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rakhshan-haghighifard--pedram
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Simulation of Chip Segmentation in Metal Cutting Using ALE Finite Element Method
, M.Sc. Thesis Sharif University of Technology ; Movahhedy, Mohammad Reza (Supervisor)
Abstract
Since it is important to obtain the suitable cutting conditions for machining and investigate the effect of various parameters on this process, the simulation of this process has been developed extensively by using the finite element method in recent years. Due to very large plastic deformation and also continuous chip flow, one of the most appropriate techniques in modeling chip formation is the arbitrary Lagrangian-Eulerian (ALE) finite element method which has been used in several papers using some traditional codes like ABAQUS or personal codes in recent years. However, one of the limitations in this method is the use of a continuous mesh retains with no change in connectivities which is...
Smart micro/nano-robotic systems for gene delivery
, Article Current Gene Therapy ; Volume 17, Issue 2 , 2017 , Pages 73-79 ; 15665232 (ISSN) ; Nejat Pishkenari, H ; Sharif University of Technology
Bentham Science Publishers B.V
2017
Abstract
Background: Small scale robotics have attracted growing attention for the prospect of targeting and accessing cell-sized sites, necessary for high precision biomedical applications and drug/gene delivery. The loss of controlled gene therapy, inducing systemic side effects and reduced therapeutic efficiency, can be settled utilizing these intelligent carriers. Methods: Newly proposed solutions for the main challenges of control, power supplying, gene release and final carrier extraction/degradation have shifted these smart miniature robots to the point of being employed for practical applications of transferring oligonucleotides (pDNA, siRNA, mRNA, etc.) in near future. Conclusion: In this...
The Status of Scientific-Technological Instruments from the Point of View of Scientific Anti-Realism
, M.Sc. Thesis Sharif University of Technology ; Akbari, Javad (Supervisor)
Abstract
One of the main arguments between scientific realists and scientific anti-realists is about observability. As a prominent anti-realist, van Fraassen and his theory of constructive empiricism and his views on observability and the use of scientific instruments, have been the subject of many debates. He believes that observation is the sole path to knowledge and observation is only possible through unaided human eye, so seeing through scientific instruments like microscopes does not count as observation, therefore the information gained from these procedures are not necessarily true.This thesis not only examines van Fraassen’s outlooks on the matter, but also examines his opponents’ view and...
A Fabrication Method of Neutrally-buoyant Magnetic Micro-robot to Improve Its Motion Control
, M.Sc. Thesis Sharif University of Technology ; Nejat Pishkenari, Hossein (Supervisor)
Abstract
Micro-robotics is one of the currently emerging technologies which has attracted attentions for its probable applications in different fields including biotechnology, diagnosis and treatment in medical engineering as well as general studies in micro-scale science and engineering. Magnetic micro-robotics is considered as the most promising group, primarily due to the biocompatibility of magnetic fields and advances in electronic circuits to produce and control such fields. One critical point in utilizing these robots is their high density in comparison with the working fluid and their tendency to sink. In this thesis, a method to fabricate buoyant magnetic robots has been proposed based on...
Optimal controller design for 3D manipulation of buoyant magnetic microrobots via constrained linear quadratic regulation approach
, Article Journal of Micro-Bio Robotics ; Volume 15, Issue 2 , 2019 , Pages 105-117 ; 21946418 (ISSN) ; Nejat Pishkenari, H ; Sitti, M ; Sharif University of Technology
Springer
2019
Abstract
We consider magnetic actuation and control of a spherical neutrally buoyant magnetic microrobot via magnetic coil setups and seek to design an optimal controller to reduce the required energy and coils’ currents. We showed that in currently employed setups, where the actuation frequency is few tens of Hertz, the nonlinear dynamics of the system can be well approximated by a set of linear constrained ones. The approximated model is obtained by consciously overlooking the rotational dynamics and the inertia terms in translational dynamics. We acquired the linear quadratic regulation (LQR) controller for the approximated model which is a constrained time-varying system. Finally, 3D manipulation...
Comparison of strengths of five internal fixation methods used after bilateral sagittal split ramus osteotomy: An in vitro study
, Article Dental Research Journal ; Volume 17, Issue 4 , 2020 , Pages 258-265 ; Ahmady, A ; Farahmand, F ; Fateh, A ; Kahali, R ; Nourani, A ; Rakhshan, V ; Sharif University of Technology
Wolters Kluwer Medknow Publications
2020
Abstract
Results on the strength and displacement of internal fixation methods for bilateral sagittal split ramus osteotomy are controversial, and some designs have not been adequately studied. Therefore, this study was conducted to compare techniques using bicortical or monocortical screws. Materials and Methods: In this in vitro study, 35 sheep hemi-mandibles were randomly assigned to five groups of seven each: fixation using (1) a 13 × 2 screw, (2) two 13 × 2 screws (arranged vertically), (3) three 13 × 2 screws, (4) 1 plate with 4 holes and four monocortical screws, and (5) a Y-shaped plate and five monocortical screws. Specimens underwent vertical forces until failure. Breakage forces and...
