Sharif Digital Repository

The PM2.5 particles are considered as one the most important pollutants of Tehran’s air due to their undesirable effect on health and environment. The particular matters which are in Tehran’s air are distributed from different sources. Because of lack of sufficient data about amount and chemical compounds of such matters in different areas, this study considers only concentration of particular matter and their composing elements in Sharif University, Tehransar, Mahalati, and Shahriyar station. By use of field measuring between 2015 to 2016 mass concentration of PM2.5 pollutant was calculated and then with the help of IC, GC/MS, and ICP chemical analysis which were conducted in University of... 

In this work, by considering the medium effects and adding the long−range interactions to the isolated pair potential, the concept of the extended effective pair potential of the Lennard−Jones (12, 6, 3) has been purposed for dense systems. Due to lack of any information regarding the parameters of this potential for any fluid, the purpose of this work is to introduce a new method to calculate these parameters using experimental pVT data. Since the extended potential of Lennard− Jones (12, 6, 3) is a general function based on which that an equation of state can be derived (equation of state III) predicts many properties of dense systems that no deviation is observed. Also it doesn’t have... 

Today, a lot of efforts have been done in order to commercialize space travels. Spacecrafts have a lot of components and producing each of them spends high costs. Components such as propellant tanks and boosters are multi segment and are released simultaneously and therefore it is economically feasible to recover them. Due to Parafoil ability in low-cost, soft (no damage to the cargo) and accurate landing, it is gradually replacing parachute. Parafoil can fly long distances after being released, so its landing point could be determined. The aim of the study is to evaluate this scenario in which some segments of launch vehicle (e.g. booster) that are equipped with Parafoil expand their... 

In recent years, global salt lakes have faced severe environmental challenges. Lake Urmia, the world’s second-largest hyper saline lake, is located in the northwest of Iran, has experienced a significant shrinkage in last years. Lake Urmia is a terminal lake where water enters through precipitation and rivers inflow and loses through evaporation. Analysis of long-term trends (1990-2018) using the Mann-Kendall test indicates no significant trend in precipitation, an increasing trend in evaporation, and a decreasing trend in river discharge. However, precipitation during 1990-1999 (beginning of accelerated lake drying) showed a decreasing trend. An investigation of the correlation between... 

In this project, the continuous phase mass transfer and backflow coefficients are optimized, using the experimental data from two RDC columns. The continuous and dispersed phases are modeled by stage wise and forward mixing model, respectively. Genetic Algorithm is applied to find the optimized parameters of the model. Olney model is employed to find the slip velocities of drops. The dispersed phase mass transfer coefficients were calculated using Handlos-Baron model. In the other part of the project, the Rigid Drop model was modified to predict the mass transfer coefficients of dispersed phase and the modification parameter was optimized by genetic algorithm. The effect of rotor speed and... 

CO2 separation from air was investigated in this work. An immobilized liquid membrane (ILM) which contains triethylene glycol (TEG) and diethanolamine (DEA) was used for this purpose. In this kind of membranes a liquid, which improves permeability of gas species through the membrane, fills the pores of a polymeric membrane as support. Because of low vapor pressure of solution, liquid loss was negligible. Transport of CO2 was facilitated due to reversible chemical reaction between CO2 and amine solution. A polyvinylidene fluoride (PVDF) membrane was chosen to have chemical resistance against the solution and prevent destruction of polymer by solution. A flat sheet and hydrophilic PVDF was... 

In this research, initially the Triethylene glycol and Diglycol amine liquid membrane which is supported by PVDF, was prepared in order to separate the Carbone dioxide from CO2-Air mixture. A polyvinylidene fluoride (PVDF) membrane was chosen to have chemical resistance to solution. The effect of Pressure, Concentration of TEG and DGA solution and the percentage of carbon dioxide in feed; in rate and permeability of CO2, N2 and O2 and also selectivity of CO2/ N2 , CO2/ O2 and N2/ O2 was investigated. Transport of CO2 was facilitated due to reversible chemical reaction between CO2 and amine solution. The experiments were done in 0.4, 0.6 and 0.8bar and different concentration of solution.... 

