Pub Date : 2025-01-18DOI: 10.1016/j.jlp.2025.105559
Ladislav Jánošík , Izabela Šudrychová , Ivana Jánošíková , Petr Gold
The paper summarizes and compares results of an evaluation of basic driving characteristics measurements of fire fighting vehicles. Two tanker trucks used by the Fire Rescue Service of the Czech Republic are compared by different chassis. A TATRA vehicle with a chassis allowing off-road driving and a SCANIA vehicle with a chassis designed for driving on paved city roads. The deceleration and acceleration characteristics of the vehicles are monitored and evaluated. Braking distance, time to stop and deceleration were monitored during the evaluation of braking characteristics. For the acceleration evaluation, start-up time and a distance to reach the desired speed were monitored. These parameters were monitored depending on the type of tyres, the test track surface and the climatic conditions.
{"title":"Firefighting vehicles’ driving dynamics under extreme load","authors":"Ladislav Jánošík , Izabela Šudrychová , Ivana Jánošíková , Petr Gold","doi":"10.1016/j.jlp.2025.105559","DOIUrl":"10.1016/j.jlp.2025.105559","url":null,"abstract":"<div><div>The paper summarizes and compares results of an evaluation of basic driving characteristics measurements of fire fighting vehicles. Two tanker trucks used by the Fire Rescue Service of the Czech Republic are compared by different chassis. A TATRA vehicle with a chassis allowing off-road driving and a SCANIA vehicle with a chassis designed for driving on paved city roads. The deceleration and acceleration characteristics of the vehicles are monitored and evaluated. Braking distance, time to stop and deceleration were monitored during the evaluation of braking characteristics. For the acceleration evaluation, start-up time and a distance to reach the desired speed were monitored. These parameters were monitored depending on the type of tyres, the test track surface and the climatic conditions.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105559"},"PeriodicalIF":3.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-16DOI: 10.1016/j.jlp.2025.105556
Vojtech Jankuj , Jan Skrinsky , Arne Krietsch , Martin Schmidt , Ulrich Krause , Richard Kuracina , Zuzana Szabová , Stefan H. Spitzer
Explosion characteristics are widely used in the process industries to determine the potential hazard of the used substances. In the American and European standards for determination of the maximum explosion pressure of dusts, the measured pressure is corrected if the tests are conducted in the 20L-sphere. This correction formula increases the measured values if they are above 5.5 bar g. It also causes, that the only two volumes for testing that are used are the standard 1m³ and the 20L-sphere because it is unclear whether corrections are necessary and, if so, what correction should be applied at other volumes.
In this article explosion tests were performed with four different dusts, lycopodium, lignite, aluminum, and nitrocellulose, in four different vessel sizes: 20 L, 250 L, 365 L, and 1000 L to investigate the influence of the vessel size.
{"title":"Simplifying standards, opening restrictions Part I: The influence of the test vessel volume on the maximum explosion pressure of dusts","authors":"Vojtech Jankuj , Jan Skrinsky , Arne Krietsch , Martin Schmidt , Ulrich Krause , Richard Kuracina , Zuzana Szabová , Stefan H. Spitzer","doi":"10.1016/j.jlp.2025.105556","DOIUrl":"10.1016/j.jlp.2025.105556","url":null,"abstract":"<div><div>Explosion characteristics are widely used in the process industries to determine the potential hazard of the used substances. In the American and European standards for determination of the maximum explosion pressure of dusts, the measured pressure is corrected if the tests are conducted in the 20L-sphere. This correction formula increases the measured values if they are above 5.5 bar g. It also causes, that the only two volumes for testing that are used are the standard 1m³ and the 20L-sphere because it is unclear whether corrections are necessary and, if so, what correction should be applied at other volumes.</div><div>In this article explosion tests were performed with four different dusts, lycopodium, lignite, aluminum, and nitrocellulose, in four different vessel sizes: 20 L, 250 L, 365 L, and 1000 L to investigate the influence of the vessel size.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105556"},"PeriodicalIF":3.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-16DOI: 10.1016/j.jlp.2025.105555
Sarka Bernatikova, Jakub Baca, Ales Dudacek, Vit Klecka
Fire investigators are key players in determining the causes of fires. Their work has changed over the years, not only in their professional approach to identifying the causes of fire, but also in relation to the protection of their health, where there have been significant improvements in recent years. Unlike firefighters, fire investigators do not usually use an isolation breathing apparatus at fire scenes when fighting a fire. This article focusses on an analysis of the risks that fire investigators face in their work, particularly in terms of physical, chemical, and biological factors. It examines the potential impact of these factors on the health and safety of fire investigators compared to emergency firefighters and proposes measures to minimise these risks. Then it specifically looks at the working environment of a fire investigator in a post-experimental fire area. It concludes with strategies and technologies aimed at protecting the health of fire investigators in the challenging post-fire environment.
