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Search Results: 1 - 10 of 272 matches for " Diene Ndiaye "
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Analytical Modeling and Determination of the Characteristic Parameters of the Different Commercial Technologies of Photovoltaic Modules  [PDF]
Ahmed Sidibba, Diene Ndiaye, Menny El Bah, Sidi Bouhamady
Journal of Power and Energy Engineering (JPEE) , 2018, DOI: 10.4236/jpee.2018.63002
Abstract: This work presents a method of optimization of the photovoltaic generator (PV) based on the electrical model with a diode. The method consists of solving a second degree equation representing the derivative of the power function. The current and the maximum voltage being determined, the maximum power is deduced. Four popular types of photovoltaic panels from different manufacturers were considered for the study: BYD Model (BYD 320P6C-36), Atersa Grupo Model (A-320P GSE), SunPower Model (E19-320) and Model operated in the 50 MW power plant of Nouakchott-Mauritania (JKM320PP-72-V) of JinkoSolar. A comparative study is carried out between the simulated results and the data of the manufacturer of different technologies. The results obtained prove the effectiveness of the proposed method and that the BYD 320P6C-36 model is the most efficient among the four different technologies studied.
Evaluation of Sawdust and Rice Husks as Fillers for Phenolic Resin Based Wood-Polymer Composites  [PDF]
Marieme Josephine Lette, Elhadji Babacar Ly, Diene Ndiaye, Akito Takasaki, Toshihiro Okabe
Open Journal of Composite Materials (OJCM) , 2018, DOI: 10.4236/ojcm.2018.83010
Abstract: We produced Wood-Polymer Composites (WPCs) with phenolic resin (PR) filled with saw dust (SD) and rice husks (RH) in a PR:fillerratio of 60:40 wt.%. RH and SD were grinded and sieved into particles <160 μm. The aim of this research work was to evaluate sawdust and rice husks as fillers for sustainable phenolic resin based WPCs. Therefore, we investigated the thermal stability of PR/RH and PR/SD WPCs then we studied and compared the tensile, flexural properties of PR/SD and PR/RH WPCs samples, as well as their dimensional stability after water absorption test. Furthermore, through ultraviolet light exposure, we evaluated the effects of photo-oxidation on the water stability and mechanical properties of PR/RH and PR/SD WPCs samples compared to unexposed ones. PR filled with SD presented better mechanical properties compared to PR/RH WPCs samples. However, PR/RH WPCs showed good mechanical properties, and better thermal resistance and better water repulsion capabilities compared to PR/SD WPCs samples. Although, long time UV exposure ended up lowering considerably the mechanical properties and water resistance of PR/SD and PR/RH WPCs, both RH and SD offer great added value as fillers for PR based WPCs; SD having better interactions with PR matrix compared to RH.
Homer’s Feasibility Analysis of a Hybrid System with a Grid Connection Option for the Mauritanian Northern Coast  [PDF]
Soukeyna Mohamed, Ismail Bidjel Ramdhane, Diene Ndiaye, Abdel Kader Mahmoud, Mohamed Elmamy, Mohamed Mahmoud Menou, Ahmed Mohamed Yahya, Issakha Youm
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.72003
Abstract: On Mauritania’s northern coast, wind and solar resources are abundant and must be used effectively. These resources have the potential to completely or partially replace the existing or projected diesel generators. The main objective of this case study is to study the possibility of using a hybrid system (HS) of the type (diesel, wind and storage). The most important part of this case study intended for this area will be to add the solar in a first phase and then the incorporation of an interconnection with the nearby network in a second phase. This interconnection will be secured by mean of medium voltage lines of 33 kV, where the nearest point is located 35 km away. Indeed, the study of the optimization model is carried out through Homer, which was developed by National Renewable Energy Laboratory [NREL]. Thus, it should be noted that the HS is analyzed on the basis of costs ($/kW) and price ($/kWh) and greenhouse gas emissions. Therefore, in order to achieve these techno-economic optimization objectives, this paper introduces a sensitivity analysis that has been proposed to determine the effect of costs on each HS configuration. In the end, HSs are needed for maximum use of renewable resources at the studied site for an uninterrupted power supply.
