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performance-assessment
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Seismic performance assessment of fixed offshore structures by endurance time method
, Article Ships and Offshore Structures ; Volume 14, Issue 7 , 2019 , Pages 709-722 ; 17445302 (ISSN) ; Mehdigholi, H ; Seif, M. S ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
The aim of this paper is to consider the ability of endurance time (ET) method to estimate the seismic response of fixed offshore platforms at various excitation levels. In this way, various sources of nonlinear behaviour and challenging issues in the ET approach are included in the three-dimensional model of a real jacket platform utilising the finite element method. In addition to common-designed, over-designed and under-designed cases of this platform have been investigated to examine the effects of the structural characteristics on the ET response. To consider the accuracy and reliability of this approach, results of the ET method are compared with results of nonlinear time history...
Seismic performance assessment of fixed offshore structures by endurance time method
, Article Ships and Offshore Structures ; Volume 14, Issue 7 , 2019 , Pages 709-722 ; 17445302 (ISSN) ; Mehdigholi, H ; Seif, M. S ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
The aim of this paper is to consider the ability of endurance time (ET) method to estimate the seismic response of fixed offshore platforms at various excitation levels. In this way, various sources of nonlinear behaviour and challenging issues in the ET approach are included in the three-dimensional model of a real jacket platform utilising the finite element method. In addition to common-designed, over-designed and under-designed cases of this platform have been investigated to examine the effects of the structural characteristics on the ET response. To consider the accuracy and reliability of this approach, results of the ET method are compared with results of nonlinear time history...
Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media
, Article Environmental Technology (United Kingdom) ; Volume 41, Issue 21 , 2020 , Pages 2750-2759 ; Allahyari, E ; Torresi, E ; Andersen, H. R ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
In this study, two moving-bed biofilm reactors (MBBR1 and MBBR2) filled with different size of carrier media (Kaldnes K1 and Kaldnes K1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m3·d) at different temperatures (26 and 15°C, in MBBR1 and MBBR2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR1, however, hydrolyzed uniformly within biofilm in...
seismic performance assessment of SMRF structures subjected to mainshock-aftershock seismic sequences by endurance time method
, Article Journal of Earthquake Engineering ; 2020 ; Estekanchi, H. E ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
Seismic performance of postmainshock buildings considering seismic mainshock-aftershock sequences are studied. The case studies correspond to three SAC steel MRF buildings of three, nine and twenty stories. The 2-D models are able to capture important properties of deterioration of strength and stiffness. Endurance time method is used to predict the response of structures in different hazard levels. Results are compared with those from of nonlinear incremental dynamic analysis. Maximum dynamic seismic responses of structures are captured during synthetic mainshock-aftershock seismic sequences which are produced by endurance time method. Interactional-conceptual curves for different seismic...
Value based seismic design of structures using performance assessment by the endurance time method
, Article Structure and Infrastructure Engineering ; Volume 16, Issue 10 , January , 2020 , Pages 1397-1415 ; Estekanchi, H. E ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
A framework for optimal seismic design of structures, considering maximum value as the design objective, is introduced. In this framework, the value parameter incorporates a comprehensive set of performance indicators. Decision indicators are mapped into equivalent economic values and are directly involved in the design process. This approach leads to optimal assignment of the available resources to meet infrastructure requirements. The construction cost and the risk of seismic consequences are considered as the value components. FEMA-P58 methodology is utilized in estimation of the seismic consequences including the repair cost, repair time, injuries and casualties. Endurance Time method is...
Application of mean-covariance regression methods for estimation of edp|im distributions for small record sets
, Article Journal of Earthquake Engineering ; 2021 ; 13632469 (ISSN) ; Rahimzadeh Rofooei, F ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
The performance of several regression methods is investigated to estimate the distribution of engineering demand parameters conditioned on intensity measures (EDP|IM) for small record sets. In particular, the performance of the multivariate ordinary least squares (OLS), a simultaneous mean-variance regression (MVR) done by a penalized weighted least-square loss function, and a mean-covariance/variance regression based on expectation maximization method (EM) are assessed. The efficiency of the introduced methods is compared with FEMA-P58 methodology. Performance assessment of EM and MVR methods shows that the overall increase in efficiency is about 25–45% for maximum inter-story drift ratios,...
