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Hot Ductility of Severe Plastic Deformed aa6061 Aluminum Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 322-330页

作者： ali Akbar Khamei Kamran Dehghani Mining and Metallurgical Engineering Department Amirkabir University of Technology

The hot ductility of 6061 aluminum alloy,which was subjected to two different severe plastic deformations（SPD）,was studied at different temperatures and strain *** tensile tests were carried out at the temperature range of 300-500 ℃ and at the strain rates of 0.0005-0.01 s^（-1）.The microstructure evolution was characterized using optical microscopy,transmission electron microscopy and X-ray diffraction *** influences of the microstructure after SPD,thermomechanical parameters（temperature and strain rate） and specimen size on the hot formability of this alloy were then *** results show that a decrease in grains/subgrains exhibited significant effect on the hot ductility of SPDed *** constitutive equations were then developed to model the hot formability of the studied *** developed model can be represented by Zener-Hollomon parameter in a hyperbolic sinusoidal equation *** the changes of elongation to failure and Zener-Hollomon parameter indicate that the hot ductility of the alloy is more sensitive to the temperature rather than to the strain *** uniform elongation is independent of the specimen size,but the postnecking elongation increases dramatically as the ratio of l/A^（1/2） decreases.

关键词： Al-Mg-Si alloy Deformation behavior Equal channel angular pressing(ECAP) Rolling Hot tensile deformation

Rapid isolation and identification of Mycobacterium tuberculosis from pulmonary tuberculosis patients

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Asian Pacific Journal of Tropical Medicine 2009年第3期2卷 70-73页

作者： Al-Sulami aa ali ZM Al-Maleky DA College of Education Basrah UniversityIraq

Objective:The Study aimed to develop a rapid inexpensive and simple method for preliminary isolation and detection of *** from clinical *** to probe the impact of deteriorating health measures on the pulmonary tuberculosis control program in Basra ***:A simple monophasic-diphasic setup (MDCS) was used for the isolation and preliminary identification of *** setup consists of a slanted Lowenstein-Jensen medium,the bottom of it is covered with 1 mL of tuberculosis broth thus establishing a diphasic solid liquid environment at the bottom of the screw capped test tube and above them a monophasic ***:During 7 months period from the beginning of December 2003 to the end of June 2004,1 295 cases were managed in Tuberculosis and Chest Diseases Clinic in Basra *** 348 cases were diagnosed as active pulmonary *** consist of 232 new cases and 116 previously registered *** MDCS method showed higher recovery of isolation rate of ***(92.3%) than Lowenstein-Jensen,and pyruvate methods with 78.1%and 51.9%*** this method revealed more rapid appearance of results of 12 days than Lowenstein-Jensen,and pyruvate media with 22 days and 23 days respectively by the traditional culturing *** the study revealed that drug resistance against one or more anti tuberculosis drugs was 23.1%for new cases and 70.8%for the old *** drug resistance accounts for 20%of total isolates from old *** was based on using the critical concentration and 1%proportional *** was more common among males than females with 69.4%and 30.6%respectively. A significant correlation(P<0.05) was found between the productive age group(25-54) and incidence of tuberculosis. Tuberculosis was higher among married(83.8%) than unmarried peoples(22%).Children,husbands and wives showed higher infection rates than others indicating kinship *** of treatment was highly

关键词： Mycobacterium tubercolosis Pulmonary tubercalosis Detection Isolation

Improvement of microstructure and corrosion properties of friction stir welded aa5754 by adding Zn interlayer

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 967-973页

作者： ali Shamsipur Amir Anvari Ahmad Keyvani Department of Mining and Metallurgical Engineering Amirkabir University of Technology School of Metallurgy and Materials Engineering Faculty of Technology and EngineeringShahrekord University

This study investigated the effect of Zn foil layers on the microstructure and corrosion characteristics of friction stir welded aluminum alloy *** of various joints were prepared by applying different rotational and welding speeds,and their microstructures were evaluated via a metallographic technique and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy elemental *** anticorrosion behavior of joints in the absence and presence of a Zn interlayer was studied by cyclic potentiodynamic polarization test in 3.5 wt% Na Cl aqueous solution,and sound welds were obtained in the presence of the Zn interlayer *** results revealed that the joint made at a rotational speed of 800 r/min and traveling speed of 15 mm/min achieved a chemical composition identical to that of aluminum alloy 7 xxx series,and as such,it showed the best resistance to corrosion.

