Synthesis and characterization of an antibacterial nanocomposite derived from two metal-organic frameworks for dye adsorption and antibacterial activity applications

, Article Chemical Engineering Research and Design ; Volume 198 , 2023 , Pages 34-45 ; 02638762 (ISSN) Talebi Deylamani, S ; Ghobadi Nejad, Z ; Borghei, M ; Yaghmaei, S ; Sharif University of Technology

Institution of Chemical Engineers 2023

Abstract

In recent years, humans have been forced to create effective water treatment methods because of the increasing water contamination caused by various industrial activities. This study focuses on synthesizing a nanocomposite consisting of two metal-organic frameworks based on ZIF-8 with effective antibacterial characteristics and water-stable, highly porous UiO-66-NH2. After characterizing the synthesized nanocomposite, its application as (i) an adsorbent for methylene blue (MB) removal from a polluted aqueous environment and (ii) an antibacterial agent; was considered. The impact of different factors on the uptake of MB, including dye concentration, adsorption temperature, and the initial pH...

Synthesis, Characterization and Applications of Antibacterial Metal-Organic Framework Nanocomposites for Water Remediation

, M.Sc. Thesis Sharif University of Technology Talebi Deylamani, Sara (Author) ; Borghei, Mehdi (Supervisor) ; Yaghmaei, Soheila (Supervisor) ; Ghobadi Nejad, Zahra (Co-Supervisor)

Abstract

Contaminants in drinking water, including microbial contaminants, have a great impact on the health of people in the community and can seriously threaten public health. In recent years, diseases caused by pathogenic bacteria due to the consumption of contaminated water have led to many deaths. As a result, water treatment has been one of the most important human concerns. Among the new water treatment technologies, metal-organic(MOF) frameworks are a new generation of porous materials that have properties such as high surface area, water stability and functionality due to their dual structure. As a result, they are widely used today in various scientific fields, including water purification....

Approximation Algorithms for Minimum Feedback Arc Set and Correlation Clustering

, M.Sc. Thesis Sharif University of Technology Ostovari Deylamani, Mojtaba (Author) ; Zarei, Alireza (Supervisor)

Abstract

In this thesis, using linear programming, we present approximation algorithms for two groups of related problems, all of which are better than previously known algorithms in terms of approximation factor or running time. The first problem is the minimum feedback arc set on tournaments, a well-known NP-hard problem. In this problem, a tournament (complete directed weighted graph) is given as input, and the goal is to find a minimum-sized subset of its edges, whose removal makes the tournament acyclic. We will present a randomized 2.127-approximation algorithm based on the standard linear programming of this problem, for tournaments that satisfy probability constraints. We also introduce a...

Coding advantage decomposition inequality for the space-frequency block codes

, Article IET Communications ; Vol. 8, Issue. 4 , 2014 , Pages 500-507 ; ISSN: 17518628 Morsali, A ; Tofigh, S ; Mohammadian, Z ; Talebi, S ; Sharif University of Technology

2014

Abstract

In this study, the authors present a new criterion which can be used to decompose the coding advantage (CA) of space-frequency block codes (SFBCs). The proposed decomposition separates the CA into two parts, called precoder-CA and channel-CA. The precoder-CA represents the effects of the precoder and the signal constellation, and can be used in the design of the precoder of SFBCs. The channel-CA, on the other hand, gives an indication of the effects of the channel characteristics, and can be utilised for optimising the permutation parameter. The authors have shown that the proposed decomposition method leads to a lower computational complexity for the optimisation procedure compared with the...

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) Norouzi, N ; 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...

Optimum and reliable routing in VANETs: An opposition based ant colony algorithm scheme

, Article 2013 International Conference on Connected Vehicles and Expo, ICCVE 2013 - Proceedings ; 2013 , Pages 926-930 Kazemi, B ; Ahmadi, M ; Talebi, S ; Sharif University of Technology

IEEE Computer Society 2013

Abstract

By the advancement in technology on one side, and governmental as well as social demands for lowest rate of driving accidents and reliable communication among vehicles on the other side, particularly in highways, vehicular ad-hoc networks (VANETs) are of special interest as a reliable approach to this aim. VANET is typically defined as the communication network for wireless communicating between vehicles in a region. One of the most important challenges in such networks is reliable routing of data packages among the vehicle users. Several VANET routing topologies are published in the literature; however, there is still a lack of reliable scheme. This is due to the nature of users behaviour...

