906 resultados para Rolling (Metal-work)
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Pt/SnO2 nanowires/SiC based metal-oxidesemiconductor (MOS) devices were fabricated and tested for their gas sensitivity towards hydrogen. Tin oxide (SnO2) nanowires were grown on SiC substrates by the vapour liquid solid growth process. The material properties of the SnO2 nanowires such as its formation and dimensions were analyzed using scanning electron microscopy (SEM). The currentvoltage (I-V) characteristics at different hydrogen concentrations are presented. The effective change in the barrier height for 0.06 and 1% hydrogen were found to be 20.78 and 131.59 meV, respectively. A voltage shift of 310 mV at 530°C for 1% hydrogen was measured.
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Ian Hunter's early work on the history of literature education and the emergence of English as school subject issued a bold challenge to traditional accounts that have in the main focused on English either as knowledge of a particular field or as ideology. The alternative proposal put forward by Hunter and supported by detailed historical analysis is that English exists as a series of historically contingent techniques and practices for shaping the self-managing capacities of children. The challenge for the field is to advance this historical work and to examine possible implications for English teaching.
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Engagement is believed to be critical to a successful first year experience. This paper examines a range of strategies introduced into a first year Social Work and Human Services unit at Queensland University of Technology. The focus of these strategies was to enhance student engagement through building connections with peers, lecturers and the Social Work and Human Services professions. It is argued in this paper that students are more likely to continue with their studies if they are supported in building an emerging identity as both a university student and as a Social Work or Human Services practitioner. A range of strategies was introduced, including restructuring the unit to include an early intensive teaching block; inviting current practitioners to speak with students about the realities of practice; and embedding an academic skills component into the unit. Feedback from students highlighted the success of these strategies in developing their academic skills, building connections and embedding a sense of fit with the profession.
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This article reports on the design and implementation of a computer-aided sheet nesting system (CASNS) for the nesting of two-dimensional irregular-shaped sheet-metal blanks on a given sheet stock or coil stock. The system is designed by considering several constraints of sheet-metal stamping operations, such as bridge width and grain orientation, and design requirements such as maximizing the strength of the part hen subsequent bending is involved, minimization of scrap, and economic justification for'a single or multiple station operation. Through many practical case studies, the system proves its efficiency, effectiveness and usefulness.
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This article reports on the design and implementation of a Computer-Aided Die Design System (CADDS) for sheet-metal blanks. The system is designed by considering several factors, such as the complexity of blank geometry, reduction in scrap material, production requirements, availability of press equipment and standard parts, punch profile complexity, and tool elements manufacturing method. The interaction among these parameters and how they affect designers' decision patterns is described. The system is implemented by interfacing AutoCAD with the higher level languages FORTRAN 77 and AutoLISP. A database of standard die elements is created by parametric programming, which is an enhanced feature of AutoCAD. The greatest advantage achieved by the system is the rapid generation of the most efficient strip and die layouts, including information about the tool configuration.
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Introduction: Participants may respond to phases of a workplace walking program at different rates. This study evaluated the factors that contribute to the number of steps through phases of the program. The intervention was automated through a web-based program designed to increase workday walking. Methods: The study reviewed independent variable influences throughout phases I–III. A convenience sample of university workers (n=56; 43.6±1.7 years; BMI 27.44±.2.15 kg/m2; 48 female) were recruited at worksites in Australia. These workers were given a pedometer (Yamax SW 200) and access to the website program. For analyses, step counts entered by workers into the website were downloaded and mean workday steps were compared using a seemingly unrelated regression. This model was employed to capture the contemporaneous correlation within individuals in the study across observed time periods. Results: The model predicts that the 36 subjects with complete information took an average 7460 steps in the baseline two week period. After phase I, statistically significance increases in steps (from baseline) were explained by age, working status (full or part time), occupation (academic or professional), and self reported public transport (PT) use (marginally significant). Full time workers walked more than part time workers by about 440 steps, professionals walked about 300 steps more than academics, and PT users walked about 400 steps more than non-PT users. The ability to differentiate steps after two weeks among participants suggests a differential affect of the program after only two weeks. On average participants increased steps from week two to four by about 525 steps, but regular auto users had nearly 750 steps less than non-auto users at week four. The effect of age was diminished in the 4th week of observation and accounted for 34 steps per year of age. In phase III, discriminating between participants became more difficult, with only age effects differentiating their increase over baseline. The marginal effect of age by phase III compared to phase I, increased from 36 to 50, suggesting a 14 step per year increase from the 2nd to 6th week. Discussion: The findings suggest that participants responded to the program at different rates, with uniformity of effect achieved by the 6th week. Participants increased steps, however a tapering off occurred over time. Age played the most consistent role in predicting steps over the program. PT use was associated with increased step counts, while Auto use was associated with decreased step counts.
