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    Removal of zirconium from aqueous solution by Aspergillus niger

    , Article Scientia Iranica ; Vol. 21, Issue. 3 , 2014 , pp. 772-780 ; ISSN: 10263098 Kalantari, H ; Yaghmaei, S ; Roostaazad, R ; Mohammad-Beigi, H ; Sharif University of Technology
    2014
    Abstract
    Removal of zirconium from its dilute aqueous solution using Aspergillus niger as a dried and living biomass was investigated. Through that, the effect of some operational parameters on biosorption, including pH, temperature, contact time, initial concentration of zirconium and dose of biomass, were studied. Based on the results, it was concluded that the uptake of zirconium by both dried and living biomasses is pH dependent, and maximum uptake was observed in pH = 3.1 for both biomasses. The maximum uptake capacity of the living biomass was obtained at 30°C. However, the biosorption of zirconium by dried biomass was not affected by temperature. The maximum uptake capacity for living and... 

    Effect of pH, citrate treatment and silane-coupling agent concentration on the magnetic, structural and surface properties of functionalized silica-coated iron oxide nanocomposite particles

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 44, Issue 3 , December , 2011 , Pages 618-627 ; 13869477 (ISSN) Mohammad Beigi, H ; Yaghmaei, S ; Roostaazad, R ; Bardania, H ; Arpanaei, A ; Sharif University of Technology
    2011
    Abstract
    Superparamagnetic iron oxide nanoparticles were synthesized by coprecipitation of iron chloride salts at various pH values (9, 10, 11 and12) that were adjusted using an ammonia solution. Increasing the pH from 9 to 12 led to decreases in the size of iron oxide nanoparticles from 7.9±1.4 to 5±0.6 nm and the saturation magnetization (M s) from 82.73 to 67.14 emu/g, respectively, when analyzed with transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). X-ray diffraction patterns as well as M s values showed that magnetite is the dominantly synthesized phase in the examined pH values. Unmodified iron oxide nanoparticles were coated with silica via the hydrolysis and... 

    Kinetics, experimental and simulation studies of Chinese Hamster Ovary cell growth in a packed-bed bioreactor

    , Article World Applied Sciences Journal ; Volume 15, Issue 11 , 2011 , Pages 1568-1575 ; 18184952 (ISSN) Shakibaie, M ; Tabandeh, F ; Zomorodipour, A. R ; Mohammad-Beigi, H ; Ebrahimi, S ; Habib Ghomi, H ; Sharif University of Technology
    2011
    Abstract
    To figure out the relationship between nutrient deprivation and cell growth, simulation can be effective. In the present work, the growth of Chinese Hamster Ovary (CHO) cells was simulated based on stoichiometric and kinetics calculations. The simulation results were compared to the experimental data from a packed-bed bioreactor and a good agreement was observed. The kinetic parameters (K Glc, K Amn, K Lact and μ Max) were optimized by a genetic algorithm method using stoichiometric parameters (Y X/Glc, Y X/Amm, and Y Lac/Glc). The stoichiometric and kinetic parameters were used in the simulation to study the growth of CHO cells. The concentrations of the toxic by-products, ammonium and... 

    Quantum achievability proof via collision relative entropy

    , Article IEEE Transactions on Information Theory ; Vol. 60, issue. 12 , 2014 , pp. 7980-7986 ; ISSN: 00189448 Beigi, S ; Gohari, A
    2014
    Abstract
    In this paper, we provide a simple framework for deriving one-shot achievable bounds for some problems in quantum information theory. Our framework is based on the joint convexity of the exponential of the collision relative entropy and is a (partial) quantum generalization of the technique of Yassaee et al. from classical information theory. Based on this framework, we derive one-shot achievable bounds for the problems of communication over classical-quantum channels, quantum hypothesis testing, and classical data compression with quantum side information. We argue that our one-shot achievable bounds are strong enough to give the asymptotic achievable rates of these problems even up to the... 

    Comparison of different strategies for the assembly of gold colloids onto Fe3O4@SiO2 nanocomposite particles

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 49 , 2013 , Pages 30-38 ; 13869477 (ISSN) Mohammad Beigi, H ; Yaghmaei, S ; Roostaazad, R ; Arpanaei, A ; Sharif University of Technology
    2013
    Abstract
    Three strategies were employed for the assembly of gold nanoparticles on silica-coated magnetite particles (SCMPs). In strategy I, citrate-coated gold nanoparticles were attached on the surface of amine-SCMPs. In strategy II, amine-SCMPs were coated with carboxylated gold nanoparticles via amide bond formation. In strategy III, the thiol-SCMPs surface was coated with gold nanoparticles. Among the above examined strategies, coating amine-SCMPs with gold nanoparticles via strategy I resulted in a better coverage and stronger intensity of absorption bands. Furthermore, results obtained through strategy I showed that decreasing the pH of the solution from 7 to 3 leads to a further red-shift of... 

