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Chinese Physics Letters 2012年第10期29卷 116-119页

作者： M.Erfanian Nakhchi M.R.h.Nobari h.basirat tabrizi Department of Mechanical Engineering Amirkabir University of Technology15875 TehranIran

Steady non-similarity thermal boundary layer flow over a stretching flat plate is *** velocity and temperature on the surface are assumed to vary with the *** energy equation is solved with the homotopy analysis method which is suitable for strongly non-linear *** approach is more general than the similarity methods and is valid in the whole spatial and temporal *** results are compared with the similarity solutions for special cases of velocity and temperature profiles on the *** effect of different parameters on the Nusselt number and temperature profiles is investigated.

关键词： problems similarity stretching

Green's function solution for transient heat conduction in annular fin during solidification of phase change material

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Applied Mathematics and Mechanics(English Edition) 2012年第10期33卷 1265-1274页

作者： A.h.MOSAFFA F.TALATI M.A.ROSEN h.basirat-tabrizi Faculty of Mechanical Engineering University of Tabriz Faculty of Engineering and Applied Science University of Ontario Institute of TechnologyL1H 7K4 OshawaOntarioCanada Department of Mechanical Engineering Amirkabir University of Technology

The Green＇s function method is applied for the transient temperature of an annular fin when a phase change material （PCM） solidifies on it. The solidification of the PCMs takes place in a cylindrical shell storage. The thickness of the solid PCM on the fin varies with time and is obtained by the Megerlin method. The models are found with the Bessel equation to form an analytical solution. Three different kinds of boundary conditions are investigated. The comparison between analytical and numerical solutions is given. The results demonstrate that the significant accuracy is obtained for the temperature distribution for the fin in all cases.

关键词： annular fin analytical solution Green's function phase change material(PCM) solidification thermal energy storage

Influences of the fluidizing and spouting pulsation on particle motion in spout-fluid beds

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Particuology 2018年第1期16卷 139-148页

作者： Maysam Saidi hassan basirat tabrizi Department of Mechanical Engineering Faculty of Engineering Razi University Kermanshah lran Department of Mechanical Engineering Amirkabir University of Technology Tehran lran

Effects of variable airflow on particle motion in spout-fluid beds are studied. Computational fluid dynam- ics using Navier-Stokes equations for the gas phase coupled with the discrete element method using Newton＇s laws for the solid phase have been employed. Results indicate that increasing the fluidizing velocity diminishes dead zones and increases both the total height of the bed and the traversed distance by particles in the steady spout-fluid bed. In pulsed airfows, two configurations are investigated, namely, the spouted pulsed-fluidized bed with pulsed flow of the fluidizing velocity, and the pulsed-spouted flu- idized bed with pulsed flow of the spouting velocity. The positive effect of pulsation on particle motion is shown and the effects of parameters, such as amplitude and frequency, on the dynamics of the bed are investigated in each configuration. An increase of up to 19% in traversed distance is found for the range studied, which suggests flow pulsation as a promising technique for increasing particle mixing in spout-fluid beds.

关键词： Computational fluid dynamics Discrete element method Flow pulsation Gas-solid Particle Spout-fluid bed

Thermal treatment effect on structural features of mechano-synthesized fluorapatite-titania nanocomposite: A comparative study

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Journal of Advanced Ceramics 2014年第1期3卷 31-42页

作者： Bahman NASIRI-tabrizi Materials Engineering Department Najafabad BranchIslamic Azad UniversityNajafabadIsfahanIran

The influence of thermal treatment on the structural features of mechano-synthesized fluorapatite-titania composite nanopowders was studied.A mixture of calcium and phosphate reagents was mixed with a certain amount of titania(20 wt%)and then was mechanically activated for 5 h,10 h and 15 h *** that,the mechano-synthesized powders were annealed at 700℃for 2 *** crystallite size of the composite nanopowders estimated from Williamson-hall method was in good agreement with transmission electron microscopy(TEM)*** electron microscopy(SEM)/TEM images confirmed the formation of a cluster-like composite which was composed of ellipse-like nanoparticles with an average size of about 16±7 nm after 15 h of *** the milling process,large variations in mechanochemical behavior of the CahPO_(4)-Ca(Oh)_(2)-CaF2-TiO_(2) system were *** the beginning of milling,no trace of the composite was found due to the lack of sufficient time for the mechanical *** the mechanical activation time increased to 15 h,composite nanopowders with the crystallite size of around 21.66 nm were *** heating at 700℃,the recovery of crystallinity occurred and the fraction of crystalline phase reached a maximum around 88.79%for the 10-h milled *** indicated that the structural features of the composite were strongly influenced by the subsequent annealing.

