检索结果-南通市图书馆

Advances in Materials Physics and Chemistry 2024年第8期14卷 137-145页

作者： Wedjers Max Robin Manouan Bi Irié Hervé Gouré Doubi Lébé Prisca Marie-Sandrine Kouakou Atta Kouamé Brice Koffi Alfred Niamien Kouamé Namory Méité UFR Sciences et Technologies Universit de Man Man Cte dIvoire UFR Sciences Biologiques Universit Peleforo GON COULIBALY Korhogo Cte dIvoire laboratoire de constitution et de raction de la matire Universit Felix Houphout-Boigny Abidan Cte dIvoire

This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.

关键词： Quartz Kaolinite Mountain District Low-Carbon Cements

Habits on Social Networks at Workplace: A Survey of Motivations and Behaviour

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第8期14卷 2154-2168页

作者： Thomas Kakou Kouassi Douatia Koné Aliou Bamba Aladji Kamagaté Olivier Asseu Yvon Kermarrec laboratoire des Sciences et Technologies de lInformation et de la Communication (LASTIC) Ecole Superieure Africaine des TIC (ESATIC) Abidjan Cte dIvoire Institut National Polytechnique Houphout Boigny (INPHB) Yamoussoukro Cte dIvoire departement de Mathematiques Physique et Chimie Universit Plforo Gon Coulibaly (UPGC) Korhogo Cte dIvoire Agence Nationale de la Recherche (ANR) Paris France laboratoire des Sciences et Techniques de linformation de la Communication et de la Connaissance (Lab-STICC) IMT Atlantique Brest France

This article explores the use of social networks by workers in Abidjan, Côte d’Ivoire, with particular emphasis on a descriptive or quantitative analysis aimed at understanding motivations and methods of use. More than five hundred and fifty questionnaires were distributed, highlighting workers’ preferred digital channels and platforms. The results indicate that the majority use social media through their mobile phones, with WhatsApp being the most popular app, followed by Facebook and LinkedIn. The study reveals that workers use social media for entertainment purposes and to develop professional and social relationships, with 55% unable to live without social media at work for recreational activities. In addition, 35% spend on average 1 to 2 hours on social networks, mainly between 12 p.m. and 2 p.m. It also appears that 46% believe that social networks moderately improve their productivity. These findings can guide marketing strategies, training, technology development and government policies related to the use of social media in the workplace.

关键词： Social Network Social Media Applications Poisson’s Law Statistics Digital Supports Workers Productivity

Corrective Effect of the Angle of Incidence of the Magnetic Field Intensity on the Performance (Series and Shunt Resistances) of a Bifacial Silicon Solar Cell

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Power Engineering 2024年第9期16卷 313-323页

作者： Idrissa Sourabié Mahamadi Savadogo Boubacar Soro Ramatou Saré Christian Zoundi Martial Zoungrana Issa Zerbo laboratoire de Chimie Analytique de Physique Spatiale et nergtique (L@CAPSE) Ecole Doctorale Sciences et Technologies Universit Norbert ZONGO Koudougou Burkina Faso laboratoire denergies Thermiques Renouvelables (L.E.T.RE) Ecole Doctorale Sciences et Technologies Universit Joseph KI-ZERBO Ouagadougou Burkina Faso

This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystalline silicon solar cell. The cell is illuminated simultaneously from both sides. The continuity equation for the excess minority carriers is solved at the emitter and at the depth of the base respectively. The analytical expressions for photocurrent density, photovoltage, series resistance and shunt resistance were deduced. Using these expressions, the values of the series and shunt resistances were extracted for different values of the angle of incidence of the magnetic field intensity. The study shows that as the angle of incidence increases, the slopes of the minority carrier density for the two modes of operation of the solar cell decrease. This is explained by a drop in the accumulation of carriers in the area close to the junction due to the fact that the Lorentz force is unable to drive the carriers towards the lateral surfaces due to the weak action of the magnetic field, which tends to cancel out as the incidence angle increases, and consequently a drop in the open circuit photovoltage. This, in turn, reduces the Lorentz force. These results predict that the p-n junction of the solar cell will not heat up. The study also showed a decrease in series resistance as the incidence angle of the magnetic field intensity increased from 0 rad to π/2 rad and an increase in shunt resistance as the incidence angle increased. His behaviour of the electrical parameters when the angle of incidence of the field from 0 rad to π/2 rad shows that the decreasing magnetic field vector tends to be collinear with the electron trajectory. This allows them to cross the junction and participate in the external current. The best orientation for the Lorentz force is zero, in which case the carriers can move easily towards the junction.

