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Showing 5 results for Goodarzi
Human errors identification using the human factors analysis and classification system technique (HFACS)
G. A. Shirali, E. Karami, Z. Goodarzi,
Volume 3, Issue 3 (12-2013)
Abstract

Introduction: Although risk assessment and accident prevention program have been widely used in industries such as steel industry, there are still numerous accidents in these industries. Hence, applying an accident analysis method can identify the root causes and casual factors of accidents and causal factors. Human Factors Analysis and Classification System can identify human errors in the steel industry by using an analysis of past events. The aim of this study was to identify the human errors in the steel industry using the HFACS methodology.

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Material and Method: In this study first, incident reports of industries with high risk, such as Ahvaz steel and pipe industries existing in the department of work and social security was gathered. Then, an analysis of accident was done based on HFACS model. This model has 4 levels and 18 categories which are 1 - unsafe acts of operators (that includes four subtypes) 2 - pre-conditions for unsafe acts (with seven categories) 3 - unsafe supervision (includes four categories) and 4 - the effect of association (with three categories).

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Result: In this study, 158 reports of accident in Ahvaz steel industry were analyzed by HFACS technique. This analysis showed that most of the human errors were: in the first level was related to the skill-based errors, in the second to the physical environment, in the third level to the inadequate supervision and in the fourth level to the management of resources.

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Conclusion: Studying and analyzing of past events using the HFACS technique can identify the major and root causes of accidents and can be effective on prevent repetitions of such mishaps. Also, it can be used as a basis for developing strategies to prevent future events in steel industries.


Analyzing Hazards using System Theoretic process analysis (STPA) Methodology: A Case Study In The emergency extinguishing systems of Thermal power plant
E. Karami, Z. Goodarzi, T. Hosseinzadeh, G.a. Shirali,
Volume 5, Issue 1 (4-2015)
Abstract

Introduction: The weaknesses of traditional hazard analysis methods lead to their inefficiency to utilization for modern socio-technical systems. System Theoretic Process Analysis (STPA), which is in the category of systematic analysis methods, has a powerful logic to identify hazards in such systems,as a suitable alternative method. This study aimed to analyze hazards associated with extinguishing systems of steam unit of a power plant, using STPA method.

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Material and Method: The present research is a qualitative case study. The related hazards were defined using STPA method.Following, the safety control structure diagrams in different parts were plotted and inadequate control measures and its causal factors were identified.

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Result: For steam unit of power plant, the most tragic incidents wererelated to hazards and risks of turbine device (switch the turbine cycle). Then, according to the plotted diagram for structure of safety control extinguishing systems associated with switching the turbine cycle, PLC system was determined as the most important part of the control system and operator was identified as the strategic and effective part of a control system. Following, more than 54 causal factors were identified, considering the relevant details about the risks analysis of the turbine.

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Conclusion: Due to its systematic structure,STPA method can be effective for a more complete identification of risks and causal factors which causing hazards in the emergency extinguishing systems. Therefore, development of such tools for those operators involved in safety-critical systems will be useful in terms of safety.


Effect of Buildings around Highways on the Efficiency of T-Shaped Parallel Acoustic Barriers: A Theoretical Study
Esmaeil Karami, Mohammadreza Monazzam, Keykaous Azrah, Mehdi Mohammadian, Zahra Goodarzi,
Volume 12, Issue 1 (3-2022)
Abstract
Introduction: Over recent years, various programs have been conducted to reduce noise, indicating the increasing concerns of society over noise pollution. This study has been performed to enhance the performance of parallel barriers on two sides of a highway considering the surrounding buildings.
Material and Methods: The 2D boundary element simulation method was employed to predict the noise reduction in barriers. Regarding the effect of buildings and water canals, various kinds of models were investigated to compare the effectiveness of different boundary barriers in real conditions from a listener’s perspective.
Results: The use of a single YA model could improve the performance of parallel barriers by 3.5 dB compared to that of a TS model. Moreover, by using a pair of barriers, no significant change was observed in the performance of the second barrier. However, by using parallel barriers along the surrounding buildings, the TD model improved the efficiency by 3 dB compared to the TS model. The rise in the frequency resulted in remarkable adverse effects on the barrier performance, such that the surrounding buildings at a distance of 8 m had a negative effect on the performance of the parallel barriers by almost 8.34 dB.
Conclusion: In general, by ignoring the buildings, the use of a pair of TZ barriers showed a higher performance. Meanwhile, by considering the buildings in the design model, the TD model was found to be optimum. Therefore, it can be concluded that choosing an ideal barrier only based on the noise behind it cannot indicate its behavioral and acoustic characteristics in a real environment.
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.

Investigation of the effects of using ribs on cyclone’s vortex finder on its performance
Zahra Tarin, Abdulrahman Bahrami, Mohsen Goodarzi, Farshid Ghorbani-Shahna,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Generally, geometrical parameters of the cyclone have a profound effect on determining its performance. The air outlet (Vortex Finder) as one of the cyclone’s components has a significant impact on the cyclone’s internal flow pattern, pressure drop and even dust removal efficiency.
Material and Methods: Two different air outlets were designed in order to be easily installed and removed. The ribs (both in the opposite and the same swirl direction with the air flow) were inserted at the inner wall of the vortex finder. The step length of the blades was calculated to be 1.5. The dust feeder was injected the silica particles with a concentration about of 2.1 gr/m3 into the inlet air. The results of dust removal efficiency of the cyclone were calculated and compared for three groups of total dust, PM10 and PM2.5 in different experimental conditions.
Results: Installation of spiral blades in same swirl direction as the air flow inside the cyclone increased 7.75, 7.73 and 6.75 percent in total efficiency, PM10 and PM2.5, respectively. The dust removal efficiencies for total dust, PM10 and PM2.5 increased by 2.6%, 2.33% and 1.5%, respectively, when the swirl direction of ribs and air flow was the opposite. The effect of helical blades on pressure drop for the first experimental setup (same direction) decreased by (- 2.5%) and in the second one (opposite direction) increased by (+ 2.03%). The best quality factor was also calculated for the cyclone with the blade aligned with the air flow direction.
Conclusion: Use of ribs in the inner wall of the cyclone vortex finder,  especially when the rotation direction of the ribs and airflow are the same, leads to a decrease in pressure drop and increase in dust collection efficiency which finally leads to improvement of cyclone performance.

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