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The relationship between abduction deficit and reoperation among patients with infantile esotropia

International Journal of Ophthalmology(English edition) 2018年第3期11卷 478-483页

作者： Zhale Rajavi Hamideh Sabbaghi pooya.torkian Narges Behradfar Mehdi Yaseri Mohadeseh Feizi Mohammad Faghihi Kourosh Sheibani Ophthalmic Epidemiology Research Center Shahid Beheshti University of Medical Sciences Department of Ophthalmology School of Medicine Shahid Beheshti University of Medical Sciences Ophthalmic Research Center Shahid Beheshti University of Medical Sciences Department of Optometry School of Rehabilitation Shahid Beheshti University of Medical Sciences School of Medicine Shahid Beheshti University of Medical Sciences Department of Epidemiology and Biostatistics Tehran University of Medical Sciences Torfeh Eye Hospital Shahid Beheshti University of Medical Sciences Basir Eye Health Research Center Basir Eye Clinic

AIM： To determine the relationship between abduction deficit and reoperation among patients with infantile esotropia （IET）. METHODS： The records of 216 patients （432 eyes） with lET who underwent surgery, from 2010 to 2015 were studied. Patients with lET whose deviation appeared before 6mo of age and had stable preoperative deviation in two examinations with at least 2wk apart and a minimum 3too postoperative follow up were included. Cases with early onset accommodative esotropia, congenital cataract, retinopathy of prematurity （ROP）, manifest nystagmus, fundus lesions, neurologic and ophthalmic anomalies, 6th nerve palsy and Duane＇s syndrome were excluded. Preoperative abduction deficit was considered from -1 to -3 grading scale. Three months after surgery, children were classified into no-need reoperation [deviation〈15 prism diopters （PD）], and need-reoperation groups （deviaUon〉15 PD）. RESULTS： In this retrospective study, 117 female and 99 male patients with the mean surgical age of 4.7±6.4y were included. Reoperation rate was 33.3% and 16.0% in lET patients with and without abduction deficit, respectively in patients who had a history of late surgery. Abduction deficit increased the odds of reoperation by 82% [OR=1.82, 95% confidence interval （CI） =1.05 to 3.19, P=0.003] in patients who had a history of late surgery （〉2 years old, P=0.021）. Abduction deficit was improved significantly after operation （P〈0.001）. CONCLUSION： Based on our results, abduction deficit can be considered as a risk factor of reoperation in lET patients who are operated at the age of more than 2y.

关键词： infantile esotropia abduction deficit reoperation rate

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Topology optimization of shear wall structures under seismic loading

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Earthquake Engineering and Engineering Vibration 2020年第1期19卷 105-116页

作者： pooya Zakian Ali Kaveh Department of Civil Engineering Faculty of EngineeringArak UniversityArak 38156-8-8349Iran Centre of Excellence for Fundamental Studies in Structural Engineering Iran University of Science and TechnologyNarmakTehran-16Iran

A topology optimization formulation is developed to find the stiffest structure with desirable material distribution subjected to seismic loads. Finite element models of the structures are generated and the optimality criteria method is modified using a simple penalty approach and introducing fictitious strain energy to simultaneously consider both material volume and displacement constraints. Different types of shear walls with/without opening are investigated. Additionally, the effects of shear wall-frame interaction for single and coupled shear walls are studied. Gravity and seismic loads are applied to the shear walls so that the definitions provide a practical approach for locating the critical parts of these structures. The results suggest new viewpoints for architectural and structural engineering for placement of openings.

关键词： topology optimization seismic loads shear wall minimum compliance multiple constraints fi nite element analysis

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Hybrid algorithms for handling the numerical noise in topology optimization

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Acta Mechanica Sinica 2020年第2期36卷 536-554页

作者： pooya Rostami Javad Marzbanrad Vehicle Dynamical Systems Research Laboratory School of Automotive EngineeringIran University of Science and TechnologyNarmakTehranIran

This paper presents new hybrid methods for the identification of optimal topologies by combining the teaching-learning based optimization(TLBO)and the method of moving asymptotes(MMA).The topology optimization problem is parameterizing with a low dimensional explicit method called moving morphable components(MMC),to make the use of evolutionary algorithms more ***-based solvers have good performance in solving large-scale topology optimization ***,in unconventional cases same as crashworthiness design in which there is numerical noise in the gradient information,the uses of these algorithms are *** standard evolutionary algorithms can solve such problems since they don’t need gradient ***,they have a high computational *** paper is based upon the idea of combining metaheuristics with mathematical programming to handle the probable noises and have faster convergence *** to the ease of computations,the compliance minimization problem is considered as the case study and the artificial noise is added in gradient information.

