525 resultados para Transport Sustainability
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Plasma nanoscience is an emerging multidisciplinary research field at the cutting edge of a large number of disciplines including but not limited to physics and chemistry of plasmas and gas discharges, materials science, surface science, nanoscience and nanotechnology, solid-state physics, space physics and astrophysics, photonics, optics, plasmonics, spintronics, quantum information, physical chemistry, biomedical sciences and related engineering subjects. This paper examines the origin, progress and future perspectives of this research field driven by the global scientific and societal challenges. The future potential of plasma nanoscience to remain a highly topical area in the global research and technological agenda in the age of fundamental-level control for a sustainable future is assessed using a framework of the five Grand Challenges for Basic Energy Sciences recently mapped by the US Department of Energy. It is concluded that the ongoing research is very relevant and is expected to substantially expand to competitively contribute to the solution of all of these Grand Challenges. The approach to controlling energy and matter at nano- and subnanoscales is based on identifying the prevailing carriers and transfer mechanisms of the energy and matter at the spatial and temporal scales that are most relevant to any particular nanofabrication process. Strong accent is made on the competitive edge of the plasma-based nanotechnology in applications related to the major socio-economic issues (energy, food, water, health and environment) that are crucial for a sustainable development of humankind. Several important emerging topics, opportunities and multidisciplinary synergies for plasma nanoscience are highlighted. The main nanosafety issues are also discussed and the environment- and human health-friendly features of plasma-based nanotech are emphasized.
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The electronic transport in both intrinsic and acid-treated single-walled carbon nanotube networks containing more than 90% semiconducting nanotubes is investigated using temperature-dependent resistance measurements. The semiconducting behavior observed in the intrinsic network is attributed to the three-dimensional electron hopping mechanism. In contrast, the chemical doping mechanism in the acid-treated network is found to be responsible for the revealed metal-like linear resistivity dependence in a broad temperature range. This effective method to control the electrical conductivity of single-walled carbon nanotube networks is promising for future nanoscale electronics, thermometry, and bolometry. © 2010 American Institute of Physics.
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A comparative study involving both experimental and numerical investigations was made to resolve a long-standing problem of understanding electron conductivity mechanism across magnetic field in low-temperature plasmas. We have calculated the plasma parameters from experimentally obtained electric field distribution, and then made a 'back' comparison with the distributions of electron energy and plasma density obtained in the experiment. This approach significantly reduces an influence of the assumption about particular phenomenology of the electron conductivity in plasma. The results of the experiment and calculations made by this technique have showed that the classical conductivity is not capable of providing realistic total current and electron energy, whereas the phenomenological anomalous Bohm mobility has demonstrated a very good agreement with the experiment. These results provide an evidence in favor of the Bohm conductivity, thus making it possible to clarify this pressing long-living question about the main driving mechanism responsible for the electron transport in low-temperature plasmas.
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The holistic urban experience we perceive when immersed in an urban context is at the heart of urban informatics. This experience encompasses all urban elements such as architecture, people, and culture. Urban informatics explores the possibilities and opportunities created by new technologies and information for enhancing the urban experience. Public transport is an essential urban experience. Everyday, urban dwellers takes public transport to commute and move between different parts of the city. Public transport serves people from all over the city and moves them through different places in the city, using different means of transportation. The nature of public transport—involving people, places, and technologies, makes it a fitting context for urban informatics interventions. There are three main aspects of the public transport experience that can readily benefit from urban informatics interventions the: pragmatic aspect, hedonistic aspect, and social aspect. From the pragmatic perspective, these interventions can help people to be more efficient and effective in taking public transport. Hedonistic-related interventions aim to bring enjoyment and fun to our mundane commute. Finally, urban informatics can strengthen the sense of community in a socially-passive context like public transport environments through adopting socially focused interventions.
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Purpose This study explores recent claims that humans exhibit a minimum cost of transport (CoTmin) for running which occurs at an intermediate speed, and assesses individual physiological, gait and training characteristics. Methods Twelve healthy participants with varying levels of fitness and running experience ran on a treadmill at six self-selected speeds in a discontinuous protocol over three sessions. Running speed (km[middle dot]hr-1), V[spacing dot above]O2 (mL[middle dot]kg-1[middle dot]km-1), CoT (kcal[middle dot]km-1), heart rate (beats[middle dot]min-1) and cadence (steps[middle dot]min-1) were continuously measured. V[spacing dot above]O2 max was measured on a fourth testing session. The occurrence of a CoTmin was investigated and its presence or absence examined with respect to fitness, gait and training characteristics. Results Five participants showed a clear CoTmin at an intermediate speed and a statistically significant (p < 0.05) quadratic CoT-speed function, while the other participants did not show such evidence. Participants were then categorized and compared with respect to the strength of evidence for a CoTmin (ClearCoTmin and NoCoTmin). The ClearCoTmin group displayed significantly higher correlation between speed and cadence; more endurance training and exercise sessions per week; than the NoCoTmin group; and a marginally non-significant but higher aerobic capacity. Some runners still showed a CoTmin at an intermediate speed even after subtraction of resting energy expenditure. Conclusion The findings confirm the existence of an optimal speed for human running, in some but not all participants. Those exhibiting a COTmin undertook a higher volume of running, ran with a cadence that was more consistently modulated with speed, and tended to be aerobically fitter. The ability to minimise the energetic cost of transport appears not to be ubiquitous feature of human running but may emerge in some individuals with extensive running experience.
