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Comparative Study of Linear and Non-Linear Controls of Three-Phase Shunt Active Filters for Improving the Quality of Electrical Energy

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Energy and Power Engineering 2019年第3期11卷 149-166页

作者： Mamane adamou Nabil Alkassoum André Foulani Amadou Seidou Maiga Department of Physics (FAST) Abdou MOUMOUNI University Niamey Niger Departments of Applied Physics Gaston Berger University Saint-Louis Senegal

The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electrical energy. We used two TSA control models which differ in the method of disturbed currents detection, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives more promising results than the linear control method. When connecting a non-linear load (televisions, lamps, variable speed drives, etc.) directly to the public distribution network, the non-linear nature of the load causes the source current to be deformed due to the presence of harmonic currents and voltages. These harmonics thus generate a high reactive power, and therefore considerable electrical losses in the network. One of the solutions to reduce losses on the electricity grid is to incorporate an electronic circuit called a filter into the electricity grid. This work carried out a comparative study of two types of control of a three-phase shunt active filter (TSAF) in order to carry out a system for cleaning up electricity networks in order to improve the quality of electrical energy. We used two TSA control models that differ in the method of detecting disturbed currents, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives better results than the linear control method.

关键词： Power Quality Active Three-Phase Shunt Filter Non-Linear Control Linear Control

Influence of Re-Greening on the Infiltrability of Soils in South-Central Niger

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Journal of Water Resource and Protection 2014年第19期6卷 1731-1742页

作者： adamou Mahaman Moustapha Issoufou Baggnian Nazoumou Yahaya Toudou Adam Faculty of Agronomy Abdou Moumouni University Niamey Niger Faculty of Sciences and Technics Abdou Moumouni University Niamey Niger

In the Sahel, the climate and the agricultural practices are the main factors used to observe regreening process. But the extension of the latter not being uniform in the farming fields, we can suppose that there are other factors that contribute to the re-greening of certain zones and not others. The infiltrability of soils is considered as an important factor for these changes in the last decades. The influence of re-greening on the infiltrability of soils in the southern strip of Niger was studied through a comparison of zones according to the type of sandy soils (Jigawa/Rerey), siltyclay (Guiéza), silty-sandy (Hako) and clay-silty-sandy (Laka). The evaluated parameters are the texture, the infiltrability and the ecological characteristics (specific index of regeneration “SIR” and the Importance Value Index “IVI”). The main conclusions were: the soils of Niger South-Central are characterized by a sandy texture for more than 80%. The soils which are very sandy (“Jigawa”, “Rerey” and “Guieza”) are more permeable and have more trees contrary to the soil Hako and Laka. Their encrusting has the tendency to reduce the vegetation cover on the soil. The infiltration measurements indicated that the rate of initial and stationary infiltration diminishes while going down towards the South. In fact, it has been recorded a rate of 123 mm/min of initial infiltration and 87 mm/min stationary in Dan Saga on the sandy soils against 76 mm/min and 65 mm/min in Daré respectively for the initial and stationary rate. Therefore, the infiltration seems to influence the density, the SIR and the IVI of the trees from the North towards the South. Some additional work is necessary in order to determine the contribution of Farmer Managed Natural Regeneration (FMNR) in the improvement of the quality of soils and the movement of water in the superficial zones of the soil.

关键词： Infiltrability Specific Index of Regeneration Importance Value Index Superficial Zones

Model for Anticipating Failures by Omission in Calculation Grids

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Open Journal of Optimization 2021年第3期10卷 71-87页

作者： Ramadane adamou Yougouda Marcellin Nkenlifack Vivient Corneille Kamla Laurent Bitjoka ENSAI University of Ngaoundere Ngaoundere Cameroon URIFIA Department of Mathematics and Computer Science Faculty of Science University of Dschang Dschang Cameroon

Computer grids are infrastructures in which heterogeneous and distributed resources offer very high computing or storage performance. If they offer extreme computing performance, they are also subject to the appearance of many failures related to this type of architecture. While performing tasks, if the response time of a node in the system incomprehensibly exceeds the requirements of the specifications, the node experiences an omission failure. The task running in the failed node will be unavailable until the node resumes normal activity. Waiting not being a possible solution, many fault tolerance methods have been proposed. Despite this large number of fault tolerance methods on offer, computer grids are still prone to many failures by omission. In this work, a numerical study of the failures by omission which occur in the calculation grids during the execution of the tasks was carried out and a model allowing anticipating its failures was proposed with the formalism PDEVS (Parallel Discret EVent system Specification).

