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Pattern recognition analysis of gas chromatographic and infrared spectroscopic fingerprints of crude oil for source identification
, Article Microchemical Journal ; Volume 153 , 2020 ; Parastar, H ; Sharif University of Technology
Elsevier Inc
2020
Abstract
In this study, a chemometric strategy was developed for analysis of gas chromatographic (GC) and infrared spectroscopic (FT-IR) fingerprints of nine crude oil samples from the main oil wells of Iran to classify them and to find their origins. In this regard, a fractionation method based on saturated, aromatic, resin, and asphaltene (SARA) test was used. Then, these fractions were analyzed by GC-FID and GC–MS. Also, nine crude oil samples were analyzed by FT-IR. The obtained GC fingerprints were aligned using correlation optimized warping (COW) and auto-scaled, and then analyzed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Evaluation of PCA scores plot...
Vis-NIR hyperspectral imaging coupled with independent component analysis for saffron authentication
, Article Food Chemistry ; Volume 393 , 2022 ; 03088146 (ISSN) ; Parastar, H ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
In the present contribution, visible-near infrared hyperspectral imaging (Vis-NIR-HSI) combined with a novel chemometric approach based on mean-filed independent component analysis (MF-ICA) followed by multivariate classification techniques is proposed for saffron authentication and adulteration detection. First, MF-ICA was used to exploit pure spatial and spectral profiles of the components. Then, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to find patterns of authentic samples based on their distribution maps. Then, detection of five common plant-derived adulterants of saffron including safflower, saffron style, calendula, rubia and turmeric were...
Multiple adulterants detection in turmeric powder using Vis-SWNIR hyperspectral imaging followed by multivariate curve resolution and classification techniques
, Article Microchemical Journal ; Volume 185 , 2023 ; 0026265X (ISSN) ; Talebian, S ; Parastar, H ; Sharif University of Technology
Elsevier Inc
2023
Abstract
In the present contribution, visible and short wavelengths of near infrared hyperspectral imaging (Vis-SWNIR-HSI) combined with different chemometric techniques is proposed as a novel technique for turmeric authentication and multiple adulterants (corn flour, rice flour, starch, wheat flour, and zedoary) detection. In this regard, twenty-three samples of turmeric were collected as whole rhizomes or powdered from seven countries and then their VIS-SWNIR hyperspectral images were obtained in 400–1000 nm using SPECIM IQ HSI device. Two multivariate resolution techniques of multivariate curve resolution-alternating least squares (MCR-ALS) and mean-field independent component analysis (MF-ICA)...
Application of arbitrary Lagrangian–Eulerian unstructured finite volume lattice Boltzmann method to simulate compressible viscous flows over moving bodies
, Article Meccanica ; Volume 58, Issue 12 , 2023 , Pages 2329-2346 ; 00256455 (ISSN) ; Hejranfar, K ; Azampour, M. H ; Sharif University of Technology
Springer Science and Business Media B.V
2023
Abstract
In this work, a central difference unstructured finite volume lattice Boltzmann method (FVLBM) in an arbitrary Lagrangian–Eulerian (ALE) framework is applied to effectively simulate the compressible viscous flows over moving bodies. Here, the two-dimensional compressible LB equation based on the multispeed Watari model is formulated in the ALE framework on an unstructured body-fitted mesh and the resulting equation is discretized by using the cell-centered finite volume method in which a central averaging scheme is made to calculate the numerical fluxes. A suitable dissipation term is added to the formulation to ensure the stability of the numerical scheme applied. The time integration is...
Mutual information map as a new way for exploring the independence of chemically meaningful solutions in two-component analytical data
, Article Analytica Chimica Acta ; Volume 1227 , 2022 ; 00032670 (ISSN) ; Abdollahi, H ; Tauler, R ; Rukebusch, C ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In the present contribution, a new approach based on mutual information (MI) is proposed for exploring the independence of feasible solutions in two component systems. Investigating how independent are different feasible solutions can be a way to bridge the gap between independent component analysis (ICA) and multivariate curve resolution (MCR) approaches and, to the best of our knowledge, has not been investigated before. For this purpose, different chromatographic and hyperspectral imaging (HSI) datasets were simulated, considering different noise levels and different degrees of overlap for two-component systems. Feasible solutions were then calculated by both grid search (GS) and...
