61,346 research outputs found

    Pulsar Pair Cascades in Magnetic Fields with Offset Polar Caps

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    Neutron star magnetic fields may have polar caps (PC) that are offset from the dipole axis, through field-line sweepback near the light cylinder or non-symmetric currents within the star. The effects of such offsets on electron-positron pair cascades are investigated, using simple models of dipole magnetic fields with small distortions that shift the PCs by different amounts or directions. Using a Monte Carlo pair cascade simulation, we explore the changes in the pair spectrum, multiplicity and energy flux across the PC, as well as the trends in pair flux and pair energy flux with spin-down luminosity, L_{sd}. We also give an estimate of the distribution of heating flux from returning positrons on the PC for different offsets. We find that even modest offsets can produce significant increases in pair multiplicity, especially for pulsars that are near or beyond the pair death lines for centered PCs, primarily because of higher accelerating fields. Pair spectra cover several decades in energy, with the spectral range of millisecond pulsars (MSPs) two orders of magnitude higher than for normal pulsars, and PC offsets allow significant extension of all spectra to lower pair energies. We find that the total PC pair luminosity L_{pair} is proportional to L_{sd}, with L_{pair} ~ 10^{-3} L_{sd} for normal pulsars and L_{pair} ~ 10^{-2} L_{sd} for MSPs. Remarkably, the total PC heating luminosity for even large offsets increases by less than a factor of two, even though the PC area increases by much larger factors, because most of the heating occurs near the magnetic axis.Comment: 41 pages, 17 figures, accepted for publication in Ap

    Minimum wages in Australia: an analysis of the impact on small and medium sized businesses

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    A survey of 1800 small and medium sized businesses is used to shed light on the number of workers covered by minimum wage legislation in Australia. Estimates are obtained and reported of the employment effects of changing the way in which minimum wages are set in Australia.Minimum wage; small and medium enterprises; random survey

    The invertebrate fauna of the mature timber habitat. Survey of areas - site reports - Scotland

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    Is street art good or bad for you?

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    Economic growth can occur within a monolithic, grey urban environment, allowing for decaying facades and deteriorating public spaces. Where artists provide a colorful facelift to urban infrastructure, cities learn to channel the creative capacity of street art. The public good aspect thereby becomes significant in street art’s dimension of wide accessibility and going beyond the controversy of graffiti. This paper explores the case for supporting street art, as a driver for innovation in urban economies. We review the influence of cultural goods on the well-being of various demographic groups and explore the learning process in their consumption. The paper evaluates the willingness to pay towards public culture by controlling for conscious and unconscious exposure to street art in the public space. From a set of 970 field-based interviews, cultural goods ultimately emerge as a promotor of public well-being. Education is the strongest individual characteristic linked with the appreciation of public art. The better skilled further increase their support for potentially controversial cultural goods when works of street art are explicitly presented. A ‘skilled consumption’ emerges for such novel public goods, with further potential for increasing public tolerance through ongoing exposure to art in the urban environment. Finally, as the value of public art amongst the active population is primarily linked to its potential to drive creativity, we will reframe it as a promotor of dynamic local economies, going beyond individual preferences and well-being

    The harmonisation of private international law in Europe: taking the character out of family law?

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    This article examines the recent expansion of EU regulation of the private international law aspects of divorce and its consequences. The application of Brussels IIbis, the Maintenance Regulation, Rome III and the proposed Rome IV to a typical divorce case will be investigated to see if this unwieldy system is coherent in application. It is argued that the envisaged framework for international divorce is becoming unmanageable and that the characterisation of divorce by the EU into the three snapshots of decree, maintenance and matrimonial property ignores the ties between these three events provided by domestic policy

    Confessional Identity and Christian Unity

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    Whose body? A study of attitudes towards the dead body in early modern Paris

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    This chapter examines attitudes towards the dead body, as exemplified by arrangements for funerals and burials, in Paris between around 1550 and 1670. It seeks to establish, not so much what people said should happen to the bodies of the dead, but what happened in practice - the care, or lack of it, which the living accorded to the corpses of their contemporaries and predecessors - and to use this to further our understanding of the mentality of early modern urban dwellers. It is part of a wider enquiry, to explore the attitudes of the living to the dead in Paris and London, and to consider the ways in which this can illuminate the nature of these two metropolitan societies, in the sixteenth and seventeenth centuries. Looking at the treatment of the corpse can also take discussion of the body, and the ways in which it is apprehended and understood, a stage further than the predominant focus on the living; dead bodies were as variably constructed, as liable to objectification (even commodification), as exposed to contest and competition over meaning as living ones. This particular study highlights the issues of control and ownership, among the complexity of reactions to the materiality of bodies, and offers an insight into power relations in a wider social and spatial environment

    Sons, apprentices and successors in late medieval and early modern London: the transmission of skills and work opportunities

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    Book synopsis: The existence and changing of generations in family life, business and politics was a central feature of towns as well as rural societies in earlier times. Even so, it remains understudied by urban historians of the pre-modern period. This book aims to fill some of this gap, containing twelve studies of generations in late medieval and early modern European towns, ranging from the Mediterranean to the Nordic countries, with a time-span from the fourteenth to the early nineteenth century. Dealing with topics like succession and inheritance, family consciousness, as well as relations and conflicts within and between generations, the articles demonstrate the importance and potential of generational studies on pre-modern towns. The book will appeal to anyone who takes an interest in urban social and cultural history, legal and family history in medieval and early modern times
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