    Assessing Success in Iranian Petrochemical Projects “A Lifecycle Approach”

    , M.Sc. Thesis Sharif University of Technology Shariatfar, Moeed (Author) ; Mortaheb, Mohammad Mehdi (Supervisor) ; Beigi, Hassan (Co-Advisor)
    Abstract
    For sometimes researchers and practitioners have realized that the traditional success criteria, known as iron triangle (time, cost, quality), are not adequate indicators to align a project execution with the long term success trend of an organization. Many other success criteria in addition to time, cost and quality of a project can negatively or positively affect the long term success of an organization. Evaluating the project life cycle success is to some extent more judgmental and usually there is no agreed upon measures defined prior to the project execution. There are many stakeholders affected or involved in the life cycle of a project like; owner, contractor, operator, customers,... 

    Batch equilibrium and kinetics studies of Cd (II) ion removal from aqueous solution using porous chitosan hydrogel beads

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 28, Issue 3 , 2009 , Pages 81-89 ; 10219986 (ISSN) Mohammad Beigi, S ; Babapoor, A ; Maghsoodi, V ; Mousavi, S. M ; Rajabi, N ; Sharif University of Technology
    2009
    Abstract
    In this study chitosan hydrogel beads with porosity ∼ 0.86 and diameter ∼ 2 ± 0.07 mm were prepared from 85 % deacetylated chitosan for removal of Cd2+ ions from aqueous solutions. Chitosan powder was dissolved into dilute acetic acid as solvent and formed into spherical beads using a phase inversion technique. The effect of temperature, initial concentration of Cd2+ ions, and the period of agitation were perused to achieve the best isotherm model. Freundlich model was better fitted than Langmuir model (R2 > 0.99 and R2> 0.93 respectively, at pH of 6.3, and shaker speed of 200 rpm), the constants of Langmuir and Freundlich models were calculated, which RL value and qmax (mg/g wet weight) at... 

    On dimension bounds for auxiliary quantum systems

    , Article IEEE Transactions on Information Theory ; Vol. 60, Issue. 1 , Jan , 2014 , PP . 368-387 ; ISSN: 00189448 Beigi, S ; Gohari, A ; Sharif University of Technology
    2014
    Abstract
    Expressions of several capacity regions in quantum information theory involve an optimization over auxiliary quantum registers. Evaluating such expressions requires bounds on the dimension of the Hilbert space of these auxiliary registers, for which no nontrivial technique is known; we lack a quantum analog of the Carathéodory theorem. In this paper, we develop a new non-Carathéodory-type tool for evaluating expressions involving a single quantum auxiliary register and several classical random variables. As we show, such expressions appear in problems of entanglement-assisted Gray-Wyner and entanglement-assisted channel simulation, where the question of whether entanglement helps in these... 

    Leveraging User-Item Interactions for Trust Prediction

    , M.Sc. Thesis Sharif University of Technology Beigi, Ghazaleh (Author) ; Jalili, Mahdi (Supervisor)
    Abstract
    Trust prediction, the ability to identify how much to trust to allocate an unknown user, is an important prerequisite toward the development of scalable on-line e-commerce communities. We are more likely to purchase an item from a seller on an e-commerce websites such as eBay or Amazon, if our trusted acquaintances have reported positive experiences with that seller in the past. Reviews from trusted users will carry more weight towards the purchasing decision than reviews from anonymous or unknown customers. Thus, these platforms must support computational mechanisms for propagating trust between users. One of the significant challenges in the trust prediction problem is the unprecedented... 

    Link Prediction in Complex Networks

    , M.Sc. Thesis Sharif University of Technology Asghari, Mohammad (Author) ; Beigi, Hamid (Supervisor)
    Abstract
    With the growth of social networks, link prediction has attracted great attention. Completing partially observed networks, recognizing errors in observed links, predicting the network’s future structure to aid decision making, and presenting users with favorable links are some the motivations that have made link prediction important and effective for complex networks. In this work, we analyze link prediction in DBLP’s author network and attempt to increase the accuracy of state-of-the-art link prediction techniques by extracting discriminative information from the available metadata. Abstracts are an important resource that indicate an author’s field of study. Extracting the concepts an... 

