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Smart Grid and Renewable Energy 2024年第1期15卷 1-14页

作者： amadou konfe Boureima Kabore Yves Christian Nonguierma Fatimata Ouedraogo Sié Kam Laboratory of Thermal and Renewable Energies University Joseph Ki-Zerbo Ouagadougou Burkina Faso Physic Department University Norbert Zongo Koudougou Burkina Faso Photonics and Nolinear Optics Laboratory University of Moncton Moncton Canada

In this paper, we propose a thermal model of a hybrid photovoltaic/thermal concentration system. Starting from the thermal balance of the model, the equation is solved and simulated with a MATLAB code, considering air as the cooling fluid. This enabled us to evaluate some of the parameters influencing the electrical and thermal performance of this device. The results showed that the temperature, thermal efficiency and electrical efficiency delivered depend on the air mass flow rate. The electrical and thermal efficiencies for different values of air mass flow are encouraging, and demonstrate the benefits of cooling photovoltaic cells. The results show that thermal efficiency decreases air flow rate greater than 0.7 kg/s, whatever the value of the light concentration used. The thermal efficiency of the solar cell increases as the light concentration increases, whatever the air flow rate used. For a concentration equal to 30 sun, the thermal efficiency is 0.16 with an air flow rate equal to 0.005 kg/s;the thermal efficiency increases to 0.19 with an air flow rate equal to 0.1 kg/s at the same concentration. An interesting and useful finding was that the proposed numerical model allows the determination of the electrical as well as thermal efficiency of the hybrid CPV/T with air flow as cooling fluid.

关键词： PV Cell Concentrating Thermal Energy Conversion Cooling Hybrid System

Numerical Assessment of the Thermal Efficiency of a Concentrated Photovoltaic/Thermal (CPV/T) Hybrid System Using Air as Heat Transfer Fluid

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Numerical Study of Heat Transfer in a Differentially Heated Cavity

Smart Grid and Renewable Energy（智能电网与可再生能源） 2024年第1期

作者： amadou konfe Boureima Kabore Yves Christian Nonguierma Fatimata Ouedraogo SiéKam

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Energy and Power Engineering 2023年第12期15卷 500-516页

作者： amadou konfe Adrien Sanebaye Alfred Bayala Sié Kam Laboratory of Thermal and Renewable Energies University Joseph Ki-Zerbo Ouagadougou Burkina Faso

Laminar natural convection is studied in a square cavity filled with air whose two vertical sides are subject to a temperature difference, while the other two horizontal sides are adiabatic. The hot and cold wall temperatures are kept constant. We have presented a dynamic and thermal study of pure natural convection for different values of the Rayleigh number. The numerical simulation was carried out for Rayleigh numbers ranging from 102, 103, …, 105 and the Prandtl number is Pr = 0.71. We used the COMSOL Multiphysic 5.1 software, which allows us to simultaneously solve the coupled physical phenomena in a square enclosure containing air under the Boussinesq approximation. For the coupling of natural convection with radiation from radiative surfaces, both horizontal faces are subjected to radiative flux, and the emissivity of the surfaces varies from ε = 0.1 to 0.8. We have seen that a circulation process is involved. The fluid that is subjected to a high temperature near the hot wall rises to the ceiling and the fluid near the cold wall sinks. This movement continues until the fluid reaches thermal equilibrium. In a natural convection-surface radiation coupling, simulation results indicate that radiative exchange decreases as a function of the Rayleigh number. Surface radiation reduces the flow in the cavity.

关键词： Natural Convection Square Cavity Natural Convection Radiation Coupling

Thermal Study and Modeling of the Cold Room of a Solar Adsoption Refrigerator

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Open Journal of Applied Sciences 2023年第11期13卷 1996-2006页

作者： amadou konfe Mahamadi Savadogo Loukman Ouedraogo Ousmane Moctar Sié Kam Laboratory of Thermal and Renewable Energies University Joseph Ki-Zerbo Ouagadougou Burkina Faso Sciences and Technologies Faculty University of Agadez Agadez Niger

