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(Liquid + liquid) equilibria of binary polymer solutions using a free-volume UNIQUAC-NRF model
, Article Journal of Chemical Thermodynamics ; Volume 38, Issue 7 , 2006 , Pages 923-928 ; 00219614 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Kontogeorgis, G. M ; Sharif University of Technology
2006
Abstract
In this work, a modified free-volume (FV) model based on the UNIQUAC-Nonrandom factor (UNIQUAC-NRF) model developed by Haghtalab and Asadollahi was proposed. While the combinatorial part of the proposed model for activity coefficient takes the same form as that of the entropic free-volume (entropic-FV) model, the residual part is similar to that of the UNIQUAC-NRF model. The proposed model, i.e., the FV-UNIQUAC-NRF model overcomes the main shortcoming of the original UNIQUAC-NRF model in predicting the lower critical solution temperature (LCST) for polymer solutions. The appearance of the LCST is believed to be attributed to the existence of the free volume differences between polymer and...
(Liquid + liquid) equilibrium for ternary mixtures of {heptane + aromatic compounds + [EMpy][ESO4]} at T = 298.15 K
, Article Journal of Chemical Thermodynamics ; Volume 43, Issue 10 , 2011 , Pages 1530-1534 ; 00219614 (ISSN) ; Vossoughi, M ; Pazuki, G. R ; Safekordi, A. A ; Heydari, A ; Akbari, J ; Yavari, M ; Sharif University of Technology
2011
Abstract
(Liquid + liquid) equilibrium (LLE) data for the ternary systems (heptane + toluene + 1-ethyl-3-methylpyridinium ethylsulfate) and (heptane + benzene + 1-ethyl-3-methylpyridinium ethylsulfate) were measured at T = 298.15 K and atmospheric pressure. The selectivity and aromatic distribution coefficients, calculated from the equilibrium data, were used to determine if this ionic liquid can be used as a potential extracting solvent for the separation of aromatic compounds from heptane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations
(WO3)x-(TiO2)1-x nano-structured porous catalysts grown by micro-arc oxidation method: Characterization and formation mechanism
, Article Materials Chemistry and Physics ; Volume 124, Issue 1 , 2010 , Pages 203-207 ; 02540584 (ISSN) ; Moshfegh, A. Z ; Golestani Fard, F ; Molaei, R ; Sharif University of Technology
2010
Abstract
Very recently, we fabricated (WO3)x-(TiO 2)1-x layers via micro-arc oxidation process under different applied voltages. Morphological and topographical studies, accomplished by SEM and AFM techniques, revealed that the pores size as well as the surface roughness increased with the voltage. Phase structure and chemical composition of the layers were also investigated by XRD and XPS and the results showed the grown layers consisted of titanium and tungsten oxides. It was found that WO3 dispersed in the TiO2 matrix and also doped into the TiO2 lattice. In addition, optical properties of the synthesized layers were studied employing a UV-vis spectrophotometer. Band gap energy of the layers was...
(t,k)-Hypergraph anonymization: An approach for secure data publishing
, Article Security and Communication Networks ; Volume 8, Issue 7 , September , 2015 , Pages 1306-1317 ; 19390114 (ISSN) ; Hadavi, M. A ; Jalili, R ; Sharif University of Technology
John Wiley and Sons Inc
2015
Abstract
Privacy preservation is an important issue in data publishing. Existing approaches on privacy-preserving data publishing rely on tabular anonymization techniques such as k-anonymity, which do not provide appropriate results for aggregate queries. The solutions based on graph anonymization have also been proposed for relational data to hide only bipartite relations. In this paper, we propose an approach for anonymizing multirelation constraints (ternary or more) with (t,k) hypergraph anonymization in data publishing. To this end, we model constraints as undirected hypergraphs and formally cluster attribute relations as hyperedge with the t-means-clustering algorithm. In addition,...
