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Determining the optimal index of heat stress in foundry, die casting and road construction industries using FAHP-Topsis
Maryam Dehghanipoor, Manuchehr Omidvari, Farideh Golbabaiei ,
Volume 6, Issue 4 (12-2016)
Abstract

Introduction: Heat stress is one of the harmful risks in casting and die casting industries, which can not only cause work-related diseases but also can impair the performance and safety of workers. Since the indicators that are used to evaluate heat stress are very different, it is very difficult to choose a suitable index. The aim of this study was to determine the optimum heat stress index in foundry, die-cast, and road construction industries using FAHP and Topsis methods.

Material and Method: In order to determine optimum heat stress index in foundry, die-cast, and road construction industries, first, the prioritization criteria were defined by experts (including ease of measurement, measurement accuracy, comprehensiveness, time, cost, and correlation). Then, considering these criteria, the best heat stress index was determined based on experts’ opinions and using FAHP and Topsis methods.

Result: The results of this study suggest that given the current conditions and criteria, WBGT and P4SR is the best indices for foundry, die casting and construction.

Conclusion: The results showed that according to comprehensiveness, accuracy and correlation criteria, the WBGT index is considered as the best indicator of heat stress assessment in foundry, die-cast and road construction industries. Moreover, the HSI ranked in the last place due to the complexity and cost of its calculation.


Determination of optimum index for heat stress assessment on the basis of physiological parameters, in steel industries
Masoud Hamerezaee, Farideh Golbabaei, Parvin Nasiri, Kamal Azam, Somayeh Farhang Dehghan, Asad Fathi, Faezeh Darabi,
Volume 8, Issue 2 (6-2018)
Abstract

Introduction: Heat stress is one of the hazardous agents in the steel industries which can threaten the health and safety of workers and lead to serious occupational diseases. The aim of the study was to assess the heat stress in the steel industries and compare PHS (Physiological Strain Index), WBGT (Wet-Bulb Globe Temperature), DI (Discomfort Index) and HSI (Heat Stress Index) indices for the estimation of heat stress and to determine the optimum index for steel industries.
 

Material and Method: This descriptive-analytic study was conducted among 220 workers engaged in two steel industries in Iran. Environmental and physiological parameters were measured according to ISO 7726 and ISO 9886 in three times of measurement, and finally the time-weight average of the heat stress indices were calculated. All data were analyzed using SPSS ver.  20.
 

Result: The time-weight average of WBGT (28.28 oC), DI (29.11 oC), HIS (65.7 %) indices were higher than the recommended limits. Physiological parameters (oral, tympanic and skin temperatures, systolic and diastolic pressures and heart rate) had the greatest value in the second time of measurement (afternoon). WBGT index comparing to the PHS, DI and HSI indices had highest correlation with oral, tympanic and skin temperatures and heartbeat (r=0.314 , 0.408 , 0.459 , 0.302, respectively; P < 0.05), while systolic and diastolic blood pressures showed no significant correlation with WBGT (P > 0.05). The WBGT index had the highest correlation with studied indices which was 0.945, 0.681 and 0.600 for DI, PHS and HSI, respectively.
 

Conclusion: This study assessed the optimal index with regard to the physiological parameters, and it was concluded that the WBGT index has the highest correlation with the most of physiological parameters, and therefore, WBGT index can be the most optimum index to heat stress assessment   in the studied steal industries.


Investigating the protective effects of aqueous extract of the wormwood plant (Artemisia absinthium) on alumina nanoparticle-induced pulmonary toxicity in male Wistar rats
Esmaeil Karami, Zahra Goodarzi, Reza Chahardoli, Mahmoud Ghazi Khansari, Mehrafarin Kiani, Seyed Jamaleddin Shahtaheri,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Although aluminum oxide nanoparticles (Al2O3-NPs) are the most widely used nanomaterials, limited studies have been reported on their toxicology. Therefore, the present study aimed to investigate the potential toxicity of aluminum oxide (alumina) nanoparticles and the protective role of aqueous extract of wormwood plant on nanomaterial-induced disorders in the lung of rats.
Material and Methods: Here, 36 male Wistar rats were randomly divided into six groups. Next, the rats were first exposed to 200 mg/kg of the aqueous extract of wormwood plant (by gavage) for 15 days and then received a dose of 30 mg/kg of aluminum oxide nanoparticles as an intraperitoneal injection for 14 days. Furthermore, various features of clinical signs, body weight, biochemical parameters, gene expression changes, lung weight ratio, histopathological observations, and metal content in lung tissue were evaluated during the experiment. Eventually, the ANOVA (Analysis of Variance) and Tukey’s range test were employed to analyze and compare the mean of the data.
Results: The results revealed that aluminum oxide nanoparticles at a concentration of 30 mg/kg body weight led to changes in antioxidant enzyme activities, e.g., T-SOD, CAT, GPx, and TAC, lipid peroxidation, and iNOS for exposed rats. Also, the above biochemical disorders were associated with altered expression of oxidative stress-related genes (HO-1, MT-1) and histological changes in the lung tissue. On the other hand, simultaneous intake of aqueous extract of wormwood plant and aluminum oxide nanoparticles in rats significantly improved the studied parameters (p <0.05).
Conclusion: Our findings showed that the γ-Al2O3 NPs were more toxic than α-Al2O3 NPs, which can be attributed to changes related to their size and shape characteristics. Also, it was observed that the wormwood plant could play a protective role against aluminum oxide nanoparticles-induced pulmonary toxicity in rats.

The Impact of Chisel Shape and Length on Hand-Arm Vibration Transmitted from Electrical Demolition Hammer Handle on Concrete Surfaces
Kaykāvus Azrah, Ali Khavanin, Majid Shahi, , Mahbubeh Parsaeian, Mohammad Reza Monazzam,
Volume 12, Issue 4 (12-2022)
Abstract
Introduction: This study aims to determine the amount of hand-arm vibration transmitted from heavy electric destruction tools and the effect of using chisel with different lengths and shapes when demolishing concrete surfaces.
Material and Methods: To evaluate the magnitude of hand-arm vibration on the left and right handles of two powerful electric demolition hammers commonly applied in Iranian construction work and urban services, 323 measurements were made (RONIX and NEC). The demolition procedure was carried out by two experienced users on 49 concrete slabs of the same grade (20 C) with thicknesses of 10 and 15 cm while utilizing standard tools, such as hammers with two different chisel head shapes (flat and point) and lengths (40 and 60 cm). Utilizing two SVANTEK vibration meters concurrently on each hammer handle, measurement and evaluation were according to the ISO 5349:1, 2 procedures.
Results: The mean effective (frequency weighted root mean square) acceleration (awrms) for the Vector Sum Values (VSV) in the hammer handles were 15.71 m/s2. The primary vibrational axis transmitted to the handle of tool was the vertical axis, at 13.60 m/s2. When employing flat and point chisel, the mean awrms were 16.59 m/s2 and 14.82 m/s2, respectively. The difference between the results of 60 and 40 chisel was a little more than 2m/s2. The dominant and harmonic frequencies of the tools were generally in the range of 25 Hz to 80 Hz and 200 Hz to 400 Hz
Conclusion: The mean results generally indicated that point chisel with shorter lengths (40 cm) accelerates at a lower rate than flat chisel with longer lengths (60 cm). In the frequency range below 40 Hz, the RONIX hammer produced a larger acceleration than the NEC hammer indicating that the NEC hammer had a higher safety competitive advantage compared to the another hammer.
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