1,735,141 research outputs found

    2195. Honorius Augustodunensis, polygraphe

    No full text
    2195. Honorius Augustodunensis, polygraphe. In: Molinier Auguste. Les Sources de l'histoire de France - Des origines aux guerres d'Italie (1494). II. Époque féodale, les Capétiens jusqu'en 1180. Paris : A. Picard et fils, 1902. p. 313

    Biaxial Testing of 2195 Aluminum Lithium Alloy Using Cruciform Specimens

    No full text
    A cruciform biaxial test specimen was used to test the effect of biaxial load on the yield of aluminum-lithium alloy 2195. Fifteen cruciform specimens were tested from 2 thicknesses of 2195-T8 plate, 0.45 in. and 1.75 in. These results were compared to the results from uniaxial tensile tests of the same alloy, and cruciform biaxial tests of aluminum alloy 2219-T87

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Microstructural Characterization of Aluminum-Lithium Alloys 1460 and 2195

    Get PDF
    Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) techniques were employed to characterize the precipitate distributions in lithium-containing aluminum alloys 1460 and 2195 in the T8 condition. TEM examinations revealed delta prime and T1 as the primary strengthening precipitates in alloys 1460 and 2195 respectively. TEM results showed a close similarity of the Russian alloy 1460 to the U.S. alloy 2090, which has a similar composition and heat treatment schedule. DSC analyses also indicate a comparable delta prime volume fraction. TEM study of a fractured tensile sample of alloy 1460 showed that delta prime precipitates are sheared by dislocations during plastic deformation and that intense stress fields arise at grain boundaries due to planar slip. Differences in fracture toughness of alloys 1460 and 2195 are rationalized on the basis of a literature review and observations from the present study

    B218 Weld Filler Wire Characterization for Al-Li Alloy 2195

    No full text
    NASA Marshall Space Flight Center, Lockheed Martin Space Systems- Michoud Operations, and McCook Metals have developed an aluminum-copper weld filler wire for fusion welding aluminum lithium alloy 2195. The aluminum-copper based weld filler wire has been identified as B218, a McCook Metals designation. B218 is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties over the 4043 aluminum-silicon weld filler wire, which is currently used to weld 2195 on the Super Lightweight External Tank for the NASA Space Shuttle Program. An initial characterization was performed consisting of a repair weld evaluation using B218 and 4043 weld filler wires. The testing involved room temperature and cryogenic repair weld tensile testing along with fracture toughness testing. From the testing, B218 weld filler wire produce enhanced repair weld tensile strength, ductility, and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding aluminum lithium alloy 2195 over 4043

    Aluminum 2195 T8 Gore Development for Space Launch System Core and Upper Stage

    Get PDF
    Gores are pie-shaped panels that are welded together to form the dome ends of rocket fuel tanks as shown in figure 1. Replacing aluminum alloy 2219 with aluminum (Al)-lithium (Li) alloy 2195 as the Space Launch System (SLS) cryogenic tank material would save enormous amounts of weight. In fact, it has been calculated that simply replacing Al 2219 gores with Al 2195 gores on the SLS core stage domes could save approximately 3,800 pound-mass. This is because the Al-Li 2195 alloy exhibits both higher mechanical properties and lower density than the SLS baseline Al 2219 alloy. Indeed, the known advantages of Al 2195 led to its use as a replacement for Al 2219 in the shuttle external tank program. The required thicknesses of Al 2195 gores for either SLS core stage tanks or upper stage tanks will depend on the specific design configurations. The required thicknesses or widths may exceed the current experience base in the manufacture of such gores by the stretch-forming process. Accordingly, the primary objective of this project was to enhance the formability of Al 2195 by optimizing the heat treatment and stretch-forming process for gore thicknesses up to 0.75 inches, which envelop the maximum expected gore thicknesses for SLS tank configurations

    The Effects of Retrogression and Reaging on Aluminum Alloy 2195

    Get PDF
    A retrogression and reaging (RRA) treatment was performed on 2195 Al-Li Alloy. The exposure times were from 5 to 60 min, and the temperatures were from 200 to 250 A degrees C. Samples that were exposed to a salt spray test had overall similar mechanical properties as compared to those that were not exposed. The percent elongation, however, was significantly deteriorated due to the salt spray exposure. The mechanical properties of the 2195 samples were compared to those of 2099 samples exposed to similar treatments in an earlier study

    Harris, Sophronia (Campbell), 1833-1925 (SC 2195)

    Get PDF
    Finding aid and scan (Click on Additional Files below) for Manuscripts Small Collection 2195. Letter, 11 March 1867, from Sophronia Harris, Madisonville, Kentucky, to Nell A. Durkee, Paw Paw, Michigan. She expresses sympathy over the death of Durkee’s father, notes other incidents of death and illness, gives news of family and mutual friends, and asks about Durkee’s sweetheart

    Variations on the Author

    Get PDF
    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
    corecore