Pressure-Dependent Models in Ship Piping Systems

This paper aims to evaluate the feasibility of pressure-dependent models in the design of ship piping systems.For this purpose,a complex ship piping system is designed to operate in firefighting and bilge services through jet pumps.The system is solved as pressure-dependent model by the piping system analysis software EPANET and by a mathematical approach involving a piping network model.This results in a functional system that guarantees the recommendable ranges of hydraulic state variables(flow and pressure)and compliance with the rules of ship classification societies.Through this research,the suitability and viability of pressure-dependent models in the simulation of a ship piping system are proven.

The Association between Fear of COVID-19,Obsession with COVID-19,and Post Traumatic Stress Disorder in Korean Emergency Rescue Firefighters:A Cross-Sectional Study

During the rapid spread of COVID-19,first responders are at risk of being exposed to COVID-19 due to their role in providing first aid and responding to an unspecified number of people.This uncertainty can have adverse mental health effects,such as increased anxiety and fear.This study aimed to investigate the degree of association between fear of COVID-19,obsession with COVID-19,and post-traumatic stress disorder(PTSD)in emergency rescue firefighters.The participants were 150 emergency rescue firefighters working in Region S,Korea.They filled out self-report questionnaires:The data obtained through the Fear of COVID-19 Scale,Obsession with COVID-19 Scale,and Impact of Event Scale-Revised Korean version were subjected to nonparametric statistical analysis using SPSS WIN 25.0.The study found a significant correlation between emergency rescue firefighters’fear of COVID-19,obsession with COVID-19,and PTSD.Fear and obsession with COVID-19 were higher among first responder firefighters who were directly involved in COVID-19-related tasks.Furthermore,a one-point increase in obsession was associated with a 2.837-point increase in PTSD.Based on the results,we found that there is a need for effective control of obsessions and fears among first responder firefighters during COVID-19,and we suggest that there is a need for mental health care for first responder firefighters during the pandemic through the development and support of programs to prevent and mitigate obsessions.

Optimal Spatial Allocation of Initial Attack Resources for Firefighting in the Republic of Korea Using a Scenario Optimization Model

【Title】 This study explores the optimal spatial allocation of initial attack resources for firefighting in the Republic of Korea. To improve the effectiveness of Korean initial attack resources with a range of policy goals, we create a scenario optimization model that minimizes the expected number of fires not receiving a predefined response. In this study, the predefined response indicates the number of firefighting resources that must arrive at a fire before the fire escapes and becomes a large fire. We use spatially explicit GIS-based information on the ecology, fire behavior, and economic characterizations important in Korea. The data include historical fire events in the Republic of Korea from 1991 to 2007, suppression costs, and spatial information on forest fire extent. Interviews with forest managers inform the range of we address in the decision model. Based on the geographic data, we conduct a sensitivity analysis by varying the parameters systematically. Information on the relative importance of the components of the settings helps us to identify “rules of thumb” for initial attack resource allocations in particular ecological and policy settings.

Introduction of firefighting methods in U.S. underground mines

Underground mine fire always exists since the mining activity was practiced.It poses a severe safety hazard to the mine workers and may also cause a tremendous economic loss to the mines.Methods for controlling and extinguishing fires in underground mine have long been studied and there have been significant improvements.In order to know clearly about the firefighting technology used,this paper summarizes most of the underground mine firefighting methods used in the United States the past 150 years.This paper describes not only the accepted firefighting theories,but also the technologies,both direct and indirect attacking,in accordance to regulations or codes,with special attention is given to the indirect attack method and its related technologies.Further research needed is also briefly discussed at the end of this paper.

Research on the effect of the component proportion in the new water mist additive on firefighting performance

Water mist technology provides efficient firefighting performance while there is still room for improvement. So varieties of additives have been studied in recent years both at home and abroad. The self-made additives are used to compare the firefighting performance of diesel and heptane fire in open space. By adjusting the concentration of substance in the additives and conducting the experiment under the pressure of 0.3 MPa,0.5 MPa and 0.7 MPa,extinguish time and temperature are measured in the experiment. Through the experiments using different fuels,it can be found when the fuel is heptane that has a lower ignition point and a higher evaporation rate, the water mist additive can still significantly improve the firefighting performance. According to the data based on different concentrations of fluorinated surfactants,we find that fluorinated surfactants are the main substance to improve the performances by changing physical property of water mist. Optimal proportion of the additives for firefighting performance is found by experiment results.