Numerical Simulation of 2D Compressible Mixing Layer Flow using Vorticity Confinement Method
, M.Sc. Thesis Sharif University of Technology ; Hejranfar, Kazem (Supervisor)
Abstract
The main objective of this study is to evaluate the accuracy and performance of the vorticity confinement (VC) method implemented in a second-order finite volume flow solver for solving two-dimensional compressible mixing layer flows. The spatial discretization of the system of governing equations is performed by a second-order central difference finite volume method and a fourth-order Runge-Kutta method is used for the time integration. To have a stable solution, the second- and fourth-order numerical dissipation terms are applied. At first, two problems, namely, the advection of an isentropic vortex and the shock-vortex interaction are numerically solved and the effects of the confinement...
Development of a Lattice Boltzmann Method in an Arbitrary Lagrangian-Eulerian Framework for Simulating Compressible Flows over Moving Bodies
, Ph.D. Dissertation Sharif University of Technology ; Hejranfar, Kazem (Supervisor)
Abstract
The objective of this study is to develop and apply an arbitrary Lagrangian-Eulerian unstructured finite-volume lattice-Boltzmann method (ALE-FVLBM) for solving two-dimensional compressible flows around moving bodies. The two-dimensional compressible form of the LB equation, along with the Batangar-Gross-Crook (BGK) approximation for modeling the collision operatore, and the D2Q65 Watari model for modeling the equilibrium distribution function, are considered here. The resulting LB equation is formulated in the ALE framework on an unstructured body-fitted mesh to correctly model the body shape and properly incorporate the mesh movement due to the body motion. The spatial discretization of...
Development of Chemometric Pattern Recognition Methods Combined with Gas Chromatography for The Analysis of Chromatographic Fingerprints of Crude Oils and Identification of Thier Sources
,
M.Sc. Thesis
Sharif University of Technology
;
Parastar Shahri, Hadi
(Supervisor)
Abstract
In recent years, with increasing spills of oil and related petroleum products in the marine environment , the need for source identification of crude oil is increasing rapidly. Oil spill can have serious biological and economic impacts. There are many oil tankers on the surface of the sea and 0.68х109 kg crude oil spilled into soil per year . The source identification of oil spills can be a considerable challenge so these studies analytically and environmentally are important. The purpose of this study was to provide an update of the state-of-the-art of oil fingerprinting techniques to demonstrate the use of a rapid, inexpensive and useful technique for distinguishing between crude oils. In...
Development and Application of Chemometric Methods for Hyperspectral Image Analysis for Authentication and Adulteration Detection in Food (Saffron and Turmeric)
, Ph.D. Dissertation Sharif University of Technology ; Parastar Shahri, Hadi (Supervisor) ; Abdollahi, Hamid (Supervisor)
Abstract
The use of hyperspectral images to detect food fraud has become popular and it is necessary to develop chemometrics methods for analyzing the data from these images. Additionally, food authenticity has become a major challenge, and the focus of this thesis is on developing multivariate methods in chemometrics to extract useful information from data obtained from food authenticity verification using hyperspectral imaging (HSI). This thesis consists of six chapters. In the first chapter, a brief introduction to the fundamentals of hyperspectral imaging and food authenticity verification is presented. In the second chapter, the data structure of these images and chemometric methods including...
Arbitrary Lagrangian-Eulerian unstructured finite-volume lattice-Boltzmann method for computing two-dimensional compressible inviscid flows over moving bodies
, Article Physical Review E ; Volume 101, Issue 2 , 2020 ; Hashemi Nasab, H ; Azampour, M. H ; Sharif University of Technology
American Physical Society
2020
Abstract
The objective of this study is to develop and apply an arbitrary Lagrangian-Eulerian unstructured finite-volume lattice-Boltzmann method (ALE-FVLBM) for solving two-dimensional compressible inviscid flows around moving bodies. The two-dimensional compressible form of the LB equation is considered and the resulting LB equation is formulated in the ALE framework on an unstructured body-fitted mesh to correctly model the body shape and properly incorporate the mesh movement due to the body motion. The spatial discretization of the resulting system of equations is performed by a second-order cell-centered finite-volume method on arbitrary quadrilateral meshes and an implicit dual-time stepping...
