1000 resultados para Terrestrial radiation


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Over the last 5–10 years, marine spatial planning (MSP) has emerged as a new management regime for national and international waters and has already attracted a substantial body of multi-disciplinary research on its goals and policy processes. This paper argues that this literature has generally lacked deeper reflexive engagement with the emerging system of governance for our seas that has meant that many of MSP’s core concepts, assumptions and institutional arrangements have not been subject rigorous intellectual debate. In an attempt to initiate such an approach, this article explores the relationship between MSP and its land-based cousin, terrestrial spatial planning (TSP). While it is recognized that there are inherent limitations to a comparison of these two systems, it is argued that the tradition of social science debate over the purpose and processes of TSP can be used as a useful stimulus for a more rigorous reflection of such issues as they relate to MSP. The article therefore explores some of the parallels between MSP and TSP and then discusses some of the key intellectual traditions that have shaped TSP and the implications these may have for future marine planning practice. The article concludes with a number of potentially useful new avenues that may form the basis of a critical research agenda for MSP.

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Geoscience methods are increasingly being utilised in criminal, environmental and humanitarian forensic investigations, and the use of such methods is supported by a growing body of experimental and theoretical research. Geoscience search techniques can complement traditional methodologies in the search for buried objects, including clandestine graves, weapons, explosives, drugs, illegal weapons, hazardous waste and vehicles. This paper details recent advances in search and detection methods, with case studies and reviews. Relevant examples are given, together with a generalised workflow for search and suggested detection technique(s) table. Forensic geoscience techniques are continuing to rapidly evolve to assist search investigators to detect hitherto difficult to locate forensic targets.

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Bioresorbable polymers have been widely investigated as materials exhibiting significant potential for successful application in the fields of tissue engineering and drug delivery. Further to the ability to control degradation, surface engineering of polymers has been highlighted as a key method central to their development. Previous work has demonstrated the ability of electron beam (e-beam) technology to control the degradation profiles and bioresorption of a number of commercially relevant bioresorbable polymers (poly-l-lactic acid (PLLA), Llactide/DL-lactide co-polymer (PLDL) and poly(lactic-co-glycolic acid (PLGA)). This work investigates the further potential of ebeam technology to impart added biofunctionality through the manipulation of polymer (PLLA) surface properties. PLLA samples were subjected to e-beam treatments in air, with varying beam energies and doses. Surface characterization was then performed using contact angle analysis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy. Results demonstrated a significant increase in surface wettability post e-beam treatment. In correlation with this, XPS data showed the introduction of oxygen-containing functional groups to the surface of PLLA. Raman spectroscopy indicated chain scission in the near surface region of PLLA (as predicted). However, e-beam effects on surface properties were not shown to be dependent on beam energy or dose. E-beam irradiation did not seem to affect the surface roughness of PLLA as a direct consequence of the treatment.

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A red-pigmented, radiation-resistant, Gram-negative, rod-shaped bacterium isolated from irradiated pork is described. The D,, values in buffer solution and on pork mince are 3.45 and 5.05 kGy respectively. The strain has been identified as a Deinobacter species

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We present a generic transfer matrix approach for the description of the interaction of atoms possessing multiple ground state and excited state sublevels with light fields. This model allows us to treat multi-level atoms as classical scatterers in light fields modified by, in principle, arbitrarily complex optical components such as mirrors, resonators, dispersive or dichroic elements, or filters. We verify our formalism for two prototypical sub-Doppler cooling mechanisms and show that it agrees with the standard literature.

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The Born-Oppenheimer approximation is the keystone for molecular dynamics simulations of radiation damage processes; however, actual materials response involves nonadiabatic energy exchange between nuclei and electrons. In this work, time dependent density functional theory is used to calculate the electronic excitations produced by energetic protons in Al. We study the influence of these electronic excitations on the interatomic forces and find that they differ substantially from the adiabatic case, revealing a nontrivial connection between electronic and nuclear stopping that is absent in the adiabatic case. These results unveil new effects in the early stages of radiation damage cascades.

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Comparison of flow duration curves for a weir draining an undrained raised peat with those generated 20 years previously reveal that more recent curves reflect to be flatter with a lower Q95/Q5 ratio. Comparison of the bog topography for the same period revealed that although marginal drainage/peat reclamation had resulted in desiccation of peat around the bog margin and more frequent intense runoff, the central part of the bog had subsided to form an enclosed basin ,resulting in the creation of newly formed lakes that gave the central part of the bog an improved capacity to store, and more slowly discharge, water. Interrogation of groundwater monitoring data revealed a net decline in groundwater levels of up to three metres in the glacial tills underlying the bog associated with deepening and expansion of a marginal drain network which penetrated the base of the peat. Comparing organic carbon levels in peat the central part of the bog over a ten year period revealed an overall increase, with changes being most marked in deeper fen peat layers. These findings suggest that the decline in groundwater levels in the peat substrate resulted in an increase in effective stress in the peat causing greater subsidence in the central part of the bog due to greater overall thickness. Study results highlight how the hydrology of apparently isolated obotrophic raised bog ecosystems may be influenced by groundwater pressures in deeper deposits, and how marginal drains may have the capacity to impact areas at significant distances.