Short Evacuation Research Articles

Integrated assessment of bioaerosol dispersion patterns and infection risk in a typical urban environment: Implications for urban biosecurity management

Exposure to bioaerosols in high-density urban environments will pose a severe threat to human life and health and present significant challenges to the sustainability and resilience of cities. In this study, the aerodynamic dispersion patterns of bioaerosols at two release locations (open and dense areas) under both thermal conditions in Zhongguancun, Beijing, are investigated. By coupling a dose-response model and an improved cellular automaton, the infection risk within exposed populations was assessed, and emergency evacuation strategies for distinct populations in high-risk areas were devised. This study reveals that bioaerosol distribution is notably influenced by factors such as thermal conditions, release locations and pedestrian height. Bioaerosol concentration above the release source decreases with increasing pedestrian height at two release locations. Under the same exposure time, the infection probability of different groups in this area declines with pedestrian height increases, with adult males having the highest and elderly females having the lowest probability. Thermal conditions and building layout near the release source were second only to exposure time in influencing infection probability and evacuation path. Proximity to the release source indicates a high infection probability but a short evacuation distance to safe areas, while downstream areas exhibit lower infection probability but require longer evacuation distances. The layout of buildings near the release source has the most significant effect on evacuation time. Evacuation for high-risk populations should be prioritized upstream or either side of the mainstream. This study aims to mitigate potential biological threats, address challenges in enhancing urban biosecurity management, and enable sustainable urban development.

Evaluation of Tsunami Evacuation Plans for an Underground Mall Using an Agent-Based Model

Tsunamis resulting from earthquakes can cause extensive damage, including infrastructure destruction, injuries, and fatalities. To address these risks, numerous tsunami evacuation simulations have been conducted to assess evacuation strategies and identify issues, particularly in Japan, where the Nankai Trough earthquake is anticipated, affecting underground malls in urban areas. Our previous research primarily focused on evacuating from underground to the surface, neglecting surface evacuation. Therefore, this study extended the previous study to include horizontal evacuation following the exit from the underground mall to ground level. It also considered the impact of pedestrian road crossings as interactions with vehicular traffic within the simulation to enhance realism and verify the evacuation risk. The study also explores scenarios where evacuation guide stairs are unavailable, comparing the effectiveness of alternative staircases in the evacuation plan. Results indicate that while using alternative staircases temporarily increases the number of evacuees reaching the surface, road crossings on evacuation routes become significant bottlenecks, leading to surface congestion and delayed evacuations. This raises doubts about the effectiveness of alternative staircases and highlights the need to consider alternative evacuation routes as a secondary plan. Additionally, the study reveals that reduced pedestrian flow at road crossings can significantly impact on evacuation times. Ultimately, this study demonstrated that achieving a short evacuation time from underground malls to the ground level might not always yield the best evacuation plan. It underscored the importance of considering aboveground factors in evacuation planning to ensure safety in the event of a tsunami caused by an earthquake.

Hybrid induction vacuum swing adsorption, a rapid and fully electrified carbon capture process

In this study, a fully electrified temperature vacuum swing adsorption (TVSA) was experimentally investigated for adsorbent regeneration in post-combustion carbon capture. To this purpose, consecutive adsorption/electrified-desorption steps were carried out in a fixed bed, packed with composite extrudates of 13X zeolite and Fe3O4 powder, where the heating was performed electrically via induction. Different strategies of simultaneous and sequential heating and evacuation, as well as only heating (TSA) or evacuation (VSA), were applied for adsorbent regeneration. The adsorbate loading, bed pressure, bed temperature, and mole fraction of CO2 at the outlet were chosen as performance indicators. Using only vacuum evacuation, it took 23 times longer (regeneration time) to reach a 90% regeneration level compared to the inductive TVSA process, using one minute of heating at an electrical current of 74.1 A, either before subsequent evacuation or during the beginning of this evacuation. A series of three-minute adsorption-regeneration experiments, in particular VSA and TVSA, were performed to assess the effect of omitting the long cooldown and partial bed regeneration on the subsequent adsorption steps. Over 66% of the total bed capacity could be maintained as working capacity with very short (1 min) heating and (2 min) evacuation times. These are amongst the shortest reported times for thermally assisted regeneration methods of extruded adsorbents.

