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Livestock induces strong spatial heterogeneity of soil CO2, N2O and CH4 emissions within a semi-arid sylvo-pastoral landscape in West Africa

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Journal of Arid Land 2017年第2期9卷 210-221页

作者： Mohamed H ASSOUMA Dominique SERCA Frederic GUERIN Vincent BLANFORT philippe lecomte Ibra TOURE Alexandre ICKOWICZ Raphael J MANLAY Martial BERNOU Jonathan VAYSSIERES CIRAD-UMR Selmet Campus International Baillarguet Montpellier 34398 France DP PPZS ISRA-LNERV BP 2057 Dakar Hann Senegal Laboratoire d'Aerologie-OMP Universite Paul Sabatier 14 Avenue Edouard Belin Toulouse 31400 France Geosciences Environnement Toulouse UMR 5563 & UR 234 IRD Universite Paul Sabatier Avenue Edouard Belin 14 Toulouse 31400 France CILSS 03 BP 7049 Ouagadougou Burkina Faso AgroParisTech-UMR Eco&Sols 2 place Viala Montpellier SupAgro Montpellier 34060 France IRD-UMR Eco&Sols 2 place Viala Montpellier SupAgro Montpellier 34060 France

Greenhouse gas （GHG） emissions from the surface soils and surface water receiving animal excreta may be important components of the GHG balance of terrestrial ecosystems, but the associated processes are poorly documented in tropical environments, especially in tropical arid and semi-arid areas. A typical sylvo-pastoral landscape in the semi-arid zone of Senegal, West Africa, was investigated in this study. The study area （706 km2 of managed pastoral land） was a circular zone with a radius of 15 km centered on a borehole used to water livestock. The landscape supports a stocking rate ranging from 0.11 to 0.39 tropical livestock units per hectare depending on the seasonal movements of the livestock. Six landscape units were investigated （land in the vicinity of the borehole, natural ponds, natural rangelands, forest plantations, settlements, and enclosed plots）. Carbon dioxide （CO2）, nitrous oxide （N2O） and methane （CH4） fluxes were measured with static chambers set up at 13 sites covering the six landscape units, and the 13 sites are assumed to be representative of the spatial heterogeneity of the emissions. A total of 216 fluxes were measured during the one-year study period （May 2014 to April 2015）. At the landscape level, soils and surface water emitted an average 19.8 t C-CO2 eq/（hm2.a）（CO2： 82%, N2O： 15%, and CH4： 3%）, but detailed results revealed notable spatial heterogeneity of GHG emissions. CO2 fluxes ranged from 1148.2 （±91.6） mg/（m2.d） in rangelands to 97,980.2 （±4,861.7） mg/（m2.d） in surface water in the vicinity of the borehole. N2O fluxes ranged from 0.6 （±0.1） mg/（m2.d） in forest plantations to 22.6 （±10.8） mg/（m2.d） in the vicinity of the borehole. CH4 fluxes ranged from -3.2 （±0.3） mg/（m2.d） in forest plantations to 8788.5 （±2295.9） mg/（m2.d） from surface water in the vicinity of the borehole. This study identified GHG emission ＂hot spots＂ in the landscape. Emissions from the surface soils were significantly higher in the landscape units most freq

关键词： greenhouse gases soil surface water livestock landscape Senegal

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Optimization of Contents of Three Raw Clay Materials in Formulation of a Porcelain

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Journal of Materials Science and Chemical Engineering 2022年第1期10卷 41-58页

作者： Youssouf Sawadogo Moustapha Sawadogo Moussa Ouédraogo Mohamed Seynou Gisèle lecomte-Nana philippe Blanchart Moussa Gomina Lamine Zerbo Laboratory of Molecular Chemistry and Materials (LC2M) University Joseph KI-ZERBO Burkina Faso Institute of Research in Ceramic (IRCER) UMR-CNRS European Ceramic Center Limoges France Laboratory of Cristallography and Material Sciences (CRISMAT) UMR National Graduate School of Engineering of Caen (ENSICAEN) Caen France

Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting method, were prepared with different percentages of kaolinitic clay, sand and pegmatite referenced respectively NONG, SAB and PEG. The physico-chemical, mechanical and mineralogical characteristics were evaluated on specimens formulated and sintered at different temperatures from 1200˚C to 1300˚C. X-ray diffraction has revealed the presence of mullite and quartz as essentially crystalline phases. The specimen formulated with 55% NONG, 25% PEG and 20% SAB and sintered at 1240˚C gives better performance (water absorption: 0.17%, density: 2.42, open porosity: 0.42% and flexural strength: 53.54 MPa).

关键词： Raw Minerals Porcelain Characterization Chemical Durability and Phase Transformations

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Net-Shape Clay Ceramics with Glass Waste Additive

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Materials Sciences and Applications 2014年第8期5卷 592-602页

作者： Chantale Njiomou Djangang Elie Kamseu Antoine Elimbi Gisèle Laure lecomte philippe Blanchart Department of Inorganic Chemistry University of Yaounde I Yaounde Cameroon Department of Engineering “Enzo Ferrari” University of Modena and Reggio Emilia Modena Italy LAM Local Materials Promotion Authority/MIPROMALO Yaounde Cameroon GEMH ENSCI Limoges France

In this paper, a glass powder from waste containers was mixed (10 - 40 wt.%) with a kaolinitic sandy clay from Cameroon to elaborate net-shape ceramics, fired at 1100°C. The sintering behavior was from dilatometry and thermo gravimetric analyses together with the characterization of porosity and flexural strength. The increase of glass to kaolinite ratio reduces the sintering shrinkage leading to a none-densification sintering when 40 wt.% of glass is added in the mixture. The volume variation during the whole firing process is from the individual volume variations during the quartz transformation, the structural reorganization of kaolinite and during sintering. Quartz size and relative quantity have a significant role on the first processes since it leads to either cohesive or un-cohesive behavior. But the glass quantity strongly controls the second and the third thermal processes because glass additions change the recrystallization processes, leading to the formation of dense clay-glass agglomerates distributed within the three dimensional quartz network.

