Short and long term variations in the concentrations of gaseous and particulate pollutants in Ankara and assessment of traffic contribution

Genç, Derya Deniz
Spatial and temporal variations and factors affecting these variations in concentrations of measured parameters at two different groups of stations in Ankara are investigated in this study. The first group consists of three curbside stations that are under the direct influence of traffic emissions, on the other hand, the other group is composed of eight residential stations in which domestic heating is the main emission source. State of air quality in Ankara is determined through comparison with air quality data generated in other countries and available air quality standards. Based on this comparison, although air quality has improved in recent years, it is still not one of the clean cities around the world. Although measured concentrations of pollutants comply with standards in the Turkish Air Quality Regulation, further reduction in concentrations will be necessary, if EU directives become effective in the country. Relation between measured concentrations and meteorological parameters are also investigated. Wind speed and mixing height are the two parameters that are most closely related to measured concentrations at residential stations. However, at curbside stations concentrations are determined by emissions. Qualitative comparison of two groups of stations emphasizes the contribution of motor vehicle emissions on residential areas. Seasonal and diurnal variations of measured parameters and lower winter-to-summer ratio of SO2 indicate contribution of diesel vehicle emissions to SO2 levels at curbside stations. Contribution of traffic emissions are also observed in terms of well defined bimodal traffic pattern of SO2 and PM-10 at non-curbside stations. Seasonal and diurnal pollutant ratios are investigated to apportion different source types that are effective in each group of station. PM-to-SO2, NO-to-NO2, PM-10-to-NOX and SO2-to-NOX ratios are found to be good


Microscopic study of nuclear level density
Gholami, Mehrdad; Kıldır, Mehmet; Department of Chemistry (2007)
Level densities and spin cut-off factors have been investigated within the microscopic approach based on BCS Hamiltonian. In particular the spin cut-off parameters have been calculated at neutron binding energies over a large range of nuclear mass using the BCS theory. The results are compared with their corresponding macroscopic values. It is found that the values of spin cut-off parameter do not increase smoothly with A as expected based on macroscopic theory. Instead, the values of spin cut-off parameter...
Raman bandwidths calculated for the librational ( a -phase) and internal (8, d loc and d phases) modes in solid N 2 using pseudospin-phonon coupling (PS) and energy-fluctuation (EF) models
Yurtseven, Hasan Hamit (Elsevier BV, 2020-10-01)
This study gives the calculation of the Raman bandwidths using the models of the pseudospin-phonon coupling (PS) and energy fluctuation (EF) where the Raman frequency calculated from the molecular field theory, is considered as the order parameter close to the phase transitions in nitrogen. In particular, we study the temperature dependence of the Raman bandwidths and frequency shifts of the Eg librational mode (zero pressure) and the internal modes of and (at various pressures) for the solid nitrogen by ...
Exploring representation of nature of science aspects in 9th grade chemistry textbooks
Esmer, Feyza; Geban, Ömer; Department of Secondary Science and Mathematics Education (2011)
The aim of this study was to examine the representation of Nature of Science (NOS) aspects in 9th grade chemistry textbooks. Two textbooks nation-wide used are analyzed, one of them is written in Turkish the other in English. These textbooks were written according to 2008-2009 education program’s curriculum. A qualitative oriented approach was employed and ethnographic content analysis was used as the methodological framework for this research as Irez (2006) has performed. Data were analyzed by means of boo...
Thermal activation energy of crystal and amorphous nano-silicon in SiO2 matrix
Wang, Jiwei; Righini, Marcofabio; Gnoli, Andrea; Foss, Steinar; Finstad, Terje; Serincan, Ugur; Turan, Raşit (Elsevier BV, 2008-09-01)
Temperature and size dependence of photoluminescence (PL) of nano-silicon embedded in SiO2 matrix samples were studied. In these measurements, four samples with deferent implantation dose showed their similar tendency. Their nano-structure was investigated by high resolution electron microscopy (HREM) and selected area diffraction (SAD) which confirmed that only those prepared with the higher Si implantation dose formed crystal nano-silicon. The further analysis of the dependence of thermal activation energ...
Critical behaviour of the specific heat calculated using the Raman frequencies of the lattice and internal modes near the lambda-phase transition in NH4Br
Sen, S.; Yurtseven, Hasan Hamit (Elsevier BV, 2007-05-27)
We calculate here the specific heat of NH4Br using our Raman frequency shifts for the lattice mode Of nu(7) TA (56 cm(-1)) and the internal mode Of nu(2) (1684 cm(-1)) near its lambda-phase transition (T-lambda = 234 K, P = 0). By analyzing our Raman frequency shifts, values of alpha = 0. 19 (T < T-lambda, and T > T-lambda) for the lattice mode, and alpha = 0.45 (T < T-lambda) and alpha = 0.57 (T > T-lambda) for the internal mode, are used as the values of the critical exponent for the specific heat to pred...
Citation Formats
D. D. Genç, “Short and long term variations in the concentrations of gaseous and particulate pollutants in Ankara and assessment of traffic contribution,” M.S. - Master of Science, Middle East Technical University, 2005.