Academic literature on the topic 'Certification UL2'

The main aim of the this diploma thesis is the wing design of the UAV aircraft, including the appropriate material choice, calculation of the wing load and also strength analysis. Other goals include the design of the location and volume of fuel tanks, as well as the design of wingspan reduction after landing.

L’évolution et le succès qu’a connu Internet les dernières années a profondément marqué le domaine du génie logiciel et plus particulièrement des aspects tels que la conception, l’implémentation et l’exploitation de systèmes distribués. Cette ouverture qu’offre la toile aux systèmes brave les limites architecturales et géographiques pour permettre une interconnexion permanente des utilisateurs. Cependant, ce flux de communication et de code mobile comporte des risques de sécurité qui vont à l’encontre des politiques des entreprises concernées par ces échanges. Étant données la multitude et la diversité des intervenants, des mesures préventives s’imposent pour remédier à cette faille sécuritaire. Ce mémoire s’inscrit dans le cadre d’une contribution à cet effort, par la voie de la certification. En effet, le potentiel de l’approche proposée émerge de la synthèse des techniques fondamentales de ce domaine, qui sont le code incorporant une preuve (PCC), le langage assembleur typé (TAL) et le code incorporant un modèle (MCC). Toujours dans l’optique de renforcer la relation de confiance entre le producteur et le consommateur, et au-delà de la vérification du respect du code envers une politique de sécurité, notre projet qui s’intitule «code incorporant un modèle certifié» (CMCC) couvre en plus des aspects pratiques jusque là souvent délaissés par les concepteurs.

Nous avons utilisé un sondage en méthode-Q – une technique d’étude de la subjectivité – pour explorer les différentes perceptions de la certification forestière au Québec. Nous avons découvert trois discours distincts. Aussi, nous avons effectué une analyse des changements institutionnels en cours dans le milieu forestier québécois. Nous prévoyons que le régime forestier subira un important effort de décentralisation et que la certification forestière y jouera un rôle. Si cela s’avère vrai, ceux qui perçoivent la certification comme un outil de gestion feront valoir le leadership des industriels forestiers en matière de certification. Ils voudront sécuriser le rôle traditionnel d’aménagiste et de gestionnaires des forêts publiques assumé par les firmes privées. D’autre part, ceux qui voient la certification comme un outil de relation publique devrait s’opposer à la réforme envisagée. Ils demanderont des preuves de l’efficacité de la certification forestière pour améliorer l’aménagement forestier. Finalement, ceux qui voient la certification comme un outil de gouvernance approuveront la réforme et chercheront à la catalyser. Ils demanderont à ce que les processus de participation publique soient précisés de manière à améliorer le partage des pouvoirs et la distribution équitable des responsabilités en aménagement forestier.<br>We have used a Q-methodology survey – a subjectivity studying technique – to explore different perceptions of forest certification in Quebec. Three different viewpoints were discovered. We have also done an analysis of institutional changes within Quebec's forest sector. As a result, we expect Quebec's forest regime to undergo an important effort of decentralization in which forest certification will play an important role. First, we have individuals who primarily view certification as a tool of management and who may place greater importance on forest industries' certification leadership. People in this category may want the traditional role of private firms as developers and managers of the crown's forests to be secured. On the other hand, there are people who view certification as a tool for public relations and who may be opposed to preserving the traditional role of private firms. For this group of people, proof of improvement of certified forest practices would be a requirement. Finally, people who view certification as a tool of governance may approve of reform and thus, try to catalyze it. Such individuals will demand an enhancement of public involvement processes in the forest sector. This group of people will want forest management responsibilities and power to be more equitable.

