检索结果-南通市图书馆

Acta Metallurgica Sinica(english Letters) 2017年第3期30卷 201-211页

作者： H.R.Bakhsheshi-Rad e.hamzah H.T.Low M.H.Cho M.Kasiri-Asgarani S.Farahany A.Mostafas M.Medraj Advanced Materials Research Center Department of Materials Engineering Najafabad Branch Islamic Azad University Najafabad Iran Department of Materials Manufacturing and Industrial Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia 81310 Johor Bahru Johor Malaysia Research and Development Centre KISWIRE Sdn. BhdJohor Bahru Johor Malaysia Department of Materials and Mechanical engineering Buein Zahra Technical University Qazvin *** Iran Department of Mechanical and Materials engineering Masdar Institute of Science and TechnologyP. O. Box: 54224 Masdar City Abu Dhabi UAE Department of Mechanical engineering Concordia University 1455 De Maisonneuve Blvd. West Montreal QCH3G 1MS Canada

Ternary Zn-0.5A1-0.5Mg and quatemary Zn-0.5A1-0.5Mg-xBi （x = 0.1, 0.3 and 0.5） alloys were studied to evaluate the thermal and structural characteristics, mechanical properties, cytotoxicity and in vitro degradation behavior. Thermal analysis and microstructural observations showed that Zn-0.5A1-0.5Mg is composed of FCC-A1 ＋ HCP- Zn ＋ Mg2（Zn,A1）ll while a new phase a-Mg3Bi2 appeared after the addition of Bi to the Zn-0.5A1-0.5Mg ternary alloy. The results revealed that the quaternary Zn-A1-Mg-Bi alloys have higher tensile strength, elongation and hardness but slightly lower corrosion resistance than those of the temary Zn-AI-Mg alloy. Based on the MTT assay, the Zn-A1-Mg and Zn-A1-Mg-Bi alloys were found to be biocompatible, and thus, they can be considered for further investigation in an in vivo environment.

关键词： Zn-AI-Mg-Bi Microstructure Mechanical property Corrosion Cytotoxicity

Correlation of microstructural and corrosion characteristics of quaternary shape memory alloys Cu-Al-Ni-X(X=Mn or Ti)

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2015年第4期25卷 1158-1170页

作者： S.N.SAUD e.hamzah T.ABUBAKAR H.R.BAKHSHeSHI-RAD Faculty of Mechanical engineering Universiti Teknologi MalaysiaJohor Bahru 81310 Johor Malaysia

The effects of different contents(0.4%, 0.7%, and 1.0%, mass fraction) of Mn or Ti additions on the micro structure, shape memory effect and the corrosion behaviour of Cu-Al-Ni shape memory alloys were studied by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, differential scanning calorimetry and electrochemical and immersion tests in NaCl solution. It was observed that the microstructure, shape memory effect and corrosion characteristics are highly sensitive to the composition variations. It was found that the highest strain recovery was with 0.7% addition of Mn or Ti. This may be attributed to the presence of precipitation with a high volume fraction and the grain refinement. The electrochemical test showed that the formation of oxide layers in both Cu-Al-Ni-Mn and Cu-Al-Ni-Ti shape memory alloys(SMAs) provided good passivation which enhanced the corrosion resistance of the alloys. Immersion test showed that in Cu-Al-Ni-Mn SMAs, pitting corrosion occurred through feebleness in the oxide layer. A corrosion product adjacent to the pits was rich in Al/Mn oxide and depleted in Cu while inside of the pit it was rich in Cu. In Cu-Al-Ni-Ti SMAs, localized corrosion occurred on the surface of the specimens and dealuminization attack was also observed in the matrix.

