In this work, we have produced biogas by co-digestion of cow dung and slaughterhouse wastewater under different climate temperatures in two countries: N’Djamena in Chad, a country of Central Africa and Dakar in Seneg...In this work, we have produced biogas by co-digestion of cow dung and slaughterhouse wastewater under different climate temperatures in two countries: N’Djamena in Chad, a country of Central Africa and Dakar in Senegal, a country of West Africa. In a first approach, we put the cow dung in cans of 1.5 L, hermetically closed. The goal was to know how long you could produce biogas. Then we built a bio-digester to produce biogas for cooking. Each bio-digester was exposed to receive solar heat that varied between 27°C to 41°C in Chad and between 24°C to 30°C in Senegal. Influenced by the high temperature and a minimum residence time, the experiments showed that the N’Djamena test produced biogas more quickly than the Dakar test which, on the contrary, had a low temperature and a long residence time. The production of biogas began at the end of seven days with flammability on the twenty-first day for the bio-digester in Chad and after twenty-seven days with a flammability on the thirty-sixth day for the bio-digester of Senegal. The different digestates were valorised in fertilizers, bricks and green coal. Our research aims to meet the living conditions of the rural world specifically for women by reducing their work and thus allowing them to have more time to self-educate and educate their children.展开更多
The evolution of global mobile data over the past decades in broadcasting, Internet of Things (IoT), education, healthcare, commerce, and energy has put strong pressure on 3G/4G mobile networks to improve their servic...The evolution of global mobile data over the past decades in broadcasting, Internet of Things (IoT), education, healthcare, commerce, and energy has put strong pressure on 3G/4G mobile networks to improve their service offerings. These generations of mobile networks were initially invented to meet the requirements of the above-mentioned applications. However, as the requirements in these applications continue to increase, new mobile technologies such as 5G (fifth generation), 5G and beyond (B5G, beyond fifth generation), and 6G (sixth generation) are still progressing and being experimented. These networks are very heterogeneous generations of mobile networks that will have to offer very high throughput per user, good energy efficiency, better traffic capacity per area, improved spectral efficiency, very low latency, and high mobility. To meet these requirements, the radio interface of future mobile networks will have to be flexible and rationalized the available frequency resources. Therefore, new modulation methods, access techniques and waveforms capable of supporting these technological changes are proposed. This review presents brief descriptions of the types of 5G, B5G, and 6G waveforms. The 5G consists of OFDM including its transmission techniques: generalized frequency division multiplexing (GFDM), filter bank based multi-carrier (FBMC), universal filtered multi-carrier (UFMC), and index modulation (IM). Meanwhile, the 6G covers orthogonal time frequency space (OTFS), orthogonal chirp division multiplexing (OCDM) and orthogonal time sequence multiplexing (OTSM). The networks’ potentialities, advantages, disadvantages, and future directions are outlined.展开更多
The three measurement periods: the TOMS Nimbus-7 TOMSN7L3 v008 from 1978 to 1993, the TOMS EP TOMSEPL3 v008 from 1996 to 2005 and the OMI OMTO3d v003 from 2004 to 2008 have allowed the presence of dust to be observed ...The three measurement periods: the TOMS Nimbus-7 TOMSN7L3 v008 from 1978 to 1993, the TOMS EP TOMSEPL3 v008 from 1996 to 2005 and the OMI OMTO3d v003 from 2004 to 2008 have allowed the presence of dust to be observed in the 10°North to 20°North latitudinal band (10 - 20 band) of Africa. The 10 - 20 band has a permanent dust presence. The AERONET data show AOD peaks exceeding 2 in Senegal and Niger (on an AOD scale). The statistical study reveals intra-annual relationships in deposition. In Senegal, a significant deposition is observed.展开更多
文摘In this work, we have produced biogas by co-digestion of cow dung and slaughterhouse wastewater under different climate temperatures in two countries: N’Djamena in Chad, a country of Central Africa and Dakar in Senegal, a country of West Africa. In a first approach, we put the cow dung in cans of 1.5 L, hermetically closed. The goal was to know how long you could produce biogas. Then we built a bio-digester to produce biogas for cooking. Each bio-digester was exposed to receive solar heat that varied between 27°C to 41°C in Chad and between 24°C to 30°C in Senegal. Influenced by the high temperature and a minimum residence time, the experiments showed that the N’Djamena test produced biogas more quickly than the Dakar test which, on the contrary, had a low temperature and a long residence time. The production of biogas began at the end of seven days with flammability on the twenty-first day for the bio-digester in Chad and after twenty-seven days with a flammability on the thirty-sixth day for the bio-digester of Senegal. The different digestates were valorised in fertilizers, bricks and green coal. Our research aims to meet the living conditions of the rural world specifically for women by reducing their work and thus allowing them to have more time to self-educate and educate their children.
文摘The evolution of global mobile data over the past decades in broadcasting, Internet of Things (IoT), education, healthcare, commerce, and energy has put strong pressure on 3G/4G mobile networks to improve their service offerings. These generations of mobile networks were initially invented to meet the requirements of the above-mentioned applications. However, as the requirements in these applications continue to increase, new mobile technologies such as 5G (fifth generation), 5G and beyond (B5G, beyond fifth generation), and 6G (sixth generation) are still progressing and being experimented. These networks are very heterogeneous generations of mobile networks that will have to offer very high throughput per user, good energy efficiency, better traffic capacity per area, improved spectral efficiency, very low latency, and high mobility. To meet these requirements, the radio interface of future mobile networks will have to be flexible and rationalized the available frequency resources. Therefore, new modulation methods, access techniques and waveforms capable of supporting these technological changes are proposed. This review presents brief descriptions of the types of 5G, B5G, and 6G waveforms. The 5G consists of OFDM including its transmission techniques: generalized frequency division multiplexing (GFDM), filter bank based multi-carrier (FBMC), universal filtered multi-carrier (UFMC), and index modulation (IM). Meanwhile, the 6G covers orthogonal time frequency space (OTFS), orthogonal chirp division multiplexing (OCDM) and orthogonal time sequence multiplexing (OTSM). The networks’ potentialities, advantages, disadvantages, and future directions are outlined.
文摘The three measurement periods: the TOMS Nimbus-7 TOMSN7L3 v008 from 1978 to 1993, the TOMS EP TOMSEPL3 v008 from 1996 to 2005 and the OMI OMTO3d v003 from 2004 to 2008 have allowed the presence of dust to be observed in the 10°North to 20°North latitudinal band (10 - 20 band) of Africa. The 10 - 20 band has a permanent dust presence. The AERONET data show AOD peaks exceeding 2 in Senegal and Niger (on an AOD scale). The statistical study reveals intra-annual relationships in deposition. In Senegal, a significant deposition is observed.
