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Additive manufacturing of biodegradable magnesium-based materials:Design strategies,properties,and biomedical applications

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Journal of Magnesium and Alloys 2023年第3期11卷 801-839页

作者： Farzad Badkoobeh Hossein Mostaan mahdi rafiei Hamid Reza Bakhsheshi-Rad Seeram Rama Krishna Xiongbiao Chen School of Metallurgy and Materials Engineering College of EngineeringUniversity of TehranTehranIran Faculty of Engineering Department of Materials and Metallurgical EngineeringArak UniversityArakIran Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore 117576Singapore Department of Mechanical Engineering College of EngineeringUniversity of SaskatchewanSaskatoonSK S7N 5A9Canada

Magnesium(Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal *** addition to biodegradability,their inherent biocompatibility and similar-to-bone density make Mg-based alloys good candidates for fabricating surgical bioimplants for use in orthopedic and traumatology *** this end,nowadays additive manufacturing(AM)along with three-dimensional(3D)printing represents a promising manufacturing technique as it allows for the integration of bioimplant design and manufacturing processes specific to given ***,this technique also faces many new challenges associated with the properties of Mg-based alloys,including high chemical reactivity,potential for combustion,and low vaporization *** this review article,various AM processes to fabricate biomedical implants from Mg-based alloys,along with their metallic microstructure,mechanical properties,biodegradability,biocompatibility,and antibacterial properties,as well as various post-AM treatments were critically ***,the challenges and issues involved in AM processes from the perspectives of bioimplant design,properties,and applications were identified;the possibilities and potential scope of the Mg-based scaffolds/implants are discussed and highlighted.

关键词： Magnesium alloy Additive manufacturing 3D Printing Bone tissue engineering Scaffold Mechanical and biological properties

Role of interlayer composition in microstructure and mechanical properties during TLP bonding of GTD-111/IN-718 superalloys

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Transactions of Nonferrous Metals Society of China 2022年第3期32卷 908-926页

作者： Ali IZADI GHAHFEROKHI Masoud KASIRI-ASGARANI Kamran AMINI mahdi rafiei Reza EBRAHIMI-KAHRIZSANGI Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahanIran

An investigation was carried out to assess the applicability of transient liquid phase bonding of two dissimilar super-alloys with different interlayers. The effect of using three types of interlayer such as BNi-2, BNi-3, and BNi-9 on microstructure and mechanical properties was studied in the GTD-111/IN-718 system at 1100 ℃ for different bonding time. To determine the compositional changes and microstructure in the joint region, field emission scanning electron microscopy equipped with energy dispersive spectroscopy was utilized. The formation of Ni_(3)B in the athermally solidified zone(ASZ) is controlled by the B content and, accordingly, the morphology of Ni_(3)Si is governed by the Si content. The Cr content might impede the relocation of B from the interlayer into the base metal and the formation of CrB inside the ASZ is dominated by the Cr content. The high micro-hardness of the eutectic compounds is originated from the formation of boride matrixes such as Ni or Cr boride. The shear strength of the joint using BNi-9 after the completion of isothermal solidification is lower compared that that using BNi-3 and BNi-2, which could be related to the absence of Si in the filler metals constituent and the significant presence of Cr in BNi-9.

关键词： transient liquid phase bonding Ni-based superalloy isothermal solidification Ni-B compounds

Mechanical properties,corrosion behavior and biocompatibility of orthopedic pure titanium−magnesium alloy screw prepared by friction welding

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Transactions of Nonferrous Metals Society of China 2020年第11期30卷 2952-2966页

作者： Mojtaba Sadeghi GOGHERI Masoud KASIRI-ASGARANI Hamid Reza BAKHSHESHI-RAD Hamid GHAYOUR mahdi rafiei Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran

The dissimilar joining of biodegradable magnesium alloy to pure commercial titanium by rotational friction welding with rotational speeds of 1100,1200 and 1300 r/min for the production of bio-screw was *** metallographic analysis revealed that a good joining was obtained at the Ti/Mg alloy *** the magnesium alloy side,various regions such as the weld center zone(WCZ),dynamic recrystallization zone(DRX),thermo-mechanically affected zone(TMAZ)and partially deformed zone(PDZ)were *** highest tensile and shear strengths were 173 and 103.2 MPa,respectively at a rotational speed of 1300 r/*** Ti/Mg alloy dissimilar friction welded joint failed at the vicinity of the intermetallic zone containing Ti3Al *** hardness values from the base metal magnesium alloy to the joining point increased mainly due to grain refinement(8.57μm in diameter)and the presence of titanium particles,while the hardness values were constant on the titanium *** was also found that the corrosion rate of the Ti/Mg alloy joint was higher compared with that of the Ti and Mg alloy from the immersion ***,the sample with a rotational speed of 1300 r/min showed better biocompatibility and a cell viability of 98.12%due to better corrosion resistance.

关键词： Mg alloy pure commercial titanium friction welding shear strength biodegradability

Er_(2)TiO_(5)@Ag nanocomposites:Enhanced photocatalysis and bacteria inactivation,and cytotoxicity

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Journal of Rare Earths 2024年第5期42卷 851-858,I0002页

作者： Mehdi Nazeri Hossein Sedaghat Reza rafiei Mohammad Amin Farzin Seyed Mostafa Hosseinpour Mashkani Department of Parasitology and Mycology Kashan University of Medical SciencesKashanIran Department of Microbiology Kashan University of Medical SciencesKashanIran General Medicine Student School of MedicineKashan University of Medical SciencesKashanIran Student Research Committee Kashan University of Medical SciencesKashanIran Institute for Biomedical Materials and Devices School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyNSW2007Australia

In this study,we successfully synthesized Er_(2)TiO_(5)@Ag nanocomposites(NCPs) using the ultrasonicmediated sol-gel technique to create a multifunctional material with enhanced photocatalytic and antibacterial *** visible light photocatalytic activities of Er_(2)TiO_(5) nanoparticles(NPs) and Er_(2)TiO_(5)@Ag NCPs were systematically evaluated under various conditions,including different concentrations of Basic Blue 41(BB 41) dye and *** results reveal a remarkable improvement in the photocatalytic degradation efficiency of Er_(2)TiO_(5)@Ag NCPs(95%) compared to Er_(2)TiO_(5) NPs(80%).Furthermore,the antibacterial efficacy of Er_(2)TiO_(5) NPs and Er2TiO_5@Ag NCPs were extensively examined against Gram-positive and Gram-negative ***,Er_(2)TiO_(5)@Ag NCPs exhibit significantly higher minimum bactericidal concentration(MBC) values compared to Er_(2)TiO_(5) *** antibacterial effect of Er_(2)TiO_(5)@Ag NCPs is particularly pronounced against *** and Pseudomonas aeruginosa,while demonstrating moderate effects on Escherichia coli and Enterococcus *** assess the biocompatibility of the synthesized materials,we investigated their internalization by MCF-7 ***,both Er_(2)TiO_(5) NPs and Er_(2)TiO_(5)@Ag NCPs are found to be effectively internalized by the cells,suggesting their potential application in biomedical ***,our study unveils the exceptional potential of Er_(2)TiO_(5)@Ag NCPs as a dual-action solution,simultaneously possessing enhanced photocatalytic efficiency and potent antibacterial *** multifunctional nanocomposite not only outperforms Er_(2)TiO_(5) and Ag but also paves the way for innovative applications in sustainable environmental remediation and advanced biomedical technologies,promising a brighter and cleaner future.

