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Microstructural evolution,mechanical properties,and corrosion resistance of a heat-treated Mg alloy for the bio-medical application

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Journal of Magnesium and Alloys 2019年第1期7卷 80-89页

作者： Mohammad Janbozorgi Kimia Karimi taheri ali Karimi taheri Department of Materials Science and Engineering Sharif University of TechnologyAzadi Ave.TehranIran School of Medicine Shahid Beheshti University of Medical ScienceTehranIran

During the recent years,some Mg based alloys have extensively been considered as a new generation of degradable and absorbable bio-medical *** this work,the Mg-2Zn-1Gd-1Ca(wt%)alloy as a new metallic bio-material was produced by the casting process followed by the heat *** samples of the alloy were solution treated at temperatures of 500,550,and 600°C and then quench aged at temperatures of 125,150,and 175°*** results of SEM-EDS examinations indicated that the alloy microstructure consists ofα-Mg matrix and the Ca_(2)Mg_(6)Zn_(3)and Mg_(3)Gd_(2)Zn_(3)secondary *** regard to the results of Vickers hardness test,the temperatures of 500°C and 150°C were selected as the optimum solutionizing and aging temperatures,***,the dissolution of casting precipitates and production of lattice distortion occurring after the solution treatment led to the reduction in ultimate shear strength up to 21%.But,the precipitation hardening and morphological changes taking place during the aging treatment improved the ultimate shear strength up to 32%.Furthermore,the results of electro-chemical and weight-loss measurements in a simulated body fluid indicated that the heat-treated alloy is a promising candidate for the Mg based alloys recently considered for the bio-medical applications.

关键词： Mg alloys Bio-medical applications Microstructural evolution Mechanical properties Corrosion resistance

Optimization of cement-based grouts using chemical additives

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 623-637页

作者： Mohammad Reza Azadi ali Taghichian ali taheri Faculty of Science and Technology Federation University Australia Mewbourne School of Petroleum and Geological Engineering University of Oklahoma Department of Earth Science and Engineering Imperial College

Grout injection is used for sealing or strengthening the ground in order to prevent water entrance or any failure after *** are many methods of *** grouting is one of the most common types in which the grout material is injected to the pore spaces of the *** grouting operations,the grout quality is important to achieve the best *** are four main characteristics for a grout mixture including bleeding,setting time,strength,and *** this paper,we try to build some efficient grouting mixtures with different water to cement ratios considering these *** ingredients of grout mixtures built in this study are cement,water,bentonite,and some chemical additives such as sodium silicate,sodium carbonate,and triethanolamine(TEA).The grout mixtures are prepared for both of the sealing and strengthening purposes for a structural *** of each abovementioned ingredient is profoundly *** each ingredient may have positive or negative aspect,an optimization of appropriate amount of each ingredient is *** optimization is based on 200 grout mixture samples with different percentages of ***,some of these grout mixtures are chosen for the introduced *** should be mentioned that grouting operations depend on various factors such as pressure of injection,ground structure and grain size of ***,quality of a grout can be helpful to make an injection easier and *** example,during the injection,a wrong estimated setting time can destroy the injected grout by washing the grout or setting early which prevents *** paper tries to show some tests in easy way to achieve a desirable sample of grout.

关键词： Permeation grouting Bleeding Setting time Chemical additives Cement-based grout

Hot deformation behavior of Fe-29Ni-17Co alloy

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Transactions of Nonferrous Metals Society of China 2013年第11期23卷 3271-3279页

作者： Mohammad YAZDANI Seyed Mehdi ABBASI ali Karimi taheri Amir MOMENI Department of Materials Science and Technology Sharif University of Technology Metallic Materials Research Center (MMRC-MA) Department of Materials Science and Engineering Hamedan University of Technology