Large-Scale Evacuation Shelter Selection Method Through Iterations of Pedestrian Simulations With Dynamic Congestion Reproduction

It is necessary to optimize evacuation guidance to shelters in short evacuation time. The state-of-the-art method based on an idea of combinatorial optimization problems related to evacuees’ locations and the capacities of nearby shelters has been developed, while it cannot mitigate the effect of congestion on roads/streets after evacuation starts. In this study, to cover this problem, we develop a new method that utilizes simulations for estimating the effect of congestion on roads/streets during evacuation and reassigning shelters to evacuees based on the simulation results. By iterating this step, our method derives the congestion-aware solutions for shelter selection that can realize more smooth evacuation. To evaluate our method, we conducted multi-agent simulations assuming a disaster situation in a sightseeing spot. Specifically, we examined a hypothetical case scenario involving the evacuation of 30,000 visitors from the Gion Festival. We compared the proposed method with conventional methods, such as the nearest shelter selection method and our previous method. We found that our proposed method reduced average and total evacuation time and congestion on roads compared to the conventional methods including the nearest shelter selection method and our previous method that only employs combinatorial optimization without estimating congestion. From this result, our idea of simulation-based congestion estimation has an impact of easing congestion during evacuation and preventing overcapacity of shelters at the same time. It shows the possibilities of help in developing congestion-aware evacuation strategies in emergency situations of crowded areas like huge cities or sightseeing spots.

Machine learning to reveal hidden risk combinations for the trajectory of posttraumatic stress disorder symptoms

The nature of the recovery process of posttraumatic stress disorder (PTSD) symptoms is multifactorial. The Massive Parallel Limitless-Arity Multiple-testing Procedure (MP-LAMP), which was developed to detect significant combinational risk factors comprehensively, was utilized to reveal hidden combinational risk factors to explain the long-term trajectory of the PTSD symptoms. In 624 population-based subjects severely affected by the Great East Japan Earthquake, 61 potential risk factors encompassing sociodemographics, lifestyle, and traumatic experiences were analyzed by MP-LAMP regarding combinational associations with the trajectory of PTSD symptoms, as evaluated by the Impact of Event Scale-Revised score after eight years adjusted by the baseline score. The comprehensive combinational analysis detected 56 significant combinational risk factors, including 15 independent variables, although the conventional bivariate analysis between single risk factors and the trajectory detected no significant risk factors. The strongest association was observed with the combination of short resting time, short walking time, unemployment, and evacuation without preparation (adjusted P value = 2.2 × 10−4, and raw P value = 3.1 × 10−9). Although short resting time had no association with the poor trajectory, it had a significant interaction with short walking time (P value = 1.2 × 10−3), which was further strengthened by the other two components (P value = 9.7 × 10−5). Likewise, components that were not associated with a poor trajectory in bivariate analysis were included in every observed significant risk combination due to their interactions with other components. Comprehensive combination detection by MP-LAMP is essential for explaining multifactorial psychiatric symptoms by revealing the hidden combinations of risk factors.

The Role of Built Environment's Physical Urban Form in Supporting Rapid Tsunami Evacuations: Using Computer-Based Models and Real-World Data as Examination Tools

Cities are increasingly becoming hot-spots for nature-originated disasters. While the role of the urban built environment in fostering disaster resilience has been recognized for some time, it has been difficult to translate this potential into practice. This is especially challenging in the case of rapid onset crises such as near-field tsunamis when appropriate urban forms have to support the populations’ ability to autonomously carry out safe and timely responses. In this respect, much of current research remains focused on large-scale elements of urban configuration (streets, squares, parks, etc.) through which people move during an emergency. In contrast, the critical micro-scale of evacuees’ experiences within the built environment is not commonly examined. This paper addresses this shortfall through a macro- and micro-scale analysis of a near-field tsunami scenario affecting the city of Vina del Mar, Chile, including a mixed-methods approach that combines computer-based models and fieldwork. The results show significant macro-scale tsunami vulnerability throughout major areas of the city, which nonetheless could be mitigated by existing nearby high ground and an urban form that allows short evacuation times. However, micro-scale outcomes show comparatively deficient spatial conditions that during an emergency might lead to dangerous outcomes including bottlenecks, falls and panic. Vertical evacuation, in turn, is confirmed as a suitable option for reducing vulnerability, but further examination of each shelter’s characteristics is required.

