251 research outputs found

    Buried Object Detection by an Inexact Newton Method Applied to Nonlinear Inverse Scattering

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    An approach to reconstruct buried objects is proposed. It is based on the integral equations of the electromagnetic inverse scattering problem, written in terms of the Green's function for half-space geometries. The full nonlinearity of the problem is exploited in order to inspect strong scatterers. After discretization of the continuous model, the resulting equations are solved in a regularization sense by means of a two-step inexact Newton algorithm. The capabilities and limitations of the method are evaluated by means of some numerical simulations

    Excavations at the Viking Barrow Cemetery at Heath Wood, Ingleby, Derbyshire

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    The cemetery at Heath Wood, Ingleby, Derbyshire, is the only known Scandinavian cremation cemetery in the British Isles. It comprises fifty-nine barrows, of which about one-third have been excavated on previous occasions, although earlier excavators concluded that some were empty cenotaph mounds. From 1998 to 2000 three barrows were examined. Our investigations have suggested that each of the barrows contained a burial, although not all contain evidence of a pyre. A full report of the 1998-2000 excavations is provided, alongside a summary of the earlier finds. The relationship of Heath Wood to the neighbouring site at Repton is examined, in order to understand its significance for the Scandinavian settlement of the Danelaw. It is concluded that Heath Wood may have been a war cemetery of the Viking Great Army of AD 873-8

    Theoretical Developments in Electromagnetic Induction Geophysics with Selected Applications in the Near Surface

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    Near-surface applied electromagnetic geophysics is experiencing an explosive period of growth with many innovative techniques and applications presently emergent and others certain to be forthcoming. An attempt is made here to bring together and describe some of the most notable advances. This is a difficult task since papers describing electromagnetic induction methods are widely dispersed throughout the scientific literature. The traditional topics discussed herein include modeling, inversion, heterogeneity, anisotropy, target recognition, logging, and airborne electromagnetics (EM). Several new or emerging techniques are introduced including landmine detection, biogeophysics, interferometry, shallow-water electromagnetics, radiomagnetotellurics, and airborne unexploded ordnance (UXO) discrimination. Representative case histories that illustrate the range of exciting new geoscience that has been enabled by the developing techniques are presented from important application areas such as hydrogeology, contamination, UXO and landmines, soils and agriculture, archeology, and hazards and climat

    Geotechnical Engineering for the Preservation of Monuments and Historic Sites III

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    The conservation of monuments and historic sites is one of the most challenging problems facing modern civilization. It involves, in inextricable patterns, factors belonging to different fields (cultural, humanistic, social, technical, economical, administrative) and the requirements of safety and use appear to be (or often are) in conflict with the respect of the integrity of the monuments. The complexity of the topic is such that a shared framework of reference is still lacking among art historians, architects, structural and geotechnical engineers. The complexity of the subject is such that a shared frame of reference is still lacking among art historians, architects, architectural and geotechnical engineers. And while there are exemplary cases of an integral approach to each building element with its static and architectural function, as a material witness to the culture and construction techniques of the original historical period, there are still examples of uncritical reliance on modern technology leading to the substitution from earlier structures to new ones, preserving only the iconic look of the original monument. Geotechnical Engineering for the Preservation of Monuments and Historic Sites III collects the contributions to the eponymous 3rd International ISSMGE TC301 Symposium (Naples, Italy, 22-24 June 2022). The papers cover a wide range of topics, which include:   - Principles of conservation, maintenance strategies, case histories - The knowledge: investigations and monitoring - Seismic risk, site effects, soil structure interaction - Effects of urban development and tunnelling on built heritage - Preservation of diffuse heritage: soil instability, subsidence, environmental damages The present volume aims at geotechnical engineers and academics involved in the preservation of monuments and historic sites worldwide

    NASA SBIR abstracts of 1991 phase 1 projects

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    The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

    Workshop on Mars Sample Return Science

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    Martian magnetic history; quarantine issues; surface modifying processes; climate and atmosphere; sampling sites and strategies; and life sciences were among the topics discussed

    Tracking population history, social structure and intergroup exchange in Neolithic to Bronze Age Europe using ancient human and virus genomes

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    Archaeogenetics has revealed two major migrations that shaped European prehistory; one starting in the 7th millennium BCE and associated with the transition to agriculture, and another with the appearence of the Corded Ware cultural complex in the early 3rd millennium BCE. However, most findings have come from studies employing a continent-wide and/or low regional density sampling approach, leaving many temporal and geographic gaps in the current European archaeogenetic record. In order to build upon previous studies, this thesis employed a high-density sampling approach to study the population structure of Neolithic to Bronze Age central Europe in finer detail. In total, genome-wide ancient DNA was analysed from 283 newly reported individuals from present-day Bohemia, Czech Republic. In doing so, new insights into population structure, genetic turnovers, and social processes were discovered and discussed. These include a genetic turnover between the Jordanow and Funnelbeaker cultural groups, a genetic turnover between Early and Late Corded Ware groups, and a genetic turnover between Bell Beaker and Únětice groups. Insights into social structure and processes revealed the likely contacts between early farming communities with hunter-gatherer groups of Eastern Europe, that the integration of pre-Corded Ware people into Corded Ware society was likely a sex-biased process, and the emergence of a strict patrilineal social system in Late Corded Ware and Bell Beaker cultural groups which broke down with the appearance of early Únětice cultural groups. Insights from a detailed investigation into an Early Bronze Age cemetery from Mikulovice revealed a genetically homogeneous group with evidence of patrilocality and families spanning up to four generations. This thesis shows the potential of more detailed, higher-resolution studies to reveal previously unknown genetic structure and social processes

    Living by the sword: the archaeology of Brisley Farm, Ashford, Kent

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    The discovery of two warrior burials, during excavations at Brisley Farm in 2001, heralded the start of a decade of research on these exceptional finds. The burials were interred about a generation apart, at c AD 10 and c AD 50 and are the latest known warrior burials from Britain, with clear national and international significance. However, these finds are just the centrepiece of investigations that have revealed widespread evidence of the development of the ancient landscape spanning some three millennia. At its height, in the Late Iron Age, Brisley Farm was the focus for an exceptional settlement that combined interrelated ritual and domestic elements and has revealed evidence of everyday life, and death, on the eve of the Roman Conquest. This volume presents the findings of ten archaeological sites investigated at Brisley Farm, Chilmington Green, Ashford, between 1998 and 2009, and at a nearby site, Christchurch CE High School, Ashford, excavated in 2003. Evidence for activity ranges from the Mesolithic through to the early post-medieval, with a focus on the development from a Bronze Age through to medieval landscape

    Geothermal Energy: Delivering on the Global Potential

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    After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology, This book draws together some of the latest developments in concepts and technology that are enabling the growing realisation of the global potential of geothermal energy in all its manifestations.After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology
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