377 research outputs found

    Barrier potential for laser written graphitic wires in diamond

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    Diamond substrates supporting an internal array of conductive graphitic wires inscribed by a femtosecond pulse laser, are useful for the detection of ionising radiation in a range of applications. Various parameters involved in the laser fabrication process were investigated in this paper to understand their impact on the electrical properties of the wires. The study revealed an effect, whereby the wires exhibit insulating behaviour until a barrier potential is overcome. When high enough voltages are applied, the wires display ohmic behaviour. The magnitude of the barrier potential, which in some cases exceeds 300 V, is shown to be strongly dependent on the laser fabrication parameters. Through process optimisation, the potential barrier may be minimised and effectively removed, coinciding with reduced values of the wire resistance

    Understanding Eurasian Convergence: Application Of Kohonen Self-Organizing Maps

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    Kohonen self-organizing maps (SOMs) are employed to examine economic and social convergence of Eurasian countries based on a set of twenty-eight socio-economic measures. A core of European Union states is identified that provides a benchmark against which convergence of post-socialist transition economies may be judged. The Central European VisegrĂĄd countries and Baltics show the greatest economic convergence to Western Europe, while other states form clusters that lag behind. Initial conditions on the social dimension can either facilitate or constrain economic convergence, as discovered in Central Europe vis-Ă -vis the Central Asian Republics. Disquiet in the convergence literature is resolved by providing an analysis of the Eurasian states over time

    Exploring break-points and interaction effects among predictors of the international digital divide

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    Cataloged from PDF version of article.The deepening of the digital divide between countries has prompted international organizations and governments to work together toward reducing the problem over the next 15 years. However, such efforts will likely succeed only if they are based on a firm grasp of the divide's underlying causes. In this paper we report the results of a comprehensive analysis of the determinants of the international digital divide. Our results confirm many findings of past research, but also extend existing knowledge in important ways. By employing Multivariate Adaptive Regression Splines (MARS), we discover non-linearities and interaction effects among the predictors. We then articulate significant policy implications based upon these findings

    The Informal Sector In Francophone Africa: Firm Size, Productivity, And Institutions

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    This book is a major step towards improving the understanding of the complex reality of informal sector firms in francophone West Africa. It innovates by concentrating on informal firms rather than informal employment (as other studies do), and identifying \u27large informal\u27 sector firms whose sales rival those of large formal-sector firms but operate in ways that are similar to small informal operators. Not only is the regulatory environment facing these two types of informal firms distinct, but policies aimed at improving their productivity need to be differentiated. This study focuses on the urban informal sector in three capital cities: Dakar (Senegal), Cotonou (Benin), and Ouagadougou (Burkina Faso). The study also breaks new ground with an eclectic methodology and primary data collection. Quantitative and qualitative firm-level data were collected involving a unique and fruitful collaboration among academic researchers, government officials, the West African economic and monetary union commission, informal and formal sector business associations, and labor unions. This volume represents the culmination of a long collaboration between the Centre de Recherches Economiques Appliquees (CREA) at the University Cheikh Anta Diop of Dakar and the World Bank

    Entrances and exits: changing perceptions of primary teaching as a career for men

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    Original article can be found at: http://www.informaworld.com/smpp/title~content=t713640830~db=all Copyright Informa / Taylor and Francis. DOI: 10.1080/03004430802352087The number of men in teaching has always been small, particularly in early childhood, but those that do come into teaching usually do so for the same reasons as women, namely enjoyment of working with children, of wanting to teach and wanting to make a difference to children's lives. However, in two separate studies, the authors have shown that on beginning teacher training in 1998, and at the point of leaving the profession in 2005, men and women tend to emphasise different concerns. This article will explore those differences and seek possible explanations for how men's views of teaching might be changing over time.Peer reviewe

    On the Timing and Nature of the Multiple Phases of Slope Instability on Eastern Rockall Bank, Northeast Atlantic

