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Effect of Primary and Eutectic Mg_2Si Crystal Modifications on the Mechanical Properties and Sliding Wear Behaviour of an Al–20Mg_2Si–2Cu–xBi Composite

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Journal of Materials Science & Technology 2016年第11期32卷 1083-1097页

作者： Saeed Farahany Hamidreza Ghandvar nur Azmah Nordin Ali Ourdjini Mohd Hasbullah Idris Department of Materials and Mechanical Engineering Buein Zahra Technical University Department of Materials Manufacturing and Industrial Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia (UTM) Department of Mechanical Engineering Faculty of Engineering University of Ottawa

This work investigated the microstructure evolution, tensile, impact, hardness, and sliding wear properties of an Al–20Mg2Si–2Cu in situ composite treated with different Bi contents. The desired modification of primary Mg2 Si particles was achieved with the addition of 0.4 wt% Bi. Increasing Bi beyond 0.4 wt%resulted in a loss of modification, possibly due to the formation of Al8 MgB iS i4 compound before the precipitation of the primary Mg2 Si. Additionally, the structure of the pseudo-eutectic Mg2 Si was transformed from plate to fibrous, which was consistent with decrease of growth temperature extracted from the cooling curve thermal analysis. Addition of Bi had an effect on the morphology of Al5 Fe Si（β）, Al2Cu（θ） and Al5Cu2Mg8Si6（Q） intermetallic compounds. The tensile strength, elongation percentage, impact toughness, and hardness increased by 6%, 13%, 75%, and 23%, respectively, due to modification of both the primary and eutectic Mg2 Si crystals. The tensile and impact fracture surfaces showed fewer decohered particles in the Bi-treated composite. The enhancement in wear resistance of the Bi-treated composite could be attributed to solid lubricant function of insoluble soft Bi phase and modification effects on Mg2 Si particles.

关键词： Al–Mg2Si Composite Modification Bismuth Mechanical properties Wear

Mechanical and degradation behaviour of biodegradable magnesium-zinc/hydroxyapatite composite with different powder mixing

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Journal of Magnesium and Alloys 2019年第4期7卷 566-576页

作者： Siti nur Hazwani Mohamad Rodzi Hussain Zuhailawati B.K.Dhindaw Biomaterials Niche Area Group School of Materials and Mineral Resources EngineeringUniversiti Sains MalaysiaEngineering Campus14300 Nibong TebalPenangMalaysia School of Minerals Metallurgical and Materials EngineeringIndian Institute of Technology BhubaneswarBhubaneswar 751007India

Magnesium-based biomaterials have recently gained great attention as promising candidates for the new generation of biodegradable *** study investigated the mechanical performance and biodegradation behaviour of magnesium-zinc/hydroxyapatite(Mg-Zn/HA)composites fabricated by different powder mixing techniques.A single step mixing process involved mechanical alloying or mechanical milling techniques,while double step processing involved a combination of both mechanical alloying and mechanical *** mechanical properties of the composite were observed when the powders were prepared using single step processing via mechanical alloying ***,Mg-Zn/HA composite fabricated through single step processing via mechanical milling technique was found to have the most desirable low degradation rate coupled with highest *** composite achieved the lowest degradation rate of 0.039×10^−3 mm/year as measured by immersion test and 0.0230 mm/year as measured by electrochemical ***:P ratio of the composite also slightly more than enough to aid the initial bone mineralization,that is 1:1.76,as the required Ca:P ratio for initial bone mineralization is between 1:1 and 1:1.67.

关键词： Magnesium-based composite Biodegradable implant Powder metallurgy Mechanical alloying Mechanical milling

Clinical considerations for critically ill COVID-19 cancer patients:A systematic review

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World Journal of Clinical Cases 2021年第28期9卷 8441-8452页

作者： Chidambaram Ramasamy Ajay Kumar Mishra Kevin John John amos Lal Department of Internal Medicine Saint Vincent HospitalWorcesterMA 01608United States Department of Medicine Bangalore Baptist HospitalBangalore 578954India Department of Medicine Division of Pulmonary and Critical Care MedicineMayo ClinicRochesterMN 55902United States