A physicochemical evaluation of modified HZSM-5 catalyst utilized for production of dimethyl ether from methanol
, Article Petroleum Science and Technology ; Vol. 32, issue. 8 , Feb , 2014 , pp. 904-911 ; ISSN: 10916466 ; Kazemeini, M ; Fattahi, M ; Amjadian, A ; Sharif University of Technology
2014
Abstract
A number of HZSM-5 catalysts modified with 5 wt% Mg, Na, Zr, and Al as well as others modified with 5-60 wt% Zn prepared by wet impregnation. These materials were characterized by the NH3-TPD, XRF, and XRD analyses and tested in a slurry reactor to determine their activities in dehydration of methanol solution in kerosene. Reactions were carried out at 230°C and 19 bar for 4 h of residence time in the reactor. Results showed that in the first series, the catalyst modified with Zr and in the second series, the one modified with 10 wt% Zn led to the highest methanol conversion. It was deduced that elimination of strong acid sites and partial replacement of active cations in the HZSM-5 zeolite...
Analysis and fast estimation of energy consumption in template based QDI asynchronous circuits
, Article 2007 International Symposium on Integrated Circuits, ISIC, Singapore, 26 September 2007 through 28 September 2007 ; 2007 , Pages 445-448 ; 1424407974 (ISBN); 9781424407972 (ISBN) ; Mirza Aghatabar, M ; Pedram, H ; Hessabi, S ; Sharif University of Technology
2007
Abstract
In this paper we analyses the energy consumption of well known family of asynchronous circuits and present a new methodology for energy estimation of these circuits at intermediate-level of abstraction. Energy estimation is performed by simulating the intermediate format of the design. The number of Read and Write accesses on the ports of the concurrent processes are counted by analyzing the conditional and computational portion during the simulation which is the base of our estimation methodology. Our proposed power estimation scheme is faster than usual post-synthesis power estimation by an order of 9, while the estimated power resides in a boundary of 11% total imprecision. © 2007 IEEE
An empirical investigation of mesh and torus NoC topologies under different routing algorithms and traffic models
, Article 10th Euromicro Conference on Digital System Design Architectures, Methods and Tools, DSD 2007, Lubeck, 29 August 2007 through 31 August 2007 ; October , 2007 , Pages 19-26 ; 076952978X (ISBN); 9780769529783 (ISBN) ; Koohi, S ; Hessabi, S ; Pedram, M ; Sharif University of Technology
2007
Abstract
NoC is an efficient on-chip communication architecture for SoC architectures. It enables integration of a large number of computational and storage blocks on a single chip. NoCs have tackled the SoCs disadvantages and are scalable. In this paper, we compare two popular NoC topologies, i.e., mesh and torus, in terms of different figures of merit e.g., latency, power consumption, and power/throughput ratio under different routing algorithms and two common traffic models, uniform and hotspot. To the best of our knowledge, this is the first effort in comparing mesh and torus topologies under different routing algorithms and traffic models with respect to their performance and power consumption....
Toward epileptic brain region detection based on magnetic nanoparticle patterning
, Article Sensors (Switzerland) ; Volume 15, Issue 9 , September , 2015 , Pages 24409-24427 ; 14248220 (ISSN) ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Sharif University of Technology
MDPI AG
2015
Abstract
Resection of the epilepsy foci is the best treatment for more than 15% of epileptic patients or 50% of patients who are refractory to all forms of medical treatment. Accurate mapping of the locations of epileptic neuronal networks can result in the complete resection of epileptic foci. Even though currently electroencephalography is the best technique for mapping the epileptic focus, it cannot define the boundary of epilepsy that accurately. Herein we put forward a new accurate brain mapping technique using superparamagnetic nanoparticles (SPMNs). The main hypothesis in this new approach is the creation of super-paramagnetic aggregates in the epileptic foci due to high electrical and...
Optimal magnetic field for crossing super-para-magnetic nanoparticles through the Brain Blood Barrier: A computational approach
, Article Biosensors ; Volume 6, Issue 2 , 2016 ; 20796374 (ISSN) ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Sharif University of Technology
MDPI AG
2016
Abstract
This paper scrutinizes the magnetic field effect to deliver the superparamagnetic nanoparticles (SPMNs) through the Blood Brain Barrier (BBB). Herein we study the interaction between the nanoparticle (NP) and BBB membrane using Molecular Dynamic (MD) techniques. The MD model is used to enhance our understanding of the dynamic behavior of SPMNs crossing the endothelial cells in the presence of a gradient magnetic field. Actuation of NPs under weak magnetic field offers the great advantage of a non-invasive drug delivery without the risk of causing injury to the brain. Furthermore, a weak magnetic portable stimulator can be developed using low complexity prototyping techniques. Based on MD...
