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Design and Multicriteria Optimization of a Two-Stage Reactive Extrusion Process for the Synthesis of Thermoplastic Polyurethanes

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Engineering（科研） 2012年第9期4卷 497-514页

作者： Sandrine Hoppe Dimitrios Meimaroglou Mauricio Camargo Christian Fonteix fernand.Pla Equipe de Recherche des Processus Innovatifs (ENSGSI) Université de Lorraine Nancy France Laboratoire Réactions et Génie des Procédés (CNRS) Université de Lorraine Nancy France Université de Lorraine Nancy France

This paper presents the implementation of two multicriteria optimization methods based on different approaches, namely, Rough Set Method (RSM) and Net Flow Method (NFM), to the manufacture by reactive extrusion of linear thermoplastic polyurethanes (TPUs), appropriate for medical applications. A preliminary study allowed determining the process operating conditions for which the polymerization time and the average residence time of the reactants in the extruder are of the same order of magnitude. Prior to the optimization, a neural network model able to predict with acceptable accuracy the effect of the operating conditions on the output process variables, was constructed and validated. This model was then used to determine, using Pareto’s concept, a set of non-dominated solutions constituting Pareto’s domain. These solutions were then ranked according to the preferences of a decision maker using NFM and RSM. This allowed providing the 10% highest ranked solutions of Pareto’s domain and proposing a set of optimal operating conditions for the production, with the lowest energy consumption, of TPUs with targeted properties and high purity. Experimental validation runs carried out under similar operating conditions gave rise to criteria values confirming the su- perior performance of NFM, without rejecting, at the same time, the values obtained using RSM.

关键词： Reactive Extrusion Thermoplastic Polyurethanes Modelling Multicriteria Optimization Decision-Making Support

Sizing of a Filter (L-C) for a 180°Control Inverter Connected to a Medium Voltage Network

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Open Journal of Applied Sciences 2021年第5期11卷 565-576页

作者： Kouakou fernand.Koffi Gondo Yake Raymond Gbegbe Georges Loum Olivier Asseu Institut National Polytechnique Félix Houphouë t Boigny (INP-HB) Yamoussoukro C&#244 te d’Ivoire Université Félix Houphouë t Boigny (UFHB) Abidjan C&#244 te d’Ivoire Ecole Supérieure Africaine des Technologies d’Information et de la Communication (ESATIC) Abidjan C&#244 te d’Ivoire

This paper studies the design and sizing of a filter (L-C) for an inverter with 180° control in Medium voltage (MV), based on formulas of the capacitance of the capacitor C and the inductance L of the filter (L-C) of an SPWM inverter. These formulas were obtained by minimizing two parameters: the reactive power of the capacitor (capped at 5% of the apparent power of the load) and the ripple of the current flowing through inductance L (capped at 10% of the current supplying the load). The application of these formulas for the calculation of the filter (L-C) of the 180° control inverter in MV is not conclusive. Studies have been carried out to make them applicable. The results show that limiting the current ripple in the inductor to 10% of the load current is a valid assumption and that limiting the reactive power of the capacitor to 5% of the apparent power of the load presents shortcomings. The results also show that setting the inductance L of the filter to Lmaxi and the capacitor C from 35 × Cmaxi to 400 × Cmaxi gives voltage and current THDs that meet the 519 IEEE-2014 standards.

关键词： filter (L-C) THD inverter with 180° control and with SPWM control mathematical iterations MV. MATLAB-SIMULINK

Pollination Efficiency of Amegilla calens(Hymenoptera: Apidae) on Gossypium hirsutumL. (Malvaceae) Variety L457 Flowers at Meskine (Maroua, Cameroon)

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Agricultural Sciences 2021年第10期12卷 1150-1167页

作者： Issaya Kodji Issaya Beaudelaine Stephanie Kengni Sidonie Fameni Tope fernand.Nestor Tchuenguem Fohouo Department of Biological Sciences Faculty of Science University of Maroua Maroua Cameroon