关键词： Calculation Grids Fault Tolerance Failures by Omissions PDEVS DEVS Modeling Simulation DEVSJAVA

Management of Secondary Leyll Syndrome Due to Anti-Covid Vaccine in a Case, at the Renaissance University Teaching Hospital, Ndjamena (CHAD)

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Journal of Biosciences and Medicines 2022年第10期10卷 47-54页

作者： Traoré Sory adamou Abassi Mana Abdelsalam Hissein Hassan Kader Ndjaye Nouradine Abakar Abdesalam Mahamt Bahar Mahamat Ali Bolti Ngamai Kotyadé Mwabanyol Loobe Regis Michel Slama Hamit Mahamat Alio Anesthesia-Resuscitation Department of the Renaissance University Teaching Hospital N’Djamena Chad Emergency Department of the N’Djamena Renaissance University Teaching Hospital N’Djamena Chad Internal Medicine Department N’Djamena Renaissance University Teaching Hospital N’Djamena Chad Surgery Department of N’Djamena Renaissance University Teaching Hospital N’Djamena Chad Ophthalmology Department of the N’Djamena Renaissance University Teaching Hospital N’Djamena Chad Head of Resuscitation Department CHU Amiens-Picardie Amiens France Laboratory Department of the Renaissance University Teaching Hospital of N’Djamena N’Djamena Chad Faculty of Human Health Sciences of the University of N’Djamena N’Djamena Chad

Introduction: Lyell’s syndrome (SL), called Toxic Epidermal Necrolysis is one of the most serious forms of medication accidents. It is an acute, rare pathology, its incidence is estimated at 1 to 2 cases out of one million inhabitants per year and its evolution can be fatal. Materials and Methods: We report the observation of a 60-year-old patient, with no significant pathological history, admitted to our intensive care unit at the Renaissance University Teaching Hospital in N’Djamena for the treatment of Toxic Epidermal Necrolysis. In whom the onset of symptoms dates back to few hours after vaccination against COVID-19 with Ag Johnson and Johnson. Results: An ophthalmology opinion was requested and the patient was put on Fucithalmic. In our case, in addition to the advanced age of the patient (60 years old), her SCORTEN was ≥5. Conclusion: The late management as well as the absence of a specific department for severe burns, which condition the presence of a technical plate was fatal to her despite multidisciplinary care: Resuscitators, Traumato-Orthopedist and ophthalmologist.

关键词： Lyell Syndrome Renaissance University Teaching Hospital N’Djamena Symptomatology Vaccination Covid-19 SCORTEN

Groundwater Annual Dynamics in the Basins of Woro and Chago (Eastern Niger) as Affected by Seasonal Variability and Anthropic Activities

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Journal of Water Resource and Protection 2013年第9期5卷 911-917页

作者： adamou Mahaman Moustapha Nazoumou Yahaya Aw Sadat Awaiss Yahaya Ambouta Karimou Abdou Moumouni University of Niamey Niamey Niger Institut National Polytechnique HB Yamoussoukro Ivory Coast

The Sahelian region is known to have extremes climatic constraints since the end of the seventies. The studied zone is characterized by an extreme spatial and temporal variability of the environmental factors, complicating the understanding of the mechanisms governing the functioning of the hydrological system in the basin. The evapotranspiration was very high (1975 mm/an), whereas the local annual rainfall was around 300 mm/year. The piezometric data showed a rise of the groundwater level during the rainy season and a decrease in the dry season. The water balance obtained using the Penman-Monteith method showed the predominance of the evapotranspiration (75% to 80% of the rainfall) on the drainage (20% to 25% of the precipitations).

