Papers by Keyword: Risk Assessment

Abstract: The optimal geometric dimensions and dependencies for gas mask filter boxes have been determined. The geometric dimensions of the filter boxes have been defined using comfort, performance, and efficiency coefficients. These coefficients have been established through computer modeling of airflow movement within gas mask filter boxes using the SolidWorks software. The base models for creating digital copies were two types of filter boxes: cylindrical and flat, which differed in their geometric dimensions.

Abstract: This study assessed the auto-mechanics' four dimensions of mental workload and posture in an automobile repair shop in San Jose Occidental Mindoro, Philippines, with issues in increasing body pains and headaches affecting efficiency and performance. Five participants were observed from January-March 2022. Due to the limitations of the NASA-TLX in evaluating the mental workload, the authors used the new Carmen-Q questionnaire. Results revealed that the auto-mechanics had been exposed to an average of twenty-nine (29) in the cognitive dimension, eighteen point five (18.5) in the temporal dimension, seventeen point five (17.5) in the emotional dimension, and seventeen points seventy-five (17.75) in performance dimension, which means that the auto-mechanic's mental workload is in the medium range and preventive measures must be done. Previous research also revealed that mental workload is linked with poorer posture; thus, this study is the first to combine mental workload with posture risk assessment. RULA and REBA techniques have been utilized to evaluate the posture, and results discovered that the risk index for tire repair and installation is two (2.00) and three (3.0) for the engine repair and installation, which means that the risk is high and change in posture is required. Statistical analysis also described that the cognitive and emotional dimension has a significant relationship with each other. In contrast, the different dimensions have no significant relationship, such as: cognitive and temporal dimensions, cognitive and performance dimensions, temporal and emotional dimensions, temporal and performance dimensions, and emotional and performance dimensions. In conclusion, this study can be considered a basis for helping the automobile repair shop design the tasks for the auto-mechanics as well as guidance in improving the working conditions and a tool for evaluating cognitive state in a critical working environment.

Abstract: River flooding is one of the most frequent catastrophic events, with dramatic consequences regarding loss of life and economic damage. For this reason, flood hazard and risk management now appear as the fundamental activities that public bodies and competent authorities must implement to reduce human and socio-economic losses. In this context, this study refers specifically to the flooding at the Boussalem city, crossed by Medjerda river in Tunisia. This work aims to assess the suitability of different numerical tools for reproducing flood dynamics using two different fully two-dimensional (2D) hydrodynamic models, both based on the Saint-Venant equations: TELEMAC-2D and HEC-RAS 6.0. The study compares the accuracy and performance of the two models in estimating flood hazard and risk. Comparative analysis is conducted on flooded area extents from both models for the 2003 flood event and return periods of 20, 50, and 100 years. This is achieved by identifying the roughness coefficient for each land cover type. The comparison encompasses flooded areas for four height classes along the Medjerda River in Tunisia: <0.5m, 0.5-1m, 1-2m, >2m. Details of the analysis of the total flooded area generated by the models show that the percentage difference between the flooded areas decreases as the discharge increases, with differences of 4%, 6%, 16%, and 27% respectively for the 2003 events and the 20, 50, and 100-year return periods. This observation indicates that TELEMAC-2D tends to generate larger estimates of flooded areas as water height increases, suggesting an increased sensitivity to extreme flood events. Conversely, for depth classes of 0.5 to 1 meter and less than 0.5 meters, HEC-RAS produces larger flooded areas than TELEMAC-2D for events with return periods of 50 and 100 years. This divergence can be explained by the influence of specific modeling methodologies of the two software packages.

Abstract: The construction of the dam project poses a significant risk of workplace accidents, particularly due to the inherent dangers associated with large-scale construction. One such incident occurred at the Karaloe Dam site in South Sulawesi in 2019, resulting in the tragic death of a heavy equipment operator who fell from a height of 85 meters along with his machinery. This study aims to identify hazards and conduct a risk assessment of workplace accidents affecting construction, workers, communities, and the environment in the Main Dam Works of the Rukoh Dam Construction Project, Pidie Regency. The determination of hazards is qualitative, employing a case study approach through direct field observation. The Identification of Hazards Risk Assessment Determination of Risk Control and Opportunities (IBPRP) method is used, along with the determination of risk levels based on the risk matrix outlined in Minister of PUPR Regulation Number 10 of 2021. The analysis yielded 23 potential hazards, comprising 14 moderate-risk categories and 9 high-risk categories. However, following control measures such as engineering solutions, administrative protocols, and the utilization of personal protective equipment, the overall potential hazards have been mitigated to a low-risk level. The potential hazard with the highest risk level at the worksite is exposure to tire blowouts from heavy vehicles, specifically dump trucks.Keywords: Project Main Dam, Hazard Identification, Risk Assessment, Risk Level

Abstract: A large vessel, such as a container ship or an oil tanker, requires painting processes that include not only application, but also cleaning, substrate preparation and corrosion treatment. Moreover, these processes take place during construction (both in the construction of blocks in the workshop and in the assembly at the dock) and also during the operation phase of its life cycle, as part of its maintenance. This research analyzes the advantages of the implementation of key enabling technologies in painting processes versus the proposal of preventive measures, collective and individual protection, and training of workers in traditional manual processes. Using the Fine-Kinney method, which assesses potential hazards and associated risks, the degree of danger of the different tasks present in the current painting processes of large vessels is measured. These risk scores is compared with those of the new activities resulting from the simulation and automation of the associated processes, analyzing their justification by confronting their level of correctness (risk mitigation) with the cost factors of their implementation. The results show that, from a health and safety point of view, the proposal of these measures is fully justified. Therefore, it can be concluded that the inclusion of key enabling technologies in the painting processes of a ship throughout its life cycle drastically reduces risk levels, improving the safety and health conditions of the workers involved, without prejudice to an increase in the cost of services or in the delivery deadlines to the client, which confirms their reliability.