Animal pollination is a key of reproduction of more plants species including Gossypium hirsutum. This Malvaceae is the best cultivated oilseed plant in tropical and subtropical regions in the world. This research evaluates the interaction between Amegilla calens and Gossypium hirsutum from 2018 to 2019 based on the activities of the solitary bee on the flowers of this plant and their productive impact in field. The experiment was focused on four repeated treatments during the flowering phase: the first two were characterised by the existence or absence of protection of the flowers regarding all insects and the other two made up of flowers designed for the exclusive visit of A. calens or open then protected again without a visit from an insect or any other organism. Daily rhythm of activity, behavioural ecology, the pollination efficiency, the fruiting rate, the number of seeds per capsule and the percentage of normal seeds were evaluated. Among twenty insects species recorded A. calens is the most abundant with 30.72% of 655 visits and the most efficient pollinator. Amegilla calens is active on G. hirsutum flowers from 6 a.m. to 5 p.m. with a maximum activity situated from 8 a.m. to 9 a.m. All visits of this solitary bee are able to fertilize the flowers of Malvaceae. The mean duration of a visit per flower for pollen harvest is also more important (23.57 ± 0.96 sec) than nectar collection (13.69 ± 0.72 sec). For the two years, through its pollination efficiency, A. calens increased the fruiting rate by 20.30%, as well as the percentage of normal seeds by 32.39%. Therefore, we concluded that A. calens is the important pollinator and increases the fecundity and number of normal seeds of G. hirsutum.

关键词： Amegilla calens Gossypium hirsutum Meskine Pollination Efficiency Yields

Molecular Identification of Co-Existence of Carbapenemase and Extended-Spectrum β-Lactamase Genes in Klebsiella pneumoniaeClinical Isolates, and Their Phylogenetic Patterns in Kenya

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Advances in Microbiology 2021年第8期11卷 399-415页

作者： Noutin fernand.Michodigni Atunga Nyacheo Juliah Khayeli Akhwale Gabriel Magoma Andrew Nyerere Kimang’a Department of Molecular Biology & Biotechnology Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI) Nairobi Kenya Institute of Primate Research (IPR) Nairobi Kenya Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya

The increasing incidence of multidrug-resistant Klebsiella pneumoniae strains has become a serious global healthcare problem. Additionally, the carriage of both extended-spectrum ß-lactamase and carbapenemase genes on plasmid and genomic DNA in K. pneumoniae clinical isolates has not been documented in Kenya. This study aimed to assess the presence of extended spectrum β-lactamase (ESBL) and carbapenemase genes on genomic and plasmid DNA in K. pneumoniae, and classify these super-bug clinical isolates based on their phylogenetic patterns. The identification of Klebsiella-like clinical isolates (n = 20) collected from Kenyatta National Hospital in Nairobi was performed using API 20E Kit. Screening and confirmation for ESBL and carbapenemase phenotypes were conducted using Kirby-Bauer disk diffusion susceptibility test protocol. Conventional PCR technique was used to characterize ESBL and carbapenemase resistant genes on both genomic and plasmid DNA. Subsequently, 16S rRNA gene amplification and sequencing were performed. The 16S rRNA gene contiguous sequences of the bacterial isolates were analyzed using the ChromasPro. The gene sequence was compared with the sequences in GenBank database, using the BLAST program of NCBI to obtain the nearest phylogenetic neighbours from the databases. Then, the sequences of MDR K. pneumoniae and its relatives were aligned using ClustalW. The evolutionary history was inferred by using the maximum likelihood algorithm in MEGA MX. The phenotypic data of antibiotic susceptibility testing revealed that 2/20 (10%) clinical isolates were resistant both to imipenem and meropenem and producers of carbapenemase. These isolates were carbapenemase producers but not extended β-lactamases. However, 3/20 (15%) isolates that co-harboured blaNDM-1, blaIMP, blaTEM, and bla-OXA were identified during genotypic analysis. The positive control used separately yielded the expected band sizes for blaIMP (275

关键词： MDR Klebsiella pneumoniae Plasmid Genomic DNA Extended Spectrum β-Lactamase Carbapenem 16S rRNA

Improving the Quality of Rubber Plants in Bagged Nurseries by the Use of Compost-Based Culture Substrates

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Open Journal of Soil Science 2021年第11期11卷 567-585页

