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    Curcumin incorporated PVA-borax dual delivery hydrogels as potential wound dressing materials—Correlation between viscoelastic properties and curcumin release rate

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 45 , 2018 ; 00218995 (ISSN) Rezvan, G ; Pircheraghi, G ; Bagheri, R ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Abstract
    Poly(vinyl alcohol) (PVA) is a biocompatible polymer which can be physically crosslinked by Borax to form hydrogel. PVA-Borax (PB) hydrogel is a promising candidate for drug delivery system. Therefore, it is necessary to find the quantitative relationship between drug release rate and network structure of PB hydrogels to predict and control drug release rate. In this work, at first step the optimum ratio of Borax: PVA was determined by studying the interactions between PVA chains and Borax molecules by means of Fourier transform infrared spectroscopy, while viscoelastic properties of prepared PB hydrogels were measured in the oscillatory shear flow field. In the following, curcumin as a... 

    Effect of Major Principal Stress Direction Rotation on Cyclic Behavior of Dense Sand Using Dynamic Hollow Cylinder Aparratus

    , M.Sc. Thesis Sharif University of Technology Baghban Rezvan, Sina (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    In the past years a lot of research has been done on effects of different parameters on dynamic behavior of soils. According to these studies, principal stress direction rotation and intermediate principal stress coefficient have a major effect on monotonic behavior of soils, but more studies needed for observingtheir effect on dynamic behavior of soils.
    In recent study undrained isotropic consolidated specimens of dense Babolsar sand subjected to α changes using dynamic hollow cylinder apparatus and the inner and outer cell pressure kept constant so that b was relative to α changes.
    Fisrt series of testswere done to find an appropriate value for induced cyclic deviator stress. The... 

    The Study on Relationship between Viscoelastic Properties and Drug Release of Wound Dress Polyvinyl Alcohol Hydrogel

    , M.Sc. Thesis Sharif University of Technology Rezvan, Gelareh (Author) ; Bagheri, Reza (Supervisor) ; Pircheraghi, Gholamreza (Supervisor)
    Abstract
    Wound is a defect or failure in the skin texture which occurs as a result of physical or heat injuries or physiological conditions. The wound dress as a temporary cover can improve wound healing process and due to the unique properties, hydrogels have become appropriate choice for this application. Hydrogel’s structure allows drug to be loaded in the wound dress. Hydrogel wound dress should have adequate fluidity to cover wound’s bed and make full contact with the skin. Sufficient cohesion and strength is also necessary to allow the wound dress to remove from wound completely. Therefore, the study on the viscoelastic properties of hydrogel is important. In this study, polyvinyl alcohol... 

    Tailoring Software Testing Techiques for Product Line Engineering

    , M.Sc. Thesis Sharif University of Technology Rezvan, Abolfazl (Author) ; Mirian-Hosseinabadi, Hassan (Supervisor)
    Abstract
    In industry it is usual to develop a family of similar software instead of a single one. Software product-line (SPL) engineering or family-based software engineering is an approach that tries to minimize needed effort and time-to-market and maximize quality of manufactured products through strategic planning for maximizing reuse among members of the family. On the other hand it is known that testing software is an indivisible part of software development process which requires considerable time and effort. With large number of products created from an SPL, it is obvious that testing should be conducted in such a way that needed effort does not maintain a linear relationship with number of... 

    Designing a Loadcell for a Walker to Measure Upper Extremities’ Forces

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Mohammad (Author) ; Zohoor, Hassan (Supervisor)
    Abstract
    In this project, two bidirectional loadcell are designed and fabricated to be installed on a walker. Then upper extremities’ forces and moments have been obtained. Results can be used for rehabilitation purposes in Spinal Cord Injuries and Cerebral Palsy cases. The method used in this project is as follows: First, since the commercial multidirectional loadcells are too expensive, the loadcell (and an appropriate electronic board) are fabricated. Ultimately, a complete gait analysis by means of VICON motion analysis and using inverse dynamic method has been held to measure upper extremities’ forces and moments in the wrist, elbow and shoulder. The results for a person with Spinal Cord Injury... 

