996 resultados para marine hydrokinetic devices


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Harvesting the Sea provides the first systematic treatment of the exploitation of various marine resources, such as large-scale fishing, fish salting, salt and purple-dye production, and oyster and fish-farming, in the Roman world and its role within the ancient economy. Bringing together literary, epigraphic, and legal sources, with a wealth of archaeological data collected in recent years, the book shows that these marine resources were an important feature of the Roman economy and, in scope and market-oriented production, paralleled phenomena taking place in the Roman agricultural economy on land. The book also examines the importance of technological innovations, the organization of labour, and the use of the existing legal framework in defence of economic interests against competitors for the same natural resource.

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Sediments from the Black Sea, a region historically dominated by forests and steppe landscapes, are a valuable source of detailed information on the changes in regional terrestrial and aquatic environments at decadal to millennial scales. Here we present multi-proxy environmental records (pollen, dinoflagellate cysts, Ca, Ti and oxygen isotope data) from the uppermost 305 cm of the core 22-GC3 (42°13.53′N, 36°29.55′E) collected from a water depth of 838 m in the southern part of the Black Sea in 2007. The records span the last ~ 18 kyr (all ages are given in cal kyr BP). The pollen data reveal the dominance of the Artemisia-steppe in the region, suggesting rather dry/cold environments ~ 18–14.5 kyr BP. Warming/humidity increase during melt-water pulses (~ 16.1–14.5 kyr BP), indicated by δ18O records from the 22-GC3 core sediment and from the Sofular Cave stalagmite, is expressed in more negative δ13C values from the Sofular Cave, usually interpreted as the spreading of C3 plants. The records representing the interstadial complex (~ 14.5–12.9 kyr BP) show an increase in temperature and moisture, indicated by forest development, increased primary productivity and reduced surface run-off, whereas the switch from primary terrigenous to primary authigenic Ca origin occurs ~ 500 yr later. The Younger Dryas cooling is clearly demonstrated by more negative δ13C values from the Sofular Cave and a reduction of pines. The early Holocene (11.7–8.5 kyr BP) interval reveals relatively dry conditions compared to the mostly moist and warm middle Holocene (8.5–5 kyr BP), which is characterized by the establishment of the species-rich warm mixed and temperate deciduous forests in the low elevation belt, temperate deciduous beech-hornbeam forests in the middle and cool conifer forest in upper mountain belt. The border between the early and middle Holocene in the vegetation records coincides with the opening of the Mediterranean corridor at ~ 8.3 kyr BP, as indicated by a marked change in the dinocyst assemblages and in the sediment lithology. Changes in the pollen assemblages indicate a reduction in forest cover after ~ 5 kyr BP, which was likely caused by increased anthropogenic pressure on the regional vegetation.

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Deccan intertrappean sediments in central India are generally considered as terrestrial deposits of Maastrichtian age, but the Cretaceous–Tertiary (K–T) position is still unknown. Here we report the discovery of the K–T transition, a marine incursion and environmental changes preserved within the intertrappean sediments at Jhilmili, Chhindwara District, Madhya Pradesh. Integrative biostratigraphic, sedimentologic, mineralogic and chemostratigraphic analyses reveal the basal Danian in the intertrappean sediments between lower and upper trap basalts that regionally correspond to C29r and the C29R/C29N transition, respectively. Intertrappean deposition occurred in predominantly terrestrial semi-humid to arid environments. But a short aquatic interval of fresh water ponds and lakes followed by shallow coastal marine conditions with brackish marine ostracods and early Danian zone P1a planktic foraminifera mark this interval very close to the K–T boundary. This marine incursion marks the existence of a nearby seaway, probably extending inland from the west through the Narmada and Tapti rift valleys. The Jhilmili results thus identify the K–T boundary near the end of the main phase of Deccan eruptions and indicate that a major seaway extended at least 800 km across India.

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Communities are increasingly empowered with the ability and responsibility of working with national governments to make decisions about marine resources in decentralized co-management arrangements. This transition toward decentralized management represents a changing governance landscape. This paper explores the transition to decentralisation in marine resource management systems in three East African countries. The paper draws upon expert opinion and literature from both political science and linked social-ecological systems fields to guide exploration of five key governance transition concepts in each country: (1) drivers of change; (2) institutional arrangments; (3 institutional fit; (4) actor interactions; and (5) adaptive management. Key findings are that decentralized management in the region was largely donor-driven and only partly tranferred power to local stakeholders. However, increased accountability created a degree of democracy in regards to natural resource governance that was not previously present. Additionally, increased local-level adaptive management has emerged in most systems and, to date, this experimental management has helped to change resource user's views from metaphysical to more scientific cause-and-effect attribution of changes to resource conditions.

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E-reading devices such as The Kindle have rapidly secured a significant place in a number of societies as at least one major platform for reading. To some extent they are part of the overarching move towards a fully digitised world but they have a distinctiveness in being deliberately “book-like”. Teachers generally have some suspicion towards “New Media”, especially when it challenges their established practice and nothing dominates the school more than the physical book. What may be the challenges but also the benefits of e-readers to teachers and students? What may be the particular challenges to those teachers who are, traditionally, the guardians of the book, that is the teachers of mother tongue literature? This article reports on a survey of English teachers in England to gauge their reactions to e-readers, both personally and professionally and describes their speculations about the place of e-readers in schools in the future. There is a mixed reaction with some teachers concerned about the demise of the book and the potential negative impact on reading. However, the majority welcome e-readers as a dynamic element within the reading environment with particular potential to enthuse reluctant readers and those with special or linguistic needs. They also, some grudgingly, view the fact that reading using this form of technology appeals to the “e-generation” and may succeed in making reading “cool”. This form of technology is, ironically (given that it appears to threaten traditional books) likely to be rapidly adopted in classrooms.

