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Bilayered heparinized vascular graft fabricated by combining electrospinning and freeze drying methods
, Article Materials Science and Engineering C ; Volume 94 , 2019 , Pages 1067-1076 ; 09284931 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Small diameter vascular grafts (<6 mm) are highly demanded for patients suffering from severe occluded arteries to be used as a bypass or substituted conduit. Fabricating a graft with appropriate structural, mechanical and cell growth properties which has simultaneously anti-thrombogenic trait is a challenge nowadays. Here, we proposed a bilayer heparinized vascular graft that can mimic the structural and mechanical characteristics close to those of the native coronary artery by combining electrospinning and freeze drying methods. In this study, the inner layer was made by co-electrospinning of synthetic polymer, poly-caprolactone (PCL) and the natural polymer, gelatin (Gel). Also, heparin...
Bilayered heparinized vascular graft fabricated by combining electrospinning and freeze drying methods
, Article Materials Science and Engineering C ; Volume 94 , 2019 , Pages 1067-1076 ; 09284931 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Small diameter vascular grafts (<6 mm) are highly demanded for patients suffering from severe occluded arteries to be used as a bypass or substituted conduit. Fabricating a graft with appropriate structural, mechanical and cell growth properties which has simultaneously anti-thrombogenic trait is a challenge nowadays. Here, we proposed a bilayer heparinized vascular graft that can mimic the structural and mechanical characteristics close to those of the native coronary artery by combining electrospinning and freeze drying methods. In this study, the inner layer was made by co-electrospinning of synthetic polymer, poly-caprolactone (PCL) and the natural polymer, gelatin (Gel). Also, heparin...
Design and Fabrication of Engineered Biomaterials for Tissue Engineering Applications such as Cardiovascular System
, M.Sc. Thesis Sharif University of Technology ; Shamlou, Amir (Supervisor)
Abstract
Cardiovascular diseases are the leading cause of death all over the world, even more common than cancers. The first reason of mortality in Iran according to statistics is the occlusion of coronary arteries. Unfortunately almost one third of patients doesn’t have enough blood vessels to be used in the bypass surgery and need artificial vessels. These artificial blood vessels with small diameters (less than 6 mm) will fail quickly. As a result there is an increasing demand for tissue engineered blood vessels which are capable of enduring high blood pressures. An artificial blood vessel should mimic both structure and mechanical properties of the real one. Blood vessels have layered structures,...
Secure data transmission using qubits
, Article 6th IEEE International Conference on Computer and Information Technology, CIT 2006, Seoul, 20 September 2006 through 22 September 2006 ; 2006 ; 076952687X (ISBN); 9780769526874 (ISBN) ; Hosseini Khayat, S ; Sharif University of Technology
2006
Abstract
A quantum protocol for secure transmission of data using qubits is presented. This protocol sends one qubit in a round-trip to transmit one bit of data. The protocol offers an improvement over the BB84 QKD protocol. BB84, in conjunction with one-time pad encryption, has been shown to be unconditionally secure. However its security relies on the assumption that the qubit source device does not emit multiple replicas of the same qubit for each transmitted bit. If this happens a multi-qubit emission attack can be launched. In addition, BB84 cannot be used to send predetermined bit strings as it generates a random bit string in the process. Our protocol does not have the above drawbacks, but...
Exergoenvironmental and exergoeconomic modelling and assessment in the complex energy systems
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 41, Issue 3 , 2022 , Pages 989-1002 ; 10219986 (ISSN) ; Choubanpisheh, S ; Talebi, S ; Khajehpour, H ; Sharif University of Technology
Iranian Institute of Research and Development in Chemical Industries
2022
Abstract
Traditionally energy systems were analyzed technically, but current environmental issues and considerations have put new constraints on the planning and managing of energy systems. Such an exergoeconomic and exergoenvironmental analysis were born. This analysis is aimed to describe the necessity and application of a new concept in environmental liability accounting based on physical quantities to overcome the weaknesses of the developed allocation methods and the internalization of external environmental damages. The proposed method is modified in environmental analysis to consider the effect of non-energy flows on a macro-surface energy system. As a case study, this method is tuned for a...
