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ghobadi-ghadikalaei--vahideh
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Some Applications of Singular Values Decomposition in Image Processing
, M.Sc. Thesis Sharif University of Technology ; Mahdavi Amiri, Nezamoddin (Supervisor)
Abstract
The field of digital image processing refers to processing digital images by means of a digital computer. One of the principal applications used in digital image processing is image compression. Image compression is the problem of reducing the amount of data required to represent a digital image. The basis of the reduction process is the removal of redundant data. One of the other principal applications of image processing is noise reduction (filtering) of images corrupted with additive noise. Filtering techniques are oriented toward modeling the degradation and applying the inverse process in order to recover the original image. Image watermarking is another application of image processing....
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...
Design of Microfluidic Chip for 3D Cell Culture
, M.Sc. Thesis Sharif University of Technology ; Saadatmand, Maryam (Supervisor)
Abstract
Understanding biological systems requires extensive knowledge of individual parameters, and to study the processes of cell differentiation and cell behavior, a suitable environment must be created with the physiological conditions of the human body. For this purpose, with the knowledge of microfluidics, a microenvironment can be provided to study the behavior of cells on a small scale. The use of bone tissue model microfluidic chips is an alternative and new method in which it is possible to study the behavior of cells to differentiate into bone and to examine the toxicity of drugs, which in itself can help in the effective and successful treatment of these cases show. Therefore, in this...
Creating and detecting micro-macro photon-number entanglement by amplifying and deamplifying a single-photon entangled state
, Article Physical Review Letters ; Volume 110, Issue 17 , April , 2013 ; 00319007 (ISSN) ; Lvovsky, A ; Simon, C ; Sharif University of Technology
2013
Abstract
We propose a scheme for the observation of micro-macro entanglement in photon number based on amplifying and deamplifying a single-photon entangled state in combination with homodyne quantum state tomography. The created micro-macro entangled state, which exists between the amplification and deamplification steps, is a superposition of two components with mean photon numbers that differ by approximately a factor of three. We show that for reasonable values of photon loss it should be possible to detect micro-macro photon-number entanglement where the macrosystem has a mean number of one hundred photons or more
Biodegradation of effluents from dairy plant by bacterial isolates
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 26, Issue 1 , 2007 , Pages 55-59 ; 10219986 (ISSN) ; Samadi, A ; Ghobadi, Z ; Sharif University of Technology
2007
Abstract
Micro flora of the effluents from a dairy factory in Tehran(Pegah Dairy Processing Plant) were isolated and screened for their ability to reduce the organic matter content and COD of the effluents. 10 bacteria were selected due to reduction in COD content from the 4th to 6th day of incubation at 30 °C and pH =11. Highest COD reduction were obtained by two isolates, BP3 and BP4, 70.7 % and 69.5 %, respectively (The initial COD concentration was 3000 mg/l and reduced to 880 and 920 mg/l).After optimization of the condition for test organisms, big reductions in COD, carbohydrate, fat and protein content of the effluents were observed by BP3 up to 84.70 %, 98 %, 45.30 % and 53 %, respectively...
