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Nickel ferrite spinel as catalyst precursor in the dry reforming of methane:Synthesis,characterization and catalytic properties

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Journal of Natural Gas Chemistry 2012年第5期21卷 595-604页

作者： Rafik Benrabaa Hamza Boukhlouf Axel Lfberg Annick Rubbens Rose-Nelle Vannier Elisabeth Bordes-Richard Akila Barama Laboratoire de Matériaux Catalytiques & Catalyse en Chimie Organique Faculté de ChimieUSTHBBP32 El Alia16111 Bab EzzouarAlgerAlgérie Unité de Catalyse et de Chimie du Solide UMR CNRS 8181Ecole Nationale Supérieure de Chimie de LilleUniversitédes Sciences et Technologies de LilleCité Scientif ique59655 Villeneuve d'AscqFrance

Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was *** ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcination,or by hydrothermal synthesis without calcination *** textural and structural properties were determined by a number of analysis methods,including X-ray diffraction （XRD）,Raman spectroscopy and X-ray photoelectron spectroscopy （XPS）,among which X-ray diffraction （XRD） was at room and variable *** synthesized oxides showed the presence of micro or nanoparticles of NiFe2O4 inverse spinel,but Fe2O3 （hematite） was also present when ammonia was used for *** reducibility by hydrogen was studied by temperature-programmed reduction （TPR） and in situ XRD,which showed the influence of the preparation *** surface area （BET）,particle size （Rietveld refinement）,as well as surface Ni/Fe atomic ratio （XPS） and the behavior upon reduction varied according to the synthesis *** catalytic reactivity was investigated using isopropanol decomposition to determine the acid/base *** catalytic performance of methane reforming with CO2 was measured with and without the pre-treatment of catalysts under H2 in 650-800 C *** catalytic conversions of methane and CO2 were quite low but they increased when the catalysts were pre-reduced.A significant contribution of reverse water gas shift reaction accounted for the low values of H2 /CO *** coking was observed as shown by the reoxidation step performed after the catalytic *** possible formation of nickel-iron alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.

关键词： dry reforming of methane NiFe2O4 spinel hydrothermal synthesis coprecipitation isopropanol decomposition

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Influence of pH on Water Hyacinth Ponds Treating and Recycling Wastewater

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Journal of Water Resource and Protection 2022年第2期14卷 86-99页

作者： Sèna Peace Hounkpe Martin Crapper Albant Sagbo Edmond Adjovi Martin Pépin Aina ecole nationale supérieure des Travaux Publics Université des Sciences Technologies Ingénierie et Mathématiques d’Abomey Abomey Benin Institute of Infrastructure and Environment School of Engineering University of Edinburgh Edinburgh UK Institut National de l’Eau Université d’Abomey-Calavi Abomey-Calavi Benin

This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under batch and subtropical environmental conditions, using pre-treated sewage with pH varying from 5 to 9. It was observed that the plants regulated the pH of the medium to within 6.4 to 7.1 during the treatment processes independently of influent wastewater pH ranges. This adjustment reduced the treatment performances and the biomass production in ponds, the alkaline conditions in ponds being less favorable to the activities of the plants. The optimal removal and biomass production was achieved with influent pH of 7 lying in the above interval. So the optimum influent pH for the growth of plants and the removal of nutrients and organic matters in WHP is within pH 6.4 to pH 7.1.

关键词： Sewage Treatment Biomass Production Water Hyacinth pH

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Quantification of Above-Ground Biomass and Carbon Sequestration Potential of Roadside Trees in the Plateau department of Benin Republic

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Journal of Geoscience and Environment Protection 2023年第9期11卷 20-27页

作者： dende Ibrahim Adekanmbi Igor Armand Yevide Kafui Inès Edna deleke Koko Adandé Belarmain Fandohan Basile Sègbégnon Michoagan Moussahoudou Issa Agossou Bruno Djossa Unité de Recherche en Foresterie et Conservation des Bioressources Ecole de Foresterie Tropicale Université Nationale d’Agriculture Porto-Novo République du Bénin

Roadside trees are effective natural solutions for mitigating climate change. despite the usefulness of trees to carbon sequestration, there is a dearth of information on the estimation of biomass and carbon stock for roadside trees in the study area. This study aimed to estimate the carbon stock and carbon dioxide equivalent of roadside trees. A complete enumeration of trees was carried out in Kétou, Pobè and Sakété within the communes of the Plateau department, Bénin Republic. Total height and diameter at breast height were measured from trees along the roads while individual wood density value was obtained from wood density database. The allometric method of biomass estimation was adopted for the research. The results showed that the total estimations for above-ground biomass, carbon stock and carbon equivalent from all the enumerated roadside trees were 154.53 mt, 72.63 mt and 266.55 mt, respectively. The results imply that the roadside trees contain a substantial amount of carbon stock that can contribute to climate change mitigation through carbon sequestration.