关键词： Cu-Al-Ni alloy shape memory effect electrochemical test alloying addition microstructure

Parameter optimization of microwave sintering porous Ti-23%Nb shape memory alloys for biomedical applications

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2018年第4期28卷 700-710页

作者： Mustafa K.IBRAHIM e.hamzah Safaa N.SAUD e.M.NAZIM A.BAHADOR Faculty of Mechanical engineering Universiti Teknologi Malaysia Faculty of Information Sciences and engineering Management & Science University

Porous Ti-23%Nb(mole fraction)shape memory alloys(SMAs)were prepared successfully by microwave sintering with excellent outer finishing(without space holder).The effects of microwave-sintering on the microstructure,phase composition,phase-transformation temperature,mechanical properties and shape-memory effect were *** results show that the density and size of porosity vary based on the sintering time and temperature,in which the smallest size and the most uniform pore shape are exhibited with Ti-23%Nb SMA after being sintered at 900°C for 30 *** microstructure of porous Ti-Nb SMA consists of predominantα',α,andβphases in needle-like and plate-like morphologies,and their volume fractions vary based on the sintering time and ***βphase represents the largest phase due to the higher content ofβstabilizer element with little intensities ofαandα'*** highest ultimate strength and its strain are indicated for the sample sintered at 900°C for 30 min,while the best superelasticity is for the sample sintered at 1200°C for 30 *** low-elastic modulus enables these alloys to avoid the problem of“stress shielding”.Therefore,microwave heating can be employed to sinter Ti-alloys for biomedical applications and improve the mechanical properties of these alloys.

关键词： biomedical Ti-23%Nb alloy microwave sintering microstructure transformation temperature mechanical properties

Bioactivity,in-vitro corrosion behavior,and antibacterial activity of silver-zeolites doped hydroxyapatite coating on magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2018年第8期28卷 1553-1562页

作者： H.R.BAKHSHeSHI-RAD e.hamzah A.F.ISMAIL M.AZIZ e.KARAMIAN N.IQBAL Advanced Materials Research Center Department of Materials EngineeringNajafabad Branch Islamic Azad University Department of Materials Manufacturing and Industrial EngineeringFaculty of Mechanical Engineering Universiti Teknologi Malaysia Advanced Membrane Technology Research Center (AMTeC) Universiti Teknologi Malaysia Department of Biomedical engineering University of Engineering and TechnologyLahore Pakistan

Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite（Ag-Zeo-HAp） coating was synthesized on Ti O2-coated Mg alloy by physical vapour deposition（PVD） assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction（XRD） analysis and field emission scanning electron microscopy（Fe-SeM） images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the Ti O2 film with a thickness of 1 μm. The potentiodynamic polarization（PDP） and electrochemical impedance spectroscopy（eIS） tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid（SBF） solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone（3.86 mm） towards escherichia coli（e. coli） compared with the Ti O2-coated Mg alloy（2.61 mm）. The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.

关键词： magnesium alloy zeolite coatiilg bioactivity conosion behavior antibacterial activity

In-vitro degradation behavior of Mg alloy coated by fluorine doped hydroxyapatite and calcium deficient hydroxyapatite

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2014年第8期24卷 2516-2528页

作者： H.R.BAKHSHeSHI-RAD e.hamzah M.DAROONPARVAR M.A.M.YAJID M.KASIRI-ASGARANI M.R.ABDUL-KADIR M.MeDRAJ Department of Materials Manufacturing and Industrial Engineering Faculty of Mechanical EngineeringUniversiti Teknologi Malaysia Materials engineering Department Najafabad Branch Islamic Azad University Najafabad Isfahan Iran Department of Mechanical engineering Concordia University 1455 De Maisonneuve Blvd.West Montreal QC H3G 1M8 Canada

Fluorine-doped hydroxyapatite(FHA) and calcium deficient hydroxyapatite(CDHA) were coated on the surface biodegradable magnesium alloy using electrochemical deposition(eD) technique. Coating characterization was investigated X-ray diffraction(XRD), Fourier-transformed infrared spectroscopy(FTIR), transmission electron microscopy(TeM), scanni electron microscopy(SeM) and energy dispersive X-ray spectroscopy(eDS). The result shows that nano-FHA coated samp presents nano needle-like structure, which is oriented perpendicular to the surface of the substrate with denser and more unifo layers compared to the nano-CDHA coated sample. The nano-FHA coating shows smaller crystallite size(65 nm) compared to t nano-CDHA coating(95 nm); however, CDHA presents thicker layer(19 μm in thickness) compared to the nano-FHA(15 μm thickness). The corrosion behaviour determined by polarization, immersion and hydrogen evolution tests indicates that the nano-FH and nano-CDHA coatings significantly decrease corrosion rate and induce passivation. The nano-FHA and nano-CDHA coatings c accelerate the formation of bone-like apatite layer and significantly decrease the dissolution rate as compared to the uncoated M alloy. The nano-FHA coating provides effective protection to Mg alloy and presents the highest corrosion resistance. Therefore, t nano-FHA coating on Mg alloy is suggested as a great candidate for orthopaedic applications.

