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No description available.

L’exploitation des traces d’interaction lors de tâches d’apprentissage permet différents types de retour d’expérience : retour immédiat pour l’apprenant sur sa tâche, retour d’expérience au niveau d’un groupe de pairs, retour d’expérience vers le tuteur en situation d’apprentissage, retour d’expérience vers les concepteurs de formation. Ces retours d’expérience s’expriment le plus souvent sous une forme synthétique : des indicateurs. Ce travaille apporte des solutions originales aux deux facettes indispensables à toute ingénierie des indicateurs : 1) intégration d’un système à base de traces comme nouvelle brique disponible pour la conception d’EIAH (intégration dans un framework de type Moodle) ; 2) Elaboration d’un processus intégré de transformations explicites de traces modélisées préparant à un calcul explicite d’indicateurs. Les connaissances de modélisation des traces, des transformations et de la description de la formule d’indicateur sont capitalisées, facilitant la réutilisation et la constitution de bibliothèques d’indicateurs « prêts à l’emploi ». Pour illustrer l’approche, nous avons développé un jeu de modèles de traces et de transformations adaptées à une situation cible choisie pour sa richesse interactive. Ce jeu de modèles pourra concerner l’apprenant seul, mais aussi le groupe de pairs et éventuellement le groupe classe pour révéler certains phénomènes, tels que la collaboration, non visibles au niveau de l’individu seul. L’outil développé, pour faire la démonstration de l’approche proposée, a été testé en vraie grandeur sur plusieurs terrains universitaires et est disponible en téléchargement pour Moodle. / The exploitation of user’s interaction historic provides different level of experience’s feedback and for different kind of users: experience feedback for teachers, student, group of students, TEL designers. This work provides novel solutions to two essential aspects to any engineering indicators: 1) Integration of a Trace Based System as a new component for TEL systems design (integration in a framework as Moodle for example); 2) Building a set of Trace models with a transformations process to compute explicitly indicators. Knowledge modeling traces, transformations, and indicators’ formula description are capitalized, allowing the reuse and the creation of indicators library “ready to use” To illustrate the approach, we have developed a set of traces models and transformations adapted to a chosen learning situation. This set of models will involve him- self, the peers group and possibly the whole class to reveal some phenomena, such as collaboration. A demonstration software has been developed and tested in three different university contexts and is available for download for Moodle.

by Mok Chuen Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1979. / Includes bibliographies.

Liu Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract (Chinese) --- p.ii / Abstract --- p.iii / Acknowledgement --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview and history --- p.1 / Chapter 1.2 --- Structure of β-cyclodextrin --- p.2 / Chapter 1.3 --- Complexation with aromatic compounds --- p.2 / Chapter 1.4 --- Scope of the thesis --- p.6 / Chapter 1.5 --- References --- p.8 / Chapter Chapter 2 --- Synthesis and characterization of β-cyclodextrin epichlorohydrin copolymer --- p.10 / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Effects of major parameters on polymerization --- p.11 / Chapter 2.3 --- Polymerization mechanisms --- p.13 / Chapter 2.4 --- Synthesis and characterization of β-cyclodextrin epichlorohydrin copolymer --- p.13 / Chapter 2.5 --- References --- p.18 / Chapter Chapter 3 --- β-Cyclodextrin epichlorohydrin copolymer as a solid-phase extraction sorbent for aromatic compounds --- p.19 / Chapter 3.1 --- Introduction --- p.19 / Chapter 3.2 --- Experimental --- p.22 / Chapter 3.3 --- Results and discussion --- p.25 / Chapter 3.3.1 --- Effect of pH on the extraction of aromatic compounds --- p.25 / Chapter 3.3.2 --- Optimum stirring time for the extraction of aromatic compounds --- p.28 / Chapter 3.3.3 --- Recoveries of aromatic compounds --- p.28 / Chapter 3.3.4 --- Analysis of synthetic standard sample --- p.30 / Chapter 3.4 --- Conclusions --- p.33 / Chapter 3.5 --- References --- p.33 / Chapter Chapter 4 --- Simultaneous determination of Ni(II) and Cu(II) in tea sample by EDXRF after preconcentration with 4-(2-pyridylazo)resorcinol-included β-cyclodextrin epichlorohydrin copolymer --- p.40 / Chapter 4.1 --- Introduction --- p.40 / Chapter 4.2 --- Experimental --- p.41 / Chapter 4.3 --- Results and discussion --- p.45 / Chapter 4.3.1 --- Optimum pH for the inclusion of PAR in β-CDEP cavity --- p.45 / Chapter 4.3.2 --- Saturation time for the inclusion of PAR in β-CDEP cavity --- p.45 / Chapter 4.3.3 --- Optimum pH for the reaction between PAR and metal ions --- p.47 / Chapter 4.3.4 --- Calibration curves and detection limits of Ni(II) and Cu(II) --- p.47 / Chapter 4.3.5 --- Analysis of synthetic standard sample --- p.50 / Chapter 4.3.6 --- Analysis of tea sample --- p.50 / Chapter 4.4 --- Conclusions --- p.53 / Chapter 4.5 --- References --- p.53 / Chapter Chapter 5 --- Conclusions --- p.55