La certification ISO 14001 sur les systèmes de gestion environnementale a connu une forte croissance depuis 1996 et représente une source de légitimité sociale pour les entreprises. Cette légitimité dépend notamment de l’indépendance du processus de vérification et des liens entre ce processus et l’amélioration des pratiques et des performances environnementales des organisations. Cependant, ces aspects demeurent encore peu étudiés dans la littérature. L’objectif de cette étude qualitative est d’analyser, à partir d’entretiens auprès de professionnels participant directement ou indirectement au processus de certification, les perceptions de l’indépendance des auditeurs, ses enjeux éthiques, et ses liens avec les pratiques environnementales des entreprises canadiennes. La construction sociale de l’indépendance des auditeurs est analysée, notamment à partir de diverses stratégies de production de sens. Ces stratégies s’appuient sur un ensemble de mécanismes procéduraux, de stéréotypes et de processus de distanciation pour créer une apparence de confiance et de confort concernant l’indépendance de l’auditeur. L’influence potentielle de la rémunération des auditeurs est également analysée; les résultats montrent que les répondants tendent à légitimer le processus actuel de rémunération en s’appuyant sur le concept d’utilisateurs-payeurs, sur la déontologie professionnelle et sur les procédures existantes. L’étude démontre également que l’absence de régulation formelle concernant la rotation des auditeurs favorise le maintien des auditeurs sur plusieurs cycles de certification qui concourt à une dynamique relationnelle entre l’auditeur et l’audité. Cette situation renforce le pouvoir du client sur le maintien des auditeurs. Si cette permanence peut avoir des répercussions positives, elle favorise également une familiarité sociale et technique qui tend à compromettre la crédibilité du processus à long terme. Enfin, l’étude montre que les audits de certification ISO 14001 sont surtout centrés sur des aspects procéduraux et tendent à négliger des aspects plus substantiels liés à l’amélioration des pratiques et des performances des organisations. Malgré les biais de désirabilité sociale inhérents aux discours des répondants, l’étude met en lumière des problèmes réels de conflits d’intérêts et de pratiques peu rigoureuses, réalité peu abordée dans la littérature. À partir de ce constat, l’étude propose de nouvelles pistes de recherches sur l’indépendance des audits de certification ISO en général. MOTS-CLÉS : Audit; certification ISO 14001; indépendance; permanence des auditeurs; systèmes de gestion environnementale; dépendance financière; stratégie de production de sens; rotation; performance.<br>The ISO 14001 certification for environmental management systems provides businesses with social legitimacy. Since its creation in 1996, this particular standard has experienced an increasing popularity. However, its legitimacy is directly linked with the independence of the audit process, as well as with, among other factors, its direct link with the improvement of the businesses’ environmental practices and performances. Nonetheless, the fact remains that these questions have rarely been explored in the formal literature. Therefore, the goal of this qualitative research is to analyse, on the basis of interviews with professionals in the field of the ISO 14001 certification process, the various perceptions of the auditor’s independence, the ethical issues it raises, and its influence on the environmental practices of Canadian businesses. The social construction of the auditor’s independence is studied through various sensemaking strategies (Schutz, 1967; Weick, 1995), among other elements. These strategies rely on procedural mechanisms, stereotypes and a distancing process to create the illusion of trust and comfort as regards the auditor’s independence. The potential influence of the auditor’s compensation has also been analysed in this study, and the results show that the participants tend to legitimize the current compensation practices by relying on the user-pay principle, on professional conduct and on the existing processes in the field. This qualitative research also shows that, in the absence of formal rules regarding auditor rotation, having the same auditor working through several certification cycles can lead to certain relationship dynamics between auditor and auditee, which increases the client’s influence on the choice of auditors. While such permanence can have positive repercussions, it can also cause a social and technical familiarity which can, in turn, jeopardize the long-term credibility of the certification process. Lastly, the study shows that ISO 14001 certification audits are primarily concerned with procedural questions, and tend to neglect the more important issues linked to improving businesses’ practices and performances. Despite the social desirability biases inherent to the study’s goals and the participants’ answers, this qualitative research reveals true problems of conflicts of interest and lax practices that remain rarely discussed in the formal literature. In closing, the study suggests new avenues of research on the independence of all types of ISO certification audits. Key words: Audit, ISO 14001 certification, independence, auditor tenure, environmental management systems, financial dependence, sensemaking strategies, rotation, performance.

