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hashemifar--zakieh
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Oppositely charged MXene fibers as a highly efficient osmotic power generator from sea and river water
, Article Journal of Materials Chemistry A ; Volume 10, Issue 46 , 2022 , Pages 24915-24926 ; 20507488 (ISSN) ; Esfandiar, A ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
Ion-exchange membrane-based reverse electrodialysis (RED) shows great potential for harvesting osmotic energy from seawater and converting it to electricity. However, their low energy conversion efficiency and huge ionic resistance hinder their application on large scales. The implementation of nanofluidic channels in RED devices can significantly improve the performance of osmotic power generators due to their selective and fast ion transport. However, technical challenges in scalable processing at the nanoscale and ion-selective membranes restrict their development in economically viable generators. Here, we report fibrous-based channels as positively and negatively charged MXene fibers...
An Analysis of a Mathematical Model Describing the Geographic Spread of Dengue Disease
, M.Sc. Thesis Sharif University of Technology ; Hesaraki, Mahmoud (Supervisor)
Abstract
We consider a system of nonlinear partial differential equations corresponding to a generalization of a mathematical model for geographical spreading of dengue disease. the mosquito population is divided into subpopulations: winged form (mature female mosquitoes) and aquatic form (comprising eggs, larvae and pupae); the human population is divided into the subpopulations:susceptible, infected and removed (or immune). On the other hand we allow higher spatial dimensions and also parameters depending on space and time. is last generalization is done to cope with possible abiotic effects as variations in temperature, humidity, wind velocity, carrier capacities, and so on; thus, the results...
Study of Ion Transport from the Two-Dimensional Structure of MXene
, M.Sc. Thesis Sharif University of Technology ; Esfandiar, Ali (Supervisor)
Abstract
Reverse electrodialysis-based membranes are one of the most promising approaches to osmotic energy production. However, conventional reverse electrodialysis membranes have high strength and insufficient mass transfer, which leads to low power density and efficiency. In recent decades, the transport of ions at the nanoscale for the manufacture of reverse electrodialysis machines has attracted much attention. Compared to conventional devices, power density and energy conversion efficiency increase dramatically due to space constraints and electrostatic interactions at the nanoscale. Lamellar nanostructures, which can be easily fabricated by stacking two-dimensional nanosheets, may be a...
Compressive Sensing in Complex Networks with Topological Constraints
, M.Sc. Thesis Sharif University of Technology ; Rabiee, Hamid Reza (Supervisor)
Abstract
Compressive Sensing (CS) is a new paradigm in signal processing and information theory, which proposes to sample and compress sparse signals simultaneously and has drawn much attention in recent years. Many signals in lots of applications have a sparse representation in some bases, so CS is used as an efficient way of data compression in many applications such as image processing and medical applications in the last couple of years. Since some of the distributed information in complex networks are compressible too, CS can be used in order to gather the distribted information on the nodes or links efficiently. Traffic analysis and performance monitoring in computer networks, topology...
UCS-NT: An unbiased compressive sensing framework for Network Tomography
, Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings ; 2013 , Pages 4534-4538 ; 15206149 (ISSN) ; 9781479903566 (ISBN) ; Rabiee, H. R ; Hashemifar, Z. S ; Sharif University of Technology
2013
Abstract
This paper addresses the problem of recovering sparse link vectors with network topological constraints that is motivated by network inference and tomography applications. We propose a novel framework called UCS-NT in the context of compressive sensing for sparse recovery in networks. In order to efficiently recover sparse specification of link vectors, we construct a feasible measurement matrix using this framework through connected paths. It is theoretically shown that, only O(k log(n)) path measurements are sufficient for uniquely recovering any k-sparse link vector. Moreover, extensive simulations demonstrate that this framework would converge to an accurate solution for a wide class of...
NETAL: A new graph-based method for global alignment of protein-protein interaction networks
, Article Bioinformatics ; Volume 29, Issue 13 , 2013 , Pages 1654-1662 ; 13674803 (ISSN) ; Khadem, A ; Hashemifar, S ; Arab, S. S ; Sharif University of Technology
2013
Abstract
Motivation: The interactions among proteins and the resulting networks of such interactions have a central role in cell biology. Aligning these networks gives us important information, such as conserved complexes and evolutionary relationships. Although there have been several publications on the global alignment of protein networks; however, none of proposed methods are able to produce a highly conserved and meaningful alignment. Moreover, time complexity of current algorithms makes them impossible to use for multiple alignment of several large networks together.Results: We present a novel algorithm for the global alignment of protein-protein interaction networks. It uses a greedy method,...
The barrier effect of a WxTa(1-x) nanolayer on formation of single-texture CoSi2 on Si(1 0 0)
, Article Semiconductor Science and Technology ; Volume 21, Issue 8 , 2006 , Pages 1181-1192 ; 02681242 (ISSN) ; Moshfegh, A. Z ; Hashemifar, S. J ; Azimirad, R ; Sharif University of Technology
2006
Abstract
We have studied the phase formation of a CoSi2 layer by solid-state reaction of ternary Co/WxTa(1-x)/Si(1 0 0) systems. The effect of cosputtered WxTa(1-x) nanometric interlayers, with different values of x (0, 0.25, 0.5, 0.75 and 1), on the degree of texturing of a CoSi2 layer and disilicide formation of the refractory metals has been investigated. The annealed samples, in a temperature range of 400-1000 °C, were analysed by x-ray diffraction, sheet resistance measurement, scanning electron microscopy, and energy-dispersive x-ray techniques. Using W0.25Ta0.75 and W interlayers, the best (1 0 0) texture of the CoSi2 layer with a thermal stability in the range of 900-1000 °C was produced. In...
Single-crystalline growth of CoSi 2 by refractory-interlayer- mediated epitaxy
, Article Applied Surface Science ; Volume 233, Issue 1-4 , 2004 , Pages 123-128 ; 01694332 (ISSN) ; Moshfegh, A. Z ; Hashemifar, S. J ; Azimirad, R ; Sharif University of Technology
Elsevier
2004
Abstract
Single-crystal epitaxial quality of CoSi 2 films grown on Si(100) by refractory-interlayer-mediated epitaxy has been investigated. Thin layers of 10 nm co-sputtered W x Ta (1-x) , as refractory metal interlayers deposited on the Si, were followed by 25 nm of evaporated Co layer. The fabricated Co/W x Ta (1-x) /Si(100) systems were annealed in a temperature range from 400 to 1000°C in an N 2 (80%) + H 2 (20%) ambient for 1h. The annealed samples were analyzed and compared by sheet resistance measurement, X-ray diffraction, scanning electron microscopy, and wavelength dispersive spectroscopy techniques. In Co/W 0.25 Ta 0.75 /Si(100) system, with the best thermal stability, the grown CoSi 2...