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Showing 12 results for Aliabadi
Study of ergonomic conditions in use of visual monitors and its relation to subjective feeling of fatigue in master science students of Hamadan University of medical science
Ghasem Hesam, Mohsen Aliabadi, Maryam Farhadian, Vahid Afshari Doust,
Volume 1, Issue 2 (Journal of Ergonomics 2013)
Abstract
Background: The use of visual monitors especially in relation to computer can cause health effects which have negative impacts on mental and physical performance of users. This study aims to determine the relation between ergonomic conditions in use of visual monitors and subjective feeling of fatigue in master science students as permanent users. Methods: In this study, 40 students in the Hamadan University of Medical Scienceswere selected based onsimplerandomapproach. For determining subjective feeling of fatigue, the standard questionnaire with reliability coefficient equal to 0.8 was distributed and completed among students. This questionnaire has 30 questions which was covered three criteria included drowsiness, difficulty of concentration and physical impairment. The data about environmental and ergonomic conditions of the workstations was also recorded. Exposure to electromagnetic radiation in very low frequency was measured using instrument model HI 3603 front of the studied monitors. Data was analyzed with SPSS 16 software. Results: The results showed mean score of drowsiness, difficulty of concentration and physical impairment were 17.8±6.5, 18.7±4.4 and 11.9±6.9, respectively. Totally, mean score feeling of fatigue was 48.5±15.7. The relation between continuous work time and feeling of fatigue was significant (P<0.05).The relation between work day time and feeling of fatigue was not significant (P>0.05). The relation between type of used monitor and feeling of fatigue was significant (P<0.05). Moreover, the relation between environmental conditions of the workstations and feeling of fatigue was not significant (P>0.05). However, descriptive results showed growing trend of feeling of fatigue in unsuitable environmental and ergonomic conditions. Moreover, exposure to electromagnetic radiation between to type monitors was statistically difference (P<0.05). Conclusion: Criterion of difficulty of concentration was allocated the maximum score of feeling of fatigue which can cause negative impacts on educational performance. Compliance with the ergonomic principles especially reduction continuous work time and use of updated monitors and optimization of lighting and acoustic conditions of the workstations can reduce feeling of fatigue among students, considerably.
Evaluation of noise pollution and acoustic comfort in the classrooms of Hamadan University of medical sciences in 2012
Mohsen Aliabadi, Neda Mahdavi, Maryam Farhadian, Masoud Shafie Motlagh,
Volume 1, Issue 2 (Journal of Ergonomics 2013)
Abstract
Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort. Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan University of medical sciences, were studied using questionnaire with reliability coefficient equal to 0.8 was completed among 413 students. Measurement of noise level was performed using sound level meter (model TES-1358) according ANSI S12.6 in classrooms. Result : The results showed the background noise level and outdoor noise level were equal 46.97 ± 3 dB(A), and 57.16 ± 4.8 dB(A) , respectively. The background noise was higher than the recommended limit equal to 45 dB(A) (P<0.01). The construction activities are most important annoying factor and concentration disturbance are most complication of noise. Signal to noise ratio within the classroom was 13.14±3.54 dB (A), which was inappropriate compared with the recommended limit 15 dB (A) (P<0.01). The difference in speech intelligibility at various levels of signal to noise ratio was significant (p<0.05). Conclusion: The results confirmed the studied classrooms haven’t acceptable acoustic conditions and background noise level was affected by outdoor noise. In regard to confirmation of the effects of noise on the student attention, the acoustic interventions is must be considered.
Study of public exposure to microwave radiation from wireless (WiFi) systems in Hamadan University of medical sciences
Nematullah Kurd, Abdulmajid Garkaz, Mohsen Aliabadi, Maryam Farhadian,
Volume 1, Issue 3 (Journal of Ergonomics 2014)
Abstract

Introduction: Due to the increase of public concern about the physical and psychological effects of radiation on the health of users, the present study aimed to determine the extent of public exposure to microwave emissions from wireless system in an educational setting.