关键词： Clay Waste Glass Powder Sintering Composite Cameroon

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Genomic profile concordance between pancreatic cyst fluid and neoplastic tissue

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World Journal of Gastroenterology 2019年第36期25卷 5530-5542页

作者： Arthur Laquière Arnaud Lagarde Bertrand Napoléon Raphael Bourdariat Alexandre Atkinson Gianfranco Donatelli Bernard Pol Laurence lecomte Laurence Curel Romina Urena-Campos Thierry Helbert Vincent Valantin Francois Mithieux Jean Pascal Buono philippe Grandval Sylviane Olschwang Department of Gastroenterology Saint Joseph Hospital Marseille 13008 France AP-HM Timone Hospital Marseille 13005 France RGDS Clairval Hospital Marseille 13009 France Aix-Marseille Univ INSERM MMG Marseille 13385 France AP-HM Conception Hospital Marseille 13385 France RGDS Jean Mermoz Hospital Lyon 69008 France RGDS Les Peupliers Hospital Paris 75013 France Department of Digestive Surgery Saint-Joseph Hospital Marseille 13008 France Department of Clinical Research Saint Joseph Hospital Marseille 13008 France European Hospital Marseille 13003 France Pathological Anatomy and Cytology MEDIPATH Eguilles 13510 France

BACKGROUND DNA mutational analysis of pancreatic cystic fluid (CF) is a useful adjunct to the evaluation of pancreatic cysts. KRAS/GNAS or RAF/PTPRD/CTNNB1/RNF43 mutations are highly specific to precancerous or advanced neoplasia. Several studies recently demonstrated the ability of next-generation sequencing (NGS)analysis to detect DNA mutations in pancreatic CF, but few studies have performed a systematic comparative analysis between pancreatic CF and neoplastic surgical tissue (NT). The value of CF-NGS analysis indicators for determining surgical resection necessitates evaluation. AIM To confirm whether CF genomic profiles are a reliable malignancy predictor by comparing NGS mutational analyses of CF and NT. METHODS Patients requiring surgery for high-risk pancreatic cysts were included in a multicenter prospective pilot study. DNA from CF (collected by endoscopic ultrasound-guided fine needle aspiration (known as EUS-FNA)) and NT (collected by surgery) were analyzed by NGS. The primary objective was to compare the mutation profiles of paired DNA samples. The secondary objective was to correlate the presence of specific mutations (KRAS/GNAS, RAF/ PTPRD/CTNNB1/RNF43/POLD1/TP53) with a final cancer diagnosis. Sensitivity and specificity were also evaluated. RESULTS Between December 2016 and October 2017, 20 patients were included in this pilot study. Surgery was delayed for 3 patients. Concordant CF-NT genotypes were found in 15/17 paired DNA, with a higher proportion of mutated alleles in CF than in NT. NGS was possible for all pancreatic CF collected by EUS-FNA. In 2 cases, the presence of a KRAS/GNAS mutation was discordant between CF and NT. No mutations were found in 3 patients with NT or pancreatic cysts with high-grade dysplasia. The sensitivity and specificity of KRAS/GNAS mutations in CF to predict an appropriate indication for surgical resection were 0.78 and 0.62, respectively. The sensitivity and specificity of RAF/PTPRD/CTNNB1 /RNF43/POLD1/TP53 mutatio

关键词： Pancreatic cancer Pancreatic cystic neoplasms Pancreatic adenocarcinoma Malignancy prediction Neoplastic surgical tissue Pancreatic cystic fluid Molecular analysis Next-generation sequencing DNA mutations

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Usability of a Natural Tuff as Admixture in Clinker and Its Influence on the Physico-Chemical and Mechanical Properties of Mortar

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Journal of Minerals and Materials Characterization and Engineering 2021年第5期9卷 480-498页

作者： Lamine Zerbo Moustapha Sawadogo Youssouf Sawadogo Salfo Salogo Moussa Ouedrago Mohamed Seynou Gisèle lecomte-Nana philippe Blanchart Laboratoire de Chimie Moléculaire et des Matériaux (LC2M) University Joseph Ki-Zerbo Ouagadougou Burkina Faso Centre Européen de la Céramique Limoges France

The mechanical and physical properties of TUFF from Korsimoro (Burkina Faso) were investigated for use as admixtures in clinker to make pozzolanic cement. Six different cement mortar specimens were prepared by replacing clinker with TUFF in ratios of 0%, 5%, 8%, 10%, 13% and 15% by mass. The flexural and compressive strengths of the specimens were determined at the ages of 2, 7, 28 and 60 days. The effects of the TUFF replacement ratio on workability, setting time and volume expansion were also examined. Based on the results, it was concluded that Korsimoro TUFF has pozzolanic activity and is suitable for use as an alternative adherent material in the cement industry.

关键词： Pozzolan Tuff Admixture Cement Mortar

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