IF band width optimization of envelope detection system in presence of phase noise
, Article IET International Radar Conference 2009, Guilin, 20 April 2009 through 22 April 2009 ; Issue 551 CP , 2009 ; 9781849190107 (ISBN) ; Mirzaei, S ; Norouzi, Y ; Sharif University of Technology
2009
Abstract
In many radar and EW applications, after some processing, the envelope of the received pulse is calculated and is used for target detection. Most of the time only the effect of thermal noise is considered in such detectors, but in most of the practical applications, before envelope detection, the signal should be down converted from radio frequency (RF) to an intermediate frequency (IF). In this case, the phase noise of the local oscillator will affect the signal, too. Surprisingly, in contrast to thermal noise, the effect of phase noise on the envelope of signal becomes more considerable whenever the IF bandwidth is decreased. So there exists an optimum IF bandwidth for the receiver. In...
Approximating the distribution of flaws in magnetic materials using the generalized inverse
, Article 2011 IEEE International Conference on Imaging Systems and Techniques, IST 2011 - Proceedings, 17 May 2011 through 18 May 2011, Batu Ferringhi ; May , 2011 , Pages 137-141 ; 9781612848969 (ISBN) ; Abdollahi Jahdi, S ; Norouzi, E ; Sharif University of Technology
2011
Abstract
Non-destructive identification of voids in ferromagnetic materials is of great importance for industrial applications. Magnetic flux leakage technique is used here to examine the defected structure. To this end, an inverse problem should be solved in order to infer the location and depth of internal flaws from the measured leaked magnetic signals. Currently generalized inverse method and singular value decomposition are used for solving such inverse problem. Considering the cracks separation has significant effect on the absolute value of magnetic flux leakage signals, we study different distributions of cracks. In this paper, the magnetic dipole model is proposed to reconstruct the extent...
Angle of arrival-based target localisation with low Earth orbit satellite observer
, Article IET Radar, Sonar and Navigation ; Volume 10, Issue 7 , 2016 , Pages 1186-1190 ; 17518784 (ISSN) ; Kashani, E. S ; Ajorloo, A ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
In triangulation (or angle of arrival) target localisation method, the surface of the Earth is approximated by a flat plate. This approximation, while acceptable for low-altitude observers (such as unmanned aerial vehicles), is not a correct model for high-altitude observers (such as low Earth orbit - LEO satellites). In this study, the authors have discussed triangulation method using a LEO satellite observer over a spherical surface and have shown that, using spherical trigonometry and singular value decomposition (SVD), a straight forward solution can be found for target localisation problem. Also, error bound is discussed and analysed using both SVD as well as simulation. © The...
Electrochemical potential noise analysis of Cu-BTA system using wavelet transformation
, Article Journal of Electroanalytical Chemistry ; Volume 633, Issue 1 , 2009 , Pages 240-245 ; 15726657 (ISSN) ; Roshan, M. S ; Norouzi, S ; Sadrnezhaad, S. K ; Jafari, A ; Sharif University of Technology
Elsevier
2009
Abstract
Electrochemical potential noise analysis was used to investigate corrosion behavior of copper electrodes in presence of 0.001, 0.005, 0.01 and 0.02 M benzotriazole (BTA) inhibitor. Energy distribution of the potential noise was obtained from wavelet transformation using the 4th order Daubechies pattern. Two lowest frequencies were added-up and fitted to the impulse response of the first order circuit to achieve the time-constant vs. concentration (T-C) diagram. T-C diagram can be used either as a conventional diagram of inhibition efficiency or a tool for evaluation of the surface film dielectric constant. The assumptions made in this treatment were confirmed by EIS method. © 2009 Elsevier...
Conceptual duct shape design for horizontal-axis hydrokinetic turbines
, Article Scientia Iranica ; Volume 23, Issue 5 , 2016 , Pages 2113-2124 ; 10263098 (ISSN) ; Rad, M ; Khayat, M ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
In the present paper, conceptual duct shape design for kinetic energy extraction with hydrokinetic turbines is discussed. The goal is to find a single-passage axisymmetric geometry that holds stable flow with maximum kinetic energy flux at duct throat. For finding the optimum duct shape, the fluid flow was numerically simulated in a wedge shaped space with Flow-Simulation Software. In a multi-stage conceptual design, tabulated configurations were employed to study each geometrical characteristic separately. These include curvature of profile camber, trailing edge shape, profile tip shape, and duct exit cross sectional area. The revolved profile of each duct consists of a well constrained...
