The Solutions of DC-DC Converters for Renewable Energy System

Photovoltaic and wind systems have been used for a few years to bring a new power supply to many applications, while preserving the environment. This chapter is interested in this work at low and medium power, a few 100 W, for applications to housing and buildings. The works consider a system in which the various sources of renewable energies are connected to each other in a parallel structure which supposes the use of specialized converters accepting at the input voltages of the order of a few tens of volts, and giving out several hundred of volts. The DC-DC converters with magnetic coupling will be analyzed more particularly to show the technological limits. In particular, the influence of the magnetic circuit and the leakage flows will be studied in more detail

EFFECTS OF SOURCE DOPING PROFILE ON DEVICE CHARACTERISTICS OF LATERAL AND VERTICAL TUNNEL FIELD-EFFECT TRANSISTORS

The source doping engineering, the low bandgap material and the vertical tunneling structure have recently been considered as most effective techniques to resolve the on-current issue in tunnel field-effect transistors (TFETs). In this paper, the effects of source doping profile, including the concentration and gradient, on the device characteristics are adequately elucidated in lateral and vertical TFETs using low bandgap germanium to allow a comprehensive comparison between the two major TFET architectures for the first time. Similar dependences of the on-current on the source concentration are observed in lateral and vertical TFETs, except that the on-current of vertical TFETs is always greater than that of lateral TFETs approximately one order of magnitude. With different contributions of the lateral and vertical tunneling components in the subthreshold region, the subthreshold swing of vertical TFETs first decreases at small concentrations, then increases at medium values, and finally decreases again at high concentrations, whereas that of lateral counterparts always decreases exponentially with increase in the source concentration. The on-current of lateral TFETs is significantly decreased, while that of vertical TFETs is almost invariable with increasing the source doping gradient. With competitive advantages of the vertical TFET architecture in on-current, subthreshold swing and device fabrication, vertical TFETs using low bandgap semiconductors are promising for use in low power applications

BLENDED LEARNING IN BADMINTON TRAINING FOR PROFESSIONALS: STUDENTS’ PERCEPTIONS AND PERFORMANCE IMPACTS

As with other subject areas, badminton instruction for practitioners is experiencing a lot of changes under the impact of technology. Recently there has been the possibility of moving badminton training classes to the online platform but there is no consensus on its efficacy. This study is conducted to study the effects of blended learning activities on the perceptions and performance of students in physical education. Forty students in physical education are selected and divided into two groups: an experimental group, and a control group. All groups in face-to-face learning sessions have the same curriculum, course-book, equipment and teaching method. The questionnaire and interview data show that students in blended class sessions had positive perceptions of learning activities.  Article visualizations

Architecture Parallel for the Renewable Energy System

This chapter present one possible evolution is the parallel topology on the high-voltage bus for the renewable energy system. The system is not connected to a chain of photovoltaic (PV) modules and the different sources renewable. This evolution retains all the advantages of this system, while increasing the level of discretization of the Maximum Power Point Tracker (MPPT). So it is no longer a chain of PV modules that works at its MPPT but each PV module. In addition, this greater discretization allows a finer control and monitoring of operation and a faster detection of defects. The main interest of parallel step-up voltage systems, in this case, lies in the fact that the use of relatively high DC voltages is possible in these architectures distributed

STUDY ON TREATMENT OF THE LEACHATE FROM LANDFILL SITE AT NAMSON, SOCSON, HANOI

Joint Research on Environmental Science and Technology for the Eart

Under the State's Thumb: Results from an Empirical Survey of Civic Organizations in Vietnam

Civic organizations (COs) are neither a good nor a bad thing. They are not inherently fighters for democracy or supporters of authoritarian rule. The way they develop depends on the impact that various forms of state power have on them and on their influence on the state. Vietnamese COs appear to be no exception. When we examine just one direction of these interdependent and reciprocal relations, it becomes clear that under the constraints of the Vietnamese state's infrastructural power many Vietnamese COs develop features of intra-organizational authoritarianism; that they help to embed the state and the Communist Party more deeply within Vietnamese society; and, finally, that they contribute to bringing the society further under the control of the state and the party. However, this occurs to a very different degree depending on the type of CO. NGOs and faith-based organizations in particular, at least in the field of gender norms and practices, seem to resist the state's discursive power. This could imply challenges to the state's and the party's control of politics and society and leads the authors to draw far-reaching conclusions as far as developmental cooperation with and potential support for various types of Vietnamese COs is concerned