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文章速递Elaboration and Characterization of a Fiber Composite Material Made of Petioles of the <i>Elaeis guineensis</i>(Oil Palm) 认领
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作者 Ze Eric Parfait Tchotang Théodore +3 位作者 Souck Joseph Loic Nfor Clins Wiryikfu Pondi Joseph Mpoung Léon Arnaud 《复合材料期刊(英文)》 2020年第4期106-117,共12页
The aim of this study is to characterize physically and mechanically a polyester/fiber palm petiole composite material. This work made it possible to provide the local database of composite materials but also to devel... The aim of this study is to characterize physically and mechanically a polyester/fiber palm petiole composite material. This work made it possible to provide the local database of composite materials but also to develop agricultural waste. According to BSI 2782 standard three formulations [A (10% fiber, 90% polyester);B (20% fiber, 80% polyester) and C (30% fiber, 70% po</span><span style="font-family:Verdana;">lyester)]. Water Absorption rate, density, compressive and three points</span><span style="font-family:Verdana;"> bending tests are carried out on the samples obtained by the contact molding method for each formulation. The material composite obtained by adding fibers from palm oil petiole has a density of 17.98% lower than the one made of pure polyester. Fiber reinforcement rate has no impact on the density of the composite. Formulation A most absorbs water while formulation C has good tensile/compression characteristics and the greatest breaking stress in bending among the three formulations. 展开更多
关键词 Elaboration Characterization Physico-Mechanical Composite Polyester Petioles Oil Palm
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Extraction and Characterization of Bagasse Fibres from Sugar Cane (<i>Saccharum officinarum</i>) for Incorporation into a Mortar 认领
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作者 Tchotang Theodore Carlos Mozer +4 位作者 Pondi Joseph Jeme Njie Nfor Clins Ze Eric Parfait Souck Joseph Loic 《应用科学(英文)》 2020年第8期521-533,共13页
The paper reported a comparative study of the methods of extraction of <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;&qu... The paper reported a comparative study of the methods of extraction of <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">vegetable fibres encountered in the literature;three main ones was chose, namely: combing, retting with pre-treatment of the bagasse in salt and distilled water,</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">and Chemical extraction at three concentration levels of soda (2N, 1N, 0.1N) </span><span style="font-family:Verdana;">with pre-treatment of bagasse with salt water and distilled water. After extracting the fibres using these methods, it appeared that the natural methods (retting and combing) have a higher yield of around 70% compared to the</span><span style="font-family:Verdana;"> chemical method which has a low yield of around 40%. The fibres obtained by the chemical extraction method (1N-BPD) had the best characteristics</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span> 展开更多
关键词 BAGASSE CHARACTERIZATION ELABORATION EXTRACTION Fibre
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The Physico-Chemical Characterization of Mesoporous Sulfated Zirconia Nanoparticles Prepared under Structure-Directing-Free for <i>n</i>-Hexane Isomerization 认领
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作者 Gongyi Guo Yuli Chen Shi Xu 《矿物质和材料特性和工程(英文)》 2020年第3期59-83,共25页
This article describes the physico-chemical characterization of the sulfated zirconia catalysts prepared from zirconyl chloride, acetic acid and ammonium persulfate system under structure-directing-free and calcined a... This article describes the physico-chemical characterization of the sulfated zirconia catalysts prepared from zirconyl chloride, acetic acid and ammonium persulfate system under structure-directing-free and calcined at 650°C. The catalysts were characterized via an array of characterization techniques such as surface acidity and texture measurements, X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDXS), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), thermogravimetric measurement (TG) coupled with a quadrupole mass spectrometer (MS), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and/or mass spectrometry (ICP-MS). It is clear from TG-MS, ICP-AES, and IR analyses that the precursor of the catalyst is a sulphur species-doped zirconium oxy-hydroxyl acetate complex. The presence of zirconium-bound sulfate groups results in the superacidity of the catalyst and hence high activity in n-hexane isomerization. It is shown from nitrogen adsorption and desorption, FESEM, and HRTEM measurements that the materials exhibit mesoporous and nanocrystalline structure. 展开更多