Montmorillonite nanoclay-based self-healing coatings on AA 2024-T4

Cation-exchanged montmorillonite (MMT), which is an aluminum-pillared clay, was dispersed into an organic–inorganic hybrid silica matrix sol. Cationic inhibitors Ce3+/Zr4+ were introduced into montmorillonite by two methods, namely (1) physical mixing of MMT with the inhibitor solutions and (2) physical mixing for short durations and evacuation of the mixture of MMT and inhibitor solutions. Coatings using these sols were deposited on aluminum alloy AA 2024-T4 substrates, by the dip coating technique followed by thermal curing at 130°C for 1 h. TEM, BET, and XRD analyses were carried out for the inhibitor-modified montmorillonite powders. Potentiodynamic polarization and electrochemical impedance spectroscopic analyses were carried out on uncoated and coated substrates to evaluate the corrosion protection property after exposure to 3.5 wt% NaCl for varying time durations, up to 120 h. Self-healing ability was evaluated using SVET analysis by creating an artificial scribe on the surface and exposure to 3.5 wt% NaCl. Elemental mapping was carried out on scribed substrates before and after exposure to 5 wt% salt fog. Sols containing montmorillonite intercalated with cationic inhibitors when deposited on AA 2024-T4 substrates exhibited low corrosion currents after a prolonged duration of exposure to corrosion medium.

Examining the role of urban form in supporting rapid and safe tsunami evacuations: a multi-scalar analysis in Viña del Mar, Chile

Abstract Cities are increasingly becoming hot-spots for nature-originated disasters. While the role of the urban built environment in fostering disaster resilience has been recognized for some time, it has been difficult to translate this potential into practice. This is especially challenging in the case of rapid onset crises such as near-field tsunamis, when appropriate urban forms have to support the populations’ ability to autonomously carry out safe and timely responses. In this respect, much of current research remains focused on large-scale elements of urban configuration (streets, squares, parks, etc.) through which people move during an emergency. In contrast, the critical micro-scale of evacuees’ experiences within the built environment is not commonly examined. This paper addresses this shortfall through a macro- and micro-scale analysis of a near-field tsunami scenario affecting the city of Vina del Mar, Chile, including a mixed-methods approach that combines computer-based models and fieldwork. The results show significant macro-scale tsunami vulnerability throughout major areas of the city, which nonetheless could be mitigated by existing nearby high ground and an urban form that allows short evacuation times. However, micro-scale outcomes show comparatively deficient spatial conditions that during an emergency might lead to dangerous outcomes including bottlenecks, falls and panic. Vertical evacuation, in turn, is confirmed as a suitable option for reducing vulnerability, but further examination of each shelter’s characteristics is required.

Evolution of pedestrian evacuation considering different human behaviors

Pedestrian evacuation becomes more complicated when different human behaviors are considered. In this paper, pedestrian evacuation considering two different kinds of human behaviors is studied by using a cellular automaton (CA) model. Two types of evacuees, cooperators and defectors, are initially randomly distributed in a square room with one exit and they interact with their neighbors following the snowdrift game theory (characterized by the parameter “[Formula: see text]”) during the evacuation process. Cooperators and defectors are mutually changed according to two typically different kinds of evacuees’ judgements, namely, judgement based on neighbors’ strategies (we call it herding behavior) and judgement based on neighbors’ payoffs (we call it independent behavior), which leads to the corresponding evacuee clusters. It is found from a large amount of numerical simulations that the proportions of the corresponding evacuee clusters are evolved to respectively consistent states despite 11 typically different initial evacuee cluster ratios, largely owing to self-organization effect. Moreover, for other 200 randomly chosen initial evacuee cluster ratios, Monte-Carlo simulations show that the proportions of the corresponding evacuee clusters are evolved stably, without any oscillation, and when the initial number of pedestrians of two different kinds of behaviors are comparable, the proportions are evolved to respectively consistent states despite different initial evacuee cluster ratios, indicating that some regular phenomena occur during the evacuation process. Furthermore, it is found that the moderate values of [Formula: see text] is necessary for short evacuation time, and for the fixed values of [Formula: see text], the initial ratio of pedestrians of herding behavior has a great influence on the final evacuation time.

