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

Numerical investigation of effects of uniform magnetic field on heat transfer around a sphere

, Article International Journal of Heat and Mass Transfer ; Volume 114 , 2017 , Pages 703-714 ; 00179310 (ISSN) Abbasi, Z ; Molaei Dehkordi, A ; Abbasi, F ; Sharif University of Technology

Elsevier Ltd 2017

Abstract

In this article, ferrohydrodynamic forced-convection heat transfer from a heated sphere embedded in a ferrofluid in the presence of the uniform external magnetic field has been studied numerically for the first time over a wide range of Reynolds number value, nanoparticle diameter, particle volume fraction, and magnetic field intensity. Despite the uniform external magnetic field applied, the internal magnetic field near the sphere could be nonuniform due to the considerable difference between the relative magnetic permeability of the sphere and the surrounding medium. Kelvin body force arises from this nonuniformity and induces vortexes near the sphere. These vortexes disturb the boundary...

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...

A method for simulation of vapour cloud explosions based on computational fluid dynamics (CFD)

, Article Journal of Loss Prevention in the Process Industries ; Volume 24, Issue 5 , 2011 , Pages 638-647 ; 09504230 (ISSN) Tauseef, S. M ; Rashtchian, D ; Abbasi, T ; Abbasi, S.A ; Sharif University of Technology

2011

Abstract

The effectiveness of the application of CFD to vapour cloud explosion (VCE) modelling depends on the accuracy with which geometrical details of the obstacles likely to be encountered by the vapour cloud are represented and the correctness with which turbulence is predicted. This is because the severity of a VCE strongly depends on the types of obstacles encountered by the cloud undergoing combustion; the turbulence generated by the obstacles influences flame speed and feeds the process of explosion through enhanced mixing of fuel and oxidant. In this paper a CFD-based method is proposed on the basis of the author's finding that among the various models available for assessing turbulence, the...

Thin film graphene oxide membrane: challenges and gas separation potential

, Article Korean Journal of Chemical Engineering ; Volume 35, Issue 5 , May , 2018 , Pages 1174-1184 ; 02561115 (ISSN) Abbasi, F ; Karimi Sabet, J ; Ghotbi, C ; Abbasi, Z ; Sharif University of Technology

Springer New York LLC 2018

Abstract

Graphene oxide membranes were prepared by vacuum and pressurized ultrafiltration methods on the 12% modified Polyacrylonitrile (12mPAN) substrate to specify challenges, salient features, future directions, and potential of GO membrane for separation fields using characterization techniques and gas separation test (studied gases are CO2, He and N2), which is an efficient tool for better understanding of GO membrane behavior. GO membrane structure was examined over a wide range of parameters, such as pore size range of substrate and its surface properties, pH of GO dispersion, GO content, synthesis pressure, operating pressure and temperature. The results show that the GO content does not hold...

Conversion of CO into CO2 by high active and stable PdNi nanoparticles supported on a metal-organic framework

, Article Frontiers of Chemical Science and Engineering ; 2021 ; 20950179 (ISSN) Abbasi, F ; Karimi Sabet, J ; Abbasi, Z ; Ghotbi, C ; Sharif University of Technology

Higher Education Press Limited Company 2021

Abstract

The solubility of Pd(NO3)2 in water is moderate whereas it is completely soluble in diluted HNO3 solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH2(Cr) were synthesized by aqueous solution of Pd(NO3)2 and Pd(NO3)2 solution in dilute HNO3 and used for CO oxidation reaction. The catalysts synthesized with Pd(NO3)2 solution in dilute HNO3 showed lower activity. The aqueous solution of Pd(NO3)2 was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd70Ni30/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd + Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution...

Conversion of CO into CO2 by high active and stable PdNi nanoparticles supported on a metal-organic framework

, Article Frontiers of Chemical Science and Engineering ; 2021 ; 20950179 (ISSN) Abbasi, F ; Karimi Sabet, J ; Abbasi, Z ; Ghotbi, C ; Sharif University of Technology

Higher Education Press Limited Company 2021

Abstract

The solubility of Pd(NO3)2 in water is moderate whereas it is completely soluble in diluted HNO3 solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH2(Cr) were synthesized by aqueous solution of Pd(NO3)2 and Pd(NO3)2 solution in dilute HNO3 and used for CO oxidation reaction. The catalysts synthesized with Pd(NO3)2 solution in dilute HNO3 showed lower activity. The aqueous solution of Pd(NO3)2 was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd70Ni30/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd + Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution...

Conversion of CO into CO2 by high active and stable PdNi nanoparticles supported on a metal-organic framework

, Article Frontiers of Chemical Science and Engineering ; Volume 16, Issue 7 , 2022 , Pages 1139-1148 ; 20950179 (ISSN) Abbasi, F ; Karimi Sabet, J ; Abbasi, Z ; Ghotbi, C ; Sharif University of Technology

Higher Education Press Limited Company 2022

Abstract

The solubility of Pd(NO3)2 in water is moderate whereas it is completely soluble in diluted HNO3 solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH2(Cr) were synthesized by aqueous solution of Pd(NO3)2 and Pd(NO3)2 solution in dilute HNO3 and used for CO oxidation reaction. The catalysts synthesized with Pd(NO3)2 solution in dilute HNO3 showed lower activity. The aqueous solution of Pd(NO3)2 was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd70Ni30/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd + Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution...

Improved method for increasing accessible pores of MIL-101(Cr) by encapsulation and removal of Phosphotungstic acid (PTA): Pd/PTA-MIL-101(Cr) as an effective catalyst for CO oxidation

, Article Journal of Cleaner Production ; Volume 347 , 2022 ; 09596526 (ISSN) Abbasi, F ; Karimi Sabet, J ; Abbasi, Z ; Ghotbi, C ; Sharif University of Technology

Elsevier Ltd 2022

Abstract

This study forwards a novel and simple approach for encapsulation of Phosphotungstic acid (PTA) into MIL-101(Cr) cavities to develop PTA-MIL-101(Cr) with a high surface area. In this method, the resulting surface area of PTA-MIL-101(Cr) (3563 m2/g) is 1.72 times that of MIL-101(Cr) due to the existence of more accessible pores which are formed by leaching of PTAs incorporated inside MIL-101(Cr) pores during the intense washing. Catalysts are investigated in CO oxidation under atmospheric pressure and feed composition of 1%CO, 20%O2, and 79%He. 3%Pd/PTA-MIL-101(Cr) shows 100%CO conversion at T = 145 °C and outperforms PTA, PTA-MIL-101(Cr), Pd/PTA, 1–3%Pd/MIL-101(Cr), Pd-PTA/MIL-101(Cr), and...

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...

Investigation into the effects of weld zone and geometric discontinuity on the formability reduction of tailor welded blanks

, Article Computational Materials Science ; Volume 59 , 2012 , Pages 158-164 ; 09270256 (ISSN) Abbasi, M ; Ketabchi, M ; Ramazani, A ; Abbasi, M ; Prahl, U ; Sharif University of Technology

2012

Abstract

Numerous advantages of application of tailor welded blanks (TWBs) in automobile industry, namely reduction of weight, fuel consumption and air pollution, have made the manufacturers eager to investigate in this field. On the other hand, while experiments generally provide valuable information in regard with mechanical behaviors, but utilization of simulation methods has extended vastly due to time and cost saving issues. One challenging issue in numerically analyzing the forming behavior of transversely welded TWBs, welded by laser welding methods, has been the presence of weld zone. While some researchers believe that during simulation, the weld zone can be neglected due to its minority and...

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...