Novelis Inc. recently developed and patented a unique Direct Chill (DC) casting process known as Fusion Novelis Technology. In this process a chill bar is inserted into the DC casting mould which permits for the first time the co-casting of laminate of clad ingots. These ingots can then be rolled down into clad sheet and offer distinct advantages over traditional aluminum clad sheet processing routes (i.e. brazing and roll bonding). The research presented in this Master’s Thesis was done as part of a larger collaborative research and development project with Novelis Inc. The main objective of this research was to investigate the Novelis Fusion Technology and understand it from a scientific viewpoint. The research has been multi faceted and has included: the creation of a thermal fluid model using the commercial software package CFD to model the first the DC and then Fusion casting process, as well as the design and testing of an experimental DC and Fusion caster at the Novelis Global Technology Centre (NGTC) in Kingston, Ontario. This MASc research has been focused on performing both traditional DC (for AA6111, AA3004 and AA4045) and novel Fusion (AA3004/AA4045) casting experiments. First the series of DC casting experiments was performed. During the experiments two arrays of 5 thermocouples were embedded in the ingot during the cast to capture the thermal history of the ingot. Melt poisoning with a zinc rich alloy was also performed as an independent method of determining the sump depth and shape. Other temperature measurements during the experiment (i.e. alloy superheat, mould temperature, cooling water temperature) were done to gather meaningful data for model validation. A series of Fusion casting experiments was performed after the DC casting trials. Three successful Fusion casting trials were performed at NGTC using a lab scale caster with a 152 mm × 381 mm rectangular mould divided in half by a water cooled copper chill bar. For the Fusion casting experiments the AA3003-Core/AA4045-Clad alloy system was chosen since this alloy system has already been commercially produced using this novel technology. In addition to embedded thermocouples in the Fusion cast ingot, and other temperature measurements as for the DC casting experiments, temperature measurements of the chill bar were performed to gather information for model validation. The effect of melt poisoning as the interface of the composite ingot forms was unknown, so only the core of one experimental ingot was poisoned; this gave enough information about the depth and asymmetrical shape of the AA3003-Core sump. The Fusion cast ingots were characterized (both optically and using SEM techniques) at four distinct locations across the width of the ingot, consistent with different thermal histories at the interface and regions where good and poor interfaces were found in the solidified ingot. No clear correlation between thermal history and the quality of the interface could be found indicating that the interface formation during Fusion casting is extremely complicated and other factors such as oxide formation and wetting mechanisms of the AA4045 on the AA3004 need to be understood to gain a more in depth understanding of the conditions necessary to form a defect free interface. Comparisons of the measured thermal histories and sump depth and shape measurements to the model predictions were excellent.

This study focused on the development of a proposal for a secondary alternative program that would be effective in the state of Kuwait. A professional preparation program that would function in support of the alternative school was also included. The investigator attempted to find the answers to the following questions: What are some of the major features of selected secondary school alternative programs in southeastern Arizona? How could these features be utilized in developing an alternative program for the secondary schools of Kuwait? What type of staff preparation program would be appropriate to effectuate the proposed alternative program? A review of the major elements of Kuwaiti history and culture was presented. Additionally, a summary of the development of the educational institutions in Kuwait was included, with special attention to current methods and practices. A review of the related literature indicated that the alternative school movement has become widespread in the United States as a means of providing youngsters with educational experiences different from those found in traditional schools. The recent increase in the number of alternative schools seems to be based on the assumption that differences among students require diversity in learning experiences. A theoretical framework was formulated from the literature to guide the collection of further data. It consisted of the following categories: (1)philosophy; (2)structure; and (3)function. Under each of these categories, several sub-categories were discussed. The study was conducted by the investigator as a participant observer in local alternative programs in a southwestern metropolitan area. The alternative programs under investigation participated in the study on a voluntary basis and included Cougar Alternative High School, Jefferson Alternative High School, Jackson High Alternative School, and Oak High School. The first three schools listed above serve a population of individuals who could not attend regular secondary schools. The fourth program is a conventional high school that includes an alternative program as part of its function. An interview schedule consisting of various questions regarding philosophy, structure, and function was developed and completed by selected staff at the schools under investigation. The resulting data was recorded and analyzed according to the three framework categories. A proposal for a secondary alternative program appropriate to the country of Kuwait was formulated, and a staff preparation program was included. A major element in the structure of the proposed program was the development of a cross-cultural team consisting of United States and Kuwait members and a representative from Kuwait University. The cross-cultural team would focus on the training of Kuwaiti educators for the proposed secondary alternative school. The investigator would function as coordinator for the training program and director of the proposed alternative program.