{"title":"The working environment of a fire investigator after experimental fires: Challenges and experiences","authors":"Sarka Bernatikova, Jakub Baca, Ales Dudacek, Vit Klecka","doi":"10.1016/j.jlp.2025.105555","DOIUrl":"10.1016/j.jlp.2025.105555","url":null,"abstract":"<div><div>Fire investigators are key players in determining the causes of fires. Their work has changed over the years, not only in their professional approach to identifying the causes of fire, but also in relation to the protection of their health, where there have been significant improvements in recent years. Unlike firefighters, fire investigators do not usually use an isolation breathing apparatus at fire scenes when fighting a fire. This article focusses on an analysis of the risks that fire investigators face in their work, particularly in terms of physical, chemical, and biological factors. It examines the potential impact of these factors on the health and safety of fire investigators compared to emergency firefighters and proposes measures to minimise these risks. Then it specifically looks at the working environment of a fire investigator in a post-experimental fire area. It concludes with strategies and technologies aimed at protecting the health of fire investigators in the challenging post-fire environment.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105555"},"PeriodicalIF":3.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-13DOI: 10.1016/j.jlp.2025.105554
V.Yu. Plaksin, I.A. Kirillov
This article presents a theoretical approach for quantifying the flammability and explosion limits of hydrogen-air mixtures over a wide range of temperatures (from 90 K to 850 K) at normal pressure. In a first part of paper, a critical review of the published results is made. We demonstrate that existing empirical datasets and phenomenology-based analytical and computational models critically depend upon features of experimental facility, measurement procedure and criterion for combustion limits. This dependence results into variations of values of concentration limits, obtained in different experimental setups, making it difficult to reconcile data and limiting predictive capabilities and conservatism of the empirical datasets. Further, we describe a non-empirical framework for studying the fundamental concentration limits for the basic combustion models in hydrogen-air mixtures – adiabatic spherical flame balls, plane deflagration flames, plane detonation waves. This framework does not rely on experimental combustion data, but rather uses mathematical models based on “the first physical and chemical principles”. The proposed framework introduces three innovations: 1) the first non-empiric explanation of the ternary "hydrogen-air-water steam" flammability diagram's structure for slow ascending and descending flames, 2) the first theoretical explanation of the quasi-invariance of the adiabatic flame temperature for the near-limits flames, 3) the new kinetic criterion for flame acceleration, which provides conservative predictions for both the lower and the upper concentration limits of the flame acceleration. We conclude this work by discussion of additional features for empowering of the non-empirical models and future experiments that could further improve overall knowledge of nature and quantitative accuracy of the concentration limits.
