5,235 research outputs found

    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

    Local seed systems for beans in Malawi

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    Trends in total column ozone measurements

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    It is important to ensure the best available data are used in any determination of possible trends in total ozone in order to have the most accurate estimates of any trends and the associated uncertainties. Accordingly, the existing total ozone records were examined in considerable detail. Once the best data set has been produced, the statistical analysis must examine the data for any effects that might indicate changes in the behavior of global total ozone. The changes at any individual measuring station could be local in nature, and herein, particular attention was paid to the seasonal and latitudinal variations of total ozone, because two dimensional photochemical models indicate that any changes in total ozone would be most pronounced at high latitudes during the winter months. The conclusions derived from this detailed examination of available total ozone can be split into two categories, one concerning the quality and the other the statistical analysis of the total ozone record

    Layer-by-Layer Nanoparticle Assembly for Biomedicine: Mechanisms, Technologies, and Advancement via Acoustofluidics

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    \ua9 2024 The Authors. Published by American Chemical Society.The deposition of thin films plays a crucial role in surface engineering, tailoring structural modifications, and functionalization across diverse applications. Layer-by-layer self-assembly, a prominent thin-film deposition method, has witnessed substantial growth since its mid-20th-century inception, driven by the discovery of eligible materials and innovative assembly technologies. Of these materials, micro- and nanoscopic substrates have received far less interest than their macroscopic counterparts; however, this is changing. The catalogue of eligible materials, including nanoparticles, quantum dots, polymers, proteins, cells and liposomes, along with some well-established layer-by-layer technologies, have combined to unlock impactful applications in biomedicine, as well as other areas like food fortification, and water remediation. To access these fields, several well-established technologies have been used, including tangential flow filtration, fluidized bed, atomization, electrophoretic assembly, and dielectrophoresis. Despite the invention of these technologies, the field of particle layer-by-layer still requires further technological development to achieve a high-yield, automatable, and industrially ready process, a requirement for the diverse, reactionary field of biomedicine and high-throughput pharmaceutical industry. This review provides a background on layer-by-layer, focusing on how its constituent building blocks and bonding mechanisms enable unmatched versatility. The discussion then extends to established and recent technologies employed for coating micro- and nanoscopic matter, evaluating their drawbacks and advantages, and highlighting promising areas in microfluidic approaches, where one distinctly auspicious technology emerges, acoustofluidics. The review also explores the potential and demonstrated application of acoustofluidics in layer-by-layer technology, as well as analyzing existing acoustofluidic technologies beyond LbL coating in areas such as cell trapping, cell sorting, and multidimensional particle manipulation. Finally, the review concludes with future perspectives on layer-by-layer nanoparticle coating and the potential impact of integrating acoustofluidic methods

    Quenched QCD with O(a) improvement: I. The spectrum of light hadrons

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    We present a comprehensive study of the masses of pseudoscalar and vector mesons, as well as octet and decuplet baryons computed in O(a) improved quenched lattice QCD. Results have been obtained using the non-perturbative definition of the improvement coefficient c_sw, and also its estimate in tadpole improved perturbation theory. We investigate effects of improvement on the incidence of exceptional configurations, mass splittings and the parameter J. By combining the results obtained using non-perturbative and tadpole improvement in a simultaneous continuum extrapolation we can compare our spectral data to experiment. We confirm earlier findings by the CP-PACS Collaboration that the quenched light hadron spectrum agrees with experiment at the 10% level.Comment: 36 pages, 7 postscript figures, REVTEX; typo in Table XVIII corrected; extended discussion of finite-size effects in sections III and VII; version to appear in Phys. Rev.

    Review of harm-benefit analysis in the use of animals in research

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    This is the final version of the report. Available from the Home Office via the link in this recordReport of our review of the processes of harm-benefit analysis (HBA) carried out under the UK Animals (Scientific Procedures) Act 1986 (A(SP)A).Report of the Animals in Science Committee Harm-Benefit Analysis Sub-Group chaired by Professor Gail Davies. The Animals in Science Committee Harm-Benefit Analysis subgroup, chaired by Professor Gail Davies, has produced a review of the harm-benefit analysis (HBA). This review is an analysis of the underpinnings and implementation of the HBA which remains a crucial step in the justification of the use of animals in science. It is published in response to a ministerial commission.Animals in Science Committe

    Boreal forest fire emissions in fresh Canadian smoke plumes: C_1-C_(10) volatile organic compounds (VOCs), CO_2, CO, NO_2, NO, HCN and CH_3CN

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    Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO_2, CO, CH_4, CH_2O, NO_2, NO, HCN and CH_3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH_2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO_2, CO and CH_4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg^(−1)), followed by methanol, NO_2, HCN, ethene, α-pinene, β-pinene, ethane, benzene, propene, acetone and CH_3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr^(−1) in the form of NMVOCs, with approximately 41% of the carbon released as C_1-C_2 NMVOCs and 21% as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH_2Cl_2, (6.9 ± 8.6) × 10^(−4)gkg^(−1), was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl_3) or methyl chloroform (CH_3CCl_3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere

    Orbitally excited and hybrid mesons from the lattice

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    We discuss in general the construction of gauge-invariant non-local meson operators on the lattice. We use such operators to study the PP- and DD-wave mesons as well as hybrid mesons in quenched QCD, with quark masses near the strange quark mass. The resulting spectra are compared with experiment for the orbital excitations. For the states produced by gluonic excitations (hybrid mesons) we find evidence of mixing for non-exotic quantum numbers. We give predictions for masses of the spin-exotic hybrid mesons with $J^{PC}=1^{-+},\ 0^{+-},and, and 2^{+-}$.Comment: 31 pages, LATEX, 8 postscript figures. Reference adde
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