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Fabrication and characterization of nanocrystalline Al/Al_(12)(Fe,V)_3Si alloys by consolidation of mechanically alloyed powders

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International Journal of Minerals,Metallurgy and Materials 2014年第7期21卷 711-719页

作者： hamid ashrafi Rahmatollah Emadi Mohammad Hosein Enayati Department of Materials Engineering Isfahan University of Technology

The aim of this study was to produce bulk nanocrystalline Al/Al12（Fe,V）3Si alloys by mechanical alloying （MA） and subsequent hot pressing （HP） of elemental powders. A nanostructured Al-based solid solution was formed by MA of elemental powders for 60 h. After HP of the as-milled powders at 550℃ for 20 min, the Al12（Fe,V）3Si phase was precipitated in a nanocrystalline Al matrix. Scanning electron microscopy （SEM） images of the bulk samples represented a homogeneous and uniform microstructure that was superior to those previously obtained by rapid solidification-powder metallurgy （RS-PM）. Nanostructured Al-8.5Fe-1.3V-1.7Si and Al-11.6Fe-1.3V-2.3Si alloys ex-hibited high HV hardness values of～205 and～254, respectively, which are significantly higher than those reported for the RS-PM counter-parts.

关键词： aluminum alloys nanostructured materials mechanical alloying hot pressing hardness

Void Formation and Plastic Deformation Mechanism of a Cold-Rolled Dual-Phase Steel During Tension

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Acta Metallurgica Sinica(English Letters) 2020年第2期33卷 299-306页

作者： hamid ashrafi Morteza Shamanian Rahmatollah Emadi Ehsan Ghassemali Department of Materials Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran School of Engineering J?nk?ping UniversityBox 102655111 J?nk?pingSweden

The void formation and plastic deformation micromechanisms of a cold-rolled DP600 steel during tensile loading were studied by scanning electron microscopy(SEM) and electron backscatter diffraction(EBSD).The SEM observations revealed that the main void nucleation mechanism in the DP600 steel is decohesion at the ferrite-martensite *** voids were mostly observed between the closely spaced martensite islands situated at the boundaries of relatively finer ferrite *** EBSD results indicated a strain gradient developed from the ferrite-martensite and ferrite-ferrite interfaces into the interior of ferrite grains during the tensile deformation,which led to a stress concentration at these ***,it was demonstrated that local misorientation inside the finer ferrite grains surrounded by martensite islands was higher than that for the coarser ferrite grains,which made the former more prone to void initiation.

关键词： Dual-phase steel Void nucleation Fracture mechanism

3D point cloud data to quantitatively characterize size and shape of shrub crops

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Horticulture Research 2019年第1期6卷 1189-1205页

作者： Yu Jiang Changying Li Fumiomi Takeda Elizabeth A.Kramer hamid ashrafi Jamal Hunter School of Electrical and Computer Engineering College of EngineeringThe University of GeorgiaAthensGA 30602USA Appalachian Fruit Research Station United States Department of Agriculture-Agricultural Research ServiceKearneysvilleWV 25430USA Department of Agricultural and Applied Economics College of Agricultural and Environmental SciencesThe University of GeorgiaAthensGA 30602USA Department of Horticultural Science North Carolina State UniversityRaleighNC 27695USA Department of Entomology College of Agricultural and Environmental SciencesThe University of GeorgiaAthensGA 30602USA

Size and shape are important properties of shrub crops such as blueberries,and they can be particularly useful for evaluating bush architecture suited to mechanical *** overall goal of this study was to develop a 3D imaging approach to measure size-related traits and bush shape that are relevant to mechanical harvesting.3D point clouds were acquired for 367 bushes from five genotype *** cloud data were preprocessed to obtain clean bush points for characterizing bush architecture,including bush morphology(height,width,and volume),crown size,and shape descriptors(path curveλand five shape indices).One-dimensional traits(height,width,and crown size)had high correlations(R^(2)=0.88–0.95)between proposed method and manual measurements,whereas bush volume showed relatively lower correlations(R^(2)=0.78–0.85).These correlations suggested that the present approach was accurate in measuring one-dimensional size traits and acceptable in estimating three-dimensional bush *** results demonstrated that the five genotype groups were statistically different in crown size and bush *** differences matched with human evaluation regarding optimal bush architecture for mechanical *** particular,a visualization tool could be generated using crown size and path curveλ,which showed great potential of determining bush architecture suitable for mechanical harvesting ***,the processing pipeline of 3D point cloud data presented in this study is an effective tool for blueberry breeding programs(in particular for mechanical harvesting)and farm management.