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    One of the most challenging tasks when studying large submarine landslides is determining whether the landslide was initiated as a single large event, a chain of events closely spaced in time or multiple events separated by long periods of time as all have implications in risk assessments. In this study we combine new multichannel seismic profiles and new sediment cores with bathymetric data to test whether the Rockall Bank Slide Complex, offshore western Ireland, is the composite of multiple slope collapse events and, if so, to differentiate them. We conclude that there have been at least three voluminous episodes of slope collapse separated by long periods of slope stability, a fourth, less voluminous event, and possibly a fifth more localized event. The oldest event, Slide A (200 km3), is estimated to be several hundred thousand years old. The second event, Slide B (125 km3), took place at the same location as slide A, reactivating the same scar, nearly 200 ka ago, possibly through retrogression of the scarp. Slide C (400 km3) took place 22 ka ago and occurred further north from the other slides. Slide D was a much smaller event that happened 10 ka ago, while the most recent event, albeit very small scale, took place within the last 1,000 years. This study highlights the need to thoroughly investigate large slide complexes to evaluate event sequencing, as seismic studies may hide multiple small‐scale events. This work also reveals that the same slide scarps can be reactivated and generate slides with different flow behaviors

    Birmingham’s Eastside story: making steps towards sustainability?

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    Sustainability has come to play a dominant discursive role in the UK planning system, particularly relating to urban regeneration. The purpose of this paper is to evaluate the role that sustainability plays in a major regeneration programme, known as Eastside, currently underway in Birmingham, the UK. That this ÂŁ6 billion redevelopment is now widely talked about by such key players as Birmingham City Council and the Regional Development Agency, Advantage West Midlands, as having a central sustainability agenda points to the growing importance of the ideal of sustainability in planning and regeneration agendas. In this paper, we investigate in detail how and why sustainability has become part of the planning discourse for Eastside and critically evaluate what impact, if any, this is having on public policy decision-making

    ‘Sons of athelings given to the earth’: Infant Mortality within Anglo-Saxon Mortuary Geography

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    FOR 20 OR MORE YEARS early Anglo-Saxon archaeologists have believed children are underrepresented in the cemetery evidence. They conclude that excavation misses small bones, that previous attitudes to reporting overlook the very young, or that infants and children were buried elsewhere. This is all well and good, but we must be careful of oversimplifying compound social and cultural responses to childhood and infant mortality. Previous approaches have offered methodological quandaries in the face of this under-representation. However, proportionally more infants were placed in large cemeteries and sometimes in specific zones. This trend is statistically significant and is therefore unlikely to result entirely from preservation or excavation problems. Early medieval cemeteries were part of regional mortuary geographies and provided places to stage events that promoted social cohesion across kinship systems extending over tribal territories. This paper argues that patterns in early Anglo-Saxon infant burial were the result of female mobility. Many women probably travelled locally to marry in a union which reinforced existing social networks. For an expectant mother, however, the safest place to give birth was with experience women in her maternal home. Infant identities were affected by personal and legal association with their mother’s parental kindred, so when an infant died in childbirth or months and years later, it was their mother’s identity which dictated burial location. As a result, cemeteries central to tribal identities became places to bury the sons and daughters of a regional tribal aristocracy

    Public opinion on energy crops in the landscape: considerations for the expansion of renewable energy from biomass

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    Public attitudes were assessed towards two dedicated biomass crops – Miscanthus and Short Rotation Coppice (SRC), particularly regarding their visual impacts in the landscape. Results are based on responses to photographic and computer-generated images as the crops are still relatively scarce in the landscape. A questionnaire survey indicated little public concern about potential landscape aesthetics but more concern about attendant built infrastructure. Focus group meetings and interviews indicated support for biomass end uses that bring direct benefits to local communities. Questions arise as to how well the imagery used was able to portray the true nature of these tall, dense, perennial plants but based on the responses obtained and given the caveat that there was limited personal experience of the crops, it appears unlikely that wide-scale planting of biomass crops will give rise to substantial public concern in relation to their visual impact in the landscape
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