检索结果-南通市图书馆

Contribution to the Characterization of Laterites Developed on Granitic Rock in Mbanga (Littoral-Cameroon): Significance in the Sustainable Pavements Design

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2024年第3期12卷 181-191页

作者： Willy Chance Guimezap Kenou Vladimir Willianov Keubou Tatapzia Bertile Ilalie Manefouet Institut Universitaire de la cô te P&#244le de Recherche de l&#8217Inovation et de l&#8217Entreprenariat (PRIE) Douala Cameroun Faculty of Sciences University of Dschang Dschang Cameroon

The materials studied were lateritic soils from Souza-Mbanga-Cameroon, with a view to their better use in road geotechnics. In order to achieve the set objective, the work was carried out in two phases, firstly in the field, to provide a morpho-structural description of the soil profiles, followed by a laboratory phase to analyse the samples collected in the field. The results of the physical characterisation of the soil samples show that, for average values, the water content is 9.87%, the percentage of fines 48%, the plasticity index 21.6%, the liquidity limit 50.91%, and the consistency index 1.97. These soils are classified as silty sands in the LCPC classification and as fine soils in the GTR classification. The average value of the maximum dry density is 1.81 g/cm3 and that of the water content at the modified Proctor optimum is 16.24%. The CBR index is between 1.8% and 17.8%, showing that these soils belong to classes S1, S2, S3, S4 and S5. Souza-Mbanga lateritic soils can be used in their natural state as subgrades.

关键词： Soils Souza-Mbanga characterisation CBR

夏洛蒂·勃朗特小说中的“注视”与“被注视”

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

characterisation of Zinc Oxynitride Thin Films Prepared Using Zinc(II) Complex of Hexamethylenetetramine as the Precursor

外国文学研究 2024年第3期

作者：闫梦梦

本文的导言部分考察夏洛蒂·勃朗特的视觉体验，并探讨这些真实体验对其在小说中进行视觉处理的影响。同时，导言讨论19世纪在英国流行的相面术和颅相学这两种通过外在特征分析心灵和人格的方法，以及它们对勃朗特在小说人物处理上的影... 详细信息

本文的导言部分考察夏洛蒂·勃朗特的视觉体验，并探讨这些真实体验对其在小说中进行视觉处理的影响。同时，导言讨论19世纪在英国流行的相面术和颅相学这两种通过外在特征分析心灵和人格的方法，以及它们对勃朗特在小说人物处理上的影响。第一节分析了人物的外形和内心世界之间的联系，包括注视者注视的方式和被注视者对他人注视的反应形式。第二节重点讨论了性别对注视互动的重要性，并探究性别化注视的互动如何在男性和女性关系中发挥作用。结语部分通过梳理勃朗特每一部小说的结尾再次强调“视觉”在勃朗特小说中的重要性。

关键词：夏洛蒂·勃朗特注视与被注视小说人物塑造　　Charlotte Brontcharacterisation

来源：人大复印报刊资料评论

在线全文

人大复印报刊资料

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2022年第8期13卷 479-489页

作者： Olumide Oluwole Akinwunmi Oluwaseun Philip Adelabu Adetokunbo Temitope Famojuro Olakunle A. Akinwumi Priscilla Oluwatumilara Olaopa Kehinde Folorunso Olafisan Ezekiel Oladele Bolarinwa Ajayi Department of Physics and Engineering Physics Obafemi Awolowo University Ile-Ife Nigeria Department of Chemistry Obafemi Awolowo University Ile-Ife Nigeria

A Zinc(II) complex of hexamethylenetetramine was prepared as a single source precursor and used to deposit zinc oxynitride thin films. The thin films were deposited on soda-lime glass substrates using the Metal Organic Chemical Vapour Deposition (MOCVD) technique at the deposition temperature of 370°C and 390°C, respectively. The Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the functional groups in the precursor, with stretching frequency for O-H, N-H, and C-H observed. The deposited films were characterized using UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM), Elemental diffraction X-ray (EDX), and X-ray Diffractometer (XRD). A direct bandgap of 3.15 eV and 3.18 eV was obtained from the film deposited at 370°C and 390°C, respectively, using the Envelope Method. In comparison, a bandgap of 3.19 eV and 3.21 eV was obtained using the absorption spectrum fitting (ASF) method. The SEM revealed that the film is homogeneous, dense, and compact, composed of cluster grains. The EDX confirmed the presence of Zinc, Nitrogen and Oxygen. The X-ray Diffraction indicated the polycrystalline nature of the film.