 Materials and Methods: In this cross-sectional study, the effective intensity of microwave radiation were measured in 110 stations including the location of antennas access points, inside the classrooms, corridors and next to computers in five faculties of Hamadan University of Medical Sciences. Microwave meter HI 2200 model made by Holaday Co. was used to measure radiation according to the standard method No. C95.3. 

Results: The effective intensity of exposure to microwave radiation emitted in the studied university was equaled to 0.304±0.675 µW/cm2 which was lower than the international exposure limits. However, there were significant differences in the intensities of microwave radiation in terms of measurement locations (P=0.0001). The Highest intensity of microwave radiation was allocated to access points which were equaled to 1.731±0.214 µW/cm2.

 Conclusion: Although the intensity of microwave exposure from wireless networks at the university level was lower than the international limits and due to the failure to obtain conclusive evidence on the health effects of radiation exposure on humans at various levels, it seems to be necessary to inform users about radiation health risks to increase their awareness in educational settings.  Normal 0 false false false EN-US X-NONE AR-SA
Study of occupational exposure to non-ionizing radiations and the effectiveness of personal protective equipment in common arc welding processes
Amir Aliabadi, Ghasem Hesam, Zahra Moradpoor,
Volume 2, Issue 4 (Journal of Ergonomics 2015)
Abstract

Introduction: Welding is considered to be one of the main sources of occupational exposure to non ionizing radiations. The present study was conducted to examine the rate of occupational exposure to non-ionizing radiation in common welding processes.

Materials and Methods: In the present descriptive analytical study, occupational exposure to different types of non-ionizing radiations including electromagnetic fields with extremely low frequency and ultraviolet and infrared radiations were examined in five types of arc welding processes at the welding department of the technical and vocational training center of Malayer. Electric field intensities and magnetic field intensities were measured using the HOLADAY HI-3604 instrument and based on the ANSI/IEEE Std 644-1994 method. Ultraviolet and infrared radiation intensities were measured using Hagner-EC1 radiometer (made in Sweden).

Results: Electric field intensities and magnetic field intensities were lower than the exposure limits in the different types of welding processes examined. Nevertheless, the intensity of UV-B radiation exposure was higher than the exposure limits in the different types of welding processes examined, while UV-A radiation exposure was only higher than the exposure limits in arc welding. The results of measuring UV radiation intensities transmitted through protective goggles revealed the acceptable shade number of the lenses used. However, welders' clothing did not provide adequate protection. Moreover, the results showed that welders' infrared radiation exposure degree was much lower than the exposure limits.

Conclusion: The intensity of exposure to non-ionizing radiations was influenced by the type of welding process taken. Given the overexposure of welders to UV-B radiation in unshielded conditions, wearing clothes with an Ultraviolet Protection Factor of 50 is necessary for providing better protection.


The intensity of electromagnetic fields emitted by common compact fluorescent lamps
Mahtab Azizi, Mohsen Aliabadi, Rostam Golmohammadi ,
Volume 3, Issue 2 (Journal of Ergonomics 2015)
Abstract

Introduction: In recent years, compact fluorescent lamps have been more widely used across the country as a means of optimizing energy consumption. Given the health consequences of lighting sources, the present study was conducted to investigate the intensity of electromagnetic fields emitted by common compact fluorescent lamps.

Materials and Methods: The study examined 54 compact fluorescent lamp bulbs manufactured in local and international factories. The intensity of the electromagnetic fields emitted was measured at a very low frequency (VLF) and an extremely low frequency (ELF) using field measuring devices (Holaday HI 3603 and HI 3604 models). The data obtained were analyzed in SPSS.

Findings: The intensity of the emitted electric and magnetic fields decreased with the increase in their distance from the sources. At the reference point of 25 cm, the effective intensity of the electric field was 2.25 v/m at the very low frequency and 15.39 v/m at the extremely low frequency. The intensity of the magnetic fields was 0.47 mA/m at the very low frequency and 9.41 mA/m at the extremely low frequency. All the values were below the national exposure limits. There was a significant difference between the effective intensity of the electric and magnetic fields based on the lamps' manufacturers (p<0.05).