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We report the study of the thermal transport management of monolayer graphene allotrope nanoribbons (size ∼20 × 4 nm2) by the modulation of their structures via molecular dynamics simulations. The thermal conductivity of graphyne (GY)-like geometries is observed to decrease monotonously with increasing number of acetylenic linkages between adjacent hexagons. Strikingly, by incorporating those GY or GY-like structures, the thermal performance of graphene can be effectively engineered. The resulting hetero-junctions possess a sharp local temperature jump at the interface, and show a much lower effective thermal conductivity due to the enhanced phonon–phonon scattering. More importantly, by controlling the percentage, type and distribution pattern of the GY or GY-like structures, the hetero-junctions are found to exhibit tunable thermal transport properties (including the effective thermal conductivity, interfacial thermal resistance and rectification). This study provides a heuristic guideline to manipulate the thermal properties of 2D carbon networks, ideal for application in thermoelectric devices with strongly suppressed thermal conductivity.
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Safety at railway level crossings (RLX) is one part of a wider picture of safety within the whole transport system. Governments, the rail industry and road organisations have used a variety of countermeasures for many years to improve RLX safety. New types of interventions are required in order to reduce the number of crashes and associated social costs at railway crossings. This paper presents the results of a large research program which aimed to assess the effectiveness of emerging Intelligent Transport Systems (ITS) interventions, both on-road and in-vehicle based, to improve the safety of car drivers at RLXs in Australia. The three most promising technologies selected from the literature review and focus groups were tested in an advanced driving simulator to provide a detailed assessment of their effects on driver behaviour. The three interventions were: (i) in-vehicle visual warning using a GPS/smartphone navigation-like system, (ii) in-vehicle audio warning and; (iii) on-road intervention known as valet system (warning lights on the road surface activated as a train approaches). The effects of these technologies on 57 participants were assessed in a systematic approach focusing on the safety of the intervention, effects on the road traffic around the crossings and driver’s acceptance of the technology. Given that the ITS interventions were likely to provide a benefit by improving the driver’s awareness of the crossing status in low visibility conditions, such conditions were investigated through curves in the track before arriving at the crossing. ITS interventions were also expected to improve driver behaviour at crossings with high traffic (blocking back issue), which were also investigated at active crossings. The key findings are: (i) interventions at passive crossings are likely to provide safety benefits; (ii) the benefits of ITS interventions on driver behaviour at active crossings are limited; (iii) the trialled ITS interventions did not show any issues in terms of driver distraction, driver acceptance or traffic delays; (iv) these interventions are easy to use, do not increase driver workload substantially; (v) participants’ intention to use the technology is high and; (vi) participants saw most value in succinct messages about approaching trains as opposed to knowing the RLX locations or the imminence of a collision with a train.
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Three initiatives with respect to water reporting in the mining sector are compared in this paper to understand the quantities that are asked for by each initiative and the guidelines of those initiatives through means of a case study. The Global Reporting Initiative (GRI) was chosen because it has achieved widespread acceptance amongst mining companies and its water-related indicators are widely reported in corporate sustainability reporting. In contrast, the Water Footprint Network, which has been an important initiative in food and agricultural industries, has had low acceptance in the mining industry. The third initiative is the Water Accounting Framework, a collaboration between The Minerals Council of Australia and the Sustainable Minerals Institute of the University of Queensland. A water account had previously been created according to the Water Accounting Framework for the case study site, an open pit coal mine in the Bowen Basin. The resulting account provided consistent data for the Global Reporting Initiative (GRI) and the Water Footprint attributable to mining but in particular, a deficiency in the GRI indicator of EN10 reuse and recycling efficiency was illustrated quantitatively. This has far-reaching significance due to the widespread use of GRI indicators in mining corporate reports.
