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Optimization of a vanillin assay for determination of anthocyanins using D-optimal design
, Article Analytical Methods ; Volume 4, Issue 3 , Feb , 2012 , Pages 824-829 ; 17599660 (ISSN) ; Roohi, T ; Moghaddam, G ; Khoshayand, F ; Shahbazikhah, P ; Oveisi, M. R ; Hajimahmoodi, M ; Sharif University of Technology
2012
Abstract
The vanillin assay is a spectrophotometric method for anthocyanin determination that is simple, quick and inexpensive. The method is preferred because of its high sensitivity, specificity and simplicity; however, the results of this test are influenced by several factors. Hence, a D-optimal experimental design approach was investigated to simultaneously, without loss of information, optimize five factors that influence the vanillin assay: acid normality, vanillin concentration, temperature, time and acid type. Further optimization with a D-optimal design and response surface analysis (RSM) showed that a second-order polynomial model fit the experimental data appropriately. The optimum...
Design of experiment, preparation, and in vitro biological assessment of human amniotic membrane extract loaded nanoparticles
, Article Current Pharmaceutical Biotechnology ; Volume 21, Issue 3 , 2020 , Pages 256-267 ; Atyabi, F ; Khoshayand, M. R ; Mahbod, R ; Cohan, R. A ; Akbarzadeh, I ; Bakhshandeh, H ; Sharif University of Technology
Bentham Science Publishers
2020
Abstract
Background: Human amniotic membrane grafting could be potentially useful in ocular surface complications due to tissue similarity and the presence of factors that reduce inflammation, vascu-larization, and scarring. However, considerations like donor-derived infectious risk and the requirement of an invasive surgery limit the clinical application of such treatments. Moreover, the quick depletion of bioactive factors after grafting reduces the efficacy of treatments. Therefore, in the current study, the possibility of nano delivery of the bioactive factors extracted from the human amniotic membrane to the ocular surface was investigated. Materials and Methods: Nanoparticles were prepared...
Analysis of porosity distribution of large-scale porous media and their reconstruction by Langevin equation
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 83, Issue 2 , February , 2011 ; 15393755 (ISSN) ; Sahimi, M ; Rasaei, M. R ; Tabar, M. R. R ; Sharif University of Technology
2011
Abstract
Several methods have been developed in the past for analyzing the porosity and other types of well logs for large-scale porous media, such as oil reservoirs, as well as their permeability distributions. We developed a method for analyzing the porosity logs φ(h) (where h is the depth) and similar data that are often nonstationary stochastic series. In this method one first generates a new stationary series based on the original data, and then analyzes the resulting series. It is shown that the series based on the successive increments of the log y(h)=φ(h+δh)-φ(h) is a stationary and Markov process, characterized by a Markov length scale hM. The coefficients of the Kramers-Moyal expansion for...
Attacks on a lightweight mutual authentication protocol under EPC C-1 G-2 standard
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 1 June 2011 through 3 June 2011 ; Volume 6633 LNCS , June , 2011 , Pages 254-263 ; 03029743 (ISSN) ; 9783642210396 (ISBN) ; Alagheband, M. R ; Aref, M. R ; Sharif University of Technology
2011
Abstract
Yeh et al. have recently proposed a mutual authentication protocol based on EPC Class-1 Gen.-2 standard. They claim their protocol is secure against adversarial attacks and also provides forward secrecy. In this paper we show that the proposed protocol does not have cited security features properly. A powerful and practical attack is presented on this protocol whereby the whole security of the protocol is broken. Furthermore, Yeh et al.'s protocol does not assure the untraceabilitiy and backwarduntraceabilitiy attributes. We also will propose our revision to safeguard the Yeh et al.'s protocol against cited attacks
Time-Sharing improves dynamic index coding delay
, Article 2019 Iran Workshop on Communication and Information Theory, IWCIT 2019, 24 April 2019 through 25 April 2019 ; 2019 ; 9781728105840 (ISBN) ; Mojahedian, M. M ; Aref, M. R ; Pakravan, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, we show how time-sharing method may reduce transmission delay in the dynamic index coding scenario. We propose a novel time-shared dynamic index coding transmission scheme that achieves the maximum index coding gain for a complete bi-directional side information graph and formulate a constrained optimization problem to tune the transmission scheme for the minimum transmission delay. A closed-form solution is presented for the special case of two-user. We also use analytical and simulation results to provide graphical intuition for the obtained results