Quantum optomechanics in the bistable regime
, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 84, Issue 3 , September , 2011 ; 10502947 (ISSN) ; Bahrampour, A. R ; Simon, C ; Sharif University of Technology
2011
Abstract
We study the simplest optomechanical system with a focus on the bistable regime. The covariance matrix formalism allows us to study both cooling and entanglement in a unified framework. We identify two key factors governing entanglement; namely, the bistability parameter (i.e., the distance from the end of a stable branch in the bistable regime) and the effective detuning, and we describe the optimum regime where entanglement is greatest. We also show that, in general, entanglement is a nonmonotonic function of optomechanical coupling. This is especially important in understanding the optomechanical entanglement of the second stable branch
Optomechanical entanglement in the presence of laser phase noise
, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 84, Issue 6 , 2011 ; 10502947 (ISSN) ; Bahrampour, A. R ; Simon, C ; Sharif University of Technology
2011
Abstract
We study the simplest optomechanical system in the presence of laser phase noise (LPN) using the covariance matrix formalism. We show that for any LPN model with a finite correlation time, the destructive effect of the phase noise is especially strong in the bistable regime. This explains why ground-state cooling is still possible in the presence of phase noise, as it happens far away from the bistable regime. We also show that the optomechanical entanglement is strongly affected by phase noise
Biodegradation of cyanide under alkaline conditions by a strain of pseudomonas putida isolated from gold mine soil and optimization of process variables through response surface methodology (RSM)
, Article Periodica Polytechnica Chemical Engineering ; Volume 62, Issue 3 , May , 2018 , Pages 265-273 ; 03245853 (ISSN) ; Yaghmaei, S ; Ghobadi Nejad, Z ; Sharif University of Technology
Budapest University of Technology and Economics
2018
Abstract
In regard to highly poisonous effects of cyanide ion, concerns have been focused recently on treatment of such compounds in different ways. Four bacterial strains (C1-C4) capable of using cyanide as nitrogen source were isolated from contaminated gold mine soil samples under alkaline conditions at 30 °C, pH 9.5-10.5, and agitation speed 150 rpm. The gram-negative bacterium C3 (identified as Pseudomonas parafulva NBRC 16636(T) by 16S rRNA gene sequencing) was able to tolerate cyanide up to 500 ppm besides removing 93.5% of 200 ppm cyanide in 13 days which was confirmed by microorganisms growth. The addition of basal salts enhanced the removal efficiency of C3 by 16%. Cyanide removal...
Investigation on the solubility of SO2 and CO2 in imidazolium-based ionic liquids using NPT Monte Carlo simulation
, Article Journal of Physical Chemistry B ; Volume 115, Issue 46 , 2011 , Pages 13599-13607 ; 15206106 (ISSN) ; Taghikhani, V ; Elliott, J. R ; Sharif University of Technology
2011
Abstract
The solubility of sulfur dioxide (SO2) and carbon dioxide (CO2) at P = 1 bar in a series of imidazolium-based room-temperature ionic liquids (RTILs) is calculated by Monte Carlo simulation in NPT ensemble using the OPLS-UA force field and Widom particle insertion method. The studied ILs were 1-butyl-3-methylimidazolium ([bmim]+) tetrafluoroborate ([BF4]-), [bmim]+ hexafluorophosphate ([PF 6]-), [bmim]+ bromide ([Br]-), [bmim]+ nitrate ([NO3]-), [bmim]+ bis-(trifluoromethyl) sulfonylimide ([Tf2N]-), and 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]). To validate the simulations, the liquid density of studied ILs and the solubility of CO2 in [bmim][PF6] was compared with...
Aeroelastic Analysis of a Complete Aircraft Via State Space Modeling
, M.Sc. Thesis Sharif University of Technology ; Keshavarz Haddad, Gholamreza (Supervisor)
Abstract
This dissertation presents aeroelastic stability analysis (flutter) pertinent to the complete flexible aircraft based on analytical dynamics, structural dynamics and aerodynamics. The unified formulation is based on fundamental principles and incorporates in a natural manner both rigid body motions of the aircraft as a whole and elastic deformations of the flexible components (fuselage, wing and empennage), as well as the aerodynamic, propulsion and gravity forces. The aircraft motion is described in terms of three translations and three rotations of a reference frame attached to the undeformed fuselage, and acting as aircraft body axes, and elastic displacements of each of the flexible...
Production of extracellular protease and determination of optimal condition by bacillus licheniformis BBRC 100053
, Article International Journal of Engineering, Transactions B: Applications ; Volume 22, Issue 3 , 2009 , Pages 221-228 ; 1728-144X (ISSN) ; Yaghmaei, S ; Haji Hosseini, R ; Sharif University of Technology
Materials and Energy Research Center
2009
Abstract
The production of protease by Bacillus licheniformis BBRC 100053 was studied. The most appropriate medium for the growth and protease production is composed of: lactose 1%, yeast extract 0.5%, peptone 0.5%, KH2 PO 4 0.1%, MgSO4 .7H2 O 0.02%. Enzyme production corresponded with growth and reached a maximums level (589 U/ml) during the stationary phase at 35°C, pH equivalent to 10 and with 150 rpm after 73 hours. Protease activity was highest at pH 8 and 45°C. The best carbon sources are respectively lactose and maltose and the best nitrogen source is peptone. The protease was highly active and stable from pH 7.0 to 11.0 with an optimum at pH 7-8....
