Sharif Digital Repository

Total air particulate matter of the city of Isfahan has been measured for elemental characterization in four principal directions of the city and during the year 2007-2008. High volume air samplers using whatman 41 filters have been utilized and instrumental neutron activation analysis has been used as the analytical method. Twenty one elements arising from seasonal and geographical distributions of the various elements have been determined. These distribution patterns have been discussed in view of the prevailing wind direction, location of the industrial facilities, and the Pearson correlation coefficients  

Because of production of large volumes of Produces Water during oil exploration, it is necessary to purify this water for reuse or discharging to environment. Thus, finding a suitable method for removing contaminations seems necessary. In the present study, removal of soluble and dispersed organic contaminants from produced water by Dissolved Air Precipitation/ Solvent Sublation has been studied. Combination of floatation by dissolved air and extraction with solvent has been used for removal of organic compounds in order to study simultaneous effect of both methods on removal efficiency. Samples used in the experiments were tested in two groups: the first group was synthesized samples of... 

Domed roofs were commonly used in buildings with large areas. These roofs played an important role in the Iranian architecture and had a great effect on the buildings cooling loads. Solar energy absorption causes the roof temperature to increase in comparison with its ambient atmosphere. Wind flow removes some of the heat from the roof, and the rest goes thorough the roof and enters the building.The eometrical configuration of these domed roofs causes the wind velocity to increase over them, resulting in an increase in the convection heat transfer coefficient. Also, the heat transfer of the roof is accentuated by the fact that the area of a domed configuration is considerably greater than a... 

An automatic air traffic controller system is designed in this research. The major goal is to aid the human controller in decision making at real air traffic control situations. The air traffic system is modeled by queuing theory. Since respond rapidity is very important in air traffic control, so the fuzzy logic is utilized to construct a rule-base. This rule-base determines optimum policies while considering the operational matters, minimum separation distance requirements, air traffic controller techniques, and work-load. This project is an initial design for air traffic automation system which considers scheduling optimality as well as delay reduction. The case study is done on Denver... 

Using clean and renewable energy as driving force for vehicles is becoming more and more important because of rising fuel prices and also environmental concerns. Using solar and wind power for direct use in vehicles seems impractical with today’s technology. Compressed air can serve as an intermediate medium to store energy and utilize it for running vehicles. The main purpose of this research was to conceptually design an air driven vehicle with acceptable performance in a city for everyday life. After a brief history, at first step advantages and disadvantages of using air as driving force of vehicle is studied. This study was carried out in different categories including cost, capability... 

This thesis proposes a dynamic model for studding influences of suspension components behavior on rail vehicle dynamics. As the air springs are very important isolating component in rail vehicles, a new complete nonlinear air spring model, with taking into consideration of thermo–dynamical effects, is developed. The model coefficients are tuned based on the real test data and it can be easily used in dynamic modeling of air springs. The new proposed vehicle model is a complete track–vehicle model with 70 degree of freedoms which is addressed as a modular type. Experimental results from complete rail–vehicle field test, showed remarkable agreement between proposed model and test results.... 

Building simple and effective models are essential to many applications, such as building performance diagnosis and optimal control. Detailed physical models are time consuming and often not cost-effective. Black box models require large amount of training data and may not always reflect the physical behaviors. In this study, a method is proposed to simplify the building thermal model and to identify the parameters of the simplified model. For instance, predicting the next-24-hour load in a building is essential for the optimal control of heating, ventilating and air-conditioning (HVAC) systems that use thermal or cool storage technology. In the first phase of this study, equations for... 

Concentrations of air pollutants emitted by motor vehicles in traffic tunnels, due to low access of tunnels to Open space increases rapidly. Increasing the tunnel pollutant concentration, decreases tunnel air quality level which is very dangerous for human health. Thus study of traffic tunnel air pollution concentration and dispersion is important for offering control strategies in these spaces. This investigation has been tried to study vehicular pollutants emission and dispersion inside traffic tunnel by data collection that involves traffic, meteorology and air pollutants characteristics in a urban tunnel. So data collection was carried out in the Resalat tunnel located in urban... 

Pipeline transfer is the most commonly method for natural gas transportation. Potential force of natural gas transportation in pipeline is pressure difference that is generated in Gas Compressor Stations (GCS). For each 100 to 150 km of pipeline, one GCS is required that pressure is increased usually from 700 to 1000 psig. Each station contains different process equipments such as turbines, compressors, scrubbers, filters, air coolers, throttling valves and pipes with instruments. It is shown that about 10 percent of the generated pressure difference, decays in GCS.
In this thesis, pressure losses are studied and initiatives are purposed to reduce them in a Gas Compressor Station. Then... 

There are many applications for micro aerial vehicles (MAV) and in nature they are flying as birds and insects. It can be said that a MAV that can mimic flying capabilities of birds and insects can be used as a solution for flying in low Reynolds number regimes. It seems that Flapping Wing MAVs have better performance than fixed and rotary wings MAV in low Reynolds number regimes. So far there haven’t been many theories and methods introduced for controlling flapping wing MAVs and many researches failed to provide a convenient way for designing an effective controller. On the other hand, models presented in literature for aerodynamics, dynamics and kinematics of flapping wing are not... 

