10,607 research outputs found

    Glycyl-L-proline hemihydrate at 298 K

    Get PDF

    A computer graphics program for general finite element analyses

    Get PDF
    Documentation for a computer graphics program for displays from general finite element analyses is presented. A general description of display options and detailed user instructions are given. Several plots made in structural, thermal and fluid finite element analyses are included to illustrate program options. Sample data files are given to illustrate use of the program

    On some singularities of the correlation functions that determine neutrino opacities

    Get PDF
    Certain perturbation graphs in the calculation of the effects of the medium on neutrino scattering in supernova matter have a nonintegrable singularity in a physical region. A number of papers have addressed the apparent pathology through an ansatz that invokes higher order (rescattering) effects. Taking the Gamow-Teller terms as an example, we display an expression for the spin-spin correlation function that determines the cross-sections. It is clear from the form that there are no pathologies in the order by order perturbation expansion. Explicit formulae are given for a simple case, leading to an answer that is very different from one given by other authors.Comment: 8 page

    Many-Body Corrections to Charged-Current Neutrino Absorption Rates in Nuclear Matter

    Get PDF
    Including nucleon--nucleon correlations due to both Fermi statistics and nuclear forces, we have developed a general formalism for calculating the charged--current neutrino--nucleon absorption rates in nuclear matter. We find that at one half nuclear density many--body effects alone suppress the rates by a factor of two and that the suppression factors increase to ∼\sim5 at 4×10144\times10^{14} g cm−3^{-3}. The associated increase in the neutrino--matter mean--free--paths parallels that found for neutral--current interactions and opens up interesting possibilities in the context of the delayed supernova mechanism and protoneutron star cooling.Comment: 11 pages, APS REVTeX format, 1 PostScript figure, uuencoded compressed, and tarred, submitted to Physical Review Letter

    Women's experiences of pregnancy, childbirth, and the postnatal period in the Gambia: A qualitative study

    Get PDF
    Objective: In sub-Saharan African countries, there are unique cultural factors and adverse physical conditions that contribute to women's experiences of pregnancy and birth. The objective of this study was to qualitatively explore women's experiences of pregnancy, childbirth, the postnatal period, and maternal psychological distress in The Gambia. Design and methods: Semi-structured interviews were carried out with 55 women who had given birth within the previous year. Results: Thematic analysis identified five themes: (1) transition to adulthood, (2) physical difficulties, (3) value of children in relation to others, (4) children as a strain, and (5) going through it alone. The results suggest that having a child is a defining point in women's lives associated with happiness and joy. However, women also described situations which could lead to unhappiness and distress in the perinatal period. A child conceived out of wedlock or a baby girl can be sources of distress because of negative cultural perceptions. The strain of having a child, particularly the additional financial burden, and minimal support from men were also a concern for women. Finally, women recognized the danger associated with delivery and expressed recurrent worries of complications during childbirth which could result in the death of them or the baby. Conclusions: Further research is needed to identify women vulnerable to psychological distress so that health services and target interventions can be developed accordingly

    The discovery of optical emission from the SNR G 126.2 + 1.6

    Get PDF
    Interference filter photographs were used to identify an arc of nebulosity that is coincident with the radio contours of the galactic supernova remnant G 126.2 + 1.6. Spectrophotometry of the filament shows that the emission line spectrum matches the spectra of other galactic supernova remnants. In particular, the arc shows the usual strong SII, and NII emission lines seen in other remnants and unusually strong OII emission as seen in a few remnants. The spectrum can be adequately matched by a shock of velocity near 100 km/s in an interstellar cloud of density 3. If the SNR is at a distance of 4.5 kpc as indicated by the radio signal-D relation, then the observed pressure in the filament requires an initial energy near 4 x 10 to the 51st power (d/4.5 kpc) to the 3rd power ergs

    A Framework to Manage the Complex Organisation of Collaborating: Its Application to Autonomous Systems

    Full text link
    In this paper we present an analysis of the complexities of large group collaboration and its application to develop detailed requirements for collaboration schema for Autonomous Systems (AS). These requirements flow from our development of a framework for collaboration that provides a basis for designing, supporting and managing complex collaborative systems that can be applied and tested in various real world settings. We present the concepts of "collaborative flow" and "working as one" as descriptive expressions of what good collaborative teamwork can be in such scenarios. The paper considers the application of the framework within different scenarios and discuses the utility of the framework in modelling and supporting collaboration in complex organisational structures
    • …
    corecore