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Sustainability is a global issue that urgently needs addressing, the most serious consequences of which concern children and future generations. This insightful research text tackles one of the most significant contemporary issues of our times – the nexus between society and environment – and how early childhood education can contribute to sustainable living. By offering international and multidisciplinary research perspectives on Early Childhood Education for Sustainability, each chapter explores and investigates the complex topic of sustainability and its relationship to early childhood education. A particular emphasis that runs through this text is young children as empowered citizens, capable of both contributing to and creating change for sustainability. The chapter authors work from, or are aligned with, a transformative education paradigm that suggests the socio-constructivist frameworks currently underpinning Early Childhood Education require reframing in light of the social transformations necessary to address humanity’s unsustainable, unjust and unhealthy living patterns. This research text is designed to be provocative and challenging; in so doing it seeks to encourage exploration of current understandings about Early Childhood Education for Sustainability, offers new dimensions for more deeply informed practice, and proposes avenues for further research in this field.
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Prosperity and environmental sustainability of cities are inextricably linked. Cities can only maintain their prosperity when environmental and social objectives are fully integrated with economic goals for the purpose of a sustainable urban development. Sustainability assessment helps policy-makers decide what actions they should and should not take in an attempt to make our cities more sustainable. There are numerous models available for measuring and evaluating urban sustainability, and they focus their analysis on a specific scale—i.e., micro, mezzo, or macro. In most cases these results are inadequate for the other scales, though generating reliable results for that particular scale. The paper introduces a multiscalar urban sustainability approach by linking two sustainability assessment models evaluate sustainability performances in micro- and mezzo-levels and generate multiscalar results for the macro-level. The paper puts this approach into test in Gold Coast, Australia, and sheds light on the development of a more accurate sustainability analysis that may be interconnected with UN-Habitat’s City Prosperity Index.
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This publication arose from the interests of the chapter authors, ‘a small group of thoughtful people’ almost all of whom participated in one or both Transnational Dialogues in Research in Early Childhood Education for Sustainability, held in Stavanger, Norway in 2010 and Brisbane, Australia in 2011 (Refer Appendix 1 for list of participants). These meetings were the first time that a critical mass of researchers from vastly different parts of the globe - Norway, Sweden, Australia and New Zealand at the inaugural meeting, with additional participants from Korea, Japan and Singapore attending the second - had come together to debate, discuss and share ideas about research and theory in the emerging field of Early Childhood Education for Sustainability (ECEfS. Some of the researchers who joined these Transnational Dialogues, had met serendipitously at earlier conferences and meetings, or corresponded via email, but many had never met face-to-face. Now a significant number are contributing authors in this text. It is a testament to these researchers’ interest in this agenda that they mostly self-funded their travel and other costs to attend the Transnational Dialogues research meetings. While most chapter authors come from the field of early childhood education, a few are more aligned with education for sustainability/environmental education, while a much smaller number are already working at the intersection of early childhood education and education for sustainability. What we share as a group is a range of perspectives and orientations to research and to the research focus at the heart of this book - young children and their actual and potential capabilities as agents of change for sustainability. As researchers, regardless of experience and perspectives, participants knew they had something extra to offer - their expertise as researchers - providing scholarly insights into the work of practitioners, applying critically reflective lenses to curricula, pedagogies and assumptions, testing of ideas and theories, and presenting a sense for where ECEfS might fit or, indeed, go beyond norms and orthodoxies. This is a text, then, for both researchers and those whose primary interests lie in daily interactions with children, families and communities.
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This chapter calls for rethinking about the rights base of early childhood education. The United Nations Convention on the Rights of the Child (UNCRC) (UNICEF1989) has been seen as an important foundation internationally for early childhood education practise. In this paper, I argue that whilst the UNCRC (1989) still serves its aspirational purpose, it is an inadequate vehicle for enacting early childhood education in the twenty-first century given the pressing challenges of sustainability. The UNCRC emerged from an individual rights perspective, and despite attempts to broaden the rights agenda towards greater child participation and engagement, these approaches offer an inadequate response to global sustainability concerns. In this chapter, I propose a five dimensional approach to rights that acknowledges the fundamental rights of children as espoused in the UNCRC and the call for agentic rights as advocated more recently by early childhood academics and practitioners. Additionally, however, discussion of collective rights, intergenerational rights and bio/ecocentic rights are forwarded, offering a expanded way to think about rights with implications for how early childhood education is practised and researched.