关键词 Physico-Chemical Characterization MESOPOROUS Nanoparticle SULFATED Zirconia N-HEXANE ISOMERIZATION
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Proximate and Major Minerals Components of the Edible Pulp of <i>Momordica charantia</i>Fruit 认领
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作者 Samba Balde Nicolas Cyrille Ayessou +3 位作者 Oumar Ben Khatab Cisse Papa Guedel Faye Mady Cisse Codou Mar Diop 《食品与营养科学(英文)》 2020年第1期32-39,共8页
Momordica charantia (Cucurbitaceae), is a plant commonly used in traditional medicine in Senegal whose fruits are weakly consumed by the population. However, no data exists on the nutritional intake of the latter. Thi... Momordica charantia (Cucurbitaceae), is a plant commonly used in traditional medicine in Senegal whose fruits are weakly consumed by the population. However, no data exists on the nutritional intake of the latter. This work aims to determine the physicochemical and biochemical characteristics of the pulp of Momordica charantia. The study focused on two lots of fruits from two geographically different regions of Senegal (Dakar and Fatick). The biochemical analyses of the pulp showed average values of protein from 2.39 ± 0.01 g/100 g to 3.19 ± 0.01 g/100 g;reducing sugar from 4.22 ± 0.10 g/100 g to 3.55 ± 0.10 g/100 g;totals sugar from 4.43 ± 0.02 g/100 g to 3.38 ± 0.58 g/100 g. The average contents of polyphenol and flavonoids were respectively from 1.91 ± 0.04 g/100 g to 1.04 ± 0.09 g/100 g and 32.59 ± 0.04 mg/100 g and 20.75 ± 1.19 mg/100 g. According to these results, the fruit of M. charantia may be considered as rich in antioxidant. At the opposite, it is very weak in mineral elements, such as calcium and potassium (1.01 mg/100 g;3.38 mg/100 g). Meanwhile, the seeds content 24% of lipids. Thus, investigations should be done on its biological proprieties, physical and biochemical components. 展开更多
关键词 Momordica charantia Characterization PULP
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Instrumental Characterization of Pretoria Clay Soil by XRF, XRD and SEM 认领
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作者 Adeyinka Olaseinde Mxolisi Brendon Shongwe +1 位作者 Joseph Babalola Adeshina Luqman Adisa 《矿物质和材料特性和工程(英文)》 2020年第1期1-8,共8页
The products of refractory materials are used for lining furnace, incinerators and kilns among other uses and they have the potential of withstanding high temperature without deformation. The objective of the research... The products of refractory materials are used for lining furnace, incinerators and kilns among other uses and they have the potential of withstanding high temperature without deformation. The objective of the research was to charac-terize the clay soil sample collected from Tshwane University of Technology in Pretoria. The sample, collected from a location Latitude 25.0969°S and Longi-tude 28.1624°E, was oven-dried, pulverized and sieved in the laboratory. Min-eralogical and elemental compositions of the sample were determined by using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) analytical methods. The XRF analysis revealed Fe2O3, Al2O3 and SiO2 as the major constituents, while the other elements occur in minor quantities. Mineralogically, the three samples contain Montmorillonite, Kaolinite and Bentonite, while Samples A contained Quartz in addition to ear-lier mentioned minerals, samples B and C contained Albite. 展开更多
关键词 CHARACTERIZATION Clay MINERALS Soil XRD XRF SEM
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Genetic Diversity in the Semi-Arid Grown Cowpea(<i>Vigna unguiculata</i>L. Walp)Accessions Using Morphological and Molecular Characterization 认领
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作者 Seif M. Gasim 《农业科学(英文)》 2020年第8期692-706,共15页
Assessment of genetic diversity of the indigenous crop accessions is extremely important for breeders to identify potential parents in cross-breeding programs. Fourteen cowpea accessions collected from different part&... Assessment of genetic diversity of the indigenous crop accessions is extremely important for breeders to identify potential parents in cross-breeding programs. Fourteen cowpea accessions collected from different part<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> of Sudan were used for characterization at morphological and molecular levels. The seeds of the accessions were sown in the field using a randomized complete block design with three replicates. Sixteen morphological descriptors (9 qualitative and 7 quantitative) and 20 Random Amplified Polymorphic DNA (RAPD) markers were used for characterization of the accessions. The results of morphological data revealed considerable variability within and between state’s accessions. Some morphological traits revealed similarity between accessions from different states. Among the 20 RAPD markers used, 18 were polymorphic. A total of 379 polymorphic patterns were generated;polymorphic information content (PIC) ranged from 0.63 to 0.98 with an average of 0.9. The number of fragment detected ranged from 2 for OPL-11 to 51 for OPY-2 with an average of 26.06/primer and 27.07/genotype. One to five (1</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">5) unique fragments of different sizes were detected for particular accessions, which may provide a valuable resource for breeding superior cowpea cultivars in Sudan and other semi-arid zones. Genetic similarity was ranged from 0.02 to 0.47 with an average of 0.25. Highest genetic similarity was between genotypes HS 展开更多