关键词： magnesium alloy fluorine-doped hydroxyapatite calcium deficient hydroxyapatite electrodeposition corrosion behavior

Orbit Weighting Scheme in the Context of Vector Space Information Retrieval

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第7期80卷 1347-1379页

作者： Ahmad Ababneh Yousef Sanjalawe Salam Fraihat Salam Al-e’mari hamzah Alqudah Department of Computer Science Faculty of Information TechnologyAmerican University of MadabaAmman11821Jordan Department of Cybersecurity Faculty of Information TechnologyAmerican University of MadabaAmman11821Jordan Artificial Intelligence Research Center(AIRC) College of Engineering and Information TechnologyAjman UniversityP.O.Box 346Ajman13306United Arab Emirates Information Security Department Faculty of Information TechnologyUniversity of PetraAmman11196Jordan Department of Data Science and Artificial Intelligence Faculty of Information TechnologyAmerican University of MadabaAmman11821Jordan

This study introduces the Orbit Weighting Scheme(OWS),a novel approach aimed at enhancing the precision and efficiency of Vector Space information retrieval(IR)models,which have traditionally relied on weighting schemes like tf-idf and *** conventional methods often struggle with accurately capturing document relevance,leading to inefficiencies in both retrieval performance and index size *** proposes a dynamic weighting mechanism that evaluates the significance of terms based on their orbital position within the vector space,emphasizing term relationships and distribution patterns overlooked by existing *** research focuses on evaluating OWS’s impact on model accuracy using Information Retrieval metrics like Recall,Precision,InterpolatedAverage Precision(IAP),andMeanAverage Precision(MAP).Additionally,we assessOWS’s effectiveness in reducing the inverted index size,crucial for model *** compare OWS-based retrieval models against others using different schemes,including tf-idf variations and *** reveal OWS’s superiority,achieving a 54%Recall and 81%MAP,and a notable 38%reduction in the inverted index *** highlights OWS’s potential in optimizing retrieval processes and underscores the need for further research in this underrepresented area to fully leverage OWS’s capabilities in information retrieval methodologies.

关键词： Information retrieval orbit weighting scheme semantic text analysis Tf-Idf weighting scheme vector space model

Oxygen uptake response to switching stairs exercise by non-parametric modeling

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第2期22卷 315-325页

作者： Hairong Yu Chenyu Zhang Kai Cao hamzah M.Alqudah Steven Weidong Su Key Laboratory of Child Development and Learning Science of Ministry of education and the School of Biological Science and Medical engineering Southeast UniversityNanjing210096JiangsuChina College of Artificial Intelligence and Big Data for Medical Science Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117ShandongChina Faculty of engineering and Information Technology University of Technology SydneyUltimoNSW2007Australia

Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e., ascending or descending) of the stair exercise, utilizing an experimental dataset that includes ten participants and covers various exercise periods. Based on the designed experiment protocol, a non-parametric modeling method with kernel-based regularization is generally applied to estimate the oxygen uptake changes during the switching stairs exercise, which closely resembles daily life activities. The modeling results indicate the effectiveness of the non-parametric modeling approach when compared to fixed-order models in terms of accuracy, stability, and compatibility. The influence of exercise duration on estimated fitness reveals that the model of the phase-oxygen uptake system is not time-invariant related to respiratory metabolism regulation and muscle fatigue. Consequently, it allows us to study the humans’ conversion mechanism at different metabolic rates and facilitates the standardization and development of exercise prescriptions.

