El continuo af'an por reducir la cantidad de act'¿nidos minoritarios (MA) procedentes del combustible quemado en los reactores de agua ligera (Light Water Reactor, LWR) y de esa forma reducir la radiotoxicidad, ha llevado a desarrollar nuevos conceptos de combustible nuclear. El nuevo combustible por empaquetamiento de esferas (Sphere-Pac, SP) ofrece la oportunidad de reintroducir los MA en una matriz y quemarlos en un reactor r'apido de neutrones, donde se facilitan ciclos mu'ltiples por transmutaci'on de elemen- tos. Este combustible se puede utilizar tambi'en en un sistema subcr'¿tico r'apido de neutrones, es decir, un sistema nuclear accionado por un acelera- dor de part'¿culas (Accelerator Driven System, ADS), donde la subcriticidad (seguridad de parada del reactor) permite utilizar combustibles con mayor contenido de MA que en un reactor normal, reduciendo eficazmente en un solo paso la radiotoxicidad. El combustible SP se produce a partir de una soluci'on base (formada por metales y elementos qu'¿micos) mediante un proceso de gelificaci'on in- terna. Este proceso garantiza una buena homogeneidad del producto final y un riesgo de contaminaci'on mucho menor si se compara con la fabricaci'on cl'asica de pellets (combustible comprimido), puesto que se evita el uso de prensas y amoladoras. La gelificaci'on interna es una reacci'on qu'¿mica acu- osa que se produce al calentar la soluci'on hasta 80 ± 5¿ C. Cuando se realiza el proceso por calentamiento electromagn'etico, se observan algunas venta- jas con respecto al calentamiento tradicional por conducci'on (contacto de la muestra con aceite de silicio precalentado): se evita la etapa de reciclado del aceite y de los disolventes org'anicos necesarios para eliminar el aceite de la superficie de las part'¿culas producidas. En la unidad de gelificaci'on in- terna por microondas (Microwave Internal Gelation, MIG), las microondas representan una alternativa mucho m'as simple y segura: el calentamiento volum'etrico sin contacto facilita la producci'on a distancia del combustible en celdas calientes y adem'as reduce los residuos de l'¿quido contaminado. Esta tesis se enmarca dentro del proyecto Platform for Innovative Nu- clear FuEls (PINE), que tiene como objetivo fundamental la producci'on de combustible SP por MIG. En el sistema MIG, el tiempo de calentamiento es muy corto (del orden de decenas de milisegundos), por lo que se deben optimizar los par'ametros que contribuyen al calentamiento por microondas y es necesario conocer en profundidad la interacci'on entre las microondas y las muestras. En la primera parte de este trabajo se investiga un modelo t'ermico basado en diferencias finitas en el dominio del tiempo (FDTD), el cual es capaz de determinar, en cada instante durante el proceso de calentamiento, el comportamiento t'ermico de un punto definido dentro del material que se calienta. Adem'as se presenta una descripci'on detallada de los par'ametros m'as relevantes del modelo, incluyendo las condiciones de contorno (entre ellas la convecci'on). Por otra parte, se implementa anal'¿ticamente y se valida con diferentes t'ecnicas: una basada en teor'¿a de la f'¿sica, otra basada en la herramienta de ecuaciones diferenciales parciales (PDEtools) y la u'ltima basada en ejemplos encontrados en la literatura. En segundo lugar, se investigan los posibles disen¿os de cavidades de microondas para su aplicaci'on en MIG. Tanto las cavidades (selecci'on de los modos, frecuencia de resonancia, factores de calidad, etc.) como su posterior caracterizaci'on, se detallan con el objetivo de especificar el acoplamiento de energ'¿a. Los mecanismos de transferencia de energ'¿a de las cavidades se explican utilizando el m'etodo de perturbaci'on, con el que adem'as se analizan las p'erdidas de la cavidad cuando se coloca una muestra diel'ectrica en su interior. Con el modelo de transferencia de energ'¿a desar- rollado, se obtiene la tasa de generaci'on de calor por microondas, que se aplica al modelo t'ermico FDTD mencionado anteriormente. Los resultados anal'¿ticos demuestran la viabilidad de producir esferas gelificadas por MIG. Seguidamente se introducen los principales par'ametros relacionados con el calentamiento de un material por microondas, es decir, las propiedades diel'ectricas. Se desarrolla un nuevo procedimiento que permite medir estas propiedades en gotas que caen libremente a trav'es de una cavidad de mi- croondas. Se presenta el montaje experimental, cuya viabilidad se prueba a trav'es de diferentes experimentos. Las propiedades diel'ectricas medidas se incluyen en los modelos (perturbacional y t'ermico) con la intenci'on de determinar la potencia absorbida por la sustancia (en forma de gotas) y la temperatura que alcanza. En la u'ltima parte se presenta la implementaci'on del sistema MIG apli- cada al proyecto PINE, fundamental para la pr'actica de calentamiento (basado en frecuencias altas) dentro del laboratorio. Las propiedades de cada dispositivo se evaluan para realizar un estudio de potencia antes del ensamblaje del sistema MIG. De esa forma se evitan fallos al poner el sis- tema en funcionamiento. Adem'as se aportan las t'ecnicas experimentales y los resultados. La producci'on con 'exito de esferas gelificadas demuestra, sin duda, el uso favorable de las microondas en la producci'on de combustible SP por gelificaci'on interna. / In the continuous aim to reduce the amount of minor actinides (MA) from the spent fuel of Light Water Reactors (LWR) and therefore reduce its radiotoxicity (radioactive toxicity), new nuclear fuel concepts have been