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Polymer matrix nanocomposites for heavy metal adsorption: a review
, Article Journal of the Iranian Chemical Society ; Volume 17, Issue 6 , 31 January , 2020 , Pages 1259-1281 ; Keikavousi Behbahan, A ; Sharif University of Technology
Springer
2020
Abstract
Heavy metals belong to a group of lethal environmental pollutants. Ongoing efforts targeted at safeguarding public health have led to considerable attention being focused on methods that allow efficient extraction of these toxic substances. Polymer nanocomposites (PNCs) with their special characteristics are a class of adsorbents that demonstrate high potential for use in heavy metal extraction. As this process of removal is predominantly governed by adsorption, various parameters in PNCs’ chemical structure, as well as the metal solutions, can have a significant effect on the adsorption process. Herein, this review undertakes a survey of recently developed PNCs and their metal adsorption...
Analysis of alternative new pesticide (fluopyram, flupyradifurone, and indaziflam) residues in pistachio, date, and soil by liquid chromatography triple quadrupole tandem mass spectrometry
, Article Soil and Sediment Contamination ; Volume 30, Issue 4 , 2021 , Pages 373-383 ; 15320383 (ISSN) ; Keikavousi Behbahan, A ; Moradi, F ; Aboul Enein, H. Y ; Sharif University of Technology
Bellwether Publishing, Ltd
2021
Abstract
Fluopyram, flupyradifurone, and indaziflam are novel systemic pesticides developed by Bayer. Based on available data, these pesticides appears to have a favorable safety profile in the case of pesticide residue problems. Herein, we report an effective analytical method for the determination of novel pesticides were developed using ultra-high performance liquid chromatography with tandem mass spectrometry coupled with a quick, easy, cheap, effective, rugged, and safe procedure. These target compounds were extracted with acetonitrile and cleaned up with PSA, and were separated successfully between 10.2 and 18.3 min using a C18 chromatographic column connected to an electrospray ionization...
From waste to health: Application of MOF modified walnut biochars for the determination of twenty pesticides in wheat flour by ultra-high performance liquid chromatography-tandem mass spectrometry
, Article Food Chemistry ; Volume 405 , 2023 ; 03088146 (ISSN) ; Mahdavi, V ; Radpour, S ; Javanmardi, H ; Bagheri, H ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
In this research, walnut shell along with a Ni-metal organic framework (Ni-MOF) was thermally treated to obtain a highly efficient biochar. A µ-solid phase extraction (µ-SPE) setup containing the optimized walnut modified biochar was implemented for the extraction of 20 wheat specified pesticides with a wide range of polarities. The modified biochars were characterized and the role of Ni-MOF on the porosity of the obtained biochars was investigated. After optimizing the extraction parameters, the 50 %-Ni-MOF-walnut shell biochar was selected. Accordingly, the precision for intra-day (2.4–25 %), inter-day (7–28.3 %) and synthesis procedure (4.1–26.7 %) was calculated. The limits of detection...
Preparation and evaluation of various banana-based biochars together with ultra-high performance liquid chromatography-tandem mass spectrometry for determination of diverse pesticides in fruiting vegetables
, Article Food Chemistry ; Volume 360 , 2021 ; 03088146 (ISSN) ; Mahdavi, V ; Roustaei, Z ; Bagheri, H ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Biomass, originates from plant- or animal-based materials with a huge potential to be reused. Here we report a simple, rapid and inexpensive method for preparation of modified biochars derived from the banana peel followed by their applications in pipette-tip micro solid-phase extraction (PT-µSPE). Due to the contribution of various effective parameters on modification of banana peel biochars (BPBs), Taguchi design was used to optimize activation temperature, activation repetition, treatment material and impregnation ratio. Efficiency of the prepared BPBs were studied by extraction of twelve various pesticides, as model analytes with an extended range of log P values (1.4–5.7), followed by...
Surveying the hybrid of radiation and magnetic parameters on Maxwell liquid with TiO2 nanotube influence of different blades
, Article Heat Transfer ; Volume 51, Issue 6 , 2022 , Pages 4858-4881 ; 26884534 (ISSN) ; Fathollahi, R ; Pasha, P ; Mahmoudi, M ; Samimi Behbahan, A ; Domiri Ganji, D ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
In this paper, the impacts of Maxwell nanoliquid transmission, rectangular with titanium oxide nanoparticles are explored over the triangular, chamfer blades. The innovation of this paper is the use of the number of chamfers, rectangular, and triangular blades at the top and bottom of a stretched plate to study physical nanofluid parameters such as temperature and the effects of magnetism. Also, by determining the appropriate height and length for the blades, we achieve the best optimization of temperature and velocity of nanofluid between the plate and the blades, which improves heat transfer and with a more and better effect of magnetic effects. The finite element method is utilized for...
