Desert aerosols suspended in the atmosphere are a very marked fact in West Africa with estimates ... more Desert aerosols suspended in the atmosphere are a very marked fact in West Africa with estimates of 400 to 1000 million tons produced annually and concentrations exceeding 50 µg·m³ in Burkina. In Bamako, the daily dust concentration can go up to reach 504 µg/m³. The Sahara and the Sahel are recognized as the primary desert aerosol producing regions. Source areas continue to be discovered as the desert advances. Previous studies have mainly focused on the spatial and temporal variability of aerosols. The current question is: What makes an area a source of dust emission? Our study brings together all the climatic parameters of the 10–20 band, as well as the soil types and their characteristics; it reveals 4 soils characteristic of fine sandy semi-arid soils in Chad. The Ouadaï plateau in Chad was identified as a source area for dust emissions. We noted for JFM (January, February, March) that the strongest wind intensities were located mainly towards Chad for average rmaximum temperatu...
2020 IEEE International Conf on Natural and Engineering Sciences for Sahel's Sustainable Development - Impact of Big Data Application on Society and Environment (IBASE-BF), 2020
In this paper a multiband antenna is presented for radiofrequency energy harvesting. The antenna ... more In this paper a multiband antenna is presented for radiofrequency energy harvesting. The antenna is designed by creating slots on the radiating element. We used Koch's fractal geometry to create iterations on the radiating element. Our proposed antenna operates in the four bands (800 MHz from GSM and LTE, 1800 MHz from GSM, 2100 MHz from UMTS and 2400 MHz Wifi). The design of this antenna allowed to obtain a greater bandwidth with the third iteration of the fractal geometry around the resonance frequencies. For a threshold of -10 dB, we moved from the 20 MHz bandwidth of the slot-less antenna to the 67.4 MHz bandwidth of the antenna with the third iteration for the 2400 MHz frequency. We also noted a gain varying between 0.61dB and 5.11dB.
The omnipresence of connected objects leads to the quasi-permanent presence of electromagnetic wa... more The omnipresence of connected objects leads to the quasi-permanent presence of electromagnetic waves from different sources in our environment. This article presents a new electromagnetic energy harvesting device, rectenna type, which offers the advantage of being versatile. Indeed, the proposed prototype is compatible with three frequency bands of radio standards widely deployed today (UHF RFID, GSM-1800, and UMTS-2100), and its performances remain good for low to very low ambient power levels as well as for different loads depending on the targeted application. The proposed solution is based on a tri-band antenna with very good efficiency and a bandwidth of at least 80 MHz for each of the operating frequencies. Moreover, the associated rectifier circuit is also tri-band and offers good performance in terms of RF-to-DC conversion efficiency for input levels varying in a rather wide range of power levels. The study is based on a design phase by simulation until the realization of pr...
Desert aerosols suspended in the atmosphere are a very marked fact in West Africa with estimates ... more Desert aerosols suspended in the atmosphere are a very marked fact in West Africa with estimates of 400 to 1000 million tons produced annually and concentrations exceeding 50 µg·m³ in Burkina. In Bamako, the daily dust concentration can go up to reach 504 µg/m³. The Sahara and the Sahel are recognized as the primary desert aerosol producing regions. Source areas continue to be discovered as the desert advances. Previous studies have mainly focused on the spatial and temporal variability of aerosols. The current question is: What makes an area a source of dust emission? Our study brings together all the climatic parameters of the 10–20 band, as well as the soil types and their characteristics; it reveals 4 soils characteristic of fine sandy semi-arid soils in Chad. The Ouadaï plateau in Chad was identified as a source area for dust emissions. We noted for JFM (January, February, March) that the strongest wind intensities were located mainly towards Chad for average rmaximum temperatu...
2020 IEEE International Conf on Natural and Engineering Sciences for Sahel's Sustainable Development - Impact of Big Data Application on Society and Environment (IBASE-BF), 2020
In this paper a multiband antenna is presented for radiofrequency energy harvesting. The antenna ... more In this paper a multiband antenna is presented for radiofrequency energy harvesting. The antenna is designed by creating slots on the radiating element. We used Koch's fractal geometry to create iterations on the radiating element. Our proposed antenna operates in the four bands (800 MHz from GSM and LTE, 1800 MHz from GSM, 2100 MHz from UMTS and 2400 MHz Wifi). The design of this antenna allowed to obtain a greater bandwidth with the third iteration of the fractal geometry around the resonance frequencies. For a threshold of -10 dB, we moved from the 20 MHz bandwidth of the slot-less antenna to the 67.4 MHz bandwidth of the antenna with the third iteration for the 2400 MHz frequency. We also noted a gain varying between 0.61dB and 5.11dB.
The omnipresence of connected objects leads to the quasi-permanent presence of electromagnetic wa... more The omnipresence of connected objects leads to the quasi-permanent presence of electromagnetic waves from different sources in our environment. This article presents a new electromagnetic energy harvesting device, rectenna type, which offers the advantage of being versatile. Indeed, the proposed prototype is compatible with three frequency bands of radio standards widely deployed today (UHF RFID, GSM-1800, and UMTS-2100), and its performances remain good for low to very low ambient power levels as well as for different loads depending on the targeted application. The proposed solution is based on a tri-band antenna with very good efficiency and a bandwidth of at least 80 MHz for each of the operating frequencies. Moreover, the associated rectifier circuit is also tri-band and offers good performance in terms of RF-to-DC conversion efficiency for input levels varying in a rather wide range of power levels. The study is based on a design phase by simulation until the realization of pr...
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