reimagining of the Chacoan World

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    A new paradigm of the Chacoan world is presented, wherein Chaco Canyon is considered to be a mostly unoccupied architectural complex that functioned primarily as a pilgrimage destination. Chaco was the political, religious, and social focal point of people living in outlying regions. The resident population of the Canyon consisted of a small number of caretakers, charged with maintaining great house structures, food supplies, and their ceremonial contents. Chacoan chiefdoms were mostly located in large, well-watered, agriculturally-based communities situated at the base of mountains that ring the San Juan Basin, e.g., the Chuskas. Chiefly elites lived year-round in those areas, but during pilgrimages they occupied Canyon great houses associated with their respective dynasties, whereas their subjects occupied small houses situated on the Canyon floor. Not having 2000 people in the Canyon renders large-scale irrigated agriculture and massive importation of food unnecessary and provides an adequate explanation for the small number of burials found in the Canyon. Se presenta un nuevo paradigma del mundo chacoano, en el que el Cañón del Chaco es considerado como un complejo arquitectónico mayoritariamente desocupado que funcionaba principalmente como destino de peregrinación. Chaco fue el centro político, religioso y social de las personas que viven en regiones al aire libre. La población residente del Cañón consistía en un pequeño número de cuidadores, encargados de mantener grandes estructuras de casas, suministros de alimentos y su contenido ceremonial. Las jefaturas chacoanas se encontraban principalmente en grandes comunidades agrícolas bien regadas situadas en la base de montañas que anillan la cuenca de San Juan, por ejemplo, los Chuskas. Principalmente las élites vivían durante todo el año en esas áreas, pero durante las peregrinaciones ocuparon grandes casas del Cañón asociadas con sus respectivas dinastías, mientras que sus súbditos ocupaban pequeñas casas situadas en el suelo del Cañón. No tener 2000 personas en el Cañón hace que la agricultura de regadío a gran escala y la importación masiva de alimentos sean innecesarias y proporciona una explicación adecuada para el pequeño número de entierros encontrados en el Cañón

    Bianchi's classification of 3-dimensional Lie algebras revisited

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    We present Bianchi's proof on the classification of real (and complex) 33-dimensional Lie algebras in a coordinate free version from a strictly representation theoretic point of view. Nearby we also compute the automorphism groups and from this the orbit dimensions of the corresponding orbits in the algebraic variety XΛ2VVX\subseteq\Lambda^2V^*\otimes V describing all Lie brackets on a fixed vector space VV of dimension 33. Moreover we clarify which orbits lie in the closure of a given orbit and therefore the topology on the orbit space X/GX/G with G=Aut(V)G=\mathrm{Aut}(V)

    IWH-Bauumfrage im Dezember 2006: Hochstimmung zum Jahresende

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    IWH-Bauumfrage: Ostdeutsche Bauproduktion mit Schwäche bis zum Jahresende

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    IWH-Bauumfrage im April 2007: Nur schwache Frühjahrsbelebung

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