BACKGROUND The World Health Organization(WHO)on March 11,2020,had declared the novel coronavirus disease 2019(COVID-19)outbreak a global *** COVID-19 infection continues to be a pandemic and is currently causing overwhelming challenges to healthcare across the *** patients represent a unique population vulnerable to COVID-19 infection due to their advanced age,intrinsic frailty,medical comorbidities,immunosuppression,and frequent health care visits for their underlying *** analysis of COVID-19 infection among cancer patients is crucial to aid in the optimal management of these *** To identify contributors of worse outcomes in patients with malignancy and COVID-19 and to describe the role of critical *** In this review,we summarized the information from seminal articles on the presentation and management of patients with COVID-19 and malignancy that were published before December 10,*** searched the Pub Med and Medline database for“COVID-19”and“Cancer”,“Malignancy”.Studies published in English,including adults with malignancy and COVID-19 infection,were eligible to be included in this *** on patients that provided details on malignancy,clinical presentation,management,and outcome were *** details of malignancy that were included are the site of cancer,histopathological type,stage,chemotherapy,and *** of COVID-19 infection that were obtained are clinical presentation,the modality of testing,imaging,management,and *** care details that were obtained were the type of the organ dysfunction and the requirement of organ support measures,requirement of noninvasive,invasive ventilation,management of vasopressor support,and *** that did not have patient details,opinions,letters,and articles not published in English were *** articles were reviewed by 2 independent *** were screened for the above terminologies by independent clinician

关键词： COVID-19 Cancer Critical care Mortality Pandemic

Community structure of epiphytic algae on three different macrophytes at Acarlar floodplain forest(northern Turkey)

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Chinese Journal of Oceanology and Limnology 2014年第4期32卷 845-857页

作者： Hatice TUNCA Tugba ONGUN SEVINDIK Dilek nur BAL Sevil ARABACI Sakarya University Faculty of Arts and ScienceDepartment of Biology54187AdapazariTurkey

The aim of this study was to determine the species composition, biodiversity and, relative abundance of epiphytic algae and their relationship with environmental variables on three different macrophytes( Nymphaea alba, Ceratophyllum demersum, Typha latifolia) at Acarlar Floodplain Forest(AFF). Epiphytic algae were gathered monthly by collecting aquatic plants between November 2011 and October 2012, except in winter when there were no plants. In this study, 67 taxa on N. alba, 66 taxa on C. demersum and 66 taxa on T. latifolia were identified as epiphytic algae. The mean value of species richness was 17, that of diversity was 1.5 and that of evenness was 0.54 for epiphytic algae on N. alba, 17, 1.1, and 0.39 on C. demersum, and 18, 1.64, and 0.56 on T. latifolia, respectively. Oscillatoria sp. and Komvophoron crassum(Vozzen) Anagnostidis and Komárek were the most abundant and consistent epiphytic algal species, occurring in high abundance on all macrophytes. Results show that species composition of epiphytic algae was different, but diversity values were similar on all the macrophytes. The hydrological pulse is one of the most important factors determining the physical and chemical environment of the epiphytic algal community. However, substrate type also affected the colonization by F. capucina, O. sancta, P. catenata, and L. truncicola more than the epiphytic algal seasonality.

关键词： biodiversity algae water quality Nymphaea Ceratophyllum Typha

A novel (G'/G)-expansion method and its application to the Boussinesq equation

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Chinese Physics B 2014年第2期23卷 34-43页

作者： Md.nur Alam Md.Ali Akbar Syed Tauseef Mohyud-Din Department of Mathematics Pabna University of Science and Technology Department of Applied Mathematics University of Rajshahi Department of Mathematics HITEC UniversityTaxila Cantt

In this article, a novel （G＇/G）-expansion method is proposed to search for the traveling wave solutions of nonlinear evolution equations. We construct abundant traveling wave solutions involving parameters to the Boussinesq equation by means of the suggested method. The performance of the method is reliable and useful, and gives more general exact solutions than the existing methods. The new （G＇/G）-expansion method provides not only more general forms of solutions but also cuspon, peakon, soliton, and periodic waves.

关键词： (G'/G)-expansion method Boussinesq equation solitary wave solutions auxiliary nonlinear ordinary differential equation

CeO_2-TiO_2 as a visible light active catalyst for the photoreduction of CO_2 to methanol

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Journal of Rare Earths 2015年第11期33卷 1155-1161页

作者： Hamidah Abdullah Maksudur R.Khan Manoj Pudukudy Zahira Yaakob nur Aminatulmimi Ismail Department of Chemical and Process Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia Faculty of Chemical and Natural Resources Engineering Universiti Malaysia Pahang

The performance of CeO2-TiO2 photocatalyst for the photocatalytic reduction of CO2 into methanol was studied under visible light irradiation. The as-prepared catalysts were characterized for their structural, textural and optical properties using X-ray diffraction（XRD）, field emission scanning electron microscopy（FESEM）, X-ray photoelectron spectroscopy（XPS）, nitrogen physisorption analysis, UV-vis spectroscopy and photoluminescence（PL） spectroscopy. The characterization results indicated that the presence of CeO2 stabilized the anatase phase of TiO2, decreased its crystallite size, increased the surface area, reduced the band gap energy and lowered the rate of electron-hole pair recombination. The CeO2-TiO2 photocatalyst showed an increased methanol yield of 18.6 μmol/g under visible light irradiation, compared to the bare TiO2（6.0 μmol/g）.

