Assessment of air pollution in exercise centers and health risks

Background: In recent years, Tehran has faced major problems with air pollution for many reasons, and this issue has become a critical point in most of the days. However, less attention has been paid to the indoor air pollutants in exercise centers and their possible health effects. In this research, it was tried to briefly describe the characteristics and chemical composition of the aerosols present in the exercise centers of Tehran. Methods: Sampling was carried out by a high volume sampler with a value of 1.5 m3/min. Fiberglass filters were used to sample aerosol particles. The samples were then studied by scanning electron micrograph (SEM) method. Results: The results showed that average concentration of aerosol particles in the indoor and outdoor sports halls was 125 and 162 μg/m3, respectively. Therefore, there was a minor difference in the aerosols concentration inside and outside the sports venues during the competition period and in the presence of athletes. Also, chemical composition and morphology of the aerosol particles showed that there was a minor difference between the atmospheric particles inside and outside the exercise centers. Major elements found in the PM2.5 aerosol were Si, O, C, Mg, Ca, Mn and K. In general, common major crustal elements found in the atmospheric particles over all the sites were Si, Al, and Fe. Conclusion: It seems that many citizens of the polluted cities exercise indoor because of causes other than outdoor air pollution such as lack of time or appropriate facilities. Thus, it is necessary for all students, athletes, people and other health workers involved in sports and exercise medicine to know briefly about indoor air pollutants and its possible health effects on athletes who exercise in these environments. Keywords: Air pollution, Athletes, Aerosols, Outdoo

Prediction of Optimum Gas Mixture for Highest SXR Intensity Emitted by A 4kj Plasma Focus Device Using Artificial Neural Network

In this study, artificial neural network (ANN) is investigated to predict the optimum gas mixture for highest soft X-ray (SXR) intensity emitted by a 4kJ plasma focus device. To do this multi-layer perceptron (MLP) neural network is used for developing the ANN model in MATLAB 7.0.4 software. In this model, the input parameters are voltage, Percentage of nitrogen in admixture and pressure and the output is SXR intensity. The obtained results show that the proposed ANN model has achieved good agreement with the experimental data and has a small error between the estimated and experimental values. Therefore, this model is a useful, reliable, fast and cheap tool to predict the optimum gas mixture for highest SXR intensity emitted by plasma focus devices

Characterization of radio active aerosols in Tehran research reactor containment

The objectives of this research were to determine the levels of radioactivity in the Tehran research reactor containment and to investigate the mass-size distribution, composition, and concentration of radio nuclides during operation of the reactor. A cascade impactor sampler was used to determine the size-activity distributions of radioactive aerosols in each of the sampling stations. Levels of α and β activities were determined based on a counting method using a liquid scintillation counter and smear tests. The total average mass fractions of fine particles (particle diameter dp <1 µm) in all of the sampling stations were approximately 26.75 , with the mean and standard deviation of 52.15 ± 19.75 µg/m3. The total average mass fractions of coarse particles were approximately 73.2, with the mean and standard deviation of 71.34 ± 24.57 µg/m3. In addition to natural radionuclides, artificial radionuclides, such as 24Na,91Sr,131I,133I,103Ru,82Br, and 140La, may be released into the reactor containment structure. Maximum activity was associated with accumulation-mode particles with diameters less than 400 nm. The results obtained from liquid scintillation counting suggested that the mean specific activity of alpha particles in fine and coarse-modes were 89.7 and 10.26 , respectively. The mean specific activity of beta particles in fine and coarse-modes were 81.15 and 18.51 , respectively. A large fraction ofthe radionuclides' mass concentration in the Tehran research reactor containment was associated with coarse-mode particles, in addition, a large fraction of the activity in the aerosol particles was associated with accumulation-mode particles. © 2015, Vinca Inst Nuclear Sci. All rights reserved

Otolith mass asymmetry in the mugilid fish, Liza klunzingeri (Day, 1888) collected from Persian Gulf near Bandar Abbas

Se calculó la asimetría de masa, x, como la diferencia entre la masa de otolidos pareados a izquierda y derecha, dividida por la masa media. Se estudió la asimetría del otolito sacular de Liza klunzingeri. Como en otras especies de peces simétricos, el valor absoluto de x no dependió de la longitud del pez ni del ratio de cre- cimiento del otolito. El valor medio de x estuvo entre -0,2 y +0,2

Experimental Study of the Flow Field around a Circular Cylinder Using Plasma Actuators

In this paper different configurations of plasma actuator for controlling the flow around a circular cylinder made of Quartz were experimentally investigated. Three thin plasma actuator electrodes were flush-mounted on the surface of the cylinder and were connected to a DC high voltage power supply for generation of electrical discharge. Different configurations of plasma actuator were used for this study and pressure distribution experiments showed that the existence of the plasma decreases the pressure coefficient of the cylinder and the variation of the pressure coefficient can change the behavior of the lift and drag coefficient of the cylinder for all configurations. According to the pressure distribution data, two configurations of the plasma actuators made the best influence on the aerodynamic performance and also on the drag reduction

Parameter-sparse modification of Fourier methods to analyse the shape of closed contours with application to otolith outlines

-Elliptical Fourier descriptors (EFDs) have been used extensively in shape analysis of closed contours and have a range of marine applications, such as automatic identification of fish species and discrimination between fish stocks based on EFDs of otolith contours. A recent method (the ‘MIRR’ method) transforms the two-dimensional contour to a one-dimensional function by mirroring (reflecting) the lower half of the contour around a vertical axis at the right end of the contour. MIRR then applies the fast Fourier transform (FFT) to the vertical contour points corresponding to equidistant coordinate values along the horizontal axis. MIRR has the advantage of reducing the number of Fourier coefficients to two coefficients per frequency component compared with four EFDs. However, both Fourier methods require several frequency components to reproduce a pure ellipse properly. This paper shows how the methods can be easily modified so that a virtually perfect reproduction of a pure ellipse is obtained with only one frequency component. In addition, real otolith examples for cod (Gadus morhua) and Greenland halibut (Reinhardtius hippoglossoides) are used to demonstrate that the modified methods give better approximations to the large-scale shape of the original contour with fewer coefficients than the traditional Fourier methods, with negligible additional computing time