Causality and Comovement between Tax Rate and Budget Deficits: Further Evidence from Developing Countries

This paper examines the relationship between increasing budget deficits and tax rate for Benin, Côte d'Ivoire, Niger and Togo. This investigation is based on Johansen cointegration approach and Granger causality tests. The findings suggest firstly that these variables are not cointegrated for the countries under study, and the bootstrap simulations of the relation show more evidence for the robustness of the results to small sample size effects, and secondly that there is a bidirectional impact between tax rate and budget deficits. Given this bidirectional causality between these variables, variance decomposition and impulse responses are calculated to better understand the question of which effect is greater than the other.Tax Rate, Budget Deficit, Cointegration, Causality, Bootstrap

La formation des granulats plats et leur influence sur la résistance mécanique des agrégats des granites et gneiss du Togo

Cet article est consacré, d’une part, à l’étude de l’influence des différentes textures et structures des gneiss et des granites sur la formation des granulats plats lors du concassage et, d’autre part, à l’étude de l’impact du contenu de ces granulats plats sur la résistance mécanique des granulats, en général. Les résultats obtenus montrent que les roches ayant une structure grenue, donnent une meilleure qualité de forme (granulats de forme cubique) par rapport aux roches à structure porphyroblastique et lépidoblastique qui donnent beaucoup plus de granulats plats. En outre, la diminution du contenu de granulats plats contribue à améliorer la qualité des agrégats et à augmenter leur résistance mécanique.Mots-clés : Coefficient Los Angles, structure, gneiss, granite, granulat plat

Energy production and financial analysis of photovoltaic energy plants in Ivory Coast

One key factor for boosting economic growth in developing countries is the energetic independence of the countries. Renewable energies are well suited for such purpose even if effective dissemination of renewable energies is their production price. The energy production of solar plants is highly dependent of both sun radiation and climate data and therefore dependent of their location. This paper reports on the economic and financial calculations related to the energy production of a standard 20 kW photovoltaic plant connected to the electric network and located in Ivory Coast (Côte d’Ivoire). Its economic profitability in terms of economic returns of the electricity production is calculated by using capital budgeting techniques. It is demonstrated that when photovoltaic plants are considered as economic assets, the knowledge of financial and economic characteristics of the country as well as the geographical localization of photovoltaic plants, have to be taken into account in order to assess the profitability of the investment. The Levelized Cost of the Energy generated for the photovoltaic plant during its expected time of operation (25 years) is calculated and compared with other economical parameters.Keywords: photovoltaic energy production, solar energy investments, capital budgeting, net present value, profitability, levelized cost of energy, Ivory Coast. Production d'énergie et analyse financière d’une installation photovoltaïque en Côte-d’IvoireUn facteur clé pour stimuler la croissance économique dans les pays en développement est l'indépendance énergétique de ces pays. Les énergies renouvelables sont bien appropriées pour atteindre un tel objectif, même si la vulgarisation effective des énergies renouvelables dépend de leur prix de production. L’implantation des panneaux solaires est fortement dépendante à la fois de l’ensoleillement et des données climatiques. Cet article présente les calculs économiques et financiers liés à la production d'énergie électrique d'une installation photovoltaïque de 20 kW standard connectée au réseau électrique et située en Côte d'Ivoire. Sa rentabilité économique en termes de retour sur investissements de la production d'électricité est calculée en utilisant la méthode du capital budgétisé. Il est démontré que quand on considère des installations photovoltaïques comme des atouts économiques, la connaissance des caractéristiques financières et économiques du pays aussi bien que la localisation géographique de l’implantation, doivent être pris en compte pour évaluer la rentabilité de l'investissement. Le coût de l'énergie produite par l'installation photovoltaïque pendant sa durée opérationnelle (25 ans) est calculé et comparé avec d'autres paramètres économiques.Mots-clés: production d'énergie photovoltaïque, énergie solaire, investissement, budgétisation, capital, rentabilité, coût moyen actualisé de l'énergie, Côte d'Ivoire

