Background and Objective: Measurement of maximum aerobic capacity (VO2 max) is important in physiologically fitting workers to a specific job. We aimed to investigate the effect of anthropometric and demographic factors on physical work capacity. Materials and Methods: In this study, 60 students of Ahwaz University of Medical Sciences who volunteered to participate were enrolled. For data collection, we used a checklist consisted of two sections. The first section included demographic characteristics, and the second section comprised of anthropometric characteristics of students. The students' aerobic capacity was assessed by using an ergometer and according to Astrand protocol. Linear regression analysis and Pearson correlation coefficient were run to investigate the association between demographic and anthropometric variables and VO2 max. Results: Mean VO2 max of the students was equal to 2.19±0.56 lit/min and 35.95±8.97 ml/kg -1 .min -1 . Statistical analysis revealed a robust association between VO2 max and gender, weight, height, body fat percentage (P≤0.01), and shoulder width (P≤0.04). Conclusion: Among the demographic factors only gender and among the anthropometric dimensions weight, height, shoulder width, and body fat percentage were significantly associated with VO2 max. Therefore, using the regression equations mentioned in this study, it is possible to estimate the physical work capacity according to gender and anthropometric dimensions.

Background: Today, advances in different areas of science and technology along with their application in industries have led to an increase in dangerous pollutants which can resist biodegradation. Volatile organic compounds (VOCs) are regarded as important factors of air pollution in closed environments. Xylene is one of these compounds which is produced in mass quantities and widely used in industries, therefore, the removal of this compound is necessary. One of the available technologies for removing this compound is photocatalytic degradation. The present study aimed to determine the efficiency of photocatalytic removal of xylene as a pollutant in air using TiO2 -ZnO nanoparticles and TiO2 -ZnO composite coated on activated carbon under ultraviolet radiation. Methods: In this experimental study, after coating of the nanoparticles on activated carbon, the produced catalysts with a specific surface area were characterized using Brunauer-Emmett-Teller (BET) surface area and porosity analysis, scanning electron microscope (SEM), and the type and percentage of the main elements present in the bed were determined using energy dispersive x-ray spectroscopy (EDS). The tests were carried out at laboratory scale and ambient temperature. In order to produce polluted air containing 100 ppm xylene vapor at a specific flow rate and concentration, a dynamic concentrator system was used. The removal of xylene was investigated under continuous flow mode. Results: The results of the specific surface area using BET analysis and SEM images showed that nanoparticles were well coated on activated carbon. According to the results of the photocatalytic removal, the efficiencies of photocatalytic removal of xylene by AC/ZnO 5%, AC/TiO2 15%, and AC/3TiO2 /1ZnO were 80.1, 89, and 95.1%, respectively. Conclusion: According to the results, the use of ZnO-TiO2 nanocomposite on activated carbon can be an appropriate method for the photocatalytic removal of xylene from polluted air.

Background and Objective: Currently, photocatalysts have become a major focus of research in physics, chemistry, and surface engineering. It is hoped that this science help to solve various environmental problems. This study investigated the effect of ultraviolet lamp type on the removal efficiency of xylene utilizing the fixation of TiO2 nanoparticles on the activated carbon absorber and passing different concentrations of polluted air through xylene. Materials and Methods: In this experimental study, after the fixation of nanoparticles on activated carbon, the produced catalyst characteristics with the specific surface area were determined using Brunauer-Emmett-Teller (BET) analysis and scanning electron microscope (SEM). A dynamic concentrator system was used in order to produce xylene vapor. Moreover, the photocatalytic removal efficiency of xylene with three inlet concentrations of the pollutant was studied under ultraviolet rays in the wavelengths of A and C regions. Results: The results of BET analysis and SEM images showed that nanoparticles were well fixed on the surface of activated carbon. Moreover, the photocatalytic removal efficiency in the concentrations of 50, 100 and 300 ppm was equal to 87.8%, 98.9%, and 90.8%, respectively. In addition, no significant difference was observed between ultraviolet A and C regarding photocatalytic removal efficiency of xylene. Conclusion: According to the results of this study, the inlet concentration of the pollutant had an effect on its photocatalytic removal efficiency. However, there was no significant difference between ultraviolet A and C regarding photocatalytic removal efficiency of xylene.

Background and Objective:The most important goal of modeling is to acquire knowledge about the actual behavior of the system. Toxic leakage is a likely issue in process and chemical industries and one of the threatening factors for the personnel and residents involving in the mentioned industries. In this regard, the present study aimed to model the effect of ammonia leakage from the ammonia reservoirs. Materials and Methods: In the present study, the ammonia liquid release from the reservoir was modeled using ALOHA software version 5.4.7 in one of the southern refineries. This study was modeled based on the three scenarios, including the formation of the toxic vapor clouds, flammable environment, and toxic explosive atmosphere. Results: Based on the results of the present modeling, the concentration of ammonia was 1,100 ppm, 5 km around the reservoir (red range). In addition, from this area to about 160 miles (about 10 km) around the reservoir (orange range) the concentration of ammonia was 160 ppm. In the event of full leakage of ammonia from the reservoir up to 500 m, the ammonia concentration was reported to be about 90,000 ppm, which was approximately 60% of the minimum flammable concentration of ammonia gas. Furthermore, the ammonia concentration up to about 1.7 km of the tank was 15000 ppm, which was about 10% of the minimum of the flammable ammonia concentration. It should be considered that in the event of vapor cloud explosion, the explosive wave pressure is approximately 700 m from the reservoir equivalent to Psi 8 that can cause serious damage to the buildings. Conclusion: According to the results of modeling, ammonia intoxication is the most important threat to personnel. Therefore, the inspections in accordance with the manufacturer company's proposal on ammonia repositories and emergency response plans will have an effective role in the limitation of the harmful effects of toxic and dangerous emissions.

Background: Musculoskeletal disorders are one of the most common occupational diseases, and in recent years, several methods have been developed to evaluate risk factors for these types of disorders. Methods: In this cross-sectional study, 40 tasks in small industries including carpentry, turning, welding, loading and unloading, and sewing were recorded with a video camera and in the second stage, the postures were reviewed and evaluated by six raters. In total, forty of the worst and most frequent postures were analyzed by self-raters and then, the same risk levels were determined for the six methods and analyzed with correlation and Kappa agreement coefficient tests using SPSS (version 19), and then they were compared with each other using the Intraclass correlation coefficient (ICC). Results: The results revealed the importance of Kappa Coefficient in which it shows the risk level of different method and specified pair method: OCRA/SI =0.25, OCRA/HAL=0.2, SI/HAL= 0.32, SI/ RULA= 0.33, REBA/OCRA = 0.4, QEC/SI= 0.27, QEC/ RULA= 0.23Inter-rater Reliability of the methods was found as follow:ICCOCRA=0.3, ICCSI= 0.67, ICCHAL= 0.8, ICCRULA= 0.85, ICCREBA=0.8, ICCQEC=0.972.Conclusions: The results showed that there was no complete agreement among the methods. This agreement among methods is evaluated from poor to good (0.2-0.4). The ICC showed high reliability in the methods except in the OCRA method.