An improved ranking method for generalized fuzzy numbers based on Euclidian distance concept
, Article Afrika Matematika ; Volume 26, Issue 7-8 , December , 2015 , Pages 1291-1297 ; 10129405 (ISSN) ; Hosseini nasab, H ; Sepehriar, A ; Sharif University of Technology
Springer Verlag
2015
Abstract
Ranking fuzzy numbers plays a main role in many applied models, and in particular decision-making procedures. In any proposed method by the other researches some shortcomings may exist. In this paper, a new method for ranking two generalized fuzzy numbers based on Euclidian distance measure is presented. Besides from distance measure, we exploited the deviations of generalized fuzzy numbers. The proposed method is illustrated by some numerical examples and in particular the results of ranking by the proposed method and some common and existing methods for ranking fuzzy sets is compared to verify the advantages of the new approach
Introducing GyroSym: a single-wheel robot
, Article International Journal of Dynamics and Control ; Volume 8, Issue 2 , 2020 , Pages 404-417 ; Abedin Nasab, M. H ; Liu, G ; Sharif University of Technology
Springer
2020
Abstract
In this paper, GyroSym, a compact highly-stable single-wheel robot is introduced. Symmetrical flywheels have been used as its stabilization mechanism to keep the wheel upright. Thanks to the type of the flywheel used, the dynamic equations of the robot is simplified, the torque needed to tilt the spin axis is reduced, and the space is drastically minimized. Besides, a centrifugal clutch is used to smooth the motion of the robot in forward motion. Two controllers, fuzzy and fuzzy-Padé, were implemented based on their ability to stabilize the robot. Although both prevented the GyroSym from falling over, neither can entirely cancel out the effects of nonlinear behaviors that is present in the...
Rapid authentication of intact saffron stigma thorough the package using Vis-SWNIR hyperspectral imaging coupled with chemometrics
, Article Journal of Food Composition and Analysis ; Volume 124 , 2023 ; 08891575 (ISSN) ; Hashemi Nasab, F. S ; Parastar, H ; Sharif University of Technology
Academic Press Inc
2023
Abstract
This study presents a rapid method for detecting and authenticating intact saffron stigma through its packaging using visible-short wavelength near-infrared (Vis-SWNIR) hyperspectral imaging (HSI) in conjunction with chemometrics. A dataset containing 38 authentic saffron samples was utilized, and HSI images were captured within the spectral range of 400–950 nm. Multivariate curve resolution-alternating least squares (MCR-ALS) was used to obtain pure spatial and spectral profiles of the components. The resolved spatial profiles were then subjected to principal component analysis (PCA) to identify potential patterns in the authentic samples. Binary mixtures of pooled saffron samples and...
Aluminothermic-carbothermal reduction synthesis of nano crystalline Al2O3-Ti(C,N) composite with different bed types
, Article Iranian Journal of Materials Science and Engineering ; Volume 12, Issue 1 , 2015 , Pages 66-75 ; 17350808 (ISSN) ; Naghizadeh, R ; Samadi, H ; Nemati, A ; Sharif University of Technology
Iran University of Science and Technology
2015
Abstract
Ceramic-matrix composites containing TiC-TiN have been used in a variety of application because of their superior properties such as high hardness, good wear resistance and high chemical stability. In this research, effect of coke and coke/calcium beds in synthesis of Al2O3-Ti(C, N) composites using alumino-carbothermic reduction ofTiO2 has been investigated. Al, TiO2 and active carbon with additives of extra carbon and NaCl and without additives, in separate procedures, have been mixed. Afterwards, mixtures were pressed and synthesized in 1200°C for 4hrs, in coke and coke/calcium beds, separately. Al2O3-Ti(C,N) composite was synthesized in ternary system of Al-TiO2-C with excess carbon and...
Microstructure and tensile properties of squeeze cast Al-Zn-Mg-Cu alloy
, Article Materials Science and Technology ; Volume 17, Issue 6 , 2001 , Pages 639-644 ; 02670836 (ISSN) ; Ashoori, H ; Davami, P ; Sharif University of Technology
IOM Communications Ltd
2001
Abstract
It is well known that wrought aluminium alloys have tensile properties superior to those of the cast products. Wrought grade alloys cannot usually be produced by conventional casting processes to attain the same level of tensile properties. However, progress in casting methods in recent years has made it possible to produce wrought alloys by means of squeeze casting techniques. In the present study an Al-Zn-Mg-Cu alloy as been produced by squeeze casting. Tensile properties close to those of wrought products have been achieved by controlling the microstructure, pressure, and other processing parameters. © 2001 IoM Communications Ltd
Optimization of microbial culture for production of poly hydroxy butyrate (PHB) by azotobacter beijerinckii DSMZ-1041
, Article World Applied Sciences Journal ; Volume 14, Issue SPL ISS 3 , 2011 , Pages 72-82 ; 18184952 (ISSN) ; Ardjmand, M ; Nasab, A. H ; Kordi, A. S ; Sharif University of Technology
2011
Abstract
Azotobacter beijerinckii DSMZ 1041 strain was used for production of polyhydroxybutyrate (PHB) and the optimum glucose concentration, as the carbon source and ammonium chloride, as the nitrogen source were obtained 60gr/lit and 0.5gr/lit respectively. The resulting optimum PHB production was investigated 2.95gr/lit. The obtained yield of PHB with respect to glucose (Yp/s) and PHB productivity (Qp) were 0.202 g/g and 0.123 g/lit.hr, respectively. The response surface methodology (RSM) was used to verify the accuracy of the designed experiments. azotobacter beijerinckii microorganism from Deutsch sammlung von microorganismen und zellkulturen(DSMZ) bank is used for production of Poly Hydroxy...