关键词： nanocomposite fluorapatite thermal treatment Williamson-hall method structural features

Characterization of mechanothermal-synthesized hydroxyapatite-magnesium titanate composite nanopowders

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Journal of Advanced Ceramics 2013年第1期2卷 63-70页

作者： Abbas FAhAMI Bahman NASIRI-tabrizi Materials Engineering Department Najafabad BranchIslamic Azad UniversityNajafabadIsfahanIran

hydroxyapatite-magnesium titanate composite nanopowders have been developed using a mechanothermal *** treatment of the milled powders at 700℃resulted in the formation of hAp/MgTiO_(3)-MgO nanocomposite.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy dispersive X-ray spectroscopy(EDX)techniques were utilized to characterize the synthesized *** results revealed that the dominant phases after mechanical activation were hydroxyapatite,anatase(TiO_(2))and periclase(MgO);while after thermal annealing process at 700℃,hydroxyapatite along with geikielite(MgTiO_(3))and periclase(MgO)were the major *** on the XRD analysis,the evaluation of structural features of the samples indicated that the average crystallite sizes of hydroxyapatite after 10 h of milling and subsequent thermal treatment at 700℃were about 21 nm and 34 nm,*** observations illustrated that the synthesized powders contained large agglomerates which consisted of significantly finer particles with spheroidal *** is concluded that the mechanothermal method can be used to produce hydroxyapatite-based nanocomposite with appropriate structural and morphological features.

关键词： hAp/MgTiO_(3)-MgO nanocomposite characterization methods mechanothermal

Mechanochemical preparation and structural characterization of Ta-doped chlorapatite nanopowders

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Progress in Natural Science:Materials International 2016年第6期26卷 546-554页

作者： Bahman Nasiri-tabrizi Wan Jefrey Basirun Belinda Pingguan-Murphy Advanced Materials Research Center Materials Engineering DepartmentNajafabad BranchIslamic Azad University Department of Chemistry Faculty of ScienceUniversity of Malaya Department of Biomedical Engineering Faculty of EngineeringUniversity of Malaya

Nanocrystalline tantalum-doped chlorapatite（Ta-doped ClA） was successfully synthesized using a facile mechanochemical method. In the absence of the dopant, milling for 3 h led to the formation of a poorly crystalline hydroxyapatite, while in its presence of the Ta dopant, Ta-doped ClA nanopowders were produced as a result of an oncoming reaction. The results indicated that lattice micro-strain, crystallite size, crystallinity level, phase percentage and hexagonal lattice constants of the substituted apatite nanopowders were dramatically affected by the doping concentration. The a-axis and unit cell volume increased with the increase in the doping concentration, owing to the ionic radius difference of Cl;and Oh;ions. From the TEM observations, the doped powders consisted of nanoneedles with a mean size of 60 ± 20 nm in length and 14 ±4 nm in width.

关键词： Mechano-synthesis Structural features Lattice constants XRD-Rietveld refinement Ta-doped ClA

Characterization of single-crystal fluorapatite nanoparticles synthesized via mechanochemical method

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Particuology 2011年第5期9卷 537-544页

作者： Reza Ebrahimi-Kahrizsangi Bahman Nasiri-tabrizi Akbar Cham Materials Engineering Department Najafabad Branch Islamic Azad University

The synthesis of nanostructured fiuorapatite （FA; Calo（PO4）6F2） was explored from the starting materials of CahPO4, Ca（Oh）2, CaO, P205 and CaF2 via a mechanochemical process. In this research, the suitability of using the mechanochemical process to prepare a high crystalline phase of FA was studied. The characterization and structural features of the synthesized powders were evaluated using powder X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, energy dispersive X-ray spectroscopy （EDX）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM） techniques. The results from the structural studies indicate that the maximum lattice disturbance in the apatite structure after the mechanochemical process was at the （0 0 2） plane. Furthermore, the maximum particle size was below the crystallite size after 60 h of milling and subsequent thermal treatment at 600 ℃ for 1 h （heated up to 600 ℃ and kept for 1 h at this temperature）. We determined that this method gives rise to the single-crystal FA with an average size in the range of 25 ± 5 to 29 ± 9 rim. The present findings suggest that the solid-state reaction and appropriate thermal process simultaneously lead to the formation of nanostructured FA with spheroidal shape.