Virtual fire drill system supporting co-located collaboration

Background Due to the restriction of display mode,in most of the virtual reality systems with multiple people in the same physical space,the program renders the scene based on the position and perspective of the one user,so that other users just see the same scene,resulting in vision disorder.Methods To improve experience of multi-user co-located collaboration,in this study,we propose a fire drill system supporting co-located collaboration,in which three co-located users can collaborate to complete the virtual firefighting mission.Firstly,with multi-view stereoscopic projective display technology and ultra wideband(UWB)technology,co-located users can roam independently and watch virtual scenes through the correct perspective view based on their own position by wearing dedicated shutter glasses,thus carrying out different virtual tasks,which improves the flexibility of co-located collaboration.Secondly,we design simulated firefighting water-gun using the micro-electromechanical system sensor,through which users can interact with virtual environment,and thus provide a better interactive experience.Finally,we develop a workbench including a holographic display module and multi touch operation module for virtual scene assembly and virtual environment control.Results The controller can use the workbench to adjust the virtual layout in real time,and control the virtual task process to increase the flexibility and playability of system.Conclusions Our work can be employed in a wide range of related virtual reality applications.

A Method for the Application of Numerical Simulations during Firefighting Operations Using Pre-Simulated, Model-Based Fire Scenarios

The spread of fire and smoke during a fire incident plays a crucial role in rescuing people from the burning building. So it is important for the decision makers (the head of rescue staff) to get a prediction about the spread of fire inside the building through computational techniques like numerical fire simulations. But these techniques require advanced mathematical knowledge and are very time consuming. This paper presents a new method which employs a set of pre-simulated and model-based scenarios to find the closest one to the real fire and present its results to the decision makers. For this purpose, we shift the performance consuming numerical fire simulations into a former phase by integration of these simulations into the planning process of the building. This is realized by enhancing the methods of Building Information Modeling (BIM). To provide the fire simulation results during a real case, our new concept includes a scenario database where all simulated fire scenarios will be collected. In a real case, a special search algorithm will go through this database to find the closest pre-simulated fire scenario to the real fire on the basis of reported information from the burning building.

Psychotraumatic Interventions and Post-Traumatic Stress Disorder among the Lomé Firefighters

Aim: This study aimed to assess the quality of the psychological experience of mobile emergency teams, in particular firefighters (FF) in Togo and to identify the psychotraumatic interventions (PI) they face. Method: This was a cross-sectional, descriptive, statistical analysis and discourse content analysis study on the PIs of the Lomé FFs. Results: PIs were found to be: road accidents;defenestrations;self-immolation murders;bloody and non-bloody suicides;well interventions with or without drowning;extensive burns;and paediatric procedures. Adults aged 25 to 45 were at a percentage of 69.1% and with a sex ratio of 7.1. More than half of the respondents (53%) had PTSD. Conclusion: More than half of the respondents had PTSD, however, coping strategies were not explored, suggesting the need for further research.

Aerial refueling scheduling of multi-receiver and multi-tanker under spatial-temporal constraints for forest firefighting

Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest firefighting.Given the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and range.In order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver path.Then,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for tankers.Both methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling framework.The optimization problem is established as nonlinear optimization models along with restrictions.The integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified process.It has a complete solution space and excels in optimizing total fuel consumption.The decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational complexity.However,this comes at the cost of sacrificing optimality by excluding specific feasible solutions.Finally,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed methods.These simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world scenarios.This comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.

