A new pre-weld heat treatment was developed recently for IN 738 superalloy. Therefore, the research described in this master’s thesis was to study the laser weldability improvement of the alloy which had undergone the new heat treatment, FUMT and the results were compared to an existing pre-weld heat treatment, solution heat treatment (SHT). Also, thermomechanical fatigue (TMF) behavior of the welded alloy was investigated. The results showed that IN-738 welded in FUMT condition had about 70% reduction in weld cracking compared to SHT treated alloy. TMF tests showed that at higher strain ranges, the TMF life of the samples of the alloy welded in FUMT condition is comparable to unwelded samples, while at lower strain ranges, welded samples of the alloy in FUMT condition has a higher TMF life than unwelded samples. This shows that welding IN 738 superalloy in FUMT does not degrade the TMF performance of the alloy.

No description available.

The present study examines the pictorial style of pottery made in Thera and Crete in the LCI/LMIA period. The work is in two volumes. Volume I is divided into three parts. Part I comprises the introductory chapter in which there is a summary of previous research on the subject and the aims of the thesis are set out. Chapter II the context of the pictorial style of pottery is examined. Chapter III contains analysis of the forms of vases with pictorial decoration. Part II includes three chapters dealing with the Analysis of Motifs. The plants are analysed in Chapter IV, the living creatures in Chapter V and the sacred symbols in Chapter VI. Part III comprises the Synthesis. In Chapter VII an attempt is made to identify pottery workshops specializing in different vase forms and decoration. Chapter VIII examines the origin and character of the pictorial style of pottery in the Cyclades and Crete. Finally in the last Chapter IX, conclusions regarding the character, context, forms and motifs, workshops and development of the pictorial style pottery are presented. A possible ritual function of the pottery is discussed. Interrelations and influences between the cultures Of Thera and Crete on various Levels are demonstrated. Volume II contains a Catalogue Of the available pottery, presented in two groups: the first from Thera and the second from Crete. The illustrations — figures and photographic plates — come at the end of Volume II.

This thesis examines the ways in which the unique creativity brought to late Victorian applied art by the Della Robbia Pottery was a consequence of Harold Rathbone’s extended engagement with quattrocento ceramics. This was not only with the sculpture collections in the South Kensington Museum but through his experiences as he travelled in Italy. In the first sustained examination of the development of the Della Robbia Pottery within the wider histories of the Arts and Crafts Movement, the thesis makes an original contribution in three ways. Using new sources of primary documentation, I discuss the artistic response to Italianate style by Rathbone and his mentors Ford Madox Brown and William Holman Hunt, and consider how this influenced the development of the Pottery. Rathbone’s own engagement with Italy not only led to his response to the work of the quattrocento sculptor Luca della Robbia but also to the archaic sgraffito styles of Lombardia in Northern Italy. Thirdly, the thesis identifies how the Della Robbia Pottery established a commercial presence in Regent Street and beyond, demonstrating how it became, for a short time, an outstanding expression of Italianate style within the British Arts and Crafts Movement.

L’Inconel 738 est un superalliage base nickel utilisé dans les turbines de moteurs aéronautiques. Le soudage engendre souvent l’apparition de fissures, ce qui constitue un handicap pour ce matériau car on ne peut ni le réparer par rechargement, ni concevoir de pièces assemblées par soudage. L'objectif de la thèse est de définir les conditions de soudage de ce superalliage, de manière à exclure tout risque de fissuration à la suite d’opérations de rechargement, de réparation ou d'assemblage par soudage.Une étude expérimentale a tout d’abord permis de comprendre et de relier les mécanismes de fissuration aux paramètres opératoires du procédé (intensité, tension…). Puis un modèle de simulation numérique du soudage a été développé sur la base d’un couplage entre aspects thermiques, métallurgiques et mécaniques. La corrélation entre les résultats expérimentaux et numériques a permis de déterminer des critères de fissuration pour ce superalliage et d’optimiser les paramètres de soudage. / Abstract

This inter-disciplinary examination assesses the European ceramics in the collections of the Dukes of Hamilton over a number of generations. The study is based principally on the evidence found in the Hamilton and other archives, comprising both textual and visual sources. The second element that forms the foundation for the research is the connoisseurship of ceramics, both extant and those known only through documents. Evidence has revealed that the Duchesses of Hamilton play a major role in this work. A significant number of Hamilton ceramics have been newly identified and located, while their attribution, acquisition and history within the collections have been assessed and clarified.

IN-738 LC, a precipitation hardened nickel based superalloy, containing substantial amounts of Al + Ti contents, is very difficult to weld due to its high susceptibility to HAZ cracking, during welding via conventional fusion welding techniques and subsequent PWHT. The cracking is mainly intergranular in nature and associated with liquation of secondary solidification products (such as MC carbides,  -  eutectic phases), and solid state reaction products ( precipitate particles) that are present along the grain boundaries in the pre-weld material. The current research was to find effective ways to improve weldability of IN-738 LC. Laser welds were produced autogenously on conventionally solidified (CS) and directionally solidified (DS) polycrystalline, and single crystal (SC) IN-738 LC subjected to two preweld heat treatments. Weldability was assessed by measuring the total crack lengths in HAZ. The influence of grain boundaries and heat treatment on extent of cracking in IN-738 LC was studied.