Hot compression tests were carried out on a Fe-29Ni-17Co alloy in the temperature range of 900 ℃ to 1200 ℃ and at strain rates of 0.001-1 s-1. Dynamic recrystallization was found responsible for flow softening during hot compression. The flow behavior was successfully analyzed by the hyperbolic sine equation and the corresponding material constants A, n and αwere determined. The value of apparent activation energy was determined as 423 kJ/mol. The peak and steady state strains showed simple power-law dependence on the Zener-Hollomon parameter. The dynamic recrystallization kinetics was analyzed using Avrami equation and the corresponding exponent was determined to be about 2.7. This value, higher than 2 reported in the literatures, is associated with the mechanism of continuous dynamic recrystallization in the studied alloy. The flow curve up to the peak was modeled by the Cingara equation and the strain exponent, c, was determined about 0.85. The higher value of c compared with the value of 0.2 which has been reported for some stainless steels fortified the idea of extended dynamic recovery or continuous dynamic recrystallization in the studied alloy.

关键词： hot working dynamic recrystallization hot compression test flow curve modeling

Quantification of grain boundary effects on the geometrically necessary dislocation density evolution and strain hardening of polycrystalline Mg-4Al using in situ tensile testing in scanning electron microscope and HR-EBSD

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Journal of Magnesium and Alloys 2024年第5期12卷 1815-1829页

作者： Eunji Song Mohsen taheri Andani Amit Misra Department of Materials Science and Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering Texas A&M UniversityCollege StationTX 77843USA

In situ tensile testing in a scanning electron microscope(SEM)in conjunction with high-resolution electron backscatter diffraction(HR-EBSD)under load was used to characterize the evolution of geometrically necessary dislocation(GND)densities at individual grain boundaries as a function of applied strain in a polycrystalline Mg-4Al *** increase in GND density was investigated at plastic strains of 0%,0.6%,2.2%,3.3% from the area including 76 grains and correlated with(i)geometric compatibility between slip systems across grain boundaries,and(ii)plastic *** develop expressions for the grain boundary GND density evolution as a function of plastic strain and plastic incompatibility,from which uniaxial tensile stress-strain response of polycrystalline Mg-4Al are computed and compared with experimental *** findings in this study contribute to understanding the mechanisms governing the strain hardening response of single-phase polycrystalline alloys and more reliable prediction of mechanical behaviors in diverse microstructures.

关键词： Mg-Al alloys Grain boundaries Geometrically necessary dislocations Strain gradient plasticity HR-EBSD

Exergy Analysis of Charge and Discharge Processes of Thermal Energy Storage System with Various Phase Change Materials:A Comprehensive Comparison

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Journal of Thermal Science 2024年第2期33卷 509-521页

作者： Mojtaba taheri Fathollah POURFAYAZ Roghayeh HABIBI Akbar MALEKI Department of Renewable Energies and Environment Faculty of New Sciences and TechnologiesUniversity of TehranTehran***Iran Faculty of Mechanical Engineering Shahrood University of TechnologyShahrood***Iran

Thermal energy storage(TES) is of great importance in solving the mismatch between energy production and *** this regard,choosing type of Phase Change Materials(PCMs) which are widely used to control heat in latent thermal energy storage systems,plays a vital role as a means of TES ***,this field suffers from lack of a comprehensive investigation on the impact of various PCMs in terms of *** address this issue,in this study,in addition to indicating the melting temperature and latent heat of various PCMs,the exergy destruction and exergy efficiency of each material are estimated and compared with each ***,in the present work the impact of PCMs mass and ambient temperature on the exergy efficiency is *** results proved that higher latent heat does not necessarily lead to higher exergy ***,to obtain a suitable exergy efficiency,the specific heat capacity and melting temperature of the PCMs must also be *** to the results,LiF-CaF_(2)(80.5%:19.5%,mass ratio) mixture led to better performance with satisfactory exergy efficiency(98.84%) and notably lower required mass compared to other ***,the highest and lowest exergy destruction are belonged to GR25 and LiF-CaF_(2)(80.5:19.5) mixture,respectively.