Biodegradation of synthetic dye using partially purified and characterized laccase and its proposed mechanism
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 12 , 2019 , Pages 7805-7816 ; 17351472 (ISSN) ; Borghei, S. M ; Yaghmaei, S ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2019
Abstract
The supernatant obtained from the extracellular laccase produced by Phanerochaete chrysosporium was used as the enzyme source to conduct a partial purification, characterization and dye decolorization study. The partially purified enzyme was stable in the pH range of 3–5 and showed an optimum activity at pH 4.0, using guaiacol as a substrate. Laccase stability of pH was determined and discovered to retain 100% of its activity at a pH of 4.0 after 2 h. The maximum enzyme activity was obtained between 30 and 50 °C. The maximum velocity and Michaelis constant were calculated as 3.171 µM−1·min and 1628.23 µM, respectively. The enzyme was activated by Fe2+, Zn2+, Ca2+ and Cu2+, while Hg2+, Mn2+,...
Kinetic studies of Bisphenol A in aqueous solutions by enzymatic treatment
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 2 , 2019 , Pages 821-832 ; 17351472 (ISSN) ; Borghei, S. M ; Yaghmaei, S ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2019
Abstract
Bisphenol A (BPA), which is a major component in the production of various consumer products, is one of the most significant endocrine-disrupting chemicals. In this research, the biocatalytic elimination of Bisphenol A using laccase produced by Phanerochaete chrysosporium was examined and optimized. The response surface methodology was used to study the effect of independent variables such as pH, temperature, initial laccase activity, initial Bisphenol A concentration, and the interactive effects of each variable on the removal of Bisphenol A and residual enzyme activity. Based on response surface plots, the maximum Bisphenol A removal (93%) was detected at a pH value of 8, temperature...
Kinetic studies of Bisphenol A in aqueous solutions by enzymatic treatment
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 2 , Febraury , 2018 , Pages 821–832 ; 17351472 (ISSN) ; Borghei, S. M ; Yaghmaei, S ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2018
Abstract
Bisphenol A (BPA), which is a major component in the production of various consumer products, is one of the most significant endocrine-disrupting chemicals. In this research, the biocatalytic elimination of Bisphenol A using laccase produced by Phanerochaete chrysosporium was examined and optimized. The response surface methodology was used to study the effect of independent variables such as pH, temperature, initial laccase activity, initial Bisphenol A concentration, and the interactive effects of each variable on the removal of Bisphenol A and residual enzyme activity. Based on response surface plots, the maximum Bisphenol A removal (93%) was detected at a pH value of 8, temperature 40...
Some investigations on protease enzyme production kinetics using bacillus licheniformis BBRC 100053 and effects of inhibitors on protease activity
, Article International Journal of Chemical Engineering ; 2014 ; ISSN: 1687806X ; Yaghmaei, S ; Moghadam, N ; Sadeghein, B ; Sharif University of Technology
2014
Abstract
Due to great commercial application of protease, it is necessary to study kinetic characterization of this enzyme in order to improve design of enzymatic reactors. In this study, mathematical modeling of protease enzyme production kinetics which is derived from Bacillus licheniformis BBRC 100053 was studied (at 37°C, pH 10 after 73 h in stationary phase, and 150 rpm). The aim of the present paper was to determine the best kinetic model and kinetic parameters for production of protease and calculating K i (inhibition constant) of different inhibitors to find the most effective one. The kinetic parameters K m (Michaelis-Menten constant) and V m (maximum rate) were calculated 0.626 mM and...