The main interest of this interdisciplinary thesis (psychology-law) is the understanding of transphobia and discrimination against trans* people. I locate the problem of this type of discrimination in the social construction of ‘sex/gender’ categories. Particularly, I situate it in the definition of the norms that constitute ‘woman’ and ‘man’ as two essential and mutually exclusive categories that sustain the unequal binary organisation of society. People who transgress those norms have been labelled as ‘mentally ill’ by psychiatry and psychology since the end of the 19th century. The emergence of trans* activism from the 1960s and especially Trans Studies in the 1990s has allowed questioning those pathologising discourses. In the present context, we observe a tendency towards the depathologisation of trans* experiences and identities. Depathologisation is coupled with increased visibility of trans* people in the cultural domain and a more favourable public opinion towards them. However, trans* people still face serious discrimination and the norm that divides humankind into ‘women’ and ‘men’ is still very much present. Drawing on these premises I argue that the transgression of ‘sex/gender’ norms have been redefined nowadays so that the binary opposition between women and men is maintained as the norm. Thus, trans* people are still depicted as ‘abnormal’ although pathologising and psychiatric discourses are not necessarily employed today. The general objective of the thesis is to understand how this redefinition is carried out and the effects of it in two specific contexts: the legal certification of sex in the civil status of individuals in Belgium and the definition of the worker subject. The choice of these two cases responds to the fact that trans* people report facing many obstacles and discrimination in them. Based on the theoretical and methodological principles of discursive psychology and Perelmanian new rhetoric, I realised the discourse analysis of two corpora: a legislative corpus and a corpus of interviews. The legislative corpus comprises texts of Acts, bills, amendments, parliamentary debates and Circulars regulating the mention of sex in the civil status in Belgium. The second corpus includes the transcriptions of five group interviews with workers carried out with co-workers from five work organisations in Brussels. In both cases, the identification of discursive practices and their variability allowed me to elucidate the effects they produce. Specifically, it allowed me to show that, although the identified practices seem less stigmatising, they still depict trans* people as a ‘deviation from the norm’, thereby legitimising a different legal treatment towards them and justifying the discrimination and exclusion they endure at work. Moreover, the identified practices reproduce the binary organisation of society and justify discrimination against women in the workplace. The ultimate purpose of this thesis is to promote an informed critical attitude towards those discursive practices and, in this way, to contribute to the struggle against transphobia and sexism.<br>Dans cette thèse interdisciplinaire (psychologie-droit) je m’intéresse à la transphobie et la discrimination à l’égard des personnes trans*. Je situe ce problème de discrimination dans la construction sociale des catégories « sexe/genre », notamment dans la définition des normes qui constituent les catégories « femme » et « homme » comme deux catégories essentielles et mutuellement exclusives qui soutiennent l’organisation binaire et inégale de la société. Les personnes qui ont transgressé ces normes ont été étiquetées comme « malades mentales » par la psychiatrie et la psychologie depuis la fin du 19ème siècle. L’émergence de l’activisme trans* dans les années soixante et notamment des Trans Studies dans les années nonantes ont permis la remise en question de ces discours pathologisants. Dans le contexte actuel, on observe une tendance vers la dépathologisation des expériences et identités trans*, accompagnée d’une croissante visibilité des personnes trans* dans le domaine culturel et d’une opinion publique globalement plus favorable à leur égard. Par contre, les personnes trans* font encore l’objet de nombreuses discriminations et la norme qui divise l’humanité entre « femmes » et « hommes » est encore extrêmement présente. Sur la base de ces prémisses, je soutiens que la transgression des normes de « sexe/genre » a été actuellement redéfinie de façon à ce l’opposition binaire entre les femmes et les hommes est maintenue comme norme. Ainsi, les personnes trans* sont encore définies comme « anormales » alors que des discours pathologisants et psychiatrisants ne sont pas nécessairement mobilisés aujourd’hui. L’objectif général de la thèse est de comprendre comment cette redéfinition est faite et quels sont ses effets dans deux contextes spécifiques :la certification légal de la mention du sexe dans l’état civil en Belgique et la définition du sujet travailleur. Le choix de ces deux cas se justifie par le fait que ce sont deux domaines dans lesquels les personnes trans* signalent beaucoup d’obstacles et de discrimination. M’appuyant sur les principes théoriques et méthodologiques de la psychologie discursive et de la nouvelle rhétorique perelmanienne, j’ai effectué l’analyse du discours de deux corpus :un corpus législatif et un corpus d’entretiens. Le corpus législatif est composé de textes de loi, projets et propositions de loi, amendements, travaux parlementaires et circulaires régulant la mention du sexe dans l’état civil en Belgique. Le deuxième corpus inclut les transcriptions de cinq entretiens de groupe menés auprès de travailleuses et de travailleurs dans cinq organisations de Bruxelles. Dans les deux cas, l’identification des pratiques discursives et de leur variabilité m’a permis de dévoiler les effets qu’elles produisent. Spécifiquement, j’ai pu démontrer que, bien que ces pratiques semblent moins stigmatisantes aujourd’hui, elles continuent à définir les personnes trans* comme une « déviation de la norme », légitimant ainsi un traitement légal différent à leur égard et justifiant la discrimination et l’exclusion dont elles sont victimes au travail. En outre, ces pratiques discursives reproduisent l’organisation binaire de la société et la discrimination à l’égard des femmes au travail. Avec cette thèse j’espère contribuer à la promotion d’une attitude critique informée par rapport aux pratiques discursives identifiées et, par ce biais, à la lutte contre la transphobie et le sexisme.<br>Doctorat en Sciences psychologiques et de l'éducation<br>info:eu-repo/semantics/nonPublished