Three-dimensional numerical analysis of corner effect of an excavation supported by ground anchors
, Article International Journal of Geotechnical Engineering ; Volume 16, Issue 7 , 2022 , Pages 903-915 ; 19386362 (ISSN) ; Ahmadi, M. M ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
This paper presents a case study and numerical simulations of a corner of a deep excavation in Tehran supported by soldier piles and ground anchors. This study focuses on the differences between 2D and 3D numerical modelling in estimating the wall deflection at the corner locations of the excavation. Furthermore, the performance of modelling with Mohr–Coulomb constitutive law was compared with the result of a hardening soil model. The modelling procedure was calibrated against a full-scale instrumented tieback wall at Texas A&M University and the monitoring data of the excavation project. The results indicated that the hardening soil model yields reasonable predictions of wall deflection in...
Investigation of photocatalytic performance of TiO2 network and fiber geometries
, Article Desalination and Water Treatment ; Volume 57, Issue 50 , 2016 , Pages 23644-23650 ; 19443994 (ISSN) ; Sadrnezhaad, S. K ; Kheilnejad, A ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In typical photocatalytic processes slurry reactors are used in which catalyst particles have to be separated from the solution after the process ends which means much higher time and costs. Hence, immobilizing process is carried out on the catalyst to overcome this problem. In this work, fiber and network geometries were produced by particle precipitation on substrates. The obtained structures were characterized by XRD, SEM, and Brunauer–Emmett–Teller analyses. Photocatalytic performance of the samples was investigated by methyl orange degradation and also by hydrogen generation from water/methanol splitting. From the SEM images, the size range of the TiO2 particles in the network...
Enhanced separation performance of PVDF/PAN blend membrane based on PVP tuning
, Article Desalination and Water Treatment ; Volume 57, Issue 26 , 2016 , Pages 12090-12098 ; 19443994 (ISSN) ; Safekordi, A ; Hemmati, M ; Rekabdar, F ; Tavakolmoghadam, M ; Azimi Yancheshme, A ; Gheshlaghi, A ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
Ultrafiltration (UF) membranes were prepared from blends of poly(vinylidene fluoride) (PVDF)/polyacrylonitrile (PAN) via phase inversion method induced by immersion precipitation. Polyvinylpyrrolidone (PVP) was used as pore former and hydrophilic polymeric additive. N,N-dimethylacetamide (DMAc) and water were used as solvent and coagulant (non-solvent), respectively. The effect of different concentrations of PVP on the morphology and performance of the prepared membranes was investigated. Performance of the membranes was evaluated based on pure water flux and filtration of buffered bovine serum albumin (BSA) solution. The contact angle measurements indicated that the hydrophilicity of...
Combined UV-C/H2O2-VUV processes for the treatment of an actual slaughterhouse wastewater
, Article Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes ; Volume 52, Issue 5 , 2017 , Pages 314-325 ; 03601234 (ISSN) ; Bustillo Lecompte, C. F ; Mehrvar, M ; Abdekhodaie, M. J ; Sharif University of Technology
Taylor and Francis Inc
2017
Abstract
In this study, a three-factor, three-level Box-Behnken design with response surface methodology were used to maximize the TOC removal and minimize the H2O2 residual in the effluent of the combined UV-C/H2O2-VUV system for the treatment of an actual slaughterhouse wastewater (SWW) collected from one of the meat processing plants in Ontario, Canada. The irradiation time and the initial concentrations of total organic carbon (TOCo) and hydrogen peroxide (H2O2o) were the three predictors, as independent variables, studied in the design of experiments. The multiple response approach was used to obtain desirability response surfaces at the optimum factor settings. Subsequently, the optimum...
Performance of the general circulation models in simulating temperature and precipitation over Iran
, Article Theoretical and Applied Climatology ; 2018 , Pages 1-19 ; 0177798X (ISSN) ; Moghim, S ; Abrishamchi, A ; Sharif University of Technology
Springer-Verlag Wien
2018
Abstract
General Circulation Models (GCMs) are advanced tools for impact assessment and climate change studies. Previous studies show that the performance of the GCMs in simulating climate variables varies significantly over different regions. This study intends to evaluate the performance of the Coupled Model Intercomparison Project phase 5 (CMIP5) GCMs in simulating temperature and precipitation over Iran. Simulations from 37 GCMs and observations from the Climatic Research Unit (CRU) were obtained for the period of 1901–2005. Six measures of performance including mean bias, root mean square error (RMSE), Nash-Sutcliffe efficiency (NSE), linear correlation coefficient (r), Kolmogorov-Smirnov...
