Comprehensive evaluation on self-ignition risks of coal stockpiles using fuzzy AHP approaches

Self-ignition in coal stockpiles is a serious economic, environmental and safety problem. Evaluation is an effective way to identify the self-ignition hazards in implicit environment of coal piles and provides a guide for countermeasures against spontaneous combustion in coal piles. In this paper, a comprehensive evaluation system is proposed. The trapezoidal and the triangular extent fuzzy AHP methods are employed to handle the imprecision and uncertainty of the effects of factors. A coal stockpile stored at the Bulk Cargo Logistics of Tianjin Port of China and three coal piles in the Teruel basins of Spain are studied to demonstrate the validity of the index system and the effectiveness of fuzzy AHP approaches. The evaluated results indicate that the proposed evaluation system and approaches are valid and objective for evaluating self-ignition risks of coal stockpiles; compared with the trapezoidal fuzzy AHP method, the triangular extent fuzzy AHP approach is more effective to evaluate self-ignition risks of coal piles for the priorities of factors impacting self-ignition risks are highlighted by their weight comparisons' calculation using the triangular extent analysis. The comprehensive evaluation system is beneficial to manage self-ignition risks of coal piles from a holistic point of view and to establish an early warming system of self-ignition risks of coal piles.     

Mitigating construction safety risks using prevention through design

Introduction

Research and practice have demonstrated that decisions made prior to work at construction sites can influence construction worker safety. However, it has also been argued that most architects and design engineers possess neither the knowledge of construction safety nor the knowledge of construction processes necessary to effectively perform Construction Hazards Prevention through Design (CHPtD).

Method

This paper introduces a quantitative methodology that supports designers by providing a way to evaluate the safety-related performance of residential construction designs using a risk analysis-based approach. The methodology compares the overall safety risk level of various construction designs and ranks the significance of the various safety risks of each of these designs. The methodology also compares the absolute importance of a particular safety risk in various construction designs.

Results

Because the methodology identifies the relevance of each safety risk at a particular site prior to the construction stage, significant risks are highlighted in advance. Thus, a range of measures for mitigating safety risks can then be implemented during on-site construction.

Impact on industry

The methodology is specially worthwhile for designers, who can compare construction techniques and systems during the design phase and determine the corresponding level of safety risk without their creative talents being restricted. By using this methodology, construction companies can improve their on-site safety performance.     

Fire and explosion hazard analysis during surface transport of liquefied petroleum gas (LPG): A case study of LPG truck tanker accident in Kannur,Kerala, India

This paper presents an analysis and simulation of an accident involving a liquefied petroleum gas (LPG) truck tanker in Kannur, Kerala, India. During the accident, a truck tanker hit a divider and overturned. A crack in the bottom pipe caused leakage of LPG for about 20 min forming a large vapor cloud, which got ignited, creating a fireball and a boiling liquid expanding vapor explosion (BLEVE) situation in the LPG tank with subsequent fire and explosion. Many fatalities and injuries were reported along with burning of trees, houses, shops, vehicles, etc. In the present study, ALOHA (Area Locations of Hazardous Atmospheres) and PHAST (Process Hazard Analysis Software Tool) software have been used to model and simulate the accident scenario. Modeling and simulation results of the fireball, jet flame radiation and explosion overpressure agree well with the actual loss reported from the site. The effects of the fireball scenario were more significant in comparison to that of the jet fire scenario.     

Limitations of current risk assessment methods to foresee emerging risks: Towards a new methodology?

The objective of this work-in-progress is to investigate the potentialities but also the limitations of traditional risks analysis tools especially in the context of emerging technologies and develop a method facilitating the early detection of scenarios of accidents. This is certainly a challenge particularly for new industrial fields since, in this case, very little or no lesson from past accidents is available. It is believed that such situations cannot be conveniently treated using traditional risk assessment methods (HAZOP, FMEA, …) and typical examples are given. The reason is that those methods rely heavily on past accidents and are therefore “trapped” in them so that they are largely “inductive”. In terms of foreseeing the future, the shortcomings of inductive methods are recalled. The possibility to imagine the future with very little clues is then discussed on the ground of theoretical consideration and a way to do so is proposed (abduction, serendipity). Then on the basis of the observation of how the experts work and how discoveries are made, a potential new methodology is outlined.     