0-sum and 1-sum flows in regular graphs
, Article Electronic Journal of Combinatorics ; Volume 23, Issue 2 , 2016 ; 10778926 (ISSN) ; Kano, M ; Zare, S ; Sharif University of Technology
Australian National University
2016
Abstract
Let G be a graph. Assume that l and k are two natural numbers. An l-sum flow on a graph G is an assignment of non-zero real numbers to the edges of G such that for every vertex v of G the sum of values of all edges incident with v equals l. An l-sum k-flow is an l-sum flow with values from the set {±1,…, ±(k — 1)}. Recently, it was proved that for every r, r ≥ 3, r ≠ 5, every r-regular graph admits a 0-sum 5-flow. In this paper we settle a conjecture by showing that every 5-regular graph admits a 0-sum 5-flow. Moreover, we prove that every r-regular graph of even order admits a 1-sum 5-flow
1 + ϵ approximation of tree edit distance in quadratic time
, Article 51st Annual ACM SIGACT Symposium on Theory of Computing, STOC 2019, 23 June 2019 through 26 June 2019 ; 2019 , Pages 709-720 ; 07378017 (ISSN); 9781450367059 (ISBN) ; Ghodsi, M ; Hajiaghayi, M ; Seddighin, S ; Sharif University of Technology
Association for Computing Machinery
2019
Abstract
Edit distance is one of the most fundamental problems in computer science. Tree edit distance is a natural generalization of edit distance to ordered rooted trees. Such a generalization extends the applications of edit distance to areas such as computational biology, structured data analysis (e.g., XML), image analysis, and compiler optimization. Perhaps the most notable application of tree edit distance is in the analysis of RNA molecules in computational biology where the secondary structure of RNA is typically represented as a rooted tree. The best-known solution for tree edit distance runs in cubic time. Recently, Bringmann et al. show that an O(n2.99) algorithm for weighted tree edit...
1,9′-dimethyl-2′,4′-diphenyl-4′, 9′-dihydro-2′H-spiro-[indoline-3,3′-thiopyrano[2,3-b]indole] -2-thione
, Article Acta Crystallographica Section E: Structure Reports Online ; Volume 63, Issue 3 , 2007 , Pages o1306-o1307 ; 16005368 (ISSN) ; Matloubi, F. M ; Khavasi, H. R ; Sharif University of Technology
2007
Abstract
The title compound, C32H26N2S2, is a new spiro thio-oxindole derivative which was synthesized with the aim that it might be effective in treating a number of diseases. In spite of the existence of the Csp 3 atom, the thio-oxindole group is almost planar. There are a number of intra-molecular C - H⋯S hydrogen bonds. © International Union of Crystallography 2007
1.5-D sparse array for millimeter-wave imaging based on compressive sensing techniques
, Article IEEE Transactions on Antennas and Propagation ; Volume 66, Issue 4 , April , 2018 , Pages 2008-2015 ; 0018926X (ISSN) ; Fakharzadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
The goal of this paper is to reduce the antenna count in a millimeter (mm)-wave imaging system by proposing both hardware and software solutions. The concept of image sparsity in the transform domain is utilized to present the compressive sensing (CS) formulation for both mono-static and multistatic imaging at mm-wave frequencies. To reduce the complexity of the imaging system and reconstruction process, we introduce 1.5-D array structure, which is a random sparse array with orthogonal element locations. It is shown that the peak signal-to-noise ratio (PSNR) of the reconstructed image obtained by a 1.5-D array with 65% sparsity is very close to the PSNR of a uniform 2-D array for mono-static...
1H NMR based metabolic profiling in Crohn's disease by random forest methodology
, Article Magnetic Resonance in Chemistry ; Vol. 52, issue. 7 , July , 2014 , p. 370-376 ; Majari-Kasmaee, L ; Mani-Varnosfaderani, A ; Kyani, A ; Rostami-Nejad, M ; Sohrabzadeh, K ; Naderi, N ; Zali, M. R ; Rezaei-Tavirani, M ; Tafazzoli, M ; Arefi-Oskouie, A ; Sharif University of Technology
2014
Abstract
The present study was designed to search for metabolic biomarkers and their correlation with serum zinc in Crohn's disease patients. Crohn's disease (CD) is a form of inflammatory bowel disease that may affect any part of the gastrointestinal tract and can be difficult to diagnose using the clinical tests. Thus, introduction of a novel diagnostic method would be a major step towards CD treatment.Proton nuclear magnetic resonance spectroscopy ( 1H NMR) was employed for metabolic profiling to find out which metabolites in the serum have meaningful significance in the diagnosis of CD. CD and healthy subjects were correctly classified using random forest methodology. The classification model for...