Analysis of per-and polyfluoroalkyl substances(PFAS)extraction from contaminated firefighting materials:Effects of cleaning agent,temperature,and chain-length dependencies

This investigation delves into the extraction dynamics of 22 per-and polyfluoroalkyl substances from PFAS contaminated firefighting materials.Two distinct test sets were executed:one contrasting a commercial product with water following an elaborate decontamination procedure,and the other assessing seven washing agents on materials from firefighting installations,with one agent examined at 22℃and 50℃.A general tendency for improved desorption at the higher temperature was observed.Furthermore,a discernible influence of the cleaning agent's pH on the extraction of specific PFAS species was observed,elucidating the role of chemical environment in the extraction process.PFAS rebound was studied for a period of up to 157 days,this unveiled a gradual escalation in PFAS22 levels,indicative of a protracted desorption mechanism.Intriguingly,PFAS with abbreviated carbon chains(C4-C6)exhibit superior desorption efficiency compared to their elongated congeners,suggesting a chain-lengthdependent decontamination potential.A comparative scrutiny between a commercially available cleaning product,featuring multiple washing and flushing steps,and a water-only treatment regimen underscores the potential efficacy of the former.This exhaustive investigation furnishes nuanced insights into PFAS extraction complexities,offering a foundation for informed decontamination strategies.

Causes and detection of coalfield fires, control techniques, and heat energy recovery: A review

Coalfield fires are considered a global crisis that contributes significantly to environmental destruction and loss of coal resources and poses a serious threat to human safety and health. In this paper, research related to the initiation, development, and evolution of coalfield fires is reviewed. The existing detection and control techniques of coalfield fires are also reviewed. Traditional firefighting is associated with waste of resources, potential risks of recrudescence, potential safety hazards, extensive and expensive engineering works, and power shortages. Recently,coalfield fires have been recognized as having significant potential for energy conservation and heat energy recovery. Thermoelectric power generation is regarded as a suitable technology for the utilization of heat from coalfield fires. The extraction of heat from coalfield fires can also control coalfield fires and prevent reignition leading to combustion. Technologies for absorbing heat from burning coal and overlying rocks are also analyzed. In addition, the control mode of "three-region linkage" is proposed to improve firefighting efficiency. Integrating heat energy recovery with firefighting is an innovative method to control coalfield fires.

Virtual reality for immersive multi-user firefighter-training scenarios

Background Virtual reality(VR)applications can be used to provide comprehensive training scenarios that are difficult or impossible to represent in physical configurations.This includes team training for emergency services such as firefighting.Creating a high level of immersion is essential for achieving effective virtual training.In this respect,motion-capture systems offer the possibility of creating highly immersive multi-user training experiences,including full-body avatars.Methods This study presents a preliminary prototype that helps extin-guish a virtual fire on a container ship as a VR training scenario.The prototype provides a full-body and multi-user VR experience based on the synthesis of position data provided by the motion-capture system and orientation data from the VR headsets.Moreover,the prototype facilitates an initial evaluation of the results.Results The results confirm the value of using VR for training procedures that are difficult to implement in the real world.Furthermore,the results show that motion-capture-based VR technologies are particularly useful for firefighting training,in which participants can collaborate in difficult-to-access environments.However,this study also indicates that increasing the immersion in such training remains a challenge.Conclusions This study presents a prototypical VR application that enables the multi-user training of maritime firefighters.Future research should evaluate the initial results,provide more extensive training scenarios,and measure the training progress.

Hyperbranched Polymeric Fluorosurfactants:Synthesis,Surface Activity and Their Application in Firefighting Foams

Fluorosurfactants are the key ingredients in the formulations of aqueous film-forming foams(AFFFs)for extinguishing flammable liquids,thus developing high-efficient and low-toxic fluorosurfactants is desirable in AFFFs application.Herein,a series of hyperbranched polymeric fluorosu rfactants(HPFs)were successfully synthesized through sequentially modifying hyperbranched polyethylenimine(PEI)with the hydrophilic poly(ethylene glycol)(PEG)chains and the hydrophobic C6/C4-based perfluoroalkyl chains,which were verified by FTIR,^(1)H-and^(19)F-NMR.The surface tensions of all the HPFs in water were measured,and the corresponding physicochemical parameters were interpreted.It was found that the surface activities of HPFs could be tuned through adjusting the ratio of PEG to perfluoroalkyl chains,the length of perfluoroalkyl chains,the molecular weight of PEI core,but not the PEG chain length.In the binary mixture of HPFs with the commercial small molecule fluorosurfactant Capstone^(TM)1157(C1157),a strong synergism led to the elevation of surface activity,which was attributed to the efficient encapsulation of C1157 guests by the compact hyperbranched HPFs as the hosts.The utilization of HPF/C1157 as fluorosurfactant ingredients in AFFF formulations could realize much higher fire-extinguishing efficiency towards flammable oils than the control AFFFs prepa red from the polymeric Capstone^(TM)1460 or the neat C1157.