{"title":"Hydrogen flammability and explosion concentration limits for a wide temperature range","authors":"V.Yu. Plaksin, I.A. Kirillov","doi":"10.1016/j.jlp.2025.105554","DOIUrl":"10.1016/j.jlp.2025.105554","url":null,"abstract":"<div><div>This article presents a theoretical approach for quantifying the flammability and explosion limits of hydrogen-air mixtures over a wide range of temperatures (from 90 K to 850 K) at normal pressure. In a first part of paper, a critical review of the published results is made. We demonstrate that existing empirical datasets and phenomenology-based analytical and computational models critically depend upon features of experimental facility, measurement procedure and criterion for combustion limits. This dependence results into variations of values of concentration limits, obtained in different experimental setups, making it difficult to reconcile data and limiting predictive capabilities and conservatism of the empirical datasets. Further, we describe a non-empirical framework for studying the fundamental concentration limits for the basic combustion models in hydrogen-air mixtures – adiabatic spherical flame balls, plane deflagration flames, plane detonation waves. This framework does not rely on experimental combustion data, but rather uses mathematical models based on “the first physical and chemical principles”. The proposed framework introduces three innovations: 1) the first non-empiric explanation of the ternary \"hydrogen-air-water steam\" flammability diagram's structure for slow ascending and descending flames, 2) the first theoretical explanation of the quasi-invariance of the adiabatic flame temperature for the near-limits flames, 3) the new kinetic criterion for flame acceleration, which provides conservative predictions for both the lower and the upper concentration limits of the flame acceleration. We conclude this work by discussion of additional features for empowering of the non-empirical models and future experiments that could further improve overall knowledge of nature and quantitative accuracy of the concentration limits.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105554"},"PeriodicalIF":3.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-11DOI: 10.1016/j.jlp.2025.105553
Guohua Luan , Yueyang Li , Xin Li , Cong Yan , Yunhe Zhang , Binglu Zhang , Guangbo Ma , Yuntao Li , Qi Jing
Water is a necessary condition for a boilover to occur, crude oil storage tanks are extremely hazardous in the event of a boilover fire. In order to investigate the effect of water contained in the crude oil itself on the boilover phenomenon, 20 sets of replicate experiments were conducted using crude oil without deep water removal, with a water content reaching 3.45 %. As a whole, the combustion process is divided into 5 typical stages: ignition stage, stable combustion stage, pre-boilover stage, boilover stage and flame extinguishing stage, this paper focuses on analyzing the characteristics of the boilover stage. The results show that high water-content crude oil can still boilover without water layer and with a high degree of uncertainty, with a total of 6 scenarios occurring: no boilover occurred, boilover like a running pot of porridge, spray in one of the directions, the strongest boilover, continued stable combustion at the end of the boiliover, and flame extinguishing at the end of the boilover. Water contained in the crude oil will make the hot zone temperature lower, ranged between 145 °C and 165 °C. A higher oil water content can accelerate convection within the oil, which in turn weakens the process of temperature rise in the hot zone. Boilover intensity is generally weak, in most experiments maximum heat flux does not exceed 10 times the steady combustion period. Quantile-Quantile plot and Kolmogorov-Smirnov test were used to analyses the normality of boilover onset time and total burning time. Boilover onset time obeys a normal distribution, whereas total burning time excludes normality. This paper is the first to investigate the uncertainty of boilover phenomenon, to deepen the understanding of oil tank boilover fires, and to propose a research idea to analyses the boilover phenomenon from a probability perspective.
{"title":"Experimental study on boilover fire characteristics and uncertainty of high water-content crude oil","authors":"Guohua Luan , Yueyang Li , Xin Li , Cong Yan , Yunhe Zhang , Binglu Zhang , Guangbo Ma , Yuntao Li , Qi Jing","doi":"10.1016/j.jlp.2025.105553","DOIUrl":"10.1016/j.jlp.2025.105553","url":null,"abstract":"<div><div>Water is a necessary condition for a boilover to occur, crude oil storage tanks are extremely hazardous in the event of a boilover fire. In order to investigate the effect of water contained in the crude oil itself on the boilover phenomenon, 20 sets of replicate experiments were conducted using crude oil without deep water removal, with a water content reaching 3.45 %. As a whole, the combustion process is divided into 5 typical stages: ignition stage, stable combustion stage, pre-boilover stage, boilover stage and flame extinguishing stage, this paper focuses on analyzing the characteristics of the boilover stage. The results show that high water-content crude oil can still boilover without water layer and with a high degree of uncertainty, with a total of 6 scenarios occurring: no boilover occurred, boilover like a running pot of porridge, spray in one of the directions, the strongest boilover, continued stable combustion at the end of the boiliover, and flame extinguishing at the end of the boilover. Water contained in the crude oil will make the hot zone temperature lower, ranged between 145 °C and 165 °C. A higher oil water content can accelerate convection within the oil, which in turn weakens the process of temperature rise in the hot zone. Boilover intensity is generally weak, in most experiments maximum heat flux does not exceed 10 times the steady combustion period. Quantile-Quantile plot and Kolmogorov-Smirnov test were used to analyses the normality of boilover onset time and total burning time. Boilover onset time obeys a normal distribution, whereas total burning time excludes normality. This paper is the first to investigate the uncertainty of boilover phenomenon, to deepen the understanding of oil tank boilover fires, and to propose a research idea to analyses the boilover phenomenon from a probability perspective.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105553"},"PeriodicalIF":3.6,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-10DOI: 10.1016/j.jlp.2025.105549
Daniel Allason , D. Michael Johnson , Andrzej Pekalski , Antoine Dutertre , Duncan Mansfield
Vapour cloud explosions (VCEs) are rare events but can lead to severe consequences in terms of harm to people and damage to onshore and offshore facilities. Research conducted in the latter part of the 20th century demonstrated the key role of congestion, such as process pipework, within the flammable cloud in accelerating the flame to high speeds. In recent years it has also become accepted that at least some major VCEs have involved flame acceleration to the point where deflagration to detonation transition (DDT) occurred (Chamberlain et al., 2019). Limiting the size of congested regions can potentially reduce the chance of DDT, however in addition the regions need to be adequately separated to avoid a fast flame from one region entering a second. Previous research into explosion safety gaps at large scale has shown that the introduction of gaps between regions can significantly reduce the magnitude of an explosion (Skjold, 2016).
However, on facilities where space is at a premium, the provision of sufficient gaps may be impossible or incur high costs. The DOWSES (Development Of Water Spray Explosion Suppression) experimental research programme studied the effect of water curtains installed in the gap between congested regions. To establish the benefit provided by the water curtains, baseline explosion experiments without water sprays were performed (with either methane- or propane-air mixtures), one of which resulted in DDT in the second congested region (Allason et al., 2019), one giving a high-pressure deflagration and one with low interaction between the congested regions.
This paper extends the reporting of results to include the experiments with water spray mitigation, not available at the time of the last publication. The experiments involved variation in water spray configuration, the type of congested region and the spacing between the congested regions. In addition, an experiment was conducted with a particulate added to the water. Detailed results from the experiments are presented: in every instance where water was introduced into the vapour cloud, the baseline explosion was significantly mitigated. In the configuration where DDT had occurred in the baseline experiment, the water sprays prevented DDT.
