948 resultados para Reveal
Resumo:
The chemically reversible solid−solid phase transformation of a TCNQ-modified glassy carbon, indium tin oxide, or metal electrode into Co\[TCNQ]2(H2O)2 material in the presence of Co2+(aq) containing electrolytes has been induced and monitored electrochemically. Voltammetric data reveal that the TCNQ/Co\[TCNQ]2(H2O)2 interconversion process is independent of electrode material and identity of cobalt electrolyte anion. However, a marked dependence on electrolyte concentration, scan rate, and method of electrode modification (drop casting or mechanical attachment) is found. Cyclic voltammetric and double potential step chronoamperometric measurements confirm that formation of Co\[TCNQ]2(H2O)2 occurs through a rate-determining nucleation and growth process that initially involves incorporation of Co2+(aq) ions into the reduced TCNQ crystal lattice at the TCNQ|electrode|electrolyte interface. Similarly, the reverse (oxidation) process, which involves transformation of solid Co\[TCNQ]2(H2O)2 back to parent TCNQ crystals, also is controlled by nucleation−growth kinetics. The overall chemically reversible process that represents this transformation is described by the reaction: 2TCNQ0(s) + 2e- + Co2+(aq) + 2H2O \[Co(TCNQ)2(H2O)2](s). Ex situ SEM images illustrated that this reversible TCNQ/Co\[TCNQ]2(H2O)2 conversion process is accompanied by drastic size and morphology changes in the parent solid TCNQ. In addition, different sizes of needle-shaped nanorod/nanowire crystals of Co\[TCNQ]2(H2O)2 are formed depending on the method of surface immobilization.
Resumo:
Disengaged and disruptive students have been an ongoing concern for teachers for many years. Teaching is complex—complex students with complex lives and complex behaviours. How best to help these students is an ever-present question without a simple answer. Solutions need to be found. Under a positive behaviour support framework when serious, disruptive behaviour requires intervention, an individualised positive behaviour support plan (PBS plan) is developed and implemented. This multicase study (Stake, 2006) investigated how task engagement was changed for boys from year four to year seven who demonstrated serious, disruptive behaviour. The individualised PBS plan was the primary tool of behaviour intervention in each of the five cases. Using the Behaviour Support Plan Quality Evaluation Scoring Guide II (BSP-QE) (Browning- Wright, Saren & Mayer, 2003) the five PBS plans were evaluated prior to implementation and rated highly in terms of technical quality. Positive changes in student task engagement were forthcoming in all five cases. Eleven advisory visiting teachers in behaviour and eleven classroom teachers, five of whom were case-study participants, took part in this study. The classroom teachers were employed in south-east Queensland primary schools located in suburbs of economic disadvantage. All 22 participants expressed very similar perceptions of serious, disruptive behaviour emphasising the collateral impact upon the teaching and learning. Data obtained through direct observations, surveys and semi-structured interviews confirmed previous research to reveal a strong link between integrity of PBS plan implementation and student behaviour change. While classroom teachers, in the main, effectively managed the implementation of the PBS plan, social validity of goals, procedures and effects; in-class technical assistance and performance feedback were identified as three enablers to effective teacher implementation of the PBS plan. While the purpose of each PBS plan was to influence change in student behaviour, this study found that changing teacher behaviour was also instrumental in achieving positive student outcomes. Changing teacher behaviour and building capacity was facilitated by trusting, collaborative partnerships established between the Advisory Visiting Teacher-Behaviour and the classroom teacher responsible for the plan implementation. The Advisory Visiting Teacher-Behaviour provides assistance to teachers dealing with students who demonstrate ongoing, problematic behaviour. The inclusion of a teaching component as part of the implementation stage of the consultation process appeared to have considerable influence upon successful intervention. Results substantiated earlier understandings of the importance of teacher instruction highlighting the value of explicit teaching and performance feedback to the delivery of effective behaviour intervention. Conclusions drawn from this study have had a major impact upon the work of a regional team of Advisory Visiting Teachers-Behaviour. The focus of behaviour intervention has moved from being primarily upon the individual student to include a greater emphasis upon the critical role of the teacher. Procedures and processes are being re-evaluated to align with evidence-based practice and to include a collaborative consultation approach to improve teacher assistance. The framework and content of staff development and training is being created directly from the findings of this study. This practical application of the results has informed better ways of providing behaviour intervention for students demonstrating serious, disruptive behaviour. What this study has clearly shown is that when it comes to behaviour intervention, the important role of the teacher cannot be underestimated.
