533 resultados para Environmental carrying capacity
Resumo:
Magnesium and its alloys have shown a great potential in effective hydrogen storage due to their advantages of high volumetric/gravimetric hydrogen storage capacity and low cost. However, the use of these materials in fuel cells for automotive applications at the present time is limited by high hydrogenation temperature and sluggish sorption kinetics. This paper presents the recent results of design and development of magnesium-based nanocomposites demonstrating the catalytic effects of carbon nanotubes and transition metals on hydrogen adsorption in these materials. The results are promising for the application of magnesium materials for hydrogen storage, with significantly reduced absorption temperatures and enhanced ab/desorption kinetics. High level Density Functional Theory calculations support the analysis of the hydrogenation mechanisms by revealing the detailed atomic and molecular interactions that underpin the catalytic roles of incorporated carbon and titanium, providing clear guidance for further design and development of such materials with better hydrogen storage properties.
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This paper investigates engaging experienced birders, as volunteer citizen scientists, to analyze large recorded audio datasets gathered through environmental acoustic monitoring. Although audio data is straightforward to gather, automated analysis remains a challenging task; the existing expertise, local knowledge and motivation of the birder community can complement computational approaches and provide distinct benefits. We explored both the culture and practice of birders, and paradigms for interacting with recorded audio data. A variety of candidate design elements were tested with birders. This study contributes an understanding of how virtual interactions and practices can be developed to complement existing practices of experienced birders in the physical world. In so doing this study contributes a new approach to engagement in e-science. Whereas most citizen science projects task lay participants with discrete real world or artificial activities, sometimes using extrinsic motivators, this approach builds on existing intrinsically satisfying practices.
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Climate change is predicted to increase the frequency and severity of extreme weather events which pose significant challenges to the ability of government and other relief agencies to plan for, cope with and respond to disasters. Consequently, it is important that communities in climate sensitive and potential disaster prone areas strengthen their resilience to natural disasters in order to expeditiously recover from potential disruptions and damage caused by disasters. Building self reliance and, particularly in the immediate aftermath of a disaster, can facilitate short-term and long-term community recovery. To build stronger and more resilient communities, it is essential to have a better understanding of their current resilience capabilities by assessing areas of strength, risks and vulnerabilities so that their strengths can be enhanced and the risks and vulnerability can be appropriately addressed and mitigated through capacity building programs. While a number of conceptual frameworks currently exist to assess the resilience level of communities to disasters, they have tended to differ on their emphasis, scope and definition of what constitutes community resilience and how community resilience can be most effectively and accurately assessed. These limitations are attributed to the common approach of viewing community resilience through a mono-disciplinary lens. To overcome this, this paper proposes an integrated conceptual framework that takes into account the complex interplay of environmental, social, governance, infrastructure and economic attributes associated with community resilience. The framework can be operationalised using a range of resilience indicators to suit the nature of a disaster and the specific characteristics of a study region.
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This article reviews some of the roles environmental lawyers have played in ensuring environmental justice in Bangladesh. It leans on law and social movement theories to explicate the choice (and ensuing success) of litigation as a movement strategy in Bangladesh. The activists successfully moved the courts to read the right to a decent environment into the fundamental right to life, and this has had the far-reaching effect of constituting a basis for standing for the activists and other civil society organisations. The activists have also sought to introduce emerging international law principles into the jurisprudence of the courts. These achievements notwithstanding, the paper notes that litigation is not a sustainable way to institute enduring environmental protection in any jurisdiction and recommends the utilisation of the reputation and recognition gained through litigation to deploy or encourage more sustainable strategies.
