La production d’hydrogène et de dioxygène par électrolyse PEM (PEM « Proton Exchange Membrane ») de l’eau s’effectue grâce à la présence de métaux nobles dans les couches catalytiques: à la cathode, le platine supporté sur du carbone est généralement utilisé (les chargements en métaux nobles sont faibles de l’ordre de 0,5 mg/cm²) ; à l’anode, la production d’oxygène s’effectue à des potentiels élevés (> 1,6 V vs. ESH). Les oxydes de métaux nobles sont utilisés seuls dans la couche active anodique et servent à la fois de catalyseurs et de conducteurs électroniques. Comme ils sont parmi les métaux les plus denses, pour obtenir une continuité électrique de la couche anodique, les chargements doivent être très élevés, de l’ordre de 2-3 mg/cm².Cette thèse propose ainsi de développer de nouveaux matériaux supports stables électrochimiquement et bons conducteurs électroniques pour séparer les fonctions de catalyse et de conduction électronique. Pour cela, des assemblages membrane électrodes intégrant des particules de titane comme support de catalyseur anodique ont été préparés dans notre laboratoire. Testés en mono-cellule de 25 cm², leurs principales caractéristiques ont été déterminées par voltampérométrie cyclique, spectroscopie d’impédance et grâce à des courbes de polarisations à différentes températures. La comparaison des résultats obtenus entre ces anodes « innovantes » et celles à base de catalyseur seul a permis de mettre en évidence la présence d’un chargement anodique seuil de 0,5 mg/cm² en dessous duquel la présence d’un support de catalyseur est nécessaire pour assurer la percolation électrique. Grâce à l’utilisation de ce support de catalyseur bon marché, les chargements anodiques ont pu être réduits jusqu’à des valeurs aussi faibles que 0,1 mg/cm² IrO2, soit une réduction de dix fois au minimum par rapport aux taux généralement employés dans la littérature, tout en maintenant des performances identiques. / It is expected that PEM water electrolysis will play a significant role in the hydrogen society as a key process for producing hydrogen from renewable energy sources but before this, substantial cost reductions are still required. Because of the high acidity of membrane materials used in PEM water electrolysers, expensive noble-metals or their oxides are required as electrocatalysts (platinum for hydrogen evolution and iridium for oxygen evolution). As the oxygen evolution reaction takes place with a large overpotential (anodic potential > 1.6 V) only few materials can be used to avoid corrosion. In state-of-the-art, noble metal oxides are generally used alone in the active layer with typical loadings of 2-3 mg/cm² and act as both catalyst and electronic conductor.In order to reduce the noble metal loadings and keep a good electronic conductivity of the catalytic layer, iridium can be supported onto a conductive and electrochemical stable material support. To gain more insights, several MEAs with anodes made of pure iridium oxide or 50 wt % IrO2/Ti anodes have been prepared and characterized using cyclic voltammetry and impedance spectroscopy, and by measuring polarization curves at different operating temperatures. Without the catalyst support, anodic loadings can be reduced down to 0,5 mg/cm² without any degradation in the electrochemical performances. By using anodes made of iridium oxide and titanium particles, further reductions of anodic loading can be made down to 0.1 mg/cm² with performances similar to those obtained with conventional loadings of several mg cm-2.

abstract: During the 2017-2018 academic year, I worked as Program Manager for a government-funded post-secondary organization in Ontario, Canada. A core part of my professional role was creating awareness and increasing the use of open educational resources (OER) in partnership with Ontario educators. I conducted this work with the support of colleagues and OER advocates at public colleges and universities. Collectively, we focused on the use of OER as an opportunity to: (a) reduce the cost of post-secondary resources, (b) diversify the types of resources used in teaching and learning, and (c) explore opportunities to create assessments and activities that empowered learners as co-creators of knowledge. Alongside my professional role during this year, I engaged in a mixed-methods action research study using change management strategies and Ajzen’s (1991) Theory of Planned Behavior. The purpose of the study was to determine the usefulness of an awareness and support strategy designed to increase the use of OER among post-secondary educators in Ontario. For many of the participants in the study (n = 38), OER were new elements in their teaching practice. I engaged in focused and meaningful dialogue with them as part of professional development sessions in order to fully explore their perspectives about use of OER. I chose two facilitation designs as the action of my action research. The first was a pair of face-to-face workshops, and the second was an open online course commonly called a MOOC (massive open online course). These were the interventions (and innovations) for the study. From the perspective of the participants, the awareness and support strategies were determined to be useful for increasing their use of OER. / Dissertation/Thesis / Doctoral Dissertation Educational Leadership and Policy Studies 2018

Present trends in the mainstream adoption of educational technology coupled to the increased acceptance and adoption of openness in terms of sharing resources and open access force higher education into a radical rethink of its structures and educational strategies. This article examines the current shift in focus from the simple production and sharing of open educational resources (OER) towards wider concepts such as open educational practices (OEP) and cultures (OEC). OER involves mostly educators whereas OEP and OEC demand the commitment of management, administrators and politicians.  This openness is already spawning alternative types of peer-based collaborative learning both inside and outside the formal education system. In particular the increased awareness of the importance of informal learning has raised a clear need for some kind of certification model and the current open badges initiative lead by Mozilla and several US authorities is examined and discussed. In 2011 the OER university partnership announced an innovative approach to combining formal and informal learning by planning to offer credible credentials for students who have acquired the necessary skills through their own learning paths. The road to future higher education may not be entirely behind the campus walls.

