Search published articles


Showing 3 results for Omidi

F Rezaei, H Kakooei, R Ahmadkhaniha, K Azam, L Omidi, S.j. Shahtaheri,
Volume 8, Issue 2 (8-2015)
Abstract

Background and Objectives: PAHs are main components of urban air pollution and are mutagenic for human being. Seasonal variations have effects on the amount of exposure to PAHs. The objectives of this research were to determine the amount of newsagent’s exposure to PAHs found in the urban atmosphere of Tehran City during warm and cold periods and comparing exposure levels in two periods. Materials and Methods: The assessment of personal exposure was performed based on NIOSH method 5515 and was analyzed by gas chromatography–mass spectrometry (GC/MS). Mann- Whitney test was used to determine the effects of seasonal variation on the amount of newsagent’s exposure to PAHs. Results: The mean levels of newsagent’s exposure to benzo[a]pyrene in the south area of Tehran City were 0.148±0.010 and 0.417±0.041 µg/m3 in summer and autumn seasons respectively. The amount was higher than the mean levels of newsagent’s exposure in other geographic areas of city. The levels of newsagent’s exposure to all PAHs (p<0.001) were significantly higher in autumn compared with summer. Conclusion: The levels of exposure to PAHs during autumn were 2 to 3 fold higher than the levels of exposure during summer. Newsagents in the south area of Tehran City were experiencing higher levels of exposures to PAHs.


A Sepahvand, H Godini, Y Omidi, M.j Tarrahi, R Rashidi, H Basiri,
Volume 9, Issue 1 (6-2016)
Abstract

Background and Objective: The presence of fungal bioaerosols in hospitals indoor environments have affected the health of patients with the defect in immunity system. Therefore, determination of the rate and species of these agents is essential. This study aimed to investigate association between fungi contamination and particulate matter (PM10, PM2.5 and PM1) concentrations in the main indoor wards and outdoor environment and to determine I/O ratio in two educational-medical hospitals of Khorramabad City.

Materials and Methods: In this description-analytical study, the concentration of fungal bioaerosols and particulate matter was measured in 10 indoor parts and 2 outdoor stations over 6 mounts. The sampling was conducted using Quick Take-30 at an airflow rate of 28.3 L/min and sampling period of 2.5 min onto Sabouraud dextrose agar medium containing chloramphenicol. The particulate matters were measured using Monitor Dust-Trak 8520. Moreover, the relative humidity and temperature were recorded using digital TES-1360.

Results: Analysis of 288 fungi samples and 864 particulate matter samples showed that the average of fungi accumulation was 59.75 CFU/m3 and the mean concentrations of PM10, PM2.5 and PM1 in the indoor environment was  27.3, 23, and 20.2 µg/m3 respectively. In addition, in ambient air the mean concentration was 135.3 CFU/m3 for fungal bioaerosols and 40.2, 35.7, and 29.8 µg/m3 for PM10, PM2.5 and PM1 respectively. At the total of fungi samples, 12.5% were negative and 87.5% were positive. Having 101.7%, Infection ward was the most contaminated ward. The operation ward in both hospitals showed the minimum fungal contamination.

Conclusions: The results of the present study showed that at all of the samplings the ratio of I/O was lower than one. It was noticed the dominancy of fungal bioaerosols and particulate matter of outdoor source on the indoor environment. In addition, a significant correlation (P < 0.001( was found between fungal bioaerosols frequency and particulate matter and as well as fungal bioaerosols frequency, relative humidity and temperature.


Iman Omidi, Hamed Forootan, Majid Mazhar, Hossein Mohammad Karimi Yazdi, Mohammad Mehdi Barjesteh,
Volume 13, Issue 4 (2-2021)
Abstract

Background and Objectives: SO2 pollution has become a serious concern. The aim of this study is SO2 removal from JP-4 fuel combustion.
Materials and Methods: Experiments were performed by thermogravimetric analysis at different temperatures and various SO2 concentration. Kinetic study of non-catalytic gas-solid reaction was performed using mathematical modeling based on random pore model.
Results: The pore size distribution curve was obtained. The structural parameters of the random pore model were measured as r=1.92×10-5, ε0=0.64, S0=1.27×106 and ψ=3.81. Thermogravimetry diagram and conversion-time curves were extracted. Fractional reaction modeling is obtained based on gas reactant.
Conclusion: The obtained kinetic parameters can be used to design flue gas desulfurization systems at low temperatures.


Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb