117 resultados para Roll crushers


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Background Many public health interventions based on apparently sound evidence from randomised controlled trials encounter difficulties when being scaled up within health systems. Even under the best of circumstances, implementation is exceedingly difficult. In this paper we will describe the implementation salvage experiences from the Melbourne Diabetes Prevention Study, which is a randomised controlled trial of the effectiveness and cost-effectiveness nested in the state-wide Life! Taking Action on Diabetes program in Victoria, Australia.

Discussion The Melbourne Diabetes Prevention Study sits within an evolving larger scale implementation project, the Life! program. Changes that occurred during the roll-out of that program had a direct impact on the process of conducting this trial. The issues and methods of recovery the study team encountered were conceptualised using an implementation salvage strategies framework. The specific issues the study team came across included continuity of the state funding for Life! program and structural changes to the Life! program which consisted of adjustments to eligibility criteria, referral processes, structure and content, as well as alternative program delivery for different population groups. Staff turnover, recruitment problems, setting and venue concerns, availability of potential participants and participant characteristics were also identified as evaluation roadblocks. Each issue and corresponding salvage strategy is presented.

Summary The experiences of conducting such a novel trial as the preliminary Melbourne Diabetes Prevention Study have been invaluable. The lessons learnt and knowledge gained will inform the future execution of this trial in the coming years. We anticipate that these results will also be beneficial to other researchers conducting similar trials in the public health field. We recommend that researchers openly share their experiences, barriers and challenges when conducting randomised controlled trials and implementation research. We encourage them to describe the factors that may have inhibited or enhanced the desired outcomes so that the academic community can learn and expand the research foundation of implementation salvage.

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The common grades of steel used in roll forming are: hot rolled carbon steel, high strength low alloy and recovery annealed cold rolled sheet. These steels are prone to ageing and are often skin passed and/or roller leveled to eliminate ageing as it can lead to problems in forming. In roll forming, shape defects such as bow, twist and camber are considered to be related to very small plastic strains in the longitudinal direction and hence knowledge of the material properties in the elastic plastic transition range is necessary if the process is to be modelled accurately. Previous studies with aluminium have indicated that skin pass rolling can lead to residual stresses in the strip. In this work, the study was extended to aged carbon steel and to the effect of roller leveling on both aged material and strip that had been given a light cold rolling to simulate a skin pass treatment. The results suggest that roller leveling reduced the magnitude of residual stresses resulting from skin pass rolling.

The significant differences observed between tensile and bending test results, at and near, the elastic plastic transition reinforces the need to consider bending properties when assessing the effect of prior processing on strip for roll forming.

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In recent years, advanced high strength steels (AHSS) have been used in a wide range of automotive applications; they may have property variations through the thickness and the properties may also be dependent of prior processing including pre-straining. In order to model forming processes precisely using, for example, finite element analysis, it is important that material input data should adequately reflect these effects. It is known that shape defects in roll forming are related to small strains in material that has undergone prior deformation in a different strain path. Much research has already been performed on the change in the Young’s Modulus once a steel sheet has been plastically deformed,however many of these tests have only been conducted using tensile testing, and therefore may not take into account differences in compressive and tensile unloading. This research investigates the effect of tensile pre-straining on bending behaviour for various types of material;in bending, one half of the sheet will load and unload in compression and hence experience deformation under a reversed stress. Four different materials were pre-strained in tension with 1%, 3%, 7%, 11% and 25% elongation. Using a free bending test, moment curvature diagrams were obtained for bending and unloading. The results showed that the characteristics of the moment curvature diagram depended on the degree of pre-straining; more highly strained samples showed an earlier elastic-plastic transformation and a decreased Young's Modulus during unloading. This was compared to previous literature results using only tensile tests. Our results could influence the modeling of springback in low tension sheet operations, such as roll forming.

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Purpose: 

This article analyses the role, approach, issues and opportunities faced by non-governmental organisations (NGOs) in the promotion of agriculture in Timor Leste from independence through to the countrywide roll out of a public extension service in 2009.

Design/methodology/approach:
The research draws on semi-structured interviews with NGO personnel, local, national and international, actively involved in agricultural development to ascertain how organisations engage with communities, their objectives, inputs, coverage and impacts. The analysis is based on the framework developed by Birner et al. (2009) for pluralistic advisory services, and the discussion is framed by contemporary NGO discourse.