Efficiency improvement of a high step up high efficiency converter for photovoltaic applications based on three-state switching cell
, Article PEDSTC 2013 - 4th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2013 , Pages 454-458 ; 9781467344845 (ISBN) ; Zolghadri, M. R ; Hajimoradi, M. R ; Sharif University of Technology
2013
Abstract
This paper suggests methods for improving efficiency of a high step up high efficiency converter based on three state commutation cells. A loss analysis has been performed to identify the source of power loss. Based on this analysis, methods are presented to reduce losses in the most power dissipating elements. These methods include replacing some power diodes with large conduction losses with MOSFETs having small on-state resistance. Efficiency improvement up to %1.25 percent is verified in simulation and experimental results
Locally multipath adaptive routing protocol resilient to selfishness and wormholes
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 12 May 2010 through 13 May 2010 ; Volume 6047 LNCS , May , 2010 , Pages 187-200 ; 03029743 (ISSN) ; 9783642128264 (ISBN) ; Pakravan, M. R ; Salmasizadeh, M ; Aref, M. R ; Sharif University of Technology
2010
Abstract
Locally multipath adaptive routing (LMAR) protocol, classified as a new reactive distance vector routing protocol for MANETs is proposed in this paper. LMAR can find an ad-hoc path without selfish nodes and wormholes using a random search algorithm in polynomial-time. Also when the primary path fails, it discovers an alternative safe path if network graph remains connected after eliminating selfish/malicious nodes. The main feature of LMAR to seek safe route free of selfish and malicious nodes in polynomial time is its searching algorithm and flooding stage that its generated traffic is equiloaded compared to single-path routing protocols but its ability to bypass the attacks is much better...
Cooperation within von Willebrand factors enhances adsorption mechanism
, Article Journal of the Royal Society Interface ; Volume 12, Issue 109 , 2015 ; 17425689 (ISSN) ; Mehrbod, M ; Ejtehadi, M. R ; Mofrad, M. R ; Sharif University of Technology
Royal Society of London
2015
Abstract
von Willebrand factor (VWF) is a naturally collapsed protein that participates in primary haemostasis and coagulation events. The clotting process is triggered by the adsorption and conformational changes of the plasma VWFs localized to the collagen fibres found near the site of injury. We develop coarse-grained models to simulate the adsorption dynamics of VWF flowing near the adhesive collagen fibres at different shear rates and investigate the effect of factors such as interaction and cooperativity of VWFs on the success of adsorption events. The adsorption probability of a flowing VWF confined to the receptor field is enhanced when it encounters an adhered VWF in proximity to the...
Liquid-liquid coaxial swirl injector performance prediction using general regression neural network
, Article Particle and Particle Systems Characterization ; Volume 25, Issue 5-6 , 2009 , Pages 454-464 ; 09340866 (ISSN) ; Soltani, M. R ; Ashjaee, M ; Morad, M. R ; Sharif University of Technology
2009
Abstract
A general regression neural network technique was applied to design optimization of a liquid-liquid coaxial swirl injector. Phase Doppler Anemometry measurements were used to train the neural network. A general regression neural network was employed to predict droplet velocity and Sauter mean diameter at any axial or radial position for the operating range of a liquid-liquid coaxial swirl injector. The results predicted by neural network agreed satisfactorily with the experimental data. A general performance map of the liquid-liquid coaxial swirl (LLCS) injector was generated by converting the predicted result to actual fuel/oxidizer ratios. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA
A secure ECC-based privacy preserving data aggregation scheme for smart grids
, Article Computer Networks ; Volume 129 , 2017 , Pages 28-36 ; 13891286 (ISSN) ; Bayat, M ; Pakravan, M. R ; Aref, M. R ; Sharif University of Technology
2017
Abstract
Development of Smart Grid and deployment of smart meters in large scale has raised a lot of concerns regarding customers’ privacy. Consequently, several schemes have been proposed to overcome the above mentioned issue. These schemes mainly rely on data aggregation as a method of protecting users’ privacy from the grid operators. However, the main problem with most of these schemes is the fact that they require a large amount of processing power at the meter side. This, together with the fact that smart meters don't usually have a powerful processor, can cause the unavailability of smart meter data at the required time for operators of the grid, and at the same time prevents smart meters from...
