Grain Boundary Migration of NiO-MgO Alloys

Grain boundary engineering offers enhanced control of microstructure development during processing, leading to improved final material properties. However, using the effects of the interfacial energy anisotropy on grain boundary mobility to control microstructure development is not well understood. The NiO-MgO system is studied as it has complete solid solubility and a transition in the faceting behavior with composition due to changes in the interfacial energy anisotropy. NiO-MgO powders were produced through the amorphous citrate process and modifications to the process were made to reduce particle and agglomerate size. The powders were pressed and sintered in various conditions to produce fine grained high purity dense samples. Wet milling demonstrated a reduction in the overall particle and agglomerate size of the powders. Pressureless sintering showed an increase in the densification of the NiO-MgO compacts with increased heating rate. Wet milling and high heating rates produced near fully dense samples with relative apparent densities of \u3e95% and open porositie

Blogs and e-Portfolios: can they support reflection, evidencing and dialogue in teacher training?

A blog with explicit support for structured skills/competencies and community publishing was integrated within an e-Portfolio and evaluated with three successive cohorts of PGCE secondary students at Newcastle University in order to support reflections on practice, weekly lesson evaluations, and to evidence Teaching Quality Standards (TQS).The technologies were initially piloted with a single subject (English with Drama) in 2007/8, with roll out to all thirteen PGCE programmes in 2008/9 (156 students and seven tutors). Focus groups and questionnaires were used to investigate students' perceptions of using the blog to support both reflection and evidencing, to identify factors relating to engagement, and to explore informal use of external social networking with course-mates. Tutors' views were also captured.Students accessed the portfolio an average of sixty three times each (the range being from 4 to 254) and uploaded a total of 1,785 files over a ten month period in 2008/9. Students made an average of 27 blog entries each (36% published to a community). Analysis of questionnaire data (37% response rate) indicated that students liked the approach of linking one item of evidence to multiple TQS and feeling 'in touch' whilst on placement. Students (89%) used external social networking sites (47% of students used them for course-related purposes). The main barrier to engagement with the e-Portfolio was the perceived lack of time on a busy course.This study informs debate on the level of structure required in e-Portfolios/blogs for vocational subjects and factors relating to engagement and concurrent use of formal/institutional and informal social networking sites

Valeurs pour les jeux coopératifs à choix multiples avec applications au partage des coûts d'un réseau de distribution de gaz

The role of a gas distribution network is to connect consumers to a gas source. This network is managed by an operator, whose task incurs various costs. Some of these costs may not be attributable to a particular consumer.Assuming that the operator wishes to recover these costs by charging for its services, the problem is then how to share these costs among consumers.This thesis proposes solutions to this problem using multi-choice (cooperative) game theory.All the solutions proposed in this thesis are designed to take into account the gas demands of consumers.Furthermore, since certain ethical principles are desirable for a network operator with respect to how it bills consumers, some of our solutions are designed to satisfy these principles. These are: the independence of higher demands principle and the uniformity principle. Finally, some solutions also manage to take into account the different information provided by the distribution network.This thesis consists of seven chapters. Chapter 1 serves as an introduction. Chapter 2 introduces the notations and definitions necessary for a good understanding of the thesis. Chapters 3 to 6 contain the contributions of the thesis.Each of these contributions brings its own solutions.We axiomatically characterize each of them and discuss their relevance in the context of gas distribution. Finally, Chapter 7 concludes the thesis.Le rôle d'un réseau de distribution de gaz est de connecter des consommateurs à une source de gaz. Ce réseau est géré par un opérateur, dont la tâche engendre divers coûts. Certains de ces coûts peuvent ne pas être imputables à un consommateur particulier.En supposant que l'opérateur souhaite recouvrir ces coûts en facturant ses services, le problème est alors de déterminer comment partager ces coûts entre les consommateurs.La présente thèse propose des solutions à ce problème en mobilisant la théorie des jeux (coopératifs) multi-choix.Toutes les solutions proposées dans cette thèse sont conçues pour prendre en compte les demandes en gaz des consommateurs.De plus, comme certains principes éthiques sont souhaitables pour un opérateur de réseau en ce qui concerne la manière dont il facture les consommateurs, certaines de nos solutions sont conçues pour satisfaire à ces principes. Ces principes sont : l'indépendance aux demandes supérieure et la péréquation. Enfin, certaines solutions parviennent aussi à prendre en compte les différentes informations fournies par le réseau de distribution.Cette thèse est constituée de sept chapitres. Le Chapitre 1 fait office d'introduction. Le Chapitre 2 introduit les notations et les définitions nécessaires à la bonne compréhension de la thèse. Les Chapitres 3 à 6 contiennent les contributions de la thèse.Chacune de ces contributions apporte ses propres solutions.Nous caractérisation axiomatiquement chacune d'entre elles et discutons de leur pertinence dans le cadre de la distribution de gaz. Enfin, le Chapitre 7 conclut la thèse

