Hazard | EPFL Graph Search

A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk, a term often used synonymously in colloquial speech. Hazards can be classified in several ways; they can be classified as natural, anthropogenic, technological, or any combination, such as in the case of the natural phenomenon of wildfire becoming more common due to human-made climate change or more harmful due to changes in building practices. A common theme across many forms of hazards in the presence of stored energy that, when released, can cause damage. The stored energy can occur in many forms: chemical, mechanical, thermal hazards and by the populations that may be affected and the severity of the associated risk.

SnSb binary alloy induced heterogeneous nucleation within the confined nanospace: Toward dendrite-free, flexible and energy/power dense sodium metal batteries

Dou Du, Yujie Liu, Min Zhang

Rechargeable sodium (Na) metal batteries (SMBs) provide an alternative energy-dense, low-cost energy storage system beyond prevailing Li-ion technologies. However, their practical deployment requires the performance evaluation of Na anodes on the device level and mitigation of safety hazards, i.e., mechanical stress, electrode pulverization and dynamic interfacial properties. Here, we propose a lightweight N-doped carbon nanofiber substrate with SnSb nanocrystallites monodispersed within the mesopores (SnSb@NCNF). The alloying-induced Na15Sn4 and Na3Sb intermediates act as the heterogeneous sodiophilic "magnets" to homogenize Na ion flux and confine Na deposits within the nanospace. Additionally, the nucleation theory of metal solidification bridges the density functional theory calculations, elucidating the oriented Na propagation that maximizes the anode utilization. With the proper Na plating regulation, the SnSb@NCNF substrate (pre-stored 1 x excess Na) integrates with the NaVPO4F cathode in 5 mA h single-layer pouch cell, the prototype of which exhibits the cycling endurance (96.3% capacity retention for 500 cycles) and high specific energy/power densities even upon the repetitive mechanical flexing scenarios. The nanoconfinement of the heterogeneous nucleation process affords a feasible approach to mitigate the dendrite formation upon the geometry deformation or high areal-capacity loading, which enlightens the further exploration of the energy-dense, mechanical flexible battery system.

ELSEVIER2021

Systemic risk in the network industries: is there a governance gap?

Ian Robert Bartle, Marc Laperrouza

Systemic risks and hazards have become increasingly significant features of modern industrial society of which the network industries form a vital element. The idea of systemic risk, however, is much less prominent in the network industries compared to banking and finance. This paper addresses why there is such a difference between these sectors. It then addresses how complexity and systemic risk in the network industries should be managed and governed. Does it above all require more and better scientific and technical analysis to understand the risks and reduce uncertainty? Or does it require qualitatively different forms of governance that draw on many different types of knowledge, and involve a wider range of stakeholders? We argue in this paper that systemic risk is very important in the network industries and it needs to be a considered more explicitly than hitherto in the governance and regulation of risk in the network industries. Traditional technocratic forms of risk management and governance while necessary are not sufficient, particularly due because of heightened uncertainty and interdependence. Unless and until the problems of uncertainty are overcome, means of governing risk and uncertainty beyond the technocratic are required. In particular, judgements by different experts and stakeholders are required about the nature of the uncertainty, about the potential hazards and their consequences, and about the level of caution required. This requires a more participative and open form of risk governance, a form which draws on socio-political forms of governance as well as technocratic. This is recognised in part in the recent literature on risk governance of critical infrastructures but the literature says little about the participative governance structures which might be appropriate nor how they may be developed in the patchwork that is the European regulatory environment for the network industries.

2009

The challenges of impact evaluation: Attempting to measure the effectiveness of community-based disaster risk management

Nicola Mary Banwell, Anthony Christopher Davison, Silvia Hostettler, Alfredo Rafael Kägi Trejo

Although disaster risk management is becoming increasingly important in development cooperation, there is still a lack of robust evidence regarding its effectiveness. Few studies based on a counterfactual have been conducted in the fields of disaster management and disaster risk reduction. This article describes a methodological approach to enabling more rigorous evidence-based decision-making in community-based disaster risk mitigation, and notably for assessing the degree to which it increases preparedness for the adverse effects of hazards in vulnerable communities. The effects of actions designed to reduce disaster-induced loss, damage, injuries, fatalities and resource degradation were evaluated at a Swiss and Honduran Red Cross’ intervention area in Honduras. Our results show that the intervention has had a significant positive effect in three important areas of resilience: knowledge and preparedness (e.g., existence of an early warning system); social cohesion (e.g., community institutions); and management of natural assets (e.g., firewood consumption). Our findings indicate that the intervention program has enhanced the capacities of treated communities to prepare for future hazards and to respond in case of an emergency at both household and community levels.

2020

Systemic risk in the network industries: is there a governance gap?

Ian Robert Bartle, Marc Laperrouza

2009