Evacuation Capability Research Articles

Grindability Evaluation of Ultrasonic Assisted Grinding of Silicon Nitride Ceramic Using Minimum Quantity Lubrication Based SiO2 Nanofluid

Minimum quantity Lubrication (MQL) is a sustainable lubrication system that is famous in many machining systems. It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes. The MQL system is affirmed to exhibit an excellent machining performance, and it is highly economical. The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability, compared to pure oil-based MQL system. Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids. This work presents an experimental study on the tribological performance of SiO2 nanofluid during grinding of Si3N4 ceramic. The effect different grinding modes and lubrication systems during the grinding operation was also analyzed. Different concentrations of the SiO2 nanofluid was manufactured using canola, corn and sunflower oils. The quantitative evaluation of the grinding process was done based on the amount of grinding forces, specific grinding energy, frictional coefficient, and surface integrity. It was found that the canola oil exhibits optimal lubrication performance compared to corn oil, sunflower oil, and traditional lubrication systems. Additionally, the introduction of ultrasonic vibrations with the SiO2 nanofluid in MQL system was found to reduce the specific grinding energy, normal grinding forces, tangential grinding forces, and surface roughness by 65%, 57%, 65%, and 18% respectively. Finally, regression analysis was used to obtain an optimum parameter combinations. The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.

Fire safety assessment for alternative cruise ship design based on BWM and DEMATEL by linguistic Z‐number

AbstractThis paper proposes a risk assessment method based on the best‐worst method (BWM) and decision‐making trial and evaluation laboratory (DEMATEL) to evaluate the fire safety level of alternative design schemes for cruise ships relative to the standard‐based options. Firstly, the analytic hierarchy model of fire safety assessment is constructed by analyzing the passive fire protection system, active fire protection system, and evacuation and escape capability of cruise ship large cabins. Then, the linguistic scale functions and Z‐numbers are used to deal with the fuzzy evaluation of fire safety factors by experts, and the maximizing consensus technique is adopted to determine the weight of each expert to enhance group consistency. Considering the influence degree of each factor on fire safety and the correlation between factors, the BWM is combined with DEMATEL to establish the risk source weight calculation model. The fire safety level of alternative cruise ship designs is further determined by the fuzzy comprehensive evaluation approach. Finally, to validate the effectiveness of the proposed method, a fire safety assessment is conducted on the alternative design scheme of a luxury cruise passenger restaurant. The results confirm that the proposed method can effectively evaluate the fire safety of alternative design compared to the standard‐based scheme.

Research on emergency evacuation behavior rules of pedestrians under fire and explosion accidents in chemical parks considering social relationships

Chemical parks present a high risk of sudden accidents such as fires and explosions, given the significant number of hazardous sources present. This is why emergency evacuation after accidents is so essential. The behavior of crowds during evacuation is complex, and social relationships among pedestrians can have differentiated effects on the evacuation process. However, most of the current crowd evacuation research has focused on life scenarios and natural disaster contexts. Less attention has been paid to the emergency evacuation of crowds affected by social relations in the context of chemical accident disasters. A comprehensive evacuation model that considers the dynamic evolution of crowd transfer both within and outside the factory area is proposed in this paper. Using the Anylogic software based on the social force model, this study constructs emergency evacuation scenarios for crowd in the context of fire and explosion accidents, and toxic gas leakage incidents. Specifically, this study analyzes the impact of three factors, namely inter-personal distance, group size, and proportion of different group sizes in the total population, on the evacuation efficiency. It has been found that when large groups of pedestrians are split into smaller ones for evacuation, the evacuation efficiency can be effectively improved. The study includes calculations of the lethal range of a toxic gas and simulated the process of relocating large crowds of people to nearby shelters. In addition, a strategy for deploying pedestrian groups based on social relationships was developed for the context of mass evacuation. These measures have the potential to optimize the evacuation efficiency of pedestrian groups in chemical parks, including expanding and modifying shelters, diverting dense crowds from residential plots, using interpersonal spacing of 0.1 m, and splitting large groups of pedestrians into smaller ones. The research results can provide a reference for decision making for large-scale group evacuation in chemical parks, and improve the emergency evacuation capability and local risk response capability in chemical parks.