Conclusion: Although the intensities of the electromagnetic fields of the lamps were lower than the exposure limits, due to lack of conclusive evidence on the biological effects of fields, minimizing the public exposure to fields is essential. The use of standard-quality lamps is therefore highly recommended as a preventive measure.


Study of Noise Reduction Rate of Hearing Protection Devices Based on Microphone in Real Ear (MIRE) Under Laboratory Conditions
Azam Biabani, Mohsen Aliabadi, Rostam Golmohammadi,
Volume 4, Issue 2 (Journal of Ergonomics 2016)
Abstract

Introduction: Nominal noise reduction rate of the earmuff manufacturers can be different compared with the actual attenuation rate. The present study aimed to determine the actual noise reduction rate of common hearing protection devices using microphone in real ear method.

Materials and Methods: In this study, five brands of common earmuffs used in Iranian industries were investigated on 30 subjects under laboratory conditions. Noise reduction rates of earmuffs were measured based on the ISO 11904 standard, microphone in real ear method, using noise dosimeter (SVANTEK, SV 102 model) equipped with a microphone SV 25 model. The earmuffs comfort was also assessed by the developed questionnaire.

Results: The results showed that the real noise reduction rates of the earmuffs were between 49% to 86% of nominal reduction rates. Moreover, the actual insertion losses were much negligible at low noise frequencies. The performances of earmuffs based on manufacturers were not statistically different (Pv> 0.05). Based on subjects’ comfort scores, comfort of ear muffs were within the acceptable range. The noise reduction rates of the different earmuffs of each model were not statistically different as well (Pv > 0.05).

Conclusions: Irregular use of earmuff can reduce the real attenuation of earmuff to lower than the minimum rate acquired in this study. Proper training and adequate supervision on proper use of earmuff can affect earmuff fitting along with increasing of real noise attenuation.


Experimental study of the level of manual performance disability caused by exposure to hand-arm vibration among automobile casting workers
Azar Soltani, Mohsen Aliabadi, Rostam Golmohammadi, Majid Motamedzade,
Volume 6, Issue 1 (Journal of Ergonomics 2018)
Abstract
Background: Exposure to hand-arm vibration is one of the most common physical harmful factors. The purpose of this study was Experimental study of  the level of manual performance disability caused by exposure to hand-arm vibration among automobile casting workers.
 Methods: This study was performed on 53 casting workers as case group and 28 controls as control group. The measurement of the vibration of the worker's arms and hands was carried out in accordance with the ISO 5349 standard. The level of manual performance disability was evaluated using skeletal-muscular, sensory-neural and vascular tests. Also, a questionnaire was used for the level of disability of the arm, shoulder and hand DASH. Data were analyzed using SPSS16 software.
 Results: The 8-hour vibration exposure was 8.33 m / s2 (4.49), which is exceeded the permissible level. Skill and dexterity, fingers and grip strength of the dominant hand in the case group were decreased by 4%, 13.3% and 11%, respectively (p <0.05). The regeneration time of the dominant hand in the case group was 41.2% higher than the control group (p <0.05). Sensory-neurological complications increased in the case group compared to the control group, however, it was not statistically significant. The DASH score in the case group was 10.7 (13.4) and the control group was 4.1 (5.1).
 Conclusion: Hand-arm manual performance disability in workers exposed to vibration decreased from 4% to 14%, which confirmed the DASH score. In addition, workers showed a higher level of vascular complications compared with sensory-neurological complications.
 