The most important aspects of extensive air shower studies are finding energy, mass and the arrival direction of primary cosmic ray particles. In order for these parameters to be established, the core position of extensive air showers should be determined. In this thesis, a new method has been introduced that utilizes trigger time information of particle detectors for finding extensive air showers core location and for correcting plane wave front approximation to reconstruct their arrival direction. This method, in its simplest form, does not depend on density-sensitive detectors which are sensitive to the number of crossing particles. It is also independent of lateral distribution models.... 

Obtaining particulate matter (PM) concentration is very important in epidemiological studies. Measurement at the ground levels has been used as an accurate method to obtain PM levels. However, these measurements are more indicative of a small area around the stations than a whole region. Usually, limited space coverage and irregular distribution of air quality stations at the ground level is a restriction in the studies of air pollution and its effect on human health and environment. In this regard satellite measurements have been used for indirect estimation of PM concentration at ground levels. However, the correlation between satellite measurements and ground based data is affected by... 

Several dust storms originated from western countries deserts of Iran hit different cities in Iran and substantially elevates PM10 levels. To the date, some studies on trend and origin of the dust storm have been carried out. However, not enough information is available on the contribution of different deserts around the country to the aerosol concentration in Iranian cities. In this study, the deserts of potential dust sources have been identified and their contributions to PM10 concentration in Tehran have been investigated. The PM10 data collected over a 5 year period from 2006 to 2010 at monitoring stations in Tehran were used. A statistical approach was implemented in order to determine... 

In present thesis, experimental study of flow around a two-wing MAV using hot-wire anemometer will be performed which is divided to wake and boundary layer study. This leads to suitable understanding of various parameters affecting its wake and boundary layer. First, effects of upper wing, which has horizontal stabilizer's role, on the main wing's wake will be studied in which effects of angle of attack and distance between the two wings at its cruise velocity will be investigated. Then, effects of angle of attack, velocity and distance between wings on boundary layer of the MAV will be analyzed. Also, experiments are performed at three velocities as 10, 15 and 20 m/s, and three angles of... 

The number of operating vehicles has increased in recent years and as a result global pollutants have widely spread. Therefore, the regulations on the vehicle exhaust emissions have become much stricter. For an automobile to pass the emission tests successfully an accurate calibration of the ECU tables is needed, especially the tables which have direct impact on the amount of pollutant emissions. To achieve the optimum performance of the catalyst existing in the exhaust system of the engine, the fuel/air ratio must have nearly stoichiometric value. The present research studies the ECU strategies for implementing this objective by appropriate management and control of catalyst and oxygen... 

Aerodynamic shape optimization has been always of great importance in aerospace design. Recent advancements in computational algorithms and hardware, has made it feasible to have advanced optimization as a standard part of desing procedure. Here we have promoted aerodynamic optimization in three different applications, i. e., wing-body configuration, hydro propellers, and air propellers. First we have reviewed fluidic theoretical aspects, and have selected appropriate physical models or existing softwares. Accuracy of physical analysis or software is validated. Then different optimization algorithms are reviewed, and schemes used in this thesis are described and the softwares are validated. ... 

In this research a model is proposed which determines flight frequency and aircraft routing for an airline network. It is supposed that origin-destination demand, costs, number of aircrafts in the fleet and their capacity, aircraft maximum daily utilization hours and origin-destination fares are given. The model attempts to maximize airline profit and determines flight frequencies, number of passengers carried between two cities and number of passengers who travel with an indirect flight, considering fleet constraints and an operational aircraft routing.The model is tested with a hypothetical numerical example. The results indicate that the model uses maximum aircraft capacity and daily... 

In this study, for removing ammonia from air, biofilters which is suitable method for removing odors, volatile organic compounds and toxic materials are used. Biofiltration is an efficient, easy and cost effective, environmental friendly process for degradation of ammonia from waste air. Aim of this study is comparative study of biofilters application for ammonia elimination from industrial sites.In order to remove ammonia, two columns with 14 cm inner diameter were used. One of the columns is filled with vermicompost and mineral shell (mineral shell : vermicompost, 1 : 4) and another column is filled with concentrated sludge and scallop (scallop : concentrated sludge, 2 : 3). Each of the... 

In this thesis, possibility and advanteges of dynamic descent route assignment during busy traffics and implementing changes within navigation infrastructure is examined. Facilitating Continuous Descent Approaches (CDA) as optimum descent paths is the main goal of this research. One advantage of this project with respect to previous works in this field is dynamic CDA routing between cruise altitude and Terminal Radar Approach Control (TRACON) entry to meet the demand of traffic during peak hours.The other superiority is proposition of LASER technology as an alternative/backup NAVAID system in order to facilitate the latter.Terminal area of Hartsfield-Jackson international airport with real... 

Tehran possesses various environmental crises due to excessive population growth, a huge increase of vehicles and heavy concentrated industries. One of the most important concern is air pollution. Spectral Analysis by discrete Fourier transform are described and applied to harmonic analysis of time series for detecting Present periodicities.
The current work proposes an approach for the determine the contribution of different frequencies to the data variance using air quality measured data. In this research, we present a comprehensive review of methods for spectral analysis of nonuniformly sampled data. Because of The air quality data in Tehran have irregular sampling periods and...