scholarly journals A Critical Review of the Equivalent Stoichiometric Cloud Model Q9 in Gas Explosion Modelling

Eng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 156-180
Author(s):  
Vincent Tam ◽  
Felicia Tan ◽  
Chris Savvides

Q9 is widely used in industries handling flammable fluids and is central to explosion risk assessment (ERA). Q9 transforms complex flammable clouds from pressurised releases to simple cuboids with uniform stoichiometric concentration, drastically reducing the time and resources needed by ERAs. Q9 is commonly believed in the industry to be conservative but two studies on Q9 gave conflicting conclusions. This efficacy issue is important as impacts of Q9 have real life consequences, such as inadequate engineering design and risk management, risk underestimation, etc. This paper reviews published data and described additional assessment on Q9 using the large-scale experimental dataset from Blast and Fire for Topside Structure joint industry (BFTSS) Phase 3B project which was designed to address this type of scenario. The results in this paper showed that Q9 systematically underpredicts this dataset. Following recognised model evaluation protocol would have avoided confusion and misinterpretation in previous studies. It is recommended that the modelling concept of Equivalent Stoichiometric Cloud behind Q9 should be put on a sound scientific footing. Meanwhile, Q9 should be used with caution; users should take full account of its bias and variance.

2021 ◽  
Vol 11 (11) ◽  
pp. 5208
Author(s):  
Jianpo Liu ◽  
Hongxu Shi ◽  
Ren Wang ◽  
Yingtao Si ◽  
Dengcheng Wei ◽  
...  

The spatial and temporal distribution of tunnel failure is very complex due to geologic heterogeneity and variability in both mining processes and tunnel arrangement in deep metal mines. In this paper, the quantitative risk assessment for deep tunnel failure was performed using a normal cloud model at the Ashele copper mine, China. This was completed by considering the evaluation indexes of geological condition, mining process, and microseismic data. A weighted distribution of evaluation indexes was determined by implementation of an entropy weight method to reveal the primary parameters controlling tunnel failure. Additionally, the damage levels of the tunnel were quantitatively assigned by computing the degree of membership that different damage levels had, based on the expectation normalization method. The methods of maximum membership principle, comprehensive evaluation value, and fuzzy entropy were considered to determine the tunnel damage levels and risk of occurrence. The application of this method at the Ashele copper mine demonstrates that it meets the requirement of risk assessment for deep tunnel failure and can provide a basis for large-scale regional tunnel failure control in deep metal mines.


2007 ◽  
Vol 20 (4-6) ◽  
pp. 651-658 ◽  
Author(s):  
Yu.N. Shebeko ◽  
I.A. Bolodian ◽  
V.P. Molchanov ◽  
Yu.I. Deshevih ◽  
D.M. Gordienko ◽  
...  

2012 ◽  
Vol 508 ◽  
pp. 101-105
Author(s):  
Siegfried Radandt

Risk management is specific to the organization and its external and internal context. In this paper risk management and some concepts focusing specifically on such plants for dusty, granular and combustible products were introduced. Some examples were presented here for practical uses, which can be applied in dusty and complicated surroundings.


2015 ◽  
Vol 10 (2) ◽  
pp. 204-209 ◽  
Author(s):  
H. Baba ◽  
◽  
T. Watanabe ◽  
K. Miyata ◽  
H. Matsumoto ◽  
...  

The flooding of the Chao Phraya River in Thailand and the Great East Japan Earthquake and Tsunami, both of which occurred in 2011, reminded us of the risks of business disruption and further impacts on national, regional, and global economies through supply chains when disasters occur anywhere in the world. Considering the increasing economic losses attributable to disasters, the fourth session of the Global Platform for Disaster Risk Reduction (2013) aimed to promote resilience and foster new opportunities for public-private partnerships as part of an overall approach to improving risk governance. Furthermore, it highlighted that a growing world requires a new approach to development action, emphasizing the private sector&rquo;s role in managing disaster risks. One of the most significant private sector contributions to disaster risk management is the creation of the business continuity plan/planning (BCP) and business continuity management (BCM) systems, which were standardized as ISO22301 and disseminated in many business enterprises around the world. However, a BCP or BCM system has been neither formulated for nor implemented in most local enterprises in industry agglomerated areas, even though these are located in areas vulnerable to disasters. Moreover, in the case of large-scale disasters, a business enterprise’s capacity may be too limited to mitigate damages and maintain operations through its own efforts, even if BCPs are prepared. The main reason for this is the disruption of public infrastructure and services. In order to minimize the negative economic impacts or economic losses, particularly in the case of a large-scale disaster that disrupts the fundamental infrastructure in certain areas, it is important to conduct risk assessment on a proper scale and to prepare scenario-based disaster management plans for area-wide damage mitigation. In addition, it is essential to have integrated resource management and strategic recovery plans to support each enterprise&rquo;s BCM actions in coordination with public sector activities. Considering this backgrounds, the Japan International Cooperation Agency (JICA) and the ASEAN Coordination Center for Humanitarian Assistance on Disaster Management (AHA Center) launched the “Natural Disaster Risk Assessment and Area Business Continuity Plan Formulation for Industrial Agglomerated Areas in the ASEAN Region” project in February 2013. The project introduced the new concept of the Area BCP, which, based on a risk assessment of the area, designates a framework and direction for coordinated damage mitigation measures and recovery actions by stakeholders, including individual enterprises, industrial area managers, local authorities, and infrastructure administrators, to allow business continuation of the industrial area as a whole. The project also established Area BCM as a cyclic process of risk assessment, sharing risk and impact information, determining a common strategy of risk management, developing the Area BCP, implementing and monitoring the planned actions to continuously improve the Area BCM system, and coordinating among stakeholders, in order to improve the capability for effective business continuity of the area. This paper aims to evaluate the progress of the project and to explore lessons from the applied process of Area BCM and its benefits.


