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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

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Structural insights of mechanically induced aluminum-doped hydroxyapatite nanoparticles by Rietveld refinement

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Chinese Journal of Chemical Engineering 2017年第2期25卷 238-247页

作者： Abbas Fahami bahman nasiri-tabrizi Gary W. Beall Wan Jefrey Basirun Materials Science Engineering and Commercialization Program Texas State University San Marcos 78666 TX USA Advanced Materials Research Center Materials Engineering Department Najafabad Branch Islamic Azad University Najafabad lsfahan lran Department of Chemistry and Biochemistry Texas State University San Marcos 78666 TX USA Physics Department Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia Department of Chemistry Faculty of Science University of Malaya150603 Kuala Lumpur Malaysia

Aluminum doped hydroxyapatite （HA：AI3 ＋） nanopowders were successfully prepared via a simple and efficient one-pot mechanochemical route. The effects of dopant loading on phase compositions and structural features were assessed by Rietveld analysis. The XRD-Rietveld refinement revealed the stabilization of HA in hexagonal structure for all the samples. The sharpness and intensity of the apatite-derived XRD peaks decreased as the dopant content increased to 10% due to the increase in lattice imperfections and mechanically induced amorphization. The incorpo- ration of A13 ＋ into the HA lattice decreased the unit cell parameters. From the FfiR measurements, the representing bands of apatite were identified in all cases. The mechanosynthesized nanopowders consisted of nanospheroids with an average size of 44 - 20 nm and therefore are promising for bone tissue regeneration.

关键词： SynthesisIon exchangeMechanochemicalRietveld refinement

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Structural Characterization of Nanocrystalline Ni(50-x)Ti50Cux(X = 5, 9 wt%) Alloys Produced by Mechanical Alloying

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Advances in Nanoparticles 2013年第2期2卷 71-77页

作者： bahman nasiri-tabrizi Abbas Fahami Materials Engineering Department Najafabad Branch Islamic Azad University Isfahan Iran

Nanocrystalline Ni(50-x)Ti50Cux(X = 5, 9 wt%) alloys were successfully produced by mechanical alloying. Mechanical activation was performed at different milling times under a high purity argon (99.998 vol%) atmosphere. Phase analysis and structural features of the samples were examined by X-ray diffraction (XRD). Results revealed that NiTiCu (B2) phase was achieved after 600 min of milling. The formation of this phase was mostly related to the critical factors in determining the site replacement of elements in Ni-Ti-Cu ternary system. After 600 min of milling, the average crystallite size and lattice strain of the samples were about 5 - 10 nm and 1.057% - 1.967%, respectively. Evaluation of the full width at half maximum (FWHM) values for all the samples indicated the occurrence of anisotropic line broadening. The determined amounts of crystallinity revealed that the fraction of crystalline phase decreased with increasing weight percentage of copper up to 9% and reached a minimum value after 600 min of milling. The lattice parameters and the unit cell volume of the milled samples were always larger than the standard values. In addition, lattice parameter deviation influenced by the weight percentage of copper. Based on the obtained data, mechanical alloying process can be used for production of nanocrystalline NiTiCu alloys with different structural features.

关键词： Nanocrystalline Alloy Mechanical Alloying Phase Analysis Structural Features

Real-time assessment of tunnelling-induced damage to structures within the building information modelling framework

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Underground Space 2024年第1期14卷 99-117页

作者： Jelena Ninic Ali Gamra bahman Ghiassi School of Engineering University of BirminghamB152TTUK Centre for Structural Engineering and Informatics The University of NottinghamNG72RDUK

During the initial design phases of complex multi-disciplinary systems such as urban tunnelling,the appraisal of different design alternatives can ensure optimal designs in terms of costs,construction time,and *** enable the evaluation of a large number of design scenarios and to find an optimal solution that minimises impact of tunnelling on existing structures,the design and assessment process must be efficient,yet provide a holistic view of soil-structure interaction *** paper proposes an integrated tunnel design tool for the initial design phases to predict the ground settlements induced by tunnelling and building damage using empirical and analytical solutions as well as simulation-based meta ***,visualisation of ground settlements and building damage risk is enabled by integrating empirical and analytical models within our Building Information Modelling(BIM)framework for *** approach allows for near real-time assessment of structural damage induced by settlements with consideration of soil-structure interaction and non-linear material ***,because this approach is implemented on a BIM platform for tunnelling,first,the design can be optimised directly in the design environment,thus eliminating errors in data exchange between designers and computational ***,the effect of tunnelling on existing structures can be effectively visualised within the BIM by producing risk-maps and visualising the scaled deformation field,which allows for a more intuitive understanding of design actions and for collaborative *** a fully parametric design model and real-time predictions therefore enables the assessment and visualisation of tunneling-induced damage for large tunnel sections and multiple structures in an effective and computationally efficient way.