In this thesis, I analyze the impacts of the design and implementation of different environmental policy tools from a theoretical and empirical perspective: certificates providing information on the energy performance of buildings (chapter 1); urban road pricing schemes such as congestion charges (chapter 2); quantity-based policy tools to support production with non-polluting technologies (chapter 3).In chapter 1, co-authored with Luisa Dressler, we study how energy performance certificates (EPCs) impact the residential rental market. These certificates can help solve information asymmetries between landlords and tenants about the thermal quality of dwellings for rent, which, in turn, is expected to facilitate investment aimed at improving dwellings' energy performance. However, disclosure of EPCs is often incomplete, which hampers their effectiveness in relieving such information asymmetries. Moreover, even when a certificate is available, landlords do not always disclose it. This contradicts the so-called information unraveling result, according to which all landlords should disclose quality information unless it is costly to do so: in such a setting, information eventually unravels. Using a cross-sectional dataset of residential rental advertisements from the Belgian region of Brussels, we empirically evaluate incentives to disclose energy performance ratings. We find that two fundamental assumptions underlying the unraveling result are not confirmed in our setting: firstly, tenants value energy performance of rental property only when dwellings are of very high quality; secondly, tenants do not appear to rationally adjust their expectations when faced with dwellings that withhold their energy performance rating. Finally, we formulate specific policy advice for reforming EPC mechanisms to increase disclosure rates.In chapter 2, I study how urban congestion pricing impacts the use of sustainable mobility options such as bike sharing, presenting evidence from the city of Milan, Italy.As concern for air pollution grows in cities across the world, policies such as urban road pricing are rolled out to induce urban residents to opt for greener transport options. While several papers have analyzed the impact of urban road pricing on air pollution and on car use, this is the first analysis of its impact on sustainable travel behaviors, such as the use of bike sharing.I extend a stylized theoretical model of travel behavior to formalize the drivers of bike-sharing demand. Then, I exploit a panel dataset covering all bike-sharing trips carried out over an 8-year period in the city of Milan to estimate the impact of congestion pricing on bike-sharing use. The empirical strategy I employ in this study is based on the sudden suspension and reintroduction of congestion pricing, which generate a quasi-experimental setting. Adopting an event study approach, I find that suspending the congestion charge reduces daily bike-sharing traffic by about 5% in the short run. I show that, in Milan, congestion pricing mainly impacts bike-sharing use through the reduction of road traffic congestion, which makes cycling safer and more pleasant. The direct effect of the increased relative cost of car use is secondary in individual decisions to use bike-sharing. The role of these effects is likely to be context-specific, as they may be affected by the baseline level of urban congestion, the broader policy mix affecting the cost of driving and the specific design of the congestion pricing scheme.In chapter 3, co-authored with Renaud Foucart, we study the impact of different quantity-based tools that governments can use to support the production of homogeneous goods through clean rather than polluting inputs in a setting where production costs are uncertain.In recent years, many sectors have been disrupted by clean innovation, as clean inputs have emerged as close substitutes of polluting ones: for example, in the power sector renewable energy sources are increasingly used for electricity generation instead of fossil fuels. Whenever the negative externalities caused by polluting incumbent technologies are not internalized in production costs, emerging clean technologies are left at a disadvantage. For this reason, governments may want to design policy support schemes for emerging clean technologies.We develop a theoretical framework in which well-established polluting technologies entail known production and pollution costs, while using emerging green technologies requires higher, steeper and uncertain production costs. In this context, a government chooses between a range of quantity-based instruments to support the deployment of clean technologies based on cost estimates, as costs of production with green inputs are uncertain.We show that a cap on production with polluting inputs is the least distortionary among quantity instruments; next is a mandatory share of production with green inputs out of total production. Setting a policy objective in terms of a precise level of green inputs for production is the least efficient policy approach. This ranking results from the so-called “technology effect”, which determines the extent to which the market corrects cost estimation errors after real costs are observed.<br>Doctorat en Sciences économiques et de gestion<br>info:eu-repo/semantics/nonPublished