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Nowadays, most of the infrastructure development projects undertaken are complex in nature. Practically, public clients who do not have a good understanding of the design and management may suffer severe losses, especially for infrastructure projects. There is a need for luring the right consultant to secure client's investment in infrastructure developments. Throughout the project life cycle, consultants play vital role from the inception to completion stage of a project. A few studies in Malaysia show that infrastructure projects involving irrigation and drainage have experience problems such as poor workmanship, delay and cost overrun due to the consultant's inability or the client incompetence of recruiting consultants in time. This highlights the need of aided decision making and an efficient system to select the best consultant by using Decision Support System (DSS). On the other hand, recent trends reveal that most DSS in construction only concentrate on decision model development. These models are impractical and unused as they are complicated or difficult for laymen such as project managers to utilize. Thus, this research attempts to develop an efficient DSS for consultant selection namely consultDeSS. Driven by the motivation and research aims, this study deployed Design Science Research Methodology (DSRM) dominant with a combination of case studies at the Malaysian Department of Irrigation and Drainage (DID). Two real projects involving irrigation and drainage infrastructure were used to design, implement and evaluate the artefact. The 3-tier consultDeSS was revised after the evaluation and the design was significantly improved based on user feedback. By developing desirable tools that fit client's needs will enhance the productivity and minimize conflict within groups and organisations. The tool is more usable and efficient compared to previous studies in construction. Thus, this research has demonstrated a purposeful artefact with a practical and valid structured development approach that is applicable in a variety of problems in construction discipline.
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This paper seeks to explain the lagging productivity in Singapore’s manufacturing noted in the statements of the Economic Strategies Committee Report 2010. Two methods are employed: the Malmquist productivity to measure total factor productivity (TFP) change and Simar and Wilson’s (2007) bootstrapped truncated regression approach which first derives bias-corrected efficiency estimates before being regressed against explanatory variables to help quantify sources of inefficiencies. The findings reveal that growth in total factor productivity was attributed to efficiency change with no technical progress. Sources of efficiency were attributed to quality of worker and flexible work arrangements while the use of foreign workers lowered efficiency.
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In this paper I will explore some experience-based perspectives on information literacy research and practice. The research based understanding of what information literacy looks like to those experiencing it, is very different from the standard interpretations of information literacy as involving largely text based information searching, interpretation, evaluation and use. It also involves particular understandings of the interrelation between information and learning experiences. In following this thread of the history of information literacy I will reflect on aspects of the past, present and future of information literacy research. In each of these areas I explore experiential, especially phenomenographic approaches to information literacy and information literacy education, to reveal the unfolding understanding of people’s experience of information literacy stemming from this orientation. In addressing the past I will look in particular at the contribution of the seven faces of information literacy and some lessons learned from attending to variation in experience. I will explore important directions and insights that this history may help us to retain; including the value of understanding peoples’ information literacy experience. In addressing the present, I will introduce more recent work that adopts the key ideas of informed learning by attending to both information and learning experiences in specific contexts. I will look at some contemporary directions and key issues, including the reinvention of the phenomenographic, or relational approach to information literacy as informed learning or using information to learn. I will also provide some examples of the contribution of experiential approaches to information literacy research and practice. The evolution and development of the phenomenographic approach to information literacy, and the growing attention to a dual focus on information and learning experiences in this approach will be highlighted. Finally, in addressing the future I will return to advocacy, the recognition and pursuit of the transforming and empowering heart of information literacy; and suggest that for information literacy research, including the experiential, a turn towards the emancipatory has much to offer.
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Semiconductor nanowires (NWs) show tremendous applications in micro/nano-electro-mechanical systems. In order to fulfill their promising applications, an understanding of the mechanical properties of NWs becomes increasingly important. Based on the large-scale molecular dynamics simulations, this work investigated the tensile properties of Si NWs with different faulted stacking layers. Different faulted stacking layers were introduced around the centre of the NW by the insertion or removal of certain stacking layers, inducing twins, intrinsic stacking fault, extrinsic stacking fault, and 9R crystal structure. Stress–strain curves obtained from the tensile deformation tests reveal that the presence of faulted stacking layers has induced a considerable decrease to the yield strength while only a minor decrease to Young's modulus. The brittle fracture phenomenon is observed for all tested NWs. In particular, the formation of a monatomic chain is observed for the perfect NW, which exists for a relatively wide strain range. For the defected NW, the monatomic chain appears and lasts shorter. Additionally, all defected NWs show a fracture area near the two ends, in contrast to the perfect NW whose fracture area is adjacent to the middle. This study provides a better understanding of the mechanical properties of Si NWs with the presence of different faulted stacking layers.
