160 research outputs found

    Experimental Investigation of Distortional Buckling of Cold-Formed Stainless Steel Sections

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    This paper describes the experimental investigation of the distortional buckling of thin-walled stainless steel sections in compression. Austenitic 304, ferritic 430 stainless steel and ferritic-like 3Crl2 chromium weldable steel sheets were brake-pressed into simple-lipped channels and simple-lipped channels with intermediate stiffeners. A comprehensive procedure to determine the mechanical properties of stainless steel material is described. A total of 19 distortional tests failed at stresses greater than the proportionality stress, and hence were influenced by material non-linearity. Data required to assess current design guidelines in place for distortional buckling of stainless steel compression members are provided herein

    Design of Stainless Steel Sections Against Distortional Buckling

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    Current cold-formed stainless steel design codes for distortional buckling, including the Australian/New Zealand Standard AS/NZS 4673 (2001) and the North American ASCE (2002), have been based on cold-formed carbon steel codes without the support or corroboration of experimental evidence. As such, an experimental program on the distortional buckling of axially compressed, cold-formed stainless steel simple lipped channels and lipped channels with intermediate stiffeners was conducted. Results show that the effect of stainless steel material non-linearity is partially negated by the strength-enhanced corners, and this becomes evident in the design evaluation. Both the effective width and the direct strength (ASINZS 4600 1996) design approaches are considered. When the enhanced corner properties are ignored, the effective width design evaluation may become unconservative for sections with a corner area less than 10% of the gross area and become overly conservative for sections with a corner area greater than approximately 10% of the gross area. The direct strength evaluation provides reasonably conservatively strength predictions for sections with a corner area of at least 10% of the gross area, provided enhanced corners are ignored and the (actual) fixed end conditions are modeled in the elastic buckling analysis

    Internet Versus Mailed Questionnaires: A Randomized Comparison (2)

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    BACKGROUND Low response rates among surgeons can threaten the validity of surveys. Internet technologies may reduce the time, effort, and financial resources needed to conduct surveys. OBJECTIVE We investigated whether using Web-based technology could increase the response rates to an international survey. METHODS We solicited opinions from the 442 surgeon–members of the Orthopaedic Trauma Association regarding the treatment of femoral neck fractures. We developed a self-administered questionnaire after conducting a literature review, focus groups, and key informant interviews, for which we used sampling to redundancy techniques. We administered an Internet version of the questionnaire on a Web site, as well as a paper version, which looked similar to the Internet version and which had identical content. Only those in our sample could access the Web site. We alternately assigned the participants to receive the survey by mail (n=221) or an email invitation to participate on the Internet (n=221). Non-respondents in the mail arm received up to three additional copies of the survey, while non-respondents in the Internet arm received up to three additional requests, including a final mailed copy. All participants in the Internet arm had an opportunity to request an emailed Portable Document Format (PDF) version. RESULTS The Internet arm demonstrated a lower response rate (99/221, 45%) than the mail questionnaire arm (129/221, 58%) (absolute difference 13%, 95% confidence interval 4%-22%, P<0.01). CONCLUSIONS. Our Internet-based survey to surgeons resulted in a significantly lower response rate than a traditional mailed survey. Researchers should not assume that the widespread availability and potential ease of Internet-based surveys will translate into higher response rates.Department of Surgery, McMaster University, Hamilton, Ontario, Canad

