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    Numerical Investigation of Jet Pump Performance in Traveling Wave Thermoacoustic Engine

    , M.Sc. Thesis Sharif University of Technology Barzegari, Ali (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    Thermoacoustic engines are a promising alternative to the conventional heat engines due to the absence of moving parts in the hot region and the small temperature difference required for operation. However, the traveling wave thermoacoustic engine configuration has a relatively lower efficiency due to a phenomenon called Gedeon streaming. In this regard, a jet pump might be used to lower the negative effects of Gedeon streaming. The jet pump, which is simply an element consisting of one or more tapered holes, induces an oscillating flow through the asymmetric device and hence resulting in a time-averaged pressure drop across it. As a result, by balancing this time averaged pressure drop with... 

    ChemInform abstract: microwave-assisted rapid ketalization/acetalization of aromatic aldehydes and ketones in aqueous media [electronic resource]

    , Article Journal of Chemical Research ; September 1999, Volume -, Number 9; Page(s) 562 to 563 Pourdjavadi, A. (Ali) ; Mirjalili, Bibi Fatemeh ; Sharif University of Technology
    Abstract
    Aromatic aldehydes and ketones are readily acetalized or ketalized under microwave irradiation in the presence of water as a solvent  

    Synthesis and characterization of poly(methacrylates) containing spiroacetal and norbornene moieties in side chain [electronic resource]

    , Article Journal of Applied Polymer Science ; Volume 77, Issue 1, pages 30–38, 5 July 2000 Pourdjavadi, A. (Ali) ; Mirjalili, Bibi Fatemeh ; Sharif University of Technology
    Abstract
    A four-step synthetic strategy was applied to achieve novel methacrylic monomers. 5-Norbornene-2,2-dimethanol was prepared from a Diels–Alder reaction of cyclopentadiene and acrolein, followed by the treatment of the adduct with an HCHO/KOH/MeOH solution. The resulting 1,3-diol (1) was then acetalized with different aromatic aldehydes having OH groups on the ring to produce four spiroacetal derivatives. The reaction of methacryloyl chloride with the phenolic derivatives led to four new methacrylic monomers that were identified spectrochemically (mass, FTIR, 1H-NMR, and 13C-NMR spectroscopy). Free radical solution polymerization was used to prepare novel spiroacetal–norbornene containing... 

    Prediction of DNA/RNA Sequence Binding Site to Protein with the Ability to Implement on GPU

    , M.Sc. Thesis Sharif University of Technology Fatemeh Tabatabaei (Author) ; Koohi, Sommaye (Supervisor)
    Abstract
    Based on the importance of DNA/RNA binding proteins in different cellular processes, finding binding sites of them play crucial role in many applications, like designing drug/vaccine, designing protein, and cancer control. Many studies target this issue and try to improve the prediction accuracy with three strategies: complex neural-network structures, various types of inputs, and ML methods to extract input features. But due to the growing volume of sequences, these methods face serious processing challenges. So, this paper presents KDeep, based on CNN-LSTM and the primary form of DNA/RNA sequences as input. As the key feature improving the prediction accuracy, we propose a new encoding... 

    Cross-Lingual Speaker Adaptation for Statistical Parametric Speech Synthesis

    , M.Sc. Thesis Sharif University of Technology Saleh, Fatemeh Sadat (Author) ; Sameti, Hossein (Supervisor)
    Abstract
    Speech synthesis and its applications have been very attractive recently. The main purpose of this technique is to produce a speech signal with natural characteristics of human speech like prosody and emotion. Among all existing methods for speech synthesis, statistical parametric speech synthesis methods are more promising because ofhigher flexibility in comparison to other methods. One of the applications of speech synthesis is speech to speech translation. In these systems, the generated voice in target language should have the same characteristics as the input voice in source language. The main purpose of this research is to review and evaluate the cross lingual speaker adaptation... 

