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Geo-Electrical and Borehole Investigation of Groundwater in Some Basalts on the South-Eastern Flank of mount Cameroon, West Africa

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Journal of Water Resource and Protection 2017年第12期9卷 1526-1546页

作者： Anatole E. Djieto Lordon Christopher m. Agyingi Veronica E. manga Nenita N. Bukalo etienne T. Beka Department of Geology University of Buea Buea Cameroon Department of Environmental Science University of Buea Buea Cameroon Department of mining and Environmental Geology University of Venda Thohoyandou South Africa Hydrotech Douala Cameroon

The study area, located on the southwestern flank of mt. Cameroon, is under-lain by basalts. The occurrence of groundwater in these rocks has been evaluated in order to determine their potentials as a source of water for a water bottling and soft drink plant. To achieve this, the constant separation traversing (CST) was used and the data qualitatively analyzed to determine the occurrence of fractures as most probable borehole sites. From this analysis, three sites were selected, sites at which a vertical electrical sounding (VES) was done and interpreted. Results obtained show a four layered earth profile model type KHKH, corresponding to a typical weathered/fractured confined aquifer type curve. This profile was later confirmed from borehole information after drilling at three of the selected sites. The comparison of VES data with geological sections is corroborative. A constant rate pumping test was done at rates as well as the investigation of other hydraulic properties. The results obtained for hydraulic properties investigated for all three boreholes reveal that productivity is very good and these results also reveal that at maximum exploitation rates, lowest tolerable drawdown for all three boreholes may not be reached after ten years. Chemical analysis done in-situ and on samples at the laboratory reveal that this water has a better mineralisation compared to other bottled water brands sold on the Cameroon market.

关键词： Aquifer Constant Separation Traversing Resistivity Vertical Electrical Sounding

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Thermal Characterization of Concrete and Cement mortar from Construction Sites and Industrial Production Units in the City of Ouagadougou with a View to Standardization in Energy Certification

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Engineering（科研） 2023年第6期15卷 396-415页

作者： Saïdou Bamogo Fati Zoma etienne malbila David Y. K. Toguyeni Laboratory of Physics and Chemistry of Environment (LPCE) University JKZ-UFR Ouagadougou Burkina Faso Laboratory of Thermal and Renewable Energy (LETRE) University JKZ-UFR Ouagadougou Burkina Faso Polytechnic School of Ouagadougou (EPO) Ouaga Burkina Faso

The present study allowed to carry out a thermal characterization of concrete and cement mortar. Thermal tests were carried out with the KD2 Pro device, on concrete and mortar samples taken from twenty-six (26) construction sites of office buildings and two (2) industrial production units in the city of Ouagadougou. The tests were carried out on rectangular specimens after four weeks (4) of conservation on the site of construction or production of materials. This study seeks to determine the thermal properties of the materials, in particular the thermal conductivity, the thermal diffusivity and the thermal capacity of the samples, in the real conditions of execution of the buildings and environment. The thermal conductivity varies from 1.413 to 1.965 W/m·K, 0.940 - 1.658 W/m·K and 0.703 - 1.149 W/m·K respectively for concrete, cinder block mortar and plaster mortar. Regarding the other properties, especially the capacity and thermal diffusivity, the values vary respectively, from 1070.59 - 1974.67 kJ/kg·K and (3.74 - 6.70) × 10-7 m2/s for concrete, from 1123.69 - 1586.81 kJ/kg·K and (3.38 - 5.65) × 10-7 m2/s for plaster mortar and 1202.51 - 1736.01 kJ/kg·K and (3.82 - 7.36) × 10-7 m2/s for the mortar of building blocks. The conductivity, capacity and thermal diffusivity of industrial mortar vary from 1.019 - 1.229 W/m·K, 792.18 - 1862.58 J/kg·K and (2.75 - 6.80) × 10-7 m2/s, respectively. Only the correlations made between the thermal properties and the density of the samples of the plaster mortar, give good relations namely R2 = 0.9308 for the thermal conductivity, R2 = 0.7823 for the thermal capacity and R2 = 0.9272 for the thermal diffusivity. This study contributes to the establishment of a thermal regulation in Burkina Faso for the adoption of the West African Economic and monetary Union (WAEmU) Directive 05 on energy efficiency in buildings.