No description available.

The purpose of the study was to create a differentiated staff paradigm for a new senior high school with a prescribed learning program but without a designated faculty. The paradigm was designed by identifying elements of a viable differentiated staffing pattern from a review of related literature and research, and incorporating the elements into a predetermined learning program for the selected school. The school selected for the study was a new senior high school in Elkhart, Indiana, which was under construction at the time the study was being conducted. The school was scheduled to open in September of 1972.The review of related literature and research included an examination of existing theory related to differentiated staffing and a description of three models of existing differentiated staffing programs. A review of the planning history and basic foundations for the school being studied was presented. Concepts upon which were developed the educational specifications for the high school, and which related directly to staffing considerations for the school, were described.A rationale for the paradigm explained why the selected school appeared to be an appropriate one to consider a differentiated staffing arrangement. The rationale reviwed process considerations for development of a differentiated staff paradigm. From the review essential elements of a differentiated staffing plan were identified and these elements were used as a framework for presenting a paradigm for the selected school.General conclusions drawn from the study included:1. Sufficient research on differentiated staffing programs does not exist to draw absolute conclusions about the concept.2. The process of relating a review of research and literature to a defined learning program for an impending high school can be utilized to design a differentiated staffing paradigm for that school.3. A functional differentiated staff will be founded on specialization of job responsibilities while insuring flexible utilization of individual competencies.4. Teachers must be intimately involved in the planning and implementation of a differentiated staffing program.5. The existence of a differentiated staffing pattern in one school will affect administrative and decision-making functions on a system-wide basis.6. Individuals accepting differentiated staffing positions with broader job scope than traditional teaching assignments accept, concurrently, a greater degree of responsibility.7. The greater the responsibility in a differentiated staffing position the greater should be the remuneration and involvement in decision making in that position.8. Evaluation of performance within a differentiated staff should be based upon measured achievement of described tasks.9. The role of the principal cannot be an autonomous one in a school which employs a differentiated staffing pattern.10. Both pre-service and continuous in-service training activities are vital to success of a differentiated staffing plan.11. In order to relate specialized positions to defined goals and individual skills, periodic evaluation and resultant restructuring of a differentiated staff organization is called for.Recommendations for further study were as follows:1. If a differentiated staff plan should be implemented within the selected high school a study of the actual plan vis-a-vis the pattern posed in the paradigm should be made.2. Successes and limitations of differentiated staffing programs in achieving stated objectives should be measured.3. Contrasting methods of evaluation of performance in a differentiated staff should be compared and analyzed.4. The effect of a differentiation of assignment on staff performance and morale should be assessed.5. The effect of implementing a differentiated staffing pattern in one school on the system-wide educational program should be studied.6. The relationship between differentiated teaching assignments and a concept of accountability in achieving educational goals and objectives should be reviewed.7. The role of the principal in a differentiated staff should be analyzed and reported.

Novelis Inc. recently developed and patented a unique Direct Chill (DC) casting process known as Fusion Novelis Technology. In this process a chill bar is inserted into the DC casting mould which permits for the first time the co-casting of laminate of clad ingots. These ingots can then be rolled down into clad sheet and offer distinct advantages over traditional aluminum clad sheet processing routes (i.e. brazing and roll bonding). The research presented in this Master’s Thesis was done as part of a larger collaborative research and development project with Novelis Inc. The main objective of this research was to investigate the Novelis Fusion Technology and understand it from a scientific viewpoint. The research has been multi faceted and has included: the creation of a thermal fluid model using the commercial software package CFD to model the first the DC and then Fusion casting process, as well as the design and testing of an experimental DC and Fusion caster at the Novelis Global Technology Centre (NGTC) in Kingston, Ontario. This MASc research has been focused on performing both traditional DC (for AA6111, AA3004 and AA4045) and novel Fusion (AA3004/AA4045) casting experiments. First the series of DC casting experiments was performed. During the experiments two arrays of 5 thermocouples were embedded in the ingot during the cast to capture the thermal history of the ingot. Melt poisoning with a zinc rich alloy was also performed as an independent method of determining the sump depth and shape. Other temperature measurements during the experiment (i.e. alloy superheat, mould temperature, cooling water temperature) were done to gather meaningful data for model validation. A series of Fusion casting experiments was performed after the DC casting trials. Three successful Fusion casting trials were performed at NGTC using a lab scale caster with a 152 mm × 381 mm rectangular mould divided in half by a water cooled copper chill bar. For the Fusion casting experiments the AA3003-Core/AA4045-Clad alloy system was chosen since this alloy system has already been commercially produced using this novel technology. In addition to embedded thermocouples in the Fusion cast ingot, and other temperature measurements as for the DC casting experiments, temperature measurements of the chill bar were performed to gather information for model validation. The effect of melt poisoning as the interface of the composite ingot forms was unknown, so only the core of one experimental ingot was poisoned; this gave enough information about the depth and asymmetrical shape of the AA3003-Core sump. The Fusion cast ingots were characterized (both optically and using SEM techniques) at four distinct locations across the width of the ingot, consistent with different thermal histories at the interface and regions where good and poor interfaces were found in the solidified ingot. No clear correlation between thermal history and the quality of the interface could be found indicating that the interface formation during Fusion casting is extremely complicated and other factors such as oxide formation and wetting mechanisms of the AA4045 on the AA3004 need to be understood to gain a more in depth understanding of the conditions necessary to form a defect free interface. Comparisons of the measured thermal histories and sump depth and shape measurements to the model predictions were excellent.