关键词： exergy analysis phase change materials thermal energy storage exergy efficiency

Ethephon-Induced Abscission of “Redhaven” Peach

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American Journal of Plant Sciences 2012年第2期3卷 295-301页

作者： ali taheri John A. Cline Subramanian Jayasankar Peter K. Pauls Agriculture and Agri-Food Canada Saskatoon Research Centre 107 Science Place Saskatoon Canada University of Guelph Department of Plant Agriculture Guelph Canada. University of Guelph Department of Plant Agriculture Horticultural Experiment Station Simcoe Canada University of Guelph Department of Plant Agriculture Vineland Research Station Vineland Canada

Fruit size of peaches is an important quality factor that can be optimized by adjusting the number of fruit on the tree by hand thinning 40 - 60 days after full bloom (dafb). Hand thinning is labor intensive and therefore the development of other strategies to reduce production cost is warranted. Since ethylene plays a key role in peach fruitlet abscission, it is hypothesized that foliar applications of ethephon will induce fruit abscission and increase fruit size. Ethephon (0 to 400 mg·L–1) was applied to “Redhaven” peach trees 45 - 50 days after full bloom in 2005 and 2007 to determine the efficacy and concentration required to induce fruit abscission. Abscission was linearly related to ethephon concentration and as a result reduced fruit set by 70% to 100 %. These data indicate that ethephon in the range of 100 - 200 mg·L–1 can be used to induce adequate levels of fruit abscission of ‘Redhaven’ peaches without inducing trunk or limb gummosis.

关键词： Prunus Persica Fruit Size Ethylene Thinning Crop Load AVG

Evaluating the effect of montelukast tablets on respiratory complications in patients following blunt chest wall trauma:A double-blind,randomized clinical trial

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Chinese Journal of Traumatology 2023年第2期26卷 116-120页

作者： Soleyman Heydari Hadi Khoshmohabat ali taheri Akerdi Fathollah Ahmadpour Shahram Paydar Department of Surgery Baqiyatallah University of Medical SciencesTehranIran Trauma Research Center Baqiyatallah University of Medical SciencesTehranIran Trauma Research Center Shahid Rajaee(Emtiaz)Trauma HospitalShiraz University of Medical SciencesShirazIran

Purpose:Patients with multiple traumas are at high risk of developing respiratory complications,including pneumonia and acute respiratory distress *** pulmonary complications are associated with systemic inflammation and pulmonary neutrophilic ***-receptor antagonists are anti-inflammatory and anti-oxidant drugs subsiding airway *** present study investigates the effectiveness of montelukast in reducing pulmonary complications among trauma ***:This randomized,double-blind,placebo-control trial was conducted in patients with multiple blunt traumas and evidence of lung contusion detected via CT *** excluded patients if they met at least one of the following conditions:ality ***:In total,65 eligible patients (treatment = 31,placebo = 34) were included for the final *** treatment group had more pulmonary contusion volume (mean (SD),mm3) at the right (68726.97 (93656.54)vs.59730.27 (76551.74)) and the left side (67501.71 (91514.04)vs.46502.21 (80604.21)),higher initial C-reactive peptide level (12.16 (10.58)vs.10.85 (17.87)) compared to the placebo group,but the differences were not statistically significant (p > 0.05).At the end of the study,the mean (SD) of pulmonary contusion volume (mm3) (right side = 116748.74 (361705.12),left side = 64522.03 (117266.17)) of the treatment group were comparable to that of the placebo group (right side = 40051.26 (64081.56),left side = 25929.12 (47417.13),p = 0.228 and 0.082,respectively).Moreo

关键词： Acute respiratory distress syndrome Montelukast Leukotrienes Contusions Injuries

Remote condition monitoring of rail tracks using distributed acoustic sensing(DAS):A deep CNN-LSTM-SW based model

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Green Energy and Intelligent Transportation 2024年第5期3卷 70-85页

作者： Md Arifur Rahman Suhaima Jamal Hossein taheri The Laboratory for Advanced Non-Destructive Testing In-situ Monitoringand Evaluation(LANDTIE)Department of Manufacturing EngineeringGeorgia Southern UniversityStatesboro 30458GAUSA Information Technology Department Georgia Southern UniversityStatesboro 30458GAUSA