关键词： Concrete mortar Thermal Conductivity Thermal Capacity Thermal Diffusivity

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Normative Values of Cardio-Respiratory Endurance in Adults in Benin

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Open Journal of Therapy and Rehabilitation 2021年第4期9卷 143-153页

作者： H. etienne Alagnide D. Didier Niama Natta Emmanuel Sogbossi Wilfried Dahoueto Eric Dossa m. Antonin Agbogbo G. Toussaint Kpadonou University Clinic of Physical medicine and Rehabilitation CNHU-HKM Cotonou Benin

Cardiorespiratory endurance is a determining factor in the assessment of the state of health of a person. Objective: To determine the reference values for cardiorespiratory endurance in Beninese adults. Methods: Prospective transversal study, with a descriptive and analytical aim. It was carried out on healthy adult subjects (18 to 50 years old), of Cotonou and Abomey cities, from October 2017 to May 2018, without clinically identifiable orthopedic, cardiorespiratory, osteoarticular or neuromotor impairment. These subjects performed three different cardio-respiratory endurance tests: The six-minute walk test (WT6), cycloergometer test (CT) and the step test (ST). Data processing and analysis were done using SPSS version 22 software. A linear regression model was used to establish the prediction equation of maximal oxygen uptake (VO2 max) with the WT6 data. The significance level chosen was 5%. Results: Subjects average age was 30.0 ± 9.8 years. It was especially men (54.20%), students (42.13%), with a normal corpulence (69.91%). At WT6, they walked 365 m to 798 m (557.1 ± 93.6 m) with extreme heart rates (EHR) of 67 to 189 (136.7 ± 19.0) beats per minute. At ST, the extreme powers developed were 2.7 watts/kg and 11.8 watts/kg (6.4 ± 1.8 watts/kg), with EHR of 99 to 204 (168.4 ± 15.4) beats per minute. The predictor equation of VO2 max by WT6 was function of the subject’s weight, age and sex (R = 0.73). Conclusion- mily:Verdana;">Discussion: These normative values of cardio-respir

关键词： Cardio-Respiratory Endurance 6-minute Walk Test Step Test VO2 max Benin

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Insight on the Ultrastructure, Physicochemical, Thermal Characteristics and Applications of Palm Kernel Shells

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materials Sciences and Applications 2018年第10期9卷 790-811页

作者： Richard Ntenga etienne mfoumou Alexis Béakou martin Tango Jordan Kamga Ali Ahmed Laboratoire de mécanique et Productique (LmP) UFD SI Université de Douala Douala Cameroun Laboratoire d’Analyse Simulations et Essais (LASE) IUT Université de Ngaoundéré Ngaoundéré Cameroun Applied Research & Innovation Nova Scotia Community College Dartmouth Canada Institut Pascal UmR 6602-UCA-CNRS-SIGmA Clermont-Ferrand France Ivan Curry School of Engineering Acadia University Wolfville Canada

The ultrastructure and physicochemical and thermal properties of Palm Kernel Shells (PKS) in comparison with Coconut Kernel Shells (CKS) were investigated herein. Powder samples were prepared and characterized using Surface Electron microscopy (SEm) and Transmission Electron microscopy (TEm). Chemical and elemental constituents, as well as thermal performance were assessed by Van Soest method, TEm/EDXA and SEm/EDS techniques. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were also performed for thermal characterization. SEm/EDS and TEm/EDXA revealed that most of the PKS and CKS materials are composed of particles with irregular morphology;these are mainly amorphous phases of carbon/oxygen with small amounts of K, Ca and mg. The DSC data permitted to derive the materials’ thermal transition phases and the relevant characteristic temperatures and physical properties. Thermal Transition phases of PKS observed herein are consistent with the chemical composition obtained and are similar to those of CKS. Nonetheless, TGA/DTG showed that the combustion characteristics of PKS are higher than those of CKS. Taken together, our results reveal that PKS have nanopores and can be efficiently used for 3D printing and membrane filtration applications. moreover, the chemical constituents found in PKS samples are in agreement with those reported in the literature for material structural applications and thus, present potential use of PKS in these applications.