关键词： Angle of Incidence Magnetic Field Intensity Bifacial Polycrystalline Silicon Solar Cell Series Resistance Shunt Resistance

Statistical Study of the Geoeffectivity of Halo Coronal Mass Ejections Associated with X-Class Flares during Solar Cycles 23 and 24

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第4期14卷 950-960页

作者： Younoussa Diakite Christian Zoundi M’Bi Kabore Jean Louis Zerbo laboratoire de Chimie Analytique de Physique Spatiale et Energ&#233tique (L@CAPSE) Physics Department Universit&#233 Norbert Zongo Koudougou Burkina Faso laboratoire de Maté riaux d&#8217H&#233liophysique et Environnement (LAMHE) Physics Department Universit&#233 Nazi Boni Bobo-Dioulasso Burkina Faso

By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 december 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.

关键词： CME Halo (X) Geoeffectivity Geomagnetic Storm Solar Flare Solar Cycle

Mother-to-Child Transmission of Human Papillomavirus in Burkina Faso

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Molecular Biology 2024年第1期14卷 13-24页

作者： Koudpoko Madeleine Kabre Djénéba Ouermi Théodora Mahoukèdè Zohoncon Fatié Porzé Wilfried Traore Prosper Bado Abdoul Karim Ouattara Ouamini Pulchérie de Prisca Gnoumou Rogomenoma Alice Ouedraogo Albert Théophane Yonli Punya Akouélé Kuassi-Kpede Charlemagne Marie Ragnag-Néwendé Ouedraogo Jacques Simpore laboratoire de Biologie Moléculaire et de Génétique (LABIOGENE) Université Joseph KI-ZERBO Ouagadougou Burkina Faso Centre de Recherche Biomoléculaire Pietro Annigoni (CERBA) Ouagadougou Burkina Faso Faculté des Sciences de la Santé Université Saint Thomas d’Aquin Ouagadougou Burkina Faso laboratoire de Biologie Moléculaire H&#244pital Saint Camille de Ouagadougou (HOSCO) Ouagadougou Burkina Faso University Joseph Ki-Zerbo UFR/SDS Ouagadougou Burkina Faso

Introduction: Human papillomavirus (HPV) infection is the most widespread sexually transmitted infection in the world. Today, there is growing evidence that HPV can be transmitted early in life, and one potential route is mother-to-child transmission. Data on this route of HPV transmission are scarce in Africa and particularly in Burkina Faso, where no data on the subject are yet available. The aim of our study was to estimate the rate of mother-to-child transmission of HPV infection and to identify circulating genotypes. Methodology: Cervico-uterine samples were collected from 100 full-term pregnant women and, buccal samples were obtained from their newborns at Hopital Saint Camille de Ouagadougou (HOSCO) by the specialist physician. HPV DNA amplification and genotyping were performed by PCR followed by hybridization using the HPV Direct Flow Chips kit, detecting 36 genotypes including 18 high-risk and 18 low-risk. Results: The prevalence of HPV in newborns was 8% (8/100). Six (6) HPV-positive neonates had HPV-positive mothers, while 2 HPV-positive neonates had HPV-negative mothers. The vertical transmission rate was 26.09% (6/23). Mother-newborn genotypes were concordant. However, the genotype profile of the newborns was more restricted than that of the mothers. Conclusion: HPV DNA was found in 8% of newborns in our study. The genotype profile of the mother-newborn pair was concordant. Asymptomatic HPV infection in a pregnant woman could constitute a risk factor for vertical transmission.

