Caractérisation IV impulsionnelle et RF et Modélisation de AlGaN/GaN HEMT et graphène FET

The aim of this work is to assess the potentialities of Graphene Field Effect Transistors (G-FET) as well as to put in evidence dispersive effects of AlGaN/GaN High Electron Mobility Transistors (HEMTs). The main experimental results of this study have been obtained through the development of an advanced characterization set-up. The main objective for characterization of AlGaN/GaN HEMTs was to develop innovative characterization techniques such as very short pulses and electrical history measurements. Dedicated time-domain pulsed I-V measurements have been performed in order to characterize and model the time dependent trapping phenomena in such devices. The current collapse (Kink effect) and drain lag are directly related to quiescent and instantaneous bias points as well as thermal effects which play a prominent role. This method provides an efficient way to assess the different thermal and trapping time constants for the nonlinear modeling. The second aspect of this research work was the characterization of several graphene-based devices in order to assess the potentialities of such transistors and to derive a nonlinear device model. DC and high frequency characterization were performed. Specific test structures fabricated for accurate de-embedding at high frequencies along with the nonlinear model extraction were detailed in this work. This electrical model consistency has been checked through the comparison of measured and simulated multi-bias S-parameters. For this new material with outstanding electrical properties and promising capabilities, material and technological process are still subject to intensive research activities to improve high frequency graphene FET performances.Ces travaux de recherche se rapportent à l’évaluation des potentialités des transistors à base de graphène ainsi que la mise en évidence des effets dispersifs sur les transistors HEMTs en technologie Nitrure de Gallium. Les principaux résultats issus de ces travaux sont obtenus suite au développement d’un banc de caractérisation spécifique. L’objectif principal pour la caractérisation des transistors en technologie AlGaN/GaN a été de développer des techniques innovantes de caractérisation. Des mesures IV et RF impulsionnelles ont été réalisées afin de caractériser et modéliser les phénomènes de pièges. Cette méthode fournit un moyen efficace d’évaluer les constantes de temps thermiques et de pièges pour la modélisation non linéaire. Ces mesures illustrent ainsi l’impact des effets de pièges sur le comportement dynamique grand signal des transistors GaN. Le second aspect de ces travaux de recherche est axé sur la caractérisation de différents composants à base de graphène afin d’extraire un modèle non linéaire. Des caractérisations DC et HF ont été réalisées. Des structures spécifiques de test ont été fabriquées pour la technique de « de-embedding » permettant l’extraction du modèle non linéaire. La cohérence du modèle électrique a été vérifiée via une comparaison des paramètres S mesurés et simulés. Il est primordial de construire des modèles performants prenant en compte les nouvelles caractéristiques de ces dispositifs dans le but d’établir un lien fort entre les aspects technologiques et systèmes afin d’améliorer les performances HF des transistors à base de graphène

Effect of Zinc and Boron on Growth, Yield and Economics of Finger Millet (Eleusine coracana L.)

A field experiment was conducted during Kharif 2022 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P) to evaluate the effect of zinc and boron on growth, yield and economics of finger millet. The soil of experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 8.0), low in organic carbon (0.62 %), available N (225 kg/ha), available P (38.2 kg/ha) and available K (240.7 kg/ha). It was a Randomized block design consisting of three levels of zinc (10, 12 and 14 kg/ha) with combination of boron (0.5, 1 and 2 kg/ha), there were 10 treatments, each being replicated thrice. Data was collected from growth and yield parameters and were subjected to analysis of variance method. Results revealed that significant differences such that higher plant height (64.78 cm), maximum number of tillers/hill (6.79), higher plant dry weight (20.25 g), maximum number of fingers/plant (5.52), higher number of seeds/finger (296.52), higher test weight (3.14 g), higher grain yield (2.56 t/ha), higher straw yield (7.79 t/ha), maximum gross returns (110632.00 INR/ha), maximum net returns (74302.00 INR/ha) and maximum Benefit cost ratio (2.04) were recorded in treatment 9 [Zinc (14 Kg/ha) + Boron (2 Kg/ha)]. Zinc 14 kg/ha and boron 2 kg/ha is recommendation for application in finger millet for maximum yields

Non-Linear Electrical Modeling and Characterization of Graphene Nano Ribbon Field Effect Transistors

International audienc

Characterization and Circuit Modeling of Graphene Nano Ribbon Field Effect Transistors

International audienc

Knowledge, attitude and practice related to diabetes mellitus among general public

Background: Type 2 Diabetes Mellitus is a severe problem, which results in premature death and is a global epidemic. It can be prevented by changing the attitude, practices and bringing awareness towards the disease in the population. Aim: This study was conducted to evaluate knowledge, attitude and practice related to diabetes among general public in India. Materials and Methods: This study is a cross-sectional study and was carried out in health center in Telangana during the period 30 th March 2019 to 31 st March 2020. The sample size was 100. By convenience sampling from the outpatient department of the health centre, 100 patients were selected after considering inclusion and exclusion criteria. Results: 100 patients were involved in the study who were outpatients attending the health centre. 45% of patients were 18-35 years old, and 55% of patients were 36-65 years old. 58% were males, and 42% were females. 87% were aware of the organs which get damaged due to diabetes. 55% of patients were aware that the heart is affected, 85% of patients were aware that the kidney was affected, and 40% were aware that brain was affected by diabetes. Patients were aware of risk factors for diabetes mellitus namely obesity (70%), decreased physical activity (80%), family history of diabetes mellitus (65%), mental stress (62%) and consumption of sweets (93%) were aware was the causes of Diabetes mellitus. All patients were aware that diet control would keep blood sugar under normal levels. Conclusion: It is essential for health organisations to create more awareness through programs among the people towards T2DM as the high knowledge was not aligning with the attitude and practice towards the disease

Impact des effets de piège sur la dynamique grand signal des transistors à effet de champ sur nitrure de gallium

International audienc