{"title":"Explosion suppression with water curtains between congested regions","authors":"Daniel Allason , D. Michael Johnson , Andrzej Pekalski , Antoine Dutertre , Duncan Mansfield","doi":"10.1016/j.jlp.2025.105549","DOIUrl":"10.1016/j.jlp.2025.105549","url":null,"abstract":"<div><div>Vapour cloud explosions (VCEs) are rare events but can lead to severe consequences in terms of harm to people and damage to onshore and offshore facilities. Research conducted in the latter part of the 20th century demonstrated the key role of congestion, such as process pipework, within the flammable cloud in accelerating the flame to high speeds. In recent years it has also become accepted that at least some major VCEs have involved flame acceleration to the point where deflagration to detonation transition (DDT) occurred (Chamberlain et al., 2019). Limiting the size of congested regions can potentially reduce the chance of DDT, however in addition the regions need to be adequately separated to avoid a fast flame from one region entering a second. Previous research into explosion safety gaps at large scale has shown that the introduction of gaps between regions can significantly reduce the magnitude of an explosion (Skjold, 2016).</div><div>However, on facilities where space is at a premium, the provision of sufficient gaps may be impossible or incur high costs. The DOWSES (Development Of Water Spray Explosion Suppression) experimental research programme studied the effect of water curtains installed in the gap between congested regions. To establish the benefit provided by the water curtains, baseline explosion experiments without water sprays were performed (with either methane- or propane-air mixtures), one of which resulted in DDT in the second congested region (Allason et al., 2019), one giving a high-pressure deflagration and one with low interaction between the congested regions.</div><div>This paper extends the reporting of results to include the experiments with water spray mitigation, not available at the time of the last publication. The experiments involved variation in water spray configuration, the type of congested region and the spacing between the congested regions. In addition, an experiment was conducted with a particulate added to the water. Detailed results from the experiments are presented: <em>in every instance where water was introduced into the vapour cloud, the baseline explosion was significantly mitigated</em>. In the configuration where DDT had occurred in the baseline experiment, the water sprays prevented DDT.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105549"},"PeriodicalIF":3.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jlp.2025.105543
Fateme Rashidi, Soroush Baradaran, Mohammad Amin Sobati
The study presents a novel comprehensive approach for quantitative dynamic risk assessment in the reaction section of a biodiesel production plant. The methodology combines sequential established techniques (HAZOP analysis, Bow-Tie (BT) analysis) with a Fuzzy Bayesian Network (FBN) in process safety assessment of biodiesel production. Following a thorough process hazard identification, detailed design gaps were addressed and modified. Dynamic risk assessment was then performed by combining the BN with fuzzy approach to cover the limitations of conventional risk analysis and to deal with the uncertainty in the modeling due to lack of credible equipment failure rate data. Assessment on the effectiveness of design improvement revealed a substantial 90% risk reduction following the implementation of technical recommendations obtained from the HAZOP analysis. Sensitivity analysis using the FBN also revealed the reactor pressure transmitter and safety valves as the critical safety elements of the process. Implementing design modifications based on such analysis reduced the risk level by 95%. This study highlights the effective combination of the established methods with FBN for dynamic risk assessment and targeted design improvements, ultimately leading to enhanced safety in biodiesel production plants.
{"title":"Design improvement for enhanced process safety in a biodiesel production unit using Fuzzy Bayesian network analysis","authors":"Fateme Rashidi, Soroush Baradaran, Mohammad Amin Sobati","doi":"10.1016/j.jlp.2025.105543","DOIUrl":"10.1016/j.jlp.2025.105543","url":null,"abstract":"<div><div>The study presents a novel comprehensive approach for quantitative dynamic risk assessment in the reaction section of a biodiesel production plant. The methodology combines sequential established techniques (HAZOP analysis, Bow-Tie (BT) analysis) with a Fuzzy Bayesian Network (FBN) in process safety assessment of biodiesel production. Following a thorough process hazard identification, detailed design gaps were addressed and modified. Dynamic risk assessment was then performed by combining the BN with fuzzy approach to cover the limitations of conventional risk analysis and to deal with the uncertainty in the modeling due to lack of credible equipment failure rate data. Assessment on the effectiveness of design improvement revealed a substantial 90% risk reduction following the implementation of technical recommendations obtained from the HAZOP analysis. Sensitivity analysis using the FBN also revealed the reactor pressure transmitter and safety valves as the critical safety elements of the process. Implementing design modifications based on such analysis reduced the risk level by 95%. This study highlights the effective combination of the established methods with FBN for dynamic risk assessment and targeted design improvements, ultimately leading to enhanced safety in biodiesel production plants.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105543"},"PeriodicalIF":3.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jlp.2025.105552
Hana Vykopalová
Psychosocial risks and assessment of psychosocial risk factors in working conditions are current issues affecting the level of mental health in connection with the performance of workers in all work areas. Stress theory, stress and the importance of exposure to psychosocial risks as basic research starting points and connections to working conditions, mental health. Effects of stress on learning and memory processes. Cognitive processes and cognitive distortions, the incidence of error and their influence on the reliability of the human factor. The importance of ambivalence on risk perception. The effects of distress, the role of defence mechanisms and alexithymia and their manifestations in the workplace, the transformation of risk stressors in working conditions, as less well-known dissatisfactions. Alarming findings in the area of the prevalence and sharp increase of mental illnesses recently as a result of social isolation (Covid 19 pandemic), but also workload due to increasingly advanced technologies and digitization of work activities.
