303 research outputs found
Regulation of Securitised Products post the Financial Crisis
Securitisation has been one of the main reasons for the global financial crisis. The securitisation business has experienced a steep decline for two decades until an even stronger decline in the summer of 2007. This article analyses the regulatory developments in the structured market and the measures taken by legislators since the crisis to address the shortcomings in the securitisation market. The main problems are centred around four areas, which are analysed separately: first, misalignment of interests between investors and originators; second, inadequate capital rules failing to reflect the actual risk exposures; third, insufficient disclosure and information overload of investors; and fourth, credit rating agencies failing to give quality ratings. It concludes that while the adopted regulatory measures might have less corrective effects than envisaged, this is favourable as long as the precise consequences of the adopted measures are not clear
Future of the NOSAMS Tandetron AMS system
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 268 (2010): 854-857, doi:10.1016/j.nimb.2009.10.048.The NOSAMS 3 MV Tandetron AMS system will soon reach its 20th anniversary of operation. A critical
review of all aspects of the system is necessary to assess the analytical, economic, and operational factors that
enter into the consideration of either an upgrade or a replacement of the instrument. Recent inâhouse experience
with the design and construction of a largeâacceptance 14C AMS system gives us a benchmark with which to
compare the expected outcome of an upgrade. The present ion analysis efficiency of our Tandetron system is
roughly 1%, well below the 4% value of our new system. This affects the lower limit of analyzable sample size,
speed of analysis, exposure to systematic errors, and the upper limit of achievable singleâsample counting
statistics. At first glance it may seem obvious that a replacement (even at higher cost) would be preferable to an
upgrade. However, it will be shown that there are good reasons to consider the latter. One of the most compelling
is the fact that the Tandetron is a stateâofâtheâart and superior highâcurrent accelerator design with minimal signs
of aging and very low maintenance. Ion beam modeling calculations show that the main transmission limitation of
the instrument is caused by the design of our injector, a fourâmagnet âRecombinatorâ, making it difficult to
perform reliable AMS with negative currents exceeding 80 ÎŒA. To be acceptable, an upgrade should bring the
Tandetron to at least 3% ion efficiency by replacing the injector with a properly matched highâtransmission device.This work has been supported by the United States National Science Foundation under
Cooperative Agreements OCE-0228996 and OCE-0753487
Erwerbs- und Verkehrs-Statistik des Königstaats PreuĂen : in vergleichender Darstellung
Mit der Darstellung des PreuĂischen Staats, welche ich jetzt der Oeffentlichkeit ĂŒbergebe, ist in der vergleichenden Statistik abermals eine neue, bisher nicht betretene Bahn eröffnet. ..
Design and reality : continuous-flow accelerator mass spectrometry (CFAMS)
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 269 (2011): 3176â3179, doi:10.1016/j.nimb.2011.04.019.In 2007 we published the design of a novel accelerator mass spectrometry (AMS) system capable of analyzing gaseous samples injected continuously into a microwave plasma gas ion source. Obvious advantages of such a system are drastically reduced processing times and avoidance of potentially contaminating chemical preparation steps. Another paper in these proceedings will present the progress with the development of the microwave gas ion source that has since been built and tested at the National Ocean Sciences AMS Facility in Woods Hole. In this paper we will review the original design and present updates, reflecting our recent encouraging experience with the system. A simple summary: large acceptance ion beam optics design is beneficial to accelerator mass spectrometry in general, but essential to AMS with plasma gas ion sources
Progress with a gas-accepting ion source for Accelerator Mass Spectrometry
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 269 (2011): 3192â3195, doi:10.1016/j.nimb.2011.04.017.The National Ocean Sciences AMS (NOSAMS) facility at Woods Hole Oceanographic Institution has developed a novel, gas-accepting microwave-plasma ion-source. The source is a key component of a compact Accelerator Mass Spectrometry (AMS) system built for the analysis of 14C in a continuously flowing gas stream. The gas source produces carbon currents from a stream of CO2 with currents typical of a traditional graphite source. Details of the gas source, including ion current achieved, optimal flow rate, efficiency, and memory are presented. Additionally, data obtained from coupling a gas chromatograph to the source to will be shown