关键词： harvesting size crown

A HapMap leads to a Capsicum annuum SNP infinium array: a new tool for pepper breeding

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Horticulture Research 2016年第1期3卷 157-166页

作者： Amanda M Hulse-Kemp hamid ashrafi Joerg Plieske Jana Lemm Kevin Stoffel Theresa Hill Hartmut Luerssen Charit L Pethiyagoda Cindy T Lawley Martin W Ganal Allen Van Deynze Department of Plant Sciences University of California-DavisDavis95616CaliforniaUSA Illumina Incorporated 5200 Illumina WaySan Diego92122CAUSA TraitGenetics GmbH Am Schwabeplan 1bStadt Seeland OTGaterslebenGermany Department of Horticultural Sciences North Carolina State University2721 Founders Drive234 Kilgore HallRaleighNC 27518USA

The Capsicum genus(Pepper)is a part of the Solanacae *** has been important in many cultures worldwide for its key nutritional components and uses as spices,medicines,ornamentals and *** population growth is associated with demand for more nutritionally valuable vegetables while contending with decreasing resources and available *** conditions require increased efficiency in pepper breeding to deal with these imminent *** resequencing of inbred lines we have completed a valuable haplotype map(HapMap)for the pepper genome based on single-nucleotide polymorphisms(SNP).The identified SNPs were annotated and classified based on their gene annotation in the pepper draft genome sequence and phenotype of the sequenced inbred lines.A selection of one marker per gene model was utilized to create the PepperSNP16K array,which simultaneously genotyped 16405 SNPs,of which 90.7%were found to be informative.A set of 84 inbred and hybrid lines and a mapping population of 90 interspecific F2 individuals were utilized to validate the *** analysis of the inbred lines shows a distinct separation of bell versus chile/hot pepper types and separates them into five distinct germplasm *** interspecific population created between Tabasco(*** chile type)and P4(*** blocky type)produced a linkage map with 5546 markers separated into 1361 bins on twelve 12 linkage groups representing 1392.3 *** publically available genotyping platform can be used to rapidly assess a large number of markers in a reproducible high-throughput manner for *** a standardized tool for genetic analyses,the PepperSNP16K can be used worldwide to share findings and analyze QTLs for important traits leading to continued improvement of pepper for *** and information on the array are available through the Solanaceae Genomics Network.

关键词： breeding pepper linkage

High-density linkage map construction and identification of loci regulating fruit quality traits in blueberry

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Horticulture Research 2021年第1期8卷 2391-2403页

作者： Molla F.Mengist Hamed Bostan Elisheba Young Kristine L.Kay Nicholas Gillitt James Ballington Colin D.Kay Mario G.Ferruzzi hamid ashrafi Mary Ann Lila Massimo Iorizzo Plants for Human Health Institute North Carolina State UniversityKannapolisNCUSA Department of Horticultural Science North Carolina State UniversityRaleighNCUSA David H.Murdock Research Institute KannapolisNCUSA Department of Food Bioprocessing and Nutrition Sciences North Carolina State UniversityRaleighNCUSA

Fruit quality traits play a significant role in consumer preferences and consumption in blueberry(Vaccinium corymbosum L).The objectives of this study were to construct a high-density linkage map and to identify the underlying genetic basis of fruit quality traits in blueberry.A total of 287 F_(1) individuals derived from a cross between two southern highbush blueberry cultivars,‘Reveille’and‘Arlen’,were phenotyped over three years(2016–2018)for fruit quality-related traits,including titratable acidity,pH,total soluble solids,and fruit weight.A high-density linkage map was constructed using 17k single nucleotide polymorphisms *** linkage map spanned a total of 1397 cM with an average inter-loci distance of 0.08 *** quantitative trait loci interval mapping based on the hidden Markov model identified 18 loci for fruit quality traits,including seven loci for fruit weight,three loci for titratable acidity,five loci for pH,and three loci for total soluble *** of these loci were detected in more than one *** loci explained phenotypic variance ranging from 7 to 28% for titratable acidity and total soluble solid,and 8-13% for ***,the loci identified for fruit weight did not explain more than 10%of the phenotypic *** also reported the association between fruit quality traits and metabolites detected by Proton nuclear magnetic resonance analysis directly responsible for these fruit quality *** acids,citric acid,and quinic acid were significantly(P<0.05)and positively correlated with titratable *** molecules showed a strong and positive correlation with total soluble ***,the study dissected the genetic basis of fruit quality traits and established an association between these fruit quality traits and metabolites.

关键词： cultivar linkage traits

An optimized protocol for stepwise optimization of real-time RT-PCR analysis

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Horticulture Research 2021年第1期8卷 2474-2494页

作者： Fangzhou Zhao Nathan A.Maren Pawel Z.Kosentka Ying-Yu Liao Hongyan Lu James R.Duduit Debao Huang hamid ashrafi Tuanjie Zhao Alejandra I.Huerta Thomas G.Ranney Wusheng Liu Soybean Research Institute Nanjing Agricultural University210095 NanjingChina Department of Horticultural Science North Carolina State UniversityRaleighNC 27607USA Mountain Crop Improvement Lab Department of Horticultural ScienceMountain Horticultural Crops Research and Extension CenterNorth Carolina State UniversityMills RiverNC 28759USA Department of Entomology and Plant Pathology North Carolina State UniversityRaleighNC 27607USA College of Biosystems Engineering and Food Science Zhejiang University310058 HangzhouChina

