878 resultados para low carbon future
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Background: Cities play a significant role globally in creating carbon emissions but, as centers of major population, innovation and social practice, they also offer important opportunities to tackle climate change. The new challenges faced by cities in an ‘age of austerity’ and decentralist agendas present substantial challenges for coordinated multilevel governance. Results: Based on research carried out in 2011–2012, this paper examines the attitudes and responses of sustainability and climate change officers in UK cities that have prepared low carbon and climate change plans, in the context of these challenges. Using a conceptual framework that analyses ‘awareness’, ‘analysis’ and ‘actions’ (in the context of spending cuts and a new ‘decentralized’ policy agenda) this research suggests that progress on low-carbon futures for cities continues to be fragmented, with increased funding constraints, short-termism and lack of leadership acting as key barriers to progress. Conclusion: Recent UK national policies (including localism, austerity measures and new economic incentives) have not only created further uncertainties, but also scope for cities’ local innovation through policy leverage and self-governing actions.
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Countless cities are rapidly developing across the globe, pressing the need for clear urban planning and design recommendations geared towards sustainability. This article examines the intersections of Jane Jacobs’ four conditions for diversity with low-carbon and low-energy use urban systems in four cities around the world: Lyon (France), Chicago (United-States), Kolkata (India), and Singapore (Singapore). After reviewing Jacobs’ four conditions for diversity, we introduce the four cities and describe their historical development context. We then present a framework to study the cities along three dimensions: population and density, infrastructure development/use, and climate and landscape. These cities differ in many respects and their analysis is instructive for many other cities around the globe. Jacobs’ conditions are present in all of them, manifested in different ways and to varying degrees. Overall we find that the adoption of Jacobs' conditions seems to align well with concepts of low-carbon urban systems, with their focus on walkability, transit-oriented design, and more efficient land use (i.e., smaller unit sizes). Transportation sector emissions seems to demonstrate a stronger influence from the presence of Jacobs' conditions, while the link was less pronounced in the building sector. Kolkata, a low-income, developing world city, seems to possess many of Jacobs' conditions, while exhibiting low per capita emissions - maintaining both of these during its economic expansion will take careful consideration. Greenhouse gas mitigation, however, is inherently an in situ problem and the first task must therefore be to gain local knowledge of an area before developing strategies to lower its carbon footprint.
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Over the last decade we have seen the growth and development of low carbon lifestyle movement organisations, which seek to encourage members of the public to reduce their personal energy use and carbon emissions. As a first step to assess the transformational potential of such organisations, this paper examines the ways in which they frame their activities. This reveals an important challenge they face: in addressing the broader public, do they promote ‘transformative’ behaviours or do they limit themselves to encouraging ‘easy changes’ to maintain their appeal? We find evidence that many organisations within this movement avoid ‘transformative’ frames. The main reasons for this are organisers’ perceptions that transformational frames lack resonance with broader audiences, as well as wider cultural contexts that caution against behavioural intervention. The analysis draws on interviews with key actors in the low carbon lifestyle movement and combines insights from the literatures on collective action framing and lifestyle movements.
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Em uma conjuntura de expansão urbana, intensificação do consumo, mudança climática e escassez de petróleo, o tema das mobilidades assume inquestionável importância econômica, social e ambiental. O seminário internacional "Mobilidades Urbanas: Alicerces para Pesquisas Transnacionais" volta-se, por um lado, para a fomentação do debate em torno do paradigma das novas mobilidades - envolvendo mobilidade espacial e socioeconômica, entre outras - e de sua aplicabilidade no contexto brasileiro; por outro, para a capacitação de pesquisadores cujas investigações tematizam os processos de mobilidade social e espacial a partir de perspectivas comparativas e transnacionais.