关键词： ceria TiO2 photocatalyst CO2 photoreduction visible light methanol rare earths

The rise of Plasmodium knowlesi cases:Implication to Malaysia’s malaria-free status

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Asian Pacific Journal of Tropical Medicine 2022年第8期15卷 337-338页

作者： Ahmad Basyir Muhammad Elora Nor Azman nur Ashrina Eddie nur Iman Azmi Valerie Chong Tze Yee Zulkarnain Md Idris Department of Parasitology and Medical Entomology Faculty of MedicineUniversiti Kebangsaan MalaysiaKuala LumpurMalaysia Infectious Disease Group Faculty of MedicineUniversiti Kebangsaan MalaysiaKuala LumpurMalaysia

Malaria remains a major public health challenge *** is one of the world’s deadliest diseases,responsible for 627000 deaths worldwide in 2020 alone[1].In Malaysia,the Malaria Eradication Programme in Peninsular Malaysia and Malaysia Borneo in 1969 and 1967,respectively,drastically reduced the number of malaria cases in the country[2].Subsequently,the programme was further reinforced and improved,resulting in zero indigenous human malaria species in 2018[1].Currently,Malaysia has been identified as one of the World Health Organization(WHO)Western Pacific Region countries with zero indigenous cases for three consecutive years[1],thus eligible for the WHO certification of a malaria-free status country.

关键词： malaria cases Malaria

Inventory and sales decisions in a vendor–buyer system with imperfect items and learning in inspection

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Journal of Control and Decision 2021年第4期8卷 453-463页

作者： Wakhid Ahmad Jauhari Diah Ayu Purnasari Cucuk nur Rosyidi Department of Industrial Engineering Universitas Sebelas MaretSurakartaIndonesia

In this study,we propose a joint economic lot-sizing model to include learning process along with errors in inspection and full backordering *** aim to study pricing and inventory decisions in a two-level supply chain involving a single vendor and a single buyer in which the demand is sensitive to price and company’s advertisement *** mathematical inventory model is developed analytically and solved using a proposed *** objective of the model is to maximise joint total profit by simultaneously determining optimal shipment size,number of deliveries,backorder quantity and product selling price.A numerical example is provided to show the application of the model and to investigate the impact of key parameter’s changes on model *** comparing the integrated/centralised model to the independent/decentralised model,we note that the integrated/centralised model provides better profit to the system,along with lower selling price and smaller amount of backorder.

关键词： Lot sizing inventory model supply chain learning inspection error sensitive demand full backorder

Moving particle semi-implicit simulation on the molten Wood's metal downward relocation process

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Nuclear Science and Techniques 2021年第8期32卷 110-121页

作者： Anni nuril Hidayati Abdul Waris Asril Pramutadi Andi Mustari Dwi Irwanto nur Asiah Aprianti Department Faculty of Mathematics and Natural ScienceInstitut Teknologi BandungJalan Ganesha 10Bandung 40132Indonesia Nuclear Physics and Biophysics Research Division Physics DepartmentFaculty of Mathematics and Natural ScienceInstitut Teknologi BandungJalan Ganesha 10Bandung 40132Indonesia

In the case of a severe accident involving nuclear reactors,an important aspect that should be considered is the leakage of molten material from the inside of the reactor into the *** molten materials damage other reactor components,such as electrical tubes,grid plates and core *** this study,the moving particle semi-implicit(MPS)method is adopted and improved to analyze the twodimensional downward relocation process of molten Wood’s metal as a representation of molten material in a nuclear *** molten material impinges the Wood’s metal plate(WMP),which is mounted on a rigid dummy stainless steel in a cylindrical test *** breaching process occurs because of heat transfer between the molten material and *** formed breach areas were in good agreement with the experimental results,and they showed that the molten Wood’s metal spread above the *** solid WMP fraction decreased with time until it reached the termination time of the *** present results show that the MPS method can be applied to simulate and analyze the downward relocation process of molten material in the grid plate of a nuclear reactor.

关键词： Heat transfer Moving particle semi-implicit Phase change Relocation Severe accident