Preparation of Herbal Biomass as Extractive Phases for Trace Determination of Pesticides
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Habib (Supervisor) ; Mahdavi, Vahideh (Supervisor)
Abstract
The main approach of this thesis is to study the performance and efficiency of agricultural biomass derived extractive phases in sample preparation methods. In this regard, different types of agricultural biomasses and various important factors in the production of biochar from biomass were studied by two physical and chemical methods. Accordingly, different types of biochars have been made and applied in different extraction setups along with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and gas chromatography-electron capture (GC-ECD) to detect agricultural pesticides. Also, validated developed methods were used to investigate the safety of some highly...
Recent advances in ageing of 7xxx series aluminum alloys: A physical metallurgy perspective
, Article Journal of Alloys and Compounds ; Volume 781 , 2019 , Pages 945-983 ; 09258388 (ISSN) ; Taheri, A. K ; Taheri, K. K ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Al-Zn-Mg-Cu alloys (7xxx series Al alloys) are extensively used for their superior mechanical and corrosion performance. These properties are microstructure-sensitive and highly dependent on the formation, growth and coarsening of precipitates. To date, a wide variety of ageing procedures have been developed to tailor the evolved microstructures so as to yield a good combination of mechanical capacity and corrosion resistance of 7xxx series Al alloys. Among these methods, isothermal ageing, multi-stage ageing, non-isothermal ageing, retrogression and re-ageing (RRA), and stress ageing (i.e. creep ageing) are the most significant. In the present review, all of these approaches are...
Faster Algorithms for Quantitative Analysis of MCs and MDPs with Small Treewidth
, Article 18th International Symposium on Automated Technology for Verification and Analysis, ATVA 2020, 19 October 2020 through 23 October 2020 ; Volume 12302 LNCS , 2020 , Pages 253-270 ; Chatterjee, K ; Kafshdar Goharshady, A ; Mohammadi, K ; Pavlogiannis, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2020
Abstract
Discrete-time Markov Chains (MCs) and Markov Decision Processes (MDPs) are two standard formalisms in system analysis. Their main associated quantitative objectives are hitting probabilities, discounted sum, and mean payoff. Although there are many techniques for computing these objectives in general MCs/MDPs, they have not been thoroughly studied in terms of parameterized algorithms, particularly when treewidth is used as the parameter. This is in sharp contrast to qualitative objectives for MCs, MDPs and graph games, for which treewidth-based algorithms yield significant complexity improvements. In this work, we show that treewidth can also be used to obtain faster algorithms for the...
A self-organizing multi-model ensemble for identification of nonlinear time-varying dynamics of aerial vehicles
, Article Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering ; Volume 235, Issue 7 , 2021 , Pages 1164-1178 ; 09596518 (ISSN) ; Ahmadi, K. K. A ; Sharif University of Technology
SAGE Publications Ltd
2021
Abstract
This article presents a novel identification approach which can deal with nonlinear and time-varying characteristics of complex dynamic systems, especially an aerial vehicle in the entire flight envelope. A set of local sub-models are first developed at different operating points of the system, and subsequently a self-organizing multi-model ensemble is introduced to aggregate the outputs of the local models as a single model. The number of employed local models in the proposed multi-model ensemble is optimized using a novel self-organizing approach. Also, wavelet neural networks, which combine both the universal approximation property of neural networks and the wavelet decomposition...
Influence of heat treatment and aging on microstructure and mechanical properties of Mg-1.8Zn-0.7Si-0.4Ca alloy
, Article Materialwissenschaft und Werkstofftechnik ; Volume 50, Issue 2 , 2019 , Pages 187-196 ; 09335137 (ISSN) ; Taheri, K. K ; Taheri, A. K ; Shaeri, M. H ; Sharif University of Technology
Wiley-VCH Verlag
2019
Abstract
In order to optimize the aging treatment of Mg-1.8Zn-0.7Si-0.4Ca alloy, different times and temperatures of solid solution and age hardening were applied to the alloy specimens. Microstructures and mechanical properties of the specimens were investigated using the optical microscopy, field emission scanning electron microscopy equipped with an energy dispersive x-ray spectrometer, x-ray diffraction, hardness, and shear punch tests. The lowest hardness and strength were achieved by solution treating of the alloy at 500 °C for 8 h, presenting the optimal condition for solution treatment of the alloy. The microstructural examinations revealed three different precipitates consisting of CaMgSi,...