关键词： Basin Groundwater Drought Evapotranspiration Variation

Impact of Amegilla calensand Apis melliferaPollination on Gossypium hirsutumvar. QR1302 Flowers at Tchabbal-Mounguel (Ngaoundéré, Cameroon)

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Open Journal of Ecology 2020年第7期10卷 445-459页

作者： Sanda Mazi Moise adamou Kodji Issaya Issaya Mamoudou Jean Faïbawa Esaïe Department Biological Sciences Faculty of Science University of Ngaoundéré Ngaoundéré Cameroon School of Geology and Mining Engineering at Meiganga University of Ngaoundéré Ngaoundéré Cameroon Faculty of Medicine and Biomedical Sciences of Gaoroua University of Ngaoundéré Ngaoundéré Cameroon

The investigations were carried out from September 10 through October 13, 2017 at Tchabbal-Mounguel. On Gossypium hirsutum flowers, investigations were done on many aspects of the pollination services of Amegilla calens and Apis mellifera. G. hirsutum flowers were observed to study the activity of A. calens and A. mellifera and to evaluate their impacts on fruits and seed yields of this Malvaceae. The treatments consisted of 120 flowers left for free pollination, 120 flowers protected from insects using gauze bag nets, 200 protected flowers and visited exclusively by A. calens and A. mellifera and 100 protected flowers then opened and closed without any visit of insects or any other organisms. The results show that on cotton flowers, foragers of A. calens and A. mellifera highly collect nectar and pollen on its flowers. The highest mean number of individuals simultaneously active per 1000 flowers is 587 for A. calens and 526 for A. mellifera. Through their pollinating efficiency, A. calens and A. mellifera caused a significant increase in the fruiting rate by 7.00% and 17.33%, the number of seeds per fruit by 44.20% and 18.32% and the normal seeds by 47.78% and 5.66% respectively. Therefore, the conservation of the nests of A. calens and colonies of A. mellifera around G. hirsutum plantations are to be recommended to improve the fruit and seed yields of this Malvaceae.

关键词： Bees Pollination Efficiency Cotton Plant Yield

Epidemiological, Clinical, Paraclinical and Prognostic Profile of Children Aged 0 to 5 Years with Cerebral Palsy in Medical Department of Niamey National Hospital (NNH)

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Open Journal of Internal Medicine 2022年第1期12卷 69-83页

作者： Mamane Daou Haoua Sidibé Souleymane Brah K. Ayouba adamou Dan Koma Abdoulkader Andia Zakaria Mamadou Mahdi Konaté Yakoura Abba Kaka Daouda Inoussa Bako Sani Beydou Youssoufa Seydou Eric Adehossi Samuila Sanoussi Department of Internal Medicine H&ocirc pital National de Niamey Niamey Niger Department of Neurology H&ocirc pital National de Niamey Niamey Niger Department of Internal Medicine H&ocirc pital General de Reference Niamey Niger Department of Surgery H&ocirc pital National de Niamey Niamey Niger Department of Radiology H&ocirc pital General de Reference Niamey Niger