developed. Sphere-Pac (SP) fuel gives the opportunity to reintroduce the MA in a fuel matrix and to burn them in a fast reactor, which facilitates a multi-cycle because of its breeding feature, or in a subcritical fast system, i.e. an Accelerator Driven System (ADS) where its sub-criticality allows higher MA contents than a normal fast reactor reducing efficiently the radiotoxicity in one step. SP fuel is produced from the base solution (already containing all the elements) by internal gelation, which guarantees a good material homo- geneity and a lower contamination risk compared to the classical pellet fabrication, avoiding presses and grinding machines. The internal gelation is an aqueous chemical reaction occurring when the solution is heated up to 80 ± 5¿C. When performing the internal gelation process with electro- magnetic heating, some advantages appear with respect to the traditionally heating through conduction by contact of the sample with hot silicon oil: the recycling step of the oil and the organic solvents necessary to clean the particles from oil are avoided. In the Microwave Internal Gelation (MIG) unit, the microwaves represent a much simpler and safer alternative: the contactless volumetric heating facilitates the remote production of the fuel in hot cells and furthermore reduces the contaminated liquid waste. The fuel related project called Platform for Innovative Nuclear FuEls (PINE), in which this thesis is embedded, aims for the production of SP- fuel by MIG. In the MIG system, the heating time is very short (in the order of tens of milliseconds), therefore the microwave heating parameters have to be optimized and a good knowledge of the interaction between the microwaves and the samples must be achieved. In the first part of this dissertation a finite difference time domain (FDTD) thermal model capable to determine over each instant about the thermal behaviour of a definite point inside a material during heat process- ing is investigated. A detailed overview of the most relevant parameters on the model including the boundary conditions (e.g. convection) is pre- sented. Furthermore, the model is analytically implemented and validated with different techniques: a theoretical based physically validation, a par- tial differential equations (PDEtools) based validation and a validation with examples from the literature. Secondly, possible microwave cavity designs for MIG are researched. The cavities (selection of modes, resonant frequency, Q-factor, etc.) and its subsequent characterization for the coupling of energy are explained. Furthermore, the power transfer mechanisms of the cavities are explained using the perturbation method to analyse the losses when a dielectric sam- ple is placed inside a cavity. The developed power transfer model delivers the microwave heat generation rate which is applied to the FDTD thermal model mentioned in the previous paragraph. The analytical results provide a positive impression about the feasibility of producing gelated spheres by MIG. Next, the main parameters dealing with the heating of a material by microwaves are introduced. A new procedure that enables the measure- ment of dielectric properties of aqueous droplets freely falling through a microwave cavity is developed. The experimental setup is presented and several experiments prove its feasibility. The measured dielectric properties are afterwards included in the perturbation and thermal models with the main intention of determining the absorbed power by the material in form of drops and the reached temperature. In the last part the MIG system for the laboratory practice of the high frequency heating applied to the PINE project is implemented. Each device is characterized for a power study precedent to the MIG system assembly, avoiding then failures when putting the system into operation. In addition, the experimental techniques and the results are reported. Successful pro- duction of gelated spheres shows the favourable usage of microwave for the production of SP-fuel by internal gelation. / Cabanes Sempere, M. (2013). Innovative production of nuclear fuel by microwave internal gelation [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31641 / Alfresco

INTRODUCTION : Les greffons de veine saphène interne (GVS) sont encore régulièrement utilisés comme conduits en chirurgie de pontage aorto-coronarien (PAC). Les dommages subis par les segments de veine saphène pendant le prélèvement et le stockage favorisent une dysfonction endothéliale qui se manifeste par une diminution de la production d'oxyde nitrique et/ou par une augmentation du niveau de stress oxydant pouvant entraîner une défaillance du greffon veineux se traduisant par une occlusion. La solution saline héparinée est la solution de préservation de référence malgré plusieurs études démontrant ses effets néfastes sur les GVS. GALA est une solution de préservation de greffons autologues vasculaires spécialement développée pour préserver l'intégrité structurale et fonctionnelle de la couche endothéliale des greffons utilisés en chirurgie de pontages aorto-coronariens. OBJECTIF : Comparer la préservation de l'intégrité des fonctions endothéliales des greffons de veine saphène après le stockage dans la solution GALA versus dans la solution saline héparinée dans le cadre d’une étude contrôlée et randomisée en étudiant la réactivité vasculaire en chambres d’organes. RÉSULTATS : Les segments de GVS d'un total de quinze patients ont été obtenus et divisés en anneaux de 3 mm de largeur. Il n'y avait pas de différences significatives dans les