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The reaction dynamics of combustible clouds at high temperatures and pressures are a common form of energy output in aerospace and explosion accidents. The cloud explosion process is often affected by the external initial conditions. This study aims to numerically study the effects of airflow velocity, initial temperature and fuel concentration on the explosion behavior of isopropyl nitrate/air mixture in a semiconstrained combustor.

The discrete-phase model was adopted to consider the interaction between the gas-phase and droplet particles. A wave model was applied to the droplet breakup. A finite rate/eddy dissipation model was used to simulate the explosion process of the fuel cloud.

The peak pressure and temperature growth rate both decrease with the increasing initial temperature (1,000–2,200 K) of the combustor at a lower airflow velocity. The peak pressure increases with the increase of airflow velocity (50–100 m/s), whereas the peak temperature is not sensitive to the initial high temperature. The peak pressure of the two-phase explosion decreases with concentration (200–1,500 g/m³), whereas the peak temperature first increases and then decreases as the concentration increases.

Chain explosion reactions often occur under high-temperature, high-pressure and turbulent conditions. This study aims to provide prevention and data support for a gas–liquid two-phase explosion.

Sustained turbulence is realized by continuously injecting air and liquid fuel into a semiconfined high-temperature and high-pressure combustor to obtain the reaction dynamic parameters of a two-phase explosion.

This study investigated pre-evacuation times and evacuation behaviors of vulnerable people during the 2018 flooding in Shimobara, Okayama, Japan, and the flood-triggered factory explosion, a natural hazard-triggered technological accident known as a natural-hazard-triggered technological accidents (Natech). This study examined factors that affected evacuation decisions and pre-evacuation time, estimated the evacuation time in case of no explosion and identified community disaster prevention organization response efforts for vulnerable people.

Interviews with all 18 vulnerable people who experienced the event were conducted. Multiple regression analysis was used to examine the effect of six factors on evacuation time and reasons for delayed evacuation.

Factors affecting evacuation decisions included the sound of the explosion, followed by recommendations from relatives and the community disaster prevention organization. Explosion-related injuries delayed early evacuation, but experience of previous disasters and damage had a positive effect on early evacuation. The explosion sound accelerated evacuation of non-injured people; however, explosion-related injuries significantly delayed evacuation of injured individuals. The Shimobara community disaster prevention organization’s disaster response included a vulnerable people registry, visits to all local households and a multilayered approach that enabled monitoring of all households.

This is the first study to examine the evacuation behavior of vulnerable people and community responses during a Natech event.

Gas explosion is one of the most major types of accident in mining projects, and the flame front with high temperature is major hazardous factor induced by this kind of accident. Support engineering provides an available way to solve problems related to ground movements, but very likely has a great influence on the gas explosion accident process, especially the flame propagation, and then aggravates mining risk. However, until now it has not been received much attention from scientific works. The paper aims to discuss these issues.

A commercial CFD software package AutoReaGas suitable for gas explosion is used to carry out the numerical investigation of gas explosion process in a straight coal tunnel with typical support engineering, especially the unsteady explosion field and the flame propagation process in it.

Support engineering composed by multiple bars take positive influence on flame acceleration: the flame speed is much faster than that under no support bars, and the smaller support spacing induces greater flame speed near the ignition. The support bars also exert negative influence on flame acceleration: the larger support spacing induces greater flame speed in most region of the tunnel. Furthermore, a traditional viewpoint that denser obstacles induce greater explosion effects is one-sided according to this study.

At present, no one concerns the aggravating influence of support engineering on accident risk in practical mining projects because of small geometric dimension. This work examines the effect of steel support system on evolution processes of gas explosion accidents, especially the flame propagation. The conclusions provide quantitative scientific basis for this kind of the accidents in risk evolution and accident investigation of mining engineering.

Explosions are the main type of accident causing casualties in underground coal mines. Little attention has been devoted to investigating the flame propagations for methane‐air explosion in a tunnel with full scale. This paper seeks to address this topic.