{"title":"Prevalence of psychosocial risk severity, stress and cognitive dissonance in working conditions","authors":"Hana Vykopalová","doi":"10.1016/j.jlp.2025.105552","DOIUrl":"10.1016/j.jlp.2025.105552","url":null,"abstract":"<div><div>Psychosocial risks and assessment of psychosocial risk factors in working conditions are current issues affecting the level of mental health in connection with the performance of workers in all work areas. Stress theory, stress and the importance of exposure to psychosocial risks as basic research starting points and connections to working conditions, mental health. Effects of stress on learning and memory processes. Cognitive processes and cognitive distortions, the incidence of error and their influence on the reliability of the human factor. The importance of ambivalence on risk perception. The effects of distress, the role of defence mechanisms and alexithymia and their manifestations in the workplace, the transformation of risk stressors in working conditions, as less well-known dissatisfactions. Alarming findings in the area of the prevalence and sharp increase of mental illnesses recently as a result of social isolation (Covid 19 pandemic), but also workload due to increasingly advanced technologies and digitization of work activities.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105552"},"PeriodicalIF":3.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jlp.2025.105551
Miroslav Mynarz , Aleš Tulach , Marian Bojko
Quantification of time and spatial concentration profiles of a gas-air cloud caused by accidental leakage of flammable gas from damaged equipment can be of great importance for the correct prediction of the occurrence of dangerous situations. Knowing the extent of leakage and time dependence of generation of hazardous concentrations may be a good tool in the design of mitigation equipment (e.g., gas detection alarms) or in determining further measures (e.g., the extent and method of ventilation of the premises).
The paper describes the dispersion of leaked methane (natural gas) from a damaged low-pressure gas pipeline, in a confined space with a geometrically complex environment and the formation of local explosive concentrations at the lower explosion limit (LEL) of the methane-air mixture. The measurements were carried out in a middle-scale model of a building with a volume of approximately 2.7 m3. A new type of sensing system has been developed for the detection of individual concentrations, allowing the required concentrations to be recorded continuously and with greater accuracy.
The velocity of propagation of leaked gas, local explosive concentrations of a gas-air mixture, and also duration of formations of these local concentrations, could be determined using successful verification of a CFD simulation with experiments. A comparison of experimental data with simulation data demonstrated that CFD technology can be an effective aid to describe the process of flammable gas dispersion and can also predict the tendency of gas dispersion and gas distribution. The key to a successful application of CFD in dispersion simulation lies in the accuracy with which the effect of turbulence is generated, due to the complex geometry of the monitored space. Within the simulations of turbulent flow, the accordance of experimentally determined values with the values calculated in dependence on the mesh density and used turbulence model was observed. RANS equations with six turbulent models were used (Laminar; k-ε Standard; k-ε RNG; k-ε Realizable; k-ω Standard and k-ω SST). The best match of the numerical simulation results with the performed experiments was achieved using the mathematical model of turbulence k-ε RNG.