关键词： Topology optimization Teaching-learning based optimization Method of moving asymptotes Moving morphable components

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Water chemistry influences on long-term dissolution kinetics of CdSe/ZnS quantum dots

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Journal of Environmental Sciences 2020年第4期32卷 216-233页

作者： pooya Paydary Philip Larese-Casanova Department of Civil and Environmental Engineering Northeastern UniversityBostonMAUSA

Widespread usage of engineered metallic quantum dots(QDs)within consumer products has evoked a need to assess their fate within environmental *** are mixed-metal nanocrystals that often include Cd2+which poses a health risk as a nanocrystal or when leached into *** goal of this work is to study the long-term metal cation leaching behavior and the factors affecting the dissolution processes of mercaptopropionic acid(MPA)capped CdSe/ZnS QDs in aphotic *** suspensions were prepared in different water conditions,and release of Zn2+and Cd2+cations were monitored over time by size exclusion chromatography-inductively coupled plasm a-mass *** most conditions with dissolved 02 present,the ZnS shell degraded fairly rapidly over^1 week,while some of the CdSe core remained up to 80 *** MPA,Zn2+,and Cd2+temporarily delayed dissolution,indicating a moderate role for capping agent detachment and mineral *** presence of H2 O2 and the ligand ethylenediaminetetraacetate accelerated dissolution,while NOM had no kinetic *** dissolution of CdSe core was observed when 02 was absent or when QDs formed aggregates at higher concentrations with 02 *** shrinking particle model with product layer diffusion control best describes Zn2+and Cd2+dissolution *** longevity of QDs in their nanocrystal form appears to be partly controlled by environmental conditions,with anoxic,aphotic environments preserving the core mineral phase,and oxidants or complexing ligands promoting shell and core mineral dissolution.

关键词： Quantum dots CdSe/ZnS Dissolution kinetics Shrinking particle model Size exclusion chromatography Inductively coupled plasma mass spectrometry

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Finite element simulation for elastic dislocation of the North-Tehran fault:The effects of geologic layering and slip distribution for the segment located in Karaj

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 533-549页

作者： pooya ZAKIAN Hossein ASADI HAYEH Department of Civil Engineering Faculty of EngineeringArak UniversityArak 38156-88349Iran

The present study uses the finite element method for simulating the crustal deformation due to the dislocation of a segment of the North-Tehran fault located in the Karaj metropolis *** this regard,a geological map of Karaj that includes the fault segment is utilized in order to create the geometry of finite element ***,finite element analysis of homogeneous counterpart of the fault’s domain with two different sections was performed,and the results were compared to those of Okada’s analytical *** fault was modeled with the existing heterogeneity of the domain having been *** influences of both uniform and non-uniform slip distributions were ***,three levels of simplification for geometric creation of geological layers’boundaries were defined in order to evaluate the effects of the geometric complexity of the geological layering on the displacement responses obtained with the finite element *** addition to the assessment of slip distribution,layering complexity and heterogeneity,the results demonstrate both the capability and usefulness of the proposed models in the dislocation analysis for the Karaj segment of North-Tehran fault.

关键词： finite element method fault dislocation slip distribution the North-Tehran fault heterogeneity geological layering

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Mechanical properties and in vivo biodegradability of Mg-Zr-Y-Nd-La magnesium alloy produced by a combined severe plastic deformation

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Rare Metals 2021年第3期40卷 651-662页

作者： A.torkian G.Faraji M.S.Pedram School of Mechanical Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran Department of Veterinary Surgery and Radiology Faculty of Veterinary MedicineUniversity of Tehran14199-63111Iran