Helical Electrodes for Electro-Discharge Drilling: Experimental and CFD-Based Analysis of the Influence of Internal and External Flushing Geometries on the Process Characteristics

The electro-discharge (ED) drilling of precision boreholes in difficult-to-machine materials, particularly with respect to the cost-effectiveness of the overall process, is still a challenge. Flushing is one key factor for the precise machining of boreholes, especially with high aspect ratios. Therefore, the influence of internal and external flushing geometries for six types of brass tool electrodes with a diameter of 3 mm with and without a helical groove was analyzed experimentally and numerically. Using this helical external flushing channel, drilling experiments in X170CrVMo18-3-1 (Elmax Superclean) with an aspect ratio of five revealed a material removal rate (MRR) that was increased by 112% compared with a rod electrode, increased by 28% for a single-channel tool electrode and decreased by 8% for a multi-channel tool electrode. Signal analyses complemented these findings and highlighted correlations between classified discharge event types and the experimental target parameters. Amongst others, it was verified that the arcing frequency ratio drove the electrode wear rate and the beneficial frequency ratio correlated with the MRR and the surface roughness Ra. Sophisticated 3D computational fluid dynamics (CFD) models of the liquid phase were introduced and evaluated in great detail to demonstrate the validity and further elucidate the effect of the external flushing channel on the evacuation capability of debris and gas bubbles. The presented methods and models were found to be suitable for obtaining in-depth knowledge about the flushing conditions in the ED drilling working gap.

Vulnerability assessments of urban rail transit networks based on extended coupled map lattices with evacuation capability

This paper proposes the evacuation capability of station to design the extended coupled map lattices and analyzes the passenger dynamics and station states of urban rail transit networks subjected to the external disturbances. Meanwhile, the commuting ability of station is designed to study the topological vulnerability and the residual flow ratio of passenger flow is involved to study the functional vulnerability of urban rail transit networks. Moreover, three malicious attacks are used to imitate the external disturbances, and Shanghai metro network is taken as the example to illustrate the feasibility and effectiveness of the proposed model. The results show that urban rail transit networks have certain robustness subjected to the external disturbances and the global cascading failures will take place when the external disturbance R≥2.6, which indicates that R=2.6 is the critical threshold of external disturbances to smash urban rail transit networks subjected to three malicious attacks. By comparisons, we can declare that the nodes with the highest betweenness and the largest degree must be provided more protections in daily operation of urban rail transit networks, and the topological structure has a greater impact on network vulnerability compared with transportation function.

Ethical Issues Regarding Neurosurgical Management ofPenetrating Brain Injury inthe French Armed Forces.

Combat penetrating brain injury (PBI) differs significantly from PBI in civilian environments. Differences include technical factors such as the weapons involved, strained resource environments, and limited medical materials and human resources available. Ethical issues regarding the management of PBI in military settings may occur. This case study examines the case of a 20-year-old member of the French Armed Forces that suffered a penetrating brain injury in a combat situation. The four-quadrant method along with the four principles of medical ethics (respect for autonomy, beneficence, nonmaleficence, and justice) was used to analyze this case and to apply ethics to the practice of military medicine. Nowadays, we possess the medical and surgical resources as well as the aeromedical evacuation capability to save the life of a soldier with a penetrating craniocerebral wound. Nonetheless, the functional outcome of this type of wound places military doctors in an ethical dilemma. The line of conduct and clinical protocol established by the French Medical Health Service is to manage all PBIs when the patient's life can be saved and to provide all available financial and social support for the rehabilitation of patients and their family.

Dynamically Adaptive Bubbling for Upgrading Oxygen Evolution Reaction Using Lamellar Fern-Like Alloy Aerogel Self-Standing Electrodes.