Based on the numerical simulation and the analysis, the propagation rule of flame and temperature waves inside and outside the space occupied by methane/air mixture at the various concentrations in a tunnel were obtained in this work.

The original interface of methane‐air mixture and air moves forward in the explosion and the original mixture area extends. For the methane‐air mixture with rich fuel concentration, the flame speed increases with distance within a range beyond the original position of the interface between the mixture and air. The flame speed reaches maximum value outside the original area of methane‐air mixture with rich fuel concentration.

Based on the numerical simulation and the analysis, the propagation rule of flame and temperature wave inside and outside the space occupied by methane/air mixture at the various concentrations in a tunnel were obtained.

This study aims to evaluate blast loads on and the response of submerged structures.

An arbitrary Lagrangian–Eulerian method is developed to model fluid–structure interaction (FSI) problems of close-in underwater explosions (UNDEX). The “fluid” part provides the loads for the structure considers air, water and high explosive materials. The spatial discretization for the fluid domain is performed with a second-order vertex-based finite volume scheme with a tangent of hyperbola interface capturing technique. The temporal discretization is based on explicit Runge–Kutta methods. The structure is described by a large-deformation Lagrangian formulation and discretized via finite elements. First, one-dimensional test cases are given to show that the numerical method is free of mesh movement effects. Thereafter, three-dimensional FSI problems of close-in UNDEX are studied. Finally, the computation of UNDEX near a ship compartment is performed.

The difference in the flow mechanisms between rigid targets and deforming targets is quantified and evaluated.

Cavitation is modeled only approximately and may require further refinement/modeling.

The results demonstrate that the proposed numerical method is accurate, robust and versatile for practical use.

Better design of naval infrastructure [such as bridges, ports, etc.].

To the best of the authors’ knowledge, this study has been conducted for the first time.

A nonlinear‐dynamics transient computational analysis of the explosion phenomena associated with detonation of 100g of C4 high‐energy explosive buried at different depths in sand is carried out using the AUTODYN computer program. The results obtained are compared with the corresponding experimental results obtained in Ref. [1]. To validate the computational procedure and the materials constitutive models used in the present work, a number of detonation‐related phenomena such as the temporal evolutions of the shape and size of the over‐burden sand bubbles and of the detonation‐products gas clouds, the temporal evolutions of the side‐on pressures in the sand and in air, etc. are determined and compared with their experimental counterparts. The results obtained suggest that the agreement between the computational and the experimental results is reasonable at short postdetonation times. At longer post‐detonation times, on the other hand, the agreement is less satisfactory primarily with respect to the size and shape of the sand crater, i.e. with respect to the volume of the sand ejected during explosion. It is argued that the observed discrepancy is, at least partly, the result of an inadequacy of the generic materials constitutive model for the sand which does not explicitly include the important effects of the sand particle size and the particle size distribution, as well as the effects of moisture‐level controlled inter‐particle friction and cohesion. It is further shown that by a relatively small adjustment of the present materials model for sand to include the potential effect of moisture on inter‐particle friction can yield a significantly improved agreement between the computed and the experimentally determined sand crater shapes and sizes.

A dust cloud is formed by a high-pressure air blast in dust explosion experiments in the spherical 20 L chamber. The state of the dust cloud has a significant impact on the dust explosion. However, it is difficult to observe the dust distribution in the chamber during the dust dispersion. Numerical simulation was used to examine the dust distribution in the chamber with the rebound nozzle in this work. The paper aims to discuss these issues.

Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed.

Dust in the spherical 20 L chamber is in the state of very intensifying motion within 30 ms from dispersion starting. Dust in the chamber reaches a uniform state beyond 200 ms. The pressure for dust dispersion should be higher than 0.5 MPa for the aluminum dusts of larger than 50. The higher blast pressure is not always applicable to achieve a uniform dispersion. There is a best blast pressure value for a given dust to achieve a uniform dispersion in the spherical 20 L chamber.