COVID-19 and health inequality: the nexus of race, income and mortality in New York City
, Article International Journal of Human Rights in Healthcare ; 2021 ; 20564902 (ISSN) ; Teron, L ; Rasoulyan, F ; Sharif University of Technology
Emerald Group Holdings Ltd
2021
Abstract
Purpose: The purpose of this paper is to evaluate socioeconomic factors related to COVID-19 mortality rates in New York City (NYC) to understand the connections between socioeconomic variables, including race and income and the disease. Design/methodology/approach: Using multivariable negative binomial regression, the association between health and mortality disparities related to COVID-19 and socioeconomic conditions is evaluated. The authors obtained ZIP code-level data from the NYC Department of Health and Mental Hygiene and the US Census Bureau. Findings: This study concludes that the mortality rate rises in areas with a higher proportion of Hispanic and Black residents, whereas areas...
COVID-19 and health inequality: the nexus of race, income and mortality in New York City
, Article International Journal of Human Rights in Healthcare ; Volume 15, Issue 4 , 2022 , Pages 363-372 ; 20564902 (ISSN) ; Teron, L ; Rasoulyan, F ; Sharif University of Technology
Emerald Group Holdings Ltd
2022
Abstract
Purpose: The purpose of this paper is to evaluate socioeconomic factors related to COVID-19 mortality rates in New York City (NYC) to understand the connections between socioeconomic variables, including race and income and the disease. Design/methodology/approach: Using multivariable negative binomial regression, the association between health and mortality disparities related to COVID-19 and socioeconomic conditions is evaluated. The authors obtained ZIP code-level data from the NYC Department of Health and Mental Hygiene and the US Census Bureau. Findings: This study concludes that the mortality rate rises in areas with a higher proportion of Hispanic and Black residents, whereas areas...
Heavy oil thermal conversion and refinement to the green petroleum: A petrochemical refinement plant using the sustainable formic acid for the process
, Article Biointerface Research in Applied Chemistry ; Volume 10, Issue 5 , 2020 , Pages 6088-6100 ; Talebi, S ; Fabi, M ; Khajehpour, H ; Sharif University of Technology
AMG Transcend Association
2020
Abstract
In this study, heat oil conversion experiments using steam and formic acid as a hydrogen carrier be carried out in a batch reactor at T = 380 degrees of Celsius and P = 165 bar. Material balance and product distribution were calculated after the process. Properties of crude oil before and after thermal conversion, including viscosity, API gravity, SARA measurement, and elemental analysis, were analyzed. It has been presented that the use of formic acid as a hydrogen carrier solvent reduces the formation of coke and gaseous products and enhances the performance of liquid products. Also, the viscosity of the refined oil decreased by 23.2% due to the addition of formic acid compared to the...
Exergy and exergoeconomic analysis of hydrogen and power cogeneration using an HTR plant
, Article Nuclear Engineering and Technology ; Volume 53, Issue 8 , 2021 , Pages 2753-2760 ; 17385733 (ISSN) ; Talebi, S ; Fani, M ; Khajehpour, H ; Sharif University of Technology
Korean Nuclear Society
2021
Abstract
This paper proposes using sodium-cooled fast reactor technologies for use in hydrogen vapor methane (SMR) modification. Using three independent energy rings in the Russian BN-600 fast reactor, steam is generated in one of the steam-generating cycles with a pressure of 13.1 MPa and a temperature of 505 °C. The reactor's second energy cycles can increase the gas-steam mixture's temperature to the required amount for efficient correction. The 620 ton/hr 540 °C steam generated in this cycle is sufficient to supply a high-temperature synthesis current source (700 °C), which raises the steam-gas mixture's temperature in the reactor. The proposed technology provides a high rate of hydrogen...
Performance evaluation of k out of n detector
, Article 14th European Signal Processing Conference, EUSIPCO 2006, Florence, 4 September 2006 through 8 September 2006 ; 2006 ; 22195491 (ISSN) ; Greco, M. S ; Nayebi, M. M ; Sharif University of Technology
2006
Abstract
In this paper the problem of k out of n detection, between sequence of M random bits is addressed. The main application of the result is in a radar system, when we want to detect a target (with unknown time of arrival (TOA)), using binary integration. Another application is in ESM systems, when the system wants to detect the existence of a swept jammer or a gated noise jammer. But as any other mathematical problem, it may have some other applications. In this paper some simple equations for P fa and P d calculation of a detector which detects the existence of sequence of n ones between M random bits, is derived. These equations are then used to find the optimal detector structure in some...