    Assessing the Hydro-mechanical Behavior of Undisturbed Collapsible Soils by Conducting Unsaturated Odeometer Tests Case Study: Gorgan Loess

    , M.Sc. Thesis Sharif University of Technology Beigi, Majid (Author) ; Haeri, Mohsen (Supervisor)
    Abstract
    The deposits in many regions in Iran, particularly eastern zones like Golestan, Semnan, Khorasan, Yazd, Kerman, Hormozgan, Sistan and Baluchestan provinces consist of Aeolian deposits of loess, which are categorized as collapsible soils. This kind of soil show sufficient shear strength and low deformability in dry or natural condition. However, if a structure is built on the soil and water seeps or infiltrates into the soil due to several reasons such as sewer leakage, water seepage or heavy precipitations in a way that its moisture reaches to a critical value, the interparticle bonds may break or the present suction in the soil may decrease in a way that the soil experiences sudden... 

    On the duality of additivity and tensorization

    , Article IEEE International Symposium on Information Theory - Proceedings, 14 June 2015 through 19 June 2015 ; Volume 2015-June , 2015 , Pages 2381-2385 ; 21578095 (ISSN) ; 9781467377041 (ISBN) Beigi, S ; Gohari, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    A function is said to be additive if, similar to mutual information, expands by a factor of n, when evaluated on n i.i.d. repetitions of a source or channel. On the other hand, a function is said to satisfy the tensorization property if it remains unchanged when evaluated on i.i.d. repetitions. Additive rate regions are of fundamental importance in network information theory, serving as capacity regions or upper bounds thereof. Tensorizing measures of correlation have also found applications in distributed source and channel coding problems as well as the distribution simulation problem. Prior to our work only two measures of correlation, namely the hypercontractivity ribbon and maximal... 

    Monotone measures for non-local correlations

    , Article IEEE Transactions on Information Theory ; Volume 61, Issue 9 , 2015 , Pages 5185-5208 ; 00189448 (ISSN) Beigi, S ; Gohari, A ; Sharif University of Technology
    2015
    Abstract
    Non-locality is the phenomenon of observing strong correlations among the outcomes of local measurements of a multipartite physical system. No-signaling boxes are the abstract objects for studying non-locality, and wirings are local operations on the space of no-signaling boxes. This means that, no matter how non-local the nature is, the set of physical non-local correlations must be closed under wirings. Then, one approach to identify the non-locality of nature is to characterize the closed sets of non-local correlations. Although non-trivial examples of wirings of no-signaling boxes are known, there is no systematic way to study wirings. In particular, given a set of no-signaling boxes, we... 

    Two-way channel simulation

    , Article IWCIT 2015 - Iran Workshop on Communication and Information Theory, 6 May 2015 through 7 May 2015 ; 2015 ; 9781479982356 (ISBN) Beigi, S ; Gohari, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    In this paper, we consider the problem of simulating one copy of a zero-capacity two-way channel from arbitrary many copies of another two-way channel. The motivation for this problem comes from foundation of quantum physics where zero-capacity two-way channels (a.k.a. no-signaling boxes) serve as the abstract objects for studying non-locality. We provide necessary conditions for the possibility of channel simulation using two measures of correlation, namely maximal correlation and hypercontractivity ribbon. It is shown that when these measures are defined appropriately for two-way channels, they are monotonically decreasing under local operations. Our result allows us to establish a... 

    A Thesis Submitted in Partial Fulfillment of the Requirement for the Degree of Master of Science in Computer Engineering

    , M.Sc. Thesis Sharif University of Technology Karimi, Saeed (Author) ; Beigi, Hamid (Supervisor)
    Abstract
    The modern science of networks has brought significant advances to our understanding of complex systems. One of the most relevant features of graphs representing real systems is community structure, or clustering, i. e. the organization of vertices in clusters, with many edges joining vertices of the same cluster and comparatively few edges joining vertices of different clusters. Such clusters, or communities, can be considered as fairly independent compartments of a graph, playing a similar role like, e. g., the tissues or the organs in the human body. Detecting communities is of great importance in sociology, biology and computer science, disciplines where systems are often represented as... 

