166 research outputs found
Goal driven optimization of process parameters for maximum efficiency in laser bending of advanced high strength steels
Laser forming or bending is fast becoming an attractive option for the forming of advanced high strength steels (AHSS), due primarily to the reduced formability of AHSS when compared with conventional steels in traditional contact-based forming processes. An inherently iterative process, laser forming must be optimized for efficiency in order to compete with contact based forming processes; as such, a robust and accurate method of optimal process parameter prediction is required. In this paper, goal driven optimization is conducted, utilizing numerical simulations as the basis for the prediction of optimal process parameters for the laser bending of DP 1000 steel. A key consideration of the optimization process is the requirement for minimal microstructural transformation in automotive grade high strength steels such as DP 1000
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Species distribution model transferability and model grain size – finer may not always be better
Species distribution models have been used to predict the distribution of invasive species for conservation planning. Understanding spatial transferability of niche predictions is critical to promote species-habitat conservation and forecasting areas vulnerable to invasion. Grain size of predictor variables is an important factor affecting the accuracy and transferability of species distribution models. Choice of grain size is often dependent on the type of predictor variables used and the selection of predictors sometimes rely on data availability. This study employed the MAXENT species distribution model to investigate the effect of the grain size on model transferability for an invasive plant species. We modelled the distribution of Rhododendron ponticum in Wales, U.K. and tested model performance and transferability by varying grain size (50 m, 300 m, and 1 km). MAXENT-based models are sensitive to grain size and selection of variables. We found that over-reliance on the commonly used bioclimatic variables may lead to less accurate models as it often compromises the finer grain size of biophysical variables which may be more important determinants of species distribution at small spatial scales. Model accuracy is likely to increase with decreasing grain size. However, successful model transferability may require optimization of model grain size
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Palm oil, land rights and ecosystem services in Gbarpolu County, Liberia
As part of the rebuilding efforts following the long civil war, the Liberian government has renegotiated long-term contracts with international investors to exploit natural resources. Substantial areas of land have been handed out in large-scale concessions across Liberia during the last five years. While this may promote economic growth at the national level, such concessions are likely to have major environmental, social and economic impacts on local communities, who may not have been consulted on the proposed developments. This report examines the potential socio-economic and environmental impacts of a proposed large-scale oil palm concession in Bopolu District, Gbarpolu County in Liberia. The research provided an in-depth mapping of current resource use, livelihoods and ecosystems services, in addition to analysis of community consultation and perceptions of the potential impacts of the proposed development.
This case study of a palm oil concession in Liberia highlights wider policy considerations regarding large-scale land acquisitions in the global South:
• Formal mechanisms may be needed to ensure the process of Free, Prior, Informed Consent takes place effectively with affected communities and community land rights are safeguarded.
• Rigorous Environmental and Social Impact Assessments need to be conducted before operations start. Accurate mapping of customary land rights, community resources and cultural sites, livelihoods, land use, biodiversity and ecosystems services is a critical tool in this process.
• Greater clarity and awareness-raising of land tenure laws and policies is needed at all levels. Good governance and capacity-building of key institutions would help to ensure effective implementation of relevant laws and policies.
• Efforts are needed to improve basic services and infrastructure in rural communities and invest in food crop cultivation in order to enhance food security and poverty alleviation. Increasing access to inputs, equipment, training and advice is especially important if male and female farmers are no longer able to practice shifting cultivation due to the reduction/ loss of customary land and the need to farm more intensively on smaller areas of land
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The compositional and configurational heterogeneity of matrix habitats shape woodland carabid communities in wooded-agricultural landscapes
Landscape heterogeneity (the composition and configuration of matrix habitats) plays a major role in shaping species communities in wooded-agricultural landscapes. However, few studies consider the influence of different types of semi-natural and linear habitats in the matrix, despite their known ecological value for biodiversity.
Objective To investigate the importance of the composition and configuration of matrix habitats for woodland carabid communities and identify whether specific landscape features can help to maintain long-term populations in wooded-agricultural environments.
Methods Carabids were sampled from woodlands in
36 tetrads of 4 km2 across southern Britain. Landscape
heterogeneity including an innovative representation
of linear habitats was quantified for each tetrad.
Carabid community response was analysed using ordination methods combined with variation partitioning and additional response trait analyses.