    Hydroelastic Analysis of Surface Piercing Propeller

    , M.Sc. Thesis Sharif University of Technology Fatemeh, Shahreki (Author) ; Seif, Mohamad Saeed (Supervisor)
    Abstract
    Surface piercing propellers are particular type of supercavitating propellers that are commonly used for High-speed vessels. Most studies on this type of propellers has been investigating the hydrodynamic forces. But in recent years with increase in SPPs diameter used in vessels, structural analysis of this type of propellers is considered. For this purpose, studies on the stresses exerted on the propeller structures under load is done with the help of Hydro elastic methods. In this type of analysis, structura of propeller is intended to be flexible and Displacements under pressure checked and Tensions resulting from it are studied.
    The present Thesis using ANSYS software to analyze a... 

    Data-Driven Pricing Based on Demand Prediction Using Machine Learning Methods

    , M.Sc. Thesis Sharif University of Technology Khosroshahi, Fatemeh Zahra (Author) ; Sedghi, Nafiseh (Supervisor)
    Abstract
    Pricing plays an important and essential role in the profit and income of companies. The importance of pricing is not only related to its role in the company's profitability, but it also changes the customer's understanding and loyalty towards the company and can create the company's reputation or destroy it. Determining the right price will increase product sales and increase customer loyalty and create a competitive advantage for the company. One of the most important and influential variables in product pricing is the amount of demand. The main challenge of companies for product pricing is the uncertainty in their demand. In order to deal with this problem, data-driven pricing is used.... 

    Design of Low-Power Zero Temperature Coefficient (ZTC) CMOS Oscillators

    , M.Sc. Thesis Sharif University of Technology Shahidani, Mohammad Aref (Author) ; Akbar, Fatemeh (Supervisor)
    Abstract
    The increasing demand for autonomous vehicles and reliable communication protocols and hardware interfaces, such as CAN bus and USB, underscores the necessity for stable clock sources that maintain a low temperature coefficient (TC) over wide temperature ranges. This demand is particularly emphasized in applications such as wearables, network sensors, downhole devices, WSNs, and IoT, where long-lasting battery life and frequency-stable clock sources over a broad temperature range (e.g. -20 °C to 100 °C) are crucial. Traditionally, variations in frequency caused by temperature have been mitigated by employing off-chip components like crystals or ceramic based oscillators, but this approach... 

    Silica chloride/wet SiO2 as a novel heterogeneous system for the deprotection of acetals under mild conditions [electronic resource]

    , Article Phosphorus, Sulfur, and Silicon and the Related Elements ; Volume 178:2667-2670, Issue 12, 2003 Mirjalili, B. F. (BiBi Fatemeh) ; Pourjavadi, Ali ; Zolfigol, Mohammad Ali ; Bamoniri, Abdolhamid
    Abstract
    A combination of silica chloride and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under mild and heterogeneous condition  

    Preparation of mesoporous nanostructure NiO–MgO–SiO2 catalysts for syngas production via propane steam reforming

    , Article International Journal of Hydrogen Energy ; Volume 45, Issue 11 , 2020 , Pages 6604-6620 Barzegari, F ; Kazemeini, M ; Farhadi, F ; Rezaei, M ; Keshavarz, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In this research, the propane steam reforming (PSR) as a promising alternative route over a mesoporous NiO–MgO–SiO2 catalyst to produce syngas (SG) was undertaken. This catalyst was prepared using a co-precipitation method followed by hydrothermal treatment. The influence of such catalyst preparation factors as the hydrothermal time and temperature, pH and calcination temperature on the physicochemical characteristics of the prepared samples were examined. Next, these materials were characterized through the BET-BJH, XRD, TPR, and FTIR analyses. The thermal stability of this catalyst was tested through the TGA and DTA techniques. Furthermore, the deactivation of the calcined catalysts at... 

    Propane steam reforming on mesoporous NiO–MgO–SiO2 catalysts for syngas production: Effect of the MgO/SiO2 molar ratio

    , Article International Journal of Hydrogen Energy ; Volume 45, Issue 46 , 2020 , Pages 24840-24858 Barzegari, F ; Kazemeini, M ; Rezaei, M ; Farhadi, F ; Keshavarz, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In this research, a series of NiO-xMgO-SiO2 catalysts with various MgO/SiO2 molar ratios were prepared via precipitation method followed by a hydrothermal treatment in the presence of PVP as surfactant. The synergic effect between MgO and SiO2 leading to the various characteristic and catalytic performance during propane steam reforming was investigated in detail. The results showed that 15 wt% NiO-0.5MgO–SiO2 catalyst possessed the highest catalytic activity (68.9% conversion for C3H8 at 550 °C) with a negligible amount of carbon formation after 20 h of reaction duration. This superior catalytic performance can be attributed to the enhanced basicity strength along with strong metal-support... 

