High-electron-mobility transistors based on gallium nitride technology are the most recently developed power electronics devices involved in power electronics applications. This article critically overviews the advantages and drawbacks of these enhanced, wide-bandgap devices compared with the silicon and silicon carbide MOSFETs used in power converters. High-voltage and low-voltage device applications are discussed to indicate the most suitable area of use for these innovative power switches and to provide perspective for the future. A general survey on the applications of gallium nitride technology in DC-DC and DC-AC converters is carried out, considering the improvements and the issues expected for the higher switching transient speed achievable.

Background: Malnutrition constitutes a public health problem throughout the world and particularly in developing countries. Aims: The objective of the study is to assess the impact of an elementary integrator composed of Spiruline (Spirulina platensis) and Misola (millet, soja, peanut) produced at the Centre Medical St Camille (CMSC) of Ouagadougou, Burkina Faso, on the nutritional status of undernourished children. Materials and methods: 550 undernourished children of less than 5 years old were enrolled in this study, 455 showed severe marasma, 57 marasma of medium severity and 38 kwashiorkor plus marasma. We divided the children randomly into four groups: 170 were given Misola (731 ± 7 kcal/day), 170 were given Spiruline plus traditional meals (748 ± 6 kcal/day), 170 were given Spiruline plus Misola (767 ± 5 kcal/day). Forty children received only traditional meals (722 ± 8 kcal/day) and functioned as the control group. The duration of this study was eight weeks. Results and Discussion: Anthropometrics and haematological parameters allowed us to appreciate both the nutritional and biological evolution of these children. The rehabilitation with Spiruline plus Misola (this association gave an energy intake of 767 ± 5 kcal/day with a protein assumption of 33.3 ± 1.2 g a day), both greater than Misola or Spiruline alone, seems to correct weight loss more quickly. Conclusion: Our results indicate that Misola, Spiruline plus traditional meals or Spiruline plus Misola are all a good food supplement for undernourished children, but the rehabilitation by Spiruline plus Misola seems synergically favour the nutrition rehabilitation better than the simple addition of protein and energy intake.

The present paper deals with the problem of reducing electromagnetic interference (EMI) of switched-mode power converters using gate controlled devices such as IGBTs and power MOSFETs. In order to reduce power losses, these systems rely on fast on/off time pulses, thus producing emissions due to the high-frequency spectral content of pulses. An original design method for switched-mode power supplies is developed allowing to obtain an acceptable compromise between power losses and EMI. Emphasis is placed on the analysis of the commutation cell of the switching static converter in order to demonstrate that it is possible to control the emissions of the device by handling the parameters of the driver circuit. Theoretical analysis is discussed and compared with experimental results of the investigation on the spectrum amplitude of the emissions.