关键词： Zinc Oxynitride Metal Organic Chemical Vapour Deposition (MOCVD) Precursor characterisation Thin Film

characterisation of Meteorological Drought in Northern Nigeria Using Comparative Rainfall-Based Drought Metrics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2023年第2期15卷 51-70页

作者： Onemayin David Jimoh Martins Yusuf Otache Adeolu Richard Adesiji Rotimi Saka Olaleye James Agajo Department of Civil Engineering Federal University of Technology Minna Nigeria Department of Agricultural & Bioresources Engineering Federal University of Technology Minna Nigeria Department of Agricultural Economics & Farm Management Federal University of Technology Minna Nigeria Department of Computer Engineering Federal University of Technology Minna Nigeria

Meteorological droughts occur when there is deficiency in rainfall;i.e. rainfall availability is below some acclaimed normal values. Hence, the greater challenge is to be able to obtain suitable methods for assessing drought occurrence, its onset or initiation and termination. Thus, an attempt was made in this paper to evaluate the performance of Standardised Precipitation Index (SPI) and Standardised Precipitation Anomaly Index (SPAI) to characterise drought in Northern Nigeria for purposes of comparison and eventual adoption of probable candidate index for the development of an Early Warning System. The findings indicated that despite the fact that the annual timescale may be long, it can be employed to obtain information on the temporal evolution of drought especially, regional behaviour. However, monthly timescale can be more appropriate if emphasis is on evaluating the effects of drought in situations relating to water supply, agriculture and groundwater abstractions. The SPAI can be employed for periodic rainfall time series though;it accentuates drought signatures and may not necessarily dampen high fluctuations due to implications of high climatic variability considering the stochastic nature and state transition of drought phenomena. On the other hand, the temporal evolution of SPI and SPAI were not coherent at different temporal accumulations with differences in fluctuations. However, despite the differences between the SPI and SPAI, generally at some timescales, for instance, 6-month accumulation, both spatial and temporal distributions of drought characteristics were seemingly consistent. In view of the observed shortcomings of both indices, especially the SPI, the Standardised Nonstationary Precipitation Index (SnsPI) should be looked into and too, other indexes that take into consideration the implications of global warming by incorporating potential evapotranspiration may be deemed more suitable for drought studies in Northern Nigeria.

关键词： characterisation Timescale Meteorological Drought Metrics

Cuttlebone： characterisation, Application and Development of Biomimetic Materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2012年第3期9卷 367-376页

作者： Joseph Cadman Shiwei Zhou Yuhang Chen Qing Li School of Aerospace Mechanical and Meehatronic Engineering The University of Sydney NSW 2006 Australia Innovative Structures Group School of Civil Environmental and Chemical Engineering RMIT University GPO Box 2476 Melbourne 3001 Australia School of Engineering and Physical Sciences Heriot-Watt University Edinburgh EH14 4AS UK

Cuttlebone signifies a special class of ultra-lightweight cellular natural material possessing unique chemical, mechanical and structural properties, which have drawn considerable attention in the literature. The aim of this paper is to better understand the mechanical and biological roles of cuttlebone. First, the existing literature concerning the characterisation and potential applications inspired by this remarkable biomaterial is critiqued. Second, the finite element-based homogenisation method is used to verify that morphological variations within individual cuttlebone samples have minimal impact on the effective me- chanical properties. This finding agrees with existing literature, which suggests that cuttlebone strength is dictated by the cut- tlefish habitation depth. Subsequently, this homogenisation approach is further developed to characterise the effective me- chanical bulk modulus and biofluidic permeability that cuttlebone provides, thereby quanti lying its mechanical and transporting functionalities to inspire bionic design of structures and materials for more extensive applications. Finally, a brief rationale for the need to design a biomimetic material inspired by the cuttlebone microstructure is provided, based on the preceding inves- tigation.

关键词： cuttlebone characterisation biomimetic homogenisation

On mechanical properties of nanocomposite hydrogels:Searching for superior properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Materials Science 2022年第2期4卷 83-96页

作者： Wenjin Xing Youhong Tang Institute for NanoScale Science and Technology College of Science and EngineeringFlinders UniversitySouth Australia 5042Australia

Nanocomposite hydrogels are the combination of known components that are a hydrogel and nanometre-sized fillers,typically leading to improved mechanical properties or new functionalities.With simplicity of design and ease of synthesis,recent advances have highlighted that this family of hydrogels holds the significant promise of application in diverse biomedical and engineering fields.The elaborate design and investigation as well as suitable application of nanocomposite hydrogels require the synergy of mechanics,materials science,engineering,and biology.Despite similarities in design and fabrication,the data of mechanical properties for nanocomposite hydrogels scatter in a large space.It is worthwhile comparing various nanocomposite hydrogels for similarities and differences in mechanical properties to aid in designing novel hydrogels with extreme properties,and guide practical applications.This review aims to fill,in the literature,the missing gap of addressing mechanical measurement methods and comparison of mechanical properties in this ever-evolving broad area of research.Finally,the challenges and future research opportunities are highlighted.