作者： Jean Lopez Essehi Eric Francis Soumahin Guy fernand.Yao Samuel Obouayeba Albert Yao-Kouamé National Agricultural of Research Centre Food Crop Research Station Soil Water and Plant Central Laboratory Bouaké C&#244 te d’Ivoire University Jean Lorougnon Guédé Training and Research Unit of Agroforestry Laboratory of Physiology and Plant Pathology Daloa C&#244 te d’Ivoire National Agricultural of Research Centre Research Station of Bimbresso Hevea Program Bimbresso C&#244 te d’Ivoire University Félix Houphouë t-Boigny Training and Research Unit of Earth Sciences and Mineral Resources Department of Soil Sciences Abidjan C&#244 te d’Ivoire

The decrease of fertility soils, the rarity of quality potting soil used to fill nursery bags, the high cost of chemical fertilisers and the problems associated with their use are leading planters and rubber nurserymen in developing and/or expanding areas to look for alternative and sustainable fertilization. In this perspective, a trial was carried out at Research Station of CNRA-Bimbresso and in a farmer’s environment in order to evaluate the agronomic quality of compost made from chicken droppings and dry Panicum maximum straw to improve the growth of rubber plants in bagged nurseries. Mixtures based on potting soil and/or compost in different proportions were prepared. The follow-up of the trial focused on determination of the physico-chemical characteristics of the soils, measurement of the parameters of vegetative growth and the grafting success rate evaluation of rubber plants in nursery. The results obtained show that compost-based crop substrates increase soil organic matter, nitrogen, exchangeable bases, etc., in proportion to the doses applied. For the pH, the application of compost resulted in a reduction in soil acidity of about 1.3 unit compared to the initial values at the two study sites. The vegetative behaviour of the rubber plants also shows that qualitative (height and collar diameter) and quantitative (grafting success rate) improvements were recorded in the plants raised in compost-based substrates. The production of rubber plants in bagged nurseries was optimal with compost doses of 27 t⋅ha−1 (at Bimbresso, in the southeast) and 27 t⋅ha−1 combined with fractionated application of urea (at Kimoukro, in the centre), which under the conditions of the present study may be the recommended doses on rubber plants in bagged nurseries at C

关键词： Compost Soils Parameters Vegetative Growth Hevea brasiliensis Côte d’Ivoire

Agronomic Performances of Compost Associated with Pollinating Insects on the Growth and Yield of Glycine max (L.) Merril under Field Conditions

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Open Journal of Ecology 2022年第3期12卷 175-197页

作者： Mohamadou Moussa Kengni Beaudelaine Stephanie Steve Takoukam Toukam Albert Ngakou Tchuenguem Fohouo fernand.Nestor Department of Parasitology and Parasitic Pathologies School of Science and Veterinary Medicine University of Ngaoundere Ngaoundere Cameroon Department of Biological Sciences Faculty of Science University of Maroua Maroua Cameroon Department of Biological Sciences Faculty of Science University of Ngaoundere Ngaoundere Cameroon

Soybean is an oilseed crop legume cultivated for its benefits as a source of protein to human or animal food. The cultivation of soybean will promote the diversification of income sources for rural population. Like other crops, soybean flowers are visited by insects. It is expected that within the biodiversity conservation program, anthophilous insects including bees, generally increase fruit and seed yields of many plant species. Therefore, the effect of insect pollinators and compost on growth and yield parameters of Glycine max was assessed for two cropping seasons (2018 and 2019) in the field. The experiment was set up in a complete randomized block design with three treatments: subplots applied with compost;subplots applied with fertilizer-NPK;subplots applied neither with compost, nor with fertilizer-NPK. Two other treatments were designed by plants with flowers protected against insects or flowers pollination free. Results indicate that root nodules formed by soybean plants in plots that received compost were significantly higher (P G. max flowers respectively. Lipotriches collaris was the most insect species frequently observed in the field, with 44.20% and 43.34% visits yearly respectively. The synergistic effect of insects and compost increased the number of seeds per pod by 28.27% and the percentage of normal seeds by 24.47%. Hence, applying Glycine max seeds at sowing with compost and in an environment with hives close to field could be recommended in agricultural development programs of farmers for a sustainable improvement of pods and seed yield of this valuable crop.