An efficient cooperative message authentication scheme in vehicular ad-hoc networks
, Article 2017 14th International ISC (Iranian Society of Cryptology) Conference on Information Security and Cryptology, ISCISC 2017, 6 September 2017 through 7 September 2017 ; 2018 , Pages 37-41 ; 9781538665602 (ISBN) ; Asaar, M. R ; Salmasizadeh, M ; Aref, M. R ; Sharif University of Technology
2018
Abstract
Real-time applications play a significant role in the area of VANET, and are mainly required for these kinds of networks. On the other hand, when the number of messages received by vehicles increases in the network, then the applied computation load becomes extremely high and consequently, delay on the message authentication process significantly increases. This paper is presented with the aim of introducing a novel cooperative message authentication (CMA) scheme for VANET, the main purpose of which is alleviating the computation load on vehicles while verifying messages by using two-part identity-based signature. The scheme enables vehicles to verify only a limited number of the total...
Neural network prediction of a liquid-liquid coaxial swirl injector performance map
, Article 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 10 January 2005 through 13 January 2005 ; 2005 , Pages 11401-11408 ; Soltani, M. R ; Morad, M. R ; Ashjaee, M ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc
2005
Abstract
A general regression neural network technique is applied for design optimization of liquid-liquid coaxial swirl injectors. Phase Doppler Anemometry measurements for velocity and SMD distributions for various Reynolds numbers are used to train the neural network to generate the injector's performance map. Excellent agreement between the predicted values and the measurements is obtained. It is observed that by reducing the number of randomly selected training samples to about one third of the number of prediction points, one may reconstruct the velocity field in the extrapolation regime with an accuracy of 93%. Copyright © 2005 by the American Institute of Aeronautics and Astronautics, Inc....
Velocity field reconstruction in the mixing region of swirl sprays using general regression neural network
, Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 127, Issue 1 , 2005 , Pages 14-23 ; 00982202 (ISSN) ; Soltani, M. R ; Morad, M. R ; Ashjaee, M ; Sharif University of Technology
2005
Abstract
A general regression neural network technique is proposed for design optimization of pressure-swirl injectors. Phase doppler anemometry measurements for velocity distributions are used to train the neural network. An overall optimized value for the width of the probability is determined. The velocity field in the extrapolation regime is reconstructed with an accuracy of 93%. Excellent agreement between the predicted values and the measurements is obtained. The results indicate that the capability of performing designand optimization studies for pressure-swirl injectors with sufficient accuracy exists by applying modest amount of data in conjunction with an overall optimized value for the...
Turning toxic nanomaterials into a safe and bioactive nanocarrier for co-delivery of DOX/pCRISPR
, Article ACS Applied Bio Materials ; Volume 4, Issue 6 , 2021 , Pages 5336-5351 ; 25766422 (ISSN) ; Bagherzadeh, M ; Ghadiri, A. M ; Fatahi, Y ; Aldhaher, A ; Makvandi, P ; Dinarvand, R ; Jouyandeh, M ; Saeb, M. R ; Mozafari, M ; Shokouhimehr, M ; Hamblin, M. R ; Varma, R. S ; Sharif University of Technology
American Chemical Society
2021
Abstract
Hybrid bioactive inorganic-organic carbon-based nanocomposites of reduced graphene oxide (rGO) nanosheets enlarged with multi-walled carbon nanotubes (MWCNTs) were decorated to provide a suitable space forin situgrowth of CoNi2S4and green-synthesized ZnO nanoparticles. The ensuing nanocarrier supplied π-π interactions between the DOX drug and a stabilizing agent derived from leaf extracts on the surface of ZnO nanoparticles and hydrogen bonds; gene delivery of (p)CRISPR was also facilitated by chitosan and alginate renewable macromolecules. Also, these polymers can inhibit the potential interactions between the inorganic parts and cellular membranes to reduce the potential cytotoxicity....
Development of a wearable measuring system for respiratory plethysmography
, Article Proceedings of the 8th IASTED International Conference on Biomedical Engineering, Biomed 2011, 16 February 2011 through 18 February 2011 ; February , 2011 , Pages 295-299 ; 9780889868663 (ISBN) ; Ramezanzadeh, M ; Narimani, R
2011
Abstract
Assessment of respiratory volume is widely used in clinical application in order to assess the case of respiratory illness, and the progression of the respiratory syndrome. Respiratory plethysmography is used to determine the changes of chest volume to monitor the breathing. A wearable respiration measuring system has been introduced for detection of volume variations of chest. The system consists of a flexible sensor, stretchable cloth and electrical board. The flexible sensor, whose electrical voltage is produced by body movements, is installed inside the shirt and closely contacts the chest. The low frequency components of body movements recorded by the sensor are mainly generated by...
