Safety Engineering Research Articles

Dual-axis fiber Bragg grating tilt sensor based on universal joint structure

Inclination angle measurement is widely used in fields such as infrastructure health, power engineering safety, and earthquake monitoring. In response to the problem that existing inclinometers based on the pendulum structure can only measure a single axial inclination angle, a dual-axis Fiber Bragg Grating (FBG) tilt sensor based on a universal joint structure is proposed. SolidWorks was used to establish a sensor model and conduct theoretical analysis. The structural parameters of the sensor were optimized using the control variable method. Based on the optimization results, a physical sensor was developed, and an inclination and temperature testing system was set up for performance testing. The results show that within a measurement range of ± 5°, the sensitivities of the X and Y axes of the sensor are 229.8 pm/° and 224.9 pm/°, respectively, with a resolution of approximately 4.4 × 10-4°. The tilt accuracy of the sensor is approximately 0.48°, and it exhibits good creep resistance and stability during long-term measurements, as well as temperature self-compensation capabilities. The research results provide a new reference for the development of similar dual-axis tilt measurement sensors.

Performance investigations on fluorine-rubber-tube-laying pumping wet shotcrete filled with microencapsulated phase change materials

The challenge of mitigating adverse climatic conditions is a critical issue that affects worker safety and operational efficiency in underground engineering. This study introduces an innovative approach using pumping wet shotcrete as an insulating material, incorporated with microencapsulated phase change materials (MPCMs) and filled within fluorine rubber tubes to address this concern. The MPCMs were synthesized via suspension polymerization, utilizing paraffin as the core material and modified SiO2-poly (lauryl methacrylate) as the shell material. To determine the optimal composition for practical application, an orthogonal experimental design was employed, complemented by comprehensive performance testing. The results indicated that a mix of 1375 kg/m3 of sand, 120 kg/m3 of ceramsite, and 1 g/cm of SiO2-MPCMs in each fluorine rubber tube having an inner diameter of 13 mm, provided the best balance between multiple properties. Notably, the insulation performance improved by 60–75 % compared to traditional pumping wet shotcrete, demonstrating a significant enhancement in thermal management capabilities. The findings contribute substantially to the field of thermal management in mines, presenting a novel technique that could be instrumental in improving safety and efficiency in deep underground operations.

Effects of Olivine Alteration on Micro-Internal Structure and Geomechanical Properties of Basalts and Strength Prediction in These Rocks

Understanding the variations of the geomechanical properties of rocks in geotechnical projects from the perspective of their micro-structures and alteration conditions is crucial for ensuring the safety and long-term sustainability of rock engineering (e.g., tunnels, slopes, mining). This study was carried out on basaltic rocks from the Akcakale and Mersin vicinities in Trabzon City to investigate the geomechanical and mineralogical properties in comparison with the uniaxial compressive strength (UCS). This study was conducted in three different locations (A1, M2, and M3) where the basaltic rocks outcrop belongs to the same lithological formation. During this study, quite different results were obtained from the basalt samples taken from different sites and the reasons for these differences were examined by petrographic, SEM (Scanning Electron Microscopy), and EDS (Energy Dispersive Spectroscopy) analyses. Since the number of comprehensive studies on basalts is very limited, this study aims to investigate practical and useful equations in the estimation of the UCS for various alteration conditions. Statistically, significant relationships were observed between geomechanical properties with the UCS and serpentinization rate (SR). This study revealed that the serpentinization of the olivine mineral is the most important factor causing the differences in the experimental results. The proposed equations for estimating the UCS are particularly significant for geotechnical applications where direct sampling is challenging, such as in weak-rock environments.