Permanent implants are going to be replaced by the implementation of biodegradable magnesium-based implants in fixation of internal bone fractures because of many concerns associated with conventional ***,biodegradable magnesium-based biomaterials exhibit higher biodegradation rate and low mechanical properties which are the main *** work aims to almost overcome both disadvantageous by grain refining of a WE43 magnesium alloy containing 93.04 wt% Mg,4.12 wt% Y,2.15 wt% Nd,0.43 wt% Zr,and 0.26 wt%*** this study,the consequences of combined severe plastic deformation(SPD) on the mechanical properties,microstructure,and in vivo degradation behavior of WE43 magnesium alloy were *** do so,WE43 magnesium alloy was chosen and processed through multipass equal channel angular pressing(ECAP) at 330℃ for up to four passes followed by an extrusion *** results showed that higher strength and hardness with minimum ductility less was obtained in the sample processed via two-pass ECAP followed by *** vivo biodegradation experiments showed higher degradation rate for the unprocessed coarse-grained(CG) WE43 *** two-pass ECAP and extruded sample with ultrafine-grained(UFG) structure exhibited the lowest in vivo biodegradation rate besides appropriate mechanical *** may be concluded that the WE43 magnesium alloy processed via two-pass ECAP and extrusion could be a very promising candidate for biodegradable implants from both mechanical and biocorrosion viewpoints.

关键词： Implant Severe plastic deformation WE43 Grain refinement Hardness Mechanical properties

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Diffusion-free valve for preprogrammed immunoassay with capillary microfluidics

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Microsystems & Nanoengineering 2023年第4期9卷 197-209页

作者： pooya Azizian Jasmina Casals-Terré Jordi Ricart Joan M.Cabot Energy and Engineering Department Leitat Technological CenterTerrassaBarcelonaSpain Mechanical Engineering Department Technical University of CataloniaTerrassaBarcelonaSpain

By manipulating the geometry and surface chemistry of microfluidic channels,capillary-driven microfluidics can move and stop fluids spontaneously without external ***,complex microfluidic circuits can be preprogrammed by synchronizing the capillary pressures and encoding the surface tensions of microfluidic chips.A key component of these systems is the capillary ***,the main concern for these valves is the presence of unwanted diffusion during the valve loading and activation steps that can cause *** this study,we design and validate a novel diffusion-free capillary valve:theπ-*** valve consists of a 3D structure and a void *** void acts as a spacer between two fluids to avoid direct *** the valve is triggered,the air trapped within the void is displaced by pneumatic suction induced from the capillary flow downstream without introducing a gas bubble into the *** proposed design eliminates diffusive mixing before valve *** simulation is used to study the function and optimize the dimensions of theπ-valve,and 3D printing is used to fabricate either the mould or the microfluidic chip.A comparison with a conventional valve(based on a constrictionexpansion valve)demonstrates that theπ-valve eliminates possible backflow into the valve and reduces the mixing and diffusion during the loading and trigger *** a proof-of-concept,this valve is successfully implemented in a capillary-driven circuit for the determination of benzodiazepine,achieving the successive release of 3 solutions in a 3Dprinted microfluidic chip without external *** results show a 40%increase in the fluorescence intensity using theπ-valve relative to the conventional ***,theπ-valve prevents cross-contamination,minimizes sample use,and facilitates a sophisticated preprogrammed release of fluids,offering a promising tool for conducting automated immunoassays applicable at point-of-

关键词： capillary steps eliminate

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A symmetric substructuring method for analyzing the natural frequencies of conical origami structures

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 203-210页

作者： Chenhao Lu Yao Chen Weiying Fan Jian Feng pooya Sareh Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education and National Prestress Engineering Research CenterSoutheast UniversityNanjing 211189China School of Engineering University of LiverpoolLiverpool L693BXUnited Kingdom Creative Design Engineering Lab(Cdel) School of EngineeringNewcastle UniversityNewcastle upon Tyne NE17RUUnited Kingdom Escuela Técnica Superior de Ingeniería y Diseño Industrial Universidad Politécnica de Madrid(UPM)Madrid 28012Spain