Cost allocation in energy distribution networks

This paper presents a cost allocation problem arising from energy distribution and proposes cost allocation rules that depend on the distribution network and consumer demands. To determine relevant rules, we adopt a normative approach and compare two principles: (i) the connection principle and (ii) the uniformity principle. The Connection rule is proposed in accordance with (i), while the Uniform rule is developed in line with (ii). However, (i) and (ii) are incompatible. To make a trade-off between them, we propose a family of Mixed rules. Each rule is axiomatically characterized. Then, we demonstrate that the Connection rule coincides with the multi-choice Shapley value of a specific multi-choice game derived from the original problem. Moreover, the Connection rule is in the Core of this game. Similarly, we show that the Uniform rule and the Mixed rules coincide with other solution concepts from multi-choice games

Cost allocation in energy distribution networks

This paper presents a cost allocation problem arising from energy distribution and proposes cost allocation rules that depend on the distribution network and consumer demands. To determine relevant rules, we adopt a normative approach and compare two principles: (i) the connection principle and (ii) the uniformity principle. The Connection rule is proposed in accordance with (i), while the Uniform rule is developed in line with (ii). However, (i) and (ii) are incompatible. To make a trade-off between them, we propose a family of Mixed rules. Each rule is axiomatically characterized. Then, we demonstrate that the Connection rule coincides with the multi-choice Shapley value of a specific multi-choice game derived from the original problem. Moreover, the Connection rule is in the Core of this game. Similarly, we show that the Uniform rule and the Mixed rules coincide with other solution concepts from multi-choice games

Valeurs pour les jeux coopératifs à choix multiples avec applications au partage des coûts d'un réseau de distribution de gaz

Le rôle d'un réseau de distribution de gaz est de connecter des consommateurs à une source de gaz. Ce réseau est géré par un opérateur, dont la tâche engendre divers coûts. Certains de ces coûts peuvent ne pas être imputables à un consommateur particulier.En supposant que l'opérateur souhaite recouvrir ces coûts en facturant ses services, le problème est alors de déterminer comment partager ces coûts entre les consommateurs.La présente thèse propose des solutions à ce problème en mobilisant la théorie des jeux (coopératifs) multi-choix.Toutes les solutions proposées dans cette thèse sont conçues pour prendre en compte les demandes en gaz des consommateurs.De plus, comme certains principes éthiques sont souhaitables pour un opérateur de réseau en ce qui concerne la manière dont il facture les consommateurs, certaines de nos solutions sont conçues pour satisfaire à ces principes. Ces principes sont : l'indépendance aux demandes supérieure et la péréquation. Enfin, certaines solutions parviennent aussi à prendre en compte les différentes informations fournies par le réseau de distribution.Cette thèse est constituée de sept chapitres. Le Chapitre 1 fait office d'introduction. Le Chapitre 2 introduit les notations et les définitions nécessaires à la bonne compréhension de la thèse. Les Chapitres 3 à 6 contiennent les contributions de la thèse.Chacune de ces contributions apporte ses propres solutions.Nous caractérisation axiomatiquement chacune d'entre elles et discutons de leur pertinence dans le cadre de la distribution de gaz. Enfin, le Chapitre 7 conclut la thèse.The role of a gas distribution network is to connect consumers to a gas source. This network is managed by an operator, whose task incurs various costs. Some of these costs may not be attributable to a particular consumer.Assuming that the operator wishes to recover these costs by charging for its services, the problem is then how to share these costs among consumers.This thesis proposes solutions to this problem using multi-choice (cooperative) game theory.All the solutions proposed in this thesis are designed to take into account the gas demands of consumers.Furthermore, since certain ethical principles are desirable for a network operator with respect to how it bills consumers, some of our solutions are designed to satisfy these principles. These are: the independence of higher demands principle and the uniformity principle. Finally, some solutions also manage to take into account the different information provided by the distribution network.This thesis consists of seven chapters. Chapter 1 serves as an introduction. Chapter 2 introduces the notations and definitions necessary for a good understanding of the thesis. Chapters 3 to 6 contain the contributions of the thesis.Each of these contributions brings its own solutions.We axiomatically characterize each of them and discuss their relevance in the context of gas distribution. Finally, Chapter 7 concludes the thesis

Sharing the Cost of a Gas Distribution Network.

International audienceSharing the Cost of a Gas Distribution Network

Sharing the Cost of a Gas Distribution Network.

International audienceSharing the Cost of a Gas Distribution Network