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Effect of Fiber Loading and Compatibilizer on Rheological, Mechanical and Morphological Behaviors

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Open Journal of Polymer Chemistry 2012年第2期2卷 31-41页

作者： Inul Azianti Noranizan ishak Ahmad Universiti Kebangsaan Malaysia Bangi Malaysia

This study presents the composites prepared by melt blending based on high-density polyethylene, containing various amounts of kenaf fiber loadings and polyethylene-grafted maleic anhydride (PE-g-MA) in an internal mixer were prepared and investigated. Fourier transform infrared spectroscopy was used to characterize both untreated and treated ke- naf fibers. A rheological study of the composites showed a high complex viscosity and dynamic shear storage modulus between untreated and treated composites and composites with compatibilizer. A mechanical test showed that the ten- sile strength and tensile modulus were optimal with 20% fiber loading but decreased with 30% fiber loading for both the untreated and treated composites. The composite with PE-g-MA showed an improved mechanical strength. This phenomenon is due to an increase in the interfacial adhesion between the fiber and matrix leading to an improvement in the compatibility of the blend. Treatment of the kenaf fiber improved in the mechanical and impact strengths in com- parison to the untreated kenaf composites. This behavior was supported by a morphology analysis of the fractured sur- faces revealed that strong interfaces were formed on addition of the compatibilizer.

关键词： Fiber Treatment Rheology Morphology Mechanical Properties

An Assessment of Land Cover Change in Gashaka-Gumti National Park, Nigeria

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Journal of Geoscience and Environment Protection 2023年第6期11卷 184-196页

作者： danjuma Andembutop Kwesaba Oruonye Emeka Daniel David Delphine Ezekiel Benjamin Department of Geography Taraba State University Jalingo Nigeria

The paper assessed the land cover change in Gashaka-Gumti National Park between 1991 and 2021. To achieve this, LandSat data of years 1991, 2001, 2011 and 2021 were obtained from the United States Geological Survey online resource. The findings of the study revealed that there is decrease in the different land cover types over time as a result of anthropogenic activities of the enclave dwellers. The study observed that the continuous existence of enclaves within and around the Park constitutes a serious threat to the survival of the Park. The study recommended that the federal government should consider resettlement of the enclave dwellers to give way for the development of the Park.

关键词： Wildlife Ecosystem Forest Cover Grass Land Water Body and Anthropogenic Activities

Comparative Analysis of the Effects of Pressure on the Mechanical Properties and Microstructure of Die Cast Aluminum Alloys

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Journal of Minerals and Materials Characterization and Engineering 2016年第6期4卷 347-363页

作者： Kenneth N. Obiekea Shekarau Y. Aku danjuma S. Yawas Department of Mechanical Engineering Ahmadu Bello University Zaria Nigeria

A study of the effects of pressure on the microstructure and mechanical properties of two aluminum alloys (A1350 and A380) was carried out and subsequent analysis made. Pressure was regulated at various levels in the die cast machine. Samples of both alloys were cast under varying regulated applied pressure. The mechanical properties of both alloy casts were tested and microstructure analysis done and the results compared for both alloys. The results obtained show that hardness, tensile strength, yield strength and impact strengths for both alloy cast samples followed similar pattern in the casting process. The hardness values increased with applied pressure but not too significantly in both alloy casts as pressure rose in the casting process. The yield strength of both alloy casts also increased with applied pressure. The impact strength and elongations also increased with applied pressure in both alloy casts. Also the microstructure analysis carried out on both alloy casts showed similar pattern of structural changes in the morphologies of both alloy casts as grains became fine as pressure rose from 350 to 1400 kg/cm2. Models were developed for the results and for all the models developed, a close relationship with the experimental results were underlying in view of the small errors generated by them and can be used to predict the experimental values.

关键词： Aluminum Alloys Die Casting Microstructure Pressure

Effects of Gas Metal Arc Welding Techniques on the Mechanical Properties of Duplex Stainless Steel

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Journal of Minerals and Materials Characterization and Engineering 2013年第5期1卷 222-230页

作者： Tanimu Ibrahim danjuma S. Yawas Shekarau Y. Aku Mechanical Engineering Department Ahmadu Bello University Zaria Nigeria Plant and Equipment Department Salini Nigeria Limited Abuja Nigeria

The study has compared the effect of gas metal arc welding techniques on some mechanical properties of duplex stainless steel. The samples after welded were given post weld heat treatment (quenching in engine and neem oil). After the analyses, it was established that duplex stainless steel can be weld successfully using gas metal arc welding process (GMAW). Both Lubricating oil and neem oil can serve as quenching medium for post welding heat treatment of duplex stainless steel. The results of the studies also show that welding and heat treatment really affect the mechanical properties of the alloy;the control strength was 811.47 MN/m2 while that of the welded samples ranged from 177.07 to 257.32 MN/m2. The control impact energy was 162.70 J, while that of the welded samples ranged from 38.64 J to 56.20 J. The research also shows that the stress relief heat treatment gives better strength (A3 = 331 MN/m2) compared to those that were quenched in lubricating oil (A2 = 329 MN/m2) and neem oil (A1 = 222 MN/m2), but the reverse is the case in terms of toughness.