Drift-flux correlation for bubbly to annular two-phase flows under microgravity conditions

In light of the substantial importance of accurate void fraction predictions for the engineering design and safety evaluation of two-phase systems utilized in space-related applications, this study is dedicated to the investigation of the drift-flux correlation specifically for microgravity conditions. The present study has collected 458 experimental void fraction data taken in microgravity bubbly to annular flows. The analysis of the collected experimental data evident that (1) the distribution parameters vary with the flow conditions, and (2) the drift velocities under microgravity conditions are exceedingly small. However, the distribution parameter models of the reviewed existing drift-flux correlations fail to accurately capture the variation of distribution parameters with flow conditions under microgravity conditions. Moreover, there is a lack of a simple yet effective way to model the drift velocity of microgravity two-phase flow. To overcome the above weaknesses, a new drift-flux correlation has been proposed by (1) taking the flow condition effect on the variation of asymptotic distribution parameters into consideration, and (2) employing the concept of effective body acceleration and considering the decay of drift velocity in annular flow. The newly proposed drift-flux correlation has been evaluated by checking against the collected data and shows good predictive ability.

Cost-effective, open-source light shutters with Arduino control

In optical experiments, shutters are devices that open or close a path of light. They are often used to limit the duration of light exposure onto a target or onto a detector to reduce possible light-induced damage. Many commercial shutters are available for different applications – some provide very fast opening and closing times, some can handle large optical powers, and others allow for fail-safe operation. Many of these devices are costly and offer limited control options. Here we provide an open-source design for a low-cost, general purpose shutter system based on ubiquitous actuators (servo motors or solenoids) that are connected to an Arduino-based controller. Several shutters can be controlled by one controller, further reducing system cost. The state of the shutters can be controlled via a display built into the controller, by serial commands via USB, or by electrical control lines. The use of a microcontroller makes the shutter controller adaptable – only control options that are used need to be included, and the design accommodates a selection of display and actuator options. We provide designs for all required components, including 3D print files for the actuator holders and cases, the Arduino code, libraries for serial communication (C and python), and example graphical user interfaces for testing.

STRENGTH CALCULATION METHODOLOGY FOR THE TECHNOLOGICAL CONTAINERS FOR CHEMICAL HEAT TREATMENT OF WORKPIECES

Purpose. Development of a strength calculation methodology for the special technological containers for chemical heat treatment of workpieces, which considers the consequences of complex influence of the load and the main technological factors. Creation of possibility of full-value mathematical modelling of the special technological containers with complex three-dimensional geometric shape for chemical heat treatment of workpieces using the finite element method. Research methods. Mathematical modeling taking into account the hypothesis of linear failure accumulation from low-cycle fatigue and creep of material. Results. A strength calculation methodology for the special technological containers for chemical heat treatment of workpieces has been developed, which considers the consequences of complex influence of the load and the main technological factors: high-temperature corrosion, interaction with the chemical environment, creep, low-cycle fatigue. This methodology makes it possible to determine safe operation life of the containers. Load combinations have been considered. The main features of the design of the technological containers for chemical heat treatment of workpieces have been considered. Scientific novelty. It has been considered at calculations of the special technological containers the consequences just of the complex influence of the load and the main technological factors which occur during the chemical heat treatment of workpieces: high-temperature corrosion, interaction with the chemical environment, creep, low-cycle fatigue. Practical value. The developed methodology provides the possibility of full-value mathematical modelling of the special technological containers for chemical heat treatment of workpieces using the finite element method. It opens a way for multi-criteria optimization of the design of the containers with complex three-dimensional geometric shape with prospect of reduction of their weight with a certain resource of safe operation. This is one of the main factors of the practical value of this work because the containers for chemical heat treatment of workpieces are made of expensive heat-resistant steels. One factor more is the possibility to determine safe operation life and thus satisfy the requirements of safety engineering.