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Video presented as part of Smart Services CRC Participants conferences. This video shows an example of the latest version of our middleware linking the YAWL workflow engine to Open Simulator. We have created a simple example of an accident victim being brought into a Hospital to be processed. The preliminary interface to the YAWL accident treatment workflow is shown as a worklist on the left of the image. The tasks are presented to the avatar via this interface, in a similar manner as done in web based workflow systems. Objects in the simulator are instrumented with a knowledge base, that enables the validation of actions within the world, to make sure that tasks are carried out correctly.
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As universities worldwide begin to appreciate the value of authentic learning experiences, so they struggle with methods of assessing the outcomes from such experiences. This chapter describes the application of an assessment matrix developed by Queensland University of Technology (QUT) in Australia, to the assessment requirements and practices relating to work integrated learning at the University of Surrey in the UK. Despite the very different institutional contexts and independent way in which the assessment regimes have developed, it was found that the values and outcomes being assessed and the methods used to assess them were similar. The most important feature of assessing work integrated learning experiences is fitness for purpose; hence the learning objectives and assessment of outcomes for a WIL experience must be explicitly aligned to this objective.
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The pegmatite mineral qingheiite Na2(Mn2+,Mg,Fe2+)2(Al,Fe3+)(PO4)3 has been studied by a combination of SEM and EMP, Raman and infrared spectroscopy. The studied sample was collected from the Santa Ana pegmatite, Argentina. The mineral occurs as a primary mineral in lithium bearing pegmatite, in association with beausite and lithiophilite. The Raman spectrum is characterized by a very sharp intense Raman band at 980 cm�1 assigned to the PO3�4 symmetric stretching mode. Multiple Raman bands are observed in the PO3�4 antisymmetric stretching region, providing evidence for the existence of more than one phosphate unit in the structure of qingheiite and evidence for the reduction in symmetry of the phosphate units. This concept is affirmed by the number of bands in the m4 and m2 bending regions. No intensity was observed in the OH stretching region in the Raman spectrum but significant intensity is found in the infrared spectrum. Infrared bands are observed at 2917, 3195, 3414 and 3498 cm�1 are assigned to water stretching vibrations. It is suggested that some water is coordinating the metal cations in the structure of qingheiite.
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There has been much discussion and controversy in the media recently regarding metal toxicity following large head metal on metal (MoM) total hip replacement (THR). Patients have been reported as having hugely elevated levels of metal ions with, at times, devastating systemic, neurolgical and/or orthopaedic sequelae. However, no direct correlation between metal ion level and severity of metallosis has yet been defined. Normative levels of metal ions in well functioning, non Cobalt-Chrome hips have also not been defined to date. The Exeter total hip replacement contains no Cobalt-Chrome (Co-Cr) as it is made entirely from stainless steel. However, small levels of these metals may be present in the modular head of the prosthesis, and their effect on metal ion levels in the well functioning patient has not been investigated. We proposed to define the “normal” levels of metal ions detected by blood test in 20 well functioning patients at a minimum 1 year post primary Exeter total hip replacement, where the patient had had only one joint replaced. Presently, accepted normal levels of blood Chromium are 10–100 nmol/L and plasma Cobalt are 0–20 nmol/L. The UK Modern Humanities Research Association (MHRA) has suggested that levels of either Cobalt or Chromium above 7 ppb (equivalent to 135 nmol/L for Chromium and 120 nmol/L for Cobalt) may be significant. Below this level it is indicated that significant soft tissue reaction and tissue damage is less likely and the risk of implant failure is reduced. Hips were a mixture of cemented and hybrid procedures performed by two experienced orthopaedic consultants. Seventy percent were female, with a mixture of head sizes used. In our cohort, there were no cases where the blood Chromium levels were above the normal range, and in more than 70% of cases, levels were below recordable levels. There were also no cases of elevated plasma Cobalt levels, and in 35% of cases, levels were negligible. We conclude that the implantation with an Exeter total hip replacement does not lead to elevation of blood metal ion levels.