    An Efficient Hardware Trojan Detector Using On-chip Ring Oscillator

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Mohsen (Author) ; Hesabi, Shahin (Supervisor)
    Abstract
    Nowadays integrated circuits are extremely vulnerable to hardware trojans (HT). Hardware trojans can be injected into the ICs in design or fabricate phase, and damage system’s functionality or security. In this thesis, we first describe hardware trojan definition, classification and types of HTs, negative effects, detection ways and analysis of them. Then we propose a new solution in order to solve the negative points of previous methods  

    Experimental Investigation of Microjet Engine Anomaly Detection Based on ANN Data Clustering Analysis

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Mahyar (Author) ; Saghafi, Fariborz (Supervisor)
    Abstract
    In this study, the possibility of detecting known and unknown anomalies in a micro jet engine is evaluated. the proposed method is neural network and clustering analysis. The process consists of two main parts, first part is experimental abnormal behavior simulation and second part is validation of proposed detection method. In the first part a micro jet engine (Olympuse HP) were used and we created pre-designed errors in engine normal behavior to record significant changes in its performance. Recorded outputs consist of six different variables: RPM, Exhaust gas temperature, Throttle command, Fuel pump voltage, Thrust and Fuel weight. In the second part, for analyzing data, we used... 

    The Role of Safety Attitudes and Attitudes Toward Vehicle in Urban Crashes

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Ali (Author) ; Kermanshah, Mohammad (Supervisor)
    Abstract
    Nearly 1.2 million people die in road crashes each year, and as many as 50 million are injured in the world. In Iran, approximately 800 thousand crashes occur annually killing up to 43 people per day. Given that over 90% of accidents are related to human factors, using models that incorporate driver’s attitudes and behavior can be highly predictive of crashes. The main objective of the current research is to examine the impact of drivers’ attitudes on road crashes along with other factors such as socio-demographic characteristics and vehicle type. This study uses data from a self-completed questionnaire among a representative sample of Iranian drivers living in Tehran. The Questionnaire... 

    Feasibility Study of Rapid Estimation of SF Parameter of Cells Using the Monte Carlo Simulation of Carbon Therapy in Combination with Cascade Feed-forward Neural Network (CFNN) by Bayesian Regularization Learning Algorithm

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Rezvan (Author) ; Vosoughi, Naser (Supervisor)
    Abstract
    Our main goal in this project is to calculate the cell survival fraction (SF) in unhealthy tissue after carbon ion beams are emitted and hit the target tissue. At present, in the stages of carbon therapy, it usually takes a long time to make the necessary calculations for that particular person, and this makes the treatment process progress slowly, but in this project, we intend to address this problem with Eliminating the use of neural network. The main reason is the use of carbon ions to increase efficiency in the treatment of tumors and deep cancerous tissues. To do this project, we first convert the carbon ion energy to the dose absorbed at the desired point. For this phase of the... 

    Effects of Microstructure and Salinity Concentration on Hydraulic Conductivity of Silty Clay Soils

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Saeed (Author) ; Sadeghi, Hamed (Supervisor)
    Abstract
    Various contaminants and their leachate, when they penetrate into the soil, cause changes in soil microstructure, this change in microstructure leads to changes in soil permeability and volume. In this study, first, the effects of soil microstructure change on the hydraulic conductivity of saturated soil were investigated using the change in initial saturation degree during compaction for compacted samples and the change in sample construction in reconstituted samples. Also, the simultaneous effect of changing the initial microstructure and salt solution on the hydraulic conductivity of saturated silty clay soils using a three-axial permeability device with the ability to measure volume... 

