27 research outputs found

    Analysis of Human Remains from Guana Island, BVI

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    On July 7, 2004, archaeologists from the Bermuda Maritime Museum and the College of William and Mary arrived on Guana Island in the BVI as part of the ongoing investigation of the island’s archaeological and architectural heritage sponsored by the island’s owners, Dr. Henry and Gloria Jarecki. Upon their arrival, the archaeologists were informed of the discovery of human remains on the island and subsequent recovery efforts by the Road Town Police. In the days that followed, archaeologists Mark Kostro and Dr. Marley Brown contacted the Institute for Historical Biology (IHB) at the College of William and Mary in order to notify the staff of the human remains’ discovery. Police Commissioner Barry Webb granted their request for custody of the remains for assessment and analysis pending a preliminary inventory to be carried out at the Road Town Police Station. Mark Kostro and Melissa Eaton, Anthropology graduate students from the College of William and Mary, carried out the requested preliminary inventory on July 30, 2004 with materials provided by the Institute for Historical Biology. Dr. Marley R. Brown III, research professor at William and Mary, provided additional assistance with the inventory. The inventory was carried out in the presence of a representative of the Royal British Virgin Islands Police Service, Constable Forbes Washington

    From university to industry - challenges in upscaling optical microstructures for daylight redirection in buildings

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    In this paper we present some of the challenges faced when upscaling optical microstructures from a lab scale 1x1 cm sized proof of concept sample to a square meter sized object that can be installed in a building. The optical microstructure in question is obtained by a chain of fabrication steps, all linked with each other and with a certain level of complexity. Each of the total of 8 distinct steps presented difficulties that will be briefly introduced in this paper. On a less technical level, long term commitment of public funding and industrial partners was the base for the first upscaling of this complex technologies for pilot production. Taking the best from two worlds: industry and academia has proven effective in the development of such a novel technology

    Monte Carlo simulations of quantum dot solar concentrators: ray tracing based on fluorescence mapping

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    One promising application of semiconductor nanostructures in the field of photovoltaics might be quantum dot solar concentrators. Quantum dot containing nanocomposite thin films are synthesized at EPFL-LESO by a low cost sol-gel process. In order to study the potential of the novel planar photoluminescent concentrators, reliable computer simulations are needed. A computer code for ray tracing simulations of quantum dot solar concentrators has been developed at EPFL-LESO on the basis of Monte Carlo methods that are applied to polarization-dependent reflection/transmission at interfaces, photon absorption by the semiconductor nanocrystals and photoluminescent reemission. The software allows importing measured or theoretical absorption/reemission spectra describing the photoluminescent properties of the quantum dots. Hereby the properties of photoluminescent reemission are described by a set of emission spectra depending on the energy of the incoming photon, allowing to simulate the photoluminescent emission using the inverse function method. By our simulations, the importance of two main factors is revealed, an emission spectrum matched to the spectral efficiency curve of the photovoltaic cell, and a large Stokes shift, which is advantageous for the lateral energy transport. No significant energy losses are implied when the quantum dots are contained within a nanocomposite coating instead of being dispersed in the entire volume of the pane. Together with the knowledge on the optoelectronical properties of suitable photovoltaic cells, the simulations allow to predict the total efficiency of the envisaged concentrating PV systems, and to optimize photoluminescent emission frequencies, optical densities, and pane dimensions. Keywords: quantum dots, photoluminescence, fluorescent planar solar concentrators, photovoltaics, solar cells, Monte Carlo simulations, ray tracing, polarizatio

    Controls Middleware: the New Generation

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    A new Controls Middleware (CMW) for the "LHC era" has been recently designed and implemented to serve the CERN accelerator sector. It is object-oriented and supports two conceptual models: The Device model traditionally used in accelerator controls and the Topic model, which is widely used in the commercial world. Unlikely previous middleware solutions, developed in the 80's, this middleware is completely build upon commercial standards: CORBA for synchronous calls, JMS (Java Message Service) for message passing and OPC (OLE for Process Control) for integration of industrial equipment. The subscription paradigm is supported in both Device and Topic models. This paper presents the system architecture and an overview of the user facilities and API's. The experience with CMW, the issues of integration of CORBA, JMS and OPC and system administration are addressed as well

    A Case for Lorentzian Relativity

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    The Lorentz transformation (the LT) is explained by changes occurring in the wave characteristics of matter as it changes inertial frame. This explanation is akin to that favoured by Lorentz, but informed by later insights, due primarily to de Broglie, regarding the underlying unity of matter and radiation. To show the nature of these changes, a massive particle is modelled as a standing wave in three dimensions. As the particle moves, the standing wave becomes a travelling wave having two factors. One is a carrier wave displaying the dilated frequency and contracted ellipsoidal form described by the LT, while the other (identified as the de Broglie wave) is a modulation defining the dephasing of the carrier wave (and thus the failure of simultaneity) in the direction of travel. The superluminality of the de Broglie wave is thus explained, as are several other mysterious features of the optical behaviour of matter, including the physical meaning of the Schrödinger Eqn. and the relevance to scattering processes of the de Broglie wave number. Consideration is given to what this Lorentzian approach to relativity might mean for the possible existence of a preferred frame and the origin of the observed Minkowski metric
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