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The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues. However, limited work has been done examining the 3-way interaction between use of equipment, user perceptual quality and quality of service. Our work measures user perceptual quality with the quality of perception (QoP) metrics which comprises levels of informational transfer (objective) and user satisfaction (subjective) when users are presented with multimedia video clips at three different frame rates, using four different display devices. Finally, our results will show that variation in frame-rate does not impact a user’s level of information assimilation (IA), however, does impact a users’ perception of multimedia video ‘quality’.

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Although Marine Protected Areas (MPAs) are an increasingly popular policy tool for protecting marine stocks and biodiversity, they pose high costs for small-scale fisherfolk in poor countries. With Tanzania’s Mnazi Bay Ruvuma Estuary Marine Park as an example, we develop a spatial economic decision-modelling framework as a lens to examine fishers’ reactions to incentives created by an MPA. We argue that MPAs in poor countries can only contribute to sustainability if management induces changes in incentives to fish through a combination of enforcement (‘sticks’) and livelihood projects (‘carrots’). We emphasise practical implementation issues and implications for fostering marine ecosystem sustainability.

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This study examines the relationship between community based organisations and marine and coastal resource management in the Western Indian Ocean Region.

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Middle Pleistocene deposits at Hackney, north London comprise a thick unit of organic sands and silts occupying a channel near the confluence of the River Thames in south-eastern England and its left-bank tributary the River Lea. They represent a short time interval, perhaps no more than a few years, within a late Middle Pleistocene interglacial. The organic sediments are overlain by unfossiliferous sands and gravels indicating deposition on the floodplain of a braided river under cool or cold climatic conditions. The fossil plant, insect, mollusc and vertebrate remains from the interglacial deposits all indicate climatic conditions with summers warmer than the present in SE England, and winters with a similar thermal climate. The biostratigraphic evidence suggests that the time period represented by the organic unit is part of MIS 9, although the geochronological evidence for such an age is inconclusive. The palaeontological evidence strongly suggests that this temperate stage was warmer than the succeeding temperate stage MIS 7 or the Holocene, and approaching the Ipswichian (MISs 5e) in its warmth. The multidisciplinary description of the Hackney deposits is one of the first to reconstruct terrestrial conditions in Marine Isotope Stage 9 in Western Europe.

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Purpose – The aim of this paper is to present a conceptual valuation framework to allow telecare service stakeholders to assess telecare devices in the home in terms of their social, psychological and practical effects. The framework enables telecare service operators to more effectively engage with the social and psychological issues resulting from telecare technology deployment in the home and to design and develop appropriate responses as a result. Design/methodology/approach – The paper provides a contextual background for the need for sociologically pitched tools that engage with the social and cultural feelings of telecare service users before presenting the valuation framework and how it could be used. Findings – A conceptual valuation framework is presented for potential development/use. Research limitations/implications – The valuation framework has yet to be extensively tested or verified. Practical implications – The valuation framework needs to be tested and deployed by a telecare service operator but the core messages of the paper are valid and interesting for readership. Social implications – In addressing the social and cultural perspectives of telecare service stakeholders, the paper makes a link between the technologies in the home, the feelings and orientations of service users (e.g. residents, emergency services, wardens, etc.) and the telecare service operator. Originality/value – The paper is an original contribution to the field as it details how the sociological orientations of telecare technology service users should be valued and addressed by service operators. It has a value through the conceptual arguments made and through valuation framework presented.

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A parallel pipelined array of cells suitable for real-time computation of histograms is proposed. The cell architecture builds on previous work obtained via C-slow retiming techniques and can be clocked at 65 percent faster frequency than previous arrays. The new arrays can be exploited for higher throughput particularly when dual data rate sampling techniques are used to operate on single streams of data from image sensors. In this way, the new cell operates on a p-bit data bus which is more convenient for interfacing to camera sensors or to microprocessors in consumer digital cameras.

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In this study, we examine seasonal and geographical variability of marine aerosol fine-mode fraction ( fm) and its impacts on deriving the anthropogenic component of aerosol optical depth (ta) and direct radiative forcing from multispectral satellite measurements. A proxy of fm, empirically derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5 data, shows large seasonal and geographical variations that are consistent with the Goddard Chemistry Aerosol Radiation Transport (GOCART) and Global Modeling Initiative (GMI) model simulations. The so-derived seasonally and spatially varying fm is then implemented into a method of estimating ta and direct radiative forcing from the MODIS measurements. It is found that the use of a constant value for fm as in previous studies would have overestimated ta by about 20% over global ocean, with the overestimation up to �45% in some regions and seasons. The 7-year (2001–2007) global ocean average ta is 0.035, with yearly average ranging from 0.031 to 0.039. Future improvement in measurements is needed to better separate anthropogenic aerosol from natural ones and to narrow down the wide range of aerosol direct radiative forcing.