Computational tool-assisted primer design for real-time reverse transcription(RT)PCR(qPCR)analysis largely ignores the sequence similarities between sequences of homologous genes in a plant *** can lead to false confidence in the quality of the designed primers,which sometimes results in skipping the optimization steps for ***,the optimization of qPCR parameters plays an essential role in the efficiency,specificity,and sensitivity of each gene’s ***,we proposed an optimized approach to sequentially optimizing primer sequences,annealing temperatures,primer concentrations,and cDNA concentration range for each reference(and target)*** approach started with a sequence-specific primer design that should be based on the single-nucleotide polymorphisms(SNPs)present in all the homologous sequences for each of the reference(and target)genes under *** combining the efficiency calibrated and standard curve methods with the 2−ΔΔCt method,the standard cDNA concentration curve with a logarithmic scale was obtained for each primer pair for each *** a result,an R 2≥0.9999 and the efficiency(E)=100±5% should be achieved for the best primer pair of each gene,which serve as the prerequisite for using the 2^(−ΔΔCt) method for data *** applied our newly developed approach to identify the best reference genes in different tissues and at various inflorescence developmental stages of Tripidium ravennae,an ornamental and biomass grass,and validated their utility under varying abiotic stress *** also applied this approach to test the expression stability of six reference genes in soybean under biotic stress treatment with Xanthomonas axonopodis ***(Xag).Thus,these case studies demonstrated the effectiveness of our optimized protocol for qPCR analysis.

关键词： optimization analysis stepwise

Temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries on magnetic resonance imaging

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Neural Regeneration Research 2025年第11期20卷 3144-3150页

作者： Holly Flyger Samantha J.Holdsworth Alistair J.Gunn Laura Bennet hamid Abbasi Mātai Medical Research Institute Tairāwhiti GisborneNew Zealand Department of Anatomy&Medical Imaging Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand Center for Brain Research The University of AucklandAucklandNew Zealand Auckland Bioengineering Institute The University of AucklandAucklandNew Zealand

Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental *** assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and *** present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic *** review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent *** review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic *** challenges limit the timing consistency,particularly the need for intensive care and clinical ***,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain injury may continue to evolve for weeks after *** suggests that in the future it will be important to explore a wider range of times after hypo

关键词： magnetic resonance imaging neonatal hypoxic-ischemic encephalopathy neurodevelopmental outcomes prognostic biomarkers in neuroimaging scan timing therapeutic hypothermia

Characterization and corrosion behavior of Al-Co-rare earth(Ce-La)amorphous alloy

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Journal of Rare Earths 2023年第5期41卷 771-779,I0006页

作者： Seyed Ali Mousavi Sayed hamid Hashemi Ali ashrafi Reza Shoja Razavi Seyyed Mehdi Ghazi Mirsaeed Faculty of Materials and Manufacturing Technologies Malek Ashtar University of TechnologyTehran167885611Iran Department of Materials Engineering Malek Ashtar University of TechnologyIsfahanShahin-shahrIran Department of Materials Engineering Isfahan University of TechnologyIsfahan***Iran

A new Al-based amorphous alloy with excellent corrosion resistance and high thermal stability was produced in the Al-Co-RE(Ce-La)*** this regard,two different amorphous-nanocrystalline ribbons:Al_(87.6)-Co_(6.4)-Ce_(3.8-)La_(2.2)(M_(1))and Al_(82.3)-Co_(10.1)-Ce_(4.8)-La_(2.8)(M_(2))were prepared using melt *** results reveal the supercooled liquid region(ATx)of 218℃which shows that the M2alloy has higher thermal stability in comparison to the *** M2ribbons present the superior corrosion resistance because of the formation of amorphous *** icorr,Ecorr,Epit,and Epit-Ecorrvalues of fully amorphous Al-Co-Ce-La metallic ribbons have a better trend of anti-corrosion performance compared to other crystalline and amorphous aluminum alloys.

关键词： Amorphous alloys Melt-spinning Rare earth metal Corrosion behavior

A multiscale material model for heterogeneous liquid droplets in solid soft composites

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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1292-1299页

作者： hamid GHASEMI Department of Mechanical Engineering Arak University of TechnologyArak 38181-41167Iran

Liquid droplets in solid soft composites have been attracting increasing attention in biological *** contrary with conventional composites,which are made of solid elastic inclusions,available material models for composites including liquid droplets are for highly idealized configurations and do not include all material real *** are also all deterministic and do not address the uncertainties arising from droplet radius,volume fraction,dispersion and *** research revisits the available models for liquid droplets in solid soft composites and presents a multiscale computational material model to determine their elastic moduli,considering nearly all relevant uncertainties and heterogeneities at different length *** effects of surface tension at droplets interface,their volume fraction,size,size polydispersity and agglomeration on elastic modulus,are *** micromechanical material models are incorporated into the presented computational *** results clearly indicate both softening and stiffening effects of liquid droplets and show that the model can precisely predict the effective properties of liquid droplets in solid soft composites.

关键词： liquid in solid soft composite computational modeling multiscale model heterogeneity