فهرست مطالب

  • Volume:10 Issue: 4, 2020
  • تاریخ انتشار: 1398/12/04
  • تعداد عناوین: 8
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  • Keivan Saedpanah, Mohsen Aliabadi *, Rostam Golmohammadi, Majid Motamedzade Pages 180-190

    A decrease in body temperature can impair manual performance leading to a lowered capacity to carry out a certain activity. This study aimed to analyze the extent of the effects of extreme cold air exposure on workers’ manual performance. The study population was consisted of 50 outdoor auto mechanics who participated in two experiments carried out in winter and spring. Following a standard method, air environmental factors in each workstation and the physiological responses of the participants were measured. The touch sensory test was conducted to determine the sensory function of their hands. The grip strength and manual dexterity tests were also performed to assess the manual work disability. The hand and pinch grip strength of the auto mechanics were, respectively, reduced by 10.3% and 10.1% in cold air, as compared with the neutral air. The manual dexterity of the auto mechanics was also decreased from 6.3% to 8.8 % in cold air, as compared with neutral air. The prevalence of finger sensation disorders in auto mechanics was 62% in cold air, while it was only 4% in neutral air. There was also a significant correlation between finger skin temperature and manual dexterity (r=-0.80, p<0.01), handgrip strength (r=0.74, p<0.01), and pinch grip strength (r=0.79, p<0.01). There was also a significant correlation between finger sensory function and manual dexterity (r=0.65, p<0.01). During extreme cold air exposure, the physiological and sensory changes significantly reduced the manual performance of the auto mechanics. This study could empirically provide a database for further research on other aspects of the performance of the workers exposed to cold air.

    Keywords: Manual performance, Outdoor workers, Extreme cold air, Occupational exposure
  • Tayebe Rahimi Pordanjani *, Ali Mohamadzade Ebrahimi Pages 191-198

    The purpose of this study was to investigate the moderator role of psychological capital in relationships between occupational stress and work-life quality among the staff of the University of Bojnord. In this cross-sectional study, the population was all employees (faculty and non-faculty members) working at the University of Bojnord. Totally, 150 employees were selected by stratified random sampling. The questionnaires used in this study were occupational stress, psychological capital, and work-life quality. The research hypothesis was examined by the multiple regression analysis in SPSS V22 0 Statistical Analysis Software. According to the findings, the correlation coefficient between occupational stress and work-life quality (r=-0.595, p<0.0001) and between psychological capital and work-life quality (r=0.421, p<0.0001) was significant, statistically. The interaction of occupational stress and psychological capital, beyond the effects of the main variables, caused an increase of 2.8% in the variance of the model, indicating that these variables have a significant interaction with each other in predicting the quality of work-life (ΔR2=0.028, ΔF= 6.15, p< 0.02). The results also showed the importance of psychological capital as a moderator of the relationships between occupational stress and work-life quality among the university staff. To reduce the effects of occupational stress on the quality of work-life, university authorities are advised to enhance the psychological capital of their employees through practical-training protocols.

    Keywords: Occupational stress, Psychological capital, Work life quality, faculty members, Non-faculty members
  • Samira Ghiyasi * Pages 199-208

    The purpose of this study was to determine the level of risk perception and to assess and rate the factors of unsafe behavior among the firefighters in Tehran City. The study investigated the effect of “education and awareness”, “personality capability”, “coordination in teamwork”, “environmental factors and neurological stresses”, and “motivational systems” on risk perception and unsafe behavior of the firefighters working in operational units. The data were collected by interviews and the risk perception questionnaire made by the research team. The validity and reliability of the questionnaire were investigated and then, it was used for data collection. The sample size consisted of 510 operational personnel, including directors and deputies of the city districts, station heads, commanders, caretakers, and firefighters, who were selected by random sampling allocation. The findings showed that education and awareness, personality capability, coordination in teamwork and motivational systems were the factors influence the firefighters’ risk perception and unsafe behavior. The results also demonstrated that risk perception plays an important role in the rate of unsafe behavior among firefighters and is influenced by some important organizational and individual characteristics that are highly recommended to be considered in high-risk processes and operations.

    Keywords: Risk Perception, Unsafe behavior, Firefighters, Tehran fire stations
  • Mohammad Reza Monazzam, Monireh Hosseini *, Mohsen Meshkani Pages 209-217

    Undoubtedly, one of the main sources of noise pollution in cities is educational centers. The subject of discussion in the related studies has always been the effects of noise pollution on educational centers, but almost none of them have ever looked at the subject from the perspective that these centers can also be an important source of noise pollution in urban areas. Therefore, this research, with a different approach, addresses the effect of educational centers as an important source of noise pollution in urban areas. For this purpose, a total number of 32 state and nonprofit schools were selected randomly from the north, south, east, and west of Tehran City. After identifying the different sources of noise in the schools, the sound level was measured by TES sound level meter (model, 1358), at distances of 10, 20, and 30 m from the educational centers. The measured parameters included 10-minute equivalent sound pressure level (Leq10min), maximum sound level (Lmax), and minimum sound level (Lmin). Daily average sound level (Ld) was another parameter calculated for a period of 15 hours (from 7 am to 22 pm). According to the results, at the nearest distance to the schools (10 m), the highest average Lmax was 69 dB(A), measured at the time of students’ departure and its lowest was 64.7 dB(A) measured at the time the students had the physical education class. The highest and average Ld levels at the distance of 10 m from the schools were 65.2 dB(A) and 59.2 dB(A), respectively rep-orted from the male state primary-schools and female nonprofit high-schools. The average outdoor Leq and Ld level in the areas surrounding the target schools was about 5.5 dB(A) higher than the ambient noise. According to the results of the study, noise emitted from schools may be considered as a disruptive factor in urban environments, which needs to be addressed more.