关键词： Duplex Stainless Steel Welding Techniques Tensile Strength Hardness Number Impact Energy Heat Treatment

Effects of Pressure on the Mechanical Properties and Microstructure of Die Cast Aluminum A380 Alloy

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Journal of Minerals and Materials Characterization and Engineering 2014年第3期2卷 248-258页

作者： Kenneth N. Obiekea Shekarau Y. Aku danjuma S. Yawas Department of Mechanical Engineering Ahmadu Bello University Zaria Nigeria

In this paper, the mechanical properties and microstructure of die cast aluminium A380 alloy casts produced under varying pressure was investigated experimentally and compared. The results obtained show better mechanical properties i.e. hardness, tensile strengths and impact strengths in the die cast A380 alloy sample that solidified at high pressure when pressure was regulated across five samples of the castings. The hardness of the die cast A380 samples that solidified under different applied pressures varied from 76 to 85 HRN. Also tensile strength, yield strength and elongation of the samples showed an increase with increased pressure. Also the results of SEM and metallography show that at high pressure, structural changes occurred as a fine microstructure was obtained with increase of pressure.

关键词： A380 Alloy Die Casting Microstructure Pressure

Factors Influencing Consumer Use of Third-party Mobile Payment Apps ——A Case Study Of Sweden

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Factors Influencing Consumer Use of Third-party Mobile Payme...

作者： Guorgis ishak 上海交通大学

学位级别：硕士

The aim of this study is to identify possible driving factors which influence consumer use of third-party mobile payment apps in *** will be done by answering the question: what factors influence the use of third-party mobile payment apps by Swedish *** is often perceived as a front-runner when it comes to abounding the cash payment system while often being praised for its innovation and start-ups in the financial technology and IT *** one of the most innovative countries in the world with a high mobile phone penetration and access to fast broadband,developers have been able to offer various types of mobile payment *** mobile payment adoption and use are increasing,it is happening at a slower pace than expected,and Swedes have been cautious in using third party mobile payment *** party mobile payment apps are today more relevant than ever *** in financial technology has increased more than tenfold in the last five years and is expected to *** important factor is the Revised Payment Service Directive taken by the European Union that allow third-party providers to fully complete with *** on the unified theory of acceptance and use of technology（UTAUT）,five different hypotheses were established in order to examine the model and the factors influencing consumers use of third-party mobile payments apps in *** data used for this study was primary data collected through a questionnaire based on constructs of the *** result of the study did not fully support UTAUT-model（Venkatesh et al.,2003）.When the hypotheses were tested by a multiple linear regression analysis,Performance Expectancy（PE）,Effort Expectancy（EE）,and Facilitating Conditions（FC）proved to have a positive significant influence on the use of third-party mobile payment apps by consumers,while Social Influence（SI）and Trust（TR）proved to have a non-significant positive influence on the use of third-party mobile payment.

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Enhanced Metaheuristics with Trust Aware Route Selection for Wireless Sensor Networks

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Computer Systems Science & Engineering 2023年第8期46卷 1431-1445页

作者： A.Francis Saviour Devaraj T.Satyanarayana Murthy Fayadh Alenezi E.Laxmi Lydia Mohamad Adzhar Md Zawawi Mohamad Khairi ishak Department of IT The University of Technology and Applied Sciences-IbriPO Box:466IbriPostal Code:516Sultanate of Oman Chaitanya Bharathi Institute of Technology HyderabadTelanganaIndia Department of Electrical Engineering College of EngineeringJouf UniversitySaudi Arabia Department of Computer Science and Engineering Vignan’s Institute of Information TechnologyVisakhapatnam530049India School of Electrical and Electronic Engineering Engineering CampusUniversiti Sains MalaysiaNibong Tebal14300PenangMalaysia

Recently,a trust system was introduced to enhance security and cooperation between nodes in wireless sensor networks(WSN).In routing,the trust system includes or avoids nodes related to the estimated trust values in the routing *** article introduces Enhanced Metaheuristics with Trust Aware Secure Route Selection Protocol(EMTA-SRSP)for *** presented EMTA-SRSP technique majorly involves the optimal selection of routes in *** accomplish this,the EMTA-SRSP technique involves the design of an oppositional Aquila optimization algorithm to choose safe routes for data *** the clustering process,the nodes with maximum residual energy will be considered cluster heads(CHs).In addition,the OAOA technique gets executed to choose optimal routes based on objective functions with multiple parameters such as energy,distance,and trust *** experimental validation of the EMTA-SRSP technique is tested,and the results exhibited a better performance of the EMTA-SRSP technique over other approaches.