The diploma thesis involves the design of certification static strength tests for the newly developed aircraft of the TL-Ultralight company. At the beginning of the work, the theory of aircraft testing is generally discussed with emphasis on static strength tests. Furthermore, an analysis of the requirements of the Czech regulation UL 2 and the German LTF-UL, which represent the certification basis for this aircraft, is performed. The requirements of regulations on the construction of the aircraft (or its individual parts) and the requirements for strength tests are discussed in detail. Based on the regulation and the provided calculation protocols, individual test cases and test plans of the wing, tail surfaces, engine bed, and chassis are calculated and prepared. In the end, the calculation of the rocker system and the basic design of jigs are performed.

La thèse s’attache à définir la certification équitable depuis une perspective juridique. Tant l’analyse de sa dimension formelle que matérielle permettent de conclure qu’elle est caractérisée par un dualisme face au droit étatique. Elle entretient à la fois une relation d’autonomie et d’hétéronomie à l’égard des ordres juridiques étatiques. Sur le plan formel, le caractère autonome du régime équitable est révélé par l’existence d’un ordre juridique distinct des ordres étatiques. En effet, les institutions du régime équitable jouent le rôle de tiers impartial et désintéressé à l’égard des producteurs du Sud et des acheteurs du Nord. Le rapport d’hétéronomie se manifeste par l’intervention d’éléments provenant d’ordres juridiques étatiques au sein du régime. Celle-ci contribue à sécuriser et à bonifier le régime équitable. Sur le plan matériel, l’autonomie du régime se traduit par des dispositions inédites. Bien qu’originales par rapport aux normes d’origine étatique, l’analyse de ces normes montre qu’elles ne se placent cependant pas en situation de concurrence face à celles-ci. Elles interviennent plutôt comme complément. Les standards de la certification équitable ne comportent cependant pas que des normes inédites. Plusieurs reprennent textuellement des dispositions d’instruments juridiques internationaux et nationaux d’origine étatique, alors que d’autres les traduisent dans un langage plus accessible et adapté au contexte de leurs destinataires. Dans ces deux cas, il s’agit de réitérer le droit en vigueur plutôt que de s’y opposer en ne se limitant pas à le répéter mais plutôt en facilitant sa connaissance et sa mise en œuvre par des mesures concrètes<br>The thesis aims to define fairtrade certification from a legal perspective. Both its formal and its material dimensions allow concluding that it is characterized by a dualism towards state law. It is both autonomous and heteronomous in relation to state legal orders. On the formal dimension, the fairtrade regime autonomy is revealed by the existence of a legal order distinct from state orders. Indeed, fairtrade regime institutions act as the impartial and disinterested third party towards the producers of the South and the buyers of the North. The heteronomy is shown by interventions, in the fairtrade regime, of elements originated in state legal orders. These interventions contribute to secure and improve the fairtrade regime. On the material dimension, the regime’s original provisions reveal its autonomy. The analysis concludes that these provisions although novel if compared to state norms are not competing with the latters. To the contrary, they intervene as a complement to state legal orders. Fairtrade standards do not only contain unprecedented norms. Several simply reproduce the exact wording of state legal instruments, while other translate them into a more accessible and context adapted language. In both cases, they reiterate the law instead of contradicting it. The regime’s main appeal is that it does not repeat the law but contributes to facilitate its understanding and implementation by concrete measures

The Department of Energy Headquarters Certifying Official has issued a Certificate of Compliance for the shipment of sodium debris bed experiments (DBE) in the NAC International’s Legal Weight Truck (NAC-LWT) casks. The shipment is part of a major de-inventory project at Sandia National Laboratories. The sodium debris bed experiments consist of crucibles containing UO2 immersed in sodium. The uranium is 93% enriched U235. Potential sodium-water reaction and criticality safety under hypothetical accident conditions of transport are the two major technical issues for the design and certification of the NAC-LWT casks for the DBE shipment. The certification review took ≈ 13 months, including one round of questions and responses and source-verification QA audits of the fabrication and welding of the DBE transport canisters at two locations.