Adopting renewable electricity to produce "green" hydrogen has been a critical challenge because at a high current density the mass transfer capability of most catalytic electrodes deteriorates significantly. Herein, a unique lamellar fern-like alloy aerogel (LFA) electrode, showing a unique dynamically adaptive bubbling capability and can effectively avoid stress concentration caused by bubble aggregation is reported. The LFA electrode is intrinsically highly catalytic-active and shows a highly porous, resilient, hierarchically ordered, and well-percolated conductive network. It not only shows superior gas evacuation capability but also exhibits significantly improved stability at high current densities, showing the record lowest oxygen evolution reaction (OER) overpotential of 244mV at 1000mA cm-2 and stably over 6000 h. With the merits of mechanical robustness, excellent electron transport, and efficient bubble evacuation, LFA can be self-standing catalytic electrode andgas diffusion layers in anion-exchange-membrane water electrolysis (AEMWE), which can achieve 3000 mA cm-2 at a low voltage of 1.88V and can sustain stable electrolysis at 2000 mA cm-2 for over 1300 h. This strategy can be extended to various gas evolution reactions as a general design rule for multiphase catalysis applications.

A ship evacuation model considering the interaction between pedestrians based on cellular automata

This paper proposes the CAIE (cellular automata with interaction effect) model to evaluate ship passenger evacuation capability. The CAIE model simulates the interaction between passengers by establishing the friction and repulsive force model between passengers, derives the formula of the desired velocity's effect on the movement ability, reflects the influence of a high-density environment on the movement velocity of personnel, and defines push-crossing behavior rules to simulate opposite-flow movement. The proposed CAIE model is verified by passenger evacuation simulation experiments in single-exit cabins under the condition of opposite passenger traffic. The results demonstrate that the CAIE model has similar passenger movement rules as the social force model in terms of the arching and faster-is-slower phenomena. The results also show that the CAIE model meets the test requirements for the MSC.1/Circ.1533 communication of the advanced evacuation simulation model. Finally, the evacuation simulation analysis is performed on a small polar cruise ship using the CAIE model, Pathfinder software, and Maritime Exodus software. The comparison results indicate that the simulation results of the three models and their distributions of evacuation time are consistent. Therefore, the proposed CAIE model can be used to evaluate the evacuation ability of ships.

Developing a Robotic and Autonomic Medical Evacuation (RAS MEDEVAC) capability for remote and rural populations.

The inherent clinical risks associated with remote and rural environments are potentially mitigated by timely air ambulance transfer, yet this involves other costs, operational constraints and limitations. The development of a RAS MEDEVAC capability may present the opportunity to enhance clinical transfers and outcomes across remote and rural areas as well as more conventional civilian and military environments.Methods The authors propose a multi-phase approach to assist RAS MEDEVAC capability development.Results RAS MEDEVAC capability development could be enhanced by a step-wise approach that: (a) incorporates a clear understanding of related clinical (including aviation medicine), vehicle and interface principles; (b) understands opportunities and limitations of related technology advancements; and (c) develops a new glossary and taxonomy to describe echelons of care and phases of medical transfer.Discussion RAS MEDEVAC presents the opportunity to exploit a number of potential capability characteristics - speed, flexibility, safety (including sparing/avoidance of human escorts), persistence, availability, reliability, expendability and acceptability. The application of a staged, multi-phase approach could allow for a structured review of relevant clinical, technical, interface and human factors that would be matched to product availability to inform future capability development. Particular consideration will need to be played to balancing new concepts of risk as well as considering ethical and legal factors.

서울시 다중이용업소 관계인 및 이용자의 안전의식 제고 방안

Publicly Used Establishments(PUE) are crowded by an unspecified number of people. The event of an accident such as a fire can cause great damage to life and property in PUE. The most important point is to strengthen the safety consciousness and increase evacuation capability of managers and visitors in PUE. This is because the primary responsibility for the initial response to a fire lies with the person concerned. Previous studies focused on managers of PUE, and few studies have diagnosed the actual situation for visitors. Therefore, we selected 200 managers and 300 visitors as the subjects of our study. we surveyed their recognitions and experiences. The research contents in this study are as follows. First, by reviewing the literatures related to safety culture, we divided them into three elements(experience and awareness, knowledge and competence, physical and institutional environment), and designed measurement tools. Second, we surveyed safey consciousness and diagnosed evacuation capability. Third, we derived the main implications from the survey and the diagnosis, and compared the difference in perception between managers and visitors. Finally, we proposed policies on improving safety consciousness for managers and visitiors of PUE in terms of evacuation capability.