关键词： Security wireless sensor networks trust factor routing protocol privacy

Comparative Analysis of COVID-19 Detection Methods Based on Neural Network

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Computers, Materials & Continua 2023年第7期76卷 1127-1150页

作者： Inès Hilali-Jaghdam Azhari A Elhag Anis Ben ishak Bushra M.Elamin Elnaim Omer Eltag Mohammed Elhag Feda Muhammed Abuhaimed S.Abdel-Khalek Computer Sciences and Information Technology Programs Applied CollegePrincess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia Department of Mathematics and Statistics College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Quantitative Methods Higher Institute of ManagementUniversity of Tunis1073Tunisia Department of Computer Science College of Science and Humanities in Al-SulailPrince Sattam Bin Abdulaziz UniversityAl KharjSaudi Arabia Department of Computer Science Faculty of Science and ArtsKing Khalid UniversityAbha61421Saudi Arabia Department of Mathematics Faculty of ScienceSohag UniversitySohagEgypt

In 2019,the novel coronavirus disease 2019(COVID-19)ravaged the *** of July 2021,there are about 192 million infected people worldwide and 4.1365 million *** present,the new coronavirus is still spreading and circulating in many places around the world,especially since the emergence of Delta variant strains has increased the risk of the COVID-19 pandemic *** symptoms of COVID-19 are diverse,and most patients have mild symptoms,with fever,dry cough,and fatigue as the main manifestations,and about 15.7%to 32.0%of patients will develop severe *** are screened in hospitals or primary care clinics as the initial step in the therapy for *** transcription-polymerase chain reaction(PCR)tests are still the primary method for making the final diagnosis,in hospitals today,the election protocol is based on medical imaging because it is quick and easy to use,which enables doctors to diagnose illnesses and their effects more *** to this approach,individuals who are thought to have COVID-19 first undergo an X-ray session and then,if further information is required,a CT-scan *** methodology has led to a significant increase in the use of computed tomography scans(CT scans)and X-ray pictures in the clinic as substitute diagnostic methods for identifying *** provide a significant collection of various datasets and methods used to diagnose COVID-19,this paper provides a comparative study of various state-of-the-art *** impact of medical imaging techniques on COVID-19 is also discussed.

关键词： Neural networks frameworks intelligent systems COVID-19 CT

Hereditary gastric cancer:Three rules to reduce missed diagnoses

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World Journal of Gastroenterology 2020年第13期26卷 1382-1393页

作者： Paula Assumpcao Taíssa Araújo André Khayat Geraldo ishak Sidney Santos Williams Barra Joao Felipe Acioli Benedito Rossi Paulo Assumpcao Programa de Pós-Graduacao em Genética e Biologia Molecular Universidade Federal do ParáBelém 66075-110Brazil Núcleo de Pesquisas em Oncologia Universidade Federal do ParáBelém 66073-000Brazil Hospital Universitário Joao de Barros Barreto Universidade Federal do ParáBelém 66073-000Brazil Centro de Oncologia e Aconselhamento Genético Hospital Sírio LibanêsSao Paulo 01308-050Brazil

Gastric cancer remains one of the most lethal *** incidence and mortality rates are quite *** main reason for the high mortality is diagnosis at advanced stages of disease,when treatment options are *** of the supposed strategies to overcome late-stage diagnosis is identifying people at high risk with the aim of establishing rigorous clinical control,including routine endoscopy and *** gastric cancer(HGC)syndromes,though representing a sizeable group to monitor for prevention or,at least,for early diagnosis,are apparently extremely *** low rate of HGC diagnosis might be related to the low rates of suspicion,insufficient familiarity about clinical diagnosis criteria,and the supposed conditional necessity of a molecular *** this review,we will discuss simple measures to increase HGC diagnosis by applying three rules that might provide an opportunity for precision care to benefit the families affected by this disease.

关键词： Hereditary gastric cancer Rules Diagnosis