Dynamic analysis of magnetic nanoparticles crossing cell membrane
, Article Journal of Magnetism and Magnetic Materials ; Volume 429 , 2017 , Pages 372-378 ; 03048853 (ISSN) ; Shamloo, A ; Ghafar Zadeh, E ; Alasty, A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Nowadays, nanoparticles (NPs) are used in a variety of biomedical applications including brain disease diagnostics and subsequent treatments. Among the various types of NPs, magnetic nanoparticles (MNPs) have been implemented by many research groups for an array of life science applications. In this paper, we studied MNPs controlled delivery into the endothelial cells using a magnetic field. Dynamics equations of MNPs were defined in the continuous domain using control theory methods and were applied to crossing the cell membrane. This study, dedicated to clinical and biomedical research applications, offers a guideline for the generation of a magnetic field required for the delivery of...
Proposal and assessment of a new geothermal-based multigeneration system for cooling, heating, power, and hydrogen production, using LNG cold energy recovery
, Article Renewable Energy ; Volume 135 , 2019 , Pages 66-87 ; 09601481 (ISSN) ; Rostamzadeh, H ; Zamani Pedram, M ; Ghaebi, H ; Amidpour, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Multigeneration systems (MGSs) driven by renewable sources are proved as cutting-edge technologies for multiple productions purposes to curb greenhouse gas emissions. With this regard, a novel geothermal-based MGS is proposed to produce multiple commodities of cooling, heating, power, and hydrogen, simultaneously, using liquefied natural gas (LNG) as cold energy recovery. The system is composed of an organic Rankine cycle (ORC), an ejector refrigeration cycle (ERC), an LNG power generation system, and a proton exchange membrane (PEM) electrolyzer system. To demonstrate the feasibility of the proposed MGS, energy, exergy, and exergoeconomic analysis are employed as the most effective tools...
Reimbursing the handshake overhead of asynchronous circuits using compiler pre-synthesis optimizations
, Article 11th EUROMICRO Conference on Digital System Design Architectures, Methods and Tools, DSD 2008, Parma, 3 September 2008 through 5 September 2008 ; 2008 , Pages 290-297 ; 9780769532776 (ISBN) ; Mirza Aghatabar, M ; Najibi, M ; Pedram, H ; Sadeghi, A ; Sharif University of Technology
2008
Abstract
Asynchronous circuits have many advantages vs synchronous design styles like high performance and lower power consumption; however, there is a drawback of big overhead in handshake circuitry of these circuits. In this paper, we have reduced the amount of these extra circuits by take advantage of some compiler techniques. The compiler methods can be used innovatively to improve the synthesis results in terms of both power consumption and area, since these code motions lead to removing of completion detection and validity check parts of asynchronous designs. To the best of our knowledge this is the first effort in using the compiler pre-synthesis optimizations in asynchronous circuits to...
Steered molecular dynamic simulation approaches for computing the blood brain barrier (BBB) diffusion coefficient
, Article IFMBE Proceedings ; Volume 51 , 2015 , Pages 1699-1703 ; 16800737 (ISSN) ; 9783319193878 (ISBN) ; Shamloo, A ; Alasti, A ; Zadeh, E. G ; Jaffray D. A ; Sharif University of Technology
Springer Verlag
2015
Abstract
In the recent years a great attention of research deals with different physical and biological aspects of the BBB structure, a robust shield that separates the blood and brain, a recent research held by the authors of this paper has focused on figuring out computing the diffusion coefficient of endothelial cell membrane. In this study, the major efforts have been concentrated on calculating a standardized measure for the amount of permeability and diffusion of this barrier. As a result, this work is dedicated to molecular dynamics (MD) simulation of calculating the interaction force between nano-particle and BBB membrane. data is recorded by using steered molecular dynamics simulation and...