Study on Evacuation Behavior of Urban Underground Complex in Fire Emergency Based on System Dynamics

During a fire evacuation, long lateral evacuation distances, large crowds waiting for evacuation at the same level, and easily panicked populations are common. This research aimed to look into the large-scale evacuation behavior of urban underground complexes with limited evacuation and egress during a fire. A simplified model for large-scale group evacuation of urban subsurface complexes was constructed using system dynamics theory. The Vensim software was used for quantitative simulation. The model could represent the typical phenomenon of group evacuation behaviors, such as quick or slow, under seven operating situations with total initial numbers of 350, 400, 450, 500, 1000, 2000, and 4000. The results of an analysis of critical affecting factors show “total initial number” and “panic state” during a large-scale group evacuation: a large beginning population will result in a rapid reduction in system evacuation capability, delaying the completion of the evacuation process significantly; meanwhile, if the level of panic is deficient, the system’s evacuation efficiency will remain low for an extended period, making it difficult to evacuate trapped persons promptly. According to the findings, the developed system dynamics model, which combines the advantages of a continuous model with the advantages of a discrete model, is very accurate. At the same time, we should emphasize the importance of the evacuation guide and reinforce the fire education and behavior drills for the building’s workers. This research presents a simplified model for the evacuation of large groups of people from metropolitan underground complexes. Furthermore, the findings may give theoretical support for the development of rules and safety management practices.

Novel micro-deep-hole drill with variable web thickness and flute width

This study proposes a novel micro-deep-hole drill with variable web thickness and flute width to effectively improve the problem of tool breakage and chip clogging during micro-deep-hole drilling. Firstly, the failure form and failure mechanism of micro-drill are explored by performing drilling experiments, and it is found that the torsion fracture and bending fracture are the main premature failure modes of micro-deep-hole drilling tools. The static simulation analysis of micro-drill is further conducted to investigate the influence of geometric parameters on the stiffness and strength of high-aspect-ratio micro-drill, and the results indicate that the web thickness ratio and flute width have significant effects on drill tip stiffness and spiral groove root strength. To balance the rigidity, strength and chip evacuation capability of micro-deep-hole drilling tools, the new micro-drill with variable web thickness and flute width is developed, supplemented by comparative experiments. The results confirm that the new micro-drill has better chip removal ability, greatly reduces the drilling force, torque, drill tip wear and material peeling phenomenon, and significantly enhances the machining quality of hole wall.

Progressive disaster evacuation in cloud datacenter network

SummaryIn cloud datacenter network, deadline‐aware disaster evacuation transfers the endangered data out of disaster zone using limited residual network resources. Previous work has not jointly considered the selection of safe datacenter and reasonable allocation of bandwidth proportion in time‐varying postdisaster network environment. Therefore, they cannot make full use of network transmission capability. Based on our earlier work, we propose a new time‐varying disaster evacuation strategy with flexible traffic scheduling. We aim to maximize disaster evacuation capability in the disaster spread scenario. We construct a new disaster‐aware time‐expanded network model to divide time slots according to progressive disaster spread, and optimize the utilization of evacuation capability in the current disaster stage. In each time slot, we carry out two‐step optimization including safe datacenter selection and proportional bandwidth allocation. Especially, we select store‐and‐forward node to ensure the safety of evacuated data in the next time slot, and use marked evacuation routing search based on transmission requirement to improve the utilization of evacuation capability. Through extensive simulations we demonstrate that our strategy achieves better performance with higher evacuation transmission efficiency in the disaster spread scenario.

Method of Grading Subway Stations Based on Evacuation Capability: A Quantitative Method

Stations are the main components of the subway systems. Despite the progress in the construction and maintenance, stations have always been exposed to the natural and man-made disasters. In such incidents, the station’s evacuation capability has a direct relation with a passenger's life. Various factors affect the station's evacuation capability. Investigation of these factors and evaluation of the station’s evacuation capability have important roles in protecting a passenger's life. For this purpose, the catastrophic events that lead to the evacuation of a station and the factors affecting the evacuation of the station are identified. Due to the difference in the catastrophic event probabilities at each station, the risk of catastrophic events is evaluated. Then the station score is calculated according to the value and weight of the evacuation factors and the wighted influence of the catastrophic events. Accordingly, the proposed model is implemented in the Tehran subway. Based on the results obtained, uncrowded stations, even though served by a small number of passengers, may also have a low evacuation capacity and lead to casualties in an emergency situation. This is due to the lack of emergency management and safety facilities. Also by assessing the risk of catastrophic events at stations and equipping stations on its basis, the degree of safety and evacuation capability can be improved more effectively. The sensitivity analysis of the evacuation factors show that the most effective way to increase the station’s evacuation capability is to improve its status in management factors. Using the proposed model to evaluate the station's evacuation capability is an appropriate method for identifying the stations that have a poor evacuation capability.

