5,266 research outputs found

    Paleoenvironmental analysis of the Mangere Formation, Mangere Island, Chatham Islands, New Zealand : a thesis submitted in Earth Science for the degree of Master of Science at Massey University

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    Mangere Island consists almost entirely of alkali basalt of the late Miocene early Pliocene Rangiauria Formation (Campbell et al., 1993) with outcrops of the sedimentary Tupuangi Formation on the east coast and the Mangere Formation (Campbell, et al., 1993), a sedimentary remnant, mainly lacustrine but also partly marine, lying between the northeastern and southwestern groups of volcanic vents of Mangere Island: As a result of the present work the sedimentary Mangere Formation of Campbell et al. (1993) has been divided into two formations, Mangere Formation and the overlying Parakeet Formation. Mangere Formation consists of (1) a Basal member (32m of mudstone), and (2) a Cyclic member (12.6m of alternating sandstones and mudstones). Parakeet Formation has (1) a Carbonaceous member (0.6m Of organic rich mudstones), (2) a Skua member (16.8m of tuffaceous siltstone), and (3) a capping rhyolitic tephra. The Basal member of the Mangere Formation is underlain by a breccia that is texturally extremely variable (Bag End breccia). A sedimentary outcrop on the eastern coast of Mangere Island is lithologically and mineralogically identical to Tupuangi Formation on Pitt Island as well as having the same Cretaceous pollen suite. Thus it is inferred that, at the time of Rangiauria volcanism, Tupuangi Formation and its overlying Tertiary strata extended from Pitt Island at least as far as Mangere Island. An arm of the sea between two Mangere Island volcanic centres extended towards Waihere Bay, Pitt Island. At some time in the late Pliocene, volcanic debris avalanches from the northeast and southwest groups of vents formed a debris dam that blocked off the seaward side of the sea arm, resulting in the formation an oligotrophic fresh water lake. As a result of a low energy regime and vegetated slopes, the lake filled to ca. 30m with very fine sediment (the Basal member) from both the volcanics of Mangere Island and the quartzofelspathic Tupuangi Formation of Pitt/Mangere Island. Following this a debris dam, formed by volcanic debris avalanches, was breached by a rising sea. Local marine influence in storms destablised the slopes surrounding the then shallow lake resulting in the influx of coarse sands which alternated with mudstones deposited during quieter periods (the Cyclic Member). At the end of this period there was a eustatic fall of sea level or tectonic uplift or both, probably resulting in subaerial erosion and an unconformity between the Cyclic and Carbonaceous Members. A second shallow fresh water lake (the Carbonaceous member) was established on the top of the Cyclic member. This lake was later overwhelmed by wind-blown material derived from a deposit of Paleocene Red Bluff Tuff exposed probably by a falling sea level or marine erosion. The reworked Red Bluff Tuff was later covered by a layer of rhyolitic tephra probably from the Taupo Volcanic Zone (TVZ), North Island, New Zealand. The distinctive jointing pattern seen in the sandstone units of the Cyclic member resulted from doming with a principal stress directed northwest-southeast. This probably correlates with tectonic uplift in the Castlecliffian. The lack of any positive time markers makes dating the formation rather indeterminate, but the Basal and Cyclic members (Mangere Formation) are probably upper Mangapanian and the Skua member probably Quaternary. The sequence is generally lacking in fossils, except for palynomorphs which occur throughout, and ostracods which occur only in the Cyclic member. Neither proved useful for dating the sequence. The pollen diagrams show a consistent coastal plant association of small trees, shrubs, herbs and ferns throughout the history of the sequence, with the implication that climate during this time did not vary greatly from a mild, moist, equable mean