关键词： Non-parametric modeling Interval stair training exercise Kernel method.Cardiorespiratory response Oxygen uptake

Risk factors for hepatocellular carcinoma associated with hepatitis C genotype 3 infection:A systematic review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1596-1612页

作者： hamzah Z Farooq Michael James Jane Abbott Patrick Oyibo Pip Divall Naheed Choudhry Graham R Foster Blizard Institute Queen Mary University of LondonLondon E12ATUnited Kingdom School of Health and Psychological Sciences University of LondonLondon EC1V 0HBUnited Kingdom University Hospitals of Leicester Library University Hospitals of Leicester NHS TrustLeicester LE39QPUnited Kingdom

BACKGROUND Hepatitis C virus(HCV)is a blood-borne virus which globally affects around 79 million people and is associated with high morbidity and *** infection leads to cirrhosis in a large proportion of patients and often causes hepatocellular carcinoma(HCC)in people with *** the 6 HCV genotypes(G1-G6),genotype-3 accounts for 17.9%of *** genotype-3 responds least well to directly-acting antivirals and patients with genotype-3 infection are at increased risk of HCC even if they do not have *** To systematically review and critically appraise all risk factors for HCC secondary to HCV-G3 in all ***,we studied possible risk factors for HCC due to HCV-G3 in the literature from 1946 to *** This systematic review aimed to synthesise existing and published studies of risk factors for HCC secondary to HCV genotype-3 and evaluate their strengths and *** searched Web of Science,Medline,eMBASe,and CeNTRAL for publications reporting risk factors for HCC due to HCV genotype-3 in all settings,*** Four thousand one hundred and forty-four records were identified from the four databases with 260 records removed as *** thousand eight hundred and eighty-four records were screened with 3514 *** hundred and seventy-one full-texts were assessed for eligibility with seven studies included for *** the seven studies,three studies were retrospective case-control trials,two retrospective cohort studies,one a prospective cohort study and one a cross-sectional study *** were based in hospital settings with four in Pakistan,two in South Korea and one in the United *** total number of participants were 9621 of which 167 developed HCC(1.7%).All seven studies found cirrhosis to be a risk factor for HCC secondary to HCV genotype-3 followed by higher age(five-studies),with two studies each showing male sex,high alpha feto-protein,directly-acting antivirals trea

关键词： Hepatocellular carcinoma Hepatitis C Genotype 3 Systematic review Blood-borne viruses Liver cancer

Microwave sintering effects on the microstructure and mechanical properties of Ti–51at%Ni shape memory alloys

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 280-288页

作者： Mustafa K. Ibrahim e. hamzah Safaa N. Saud e. N. e. Abu Bakar A. Bahador Faculty of Mechanical engineering Universiti Teknologi Malaysia 81310 UTM Johor Bahru Johor Malaysia Faculty of Information Sciences and engineering Management & Science University Shah Alam Selangor Malaysia

Ti–51at%Ni shape memory alloys(SMAs) were successfully produced via a powder metallurgy and microwave sintering *** influence of sintering parameters on porosity reduction,microstructure,phase transformation temperatures,and mechanical properties were investigated by optical microscopy,field-emission scanning electron microscopy(Fe-SeM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),compression tests,and microhardness *** the microwave temperature and holding time was found to strongly affect the density of porosity,presence of precipitates,transformation temperatures,and mechanical *** lowest density and smallest pore size were observed in the Ti–51at%Ni samples sintered at 900°C for 5 min or at 900°C for 30 *** predominant martensite phases of β2 and β19′ were observed in the microstructure of Ti–51at%Ni,and their existence varied in accordance with the sintering temperature and the holding *** the DSC thermograms,multi-transformation peaks were observed during heating,whereas a single peak was observed during cooling;these peaks correspond to the presence of the β2,R,and β19′ *** maximum strength and strain among the Ti–51at%Ni SMAs were 1376 MPa and 29%,respectively,for the sample sintered at 900°C for 30 min because of this sample's minimal porosity.

关键词： titanium nickel alloys shape memory effect powder metallurgy (PM) microwave heating sintering microstructure mechanical properties

effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 326-330页

作者： Nurul A.Yunus Mohd H.Ani hamzah M.Salleh Rusila Z.A.Rashid Tomohiro Akiyama Hadi Purwanto Nur e.F.Othman Faculty of engineering International Islamic University Malaysia Center for Advanced Research of energy and Materials Faculty of EngineeringHokkaido University

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch （eFB） was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the mag-netization of samples was measured using a vibrating sample magnetometer （VSM）. When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was par-tially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic proper-ties

关键词： iron ores ore reduction ore roasting bio-char magnetic properties