Eliminating the Occurrence and Consequences of Toxic Release in Petrochemical Industry through Intervention of Safety Engineering Tools

The aim in this project is to analyze the risk associated with different toxic releases which is occurring in the chemical industry and to minimize its release using safety engineering tool in order to make the working environment safer. The sector of petrochemical industries is very important and have specific place in our country. Since the beginning, the Indian petrochemical industry has shown an enviable growth rate. This industry also contributes largely to the economy of the country and the growth and development of manufacturing industry as well. Petrochemical industry has a high risk of toxic release. The main causes of accidents are the chemical splashes which can occur for instance when a pipe or a tank burst under pressure or during disassembling operations of pipes or valves. There are a number of ways of toxic release at each and every process of petrochemical industry. We have identified the way in each process of the petrochemical industry. We have taken H2S as toxic gas and performed analysis, with the help of Bowtie methodology. Result obtained by evaluating various processes in petrochemical industry, we found that H2S can be released in three major sections i.e. transportation, storage and processing units. Using bowtie method, resolutions has been done to decrease or eliminate the possibilities of leakage of H2S

Cloud inversion analysis of surrounding rock parameters for underground powerhouse based on PSO-BP optimized neural network and web technology

Aiming at the shortcomings of the BP neural network in practical applications, such as easy to fall into local extremum and slow convergence speed, we optimized the initial weights and thresholds of the BP neural network using the particle swarm optimization (PSO). Additionally, cloud computing service, web technology, cloud database and numerical simulation were integrated to construct an intelligent feedback analysis cloud program for underground engineering safety monitoring based on the PSO-BP algorithm. The program could conveniently, quickly, and intelligently carry out numerical analysis of underground engineering and dynamic feedback analysis of surrounding rock parameters. The program was applied to the cloud inversion analysis of the surrounding rock parameters for the underground powerhouse of the Shuangjiangkou Hydropower Station. The calculated displacement simulated with the back-analyzed parameters matches the measured displacement very well. The posterior variance evaluation shows that the posterior error ratio is 0.045 and the small error probability is 0.999. The evaluation results indicate that the intelligent feedback analysis cloud program has high accuracy and can be applied to engineering practice.

Theoretical and experimental study of unsteady behavior of marine diesel engine under fluctuating back pressure condition

In order to meet the increasingly urgent emission reduction requirements, underwater exhaust has emerged as a promising technology for marine diesel engines and has received widespread attention in recent years. However, under fluctuating high back pressure conditions, the diesel engine as a whole operates in an unsteady state, with significant fluctuations in output power and exhaust temperature, posing a serious threat to their stability and safety. This paper focuses on the unsteady operating characteristics of diesel engines and its impact on the engine output power, efficiency and safety under fluctuating high back pressure conditions. Firstly, based on model order reduction and the first Lyapunov approximation theorem, the theoretical derivation reveals that the filling and emptying effects in the intake and exhaust pipes and the shaft moment of inertia of the turbocharger are the main causes of the unsteady of the engine under fluctuating high back pressure conditions. The factors influencing the strength of engine unsteadiness, including wave period, wave amplitude, mean back pressure and engine properties, are identified. Then, diesel engine experiments under different fluctuating high back pressure conditions are performed and the conclusions derived from the theoretical analysis are validated through experiments. Based on the research results mentioned above, this paper proposes a criterion to determine the unsteadiness of diesel engines. Through comparison with experimental data, it is found that this criterion effectively reflects the strength of engine unsteadiness, with a correlation coefficient of 0.9169 with the unsteady parameter.

Post mission disposal of Megha-Tropiques-1 through controlled atmospheric Re-entry to be published in: The journal of space safety engineering

Controlled Re-Entry Experiment of Megha-Tropiques 1 (CREEM), an immensely challenging and significant exercise, was successfully executed on 7 March 2023 by Indian Space Research organization (ISRO) as part of its ongoing efforts to improve compliance with internationally accepted space debris mitigation guidelines. In this paper, we present the overall strategy of CREEM which was primarily shaped by the stringent requirements of targeted impact within a pre-designated zone and ensuring visibility during the final de-boosting burns. We specifically address how the strategy was driven by the on-board and operational constraints, the rationale for the selection of the target region, the de-orbiting maneuver performance details, and the operational workarounds to ensure required subsystem performance. The external coordination related aspects and the lessons learnt are also presented.

