Search results for "KAM"
showing 10 items of 720 documents
Investigating teacher leadership in Cameroon secondary education : a case of two public schools
2018
Teacher leadership is crucial in improving schools and enhancing student learning. In Cameroon, the hierarchical nature of leadership and the internal school structures encourage the partition of roles and responsibilities and a clear separation of power and authority. Teachers in Cameroon work within a more imposed system, where the national curriculum is design and impose on them. As a result, teachers do not perform activities geared towards leadership. To improve on teacher leadership practices in Cameroon and learn from exemplar systems (e.g., Finland), it is important to examine how teacher leadership is practiced and how it can be improved. Accordingly, the purpose of this study is t…
Structural assessment of a whole toroidal sector of the HELIAS 5-B breeding blanket
2021
Abstract The European roadmap for the realization of fusion energy considers the stellarator line as a possible long-term alternative to a tokamak DEMO. In this context, from the plasma physics standpoint, the most promising option is a five-field period power plant called HELIcal-axis Advanced Stellarator (HELIAS) 5-B. In order to allow the electricity production, the HELIAS 5-B reactor must be endowed with a breeding blanket (BB). Hence, in this paper, the advancements in the HELIAS 5-B BB design are reported. In particular, the structural assessment of a whole BB period, extending along toroidal direction for 72 °, is depicted. A geometric configuration encompassing dummy BB segments has…
Preliminary structural assessment of the HELIAS 5-B breeding blanket
2019
Abstract The European Roadmap to the realisation of fusion energy, carried out by the EUROfusion consortium, considers the stellarator concept as a possible long-term alternative to a tokamak fusion power plant. To this purpose a pivotal issue is the design of a HELIcal-axis Advanced Stellarator (HELIAS) machine equipped with a tritium Breeding Blanket (BB), considering the achievements and the design experience acquired in the pre-conceptual design phase of the tokamak DEMO BB. Therefore, within the framework of EUROfusion Work Package S2 R&D activity, a research campaign has been launched at KIT. The scope of the research has been the determination of a preliminary BB segmentation scheme …
Overview of the JET results in support to ITER
2017
The 2014–2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L–H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent m…
Experimental tests on Li-ceramic breeders for the helium cooled pebble bed (HCPB) blanket design
2003
The Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) to be tested in ITER (International Thermonuclear Experimental Reactor) Reactor foresees the utilization of Lithiate ceramics as Tritium breeder in form of pebble beds. Since 1998, ENEA has launched many experimental activities for the evaluation of the breeder thermomechanics and the interaction between the pebble beds and the prismatic steel containment walls. Main objectives of these activities are the measurement of the pebble bed effective thermal conductivity, the wall heat transfer coefficient, the pressure loads and deformations on the lateral walls and their dependency from the mechanical constraints. The paper presents …
Hippocampal theta (3-8 Hz) activity during classical eyeblink conditioning in rabbits
2007
In 1978, Berry and Thompson showed that the amount of theta (3–8 Hz) activity in the spontaneous hippocampal EEG predicted learning rate in subsequent eyeblink conditioning in rabbits. More recently, the absence of theta activity during the training trial has been shown to have a detrimental effect on learning rate. Here, we aimed to further explore the relationship between theta activity and classical eyeblink conditioning by determining how the relative power of hippocampal theta activity [theta/(theta + delta) ratio] changes during both unpaired control and paired training phases. We found that animals with a higher hippocampal theta ratio immediately before conditioning learned faster a…
Development of helium coolant DEMO first wall model for SYCOMORE system code based on HCLL concept
2018
Abstract The conceptual design of the demonstration fusion power reactor, known as DEMO, is ongoing and several reactor configurations have to be investigated by exploring different design parameters. For these reasons, within the European framework, systems codes like SYCOMORE (SYstem COde for MOdelling tokamak REactor) have been developed. SYCOMORE includes several specific modules, one of which is aimed to define a suitable design of the helium breeding blanket. The research activity has been devoted to improve the method to define automatically the First Wall design starting from thermal-hydraulic and thermo-mechanical considerations, using analytical design formulae and, also, taking i…
Initial layout of DEMO buildings and configuration of the main plant systems
2018
Abstract The realization of a Demonstration Fusion Power Reactor (DEMO) to follow ITER, with the capability of generating several hundred MW of net electricity and operating with a closed fuel-cycle is viewed by Europe and many of the nations engaged in the construction of ITER as the remaining crucial step towards the exploitation of fusion power. The development of suitable configurations of plant systems inside the tokamak building to allow for the various maintenance operations and to meet the numerous system operating functions and safety requirements is one of the initial priorities. A task to establish an initial layout of the DEMO buildings and the integration of the main plant syst…
Status of ITER TBM port plug conceptual design and analyses
2014
The test blanket module port plug (TBM PP) consists of a TBM frame and two TBM-sets. However, at any time of the ITER operation, a TBM set can be replaced by a dummy TBM. The frame provides a standardized interface with the vacuum vessel (VV)/port structure and provides thermal isolation from the shield blanket. As one of the plasma-facing components, it shall withstand heat loads while at the same time provide adequate neutron shielding for the VV and magnet coils. The frame design shall provide a stable engineering solution to hold TBM-sets and also provide a mean for rapid remote handling replacement and refurbishment. This paper presents main design features of the conceptual design of …
Conceptual Design and Modeling of Fast Discharge Unit for Quench Protection of Superconducting Toroidal Field Magnets of DTT
2020
The paper deals with the modelling and simulation of a Fast Discharge Unit (FDU) for quench protection of the Toroidal Field (TF) magnets of the Divertor Tokamak Test, an experimental facility under design and construction in Frascati (Italy). The FDU is a safety key component that protects the superconducting magnets when a quench is detected through the fast extraction of the energy stored in superconducting magnets by adding in the TF magnets a dump (or discharge) resistor. In the paper, two different configurations of dump resistors (fixed and variable respectively) have been analysed and discussed. As a first result, it is possible to underline that the configuration with variable dump…