3,954 research outputs found

    Metallic diffusion measured by a modified Knudsen technique

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    Diffusion coefficient of a metal in high temperature system is determined. From the measurement of the weight loss from a Knudsen cell, the vapor pressure of the escaping species can be calculated. If the only way this species can enter the Knudsen cell is by diffusion through a foil, the weight loss is diffusion flux

    Diffusion measurements using a modified Knudsen technique

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    Diffusion flux and vapor pressure for escaping gas from measurement of steady state weight loss of Knudsen cel

    Atom interferometry in an optical cavity

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    We propose and demonstrate a new scheme for atom interferometry, using light pulses inside an optical cavity as matter wave beamsplitters. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beamsplitters (<100μW<100 \mathrm{\mu W}), large momentum transfer beamsplitters with modest power, or new self-aligned interferometer geometries utilizing the transverse modes of the optical cavity. As a first demonstration, we obtain Ramsey-Raman fringes with >75%>75\% contrast and measure the acceleration due to gravity, g\mathit{g}, to 60μg/Hz60 \mathrm{\mu \mathit{g} / \sqrt{Hz}} resolution in a Mach-Zehnder geometry. We use >107>10^7 cesium atoms in the compact mode volume (600μm600 \mathrm{\mu m} 1/e21/e^2 waist) of the cavity and show trapping of atoms in higher transverse modes. This work paves the way toward compact, high sensitivity, multi-axis interferometry.Comment: 5 pages, 6 figure

    Les milites en pays d'Auvergne et sur ses marges dans la première moitié du Xe siècle d'après la Vita Geraldi

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    Châteaux, églises et seigneurs en Auvergne au Xe siècle. Lieux de pouvoir et formes d'encadrement. Journée d'étude du 6 mai 2010 à l'Université Blaise Pascal (Clermont II).Avec cette étude des milites dans la Vita Geraldi, on constate que les milites de la première moitié du Xe siècle sont très proches de leurs homologues et successeurs du XIe siècle : ils constituent des groupes de cavaliers lourdement armés de quelques dizaines d'individus, agissant au service d'un seigneur. En revanche, l'examen de la relation qui les unit à ce seigneur fait ressortir leur grande hétérogénéité sociale. De fait, outre des aristocrates de tous niveaux, présents comme vassaux ou comme jeunes gens placés en fosterage, on trouve parmi les milites de Géraud et des autres grands des gens d'origine sociale assez modeste : humbles hommes libres recommandés à plus puissant qu'eux, agents domaniaux en quête d'ascension sociale individuelle, voire même d'anciens domestiques, dont certains pourraient bien être d'origine servile. Les milites de la première moitié du Xe siècle ne formaient donc absolument pas un milieu social homogène

    Narrative In Police Communication: The Art Of Influence And Communication For The Modern Police Organization

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    Violence in the City of Rockford, Illinois and surrounding cities has made the Rockford Police Department’s communication vitally important for shaping the future of the community. The primary objective of this project was to gain a greater understanding of how the local police department utilizes one particular communication channel: social media. While some research examining law enforcement’s use of social media exists, this study is unique as it specifically applies Fisher’s (1984) narrative paradigm and key concepts related to public relations functions including relationship building. The analysis revealed that the department does utilize some narrative concepts, but could certainly reevaluate their use of social media to enhance their communication with the community

    À propos de l'esthétique des corps virils chez Bernard d'Angers : beauté cléricale et beauté chevaleresque