    The supervision of mixed financial services groups in Europe

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    Over time, the banking, insurance and securities sectors have become increasingly interlinked and one way through which this occurs is via financial conglomerates. Such groups, in particular those that combine banking and insurance, have over time become more important in Europe. They require an appropriate regulatory and supervisory set-up to deal with the specific risks they raise. In the EU, this regulatory set-up was introduced with the Financial Conglomerates Directive (2002) and which Member States are now implementing into national law. The Directive introduces a regime of supplementary supervision, in addition to the one that already exists for the regulated entities of the conglomerate. The Directive covers areas such a capital requirements, intra-group transactions, large exposures, organisational requirements and information exchange between authorities. The paper further compares the regime in the US and the EU. It concludes with issues that might require attention from authorities in the future.cross-sector risk, European Union, financial conglomerate, financial regulation, financial supervision.

    Quiescent and flaring X-ray emission from the nearby M/T dwarf binary SCR 1845-6357

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    We investigate an XMM-Newton observation of SCR 1845-6357, a nearby, ultracool M8.5/T5.5 dwarf binary. The binary is unresolved in the XMM detectors, however the X-ray emission is very likely from the M8.5 dwarf. We compare its flaring emission to those of similar very low mass stars and additionally present an XMM observation of the M8 dwarf VB 10. We detect quasi-quiescent X-ray emission from SCR 1845-6357 at soft X-ray energies in the 0.2-2.0 keV band, as well as a strong flare with a count rate increase of a factor of 30 and a duration of only 10 minutes. The quasi-quiescent X-ray luminosity of log L_x = 26.2 erg/s and the corresponding activity level of log L_x/L_bol = -3.8 point to a fairly active star. Coronal temperatures of up to 5 MK and frequent minor variability support this picture. During the flare, that is accompanied by a significant brightening in the near-UV, plasma temperatures of 25-30 MK are observed and an X-ray luminosity of L_x= 8 x 10^27 erg/s is reached. SCR 1845-6357 is a nearby, very low mass star that emits X-rays at detectable levels in quasi-quiescence, implying the existence of a corona. The high activity level, coronal temperatures and the observed large flare point to a rather active star, despite its estimated age of a few Gyr.Comment: Accepted by A&A, 6 pages, 5 figure

    WHIZARD 2.2 for Linear Colliders

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    We review the current status of the WHIZARD event generator. We discuss, in particular, recent improvements and features that are relevant for simulating the physics program at a future Linear Collider.Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS13), Tokyo, Japan, 11-15 November 201

    Organizational Innovations of Firms from the 1850s in the USA and Japan

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    Organizational Innovations (OIs) are defined as disembodied technology as against embodied technology or technical (technological) innovations. The firms, as we see them today in the USA, Japan and many other countries, are organized according to OIs that took place in the USA and Japan in the last 150 years or so. A historical review during that period will identify OIs in these two countries. OIs such as integration of production and distribution, focal factories, and just-in-time cum quality control (JIT/QC) are more thoroughly described.organizational innovations, disembodied technology, firms, economic growth, historical review

    An emerging market for corporate control? The Mannesmann takeover and German corporate governance

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    Corporate governance in Germany is often described as a bank-oriented, block-holder or stakeholder model where markets for corporate control have not played a significant role. This case study of the hostile takeover of Mannesmann AG by Vodafone in 2000 demonstrates how systemic changes during the 1990s have eroded past institutional barriers to takeovers. These changes include the strategic reorientation of German banks from the house bank to investment banking, the growing consensus and productivity orientation of employee co-determination and corporate law reform. A significant segment of German corporations are now subjected to a market for corporate control. The implications for the German model are examined in light of both claims by agency theory for the efficiency of takeover markets, as well as the institutional complementarities within Germany's specific variety of capitalism. While the efficiency effects are questionable, the growing pressures for German corporations to achieve the higher stock market valuations of their Anglo-American competitors threaten the distributional compromises underlying the German model. --

