Sharif Digital Repository

Due to the continuing progress in CMOS technology and increased number of cores within a chip, multiple components with different levels of criticality have been integrated into a common hardware platform. These systems with these characteristics are known as Mixed-Criticality Systems (MCS). Also, due to the migration towards multi-core systems, power consumption and specifically instantaneous power consumption is the main concern. To avoid the use of cooling technology, we need to reduce the instantaneous power consumption of the system. However, most existing approaches in MCS have paid attention to reliability guaranteed and energy minimization. Therefore, we consider a dynamic scheduling... 

Enanthioselective synthesis of biological molecules are so important in synthetic chemistry, and because of their biological activities, β-amino carbonyl compounds have earned so much attention in this area of chemistry. Mannich reaction is a classical method for synthesis of these molecules. The Mannich reaction is a three-component reaction between an enolizable CH-acidic carbonyl compound, an amine, and an aldehyde producing β-amino carbonyl compounds. But acidic or basic difficult circumstances, long reaction time, low yield and enantioselectivity, are the drawbacks of classical methods. In this project, we used titania-based solid acid as an enantioselective catalyst to overcome these... 

This thesis contains two parts .In the first part a catalyst such as AlCl3/Al20 has been demonstrated to catalyze Michael addition reaction of amines to a,�- unsaturated compounds with high yields , short reaction time and under solvent-free condition.The Michael addition to a,�- unsaturated compounds produces quantitively the mono addition products.The next part is about olefins epoxidation . Alkene epoxidation is a useful reaction in organic synthesis. Epoxides play an important role in industrial intermediates for the production of fine chemicals as well as pharmaceuticals .The hydrogen peroxide has been used as an oxidant because it is considered as an economical and appropriate reagent... 

This thesis contains four chapters. In first chapter the role of water in organic reactions as a ecofriendly solvent, computational chemistry and dynamic nuclear magnetic resonance were studied. In the second chapter synthesis of new 4-hydroxy pyrrole derivatives in water were reported. For the synthesis of these compounds arylglyoxal derivatives, 1,3-dicarbonyl compounds and ammonium acetate were used. The reaction conditions are very mild. The third chapter contains the synthesis of new (4 or 5)-Aryl-2-aryloeil-(1H)-imidazole compounds in aqueous media. We also investigated the tauto-isomerisation of isomeric imidazoles during this reaction using DNMR technique. In forth chapter a... 

The study of the religious experience is always one of the most important topics in researches related to the religion field. Religious and mystical experiences have always been one of the key religious concepts. The religious experience, like other human experiences, always comes with reactions in the human brain. Study of the religious experience from a neuroscience perspective can help us to answer questions and issues in the field of religious experience and cognitive credit of it. Assessment of what happens in the people’s brain during rituals like meditation or deep concentration provides a good window into understanding of what this means for people, being mystical or religious or... 

In this research, piezocatalysts ceramics Bi4Ti3-xMnxO12 (x=0,0.1,0.2,0.3) were synthesized by hydrothermal method and utilized in the process of rhodamine B piezocatalytic degradation.These piezocatalysts were characterized using XRD, FE-SEM, FT-IR, DRS and PL methods. The results of XRD patterns confirmed the formation of orthorhombic crystal structure of Bi4Ti2.9Mn0.1O12 and Bi4Ti3O12 piezocatalysts. FT-IR spectroscopy confirmed the existence of chemical bonds of piezocatalysts. FE-SEM images showed the formation of Bi4Ti2.9Mn0.1O12 and Bi4Ti3O12 nanoplates. Using DRS analysis data, the absorption edge wavelength and energy gap of the synthesized piezocatalysts were obtained. Also, the... 

Due to the long physical distance between the users and the cloud data centers, the idea of considering fog layer was established to bring computations closer to the edge of the network, and provide a solution for latency-sensitive applications. In such applications, the tasks are offloaded, and assigned to the available virtual machines in the cloud or fog layers, which directly contribute to Quality of Service (QoS) requirements. Among various applications, the real-time applications require their tasks to finish before their deadlines. Therefore, an assignment or a scheduling algorithm is needed to assign incoming tasks to virtual machines in cloud or fog layer. Most of the research on... 

In the first stage of this research, different amounts of glycidoxypropyltrimethoxysilane (GPS) were grafted as a coupling agent on the surface of nanosilica particles (NS). Surface characterization was done by Particle Size Analyzer and Thermal Gravimetric Analyzer (TGA) and that way, samples were distinguished from each other. More comparisons were taken by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Then the different amounts of modified NS were added into the matrix of an epoxy resin and the physical and mechanical properties of samples were tested with Abrasion Resistance test, Tensile Strength test, Thermal Mechanical Analysis (TMA),... 

