769 research outputs found

    Advanced supersonic technology propulsion system study

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    This study had the objectives of determining the most promising conventional and variable cycle engine types; the effect of design cruise Mach number (2.2, 2.7 and 3.2) on a commercial supersonic transport; effect of advanced engine technology on the choice of engine cycle; and effect of utilizing hydrogen as the engine fuel. The technology required for the engines was defined, and the levels of development to ensure availability of this technology in advanced aircraft propulsion systems were assessed. No clearcut best conventional or variable cycle engine was identified. The dry bypass turbojet and the duct burning turbofans were initially selected as the best conventional engines, but later results, utilizing augmentation at takeoff, added the mixed-flow augmented turbofan as a promising contender. The modulating air flow, three-rotor variable cycle engine identified the performance features desired from VCE concepts (elimination of inlet drag and reduction in afterbody drag), but was a very heavy and complex engine

    Application of sensitivity analysis – preliminary step of the process parameters estimation

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    Simulation of any physical process requires definition of the physical model, method – analytical or numerical, to solve the set of equations describing the physical model and the parameters expressing the body properties and boundary conditions. This paper focus on two latter aspects of the numerical simulation process. Precise determination of the model quantities are crucial for high quality of the model predictions and accurate reflection of real system. Determination of the process parameters is defined as an inverse problem. Following this the sensitivity analysis is applied as the preliminary step of the inverse analysis to reduce the number of model evaluations and to increase the inverse calculations robustness and efficiency. Sensitivity analysis techniques show how "sensitive" is a model to its input parameters variations and to changes of the model structure. As the example the sensitivity analysis was applied to the 2D DC borehole resistivity measurements simulation problem solved with hp-Finite Element Method

    "It is treachery to marry without espousing" - Montaigne and his concept of marriage

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    This article is an attempt to look into an issue, many times undertaken by critics, of Montaigne’s attitude towards marriage. Major reflections on the subject are described by the author of the Essays in the chapter « Upon some verses of Virgil » (III, 5). However, comments scattered around other places, often contradictory in their nature, create a picture full of ambiguities.This article is an attempt to look into an issue, many times undertaken by critics, of Montaigne’s attitude towards marriage. Major reflections on the subject are described by the author of the Essays in the chapter « Upon some verses of Virgil » (III, 5). However, comments scattered around other places, often contradictory in their nature, create a picture full of ambiguities

    2012 Haida Gwaii Quake: Insight Into Cascadia\u27s Subduction Extent

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    The limits of Cascadia were first defined to contain nearly the entire margin of the Pacific Northwest, from Cape Mendocino through the Alaska Panhandle [Schuchert, 1910; Schuchert and Barrell, 1914]. Since that time, the boundary of Cascadia has shrunk to become essentially synonymous with the region where the Juan de Fuca plate subducts beneath the North American plate. As a consequence, seismic hazard assessments in the Pacific Northwest have conventionally focused on the potential for large megathrust earthquakes along the interface of the Juan de Fuca and North American plates

    Disseny i implementació d'un marc de treball (framework) de presentació per aplicacions J2EE

