33 research outputs found
Gastrointestinal Parasites of the Northern River Otter, Lontra canadensis (Carnivora: Mustelidae), from Arkansas
Re-casting experience and risk along rocky coasts: A relational analysis using qualitative GIS
The information, practices and views in this article are those of the author(s) and do not necessarily reflect the opinion of the Royal Geographical Society (with IBG). © 2018 Royal Geographical Society (with the Institute of British Geographers). This study invites readers to experience risk on Australiaâs hazardous rocky coasts with the rock fishing community. In the paper, we offer an understanding of risk that is relational, a process that emerges within humanâenvironment interactions in a dynamic coastal space that is constantly changing. Exploring the in situ and ongoing sensory attunement of the fishers, we contend, expands upon the quantitative understandings that tend to be deployed by risk managers, offering an innovative approach to conceptualising risk. In identifying how fishers perceive and experience a rocky coastal location in Sydney, Australia, we track rock fishersâ movements using global positioning systems (GPS), undertake participant observation, and draw on video footage, semi-structured interviews and participatory sketch maps. In doing so, fishersâ perceptions of socio-environmental stimuli were spatially represented in a GIS, with sketch mapping being the proxy and/or the window into perceptionâenvironment relations that produce risk. We contend that the findings show that experienced fishers are more capable of anticipating and reacting to hazardous situations âsafelyâ because they are more attuned to how changing coastal conditions affect risk. This study draws attention to the spatial and temporal phenomena that drive risk perceptions as well as the implications for future perception-oriented research that adopt a relational understanding
Revisiting the 'Missing Middle' in English Sub-National Governance
In the light of the new Coalition Governmentâs proposed ârescalingâ of sub-national governance away from the regional level, it is an opportune time to re-consider the strength and weaknesses of the city or sub-regional approach to economic development and to search, once more, for the âmissing middleâ in English Governance. In this context, the article initially assesses the case for city or sub regions as tiers of economic governance, before examining the lessons to be learnt from the experiences of the existing city regions in the North East of England. It argues that while contemporary plans to develop Local Enterprise Partnerships (LEPs) can be usefully considered within the context of the emerging city regional developments under the previous Labour Governments, a number of important challenges remain, particularly in relation to ensuring accountable structures of governance, a range of appropriate functions, adequate funding, and comprehensive coverage across a variety of sub-regional contexts. While the proposals of the new Government create the necessary âspaceâ to develop sub-regional bodies and offer genuine opportunities for both city and county LEPs, the scale of the sub-regional challenge should not be underestimated, particularly given the context of economic recession and major reductions in the public sector
Correlation between processing parameters and mechanical properties as a function of substrate polarisation and depth in a nitrided 316 L stainless steel using nanoindentation and scanning force microscopy
The effects of substrate polarisation in a nitrided 316L stainless steel have been investigated in an attempt to accurately correlate processing parameters with surface mechanical properties. Nanoindentation allows the Vickers hardness to be measured at precise depths, meaning that the variation in properties with nitriding depth can be evaluated and correlated with the process parameters. By combining such measurements with surface imaging techniques (scanning force microscopy and scanning electron microscopy) and electron probe micro-analysis, it is possible to explain both the mechanical property and microstructural variations of such layers, having been produced in a low pressure arc plasma discharge at 680 K with a mixed Ar-N2 gas. In this study the nanoindentation technique is presented as a new and valid method for the characterisation of nitrided layers, shown by hardness measurements on four nitrided layers produced with different substrate polarisation potentials. The net advantages of such an approach over conventional methods (e.g. microhardness testing) and the possibility of analysing microstructural phases previously not well detected by X-ray diffraction, make nanoindentation an attractive tool for a more complete understanding of the nitriding process
Use of Gold Nanoparticles To Enhance Capillary Electrophoresis
We describe here the use of gold nanoparticles to manipulate the selectivity between solutes in capillary electrophoresis. Two different gold-based nanoparticles were added to the run buffer. In one case, the nanoparticles were stabilized with citrate ions, but in another study, the gold nanoparticles were capped with mercaptopropionate ions (thiol-stablized). Citrate-stabilized gold nanoparticles were used in conjunction with capillaries treated with poly(diallyldimethylammonium chloride) (PDADMAC). The positively charged PDADMAC layer on the capillary walls adsorbs the negatively charged gold nanoparticles. The model solutes that were used to study the effect of the presence of the citrate-stabilized gold nanoparticles are structural isomers of aromatic acids and bases. The presence of the PDADMAC layer and the PDADMAC plus the gold nanoparticles changes both the electroosmotic mobility and the observed mobility of the solutes. These changes in the mobilities influence the observed selectivities and the separations of the system. Thiol-stabilized gold nanoparticles were used without PDADMAC in the capillary. The model solutes studied in this part are various aromatic amines. In this case as well, the presence of the gold nanoparticles modifies the electroosmotic mobility and the observed mobility of the solutes. These changes in the mobilities are manifested in selectivity alterations. The largest change in the selectivities occurs at low concentrations of the gold nanoparticles in the run buffer. The presence of nanoparticles improves the precision of the analysis and increases the separation efficiency. Nanodispersions have attracted extensive attention in various fields of physics, biology, and chemistry. [1][2][3][4][5] Physicists and chemists are intrigued by the gradual transition of the nanomaterial properties from molecule-like to those of solid-state properties by a change of a single variable, the particle size. This property has practical and future applications for nonlinear optics and electronics. The large surface area of nanomaterials intrigues chemical engineers and catalysis scientists. Surprisingly, very little research has been devoted to the application of nanoparticles for chemical separation. In this work, we demonstrate the utility and versatility of organically modified gold nanoparticles in capillary electrophoresis (CE) separations. The nanoparticles serve as large surface area platforms for organofunctional groups that interact with the capillary surface, the analytes, or both. Thus, the apparent mobilities of target analytes, as well as the electroosmotic flow, can be altered leading to enhanced selectivities. Separation of various benzene derivatives demonstrates these capabilities. Metallic nanodispersions can be prepared in aqueous and organic solvents using diverse procedures. 1,2,6-9 Nanodispersions can be stabilized in organic solvents by the solvent itself, 10 by the addition of long chain surfactants, 11,12 or by specific ligands. 13 Stabilization of metal nanodispersions in aqueous solutions is somewhat more complicated. Several successful stabilization methods are available that are based on capping of the metal nanoparticles (e.g., citrate, 6 3-mercaptopropionate, 1