2,060 research outputs found

    KALDOR’S WAR

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    Good practice in educational research : An outline using four paradigms

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    This article employs four different research papers (a case study, an action research project, an ethnography and a quantitative nomothetic study) to illustrate some of the basic concepts which make up sound educational research. Issues such as research design, sampling, data collection, data analysis and validity are all discussed. Particular emphasis is placed in the paper on the need for transparency on the part of researchers when presenting their findings

    Failure in composite materials

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    The economic and efficient exploitation of composite materials in critical load bearing applications relies on the ability to predict safe operational lives without excessive conservatism. Developing life prediction and monitoring techniques in these complex, inhomogeneous materials requires an understanding of the various failure mechanisms which can take place. This article describes a range of damage mechanisms which are observed in polymer, metal and ceramic matrix composites

    Ripple Effect Mapping of Youth & Adult Dyad Pairs Demonstrating Community Impact from iCook 4-H Intervention

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    Introduction: Creating effective dissemination and implementation tools within community based, obesity prevention research is needed to bridge the current science to practice gap. Ripple Effect Mapping (REM) using Community Capitals Framework (CCF) is a community impact evaluation tool that is hypothesized to positively capture activity during dissemination within community programs. Although REM is a proposed impact evaluation method, it has not been widely adopted within the research sector. In order to facilitate the translation of research into evidenced based practice, a stepwise process must be described and tested to determine efficacy and effectiveness, followed by a method to translate findings into useable and understandable information for the immediate users, the community, and larger public.;Purpose: The purpose of this study was to examine REM as an effective impact evaluation tool in determining participants\u27 (youth/adult dyads) perceptions of the ripple effect of a 24 month, iCook 4-H multistate intervention program on self, family and community for future dissemination.;Methods: Seventy dyad (A=adult, Y=youth) participants (35=A, 35=Y ages 9-10 years) participated across 5 states (10 groups; ME, NE, SD, TN, WV). Three core themes of iCook 4-H were assessed: cooking, eating and playing together. Group dyads responded to open ended questions by leader driven dialogue about ways in which the iCook program has affected the individual, family and community. Three main questions were asked: 1) what are people doing differently as a result of the iCook program; 2) who has benefited from the iCook program and how; 3) are there changes in the way community groups and institutions do things as a result of the iCook program? Questions and dialogue were recorded by trained note-takers using a template with set instructions. Directed data content analysis was used to determine individual, family and community impact.;Results: Participants reported adopting new behaviors such as an increase in physical activity, frequency of trying new foods were increased and improved communication skills as well as increased harmony within family units. Directed content analysis resulted in one theme, seven categories with eight subcategories, and 41 supporting subcategories. Participants reported positive family behavior change affecting all capitals within the CCF leading to an amplified awareness of the importance of togetherness.;Conclusions: Findings indicate that the REM evaluation tool was an effective approach in determining participant perceptions for future dissemination and implementation. Additionally, findings show youth obesity prevention programs such as the iCook 4-H program have the potential to positively affect self, families and communities. Applying a tool such as REM can be used by researchers, community members and participants as an effective evaluation tool to demonstrate through a visual mapping image, the positive effects of obesity prevention programs to further the dissemination and implementation mileage, replicability and sustainably

    Warp propagation in astrophysical discs

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    Astrophysical discs are often warped, that is, their orbital planes change with radius. This occurs whenever there is a non-axisymmetric force acting on the disc, for example the Lense-Thirring precession induced by a misaligned spinning black hole, or the gravitational pull of a misaligned companion. Such misalignments appear to be generic in astrophysics. The wide range of systems that can harbour warped discs - protostars, X-ray binaries, tidal disruption events, quasars and others - allows for a rich variety in the disc's response. Here we review the basic physics of warped discs and its implications.Comment: To be published in Astrophysical Black Holes by Haardt et al., Lecture Notes in Physics, Springer 2015. 19 pages, 2 figure