Tidal energy is nowadays one of the fastest growing types of marine renewable energy. In particular, horizontal axis tidal turbines (HATT) are the most advanced designs and the most appropriate for standardisation. It is however, in the interest of the industry to provide a set of standard practises in order to help in the process of designing this type of marine converters. DNV GL is producing this standard with the support of Alstom and as part of the ReDAPT project commissioned and co-funded by the ETI (Energy Technologies Institute). The work undertaken by DNV GL to produce this standard involves the identification of the uncertainties that designers need to address during the design process. Unlike other marine structures, HATTs are usually located in very energetic areas where no other marine structure has been before. Site characterisation is one of the largest sources of uncertainty e.g. turbulence. Key inputs like turbine inflow conditions or predictions of extreme values are still grey areas due to the limited site measurements and the uncertainty of the metocean models. Numerical models of HATTs are still quite uncertain often dependent on experience of the people running them. As part of ReDAPT project there is an ongoing effort in validation and evaluation of the accuracy of these numerical models and some of the results are used in this calibration study. The new standard for HATTs deals with the loading uncertainty in a whole new way by introducing a new parameter that is added to the traditional partial safety factors for loads. This new standard uses the traditional safety factors from the offshore structures standards and allows changing them based on the level of uncertainty that was introduced during the design process. This paper describes the process of calibration of the partial safety factors in ULS for loads of HATTs that was part of the work in the creation of the new standard. The reliability based calibration involved the formulation of failure criteria, the identification of stochastic variables in the failure criteria, calculation of reliability against failure and ultimately the new set of partial safety factors for loads and a methodology for adjustment of the factors in a case by case basis.

Turbine inlet temperatures have now approached 1650°C (3000°F) at maximum power for the latest large commercial turbofan engines, resulting in high fuel efficiency and thrust levels approaching or exceeding 445 kN (100,000 lbs.). High reliability and durability must be intrinsically designed into these turbine engines to meet operating economic targets and ETOPS certification requirements. This level of performance has been brought about by a combination of advances in air cooling for turbine blades and vanes, computerized design technology for stresses and airflow and the development and application of rhenium (Re) containing, high γ′ volume fraction nickel-base single crystal superalloys, with advanced coatings, including prime-reliant ceramic thermal barrier coatings (TBCs). Re additions to cast airfoil superalloys not only improve creep and thermo-mechanical fatigue strength but also environmental properties, including coating performance. Re slows down diffusion in these alloys at high operating temperatures.(1) At high gas temperatures, several issues are critical to turbine engine performance retention, blade life and integrity. These are tip oxidation in particular for shroudless blades, internal oxidation for lightly cooled turbine blades and TBC adherence to both the airfoil and tip seal liner. It is now known that sulfur (S) at levels &lt; 10 ppm but &gt; 0.2 ppm in these alloys reduces the adherence of α alumina protective scales on these materials or their coatings by weakening the Van der Waal’s bond between the scale and the alloy substrate. A team approach has been used to develop an improvement to CMSX-4® alloy which contains 3% Re, by reducing S and phosphorus (P) levels in the alloy to &lt; 2 ppm, combined with residual additions of lanthanum (La) + yttrium (Y) in the range 10–30 ppm. Results from cyclic, burner rig dynamic oxidation testing at 1093°C (2000°F) show thirteen times the number of cycles to initial alumina scale spallation for CMSX-4 [La + Y] compared to standard CMSX-4. A key factor for application acceptance is of course manufacturing cost. The development of improved low reactivity prime coats for the blade shell molds along with a viable, tight dimensional control yttrium oxide core body are discussed. The target is to attain grain yields of single crystal CMSX-4 (ULS) [La + Y] turbine blades and casting cleanliness approaching standard CMSX-4. The low residual levels of La + Y along with a sophisticated homogenisation/solutioning heat treatment procedure result in full solutioning with essentially no residual γ/γ′ eutectic phase, Ni (La, Y) low melting point eutectics and associated incipient melting pores. Thus, full CMSX-4 mechanical properties are attained. The La assists with ppm chemistry control of the Y throughout the single crystal turbine blade castings through the formation of a continuous lanthanum oxide film between the molten and solidifying alloy and the ceramic core and prime coat of the shell mold. Y and La tie up the &lt; 2 ppm but &gt; 0.2 ppm residual S in the alloy as very stable Y and La sulfides and oxysulfides, thus preventing diffusion of the S atoms to the alumina scale layer under high temperature, cyclic oxidising conditions. La also forms a stable phosphide. CMSX-4 (ULS) [La + Y] HP shroudless turbine blades will commence engine testing in May 1998.