    Gamma ray fluorescence for in situ evaluation of ore in Witwatersrand gold mines

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    A Thesis Submitted to the Faculty of Science University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy Johannesburg 1979A system tor quantitative in situ evaluation of ore in Witwatersrand gold mines was researched and subsequently developed. The principle of measurement is based on the excitation of gold K x-rays in rock face samples by the 88 keV gamma radiation from a Cadmium-109 radioisotope source. The X-rays and scattered radiation from the rock matrix are detected by a hyperpure germanium detector cooled by liquid nitrogen in a portable probe. In the fluorescence spectrum the intensity ratio of the gold Kb peaks to their immediate scattered background is evaluated and quantitatively converted in the portable analyser to area concentration units. All aspects of the physical and instrumental measurement had to be investigated to arrive at a system capable ot quantitative evaluation of trace concentrations in stope face ore samples. The parameters of efficiency of excitation of the gold K X-rays, and the energy distribution after scattering from the rock matrix at different angles were investigated from basic principles to determine an optimum source - sample - detector g e o m e t r y which would allow quantitative evaluation of homogeneous ore concentrations, for edged-on measurement of rough-surfaced thin layer deposits a method or controlling the measurement geometry through ratemeter feedback was developed to allow conversion of mass concentration values to units of area concentration. The parameters of spectrum evaluation were investigated from fundamental principles to allow quantitative assessment of different methods of peak evaluation for optimization of the method as a whole. The basic concepts of random signal processing times were developed together with new concepts of pileup parameters to allow a quantitative description of the data acquisition rate of a complete analog pulse processing system. With this foundation a practical measuring geometry and optimum values for signal processing time parameters, for detector size and for discriminator positions for spectrum evaluation could be determined. Parallel with the derivation of optimum measurement parameters went the development of instruments, their field testing and appraisal of the method. The underground results obtained with prototype versions of the gamma ray fluorescence analyser were in all instances found to have a highly significant correlation with those obtained from the same locations by conventional chip or bulk sampling and fire assay. The development of the gamma ray fluorescence method has shown the potential of the method to serve as an ore valuation tool and to assist in the geological identificaion of strata in Witwatersrand gold mines

    Crossing the c=1 barrier in 2d Lorentzian quantum gravity

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    In an extension of earlier work we investigate the behaviour of two-dimensional Lorentzian quantum gravity under coupling to a conformal field theory with c>1. This is done by analyzing numerically a system of eight Ising models (corresponding to c=4) coupled to dynamically triangulated Lorentzian geometries. It is known that a single Ising model couples weakly to Lorentzian quantum gravity, in the sense that the Hausdorff dimension of the ensemble of two-geometries is two (as in pure Lorentzian quantum gravity) and the matter behaviour is governed by the Onsager exponents. By increasing the amount of matter to 8 Ising models, we find that the geometry of the combined system has undergone a phase transition. The new phase is characterized by an anomalous scaling of spatial length relative to proper time at large distances, and as a consequence the Hausdorff dimension is now three. In spite of this qualitative change in the geometric sector, and a very strong interaction between matter and geometry, the critical exponents of the Ising model retain their Onsager values. This provides evidence for the conjecture that the KPZ values of the critical exponents in 2d Euclidean quantum gravity are entirely due to the presence of baby universes. Lastly, we summarize the lessons learned so far from 2d Lorentzian quantum gravity.Comment: 21 pages, 18 figures (postscript), uses JHEP.cls, see http://www.nbi.dk/~ambjorn/lqg2 for related animated simulation

    Information Processing Constraints and Asset Mispricing

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    I analyse a series of natural quasi-experiments - centred on betting exchange data on the Wimbledon Tennis Championships - to determine whether information processing constraints are partially responsible for mispricing in asset markets. I find that the arrival of information during each match leads to substantial mispricing between two equivalent assets, and that part of this mispricing can be attributed to differences in the frequency with which the two prices are updated inplay. This suggests that information processing constraints force the periodic neglect of one of the assets, thereby causing substantial, albeit temporary, mispricing in this simple asset market
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