关键词： Biomass materials Palm Kernel Shell SEm & TEm Ultrastructure Thermal Properties Physico-Chemical Properties

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Characterization of Tannin-Based Resins from the Barks of Ficus platyphyllaand of Vitellaria paradoxa: Composites’ Performances and Applications

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materials Sciences and Applications 2017年第12期8卷 899-917页

作者： Richard Ntenga Frederic Djoda Pagore Antonio Pizzi etienne mfoumou Louis-max Ayina Ohandja Laboratoire de mécanique et Productique (LmP) UFD SI Université de Douala Douala Cameroun Laboratoire d’Analyse Simulations et Essais (LASE) IUT Université de Ngaoundéré Ngaoundere Cameroun ENSTIB-LERmAB Nancy University 27 rue du Merle Blanc Epinal France Department of Physics King Abdulaziz University Jeddah KSA Applied Research & Innovation Nova Scotia Community College Dartmouth Canada Laboratory of materials mechanics Structures and Integrated Manufacturing National Advanced School of Engineering University of Yaoundé 1 Yaoundé Cameroon

This work investigates the physico-chemical and mechanical properties of tannins extracted from wood for composite materials manufacturing. Sustainable knowledge (in terms of physico-chemical properties and behaviours) of the material is needed to further enhance its applications. The condensed tannins extracted from the Bark of Ficus platyphylla (BFP) and the Bark of Vitellaria paradoxa (BVP) were analyzed using matrix Assisted Laser Desorption/Ionization Time-Of-Flight (mALDI-TOF), mass Spectroscopy and Attenuated Total Reflectance Fourier Transform mid-InfraRed (ATR-FT mIR) spectra in the ranges 1800 cm-1 and 600 cm-1, as well as using CP mAS 13C-NmR. It was found that, these two tannins are procyanidin/prodelphinidin and made up of catechin/epicatechin, gallocatechin/epigallocatechin units, fisetinidin, galloyl and carbohydrates residues. Furthermore, BFP and BVP tannin bonded particleboard densities lie in the range recommended by NF EN 326-1994 standard. The resins also yielded good internal bond strength results of the panels, above relevant international standard specifications minimum requirements for interior-grade panels. The Transmission Electron microscopy with Energy Dispersive X-ray Spectroscopy Analysis (TEm/ EDXA) are showing the ultrastructure and reveal that most of the resin material appears to be in an amorphous phase mainly composed of carbon/oxygen with small amounts of K, Ca and mg. These particles have a very irregular morphology.

关键词： Wood Condensed Tannins Fibre/matrix Bond mechanical Properties Active Correlated Transmission Electron microscopy (ACTEm) matrix Assisted Laser Desorption/Ionization Time-Of-Flight (mALDI-TOF)

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morpho-Physical and Psycho-Social Determinants of Low Back Pain in midwives Population in Benin

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Open Journal of Therapy and Rehabilitation 2017年第4期5卷 107-117页

作者： H. etienne Alagnidé Natta D. Didier Niama Herman Azanmasso m. Germain Houngbedji E. Eric Dossa G. Toussaint Kpadonou Physical medicine and RehabilitationDepartment of CNHU-HKm (Centre National Hospitalier et Universitaire-Hubert K. mAGA) Cotonou Benin

Background: Low back pain is a real public health problem. Lots of studies have been done about it, but not in midwives group. The latter seem to be exposed to low back pain due to morphological, physical and psycho-social factors. We therefore study the place of these factors in the occurrence of low back pain in midwives. method: Prospective, cross-sectional and analytical study, it is done with 102 midwives of university hospitals in Benin. They were interviewed and examined. An eventual link with their history of low back pain, for at least 3 months during the last 12 months before the study, was checked to their morphological aspects (spinal curvatures, BmI), physical examinations data (strength and muscular flexibility) and psycho-social factors (relationship with colleagues and either, stress, ...). The effect of these factors was assessed using relative risk (RR) with a 95% confidence interval. Results: Different morpho-physical and psychosocial disturbances were observed in midwives. 81% had a history of low back pain. The latter have a statistically significant relationship with the different factors studied. These were mostly exposure factors, but poor midwife relationship with their hierarchical superiors was a protective factor (RR = 0.69 and p = 0.0106). Discussion-Conclusion: In Benin, health workers and especially midwives are very exposed to low back pain. The latter are often associated with different morphological, physical and psycho-social disturbances. The knowledge of those parameters is interesting to reduce this high prevalence of low back pain in midwives.