关键词： Soybean Lipotriches collaris Compost Pollination Yields

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

混杂纤维筋（HFRP）混凝土梁的抗弯性能试验研究

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混杂纤维筋（HFRP）混凝土梁的抗弯性能试验研究

作者：费尔南（Muhirwa fernand. 东南大学

学位级别：硕士

纤维增强复合材料（FRP）是土木工程界对高强度复合材料常用的一个术语。复合材料以其高比强度、高刚度、耐腐蚀性和电磁透明性而闻名。纤维筋替代传统钢筋在混凝土结构中的应用,在建筑领域得到了广泛的认可。玻璃纤维（GFRP）,碳纤维（... 详细信息

纤维增强复合材料（FRP）是土木工程界对高强度复合材料常用的一个术语。复合材料以其高比强度、高刚度、耐腐蚀性和电磁透明性而闻名。纤维筋替代传统钢筋在混凝土结构中的应用,在建筑领域得到了广泛的认可。玻璃纤维（GFRP）,碳纤维（CFRP）和玄武岩纤维（BFRP）和芳纶纤维（AFRP）是FRP复合材料中最常见的类型。FRP筋在混凝土结构中的应用越来越广泛,以克服传统钢筋锈蚀带来的普遍问题。目前FRP筋在结构中的应用并不广泛,其原因在于FRP筋的弹性模量较低导致结构扰度较大,裂缝较多,同时FRP筋是线弹性材料,断裂应变较小,容易发生脆性破坏就导致FRP混凝土梁的延性降低。GFRP筋的延性较好,但弹性模量较低,CFRP筋的弹性模量最高,但延性较差,造价最高,BFRP筋的有比较高拉伸强度,抗疲劳性比较差,弹性模量比较低。为了解决一种纤维筋造价高、延性和弹性模量低的问题,我们研制出一种新型混杂纤维筋（HFRP）。本文使用的新型混杂纤维筋HFRP筋是有两或两种种以上的纤维筋的连续增强纤维通过协调匹配,产生协调混杂效应而制成的一种新型复合材料筋。混杂筋不仅有较高的强度,弹性模量和韧性,并且还可以减轻重量,降低成本,提高经济效益。对该混杂筋的力学性能进行了研究。本研究旨在探讨混杂纤维筋混凝土梁的受弯性能,通过实验、有限元分析和数值模型实现的。本研究重点是混杂FRP配筋率、弯曲性能、挠度、极限承载力和破坏模式的影响。试验结果表明,HFRP配筋率是显著提高抗弯承载力的主要参数。与同时采用HFRP筋和钢筋作为纵筋的试件相比,在钢筋断裂前,试件在混凝土压碎后表现出良好的延性。此外,HFRP筋的断裂过程是通过一种纤维的初始断裂来实现的,这种纤维是由一种纤维构成的.采用Abaqus/Standard建立了四点弯曲简支梁的有限元模型。将有限元计算结果与试验结果进行了比较,结果表明,该结构具有良好的抗弯性能,极限承载力与试验结果吻合。最后,对HFRP-RC梁的破坏模式预测和极限弯矩计算进行了分析研究。结果表明,HFRP筋和钢筋作为纵向钢筋的试件表现出不同的破坏模式,部分试件发生了钢筋断裂,这与以现有理论预测的破坏模式相矛盾,配筋率较高的试件未发生生钢筋断裂,对其他构件,理论极限荷载与试验结值吻合较好,偏差小于5%高配筋率。

关键词：混杂纤维筋(HFRP) 钢筋混凝土梁有限元分析配筋率受弯性能

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不断拓展领域的再制造

表面工程与再制造 2016年第3期16卷 71-72页

作者： fernand.Weiland 韩群 APRA欧洲再制造协会中南财经政法大学外语学院瑞曼科技(南阳)创新工场

汽车再制造和工业泵、压缩机甚至IT设备再制造有什么共同点？虽然这些组件可能无法严格按照汽车再制造定义来进行再制造,但是他们之间的共同点“相当多”：可以使得零件再次变新,延长其使用寿命并且在保护资源改善环境方面做出显著贡献... 详细信息

汽车再制造和工业泵、压缩机甚至IT设备再制造有什么共同点？虽然这些组件可能无法严格按照汽车再制造定义来进行再制造,但是他们之间的共同点“相当多”：可以使得零件再次变新,延长其使用寿命并且在保护资源改善环境方面做出显著贡献。虽然汽车再制造可能是再制造业中的国王,但其他的再制造领域正变得越来越重要,并且呈现出不断发展的趋势。

关键词：工业泵小型打印机再制造产品使用寿命再制造过程世界资源天然气产业制造品规模经济生产厂商