IoT System for Intelligent Firefighting in the Electric Power Industry

Traditional fire safety management in the electric power industry has significant drawbacks,including a lack of data,difficulty of maintenance,lack of supervision,and lack of interaction.This type of management lags behind current advanced safety management concepts such as“gate advancement”and“full process man-agement”,and it fails to meet the needs of future energy internet construction and development.In response to these problems,an internet of things system for smart firefighting in the electric power industry was constructed in this study.This system defines a centralized information window,trains a power intelligent firefighting brain,establishes a firefighting cloud management and control system,constructs a power firefighting interaction mech-anism,and performs multi-party coordination of firefighting mechanisms to realize concept of“a whole network on one screen and everything in one network”for managing fires.

Modeling Thermal Protective Performance of Multilayer Fabrics for Firefighters

This paper is to report a prediction model for thermal protective performance of multilayer fabrics based on Matlab neural network toolbox. Then a back propagation (BP) neural network model is developed to predict thermal protective performance of multilayer fabrics for firefighters. The network consists of twelve input nodes, six hidden nodes, and one output node. The inputs are weight, thickness, density of warp and weft, limited oxygen index (LOI), and heat conductivity of each-layer fabric. Thermal protective performance (TPP) rating of multilayer fabrics is the output. In this paper, the data from the experiments are used as learning information for the neural network to develop a reliable prediction model. Finnally the model performance is verified, and the proposed model can be applied to predict the thermal protective performance of multilayer fabrics for firefighters.

Computer-Based Estimation of Spine Loading during Self-Contained Breathing Apparatus Carriage

Firefighters’low back disorders(LBDs)are closely related to excessive spine loading when using the self-contained breathing apparatus(SCBA)continuously.The purpose of this study was to quantify firefighters’spine loading and evaluate the effects of strap lengths of SCBA on altering spine loading.Computer-based musculoskeletal models of three varying-strapped SCBA conditions and a control condition(CC)with no SCBA equipped were developed.The model was driven using three-dimensional(3 D)inertial motion capture data from twelve male subjects performing a walking task and the predicted ground reaction force(GRF).Electromyography(EMG)activities were also recorded to validate the results from the model.The 4 th-5 th lumbar vertebra(L4/L5)joint reaction forces,as well as erector spinae and rectus abdominis forces,were finally obtained.Results demonstrated that carrying SCBA significantly increased the compressive force and anteroposterior shear force at the spine.The risk of potential LBDs increased by about 17.77%.Dynamic balance of erector spinae and rectus abdominis contraction was also disturbed when carrying SCBA,indicating a higher risk of spine muscle strain.Adjustment of SCBA strap length was an efficient method to influence spine loading.The medium-fitting strap(MS)with a length of around 101 cm generated minimum joint reaction forces and achieved the optimum dynamic balance of spine muscle contraction,which was recommended for firefighters.

Comparison of Urinary PAHs among Firefighters and Asphalt Pavers

Objective: The purpose of the investigation is to examine urinary biomarkers of polycyclic aromatic hydrocarbon (PAH) exposure among firefighters and asphalt workers. Methods: Average concentrations of urinary PAHs were used for comparative analysis between groups of firefighters and asphalt pavers. Microsoft Excel was used to perform calculations and the t-test was utilized for statistical analysis. Results: When compared to the National Institute of Standards and Technology (NIST) standard for smokers and non-smokers, firefighters demonstrated various statistically significant differences in urinary PAH concentrations. Asphalt workers had statistically significant higher urinary concentrations in three PAHs as compared to the NIST smoker mean. Conclusions: Firefighters did not demonstrate a substantial change in urinary PAH metabolite levels when compared to controls. Asphalt pavers experienced concentrations that were in some cases increased by orders of magnitude compared to controls.