Dust cloud generation is essential for understanding dust explosions. Dust cloud deflagration parameters depend on the uniformity and concentration of dusts dispersed by a high-pressure air blast. Numerical simulation was used to examine the multiphase flow of the dust air mixture in this work. Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed. The data are useful for understanding the basics of dust cloud formation.

The data are useful for evaluating dust explosion experimental parameters.

Dispersible uniformity has a strong impact on measured parameters of dust explosion in a chamber. However, it is difficult to observe the dust particles distribution during the dispersion. Numerical simulation was used to examine the dust particles distribution and its influencing factors during the dispersion in this work. New finding is: the approach to examine the distribution of dust particles dispersed by a high-pressure blast in a chamber; the variation of dispersible uniformity and its influencing factors when dust is injected into the spherical 20 L chamber by high-pressure air blast.

The paper attempts to highlight and discuss the limitations of the current discourse around the role of hydrogen‐based energy in a more sustainable future.

The paper draws upon preliminary findings from qualitative fieldwork in three case studies. Focus groups were conducted with members of the public in three different areas of the UK where hydrogen projects are being planned and/or developed. Findings are connected to evidence gathered in other similar studies addressing the relationship between publics and new technologies.

In the case of hydrogen energy and its role in a future economy, questions about safety were present but did not dominate the debate. Participants in our focus groups were not only concerned about the technical and economic aspects of hydrogen technologies, but they also wanted to understand what hydrogen as an energy carrier and fuel would mean for them and in their daily lives; whether it would deliver the promise of realising a better future, for the global environment and the people; and whether it would disrupt people's lifestyles and require a significant change in collective and individual behaviour. Moreover, a frequent issue raised by many people was their ambivalence about what, and whom, to trust in the provision of information about hydrogen.

This research on public attitudes to a future hydrogen economy provides empirical insights about the socio‐cultural contexts in which lay understandings of new, unfamiliar technologies and technological systems are developed, and what issues are raised by members of the general public when an informed debate is encouraged. The research attempts to contribute to the wider debate about public engagement in technological change.

The paper aims to show how resource‐based views of the firm inadequately address the strategic importance of acquiring and using symbolic capital within the wider discursive institutional environment.

A single case using publicly available data on the strategic activities of the oil and gas firm BP was constructed.

Combining case data with a review of literature on firm capabilities and organization studies, the paper identifies a previously unacknowledged foundational strategic capability: securing a licence to act. It finds BP strategists understanding this capability as the realization of credibility and authority arising from the conscious and skilled articulation of firm commitments and activities.

Generalising from the case, the paper argues for the importance to firm performance of an understanding of how capabilities evolve in relation to the use of symbolic capital within inherently complex institutional environments. This leads beyond a purely economic view of institutional settings to cover market‐based political and social interests.

The purpose of this paper is to re-open a debate as to whether candidates for public leadership should be screened for psychopathy.

This is a conceptual paper which examines the diffuse literature concerning psychopaths in public leadership positions.

Psychopathy researchers have been divided as to whether psychopathic individuals should be screened out of leadership positions in public and corporate life. Recent evidence from bullying research and historical research into psychopaths in politics sheds new light on this issue.

There is increasing evidence that psychopaths are detrimental to the organisations they work for, to other employees, to the environment and to society. Screening for psychopathy should therefore be considered. This may help to prevent governments entering into illegal wars and committing crimes against humanity. Screening in the corporate sector may also help prevent the worst excesses of greed and fraud that were evident in collapses like Enron and the Mirror Group as well as in the events leading up to the global financial crisis of 2008.

The paper makes a contribution to the literature on public leadership by bringing together the diverse reports on the effects of psychopaths in public organisations like the National Health Service, publicly listed corporations, academia and politics. The paper uses historical and corporate examples to illustrate the initially favourable impression that psychopathic leaders can make but the ultimately disastrous outcomes they engender.