In this work, we are interested in the study of the thermal exchanges which take place at the evaporator of an adsorption refrigerator. Due to the cost of designing experimental devices and the impossibility of studying the influence of certain parameters experimentally, an alternative would be simulation. The aim is to provide a model for predicting the thermal behavior of the various elements in the cold room of an adsorption solar refrigerator. A dynamic modelling of the refrigerator taking into account fluid flow, heat and mass transfer phenomena in the cold room was made. The calculation code obtained using COMSOL 5.1 software makes it possible to analyze and study the influence of the various parameters on the performance of the system. In a second step, the theoretical results obtained were compared with the experimental results in order to validate the model. The analysis of the influence of the physical-thermal properties of the insulating material on the temperature of the chamber makes it possible to conclude that a material having a low density ρ, a low thermal conductivity λ and a low specific heat capacity offers better performance to the cold room. Better thermal insulation also implies having a reasonable insulation thickness.

关键词： Thermal Evaporating Adsorption Cooling Modeling

Establishment of a Model for the Calculation of the COP of a Solar Adsorption Refrigerator

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Smart Grid and Renewable Energy 2023年第11期14卷 197-208页

作者： amadou konfe Gilbert G. Nana Salif Ouedraogo Sié Kam Laboratory of Thermal and Renewable Energies University Joseph Ki-Zerbo Ouagadougou Burkina Faso

This paper deals with the evaluation of the Coefficient of Performance (COP) of solar adsorption refrigeration. In the literature, simulation models to predict the thermal behaviour and the coefficient of performance of these systems are uncommon. This is why we suggest a model to simulate the operation of the machine in a typical hot and dry climate of the city of Ouagadougou. The objective is to provide a model for calculating the COP from the measurement of the ambient temperature and the irradiation of a given site. Starting from mathematical modelling, a resolution and simulation were made with COMSOL software based on the Dubinin-Astakhov adsorption model, the heat transfer balance equations, and the Linear Driving Force (LDF) model to describe the thermal behaviour of the system. A one-week measurement sequence on the adsorption solar refrigerator at the Albert Schweitzer Ecological Centre (CEAS) validated the numerical results. The measurement shows that for the days with high sunshine, the temperature of the reaction medium reaches 110°C, and the pressure reaches 500 mbar. This leads to a production of cold that allows it to reach the temperature of -5°C at the evaporator. Under these conditions, the COP is worth 14%. These results are obtained both by numerical simulation using the COMSOL 5.1 software and after a measurement session on the solar refrigerator available to the CEAS. We obtained an experimental and theoretical coefficient of performance varying between 9% and 14% with a difference of between 0% and 3%. We conclude that our model is suitable to estimate the COP of any device based on its thermal properties, the ambient temperature and the irradiation of a given site.

关键词： Solar Refrigeration Adsorption Coefficient of Performance Modelling

Effect of the Orientation on the Comfort of a Building Made with Compressed Earth Block

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Smart Grid and Renewable Energy 2021年第7期12卷 99-112页

作者： Fati amadou Oumarou Adama Ouedraogo Sikoudouin Maurice Thierry Ky Ramchandra Bhandari amadou konfe Ramatou Konate Rabani Adamou Dieudonné Joseph Bathiebo Sié Kam Laboratory of Renewable Thermal Energies University Joseph KI-ZERBO: UFR/SEA Ouagadougou Burkina Faso Faculty of Science and Technologies Department of Chemistry University Abdou Moumouni Niamey Niger Centre Universitaire Polytechnique de Kaya (CUP-Kaya) University Joseph KI-ZERBO Ouagadougou Burkina Faso Institute for Technology and Resources Management in the Tropics and Subtropics: ITT Cologne Germany

Thermal comfort is one of the most important requirements that scientists and building designers must meet to ensure the indoor air quality knowing its importance on productivity and the health of occupants. However, it has never been of great concern for architects and architectural historians and seldom explores it. Buildings are the large consumer of the most energy consumption (around 40% worldwide) and generate around 35% of GHGs like CO2 that leads to extreme climate change. Hence, general and specific eco-friendly solutions in the field of building construction are required. Analysis of this study shows that air conditioning consumption can be significantly reduced thanks to the compressed earth bricks and by taking into account the climate and the orientation of the facades. However, this paper establishes viable low-cost option of building energy consumption while maintaining the thermal comfort and good indoor air quality. This work explains the effect of a single residential room orientation, by reducing the thermal amplitude, and improving the thermal phase shift in Ouagadougou climate conditions in April. Internal temperature was modelled with 8 cardinal orientations. The result corresponds to a decrease of thermal amplitude damping greater than 4°C between East-West and North-South sides and, with a thermal phase shift of 4 hours 30 minutes between the Nord and West walls.