关键词： Mother-to-Child Transmission Human Papillomavirus PCR Genotypes Burkina Faso

Regional Climate Models in the Simulation of the Drought of the 1970’s and 1980’s Years in Senegal (In West Africa)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2024年第9期16卷 585-604页

作者： Mamadou Sarr Adoum Mahamat Moussa Malick Wade El Hadji deme Bouya Diop laboratoire des Sciences de lAtmosphre et des Ocans Matriaux-Energies-Dispositifs (LSAO-MED) Universit Gaston Berger Saint-Louis Sngal Ecole Nationale Suprieur des TIC (ENASTIC) NDjamena Tchad laboratoire detudes et de Recherches en Statistique et Dveloppement (LERSTAD) Universit Gaston Berger Saint-Louis Sngal

West Africa was hit by an unprecedented drought in the 1970’s and 1980’s years, with dramatic consequences for surface and groundwater resources. In the context of climate change, there are many studies for the prediction of the increase in the occurrence of these droughts. To predict this situation in the Senegalese region, it is necessary to use regional climate models, which carrying out the study. This work deals with the interest to examine the capacity of the RCMs (regional climate models) in order to reproduce the deficit on the 1970’s year rainfall in Senegal. In this work, we used daily precipitation data from five (5) regional climate models to characterize the droughts in Senegal by using the SPI (Standardized Precipitation Index) on different time scales (3, 6, 12 and 24 months). For this purpose, the index was calculated over two distinct periods: 1951-1969 and 1970-1990. The results show that the period 1970-1990 was drier than the period 1951-1969. For the zonal average, the results show that the North of Senegal was more affected by this deficit rainfall than the South part. The analysis of the interannual variability of rainfall for some stations in Senegal shows that the drought did not start at the same time throughout the zone.

关键词： Climate Change Drought SPI (Standardised Precipitation Index) Senegal

Study of the Viscosity and Specific Gravity of the Ternary Used Frying Oil (UFO)-Bioethanol-Diesel System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science and Chemical Engineering 2024年第4期12卷 53-66页

作者： Konan Edmond Kouassi Abollé Abolle N’guessan Luc Brou David Boa N’guessan Raymond Kre Kouassi Benjamin Yao laboratoire de Thermodynamique et Physico-Chimie du Milieu (LTPCM) UFR-SFA UNA Abidjan C&#244te d&#8217Ivoire laboratoire de Physiques Fondamentales et Appliqué es (LPFA) UFR-SFA UNA Abidjan C&#244te d&#8217Ivoire laboratoire des Procé d&#233s Industriels de Synth&#232se de l&#8217Environnement et des Energies Nouvelles (LAPISEN) de l&#8217Institut National Polytechnique F&#233lix Houphou&#235t Boigny de Yamoussoukro Yamoussoukro C&#244te d&#8217Ivoire

Fossil fuels cover around 80% of global energy consumption. However, the problems linked to their use justify the choice of using biofuel. In order to reduce as much as possible, diesel rate, an increase in the number of additives may be considered. Thus, in this work, the study of the used frying oil (UFO), bioethanol and diesel ternary system was undertaken. It emerges from this study that the addition of bioethanol reduces the viscosity and the density of the ternary system and permits a 90% substitution rate for diesel between the UFO and bioethanol. Finally, the percentage of oil becomes 40% after adding alcohol compared to the binary diesel crude vegetable oil mixture where this rate is 30%.