关键词： Above-Ground Biomass Allometric Model Carbon Sequestration Roadside Trees Bénin Republic

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Efficacy of Beneficial Fungi Isolates in Solanum lycopersicum L. Protection against Lepidopteran Insects through a Leaf Inoculation Technique

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Advances in Microbiology 2023年第2期13卷 89-105页

作者： Joelle Toffa Elie Ayitondji Dannon Yeyinou Laura Estelle Loko Hervé Bokossa Josky Adikpeto Appolinaire Adandonon Manuele Tamò International Institute of Tropical Agriculture (IITA) Tri Postal Cotonou Bénin Laboratoire d’Entomologie Appliquée Ecole Nationale Supérieure des Biosciences et Biotechnologies Appliquées/Université Laboratoire d’Entomologie Appliquée Ecole Nationale Supérieure des Biosciences et Biotechnologies Appliquées/Université Nationale des Sciences Technologies Ingénierie et Mathématiques d’Abomey au Bénin Dassa Bénin university of Abomey-Calavi (UAC) Calavi Bénin National university of Agriculture (UNA) Ketou Benin

Helicoverpa armigera is a key insect pest of tomatoes reducing drastically yields. The effect of the endophytic colonization of tomato plants by Beauveria bassiana using leaf spray as an inoculation method on damage and survival of H. armigera was assessed in a screen house. Two B. bassiana isolates (Bb 115 and Bb 11) and two tomato varieties (a local variety Tounvi and an improved variety Padma) were included in the study. The adaxial and abaxial leaf surfaces were sprayed at a concentration of 10sup>7sup> conidia/ml and 10sup>9sup> conidia/ml for each isolate and each of the two tomato varieties. Thirty days after inoculation, five discs of tomato leaf and tomato root were cut for each isolate, each concentration per isolate and for each variety. The samples were incubated at room temperature (28°C ± 2°C) and periodically checked for fungal growth. Larval survival was checked and a damage assessment was done on tomato flowers and the leaves. The results show that the lowest Mean Survival Times (MSTs) were recorded on larvae feeding on plants inoculated with Bb 11 (4.2 ± 0.8 days against 11.5 ± 0.2 days for control). Compared to the other treatments, low damage rates of the flowers of the improved variety inoculated with Bb 11 at 10sup>9sup> conidia/ml were recorded from the 6th Day After Inoculation (DAI). This rate remains low until the end of treatment. Overall flower damage was lower than leaf damage. The results showed large differences in pathogenicity, with most endophytic isolate belonging to Bb 11 when inoculated at 10sup>9sup> conidia/ml using the leaf spraying technique. Data were discussed with regard to the use of endophytism B. bassiana in an integrated tomato pest control approach.

关键词： Tomato Insect Beauveria bassiana Foliar Spray Endophytic Pest Management

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Tribological Investigation of HDPE-cuttlebone and HDPE-red Coral Composites

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Journal of Bionic Engineering 2019年第6期16卷 1068-1079页

作者： Amira Salem Walid Bensalah Salah Mezlini universite de Monastir Ecole Nationale d'Ingenieurs de Monastir(ENIM)Laboratoire de Genie Mecanique(LGM)LR99ES325019MonastirTunisia

In this paper,the tribological properties of cuttlebone(CB)-reinforced high density polyethylene(HDPE)and Red Coral(RC)-reinfbrced HDPE composites were *** composite specimens were prepared with a hot compression molding machine using different weight proportions of fillers blended with *** tribological behavior of the composite disks was studied using pin-on-disk tribometer under dry condition against stainless steel M30NW *** coefficient of friction as well as wear rate were examined to study the effects of the two fillers on the tribological perfonnance of both *** wear tests,different composites were examined using a Scanning Electron Microscope(SEM).It was fbund that the use of cuttlebone(CB)and Red Coral(RC)as reinforcement improved the tribological properties of HDPE.