The effect of Poly-ethylene-co-glycidyl methacrylate efficiency and clay platelets on thermal and rheological properties of wood polyethylene composites.  [PDF]
Ansou Malang Badji, El Hadj Babacar Ly, Diene Ndiaye, Abdou Karim Diallo, Ndickou Kebe, Vincent Verney
Advances in Chemical Engineering and Science (ACES) , 2016, DOI: 10.4236/aces.2016.64040
Abstract: Global ecological concerns have resulted in an interest in renewable natural materials. Composites based on high density polyethylene (HDPE), wood fiber (Veneer) and containing coupling agents like nanoclay (NC) and poly-ethylene-co-glycidyl methacrylate (PEGMA) were made by melt compounding and then injection molding. In this study, the effects of two variable parameters namely nanoclay and coupling agent on the rheological and thermal properties of wood polyethylene composites (WPECs) were investigated. The study investigates the morphology phase, rheology behaviors and thermal properties by scanning electron microscope, capillary rheometer and thermal gravimetric analyzer. The SEM micrographs of the composites showed that the outer surfaces of the wood were coated by a section of amorphous lignin. The state of dispersion in HDPE/pine/clay composites was improved by EGMA because it could interact with pine flour in addition to clay. The interaction of reinforcement with coupling agent and HDPE matrix is strong based on the observation of the fracture surface of composites when EGMA is present. However the addition of 2.5% clay slightly lowered the initial degradation temperature (Td) but did not improve the thermal stability. Obviously, all the composites materials exhibit viscoelastic values greater than those of neat HDPE.
Public Spending and Growth in the Countries of the Economic Community of West African States  [PDF]
Amath Ndiaye
Modern Economy (ME) , 2018, DOI: 10.4236/me.2018.911122
Abstract: Our research focuses on the impact of government spending on economic growth in the countries of the Economic Community of West African States (ECOWAS). It draws on new theories of endogenous growth, and more specifically on Rajhi model. After the tests of specification, an ARDL model was estimated for each of the countries which have cointegration relationships. For those whose cointegration relationship does not exist, a VAR estimate was made. So according to estimates, Total Public Spending in most of the countries of ECOWAS has not positive influence on the economic growth as well in the short term as in the long term. Also in most of the countries, Public Consumption did not positively affect economic growth as well in the long run as in the short run. Regarding Public Investment, we have the same results; it does not positively affects economic growth in most of the ECOWAS countries. Burkina Faso, Guinea and Ivory Coast are the three excepted countries where Total Public Spending has a positive effect on GDP growth in the long term but not in the short run. For further analysis we looked at Public Consumption and Public Investment. It is only in four out of ten countries of the sample that, we found that Public Consumption expenditures positively affect economic growth in the short term while the impact generally is negative in the long term. Regarding Public investment, it is only in three out of ten countries (Burkina Faso, Cote d’Ivoire, Ghana), that it was found determinant to economic growth in the long term.
Empirical Evidence of Economic Bipolarization in Africa
Mbaye Diene
Economics Research International , 2011, DOI: 10.1155/2011/986031
Abstract: This paper examines the degree of polarization in African countries' per capita GDP distribution between 1966 to 2004. We first use a nonparametric analysis and find that the countries tend to cluster in two classes of per capita GDP. Secondly, by using the Wolfson's bipolarization measure, the results reveal that bipolarization has been accelerating during the two first decades and is still growing. We relate the evolution of polarization during the period to the business sectors. We find that the specialization of the countries is the main factor explaining its evolution, namely, in agriculture and industry sectors.