Solute redistribution during transient liquid phase bonding of IN738LC with BNi-3 interlayer
, Article Materials Science and Technology ; Volume 24, Issue 4 , 2008 , Pages 449-456 ; 02670836 (ISSN) ; Ekrami, A ; Ohsasa, K ; Matsuura, K ; Sharif University of Technology
2008
Abstract
Redistribution of alloying elements in the transient liquid phase (TLP) bonding zone of IN738LC/ BNi-3/IN738LC was studied to investigate microstructural evolution in this area. Wavelength dispersive spectrometry and electron probe microanalysis revealed that, during non-isothermal solidification in the TLP bonding zone, enrichment of residual liquid phase with the positive segregating elements caused formation of intermetallic in the bonding zone. Scanning electron microscopy observation Indicated that the redistribution of alloying elements, between TLP bonding zone and base alloy, resulted In formation of a γ′ boundary layer, containing high density of fine γ′, around the bonding zone....
Microstructural evolution in the transient-liquid-phase bonding area of IN-738LC/BNi-3/IN-738LC
, Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 39, Issue 10 , 2008 , Pages 2389-2402 ; 10735623 (ISSN) ; Ekrami, A ; Ohsasa, K ; Matsuura, K ; Sharif University of Technology
2008
Abstract
Transient-liquid-phase (TLP) bonding of the IN-738LC base alloy with BNi-3 interlayer was investigated in this article. Effects of the TLP bonding thermal cycle on the base alloy were studied microstructurally and macrostructurally. Microscopic investigation revealed that the microstructural evolution in the TLP bonding area was affected substantially by the bonding temperature. Therefore, a critical bonding temperature (Tcr) was defined for TLP bonding of IN-738LC/ BNi-3/IN-738LC samples. Unlike bonding below Tcr, TLP bonding at temperatures higher than Tcr resulted in formation of individual γ-γ' colonies in the adjacent base alloy to TLP bonding zone and caused significant reduction in...
Influence of Mold Preheating and Silicon Content on Microstructure and Casting Properties of Ductile Iron in Permanent Mold
, Article Journal of Iron and Steel Research International ; Volume 18, Issue 3 , 2011 , Pages 34-39 ; 1006706X (ISSN) ; Behnam, A. A ; Sharif University of Technology
2011
Abstract
The effects of the mold preheating and the silicon content of ductile iron on the percentage of carbides, graphite nodule counts and shrinkage volume were investigated. The results showed that the percentage of carbides and the shrinkage volume decreased when the mold preheating increased. The ductile iron with the carbon equivalent of 4.45% and the silicon content of 2.5% without any porosity defects was achieved when the mold preheating was 450 °C. Increasing the silicon content in the range of 2.1%-3.3% led to the increase in graphite nodule count and graphite size and the decrease in percentage of carbides. It is due to the increase in induced expansion pressure during the graphite...
Circuit model for periodic array of slits with multiple propagating diffracted orders
, Article IEEE Transactions on Antennas and Propagation ; Vol. 62, Issue 8 , August , 2014 , pp. 4041-4048 ; ISSN: 0018-926X ; Shirmanesh, G. K ; Khavasi, A ; Mehrany, K ; Sharif University of Technology
2014
Abstract
We propose an analytical circuit model for accurate analysis of one-dimensional periodic array of metallic strips. The proposed model is valid not only in subwavelength regime, but also for wavelengths shorter than the period of structure. The working frequency can reach the visible range and thus electromagnetic properties of periodic arrays of nano-slits can be analyzed by the proposed model. The proposed model remains valid for arbitrary incident angles even when nonspecular diffracted orders become propagating. Analytical expressions are derived explicitly in order to describe the parameters of the proposed circuit model. The circuit model is derived by assuming that only one guided mode...
Displacement ratios for structures with material degradation and foundation uplift
, Article Bulletin of Earthquake Engineering ; Volume 17, Issue 9 , 2019 , Pages 5133-5157 ; 1570761X (ISSN) ; Vafaei, A ; Kildashti, K ; Hamidia, M ; Sharif University of Technology
Springer Netherlands
2019
Abstract
In this paper, combined effects of material degradation, p-delta, and foundation uplift are incorporated in a soil-structure-interaction (SSI) framework to assess seismic response of a single-degree-of-freedom system. The considered phenomenological systems represent a column with a lumped mass on top is placed on a rigid foundation. The foundation is mounted on Winkler springs and dashpots to take account of soil-foundation compliance and material/radiation damping. The springs are tensionless to guarantee that uplift is properly modelled. The model is verified for two specific limit cases with the code and literature to make sure that the model is capable of capturing SSI and foundation...