2020 ◽  
Vol 13 (37) ◽  
pp. 3910-3943
Author(s):  
Ilias Chalvatzis ◽  

Objectives: Risk Management has been recognized as a critical issue in computer infrastructures, especially in medium to large scale organizations and enterprises. The goal of this research report is to provide a practical comprehensive virtual machine based framework for assessing the performance of vulnerability scanners applied to such enterprises, focused to small and medium size ones towards a risk evaluation analysis. Moreover, the purpose of this paper is to compare three of the most well-known free vulnerability scanners (Nessus, OpenVAS, Nmap Scripting Engine) with regards to how they can be used to systematise the process of Risk Assessment in an enterprise, based on the herein presented experimental evaluation framework involving virtual machine testing. Method: The proposed methodology is based on developing a framework for suitable setup and usage of virtual machines making risk analysis practical and being capable of comparing different vulnerability scanners. Findings: The herein developed framework is shown to be efficient with regards to comparison and selection of candidate risk analysis software with easily accessed and affordable infrastructure. Novelty: Although there might be few other similar comparisons of vulnerability scanners in the literature, the main herein contribution is the provision of a practical and above all easily reproducible framework for small business enterprises to establish proper selection procedures of such security software without spending a lot of money for expensive testing infrastructure. Keywords: Vulnerability Scanning; risk assessment; nessus; OpenVAS; Nmap scripting engine


2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Zhaohui Shang ◽  
Huibin Yan ◽  
Weidong Ruan ◽  
Yong Bai

Proper design of the explosion loads is of vital importance in the risk assessment of explosions for offshore oil and gas installations. A quantitative assessment method for gas explosion loads in process modules of offshore platform is proposed in this paper. The proposed approach achieves the following three objectives: (a) defining a suitable number of leak scenarios quantitatively based on the Latin Hypercube Sampling (LHS) technique and statistical analysis; (b) defining the explosion scenarios according to the computational fluid dynamics (CFD) dispersion analysis results in the sampled leak scenarios; (c) designing the explosion loads on interested areas according to the CFD analysis results in different explosion scenarios and exceedance probability methods. The proposed method was applied to a process module of an example offshore platform. The pressure loads on interested areas of the example platform are very close to that suggested in Det Norske Veritas (DNV) codes. The method developed in this paper can benefit the engineers on better assessment of gas explosion risk in process modules for offshore installations.


2014 ◽  
Vol 651-653 ◽  
pp. 1711-1716
Author(s):  
Yao Yu Jin

Due to the risk of large-scale public welfare project and a wide variety of intricate link between various risks, the success of its projects is a great significance for the development of China's construction industry, many issues still need further research, particularly research project risk assessment. the theoretical research evaluation of large-scale public welfare project risks are becoming a core of project risk management, this paper presents a comprehensive evaluation of large-scale public utilities engineering project risk based on entropy method, and through case studies, large public utilities project risk management provides a simple, more objective methods of analysis for policy-makers to play the role of the project.


2020 ◽  
pp. SP508-2019-157
Author(s):  
Franco Oboni ◽  
César Henri Oboni

AbstractLandslides of natural and man-made slopes represent hazardous geomorphological processes that contribute to highly variable risks. Their consequences generally include loss of life and infrastructural, environmental and cultural assets damage.Prioritizing and mitigating slope risks in a sustainable manner, while considering climate change, is related to geoethics, as any misallocation of resources will likely lead to increased risk to the public.Until recently there was little recognition of the causes and global impacts of human actions. Today, threat-denying humans can be identified as acting inappropriately and ultimately unethically. Sustainable risk management and ethical issues should be discussed simultaneously to avoid the ‘discipline silo trap’ and hazardous omissions.This contribution discusses slope risk management at various scales, i.e. how to ensure better allotment of mitigative funds while complying with sustainability goals and geoethical requirements. In 1987, the World Commission on Environment and Development published a report (also known as the Brundtland Report (Brundtland 1987. World Commission on Environment and Development Report)) that defined sustainable development as meeting the needs of the present without compromising the ability of future generations to meet their own needs.The three case histories discussed in this contribution show how sustainability and ethics can be fostered by using rational, repeatable, transparent quantitative risk assessment applicable at the local scale as well as on a large scale.


2022 ◽  
Vol 354 ◽  
pp. 00005
Author(s):  
Florin Ionel Burdea ◽  
Monica Crinela Burdea

Industrial explosive storage sites are considered to be areas of major risk to industrial, public and occupational safety and security, due to the possibility of major accidents, due to the nature of the explosive substances and due to the serious consequences of an explosion.on these sites. The explosion risk assessment for explosives depots requires an analysis of all possible occurrences of the initiating events that could lead to a potential explosion, followed by an analysis of security measures, all of which are quantified by the development of accident trees and sequences. for each possible trigger. This paper presents the principles of designing a specialized computer application in the field of explosion risk management at explosives depots for civilian use. This application allows to ensure the necessary premises for the elaboration, in objective and specific conditions, of the necessary documents for these types of technical infrastructures, from their design phase and the quantification of the degree of damage on the analyzed locations but also in the areas that are located.


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