Railroad condition monitoring is paramount due to frequent passage through densely populated *** significance arises from the potential consequences of accidents such as train derailments,hazardous materials leaks,or collisions which may have far-reaching impacts on communities and the surrounding *** a solution to this issue,the use of distributed acoustic sensing(DAS)-fiber optic cables along railroads provides a feasible tool for monitoring the health of these extended ***,analyzing DAS data to assess railroad health or detect potential damage is a challenging *** to the large amount of data generated by DAS,as well as the unstructured patterns and substantial noise present,traditional analysis methods are ineffective in interpreting this *** paper introduces a novel approach that harnesses the power of deep learning through a combination of CNNs and LSTMs,augmented by sliding window techniques(CNN-LSTM-SW),to advance the state-of-the-art in the railroad condition monitoring *** well as it presents the potential for DAS and fiber optic sensing technologies to revolutionize the proposed CNN-LSTM-SW model to detect conditions along the rail track *** insights from the data of High tonnage load(HTL)-a 4.16 km fiber optic and DAS setup,we were able to distinguish train position,normal condition,and abnormal conditions along the ***,our investigation demonstrated that the proposed approaches could serve as efficient techniques for processing DAS signals and detecting the condition of railroad infrastructures at any remote distance with DAS-Fiber optic cable ***,in terms of pinpointing the train's position,the CNN-LSTM architecture showcased an impressive 97%detection *** a sliding window,the CNN-LSTM labeled data,the remaining 3%of misclassified labels have been improved dramatically by predicting the exact locations of each type of ***,these prop

关键词： Distributed acoustic sensing(DAS)-Fiber optic cable Railroad condition monitoring and anomaly detection High tonnage load(HTL) Convolutional neural network-long short-term memory-sliding window(CNN-LSTM-SW)

Phenotypic and genotypic detection of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from urinary tract infections in Zabol,Iran

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Journal of Coastal Life Medicine 2014年第9期 732-737页

作者： Saeide Saeidi Mehdi Ghamgosha Ramezan ali taheri Yasub Shiri Mahmood Solouki Kazem Hassanpour Gholamreza Farnoosh Department of Agronomy and Plant Breeding Agriculture Research CenterZabol UniversityZabolIran Neurosciences Research Center Baqiyatallah University of Medical SciencesTehranIran Nanobiotechnology Research Centre Baqiyatallah University of Medical SciencesTehranIran Department of Biotechnology Faculty of AgricultureZabol UniversityZabolIran Medical School Sabzevar University of Medical SciencesSabzevarIran Applied Biotechnology Research Centre Baqiyatallah University of Medical SciencesTehranIran

Objective:To investigate the role of a rapid polymerase chain reaction(PCR)assay in comparison with traditional empiric therapy in detection of extended spectrum β-lactamase(ESBL)producer Escherichia coli(***).Methods:Ninety isolates of *** from urinary tract infection were collected and screening of ESBL resistance using disc diffusion method,minimum inhibitory concentration(MIC)for ceftazidime and detection of TEM resistant gene by PCR were ***:The results of disc diffusion method showed that forty out of ninety *** isolates were ESBLs producing *** susceptibility of *** isolates to 9 antibacterial agents were ***,all isolated *** were resistant to all 9 antibacterial agents by these percentage:ceftriaxon(100%),ceftazidime(100%),amoxicillin(100%),erythromycin(100%),azithromycin(95%),cefixime(87.5%),tetracyclin(87.5%),nalidixic acid(85%)and difloxcain(75%).The abundance of antibiotic-resistant TEM gene according to PCR was 30%.Totally 82.5%of strains tested by MIC were observed as ***:We conclude that the TEM gene PCR assay is a rapid,sensitive and clinically useful test,particularly for the early detection of ESBLs-producing ***.

关键词： Antibiotic resistance Extended spectrumβ-lactamase TEM resistance gene Polymerase chain reaction Urinary tract infection E.coli