The Field Study of the Effect of Noise Exposure on Cognitive Function and Sleep Quality
Mostafa Rahmiani-Iranshahi, Mohsen Aliabadi, R Rostam Golmohamadi, Alireza Soltanian, Mohammad Babamiri,
Volume 9, Issue 1 (Iranian Journal of Ergonomics 2021)
Abstract
Background and Objectives: Noise is known as an intruder in job environments and has non-hearing effects. The impact of noise on cognitive functions depends on the type of noise and the dose of noise exposure. This study aims to investigate the effect of noise exposure on cognitive functions and sleep quality.
Methods: This descriptive-analytical cross-sectional study was performed on 169 workers in three metal, chemical, and food industries in Hamedan in 1399. A continuous performance test was used to evaluate cognitive functions. The Petersburg questionnaire assessed participant's sleep quality. Using SVAN 971 analyzer and TES dosimeter, the level of noise exposure and the dominant frequency was measured. Data were also analyzed using linear and multiple regression in SPSS software (version 16).
Results: There is a significant difference in the level of noise exposure with changes in cognitive functions and sleep quality in the present study (P<0.001). The results of linear regression showed that there is a significant relationship between cognitive function and the level of exposure to sound (P<0.001). After identifying and determining the input variables, using multiple regression, an appropriate model was developed to predict sleep quality and sustained attention in the face of noise.
Conclusion: Based on the results of this study, predictive models with the appropriate coefficient of determination can be good models for assessing the quality of sleep and attention of people in the face of noise, which can be implemented and measured in a shorter time.

Experimental Study of Exposure to Human Vibration and Its Relationship with Physical Performance in Mining Equipment Operators
Mohsen Aliabadi, Ramin Rahmani, Ebrahim Darvishi, Maryam Farhadian, Masoud Shafiee Motlagh, Neda Mahdavi,
Volume 9, Issue 3 (Iranian Journal of Ergonomics 2021)
Abstract
Background: Exposure to vibration is one of the occupational agents that causes a variety of health effects. The aim of this study was to determine the association between exposure to human vibration and the physical performance of mining drivers.
Methods: In the present study, 65 drivers working in one of the Iron Ore mines, were asked to complete the standard questionnaire for assessing the level of disability of the arm, shoulder and hand (DASH). Exposure to human vibration was measured using Svantek 106 vibrometer. Drivers' physical performance was assessed based on grip strength, Pegboard dexterity, and monofilament finger sensory tests. Data were analyzed using SPSS 21 software.
Results: The average vibration acceleration whole body (WBV) and hand-arm (HAV) were 1.00±0.23 and 2.46±0.68 m/s2 respectively. There was a significant relationship between exposure to HAV and grip strength and hand dexterity (p <0.05). According to the DASH score, 56.9% of drivers had mild and 43.1% had moderate upper limb disability. The results of the multiple regression model with a coefficient of determination of 0.207 showed that the WBV in the presence of other predictor variables had a significant effect on DASH score (p<0.05).
Conclusion: In mining truck drivers, WBV exposure was higher and HAV exposure was lower than the national exposure limits. The results confirmed that WBV caused by mining trucks is the most important risk factor affecting the level of drivers' disability.

Performance of Vests based on Nanofibers and Packages of Phase Change Materials to Reduce Thermal Stress in a Hot Work Environment: An Experimental Study
Ali Davoodizadeh, Mohsen Aliabadi, Majid Habibi Mohraz, Maryam Farhadian, Masoud Shafiee Motlagh,
Volume 11, Issue 2 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: This study aimed to investigate the effectiveness of cooling vests based on nanofibers and packages of phase change materials (PCM) in reducing the thermal stress of medical personnel in hot workplaces.
Methods: In this experimental study, 20 males were exposed to 10 combined scenarios of temperatures of 24°C and 32°C in a room simulating atmospheric conditions and having 5 samples of cooling vests. Physiological parameters, including skin surface temperature, tympanic temperature, and oral temperature were measured before and after exposure to air temperature conditions by simulating the activity metabolism of hospital workers. The normal distribution of the data was checked with the Kolmogorov-Smirnov test, and the analysis of the effect of the scenarios was performed through the analysis of variance with repeated measurements.
Results: The results confirmed that in the condition without a vest, the air temperature of 32°C compared to the air temperature of 24°C had a greater effect in increasing the tympanic body temperature (P<0.05). The significant effect of using nanofiber vests along with PCM packages was observed in reducing skin temperature, tympanic temperature, and oral temperature in hot temperature conditions with effect sizes of 0.498, 0.568, and 0.349, respectively (P<0.05). The effect size of increasing the air temperature was lower than that of the type of cooling vests on the physiological responses, indicating that the effectiveness of the designed vests is enhanced with an increase in temperature (P<0.05).
Conclusion: The use of nanofiber cooling vests and PCM packages is effective in maintaining the body temperature stability of medical personnel in hot environments due to ideal weight and acceptable effect size.