{"title":"CFD-based simulation of flammable gas dispersion in a complex geometry","authors":"Miroslav Mynarz , Aleš Tulach , Marian Bojko","doi":"10.1016/j.jlp.2025.105551","DOIUrl":"10.1016/j.jlp.2025.105551","url":null,"abstract":"<div><div>Quantification of time and spatial concentration profiles of a gas-air cloud caused by accidental leakage of flammable gas from damaged equipment can be of great importance for the correct prediction of the occurrence of dangerous situations. Knowing the extent of leakage and time dependence of generation of hazardous concentrations may be a good tool in the design of mitigation equipment (e.g., gas detection alarms) or in determining further measures (e.g., the extent and method of ventilation of the premises).</div><div>The paper describes the dispersion of leaked methane (natural gas) from a damaged low-pressure gas pipeline, in a confined space with a geometrically complex environment and the formation of local explosive concentrations at the lower explosion limit (LEL) of the methane-air mixture. The measurements were carried out in a middle-scale model of a building with a volume of approximately 2.7 m<sup>3</sup>. A new type of sensing system has been developed for the detection of individual concentrations, allowing the required concentrations to be recorded continuously and with greater accuracy.</div><div>The velocity of propagation of leaked gas, local explosive concentrations of a gas-air mixture, and also duration of formations of these local concentrations, could be determined using successful verification of a CFD simulation with experiments. A comparison of experimental data with simulation data demonstrated that CFD technology can be an effective aid to describe the process of flammable gas dispersion and can also predict the tendency of gas dispersion and gas distribution. The key to a successful application of CFD in dispersion simulation lies in the accuracy with which the effect of turbulence is generated, due to the complex geometry of the monitored space. Within the simulations of turbulent flow, the accordance of experimentally determined values with the values calculated in dependence on the mesh density and used turbulence model was observed. RANS equations with six turbulent models were used (Laminar; k-ε Standard; k-ε RNG; k-ε Realizable; k-ω Standard and k-ω SST). The best match of the numerical simulation results with the performed experiments was achieved using the mathematical model of turbulence k-ε RNG.</div></div>","PeriodicalId":16291,"journal":{"name":"Journal of Loss Prevention in The Process Industries","volume":"94 ","pages":"Article 105551"},"PeriodicalIF":3.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-09DOI: 10.1016/j.jlp.2025.105550
Ramon Swell Gomes Rodrigues Casado , Marcelo Hazin Alencar , Adiel Teixeira de Almeida
Considering the dense network of natural gas pipelines, gas transportation companies face the dilemma of maintaining a profitable operation while ensuring efficient risk management. The inherent uncertainties in risk assessment and the need for well-founded strategic decisions further exacerbate this challenge. To address these issues, the paper proposes a risk-based portfolio selection approach, incorporating global sensitivity analysis, which helps prioritize high-risk areas for pipeline maintenance and integrity. As a result, this approach optimizes resource allocation and ensures better allocation to the most critical areas. The main innovation of the study lies in developing a robust methodology that guides actions in the natural gas transportation system, handling uncertainties, and considering both safety concerns and organizational constraints. The developed model is divided into three parts. The first part uses a multidimensional risk assessment methodology to evaluate the consequences across three dimensions: environmental, financial, and human. These dimensions are associated with potential accidents caused by pipeline leaks and their impacts. The second part employs a hybrid search algorithm to select the most critical sections of the pipeline portfolio. The last part uses Monte Carlo simulation to comprehensively analyze the uncertainties involved in risk assessment. A case study is presented to validate the proposed methodology. Based on the results, the approach offers more reliable decision-making when selecting the most critical zones, and decision sensitivity levels are statistically estimated for each pipeline section. This information guides managers in efficiently allocating resources to mitigate losses and maintain operational integrity. Thus, the proposed structured procedure decisively supports risk management in natural gas transportation and guides strategic decisions.
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