关键词： Thermal Comfort Building Optimal Orientation Thermal Amplitude Thermal Phase Shift Energy Consumption Optimal Orientation

Evaluation of Nutritional Composition of Two Fonio Ecotypes Grown in Casamance (Sénégal)

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Open Journal of Applied Sciences 2024年第2期14卷 533-544页

作者： amadou Bouye Seydi amadou Diop Animal Physiology Laboratory Department of Animal Biology Faculty of Science and Technology Cheikh Anta Diop University Dakar Senegal Analytical Chemistry and Bromatology Laboratory Faculty of Medicine Pharmacy and Odontology of Dakar Cheikh Anta Diop University Dakar Senegal

In order to better understand the cultural route, biochemical and nutritional composition of two ecotypes of fonio, a study was carried out in village of Tambananing located approximately 7 km from Sédhiou. The objective of studies was to determine nutritional composition of two ecotypes of fonio: the first called momo in short-cycle mandinka (75 - 90 days) and the other called medium-cycle dibong (90 - 110 days). For this, samples of two ecotypes were collected in an experimental field which was split into two equal parts, one sown with the momo ecotype and the other with the dibong ecotype. The nutritional composition (sugars, fats, proteins, minerals, ash, etc.) and the physicochemical properties (pH, humidity, water activity, color, etc.) of fonio’s were determined by appropriate physicochemical methods. The two ecotypes exhibited quite similar physicochemical properties. The levels of biochemical compounds were relatively close with protein contents of 7.05 ± 0.06 mg/100g for the momo ecotype and of 8.02 ± 0.04 mg/100g for the dibong ecotype, in carbohydrates (76.37 ± 1.2 mg/100g for momo and 78.7 ± 1.5 mg/100g for dibong) and in fat (2.92 ± 0.05 mg/100g for momo and 3.14 ± 0.004 mg/100g for dibong). Identical mineral element contents were found except for iron, an element for which the contents were 10.80 ± 0.008 mg/100g for the momo ecotype and 99.59 ± 0.005 mg/100g for the dibong ecotype. Thus, two ecotypes of fonio present a fairly interesting nutritional composition and their consumption deserves to be popularized and could contribute effectively to fight against the problems of malnutrition of certain vulnerable groups.

关键词： Biochemical Composition Ecotypes Fonio Casamance

Design of an Interconnection Architecture and Sizing of Two (2) EPC Core Networks: The Case of Orange-Guinea

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Journal of Energy and Power Engineering 2024年第2期18卷 59-70页

作者： Mamadou Sadigou Diallo Kadiatou Aissatou Barry amadou Lamarana Bah Mamadou Sanoussy Camara Janvier Fotsing amadou Barry amadou Oury Bah Gamal Abdel Nasser University of Conakry(UGANC) P.O.BOX 1147Conakry 001BP 1147Republic of Guinea National Advanced School of Engineering University of Yaoundé1Yaoundé1001BP 337Republic of Cameroon

With the arrival of the 4G and 5G,the telecommunications networks have experienced a large expansion of these *** enabled the integration of many services and adequate flow,thus enabling the operators to respond to the growing demand of *** rapid evolution has given the operators to adapt,their methods to the new technologies that *** complexity becomes more important,when these networks include several technologies to access different from the heterogeneous network like in the 4G *** dimensional new challenges tell the application and the considerable increase in demand for services and the compatibility with existing networks,the management of mobility intercellular of users and it offers a better quality of ***,the proposed solution to meet these new requirements is the sizing of the EPC(Evolved Packet Core)core network to support the 5G access *** the case of Orange Guinea,this involves setting up an architecture for interconnecting the core networks of Sonfonia and *** objectives of our work are of two orders:(1)to propose these solutions and recommendations for the heart network EPC sizing and the deployment to be adopted;(2)supply and architectural interconnection in the heart network EPC and an existing heart *** our work,the model of traffic in communication that we use to calculate the traffic generated with each technology has link in the network of the heart.