Intelligent navigation of emergencyvehicles

, Article Proceedings - 4th International Conference on Developments in eSystems Engineering, DeSE 2011, 6 December 2011 through 8 December 2011, Dubai ; 2011 , Pages 318-323 Salehinejad, H ; Pouladi, F ; Talebi, S ; Sharif University of Technology

2011

Abstract

This paper presents a centralized structure for optimum navigation of emergency vehicles with emphasis on ambulances in disaster situations. In this system, an enhanced fuzzy controlled ant colony system (FCACS) based search engine is proposed for optimum route selection. Performance of the system is evaluated by simulating it on a part on London, UK

Optimization of composite patch repair for inclined crack on aluminum plate using genetic algorithm

, Article 30th Congress of the International Council of the Aeronautical Sciences, ICAS 2016, 25 September 2016 through 30 September 2016 ; 2016 ; 9783932182853 (ISBN) Talebi, B ; Abedian, A ; Firooz, S ; Sharif University of Technology

International Council of the Aeronautical Sciences 2016

Abstract

In this study, a composite patch repair will be designed for an aluminum plate with a central crack placed at 45 degrees to the applied unidirectional tensile load carried by the plate. In this state, the condition of loading is mixed mode. In the first step, behavior of the crack repaired by the composite patch under the applied tensile load is simulated by using ABAQUS commercial software. The crack growth process is modeled with the extended finite element method (XFEM) and the cohesive zone model (CZM) is used to model any damage progression in the adhesive of the composite patch repair. The shape of the five layer composite patch is assumed to be elliptical. For design optimization, the...

PAPR reduction of OFDM signals using harmony search algorithm

, Article 2011 18th International Conference on Telecommunications, ICT 2011, 8 May 2011 through 11 May 2011, Ayia Napa ; 2011 , Pages 90-94 ; 9781457700248 (ISBN) Kermani, E. M ; Salehinejad, H ; Talebi, S ; Sharif University of Technology

2011

Abstract

Orthogonal frequency division multiplexing (OFDM) is one of the widely used multiplexing techniques in wireless communications and especially cognitive radio networks. One of the key challenges of this technique is its high peak to average power ratio (PAPR) of the transmitted signal. This paper, introduces a new approach to PAPR reduction of OFDM signals using harmony search algorithm (HSA) based on the partial transmit sequence (PTS) method. The simulation results demonstrate that the proposed algorithm has better PAPR reduction performance as an accurate and low complexity approach for OFDM systems

Binder-free 3D graphene nanostructures on Ni foam substrate for application in capacitive deionization

, Article Diamond and Related Materials ; Volume 120 , 2021 ; 09259635 (ISSN) Talebi, M ; Ahadian, M. M ; Shahrokhian, S ; Sharif University of Technology

Elsevier Ltd 2021

Abstract

Hereby a simple, low-cost and scalable route is being presented for preparation of binder-free electrodes of reduced graphene oxide (RGO) on Ni foam (Ni/Gr). In this regard, the Ni foams are dipped in graphene oxide (GO) slurry. Next, the GO loaded Ni foams are kept in a freeze dryer for 24 h and heated up to 800 °C in an inert atmosphere. In this approach, the amount of active materials can be easily optimized for capacitive deionization (CDI). The characterization of Ni/Gr electrodes revealed a 3D porous assembly of RGO on Ni substrate which is helpful for the fast ion diffusion and rapid electron transport. The electrochemical performance of the prepared electrodes is investigated in both...