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    Aquest document cobrirà diferents aspectes relacionats amb el disseny d'un framework de presentació orientat a aplicacions web. Començarem analitzant quins serien els aspectes o característiques esperades d'una solució d'aquest tipus, sempre des de la subjectivitat i l'experiència, com pot ser el concepte de zero configuration, el qual intenta reduir el nombre de fitxers de configuració necessaris per a la posada en marxa, o el de convention over configuration, el qual intenta reduir el nombre de decisions que els desenvolupadors hagin de prendre, guanyant en flexibilitat però sense perdre flexibilitat, i sobretot permetent al desenvolupador concentrar-se en aquells aspectes que són particulars a la seva solució.Este documento cubrirá diferentes aspectos relacionados con el diseño de un framework de presentación orientado a aplicaciones web. Comenzaremos analizando cuales serían los aspectos o características esperadas de una solución de este tipo, siempre desde la subjetividad y la experiencia, como puede ser el concepto de zero configuration, el cual intenta reducir el número de ficheros de configuración necesarios para la puesta en marcha, o el de convention over configuration, el cual intenta reducir el número de decisiones que los desarrolladores deban tomar, ganando en flexibilidad pero sin perder flexibilidad, y sobre todo permitiendo al desarrollador concentrarse en aquellos aspectos que son particulares a su solución.This paper will cover different aspects for the design of a web-oriented presentation framework. First of all, the aspects or features expected of this kind of solution are analysed, always from experiences and subjectivity, such as the concept of zero configuration, which attempts to reduce the number of configuration files needed for setup, or the convention over configuration, which aims to reduce the number of decisions that developers must take, gaining flexibility without losing flexibility, and above all allowing the developer to concentrate on those particular aspects of their solution

    High mercury emission (both forms: Hg0 and Hg2+) from the wet scrubber in a full-scale lignite-fired power plant

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    The paper describes and discusses the results of research on mercury behaviour, especially its high emission, in both forms: elemental (Hg-0) and oxidised (Hg2+) from the wet flue gas desulphurisation scrubber (WFGD) in a lignite-fired power plant located in central Europe. The presented results involve the collection of lignite power plant samples (liquid, solid, gas) and different laboratory chemical analyses to try to understand the mechanism of mercury re-emission from the wet flue gas desulfurization system. It was noted that 67-80% of the total inlet mercury concentration left the WFGD scrubber. Moreover, the oxidised form of mercury was the main emitted form (about 60-70% of the total mercury concentration). The results show that mercury was found in very high concentration (10 mu g/g) (range: ppm) in the WFGD solid by-products, whereas the liquid phase contained only 1 mu g//l (range: ppb). Considering literature reports and presented data from the investigated power station, we believe that iron (Fe), which occurs in very high concentrations in solid WFGD samples (1.81% wt. Fe) and lignite (up to 20 g/kg Fe) is mainly responsible for disrupting the mercury absorption in the scrubber, the partitioning of the mercury between phases and leads to its reemission. Moreover, we believe also that a relatively high iodine ion concentration (130 mg/l) in the limestone slurry leads to mercury emission in its oxidised form, mainly as Hgl(2), which is highly volatile. Other minor components from limestone dissolution such as Mn, Al and Mg may additionally enhance that "complex" mercury behaviour.Web of Science270art. no. 11749

    Transient Detection and Modeling of Continuous Geodetic Data

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    Transient surface deformation has been observed by continuously operating Global Positioning System stations in the Puget Sound area during the past decade. This surface deformation is associated with processes occurring on or near the subducting plate boundary between the Juan de Fuca and North American plates. This thesis is composed of two studies of transient deformation along the Cascadia plate margin and a discussion of the methodologies employed in these studies. We model one 7-week episode of transient deformation that occurred during 2003 beneath the Puget Sound area. Additionally, we utilize a combination of continuous Global Positioning System and seismic data to provide evidence for the occurrence of transient deformation in southern Cascadia. The remainder of the thesis focuses on the methodologies utilized in both identifying and modeling these episodes of transient deformation

    A Catalog of Felt Intensity Data for 570 Earthquakes in India from 1636 to 2009

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    Eight thousand three hundred thirty-nine intensity observations have been evaluated for earthquakes that occurred on the Indian subcontinent and surrounding plate boundaries from the seventeenth century to the present. They characterize 570 earthquakes, more than 90% of which occurred in the past two centuries. The electronic supplement to this article lists these data using European Macroseismic Scale (EMS-98) intensities with their geographic coordinates. We summarize these data graphically in the form of a spatially averaged intensity map for the subcontinent, a map that emphasizes the features of many previously published earthquake hazard maps for the Indian plate, but which more faithfully depicts regional amplification and attenuation. We also estimate the probable return time for future damaging shaking in five of India’s largest cities
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