关键词 Cowpea Accessions Genetic Diversity Characterization Morphological Markers RADP Markers Polymorphism
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Assessing Groundwater Contamination Risk and Detection of Unknown Sources Using a Multi-Component Reactive Transport Model 认领
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作者 Haniel Torres 《地球科学和环境保护期刊(英文)》 2020年第5期132-158,共27页
One of the most serious and important environmental issues related to the mining sector in Central Queensland is the contamination of abandoned mine sites. Representative of this issue is the abandoned Mount Morgan go... One of the most serious and important environmental issues related to the mining sector in Central Queensland is the contamination of abandoned mine sites. Representative of this issue is the abandoned Mount Morgan gold mine. The potential dispersal of acid mine drainage (AMD), a product of more than 100 million tons of sulphide-rich waste rock, into the surrounding environment, is the most challenging environmental problem currently facing this abandoned mine site. The abandoned Mount Morgan gold mine has multiple pollutant species that involve complex geochemical processes. The present study simulated the flow and transport processes founded on hydrological and geochemical conditions of the real-life field at the mine site. To assess the groundwater contamination risk and detect unknown pollution sources, few chemical species such as Iron and Sulphur were considered as the contaminants. The flow model was simulated using the computer code MODFLOW, and PHT3D was used for the simulation of advection, dispersion and chemical reactions of constituents dissolved in this groundwater system, and to mimic the reactive chemical transport processes in the polluted groundwater. To improve on results from other studies (Datta et al., 2017;Scotney, 2016;Doyle, 2016), a calibrated model was a main focus for this study. Field concentration measurements were matched with the flow simulation outcomes to calibrate the model. The results obtained showed a great potential to model transport of contaminants in the groundwater system using a real-world situation. 展开更多
关键词 GROUNDWATER CONTAMINATION Source Characterization PHT3D Chemically REACTIVE Transport Simulation Mine Site CONTAMINATION
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The Integrated Approach to Seismic Attributes of Lithological Characterization of Reservoirs: Case of the F3 Block, North Sea-Dutch Sector 认领
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作者 Oumarou Sanda Djeddi Mabrouk +3 位作者 Tabod C. Tabod Jean Marcel Jean M. Abate Essi Simon Ngos III 《地震研究(英文)》 2020年第3期273-288,共16页
Technological development, particularly the development of signal processing, has contributed to the improvement of the quality of results in the analysis of the characteristics of hydrocarbon reservoirs. This scienti... Technological development, particularly the development of signal processing, has contributed to the improvement of the quality of results in the analysis of the characteristics of hydrocarbon reservoirs. This scientific advance is especially marked by the introduction of seismic attributes in the characterization of reservoirs. This paper is aimed at evaluating the contribution of seismic attributes in the lithological characterization of hydrocarbon accumulation zones. Thus, it has been found that instantaneous attributes make it possible to highlight the different properties of reservoir rocks. Techniques for extracting three-dimensional volume attributes have been applied to a 3D seismic data volume of the F3 block in the Dutch sector of the North Sea. The purpose of using these volume attributes is to extract signal characteristics from lithofacies in hydrocarbon zones. The results provide a remarkable contribution to instantaneous seismic attributes in reservoir location, hydrocarbon detection, and reservoir lithological prediction. The instantaneous amplitude, the derivative of amplitude 1, the factor Q, the energy and the Hilbert transform are attributes which highlight the presence of hydrocarbons through the bright spots. Thus, curvature, similarity, dip, and coherence are useful in the determination of traps such as faults and anticlines. The crossing of the instantaneous amplitude and the instantaneous frequency makes it possible to analyze the lithofacies. In the same way, the analysis of the crossed diagrams between the porosity and the instantaneous amplitude made it possible to define the different layers of the reservoir. 展开更多