The INDICATE safety program: evaluation of a method to proactively improve airline safety performance

A number of recent and highly publicised fatal aircraft accidents, within the Australian regional airline industry, has highlighted the need for operators of regular public transport aircraft to be more proactive in identifying and addressing aviation safety hazards. Despite this need, there are currently few proactive safety management programs that are practical, simple, cost effective and which reliably demonstrate improvements in airline safety performance. This paper outlines a new proactive airline safety program called INDICATE (Identifying Needed Defences In the Civil Aviation Transport Environment) that has been applied within the Australian regional airline industry. To evaluate the INDICATE program, a major Australian regional airline agreed to implement the program in one of its operational bases while another base was used as a control group. Five evaluation criteria were applied to determine whether the program would have a positive influence on the airline's safety performance. These criteria included airline safety culture, staff risk perception of aviation safety hazards, willingness of staff to report safety hazards, action taken on identified safety hazards and staff comments about safety management within the airline. Results from the trial suggest that the program can have a positive influence on airline safety performance, specifically: improving staff confidence in how safety is managed, increasing staff willingness to report safety hazards and incidents, improving organisational safety culture and reducing staff perceptions of the severity and likelihood of safety hazards occurring within the airline. The success of the trial has resulted in a number of Australian and International airlines adopting the program.     

Prediction models for the flash point of pure components

The flash point for a liquid is defined as the lowest temperature at which its vapor forms a spontaneously ignitable mixture when brought in contact with air. Having a good estimation of the flash point temperature at normal conditions is relevant because it is one of the main properties used to characterize fire and explosion hazards for liquids. Most of predictive correlations in the literature include a physical effect by including the normal boiling temperature in their formulation. To achieve combustion, sufficient evaporation is required and then a part of the liberated energy from the combustion is used to support the evaporation. Thus the evaporation energy and a chemical effect given by the heat of reaction are incorporated in this work. It is firstly verified that the relation between the flash point temperature and the normal boiling temperature tends to be a constant. Thus a heuristic approach based on 611 chemical species of diverse families indicates that this relation is around 0.75. The dispersion of the error has been reduced by using two proposed correlations where both physical and chemical properties are included in the model. In particular, the second equation is based on the group contributions method, which has been developed for alkanes. This method is in fact a combination of the group contributions method and the first model to overcome the difficulties in predicting isomeric differences.     

Human factors analysis of China's confined space operation accidents from 2008 to 2018

In recent years, several accidents in confined spaces have threatened the safety of staff and property in industries. A statistical analysis of 120 fatal accidents involving confined space operations in China from 2008 to 2018 was conducted in this study. The causes and characteristics of confined space operations accidents (CSOAs) were summarized. Focusing on the impact of human factors on CSOAs, the HFACS-MCS (HFACS-Modified Confined Space Accident) model, which consists of 5 levels and 21 factors, was established based on HFACS (Human Factors Analysis and Classification System). The chi-square (χ2) test and the OR analysis were implemented to analyze the statistically significant correlations between adjacent levels in the model. Finally, three human influence paths in CSOAs were derived. The results show that inadequate safety culture, organizational process vulnerability, inadequate supervision, supervisory violations, decision errors, and operational violations are the principal causes of the accidents. Besides, hurried and ad hoc rescue often caused more casualties. The targeted pre-accident prevention and post-accident emergency rescue countermeasures are proposed to prevent the recurrence of CSOAs and secondary accidents.     

关于环境监测中重金属污染现状及对策研究

随着我国经济正在不断发展,环境污染问题也在日益加剧,严重影响生态环境的稳定发展。尤其是重金属污染,会危害人们的身体健康,而且重金属一旦进入人体,就难以有效地排除。因此,相关环境部门应该重视重金属污染处理,提高环境监测的效率,制定针对性监测与处理方案,避免其影响人们的正常生活。基于此,本文分析了环境监测中重金属污染的现状,并阐述了相关对策,仅供参考。     

Fire hazards at the urban-wildland interface: What the public expects

Urban-wildland issues have become among the most contentious and problematic issues for forest managers. Using data drawn from surveys conducted by the authors and others, this article discusses how public knowledge and perceptions of fire policies and fire hazards change over time, the kinds of policy responses homeowners prefer as a way of preventing fire hazards at the urban-wildland interface, and how citizens view their own obligations as participants in interface issues. These data show that public attitudes toward fire have changed significantly over the past two decades and that educating the public about fire and the managers' use of fire can have positive effects on behavior. Yet, modifying the individual's behavior in regard to interface fire risks must also deal with important issues of individual incentives, the distribution of costs, and unanticipated policy impacts.     

重大危险源的辨识与控制

危险源控制是安全工作的中心任务。为了有效地控制危险源，首先必须辨识危险源，评价其导致事故的危险性，寻求其控制方法和措施。本大提出了两类危险源的概念，并以某乙烯厂Ｂ罐区为例，探讨两类危险源辨识与控制的基本原则和方法。