2,6-Bis(diphenylphosphino)pyridine: A simple ligand showing high performance in palladium-catalyzed CN coupling reactions
, Article Tetrahedron Letters ; Vol. 55, issue. 30 , July , 2014 , p. 4098-4101 ; ISSN: 00404039 ; Rafiee, E ; Jamali, S ; Joshaghani, M ; Sharif University of Technology
2014
Abstract
The use of commercially available 2,6-bis(diphenylphosphino)pyridine as a ligand in conjunction with K2CO3, DMAc and TBAB is an effective method for the palladium-catalyzed CN coupling of a variety of aryl halides with anilines, N-heterocyclic aromatic amines, and a cyclic secondary amine. The reactions proceed in good to excellent yield (up to 98%) while the loading of Pd(OAc)2 was as low as 0.025 mol %
2-(5-Bromo-2-hydroxyphenyl)-1,2-dihydroquinazolin-4(3H)-one
, Article Acta Crystallographica Section E: Structure Reports Online ; Volume 65, Issue 1 , December , 2008 ; 16005368 (ISSN) ; Najafpour, M. M ; McKee, V ; Sharif University of Technology
2008
Abstract
The asymmetric unit of the title compound, C14H 11BrN2O2, contains two independent mol-ecules connected into a dimer by inter-molecular N - H⋯O hydrogen bonds involving the amine and carbonyl groups. The dimers are further connected by O - H⋯O hydrogen bonds, forming chains running parallel to the a axis, which are stabilized through π-π stacking inter-actions, with a centroid-centroid distance of 3.679 (8) Å. The dihedral angle between the two aromatic rings is 89.2 (4)°
2-D spectral estimation in CW forward scatter radars
, Article Proceedings International Radar Symposium, 24 June 2015 through 26 June 2015 ; Volume 2015-August , 2015 , Pages 664-669 ; 21555753 (ISSN); 9783954048533 (ISBN); 9783954048533 (ISBN); 9783954048533 (ISBN) ; Bagheri, A. M ; Azarbar, A ; Nayebi, M. M ; Rohling H ; Rohling H ; Rohling H ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
In CW forward scatter radars, Space-Time processing by 2-D FFT is used to estimate Doppler frequency shift and angle of arrival concurrently. 2-D periodogram and 2-D Capon methods are two famous spectral estimation methods which can be substituted for 2-D FFT. Here we will provide analysis of performance for these methods beside their cons and pros
2-[Bis(5-chloro-2-pyridylamino)methyl]pyridine monohydrate
, Article Acta Crystallographica Section E: Structure Reports Online ; Volume 64, Issue 12 , 2008 , Pages - ; 16005368 (ISSN) ; Najafpour, M. M ; McKee, V ; Sharif University of Technology
2008
Abstract
In the title compound, the dihedral angles between the 2-amino-5-chloro- pyridyl rings and the pyridine ring are 56.26 (6)° and 78.83 (5)°; the angle between the 2-amino-5-chloro-pyridyl rings is 72.42 (5)°. The solvent water mol-ecules are linked to the organic compound by N - H⋯O, O - H⋯O, N - H⋯N and O - H⋯N hydrogen bonds. π⋯π Stacking inter-actions are also observed between the 2-amino-5-chloro-pyridyl rings (centroid⋯centroid distance = 3.243 Å). © 2008
27Al and 31P NMR investigations of soluble aluminophosphate species in alcohol-water mixtures
, Article Journal of Solution Chemistry ; Volume 41, Issue 5 , 2012 , Pages 888-897 ; 00959782 (ISSN) ; Nejad Darzi, S. K. H ; Tafazzoli, M ; Sharif University of Technology
2012
Abstract
In this work, phosphorus-31 and aluminum-27 nuclear magnetic resonance techniques were used to characterize the distribution of soluble aluminophosphate species in methanol + water and ethanol + water mixtures. The assignment of the peaks to alu-minate species was attempted, clarifying earlier work and producing information on the different aluminophosphate complexes. Nine peaks were observed at -0.41, -6.4, -7.5, -7.9, -13.1, -13.9, -16.6, -18.1 and -20.6 ppm. Four new peaks appeared in the 31P NMR spectra of the alcoholic aluminophosphate solutions and their intensities changed with changes of the alcohol:water volume ratio. These new peaks were observed in the presence of methanol or...
2D Hash Chain robust Random Key Distribution scheme
, Article Information Processing Letters ; Volume 116, Issue 5 , 2016 , Pages 367-372 ; 00200190 (ISSN) ; Alexiou, N ; Ahmadian, M ; Aref, M. R ; Papadimitratos, P ; Sharif University of Technology
Elsevier
2016
Abstract
Many Random Key Distribution (RKD) schemes have been proposed in the literature to enable security applications in Wireless Sensor Networks (WSNs). A main security aspect of RKD schemes is their resistance against node capture attacks, since compromising the sensors and capturing their keys is a common risk in such networks. We propose a new method, based on a 2-Dimensional Hash Chain (2DHC), that can be applied on any RKD scheme to improve their resilience. Our method maintains the flexibility and low cost features of RKD schemes and it doesn't require any special-purpose hardware or extra memory to store keys in the sensors. We demonstrate that our approach significantly increases the...