Posttraumatic Stress Disorder Mediated by Exposure Level in French Civil Firefighters Following a Terrorist Attack: Some Hypotheses towards a Structural Model

To date, few studies have investigated the impact of organizational factors such as organizational status or the rank of firefighters on the development of posttraumatic stress disorder (PTSD) following a terrorist attack. To fill this gap in the scientific literature, this field study aimed to investigate the consequences of terrorist attacks on firefighters’ psychological health in terms of PTSD. Data were collected in France following two terrorist attacks. PTSD was assessed with the PCL-S (DSM-IV) 3 to 6 months after the events. Confirmatory factor analyses (CFAs) with existing PTSD models were inconclusive, leading us to find a two-factor model via an exploratory factor analysis (EFA). A cluster analysis showed different symptom profiles that were influenced by the exposure level. Elements for a structural model explaining PTSD symptoms are proposed and suggest a central role of the exposure level. Firefighters I/II represented an at-risk sub-population, suggesting that PTSD was mainly experienced among those who performed tasks not common to their occupation.

Spatial Resilience to Wildfires through the Optimal Deployment of Firefighting Resources:Impact of Topography on Initial Attack Effectiveness

Strongly affected by the escalating impacts of climate change,wildfires have been increasing in frequency and severity around the world.The primary aim of this study was the development of specific territorial measures—estimating the optimal locations of firefighting resources—to enhance the spatial resilience to wildfires in the fire-prone region of Chalkidiki Prefecture in northern Greece.These measures focus on the resistance to wildfires and the adaptation of strategies to wildfire management,based on the estimation of burn probability,including the effect of anthropogenic factors on fire ignition.The proposed location schemes of firefighting resources such as vehicles consider both the susceptibility to fire and the influence of the topography on travel simulation,highlighting the impact of road slope on the initial firefighting attack.The spatial scheme,as well as the number of required firefighting forces is totally differentiated due to slope impact.When we ignore the topography effect,a minimum number of fire vehicles is required to achieve the maximization of coverage(99.2%of the entire study area)giving priority to the most susceptible regions(that is,employing 18 of 24 available fire vehicles).But when we adopt more realistic conditions that integrate the slope effect with travel time,the model finds an optimal solution that requires more resources(that is,employing all 24 available fire vehicles)to maximize the coverage of the most vulnerable regions within 27 min.This process achieves 80%of total coverage.The proposed methodology is characterized by a high degree of flexibility,and provides optimized solutions to decision makers,while considering key factors that greatly affect the effectiveness of the initial firefighting attack.

Between the Craft and the Mud:An Analysis of the Work and Health Relationship of Firefighters in the Breach of the Córrego do Feijão Dam-Brumadinho/MG

Faced with the rupture of the Vale S.A.tailings dam that hit the city of Brumadinho(MG),the article sought to better understand the organisation of work of military firefighters who participated in the search and rescue operation and the relationship between work and health present in this scenario.This is qualitative research with a focus on the subjective production of the speeches of seven firefighters who were interviewed individually with a semi-structured script,using as a basis of analysis the ergological perspective and the productions of the psychodynamics of work.The firefighters experienced a scenario with risks of injury,contamination,and even death.In the interviews,they showed that the more than twelve hours of work were responsible for sleep problems during and after the performance,as well as the food provided and the lack of time for physical exercise proved to be aggravating factors for their health.Working in the tailing’s mud combined the development of musculoskeletal problems and anxiety,due to the possibility of contamination by metals present in the mud.The work relationships show a high degree of trust and recognition between the firefighters and the affected population,which helped in the motivation and continuation of the operation until the present moment.The work in this operation that gained national prominence was responsible for the feeling of pride and for feeling more capable and prepared to act in other disasters.This research is expected to broaden the discussion about the work-health relationship of military firefighters exposed to disasters,as well as serve as a subsidy to encourage the creation of public policies focused on the health of these workers.