Use of the OSCAR-Fusion V1.4.a code for a preliminary assessment of the ACP contamination within the main ITER water cooling circuit

One of the main objectives of ITER is to produce 500 MW of power from a deuterium-tritium plasma for several seconds. This goal presents two inherent challenges: firstly, in-vessel components will require active cooling to remove the heat coming from the fusion reaction (i.e., mainly fast neutrons and alpha particles). Secondly, the materials exposed to the neutron flux will yield activated corrosion products (ACPs) in all primary cooling circuits of ITER. From a safety point of view, ACPs are one of the contributors to the Occupational Radiation Exposure (ORE), they represent a source of radiological waste and also contribute to the source term for accidental scenarios involving the loss of primary confinement. Therefore, ACPs assessment is key to estimate radiological impact for nuclear workers and the public. ITER nuclear safety engineers adopted OSCAR-Fusion v1.4.a code to assess the ACPs inventory in the Integrated Blanket ELMs and Divertor (IBED) cooling loop. This paper describes the selection of input data, the modelling of the circuits and the operational scenarios used in OSCAR-Fusion calculations. This study also examines the outcomes of such calculations, notably in terms of ACPs inventory, emphasizing the impact on the ORE and highlighting its driving parameters. Additionally, the paper offers recommendations for better ACPs management in the context of the ITER project and in accordance with the ALARA principle.

The attitude of occupational health and safety engineering students towards the field of study and future career at Ilam University of Medical Sciences

Introduction: One of the important factors of students' success is a positive attitude towards their field of study and future career. Occupational health and safety engineering is a science that works in the field of employee health and work environment safety. Therefore, it is very important to know the factors affecting the attitude of students in occupational health and safety engineering. Methodology: In this study, 62 students of occupational health engineering of Ilam University of Medical Sciences were examined in the academic year of 2020-2021. The data were collected using the questionnaire of the University of Minnesota, containing 17 questions with a Likert spectrum scale. The data were analyzed using SPSS software. Results: From 66 questionnaires, the mean and standard deviation of the attitude score towards the field of study (28.97 ± 4.25) and the mean and standard deviation of the attitude score towards the future career (24.8 ± 4.7) were calculated. Considering the score of 22 and 19 as the average score of the attitude towards the field of study and future career, the scores obtained are more than the acceptable score. Conclusion: The findings of the present study show a positive attitude towards the field of study and future career. Matching the capacity of accepting students with the needs of the labor market, familiarizing students with university courses before the national entrance exam, providing advice and support to students in justifying the course and work environment, and better communication between industry and university will improve students' attitudes.

Understanding Crowd Responses to Perceived Hostile Threats: An Innovative Multidiscplinary Approach

People facing threat may evacuate, help others, share information, ignore the threat and the plight of others, or enact a combination of these behaviours. Accurate conceptual models of crowd behaviours must consider why and when these behaviours occur, as well as how people's responses may vary across different scenarios. Researchers have investigated crowd responses to threats using a variety of methods, such as interviews, observational analysis and virtual reality experiments. Each methodology offers benefits to understanding collective responses to threats, but each methodology also has limitations. Importantly, very little research has explored crowd responses in false alarm situations where crowd members misperceive that a threat exists. In this paper, we describe a new programme of work which combines approaches from safety engineering and crowd psychology to gain a thorough understanding of crowd behaviour in response to real and misperceived threats, and the processes underpinning the behaviour. We focus on how we identified and addressed the similarities and differences in our research questions, conceptual approaches to research, and methodological abilities. We demonstrate how our multidisciplinary approach provides a framework for combining diverse research methods that collectively build knowledge to create more accurate models of crowd responses to (mis)perceived threats.