Investigation of the effect of nanosilica on rheological, thermal, mechanical, structural, and piezoelectric properties of poly(vinylidene fluoride) nanofibers fabricated using an electrospinning technique

, Article Industrial and Engineering Chemistry Research ; Volume 56, Issue 44 , 2017 , Pages 12596-12607 ; 08885885 (ISSN) Haddadi, S. A ; Ahmad Ramazani, S. A ; Talebi, S ; Fattahpour, S ; Hasany, M ; Sharif University of Technology

2017

Abstract

The effects of different nano-SiO2 contents on the rheological properties of poly(vinylidene fluoride) (PVDF) solution and mechanical, thermal, structural, and piezoelectric properties of composite nanofibers were investigated. Results showed an increase in fiber diameter (∼125 to 350 nm) and ∼450% increase in tensile strength as the content of nano-SiO2 particles increased. The degree of crystallinity decreased by 19% as the nano-SiO2 content increased by 2% (w/w). Further investigation demonstrated that silica could significantly improve the piezoelectric properties of PVDF nanofibers as the output voltage showed an increase in the presence of silica attributed to change in the crystalline...

On the coding advantages of the quasi-orthogonal space-frequency block codes

, Article IET Communications ; Vol. 8, Issue. 4 , 2014 , Pages 525-529 ; ISSN: 17518628 Shahabinejad, M ; Morsali, A ; Talebi, S ; Shahabinejad, M ; Sharif University of Technology

2014

Abstract

In this study, the authors show that the coding advantage (CA) of quasi-orthogonal space-frequency block codes (QOSFBCs) could be decomposed into two parts, namely intrinsic CA (ICA) and extrinsic CA (ECA). Then, by using the ICA, the authors demonstrate that the optimum precoder of the QOSFBCs could be analytically derived without any requirement of the exhaustive search. Then, by improving the ECA, the authors enhance performances of the QOSFBCs efficiently - up to 4dB. Finally, the authors show that a very fast optimisation process for the QOSFBCs is viable over any arbitrary frequency-selective channel

Fast two-stage global motion estimation: A blocks and pixels sampling approach

, Article Smart Innovation, Systems and Technologies ; Volume 11 SIST , 2011 , Pages 143-151 ; 21903018 (ISSN) ; 9783642221576 (ISBN) Ahmadi, A ; Pouladi, F ; Salehinejad, H ; Talebi, S ; Sharif University of Technology

2011

Abstract

Global motion estimation (GME) is an important technique in image and video processing. Whereas the direct global motion estimation techniques boast reasonable precision they tend to suffer from high computational complexity. As with indirect methods, though presenting lower computational complexity they mostly exhibit lower accuracy than their direct counterparts. In this paper, the authors introduce a robust algorithm for GME with near identical accuracy and almost 50-times faster than MPEG-4 verification model (VM). This approach entails two stages in which, first, motion vector of sampled block is employed to obtain initial GME then Levenberg-Marquardt algorithm is applied to the...

Improved initial value prediction for global motion estimation

, Article European Signal Processing Conference, 23 August 2010 through 27 August 2010, Aalborg ; 2010 , Pages 2022-2026 ; 22195491 (ISSN) Ahmadi, A ; Salehinejad, H ; Talebi, S ; Koroupi, F ; Sharif University of Technology

2010

Abstract

Global motion estimation (GME) algorithms have an imperative role in object-based applications. Gradient-based GME is a well known method among these algorithms. Such algorithms require an initial value for their initialization step. Well estimation of this value plays a significant role in the accuracy of GME. This work introduces a simple but efficient technique for initial value prediction of GME. This technique employs a long-term predictor as well as global motions of previous frames. Simulations results demonstrate faster convergence and less computational complexity of the proposed method versus common presented techniques in the literature with almost same efficiency

Utility constrained energy minimization in aloha networks

, Article 2007 4th Annual IEEE Consumer Communications and Networking Conference, CCNC 2007, Las Vegas, NV, 11 January 2007 through 13 January 2007 ; January , 2007 , Pages 665-669 ; 1424406668 (ISBN); 9781424406661 (ISBN) Khodaian, A ; Hossein Khalaj, B ; Talebi, M. S ; Sharif University of Technology

2007

Abstract

In this paper we consider the issue of energy efficiency in random access networks and show that optimizing transmission probabilities of nodes can enhance network performance in terms of energy consumption and fairness. First, we propose a heuristic power control method that improves throughput, and then we model the Utility Constrained Energy Minimization (UCEM) problem in which the utility constraint takes into account single and multi node performance. UCEM is modeled as a convex optimization problem and Sequential Quadratic Programming (SQP) is used to find optimal transmission probabilities. Numerical results show that our method can achieve fairness, reduce energy consumption and...

