30 research outputs found

    The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

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    This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe

    A novel approach in voltage transient technique for the measurement of electron mobility and mobility-lifetime product in CdZnTe detectors

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    In this study, a new measurement method based on voltage transients in CdZnTe detectors response to low energy photon irradiations is applied to measure the electron mobility (μe) and electron mobility-lifetime product (μτ)e in a CdZnTe detector.In the proposed method, the pulse rise times are derived from low energy photon response to 59.5 keV(241Am), 88 keV(109Cd) and 122 keV(57Co) γ-rays for the irradiation of the cathode surface at each detector for different bias voltages. The electron (μτ)e product was then determined by measuring the variation in the photopeak amplitude as a function of bias voltage at a given photon energy using a pulse-height analyzer. The (μτ)e values were found to be (9.6 ± 1.4)x10−3cm2 V−1 for 1000 mm3, (8.4 ± 1.6)x10−3cm2 V−1 for 1687.5 mm3 and (7.6 ± 1.1)x10-3 cm2 V−1 for 2250 mm3 CdZnTe detectors. Those results were then compared with the literature (μτ)e values for CdZnTe detectors.The present results indicate that, the electron mobility μe and electron (μτ)e values in CdZnTe detectors can be measured easily by applying voltage transients response to low energy photons, utilizing a fast signal acquisition and data reduction and evaluation. Keywords: CdZnTe, Electron mobility, Mobility-lifetime product, Transient pulse, Rise time, Charge Carrier, Digital pulse processin

    Comparing the lifestyles and environmental perceptions of rural and urban children: a case study in Turkey

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    This study aims to compare lifestyles and environmental perceptions of urban and rural children. Ninety-two students completed a questionnaire and were given two means (drawing or wring) to express their thoughts regarding (1) the activity and play areas, (2) their neighborhood and (3) their city. The results showed higher levels of parental supervision and restrictions on the independent mobility of the urban children in outdoor areas. This and other differences regarding the life styles are reflected in the children's drawings of various settings. The results have applied value for planners and urban designers, and additional research is currently underway
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