Entropy Weight-Logarithmic Fuzzy Multiobjective Programming Method for Evaluating Emergency Evacuation in Crowded Places: A Case Study of a University Teaching Building

The teaching buildings in colleges and universities are crowded and prone to accidents. The emergency evacuation capability of these buildings is evaluated by applying the methods of fault tree, entropy weight-logarithmic fuzzy multiobjective programming (E-LFMP) and fuzzy comprehensive evaluation. An index system was constructed using the basic event structure importance of the accident tree, and the influencing factors were more systematic. In order to improve the objectivity and rationality of the evaluation process and results, this study combines the entropy weight method and multi-objective fuzzy logarithmic programming (LFMP) method to form the entropy weight-logarithmic fuzzy multiobjective programming. Consequently, the weights of different levels of index factors were analyzed and calculated, and more comprehensive content was considered. The fuzzy comprehensive evaluation model is established to evaluate the emergency evacuation ability of a teaching building. The maximum membership degree is 0.4025, and the corresponding grade is “general”, indicating that its emergency evacuation ability must be improved. Based on the weight ratio and grade results of indicators in the evaluation model of emergency evacuation capability, safety rectification measures and suggestions were put forward from the aspects of improving information systems, widening evacuation channels and strengthening safety channel maintenance.

Examination of Advanced Treatment Technologies for Textile Dye Wastewater

The worldwide population is developing and along these lines, the world may event incredible freshwater shortage. Our water assets are lacking and, thus, water management and reusing techniques are the main choices for receiving freshwater later on decades. Accordingly, there is an incredible requirement for the advancement of proper, reasonable and quick wastewater. The common plan of this investigation is based on assessment and comparison, of the chance of apply advanced treatment techniques (Aeration process and Fenton oxidation process) for the exclusion of residuals organic pollutant present in Dye wastewater. The various procedures, which influence the compound oxidation, for colors in their fluid arrangements are considered by utilizing Aeration and Fenton's responses. These Processes are Aeration and Fenton Oxidation Process- (Hydrogen peroxide dose). Finally, EC, COD, BOD, Turbidity, TDS, TSS, and Phosphate, when the oxidation procedure is determined to guarantee the flawless obliteration of natural colors during their expulsion fromwastewater. The Compared optimum conditions were 6ml/l of Fenton (H2O2) demonstrate that Fenton's oxidation procedure effectively accomplished excellent evacuation capability.

Resuscitation and Evacuation from Low Earth Orbit: A Systematic Review.

Provision of critical care and resuscitation was not practical during early missions into space. Given likely advancements in commercial spaceflight and increased human presence in low Earth orbit (LEO) in the coming decades, development of these capabilities should be considered as the likelihood of emergent medical evacuation increases. PubMed, Web of Science, Google Scholar, National Aeronautics and Space Administration (NASA) Technical Server, and Defense Technical Information Center were searched from inception to December 2018. Articles specifically addressing critical care and resuscitation during emergency medical evacuation from LEO were selected. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines. The search resulted in 109 articles included in the review with a total of 2,177 subjects. There were two Level I systematic reviews, 33 Level II prospective studies with 647 subjects, seven Level III retrospective studies with 1,455 subjects, and two Level IV case series with four subjects. There were two Level V case reports and 63 pertinent review articles. The development of a medical evacuation capability is an important consideration for future missions. This review revealed potential hurdles in the design of a dedicated LEO evacuation spacecraft. The ability to provide critical care and resuscitation during transport is likely to be limited by mass, volume, cost, and re-entry forces. Stabilization and treatment of the patient should be performed prior to departure, if possible, and emphasis should be on a rapid and safe return to Earth for definitive care.

