Electrical Mobility Spectrometer Modeling and Design

, M.Sc. Thesis Sharif University of Technology Saifi, Reza (Author) ; Saeedi, Mohammad Saeed (Supervisor) ; Sani, Mahdi (Co-Advisor)

Abstract

Aerosol measurement is used in different fields such as nanotechnology and materials science, environmental air pollution monitoring and air quality measurements, combustion and engine exhaust, inhalation toxicology and medical studies. One of the most prevalent methods for aerosol measurement uses electrical mobility. An electrical mobility spectrometer (EMS) is used to classify particles ranging from 10 – 1000 nanometers, under the influence of an electric field. There are two electrodes in EMS between which the aerosol and sheath air flow. Charged particles in the aerosol and sheath enter the device from one end and are subjected to an electric field. Passing through the annulus,...

Synthesis of Coordination Polymers with Different Morphologies and Their Deployment in Solid Phase Microextraction of Volatile Organic Compounds in Environmental Samples

, M.Sc. Thesis Sharif University of Technology Doosti, Mahsa (Author) ; Bagheri, Habib (Supervisor)

Abstract

Coordination polymers are a wide range of metal-organic polymers that have good potential for use as extraction phase in solid phase extraction and solid phase microextraction. Also, these polymers can be synthesized in various morphologies such as nanorods, microspheres, nanofibers, etc. to demonstrate the effect of morphology on extraction efficiency.In this study, the extraction efficiency of a coordination polymer with two morphologies (nanorods and microspheres) and different nitrogen percentages was investigated in needle trap device using gas chromatography-mass spectrometry to measure polycyclic aromatic hydrocarbons as model analytes.PAHs were measured in conventional cigarette...

Investigation of the Influence of Meteorology-Chemistry Interaction on the Results of Air Quality Modeling During a Highly Polluted Episode in Tehran

, M.Sc. Thesis Sharif University of Technology Sadeghi Maleki, Ensiyeh (Author) ; Firoozabadi, Bahar (Supervisor) ; Hosseini, Vahid (Supervisor)

Abstract

Atmospheric aerosols scatter or absorb a fraction of the incoming solar radiation to cool or warm the atmosphere, decreasing surface temperature and altering atmospheric stability to further affect the dispersion of air pollutants in the planetary boundary layer. This study aims to evaluate the impacts of meteorology-chemistry interaction on the meteorology and air quality simulations over Tehran megacity. The Coupled Weather Research and Forecasting-Community Multiscale Air Quality (WRF-CMAQ) modeling system was applied to model a period of time from 3rd to 23rd December of 2017. Comprehensive model evaluations for meteorology demonstrated that the modeling system had the capacity to...

Evaluation of Effective Parameters in Trapping Aerosols and Examination of Possibility of Detecting Distortions of Microdroplets by Means of Optical Tweezer

, M.Sc. Thesis Sharif University of Technology Khajeh, Ahmad (Author) ; Seyed Reihani, Nader (Supervisor)

Abstract

Optical tweezer is a highly focused laser beam that could be used to trap micro and nano particles in three dimensions. It could be used to measure(or apply) piconewton range forces. Most of the optical tweezers experiments have been done in liquid mediums. In last few years, trapping particles which are floating in gas mediums(called aerosols) have been considered extensively. In this thesis, the changes in trap stiffness and conversion factor due to changes in laser power, trapping depth and particle are evaluated. It is shown that changing these three parameters, cause considerable changes in trap stiffnes and conversion factor. Linear behavior of trap stiffness versus laser power,...