    Parametric Investigation on Microstructure and Mechanical Properties of Ultrasonic Spot welded Aluminium and Copper Sheets

    , M.Sc. Thesis Sharif University of Technology Yosefi, Ali (Author) ; Kokabi, Amir Hossain (Supervisor) ; Abedini, Rezvan (Co-Supervisor)
    Abstract
    Ultrasonic metal welding is a solid state welding process and is widely used in welding the connections of lithium-ion battery batteries in hybrid and plug-in hybrid vehicles. This welding process has advantages over fusion welding processes such as; Shorter time, no heat affected area, optimal energy consumption, cheaper equipment and no harm to the environment. The aim of this study was to investigate the effect and optimization of time, normal pressure and oscillation amplitude parameters in order to achieve the maximum tensile-shear test force and T-peel test in the dissimilar welding of 1050 aluminum and copper (purity above 99.9%). In order to achieve the optimal state of welding... 

    The ion streaming effect on weibel instability in the relativistic dense plasma

    , Article Contributions to Plasma Physics ; Volume 57, Issue 8 , 2017 , Pages 351-356 ; 08631042 (ISSN) Khodadadi Azadboni, F ; Mahdavi, M ; Sharif University of Technology
    2017
    Abstract
    The Weibel instability plays an important role in stopping hot electrons and energy deposition mechanism in fast ignition of inertial fusion process. In this paper, the ion Weibel instability in counter propagating electron-ion plasmas is investigate. The obtained results show that the growth rate of Weibel instability will be decreased about 40% with the anisotropy velocity as vxe = 2vze = 20; the ion density ratio, b = n0i1/n0i2, and density gradient, are increasing 50 and 90% respectively. The ion streaming in density gradient of dense plasma leads to increasing the Weibel instability growth rate and its amplification through ion streaming in the large wavenumber. The maximum unstable... 

    Numerical Solution of Hypersonic Axisymmetric Flows Including Real Gas Effects Using Compact Finite-Difference Scheme

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Polin (Author) ; Hejranfar, Kazem (Supervisor)
    Abstract

    The numerical solution of the parabolized Navier-Stokes (PNS) equations for accurate computation of hypersonic axisymmetric flowfield with real gas effects is obtained by using the fourth-order compact finite-difference method. The PNS equations in the general curvilinear coordinates are solved by using the implicit finite-difference algorithm of Beam and Warming type with a high-order compact accuracy. A shock fitting procedure is utilized in the compact PNS scheme to obtain accurate solutions in the vicinity of the shock. To stabilize the numerical solution, numerical dissipation term and filters are used. The main advantage of the present formulation is that the basic flow variables... 

    Analysis and Modeling of User Behavior over Social Media

    , Ph.D. Dissertation Sharif University of Technology Khodadadi, Ali (Author) ; Rabiee, Hamid Reza (Supervisor)
    Abstract
    Nowadays many of us spend a big part of our daily times on social media.One of the most important research problems in social media analysis is how to engage users. The trace of user activity over these websites is a valuable resource for user understanding and engagement, but this data is very huge and unstructured. An approach to deal with this problem is user behavior modeling. In this process, first a behavioral model is considered for users, then using the activity data and the behavioral model, some parameters are learned. Finally, using the learned parameters, a user profile is constructed for each user. This profile can be used for user engagement and many other applications.... 

    Synthesis and structure activity relationship of pyridazine-based inhibitors for elucidating the mechanism of amyloid inhibition

    , Article Chemical Research in Toxicology ; Volume 31, Issue 10 , 2018 , Pages 1092-1104 ; 0893228X (ISSN) Kalhor, H. R ; Nazari Khodadadi, A ; Sharif University of Technology
    American Chemical Society  2018
    Abstract
    Conformational diseases, constituting a large number of diseases, have been connected with protein misfolding, leading to aggregation known as amyloid fibrils. Mainly due to the lack of detailed molecular mechanisms, there has not been an effective drug to combat amyloid-associated diseases. Recently, a small organic pyridazine-based molecule (RS-0406) has shown significant reductions in amyloid fibrils in both in vitro and in vivo animal studies. However, no information on molecular details of inhibition for the small molecule has been reported. In this work, we have decided to explore structure-activity relationship of pyridazine-based compounds to investigate structural parameters for... 