niveaux de contraction en réponse au chlorure de potassium, à la phényléphrine, ni dans les concentrations de phényléphrine nécessaires pour atteindre le niveau de contraction cible entre les anneaux du groupe GALA versus le groupe de saline héparinée. Les courbes dose-réponse du groupe solution GALA ont démontré une amélioration significative des relaxations dépendantes de l'endothélium par rapport au groupe solution saline héparinée. Les contractions et relaxations indépendantes de l'endothélium induites respectivement par la phényléphrine et le nitroprussiate de sodium étaient similaires dans les anneaux de GVS des deux groupes. CONCLUSION : L’utilisation intra-opératoire d'une solution développée spécifiquement pour la préservation de l’intégrité endothéliales présente un potentiel d’avantages cliniques chez les patients qui subissent une chirurgie de PAC. Les observations précédentes suggèrent que la solution GALA pourrait réduire la dysfonction endothéliale associée à la défaillance des greffons veineux et incite des évaluations à long terme plus approfondies dans le cadre d’essais cliniques. / INTRODUCTION: Saphenous vein grafts (SVGs) are still commonly used as conduits for coronary artery bypass grafting (CABG). Injury to SVGs during harvesting and storage promotes endothelial dysfunction, which is attributed to a decrease in production of nitric oxide and/or increased level of oxidative stress that can lead to vein graft failure (VGF). Heparinized saline is still the standard of care intraoperative preservation solution despite several studies demonstrating its detrimental effects on SVGs. GALA is an innovative one-time intraoperative graft storage solution developed to preserve endothelial integrity. OBJECTIVE: To investigate, in a randomized controlled study, endothelial functional integrity of saphenous vein grafts following storage in GALA vs heparinized saline using ex vivo vascular reactivity studies in organ chamber experiments. RESULTS: Segments of saphenous vein grafts from a total of fifteen patients were obtained and divided into 3 mm wide rings for evaluation. There were no significant differences in the levels of contraction in response to potassium chloride and to phenylephrine between groups, nor in the concentrations of phenylephrine needed to achieve the target level of contraction in saphenous vein graft rings. Concentration-response curves of the GALA group demonstrated a significant improvement in endothelium-dependent relaxations compared to the heparinized saline group. Endothelium-independent contractions and relaxations induced by phenylephrine and sodium nitroprusside, respectively, were not altered in saphenous vein graft rings from both groups. CONCLUSIONS: Intraoperative application of a solution developed for graft preservation demonstrated a potential benefit to protect endothelial and vascular functional integrity in saphenous vein grafts of patients undergoing CABG. These data suggest that the GALA solution may reduce endothelial dysfunction associated with vein graft failure and warrant further long-term evaluation in clinical trials.

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This research challenges the hypothesis that Biko was anti-liberal and anti-white. Biko's clearly defined condemnation of traditional South African white liberals such as Alan Paton is hypothesised as a strategic move in the liberation struggle designed to neutralise the "gradualism" of traditional white liberalism which believe that racism could be ultimately superseded by continually improving education for blacks. Biko neutralised apartheid racism and traditional white liberalism by affirming all aspects of blackness as positive values in themselves, and by locating racism as a white construct with deep roots in European colonialism and pseudoDarwinian beliefs in white superiority. The research shows that Biko was neither anti-liberal nor anti-white. His own attitudes to the universal rights, dignity, freedom and self-determination of all human beings situate him continuously with all major human rights theorists and activists since the Enlightenment. His unique Africanist contribution was to define racist oppression in South Africa as a product of the historical conditioning of blacks to accept their own alleged inferiority. Biko's genius resided in his ability to synthesize his reading of Marxist, Africanist, European and African American into a truly original charter for racial emancipation. Biko' s methodology encouraged blacks to reclaim their rights and pride as a prelude to total emancipation. The following transactions are described in detail: Biko's role in the founding of SASO and Black Consciousness; the paradoxical relations between white liberal theologians, Black Consciousness and Black Theology; the influence on BC of USA Black Power and Black Theology; the role of Black Theologians in South African churches, SACC and WCC; synergic complexities ofNUSAS-SASO relations; relations between BC, ANC and PAC; the early involvement of women in BCM; feminist issues in the liberation struggle; Biko's death in detention; world-wide and South African liberal involvement in the inquest and anti-apartheid organisations. / History / D. Litt. et Phil. (History)

This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

