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Fluence Map Optimization in IMRT Planning under Uncertainty
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
Cancer is one of the main causes of death among all people around the world. This shows that more and more attention should be paid to cure cancer. One of the most common cancer treatments is radiation therapy. Among all radiation therapy treatments, Intensity-Modulated Radiation Therapy is a very effective and flexible ways to treat cancer. There are numerous mathematical problems to find the perfect treatment plan. One of these mathematical problems is Fluence Map Optimization in which we try to find the best dose intensity for each tumor and surrounding organs. The main purpose in this problem is to minimize the number of cancerous cells which are being destroyed while minimizing the...
Seismic Risk Assessment of Tehran Masonry School Buildings
, M.Sc. Thesis Sharif University of Technology ; Bakhshi, Ali (Supervisor)
Abstract
This thesis aims to assess the seismic risk of the community of schools with masonry buildings in the Tehran metropolitan in the next 50 years and to prioritize the buildings of this community for seismic retrofit based on the optimal mitigation of risk of the community. Tehran is among the largest cities with the highest level of seismic risk in the world, and Masonry buildings are among the structures with poor seismic performance; Therefore, it is essential to conduct a comprehensive and accurate evaluation of the seismic risk of schools, as one of the most critical and sensitive occupancies, in this region and with this type of structure. It is also very beneficial to reduce the seismic...
Experimental and numerical investigation of the effect of a speed bump on car noise emission level
, Article Applied Acoustics ; Volume 68, Issue 11-12 , 2007 , Pages 1346-1356 ; 0003682X (ISSN) ; Hodaei, M ; Alimohammadi, I ; Sharif University of Technology
2007
Abstract
The noise emission level associated with two types of speed reducers has been investigated numerically and experimentally for different dimensions and different speeds of vehicle (20, 40 and 60 km/h) and zero acceleration. Numerical analysis has been performed using an FEM method in the ANSYS environment. The experiments show that for a bump of height 0.04 m, the peak noise level is increased by between 1 and 14 dB (A) whereas, for bump of height 0.055 m, the peak noise level increases by between 1 and 19 dB (A). There is an excellent agreement between the numerical and experimental results. © 2006 Elsevier Ltd. All rights reserved
Surface modification of polyether ether ketone implant with a novel nanocomposite coating containing poly (vinylidene fluoride) toward improving piezoelectric and bioactivity performance
, Article Colloids and Surfaces B: Biointerfaces ; Volume 222 , 2023 ; 09277765 (ISSN) ; Ramazani S. A., A ; Sharif University of Technology
Elsevier B.V
2023
Abstract
Polyether ether ketone (PEEK) is an appropriate biomaterial for orthopedic implant applications due to its superior mechanical properties, chemical resistance, nontoxicity, and Magnetic resonance imaging (MRI) compatibility. Unfortunately, the inherent bio-inertness of PEEK restricted its application and required some modification to provide better bioactivity. Besides it, the generated electrical signals in the bone due to its piezoelectricity features have a vital role in regulating bone repair and regeneration. We aimed to modify the surface of PEEK with a dual-functionality nanocomposite that provides surface bioactivity and simulates the piezoelectricity of bone. So, we introduced a...
Studying Synchronization Control in Complex Systems
, M.Sc. Thesis Sharif University of Technology ; Rahimi Tabar, Mohammad Reza (Supervisor)
Abstract
In this thesis, we review recent advances on controlling of complex systems. We provide in details, the concepts of synchronizability and synchronization controllability.Then we will investigate synchronization controllability under different pinning schemes, and propose a new pinning strategy to increase controllability and consequently decrease the number of required pinned nodes (known as driver nodes) to assure a stable synchronized state. We also study the network characteristics of resulted sequence of driver nodes. Finally, we will employ our proposed schemes to study the controllability of complex networks of chaotic Rossler oscillators
Falcaria vulgaris leaves extract as an eco-friendly corrosion inhibitor for mild steel in hydrochloric acid media
, Article Scientific Reports ; Volume 13, Issue 1 , 2023 ; 20452322 (ISSN) ; Ghaderi, M ; Ramazani Saadatabadi, A ; Mahdavian, M ; Sharif University of Technology
Nature Research
2023
Abstract
Undoubtedly, metal corrosion is one of the most challenging problems faced by industries. Introducing corrosion inhibitors is a reasonable approach to protecting the metal surface. Due to environmental concerns and the toxicity of industrial organic corrosion inhibitors, researchers are continually exploring acceptable replacements. The current study focused on the application of Falcaria Vulgaris (FV) leaves extract to mitigate mild steel (MS) corrosion in a 1 M HCl environment. The polarization findings demonstrated that the corrosion current density decreased from 264.0 µA/cm2 (for the sample submerged in the blank solution) to 20.4 µA/cm2 when the optimal concentration of 800 ppm of FV...
