544 research outputs found

    Infiltrated carbon foam composites

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    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems

    Volume 18. Article 3. Studies on two skates: Raja erinacea Mitchill, Raja eglanteria Bosc.

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    https://elischolar.library.yale.edu/bulletin_yale_bingham_oceanographic_collection/1164/thumbnail.jp

    Computing the Cassels–Tate pairing on the 3-Selmer group of an elliptic curve

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    We extend the method of Cassels for computing the Cassels-Tate pairing on the 2-Selmer group of an elliptic curve, to the case of 3-Selmer groups. This requires significant modifications to both the local and global parts of the calculation. Our method is practical in sufficiently small examples, and can be used to improve the upper bound for the rank of an elliptic curve obtained by 3-descent

    Dioctahedral mixed K-Na-micas and paragonite in diagenetic to low-temperature metamorphic terrains: bulk rock chemical, thermodynamic and textural constraints

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    Abstract Metamorphic mineral assemblages in low-temperature metaclastic rocks often contain paragonite and/or its precursor metastable phase (mixed K-Na-white mica). Relationships between the bulk rock major element chemistries and the formation of paragonite at seven localities from Central and SE-Europe were studied, comparing the bulk chemical characteristics with mineral assemblage, mineral chemical and metamorphic petrological data. Considerable overlaps between the projection fields of bulk chemistries of the Pg-free and Pg-bearing metaclastic rocks indicate significant differences between the actual (as analyzed) and effective bulk chemical compositions. Where inherited, clastic, inert phases/constituents were excluded, it was found that a decrease in Na/(Na+Al*) and in K/(K+Al*) ratios of rocks favors the formation and occurrence of Pg and its precursor phases (Al* denotes here the atomic quantity of aluminum in feldspars, white micas and “pure” hydrous or anhydrous aluminosilicates). In contrast to earlier suggestions, enrichment in Na and/or an increase in Na/K ratio by themselves do not lead to formation of paragonite. Bulk rock chemistries favorable to formation of paragonite and its precursor phases are characterized by enrichment in Al and depletion in Na, K, Ca (and also, Mg and Fe2+). Such bulk rock chemistries are characteristic of chemically “mature” (strongly weathered) source rocks of the pelites and may also be formed by synand post-sedimentary magmatism-related hydrothermal (leaching) activity. What part of the whole rock is active in determining the effective bulk chemistry was investigated by textural examination of diagenetic and anchizone-grade samples. It is hypothesized that although solid phases act as local sources and sinks, transport of elements such as Na through the grain boundaries have much larger communication distances. Sodium-rich white micas nucleate heterogeneously using existing phyllosilicates as templates and are distributed widely on the thin section scale. The results of modeling by THERMOCALC suggest that paragonite preferably forms at higher pressures in low-T metapelites. The stability fields of Pg-bearing assemblages increase, the Pg-in reaction line is shifted towards lower pressures, while the stability field of the Chl-Ms-Ab-Qtz assemblage decreases and is shifted towards higher temperatures with increasing Al* content and decreasing Na/(Na+Al*) and K/(K+Al*) ratios

    The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

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    The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76-Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76-Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76-Ge neutrinoless double-beta decay Q-value of 2039 keV.Comment: Submitted to AIP Conference Proceedings, 19th Particles & Nuclei International Conference (PANIC 2011), Massachusetts Institute of Technology, Cambridge, MA, USA, July 24-29, 2011; 3 pages, 1 figur

    The Majorana experiment: an ultra-low background search for neutrinoless double-beta decay

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    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.Comment: Presentation for the Rutherford Centennial Conference on Nuclear Physic

    Initial Medical Attention on Patients with Early-Stage Non-Small Cell Lung Cancer

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    Detection of early stage non-small cell lung cancer (NSCLC) is commonly believed to be incidental. Understanding the reasons that caused initial detection of these patients is important for early diagnosis. However, these reasons are not well studied.We retrospectively reviewed medical records of patients diagnosed with stage I or II NSCLC between 2000 and 2009 at UT MD Anderson Cancer Center. Information on suggestive LC-symptoms or other reasons that caused detection were extracted from patients' medical records. We applied univariate and multivariate analyses to evaluate the association of suggestive LC-symptoms with tumor size and patient survival.Of the 1396 early stage LC patients, 733 (52.5%) presented with suggestive LC-symptoms as chief complaint. 347 (24.9%) and 287 (20.6%) were diagnosed because of regular check-ups and evaluations for other diseases, respectively. The proportion of suggestive LC-symptom-caused detection had a linear relationship with the tumor size (correlation 0.96; with p<.0001). After age, gender, race, smoking status, therapy, and stage adjustment, the symptom-caused detection showed no significant difference in overall and LC-specific survival when compared with the other (non-symptom-caused) detection.Symptoms suggestive of LC are the number one reason that led to detection in early NSCLC. They were also associated with tumor size at diagnosis, suggesting early stage LC patients are developing symptoms. Presence of symptoms in early stages did not compromise survival. A symptom-based alerting system or guidelines may be worth of further study to benefit NSCLC high risk individuals

    Motivations and experiences of museum visitors: The case of the Imperial War Museum, United Kingdom

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    This study explores motivations of visitors to the Imperial War Museum (North and South), United Kingdom, with a view to understanding why people visit museums associated with conflicts. Though museums are part of the education and leisure industry, the distinction between education and leisure is often blurred. There are a number of reasons why people visit museums. Motives of museum visitors can be grouped into intrinsic and extrinsic factors. This study analysed the extent to which museum visitors are motivated by extrinsic and intrinsic factors. Semi-structured interviews with visitors were conducted w at the Imperial Museum of War (North and South), United Kingdom. The findings do establish that extrinsic motivations are more dominant than the intrinsic ones for visiting the Imperial War Museum. The importance of extrinsic factors in motivating museum visitors would suggest that providing an opportunity for a good day out has more appeal to the visitors than the collections in the museum for the average visitors. The experiencing of museum in its totality is more important than the individual collections or the theme of the museum to the mainstream visitor. This work has made a contribution to understanding visitor motivations, which are multi-facetted, complex and not necessarily fully understood by the visitors themselves

    Participatory Augering: A methodology for challenging perceptions of archaeology and landscape change

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    Public engagement is a significant feature of twenty-first-century archaeological practice. While more diverse audiences are connecting with the discipline in a multitude of ways, public perceptions of archaeology are still marred by stereotypes. Community excavations of ‘sites’ to discover ‘treasures’ which tell us about the ‘past’ overshadow other forms of public research output and hinder the potential of the discipline to contribute to contemporary society more widely. This paper proposes participatory augering as an active public engagement method that challenges assumptions about the nature of archaeological practice by focusing on interpretation at a landscape-scale. Through exploration of recent participatory augering research by the REFIT Project and Environmental Archaeologist Mike Allen, this paper demonstrates how the public can contribute to active archaeological research by exploring narratives of landscape change. Evaluation of the existing case studies reflects the potential of the approach to engage audiences with new archaeological methods and narratives which have the potential to transform perceptions of the discipline and, through knowledge exchange, drive community-led contributions to contemporary landscape management
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