Performance of the general circulation models in simulating temperature and precipitation over Iran
, Article Theoretical and Applied Climatology ; Volume 135, Issue 3-4 , 2019 , Pages 1465-1483 ; 0177798X (ISSN) ; Moghim, S ; Abrishamchi, A ; Sharif University of Technology
Springer-Verlag Wien
2019
Abstract
General Circulation Models (GCMs) are advanced tools for impact assessment and climate change studies. Previous studies show that the performance of the GCMs in simulating climate variables varies significantly over different regions. This study intends to evaluate the performance of the Coupled Model Intercomparison Project phase 5 (CMIP5) GCMs in simulating temperature and precipitation over Iran. Simulations from 37 GCMs and observations from the Climatic Research Unit (CRU) were obtained for the period of 1901–2005. Six measures of performance including mean bias, root mean square error (RMSE), Nash-Sutcliffe efficiency (NSE), linear correlation coefficient (r), Kolmogorov-Smirnov...
The extent of EFQM effectiveness in routine and non-routine organizations based on multivariate techniques: an empirical study
, Article Operational Research ; 2016 , Pages 1-31 ; 11092858 (ISSN) ; Noorossana, R ; Najmi, M ; Sharif University of Technology
Springer Verlag
2016
Abstract
Despite the fact that a variety of analyses are conducted based on the performance of business excellence models according to organization type such as ownership, size and etc., the performance of organizations based on the factor of being routine or non-routine has not been investigated yet. In this paper, implementation of the European Foundation for Quality Management (EFQM) model for these types of organizations (routine and non-routine) has been examined. In order to do that, first we have developed a methodology to classify organizations into routine and non-routine categories. Then we have used discriminant analysis based on three factors, including process uncertainty, knowledge...
The extent of EFQM effectiveness in routine and non-routine organizations based on multivariate techniques: an empirical study
, Article Operational Research ; Volume 19, Issue 1 , 2019 , Pages 237-267 ; 11092858 (ISSN) ; Noorossana, R ; Najmi, M ; Sharif University of Technology
Springer Verlag
2019
Abstract
Despite the fact that a variety of analyses are conducted based on the performance of business excellence models according to organization type such as ownership, size and etc., the performance of organizations based on the factor of being routine or non-routine has not been investigated yet. In this paper, implementation of the European Foundation for Quality Management (EFQM) model for these types of organizations (routine and non-routine) has been examined. In order to do that, first we have developed a methodology to classify organizations into routine and non-routine categories. Then we have used discriminant analysis based on three factors, including process uncertainty, knowledge...
Conceptual arrangement and basic design of drinking water reverse osmosis desalination plants
, Article International Journal of Environmental Science and Technology ; Volume 18, Issue 12 , 2021 , Pages 4019-4036 ; 17351472 (ISSN) ; Farhadi, F ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
To propose a conceptual arrangement of reverse osmosis desalination plants, four comprehensive decision algorithms and a software are developed. Typically, commercial software predict the performance of the reverse osmosis membranes based on their pre-determined configuration; however, the developed decision algorithms and the developed software in this study have the capability of introducing the conceptual arrangement of pretreatment units, reverse osmosis membranes, and energy recovery devices for both seawater and brackish water reverse osmosis plants. To perform a comprehensive study, alongside the developed software and the decision algorithms, both design considerations of the...
CO2 separation by supported liquid membranes synthesized with natural deep eutectic solvents
, Article Environmental Science and Pollution Research ; Volume 28, Issue 26 , 2021 , Pages 33994-34008 ; 09441344 (ISSN) ; Khan, A. L ; Gilani, M. A ; Aslam, M ; Khan, A. U ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Betaine-based natural deep eutectic solvents (NADESs), a new class of green solvents, were immobilized into a porous polyvinylidene fluoride (PVDF) support and evaluated for the separation of CO2 from CO2/N2 and CO2/CH4 mixtures. Two types of NADESs were synthesized by mixing betaine (hydrogen bond acceptor-HBA) with malic acid and tartaric acid (hydrogen bond donors-HBD) respectively. FTIR and Raman spectroscopy were studied to confirm the synthesis and purity of the NADESs. The thermal strength of the NADESs was investigated using thermogravimetric analysis. The gas permeation results of the fabricated NADES-based-supported liquid membranes (NADES-SLMs) showed that the permeability of CO2...