Intelligent Force Control for Hydraulic Manipulator within the Impedance Control Framework
, M.Sc. Thesis Sharif University of Technology ; Khayyat, Amir Ali Akbar (Supervisor)
Abstract
The main concept of this thesis is to simulate, develop, and analyze the performance of force control method by applying to a Unimate MK-II hydraulic manipulator. In this investigation, simulation studies are based on the concept of impedance control technique. Position-based formulation of impedance control is employed. First in this research, a PID controller is employed and is shown to be capable of performing position control task precisely despite the fact that inertia, joint stiction, valve deadband and other nonlinearities are presented. Although trajectory tracking is performed well after several investigations, we have concluded that the impedance control cannot perform a desirable...
A machine learning approach to optimize the performance of a combined solar chimney-photovoltaic thermal power plant
, Article Renewable Energy ; Volume 212 , 2023 , Pages 717-737 ; 09601481 (ISSN) ; Shakibi, H ; Alimohammadi, M ; Naghdbishi, A ; Goodarzi, S ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
Solar Chimney Power Plant (SCPP) is a renewable energy system that indirectly converts solar energy to electricity. However, the efficiency of SCPP is not sufficient for practical applications. Integrating SCPPs with Photovoltaic-Thermal systems (PVT) could enhance their performance to levels acceptable for industrial adoption. This study investigates the combined SCPP-PVT performance for the weather conditions of Austin (Texas), San Diego (California), and Phoenix (Arizona), all on a similar latitude. Various configurations of this combined system are numerically simulated, and their efficiencies are compared with a conventional SCPP, SCPP-Photovoltaic (PV), and stand-alone PV modules....
Graphene-based nanoparticles as potential treatment options for parkinson’s disease: A molecular dynamics study
, Article International Journal of Nanomedicine ; Volume 15 , 2020 , Pages 6887-6903 ; Khedri, M ; Jahromi, A. M ; Maleki, R ; Rezaian, M ; Sharif University of Technology
Dove Medical Press Ltd
2020
Abstract
Introduction: The study of abnormal aggregation of proteins in different tissues of the body has recently earned great attention from researchers in various fields of science. Concerning neurological diseases, for instance, the accumulation of amyloid fibrils can contribute to Parkinson’s disease, a progressively severe neurodegenerative disorder. The most prominent features of this disease are the degeneration of neurons in the substantia nigra and accumulation of α-synuclein aggregates, especially in the brainstem, spinal cord, and cortical areas. Dopamine replacement therapies and other medications have reduced motor impairment and had positive consequences on patients’ quality of life....
Multilayered mesoporous composite nanostructures for highly sensitive label-free quantification of cardiac troponin-i
, Article Biosensors ; Volume 12, Issue 5 , 2022 ; 20796374 (ISSN) ; Amidian, M. A ; Sheybanikashani, S ; Mahdavi, H ; Alimohammadi, H ; Syedmoradi, L ; Mohandes, F ; Zarrabi, A ; Tamjid, E ; Omidfar, K ; Simchi, A ; Sharif University of Technology
MDPI
2022
Abstract
Cardiac troponin-I (cTnI) is a well-known biomarker for the diagnosis and control of acute myocardial infarction in clinical practice. To improve the accuracy and reliability of cTnI electrochemical immunosensors, we propose a multilayer nanostructure consisting of Fe3O4-COOH labeled anti-cTnI monoclonal antibody (Fe3O4-COOH-Ab1 ) and anti-cTnI polyclonal antibody (Ab2 ) conjugated on Au-Ag nanoparticles (NPs) decorated on a metal–organic framework (Au-Ag@ZIF-67-Ab2 ). In this design, Fe3O4-COOH was used for separation of cTnI in specimens and signal amplification, hierarchical porous ZIF-67 extremely enhanced the specific surface area, and Au-Ag NPs synergically promoted the conductivity...