关键词 SEISMIC SEISMIC Attributes CHARACTERIZATION LITHOLOGY Reservoir
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Isotopic and Petrographic Evidence as a Proxy in Paleoclimatic Reconstructions from Flowstones in Southern Spain 认领
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作者 Concepción Jiménez de Cisneros Antonio González-Ramón +2 位作者 Cristina Sequero Bartolomé Andreo Ian J. Fairchild 《地质学期刊(英文)》 2020年第6期597-611,共15页
Changes in the morphology and mineralogy of speleothems (flowstones) clearly respond to climate-related phenomena, such as drip rate variability and temperature-modulated cave ventilation. Detailed petrographic observ... Changes in the morphology and mineralogy of speleothems (flowstones) clearly respond to climate-related phenomena, such as drip rate variability and temperature-modulated cave ventilation. Detailed petrographic observations have been coupled with <em><em style="font-family:Verdana;white-space:normal;"><em style="font-family:Verdana;white-space:normal;">δ</em></em></em><sup style="font-family:Verdana;white-space:normal;">18</sup><span style="font-family:Verdana;white-space:normal;">O</span><sup></sup> and <span style="font-size:12px;font-family:Verdana;"><em>δ</em></span><span style="font-size:12px;font-family:Verdana;"><sup>13</sup>C values. Fabrics may show changes related to variations in supersaturation, drip rate or input of detrital particles or organic compounds. Fabrics formed under relatively constant and regular drips (columnar compact, open and elongated) show similar <em>δ</em><sup>18</sup>O and <em>δ</em><sup>13</sup>C values, which are more negative than those of micrite and microsparite. The combination of internal microstratigraphy studies and isotopic data (<em>δ</em><sup>18</sup>O and <em>δ</em><sup>13</sup>C) from two flowstones collected from two caves in the north of Almeria province (SE Spain), suggest a spectrum of environmental conditions ranging from wetter to drier periods. Both records constitute a very useful tool for screening and interpreting high-resolution paleoclimate reconstructions.</span> 展开更多
关键词 SPELEOTHEMS Flowstones Fabrics Isotopic Characterization CAVE Paleoclimatic Changes
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Research progress on multiscale structural characteristics and characterization methods of iron ore sinter 认领
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作者 Wei Wang Xu-heng Chen +3 位作者 Run-sheng Xu Jun Li Wen-jun Shen Su-ping Wang 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2020年第4期367-379,共13页
At present,blast furnace ironmaking is still the main process for producing molten iron,and sinters are the main raw material for blast furnace ironmaking.A sinter with good metallurgical performance can not only ensu... At present,blast furnace ironmaking is still the main process for producing molten iron,and sinters are the main raw material for blast furnace ironmaking.A sinter with good metallurgical performance can not only ensure smooth operation of the blast furnace but also reduce the blast furnace fuel ratio and increase the molten iron production.Structure is the most important factor affecting the metallurgical properties of the sinter.Thus,the research progress of sinter pore and mineral phase structures was reviewed and the mechanism by which they influence sinter properties was expounded.Multiscale characterization methods for the sinter and their advantages and disadvantages were introduced,and the future research direction of sinter was discussed. 展开更多
关键词 Iron ore sinter Pore structure Mineral phase structure Characterization method Multiscale characterization
Modelling of Photovoltaic Modules Optical Losses Due to Saharan Dust Deposition in Dakar, Senegal, West Africa 认领
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作者 Dialo Diop Mamadou Simina Drame +3 位作者 Moussa Diallo David Malec Dominique Mary Philippe Guillot 《智能电网与可再生能源(英文)》 2020年第7期89-102,共14页