    Vertices and the CJT Effective Potential

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    The Cornwall-Jackiw-Tomboulis effective potential is modified to include a functional dependence on the fermion-gauge particle vertex, and applied to a quark confining model of chiral symmetry breaking.Comment: 10 pages (latex), PURD-TH-93-1

    Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage, or legumes. 5. Wheat yields, nitrogen benefits and water-use efficiency of chickpea-wheat rotation

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    In this study, the benefits of chickpea–wheat rotation compared with continuous wheat cropping (wheat–wheat rotation) were evaluated for their effects on soil nitrate nitrogen, wheat grain yields and grain protein concentrations, and water-use efficiency at Warra, southern Queensland from 1988 to 1996. Benefits in terms of wheat grain yields varied, from 17% in 1993 to 61% in 1990, with a mean increase in grain yield of 40% (825 kg/ha). Wheat grain protein concentration increased from 9.4% in a wheat–wheat rotation to 10.7% in a chickpea–wheat rotation, almost a 14% increase in grain protein. There was a mean increase in soil nitrate nitrogen of 35 kg N/ha.1.2 m after 6 months of fallow following chickpea (85 kg N/ha) compared with continuous wheat cropping (50 kg N/ha). This was reflected in additional nitrogen in the wheat grain (20 kg N/ha) and above-ground plant biomass (25 kg N/ha) following chickpea. Water-use efficiency by wheat increased from a mean value of 9.2 kg grain/ha. mm in a wheat–wheat rotation to 11.7 kg grain/ha.mm in a chickpea–wheat rotation. The water-use efficiency values were closely correlated with presowing nitrate nitrogen, and showed no marked distinction between the 2 cropping sequences. Although presowing available water in soil in May was similar in both the chickpea–wheat rotation and the wheat–wheat rotation in all years except 1996, wheat in the former used about 20 mm additional water and enhanced water-use efficiency. Thus, by improving soil fertility through restorative practices such as incorporating chickpea in rotation, water-use efficiency can be enhanced and consequently water runoff losses reduced. Furthermore, beneficial effects of chickpea in rotation with cereals could be enhanced by early to mid sowing (May–mid June) of chickpea, accompanied by zero tillage practice. Wheat of ‘Prime Hard’ grade protein (≄13%) could be obtained in chickpea–wheat rotation by supplementary application of fertiliser N to wheat. In this study, incidence of crown rot of wheat caused by Fusarium graminearum was negligible, and incidence and severity of common root rot of wheat caused by Bipolaris sorokiniana were essentially similar in both cropping sequences and inversely related to the available water in soil at sowing. No other soil-borne disease was observed. Therefore, beneficial effects of chickpea on wheat yields and grain protein were primarily due to additional nitrate nitrogen following the legume crop and consequently better water-use efficiency

    Collider signals from slow decays in supersymmetric models with an intermediate-scale solution to the mu problem

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    The problem of the origin of the mu parameter in the Minimal Supersymmetric Standard Model can be solved by introducing singlet supermultiplets with non-renormalizable couplings to the ordinary Higgs supermultiplets. The Peccei-Quinn symmetry is broken at a scale which is the geometric mean between the weak scale and the Planck scale, yielding a mu term of the right order of magnitude and an invisible axion. These models also predict one or more singlet fermions which have electroweak-scale masses and suppressed couplings to MSSM states. I consider the case that such a singlet fermion, containing the axino as an admixture, is the lightest supersymmetric particle. I work out the relevant couplings in several of the simplest models of this type, and compute the partial decay widths of the next-to-lightest supersymmetric particle involving leptons or jets. Although these decays will have an average proper decay length which is most likely much larger than a typical collider detector, they can occasionally occur within the detector, providing a striking signal. With a large sample of supersymmetric events, there will be an opportunity to observe these decays, and so gain direct information about physics at very high energy scales.Comment: 24 pages, LaTeX, 4 figure
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