The safety case and the lessons learned for the reliability and maintainability case

This paper examine the safety case and the lessons learned for the reliability and maintainability case

Bacterial-foraging optimization algorithm for non-hazardous plant layouts

PresentationThe following article approaches a safe plant layout design problem based on a bacterial-foraging optimization algorithm. Our approach finds the position in the two dimensional plane for each main process unit and evaluates the possibility of secondary contention for pertinent units, in order to minimize capital costs associated to equipment loss, piping, secondary contention, and usage of area. Fire and Explosion hazard is considered as the relevant safety aspect for distribution, and it is assessed through Dow’s Fire and Explosion Index. The proposed solution approach provides an alternative to hard-optimization methods, by allowing greater flexibility in accounting for both safety and economic aspects, while providing high quality solutions in a limited computation time. The aim of our proposed solution approach is to provide support to expert decision-making during the early plant layout design steps. A case study based on an acrylic-acid production plant, which has been used by several other papers that appeared in the literature, serves the purposes of showing the appropriateness and effectiveness of the method

Alternative sweetener from curculigo fruits

This study gives an overview on the advantages of Curculigo Latifolia as an alternative sweetener and a health product. The purpose of this research is to provide another option to the people who suffer from diabetes. In this research, Curculigo Latifolia was chosen, due to its unique properties and widely known species in Malaysia. In order to obtain the sweet protein from the fruit, it must go through a couple of procedures. First we harvested the fruits from the Curculigo trees that grow wildly in the garden. Next, the Curculigo fruits were dried in the oven at 50 0C for 3 days. Finally, the dried fruits were blended in order to get a fine powder. Curculin is a sweet protein with a taste-modifying activity of converting sourness to sweetness. The curculin content from the sample shown are directly proportional to the mass of the Curculigo fine powder. While the FTIR result shows that the sample spectrum at peak 1634 cm–1 contains secondary amines. At peak 3307 cm–1 contains alkynes

Fire behavior and risk analysis in spacecraft

Practical risk management for present and future spacecraft, including space stations, involves the optimization of residual risks balanced by the spacecraft operational, technological, and economic limitations. Spacecraft fire safety is approached through three strategies, in order of risk: (1) control of fire-causing elements, through exclusion of flammable materials for example; (2) response to incipient fires through detection and alarm; and (3) recovery of normal conditions through extinguishment and cleanup. Present understanding of combustion in low gravity is that, compared to normal gravity behavior, fire hazards may be reduced by the absence of buoyant gas flows yet at the same time increased by ventilation flows and hot particle expulsion. This paper discusses the application of low-gravity combustion knowledge and appropriate aircraft analogies to fire detection, fire fighting, and fire-safety decisions for eventual fire-risk management and optimization in spacecraft

Automating allocation of development assurance levels: An extension to HiP-HOPS

Controlling the allocation of safety requirements across a system's architecture from the early stages of development is an aspiration embodied in numerous major safety standards. Manual approaches of applying this process in practice are ineffective due to the scale and complexity of modern electronic systems. In the work presented here, we aim to address this issue by presenting an extension to the dependability analysis and optimisation tool, HiP-HOPS, which allows automatic allocation of such requirements. We focus on aerospace requirements expressed as Development Assurance Levels (DALs); however, the proposed process and algorithms can be applied to other common forms of expression of safety requirements such as Safety Integrity Levels. We illustrate application to a model of an aircraft wheel braking system

Introducing the STAMP method in road tunnel safety assessment

After the tremendous accidents in European road tunnels over the past decade, many risk assessment methods have been proposed worldwide, most of them based on Quantitative Risk Assessment (QRA). Although QRAs are helpful to address physical aspects and facilities of tunnels, current approaches in the road tunnel field have limitations to model organizational aspects, software behavior and the adaptation of the tunnel system over time. This paper reviews the aforementioned limitations and highlights the need to enhance the safety assessment process of these critical infrastructures with a complementary approach that links the organizational factors to the operational and technical issues, analyze software behavior and models the dynamics of the tunnel system. To achieve this objective, this paper examines the scope for introducing a safety assessment method which is based on the systems thinking paradigm and draws upon the STAMP model. The method proposed is demonstrated through a case study of a tunnel ventilation system and the results show that it has the potential to identify scenarios that encompass both the technical system and the organizational structure. However, since the method does not provide quantitative estimations of risk, it is recommended to be used as a complementary approach to the traditional risk assessments rather than as an alternative. (C) 2012 Elsevier Ltd. All rights reserved

Safety and security management through an integrated multidisciplinary model and related integrated technological framework

The purpose of this paper is to illustrate a multidisciplinary model for safety and security management (IMMSSM) which can be implemented by means of a suitable Integrated Technological System Framework (ITSF) that can be based on Internet of Things (IoT)/Internet of Everything (IoE), showing also the significant role played by the integration of the elements that compose the model itself, thanks to a proper genetic algorithm studied for the specific context