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Solar chemical looping reforming of methane combined with isothermal H2O/CO2 splitting using ceria oxygen carrier for syngas production

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Journal of Energy Chemistry 2020年第2期29卷 60-72页

作者： Srirat Chuayboon stéphane Abanades Sylvain Rodat Processes Materials and Solar Energy LaboratoryPROMES-CNRSFont-Romeu 66120France Department of Mechanical Engineering King Mongkut's Institute of Technology LadkrabangPrince of Chumphon CampusChumphon 86160Thailand Universite Grenoble Alpes Le-Bourget-du-Lac F-73375France CEA-LJTEN Laboratoire des Systemes Solaires Haute Temperature(LSHT) Grenoble F-38054France

The chemical looping reforming of methane through the nonstoichiometric ceria redox cycle(CeO2/CeO2-δ) has been experimentally investigated in a directly irradiated solar reactor to convert both solar energy and methane to syngas in the temperature range 900–1050 °C. Experiments were carried out with different ceria shapes via two-step redox cycling composed of endothermic partial reduction of ceria with methane and complete exothermic re-oxidation of reduced ceria with H2 O/CO2 at the same operating temperature, thereby demonstrating the capability to operate the cycle isothermally. A parametric study considering different ceria macrostructure variants(ceria packed powder, ceria packed powder mixed with inert Al2 O3 particles, and ceria reticulated porous foam) and operating parameters(methane flow-rate, reduction temperature, or sintering temperature) was conducted in order to unravel their impact on the bed-averaged oxygen non-stoichiometry(δ), syngas yield, methane conversion, and solar reactor performance. The ceria cycling stability was also experimentally investigated to demonstrate repeatable syngas production by alternating the flow between CH4 and H2 O(or CO2). A decrease in sintering temperature of the ceria foam was beneficial for increasing syngas selectivity, methane conversion,and reactor performance. Increasing both CH4 concentration and reduction temperature enhanced δ with the maximum value up to 0.41 but concomitantly favored CH4 cracking reaction. The ceria reticulated porous foam showed better performance in terms of effective heat transfer, due to volumetric absorption of concentrated solar radiation and uniform heating with lower solar power consumption, thereby promoting the solar-to-fuel energy conversion efficiency that reached up to 5.60%. The energy upgrade factor achieved during cycle was up to 1.19. stable patterns in the δ and syngas yield for consecutive cycles with the ceria foam validated material performance stability.

关键词： Chemical looping Methane reforming Ceria structure Concentrated solar power Syngas production H2O/CO2 splitting

Contribution to the study of the Incidence of Post-streptococcal Complications in Republic Central African Republic from 2015 to 2018

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Open Journal of Epidemiology 2024年第1期14卷 110-121页

作者： Zéphirin Dalengat Vogbia Ernest Lango Yaya Jean De Dieu Longo Augustin Balekouzou Gaspard Tekpa Christian Maucler Pamaticka stéphanie Judith N’Yetobouko Maurel Anicet Adonis Ouoko Fatigbia Christian Diamant Mossoro Kpindet Gérard Gresenguet Epidemiology and Research Service National Reference Center for Sexually Transmitted Infections and Anti-Retroviral Therapy Ministry of Health Bangui Central African Republic Direction of National Laboratory of Clinical Biology and Public Health Ministry of Health Bangui Central African Republic Training Project Manager and Heald of Public Departement Ministry of Health Bangui Central African Republic Faculty of Health Sciences Doctoral School of Human and Veterinary Health Sciences University of Bangui Bangui Central African Republic National Committee for the Fight against AIDS Primature Bangui Central African Republic Infectious Disease Department The Sino Central African Friendship University Hospital Center Bangui Central African Republic Epidemiology Department Bangui National University Hospital Center Bangui Central African Republic

