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sotoudeheian--saeed
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Estimating ground-level PM2.5 concentrations by developing and optimizing machine learning and statistical models using 3 km MODIS AODs: case study of Tehran, Iran
, Article Journal of Environmental Health Science and Engineering ; Volume 19, Issue 1 , 2021 ; 2052336X (ISSN) ; Arhami, M ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Purpose: In this study we aimed to develop an optimized prediction model to estimate a fine-resolution grid of ground-level PM2.5 levels over Tehran. Using remote sensing data to obtain fine-resolution grids of particulate levels in highly polluted environments in areas such as Middle East with the abundance of brightly reflecting deserts is challenging. Methods: Different prediction models implementing 3 km AOD products from the MODIS collection 6 and various effective parameters were used to obtain a reliable model to estimate ground-level PM2.5 concentrations. In this regards, the linear mixed effect model (LME), multi-variable linear regression model (MLR), Gaussian process model (GPM),...
Investigating the Relationship Between Measured Parameters by Satellite and Ground-Level Concentrations of PM
, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad (Supervisor)
Abstract
Obtaining particulate matter (PM) concentration is very important in epidemiological studies. Measurement at the ground levels has been used as an accurate method to obtain PM levels. However, these measurements are more indicative of a small area around the stations than a whole region. Usually, limited space coverage and irregular distribution of air quality stations at the ground level is a restriction in the studies of air pollution and its effect on human health and environment. In this regard satellite measurements have been used for indirect estimation of PM concentration at ground levels. However, the correlation between satellite measurements and ground based data is affected by...
Developing Models to Estimate Ground Level PM2.5 Concentrations Using Satellite Measurements
, Ph.D. Dissertation Sharif University of Technology ; Arhami, Mohammad (Supervisor)
Abstract
In this study different prediction models including linear mixed effect (LME), multi-variable linear regression (MLR), gaussian process model (GPM), artificial neural network (ANN) and support vector regression (SVR) were developed using satellite AOD product - with spatial resolution of 3 km – coupled with various auxiliary parameters to estimate ground-level PM2.5 over Tehran. The influence of site effect term on performance of LME models was evaluated using random intercept for monitoring sites. Results showed LME models without this term were able to explain variabilities of PM2.5 in ranges of 60 – 66% and 35 – 41% during model fitting and cross-validation (CV), respectively. By...
Impact of middle eastern dust sources on PM10 in iran: highlighting the impact of tigris-euphrates basin sources and lake urmia desiccation
, Article Journal of Geophysical Research: Atmospheres ; Volume 121, Issue 23 , 2016 , Pages 14,018-14,034 ; 2169897X (ISSN) ; Salim, R ; Arhami, M ; Sharif University of Technology
Blackwell Publishing Ltd
2016
Abstract
Contribution of different Middle Eastern dust origins to PM10 (PM with aerodynamic diameters less than 10 µm) levels in several receptor large cities in Iran was investigated. Initially, the major regional dust episodes were determined through statistical analysis of recorded PM levels at air quality stations and verified using satellite images. The particles dispersion was simulated by Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) to regenerate PM10 during the dust episodes. The accuracy of the modeled results was rather convincing, with an average squared correlation coefficient (R2) of 0.7 (max = 0.95). Consequently, the contributions of different dust sources to the...
Using high-resolution climate models to identify climate change hotspots in the middle east: A case study of iran
, Article Climate ; Volume 10, Issue 11 , 2022 ; 22251154 (ISSN) ; Jalilvand, E ; Kermanshah, A ; Sharif University of Technology
MDPI
2022
Abstract
The adverse effects of climate change will impact all regions around the world, especially Middle Eastern countries, which have prioritized economic growth over environmental protection. However, these impacts are not evenly distributed spatially, and some locations, namely climate change hotspots, will suffer more from climate change consequences. In this study, we identified climate change hotspots over Iran—a developing country in the Middle East that is facing dire economic situations—in order to suggest pragmatic solutions for vulnerable regions. We used a statistical index as a representative of the differences in climatic parameters for the RCP8.5 and RCP4.5 forcing pathways between...
Effect of empty bed residence time on biotrickling filter performance: Case study-triethylamine
, Article International Journal of Environmental Science and Technology ; Vol. 11, issue. 1 , 2014 , pp. 183-190 ; ISSN: 17351472 ; Bayat, R ; Keshavarzi Shirazi, H ; Sotoudeheian, S ; Sharif University of Technology
2014
Abstract
In this study, a laboratory-scale biotrickling filter (BTF) is used to remove Triethylamine (TEA) from gaseous wastes. The BTF is made of stainless steel with a height of 210 cm and an internal diameter of 21 cm packed with lava rocks. TEA elimination pattern was evaluated by changing empty bed residence times (EBRTs). The maximum elimination capacity (EC) has been determined to be 87 g/m3/h. At all EBRTs 52, 31, 20, and 10 s, contaminant transferring from gas phase to liquid was more than the EC. Also, the removal efficiency was 100 % for a mass loading of 100 g/m3/h. While the liquid recirculation velocity of 3.466 m3/m2/h was maintained, the flow rate was adjusted to 60, 100, 156, and 312...