Airfild evacuation center: experience of the interaction between the medical service of the Armed Forces of the Russian Federation, the Disaster Medicine Service and the Ambulance Service

Relevance. One of the important tasks in the provision of emergency medical care to victims of the mass-causalty incident is a medical triage in order to determine the priority of medical care and the priority of medical evacuation.Intention. To work out issues of interaction between the medical service of the Armed Forces of Russia, the Disaster Medicine Service and the Ambulance Service.Methodology. The program of the 16th All-Russian Congress “Ambulance 2017”, tactical and special exercises on the deployment of airfield evacuation center were included as a training and demonstration event . According to the plan of the exercise, several mass-causalty areas resulted from terrorist attacks along the border of the Leningrad Region.Results and discussion. To accomplish the tasks, an evacuation center was deployed with a capacity of up to 200 wounded and sick per day, evacuation capability of 32 stretcher wounded, and 4 h deployment time. During the exercise, non-invasive screening studies to proactively diagnose intracranial hematomas (portable infrared scanner), tension pneumothorax, hemopericardium, intrapleural and intra-abdominal bleeding (portable US device using FAST protocol), acute blood loss (portable laboratory analyzer) were performed in addition to standard examinations. To determine the priority of medical evacuation of victims, an improved Revised Trauma Score (RTS) scale with user-friendly software for Android mobile devices (smartphone, tablet) was used. In case of mass-causalty event and a shortage of specialized sanitary transport, those who needed urgent specialized medical care were transferred from an evacuation center via radial evacuation to specialized medical organizations subordinated to the Ministry of Defense, the Ministry of Health and the subjects of Russia.Conclusion. The feasibility of deploying an airfield evacuation center to eliminate the health effects of emergencies was determined by potential discrepancy between evacuation capacities of air transport and ambulances, on one hand, and the need to temporarily accommodate (including isolation) and provide emergency health care to victims.

Rancang Bangun Sistem Penentuan Jalur Evakuasi Keluar Gedung Rumah Sakit Saat Kondisi Darurat Menggunakan Algoritma Dijkstra Dengan Antrian Prioritas

Disaster is a sudden event, such as an accident or a natural catastrophe, that causes great damage or loss of life. Disasters can occur at any time, therefore a mechanism is needed to evacuate out of the building during a disaster. Generally public facilities have provided instructions and evacuation routes outside the building. Based on the severity of the disaster and the evacuation capability of the victim, the evacuation strategy can range from evacuation as soon as possible, evacuate slowly, move to a safe location inside the building or take refuge in the available protection room and wait for the rescue team to arrive.
 The algorithm for finding the shortest paths can be used to determine the evacuation route. But this path is still static, if the route damaged in then the evacuation route would become useless. The time for the evacuation process can also increase if the condition of the evacuation route is not known whether damaged or not. The solution to solve this problem is to make a system that can help find the safest and shortest evacuation routes during emergencies. This system consist of microcontroller Arduino Mega to control the system and led for evacuation sign. The evacuation routes is determined by implementing dijkstra algorithm with priority queue to search the shortest path.

Disaster-and-Evacuation-Aware Backup Datacenter Placement Based on Multi-Objective Optimization

Backup datacenters provide massive data storage and access services, and their failure may result in huge economic losses. So their location selection requires low damage risk and high evacuation capability simultaneously. But previous works on backup datacenter placement have not jointly considered these two factors from the viewpoint of traffic engineering and might result in the unnecessary loss in case of disaster. In this paper, with the global view of network resources in the software defined network scenarios, we propose a new disaster-and-evacuation-aware backup datacenter placement strategy. To reduce backup loss risk and apply rapid post-disaster evacuation, we jointly consider expected disaster loss and evacuation latency and formulate a new disaster-and-evacuation-aware facility location problem (NP-hard) which is multi-objective. To obtain the solution according to the disaster situation assessment, we propose a disaster-and-evacuation-aware multi-objective optimization algorithm. We optimize multiple objectives owning different coefficients in different disaster situations. We introduce location-output-capability, backup-evacuation-latency, Pareto-recommendation-degree, and node-damage-loss to guide solution searching. We prune the external set according to fitness-deviation-ratio to improve convergence speed and computation efficiency of the algorithm. Through extensive simulations, we demonstrate that our algorithm is efficient and promising with less expected disaster loss and higher evacuation capability simultaneously.