Analysis of electrical conduction mechanism in the high temperature range of the nanostructured photoabsorber Cu 2 SnS 3

International audienceThe dynamic electrical conduction in the bulk ternary semiconductor compound Cu2SnS3 is studied for the first time in the high temperature range from 300 °C to 440 °C in the frequency range 1 kHz–1 MHz. New activation energy for conduction mechanism is obtained and its frequency dependence is analyzed. The Cole–Cole representation is almost half circular indicating a single contribution to total electrical conduction through the material. The activation energy for the mean relaxation process, obtained separately from the analysis of imaginary part Z″ of complex impedance Z* and from the equivalent electric circuit, is estimated to be (942 +74). The correlated barrier hopping model is considered to analyze the experimental data. The results are compared with those obtained previously in low temperature range

Analysis of electrical conduction mechanism in the high temperature range of the nanostructured photoabsorber Cu 2 SnS 3

International audienceThe dynamic electrical conduction in the bulk ternary semiconductor compound Cu2SnS3 is studied for the first time in the high temperature range from 300 °C to 440 °C in the frequency range 1 kHz–1 MHz. New activation energy for conduction mechanism is obtained and its frequency dependence is analyzed. The Cole–Cole representation is almost half circular indicating a single contribution to total electrical conduction through the material. The activation energy for the mean relaxation process, obtained separately from the analysis of imaginary part Z″ of complex impedance Z* and from the equivalent electric circuit, is estimated to be (942 +74). The correlated barrier hopping model is considered to analyze the experimental data. The results are compared with those obtained previously in low temperature range

Four decades of progress in monitoring and modeling of processes in the soil-plant-atmosphere system : applications and challenges

Efficient water resources management is an issue of major importance in the field of sustainable development, especially in the agricultural sector which represents the main consumer through irrigations. Therefore irrigation management is an important and innovating area which was the subject of several research and studies. Modeling, and more particularly, the Agent-Based Modeling (ABM), allows better representing the multiplicity of these actors, the diversity of their roles and their interactions. The main reason why we chose the agent technology in the field of gravity irrigation systems, is the complexity to manage in real-time the water distribution operations those arrive asynchronously and dynamically and to be reactive and adaptive to the dynamic and unpredictable events that characterizes the field (mainly rainy advents). Our objectives are mainly located on two levels. The first one, concerns the gravity irrigation modeling by a multi-agent technology and the agent modeling through AML language. The second one focuses on the irrigations scheduling optimization using an evolutionary algorithm. Comparisons between schedules before and after optimization are made and the results shows that our approach can be considered as an efficient tool for planning irrigation schedules by considering crops water needs

A new irrigation priority index based on remote sensing data for assessing the networks irrigation scheduling

Irrigation scheduling has become an important tool that significantly influences growth, development and production of crops, especially in arid and semi-arid regions of the South Mediterranean. In these regions, most of the irrigation scheduling of the gravity irrigation networks are not optimized in terms of timing and water quantity. In this paper, we present a way of characterizing the irrigation distribution by the extensively used irrigation systems through a new irrigation index: the "irrigation priority index" (IPI). This normalized indicator takes into account the water stress coefficient and the time of irrigation with regard to the duration of an irrigation round. The IPI ranges between -1 and 1 and decreases with irrigation priority. The IPI was used to evaluate the actual irrigation scheduling in an irrigated perimeter of 2800 ha of Tensift Al Haouz plain close to Marrakech in Morocco during the 2002-2003 winter wheat season. The obtained results showed that about 32% of the R3 zone plots receive late irrigation, when the stress was maximum (IPI less than -0.3). The sensitivity of grain yield to the IPI values was evaluated on a data set of wheat yields acquired on the 2008-2009 season. The spatial yield was simply calculated using a linear relationship between wheat yields and the spatial accumulated NDVI (Normalized Difference Vegetation Index) of the last 10 days of March (R-2 = 0.84). The result showed a clear relationship between grain yield and [PI. Indeed, with significantly positive IPI10.37, 0.63], production ranged from 3.8 to 4.7 t/ha, whereas, it was less than 2.6 t/ha when the IPI values are ranged from -0.52 to -0.16

Dielectric and modulus analysis of the photoabsorber Cu2SnS3

International audienc

Dielectric and modulus analysis of the photoabsorber Cu2SnS3

International audienc