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An estuary is formed at the mouth of a river where the tides meet a freshwater flow and it may be classified as a function of the salinity distribution and density stratification. An overview of the broad characteristics of the estuaries of South-East Queensland(Australia) is presented herein, where the small peri-urban estuaries may provide an useful indicator of potential changes which might occur in larger systems with growing urbanisation. Small peri-urban estuaries exhibits many key hydrological features and associated with ecosystem types of larger estuaries, albeit at smaller scales, often with a greater extent of urban development as a proportion of catchment area. We explore the potential for some smaller peri-urban estuaries to be used as natural laboratories to gain some much needed information on the estuarine processes, although any dynamics similarity is presently limited by critical absence of in-depth physical investigation in larger estuarine systems. The absence of the detailed turbulence and sedimentary data hampers the understanding and modelling of the estuarine zones. The interactions between the various stake holders are likely to define the vision for the future of South-East Queensland's peri-urban estuaries. This will require a solid understanding of the bio-physical function and capacity of the peri-urban estuaries. Based upon the knowledge gap, it is recommended that an adaptive trial and error approach be adopted for the future of investigation and management strategies.
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Transnational environmental crime must become a government priority, as organised criminal networks continue to exploit the environment with unprecedented profits. Such earnings come at a substantial social, economic and environmental expense for communities and their livelihoods. Indeed, organised environmental crime is identified by the United Nations as a key factor in the impoverishment, displacement and violent conflicts affecting millions of people — notably in developing societies.2 It is widely recognised that organised environmental crime syndicates, motivated by substantial financial rewards, continue to flourish and expand in disadvantaged societies with porous borders, where corruption is widespread and regulation is poor. The theft of biodiversity and the demise of animal species and habitats have resulted not only in financial loss, but also in an increase in “environmental refugees” — people dislocated and forced to migrate due to loss of livelihoods.
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In recent years a growing number of states have chosen to recognise environmental issues in their national constitutions. Some have added declarations about the value of the environment, some have sought to restrict or regulate government’s ability to take action which would potentially harm the environment, while others have proclaimed that citizens possess a right to an environment of a particular quality. A survey of these constitutional provisions reveals that the majority of reform in this area has come from developing states, including a number of states which have been designated as among the least developed countries in the world. The increasing focus on constitutional environmental rights appears to represent a shift in the attitude of developing and emerging economies, which could in turn be influential in setting the tone of the environmental rights debate more broadly, with potential to shape the future development of international law in the area. This chapter examines constitutional environmental rights in an attempt to determine whether consistent state practice can in fact be identified in this area which might form the basis of an emerging norm. It will also analyse some of the potential contributing factors to the proliferation of a constitutional right to a good environment among developing states, and the implications for the development of customary international law.
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Modern trains with different axle configurations, speeds and loads are used in railway networks. As a result, one of the most important questions of the mangers involved in bridge managements systems (BMS) is how these changes affect the structural behavior of the critical components of the railway bridges. Although researchers have conducted, many investigations on the dynamic effects of the moving loads on bridges, the influence of the changes in the speed of the train on the demand by capacity ratios of the different critical components of the bridge have not yet been properly studied. This study is important, because different components with different capacities and roles for carrying loads in the structure may be affected differently. To investigate the above phenomenon in this research, a structural model of a simply supported bridge is developed. It will be verified that the dynamic behavior of this bridge is similar to a group of railway bridges in Australia. Demand by capacity ratios of the critical components of the bridge, when it is subjected to a train load with different speeds will be calculated. The results show that the effect of increase or decrease of speed should not be underestimated. The outcome is very significant as it is contrary to what is currently expected, i.e. by reducing the speed of the train, the demand by capacity ratio of components may increase and make the bridge unsafe for carrying live load.