    Generation of attosecond electron bunches by the relativistic Weibel instability

    , Article Physics of Plasmas ; Volume 25, Issue 1 , 2018 ; 1070664X (ISSN) Khodadadi Azadboni, F ; Sadighi Bonabi, R ; Sharif University of Technology
    American Institute of Physics Inc  2018
    Abstract
    The relativistic Weibel instability and temperature anisotropy can generate electron bunches of attosecond duration which makes it an attractive method for the generation and amplification of tunable ultrashort pulses. In this paper, the effect of the relativistic Weibel instability and temperature anisotropy on generating attosecond electron bunches is investigated. Calculations show that with the reduction relativistic parameter, γ, by a factor of 2, increasing 14.6% of the relativistic Weibel instability leads to about 62% reduction of the nanobunching gain saturation time and the density perturbation generated by the temperature anisotropy and the relativistic Weibel instability. The... 

    Preparation of Titania based solid strong acid and study of its catalytic activity in esterification of Phthalic anhydride and Sebacic acid

    , Article Materials Letters ; Volume 60, Issue 6 , 2006 , Pages 715-719 ; 0167577X (ISSN) Khodadadi Moghaddam, M ; Gholami, M. R ; Sharif University of Technology
    2006
    Abstract
    Esterification of Phthalic anhydride with 2-Octanol and Sebacic acid with Ethanol has been studied in the presence of Sulfated Titania. This study showed that Sulfated Titania has strong catalytic effect on esterification reactions. The effect of some factors such as reaction temperature, molar ratio of acid to alcohol, amount of catalyst used, reaction time, calcination temperature, drying temperature and calcination atmosphere has been investigated. Equilibrium composition achieved in 80 min for Diethyl Sebacate and 20 min for Dioctyl Phthalate in various conditions. © 2005 Elsevier B.V. All rights reserved  

    A Heuristic Security-Aware Task Scheduling Algorithm in Computational Grids

    , M.Sc. Thesis Sharif University of Technology Khodadadi, Farzad (Author) ; Movaghar, Ali (Supervisor)
    Abstract
    Computational grids consist of hardware and software infrastructures which can provide end users with the power of computational networks in a ubiquitous and cheaper manner. In fact, computational grids provide the ability to use the computational power of geographically distributed and heterogeneous resources. One of the new challenges facing researchers in this area involves security in grid environment which is somehow hard to achieve, because of the distributed nature of grid resources and fast changes in resource availabilities. Since availability, integrity and confidentiality are key factors of security and system’s fault tolerance capability is directly related to resource... 

    Experimental study of Silver, Zinc and Copper ablation by Nd:YAG laser

    , M.Sc. Thesis Sharif University of Technology Khodadadi Daryan, Monireh (Author) ; Saddighi, Rasoul (Supervisor)
    Abstract
    In this project, production of nano and micro particles with laser ablation of zinc, silver and copper sheet metals in the liquid medium has been experimentally studied. For this aim, homemade Nd:YAG pulsed laser at 1064nm wavelength, 60μs pulses with excellent stability with energies up to 700mj is used. By changing the pulse intensity on the target surface, the parameters such as size, shape and optical properties of nano and micro particles are studied by UV-visible spectroscopy, DLS, and SEM techniques. In this work, by microsecond pulses of Nd:YAG and using measuring devices such as Coherent power /energy meter, the appropriate optical table, the related experiments are implemented.... 

    Predicting anchor links between heterogeneous social networks

    , Article Proceedings of the 2016 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining, ASONAM 2016, 18 August 2016 through 21 August 2016 ; 2016 , Pages 158-163 ; 9781509028467 (ISBN) Sajadmanesh, S ; Rabiee, H. R ; Khodadadi, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    People usually get involved in multiple social networks to enjoy new services or to fulfill their needs. Many new social networks try to attract users of other existing networks to increase the number of their users. Once a user (called source user) of a social network (called source network) joins a new social network (called target network), a new inter-network link (called anchor link) is formed between the source and target networks. In this paper, we concentrated on predicting the formation of such anchor links between heterogeneous social networks. Unlike conventional link prediction problems in which the formation of a link between two existing users within a single network is...