关键词： Building information modelling Soil-structure interaction Tunnelling Settlements Structural damage Visualisation Meta models

Advances in Manta Ray Foraging Optimization:A Comprehensive Survey

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Journal of Bionic Engineering 2024年第2期21卷 953-990页

作者： Farhad Soleimanian Gharehchopogh Shafi Ghafouri Mohammad Namazi bahman Arasteh Department of Computer Engineering Urmia BranchIslamic Azad UniversityUrmiaIran Department of Computer Engineering Tabriz BranchIslamic Azad UniversityTabrizIran Department of Computer Engineering Maybod BranchIslamic Azad UniversityMaybodIran Department of Software Engineering Faculty of Engineering and Natural ScienceIstinye UniversityIstanbulTurkey

This paper comprehensively analyzes the Manta Ray Foraging Optimization(MRFO)algorithm and its integration into diverse academic *** in 2020,the MRFO stands as a novel metaheuristic algorithm,drawing inspiration from manta rays’unique foraging behaviors—specifically cyclone,chain,and somersault *** biologically inspired strategies allow for effective solutions to intricate physical *** its potent exploitation and exploration capabilities,MRFO has emerged as a promising solution for complex optimization *** utility and benefits have found traction in numerous academic *** its inception in 2020,a plethora of MRFO-based research has been featured in esteemed international journals such as IEEE,Wiley,Elsevier,Springer,MDPI,Hindawi,and Taylor&Francis,as well as at international conference *** paper consolidates the available literature on MRFO applications,covering various adaptations like hybridized,improved,and other MRFO variants,alongside optimization *** trends indicate that 12%,31%,8%,and 49%of MRFO studies are distributed across these four categories respectively.

关键词： Manta ray foraging optimization Metaheuristic algorithms Hybridization Improved Optimization

Enhanced axonal regeneration and functional recovery of the injured sciatic nerve in a rat model by lithium-loaded electrospun nanofibrous scaffolds

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Bio-Design and Manufacturing 2024年第5期7卷 701-720页

作者： Banafsheh Dolatyar bahman Zeynali Iman Shabani Azita Parvaneh Tafreshi Reza Karimi-Soflou Developmental Biology Laboratory School of BiologyCollege of ScienceUniversity of TehranTehran ***Iran Department of Biomedical Engineering Amirkabir University of Technology(Tehran Polytechnic)Tehran ***Iran Department of Molecular Medicine Faculty of Medical BiotechnologyNational Institute of Genetic Engineering and BiotechnologyTehran ***Iran 123

Increasing evidence indicates that engineered nerve grafts have great potential for the regeneration of peripheral nerve injuries(PNIs).While most studies have focused only on the topographical features of the grafts,we have considered both the biophysical and biochemical manipulations in our applied *** achieve this,we fabricated an electrospun nanofibrous scaffold(ENS)containing polylactide nanofibers loaded with lithium(Li)ions,a Wnt/β-catenin signaling *** addition,we seeded human adipose-derived mesenchymal stem cells(hADMSCs)onto this engineered scaffold to examine if their differentiation toward Schwann-like cells was *** further examined the efficacy of the scaffolds for nerve regeneration in vivo via grafting in a PNI rat *** results showed that Li-loaded ENSs gradually released Li within 11 d,at concentrations ranging from 0.02 to(3.64±0.10)mmol/L,and upregulated the expression of Wnt/β-catenin target genes(cyclinD1 and c-Myc)as well as those of Schwann cell markers(growth-associated protein 43(GAP43),S100 calcium binding protein B(S100B),glial fibrillary acidic protein(GFAP),and SRY-box transcription factor 10(SOX10))in differentiated *** the PNI rat model,implantation of Li-loaded ENSs with/without cells improved behavioral features such as sensory and motor functions as well as the electrophysiological characteristics of the injured *** improved function was further validated by histological analysis of sciatic nerves grafted with Li-loaded ENSs,which showed no fibrous connective tissue but enhanced organized myelinated *** potential of Li-loaded ENSs in promoting Schwann cell differentiation of hADMSCs and axonal regeneration of injured sciatic nerves suggests their potential for application in peripheral nerve tissue engineering.

关键词： Stem cell Schwann cell differentiation Electrospun nanofibrous scaffold Lithium ion Nerve regeneration

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Rank-dependent ppredictableforward performance processes

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Probability, Uncertainty and Quantitative Risk 2024年第2期9卷 181-218页

作者： bahman Angoshtari Shida Duan Department of Mathematics University of MiamiCoral Gables FL 33146USA

Predictable forward performance processes(PFPPs)are stochastic optimal control frameworks for an agent who controls a randomly evolving system but can only prescribe the system dynamics for a short period *** is a common scenario in which a controlling agent frequently re-calibrates her *** introduce a new class of PFPPs based on rank-dependent utility,generalizing existing models that are based on expected utility theory(EUT).We establish existence of rank-dependent PFPPs under a conditionally complete market and exogenous probability distortion functions which are updated *** show that their construction reduces to solving an integral equation that generalizes the integral equation obtained under EUT in previous *** then propose a new approach for solving the integral equation via theory of Volterra *** illustrate our result in the special case of conditionally complete Black-Scholes model.

关键词： Forward performance criteria Rank dependent utility Probability distortion Time consistency Inverse investment problems Volterra integral equations Completely monotonic inverse marginals