Trichloroethylene degradation by PVA-coated calcium peroxide nanoparticles in Fe(II)-based catalytic systems: enhanced performance by citric acid and nanoscale iron sulfide
, Article Environmental Science and Pollution Research ; Volume 28, Issue 3 , 2021 , Pages 3121-3135 ; 09441344 (ISSN) ; Shan, A ; Sun, Y ; Gu, X ; Lyu, S ; Zhou, Y ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide nanoparticles (PVA@nCP) as an oxidant in Fe(II)-based catalytic systems. The nanoscale iron sulfide (nFeS), having an average particle size of 115.4 nm, was synthesized in the laboratory and characterized by SEM, TEM, HR-TEM along with EDS elemental mapping, XRD, FTIR, ICP-OES, and XPS techniques. In only ferrous iron catalyzed system (PVA@nCP/Fe(II)), TCE degradation was recorded at 58.9% in 6 h. In comparison, this value was increased to 97.5% or 99.7% with the addition of citric acid (CA) or nFeS in PVA@nCP/Fe(II) system, respectively. A comparative...
Trichloroethylene degradation by PVA-coated calcium peroxide nanoparticles in Fe(II)-based catalytic systems: enhanced performance by citric acid and nanoscale iron sulfide
, Article Environmental Science and Pollution Research ; Volume 28, Issue 3 , 2021 , Pages 3121-3135 ; 09441344 (ISSN) ; Shan, A ; Sun, Y ; Gu, X ; Lyu, S ; Zhou, Y ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide nanoparticles (PVA@nCP) as an oxidant in Fe(II)-based catalytic systems. The nanoscale iron sulfide (nFeS), having an average particle size of 115.4 nm, was synthesized in the laboratory and characterized by SEM, TEM, HR-TEM along with EDS elemental mapping, XRD, FTIR, ICP-OES, and XPS techniques. In only ferrous iron catalyzed system (PVA@nCP/Fe(II)), TCE degradation was recorded at 58.9% in 6 h. In comparison, this value was increased to 97.5% or 99.7% with the addition of citric acid (CA) or nFeS in PVA@nCP/Fe(II) system, respectively. A comparative...
Evaporation mitigation assessment by self-assembled nano-thickness films in shallow fresh water lake using fixed and semi-floating pans
, Article Environmental Processes ; Volume 9, Issue 3 , 2022 ; 21987491 (ISSN) ; Mohammadi, M ; Doulabi, M ; Iraji zad, A ; Tajrishy, M ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Controlling evaporation plays an essential role in arid and semi-arid water resources systems where it accounts for a considerable amount of reservoirs outflow. In this study, we have evaluated evaporation reduction efficiency of different kinds of self-assembled nano-thickness films. The films consist of six different combinations of stearyl and cetyl alcohols with additives such as jojoba oil, stearic acid, and calcium hydroxide. The study lasted from July to August and utilized two pairs of class A evaporation pans: one pair was semi-floating on Chitgar lake water surface while the other one was located on the shore. The experimental results showed that a monolayer containing 3:1 stearyl...
Experimental comparison of cyclic behavior of RC columns strengthened with TRC and FRP
, Article Bulletin of Earthquake Engineering ; Volume 19, Issue 7 , 2021 , Pages 2941-2970 ; 1570761X (ISSN) ; Zargaran, M ; Rahimzadeh Rofooei, F ; Attari, N. K. A ; Sharif University of Technology
Springer Science and Business Media B.V
2021
Abstract
Seven half-scale reinforced concrete (RC) columns with supporting beam were experimentally studied under combined axial and lateral cyclic loading. The specimens were categorized in two groups based on reinforcement ratios. Three specimens were strengthened with carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) sheets. Other specimens were strengthened using a high strength mortar reinforced with textile mesh (textile reinforced concrete (TRC)). Strengthening of specimens were carried out using a vertical layer and a horizontal layer of FRP sheet or two vertical and two horizontal layers of textile meshes for TRC specimens. Since the weight of each layer of...