Findings:
This article argues that NGOs have a central role in agricultural development, with particular advantages that can be built upon, however there must be explicit acknowledgement of the complex nature of the NGO and civil society, and a critical awareness of the need for strategic thinking, communication and coordination for effective aid.

Practical implication:
NGOs play a central role in agricultural development. There is a need for a more nuanced understanding of the opportunities and limitations of the NGO sector, both as service providers but also more broadly as part of civil society.

Originality/value:
Funding directed to the NGO sector for implementation of development projects is prolific. There is substantial discourse on partnerships between NGOs and other actors. However, little of the debate appears within discussions on agricultural service provision.

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Jorge Lorenzo Flores Garza’s On the Road by Jack Kerouac had its Australian premiere in July this year at the Walker Street Gallery in Melbourne. It screened as part of the ‘Outside the Outside’ series curated by Dirk de Bruyn and Glenn D’Cruz, and was introduced by Steven McIntyre.

On the Road by Jack Kerouac is the most recent work by Mexican filmmaker Jorge Lorenzo, whose previous 1/48” (2008) was listed in Cahiers du Cinéma’s top 10 most subversive films of all time. Somewhere between a book on a film, and a film of a book, Lorenzo’s work is an exact re-typing of Jack Kerouac’s On the Road, made by threading a continuous roll of 35mm negative (like Kerouac’s original scroll) through a Olivetti typewriter.

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Bending and reverse bending are the dominant material deformations in roll forming, and hence property data derived from bend tests could be more relevant than tensile test data for numerical simulation of a roll forming process. Recent investigations have shown that residual stresses change the material behavior close to the yield in a bending test. So, residual stresses introduced during prior steel processing operations may affect the roll forming process, and therefore they need to be included in roll forming simulations to achieve improved model accuracy. Measuring the residual stress profile experimentally is time consuming and has limited accuracy while analytical models that are available require detailed information about the pre-processing conditions that is generally not available for roll forming materials. The main goal of this study is to develop an inverse routine that determines a residual stress profile through the material thickness based on experimental pure bend test data. A numerical model of the skin passing (temper rolling) process is performed to introduce a residual stress profile in DP780 steel sheet. The skin passed strips are used in a pure bending simulation to record moment-curvature data and this data is then applied in an inverse analysis to predict the residual stress profile in the material. Comparison of the residual stress profile predicted by the inverse routine with that calculated by finite element analysis (FEA) indicates an inverse approach combined with pure bend test may present an alternative to predict residual stresses in sheet metals.

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Introduction: A systematic approach to managing the training of elite athletes is supported by accurate training load measurement. However, quantifying the training of elite Australian rowers is complex due to unique challenges: 1) the multi-centre, multi-state structure of the national program; 2) the variety of training undertaken, incorporating rowing-specific and non-specific modalities, with continuous and interval efforts that span the full intensity spectrum; and 3) the limitations of existing quantification methods for capturing total training loads undertaken from varied training. These challenges highlighted a need to create a consistent, location-independent framework for prescribing training in elite rowing, with a capacity to account for varied training. Methods: An in-house proprietary measure (the T2minute method) was developed at the National Rowing Centre of Excellence (NRCE), as a collaborative project between sport scientists and national squad coaches. The design phase was informed by assessments of the existing training measures, and built upon standardised intensity zones established at the Australian Institute of Sport. A common measurement unit was chosen: one T2minute equates to one minute of on-water single scull rowing at T2 intensity (∼60–72% VO2max). Each intensity zone was assigned a weighting factor according to the curvilinear relationship between power output, intensity, and blood lactate response. Each training mode was assigned a weighting factor based on whether coaches perceived it to be “harder” or “easier” than onwater rowing. With coaches’ feedback, the method was refined over a period of five months. The T2minute method was implemented as the core framework for prescribing training for elite Australian rowers throughout the 2009–2012 Olympic cycle. Results: The implementation of the T2minute method successfully established consistency with training prescription and monitoring practices within the NRCE high performance program. The national roll out this method has influenced rowing training methodology at elite and sub-elite levels in Australia. Since implementation, the method has undergone scientific validation. Further research is underway, utilising the method to explore complex relationships between rowers’ training and performance outcomes. Conclusion: The T2minute method is a novel approach that allows rowing coaches and sport scientists to utilise one consistent system to quantify load from varied training. Its implementation represents a considerable achievement in establishing a common framework for managing the training process within a complex organisational structure. This collaborative approach used to develop the T2minute method provides unique insight into the important considerations and practical challenges of applying training science to enhance elite sport performance.

