117,847 research outputs found

    Hydrodynamic signatures of stationary Marangoni-driven surfactant transport

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    We experimentally study steady Marangoni-driven surfactant transport on the interface of a deep water layer. Using hydrodynamic measurements, and without using any knowledge of the surfactant physico-chemical properties, we show that sodium dodecyl sulphate and Tergitol 15-S-9 introduced in low concentrations result in a flow driven by adsorbed surfactant. At higher surfactant concentration, the flow is dominated by the dissolved surfactant. Using Camphoric acid, whose properties are {\it a priori} unknown, we demonstrate this method's efficacy by showing its spreading is adsorption dominated

    Crystallization of Simple Fluids: Relative Stability of f.c.c. and b.c.c Structures

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    A free-energy functional for a crystal that contains both the symmetry conserved and symmetry broken parts of the direct pair correlation function is developed. The free-energy functional is used to investigate the crystallization of fluids interacting via the inverse power potential ; u(r)=Ï”(σ/r)nu(r)=\epsilon {(\sigma/r)}^n. In agreement with simulation results we find that for n=12n=12 the freezing is into close packed f.c.c structure while for soft repulsions (n≀6)(n\leq 6) b.c.c phase is more stable.Comment: 9 pages, 2 figure

    "It isn't just consultants that need a BSc": student experiences of an Intercalated BSc

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    More medical schools are moving towards a compulsory intercalated BSc. These courses have not traditionally been aimed at those students interested in general practice and have tended to have limited clinical relevance. This paper explores the perceptions of students who undertook a BSc in primary health care using qualitative methodology comprising semi-structured interviews with students just before completion of their course. Interviews were undertaken with 24 of the 26 students who started the course over a 4-year period. All the students have finished the course and have graduated with good honours degrees. Students refine existing skills and develop new, relevant skills for medicine. The students discussed the prestige (or lack) of a BSc in this field and how the course has impacted on their career decisions. A Primary Health Care BSc such as this appears to give students an in depth and to some, a positive view of general practice and primary care. The course allowed students to develop a more critical approach to medicine and enabled them to develop skills in addition to those acquired from their undergraduate medicine course. They perceived that these skills will serve them throughout their career in whatever branch of medicine they choose

    A characterization of the central shell-focusing singularity in spherical gravitational collapse

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    We give a characterization of the central shell-focusing curvature singularity that can form in the spherical gravitational collapse of a bounded matter distribution obeying the dominant energy condition. This characterization is based on the limiting behaviour of the mass function in the neighbourhood of the singularity. Depending on the rate of growth of the mass as a function of the area radius R, the singularity may be either covered or naked. The singularity is naked if this growth rate is slower than R, covered if it is faster than R, and either naked or covered if the growth rate is same as R.Comment: 12 pages, Latex, significantly revised version, including change of title. Revised version to appear in Classical and Quantum Gravit

    Undergraduate research in primary care: Is it sustainable?

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    To describe the research project component of the BSc in Primary Health Care and to discuss the issues faced by students and faculty in attempting to complete a student-led research project. Medical schools increasingly expect medical students to undertake research as part of intercalated BSc’s or in self-selected study modules. This research has historically been laboratory based, ‘piggybacking’ onto existing projects. Projects initiated by students themselves and studies in primary care or community settings are more unusual. A qualitative study, based on interviews with students and examiners, triangulated with data from the peer review process and personal observations on the running of the course. A London medical school, running an intercalated BSc in Primary Health Care. We interviewed 24 of 26 students and two external examiners during the interview period of the study. Students successfully undertook research, from initial question through to publication. Overall, 90 dissertations were completed since 1997, of which half used a qualitative methodology (45/90). Ten projects have subsequently been published; there were also 16 conference presentations and 6 research letters. Themes from the interview data include: the students’ strong sense of project ownership, the difficulties of being a novice researcher, the difficulties posed by the research governance hurdles, the beneficial and for some students adverse impact (stress and coping with unsuccessful projects) and finally, the impact on their careers. Students gain considerably from this learning process, not only by undertaking their own research, but they also gain in terms of acquisition of transferable skills such as critical appraisal and improved self-directedness. Project completion and publication rates suggest that programmes developing undergraduate initiated research projects can be as successful as those for other novice researchers. The student-led project is a fragile endeavour, but currently is sustainable. © 2008, Cambridge University Press. All rights reserved

    Exploring the Causes of Low Immunization Status in School Going Children

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    Background: Although a definitive immunization program has been advocated for children in our country, the immunization coverage is far from satisfactory. There is paucity of survey studies related to immunization pattern. Objective: This study has been undertaken to explore the social and attitudinal factors with parents resulting into adverse immunization. Material and Methods: The study was school based cross-sectional study conducted in 50 schools of Indore district selected by random sampling from three groups. Information was collected from parents by providing pre-tested questionnaire. Result: Association of parent’s literacy and socioeconomic status with successful immunization could be established. Overall coverage rate with vaccines was poor in school going girls as compared to the boys; proving thereby that gender discrimination exists putting girls in disadvantageous position. Conclusion: It can be expected that the immunization status of school children will improve if identified risk factors such as parental education, socioeconomic status, awareness status are improved and attitudinal gender discrimination is curbed
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