关键词： cuttlebone-reinforced HDPE red coral-reinforced HDPE wear rate friction coefficient wear mechanism

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Fault Diagnosis in Robot Manipulators Using SVM and KNN

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Intelligent Automation & Soft Computing 2023年第2期35卷 1957-1969页

作者： D.Maincer Y.Benmahamed M.Mansour Mosleh Alharthi Sherif S.M.Ghonein Laboratoire de Robotiques Parallélisme et Systèmes Embarquer Département Automatique et ControlUniversitédes Sciences et Technologie Houari BoumedieneAlgiersAlgeria Laboratoire de Recherche en Electrotechnique Ecole Nationale PolytechniqueB.P 182El-Harrach16200AlgiersAlgeria Electrical Engineering department College of EngineeringTaif UniversityP.O.Box 11099Taif21944Saudi Arabia

In this paper,support Vector Machine(SVM)and K-Nearest Neighbor(KNN)based methods are to be applied on fault diagnosis in a robot manipulator.A comparative study between the two classiﬁers in terms of successfully detecting and isolating the seven classes of sensor faults is considered in this *** both classiﬁers,the torque,the position and the speed of the manipulator have been employed as the input ***,it is to mention that a large database is needed and used for the training and testing *** SVM method used in this paper is based on the Gaussian kernel with the parametersγand the penalty margin parameter“C”,which were adjusted via the PSO algorithm to achieve a maximum accuracy *** were carried out on the model of a Selective Compliance Assembly Robot Arm(SCARA)robot manipulator,and the results showed that the Particle Swarm Optimization(PSO)increased the per-formance of the SVM algorithm with the 96.95%accuracy while the KNN algo-rithm achieved a correlation up to 94.62%.These results showed that the SVM algorithm with PSO was more precise than the KNN algorithm when was used in fault diagnosis on a robot manipulator.

关键词： support Vector Machine(SVM) Particle Swarm Optimization(PSO) K-Nearest Neighbor(KNN) fault diagnosis manipulator robot(SCARA)

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Comparative and Prospective Evaluation of the Carbon Potential of the Mangrove of the Sine-Saloum delta (Senegal) from 2016 to 2021

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American Journal of Plant Sciences 2023年第9期14卷 994-1008页

作者： Salimata Mouhamad Diop Massamba Thiam Ousmane Ndiaye Saliou Ndiaye Cherif Cisse ecole nationale supérieure d’Agriculture Université Iba Der Thiam de Thiès Thiès Senegal Direction des Eaux et Forêts Chasses et Conservation des Sols Dakar Senegal Association Pour la Promotion des Initiatives Locales Dakar Senegal

With the rupture of the Sangomar spit and climate change, ecosystem functions such as carbon absorption and storage by the Saloum delta Biosphere Reserve are threatened. Initiatives are carried out as a response to the degradation of the mangrove ecosystem, such as the PRECEMA project. To measure its impact, an assessment of the carbon potential of the mangrove was conducted in 2016 on permanent plots. The present study is part of the monitoring of carbon potential. It aims to contribute to the updating of information on the evaluation of carbon storage potential. The method “afforestation and reforestation of degraded mangrove habitats on a large scale CDM or AR-AM0014 version 04.0” was applied. The mangrove vegetation assessed is dominated by Rhizophora racemosa with 69.9% of the total. With a relatively bushy habit (height = 1.91 m), the height distribution shows a right skewness (Skewness = 2.17;Kurtosis = 4.07) with a tail containing more observations than a normal distribution. The distribution is observed for diameters is skewed with Skewness = 1.5 but Kurtosis = 2.3. Thus the stand is young with an average diameter of 3.90 cm and 79.6% of the trees have a diameter 5 cm. The annual increase in carbon potential of the mangrove has decreased by 80% in 5 years (2016 assessment - 2021 assessment). For a 15-year period, the total carbon stock projected by the model increases globally from 201.396 TeqCO2 in 2011 to 277,318 TeqCO2 in 2026. The projections showed an overall annual stock decrease of 14,164 TeqCO2 (94%). For 2021, the total projected stock (270.289 TeqCO2) is slightly higher than the assessed stock (251.059 TeqCO2), a difference of 7%. Also, the projected annual carbon stock for 2021 (2844 TeqCO2) is higher than the assessed stock (1353 TeqCO2), a gap of 52%.