New vector quantization-based techniques for reducing the effect of channel noise in image transmission

, Article Signal Processing ; Volume 84, Issue 11 SPEC. ISS , 2004 , Pages 2153-2163 ; 01651684 (ISSN) Dianat, R ; Marvasti, F ; Azmi, P ; Talebi, S ; Sharif University of Technology

Elsevier 2004

Abstract

In this paper, new vector quantization (VQ) based techniques for reducing the effect of channel noise in image transmission are introduced. In one of the proposed methods, i.e., component VQ (CVQ), by transmitting the components of code-vectors (and not their indices), we will be able to reduce the effect of channel noise. To decrease the output rate of CVQ, a modification of CVQ called sub-index VQ (SIVQ) is introduced. This method has error-correcting capability as well. Simulation results show that CVQ and SIVQ techniques are robust to channel errors and surpass the conventional method, in which the indices of the selected code-vectors are protected using a Reed-Solomon code. An error...

Non-statistical rational maps

, Article Mathematische Zeitschrift ; Volume 302, Issue 1 , 2022 , Pages 589-608 ; 00255874 (ISSN) Talebi, A ; Sharif University of Technology

Springer Science and Business Media Deutschland GmbH 2022

Abstract

We show that in the family of degree d⩾ 2 rational maps of the Riemann sphere, the closure of strictly postcritically finite maps contains a (relatively) Baire generic subset of maps displaying maximal non-statistical behavior: for a map f in this generic subset, the set of accumulation points of the sequence of empirical measures of almost every point in the phase space, is equal to the largest possible one, that is the set of all f-invariant measures. We also introduce an abstract setting to study non-statistical dynamics and sufficient conditions for their existence in a general family of maps. These sufficient conditions are related to the notions of “statistical instability” and...

Experimental Investigation of Biodiesel Production from Oils by Transesterification Method Catalyzed by Nano-heterogeneous Catalysts

, M.Sc. Thesis Sharif University of Technology Talebi, Soroush (Author) ;

Abstract

Today polyolefin definitely is one of the most applicable polymers in the world. One of these polymers is ultra-high molecular weight polyethylene. Being applicable in a number of high-tech industries such as military service, battery separators, and other areas, expands the usage of these polymers. Electrospinning is one of the molding methods in order to synthesize fiber polymers. Using this method, a great deal of polymer fibers have been prepared. It is worth noting that the device used for olefins should have temperature control and temperature increase ability. The electrospinning device with the temperature control has not been built in the country; therefore, this device has been...

Block circular delay diversity space-frequency codes with the enhanced performance

, Article 2012 6th International Symposium on Telecommunications, IST 2012 ; 2012 , Pages 416-419 ; 9781467320733 (ISBN) Hosseini, G. F ; Shahabinejad, M ; Shahabinejad, M ; Talebi, S ; Sharif University of Technology

2012

Abstract

In this paper, by applying a new permutation to the full-diversity block circular delay diversity (BCDD) space-frequency codes (SFCs), we show that their performance could be enhanced. Furthermore, we propose a new method for performing the permutation in the absence of partial channel state information at the transmitter. This new permutation, which is done based on artificial delay and power profiles (ADPPs), could improve the performance of the BCDD SFCs more than 3 dB as simulation results demonstrate

Maximizing quality of aggregation in delay-constrained wireless sensor networks

, Article IEEE Communications Letters ; Volume 17, Issue 11 , 2013 , Pages 2084-2087 ; 10897798 (ISSN) Alinia, B ; Yousefi, H ; Talebi, M. S ; Khonsari, A ; Sharif University of Technology

2013

Abstract

In this letter, both the number of participating nodes and spatial dispersion are incorporated to establish a bi-objective optimization problem for maximizing the quality of aggregation under interference and delay constraints in tree-based wireless sensor networks (WSNs). The formulated problem is proved to be NP-hard with respect to Weighted-sum scalarization and a distributed heuristic aggregation scheduling algorithm, named SDMAX, is proposed. Simulation results show that SDMAX not only gives a close approximation of the Pareto-optimal solution, but also outperforms the best, to our knowledge, existing alternative proposed so far in the literature