关键词： Low Back Pain midwives Nursing Staff Psychosocial Disorders morpho-Physical Disturbances Benin Cotonou

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Direct and Residual Effects of Different Levels of Chicken manure Fertilization on the Growth and Biomass Production of Brachiaria ruziziensis(Poaceae)at the Bolting in West Cameroon

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Agricultural Sciences 2019年第8期10卷 1113-1123页

作者： Gilles Jiope Azangue Fernand Tendonkeng Francois Victor Nguetsop David Fokom Wauffo etienne Tedonkeng Pamo Department of Plant Biology Faculty of ScienceUniversity of DschangDschangCameroon Department of Animal Productions Faculty of Agronomy and Agricultural SciencesUniversity of DschangDschangCameroon

The direct and residual effects of different levels of chicken manure fertilization on the growth and biomass production of B. ruziziensis at the bolting were studied in West Cameroon. The objective of this study was to evaluate the effects of different levels of chicken manure fertilization on the growth and biomass production of Brachiaria ruziziensis at the bolting. A factorial device comparing five doses of nitrogen into chicken manure (0, 25, 50, 75 and 100 kg N/ha) on plot of 6 m2 (3 × 2 m) in four replicates, (i.e. a total of 20 experimental plots) was used. Chicken manure was spread one month after planting pieces of stump during the first year. In the second year, no fertilization was brought up. 40 plants were harvested by treatment for heights and diameters measurements. The evaluation of stems biomass, leaves and whole plants was done on each plot based on the level of fertilization. The results obtained showed that chicken manure fertilization had a positive effect on the growth and biomass production of the B. ruziziensis on the direct and residual effect of fertilization. Thus, the height, diameters and biomass of whole plants in the fertilized plots were significantly larger than in the control plots. The mineralization of the organic matter contained in the chicken manure with doses of 100 kg N/ha was done on the direct and residual effect in order to assure a maximal plant growth. The level of T4 fertilization (corresponding to the dose of 100 kg N/ha) gave the best results. Referring to the result obtained, the level of T4 fertilization corresponding to 100 kg N/ha would be suitable for an optimal B. ruziziensis growth in order to avoid providing the soil with mineral fertilizer.

关键词： Brachiaria ruziziensis Chicken manure Height Diameter Biomass

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Abnormal lithium isotope composition from the ancient lithospheric mantle beneath the North China Craton

Abnormal lithium isotope composition from the ancient lithos...

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中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： Yan-Jie Tang Hong-Fu Zhang etienne Deloule Ben-Xun Su Ji-Feng Ying m.Santosh Yan Xiao State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences State Key Laboratory of Continental Dynamics Department of GeologyNorthwest University Centre National de la Recherche Scientifique CRPG School of Earth Science and Resources China University of Geosciences

Lithium elemental and isotopic compositions of olivines in peridotite xenoliths from Hebi in the North China Craton provide direct evidence for the highly variable d7Li in Archean lithospheric *** d7Li in the cores of olivines from the Hebi high-mg#peridotites(Fo.91)show extreme variation from 227 to121,in marked deviation from the d7Li range of fresh mORB(11.6 to 15.6)although the Li abundances of the olivines are within the range of normal mantle(1–2 ppm).The Li abundances and d7Li characteristics of the Hebi olivines could not have been produced by recent diffusive-driven isotopic fractionation of Li and therefore the d7Li in the cores of these olivines record the isotopic signature of the subcontinental lithospheric *** data demonstrate that abnormal d7Li may be preserved in the ancient lithospheric mantle as observed in our study from the central North China Craton,which suggest that the subcontinental lithospheric mantle has experienced modification of fluid/melt derived from recycled oceanic crust.

