L’objectif de cette recherche est d’étudier les niveaux d’engagement des enfants envers l’enseignante et les pairs selon différents contextes de classe (activités et regroupements) à l’éducation ...préscolaire cinq ans. À l’aide de l’Individual Classroom Assessment Scoring System (Downer, Booren, et al., 2010), 113 enfants (66 filles et 47 garçons) ont été observés. Les résultats démontrent que l’engagement envers l’enseignante est plus élevé lors d’activités de routines et transitions et celui envers les pairs est plus élevé lors d’activités de jeux libres et ateliers et du regroupement petits groupes. Les contextes de classe modulent les niveaux d’engagement de l’enfant dans ses interactions avec les autres.
Ocean (wave and tidal) energy is still in the prototype testing stage, with several challenges standing between the sector’s current status and the goal of commercial deployment. The study of how to ...reduce the cost of energy, to a level competitive with renewable energy alternatives, is an important aspect of sector development. A comprehensive PESTLE (Political, Economic, Social, Technological, Legal and Environmental) analysis has been carried out to reveal the risks and uncertainties that face wave and tidal energy technology within identified themes. The purpose of the PESTLE analysis was to ascertain the factors most relevant to the reduction of the Levelised Cost of Energy (LCOE), and the wider commercialisation of wave and tidal energy technology. It has been shown that two separate case studies are required in order to more accurately assess the needs of the ocean energy sector. Firstly the suitability of different geographic locations for technology deployment and secondly the progress of the technology in the development cycle; the areas that require the focus of research and development activity. With the completion of both case studies, the paths towards sector development and cost effective energy production has been presented.
Variability in the predicted cost of energy of an ocean energy converter array is more substantial than for other forms of energy generation, due to the combined stochastic action of weather ...conditions and failures. If the variability is great enough, then this may influence future financial decisions. This paper provides the unique contribution of quantifying variability in the predicted cost of energy and introduces a framework for investigating reduction of variability through investment in components. Following review of existing methodologies for parametric analysis of ocean energy array design, the development of the DTOcean software tool is presented. DTOcean can quantify variability by simulating the design, deployment and operation of arrays with higher complexity than previous models, designing sub-systems at component level. A case study of a theoretical floating wave energy converter array is used to demonstrate that the variability in levelised cost of energy (LCOE) can be greatest for the smallest arrays and that investment in improved component reliability can reduce both the variability and most likely value of LCOE. A hypothetical study of improved electrical cables and connectors shows reductions in LCOE up to 2.51% and reductions in the variability of LCOE of over 50%; these minima occur for different combinations of components.
When designing "multi-MW arrays" of Wave Energy Converters (WECs), having a low number of converters with high individual power ratings can be beneficial as the Operation and Maintenance (O&M) costs ...may be reduced. However, having converters of small dimensions or small power ratings could also be beneficial, as suggested by previous works, due to a reduction in material costs as compared to power production, and the use of small, inexpensive vessels. In this work, a case study investigating the optimum size of WEC for a 20 MW array is performed. Analysis is carried out based on the CorPower Ocean technology. In this case study, firstly a Levelized Cost of Energy (LCOE) model is created. This model incorporates the latest Capital Expenditure (CAPEX) estimates for CorPower Ocean's 250 kW prototype. Using this techno-economic model, several sizes/ratings of WEC are tested for use in a 20 MW array. Operational Expenditure (OPEX) is calculated using two different calculation approaches in order to check its influence on final indicators. OPEX is firstly calculated as a percentage of CAPEX, as shown in previous works, and secondly using a failure-repair model, taking into account individual failures of WECs in the array. Size/rating analysis is carried out for several European locations in order to establish any dependence between site location and optimal WEC size/rating. Several metrics for techno-economic assessment of marine energy converters, other than LCOE, are compared in this work. A comparison of several devices with each these metrics is performed within this study.
This paper gives a historical overview of the development of the U.K. marine energy sector from its academic beginnings in the early 1970s. It includes discussion on government support policies and ...where the sector might develop up to and beyond the end of this decade. The paper also presents two very different projects: the European Marine Energy Centre in Orkney, U.K., and the forthcoming All Waters Current and Wave Test Facility in Edinburgh, U.K., as examples of capital investment in the sector.