Introduction: Acute rheumatic fever (AAR) is a non-suppurative complication of late infection by group A. Infections due to streptococci remain a public health problem in the Central African Republic. The present study aims to determine the incidence rate of AAR cases and its complications. Methodology: This was a retrospective and analytical study over a period of 4 years (from January 2015 to December 2018) at the National Laboratory of Clinical Biology and Public Health (LNBCSP) in Bangui. It focused on samples concerning the diagnosis of AAR and patient files seen in consultation in the capital’s reference health establishments. Laboratory registers and patient consultation files were used to collect data. They were entered into Excel 2010 to be analyzed with Epi Info 7. A univariate analysis by logistic regression, Ficher’s exact test, and chi2 at the 5% threshold (p Results: We analyzed 94 cases meeting Jones’s criteria. The ages of the patients ranged from 18 to 85 years (mean age 52 years and mode 45 years). The incidence rate of AAR for the female sex was higher than that of the male sex during the study period (p > 0.05). It went from 166.6 in 2015 to 200 in 2016 and 2018 cases of AAR per 1000 people per year. The average incidence rate was 296.18 cases of AAR per 1000 people per year. The average incidence rate was 223.5 cases of AAR per 1000 people per year for joint damage. Joint damage represented 80.85% (RR = 0.62;Chi2 = 4.88;95% CI [0.39-0.97];p Conclusion: The study allowed data on the impact rate and complications of the AAR in Bangui. Special attention to data management will help produce a complete result on the problem. Joint complications predominated. Sustaining an effective surveillance system and preventing infection would help reduce the risk of AAR occurrence.

关键词： Incidence Acute Joint Rheumatism Central African Republic

Detection of ARV-Resistant Mutants in HIV-1-Infected Individuals in a Context of Systematic Switching to an Association Based on Dolutegravir in Abidjan, Côte d’Ivoire

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American Journal of Molecular Biology 2024年第3期14卷 138-151页

作者： Odegue Kpadraux Danielle Kakou-Ngazoa Solange Dechi Jean-Jacques Renaud Diallo Zelica Sina Kouamé Mireille Sylla Aboubacar Tossea Koui stéphane Kouakou Venance Adagba Marius Apia N’Chouo Kouamé Basile Touré Offianan André Dosso Mireille Molecular Biology Platform Institut Pasteur Abidjan Cte dIvoire Laboratory of the Regional Blood Transfusion Center Yamoussoukro Cte dIvoire Department of Infectious and Tropical Diseases University Hospital Treichville Abidjan Cte dIvoire Laboratory of the Regional Blood Transfusion Center San-Pdro Cte dIvoire Department of Epidemic Virus Institut Pasteur Abidjan Cte dIvoire Department of Parasitology Mycology Institut Pasteur Abidjan Cte dIvoire Department of Bacteriology-Virology Institut Pasteur Abidjan Cte dIvoire

The emergence of antiretroviral resistance mutations represents a major threat to the achievement of national and global goals for the elimination of HIV-1 infection. The global strategy in 2019 in Cte d'Ivoire is a new national policy for the management of people living with HIV with the administration of dolutegravir (DTG)-based fixed-dose combination. The aim of our study was to evaluate HIV-1 resistance to antiretrovirals (ARVs) in infected adult subjects in Cte d’Ivoire in the context of a systematic switch to a DTG-based combination. Between February 2022 and October 2023, a cross-sectional survey with random sampling was conducted in 06 services caring for people living with HIV. A total of 139 participants were included in the study. Adults with a viral load ≥ 1000 copies/mL were tested for HIV-1 ARV resistance mutations. Molecular analyses were performed using protocol of ANRS-MIE (National Agency for Research on AIDS and emerging infectious diseases). The interpretation is performed by HIVGRAD (https://***/cms/grade/). The frequencies of HIV-1 resistance to non-nucleotide reverse transcriptase inhibitors (NNRTIs), nucleotide reverse transcriptase inhibitors (NRTIs), integrase inhibitors (IINTs) and protease inhibitors (PIs) were 82%, 73%, 19% and 11% respectively. The main mutations observed in the different classes were K103N (45%), M184V (64%), E157Q (19%) and L10V/M46I/A71V/I54V (6%) respectively. This study reveals the emergence of resistance to DTG-based fixed-dose combinations, favored by high rates of resistance to NRTIs and NNRTIs. This finding underlines the need for enhanced viral load monitoring and HIV-1 genotyping tests to guide the choice of NRTIs for combination therapy. In addition, monitoring for mutations to second-generation NRTIs is essential, given the scale-up of DTG-based regimens currently underway in Cte d’Ivoire.