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Morphology changes induced in polycrystalline silver catalysts as a result of heating in either oxygen, water or oxygen-methanol atmospheres have been investigated by environmental scanning electron microscopy (ESEM), FT-Raman spectroscopy and temperature programmed desorption (TPD). The silver catalyst of interest consisted of two distinct particle types, one of which contained a significant concentration of sub-surface hydroxy species (in addition to surface adsorbed atomic oxygen). Heating the sample to 663 K resulted in the production of 'pin-holes' in the silver structure as a consequence of near-surface explosions caused by sub-surface hydroxy recombination. Furthermore, 'pin-holes' were predominantly found in the vicinity of surface defects, such as platelets and edge structures. Reaction between methanol and oxygen also resulted in the formation of 'pin-holes' in the silver surface, which were inherently associated with the catalytic process. A reaction mechanism is suggested that involves the interaction of methanol with sub-surface oxygen species to form sub-surface hydroxy groups. The sub-surface hydroxy species subsequently erupt through the silver surface to again produce 'pin-holes'.
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The techniques of environmental scanning electron microscopy (ESEM) and Raman microscopy have been used to respectively elucidate the morphological changes and nature of the adsorbed species on silver(I) oxide powder, during methanol oxidation conditions. Heating Ag2O in either water vapour or oxygen resulted firstly in the decomposition of silver(I) oxide to polycrystalline silver at 578 K followed by sintering of the particles at higher temperature. Raman spectroscopy revealed the presence of subsurface oxygen and hydroxyl species in addition to surface hydroxyl groups after interaction with water vapour. Similar species were identified following exposure to oxygen in an ambient atmosphere. This behaviour indicated that the polycrystalline silver formed from Ag2O decomposition was substantially more reactive than silver produced by electrochemical methods. The interaction of water at elevated temperatures subsequent to heating silver(I) oxide in oxygen resulted in a significantly enhanced concentration of subsurface hydroxyl species. The reaction of methanol with Ag2O at high temperatures was interesting in that an inhibition in silver grain growth was noted. Substantial structural modification of the silver(I) oxide material was induced by catalytic etching in a methanol/air mixture. In particular, "pin-hole" formation was observed to occur at temperatures in excess of 773 K, and it was also recorded that these "pin- holes" coalesced to form large-scale defects under typical industrial reaction conditions. Raman spectroscopy revealed that the working surface consisted mainly of subsurface oxygen and surface Ag=O species. The relative lack of sub-surface hydroxyl species suggested that it was the desorption of such moieties which was the cause of the "pin-hole" formation.
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Polycrystalline silver is used to catalytically oxidise methanol to formaldehyde. This paper reports the results of extensive investigations involving the use of environmental scanning electron microscopy (ESEM) to monitor structural changes in silver during simulated industrial reaction conditions. The interaction of oxygen, nitrogen, and water, either singly or in combination, with a silver catalyst at temperatures up to 973 K resulted in the appearance of a reconstructed silver surface. More spectacular was the effect an oxygen/methanol mixture had on the silver morphology. At a temperature of ca. 713 K pinholes were created in the vicinity of defects as a consequence of subsurface explosions. These holes gradually increased in size and large platelet features were created. Elevation of the catalyst temperature to 843 K facilitated the wholescale oxygen induced restructuring of the entire silver surface. Methanol reacted with subsurface oxygen to produce subsurface hydroxyl species which ultimately formed water in the subsurface layers of silver. The resultant hydrostatic pressure forced the silver surface to adopt a "hill and valley" conformation in order to minimise the surface free energy. Upon approaching typical industrial operating conditions widespread explosions occurred on the catalyst and it was also apparent that the silver surface was extremely mobile under the applied conditions. The interaction of methanol alone with silver resulted in the initial formation of pinholes primarily in the vicinity of defects, due to reaction with oxygen species incorporated in the catalyst during electrochemical synthesis. However, dramatic reduction in the hole concentration with time occurred as all the available oxygen became consumed. A remarkable correlation between formaldehyde production and hole concentration was found.