    Keywords: noise pollution, equivalent sound pressure level, daily average sound level, educational centers, school
  • Mostafa Azizi *, Ali Asghar Hayat Pages 218-225

    People's beliefs can influence their perceptions of job performance, workplace, and working conditions. The present paper aimed at apprising irrational beliefs and their impact on the organizational commitment of teachers in elementary schools. The research was based on surveys. The statistical population consisted of 211 male teachers at elementary schools of Shiraz City, who were randomly selected using the Kersji and Morgans’ sample size table. The survey tool was the 40-item questionnaire of irrational beliefs—Ahvaz version—and Allen and Meyer’s 18-item organizational commitment questionnaire. According to the results, helplessness for change (t=8.915, p<0.001), problem avoidance (t=11.945, p<0.001) and emotionally irresponsibility (t=13.092, p<0.001) were significantly lower than the mean value, while the demand for approval (t=3.969, p<0.001) was significantly higher than mean value. The results also showed that affective (t=1.602, p>0.111) and normative (t=0.833, p>0.406) commitments were at the mean level and continuous commitment (t=3.980, p<0.001) was significantly higher than the mean value. The findings confirmed the effect of irrational beliefs on the teachers’ organizational commitment. The correlation coefficient between the irrational beliefs and organizational commitment was 0.457. The coefficient value was 0.387 for affective commitment, 0.473 for continuous commitment, and 0.227 for normative commitment. The irrational beliefs, as individual factors, have a significant impact on the teacher’s organizational commitment.

    Keywords: Irrational Beliefs, Organizational Commitment, Teachers, Elementary School
  • Ehsan Asivandzadeh, ALI ASGHAR FARSHAD*, ZEYNAB JAMALIZADEH, IRAJALIMOHAMMADI, JAMILEH ABOLGHASEMI Pages 226-235

    The present study explored whether emotional intelligence and social cognitive variables were related to risky driving behavior (speed and lane deviations). Driving behavior is considered a key predictive factor in road traffic accidents. The sample comprised 75 adults aged between 20- 30 years (M = 26.80, SD = 3.175) with a valid driver’s license. The emotional intelligence was assessed by the self-report Bar-on Emotional Quotient Inventory (EQ-i) and driving behavior was measured using a driving simulator. Different driving behaviors, including speed and lane deviations, were recorded. The objective data obtained from the simulator were compared with the scores obtained from the EQ. The spearman correlations revealed that age, driving experience, and accident cases were related to the driving behavior. There was a significant negative relationship between the average speed on roads with all of the emotional intelligence subscales, except for assertiveness (r=.448), whose correlation was found to be positive. The lane deviation score showed a significant negative relationship with the subscales of emotional intelligence except for assertiveness (r=.873). In order to facilitate safer behaviors in traffic and reduce the number of accidents, it is recommended to develop programs for changing the attitude of those road users who are more likely to engage in risky behavior and encouraging safe and responsible drivers.

    Keywords: Emotional Intelligence, Social Cognitive Variables, Driving Behavior
  • YASER SHOKOUHI, PARVIN NASSIR*, IRAJ MOHAMMADFAM, KAMAL AZAM Pages 236-249

    Risk of injury or death due to occupational incidents in the oil and gas industries is higher than that of major incidents such as fire or explosion. In 2017, the largest proportion (36%) of fatalities and greatest number of incidents (24%) in the oil and gas industries were categorized as Struck-by. This study was aimed to develop a Bayesian network (BN) model for predicting occupational struck-by incident probability. Nineteen struck-by causal factors were extracted from the literature. Expert knowledge in addition to Dempster-Shafer theory was used to construct a BN. A questionnaire was developed to measure conditional probabilities of causal factors among participants. Struck-by probabilities of different states of causal factors were also estimated. The prior probability of struck-by incident was 3.09% (approximately 31 per 1000 operational workers per year). Belief updating predicted that preventing workers from being in improper position (in line of fire) would decrease the struck-by incidents by 37%. In contrary, failure of hazard warning (true state) and violation of procedures increased the struck-by probability by 4.08% (an increase of 32%) and 3.96% (an increase of 28%), respectively. The proposed BN model predicted that preventing workers from being in improper position (in line of fire) would decrease the struck-by occupational incidents by 37%. This approach was a step toward quantification of risks associated with occupational incidents. It had advantages including graphical representation of causal factors relationships, easily customizing model, and simply introducing of new evidence (belief updating).

    Keywords: Bayesian Network, Incident Prediction, Oil Industry, Struck-by Incident
  • Amir Houshang Mehrparvar, Ali Farzan, Mohammad Javad Zare Sakhvidi, Mohammad Hossein Davari * Pages 250-264

    Early detection of noise-induced hearing loss (NIHL) is important to prevent the progression of hearing loss at speech frequencies. This study, through a systematic review of literature and meta-analysis, assessed the efficacy of high-frequency audiometry for early detection of NIHL. A systematic literature search was performed in Medline, Scopus, ISI web of science, EMBASE, CINAHL, Health star, and Ovid databases. The mean difference of hearing threshold at normal and high frequencies hearing was considered as the effect size. The pooled and stratum-specific MD were also estimated. From the 3031 articles found in the initial search, 23 and 11 studies were systematically reviewed and meta-analyzed, respectively. The mean difference in the exposed subjects was higher than the non-exposed subjects at most of the hearing frequencies. The effect size was higher at high frequencies, although it was not statistically significant. The research findings indicate that high-frequency audiometry cannot be considered as a method for early detection of NIHL.

    Keywords: NIHL, pure-tone audiometry, high-frequency audiometry, conventional-frequency audiometry