关键词： Resistant Mutants Dolutegravir HIV-1 Antiretrovirals Côte d’Ivoire

Multidrug-Resistant of Escherichia coli and Salmonella spp. strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

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Open Journal of Applied Sciences 2024年第4期14卷 881-892页

作者： stéphanie Lynseh Carine Sita Bénao Dabiré Amana Métuor Abdoul Karim Ouattara Rahimatou Yasmine Wendkouni Tiemtoré Nicolas Ouédraogo Blandine Ouédraogo Rhaina Olivia Badini Lionel Eliada Benoit Bambara Serge Sougué Jacques Simporé Biomolecular and Genetic Laboratory (LABIOGENE) Pietro Annigoni Biomolecular Research Center (CERBA) Department of Biochemistry-Microbiology University Joseph Ki-Zerbo Ouagadougou Burkina Faso Department of Biochemistry-Microbiology University of D&#233dougou D&#233dougou Burkina Faso National Malaria Research and Training Centre (CNRFP) Ouagadougou Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

关键词： Multidrug-Resistant Chicken Ouagadougou Escherichia coli Salmonella spp. Antibiotic

Conversion of the refractory ammonia and acetic acid in catalytic wet air oxidation of animal byproducts

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Journal of Environmental Sciences 2011年第3期23卷 520-528页

作者： Virginie Fontanier Sofiane Zalouk stéphane Barbati Aix-Marseille Universite's-CNRS (UMR 6264)-Laboratoire de Chimie Provence:quipe Chimie de l'Environnement Continental-3 Place Victor Hugo (case 29)-13331 Marseille cedex 3France

Wet air oxidation （WAO） and catalytic wet air oxidation （CWAO） of slaughtered animal byproducts （ABPs） were investigated. Two step experiment was carried out consisting of a non-catalysed WAO run followed by a CWAO run at 170-275 ℃, 20 MPa, and reaction time 180 min. The WAO （lst step） of sample （5 g/L total organic carbon （TOC）） yielded （82.0 ±4）% TOC removal and （78.4 ± 13.2）% conversion of the initial organic-N into NH4＋-N. Four metal catalysts （Pd, Pt, Rh, Ru） supported over alumina have been tested in catalytic WAO （2nd step） at elevated pH to enhance ammonia conversion and organic matter removal, particularly acetic acid. It was found that the catalysts Ru, Pt, and Rh had significant effects on the TOC removal （95.1%, 99.5% and 96.7%, respectively） and on the abatement of ammonia （93.4%, 96.7% and 96.3%, respectively） with high nitrogen selectivity. The catalyst Pd was found to have the less activity while Pt had the best performance. The X-Ray diffraction analysis showed that the support of catalyst was not stable under the experimental conditions since it reacted with phosphate present in solution. Nitrite and nitrate ions were monitored during the oxidation reaction and it was concluded that CWAO of ammonia in real waste treatment framework was in good agreement with the results obtained from the literature for ideal solutions of ammonia.

关键词： wet oxidation, heterogeneous catalysis animal byproducts acetic acid ammonia, nitrite nitrate

Machine Learning for heat radiation modeling of bi-and polydisperse particle systems including walls

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Particuology 2023年第3期74卷 119-140页

作者： Josef Tausendschön Gero stöckl stefan Radl Institute of Process and Particle Engineering Graz University of TechnologyInffeldgasse 13/III8010GrazAustria

We investigated the ability of four popular Machine Learning methods i.e.,Deep Neural Networks(DNNs),Random Forest-based regressors(RFRs),Extreme Gradient Boosting-based regressors(XGBs),and stacked ensembles of DNNs,to model the radiative heat transfer based on view factors in bi-and polydisperse particle beds including *** training and analyzing the predictive capability of each method,an adjustment of markers used in monodisperse systems,as well as an evaluation of new markers was *** the basis of our dataset that considers a wide range of particle radii ratios,system sizes,particle volume fractions,as well as different particle-species volume fractions,we found that(i)the addition of particle size information allows the transition from monodisperse to bi-and polydisperse beds,and(ii)the addition of particle volume fraction information as the fourth marker leads to very accurate *** terms of the overall performance,DNNs and RFRs should be preferred compared to the other two *** particle-particle view factors,DNN and RFR are on par,while for particle-wall the RFR is *** demonstrate that DNNs and RFRs can be built to meet or even exceed the prediction quality standards achieved in a monodisperse system.

