This paper focuses on the modelling of a SiC-JFET. The novelty aspect is the dependence on temperature. An accurate model has been used in a previous work and an identification procedure for the main model parameters has been demonstrated. Readers have asked for a more advanced SiC JFET temperature-dependent model. A limitation of the current model versus temperature is verified and explained in order to introduce the necessity of a new temperature dependence model. A more advanced model is then considered and a comparative study between experiment and simulation of the device is established. The characteristics of three SiC JFETs devices are considered from experimental and simulation point-of-view. Simulations results clearly replicate the experimental data at different temperatures and a new validity approach, namely validity maps, is proposed. Validity domains are discussed.

Irradiation of unknown pregnancy: review of 17 cases. The article summarizes the analysis of 47 cases of pregnant women who did not know their pregnancy and had undergone one or more diagnostic radiological examinations. We distinguished two groups. The first group G1 consisting of 12 women whose exposure to radiation had been focused under diaphragmatic region and occurred during the critical period of organogenesis with a gonadal dose estimated to range 12 to 52 mGy. A therapeutic abortion had been recommended to these women. The second group G2 consisting of 35 women whose exposure to radiation interested directly or indirectly the above diaphragmatic region with dose lower than 10 mGy. To these women, a recommendation to continue their pregnancy had been given. We investigated only 17 pregnant women issues; 7 from G1 et 10 from G2. We noted that there were no spontaneous abortion or major abnormalities or malignant diseases. However, 4 minor abnormalities were identified among the examined children sample: facial dysmorphism, anus atresia, hypospadias and harelip. These anomalies could not be attributed to the irradiation effects because the conceptus received very low doses during the minimal risk gestation period. We believe that the malformations observed may be attributed to congenital malformation risk.

L'étude des expositions associées à la présence du 222Rn dans les usines de traitement de phosphates et leurs environnements nécessite la mise en ?uvre d'un certain nombre de mesures dont les résultats devront ensuite être comparés aux recommandations de la CIPR dans sa publication 65. L'objectif de ces mesures est d'une part d'identifier les lieux qui peuvent présenter une exposition potentielle par la mesure de la concentration de radon 222 et d'autre part d'estimer cette exposition pour les travailleurs par la détermination de l'énergie alpha potentielle volumique. Le niveau de l'énergie alpha potentielle volumique à la surface du dépôt de phosphogypse “ tabia " dépasse les recommandations de la CIPR dans certains points de mesure.

La présence des mines de phosphate à teneur moyenne en uranium de l'ordre de 35 ppm dans le bassin de Gafsa au Sud de la Tunisie pourrait entraîner des modifications de la radioactivité gamma des régions avoisinantes. Pour vérifier cette hypothèse nous avons procédé à des mesures comparatives sur différents types d'environnements géologiques dans la région. Ensuite, nous avons essayé d'établir le niveau de la radioactivité gamma naturelle. Ainsi, nous avons remarqué que l'influence des gisements de phosphate sur la radioactivité ambiante des secteurs environnants existe mais reste faible.