2D MXene nanocomposites: electrochemical and biomedical applications
, Article Environmental Science: Nano ; Volume 9, Issue 11 , 2022 , Pages 4038-4068 ; 20518153 (ISSN) ; Nourmohammadi Khiarak, B ; Tao, R ; Wang, Z ; Ahmadi, S ; Hassanpour, M ; Rabiee, M ; Saeb, M. R ; Lima, E. C ; Rabiee, N ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
In recent years, key questions about the interaction of 2D MXene nanomaterials in electrochemical and biomedical applications have been raised. Most research has focused on clarifying the exclusive properties of the materials; however, only limited reports have described the biomedical applications of 2D nanomaterials. 2D MXenes are monolayer atomic nanosheets resulting from MAX phase ceramics. The hydrophilic properties, metallic conductivity, stability, and exclusive physiochemical performances make them promising materials for electrochemical and biomedical applications, including CO2 reduction, H2 evolution, energy conversion and storage, supercapacitors, stimuli-responsive drug delivery...
2D analysis of the effects of geometry on the response of high-T c superconductive bolometric detectors
, Article IEEE Transactions on Applied Superconductivity ; Volume 19, Issue 3 , 2009 , Pages 484-488 ; 10518223 (ISSN) ; Kokabi, A. R ; Pourhashemi, A ; Moftakharzadeh, A ; Khorasani, S ; Banzet, M ; Schubert, J ; Sharif University of Technology
2009
Abstract
We present a new approach for analytical modeling and calculating the response of high-Tc superconductive transition edge sensors in a wide range of modulation frequencies for different configurations of the film patterns. The method used here is based on solving the heat transfer differential equation for two different time varying heat sources, which are related to the absorbed radiated power. The used method employs two-dimensional boundary conditions for describing meander-line patterned devices. The results from the applied method are in better agreement with those obtained from the frequency response measurements of the characterized samples, than the previously developed models. In...
2D computational fluid dynamic modeling of human ventricle system based on fluid-solid interaction and pulsatile flow
, Article Basic and Clinical Neuroscience ; Volume 4, Issue 1 , 2013 , Pages 64-75 ; 2008126X (ISSN) ; Framanzad, F ; Zamanian, B ; Seddighi, A. S ; Moosavi, M. H ; Najarian, S ; Bastani, D ; Sharif University of Technology
2013
Abstract
Many diseases are related to cerebrospinal fluid (CSF) hydrodynamics. Therefore, understanding the hydrodynamics of CSF flow and intracranial pressure is helpful for obtaining deeper knowledge of pathological processes and providing better treatments. Furthermore, engineering a reliable computational method is promising approach for fabricating in vitro models which is essential for inventing generic medicines. A Fluid-Solid Interaction (FSI)model was constructed to simulate CSF flow. An important problem in modeling the CSF flow is the diastolic back flow. In this article, using both rigid and flexible conditions for ventricular system allowed us to evaluate the effect of surrounding brain...
2D numerical simulation of density currents using the SPH projection method
, Article European Journal of Mechanics, B/Fluids ; Volume 38 , 2013 , Pages 38-46 ; 09977546 (ISSN) ; Firoozabadi, B ; Mahdinia, M ; Sharif University of Technology
2013
Abstract
Density currents (DCs) or gravity currents are driven by gravity in a fluid environment with density variation. Smoothed Particle Hydrodynamics (SPH) has been proved to have capabilities such as free surface modeling and accurate tracking of the immiscible-fluids interface that can be useful in the context of gravity currents. However, SPH applications to gravity currents have been limited to often-coarse simulations of high density-ratio currents. In this work, the SPH projection method is tried to solve currents with very low density-ratios (close to one), at a resolution, that captures the Kelvin-Helmholtz instabilities at the fluids interface. Existing implementations of the SPH...
2PLoc: Preserving privacy in location-based services
, Article Proceedings - SocialCom 2010: 2nd IEEE International Conference on Social Computing, PASSAT 2010: 2nd IEEE International Conference on Privacy, Security, Risk and Trust, 20 August 2010 through 22 August 2010 ; August , 2010 , Pages 707-712 ; 9780769542119 (ISBN) ; Kharrazi, M ; Jalili, R ; Sharif University of Technology
2010
Abstract
Location-based services are becoming popular for mobile users. The mobile users' location plays a key role to provide the service from one side, but it can be considered as a dimension of their privacy and so necessary to keep it anonymous to the other parties. Since one important issue is to achieve an accurate service, it is important to use the mobile's accurate location. Using the location accurately raises some concerns on behalf of the user's privacy. One solution for meeting this requirement is using tickets by the means of a third party. The tickets should have some properties for not letting a mobile user to cheat and use the ticket more than one time. This paper proposes a protocol...