Superparamagnetic nanoparticles for epilepsy detection
, Article World Congress on Medical Physics and Biomedical Engineering, 2015, 7 June 2015 through 12 June 2015 ; Volume 51 , June , 2015 , Pages 1237-1240 ; 16800737 (ISSN) ; 9783319193878 (ISBN) ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Jaffray D. A ; Sharif University of Technology
Springer Verlag
2015
Abstract
Epilepsy is the most common neurological disorder that is known with uncontrolled seizure. Around 30% of patients with epilepsy resist to all forms of medical treatments and therefore, the removal of epileptic brain tissue is the only solution to get these patients free from chronical seizures. The precise detection of an epileptic zone is key to its treatment. In this paper, we propose a method of epilepsy detection using brain magnetic field. The possibility of superparamagnetic nanoparticle (SPMN) as sensors for the detection of the epileptic area inside the brain is investigated. The aggregation of nanoparticles in the weak magnetic field of epileptic brain is modeled using potential...
Dynamic analysis of magnetic nanoparticles crossing cell membrane
, Article Journal of Magnetism and Magnetic Materials ; Volume 422 , 2017 , Pages 464- ; 03048853 (ISSN) ; Shamloo, A ; Ghafar Zadeh, E ; Alasty, E. Y. C. A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Nowadays, nanoparticles (NPs) are used in a variety of biomedical applications including brain disease diagnostics and subsequent treatments. Among the various types of NPs, magnetic nanoparticles (MNPs) have been implemented by many research groups for an array of life science applications. In this paper, we studied MNPs controlled delivery into the endothelial cells using a magnetic field. Dynamics equations of MNPs were defined in the continuous domain using control theory methods and were applied to crossing the cell membrane. This study, dedicated to clinical and biomedical research applications, offers a guideline for the generation of a magnetic field required for the delivery of...
High-level modeling approach for analyzing the effects of traffic models on power and throughput in mesh-based NoCs
, Article Proceedings of the IEEE International Frequency Control Symposium and Exposition, 4 January 2008 through 8 January 2008, Hyderabad ; 2008 , Pages 415-420 ; 0769530834 (ISBN); 9780769530833 (ISBN) ; Mirza Aghatabar, M ; Hessabi, S ; Pedram, M ; VLSI Society of India ; Sharif University of Technology
2008
Abstract
Traffic models exert different message flows in a network and have a considerable effect on power consumption through different applications. So a good power analysis should consider traffic models. In this paper we present power and throughput models in terms of traffic rate parameters for the most popular traffic models, i.e. Uniform, Local, HotSpot and First Matrix Transpose (FMT) as a permutational traffic model. We also select Mesh topology as the most prominent NoC topology and validate the presented models by comparing our results against simulation results from Synopsys Power Compiler and Modelsim From the comparison, we show that our modeling approach leads to average error of 2%...
Dynamics of Magnetic Nanoparticles in Biologically Inspired Flows under Effect of Electric and Magnetic Fields with Application in Epilepsy Detection
, Ph.D. Dissertation Sharif University of Technology ; Alasty, Aria (Supervisor) ; Ghaffarzadeh, Ebrahim (Supervisor) ; Shamloo, Amir (Co-Advisor)
Abstract
This thesis presents my Ph.D. research study focusing on the dynamic analysis of magnetic nanoparticles (MNPs) for epilepsy and blood-brain barrier (BBB) applications. In this analysis, we took into account various parameters including the magnetic field, fluid behavior, geometry and material of MNPs. Based on this computational study, the generated magnetic field in epileptic foci results in the aggregation of nanoparticles. This may offer the advantage of using MNPs as a Magnetic Resonance Imaging (MRI) contrast agent. Furthermore, in this study, we also demonstrated and discussed the advantage of MNPs for crossing BBB using the external magnetic field. The outcome of this research project...
The evaluation of PM10, PM2.5, and PM1 concentrations during the Middle Eastern Dust (MED) events in Ahvaz, Iran, from april through september 2010
, Article Journal of Arid Environments ; Volume 77, Issue 1 , 2012 , Pages 72-83 ; 01401963 (ISSN) ; Naddafi, K ; Jafarzade Haghighifard, N ; Mesdaghinia, A ; Yunesian, M ; Nabizadeh, R ; Arahami, M ; Sowlat, M. H ; Yarahmadi, M ; Saki, H ; Alimohamadi, M ; Nazmara, S ; Motevalian, S. A ; Goudarzi, G ; Sharif University of Technology
2012
Abstract
In this study, PM10, PM2.5, and PM1 concentrations were measured from April through September 2010. These measurements were made every six days and on days with dust events using a Grimm Model 1.177 aerosol spectrometer. Meteorological data were also collected. Overall mean values of 319.6 ± 407.07, 69.5 ± 83.2, and 37.02 ± 34.9 μg/m3 were obtained for PM10, PM2.5, and PM1, respectively, with corresponding maximum values of 5337.6, 910.9, and 495 μg/m3. The presence of the westerly prevailing wind implied that Iraq is the major source of dust events in this area. A total of 72 dust days and 711 dust hours occurred in the study area. The dust events occurred primarily during July. The longest...