Temos aktualumas. Lietuvos Respublikos Švietimo ir mokslo ministerijos dokumentuose apie papildomą ir neformalųjį mokinių švietimą dėmesio centre yra moksleivis. Moksleivis – tai šalies ateitis. Todėl vienas iš pagrindinių Lietuvos demokratinės švietimo politikos principų – suteikti visiems piliečiams lygias teises į mokslą, nepriklausomai nuo gyvenamos vietos, lyties, socialinės kilmės bei įsitikinimų. Labai svarbu užtikrinti kokybišką, prieinamą ne tik formalųjį švietimą, bet ir papildomą. Papildomas ugdymas turi tenkinti moksleivio poreikius ir interesus, turi padėti atsiskleisti asmenybei, pasiruošti savarankiškam gyvenimui, tapti konkurentabiliu. Šių dienų besimokantysis turi ne tik atgaminti žinias, bet ir rasti, formuluoti problemas, vertinti galimus sprendimo būdus, ieškoti alternatyvių požiūrių, kritiškai mąstyti [20]. Tik nuolatinis švietimo proceso tobulinimas, naujų metodų, mokymo priemonių ieškojimas gali patenkinti besimokančiojo poreikius ir užtikrinti kokybišką švietimą. Inovatyvios kompiuterinės technologijos vis plačiau taikomos švietimo procese. Jos gerokai pakeitė tradicinį mokymąsi, kuris dažnai perkeliamas į virtualią erdvę. Sparti IKT plėtra duoda naują impulsą tobulinti tradicinio švietimo metodus ir taikyti juos bendrojo lavinimo bei papildomo ugdymo įstaigose. Švietimo kontekste atsiranda svarbi sąvoka – e. mokymasis, kuris mokymąsi padaro patrauklesniu, prieinamesniu besimokančiajam. E. mokymasis – tai toks mokymosi būdas, kai dalis mokymosi... [toliau žr. visą tekstą] / The documents about informal and non-formal students education of the Ministry of Education and Science of the Republic of Lithuania documents, focuses attention on the student. This suggests that additional education has to meet the student's needs, helping to reveal the personality, to prepare for independent living. These days, the learner should not only reproduce knowledge, but also to find, formulate problems, evaluate possible solutions, finding alternative approaches to think critically. More and more in the educational process applied innovative computer technologies expanding learning opportunities. E. thanks to learning, which is currently increasingly being used in the education system, the learning process becomes more accessible, more attractive, more individualized. At present, the ever-popular e-learning using the open educational resources (OER). There is no unanimous OER store oriented to the main user - student, which gathers both the country and foreign OER in Lithuania . Tests of different things, learning games, videos, applications, e-books and other OER "scattered" on the Internet. For this problem, there is a need to create OER sharing system for students. During the work the OER model created for students informal learning. The model is implemented on the site OER. There students can put their created, modified OER, links to the other online resources, to view, to download the resources in the site. You can also evaluate and comment on them. Can... [to full text]

Tumours are characterised by unorganised vasculature, which often results in hypoxic regions. Hypoxia is a common cause for photon radiotherapy (RT) treatment failure, as hypoxic cells require up to 2-3 times higher doses compared to well-oxygenated cells for the same effect in terms of cell kill. The increase in dose that would be required to treat the tumours of cancer patients is limited by the radiation sensitivity of surrounding normal tissues. Using carbon ions instead of photons, the radiation dose can be conformed to the tumour to a much higher degree, resulting in an improved sparing of normal tissues. In addition, carbon ions have a much higher radiobiological effectiveness near the end of their range, which is positioned in the tumour. Also, the radiation modes of action leading to cell death when carbon ions interact with living tissues, are less sensitive to the oxygen status compared with the action modes of photons. The focus of this thesis lies in the development of models for the computation of the cell surviving fraction and tumour control probability (TCP) in hypoxic tumours after photon and carbon ion RT. The impact of fractionation was evaluated with regard to possible spatial changes in oxygenation, both for stereotactic body RT and for carbon ion RT. The feasibility of a method to determine and deliver the optimal photon dose for achieving a high TCP according to spatial variations in radiation sensitivity was evaluated in a treatment planning study. The radiobiological models were finally used for the theoretical quantification of the gain in using carbon ions instead of photons. The results show that there are great possibilities to increase the number of positive outcomes of radiation treatment of tumours if the key influential factors are taken into account, such as level and distribution of hypoxia, radiation quality and choice of fractionation schedule. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows; Paper 3: Manuscript; Paper 4: Epubl ahead of print; Paper 5: Manuscript</p>

An agile approach is most often used in software development but has been applied in other areas such as manufacturing and project management as well. Within literature, there are only a few studies that investigate the use of an agile approach for authoring educational content. This study explores how an agile approach could facilitate rapid and collaborative authoring of educational content. This qualitative study utilised a multiple case study strategy. The data were collected through semi-structured interviews and observations. The insight gained from this study indicated that the agile approach that emerged was a valuable lens through which to explore rapid and collaborative authoring of educational content. The study also revealed that community building among those participating in the authoring process is fundamental to the success of an agile approach. Further insights include offering training and support to the participants of the authoring sprints regarding an agile process, the applications utilised and imminent change. An agile approach in education emerged from the study and could be an alternative to traditional content authoring approaches for educational content. Finally, the study revealed the need for a comprehensive software package that included file sharing, instant messaging, task management, screen sharing and conferencing capabilities alongside the authoring software. / Dissertation (MEd)--University of Pretoria, 2017. / Science, Mathematics and Technology Education / MEd / Unrestricted

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Rachel Fleming, Ashley Sergiadis, and Rachel Caldwell discuss several ways that academic libraries can help OER adopters and authors improve the impact of their work, make materials more accessible, and ensure continued access.