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    à paraître dans l'édition des actes du 22e colloque d'art roman d'Issoire, concernant "Le corps et ses représentations à l'époque romane", Revue, d'Auvergne, automne 2014.In Liber miraculorum sancte Fidis (early eleventh century) Bernard d'Angers makes a physical description of a cleric, whom he delivers a topical portrait corresponding to an ideal measurement and proportion. However, the same author praises for the beauty of a knight, whose stature and physical power he insists on. So we are dealing with two opposing male aesthetic canons. To understand this contrast, we must put Bernard's text into perspective by placing it both in the literary tradition it is the heir of and in its Christian theological context. This leads to the conclusion that the ideal of fair measure is the world of the clergy's own, for whom the body reflects the soul. On the other hand, a comparison with the Vita Karoli and the Chanson de Roland can show that the laics are the ones who associate a tall and muscular body to the idea of male beauty.Dans le Liber miraculorum sancte Fidis (début du XIe siècle), Bernard d'Angers décrit le physique d'un clerc, dont il livre un portrait topique correspondant à un idéal de mesure et de proportion. Or, le même auteur célèbre la beauté d'un chevalier, à propos duquel il insiste sur sa haute stature et sa puissance physique. Nous avons donc affaire à deux canons esthétiques masculins antagonistes. Pour comprendre ce constraste, il faut remettre en perspective le texte de Bernard en le replaçant à la fois dans la tradition littéraire dont il est l'héritier et dans son contexte théologique chrétien. On aboutit ainsi à la conclusion que l'idéal de juste mesure est propre au monde des clercs, pour qui le corps reflète l'âme. Au contraire, un rapprochement avec la Vita Karoli et la Chanson de Roland permet de montrer que ce sont les laïcs qui associent haute taille et puissante musculature à l'idée de beauté masculine

    Water Conservancy Subdistrict and Your Tax Dollar

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    Water conservancy subdistrict and your tax dollar pamphlet discusses the job of the subdistrict, the benefits and cost related to subdistricts, and local planning and coordination of the Corps of Army Engineers, the Bureau of Reclamation, the Soil Conservation Services, and the Bureau of Sport Fisheries and Wildlife. Included are decision of the taxpayer in relation to water conservancy subdistricts

    (SNP051) Joseph Fray interviewed by Dorothy Noble Smith, transcribed by Peggy C. Bradley

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    Records the reminiscences of Joseph Fray, who was a member of the Chamber of Commerce in Madison County, Virginia, in the 1920s, and witness to the events that led to the founding of Camp Hoover, Skyline Drive and Shenandoah National Park. Describes the work of local, state and federal officials in the planning and construction of Camp Hoover, also known as Rapidan Camp, which was a rustic retreat where President and Mrs. Hoover could escape the heat and congestion of Washington, DC. Fray reflects on the impact Camp Hoover had on Madison County, both as a works project and through the numerous benefits, such as roads, schools, and even air mail delivery, that came in the wake of its construction. Discusses the impetus Camp Hoover had on the founding of Skyline Drive and ultimately, Shenandoah National Park. Includes references to the lives of the mountain people and their sources of income, such as tan bark peeling and basket weaving, and local entrepreneur, George Pollock, owner of Skyland resort. A woman identified in the transcript as Mrs. Fray also contributes to the interview.https://commons.lib.jmu.edu/snp/1041/thumbnail.jp

    On Thermal Bowing of Concrete Sandwich Wall Panels with Flexible Shear Connectors

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    Thermal bowing, often referred as bulging or out-of-plane wall deflection, is a common issue on sandwich panel walls caused by a temperature differential between a building interior temperature and the environment. The stresses caused by temperature changes in concrete members are widely known in the practice of bridge design, but not on sandwich wall panels. For sandwich wall panel applications, it is common to have non-composite panels when the designer expects a high temperature gradient, what yields a less economical design, but reduces the bowing. This project aimed to validate current assumptions regarding the heat flow in sandwich wall panels and to perform a parametric study of panels subject to thermal loads, varying the concrete layer thickness, panel length, type of shear connector and separation using a commercial finite element analysis software. This study concluded that current design practices either underestimate, in the case of multiplying the classical mechanics values by the reported degree of composite behavior, or overestimate the real value of bowing, by using classical mechanics. A method for determining the percentage of composite action and compute bowing was developed and recommendations addressing the importance of this type of loading were given

    Propos préliminaire : quelle est la nature et le degré de la “centralité” de Brioude ? Comment comprendre le Brivadois et sa place par rapport aux autres territoires ?

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    International audienceL'auteur se propose d'interroger les trois siècles (XIe-XIIIe siècle) des "temps féodaux" relatifs à la ville de Brioude, à travers la chronologie, les sources (hagiographiques, diplomatiques, monumentales,...), l'historiographie pour une compréhension de l'inscription territoriale de cette ville (centralité, maillage, flux, réseaux...)
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