A validated numerical-experimental design methodology for a movable supersonic ejector compressor for waste-heat recovery
, Article Journal of Thermal Science and Engineering Applications ; Volume 6, Issue 2 , Oct , 2014 ; 19485085 (ISSN) ; Persoons, T ; Murray, D. B ; Tehrani, M. S ; Farhanieh, B ; Koehler, J ; Sharif University of Technology
Web Portal ASME (American Society of Mechanical Engineers)
2014
Abstract
The aim of this paper is to develop the technical knowledge, especially the optimum geometries, for the design and manufacturing of a supersonic gas-gas ejector for a wasteheat driven vehicle cooling system. Although several studies have been performed to investigate the effects of geometrical configurations of gas-gas ejectors, a progressive design methodology of an ejector compressor for application to a vehicle cooling system has not yet been described. First, an analytical model for calculation of the ejector optimum geometry for a wide range of operating conditions is developed, using R134a as the working fluid with a rated cooling capacity of 2.5 kW. The maximum values of entrainment...
Functionalization of metal-organic frameworks with metallic nanoclusters for ultra-sensitive monitoring of morphine in biological fluids
, Article Sensors and Actuators B: Chemical ; Volume 393 , 2023 ; 09254005 (ISSN) ; Chenani, H ; Amidian, M ; Rajabi, N ; Alimohammadi, H ; Zarrabi, A ; Simchi, A ; Sharif University of Technology
Elsevier B.V
2023
Abstract
A reliable, fast, and cost-effective method of monitoring morphine (MO) concentration in biological fluids is highly desired in clinical and modern medicine. Nanotechnology has opened up new possibilities for developing morphine biosensors, but the most advanced electrodes available offer a detection limit (LOD) of ≥10 nM. This work introduces a new, ultrasensitive electrochemical biosensor based on microporous metal-organic frameworks (∼1100 cm2 g−1 surface area) modified by Ag clusters (∼2 nm) and functionalized by Au nanoparticles (∼180 nm). Electrochemical studies show that functionalizing the microporous crystalline particles (620 ± 45 nm) with metal nanoclusters enhances charge...
Biodecolourization and Biodetoxification of Dye-containing Wastewaters from Textile Dyeing by the Native Fungal Strain Phanerochaete Chrysosporium and Trametes Species
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor) ; Mosavi, Abas (Supervisor) ; Ghobadi Nehad, Zahra (Co-Supervisor)
Abstract
Treatment of Wastewater of textile industries has been always challenging due to the high organic matter which is a suitable substrate for the growth of microorganisms. Also, discharge of wastewater into the open water causes water adsorbing more sunlight, raising water temperature and therefor decreasing dissolved oxygen. In addition, the acidity of wastewater decreases the quality of agricultural soil. Among wastewater treatment methods, biological methods are cheaper, environment friendly, and produce less by product. Among all the microorganism responsible for biological treatment, fungi and enzymes are more applicable. Especially white-rot fungi are the most effective microorganism to...
Development of a novel graphene oxide-blended polysulfone mixed matrix membrane with improved hydrophilicity and evaluation of nitrate removal from aqueous solutions
, Article Chemical Engineering Communications ; 2018 ; 00986445 (ISSN) ; Nasseri, S ; Mahvi, A. H ; Nabizadeh, R ; Mousavi, S. A ; Maleki, A ; Alimohammadi, M ; Jafari, A ; Hemmati Borji, S ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
In this study, four types of mixed matrix membranes were fabricated using polysulfone (as the base polymer) and different contents of graphene oxide (GO) nanosheets (as modifier) through wet phase inversion method. Based on the amounts of GO (0, 0.5, 1, and 2 wt%), the synthesized membranes named as M1, M2, M3, and M4, respectively. The membranes characteristics were evaluated using FE-SEM, FT-IR, and water contact angle measurements. In addition, the performance of the prepared membranes was investigated in terms of basic parameters: filtrate water flux, nitrate removal efficiency, and antifouling properties. Results showed significant improvements of the characteristics of modified...
Development of a novel graphene oxide-blended polysulfone mixed matrix membrane with improved hydrophilicity and evaluation of nitrate removal from aqueous solutions
, Article Chemical Engineering Communications ; Volume 206, Issue 4 , 2019 , Pages 495-508 ; 00986445 (ISSN) ; Nasseri, S ; Mahvi, A. H ; Nabizadeh, R ; Mousavi, S. A ; Maleki, A ; Alimohammadi, M ; Jafari, A ; Hemmati Borji, S ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
In this study, four types of mixed matrix membranes were fabricated using polysulfone (as the base polymer) and different contents of graphene oxide (GO) nanosheets (as modifier) through wet phase inversion method. Based on the amounts of GO (0, 0.5, 1, and 2 wt%), the synthesized membranes named as M1, M2, M3, and M4, respectively. The membranes characteristics were evaluated using FE-SEM, FT-IR, and water contact angle measurements. In addition, the performance of the prepared membranes was investigated in terms of basic parameters: filtrate water flux, nitrate removal efficiency, and antifouling properties. Results showed significant improvements of the characteristics of modified...