关键词： friction stir welding aa5754 aluminum alloy zinc interlayer microstructure corrosion resistance

Effect of Al_2O_3 and Y_2O_3 on the corrosion behavior of ZrO_2-benzotriazole nanostructured coatings applied on aa2024 via a sol–gel method

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1344-1353页

作者： Saeid Mersagh Dezfuli ali Shanaghi Saeid Baghshahi Department of Materials Science and Engineering Tehran Science and Research BranchIslamic Azad University Materials Engineering Department Faculty of EngineeringMalayer University

zirconia-based nanostructured coatings were deposited on aa2024 to improve the corrosion resistance properties. Three different nanostructured coatings, namely, zirconia–benzotriazole, zirconia–alumina–benzotriazole, and zirconia–yttria–benzotriazole, were applied on aa2024 via a sol–gel method using the dip-coating technique. Next, the coatings were annealed at 150°C after each dipping period. The phases and morphologies of the coatings were investigated using grazing incidence X-ray diffraction(GIXRD), Fourier transform infrared spectroscopy(FT-IR), field emission scanning electron microscopy(FESEM), and atomic force microscopy(AFM). The corrosion properties were evaluated using electrochemical methods, including polarization and electrochemical impedance techniques in 3.5 wt% NaCl solution. The obtained results confirm the formation of homogeneous and crack free zirconia-benzotriazole-based nanostructured coatings. The average roughness values for zirconia-benzotriazole, zirconia-alumina-benzotriazole, and zirconia-yttria-benzotriazole nanostructured coatings were 30, 8, and 6 nm, respectively. The presence of alumina as a stabilizer on zirconia coating was found to have a beneficial impact on the stability of the corrosion resistance for different immersion times. In fact, the addition of alumina resulted in the dominance of the healing behavior in competition with the corrosion process of zirconia-benzotriazole nanostructured coating.

关键词： zirconia hybrid coatings alumina yttria aa2024 sol-gel corrosion behavior

Microstructure and wear behavior of aa6061/SiC surface composite fabricated via friction stir processing with different pins and passes

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Rare Metals 2020年第4期39卷 429-435页

作者： Hamidreza Eftekharinia Ahmad ali Amadeh alireza Khodabandeh Moslem Paidar Department of Materials Engineering University of Islamic AzadScience and Research Branch14515775 TehranIran School of Metallurgy and Materials Engineering University College of EngineeringUniversity of Tehran111554563 TehranIran Department of Materials Engineering University of Islamic AzadSouth Tehran Branch*** TehranIran

In this investigation,the effects of pin geometry and number of passes on macrostructure,microstructure,wear rate and also microhardness profile of 6061-T6 aluminum alloy surface composites fabricated via friction stir processing(FSP)were discussed by reinforcement particles of silicon carbide(SiC).The results show that after each FSP pass,a modify distribution of SiC particles is acquired and the increase in the number of passes reduces the average grain size in stir zone(SZ).Furthermore,it is discovered that pin geometry and pass number play a dominant role in the grain size of SZ and distribution of SiC particles in *** is found that after each FSP pass,wear rate is improved due to the uniform distribution of SiC particles in surface of Al/SiC ***,the results show that the square pin and smooth(straight)cylindrical pin have the highest and lowest resistance to wear,respectively.

关键词： Friction stir processing Pin geometry Silicon carbide Stir zone Wear rate

Compression properties of cost-efficient porous expanded clay reinforced aa7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat ali Gökşenli Faculty of Mechanical Engineering Istanbul Technical University34437İstanbulTurkey Faculty of Engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and *** this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a *** to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors *** this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of aa7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF ***,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive *** results show that PEC particles can be an alternative to expensive hollow spheres used in the previous ***,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

Major-effect candidate genes identified in cultivated strawberry(Fragaria×ananassa Duch.)for ellagic acid deoxyhexoside and pelargonidin-3-O-malonylglucoside biosynthesis,key polyphenolic compounds

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Horticulture Research 2020年第1期7卷 1109-1125页

作者： Jahn Davik Kjersti aaby Matteo Buti Muath alsheikh NadaŠurbanovski Stefan Martens Dag Røen Daniel James Sargent Division of Biotechnology and Plant Health Norwegian Institute of Bioeconomy ResearchÅs N-1433Norway NOFIMA AS Norwegian Institute of Food Fisheries and Aquaculture ResearchÅs N-1433Norway Department of Agriculture FoodEnvironment and ForestryUniversity of FlorenceFlorenceItaly Graminor Breeding Ltd. N-2322 RidabuNorway Department of Plant Sciences Norwegian University of Life SciencesRidabu N-1432ÅsNorway NIAB-EMR East MallingME196BJ KentUK Department of Food Quality and Nutrition Fondazione Edmund MachCentro Ricerca e InnovazioneVia E.Mach 138010 San Michele all’AdigeTNItaly Department of Genetics Genomics and BreedingNIAB-EMREast MallingME196BJ KentUK