Removal of Pharmaceuticals from Polluted Water Using Carbon Nanotube-based Membranes Coated with Enzyme
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor) ; Ghobadi Nejad, Zahra (Co-Supervisor)
Abstract
Today, presence of micropollutants, including pharmaceutical compounds, in aquatic systems has turned into a major environmental challenge threatening the health of humans and many aquatic and terrestrial organisms. In the recent years, biodegradation of pharmaceuticals using enzymes, such as laccase, has been presented as a green method for eliminating these types of pollutants. Furthermore, regarding the improved stability and reusability of immobilized enzymes, these types of biocatalysts are suitable for industrial applications. Enzymatic membrane reactor is a promising method of enzymatic treatment and fabrication of a high-efficiency enzymatic membrane is a major step to begin this...
Biodegradation of polychlorinated biphenyls by lysinibacillus macrolides and bacillus firmus isolated from contaminated soil
, Article International Journal of Engineering, Transactions B: Applications ; Volume 32, Issue 5 , 2019 , Pages 628-633 ; 1728144X (ISSN) ; Sharifi, H ; Ghobadi Nejad, Z ; Yaghmaei, S ; Sharif University of Technology
Materials and Energy Research Center
2019
Abstract
Polychlorinated biphenyls (PCBs) cause many significant ecological problems because of their low degradability, high harmfulness, and solid bioaccumulation.Two bacterial strains were isolated from soil that had been polluted with electrical transformer liquid for more than 40 years. The isolates were distinguished as Lysinibacillus macrolides DSM54Tand Bacillus firmus NBRC15306Tthrough 16S rRNA sequencing analysis.This is the primary report of an agent of the genus Bacillus firmus equipped for the removal of PCBs. The strains could develop broadly on 2-Chlorobiphenyl and 2,4-dichlorobiphenyl. GC/MS analysis of individual congeners revealed up to 80% degradation of the xenobiotics in 96h,...
Lagrangian approach for analysis of radiation pressure induced parametric instability in micro-resonators
, Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 372, Issue 41 , 2008 , Pages 6298-6300 ; 03759601 (ISSN) ; Vahedi, M ; Abdi, M ; Ghobadi, R ; Sharif University of Technology
Elsevier
2008
Abstract
We introduce a new scheme for determining radiation pressure coupling to microresonator devices. It is shown that for the input pump powers there exists a threshold value for instability behavior. Radiation pressure can couple mechanical modes of a cavity to it's optical modes, leading to parametric oscillation instability. Here we present an approximate analysis of such nonlinear effect with Hamilton's least action principle. Our Lagrangian includes no interaction term, but interaction between optical and mechanical modes has been taken into account through integration limit. © 2008 Elsevier B.V. All rights reserved
Construction of porous calcite structure using microbially induced calcite precipitation
, Article Journal of Petroleum Science and Engineering ; Volume 217 , 2022 ; 09204105 (ISSN) ; Bazargan, M ; Ghobadi Nejad, Z ; Yaghmaei, S ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Sporosarcina pasteurii is a well-known ureolytic bacteria that promotes the microbially induced calcite precipitation (MICP) process for several environmental and engineering purposes. In our work, for the first time, MICP has been implemented to form pure, porous calcite structures. The maximum urease activity of S. pasteurii was 1.91 mM urea hydrolyzed min−1 at the late-exponentially phase. A reactor has been designed to achieve semi-continuous treatments, and reagents were introduced to it by a peristaltic pump. A new alternating injection pattern was adopted to obtain well-distributed precipitation. SEM images of treated structures indicated the shapes of CaCO3 crystals at a microscale...
Macroscopic superpositions via nested interferometry: Finite temperature and decoherence considerations
, Article New Journal of Physics ; Volume 14 , November , 2012 ; 13672630 (ISSN) ; Jeffrey, E ; Ghobadi, R ; Simon, C ; Bouwmeester, D ; Sharif University of Technology
2012
Abstract
Recently, there has been much interest in optomechanical devices for the production of macroscopic quantum states. Here we focus on a proposed scheme for achieving macroscopic superpositions via nested interferometry. We consider the effects of finite temperature on the superposition produced. We also investigate in detail the scheme's feasibility for probing various novel decoherence mechanisms