Fleet routing and scheduling in bushfire emergency evacuation: A regional case study of the Black Saturday bushfires in Australia

Evacuation planning provides evidence base for effective decision-making in various aspects of disaster response, such as the selection of safe shelters, dynamic assignment of rescue vehicles, and the identification of safest routes and vehicle scheduling. However, an efficient emergency service response to a short-notice bushfire evacuation is a complicated procedure. Any failure to response promptly to short notice evacuation can adversely affect the effectiveness of operations and hence potentially contribute to increased fatalities. This study develops a Vehicle Routing Problem (VRP) model to enhance the efficiency and effectiveness of short-notice emergency response and rescue operations. This model computes the required number of vehicles and identifies the safest routes and schedules for late evacuees under various time windows and road disruption risk. A heuristic solution method is developed to tackle this highly complex nature of VRP due to operational interdependencies. The model parameters are realistically derived from the 2009 Black Saturday bushfires in Victoria, Australia. The results indicate the feasibility of evacuating 1100 late evacuees via low risk routes within the available resources of four shelters and seven rescue vehicles. However, the evacuation of late evacuees from the bushfire affected areas to safe shelters could be potentially affected when the hard constraints such as the time-window are changed. Nevertheless, the model outputs are useful in the development of emergency evacuation plans to mitigate the potential risk of fatality or injury during a bushfire.

개선된 Floor Field Model과 다른 피난시뮬레이션 모델의 비교 연구

본 연구는 보행자의 물리적 특성(크기, 모양, 자세 등)을 적용한 개선된 플로어 필드 모델(Floor field model; FFM)을 소개하고, 개선된 모델과 널리 알려진 다른 피난시뮬레이션 모델과의 비교를 통해 FFM의 한계점 파악 및 개선된 모델의 특징을 분석하고자 한다. FFM은 셀룰라 오토마타(Cellular automata)를 이용한 대표적 미시적 관점 보행 모델이지만 보행자의 크기, 모양, 자세 등의 물리적 특성을 세밀하게 반영하지 않는다. 이로 인해 보행자들 간의 충돌, 마찰 등의 현상을 모델링하기 어려우며 결과적으로 다른 모델들과 비교하였을 경우에 매우 짧은 대피 시간을 산출하고 있다. 본 연구는 물리적 현상을 반영할 수 있는 개선된 FFM을 제시하며, 개선된 모델과 기존 FFM, 시뮬렉스(Simulex), 패스파인더(Pathfinder) 등 다른 모델들과의 비교 실험을 수행하였다. 실험은 실제 캠퍼스 건물의 일부 공간을 대상으로 진행되었으며, 대피 인원의 변화에 따른 대피 양상의 비교와 각 출구별 대피 양상의 비교가 수행되었다. 이를 통해 FFM에서는 반영되지 않던 물리적 현상들이 개선된 모델에서는 상용 모델 수준으로 적용되는 점과 특히 시뮬렉스와 유사한 형태의 대피 양상을 보임을 확인하였다. In this study, we propose an improved Floor Field Model(FFM) that considers the physical characteristics of pedestrians, i.e., body size, shape, and posture. Also we analyse limits of FFM and features of improved model compared with existing evacuation simulation models. FFM is a typical microscopic pedestrian model using CA, but it does not reflect the physical characteristics of pedestrians. Because of this, FFM is difficult to modeling phenomena such as collision, friction between pedestrians. As a result, FFM calculates a very short evacuation time when compared with the other models. We performed a computational experiment to compare improved model with other models such as FFM, Simulex, Pathfinder in an actual campus building. We carried out a comparison of evacuation aspect according to the change in number of evacuees. Also we compared evacuation aspect by exit. Finally, we confirmed that improved model reflects physical phenomena which were not reflected in FFM. Especially, experimental results were very similar to the Simulex.

Consistent evolution in a pedestrian flow

In this paper, pedestrian evacuation considering different human behaviors is studied by using a cellular automaton (CA) model combined with the snowdrift game theory. The evacuees are divided into two types, i.e. cooperators and defectors, and two different human behaviors, herding behavior and independent behavior, are investigated. It is found from a large amount of numerical simulations that the ratios of the corresponding evacuee clusters are evolved to consistent states despite 11 typically different initial conditions, which may largely owe to self-organization effect. Moreover, an appropriate proportion of initial defectors who are of herding behavior, coupled with an appropriate proportion of initial defectors who are of rationally independent thinking, are two necessary factors for short evacuation time.