Performance of three-level spectrally encoded spreadtime CDMA in the presence of multiple interferences [electronic resource]
, Article IET Communications ; July 2011, Volume 5, Issue 10, P. 1328-1335 ; Mashhadi, Saeed ; Salehi, J. A ; Sharif University of Technology
Abstract
In this study the authors present an in-depth study, analysis and discussion on maximum likelihood (ML)-based receiver for a typical spectrally encoded spread-time CDMA in the presence of multiple narrowband interference (NBI) signals in an additive white Gaussian noise channel. Furthermore, the authors demonstrate that by combining useful properties of ML-based receiver and three-level codes, that is, codes with values of -1, 0, +1, the authors can introduce a new strategy in which superior performance with respect to previous receiver structure based on two-level codes, that is, codes with values of -1, +1, can be attained. With the help of an example, the authors drive, first, the...
Investigation of Multiphase Flow in Oil Wells (with Focus on Two Phase Flow), Flow Pattern Recognition and Modeling
, M.Sc. Thesis Sharif University of Technology ; Shad, Saeed (Supervisor) ; Jamshidi, Saeed (Supervisor)
Abstract
The concurrent flow of oil and water is a common occurrence in the field of multiphase flow in different fields including petroleum industry. In oil and gas, production engineers often face a situation in which more than one phase is flowing through the producers. In such conditions an accurate assessment of pressure loss inside the well plays a vital role in efficient and effective production planning. Changes in well orientation, wellbore diameter, reservoir and fluid properties as well as fluid flow rates are among parameters in which will affect the flow patterns that can occur inside a well during its life time. These flow patterns are created as a result of a competition between...
Casing Design Optimization Considering Drilling and Production Conditions
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeed (Supervisor) ; Shad, Saeed (Supervisor)
Abstract
Casing design is one of the most expensive parts in the drilling of oil wells, and any cost reduction with the basic design of these casing strings will significantly reduce the total cost of the operation. In recent years, occurring scenarios-based casing design has become popular; Because in many cases, it eliminates non-occurring scenarios such as gas kick and saves on drilling costs. In this study, we have tried to investigate all scenarios that may occur during the lifetime of the well, whether drilling or production, and for each well, based on its own field information, possible scenarios for each casing part are selected separately and the applying loads are calculated. For this...
PRI (Palm Rotation Indicator): a metric for postural stability in dynamic nonprehensile manipulation [electronic resource]
, Article Journal of MECHANIKA ; 2012, Vol. 18, No. 4, pp. 461-466 ; Meghdar, Ali ; Sohrabpour, Saeed ; Sharif University of Technology
Abstract
In this study, we discuss the postural stability of a nonprehensile manipulation problem, which deals with multibody objects. As a metric for postural stability, we define PRI. Then, the system is posturally stable, if PRI is inside the convex hull of the object-manipulator contact surface. We then discuss that dynamic biped locomotion is a special case of dynamic nonprehensile manipulation in all aspects; we prove that ZMP (zero-moment point) and FRI (zoot rotation indicator) are special cases of PRI (palm rotation indicator). Simulations and experiments corresponding to simple examples support the results
On the Domination Polynomial of Graphs
, M.Sc. Thesis Sharif University of Technology ; Akbari, Saeed (Supervisor)Some Applications of Combinatorial Nullstellensatz in Graph Theory and Combinatorics
, M.Sc. Thesis Sharif University of Technology ; Akbari, Saeed (Supervisor)
Electrochemical Determination of Piroxicam at thin Carbon
Nanoparticle Composite And Investigation of the Electrochemical Behavior and Synthesis of Catechols in the Presence of Mercapto Methyl Tetrazol as a Nucleophile
,
M.Sc. Thesis
Sharif University of Technology
;
Shahrokhian, Saeed
(Supervisor)
Abstract
The electrochemical oxidation behavior of the anti-inflammatory drug piroxicam was investigated. A carbon nanoparticle (CNP)-chitosan (CS) film-coated graphite electrode (PGE) was fabricated and the electrochemical behaviors of piroxicam on its surface was investigated by the means of cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). In comparison to the bare PGE, at the surface of the CNP-CS film modified electrode, the oxidation peak current of piroxicam increased significantly and the peak potential shifted negatively. Consequently, a simple and sensitive electroanalytical method was developed for the determination of piroxicam. The...
Chemically Modified Electrodes Based on Conducting Polymers and Carbon Nanotubes: Application to Voltammetric Determination of Some Biological and Pharmaceutical Compounds
,
M.Sc. Thesis
Sharif University of Technology
;
Shahrokhian, Saeed
(Supervisor)
Abstract
There are high attractions in the development of conducting polymer (CP) coatings to improve the electrochemical properties and biocompatibility of electrodes in the area of biosensors. In the first part of this thesis, a new type of modified electrodes, constructing multi-walled carbon nanotubes (MWCNTs) and polypyrrole is prepared in a layer-by-layer process. In this procedure, the glassy carbon electrode is casted first by a drop suspension of MWCNTs, leading to formation a thin film on its surface. In the second step, electrochemical polymerization of pyrrole in the presence of tiron (used as doping anion) is performed on the surface of the MWCNTs pre-coated electrode. The modification...