关键词： Hydrogel Nanofillers Mechanical properties Nanocomposite Design characterisation

An experimental and numerical approach-characterisation of power cartridge for water-jet application

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2018年第6期14卷 683-690页

作者： Bhupesh Ambadas Parate Sunil Chandel Himanshu Shekhar Armament Research&Development Establishment(ARDE) Dr.Homi Bhabha RoadPashanPune 411021India Defence Institute of Advanced Technology(DIAT) Giri NagarKhadakwasalaPune411025India High Energy Material Research Laboratory(HEMRL) SutarwadiPashanPune411021India

Power Cartridges are pyrotechnic devices where hot combustion gases utilized to do mechanical work for disruption of suspected Improvised Explosive Devices(IEDs). It plays a vital role either in destroying the suspicious object or making them non-functional by generating the gas pressure on burning of propellant against the water column inside the barrel, Present work is focused on characterisation,numerical solution such as deformation; strain; stress using FEM(Finite Element Method), design qualification, performance and evaluation of power cartridge for disruptor application. Experimental trials for pressure-time(P-t) measurement in closed vessel(CV), various electrical parameters like all fire current(AFC), no fire current(NFC) and ignition delay have been measured. Further, mechanical properties for brass material have been determined. An attempt has been made to characterise the power cartridge by FEM and carrying out the experiments for water-jet application.

关键词： All fire current Closed vessel Booster characterisation Disruptor Finite element method Ignition delay Maximum pressure No fire current Power cartridge Propellant&water-jet

Characterizations and dynamic results for consistent indexes under weighted consideration

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Control and Decision 2022年第1期9卷 1-12页

作者： Yu-Hsien Liao Ling-Yun Chung Department of Applied Mathematics National Pingtung UniversityPingtungTaiwanChina Graduate School of Technological and Vocational Education National Yunlin University of Science and TechnologyDouliouTaiwanChina

In real-world management systems,agents might represent constituencies of different sizes;agents might have different bargaining abilities.It is reasonable that weights are assigned to agents and any utility should be divided according to these weights.On the other hand,agents might take different activity levels to participate;agents might represent administrative areas of different scales.Therefore,we introduce two indexes to investigate the distribution mechanism by applying the maximal-utilities among activity level vectors and the weights simultaneously.In order to present the rationality for these weighted indexes,we adopt extended reductions to provide several characterisations.Based on these extended reductions,we also introduce two dynamic processes to illustrate that these weighted indexes could be reached by agents who start from an arbitrary efficient payoff vector and make successive adjustments.By focusing on a different viewpoint,we apply excess functions to propose alternative formulations and related dynamic results for these weighted indexes.

关键词： Weight reduction excess function characterisation dynamic process

Bacteriological and Physico-Chemical characterisation of Liquid Wastes: The Case of the University Hospital Centre (UHC) of Yaoundé-Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2022年第6期10卷 170-190页

作者： Luciane Marlyse Moungang Blandine Pulchérie Tamatcho Kweyang Lisyane Merveille Betyi Roland Ndifor Ache Yves Poutoum Yogne Mouhama Sani Adams Ibn Rabiou Golda Reine Zame Meva’a Aurélie Dzenga Njeunkam Claire Stephane Metsopkeng Serge Hubert Zebaze Togouet Laboratory of Hydrobiology and Environment Department of Animal Biology and Physiology Faculty of Sciences University of Yaoundé I Yaoundé Cameroon Department of Microbiology Faculty of Sciences University of Yaoundé I Yaoundé Cameroon Department of Organic Chemistry Faculty of Sciences University of Yaoundé I Yaoundé Cameroon Higher Technical Teachers Training College University of Bamenda Bamenda Cameroon

The untreated effluents generated by hospital activities contribute to the dissemination of pathogenic germs and multi-resistant bacteria, thus presenting a great potential danger for health and the environment. The objective of this study was to evaluate the microbiological and physico-chemical quality of the effluents of the Yaoundé University Hospital Centre and their impact on the environment. It was a prospective and analytical study on three sites where hospital effluents from the intensive care unit (Station A), the upstream of the wastewater treatment plant (Station B), and the gynaecology, surgery and hospitalisation departments (Station C) were sampled. Samples were collected in sterile glass bottles for bacteriological analyses and polyethylene bottles for physico-chemical analyses. The bacteriological parameters measured showed that the density of the bacterial species sought was very high at Station B with a predominance of the species Escherichia coli (57.36%). At Station A, total coliforms were very abundant (50.12%) and at Station C, the genus Pseudomonas was predominant (14.69%). Bacteria of the genus Streptococcus were represented by three species, namely: Streptococcus agalactiae, Streptococcus faecalis, and Streptococcus pneumoniae. The Pseudomonas genus was also represented by 3 species, namely Pseudomonas aeruginosa, Pseudomonas maltophilia and Pseudomonas putida. The physico-chemical parameters showed that apart from temperature and conductivity, which were in compliance with the standards, the other had values higher than these standards. This study shows that untreated hospital effluent contains most of the bacteria involved in community, nosocomial infections and would be a potential source of risk to the surrounding population.

关键词： characterisation University Hospital Centre Effluents Bacteriology of Effluents Physico-Chemistry of Wastewater