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The aim of this study was to develop reference ranges for total and appendicular lean mass measured using dual-energy X-ray absorptiometry (DXA) from a randomly selected population-based sample of men and women residing in southeastern Australia. Men (n = 1,411) and women (n = 960) aged 20–93 years, enrolled in the Geelong Osteoporosis Study, were randomly selected from the Barwon Statistical Division using the electoral roll as a sampling frame in 2001–2006 (67 % participation) and 1993–1997 (77 % participation), respectively. Using DXA (Lunar DPX-L or Prodigy Pro) at baseline for men and at the 10-year follow-up for women (2004–2008), total and appendicular lean mass were measured. Means and standard deviations for each lean mass measure (absolute and relative to height squared) were generated for each age decade, and cutpoints equivalent to T scores of −2.0 and −1.0 were calculated using data from young adult men and women aged 20–39 years. Young adult reference data were derived from 374 men and 308 women. Cutpoints for relative appendicular lean mass equal to T scores of −2.0 and −1.0 were 6.94 and 7.87 kg/m2 for men and 5.30 and 6.07 kg/m2 for women. The proportions of men and women aged ≥80 years with a T score less than −2.0 were 16.0 and 6.2 %, respectively. These reference ranges may be useful for identifying lean mass deficits in the assessment of muscle wasting and sarcopenia.

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Bending in a V-die has been well covered in the literature and the results have been used to indicate the out-come of bending in cold roll forming. However, recent work comparing springback between roll forming and single step bending has found lower springback in the roll forming process compared to single step bending. Roll forming is an incremental bending process and in this study a V-section was formed in a single operation and in multiple steps and the springback determined. The springback in V-die forming was significantly reduced by incremental forming. This suggests that the lower springback determined in roll forming compared to single step bending may be related to the incremental nature of the roll forming process.

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Objectives: The aim was to examine interrater reliability of the object control subtest from the Test of Gross Motor Development-2 by live observation in a school field setting. Design:: Reliability Study - cross sectional. Methods: Raters were rated on their ability to agree on (1) the raw total for the six object control skills; (2) each skill performance and (3) the skill components. Agreement for the object control subtest and the individual skills was assessed by an intraclass correlation (ICC) and a kappa statistic assessed for skill component agreement. Results: A total of 37 children (65% girls) aged 4-8 years (M= 6.2, SD=0.8) were assessed in six skills by two raters; equating to 222 skill tests. Interrater reliability was excellent for the object control subset (ICC= 0.93), and for individual skills, highest for the dribble (ICC= 0.94) followed by strike (ICC= 0.85), overhand throw (ICC= 0.84), underhand roll (ICC= 0.82), kick (ICC= 0.80) and the catch (ICC= 0.71). The strike and the throw had more components with less agreement. Conclusions: Even though the overall subtest score and individual skill agreement was good, some skill components had lower agreement, suggesting these may be more problematic to assess. This may mean some skill components need to be specified differently in order to improve component reliability.

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This paper explores from a phenomenological perspective the work of Australian Experimental Animator Neil Taylor (1945-), works situated between animation, performance and sculpture. Taylor’s animated scribbling repetitively and automatically inscribe the surfaces of flipbooks or note pads (Short Lives (1980-90)) and cash register rolls (Roll Film 1990 and Copy Copy 1998) often enhanced by hand-made ‘machines’ designed to facilitate and shape this idiosyncratic activity. Taylor’s work is informed by his successful wire-based sculptural practice and his 20 years experience of teaching animation to tertiary students and 8 years previously in the Australian Technical School system (a system that has since been dismantled but for which these animations remain as an aesthetic trace). His work can be generally situated inside an avant-garde project ‘that continues to explore the physical properties of film and the nature of perceptual transactions which take place between viewer and film.’ (John Hanhardt, 1976: 44) This is performative research into the minutiae of the moving image and its ability to register body gesture. Hanhardt, John G. (1976) The Medium Viewed: The American Avant-Garde Film. A History of American Avant-Garde Cinema. New York, American federation of the Arts.