关键词： 5G network 4G network(EPS(evolved packet system)) 3G network(UMTS:Universal Mobile Telecommunications System) EPC network of the heart architecture dimensional Orange Guinea technology service

Identification of Antioxidant Additives in Food Products Sold in Dakar Markets

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Open Journal of Applied Sciences 2024年第1期14卷 51-62页

作者： Alé Kane Papa amadou Diakhaté Sokhna Ndao Modou Dieng Mady Cisse amadou Diop Laboratory of Biological Agronomic and Food Sciences and Complex Systems Modelling (LABAAM) University Gaston Berger (UGB) Saint-Louis Senegal UFR of Agronomic Sciences Aquaculture and Food Technology (UFR S2ATA) UGB Saint-Louis Senegal Analytical Chemistry and Bromatology Laboratory University Cheikh Anta Diop of Dakar Dakar Senegal Department of Chemical Engineering and Applied Biology University Cheikh Anta Diop of Dakar Dakar Senegal

The use of food additives in industrial production has the advantage of improving sensory properties, technological quality and extending the shelf life of foods. Among the most widely used additives are antioxidants, which prevent oxidation, browning and rancidity reactions in foods. However, the strong presence of these additives on the market is not without risks for human health, and should be controlled to guarantee food safety. Analysis of the risks associated with consumption of foods containing these additives requires, among other things, information on the frequency of use of these additives in various consumer products. The aim of this study is therefore to identify the antioxidants present in industrial food products distributed in Dakar. The methodology adopted consists of a qualitative analysis based on the identification of additives from food labels. Investigations were carried out in 9 stores, 4 superettes and 2 supermarkets located in different districts of Dakar. The results revealed the presence of 12 antioxidant additives, dominated by citric acid (53%) and ascorbic acid (29%). These studies have also highlighted the simultaneous use of several antioxidants in the same food product. Moreover, for some artificial antioxidants identified antioxydant such as BHA and BHT, health risks are associated with their consumption. The results of this study open up prospects for the development of information databases on food additives.

关键词： Additives Antioxidant Food Products Market Risk

Comparative Study of the Protein Contents of Local and Imported Rice Consumed in Senegal

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Open Journal of Applied Sciences 2024年第2期14卷 561-571页

作者： amadou Bouye Seydi Nadina Zuleika Leite Serigne Omar Sarr Yérim Mbagnick Diop amadou Diop Animal Physiology Laboratory Department of Animal Biology Faculty of Science and Technology Cheikh Anta Diop University Dakar Senegal Analytical Chemistry and Bromatology Laboratory Faculty of Medicine Pharmacy and Odontology Cheikh Anta Diop University Dakar Senegal

Protein is essential for the growth and maintenance of the body. They play a crucial role in different biological processes. This study focuses on comparing the protein contents of local rice grown in the Senegal River valley and rice imported from Asia. The objective is to evaluate the importance of the protein nutritional value of local rice compared to imported rice. Protein contents were determined using the Kjeldahl method. The results of the protein assays show that local rice varieties such as Sahel 108 and Sahel 134 grown in the Thilène basins had protein percentages comparable to those of imported rice. The protein percentages were 15.19% ± 0.91% for the Sahel 108 variety and 16.62% ± 0.01% for the Sahel 134 variety compared to 15.8% ± 0.01% on average for imported rice. Thus from the point of view of protein content, local rice has a nutritional value identical to that of imported rice which it can validly replace. It is important in Senegal to encourage local production, which would make it possible to reduce imports on the one hand and to make quality rice available to the local Senegalese market on the other. Sahel varieties with high protein contents deserve large-scale development to meet the country’s protein needs.

关键词： Proteins Rice Nutritional Value Kjeldahl Method River Valley Senegal