关键词： Rare earth catalysis Nanocomposite Er_(2)TiO_(5)@Ag Antibacterial activity Photocatalysis Cytotoxicity

Factor of safety of strain-softening slopes

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 473-483页

作者： Hossein rafiei Renani C.Derek Martin Klohn Crippen Berger Ltd. VancouverCanada Department of Civil and Environmental Engineering University of AlbertaEdmontonCanada

Stability analysis of strain-softening slopes is carried out using the shear strength reduction method and Mohr-Coulomb model with degrading cohesion and friction *** e ffect of strain-softening behavior on the slope factor of safety is investigated by performing a series of analyses for various slope geometries and strength *** charts and equations are developed to estimate the factor of safety of strain-softe ning slopes from the results of traditional stability analysis based on perfectly-plastic *** example applications including an open pit mine in weak rock and clay shale slope with daylighting bedding planes are *** results of limit equilibrium analysis and shear strength reduction method with perfectly-plastic models were in close *** perfectly-plastic models with peak strength properties led to overly optimistic results while adopting residual strength properties gave excessively conservative *** shear strength reduction method with a strain-softening model gave realistic factors of safety while accounting for the process of strength degradation.

关键词： Slope stability analysis Factor of safety ratio Shear strength reduction Perfectly-plastic behavior Open pit slope Clay shale slope

Status of intestinal parasitic infections among rural and urban populations, southwestern Iran

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Asian Pacific Journal of Tropical Medicine 2019年第3期12卷 130-136页

作者： Molouk Beiromv Esmat Panabad Abdollah rafiei Infectious and Tropical Diseases Research Center Health Research Institute Ahvaz Jundishapur University of Medical Sciences Department of Parasitology School of Medicine Ahvaz Jundishapur University of Medical Sciences

Objective: To evaluate the prevalence and risk factors of intestinal parasitic infections in the urban and rural areas of Shushtar County,southwest ***: A total of 1 008 fecal samples were analyzed by direct smear examination,formalinether concentration,and Ziehl-Neelsen and trichrome staining; furthermore,PCR was used to distinguish Trichostrongylus and hookworm species based on 28 S rRNA ***: Totally,16.0% cases tested positive,either with a pathogenic or a non-pathogenic parasite. Protozoa were detected in 14.0%,helminths in 1.0%,protozoa and helminth coinfections were detected in 0.3%,and co-infections of two protozoa were detected in 0.7% of cases. The most common protozoa and helminths were Giardia duodenalis(7.7%) and Trichostrongylus spp.(0.5%),respectively. Among five microscopy Trichostrongylus positive cases,Trichostrongylus culbriformis was successfully identified in three isolates by sequencing. In the rural areas,the prevalence of parasitic infection was higher(9.8%) than that in the urban areas(6.2%). A significant association was found between educational level,type of drinking water,animals contact,hand-washing,and clinical symptoms. Conclusions: This study indicates that intestinal parasitic infections remain as a public health priority in Shushtar County. It seems that drinking water and environmental sanitation are the main risk factors of parasitic infections in rural areas.

关键词： Intestinal parasitic infections Risk factors Iran

Characteristic Assessment of Stabilized Polyacrylonitrile Nanowebs for the Production of Activated Carbon Nano-Sorbents

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Chinese Journal of Polymer Science 2014年第4期32卷 449-457页

作者： S.rafiei B.Noroozi Sh.Arbab A.K.Haghi Department of Textile Engineering University of Guilan

Polyacrylonitrile （PAN） nanofibers with average diameter of 300 nm were produced by electro-spinning. The nanofibers were stabilized at different temperatures in the range of 180-270 ℃in several duration times and heating rates. Fourier transforms infrared （FTIR） spectroscopy, differential scanning calorimetry （DSC） and X-ray diffraction （XRD） analyzing techniques were employed to measure the extent of stabilization reaction. By all procedures, the ranges of temperature and duration time recommended were about 250-270 ℃ and 1-2 h, respectively. Increasing the activation temperature from 800 ℃ to 1200 ℃ caused porosity and pore volume development up to 60% and 0.532 cm3/g, respectively. Pore width of all samples was calculated to be about 0.7 nm confirming micro-pore structure of the produced PAN based activated carbon nanofibers. Comparing dye adsorption for different adsorbents including chitin and granular activated carbon （GAC） showed the highest efficiency for the produced activated carbon nanofibers （ACNFs）.