关键词： Fluorapatite Single-crystal Nanoparticles Mechanochemical Crystallinity

Transcutaneous bilirubin nomogram for evaluating the risk of hyperbilirubinemia in Iranian healthy newborns

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World Journal of Pediatrics 2019年第1期15卷 72-77页

作者： Robabe Seyedi Mojgan Mirghafourvand Abdollah Jannat Dost Sakineh Mohammad-Alizadeh-Charandabi Mohammad Asghari Jafarabadi Shirin Osouli tabrizi Department of Midwifery Students Research CommitteeFaculty of Nursing and MidwiferyTabriz University of Medical Sciences.Tabriz.1ran Social Determinants of health Research Center Tabriz University of Medical SciencesTabrizIran Faculty of Medicine Tabriz University of Medical SciencesTabriz.Iran Midwifery Department Faculty of Nursing and MidwiferyTabriz University of Medical SciencesShariati-eqonobi Street.Tabriz 347-5 l 745.Iran Road Traffic Injury Research Center Faculty of HealthTabriz University of Medical SciencesTabrizIran

Background hyperbilirubinemia,which is mostly benign,is one of the most common problems in *** study was conducted to draw a skin bilirubin nomogram for evaluating the risk of hyperbilirubinemia requiring *** This cross-sectional study recruited 1066 healthy *** first transcutaneous bilirubin(TcB)measurement was performed before hospital discharge and within 12-48 h of *** neonates were followed up for 6 days after discharge based on their age at the time of *** neonates were divided into four groups based on the TcB values before discharge and age in hours,including the low-risk,medium-low-risk,medium-high-risk and high-risk *** percentage of neonates who progressed toward severe hyperbilirubinemia was then calculated in each percentile based on the follow-up TcB *** software was used to draw the *** on the TcB values at discharge and the neonate's age in hours,the skin bilirubin nomogram was drawn in 40,75 and 95 *** A total of 4.9%of the neonates were in the high-risk group,18.9%in the medium-high-risk group,34.8%in the medium-low-risk group and 41.2%in the low-risk *** risk of severe jaundice in the follow-up of the neonates in the highest-risk to the lowest-risk groups was 48.9,14.5,9.7 and 3.3%,*** The skin bilirubin nomogram can be used to predict severe hyperbilirubinemia in Iranian infants.

关键词： hyperbilirubinemia Iran Newborn Nomogram Transcutaneous bilirubin

Increased levels of miR-124 in human dental pulp stem cells alter the expression of neural markers

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Journal of Otology 2019年第4期14卷 121-127页

作者： Ameneh Mehri-Ghahfarrokhi Zahra Pourteymourfard-tabrizi Effat Farrokhi Morteza hashemzadeh Chaleshtori Mohammad-Saeid Jami Department of Molecular Medicine School of Advanced TechnologiesShahrekord University of Medical SciencesShahrekordIran Cellular and Molecular Research Center Basic Health Sciences InstituteShahrekord University of Medical SciencesShahrekordIran Department of Neurology David Geffen School of MedicineUniversity of California Los Angeles(UCLA)Los AngelesCAUSA

Auditory neuropathy is the particular form of deafness in humans which cannot be treated by replacement *** dental pulp stem cells(hDPSCs)are derived from an ectomesenchymal neural crest cell ***,they possess a promising capacity for neuronal differentiation and ***-124,a key regulator of neuronal development in the inner ear,is expressed at high levels in auditory and vestibular ***,we evaluated the possible effect of miR-124 in alteration of neural protein markers *** quantitative reverse transcription-PCR(qRT-PCR)analyses and immunofluorescence staining,we studied the expression patterns of neural progenitor markers(Nestin,NOTCh1,and SOX2)and neural markers(b-tubulin Ⅲ,GATA-3,and peripherin)upon transfection of hDPSCs with *** qRT-PCR results showed that Nestin was upregulated 6 h *** contrast,Nestin expression exhibited a decreasing trend 24 h and 48 h *** levels of b-tubulin Ⅲ,6 h and 16 h post transfection in RNA level as compared with control cells,were determined in transfected ***,b-tubulin-Ⅲ expression decreased 48 h *** immunoflourescence results indicated that transfection of hDPSCs with miR-124,only affected Nestin among the studied neural progenitor and neural marker expression in protein level.

关键词： Sensorineural hearing loss miR-124 Spiral ganglion neurons Nestin DPSCs