SCAPS empowered machine learning modelling of perovskite solar cells: predictive design of active layer and hole transport materials
, Article Photonics ; Volume 10, Issue 3 , 2023 ; 23046732 (ISSN) ; Aynehband, S ; Abdollahi, H ; Alimohammadi, H ; Rajabi, N ; Angizi, S ; Kamraninejad, V ; Teimouri, R ; Mohammadpour, R ; Simchi, A ; Sharif University of Technology
MDPI
2023
Abstract
Recently, organic–inorganic perovskites have manifested great capacity to enhance the performance of photovoltaic systems, owing to their impressive optical and electronic properties. In this simulation survey, we employed the Solar Cell Capacitance Simulator (SCAPS-1D) to numerically analyze the effect of different hole transport layers (HTLs) (Spiro, CIS, and CsSnI3) and perovskite active layers (ALs) (FAPbI3, MAPbI3, and CsPbI3) on the solar cells’ performance with an assumed configuration of FTO/SnO2/AL/HTL/Au. The influence of layer thickness, doping density, and defect density was studied. Then, we trained a machine learning (ML) model to perform predictions on the performance metrics...
Dose-dependent effects of nanoscale graphene oxide on reproduction capability of mammals
, Article Carbon ; Volume 95 , December , 2015 , Pages 309-317 ; 00086223 (ISSN) ; Ghaderi, E ; Hashemi, E ; Akbari, E ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and...
Accelerated differentiation of neural stem cells into neurons on ginseng-reduced graphene oxide sheets
, Article Carbon ; Volume 66 , January , 2014 , Pages 395-406 ; Ghaderi, E ; Abouei, E ; Hatamie, S ; Ghasemi, E ; Sharif University of Technology
2014
Abstract
Asian red ginseng was used for green reduction of chemically exfoliated graphene oxide (GO) into reduced graphene oxide (rGO). The reduction level and electrical conductivity of the ginseng-rGO sheets were comparable to those of hydrazine-rGO ones. Reduction by ginseng resulted in repairing the sp 2 graphitic structure of the rGO, while hydrazine-rGO showed more defects and/or smaller aromatic domains. The ginseng-rGO sheets presented a better stability against aggregation than the hydrazine-rGO ones in an aqueous suspension. Whilst the hydrophobic hydrazine-rGO films exhibited no toxicity against human neural stem cells (hNSCs), the hydrophilic GO and ginseng-rGO films (as more...
Contested framings and policy controversies: Analysing biosafety policy-making in Iran
, Article Science and Public Policy ; Volume 40, Issue 5 , 2013 , Pages 616-627 ; 03023427 (ISSN) ; Millstone, E ; Sharif University of Technology
2013
Abstract
Vigorous debates have taken place within and between many countries about regulatory policy regimes covering the assessment and approval of genetically modified (GM) crops. In Iran, a very vigorous and hotly contested policy debate concerning legislation covering GM crops occurred between 2004 and 2009, but it was confined within government circles with almost no public discussion. This paper analyses the Iranian policy-making process in the period 2006-9. It explains how and why a stalemate arose in disputes between ministries and departments. The chosen analytical framework draws mainly on the regulation of technological risks and the analysis of public policy-making. It deploys the...
On the possible volumes of μ-way latin trades
, Article Aequationes Mathematicae ; Volume 63, Issue 3 , 2002 , Pages 303-320 ; 00019054 (ISSN) ; Billington, E. J ; Bryant, D. E ; Mahmoodian, E. S ; Sharif University of Technology
Birkhauser Verlag Basel
2002
Abstract
A μ-way latin trade of volume s is a set of μ partial latin rectangles (of inconsequential size) containing exactly the same s filled cells, such that if cell (i, j) is filled, it contains a different entry in each of the μ partial latin rectangles, and such that row i in each of the μ partial latin rectangles contains, set-wise, the same symbols and column j, likewise. In this paper we show that all μ-way latin trades with sufficiently large volumes exist, and state some theorems on the non-existence of μ-way latin trades of certain volumes. We also find the set of possible volumes (that is, the volume spectrum) of μ-way latin trades for μ = 4 and 5. (The case μ = 2 was dealt with by Fu,...