关键词： Polyacrylonitrile Electro-spinning Stabilization Activated carbon nanofibers Adsorbent.

A dynamic credit risk assessment model with data mining techniques:evidence from Iranian banks

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Financial Innovation 2019年第1期5卷 240-266页

作者： Somayeh Moradi Farimah Mokhatab rafiei Science and Research Branch Islamic Azad UniversityTehranIran Tarbiat Modares University TehranIran

Giving loans and issuing credit cards are two of the main concerns of banks in that they include the risks of *** to the Basel 2 guidelines,banks need to develop their own credit risk assessment *** banks have such systems;nevertheless they have lost a large amount of money simply because the models they used failed to accurately predict customers’***,banks have used static models with demographic or static factors to model credit risk ***,economic factors are not independent of political fluctuations,and as the political environment changes,the economic environment evolves with *** has been especially evident in Iran after the 2008-2016 USA sanctions,as many previously reliable customers became unable to repay their debt(i.e.,became bad customers).Nevertheless,a dynamic model that can accommodate fluctuating politicoeconomic factors has never been *** this paper,we propose a model that can accommodate factors associated with politico-economic *** judgement is removed from the customer evaluation *** used a fuzzy inference system to create a rule base using a set of uncertainty ***,we train an adaptive network-based fuzzy inference system(ANFIS)using monthly data from a customer profile ***,using the newly defined factors and their underlying rules,a second round of assessment begins in a fuzzy inference ***,we present a model that is both more flexible to politico-economic factors and can yield results that are max compatible with real-life *** between the prediction made by proposed model and a real non-performing loan indicates little difference between *** risk specialists also approve the *** major innovation of this research is producing a table of bad customers on a monthly basis and creating a dynamic model based on the *** latest created model is used for assessing customers henceforth,so the whole pro

关键词： Fuzzy clustering Non-performing loan Credit risk FIS Dynamism ANFIS

Uncertainty analysis of hydrological modeling in a tropicalarea using different algorithms

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Frontiers of Earth Science 2018年第4期12卷 661-671页

作者： Ammar rafiei EMAM Martin KAPPAS Steven FASSNACHT Nguyen Hoang Khanh LINH Department of Cartography GIS and Remote SensingUniversity of Goettingen37077GoettingenGermany Colorado State University Fort CollinsCO 80523-1476USA Faculty of Land Resources and Agricultural Environment (FLRAE) Flue University of Agriculture and Forestry (F1UAF)Hue UniversityHue City 0084Vietnam

Hydrological modeling outputs are subject to uncertainty resulting from different sources of errors (e.g., error in input data, model structure, and model parameters), making quantification of uncertainty in hydrological modeling imperative and meant to improve reliability of modeling results. The uncertainty analysis must solve difficulties in calibration of hydrological models, which further increase in areas with data scarcity. The purpose of this study is to apply four uncertainty analysis algorithms to a semi-distributed hydrological model, quantifying different source of uncertainties (especially parameter uncertainty) and evaluate their performance. In this study, the Soil and Water Assessment Tools (SWAT) eco-hydrological model was implemented for the watershed in the center of Vietnam. The sensitivity of parameters was analyzed, and the model was calibrated. The uncertainty analysis for the hydrological model was conducted based on four algorithms: Generalized Likelihood Uncertainty Estimation (GLUE), Sequential Uncertainty Fitting (SUFI), Parameter Solution method (ParaSol) and Particle Swarm Optimization (PSO). The performance of the algorithms was compared using P-factor and Rfactor, coefficient of determination (R2), the Nash Sutcliffe coefficient of efficiency (NSE) and Percent Bias (PBIAS). The results showed the high performance of SUFI and PSO with P-factor>0.83, R-factor 0.91, NSE>0.89, and 0.18<0.32. Hence, we would suggest to use SUFI-2 initially to set the parameter ranges, and further use PSO for final analysis. Indeed, the uncertainty analysis must be accounted when the outcomes of the model use for policy or management decisions.

关键词： SWAT-CUP GLUE SUFI2 ParaSol PSO Vietnam