Optical characterization of a-Si : H thin films grown by Hg-Photo-CVD

Mercury-Sensitized Photo-Assisted Chemical Vapor Deposition (Hg-Photo-CVD) technique opens new possibilities for reducing thin film growth temperature and producing novel semiconductor materials suitable for the future generation of high efficiency thin film solar cells onto low cost flexible plastic substrates. This paper provides some experimental data resulting from the optical characterization of hydrogenated amorphous silicon thin films grown by this deposition technique. Experiments have been performed on samples deposited at different temperatures, with and without thermal annealing.Mercury-Sensitized Photo-Assisted Chemical Vapor Deposition (Hg-Photo-CVD) technique opens new possibilities for reducing thin film growth temperature and producing novel semiconductor materials suitable for the future generation of high efficiency thin film solar cells onto low cost flexible plastic substrates. This paper provides some experimental data resulting from the optical characterization of hydrogenated amorphous silicon thin films grown by this deposition technique. Experiments have been performed on samples deposited at different temperatures, with and without thermal annealing

Spectroscopie de vibration infrarouge du silicium amorphe hydrogéné évaporé

Ce travail porte sur l’étude des configurations des liaisons Si-H des couches minces du silicium amorphe hydrogéné évaporé (a-Si:H) préparées dans un bâti ultra-vide (UHV). L’hydrogène atomique est obtenu à l’aide d’un plasma dans un tube à décharge dirigé vers le porte-substrat. Les fréquences de vibrations et la nature des liaisons Si-H ont été analysées à partir des mesures de spectroscopie infrarouge à transformée de Fourier.Mots-clés : silicium amorphe hydrogéné, absorption infrarouge, transformée de Fourie

A Review of the Impacts SMEs as Social Agents of Economic Liberations in Developing Economies

1/w hene.f/ts 1!1 o hooming .\ 1//~ sector can be seen in the creation of a sound industrial hm,· for an emerging eumonn It rang!'~ .fi"om the prm·iswn of' employment, sources of subsistencl'. ,·,luiwble distrthution of IIK0111es to its citi::ens. to deployment of domestic savings for investments. It ul.111 include. bw not limited. to the increase in capital financial gains. important contribution to Cross I >omestic Product (CIJI'i lwrnessing c1{ natil·e raw materials. curtailing rural-urban migration and efficient uti!i::ation o(a nation·.\ resource. as can b~ seen in the case of Taiwan. South Korea, Singapore. <'t( These are cowuries that were huilt on a d\'namic SML sector 1/owever. many less developed economies /w,·e not bel'n a hie to jullt· utili::e the 111cmv henejits of this sl'ctor. perhaps due to ignorance. This revietr <'\llmined the ntenlto which these .1ocial agems (S\1/~s) which hm·e libera!i::ed several economies oflhe d, l'e!opl'd coumries. such as the { nitecl States. { nited 1\ ingdom. Wider Europe and the BRICS countrh ' 1 Bra:: if. R11.11i11. India. ( 'llina wul So111h .lji-icaJ is being treated with levity within the developing econnlllll'.\. The sttu!r howet'l.'r. focuses 011 the .)',\/Es operating within the Nigerian state. It employed in its ennrety !he re1•ie1r ofsecondw:t· duta , 1171/findings revealed a plethora of issues. Of note was the facl that despite the benefit~ of this l'ihrulll sector to the \'igerian economy. the government policies, infrastructures. finances ammtgst others are not Jhl'omble for its gr01111t all(/ sustainability. The authors recommend that the 1\igerian gm·~mlll<'llt as well os gm·emme/11 of other developing economies must invest substamial!t·to the growth. de,·elollllte/11 011(/ sustainohility of SM!~·s through the provision of essential inji·a.1tructures. 1111111111111 er. microfiiiWICI'. 1·ecurin• am/ adequate po!inji-cunework

Mortality impact of AIDS in Abidjan, 1986-1992

To quantify the mortality impact of AIDS in the city of Abidjan (Côte d'Ivoire) by a full scale analysis of mortality trends before and after the onset of the epidemic. Data on deaths registered in the 10 vital registration centers of the city between 1973 and 1992, and data on causes of deaths in the four public hospitals were coded and investigated. Data on deaths were compared with census data in order to compute death rates. Life tables were computed for each of the 20 years of the study. The trends in death rates were analysed during the 10 years before the onset of the AIDS epidemic (1973-1982) and compared with the changing death rates in the following 10 years (1983-1992). Deaths attributable to AIDS were defined as those in excess of the original trends. The evolution in the number of deaths in the hospital allowed an analysis by cause of death. There was a marked increase in death rates starting in 1986, date of the first diagnosed AIDS cases in the city. This increase was significant for both sexes, but more pronounced among men. It was concentrated primarily among young adults (aged 25-44 years) and among older children (aged 5-14 years), and most of it was considered to be attributable to AIDS and related infections, tuberculosis in particular. When data were cumulated from 1986 to 1992, approximately 25000 persons were estimated to have died of AIDS. The high number of AIDS deaths estimated in Abidjan underlines the heavy toll already paid by african populations, and calls for intensive action. (Résumé d'auteur

