pISSN: 2008-5109
eISSN: 2008-5435
Editor-in-Chief:
Mohammadreza Monazzam Esmaeilpour, PhD.
Vol 6 No 2 (2014)
Published:
2015-10-17
Original Article(s)
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Quality of working life (QoWL) is the attitudes of employees towards their job, especially their work outcomes including job satisfaction, mental health, and safety which directly influence organizational outcomes. Therefore, the aim of the present study was to evaluate train drivers' QoWL and determine its influencing factors. In this descriptive-analytical and cross-sectional study, QoWL was evaluated among 100 train drivers working in Keshesh section of Iran Railway. In this sense, WRQoL scale was used which assesses five factors of Control at Work, General Well-Being, Home-Work Interface, Job and Career Satisfaction, Stress at Work, and Working Conditions. Total score of QoWL was calculated and the effects of age, work experience, marital status, education, satisfaction with the salary, and satisfaction with the supervisor on the QoWL were assessed. Data was analyzed statistically using SPSS version 18. Working Conditions and Home-Work Interface with the mean score of 1.37 and 2 were the most critical QoWL factors, respectively. Furthermore, no significant relations were observed between demographic and background variables and total score of QoWL. Overall, the quality of working life has obtained a low score among the understudy train drivers. Therefore, appropriate measures should be adopted in order to promote QoWL of this occupational group especially in two factors of Working Conditions and Home-Work Interface.
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Noise is one of the most common workplace hazardous agents that can cause permanent hearing damage. Workers in many industries are usually exposed to noise levels with high risks of hearing loss. Accordingly this research aims to study the noise exposure and haring status of registered locksmiths who are exposed to harmful effects caused by several factors, such as key making machines loud noises. This study has been carried out in 33 key workplaces in Tehran capital city of Iran. In order to eliminate the effects of background noise, two different measurements were carried out in the same field conditions by taking in and out of key making machines .The overall sound level and octave band of noise analysis of the key making machine, during the process of Right and Left Shift Gears by considering the background noise level during off time of the machine was determined using ISO 9612 standard method. Hearing threshold of locksmiths is also determined using the NIOSH standard method. Based on results, average of right and left groove keys scraping processes and background noise levels were 92.9, 96.2 and 66.5dBA respectively. The mean noise exposure time of locksmiths was 0.2 h/day. So, the amount of the workers noise equivalent level was found to be 77.63 dBA which is lower than the ACGIH threshold limit values. The results of audiometric tests also showed no significant hearing loss among locksmiths, something can be explained by their low noise exposure levels. It is suggested to assess hearing response of the workers by other methods like ABR.
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Simultaneous exposure of highly-used chemical and physical agents are expected to happen in many occupations. In the present study the impact of simultaneous exposure to noise and formaldehyde on oxidative stress in blood and liver tissue of rat was investigated. Animal study was conducted in the School of Public Health, Shahid Beheshti University of Medical Scineces, Tehran, Iran in 2013. A total of 42 male Wistar albino rats were randomly divided into 6 groups (7 in each group). Rats in control group were not exposed to any stressor, while 2 groups were exposed to 6 and 12 ppm formaldehyde, 1 group to noise (0.7–5.7 kHz, 100 dB SPL) and 2 groups to noise + formaldehyde (8 h/d, 28 days). The level of oxidative stress in blood and liver tissue were determined through GSH and MDA measurements. Sound pressure level was monitored using a calibrated Bruel and Kjaer 2238 sound level meter (Denmark). Formaldehyde concentration was monitored four times an hour by a photo ionization detector (Photocheck +5000, Ionscience Co., UK). GSH concentrations were measured through titration and quantification of thio-nitro-benzene using spectrophotometry at 412 nm. MDA levels were quantified by absorption at 535 NM wavelengths using a spectrometer. The results revealed that exposure to both stressors significantly reduced the GHS levels and significantly increased the MDA levels in exposed rats. The level of changes in groups with simultaneous exposure was dose-dependent (p<0.05). The current study clearly confirmed that co-exposure to noise & formaldehyde has an additive effect in oxidant /antioxidant system imbalance.
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Material hazards are the most important risk in scientific laboratories. In risk assessment processing, the potential impact of assessor personal judgment is the most important issue. This study tried to develop a risk assessment pattern based on Failure Mode and Effect Analysis (FMEA) and Analytical Hierarchy Process (AHP) logics and empirical data in scientific laboratories. The most important issues were high pressure reservoirs and hardware failure fuel.The other type of data about building plan, evacuation procedure and ability of hazard detection were also collected. Both groups of data were used as input to construct the model. Information integration plays a key role in the performance of fire and spillage risk assessment. For this purpose, a method based on analytical hierarchy process theories was applied to investigate the multi-hierarchy and multi-factor assessment problems. Testing the conceptual model for material risk assessment was performed in the proposed site. The results showed that the Laboratories of Sciences and Research Campus of Azad University were not suitably safe according to the fire and spillage risk assessment model. To reduce the risk probability, all of occupants in the buildings were required to be trained and automatic fire fighting and spillage detection system and adjustable fire exit and emergency stairs should be installed.