Purification of waste water containing metal ions, is one of major environmental problems which have threaten human’s life, other creatures and even agricultural products by means of polluting suberranean water. Copper ion is one of dangerous heavy metals that exists in potable water and agricultural uses, due to serious problems in health of humans and aquatic. In recent years, different methods for purification of waste water containing heavy metal ions have been published. Right now, thorough these methods such as: filtration, coagulation, precipitation and adsorption are being used, which have their own advantages and disadvantages.In this research, new method for purification of waste... 

Quantum calculation based on the density functional theory (DFT) level and 6-311++G (d,p) basis set was employed to study the relation between the structure and radical scavenging activity of a series of hydroxybenzohydroxamic acid derivatives, namely: [HU]; hyroxyurea, [TX]; 3,4,5-trihydroxybenzamidoxime, [DX]; 3,4-dihydroxybenzohydroxamic acid, [4-HBA]; 4-hydroxybenzohydroxamic acid, [2,3-DHBA]; 2,3-Dihydroxybenzohydroxamic acid, [3,5-DHBA]; 3,5-Dihydroxybenzohydroxamic acid and [2-HBA]; 2-hydroxybenzohydroxamic acid in the gas phase, water and benzene environments. The hydrogen bond property of the studied structures and their radicals as well as radical cations was investigated using... 

One of the main uranium separations of ore that uranium percent application of enhanced design strategies in the industrial cracking furnaces are of practical interest for oil, gas and petrochemical industries. For such engineering purposes the exact simulation of temperature, species concentration and flow fields in the furnace is essential. In this paper, a study was performed to simulate 3D flue gas flow pattern, temperature and species concentration field in the radiation section of an industrial cracking furnace using the computational fluid dynamics (100-500) ppm technique. The steady-state Reynolds Averaged Navier–Stokes (Resin in pulp)equations were solved, in a finite volume scheme,... 

This thesis is divided into two parts: In part I, which is theoretical part, we were looking for a computational method which is extensively comparable with experimental results to determine pKa of wide variety of organic compounds. The pKa is an important property in many sciences such as chemistry, biology, and material science, since inclination of a compound to donate or accept a proton is fundamental to understanding many chemical and biochemical processes. Experimentally determined pKa values are not always available from literature sources and often estimated values are employed in their place. It is useful, therefore, to have reliable and accurate means of calculating relative and/or... 

Hydrogen bonding is an important weak interaction encountered in gas, liquid, as well as solid phase. The hydrogen bond plays a very vital role in many life processes and is one of the most frequently used terms in chemistry and biology. Amides have several applications as drugs, antibacterials and antifungals. Different substituents can affect the acidity of amides. Investigation have shown that hydroxyl function group can increase the acidity of many organic molecules through interamolecular hydrogen bonding. The goal of this project is to investigate the acidity of cyclic amides and barbiturates by adding hydroxyl group in the gas and solution phase. All the gas phase optimizations and... 

Hydrogen bonding is an important weak interaction encountered in gas and liquid, as well as solid phase. The hydrogen bond plays a very vital role in many life processes and is one of the most frequently used terms in chemistry and biology. Beta diketones have several applications in organic, inorganic and analytical chemistry. Different substituents can affect the acidity of beta diketones. Investigation have shown that hydroxyl function group can increase the acidity of many organic molecules through interamolecular hydrogen bonding. The goal of this project is to investigate the acidity of hydroxyl containing beta diketones in the gas and solution phase. All the gas phase optimizations... 

In this research, initially, thin film of TiO2 nanotube arrays (TNA) was deposited on Titanium foil (Ti), using anodization technique under an optimized applied voltage of 60 V, for 200 minutes. Highly smooth and ordered TNA formed by effective two-step anodization method. The TNA synthesized by this procedure, showed a better surface smoothness and tube order as compared with the TNA prepared in one-step anodization process. The electrolyte which was utilized for the anodization process, contained 90% of Ethylene Glycol (EG) in volume, 10% de-ionized water (DI) in volume, 0.1M Ammonium Fluoride (NH4F), and 0.5 ml Phosphoric Acid (H3PO4) 1M in order to adjust the pH about 5.6. Moreover, the... 

This project investigates on synthesis of β-amino carbonyl compounds with new approach to become closer to green chemistry principals.In this project, we investigated the synthesis of β-amino carbonyl compounds with aromatic amines and electron deficient alkenes in the Michael reaction using boric acid and glycerol in water as a green media. High yields of the products and easy handling are some advantages of this procedure. Also, we investigated the Michael reaction in different solvents and temperatures but gave better results in the aqueous media. Moreover, thiomorpholine derivatives were synthesized using this method to give excellent yield.
 

Dithiocarbamates are a group of compounds that nowadays have been used extensively in pharmaceutical agents, organicsynthesis and as fungicides in agriculture.We haveshown, an efficient. regiospecific method for the synthesis of cyclic dithiocarbamates by one-pot three-component cascade reaction of an amine, CS2 and α,β-unsaturated aldehyde via Michael addition/hemiamination reaction in watre under a mild and green procedure with excellent yields and complete regioselectivity