    Φ-Entropic measures of correlation

    , Article IEEE Transactions on Information Theory ; Volume 64, Issue 4 , 2018 , Pages 2193-2211 ; 00189448 (ISSN) Beigi, S ; Gohari, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    A measure of correlation is said to have the tensorization property if it does not change when computed for i.i.d. copies. More precisely, a measure of correlation between two random variables X, Y denoted by rho (X, Y), has the tensorization property if ρ(Xn, Yn)=ρ (X, Y) where (Xn, Yn) denotes n i.i.d. copies of (X, Y). Two well-known examples of such measures are the maximal correlation and the hypercontractivity ribbon (HC ribbon). We show that the maximal correlation and the HC ribbon are special cases of the new notion of Φ-ribbons, defined in this paper for a class of convex functions Φ. Φ-ribbon reduces to the HC ribbon and the maximal correlation for special choices of Φ, and is a... 

    Low power receiver with merged N-path LNA and mixer for MICS applications

    , Article AEU - International Journal of Electronics and Communications ; Volume 117 , 2020 Beigi, A ; Safarian, A ; Sharif University of Technology
    Elsevier GmbH  2020
    Abstract
    In this paper, a low power receiver for medical implant communication service (MICS) is presented. Low power design is vital in the MICS applications since the implanted chip has to work for a long time without the need to change its battery. As a result, a merged N-path low noise amplifier (LNA) and mixer block is proposed. In this structure, the LNA and down-conversion mixer share a transconductance to lower the overall power consumption. An N-path feedback is utilized around the shared transconductance not only to improve the LNA selectivity and relax the linearity requirements but also to downconvert the radio frequency (RF) component and create the intermediate frequency (IF) signal. In... 

    Intrusion Detection System in Smart Grids

    , M.Sc. Thesis Sharif University of Technology Beigi, Hossein (Author) ; Amini, Morteza (Supervisor)
    Abstract
    Smart grids are the new generation of power grids that combine the power distribution grid with the communications network. The purpose of these networks is to create a secure, two-way infrastructure for the transmission of power and information. The complex structure of smart grids, along with the inherent vulnerabilities of physical systems, old devices and protocols on the network and the need for backward compatibility, have created serious cyber risks to critical assets and infrastructures. The difference between these types of networks and conventional computer networks has made the security mechanisms developed in conventional computer networks not very suitable for these types of... 

    Photoluminescent carbon quantum dot/poly-L-Lysine core-shell nanoparticles: A novel candidate for gene delivery

    , Article Journal of Drug Delivery Science and Technology ; 2020 Hasanzadeh, A ; Mofazzal Jahromi, M. A ; Abdoli, A ; Mohammad Beigi, H ; Fatahi, Y ; Nourizadeh, H ; Zare, H ; Kiani, J ; Radmanesh, F ; Rabiee, N ; Jahani, M ; Mombeiny, R ; Karimi, M ; Sharif University of Technology
    Editions de Sante  2020
    Abstract
    Cationic polymers such as poly-L-lysine (PLL) are able to interact electrostatically with DNA to produce polymeric systems with nanometric diameters due to the neutralization and accumulation of DNA. This study integrates the outstanding properties of carbon quantum dots (CQDs) with PLL to develop a novel gene delivery vehicle with a core-shell hybrid nanostructure. The CQD/PLL core-shell nanoparticles (NPs) were, therefore, synthesized in such a way that they had narrow size distribution and an average diameter under 10 nm, both of which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy exhibited that... 

    Photoluminescent carbon quantum dot/poly-L-Lysine core-shell nanoparticles: A novel candidate for gene delivery

    , Article Journal of Drug Delivery Science and Technology ; Volume 61 , 2021 ; 17732247 (ISSN) Hasanzadeh, A ; Mofazzal Jahromi, M. A ; Abdoli, A ; Mohammad Beigi, H ; Fatahi, Y ; Nourizadeh, H ; Zare, H ; Kiani, J ; Radmanesh, F ; Rabiee, N ; Jahani, M ; Mombeiny, R ; Karimi, M ; Sharif University of Technology
    Editions de Sante  2021
    Abstract
    Cationic polymers such as poly-L-lysine (PLL) are able to interact electrostatically with DNA to produce polymeric systems with nanometric diameters due to the neutralization and accumulation of DNA. This study integrates the outstanding properties of carbon quantum dots (CQDs) with PLL to develop a novel gene delivery vehicle with a core-shell hybrid nanostructure. The CQD/PLL core-shell nanoparticles (NPs) were, therefore, synthesized in such a way that they had narrow size distribution and an average diameter under 10 nm, both of which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy exhibited that...