Abstract: The ship hull construction suffers a decrease in strength performance over its life cycle due to corrosion and fatigue. Therefore, the risk of structural failure also rises during the extended service life if maintenance is not performed properly. The budget, on the other hand, limits these activities. As a result, it is critical for ship owners to plan an optimal maintenance program. The idea of this research is to find the best way to keep the hull's structural integrity due to corrosion. A time dependent corrosion model has been developed for failure prediction purposes, based on the historical data of plate thickness reduction. Failure scenarios are carried out on local, global and fatigue strength. This research adopted a semi-quantitative risk assessment along with reliability analysis to give strategic maintenance planning by lowering the risks that would be encountered. Hence, ensuring uninterrupted service of the ship throughout the service life. Finally, this study will be very useful as reference to establish risk informed program to evaluate the risk level of components of hull that guides to adjust inspection intervals without avoiding safety requirements.

Abstract: Adaptation of the previously developed methodology for assessing risks and opportunities for assessing risk situations and identifying opportunities during operation of built-up cutting tools is made. The factors influencing performance of built-up cutting tools are analyzed. The article presents an analysis of failures of replaceable inserts of built-up cutting tools when performing face milling operations, the results of which will be taken into account when applying the developed technique.

Abstract: Lightweight steel structure buildings are a special type of illegal building in Taiwan. There are many different types of these illegal structures in Taiwan used for various purposes. The number of factories operating in one of these illegal lightweight steel buildings alone is as high as 130,000 according to the 2017 statistics. The construction of such structures is easy, fast, and the cost is low, which is why they are widely accepted by the people.[1] The materials of a lightweight steel structure are mostly steel or C-shaped steel. When this type of steel structure is exposed to temperatures above 600 °C, the structure will begin to break and bend, causing deformation and eventually collapse. Additionally, the rapid growth of the fire, the lack of establishment on fire zones, and a fierce fire, etc., all present more challenges for onsite employees to extinguish the initial fires as well as the later fire rescue attempt by firefighters. In recent years, fatal fire incidents have been rampant, causing deaths and injury to foreign workers, highlighting fire safety issues. Therefore, “whether worker accommodation should be separated from the factory” is the subject of this paper. This study is aimed at the statistical survey of lightweight steel structures for industrial and residential use (current status): using data from project investigations to present the site overview and hazard risk factors. Risk assessment for buildings with accommodation inside the factory (validation): through the statistical survey data (34 of the 188 surveyed have accommodations inside the factory, a ratio of 18.1%), the hazard risk is assessed, and the potential risks are analyzed. Fire simulation on buildings with accommodation inside the factory (hazard): use fire simulation to analyze the effective evacuation time with residential fire alarms. To develop a disaster reduction strategy based on the results of the parametric analysis of this study for buildings with accommodation inside the factory (improvement): utilizing factory fire prevention analysis, factory symposium, fire prevention announcement, fire equipment inspection and maintenance, etc., to achieve disaster reduction. Based on the results of the parametric analysis of this study, we will develop an accommodation and disaster reduction strategy (improvement): use plant fire prevention diagnosis, factory symposium, fire prevention announcement, fire equipment inspection and maintenance, etc., to achieve disaster reduction.

Abstract: The emergence of condense phenomenon, generally associated with the mould, on the inner surface of the closing elements affects not only the finishing works quality, but also the comfort conditions and, not least, the occupants’ health. The phenomenon is caused by the simultaneous action of several categories of factors. If factors related to the design and structure of closing elements can be controlled by proper design and execution respecting the quality requirements, those related to users’ behaviour and to indoor and outdoor climate conditions, have a variable and random character. Hence there is the possibility that all or most of parameters, that reflect the action of these factors simultaneously, reach values ​​that can cause mould and condensation on the surface. In these circumstances we can speak of a risk level defined as the possibility of producing an undesirable event. The risk assessment involves the precise definition of it and finding a way to calculate how often such an event may occur under particular conditions. One of the criteria to be taken into account to estimate the risk of superficial condensation is the temperature factor. The effective value of this criterion is influenced by several categories of factors that refer to the indoor climate conditions influenced by users’ behaviour, constructive and architectural features and outdoor climate. The objective of this paper is to integrate a phenomenological approach of producing the surface condensation and mould in a complex analysis, through this global criterion, using the concept of "risk”.

Abstract: Most of the monumental structures worldwide and residential structures in developing countries are built in masonry. The studies performed by various researchers prove the vulnerability of masonry structures under various circumstances, especially under earthquakes, so as to necessitate detailed contemplation. In this paper, a numerical model for nonlinear static analysis of unreinforced masonry walls is developed based on a macro-modelling approach. A detailed parametric study is also performed to analyse the effect of wall thickness as well as length on the behaviour of the masonry wall. The present numerical model can be utilized for risk assessment and seismic retrofitting of historical masonry structures.