Screening at doped nanotube junctions beyond linear response
, Article Physical Review B - Condensed Matter and Materials Physics ; Volume 65, Issue 16 , 2002 , Pages 1654151-1654155 ; 01631829 (ISSN) ; Esfarjani, K ; Esfarjani, K ; Mikami, M ; Sharif University of Technology
2002
Abstract
Screening length at doped nanotube junctions, which is of primary importance in device applications, has been a controversial issue. Employing a fully self-consistent tight-binding approach, we show that, for both sharp and smooth external potential drops, the screening length is of the order of a few carbon-ring separations. This rather strong screening of the Coulomb interaction is accompanied by the oscillation of transferred charge at the junction, and is observed for both semiconducting and metallic tubes despite minor differences
Modular framework kinematic and fuzzy reward reinforcement learning analysis of a radially symmetric six-legged robot
, Article Life Science Journal ; Volume 10, Issue SUPPL 8 , 2013 , Pages 120-129 ; 10978135 (ISSN) ; Osguie, K. G ; Khayyat, A. A. A ; Sharif University of Technology
2013
Abstract
Hexapod robots gives us the ability to study walking robots without facing problems such as stability in many aspects. It has a great deal of flexibility in movement even if a leg becomes malfunctioned. Radially symmetric (hexagonal) hexapods have more flexibility in movement than rectangular leg alignments. Because of symmetry they can move in any direction and time efficiently. Inverse kinematic problem of this kind of hexapods is solved through a modular mobile view considering six degrees of freedom for the trunk. Then typical tripod and wave gaits are analyzed and simulated through the presented formulation. In Reinforcement Learning algorithm for walking it is important how to make...
Accuracy versus run time in an adiabatic quantum search
, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 82, Issue 5 , 2010 ; 10502947 (ISSN) ; Pimachev, A. K ; Lidar, D. A ; Sharif University of Technology
2010
Abstract
Adiabatic quantum algorithms are characterized by their run time and accuracy. The relation between the two is essential for quantifying adiabatic algorithmic performance yet is often poorly understood.We study the dynamics of a continuous time, adiabatic quantum search algorithm and find rigorous results relating the accuracy and the run time. Proceeding with estimates, we show that under fairly general circumstances the adiabatic algorithmic error exhibits a behavior with two discernible regimes: The error decreases exponentially for short times and then decreases polynomially for longer times.We show that the well-known quadratic speedup over classical search is associated only with the...
Investigating the injury severity of single-vehicle truck crashes in a developing country
, Article Accident Analysis and Prevention ; Volume 137 , 2020 ; Shamshiripour, A ; Samimi, A ; Mohammadian, A. K ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Trucking plays a vital role in economic development in every country, especially countries where it serves as the backbone of the economy. The fast growth of economy in Iran as a developing country has also been accompanied by an alarming situation in terms of fatalities in truck-involved crashes, among the drivers and passengers of the trucks as well as the other vehicles involved. Despite the sizable efforts to investigate the truck-involved crashes, very little is known about the safety of truck movements in developing countries, and about the single-truck crashes worldwide. Thus, this study aims to uncover significant factors associated with injury severities sustained by truck drivers...
A new analysis method of the dry sliding wear process based on the low cycle fatigue theory and the finite element method
, Article Journal of Materials Engineering and Performance ; Vol. 23, issue. 3 , 2014 , pp. 1096-1106 ; ISSN: 10599495 ; Taheri, A. K ; Bakhtiarydavijani, A ; Sharif University of Technology
2014
Abstract
In the present work, a combination of a dynamic explicit finite element model and the low cycle fatigue theory is used to simulate the steady-state abrasive wear occurring between an as-cast eutectoid steel and a carbide-tungsten disk. While the low cycle fatigue theory has been used to model wear in softer non-ferrous alloys, this work shows its applicability and accuracy for use in harder alloys, such as the eutectoid steel used in this research which is strengthened with added chromium. The novelty of this work lies in calculating the Manson-Coffin relation constants from a coupled finite element model with experimental tests instead of the previously used Slip line method. The D...