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Precipitation of FeTiP is reported to occur in Ti-added IF steels containing high P during thermomechanical processing. An ultra-low carbon (ULC) Nb-added steel ingot containing a higher P content (< 0.8 wt-%) was produced via aluminothermic reduction of Fe2O3 followed by double electron beam melting (EBM). FeNbP coarse precipitates were observed in the as-cast microstructure. After soaking at 1050
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This work measured the effect of milling parameters on the surface integrity of low-carbon alloy steel. The Variance Analysis showed that only depth of cut did not influence on the workpiece roughness and the Pearson's Coefficient indicated that cutting speed was more influent than tool feed. All cutting parameters introduced tensile residual stress in workpiece surface. The chip formation mechanism depended specially on cutting speed and influenced on the roughness and residual stress of workpiece.
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The electrochemical behaviour of cold-rolled low carbon steel was studied on both active and passive potential regions in borate buffer solutions with and without the addition of sodium citrate (NaCit). In the active region anodic charges increased significantly and RCT values decreased with citrate, due to the formation of soluble complexes. In the passive potential region the film formed at +0.4 V in borate buffer solution with and without 0.010 M NaCit is probably enriched by Fe3O4 oxide, while films formed at +0.8 V are probably enriched by gamma-Fe2O3. The equivalent circuit [R-s(R(CT)Q)] fitted all experimental impedance data. (C) 2003 Elsevier Ltd. All rights reserved.
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In this work five methods of heat treatments are investigated in order to obtained convenient volume fractions of ferrite, bainite, martensite and retained austenite, starting with a low carbon steel and seeking the distinction of the phases, through optical microscopy. Specific chemical etching is improved. The results in tensile and fatigue tests were accomplished and the results were related with the microstructural parameters. The results show that the mechanical properties are closely related with the phases, grains size and the phases morphology. Copyright © 2001 Society of Automotive Engineers, Inc.
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The microstructure evolution and mechanical behavior during large strain of a 0.16%C-Mn steel has been investigated by warm torsion tests. These experiments were carried out at 685°C at equivalent strain rate of 0.1 s . The initial microstructure composed of a martensite matrix with uniformly dispersed fine cementite particles was attained by quenching and tempering. The microstructure evolution during tempering and straining was performed through interrupted tests. As the material was reheated to testing temperature, well-defined cell structure was created and subgrains within lath martensite were observed by TEM; strong recovery took place, decreasing the dislocation density. After 1 hour at the test temperature and without straining, EBSD technique showed the formation of new grains. The flow stress curves measured had a peculiar shape: rapid work hardening to a hump, followed by an extensive flow-softening region. 65% of the boundaries observed in the sample strained to ε = 1.0 were high angle grain boundaries. After straining to ε = 5.0, average ferrite grain size close to 1.5 μm was found, suggesting that dynamic recrystallization took place. Also, two sets of cementite particles were observed: large particles aligned with straining direction and smaller particles more uniformly dispersed. The fragmentation or grain subdivision that occurred during reheating and tempering time was essential for the formation of ultrafine grained microstructure.
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Cellulose nanofibrils have been evaluated as reinforcement material in polymeric matrixes due to their potential to improve the mechanical, optical, and dielectric properties of these matrixes as well as its environmental positive footprint. This work describes how banana nanocellulose can be used to replace others not so friendly materials in many applications including, biomaterials, automotive industries and packaging by proved with their mechanical properties. The process used is very mild to the environment and consists of a high pressure fibrillation followed by a chemical purification which affects the fiber morphology. Many fibers characterization processes were used including microscopy techniques and X-ray diffraction to study the structure and properties of the prepared nanofibers and composites. Microscopy studies showed that the used individualization processes lead to a unique morphology of interconnected web-like structure of the fibers. © 2012 Materials Research Society.
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This issue of the Bulletin compiles and analyses the principal measures adopted by a group of countries in Latin America to reduce carbon emissions in the transport sector. These measures are the first steps towards a low-carbon transport infrastructure.
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This FAL Bulletin discusses the challenges involved in creating equality in urban mobility and the need to reach towards a social sustainability framework, as existing policies often accentuate current inequities and inequalities in accessibility. Lack of access to mobility has wide-ranging effects across social groups, gender and particularly the urban poor.