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The Aim of this study was to evaluate the effect of Evaporative Media as gas turbine intake air cooling method on pressure drop of cartridge air filters. This study performed under the laboratory condition, using stainless steel test rig with specified dimensions to investigate the role of evaporative media in air cooling as well as its effects on new and used cartridge filters (as representative of clean and loaded filters). Tests were carried out at three five hours consecutive stages including, warm -dry stage (Ta=35-40°C) and relative humidity ([RH] =10-15%), cold - humid stage (Ta=22-27°C and RH=80 to 85%), and, warm-dry stage (Ta=35-40 °C and RH=10-15%) for 3 consecutive days. Findings showed that using evaporative media caused air intake temperature reduction was equal to 12.5 °C. Total pressure drop of cartridge filters was 5.13±0.84 and 3.86±0.14 mbar for used and new filters, respectively. Results of repeated measure test showed that the differences between new and used filters pressure drop was significant (P=0.001). Combined effects of humidity and dust loading on filters pressure drop demonstrated that cartridge filters were not affected by humidity (P=0.75) and the main reason of pressure drop was due to collected dust on filters. It is concluded that using evaporative media systems is suitable method for cooling gas turbine intake and increase turbine efficiency without any significant increase of filter pressure drop in hot-dry climate.
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Safety issues have always been put forward as one of the major problems and primary concerns in construction industries in many countries. This paper will focus on the impact of safety training on safety climate and its relevant factors in two sites of a construction firm. The Health and Safety Executive (HSE) guide to safety climate tool that had been validated in Iran was used to determine the impacts of safety training on safety climate and its relevant factors. For this purpose, 347 workers filled out the questionnaire before and after safety training. The relationships between demographic features of workers and safety climate factors were considered in the questionnaire. Spearman's rho test was used to determine the relationship between safety climate factors. In both sites, there were significant differences (p<0.05) between safety climate factors before and after safety training while, the level of safety climate in both sites was the same before (p=0.416) and after (p=0.547) safety training. The results of Spearman's correlations test indicated that there has been a significant relationship (p<0.05) between safety climate and its relevant factors in both sites. The results showed that some safety climate factors such as pressure for production had been influenced by demographic factors such as age and job category. Safety training can improve the level of safety climate and its relevant factors in a construction industry. Improvement of each safety climate factor can promote the level of safety climate. Demographic features affected safety climate level and its relevant factors.
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Furnace division is one of the most polluted divisions ever known in the steel industry associated with several environmental pollutions. This study attempted to choose optimally, a pollution control system for dust emission from steel furnaces with the Green and environmentally friendly approach. Three electric smelting furnaces with 3, 6 and 12-ton output capacity were selected. The level of energy cost and consumption, capital and environmental damage, and indexes of environmental sustainability in bag houses and electrostatic precipitators based on computational methods and governing equations were studied. Findings showed that the total cost of bag houses in a steel electric furnace was lower than the total cost of electrostatic precipitators in the initial year and they were almost equal in the fourth year while the total cost of the former is higher than that of the latter after twenty years - the operational lifetime of dust collectors. It may be concluded that considering the environmental sustainability and industrial ecology, it would be reasonable and more economical to use bag houses for four years and electrostatic precipitators for longer periods.
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Since maintenance plays a key role in a company's overall performance, the main goal of this study was to provide a managerial tool for constantly monitoring and improving maintenance KPIs. This was achieved by designing and implementing a Computerized Maintenance Management System (CMMS) in an Iranian mid-size plant, manufacturing power plant utilities. In this study, CMMS software was developed and deployed in order to both monitor and optimize safety and maintenance KPIs. Selected KPIs were measured yearly; before, during and 12 and 24 months after intervention. Longitudinal Data Analysis and Mixtur Model were employed to compare the improvement trend of KPIs. Results show that at the end of the intervention year, KPIs other than Mean Time to Repair (MTTR) improved. Moreover, the improvement trend of the KPIs other than MTTR continued even 12 months after intervention was stopped. Similarly, although the "LWD" safety KPI had an overall improvement, comparing its figure before and after intervention, there was a significant decrease during the last 6 months of intervention. After the deployment of the CMMS, MTTR KPI increased surprisingly. Furthermore, the decrease in the "LWD" KPI revealed that off-the-job safety has a key role.