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Now is an opportune moment to consider the shifts in youth and popular culture that are signalled by texts that are being read and viewed by young people. In a world seemingly compromised by climate change, political and religious upheavals and economic irresponsibility, and at a time of fundamental social change, young people are devouring fictional texts that focus on the edges of identity, the points of transition and rupture, and the assumption of new and hybrid identities. This book draws on a range of international texts to address these issues, and to examine the ways in which key popular genres in the contemporary market for young people are being re-defined and re-positioned in the light of urgent questions about the environment, identity, one's place in the world, and the fragile nature of the world itself. The key questions are: what are the shifts and changes in youth culture that are identified by the market and by what young people read and view? How do these texts negotiate the addressing of significant questions relating to the world today? Why are these texts so popular with young people? What are the most popular genres in contemporary best-sellers and films? Do these texts have a global appeal, and, if so, why? These over-arching themes and ideas are presented as a collection of inter-related essays exploring a rich variety of forms and styles from graphic novels to urban realism, from fantasy to dystopian writing, from epic narratives to television musicals. The subjects and themes discussed here reveal the quite remarkable diversity of issues that arise in youth fiction and the variety of fictional forms in which they are explored. Once seen as not as important as adult fiction, this book clearly demonstrates that youth fiction (and the popular appeal of this fiction) is complex, durable and far-reaching in its scope.
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Fossils and sediments preserved in caves are an excellent source of information for investigating impacts of past environmental changes on biodiversity. Until recently studies have relied on morphology-based palaeontological approaches, but recent advances in molecular analytical methods offer excellent potential for extracting a greater array of biological information from these sites. This study presents a thorough assessment of DNA preservation from late Pleistocene–Holocene vertebrate fossils and sediments from Kelly Hill Cave Kangaroo Island, South Australia. Using a combination of extraction techniques and sequencing technologies, ancient DNA was characterised from over 70 bones and 20 sediment samples from 15 stratigraphic layers ranging in age from >20 ka to ∼6.8 ka. A combination of primers targeting marsupial and placental mammals, reptiles and two universal plant primers were used to reveal genetic biodiversity for comparison with the mainland and with the morphological fossil record for Kelly Hill Cave. We demonstrate that Kelly Hill Cave has excellent long-term DNA preservation, back to at least 20 ka. This contrasts with the majority of Australian cave sites thus far explored for ancient DNA preservation, and highlights the great promise Kangaroo Island caves hold for yielding the hitherto-elusive DNA of extinct Australian Pleistocene species.
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Two hundred million people are displaced annually due to natural disasters with a further one billion living in inadequate conditions in urban areas. Architects have a responsibility to respond to this statistic as the effects of natural and social disasters become more visibly catastrophic when paired with population rise. The research discussed in this paper initially questions and considers how digital tools can be employed to enhance rebuilding processes, but still achieve sensitive, culturally appropriate and accepted built solutions. Secondly the paper reflects on the impact ‘real-world’ projects have on architectural education. Research aspirations encouraged an atypical ‘research by design’ methodology involving a focused case study in the recently devastated village Keigold, Ranongga, Solomon Islands. Through this qualitative approach specific place data and the accounts of those affected were documented through naturalistic and archival methods of observation and participation. Findings reveal a number of unanticipated results which would have been otherwise undetected if field research within the design and rebuilding process was not undertaken, reflecting the importance of place specific research in the design process. Ultimately, the study proves that it is critical for issues of disaster to be addressed on a local rather than global scale; decisions cannot be speculative, or solved at a distance, but require intensive collaborative work with communities to achieve optimum solutions. Architectural education and design studios would continue to benefit from focused community engagement and field research within the design process.
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This study uses the well-known social networking site, Facebook (FB), for a study of differences in perceptions on the use of technologies in the classroom around the world. This study is part of a larger project exploring telecollaboration and the use of online discussions between graduate students in an online masters program based in Australia and students in the graduate education program at a regional university in Greece. Postings reveal more similarities between the situations and perceptions of the participants from the different countries than differences. Most participants indicated that while they and their students had access in general to computers and the internet, they did not necessarily have this access in the classroom. Even when technologies were available in schools, participants identified a critical need for professional development to increase teachers’ use of ICT. These findings are relevant to educators and policy development in terms of implementation of ICT or social networking in the language classroom.
