Suchergebnisse

Abstract
The aim of this article is to highlight the political uses of the legal concept of waqf in a confrontation between an Orthodox and a Catholic institution during the initial phase of the schism within the Church of Antioch. The Monastery of St Catherine at Mount Sinai confronted the hospice of the Franciscans in the court of the Chief Judge of the province of Damascus in 1145/1733. The legal aspects of the lawsuit are an interesting example of the use of the Ottoman judiciary by non-Muslims, but in order to understand the political implications of the case, it needs to be analysed in the broader context of the religious and political tensions of the time. Therefore, a sketch of the history of both monasteries and their endowments is supplemented with a chapter on the role of Sylvestros, Patriarch of Antioch, in Damascus and an examination of the French and Spanish interests within this Ottoman context.

In Leichtwasserreaktoren (LWR) entstehen langlebige und radiologisch toxische Nuklide, wie z. B. Plutonium und Minore Aktinide (Neptunium, Americium, Curium, .), die nach der Brennelemententnahme für lange Zeit sicher verwahrt werden müssen. Zur Reduzierung des hochradioaktiven, langlebigen Materials wird unter anderem an der Umwandlung mittels Transmutation und Kernspaltung in kurzlebige Nuklide geforscht. Als Transmutationssyteme werden Generation-IV-Reaktoren und beschleunigergetriebene Systeme untersucht. Einer der Generation-IV-Reaktoren ist der grafitmoderierte, Helium gekühlte Hochtemperatur-Kugelhaufen-Reaktor (HTR). Die Vorteile des HTR ist zum einen die Brennelementstruktur, durch die hohe Abbrände möglich sind. Außerdem die inhärente Sicherheit, das heißt es ist möglich, den Reaktor ohne aktive Systeme in einen sicheren Zustand zu bringen, ohne dabei die Strukturen zu zerstören oder radioaktive Substanzen freizusetzen. In dieser Arbeit werden die aus den abgebrannten LWR-Brennelementen extrahierten Nuklide Plutonium, Neptunium und Americium zu neuem Brennstoff verarbeitet und in einen HTR eingesetzt. Das Ziel ist es, den Großteil der langlebigen Nuklide umzuwandeln, um damit die Menge langlebiger Nuklide und Toxizitäten im abgebrannten Brennelement zu reduzieren. Dafür wird der höchstmögliche Abbrand bestimmt. Die Grundidee stammt aus dem Projekt "Plutonium and Minor Actinides Waste Management" (PuMA) der Europäischen Union. Die Definition der Brennelement- und Reaktorgeometrie werden aus diesem Projekt entnommen. Der Referenzreaktor ist nahezu identisch zum südafrikanischen Hochtemperaturreaktor mit 400 MW_th Leistung und fester Grafitinnensäule (Pebble Bed Modular Reactor PBMR-400). Es zeigt sich, dass der maximale mittlere Entladeabbrand unterhalb von 700 MWd/kg SM liegt und nicht wesentlich von der geometrischen Form der Kugelschüttung beeinflusst wird. Untersucht wird außerdem das Verhalten des mit Plutonium- und Minoren Aktiniden-Brennstoff gefüllten stationären HTR im Vergleich zu dem mit Uran-Brennstoff betriebenen. Durch den veränderten Spaltstoff ist das Verhalten des Reaktors unterschiedlich, z. B. bei Temperaturänderung oder im Störfall. Die Temperaturen in den Plutonium- und Minoren Aktiniden-Brennelementen sind weit über den erlaubten Grenztemperaturen. Dies resultiert aus der veränderten Abbrand- und Leistungsverteilung im Vergleich zum Uran beladenen Reaktor. Eine Änderung des Reaktorkonzepts zu dem vorgegebenen Referenzsystem ist daher notwendig. Mittels verschiedener Variationen wird nach Verbesserungen gesucht. Die veränderte Nuklidzusammensetzung, deren Radiotoxizitäten und die Wärmefreisetzung der abgebrannten Brennelemente werden ebenfalls analysiert. Direkt nach Brennelemententnahme sind die Radiotoxizitäten und die Nachzerfallsleistung größer als die des frischen HTR-Brennelements, während das Abklingen dieser Werte schneller erfolgt. Durch die Forderung eines Zwischenlagers wäre es möglich, die Größe des Endlagers zu reduzieren und dadurch die Gesamtkosten zu verringern. ; Only one of many different ways to produce electric power is the Light Water Reactor (LWR).This reactor produces high level long-lived and radiotoxic nuclides like Plutonium and Minore Actinides (Neptunium, Americium, Curium, .), which have to be safely isolated and controlled in a final storage over a long time. Thus, many projects worldwide concentrate on the transformation of these long-lived nuclides into