Zugl.: Darmstadt, Techn. Univ., Diss., 2009

Le droit de retour légal est celui en vertu duquel une personne succède à des biens qui avaient été remis gratuitement au défunt décédé sans postérité. Il s’agit d’une institution ancienne dont le fondement premier était traditionnellement la conservation des biens dans la famille. Apparu en droit romain, appliqué dans l’ancien droit français, le retour légal fut inséré in extremis dans le Code Napoléon, à côté du droit de retour de nature conventionnelle qu’il est loisible aux parties de stipuler. Des trois cas de retour prévus en 1804, deux furent supprimés par la loi du 3 janvier 1972. Il fallut attendre la loi du 3 décembre 2001 pour qu’à l’article 757-3 un nouveau droit de retour légal soit instauré au bénéfice des frères et soeurs qui, du fait de la réforme, se trouvaient primés par le conjoint dans la dévolution ab intestat. Puis la loi du 23 juin 2006 instaura à son tour à l’article 738-2 un droit de retour légal au profit des père et mère qui venaient de perdre leur qualité d’héritier réservataire. Dans ces deux cas, on observe que l’instauration du droit de retour légal constitue une contrepartie, pour les uns de leur exclusion de la dévolution par le conjoint, pour les autres de la perte du bénéfice de la réserve : fonction originale pour un droit de retour légal. Si les fondements des textes nouveaux ne sont pas évidents à mettre en lumière, leurs régimes novateurs soulèvent également de nombreuses difficultés d’applications et d’interprétations. Naguère, le retour légal organisait la dévolution successorale d’un bien en fonction de son origine dont il résultait une dualité de succession. Aujourd’hui, le retour légal n’organise plus que la dévolution successorale d’une portion de bien en tenant compte de son origine et l’on doute qu’il constitue dans tous les cas une succession anomale impliquant une dualité de succession. Ces incertitudes engagent à se demander s’il est possible de déroger au retour légal et comment. Au-delà de la dérogation conventionnelle, la modification et même l’abrogation des textes doivent être envisagées. / The statutory reversion right is the right under which a person inherits assets which were returned free of charge to the deceased who died leaving no descendants. It is an old institution which primary basis is, traditionally, the preservation of assets in the family. Established in Roman law, applied in old French law, statutory reversion was inserted in extremis in the Napoleonic code (the French civil code) next to the conventional reversion right which can be stipulated by the two parties within the framework of a transfer contract inter vivos. Out of the three cases provided in 1804, two were removed by the law of January 3, 1972. But it was not until December 3, 2001 that was established, in article 757-3 of the Civil Code, a new statutory reversion right in favour of the brothers and sisters, who, as a consequence of the reform, were superseded by the spouse in the transfer under intestate succession. Then the law of June 23, 2006 established, in turn, in article 738-2 of the Civil Code, a statutory reversion right in favour of the father and mother who had just lost their qualification of rightful heirs. In both cases, we can notice that the establishment of the statutory reversion right constitutes a counterpart, on one hand according to the exclusion for transfer by the spouse, on the other hand, the loss of the benefit of reservation: a particular role for the statutory reversion right. If the bases of the new texts are not easily highlighted, their innovative schemes also raise numerous difficulties of application and interpretation. Formerly, statutory reversion established transmission of property by inheritance according to its origin from which a duality in terms of inheritance resulted. Nowadays, statutory reversion only establishes transmission of property by inheritance of a portion of goods, taking into account its origin, and this raises some doubt as to whether it shall constitute, in all cases, an anomalous succession implying duality in terms of inheritance. This results in uncertainties which lead to wonder if it is possible to derogate from the statutory reversion and how this could be done. Beyond variation by agreement, the modification and even the repeal of texts must be considered.

There is a general consensus worldwide for a need to increase the capacities of transmission lines by not physically altering the transmission structures. Amidst this challenge, dynamic thermal rating (DTR) system appears as an appropriate option. Besides that, many countries have also pledged to integrate wind energy sources into their power networks. Taking these as motivations, the purpose of this thesis is to carry out the reliability analysis of DTR system for transmission lines. The two main standards - IEEE 738 and CIGRE, use for calculating the line rating of overhead lines has been analysed and compared. It was demonstrated that the two standards yield insignificant differences in their calculated line ratings. A new methodology that can systematically assess the reliability and risk of any DTR system designs was proposed in this thesis. In the reliability assessment part, methods such as the event tree analysis (ETA), risk reduction worth (RRW) and wide range method (WRM) were used. The risks of DTR systems were evaluated by implementing them in the IEEE 24-bus reliability test network (RTN). The network's loss of load and the percentages of the conductor loss of tensile strength constitute the risks of DTR systems. In the risk assessment part, a multiple-linear regression (MLR) model was proposed to estimate missing weather values during the failure of DTR sensors. Results in this thesis show that the MLR model is accurate and has only estimation error of less than 6%. It avoids overestimating the risk of DTR systems. An optimum DTR system design was also selected. The strategic placement of DTR sensors along a transmission line is an important reliability issue too. Hence, a new DTR sensor placement algorithm that considers the effects of DTR system ratings on the amount of line sagging, conductor annealing and the correlation between DTR system ratings and actual line ratings was proposed. Results in this thesis show that the newly proposed algorithm outperforms the currently published algorithm in terms of causing no spans to sag beyond their ground clearance limits and all spans experience lesser annealing effects. The 2-dimensional movement of line spans in their longitude and latitude directions, which the currently published algorithm also lacks, are considered in the proposed algorithm. This thesis also investigates the reliability behaviours of a power network that has DTR systems and wind farms. The proposed methodology for achieving that considers the reliability of transmission lines, DTR systems, conventional generators and wind turbines. The chronological behaviour of DTR ratings and wind farm power outputs was modelled using the auto-regressive and moving-average (ARMA) model. The correlations between the ARMA models were also considered. Results in this thesis show that by considering the correlation effects, the network's reliability indices are not over and under estimated. A new reliability index for describing the amount of wind power integration named as Expected Wind Power Delivered (EWPD) was proposed as well.