Effects on the design of aeronautical fuel cell systems by inclusion of reliability requirements

The change towards carbon neutrality in air traffic involves a huge reduction of greenhouse gas emissions. This goal is beyond reach by the step wise improvement of conventional technologies. Hence, at present a solution which gains much of attraction are electric motors and electric aircraft systems in combination with fuel cells which can be run by green hydrogen. For a holistic comparison of various concepts the consideration of reliability aspects is required even at an early stage of design. In the scope of this work methods from reliability and safety engineering will be introduced and set in context of aeronautical fuel cell systems. On that basis the consequences arising by the requirement of redundancy are investigated on a system level approach. For this purpose, a model of an aeronautical fuel cell system will be set up in order to simulate a generic flight envelope at stationary points. The fuel cell system is chosen to be central-monolithic and its components are sized for the propulsion of a regional aircraft. With the aid of the system simulation, various failure scenarios are investigated from which mitigation strategies can be derived. Finally, the baseline design will be improved in terms of redundancy in order to last in a generic failure scenario. A comparison between the baseline and improved design shows that the additional redundancy comes with the cost of 4.6% weight increase and a 2.5% drop in cruise efficiency.

Structural Analysis of Deck Reinforcement on Composite Yacht for Crane Installation

The crane installation on the deck of a yacht redistributes the stress field and affects the local structural integrity and performance. The safe operation of the yacht is associated with the optimal placement of the crane on the deck and the proper local structural reinforcement. Here, the structural analysis of the bow part of a yacht made of composite materials is studied, considering the retrofit installation of a crane, in three different cases of reinforcing the deck: (a) without any reinforcement, (b) with a T-type reinforcement, and finally, (c) with a longitudinal beam. The T-type connects the longitudinal bulkhead and the deck, reinforced locally with overlamination skin and adhesive-filler. The longitudinal beam works as a local longitudinal stiffener attached to the deck and connects the second, third, and fourth transverse frames. The structural analysis is performed using the finite element method following the classification societies’ rules. The local reinforcements are made from the same composite materials as the unreinforced deck. The maximum deformations, the principal stresses, and the safety factors following Tsai-Wu and Hashin criteria are calculated and compared for the three different cases. The T-type and longitudinal reinforcements reduce deck stresses by 33%, with longitudinal reinforcement reducing deck deformation by 17%. Composite failure analysis shows the structure was near failure, and the reinforcements enhance safety; T-type is better for multiaxial loads (Tsai-Wu), and longitudinal is superior for micromechanical failure (Hashin). By considering the structural performance and safety aspects, designers and engineers can make optimal decisions regarding yacht crane installation and proper reinforcement, leading to safer and more efficient structures.

Decision-making in balancing fire safety hazards against security threats within the built environment

The built environment faces challenges from fire hazards and threats by malicious actors. Risks presented from these hazards and threats are managed through the practices of fire safety and physical security. Whilst distinct disciplines, both impact the built environment systems, resulting in potential conflict. To manage this conflict, a complex process is required. Through the framework of Governmentality, using a mixed methods approach, the study explored the process which fire safety engineers and security practitioners undertake to manage this conflict. The study produced a conceptual model that explains how practitioners operate and manage risk associated with fire safety hazards and security threats. The model indicates that the process for resolving conflicts is a dichotomy between physical security and fire safety, with fire safety being the most dominate and influential. Nevertheless, both fire safety and physical security are subservient to building regulations in this process; however unlike security, fire safety is codified through building regulations. Risk assessment and the design process are core processes, but only used in decision-making when there is conflict between the fire safety and physical security. Findings demonstrated that context remains static for greater threats, whereas context is dynamic for fire safety.