Optimizing the Use of Limb Tourniquets in Tactical Combat Casualty Care: TCCC Guidelines Change 14-02

Abstract : The early use of limb tourniquets has been documented to save lives on the battlefield, but has the potential for significant morbidity. This change has four goals: 1. Clarification of tourniquet conversion guidelines. Since its inception, Tactical Combat Casualty Care (TCCC) has emphasized the early and liberal use of tourniquets to control life-threatening hemorrhage in the Care Under Fire (CUF) phase. Because evacuation times in Iraq and Afghanistan have been relatively short, the recommendation in the TCCC Guidelines to re-evaluate the need for a tourniquet in the Tactical Field Care (TFC) phase of care and use other means of hemorrhage control has been de-emphasized in practice by users. There is often no attempt to convert tourniquets to hemostatic or pressure dressings because of the short evacuation times in Afghanistan at present. Increasingly, worldwide casualty care scenarios are anticipated to include long-range evacuation. Recent real-world events in theaters other than the Middle East have demonstrated that reinforcement of tourniquet conversion guidelines is needed at this time. 2. Clarification of effective tourniquet placement. Ineffective venous tourniquets have been shown to be a relatively common occurrence that increases blood loss and complications.1-3 Optimal use of limb tourniquets must result in both cessation of bleeding and stoppage of the distal pulses in the extremity. 3. Clarification of the location of tourniquet placement during CUF. During a prehospital trauma care assessment in Afghanistan in 2012, inconsistencies relating to tourniquet placement were noted between the TCCC guidelines and actual training in some TCCC courses. In particular, high and tight tourniquet placement (also termed hasty tourniquet placement) is not specified in the TCCC Guidelines, which call for tourniquet placement proximal to the bleeding site in the CUF phase.

Walking between the Drops: Israeli Defense Forces’ Fluid Resuscitation Protocol

BackgroundCurrent research in trauma resuscitation indicates that it is important to strike a balance between withholding intravenous fluid therapy, on one hand, and giving too much, on the other. The Israel Defense Forces’ former protocol for prehospital fluid administration in the trauma setting was intended to navigate this balancing act. It turned out that the protocol was not being appropriately implemented in field conditions. ObjectivesWe describe our process improvement, which resulted in our revised protocol. Our goal in drafting the new protocol was to achieve yet another balance, this time between the recommendations derived from accumulating science, and the efficacy with which they could likely be implemented in the field. DiscussionWe review the available research in prehospital fluid administration, and then develop our current protocol. Per our a priori requirements, the protocol is unified in that medical personnel from a very wide spectrum of caregivers can apply it; and it is appropriate for both short evacuation time scenarios (e.g., low-intensity conflicts) and lengthier evacuation scenarios (e.g., high-intensity conflicts). ConclusionSurvival is likely improved if guidelines do not add unnecessary complexity and are easily implemented. We believe that the current protocol is suitable for the large majority of trauma patients, and helps guide providers toward a primary decision-point regarding fluid administration. Nonetheless, as long as only coarse clinical parameters for identifying shock are available, and data regarding optimal treatment are conflicting, offering truly balanced fluid resuscitation guidelines is a lot like walking between the drops.

Mapping the vulnerability for evacuation of the Campi Flegrei territorial system in case of a volcanic unrest

Over the past few decades, intense urban expansion has occurred over the Campi Flegrei territorial system without considering the volcanic risk. In this active volcanic area, where a short period evacuation could be necessary, the emergency management cannot be based solely on hazard-related information. The territorial and social features must also be considered. In this framework, the main purpose of this research is to point out the seriousness of the present setting of the Campi Flegrei territorial system in case an evacuation is necessary. Following the concept of regional evacuation, the zone to be involved in emergency planning was identified as the whole of the area threatened by the volcanic events of the past 10 ka. Inside this area the spatial relation between the resident distribution and the outflows of roads, railway stations and harbours, to facilitate evacuation, was investigated. A spatial relational GIS-based procedure was used to draw the territorial system vulnerability map, depicting the zones with different capabilities to support the evacuation of residents in case of volcanic activity. Based on the concept that people could leave the dangerous area by the means of transport supplied by Civil Protection, and using the threshold value of over-crowding of 0.70 people/m2, we identified the collection areas for residents to be immediately evacuated in case of volcanic unrest, and five macrozones displaying different capabilities to cope with an emergency phase.