    The influence of lanthanide on NiO-MgO-SiO2 catalysts for syngas production via propane steam reforming

    , Article Molecular Catalysis ; Volume 499 , 2021 ; 24688231 (ISSN) Barzegari, F ; Rezaei, M ; Kazemeini, M ; Farhadi, F ; Keshavarz, A ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    In this study, 15 wt. % NiO-MgO-SiO2 catalysts modified by La2O3 promoter were prepared through a co-precipitation route and employed for syngas production via propane steam reforming. Various techniques including X-Ray diffraction, BET, TPR, CO2-TPD, CO-chemisorption, TPO, and Scanning electron microscopy were utilized to characterize the final samples. The results indicated that the incorporation of La2O3 enhanced the metal-support interaction providing less reducible Ni species. In comparison with the La-free catalyst, the promoted ones possessed higher metal dispersion and smaller Ni particles. Nonetheless, excessive amounts of La covering the active sites negatively decreased the Ni... 

    Influence of metal loading and reduction temperature on the performance of mesoporous NiO–MgO–SiO2 catalyst in propane steam reforming

    , Article Journal of the Energy Institute ; Volume 96 , 2021 , Pages 38-51 ; 17439671 (ISSN) Barzegari, F ; Farhadi, F ; Rezaei, M ; Kazemeini, M ; Keshavarz, A ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    In this research, a series of NiO–MgO–SiO2 catalyst samples with various nickel contents (5, 10, 15 and 20 wt %) were prepared by a co-precipitation method followed by a hydrothermal treatment and employed in propane steam reforming. The analyses revealed that the enhancement of the nickel content up to 15 wt % improved the propane conversion to 98.6% at 550 °C. Nonetheless, further increase in the nickel loading reduced the catalyst activity due to the formation of larger and more poorly dispersed active sites. Besides, 15 wt % nickel loading led to the high resistance against coke deposition with no detectable carbon on the catalyst surface. In addition, it was revealed that, the decrease... 

    , M.Sc. Thesis Sharif University of Technology Barzegari, Fatemeh (Author) ; Farhadi, Fathollah (Supervisor) ; Bozorg Mehri, Ramin (Supervisor)
    Abstract
    In the present work, a comprehensive economic, environmental and dynamic behavior analysis with multi-objective optimization for the unit 400 of BandarEmam aromatic plant are provided and the interaction between decision variables in these criterions is discussed. In the first part, potential of seven environmental features of the operational plant are qualified and normalized using life cycle assessement (LCA) for both process waste and utility environmental impacts. By choosing the number of trays and feed stage in three distillation columns as decision variables, optimization is performed to determine the best structural variables values based on the total annual cost and Environmental... 

    The Impact of AV and CAV Vehicles on Capacity and Traffic Flow with Cooperative Lane changing in Mixed Traffic Environment

    , M.Sc. Thesis Sharif University of Technology Zanjani, Fatemeh Sadat (Author) ; Nassiri, Habibollah (Supervisor)
    Abstract
    Autonomous vehicles, as an integral part of intelligent transportation systems, will play a significant role in the future of transportation services. These vehicles have a high potential to improve road traffic capacity and the efficiency of transportation systems. One type of autonomous vehicle is the connected and autonomous vehicle (CAV), which can communicate with each other, roadside units, traffic control signals, and other infrastructures or devices. This study investigates the impact of autonomous vehicles and connected and autonomous vehicles on the traffic flow of the Tehran-Karaj freeway and vice versa, under various penetration rates and in a mixed traffic environment. In this... 

    Syngas production through CO2 reforming of propane over highly active and stable mesoporous NiO-MgO-SiO2 catalysts: Effect of calcination temperature

    , Article Fuel ; Volume 322 , 2022 ; 00162361 (ISSN) Barzegari, F ; Kazemeini, M ; Rezaei, M ; Farhadi, F ; Keshavarz, A. R ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    In this contribution, NiO-MgO-SiO2 catalyst was prepared and calcined at different temperatures of 500, 600, 700 and 800 °C. The resulting samples were characterized by BET-BJH, XRD, TPX, CO-chemisorption, EDS and SEM analyses. These were employed toward syngas production via propane dry reforming. The increment in the calcination temperature from 500 to 800 °C decreased the basicity of the catalysts. In addition, the active surface area and Ni dispersion were gradually declined by increasing the calcination temperature from 600 to 700 °C due to active metal sintering during the activation process. The calcined sample at 600 °C displayed the highest propane and CO2 conversions of 93% and 78%... 

    Effect of rare-earth promoters (Ce, La, Y and Zr) on the catalytic performance of NiO-MgO-SiO2 catalyst in propane dry reforming

    , Article Molecular Catalysis ; Volume 522 , 2022 ; 24688231 (ISSN) Barzegari, F ; Rezaei, M ; Kazemeini, M ; Farhadi, F ; Keshavarz, A. R ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    In this contribution, NiO-MgO-SiO2 catalysts containing 3 wt. % of CeO2, La2O3, Y2O3, and Zr2O3 were examined for propane dry reforming at 550-750 °C. The samples were synthesized by a co-precipitation route, followed by a hydrothermal treatment, and characterized by BET, XRD and TPX analyses. The results indicated that the addition of promoters enhanced the metal-support interaction and basic characteristics, while the acidic nature of the promoted catalyst was changed in a different way. The highest propane conversion of 39.6% was observed over Ce-promoter sample, while the un-promoted catalyst possessed a value of 36.8% at 700 °C. Nevertheless, La and Y-promoted catalysts possessed a... 

    A Comprehensive Review of Studies Conducted in Entrepreneurship Education in Order to Achieve a Codified Framework

    , M.Sc. Thesis Sharif University of Technology Emamjome, Fatemeh Sadat (Author) ; Feyzbakhsh, Alireza (Supervisor)
    Abstract
    In the current situation and considering the economic conditions, entrepreneurship and self-employment are important factors of business growth. To prepare people in this field, there is a need for effective training that can motivate people. Identifying the effective methods and different dimensions of the entrepreneurship education framework that can lead to setting up a successful program for training people and facilitate the way to achieve the goal of education is one of the important goals of this research. By studying the literature from 2010 onwards, this research systematically examined 96 articles and tried to improve the framework of entrepreneurship education that was stated in... 

    Evaluation of the Damage to Steel MRF Structures Under Near Field Earthquake Pulses Using a Performance-Based Design Approach

    , M.Sc. Thesis Sharif University of Technology Mousavi, Fatemeh Sadat (Author) ; Rahimzadeh Rofooei, Fayaz (Supervisor)
    Abstract
    Research on the characteristics of the near field earthquakes has been very popular in recent years due to the considerable damages they have caused to the structures located within the vicinity of seismic sources. The incapability of response spectra for structural damage assessment has been revealed through recent investigations. The recorded data show that the near field earthquakes are often accompanied by a large energy pulse in the beginning of the records caused by the so-called directivity phenomenon. That has encouraged many researchers to study the possibility of using the velocity pulse of these records to evaluate the imposed seismic demands on structures. Thus, investigating the... 

    Oxidative Addition of Amines to Aldehydes Catalyzed by Supported Cobalt Nanoparticles on SBA-15

    , M.Sc. Thesis Sharif University of Technology Raeisi, Mojdeh (Author) ; Saidi, Mohamad Reza (Supervisor) ; Rajabi, Fatemeh (Co-Advisor)
    Abstract
    Considering the widespread applications of amides, synthesis of these compounds is of great importance. The one pot oxidative addition of amines to aldehydes is one of the most simple and appealing approaches to synthesis amides. With the aim of developing a mild and convenient approach towards preparation of amides, numerous methods have been reported for this important process over the past few decades. These improvements have been mostly related to the optimization of reaction conditions and the use of more challenging substrates including diverse derivatives of aldehydes, and also design a novel and effective catalytic systems. Due to the various advantages of supported heterogeneous...