Evolving data stream clustering based on constant false clustering probability
, Article Information Sciences ; Volume 614 , 2022 , Pages 1-18 ; 00200255 (ISSN) ; Bagheri Shouraki, S ; Norouzi, Y ; Sharif University of Technology
Elsevier Inc
2022
Abstract
Today's world needs new methods to deal with and analyze the ever-increasingly generated data streams. Two of the most challenging aspects of data streams are (i) concept drift, i.e. evolution of data stream over time, which requires the ability to make timely decisions against the high speed of receiving new data; (ii) limited memory storage and the impracticality of using memory due to the large amount of data. Clustering is one of the common methods to process data streams. In this paper, we propose a novel, fully-online, density-based method for clustering evolving data streams. In recent years, a number of methods have been proposed, which also have the ability to cluster data streams....
Numerical and experimental investigations for design of a high performance microhydro-kinetic turbine
, Article International Journal of Engineering, Transactions B: Applications ; Volume 30, Issue 5 , 2017 , Pages 785-790 ; 1728144X (ISSN) ; Rad, M ; Khayat, M ; Sharif University of Technology
2017
Abstract
Design and manufacturing of a high performance micro-hydro-kinetic turbine is discussed in the present paper. The main goal is manufacturing an equipped experimental model of hydro-kinetic turbine with highest energy absorption from water current. A multi-shape ducted turbine comprised of a multi-part diffuser was manufactured that can be converted to many experimental models for studying various diffuser enhancing effects. Turbine's rotor included a three-blade axial propeller and a mixed six-blade propeller with high power coefficient. Simple experiments on propeller were performed for flow visualization, torque measurement and illustrating dynamic balance at high speed rotation in air and...
Advances in skin regeneration: application of electrospun scaffolds
, Article Advanced Healthcare Materials ; Volume 4, Issue 8 , 2015 , Pages 1114-1133 ; 21922640 (ISSN) ; Boroujeni, S. M ; Omidvarkordshouli, N ; Soleimani, M ; Sharif University of Technology
Wiley-VCH Verlag
2015
Abstract
The paucity of cellular and molecular signals essential for normal wound healing makes severe dermatological ulcers stubborn to heal. The novel strategies of skin regenerative treatments are focused on the development of biologically responsive scaffolds accompanied by cells and multiple biomolecules resembling structural and biochemical cues of the natural extracellular matrix (ECM). Electrospun nanofibrous scaffolds provide similar architecture to the ECM leading to enhancement of cell adhesion, proliferation, migration and neo tissue formation. This Review surveys the application of biocompatible natural, synthetic and composite polymers to fabricate electrospun scaffolds as skin...
Extended-gate field-effect transistor based sensor for detection of hyoscine n-butyl bromide in its pharmaceutical formulation
, Article Analytical and Bioanalytical Electrochemistry ; Volume 12, Issue 2 , 2020 , Pages 238-249 ; Mirzaie, S. I ; Fardmanesh, M ; Norouzi, P ; Sharif University of Technology
Center of Excellence in Electrochemistry, Univ. of Tehran
2020
Abstract
A novel recognition method for selective determination of the hyoscine N-Butyl bromide (HBB), an antispasmodic agent for smooth muscles, was devised using extended gate field-effect transistor (EG-FET) as transducing unit. For this purpose a PVC membrane, containing hyoscine n-butyl-tetraphenyl borate ion-pair as recognition component, was coated on Ag/AgCl wire, which was connected to the extended metal gate. In optimal conditions, the linear range for HBB was 10-8-10-5 molL−1 with limit of detection 1.7×10-9 molL-1. The proposed sensor was applied in real sample, it showed fast response with high accuracy, and therefore it could be used as HPLC detector in the pharmaceutical samples in...
Minimum control effort trajectory planning and tracking of the CEDRA brachiation robot
, Article Robotica ; Volume 31, Issue 7 , 2013 , Pages 1119-1129 ; 02635747 (ISSN) ; Lavasani, S. M. H ; Norouzi, M ; Mousavi, M. S. R ; Sharif University of Technology
2013
Abstract
The control of a brachiation robot has been the primary objective of this study. A brachiating robot is a type of a mobile arm that is capable of moving from branch to branch similar to a long-armed ape. In this paper, to minimize the actuator work, Pontryagin's minimum principle was used to obtain the optimal trajectories for two different problems. The first problem considers brachiation between fixed branches with different distance and height, whereas the second problem deals with the brachiating and catching of a moving target branch. Theoretical results show that the control effort in the proposed method is reduced by 25% in comparison with the target dynamics method which was proposed...