<span style="font-family:Verdana;">This study aims to evaluate the optical losses of photovoltaic modules due to Saharan dust deposition in Dakar, Senegal, West Africa. For this purpose, an air-dust-gl... <span style="font-family:Verdana;">This study aims to evaluate the optical losses of photovoltaic modules due to Saharan dust deposition in Dakar, Senegal, West Africa. For this purpose, an air-dust-glass system is modeled to simulate optical losses in transmittance </span><span style="font-family:Verdana;">and reflectance. To do this, we have collected dust samples from Photo-Voltaic</span><span style="font-family:Verdana;"> (PV) surface in Dakar area (14<span style="white-space:nowrap;">°</span>42'N latitude, 17<span style="white-space:nowrap;">°</span>28'W longitude), Senegal. X-ray fluorescence reveals that silicon (Si), iron (Fe), calcium (Ca) and potassium (K) mainly </span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">compose</span></span></span></span></span><span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">d these dust samples. Then, dust refractive indices obtained from an ellipsometer were used as an input to be used in the model. Simulations show that for radiation (at normal incidence) arriving on a dust layer of 30 μm-thick (corresponding to a dust deposit of 1.63 g/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">), 79% of the visible spectrum is transmitted</span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">;</span></span></span></span><span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> 19% is reflected and 2% is absorbed. Overall, the transmittance decreases by more than 50% as of dust layer of 70 μm-thick corresponding to a dust deposit of 3.3 g/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">.</span></span></span></span></span> 展开更多
关键词 Dust Characterization Modeling ELLIPSOMETRY PV Transmittance Solar Panel Spin Coating X-Ray Fluorescence
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Elaboration and Characterization of Composite Materials Reinforced by Papaya Trunk Fibers (<i>Carica papaya</i>) and Particles of the Hulls of the Kernels of the Winged Fruits (<i>Canarium schweinfurthii</i>) with Polyester Matrix 认领
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作者 Ze Eric Parfait Noah Pierre Marcel +4 位作者 Nnomo Elobi Didine Nfor Clins Wiryikfu Betene Ebanda Fabien Ngahiyi Abbé Claude Valery Atangana Ateba 《矿物质和材料特性和工程(英文)》 2020年第5期341-352,共12页
In this work we determine the physical and mechanical properties of local composites reinforced with papaya trunk fibers (FTP) on one hand and particles of the hulls of the kernels of the garlic (PCNFA) in the other h... In this work we determine the physical and mechanical properties of local composites reinforced with papaya trunk fibers (FTP) on one hand and particles of the hulls of the kernels of the garlic (PCNFA) in the other hand. The samples are produced according to BSI 2782 standards;by combining fibers and untreated to polyester matrix following the contact molding method. We notice that the long fibers of papaya trunks improve the tensile/compression characteristics of composites by 45.44% compared to pure polyester;while the short fibers improve the flexural strength of composites by 62.30% compared to pure polyester. Furthermore, adding fibers decreases the density of the final composite material and the rate of water absorption increases with the size of the fibers. As regards composite materials with particle reinforcement from the cores of the winged fruits, the particle size (fine ≤ 800 μm and large ≤ 1.6 mm) has no influence on the Young’s modulus and on the rate of water absorption. On the other hand, fine particles improve the flexural strength of composite materials by 53.08% compared to pure polyester;fine particles increase the density by 19% compared to the density of pure polyester. 展开更多
关键词 Physical and Mechanical Characterization Composite Fibers Papaya Tree Trunk PARTICLES Shells KERNELS Garlic Fruits
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Potential of Some Granites from Foumban (West Region of Cameroon) as Fluxing Materials for Ceramics 认领
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作者 Ndigui Billong 《矿物质和材料特性和工程(英文)》 2020年第5期353-363,共11页
This study focuses on the mineralogical, geochemical and petrographic characterization of three granite rock samples (LTP, LTS and LTMB) from Foumban, West Region of Cameroon. Fusibility tests were carried out on the ... This study focuses on the mineralogical, geochemical and petrographic characterization of three granite rock samples (LTP, LTS and LTMB) from Foumban, West Region of Cameroon. Fusibility tests were carried out on the samples containing the highest amount of alkali to assess the potential of these materials as fluxing admixture for ceramics. The results show that the granite consists of alkaline feldspars, notably orthoclase and microcline of perthitic micro-texture, plagioclases (in particular albite) and also mafic minerals such as amphibole and pyroxene. The quantity of alkali in the samples is quite high (16.83% for LTS, 17.08% for LTMB and 18.87% for LTP) compared to standard data. Fusibility tests carried out on the samples having the highest alkali content (LTMB and LTP) showed that the vitreous phase appears between 1050&#176;C and 1100&#176;C in these samples when they were heated. The Fe<sub>2</sub>O<sub>3</sub> and TiO<sub>2</sub> content of LTMB (3.01% and 1.49% respectively) led to a brown colour of its fired product. Therefore, based on their composition, these materials can be used as feldspathic fluxes for the formulation of ceramic products. 展开更多