Master of Science - Chemistry / Complexation of CrIII was studied using the ligand 2, 2’ Bipyridyl (Bpy). Potentiometric titration was used in the modelling of CrIII-Bpy complexes and establishment of complex stability constants by use of ESTA software package. Investigation of the mechanism involved in the voltammetric determination of chromium by adsorptive cathodic stripping voltammetry (AdCSV) showed different behavior of chromium in 0.1 M ammonium buffer when compared to a neutral electrolyte (0.1 M sodium nitrate). Alternating current voltammetry (ACV) showed evidence of Bpy adsorption on the electrode surface (HMDE) whereas CrIII did not show any adsorption evidence but complexes of CrIII-Bpy were also adsorbed onto the electrode. Cyclic voltammogram (CV) of Bpy exhibits a reversible process and CrIII was characterized by a quasireversible process. CrIII-Bpy is investigated here as a model metal-ligand system used in analytical procedure. A set of generalized requirements for the determination of CrIII by AdCSV is proposed and discussed. It is anticipated that the generalized requirements will be applicable to any metal-ligand system used by that analytical technique. It is assumed that it should lead to an “educated” choice of a suitable ligand in order to increase selectivity and improve the detection limit in ultra trace analysis (ppb-ppt levels) by AdCSV.

In this Exegesis I explore the rehabilitation of marginalized materials through a sculptural practice. The materiality of the work focuses on the commonality of the everyday through selection editing and transparency of materials. The materiality and concern for material presence in my work are used metaphorically to explore ideas of alienation in contemporary sculpture. My work has been informed by the writing Berthold Brecht specifically his alienation effect [A-Effect], a theatrical and cinematic device "which prevents the audience from losing itself passively and completely in the character created by the actor, which consequently leads the audience to be a consciously critical observer". Through the use of situationist tactics in alienation works I seek to explore an atmosphere of fragile transience that can be recognized in ourselves even as we struggle against it.

<p>There is a widespread use of thermal hydraulic codes in nuclear industry. The codesare used to analyse the transient and steady-state behavior of the nuclear powerplants. The US Nuclear Regulatory Commission that has long experience of developing such codes are now incorporating the capabilities of their earlier codes into one modern simulation tool, called TRACE. The code is under development and validation work is required especially in the field of BWR applications. Eventually the code is expected to replace similar codes such as TRAC and Relap5.</p><p>With this in mind, a TRACE model of Forsmark 1 has been set up to investigate how well it can simulate a plant transient. On the 25th of July, 2006 there was a disturbance at Forsmark 1 that caused the RPV water level and pressure to decrease.In this project, plant data acquired during the event are used to validate the model of Forsmark 1. The validation work is focused on comparing measured and calculated water and pressure levels in the RPC during the transient.</p><p>The results show qualitatively good agreement with the validation data, however during a period of the simulations there are large discrepancies concerning the pressure and water level in the RPV. In total, 13 simulations are performed, studying the influences of parameters such as simulation time-step size, the feed water flow boundary conditions and the steam line isolation valve characteristics. Based on the results of the simulations, a number of recommendations are made regarding suggestions for further work.</p>

Graduation date: 1978

Short-term changes in the distribution, surface to 10 meters, of phytoplankton-associated trace metals (Fe, Mn, Cr, Zn, Co, Ni, and Cu) were studied in the near-shore waters off Humboldt Bay, California, through the summer of 1971. The depth distribution of phytoplankton-associated trace metals was related to local hydrography. During periods of upwelling higher concentrations of phytoplankton-associated Fe, Mn, Cr, and Zn were found at depth (10 meters) than at the surface. During periods of non-upwelling there was less stratification in their distribution. Phytoplankton-associated Cu, Go, and Ni showed no significant increase with depth during either period. The rate of change in trace metal distribution patterns of Fe, Mn, Cr, and Zn were regulated by surface wind patterns and hydrographic regimes. Again, Cu, Co, and Ni did not fluctuate in a significant fashion. The elements studied tended to fall into three ordered groups based on their behavior with respect to 1) depth distribution, 2) correlation with other metals studied, and 3) correlation with biomass indicators. The groupings were Fe, Mn, and Cr; Zn, Co, and Ni; and finally Cu. This ordering is similar to the Irving- Williams series and to the elements relative 'hardness" as a Lewis acid where Fe(III), Cr(III), and Mn(II) are considered hard Lewis acids while Zn(II), Co(II), Ni(II) and finally Cu(II) are considered borderline hard to soft Lewis acids. These properties are related to the relative affinities and selectivities of the elements for organic ligands. There also appears to be some relation between the physical (dissolved versus particulate form) and the chemical (oxidation state and ionic potential) behavior of the elements in sea water and their behavior in the phytoplankton. There was a negative correlation between most phytoplankton-associated trace metal concentrations (Fe, Mn, Cr, Zn, Co, and Ni) and biomass during non-upwelling periods and a positive correlation during upwelling periods. Copper, on the other hand, showed a positive correlation during both periods. This aberrant behavior of copper may be related to its high affinity for organic ligands and its relative softness as a Lewis acid. Since no simple negative correlation was found between phytoplankton biomass and phytoplankton-associated trace metal concentrations, biological dilution does not appear to be as important as the hydrographic regime and the chemical activities of the element in determining the concentrations of trace metals in near shore phytoplankton populations. / Graduation date: 1975