Strawberries are rich in polyphenols which impart health benefits when metabolized by the gut microbiome,including anti-inflammatory,neuroprotective,and antiproliferative *** addition,polyphenolic anthocyanins contribute to the attractive color of strawberry ***,the genetic basis of polyphenol biosynthesis has not been extensively studied in *** this investigation,ripe fruits from three cultivated strawberry populations were characterized for polyphenol content using HPLC-DAD-MSn and genotyped using the iStraw35k *** and QTL analyses identified genetic loci controlling polyphenol *** were identified on four chromosomes for pelargonidin-3-O-malonylglucoside,pelargonidin-3-O-acetylglucoside,cinnamoyl glucose,and ellagic acid deoxyhexoside ***/absence of ellagic acid deoxyhexoside and pelargonidin-3-O-malonylglucoside was found to be under the control of major gene loci on LG1X2 and LG6b,respectively,on the F.×ananassa linkage *** of gene predictions in the *** reference genome sequence identified a single candidate gene for ellagic acid deoxyhexoside biosynthesis,while seven malonyltransferase genes were identified as candidates for pelargonidin-3-O-malonylglucoside *** malonyltransferase genes were identified in the F.×ananassa‘Camarosa’genome sequence but the candidate for ellagic acid deoxyhexoside biosynthesis was absent from the‘Camarosa’*** study demonstrated that polyphenol biosynthesis in strawberry is,in some cases,under simple genetic control,supporting previous observations of the presence or absence of these compounds in strawberry *** has also shed light on the mechanisms controlling polyphenol biosynthesis and enhanced the knowledge of these biosynthesis pathways in *** above findings will facilitate breeding for strawberries enriched in compounds with beneficial health effects.

关键词： straw polyphenol breeding

Pattern of intestinal helminth infections among school children in an urban community in Ibadan,Nigeria

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Asian Pacific Journal of Tropical Medicine 2008年第3期1卷 42-47页

作者： Fatiregun aa Oluwatoba OA Department of Epidemiology Medical Statistics and Environmental HealthFaculty of Public HealthCollege of MedicineUniversity of IbadanIbadanNigeria

Despite a substantial reduction in the incidence and prevalence of parasitic diseases in the industrialized world, they continue to be an important public health problem in many developing African countries,including Nigeria. However,estimates of the prevalence of such infections among school age children,who bear the greatest health burden due to these diseases,are hard to come *** objective of this study was therefore to determine the prevalence and type of intestinal helminth infections among primary school *** study was cross-sectional in *** participants included 266 pupils recruited from three government primary schools in the Mokola area of Ibadan,*** pupils were interviewed and their stool samples examined for eggs of common *** mean age of the pupils was 9.8±2.6 years,and 128(48.1%) were *** pupils(7.1%) had intestinal helminth *** lumbricoides was found in 17 pupils(6. 4%) and was the most prevalent helminth among the children,while Trichuris trichiura was found in only two subjects(0.8%).Previous infestations and the use of public toilets were found to be significantly associated with current infections(P<0.05).This study demonstrated that the prevalence of intestinal infections was low among the pupils studied,and that Ascaris infection was the commonest infestation.

关键词： prevalence intestinal helminths school children

Corrosion Protection of 5083 aa in SalineWater by Polyacrylonitrile Nanofibers

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Journal of Renewable Materials 2021年第11期9卷 1927-1939页

作者： Enas H.ali Juman A.Naser Zainab W.Ahmed Taki A.Himdan Department of Chemistry College of Education for Pure Science-Ibn Al-HaithamUniversity of BaghdadBaghdadIraq

Polymeric nanofibers are a promising technology to protect the metal surfaces from *** the literature search,the use of polyacrylonitrile nanofibres(PANNFs)as a corrosion inhibitor coating for aluminum alloys has not been *** work includes the development of a new,lightweight,high surface area and efficient coating of PANNFs that produced using electrospinning process to resist the corrosion of aluminum alloys(aa5083)which immersed in 0.6 M NaCl at alkaline medium(pH=12)and acidic medium(pH=1)at a range of temperatures(293–323)*** PANNFs coating was successfully deposited on aa 5083 specimens,where these samples were considered as a collector electrode in the electrospinning *** corrosion experiments of the aluminum alloys coated with PANNFs before and after immersion in both corrosive mediums were investigated using cyclic potential polarization(CPP).The results confirmed that the PANNFs coating was able to protect the surface of the aluminum specimens from corrosion,by reducing the corrosion current and increasing the surface polarization resistance,thus reducing the corrosion *** protection efficiency was found in the alkaline medium 98.8%while in the acidic medium 83.3%.So,it was in both mediums decreased with the increase in *** shape,distribution and size of the polymeric nanofibers that formed the coating were also examined using field emission scanning electron microscopy(FE-SEM)and the percentages of the structural components of these fibers were detected using the X-ray dispersion spectroscopy(EDS).The surface of aluminum specimens was completely covered by *** electrospun nanofibers have worn out and lined up spacing after immersion in the corrosive *** diameters average of PANNFs was found to be about 200 and 150 nm before and after immersion,respectively.

关键词： Corrosion protection nanofibers polyacrylonitrile aluminum alloy saline medium protection efficiency