关键词 FELDSPARS GRANITE Characterization Fusibility CERAMICS Foumban Cameroon
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Utilisation of Indigenous Ceramic Raw Materials for the Production of Water Closet 认领
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作者 Z. U. Elakhame Y. J. Obe +7 位作者 Y. L. Shuaib-Babata L. K. Bankole O. J. Omowunmi I. O. Ambali O. O. Akinsanya A. J. Unachukwu R. G. Adeyemo M. Ikusedun 《矿物质和材料特性和工程(英文)》 2020年第5期364-376,共13页
The fact is that Nigeria ceramic raw materials are underutilized as a result of inadequate information on the materials which limits the local production of water closet. The emphasis of this research was on the suita... The fact is that Nigeria ceramic raw materials are underutilized as a result of inadequate information on the materials which limits the local production of water closet. The emphasis of this research was on the suitability of the physio-chemical properties of the abundant locally sourced ceramic raw materials from South-west Nigeria. The selected locally sourced raw materials included: kaolin, feldspar, silica and ball clay. The Physical properties carried out on the specimens produced include chemical analysis, shrinkage, porosity, bulk density, modulus of rupture, plasticity and viscosity. The physical property tests were done in accordance with (ASTM C). Standard and the chemical composition were identified by AAS spectrometer. However, the ratio of kaolin, feldspar, quartz and ball clay was varied in five major formulation represented as A, B, C, D and E. The clay, kaolin, quartz and feldspar used in this study were found to belong to alumina-silicate group suitable for the production of standard water closet. The samples’ properties met the required standards;hence, the materials were found suitable for production of water closet of acceptable standards. Composition A specimen gives the most suitable proportions for the production of water closet at 40% of kaolin, 25% of feldspar, 10% of quartz and 25% of ball clay respectively. 展开更多
关键词 Ceramics Materials Characterization MOULD Slip-Cast Water-Closet
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Morphological Variability of Neglected and Underutilized Legumes (NULs) Collection from Côte d’Ivoire 认领
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作者 Léonie Clémence Kouonon Kouamé Guillaume Koffi +1 位作者 Koffi Adjoumani Koudougnon Alice Estère Goba 《美国植物学期刊(英文)》 2020年第2期226-244,共19页
In order to characterize neglected and underutilized legumes seeds (NULs), prospection, collection and characterization were carried out in five administrative regions from Cote d’Ivoire. Two thousand and fifty-four ... In order to characterize neglected and underutilized legumes seeds (NULs), prospection, collection and characterization were carried out in five administrative regions from Cote d’Ivoire. Two thousand and fifty-four accessions were collected. NULs cultivation is done mainly by women (88.1% compared to 11.9% of men). Productors distinguish 22 morphotypes of NULs based on seeds shapes, colors and patterns. Morphological traits of the collected morphotypes revealed a significant phenotypic polymorphism. Quantitative analyses showed a clear structure of accessions;three main groups were revealed. The first group contains accessions with large and thick seeds, but a low index shape opposite to group II with high index shape. Seeds of group III are characterized by small width and thickness, but a high shape index. Analyses of qualitative traits revealed five groups characterized by heterogeneous or homogeneous coloured integument, inked or elevated edge of hilum, presence or absence of eye. 展开更多
关键词 NEGLECTED Legumes CHARACTERIZATION QUANTITATIVE TRAITS Qualitative TRAITS
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Use of Alternative Binder: Influence of Latex Content on Physical and Mechanical Properties of Laterite Stabilized with Raw Rubber Latex 认领
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作者 Edjikémé Emeruwa 《地质材料(英文)》 2020年第3期56-65,共10页