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The deposition of small metal clusters (Cu, Au and Al) on f.c.c. metals (Cu, Au and Ni) has been studied by molecular dynamics simulation using Finnis–Sinclair (FS) potential. The impact energy varied from 0.01 to 10 eV/atom. First, the deposition of single cluster was simulated. We observed that, even at much lower energy, a small cluster with (Ih) icosahedral symmetry was reconstructed to match the substrate structure (f.c.c.) after deposition. Next, clusters were modeled to drop, one after the other, on the surface. The nanostructure was found by soft landing of Au clusters on Cu with increasing coverage, where interfacial energy dominates. While at relatively higher deposition energy (a few eV), the ordered f.c.c.-like structure was observed in the first adlayer of the film formed by Al clusters depositing on Ni substrate. This characteristic is mainly attributive to the ballistic collision. Our results indicate that the surface morphology synthesized by cluster deposition could be controlled by experimental parameters, which will be helpful for controlled design of nanostructure.
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This presentation discusses the use of field experiences in educating social work students in culturally safe practice with Aboriginal and Torres Strait Islander peoples and communities.
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In most developing countries, the overall quality of the livelihood of labourers, work place environment and implementation of labour rights do not progress at the same rate as their industrial development. To address this situation, the ILO has initiated the concept of 'decent work' to assist regulators articulate labour-related social policy goals. Against this backdrop, this article assesses the Bangladesh Labour Law 2006 by reference to the four social principles developed by the ILO for ensuring 'decent work'. It explains the impact of the absence of these principles in this Law on the labour administration in the ready-made garment and ship-breaking industries. It finds that an appropriate legislative framework needs to be based on the principles of 'decent work' to establish a solid platform for a sound labour regulation in Bangladesh.
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Internationally, vocational education and training (VET) is challenged by increasing skills shortages in certain industries and rapidly changing skill requirements. Rigid and centralised state bureaucracies have proven inadequate to adapt to these challenges. Increasingly, partnerships between schools and industry have been established as a potential strategy to address local labour market demand and to provide school to work transition programs. Drawing on experiences in Australia, this paper reports on a case study of government-let partnerships between schools and industry. The Queensland Gateway schools initiative currently involves over 120 schools. The study aimed to understand how partnerships were constructed in this initiative. Selected partnerships were analysed in terms of the following principles of public-private partnerships – efficiency, effectiveness, sustainability, and beneficiaries. Although there are some benefits of partnership activities reported by both school and industry stakeholders, little evidence was found that the above underlying principles had been addressed to a significant extent in the Gateway school initiative. Further, these partnerships are often tenuously facilitated by individuals who have limited infrastructure or strategic support. Implications are that project stakeholders have not sufficiently accommodated theoretical perspectives on implementation and management of partnerships. Similar initiatives may be improved if stakeholders are cognisant of the underlying principles supporting successful public-private partnerships.
How does homework 'work' for young children? Children's accounts of homework in their everyday lives
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Homework is an increasing yet under-researched part of young children’s everyday lives. Framed by the international agendas of starting strong and school accountability, homework in the lives of young children has been either overlooked or considered from the perspective of adults rather than from the perspective of children themselves. This paper redresses this situation by reporting on an Australian study of 120 young children, aged four to eight years, where homework emerges as a key part of their everyday lives. Children’s own accounts of their everyday decision-making, using audio-taped conversations and concurrent paper-based timeline activities, show homework as accomplishing the institutional purposes of the school, while affording the children opportunities to demonstrate their competence in operating in an adult-generated education regime.