Research on Influences of Coating on Low Cycle Fatigue Properties of Ni-Base Superalloy René 80
, Ph.D. Dissertation Sharif University of Technology ; Nategh, Saeed (Supervisor)
Abstract
In this thesis, based on the taking-off and landing of aircraft with GE 21-J85 turbine, the low cycle fatigue (LCF) test for superalloy used in first stage blades is considered. The LCF tests were performed on both coated and uncoated Rene 80 which are used in GE 21-J85 turbine at R = (min/max) = 0, strain rate of 2 10-3 s-1 and 760oC, 871oC and 982oC. To produce specimens, an investment casting method was used so that adequate amount of polycrystalline round bars could be obtained. The specimens were all homogenized and solution treated. After the inspection, some specimens were coated with pack cementation method in CODEP-B powder in H2 atmosphere. The coated and uncoated specimens all...
Voltammetric Determination of Tryptophan and 5-Hydroxytryptophan Using Graphite Electrode Modified with a Thin Film of Graphite/Diamond Nano-mixture And Determination of omeprazole Using Graphite Electrode
,
M.Sc. Thesis
Sharif University of Technology
;
Shahrokhian, Saeed
(Supervisor)
Abstract
At the first part of this thesis, a pyrolitic graphite electrode (PGE) modified with graphite/nanodiamond film (GND) was applied as a sensitive electrochemical sensor for determination and study of electrochemical behavior of tryptophan (Trp) and 5-hydroxytryptophan (5-HTP) in aqueous solutions. The results showed that GND caused a remarkable increase in the peak currents so the GND/PGE electrode surface was more sensitive to the concentration of Trp and 5-HTP than the PGE surface. The determination of Trp and 5-HTP were investigated by stripping voltammetry. Experimental parameters such as scan rate, pH, accumulation conditions and amount of the modifier used on the PGE surface were...
Simultaneous Voltammetric Determination of Epinephrine and UricAcid in Presence of Ascorbic Acid Using Pyrolytic Graphite Electrode Modified with Nano- diamond/graphite Film & Voltammetric Determination of Levothyroxine at the Surface of Edge Plane Pyrolytic Graphite Electrode
,
M.Sc. Thesis
Sharif University of Technology
;
Shahrokhian, Saeed
(Supervisor)
Abstract
Part 1: A novel modified pyrolytic graphite electrode with nanodiamond/graphite was fabricated. The electrochemical response characteristics of the modified electrode toward the epinephrine (EN) and uric acid (UA) are studied by means of cyclic and linear sweep voltammetry. The structural morphology and thickness of the film was characterized by SEM technique.The prepared electrode shows an excellent catalytic activity in the electrochemical oxidation of EN and UA, leading to remarkable enhancements in the corresponding peak currents and lowering the peak potentials. The prepared modified electrode acts as a highly sensitive sensor for simultaneous determination of EN and UA in the presence...
Electrochemical Determination of Tyrosine and Tryptophan at the Surface of Pyrolytic Graphite Electrode Modified with Multi-Walled Carbon Nanotubes, New Coccine and Nitrazine
, M.Sc. Thesis Sharif University of Technology ; Shahrokhian, Saeed (Supervisor)
Abstract
At the first part of this thesis, a pyrolitic graphite electrode (PGE) modified with new coccine/multi-walled carbon nanotubes film (NC/MWCNT) was applied as a sensitive electrochemical sensor for determination and study of electrochemical behavior of tyrosine (Tyr) in aqueous solutions. The results showed that NC/MWCNT caused a remarkable increase in the peak current so the NC/MWCNT/PGE electrode surface was far more sensitive to the concentration of Tyr than the PGE surface. The determination of Tyr was investigated by linear sweep voltammetry (LSV). Experimental parameters, such as scan rate, pH and amount of the modifier used on the PGE surface were optimized by monitoring the LSV...
Rationality of Scientific Knowledge From the Point of View of Feyerabend
, M.Sc. Thesis Sharif University of Technology ; ZibaKalam, Saeed (Supervisor)
Abstract
Feyerabend was a philosopher of science that became famous for his purportedly anarchistic view of science and his rejection of the existence of universal methodological rules and rationality of science. Feyerabend’s view of science can be summarize in a few points; 1. On the issue of falsifiability, Feyerabend argues that no theory is ever consistent with all the relevant facts. He sees the use of ad-hoc postulates to save the dominant paradigm as an essential to the progress of science. He claims that scientists frequently depart completely from the scientific method when they use ad-hoc ideas to explain observations that are only later justified by theory. To Feyerabend, ad-hoc...