Experimental flow visulization of single swirl spray pattern at various pressure drops
, Article 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003, Huntsville, AL, 20 July 2003 through 23 July 2003 ; 2003 ; 9781624100987 (ISBN) ; Ashjaee, M ; Soltani, M. R ; Mesbahi, M. H ; Morad, M. R ; Sharif University of Technology
2003
Abstract
An experimental investigation of the flow field of pressure swirl atomizers for different pressure drops is performed. Two experimental methods are employed. For low injection pressures, a visual study is conducted while for higher pressures the velocity components and size of the droplets are measured by using Phase Doppler Anemometer. The spray formation, spray cone angle, and breakup length are visually investigated. Velocity and size of the droplets are measured on a plane of measurement along the axis of the spray so that the properties are carried out in a radial direction as a function of both pressure drop and axial distance from the nozzle. Self-similar mean axial velocity profiles...
Solvatochromic probes absorbance behavior in mixtures of 2-hydroxy ethylammonium formate with methanol, ethylene glycol and glycerol
, Article Journal of Solution Chemistry ; Volume 39, Issue 10 , 2010 , Pages 1509-1519 ; 00959782 (ISSN) ; Harifi Mood, A. R ; Elahifard, M. R ; Gholami, M. R ; Sharif University of Technology
2010
Abstract
Solute-solvent and solvent-solvent interactions were investigated for binary mixtures of an ionic liquid (IL) 2-hydroxy ethylammonium formate as with methanol, ethylene glycol and glycerol. The physicochemical properties of the solvent mixtures at 25 °C, over the whole range of mole fractions, were determined using solvatochromic probes. High normal polarity (ETN) in the alcohol-rich region confirms solute-solvent interactions in this medium. Dipolarity/polarizability (π *) show a different trend to ETN with a positive deviation from ideal behavior in IL-glycerol mixtures. However, these deviations for other solvent mixtures are insignificant. Contrary to what is observed for E TN and π*,...
Characterization of yittria stabilized zirconia/titania core-shell powders synthesized via air plasma spray method
, Article Materials Chemistry and Physics ; Volume 200 , 2017 , Pages 280-286 ; 02540584 (ISSN) ; Rahimipour, M. R ; Vaezi, M. R ; Gholamzadeh, A ; Sharif University of Technology
2017
Abstract
In this study, Yittria Stabilized Zirconia/Titania powders synthesized via air plasma spray (APS) method such as morphology changes and phase transformations of core-shell structure characterized. Phase analysis of powders was performed by XRD. The crystallite size and lattice strain of YSZ/TiO2 core-shell structure was calculated by Williamson-Hall method. Morphology was observed with scanning electron microscope. EDS and map analysis were used for core-shell characterization. Results revealed that all TiO2 nano particles were melted around YSZ powders with the thickness between 1 up to 5 μm. After spraying the YSZ/TiO2 mixture in water, strain values increased but crystallite size...
Security enhancement of an auditing scheme for shared cloud data
, Article International Journal of Internet Protocol Technology ; Volume 15, Issue 1 , 2022 , Pages 60-68 ; 17438209 (ISSN) ; Attari, M. A ; Asaar, M. R ; Aref, M. R ; Sharif University of Technology
Inderscience Publishers
2022
Abstract
In cloud storage services, public auditing mechanisms allow a third party to verify integrity of the outsourced data on behalf of data owners without the need to retrieve data from the cloud server. In some applications, the identity of data users should be kept private from the third party auditor. Oruta is a privacy preserving public auditing scheme for shared data in the cloud which exploits ring signatures to protect the identity privacy. In this paper, we propose two attacks and demonstrate that the scheme is insecure and a dishonest server can arbitrarily tamper the outsourced data without being detected by the auditor. We also propose a solution to remedy this weakness with the...
A lightweight auditing service for shared data with secure user revocation in cloud storage
, Article IEEE Transactions on Services Computing ; Volume 15, Issue 1 , 2022 , Pages 1-15 ; 19391374 (ISSN) ; Attari, M. A ; Asaar, M. R ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
As data sharing has become one of the most popular services offered by cloud storage, designing public auditing mechanisms for integrity of shared data becomes more important. Two problems which arise in shared data auditing include preserving users identity and collusion resistant revocation of users. When data stored at the cloud is shared among a group of users, different users may modify and sign different data blocks which leaks signer identities to the public verifier. Also, when a user is revoked from the group, signatures generated by this user should be re-signed by the cloud server using re-signature keys. In addition, collusion of cloud server and the revoked user should leak no...