    Supply driven mortgage choice

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    Variable mortgage contracts dominate the UK mortgage market (Miles, 2004). The dominance of the variable rate mortgage contracts has important consequences for the transmission mechanism of monetary policy decisions and systemic risks (Khandani et al., 2012; Fuster and Vickery, 2013). This raises an obvious concern that a mortgage market such as that in the UK, where the major proportion of mortgage debt is either at a variable or fixed for less than two years rate (Badarinza, et al., 2013; CML, 2012), is vulnerable to alterations in the interest rate regime. Theoretically, mortgage choice is determined by demand and supply factors. So far, most of the existing literature has focused on the demand side perspective, and what is limited is consideration of supply side factors in empirical investigation on mortgage choice decisions. This paper uniquely explores whether supply side factors may partially explain observed/ex-post mortgage type decisions. Empirical results detect that lenders’ profit motives and mortgage funding/pricing issues may have assisted in preferences toward variable rate contracts. Securitisation is found to positively impact upon gross mortgage lending volumes while negatively impacting upon the share of variable lending flows. This shows that an increase in securitisation not only improves liquidity in the supply of mortgage funds, but also has the potential to shift mortgage choices toward fixed mortgage debt. The policy implications may involve a number of measures, including reconsideration of the capital requirements for the fixed, as opposed to the variable rate mortgage debt, growing securitisation and optimisation of the mortgage pricing policies

    Constrained by managerialism : caring as participation in the voluntary social services

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    The data in this study show that care is a connective process, underlying and motivating participation and as a force that compels involvement in the lives of others, care is at least a micro-participative process. Care or affinity not only persisted in the face of opposition, but it was also used by workers as a counter discourse and set of practices with which to resist the erosion of worker participation and open up less autonomized practices and ways of connecting with fellow staff, clients and the communities they served. The data suggest that while managerialism and taylorised practice models may remove or reduce opportunities for worker participation, care is a theme or storyline that gave workers other ways to understand their work and why they did it, as well as ways they were prepared to resist managerial priorities and directives, including the erosion of various kinds of direct and indirect participation. The degree of resistance possible, even in the highly technocratic worksite in Australia, shows that cracks and fissures exist within managerialism

    Aboriginal young people’s perspectives and experiences of accessing sexual health services and sex education in Australia: A qualitative study

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    Aboriginal and Torres Strait Islander (Aboriginal) young people seek information and access health services for their sexual health needs. This study examined Aboriginal young people’s perspectives on sexual health services and sex education in Australia. Overall, 51 Aboriginal people aged 16–26 years were interviewed by peer researchers in Sydney, Australia in 2019–2020. The findings suggest that the internet was used to assess information quickly and confidentially, but Aboriginal young people questioned its reliability and accuracy. Family, Elders and peers were seen as sources of advice because they had real-life experience and highlighted intergenerational learning that occurs in Aboriginal communities. School-based sex education programmes had mixed reviews, with a preference for programmes delivered by external specialists providing anonymity, clear and accurate information about sex and relationships and positive approaches to sex education, including how to gain consent before sex. There was a need identified for school-based programmes to better consider the needs of Aboriginal young people, including those who identified as LGBTQI +. Aboriginal Medical Services were highly valued for providing culturally safe access to services, while sexual health clinics were valued for providing specialised confidential clinical services with low levels of judgement

    Prioritization strategies in clinical practice guidelines development: a pilot study

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    Objective: Few methodological studies address the prioritization of clinical topics for the development of Clinical Practice Guidelines (CPGs). The aim of this study was to validate a methodology for Priority Determination of Topics (PDT) of CPGs. Methods and results: Firstly, we developed an instrument for PDT with 41 criteria that were grouped under 10 domains, based on a comprehensive systematic search. Secondly, we performed a survey of stakeholders involved in CPGs development, and end users of guidelines, using the instrument. Thirdly, a pilot testing of the PDT procedure was performed in order to choose 10 guideline topics among 34 proposed projects; using a multicriteria analysis approach, we validated a mechanism that followed five stages: determination of the composition of groups, item/domain scoring, weights determination, quality of the information used to support judgments, and finally, topic selection. Participants first scored the importance of each domain, after which four different weighting procedures were calculated (including the survey results). The process of weighting was determined by correlating the data between them. We also reported the quality of evidence used for PDT. Finally, we provided a qualitative analysis of the process. The main domains used to support judgement, having higher quality scores and weightings, were feasibility, disease burden, implementation and information needs. Other important domains suc
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