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Perimeters of Protection Demarcation for New Boreholes of Bonoua Aquifer (Southeastern, Côte d’Ivoire) through Hydrogeological modeling

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Journal of Geoscience and Environment Protection 2017年第11期5卷 118-138页

作者： Kouamé Kan Jean Aké Gabriel etienne Koblan Armel Kouadio Djé Kouakou Bernard Jourda Jean Patrice Water and Environment Sciences and Technical Laboratory (LSTEE) UFR of Earth Sciences and Mineral Resources University of Félix Houphou&#235t-Boigny Abidjan C&#244te d’Ivoire Department of Climatology and meteorological Applications National Meteorological Direction Abidjan C&#244te d’Ivoire

Located in the southeastern of Côte d’Ivoire, Bonoua aquifer contains an enormous groundwater potential. The new boreholes have been realized in this region to support the water supply of the populations. moreover, in this region, agriculture is the main activity, whose pesticides used to guarantee the productivity, constitute a threat for groundwater. Thus, this study was undertaken in order to design a hydrogeological model able to simulate the piezometry of the Bonoua aquifer and determine the perimeters of protection for the new boreholes. The model, carried out under the Visual modflow interface, was designed in steady-state mode and calibrated manually from the piezometry of the year 2000. The value of the standardized root mean squared residual of 4.86% (mulated heads of 0.95 permits to confirm a good calibration of the model. Perimeters of protection values were determined by simulating the paths of the virtual particles of water from the calibrated model. The simulations show that generally, the groundwater of Bonoua aquifer flows from north to south and the piezometric levels obtained vary between 65 m in the north and 5 m in the south. Upstream radius of the closed perimeters of protection calculated from the model varies from 172 to 482 m. However, those of distant perimeters of protection vary from 2877 to 6441 m.

关键词： Boreholes Hydrogeological modeling Perimeters of Protection Visual modflow Bonoua Aquifer

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mineral Balance Plasticity of Cloudberry (Rubus chamaemorus) in Quebec-Labrador Bogs

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American Journal of Plant Sciences 2013年第7期4卷 1508-1520页

作者： Léon etienne Parent Serge-étienne Parent Valérie Hébert-Gentile Kristine Naess Line Lapointe Centre d’études de la Forêt Department of Biology Université Laval Québec Canada Centre d’études de la Forêt Department of Biology Université Laval Québec Canada Centre de Recherches Les Buissons Pointe-aux-Outardes Canada. Department of Soils and Agrifood Engineering Université Laval Québec Canada

The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry naturally growing in oligotrophic oceanic bogs ofQuebecandLabrador. Our objective was to relate cloudberry stand productivity to the ionomes of female ramets and explore the cause of nutrient imbalance in low-performing stands. We analyzed 13 elements in female ramets collected in 86 natural sites where crop productivity varied widely. We computed orthogonally arranged balances reflecting plant stoichiometric rules and soil biogeochemistry. Balances were expressed as isometric log ratios (ilr) between ad hoc sub-compositions. Balances were synthesized into a mahalanobis distance optimized based on receiving operating characteristics (ROC). The critical mahalanobis distance was found to be 5.29 for cutoff berry yield of3.8 g.m-2 with test performance of 0.88, as measured by the area under the ROC curve. Although past research on cloudberry focused mainly on the N/P ratio, this exploratory mineral balance analysis indicated that imbalance in the [P,N | S,C] and [Al | Nutrients] partitions appeared to be the factors limiting the most cloudberry productivity in the bogs. Some highly productive stands showed relatively high C fixation and K use efficiency. Due to the complexity of interactions, diagnosis should be conducted computing first a global imbalance index (mahalanobis distance), then examining in the balance domain binary partitions departing most from reference, and finally appreciating relative shortage, sufficiency or excess of elements in the concentration domain.

关键词： Al Toxicity Cloudberry Compositional Data Analysis Isometric Log Ratio Nutrient Balance Ionome

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