2,080 research outputs found

    KALDOR’S WAR

    Get PDF

    Good practice in educational research : An outline using four paradigms

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Full text link
    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

    Nitrogen fertiliser residues for wheat cropping in subtropical Australia

    Get PDF
    Applied nitrogen (N) recovered by fertilised wheat and by successive wheat crops in a 4-crop sequence (1987-90) was studied by applying 15N-depleted ammonium nitrate (0, 2.5, and 7.5 g/m2) to a Vertisol in the summer-dominant rainfall region of northern Australia. Recoveries of applied N by each of the 4 crops in order of cropping sequence were 60.3Š 4.2, 4.4 Š 2.3, 1 . 3 Š 0.49, and 0- 8 Š 0.56%, there being no effect of 2 tillage treatments, conventional tillage (CT) and no till (NT), on uptake of applied N. There was very low recovery of residual fertiliser N after the first wheat crop was harvested; usually <lo% of the applied N was recovered. There was evidence of a substantial N carryover benefit where fertiliser N (7.5 g/m2) was applied in 1987, but not when applied at the same rate in 1988 or 1989. Carryover effect was shown only when fertiliser N was applied after a long fallow when antecedent NOT-N was already high (100-150 v. 30-55 kg/ha with a normal summer fallow). Carryover of subsoil NO3 -N from a single N fertiliser application to the crop, as occurred with application in 1987, will provide useful buffer for declining N supplies of soil N in seasons of good crop response. Routine application of N at moderate rates (<75 kg/ha) provides an effective means of supplementing declining soil N reserves for winter cereals in this region of unreliable rainfall

    Vertices and the CJT Effective Potential

    Full text link
    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. 1. Organic matter status

    Get PDF
    Management practices involving legume leys, grain legumes, and no-tillage and stubble retention, along with nitrogen (N) fertiliser application for wheat cropping, were examined for their effectiveness in increasing soil organic matter (0-10 cm depth) from 1986 to 1993 in a field experiment on a Vertisol at Warra, Queensland. The treatments were (i) grass + legume leys (purple pigeon grass, Setaria incrassata; Rhodes grass, Chloris gayana; lucerne, Medicago sativa; annual medics, M. scutellata and M. truncatula) of 4 years duration followed by continuous wheat; (ii) 2-year rotation of annual medics and wheat (Triticum aestivum cv. Hartog); (iii) 2-year rotation of lucerne and wheat; (iv) 2-year rotation of chickpea (Cicer arietinum cv. Barwon) and wheat; (v) no-tillage (NT) wheat; and (vi) conventional tillage (CT) wheat. Fertiliser N as urea was applied to both NT wheat and CT wheat at 0,25, and 75 kg N/ha. year. The CT wheat also received N at 12.5 and 25kg N/ha. year. After 4 years, soil organic carbon (C) concentration under grass + legume leys increased by 20% (650 kg C/ha. year) relative to that under continuous CT wheat. Soil total N increased by 11, 18, and 22% after 2, 3, and 4 years, respectively, under grass + legume leys relative to continuous CT wheat. These increases in soil organic matter were mostly confined to the 0-2.5 cm layer. After the start of wheat cropping, organic C and total N levels declined steadily but were still higher than under CT wheat and higher than initial values in December 1985. Although 2-year rotations of lucerne-wheat and medic-wheat had a small effect on soil organic C, soil total N concentrations were higher than in the chickpea-wheat rotation and continuous CT wheat from November 1990 to November 1992. Soil under chickpea-wheat rotation had organic C and total N concentrations similar to continuous CT wheat, although from the former, about 70 kg/ha. year of extra N was removed in the grain from 1989 to 1993. No-tillage practice had a small effect on soil organic C, although total N concentration was higher than under CT wheat in November 1993. These effects were mainly confined to the surface 0-2.5 cm depth. The C to N ratio was only affected in soil under grass + legume leys, and no-tillage treatments. These data show that restoration of soil organic matter in Vertisol requires grass + legume leys, primarily due to increased root biomass, although soil total N can be enhanced by including legume leys for longer duration in cropping systems in the semi-arid and subtropical environment
    • 

    corecore