Psychometrics of an Occupational Cognitive Failures Questionnaire for Heavy Machinery Operators in Road and Urban Construction: A Study of Validity and Reliability
Moein Darestani, Leili Tapak, Mostafa Mirzaie Aliabadi, Neda Mahdavi,
Volume 11, Issue 3 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: Today we are witnessing tremendous growth in construction and the use of heavy machinery. As a significant portion of human errors is attributed to cognitive failures, there is a need for robust tools to assess these cognitive failures. Therefore, the primary goal of this study was to investigate the psychometrics of the current Occupational Cognitive Failures Questionnaire for Heavy Machinery Operators in Road and Urban Construction.
Methods: A total of 84 drivers of road and urban construction machinery were selected by simple random sampling method. Initially, job-related items for these people were selected for inclusion in the questionnaire, irrelevant items were removed, and proposed items were added. To assess structural validity, the tool was administered to 10 experts. Then, content validity ratios (CVR) and content validity indices (CVI) were determined for each of the items and evaluated using confirmatory factor analysis conducted in AMOS software (version 23). Cronbach's alpha coefficient was used to measure reliability. Data were analyzed in SPSS software (version 20).
Results: The final questionnaire comprised 16 items, with CVR and CVI leading to their inclusion in the final structure. The CVR of the questionnaire was 0.90. Additionally, the indices of the fitted model included CMIN/DF, TLI, CFI, IFI, GFI, AGFI, and RMSE, which were obtained at 1.16, 0.851, 0.88, 0.898, 0.86, 0.802, and 0.044, respectively. The Cronbach's alpha coefficient was calculated at 0.633.
Conclusion: The psychometrics of the Cognitive Failures Questionnaire demonstrated suitable validity and reliability for heavy machinery operators in road and urban construction. It can be effectively used for ergonomic evaluations.

The effect of tonal noise and irrelevant background speech on neurophysiological based on personality traits: An experimental study
Ali Sobhani Dargah, Mohsen Aliabadi, Rostam Golmohamadi, Maryam Farhadian, Mohamad Babamiri, Shiva Mohammadjani Kumeleh,
Volume 12, Issue 4 (Iranian Journal of Ergonomics-In Press 2025)
Abstract
Objectives: This study aimed to investigate the effect of tonal noise and background speech on neurophysiological parameters and noise annoyance based on personality characteristics.

Methods: In this experimental study, 25 male students were exposed to four scenarios of tonal noise, irrelevant speech, and broadband noise as reference in a simulated laboratory environment. The LF/HF index and galvanic skin response were recorded before and during exposure to the noise. The level of noise annoyance was determined at the end of each test session using the noise annoyance questionnaire according to ISO 15666.

Results: Repeated measures ANOVA showed that the difference between the values ​​of neurophysiological indices and noise annoyance in different noise exposure scenarios was significant (P<0.05). The effect of different tonal sound levels on galvanic skin response and noise annoyance was significant (P<0.05). Also, the effect of 65 dB tonal sound level and 55 dB speech sound level on the LF/HF index was reported to be significant (P<0.05). Also, the effect size of 1.919 in exposure to 65 dB tonal sound level had the highest value compared to other noise exposure scenarios for the noise annoyance variable.

Conclusion: Exposure to different levels of tonal noise and irrelevant speech leads to disruption of individuals' neurophysiological parameters and noise annoyance in individuals regarding some of their characteristics and personality traits.
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