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Seemingly straightforward tasks often have a way of becoming complex. This was the case for our guest editorial team charged with creating Early Childhood Australia’s Best of Sustainability publication drawn from the the Australasian Journal of Early Childhood and Every Child. The complexities we encountered ranged from the varied terminologies and understandings of constructs such as education for sustainable development, environmental education and education for sustainability, through to the fundamental lack of published research on which to draw as the basis for a special issue. It is timely to explore these complexities as we face the global challenges of The Critical Decade (DCCEE, 2011) including rising sea levels, extreme weather events and food security. At a local level, the early childhood field in Australia is seeking to interpret sustainability with systemic support from the National Quality Standards(NQS) (ACECQA, 2011), while elsewhere environmental/sustainability education is encouraged through national curricula documents (for example, Singapore Ministry of Education, 2008; Swedish National Agency for Education,2010; Ministry of Education of Korea, 2011). Both The Critical Decade and the NQS provide imperatives to drive early childhood education’s engagement with sustainability. In other words, sustainability in early childhood education is no longer optional, but essential (Elliott, 2010). While some twenty years of advocacy has led to this somewhat subdued celebratory position, in this publication we do recognise the historical contexts that have led to early childhood education for sustainability (ECEfS), as we (Elliott & Davis) phrase it, becoming almost ‘mainstream not marginal’ (Davis, 1999)— a stitching together of the isolated ‘patches of green’, first identified a decade ago by Elliott (NSW EPA, 2003). Here we weave together, through these articles, a story of the evolving history of ECEfS from our particular perspective. In so doing, we also acknowledge that there are other perspectives or ‘paths’ for this field as identified by Edwards and Cutter-McKenzie in their concluding paper to this compilation.
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REASONS FOR PERFORMING STUDY An increased incidence of metabolic disease in horses has led to heightened recognition of the pathological consequences of insulin resistance (IR). Laminitis, failure of the weight-bearing digital lamellae, is an important consequence. Altered trafficking of specialised glucose transporters (GLUTs) responsible for glucose uptake, are central to the dysregulation of glucose metabolism and may play a role in laminitis pathophysiology. OBJECTIVES We hypothesised that prolonged hyperinsulinaemia alters the regulation of glucose transport in insulin-sensitive tissue and digital lamellae. Our objectives were to compare the relative protein expression of major GLUT isoforms in striated muscle and digital lamellae in healthy horses and during hyperinsulinaemia. STUDY DESIGN Randomised, controlled study. METHODS Prolonged hyperinsulinaemia and lamellar damage were induced by a prolonged-euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged-glucose infusion (p-GI) and results were compared to electrolyte-treated controls. GLUT protein expression was examined with immunoblotting. RESULTS Lamellar tissue contained more GLUT1 protein than skeletal muscle (p = 0.002) and less GLUT4 than the heart (p = 0.037). During marked hyperinsulinaemia and acute laminitis (induced by the p-EHC), GLUT1 protein expression was decreased in skeletal muscle (p = 0.029) but unchanged in the lamellae, while novel GLUTs (8; 12) were increased in the lamellae (p = 0.03), but not skeletal muscle. However, moderate hyperinsulinaemia and subclinical laminitis (induced by the p-GI) did not cause differential GLUT protein expression in the lamellae vs. control horses. CONCLUSIONS The results suggest that lamellar tissue functions independently of insulin and that IR may not be an essential component of laminitis aetiology. Marked differences in GLUT expression exist between insulin-sensitive and insulin-independent tissues during metabolic dysfunction in horses. The different expression profiles of novel GLUTs during acute and subclinical laminitis may be important to disease pathophysiology and require further investigation.
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Exhaust emissions from motor vehicles vary widely and depend on factors such as engine operating conditions, fuel, age, mileage and service history. A method has been devised to rapidly identify high-polluting vehicles as they travel on the road. The method is able to monitor emissions from a large number of vehicles in a short time and avoids the need to conduct expensive and time consuming tests on chassis dynamometers. A sample of the exhaust plume is captured as each vehicle passes a roadside monitoring station and the pollutant emission factors are calculated from the measured concentrations using carbon dioxide as a tracer. Although, similar methods have been used to monitor soot and gaseous mass emissions, to-date it has not been used to monitor particle number emissions from a large fleet of vehicles. This is particularly important as epidemiological studies have shown that particle number concentration is an important parameter in determining adverse health effects. The method was applied to measurements of particle number emissions from individual buses in the Brisbane City Council diesel fleet operating on the South-East Busway. Results indicate that the particle number emission factors are gamma- distributed, with a high proportion of the emissions being emitted by a small percentage of the buses. Although most of the high-emitters are the oldest buses in the fleet, there are clear exceptions, with some newer buses emitting as much. We attribute this to their recent service history, particularly pertaining to improper tuning of the engines. We recommend that a targeted correction program would be a highly effective measure in mitigating urban environmental pollution.