关键词： Carbon Sequestration Mangrove Forest Sangomar

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Investigation of dynamics of discrete framed structures by a numerical wave-based method and an analytical homogenization approach

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Chinese Journal of Aeronautics 2017年第1期30卷 66-74页

作者： Zhou Changwei Sun Xiangkun Mohamed Ichchou Abdel-Malek Zine Jean-Pierre Lainé Stephane Hans Claude Boutin Laboratory of Tribology and Systems Dynamics Ecole Centrale de Lyon Ecully 69134 France Institut Camille Jordan Ecole Centrale de Lyon Ecully 69134 France Laboratory of Tribology and Systems Dynamics Ecole Nationale des Travaux Publics de l'Etat Vaulx-en-Velinx 69518 France

In this article, the analytical homogenization method of periodic discrete media（HPDM）and the numerical condensed wave finite element method（CWFEM） are employed to study the longitudinal and transverse vibrations of framed structures. The valid frequency range of the HPDM is re-evaluated using the wave propagation feature identified by the CWFEM. The relative error of the wavenumber by the HPDM compared to that by the CWFEM is illustrated in functions of frequency and scale ratio. A parametric study on the thickness of the structure is carried out where the dispersion relation and the relative error are given for three different thicknesses. The dynamics of a finite structure such as natural frequency and forced response are also investigated using the HPDM and the CWFEM.

关键词： Framed structures Homogenization method Periodic structures Wave finite element method Wave propagation

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Active Queue Management Exploiting the Rate Information in TCP-IP Networks

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 223-231页

作者： Abderrahmane Boudi Malik Loudini Laboratoire de la Communication dans les Systemes Informatiques Ecole nationale Superieure d'Informatique ESI Algiers 16309 Algeria IEEE

In this paper, we propose a new mechanism called explicit rate notification(ERN) to be used in end-to-end communications. The ERN scheme encodes in the header of transmission control protocol(TCP) packets information about the sending rate and the round trip time(RTT) of the flows. This new available information to the intermediate nodes(routers) is used to improve fairness, increase utilization, decrease the number of drops, and minimize queueing delays. Thus, it induces a better management of the queue. A comparison of our scheme with preexistent schemes, like the explicit congestion notification scheme, shows the effectiveness of the proposed mechanism.

关键词： Active queue management congestion control fairness transmission control protocol(TCP)

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Loaded Rubber-Like Materials Subjected to Small-Amplitude Vibrations

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Chinese Journal of Polymer Science 2014年第5期32卷 620-632页

作者： T.Beda J.B.Casimir K.E.Atcholi Y.Chevalier Industrial and Mechanical Engineering department Ecole Nationale Supérieure Polytechnique (ENSP) Département de Physique Faculté des Sciences Université de NGaoundéré Laboratoire d’Ingénierie des Structures Mécanique et des Matériaux (LISMMA) SUPMECA de Paris Institut de Recherche sur les Transports l’Energie et la Société (IRTES EA7274) Laboratoire Systèmes et Transport (SeT EA 3317) Université de Technologie de Belfort-Montbéliard (UTBM)

This paper proposes a constitutive law and a method for characterizing highly preloaded viscoelastic materials subjected to linear （small-amplitude） vibrations. A multiplicative non-separable variables law has been suggested to model the behavior that depends on both stretch and time/frequency. This approach allows splitting the intricate combined test performed simultaneously on both stretch and frequency, generally in a limited experimental domain up to 100 Hz, into two independent tests. Thus, on one hand, the dynamic complex modulus dependent on frequency alone is evaluated on the basis of vibration tests in a large experimental domain up to 100 kHz. On the other hand, energetic parameters are determined from a quasi-static hyperelastic tensile test. The complex modulus, dependent on both stretch and frequency, is then deduced from the results acquired from uncoupled investigations. This work shows that, in extension, the elastic modulus increases with increasing stretch, and the loss factor decreases with increasing stretch; while, in compression, around the material undeformed state, the modulus increases as the stretch increases till a certain value of compression stretch （upturn point depending on material characteristics）, and then the modulus decreases as the stretch increases. Globally, preload rigidifies materials but reduces their damping property. These results closely match a well-known observation in solid mechanics.

关键词： Elastomers Viscoelasticity Hyperelasticity Vibrations Modeling Characterization Combined modulus.

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