En 2012, les expériences ATLAS et CMS ont annoncé la découverte d’un nouvelle particule compatible avec le boson de Higgs prévu par le modèle standard. Cette particule a été postulée dans les années 1960. Elle explique comment les particules fondamentales obtiennent leurmasse. Cependant, la plupart des modèles allant au-delà du modèle standard prédisent l'existence de bosons de Higgs chargés. Les propriétés de telles particules, par exemple sa masse et son couplage aux autres particules, ne sont pas précisément prédites par la théorie, mais constituent un espace deparamètres qui doit être exploré. Des recherches de bosons de Higgs chargés ont été effectuée avant le LHC, cependant l'extension en énergie réalisée par le LHC a permis d'explorer un domaine plus large en masse. Dans ce travail nous avons cherché un boson chargé de Higgs se décomposant en une paire de quarks t et b. Aucun écart par rapport au modèle standard n'a été observé dans les données recueillies jusqu’en 2016, nous pouvons en déduire deslimites supérieures sur le taux de production d’un boson chargé de Higgs.Ces limites peuvent alors être utilisées pour exclure des parties de l’espacedes paramètres.Le LHC sera mis à niveau vers 2025 pour augmenter sa luminosité (le nombre de collisions par seconde et par cm2). Les protons sont accélérés par paquets. Ainsi, la luminosité peut être augmentée en injectant plus de protons par paquet, mais aussi en focalisant les paquets (réduisant leur taille transverse) au point de collision. Cela signifie que le taux auquel nouspouvons espérer produire des événements rares augmentera, mais aussique le taux de bruit de fond correspondant à l'empilement (le nombre de collisionsmoles de protons par croisement) augmentera. Le taux de croisement de paquets au LHCest trop élevé pour pouvoir lire et stocker toutes les don-nées produites. Ainsi nous devons utiliser un système de déclenchement quisélectionne rapidement les événements intéressants à enregistrer. Le système de déclenchementactuel n'est pas adapté au taux élevé d’empilement attendu pour la phase à hauteluminosité (HL) du LHC. Il doit donc être améliorée.Une façon de le faire est d'utiliser les informations du détecteur internequi fournit des informations sur les trajectoires de particules chargées.En utilisant des algorithmes qui peuvent être mis en œuvre dans l'électronique,un déclenchement de premier niveau sur les traces peut être rendu assez rapide pour fonctionnerdans la courte latence requise au HL-LHC. Le détecteur interne fournitdes points d’espace, des mesures des trajectoires des particules à des intervalles différents où sont installés des pistes de silicium. La quantité dedonnées du trajectomètre est trop grande, aussi effectuer des calculs sur toutes les combinaisons de points spatiaux prendrait trop de temps. Par conséquent, undéclenchement interne de premier niveau doit pouvoir sélectionner un sous-ensemble de pointsspatiaux sur lesquels effectuer le calcul. Dans cette thèse, nous avons exploré l’idée d’utiliser les régions d'intérêt fournies par le système de déclenchement d’électrons et de muonspour sélectionner une partie du volume du détecteur interne, puis de sélectionner lespoints d’espace qui correspondent aux modèles attendus des traces à haute énergie. Il a été démontré que c’est une option viable pour réduire les taux de bruit de fond tout en gardant une efficacitéélevée pour les événements que nous voulons garder, même dansdes conditions élevées d’empilement. / In 2012 the ATLAS and CMS experiments announced the discoveryof a new particle, a Higgs boson. This particle was hypothesized in the1960’s and explains how fundamental particles get their mass. However, amodel with a single Higgs boson is still not able to explain the aforemen-tioned cosmological observations. An electrically charged Higgs boson isa feature of many suggested extensions of the current model, includingsupersymmetry. The properties of such a particle, e.g. its mass and howit interacts with other particles are not fixed by theory but forms a pa-rameter space in which we must look for it. Searches for charged Higgsbosons have been performed prior to the LHC, but with the new energyscale of the LHC, the experiments have been able to look for heavier par-ticles. In this work we searched for a charged Higgs boson decaying intothe heaviest two quarks, a top and bottom pair. No deviations from thestandard model were found in the data gathered up until 2016, and hencewe can set upper limits on the production rate of a charged Higgs boson.These limits can then be used to exclude parts of the parameter space.The LHC will be upgraded around 2025 to increase the luminosity,that is the intensity of the proton beams. Protons are not acceleratedone by one at the LHC but in bunches. The luminosity can be increasedby using more protons per bunch but also by squeezing the bunches to besmaller at the point of collision. This means that the rate at which we canhope to produce rare events will increase but also that the backgroundrates and so called pile-up, the number of proton collisions per bunchcrossing, will increase. The rate of bunch crossings at the LHC is muchtoo high for ATLAS to be able to readout and store all data for eachevent, instead we use triggers that select events which look interesting.The current triggers are not suited for the high rates and pile-up of theHigh Luminosity (HL) LHC after the upgrade and must thus be improved.A way to do this is to use the information from the tracking detector thatprovides information on the trajectories of charged particles. By usingalgorithms that can be implemented in hardware a track trigger can bemade fast enough to work within the short latency required at the HL-LHC. The tracking detector provides space points, measurements of theparticle trajectories at different intervals, to which a track can be fitted.The amount of data from the tracker is very large, and performing trackfits on all the combinations of the space point would take too much time.Therefore a track trigger must be able to select a subset of space points onwhich to perform the track fit. For this thesis we have explored the idea ofusing standalone electron and muon triggers to select a part of the trackervolume, and then select space points that match precomputed patternsthat correspond to high energy particles. It has been shown that this isa viable option to reduce background rates while keeping high efficiencyfor the events we want to keep, even in high pile-up conditions.