Raw rubber Latex contents, from 0% to 30% were used to stabilize lateritic samples to provide an alternative to cement stabilization. These samples were submitted to physical tests (water resistance test, absorption t... Raw rubber Latex contents, from 0% to 30% were used to stabilize lateritic samples to provide an alternative to cement stabilization. These samples were submitted to physical tests (water resistance test, absorption test) and mechanical tests (dry compressive strength test). The results indicate that samples made of latex content less than 15% dissolve completely into water. So it was impossible to make sample with these contents. Samples with 15% of raw rubber content or more are steady after water resistance test. The absorption rate of these samples decreases as the latex content increases. It goes from 14.45% for the samples at 15% to 5.87% for those at 30%. Therefore, the compressive strength test indicates that the resistance increases from 0.37 MPa for samples without latex to 3.15 MPa for those at 30% of latex content. Also, the rheological study shows that the samples pass from a brittle behaviour to a plastic behaviour when the latex content increases. The behaviour of the sample according to these different tests shows that this material can be used in several activity areas, such as construction, road building and sports area. 展开更多
关键词 LATERITE Raw Rubber Latex SAMPLE STABILIZATION Characterization
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Characterization of Sludge Produced by Treatment of Water from the Ribaa and Bittit Karstic Springs (Meknes, Morocco) 认领
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作者 Nabila Basri Mohamed Farhaoui +2 位作者 Lamyae Talbi Mustapha Derraz Hammou Ahlaf 《水资源与保护(英文)》 2020年第7期607-617,共11页
<strong>Problem Statement:</strong> Surface Water Treatment for potable supplies typically involves coagulation, flocculation, and processes. All water treatment plants produce sludge, during the purificat... <strong>Problem Statement:</strong> Surface Water Treatment for potable supplies typically involves coagulation, flocculation, and processes. All water treatment plants produce sludge, during the purification of raw water, according to the level of the water turbidity. The aluminum sulfate is the most common coagulant used in water treatment plants of Morocco, as well as in many countries all over the world. It is difficult to manage sludge produced by the treatment plant. However, several studies, based on a set of jar test experiments, have demonstrated that it can be used in the process to improve the quality of the treated water and reduce the aluminum sulfate dose. <strong>Approach:</strong> In this study, the raw water treated and sludge produced in water treatment plant of Meknes, Morocco are investigated for chemical and bacteriological proprieties. The texture characterization of the dried sludge produced through the process of coagulation/flocculation and that of aluminum sulfate, used as coagulant aid, are obtained by nitrogen adsorption isotherms. <strong>Results:</strong> The physical properties of the raw water indicate its high turbidity during periods of heavy rainfall in the Bittit and Ribaa springs catchment area. However, these chemical properties indicate the quality of fresh water rich in magnesium, related to the dolomitic nature of the liastic aquifer. The bacteriological analysis of sludge produced in the treatment plant, confirms the elimination of pathogenic germs by the treatment process used. As regards the texture characterization the results demonstrated that the sludge presents some similarities with the sulfate. However, a clear difference is observed between the two solids, according to the pores distribution. <strong>Conclusions/Recommendations:</strong> Taking aluminum sulfate and sludge in comparison, it is possible to use the sludge for improving the coagulation process in water treatment. 展开更多
关键词 Water Treatment TURBIDITY SLUDGE Aluminum Sulfate Texture Characterization N2 Isotherms
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Identification of Fusarium Species Associated with Onion (<i>Allium cepa</i>L.) Plants in Field in Burkina Faso 认领
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作者 Konwendé Ra?ssa Kintega P. Elisabeth Zida +2 位作者 Vianney W. Tarpaga Philippe Sankara Paco Sereme 《生命科学与技术进展(英文)》 2020年第3期94-110,共17页
Many fungi limit onion production in Burkina Faso. This study aims to identify the main Fusarium species associated with onion plant in field in order to determine those involved in seedling damping-off and bulb rot, ... Many fungi limit onion production in Burkina Faso. This study aims to identify the main Fusarium species associated with onion plant in field in order to determine those involved in seedling damping-off and bulb rot, and develop adequate management strategies of these diseases. For this purpose, 36 isolates of Fusarium were isolated from onion plants in 17 sites and subjected to molecular analysis and biometric characterization. The results revealed that the isolates belong to five Fusarium species: Fusarium oxysporum (44.44% of the isolates), Fusarium proliferatum (41.66%), Fusarium solani (5.55%), Fusarium fujikuroi (5.55%) and Fusarium thapsinum (2.77%). Fusarium oxysporum, F. proliferatum, F. solani and F. fujikuroi had faster mycelial development, with a growth rate of 7.72 - 8.27 mm/d, than F. thapsinum (6.52 mm/d). Conidia of F. oxysporum, F. proliferatum and F. solani were longer (4.74 - 5.96 μm) than those of F. fujikuroi and F. thapsinum (3.20 - 4.04 μm). Fusarium solani and F. oxysporum, respectively, had the largest and most partitioned conidia. 展开更多