Overall electroelastic moduli of particulate piezocomposites with non-dilute BCC microstructure
, Article International Journal of Mechanical Sciences ; Volume 53, Issue 9 , 2011 , Pages 777-785 ; 00207403 (ISSN) ; Kargarnovin, M. H ; Sharif University of Technology
2011
Abstract
The present paper addresses an analytical method to determine the overall behavior of piezocomposite materials containing body centered cubic (BCC) distribution of arbitrary oriented ellipsoidal heterogeneities. This approach is based on the extension of the electromechanical equivalent inclusion method (EMEIM) to interacting multi-inhomogeneities. In this treatment the short and long range interactions of the piezoelectric particles are appropriately incorporated through the homogenizing eigenstrainelectric field. The periodicity of the microstructure of the medium suggests representing the eigenfields in terms of Fourier series, accounting for the matrixparticle, interparticle and...
Electroelastic fields in interacting piezoelectric inhomogeneities by the electromechanical equivalent inclusion method
, Article Smart Materials and Structures ; Volume 19, Issue 3 , 2010 ; 09641726 (ISSN) ; Kargarnovin, M. H ; Hashemi, R ; Sharif University of Technology
2010
Abstract
Consider two piezoelectric ellipsoidal inhomogeneities of arbitrary size, orientation and material constants, which in turn are surrounded by an infinite isotropic medium. The system under consideration is subjected to far-field non-uniform electromechanical loadings. Based on the extension of the electromechanical equivalent inclusion method (EMEIM), the present paper develops a unified solution for determination of the associated electroelastic fields in the vicinity of interacting inhomogeneities. Accordingly, each of the piezoelectric inhomogeneities is broken down into two equivalent inclusions with proper polynomial eigenstrains and eigenelectric fields. The robustness and efficacy of...
Buckling of cracked cylindrical shells with internal pressure subjected to an axial load
, Article 2002 ASME Presures Vessels and Piping Conference, New Orleans, LA, 17 November 2002 through 22 November 2002 ; Volume 451 , 2002 , Pages 73-80 ; 0277027X (ISSN) ; Estekanchi, H. E ; Nayeb Hashemi, H ; Sharif University of Technology
2002
Abstract
Cylindrical shells constitute the main structural component in pressure vessels and pipelines. Buckling is one of the main failure considerations when designing these cylindrical shells. Defects such as cracks may develop during manufacturing or service life of these structures. These defects can severely affect their buckling behavior due to high stress field generated around these defects. Finite Element Analyses are performed to study the buckling behavior of cylindrical shells with and without a crack, under various internal pressures. Effects of crack length and its orientation on the buckling loads of cylindrical shells having a through or a thumbnail crack are studied. The results...
Dynamic response of cracked cylindrical shells with internal pressure
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; 2002 , Pages 257-265 ; 0791836282 (ISBN); 9780791836286 (ISBN) ; Nayeb Hashemi, H ; Estekanchi, H. E ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2002
Abstract
Sub-surface cracks in pipelines with internal pressure may severely affect their dynamic response. The extreme cases of these cracks are when these cracks go through the thickness of the pipes. Dynamic responses of cracked and un-cracked pipes with fixed ends and under various internal pressures were evaluated experimentally and theoretically. In the experimental part, the effects of pipe internal pressure on the resonant frequencies and damping of the pipe were evaluated. In the theoretical part, finite element analyses were performed to find dynamic response of pipes with various crack length and orientation respect to the axis of the pipe. The experimental results showed resonant...