Conical origami structures are characterized by their substantial out-of-plane stiffness and *** investigations have commonly focused on the static characteristics of these lightweight ***,the efficient analysis of the natural vibrations of these structures is pivotal for designing conicalorigami structures with programmable stiffness and *** this paper,we propose a novel method to analyzethe natural vibrations of such structures by combining a symmetric substructuring method(SSM)and a gener-alized eigenvalue *** exploits the inherent symmetry of the structure to decompose it into a finiteset of repetitive *** doing so,we reduce the dimensions of matrices and improve computationalefficiency by adopting the stiffness and mass matrices of the substructures in the generalized eigenvalue *** element simulations of pin-jointed models are used to validate the computational results of the ***,the parametric analysis of the structures demonstrates the influences of the number of seg-ments along the circumference and the radius of the cone on the structural mass and natural frequencies of ***,we present a comparison between six-fold and four-fold conical origami structures anddiscuss the influence of various geometric parameters on their natural *** study provides a strategyfor efficiently analyzing the natural vibration of symmetric origami structures and has the potential to contributeto the efficient design and customization of origami metastructures with programmable stiffness.

关键词： Natural structural vibration Origami design Group theory Symmetric substructuring method(SSM) Generalized eigenvalue analysis

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微波辅助燃烧法制备镁铝尖晶石纳米粉体的研究(英文)

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无机材料学报 2011年第5期26卷 550-554页

作者： Leila torkian Mostafa M Amini Zohreh Bahrami Department of Applied Chemistry Islamic Azad University Department of Chemistry Shahid Beheshti University School of Chemistry Collage of ScienceUniversity of Tehran

Stoichiometric MgAl2O4 spinel nanoparticles were synthesized by microwave assisted combustion reaction from aluminium nitrate nanohydrate(Al(NO3)3.9H2O) and Sol-Gel prepared magnesium hydroxide(Mg(OH)2) in the presence of urea((NH2)2CO) as a fuel,in about 20 min of irradiation.X-ray diffraction(XRD) studies reveal that mi-crowave assisted combustion synthesis route yields single-phase spinel nanoparticles with larger crystalline size(around 75 nm) than other conventional heating *** electronic microscope(SEM) images show nanoparticles with spherical shape and homogenous *** surface area measurements(SBET) show crystals with 2.11 m2/g and 0.0033 mL/g pore volume.

关键词：微波辅助燃烧法制备镁铝尖晶石纳米粉体研究纳米材料

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Characterizing the influence of stress-induced microcracks on the laboratory strength and fracture development in brittle rocks using a finite-discrete element method-micro discrete fracture network FDEM-μDFN approach

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第6期7卷 609-625页

作者： pooya Hamdi Doug Stead Davide Elmo Simon Fraser University 8888 University Drive NBK Institute of Mining Engineering University of British Columbia

Heterogeneity is an inherent component of rock and may be present in different forms including mineralheterogeneity, geometrical heterogeneity, weak grain boundaries and micro-defects. Microcracks areusually observed in crystalline rocks in two forms： natural and stress-induced; the amount of stressinducedmicrocracking increases with depth and in-situ stress. Laboratory results indicate that thephysical properties of rocks such as strength, deformability, P-wave velocity and permeability areinfluenced by increase in microcrack intensity. In this study, the finite-discrete element method （FDEM）is used to model microcrack heterogeneity by introducing into a model sample sets of microcracks usingthe proposed micro discrete fracture network （mDFN） approach. The characteristics of the microcracksrequired to create mDFN models are obtained through image analyses of thin sections of Lac du Bonnetgranite adopted from published literature. A suite of two-dimensional laboratory tests including uniaxial,triaxial compression and Brazilian tests is simulated and the results are compared with laboratory *** FDEM-mDFN models indicate that micro-heterogeneity has a profound influence on both the mechanicalbehavior and resultant fracture pattern. An increase in the microcrack intensity leads to areduction in the strength of the sample and changes the character of the rock strength envelope. Spallingand axial splitting dominate the failure mode at low confinement while shear failure is the dominantfailure mode at high confinement. Numerical results from simulated compression tests show thatmicrocracking reduces the cohesive component of strength alone, and the frictional strength componentremains unaffected. Results from simulated Brazilian tests show that the tensile strength is influenced bythe presence of microcracks, with a reduction in tensile strength as microcrack intensity increases. Theimportance of microcrack heterogeneity in reproducing a bi-linear or S-shape failure

关键词： Finite-discrete element method(FDEM) Micro discrete fracture network(μDFN) Brittle fracture

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