Empirical Evidence of Economic Bipolarization in Africa
Mbaye Diene
Economics Research International , 2011, DOI: 10.1155/2011/986031
Abstract: This paper examines the degree of polarization in African countries' per capita GDP distribution between 1966 to 2004. We first use a nonparametric analysis and find that the countries tend to cluster in two classes of per capita GDP. Secondly, by using the Wolfson's bipolarization measure, the results reveal that bipolarization has been accelerating during the two first decades and is still growing. We relate the evolution of polarization during the period to the business sectors. We find that the specialization of the countries is the main factor explaining its evolution, namely, in agriculture and industry sectors. 1. Introduction The great advances recently done in economic growth theory, coinciding with the introduction of endogenous growth models [1, 2], have led to a rising attention on the issue of economic disparities. The models usually take into account other determinants of growth, different from capital and labor, such as human capital, public expenditures [3], and innovations [4]. Economic growth theories enhanced by the “new economic geography” models [5–7] show the importance of spatial disparities in the convergence of economies. Usually, the sigma and beta convergence developed by Barro and Sala-i-Martin [8, 9] are used for the analyses of the disparities in per capita GDP in the literature. But some authors [10–13] have shown that the convergence methodologies lead to loss of information on the dynamics of the GDP distribution. For example, they cannot capture the changes of relative positions of countries over the period, letting behind the intragroup mobility. Analysis of per capita convergence between countries has also been done by some authors: López-Bazo et al. [14], Cuadrado and Parellada [15], Fingleton and López-Bazo [16], Badinger et al. [17], Magrini [18], Miller and Genc [19], and Meliciani [20]. Bernard and Durlauf [21] use annual logarithm of real output per capita for 15?OECD countries and test the existence of convergence and common trends, from 1900 to 1987. There is a convergence for a group of countries when they have identical either stochastic or deterministic long-run trends, while common trends allow for proportionality of the stochastic elements. They found that there is no convergence for the countries but evidence for common trends exists. Bernard and Durlauf [22], Quah [12], and Anderson [23] point out that the convergence approaches also ignore the role of the polarization or formation of homogeneous groups within the distributions. The natural clustering around stable steady state equilibria is identified
Application of the p-Median Problem in School Allocation  [PDF]
Fagueye Ndiaye, Babacar Mbaye Ndiaye, Idrissa Ly
American Journal of Operations Research (AJOR) , 2012, DOI: 10.4236/ajor.2012.22030
Abstract: This paper focus on solving the problem of optimizing students’ orientation. After four years spent in secondary school, pupils take exams and are assigned to the high school. The main difficulty of Education Department Inspection (EDI) of Dakar lies in the allocation of pupils in the suburbs. In this paper we propose an allocation model using the p-median problem. The model takes into account the distance of the standards imposed by international organizations between pupil’s home and school. The p-median problem is a location-allocation problem that takes into account the average (total) distance between demand points (pupil’s home) and facility (pupil’s school). The p-median problem is used to determine the best location to place a limited number of schools. The model has been enhanced and applied to a wide range of school location problems in suburbs. After collecting necessary numerical data to each EDI, a formulation is presented and computational results are carried out.
Geomagnetic Investigation Method Using Iphone® Integrated Magnetic Sensor  [PDF]
Mapathe Ndiaye, Ababacar Diagne
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.51001
Abstract:

We carried out a geomagnetic investigation using Iphone 4S? integrated magnetic sensor. The investigated area is a faulted sedimentary terrain crossed by basaltic volcanic veins. The obtained magnetic anomaly map shows the limits between the sedimentary rocks and a magnetic body at a given depth. These results are compared to the geometry of the magnetic body as shown by geological maps. The results seem to be accurate for the determination of geometry and the depth of the magnetic body.

Métodos iterativos lineares projetados através da teoria de controle e suas aplica??es
Diene, Oumar;Bhaya, Amit;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2006, DOI: 10.1590/S0103-17592006000300003
Abstract: it is shown how to built a family of new iterative methods using a feedback control viewpoint together with appropriate choices of control liapunov function, leading to a family of time varying pi/pd controllers. the new iterative methods are used to determine the optimal coefficients of adaptive filters. simulations are performed in order to show that the new methods have the same performance as the rls algorithm.
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