The objective of this research study was to obtain a better understanding of the factors that affect lecturer and student participation in distributed collaborative learning assignments (DCLAs). A substantial number of courses worldwide have included DCLAs in their curricula in an attempt to teach students virtual communication and teaming skills, and to allow distributed students to learn course content collaboratively in a virtual environment. The execution and management of these assignments have proven to be more challenging that expected. Several attempts reported on in the literature had to be abandoned when cost exceeded the rewards for both lecturers and students. In a fouryear cyclical action research project carried out at the PETech (Port Elizabeth Technikon, currently part of the Nelson Mandela Metropolitan University, South Africa), ICT students at several of the PETech campuses were required to complete a DCLA in virtual teams. This project also had to be terminated when it was realised that virtual team learning was minimal and the time investment unacceptably high. For the research study reported on in this thesis the data collected during the four “preresearch” cycles and the experiences reported in the literature were analysed. The lessons learnt were applied to a new additional DCLA cycle which formed part of an ICT course, although this execution still showed room for improvement. A second additional cycle was then executed which had a high participation rate and was overwhelmingly labelled by the participating students as a valuable and enjoyable learning experience. Analysis of the factors affecting participation in DCLAs shows that they are numerous and tightly interlinked, and that each factor is able to take on a wide range of values. This complicates descriptive reporting as each of the DCLAs was unique with unique outcomes and would have to be reported as such in order to iii ABSTRACT iv gain an understanding of the factors. Hence, a level of abstraction was needed, which was accomplished by applying the traditional Glaserian grounded theory method to the data collected during the four “preresearch” and the two additional cycles, and from the literature on the topic. The outcome is a perceived costs and rewards (PCR) theory for participation in DCLAs. As participation is crucial for the learning experience of each student as well as his/her team members in an action learning environment, deciding on participation by continually calculating the costs versus rewards became the focal point of the theory. To the best of the author’s knowledge this research study makes a theoretical contribution to the existing body of ICT educational knowledge in the form of a perceived costs and rewards theory for DCLA participation and a practical contribution in that it provides a theory that can be used to explain, understand, interpret and predict participation in DCLAs. This research study provides guidance for future research in both of these areas.

No description available.

No description available.

The problem of this study was to determine the effectiveness of student-centered teaching in producing significant changes in certain critical thinking abilities among selected freshmen students at North Texas State College.