关键词： Biofuel UFO-Bioethanol-Diesel Ternary density Viscosity

New Fusion Approach of Spatial and Channel Attention for Semantic Segmentation of Very High Spatial Resolution Remote Sensing Images

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第2期14卷 288-319页

作者： Armand Kodjo Atiampo Gokou Hervé Fabrice Diédié Unité de Recherche et d’Expertise du Numerique (UREN) Université Virtuelle de Céte d’Ivoire Abidjan Ivory Coast laboratoire de Mathématiques et Informatique Université Peleforo Gon Coulibaly Korhogo Ivory Coast

The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requires considering spatial local context and long-term dependencies. To address this problem, the proposed approach is inspired by the MAC-UNet network which is an extension of U-Net, densely connected combined with channel attention. The advantages of this solution are as follows: 4) The new model introduces a new attention called propagate attention to build an attention-based encoder. 2) The fusion of multi-scale information is achieved by a weighted linear combination of the attentions whose coefficients are learned during the training phase. 3) Introducing in the decoder, the Spatial-Channel-Global-Local block which is an attention layer that uniquely combines channel attention and spatial attention locally and globally. The performances of the model are evaluated on 2 datasets WHDLD and DLRSD and show results of mean intersection over union (mIoU) index in progress between 1.54% and 10.47% for DLRSD and between 1.04% and 4.37% for WHDLD compared with the most efficient algorithms with attention mechanisms like MAU-Net and transformers like TMNet.

关键词： Spatial-Channel Attention Super-Token Segmentation Self-Attention Vision Transformer

Estimation of Groundwater Recharge Using Water Table Fluctuation Method in Bamako and Surrounding Areas, Mali

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2024年第9期12卷 230-245页

作者： Ibrahima Konotio Hamadoun Bokar Adama Touré Dpartement de Gologie et Mines Laboratoire Eau et Environnement Ecole Nationale dIngnieurs Abderrahmane Baba TOURE ENI-ABT Bamako Mali

Bamako’s geographic and demographic expansion is sure to increase the need for water, and the slow development of the water supply network seems unable to meet this need. The knowledge of the approximate quantity of water reaching the groundwater is crucial, given the high dependence of this city and its surrounding area on groundwater. The aim of this study is to estimate the average groundwater recharge on a monthly scale, based on measurements taken over a 24-month period by using Water Table Fluctuation (WTF). The monthly recharge values obtained from the 15 piezometers in the study area by using WTF method vary from 1.04 to 38.81 mm with an average value of 9.74 mm. As part of the precipitations, these values represent respectively 1.29%, 48.52% and 12.17% of monthly average precipitation. It appears in this study that despite the piezometers belonging to the same climatic zone, the recharge rate can be different because of many factors such as the thickness of the aquifers, the soil and geology type, the local land cover and land use activities.

关键词： Groundwater Recharge Specific Yield Hydrograph Precipitation

Petrographic and Geochemical Characters of Granites of the Banfora Belt, Burkina Faso (West Africa)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2024年第9期15卷 682-697页

作者： Abdoulaye Ouedraogo Seta Naba Hermann Ilboudo laboratoire Gosciences et Environnement (LaGE) Dpartement des Sciences de la Terre Unit de Formation et de Recherche en Sciences de la Vie et de la Terre Universit Joseph KI-ZERBO Ouagadougou Burkina Faso Bureau des Mines et de la Gologie du Burkina (BUMIGEB) Ouagadougou Burkina Faso

The Banfora’s birimian greenstones belt is located in the western part of Burkina Faso (west Africa). Recent petrographic and lithogeochemical studies have highlighted plutons intruding the metasedimentary and metavolcanic series. These plutonic rocks are composed of leucogranites belonging to the so-called Ferkessedougou’s or Ferké’s batholith, granites, granodiorites, monzodiorites and quartz monzonites. From the lithogeochemical studies, these plutonic rocks have a calc-alkaline and peraluminous character. The rare earth elements spectra of the Ferké’s leucogranites let distinguished two sub-facies. One of the sub-facies is composed of quartz monzonite to granite, while the other is granitic sensu stricto. However, all these plutonic rocks were emplaced in a geodynamic context of subduction followed by collision.

关键词： Burkina Faso Banfora Greenstones Belt Plutons Geodynamic Context Subduction