short-lived nuclides by transmutation and fission processes. Here, mainly accelerator driven systems and Generation-IV-reactors, like the graphite moderated, Helium cooled High Temperature Reactor (HTR), are in focus of research. The main advantages of the HTR are the fuel structure, which allows high burnups and the inherent safety. In case of a Loss Of Cooling Accident (LOCA), the decay heat will be dissipated without any active cooling system. This passive heat transfer is high enough to stay below the upper temperature limit in the fuel. Therefore, the fuel structure stays intact and the fission products retain inside the fuel. In this thesis, the long-lived nuclides like Plutonium, Neptunium and Americium, extracted from the spent LWR fuel, will be reused in a fresh fuel element for the HTR. To achieve the aim of reducing these nuclides and their radiotoxicity, the HTR has to operate at the highest possible burnup. Therefore parameters, like e.g. the fuel temperature or the power density distribution and also the behaviour in case of an accident have to be comparable to the HTR loaded with uranium fuel. The European Union project "Plutonium and Minore Actinide Waste Management" (PuMA) is the origin for the used reference reactor geometry, the fuel structure as well as the nuclide densities in the Plutonium and Minor Actinides fuel. The reactor design of this project is almost identical to the South African reactor concept with 400 MW_th thermal power and an inner graphite column (Pebble Bed Modular Reactor PBMR-400).For comparison also the uranium filled PBMR-400 will be calculated. It will be shown that the maximal average discharge burnup for a critical, stationary system will be less than 700 MWd/kg HM in the case of the plutonium filled reactor. The behaviour of this reactor varies, e.g. in the case of an accident or in load changes, compared to the reactor loaded with uranium fuel. Due to the different fission nuclides and the higher burnups of the plutonium fuel, the power distribution is strongly different and the temperature in the kernel is far above the upper-limit temperature. Therefore, the reference reactor design has to be adapted or the nominal power has to be reduced. Many calculations are shown with a varying reactor geometry, fuel design, nominal power and load strategy. As one result, no significant influence of the core geometry on the maximal burnup is observed. Furthermore, the reduction of the long-lived nuclides, the distribution of the radiotoxicity and the decay heat in dependence of the storage time are analyzed for the spent fuel in the reference design. The radiotoxicity and the decay heat from the spent fuel direct after removal from the reactor is higher compared with nuclide vector from a not burned plutonium fuel. In the repository the decrease of these parameters is greater than from the fresh fuel. With the request for an interim storage a smaller repository with lower total costs is possible.

Environmental history provides a perspective from which we can deepen our understanding of the past because it examines the relationships of people with their material surroundings and the effects of those relationships on the individual as well as the societal level. It is a perspective that holds particular promise for the social and political history of arid and marginal zones, as it contributes to our understanding of the reason some groups are more successful than others in coping with the same environmental stresses. Historians working on the early modern Arab East have only recently engaged with the lively field of global environmental history. After presenting a brief overview of some strands of this research, this article illustrates the potential of this approach by looking closely at a series of conflicts involving Bedouin and other power groups in the southern parts of Bilād al-Shām around the middle of the eighteenth century.

The volume contributes to a better understanding of Iranian history since 1953, with a focus on societal change and its reflection in intellectual discourse. The papers explore the attitudes of Iranians toward modernity and tradition before and after the Revolution of 1979. With insights from Oriental studies, history, sociology, literature and social anthropology, the volume offers a cross-disciplinary perspective on the intellectual, political, and social history of Iran.