Frankreichs Staatshaushalt und Wehrkraft unter den vier letzten Regierungsformen : eine statistische Skizze
A caravan city at the edge of empire? The economy of Dura-Europos in the Syrian desert
Book synopsis: The Handbook of Ancient Afro-Eurasian Economies offers in three volumes the first comprehensive discussion of economic development in the empires of the Afro-Eurasian world region to elucidate the conditions under which large quantities of goods and people moved across continents and between empires. Volume 3: Frontier-Zone Processes and Transimperial Exchange analyzes frontier zones as particular landscapes of encounter, economic development, and transimperial network formation. The chapters offer problematizing approaches to frontier zone processes as part of and in between empires, with the goal of better understanding how and why goods and resources moved across the Afro-Eurasian region. Key frontiers in mountains and steppes, along coasts, rivers, and deserts are investigated in depth, demonstrating how local landscapes, politics, and pathways explain network practices and participation in long-distance trade. The chapters seek to retrieve local knowledge ignored in popular Silk Road models and to show the potential of frontier-zone research for understanding the Afro-Eurasian region as a connected space
The passage of the bomb radiocarbon pulse into the Pacific Ocean
Author Posting. © Arizona Board of Regents on behalf of the University of Arizona, 2010. This article is posted here by permission of Dept. of Geosciences, University of Arizona for personal use, not for redistribution. The definitive version was published in Radiocarbon 52 (2010): 1182-1190.We report and compare radiocarbon observations made on 2 meridional oceanographic sections along 150°W
in the South Pacific in 1991 and 2005. The distributions reflect the progressive penetration of nuclear weapons-produced 14C
into the oceanic thermocline. The changes over the 14 yr between occupations are demonstrably large relative to any possible
drift in our analytical standardization. The computed difference field based on the gridded data in the upper 1600 m of the section
exhibits a significant decrease over time (approaching 40 to 50â° in Î14C) in the upper 200â300 m, consistent with the
decadal post-bomb decline in atmospheric 14C levels. A strong positive anomaly (increase with time), centered on the low
salinity core of the Antarctic Intermediate Water (AAIW), approaches 50â60â° in Î14C, a clear signature of the downstream
evolution of the 14C transient in this water mass. We use this observation to estimate the transit time of AAIW from its âsource
regionâ in the southeast South Pacific and to compute the effective reservoir age of this water mass. The 2 sections show small
but significant changes in the abyssal 14C distributions. Between 1991 and 2005, Î14C has increased by 9â° below 2000 m
north of 55°S. This change is accompanied overall by a modest increase in salinity and dissolved oxygen, as well as a slight
decrease in dissolved silica. Such changes are indicative of greater ventilation. Calculation of âphosphate starâ also indicates
that this may be due to a shift from the Southern Ocean toward North Atlantic Deep Water as the ventilation source of the
abyssal South Pacific.This work was performed under National Science Foundation Grant number OCE-0223434 as well
as a cooperative agreement with NSF (most recently OCE-0228996)
Radiocarbon investigation of a superlative grandidier baobab, the big reniala of Isosa
The article discloses the accelerator mass spectrometry (AMS) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfectly fused stems and exhibits a cluster structure. The calculated wood volume of the tree is 540 m 3 , which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates an age of 1000 ± 100 years for the big Reniala of Isosa
Comparative AMS radiocarbon dating of pretreated versus non-pretreated tropical wood samples
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 268 (2010): 910-913, doi:10.1016/j.nimb.2009.10.062.Several wood samples collected from Dorslandboom, a large African baobab (Adansonia
digitata L.) from Namibia, were investigated by AMS radiocarbon dating subsequent to
pretreatment and, alternatively, without pretreatment. The comparative statistical
evaluation of results showed that there were no significant differences between fraction
modern values and radiocarbon dates of the samples analyzed after pretreatment and
without pretreatment, respectively. The radiocarbon date of the oldest sample was 993 ± 20
BP. Dating results also revealed that Dorslandboom is a multi-generation tree, with several
stems showing different ages.This material is based on work supported by U.S. National Science
Foundation under Cooperative Agreement OCE-022828996. Part of the research was
supported by grants from the Romanian Academy and the Romanian National University
Research Council (PN II â ID 2354) and also by Nova Research Inc
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