Resumo:
Objectives: Experiential knowledge of elite athletes and coaches was investigated to reveal insights on expertise acquisition in cricket fast bowling. Design: Twenty-one past or present elite cricket fast bowlers and coaches of national or international level were interviewed using an in-depth, open-ended, semi-structured approach. Methods: Participants were asked about specific factors which they believed were markers of fast bowling expertise potential. Of specific interest was the relative importance of each potential component of fast bowling expertise and how components interacted or developed over time. Results: The importance of intrinsic motivation early in development was highlighted, along with physical, psychological and technical attributes. Results supported a multiplicative and interactive complex systems model of talent development in fast bowling, in which component weightings were varied due to individual differences in potential experts. Dropout rates in potential experts were attributed to misconceived current talent identification programmes and coaching practices, early maturation and physical attributes, injuries and lack of key psychological attributes and skills. Conclusions: Data are consistent with a dynamical systems model of expertise acquisition in fast bowling, with numerous trajectories available for talent development. Further work is needed to relate experiential and theoretical knowledge on expertise in other sports.
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As researchers interested in the pursuit of high quality/high equity literacy learning outcomes, we focus on the learning experiences of five early years French students, with a special regard for those who are already considered as being at-risk of educational failure. We narrow the empirical focus to a single lesson on a mechanical concept of print, that is matching lower and upper case alphabet letters. In doing so, we examine a deeply philosophical question: Which pedagogical practices dis/enable what sorts of early years students as literacy learners? We extend Cazden’s (2006) notion of ‘weaving’ knowledge across dimensions of knowing to describe how the case study teacher ‘weaves’ visible and invisible pedagogies over the four movements of a lesson. The findings reveal different pedagogical framings (Bernstein, 1996) have potentially different cognitive and social effects that constitute different kinds of literacy knowledge and oppressive subject positions for at-risk students (Young, 1990).
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In this paper we will examine passenger actions and activities at the security screening points of Australian domestic and international airports. Our findings and analysis provide a more complete understanding of the current airport passenger security screening experience. Data in this paper is comprised of field studies conducted at two Australian airports, one domestic and one international. Video data was collected by cameras situated either side of the security screening point. A total of one hundred and ninety-six passengers were observed. Two methods of analysis are used. First, the activities of passengers are coded and analysed to reveal the common activities at domestic and international security regimes and between quiet and busy periods. Second, observation of passenger activities is used to reveal uncommon aspects. The results show that passengers do more at security screening that being passively scanned. Passengers queue, unpack the required items from their bags and from their pockets, walk through the metal-detector, re-pack and occasionally return to be re-screened. For each of these activities, passengers must understand the procedures at the security screening point and must co-ordinate various actions and objects in time and space. Through this coordination passengers are active participants in making the security checkpoint function – they are co-producers of the security screening process.
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As the Latino population in the United States grows, it will become increasingly important for undergraduate students in environmental design and related disciplines to become more culturally responsive and learn how to understand and address challenges faced by population groups, such as Latino youth. To this end, we involved environmental design undergraduate students at the University of Colorado in a service-learning class to mentor Latino youth in the creation of multimedia narratives using photovoice and digital storytelling techniques. The introduction of technology was used as a bridge between the two groups and to provide a platform for the Latino youth to reveal their community experiences. Based on focus group results, we describe the impact on the undergraduate students and provide recommendations for similar programs that can promote cultural responsiveness through the use of digital technology and prepare environmental design students to work successfully in increasingly diverse communities.
Resumo:
There are several methods for determining the proteoglycan content of cartilage in biomechanics experiments. Many of these include assay-based methods and the histochemistry or spectrophotometry protocol where quantification is biochemically determined. More recently a method based on extracting data to quantify proteoglycan content has emerged using the image processing algorithms, e.g., in ImageJ, to process histological micrographs, with advantages including time saving and low cost. However, it is unknown whether or not this image analysis method produces results that are comparable to those obtained from the biochemical methodology. This paper compares the results of a well-established chemical method to those obtained using image analysis to determine the proteoglycan content of visually normal (n=33) and their progressively degraded counterparts with the protocols. The results reveal a strong linear relationship with a regression coefficient (R2) = 0.9928, leading to the conclusion that the image analysis methodology is a viable alternative to the spectrophotometry.