Preface

Proceeding of the 4th International Conference on Environmental Technology and Innovations (ICETI 2023) Dear Colleagues, We are delighted to present the proceedings of the 4th International Conference on Environmental Technology and Innovations (ICETI 2023), which was part of the IOP Conference Series: Earth and Environmental Science. This event was a collaborative effort involving several prestigious institutions: Ton Duc Thang University, National Cheng Kung University, and Cheng Shiu University in Taiwan; Thammasat University in Thailand; Universiti Sains Malaysia; and Nagaoka and Hokkaido Universities in Japan. ICETI 2023 served as a multidisciplinary platform for experts from academia, industry, and research to discuss and share advancements in Environmental science and technology, Sustainable development and conservation of natural resources, Technologies for adapting to climate change, and Occupational health and safety engineering. The conference proceedings feature a series of peer-reviewed articles that uphold our discussions' high scientific standards and integrity, highlighting our authors’ significant contributions towards innovative practices and policy development in environmental stewardship. We extend our heartfelt thanks to the editorial board and reviewers, whose meticulous work guaranteed the quality of these proceedings. Their expertise was crucial to the success of this publication. We are also grateful to our keynote speakers and all participants for their invaluable insights and contributions, which greatly enriched our conference. Their diverse perspectives and experiences are essential in advancing our sustainable future agenda. Special thanks go to the conference organizers and the support staff at Ton Duc Thang University for their unwavering commitment and effort in making this conference a success. We trust that the insights shared at ICETI 2023 will inspire ongoing research and collaboration within our community. As we look forward to future conferences, we remain committed to advancing the field of environmental technology and innovation. Together, we can continue to make significant strides towards a sustainable and prosperous future for all. Editorial Board Members of the ICETI 2023 - The Manuscript Section for the IOP List of Conference Proceedings is available in the pdf.

AI-Based Detection of Surge and Rotating Stall in Axial Compressors via Dynamic Model Parameter Estimation

Compressors are an essential component of aircraft engines. Their design and operation must be extremely reliable as engine safety and performance depend greatly on these elements. Axial compressors exhibit instabilities, such as surge or rotating stall, in a region close to the peak of their performance curves. These fluid dynamic instabilities can cause drops in efficiency, stress on the blades, fatigue, and even failures. Compressors are handled therefore by operating with a safety margin far from the surge line. Moreover, models able to predict onset instabilities and to reproduce them are of great interest. A dynamic system able to describe successfully both surge and rotating stall is the model presented by Moore and Greitzer That model has also been used for developing control laws of the compressor dynamics. The present work aims at developing an artificial neural network (ANN) approach able to predict either the permanence of the system in stable working condition or the onset instabilities from a time sequence of the compressor dynamics. Different solutions were tried to find the most suitable model for identifying the system, as well as the effects of the duration of the time sequence on the accuracy of the predicted compressor working conditions. The network was further tried for sequences with different initial values in order to perform a system analysis that included multiple variations from the initial database. The results show how it is possible to identify with high accuracy both rotating stall and surge with the ANN approach. Moreover, the presence of an underlying fluid dynamic model shares some similarities with physically informed AI procedures.

Exploration and Practice in the Curriculum Construction of Integrated Production & Education under the Background of New Engineering-Taking the Chemical Engineering Safety and Environmental Protection as an Example

Exploration and Practice in the Curriculum Construction of Integrated Production & Education under the Background of New Engineering-Taking the Chemical Engineering Safety and Environmental Protection as an Example

In situ XAFS-XRD study of the Zr-Y2O3 interaction at extra-high temperatures.

The in situ measurement technique for a metal/metal-oxide mixture at extra-high temperature above 2000 K has been desired in the field of nuclear safety engineering. In the present study, we succeeded in simultaneous XAFS-XRD measurements of the Zr oxidation [Zr + O → Zr(O) + ZrO2] up to 1952 K and ZrO2-Y2O3 reaction from 1952 to 2519 K. The chemical shift during Zr oxidation was observed in the absorption spectra around the Zr K-edge, and the interatomic cation-cation and cation-oxygen distances obtained by the fitting analysis of EXAFS during the Y2O3-ZrO2 reaction are explained. Also, the temperature dependency of the anharmonic effect was investigated by comparing the fitted second- and third-order cumulants with the theoretical ones in which the Morse potential was applied as an interatomic potential, giving a good explanation about the local structure dynamics. Finally, the applicability of the developed system to investigation of nuclear fuel materials, such as UO2-Zr, is discussed.