Abstract
This paper sets out the role of offshore renewable energy (ORE) in UK targets for Net Zero greenhouse gas emissions by 2050 and provides a review of the research challenges that face the ...sector as it grows to meet these targets. The research challenges are set out in a Research Landscape that was established by the ORE Supergen Hub following extensive consultation with the ORE community. The challenges are divided into eight themes, each challenge is described, and current progress is summarised. The progress of the ORE sector in recent years has seen huge cost reductions, which have encouraged the great ambition for the sector seen in UK Government targets. However, in order to meet these critical targets and achieve Net Zero, further innovations and novel technologies will be needed and at pace, driven forward by new research and innovation. The strategy of the Supergen ORE Hub in framing the research and innovation activities within a community-developed research landscape and working together across disciplines and with close collaboration between academia and industry is a necessary component in achieving the ambition of sustainable energy generation.
The objective of this study was to examine the genetic and environmental contributions to shyness throughout the school-age period. Participants were 553 twin pairs from the ongoing prospective ...longitudinal Quebec Newborn Twin Study. Teacher-rated measures of shyness were collected at five time-points from age 6–12 years. On average, shyness was moderately stable over time (
r
= 0.23–0.33) and this stability was almost entirely accounted for by genetic factors. Genetic factors at age 6 accounted for 44% of individual differences and these early genetic factors also explained individual differences at all subsequent ages (6–22%). Non-shared environmental factors explained most of individual differences at single time-points (51–63%), and did not account for stability in shyness. Contributions of shared environment were not significant. Our results suggest that the stability in shyness is mostly accounted for by early and persistent genetic contributions.
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Herein we report interesting reactivity of imidazole carbamate towards nucleophilic substitution with halide ions under Brønsted acidic conditions. Depending upon reaction conditions, ...halide ions could readily attack the carboxyl position and trigger decarboxylative alkyl halide formation. Alternatively, halide ions were also found to competitively undergo nucleophilic acyl substitution, which ultimately results in the generation of carbonate dimerization product.
Polyketide natural products have classically captured the attention of the organic and medicinal chemical community owing to their intricate structural architecture and their powerful biological ...properties. Polyketides are biosynthetically constructed on an enzymatic assembly line through sequential Claisen condensations with malonyl-CoA and methylmalonyl-CoA to build the carbon scaffold. Accessory domains and oxidative tailoring events in the enzymatic machinery install the intricate oxidative and stereochemical elements that are often associated with a compound’s potent biological activities. The intrinsic stereochemical elements decorating the polyketide backbone force the molecule to preferentially adopt specific conformational preferences, in which Hoffmann aptly described as “flexible molecules with a defined shape.”This thesis aims to describe the relationship between the conformational preferences and biological properties of the polyketide natural products, zampanolide, dactylolide and GEX1A. To do so, our laboratory has employed a combination of chemical and biological synthesis, computational, 1D and 2D solutional NMR studies and biological assays to describe this relationship. The characterization of these relationships represents an innovative approach to rational design to identify novel active analogues of natural products that may be further studied for their therapeutic potential.The first two chapters of this thesis provide the background and report our studies involving the covalent microtubule stabilizing agents, zampanolide and dactylolide. The compounds represent viable therapeutics for the treatment of multi-drug resistant cancer. Previously, our lab completed a total synthesis of both of the macrolides and described their low energy conformational preferences of the macrolactone ring. With this analysis, our lab identified a degree of rigidity about the southwestern region of the macrolide. This rigidity is associated with the allylic strain about the trisubstituted olefin. To probe the role the C17-methyl plays in determination the conformational preferences and the biological properties of zampanolide and dactylolide, our lab has completed a synthesis of a 13- desmethylene-17-methyl-analogue series of zampanolide and dactylolide. Additionally, the removal of the alkyl groups in the analogues abbreviates the synthesis compared to that of the natural product. Upon completion of the analogue series, our lab performed our conformational analysis and evaluated the cytotoxic effects to discern the relationship between the macrolides’ conformational preferences and antiproliferative effects of the natural products.This thesis also addresses our efforts to study the relationship between the biological activity and conformational preferences of type-I polyketide GEX1A. GEX1A proves to be an interesting lead for a therapeutic in our acute myeloid leukemia and Niemann-Pick type C disease studies and requires further evaluation of the compound’s potential as a drug candidate. Two chapters in this thesis address the background and our investigation in the characterization of GEX1A’s conformation-activation activity relationship using computational and solutional NMR studies. These studies confirm previously predicted conformational preferences of the polyketide and identifies two previously undiscovered bond rotations that promote the identification of four potential conformational families. This thesis further proposes to complete a synthesis towards a methyl-shifted analogue that is predicted to force the analogue into a specific conformational family about one of the rotatable bond dihedrals.Together, these projects highlight our lab’s over-arching program to investigate natural products’ therapeutic potential for treatment of disease. This thesis places specific interest in characterizing the conformational preferences of the natural products and relate the derived conformational families to the biological properties of the compounds.
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