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Limited research has been conducted with at-risk populations in examining perceived environmental correlates of physical activity (PA); thus, we examined this relationship among parents with young children, a group at risk for physical inactivity. Parents (252 mothers, 206 fathers) completed a questionnaire assessing measures of perceived neighborhood environment and a 1-week follow-up of PA behavior. Mothers were more likely than fathers to perceive their neighborhood as unsafe to go for walks at night and less likely to perceive transit stops within 10–15 minutes walking distance, sidewalks on most streets, and facilities to bicycle. Adjusting for demographics, shops within easy walking distance, sidewalks on most streets, and having no more than one motor vehicle were associated with being active for both sexes. Access to transit stops and free/low cost recreational facilities were also associated with mothers’ PA. These findings suggest that environmental factors may support parents being active at recommended levels.
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Between 2008 and 2010, the SettleMEN study followed a group of 233 recently arrived men from refugee backgrounds living in urban and regional Southeast Queensland with the aim of documenting their health and settlement experiences. The study found that overall, these men bring important resources that may help them to cope better with the challenges of settlement: good levels of subjective health status, mental health and wellbeing; good family and social support; and good levels of engagement in tertiary/trade education in Australia. Over time, however, their levels of wellbeing decreased as they experienced barriers to social participation and inclusion within their host community, including: unemployment and difficulties securing good jobs (even for those with tertiary/trade qualifications obtained in Australia), financial stress, difficulties accessing housing, limited interactions with neighbours, and experiences of racism and discrimination. Importantly, although men living in the Toowoomba acknowledged some of the benefits of regional settlement, they faced greater barriers to participation in the labour market, reported lower job satisfaction, and were more likely to experience social exclusion overall. In 2012 method approach and a peer interviewer model, we were able to conduct a follow 141 (61%) of the original 233 SettleMEN participants to document the impact of the January 2011 Queensland floods on their health and settlement. This broadsheet focuses on participants’ degree of exposure to and impact of the floods, their perceptions of safety and security, and their vulnerability and adaptive capacity to extreme weather events.
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In recent events, notions of political protest, civil disobedience, extremism, and criminal action have become increasingly blurred. The London Riots, the Occupy movement, and the actions of hacking group Anonymous have all sparked heated debate about the limits of legitimate protest, and the distinction between an acceptable action and a criminal offence. Long before these events, environmental activists were challenging convention in protest actions, with several groups engaging in politically motivated law-breaking. The emergence of the term ‘eco-tage’ (the sabotage of equipment in order to protect the environment) signifies the important place environmental activists hold in challenging the traditional boundaries between illegal action and legitimate protest. Many of these groups establish their own boundaries of legitimacy, with some justifying their actions on the basis of civil disobedience or extensional self-defence. This paper examines the statements of environmental activist organisations that have engaged in politically motivated law breaking. It identifies the parameters that these groups set on their illegal actions, as well as the justifications that they provide, with a view to determining where these actions fit in the vast grey area between legal protest and violent extremism.
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Australia lacks a satisfactory, national paradigm for assessing competence and capacity in the context of testamentary, enduring power of attorney and advance care directive documents. Competence/capacity assessments are currently conducted on an ad hoc basis by legal and/or medical professionals. The reliability of the assessment process is subject to the skill set and mutual understanding of the legal and/or medical professional conducting the assessment. There is a growth in the prevalence of diseases such as dementia. Such diseases impact upon cognition which increasingly necessitates collaboration between the legal and medical professions when assessing the effect of mentally disabling conditions upon competency/capacity. Miscommunication and lack of understanding between legal and medical professionals involved could impede the development of a satisfactory paradigm. A qualitative study seeking the views of legal and medical professionals who practise in this area has been conducted. This incorporated surveys and interviews of 10 legal and 20 medical practitioners. Some of the results are discussed here. Practitioners were asked whether there is a standard approach and whether national guidelines were desirable. There was general agreement that uniform guidelines for the assessment of competence/capacity would be desirable. The interviews also canvassed views as to the state of the relationship between the professions. The results of the empirical research support the hypothesis that relations between the professions could be improved. The development of a national paradigm would promote consistency and transparency of process, helping to improve the professional relationship and maximising the principles of autonomy, participation and dignity.