Introduction: Cerebral palsy is the most common motor disorder of childhood according to the Center for Disease Control and Prevention (CDC). It is much more common in premature infants. The majority of fixed organic lesions occur during the development of the central nervous system. Objective: To study the epidemiological, clinical, paraclinical and prognostic profile of children aged 0 to 5 years with Cerebral Palsy (CP) seen in consultation in the medical neurology department of the National Hospital of Niamey. Methods: This was a transverse descriptive study with prospective collection of patient records (0 - 5 years) over a 6-month period. Results: During our study, 100 children aged 0 to 5 years had to be consulted. The prevalence was 61%. 62.3% of patients were male. The mean age was 2.01 years. The majority of the patients were from the urban area (63.93%). Almost half of the mothers had no schooling. 4.92% of patients were from consanguineous marriages. Pregnancies were monitored with at least 4 prenatal visit in 86.98% of cases and 83.61% of children were born at term. In 75.41% of cases, patients were born by eutocic delivery. In 36.07% of cases, the patients were resuscitated at birth. Fetal distress was present in 29.5%. Seizures were present in 49.18% of the patients of which 50% were generalized. Tonicity was not good in 35.15% and among them 52.63% had hypertonia. 18.03% of patients had a motor deficit. For 34.43% of the patients the first nerve was affected, followed by the third nerve with 13.11%. 65.57% of the patients had fixed retardation and for 78.69% of the patients the retardation was homogeneous. Neuromalaria, meningitis and hydrocephalus were the most incriminated causes of delay in 63.51%, 19.67% and 18.03% of cases respectively. Anticonvulsants and psychoanaleptics were the most used in 49.18% and 32.79% of cases respectively. 32.79% of patients had received motor rehabilitation. All mothers had received psychotherapy. Conclusion: Cerebr

关键词： Cerebral Palsy Epilepsy NNH Niger

Model Reduction of 2-D IIR Filters

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Journal of Signal and Information Processing 2012年第4期3卷 438-456页

作者： Lahcène Mitiche Amel Baha Houda adamou-Mitiche Omar Kacem Vasil Sima National Institute for Research & Development in Informatics Bucharest Romania Science and Technology Department University of Djelfa Djelfa Algeria

The work presented in this paper concerns with analysis and synthesis of the two-dimensional Infinite Impulse Response (IIR) filters based on model order reduction. The synthesis is performed with two methods, the Prony's method (Prony modified) and Iterative method, in the spatial domain, and with the method of Semi-Definite iterative Programming (SDP), in the frequency domain. After synthesis, we make an order reduction of the filter model by the Quasi-Gramians method.

关键词： Stability Recursively Computable Linear Phase State Space Balanced Realization Model Reduction

Rise of Urban Water Table as a Cause of Flooding: Improving Knowledge in the City of Niamey (Niger Republic)

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Journal of Water Resource and Protection 2021年第12期13卷 976-999页

作者： Halidou Alassane Hado Mahaman Moustapha adamou Guillaume Favreau Marie Boucher Karmadine Hima Ibrahim Dan Dano Faculty of Agronomy Abdou Moumouni University of Niamey Niamey Niger Faculty of Science and Technics Abdou Moumouni University of Niamey Niamey Niger Grenoble Alpes University IRD CNRS Grenoble INP IGE Grenoble France Medical and Health Research Center of Niger CERMES Niamey Niger

Niamey, the capital of Niger, has experienced continuous demographic growth (+4%), accompanied by rapid urban expansion that is insufficiently controlled. This growth, combined with the effects of climate change as well as a drastic change in land use (urbanization of cultivated fields, deforestation of plateaus and erosion of slopes) disrupts the water cycle, thus leading to the superposition of three types of floods: 1) rain floods (monsoon period);2) river floods (Niger river);and 3) flooding caused by rising water table. In several neighbourhoods, the water table is now out in a sustainable manner and degrades already fragile sanitary conditions. This study aims to clarify the functioning of aquifers in the city of Niamey due to the combination of geological, geophysical and hydrogeological data. Hydrogeological investigations make it possible to identify, in areas flooded by the water table, a shallow aquifer with low capacitance (effective porosity of a few %) and low permeability (2 × 10-6 to 1 × 10-4 m/s), overlying at a level shallow clay (~10 m) and lying on the Precambrian base (schists, granites). This configuration limits flows and has led to the appearance of permanent pools created by the water table in the valley thalweg in and around the city. Thus, in Niamey, an increase of up to twenty to forty meters was observed between 1961 and 2021 with seasonal piezometric fluctuations of a pluri-metric order following the rainy season. Beyond the health impacts, this trajectory negatively impacts land and locally causes degradation or displacement of traffic axes. Containing the level of the water table appears to be essential in the long term for sustainable sanitation in the city of Niamey.

关键词： Flood Impacts Water Table Geophysics Upwelling Niamey