关键词： Discrete element method(DEM) Heat radiation modeling Machine learning View factors Wall radiation Polydisperse particles

3D finite element analysis of a two-surface wear model in fretting tests

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摩擦:英文版 2023年第12期11卷 2278-2296页

作者： stéphanie BASSEVILLE Djamel MISSOUM-BENZIANE Georges CAILLETAUD Universitéde Versailles Saint-Quentin Versailles 78000France MINES Paristech PSL Research UniversityMATCentre des MatériauxCNRS UMR 7633Evry Cedex BP 8791003France

This article aims at developing a computationally efficient framework to simulate the erosion of two contact surfaces in three-dimensional(3D),depending on the body *** framework involves finite element(FE)resolution of a fretting problem,wear computation via a non-local criterion including a wear distribution parameter(WDP),as well as updating of the geometry and automatic *** originality is based on the capability to capture the damage on each surface and obtain local and global results for a quantitative and qualitative *** simulations are carried out for two 3D contact specimens with different values of *** results highlight the importance of correctly modelling wear:One-surface wear model is sufficient from a global point of view(wear volume),or whenever the wear resistance for a body is much higher than that of another one,whereas a 3D two-surface wear model is essential to capturing local effects(contact pressure,wear footprint,etc.)related to the difference in wear resistance of the bodies.

关键词： three-dimensional(3D)finite element(FE)simulations fretting two-surface wear model titanium alloys

New perspectives for investigating respiratory failure induced by cervical spinal cord injury

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Neural Regeneration Research 2014年第22期9卷 1949-1951页

作者： Marcel Bonay stéphane Vinit Université de Versailles Saint-Quentin-en-Yvelines Unité End:icapUFR des Sciences de la Santé–Simone Veil78180 Montigny-le-BretonneuxFrance Service de Physiologie-Explorations Fonctionnelles H?pital Ambroise Paré Assistance Publique-H?pitaux de Paris(AP-HP)Groupe Hospitalier Paris Ile-de-France Ouest92104 BoulogneBillancourtFrance

Traumatic cervical spinal cord injury （SCI）, with an annual incidence of 12,000 new cases in USA （NSCISC 2013）, causes devastating locomotor and respiratory paralysis and unfortunately compromises the human patient＇s lifespan. The severity of the injury depends on the degree and the extent of the initial trauma. In fact, respiratory failure is the leading cause of mortality following upper cervical SCI. However, 80% of the injuries are incomplete, allowing some modest spontaneous recovery. To date, no effective treatment is available in order to restore the loss of function.

关键词： SCI New perspectives for investigating respiratory failure induced by cervical spinal cord injury CPP

Late-entry commercial thinning effects on Pinus banksiana:growth, yield, and stand dynamics in Québec, Canada

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Journal of Forestry Research 2019年第1期30卷 95-106页

作者： Martin-Michel Gauthier stéphane Tremblay Ministère des Forêts de la Faune et des Parcs du Québec Natural Resources Canada Canadian Forest Service

We studied late-entry commercial thinning effects on growth, yield, and regeneration in a 48-year-old jack pine(Pinus banksiana Lamb.) stand. Applied thinning intensities were 27, 32, and 47% of merchantable basal area(BA) excluding skidding trails. After 15 years, mean diameter at breast height of surviving trees in the 47% BA removal increased by 4.9 cm(25%) compared to the unthinned control. The 47% BA removal also increased gross merchantable volume(GMV) tree-1by 46% compared to the control. The 27% BA removal had twice as much GMV ha-1compared to the 47% BA removal after15 years. Moreover, cumulative GMV ha-1was much higher in the 27% BA removal than in the unthinned control. The highest thinning intensity produced larger trees on average, while the lowest thinning intensity maximized volume production per hectare. Maintenance of acceptable growing stock throughout the 15-year period in the 27% BA removal could provide other ecosystem functions such as biodiversity enhancement or wildlife habitat by delaying senescence. Regeneration data showed that a shift in species composition occurred in the understory. After 15 years, the understory was dominated by black spruce(Picea mariana(Mill.) B.S.P.), white birch(Betula papyrifera Marsh.), and trembling aspen(Populus tremuloides Michx.). If regenerating jack pine is an objective after final overstory removal, additional efforts will be needed to re-establish this species.

关键词： Jack pine Commercial thinning stand yield Succession Delayed senescence Tree regeneration