In various industries, for energy production, fossil fuels are burned. Oxygen needed for combustion, taken directly from the ambient air; So that the inert gas is about 80%. The presence of this inert gas, mainly nitrogen, reduce combustion efficiency and increase the use of combustible material. In this project with the help of membrane technology, was used to remove the amount of nitrogen in the air so that the incoming air into the combustion chamber is enriched with oxygen. For this purpose, several gas separation membrane was applied and evaluated. Then, according to the oxygen enrichment, fuel efficiency and the amount of savings, increasing chamber temperature, reduction manufacturing... 

In the present study, a heat recovery system for a distributed generation plant (DG) with a 1 MW gas combustion engine has been designed. The purpose of this designing is converting the power plant to a CHP system. For the existing heat recovery system, a shell & tube heat exchanger is designed to recover the thermal energy from exhaust gases and a plate heat exchanger is designed to recover the thermal energy from the engine jacket cooling fluid. The heat exchanger design has been calculated manually and also by use of software. In the software calculation, the heat exchanger design has been done by use of the Aspen HTFS +2006.5 software. In the manual one, the Kern equation (1950) was... 

The main objective of this project is to study the effect of the presence of nanoparticles on mass transfer in liquid-liquid systems. To do this research, TiO2/water, Al2O3/water, CNTs/water and CNTs/toluene have been used as nanofluids. The experiments of TiO2/water nanofluid were been carried out in water-acetone-toluene system at two weigh percents of TiO2 nanoparticles. The result showed that mass transfer decreased in 0.5wt% of TiO2, compared to base fluid, and it increase in 1 %wt. Also in 0.5%wt the decrease in interfacial tension decreased diameter of drops and as a result mass transfer decreased too. In 1%wt the increase in viscosity increased the diameter of drops and then the... 

Liquid-liquid extraction is one of the common chemical processes in the industry which its application is increasing day by day. Taking trend of increase of energy resources, chemical materials and industrial system into account, the necessity use of least energy consumption and material for achieving highest output and purity of products in different industries is attracted researches and industerialists.In this research we have studied the effect of presence of nano particles on both disperses and continuous liquids phases on hydrodynamic of deoplets specially their investigated system in this project was watter, toluene and acetone, and chosen nanoparticles wer carbon nanotubes and TiO2.... 

Immensity and profundity of mathematical logic have provided an opportunity for its interconnection with other branches of science, one of which is computer science where theory of dependent types and lambda calculus lounges amongst the area of their overlap. The former has been engendered for the sake of deepening the connection between mathematical logic and programming. On the other side, lambda calculus which is a formal system in mathematical logic and computer science, developed as a tool for formal computations, could also be counted as a programming discipline. It is the objective of this thsis to study the two aforementioned fields with emphasis on unification of higher-order... 

In the last three years, the lives of many people around the world have changed with the spread of the Corona virus. In order to better manage the consequences related to the spread of this disease, extensive research has been done on this virus, and researchers in data science and artificial intelligence have devoted a part of their research to studying the effects of this virus on the people in one or different societies.On the other hand, the study of social networks about a specific issue or trend topic, allows us to examine more closely the atmosphere that governs the society and analyze the emotions, feelings and the level of concern of the members of the society about that issue.The... 

The separation ofacetic acids in binary water solutions hasbeenstudied using a reverse osmosis (RO) membrane. Thin film composite polyamide membrane is used in this study.Thin-film composite (TFC) membrane was prepared through the interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on the polysulphone support membrane.The solute permeation was carried out under applied pressure of 5 bar at 25°C. In this work the effect of various synthesis conditions on the membrane performance was investigated. Parametric studies were conducted by varyingconcentration of reactants, reaction time, curing time and curing temperature. By suitable combination of these...