A capacitated network flow optimization approach for short notice evacuation planning

We present a capacity constrained network flow optimization approach for finding evacuation paths, flows and schedules so as to maximize the total evacuees for short notice evacuation planning (SNEP). Due to dynamic nature of this optimization problem, we first construct a time-expanded network that expands the static network over the planning horizon for every time interval. Since the resulting evacuation networks become extremely large to solve, we have developed Evacuation Scheduling Algorithm (ESA) to expedite the solution process. ESA utilizes Dijkstra’s algorithm for finding the evacuation paths and a greedy algorithm for finding the maximum flow of each path and the schedule to execute the flow for each time interval. We show that the complexity of ESA is O(|Nc|·n2)+O(|Nc|·m·T). Numerical experiments show a tremendous advantage of ESA over an exact algorithm (CCEP) in computation time by running up to 41,682 faster than CCEP. In many test network instances, CCEP failed to find a solution within 12hours while ESA converged to a solution in less than 0.03seconds.

018 Cold mountain: do delays to hospital increase the risk of hypothermia in mountain casualties?

IntroductionUK mountain casualties are at risk of hypothermia year-round. Mountain Rescue personnel are often taught that pre-hospital treatment of hypothermia cannot reverse cooling of casualties and so delays in evacuation...

Effect of water vapor from power station flue gas on CO 2 capture by vacuum swing adsorption with activated carbon

Due to the high absolute humidity of real flue gas, activated carbon, a hydrophobic adsorbent, was used to selectively adsorb CO 2 by vacuum swing adsorption in this study. The objective of this work is to study the feasibility and advantage of CO 2 capture along with simultaneous moisture removal by activated carbon and the effect of H 2O on CO 2 capture from wet flue gas streams. Through experiment and analysis, the “S” shape isotherms of water indicated water was easier to be desorbed from activated carbon. Then a cone shape model was proposed to depict water distribution inside the adsorption bed. As a consequence, water vapor hardly influenced the CO 2 capture performance. Moreover, the process can be operated under a relatively high vacuum pressure and short evacuation time. The preliminary results showed that our one-bed VSA process could yield a good CO 2 recovery of over 80% and a reasonable purity of 43%.

Diplanetism and microcyclic sporulation in Phytophthora ramorum

SummaryThe zoosporic phase of the pathogen Phytophthora ramorum plays a crucial role in the process of plant infection, yet little is known about the fate of zoospores failing to target their hosts. Here, we describe new stages in the life cycle of P. ramorum concerning the in vitro development of monomorphic diplanetism and microcyclic sporulation in free water. Papillate cysts were formed after zoospore suspensions of isolates of the EU1 and NA1 clonal lineages were vortexed. Cysts usually germinated directly forming an emerging tube, or indirectly by releasing a secondary zoospore, which leaves behind an empty cyst with a short evacuation tube. Germinate cysts frequently developed either an appressorium or a microsporangium both terminally. We also observed microcyclic sporulation, i.e. sporangia indirectly germinated by forming a microsporangium, as in microcyclic conidiation of true fungi. Temporal progress of encysted zoospores in solution showed that percentage of germination varied significantly among and within isolates as well as between experiments, suggesting that germination is partly ruled by internal mechanisms. Diplanetism and microcyclic sporulation in P. ramorum may provide a second opportunity for host infection and may increase the chance of long dispersal in moving water.

Evacuation Times of Civilians and Soldiers Wounded during the War in Croatia

The goal of this study was to estimate the mean time needed for evacuation of wounded persons from the site of injury to a medical institution. A database that includes medical and demographic data for persons treated in Croatian hospitals during the 1991-1995 war in Croatia was used. A total of 61.11% of wounded persons was evacuated within 1 hour. The mean evacuation time was 2.26 hours, and times for civilians and army units did not vary significantly. After wounded patients were admitted to medical institutions, the chances of survival were 98.36%. Because the wartime medical system in Croatia depended on army units for transport and on civilian medical institutions for medical procedures and later care, we conclude that the integrated model of medical care led to short evacuation times, with no significant differences between soldiers and civilians or soldiers on the two sides.