Optimisation des paramètres photovoltaïques du CIGS a l aide du simulateur AMPS-1D

[FR] Le Silicium Indium de Gallium et Cuivre (CIGS) dans sa structure chalcopyrite possède des propriétés électriques et électroniques intéressantes. Notre étude a porté sur la concentration de dopage des différentes couches constituant le CIGS et les effets des contacts avant et arrière sur les performances photovoltaïques de la cellule solaire. Nous avons fait la simulation de la variation de la concentration de dopage des différentes couches constituant le CIGS à l¿aide d¿AMPS-1D. Les effets du dopage des différentes couches constituant la cellule solaire à base de CIGS sur les paramètres photovoltaïques tel que le rendement (¿) la tension de circuit ouvert (Vco) et la densité de court-circuit(Jsc) ont été étudiés.L¿augmentation de la concentration de dopage des couches a un effet sur les performances des cellules solaires. Le plus grand rendement a été obtenu lorsqu¿on a augmenté la concentration dedopage de la couche absorbeur. L¿augmentation des conditions aux limites du contact avant diminue le rendement des cellules photovoltaïques tandis que l¿augmentation des conditions aux limites du contact arrière l¿augmente.[EN] Copper indium gallium (di) selenide (CIGS) in its chalcopyrite structure has electrical and electronic properties. Our study focused on the doping of the various layers constituting the CIGS and the effects of the front and back contacts on the photovoltaic performance of the solar cell. We simulated the variation of the doping concentration of the various layers constituting the CIGS using AMPS-1D. The effects of the doping of the various layers of the CIGS solar cell on the photovoltaic parameters such as the efficiency (¿) open circuit voltage (Vco) and the court circuit density (Jsc) have been analyzed. The increase in the doping of the layers has an effect on the performance of the solar cells. The greatest efficiency was obtained when the doping of the absorbed layer is height. The increase in the boundary conditions of the front contact decreases the efficiency of the photovoltaic cells while the increase in boundary conditions of the back contact increases.Oyedele, S.; Boko, A.; Marí, B. (2017). Optimisation des paramètres photovoltaïques du CIGS a l aide du simulateur AMPS-1D. Afrique Science. 13(2):274-283. http://hdl.handle.net/10251/101852S27428313

Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications

[EN] Wide band gap methylammonium lead halide perovskites (CH3NH3PbX3, X=halogen; CH3NH3: MA) are interesting materials for photovoltaic applications. They have recently gained substantial attention because of their high efficiency, low cost, superior optical properties. The most attractive and representative perovskites are methylammonium lead halides (CH3NH3PbX3,) denoted as MAPbX3, X = Br, Cl, I. usually the optical and structural properties of CH3NH3PbBr3 can be adjusted by introducing other extrinsic ions such as chloride and bromide. In this work, instead of replacing the halogens I or Cl with bromine (Br) as usual, we preferred to act on the post-transition metal (Pb). To this end, we replaced lead with chromium (Cr) which is a transition metal and may have the same oxidation state (+2) as lead. MAPb0.93Cr0.07Br3 thin films were deposited on ITO substrate by the spin coating process. X-ray diffraction analyses indicated the formation of a cubic perovskite with space group Pm3 m. The structural analysis reveals films with (110) and (220) as main peaks. Deposited films showed a strong absorbance in the UV¿vis range. The band gap values were estimated from absorbance measurements. It was found between 1.60 and 1.80 eV. SEM analysis shows a morphology with good coverage and no apparent crystal orientation.Soro, D.; Sidibé, M.; Fassinou, W.; Marí, B.; Sall, T.; Fofana, B.; Boko, A.... (2017). Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications. International Journal of Innovative Research in Science, Engineering and Technology. IJIRSET (Online). 6(6):10170-10176. doi:10.15680/IJIRSET.2017.0606007S10170101766