Results Woodland carabid community response was trait-specific and better explained by simultaneously considering the composition and configuration of matrix habitats. Semi-natural and linear features provided significant refuge habitat and functional connectivity. Mature hedgerows were essential for slow-dispersing carabids in fragmented landscapes. Species commonly associated with heathland were correlated with inland water and woodland patches despite widespread heathland conversion to agricultural land, suggesting that species may persist for some decades when elements representative of the original habitat are retained following landscape modification.
Conclusions Semi-natural and linear habitats have
high biodiversity value. Landowners should identify
features that can provide additional resources or
functional connectivity for species relative to other
habitat types in the landscape matrix. Agri-environment
options should consider landscape heterogeneity to identify the most efficacious changes for biodiversity
Linking social perception and provision of ecosystem services in a sprawling urban landscape: a case study of Multan, Pakistan
Urban sprawl causes changes in land use and a decline in many ecosystem services. Understanding the spatial patterns of sprawl and exploration of citizens’ perception towards the sporadic urban expansion and its impacts on an ecosystem to deliver services can help to guide land use planning and the conservation of the urban ecosystem. Here, we spatially examined land use changes in Multan, Pakistan, and investigated public perception about urban sprawl and its impacts on the quality and provision of ecosystem services, using a survey instrument. The spatial analysis of the historical land cover of Multan indicated an exponential expansion of the city in the last decade. Large areas of natural vegetation and agricultural land were converted to urban settlements in the past two decades. The citizens of Multan believe that the quality and provision of ecosystem services have declined in the recent past and strongly correlate the deteriorating ecosystem services with urban sprawl. Education and income levels of the respondents are the strongest predictors of urban ecosystem health literacy. Citizens associated with laborious outdoor jobs are more sensitive to the changes in ecosystem services. We concluded that the rapidly expanding cities, especially in the tropical arid zones, need to be prioritized for an increase in vegetation cover, and economically vulnerable settlements in these cities should be emphasized in climate change mitigation campaigns
Known or potential threats from pests and diseases to prospective tree species for high value timber plantings in northern Australia
The development of a high value timber industry in northern Australia requires high-level, long-term investment. To secure such a commitment, potential investors and growers must be confident of achieving high productivity and/or high quality end product. Pests and diseases, and their effect on tree health, can be major limiting factors to tree establishment and performance. This is especially true where native or endemic species are to be grown. Timber plantings in northern Australia are likely to be at risk from a number of pests and diseases. This includes both native and exotic species already present within the region, and species not yet present but which have potential to cause problems should they arrive. Existing and potential threats are listed and the more serious problems reviewed
M-Learning Project Report
The M-Learning Project aims to identify current developments in mobile Learning in UK higher education and to assess the use and viability of learning objects delivered via mobile technologies. The project is funded by LearnHigher and undertaken by the Centre for Research in Library and Information Management (CERLIM) in the Department of Information and Communications at MMU
Influence of interlayer temperature on microstructure of 5183 aluminium alloy made by wire arc additive manufacturing
The variations in mechanical properties compared to the traditional processed (wrought) products, porosity formation, and solidification cracking are the primary concerns that may restrict industrial applications of wire arc additive manufacturing (WAAM) aluminium alloy products. Interlayer temperature is one of the crucial factors that can adversely affect the built quality and properties of material produced using WAAM. The paper aims at the possible effects of different interlayer temperatures on the geometry and microstructure of WAAM aluminium 5183 alloy as a function of varying heat input. For a given heat input, samples built using a higher interlayer temperature (100°C) showed wider and shorter layer deposits with increased penetration compared with lower interlayer temperature (50°C) samples. Microstructure of the chosen material revealed columnar grains at each layer and equiaxed grains at layer overlap position and at top layer. Interlayer temperature had a minor influence on deposit geometry and microstructure
Listening to the forest and its curators: lessons learnt from a bioacoustic smartphone application deployment
Our natural environment is complex and sensitive, and is home to a number of species on the verge of extinction. Surveying is one approach to their preservation, and can be supported by technology. This paper presents the deployment of a smartphone-based citizen science biodiversity application. Our findings from interviews with members of the biodiversity community revealed a tension between the technology and their established working practices. From our experience, we present a series of general guidelines for those designing citizen science apps
Full Citation
Moran, Stuart, Pantidi, Nadia, Rodden, Tom, Chamberlain, Alan, Griffiths, Chloe, Zilli, Davide, Merrett, Geoff V. and Rogers, Alex (2014) Listening to the forest and its curators: lessons learnt from a bioacoustic smartphone application deployment. In, ACM CHI Conference on Human Factors in Computing Systems, Toronto, CA, 26 Apr - 01 May 2014. (doi:10.1145/2556288.255702)
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