关键词 ALLIUM cepa Fusarium Molecular IDENTIFICATION BIOMETRIC Characterization Fungal Rot
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Detection and Molecular Characterization of <i>Cronobacter sakazakii</i>Isolated from Powdered Infant Formula (PIF) from North Central Region, Nigeria 认领
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作者 Simon I. Enem Chidozie O. Ogbu +4 位作者 Chinwe E. Okoli Ene Godwin Gabriel K. Omeiza Pascal U. Umeakuana Wesley D. Nafarnda 《微生物学(英文)》 2020年第7期307-317,共11页
<i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> is an emerging ubiquitous and opportunistic pathogen that cur... <i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> is an emerging ubiquitous and opportunistic pathogen that currently contaminates a wide spectrum of foods including powdered milk and poses a lethal threat to neonates, the elderly and persons with immune deficiencies. They cause life threatening neonatal meningitis, septicemia, and necrotizing enterocolitis. A total of 360 samples of powdered infant formula were collected from postnatal hospital attendees reconstituting the PIF for their children in the North Central region of Nigeria where cases of infant mortality </span><span style="font-family:Verdana;">are </span><span style="font-family:""><span style="font-family:Verdana;">very high and presenting as enterocolitis and diarrhea. Pre-enriched samples were cultured in chromogenic </span><i><span style="font-family:Verdana;">Cronobacter</span></i><span style="font-family:Verdana;"> broth and were then further sub-cultured into a chromogenic </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> agar. They were positive, exhibiting yellowish cultures typical of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. Biochemical tests of the isolates were also carried out and indicated the presence of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The isolates were then characterized molecularly using specie specific PCR detection of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The targeted genes of interest were </span><i><span style="font-family:Verdana;">ompA</span></i><span style="font-family:Verdana;"> gene and </span><i><span style="font-family:Verdana;">CPA</span></i><span style="font-family:Verdana;"> gene. The isolates tested showed bands for </span><i><span style="font-family:Verdana;">ompA</span></i 展开更多
关键词 DETECTION Molecular Characterization Cronobacter sakazakii Powdered Infant Formula (PIF)
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Elaboration and Characterization of a Composite Material Based on <i>Canarium schweinfurthii</i>Engl Cores with a Polyester Matrix 认领
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作者 Dieunedort Ndapeu Francis Tamwo +4 位作者 Morino Bernard Nganou Koungang Ghislain Tchuen Nicodème R. Sikame Tagne Sophie Bistac Ebénezer Njeugna 《材料科学与应用期刊(英文)》 2020年第3期204-215,共12页
The aim of this work was to develop and characterize a polyester matrix composite material based on Canarium schweinfurthii Engl core granule. The particle size and the mass fractions of these cores used as fillers in... The aim of this work was to develop and characterize a polyester matrix composite material based on Canarium schweinfurthii Engl core granule. The particle size and the mass fractions of these cores used as fillers in this composite were the two optimization parameters. The experimentation of the twelve sample areas was based on the following optimization parameters: Three particles sizes of 80 1 2 3 &middot;m-3, which allows us to admit that this composite belongs to the family of light materials. The maximum compressive stress at break was obtained for the formulation 40% filler of size T3. This compressive stress at maximum rupture is in the range of 199.14 MPa. From 0% to 45% of filler, the flexural Young’s modulus of the composite increases whatever the particle size. The highest value is obtained for T2 particle size, i.e. 13.11 GPa. The static friction coefficient of the composite on wood increases as the filler content varies from 0.30 to 0.42. Thus, in view of the properties obtained, this composite can be used as alternative solutions in industrial applications, for the manufacturing of shoe heel, house ceiling, floors for housing and table support. 展开更多
关键词 Canarium schweinfurthii Engl CHARACTERIZATION Composite Polyester Filler
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