This research challenges the hypothesis that Biko was anti-liberal and anti-white. Biko's clearly defined condemnation of traditional South African white liberals such as Alan Paton is hypothesised as a strategic move in the liberation struggle designed to neutralise the "gradualism" of traditional white liberalism which believe that racism could be ultimately superseded by continually improving education for blacks. Biko neutralised apartheid racism and traditional white liberalism by affirming all aspects of blackness as positive values in themselves, and by locating racism as a white construct with deep roots in European colonialism and pseudoDarwinian beliefs in white superiority. The research shows that Biko was neither anti-liberal nor anti-white. His own attitudes to the universal rights, dignity, freedom and self-determination of all human beings situate him continuously with all major human rights theorists and activists since the Enlightenment. His unique Africanist contribution was to define racist oppression in South Africa as a product of the historical conditioning of blacks to accept their own alleged inferiority. Biko's genius resided in his ability to synthesize his reading of Marxist, Africanist, European and African American into a truly original charter for racial emancipation. Biko' s methodology encouraged blacks to reclaim their rights and pride as a prelude to total emancipation. The following transactions are described in detail: Biko's role in the founding of SASO and Black Consciousness; the paradoxical relations between white liberal theologians, Black Consciousness and Black Theology; the influence on BC of USA Black Power and Black Theology; the role of Black Theologians in South African churches, SACC and WCC; synergic complexities ofNUSAS-SASO relations; relations between BC, ANC and PAC; the early involvement of women in BCM; feminist issues in the liberation struggle; Biko's death in detention; world-wide and South African liberal involvement in the inquest and anti-apartheid organisations. / History / D. Litt. et Phil. (History)

This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

L’adoption par l’OMC de mesures de TSD utiles pour promouvoir l’agriculture des PED par le commerce agricole a favorisé l’accès des PED au marché rémunérateur de l’UE par des schémas multiples qui ne sont pas encore répartis équitablement entre les PED. Les préférences tarifaires de l’UE accordées aux PED figurent parmi les plus importants instruments de développement commercial utilisés par les pays développés. Cependant, l’effectivité des mesures de TSD reste relative à cause des limites inhérentes à leur contenu influencé par le statut particulier de l’agriculture à l’OMC. L’UE continue de bénéficier d’arrangements spéciaux et pratique un protectionnisme agricole très complexe et très décrié sur le plan externe. Les politiques commerciales, agricoles, sociales, environnementales et sécuritaires en vigueur dans le marché agricole européen neutralisent les efforts consentis par les PED, plus particulièrement les PMA et les pays ACP, pour exploiter les préférences. L’avenir de l’accès des PED au marché agricole de l’UE est actuellement lié à l’aboutissement incertain des négociations du Cycle Doha sur le TSD et l’agriculture. Les Conférences ministérielles de Bali (décembre 2013) et de Nairobi (décembre 2015) ont permis de mettre sur pied des accords partiels et a minima qui semblent maintenir le déséquilibre subtil entre un TSD peu contraignant et un statut particulier de l’agriculture toujours résistant à l’OMC, sans apporter une solution définitive au statu quo de l’accès des PED aux marchés agricoles des pays développés. Les enjeux et les perspectives de l’accès des PED au marché agricole de l’UE dépendent de la direction que prendront les travaux en cours pour répondre aux questions de développement et de libéralisation agricole dans le cadre d’un vrai cycle de développement. / The adoption by the WTO of special and differential treatment (SDT) measures that are useful for promoting the agriculture of developing countries through agricultural trade has favored the access of developing countries to the remunerative market of the EU through multiple schemes that are not yet evenly distributed between developing countries. EU tariff preferences for developing countries (DCs) are among the most important trade development instruments used by developed countries. However, the effectiveness of SDT measures remains relative because of the limitations inherent in their content influenced by the special status of agriculture in the WTO. The EU continues to benefit from special arrangements and practices agricultural protectionism that is very complex and highly criticized externally. The commercial, agricultural, social, environmental and security policies in force in the European agricultural market neutralize the efforts made by developing countries, in particular least developed countries (LDCs) and ACP countries, to exploit preferences.The future access of developing countries to the agricultural market of the EU is currently linked to the uncertain outcome of the Doha Round negotiations on SDT and agriculture. The Ministerial Conferences in Bali (December 2013) and Nairobi (December 2015) have led to the establishment of partial and minimum agreements that seem to maintain the subtle imbalance between a non-constraining SDT and a particular status of agriculture that is still resistant to The WTO without providing a definitive solution to the status quo of DCs access to agricultural markets in developed countries. The challenges and prospects of developing countries' access to the EU agricultural market depend on the direction of work in progress to address agricultural development and liberalization issues within a real development cycle.