Accidental non-stationary combustion processes are the main issue of safety considerations in connection with hydrogen technology. The overpressure loads produced by detonations but as well those imposed upon structures by fast, turbulent deflagrations are easily of sufficient strength for serious damage. Since an accidental combustion process is most likely to start as a slow deflagration, detailed knowledge of the mecbanisms of flame acceleration leading to high-speed reaction fronts is of vital importance for design guidelines and safety analysis. In this paper the parameters influencing turbulent flame acceleration processes, i.e. initial conditions and geometry of the combustion volume, are discussed and a brief outlook for necessary future research activities is provided.

The evaluation of safety parameters for binary and ternary mixtures of hydrogen and light hydrocarbons is essential for the definition of the combustion characteristics of bio-derived fuel-gas mixtures. Furthermore, with specific reference to laminar burning velocity, there is a strong need to define simple correlations, which would allow a fast prediction of global burning velocity of the mixtures starting from molar compositions and laminar burning velocity of the pure components, in analogy with Le Chatelier's rule for flammability limits. In this paper, a preliminary experimental and numerical study is performed for the assessment of safety parameters for mixtures of methane, propane and hydrogen with air at initial ambient pressure. Explosion tests have been conducted in a reinforced 5 liters steel vessel. The PREMIX module of the CHEMKIN package, coupled to the Marinov detailed reaction scheme, has been used to compute the un-stretched laminar burning velocity. For model validation, results have been compared to experimental data.

This article illustrates a contribution of the CEA Laboratory of Concrete and Clay Behavior ("LECBA") for the assessment and modeling of the Long-Term behavior of cementitious and clayey materials in the context of nuclear ILW (Intermediate Level Waste) management. In particular, we aim at presenting two main topics that are studied at the Lab. The first one is linked to safety aspects and concern hydrogen transfer within cementitious as well as clayey materials (host rock for French nuclear waste disposal). The second point concerns the assessment of durability properties of reinforced concrete structures in the disposal (pre-closure and post-closure) conditions. Experimental specific tests and phenomenological modelling are presented.

A study of open literature was performed to determine the effects of high hydrogen purity and gas pressure (in the range of 700-1000 bar) on the hydrogen embrittlement of several metallic materials. A particular focus was given to carbon, low-alloy and stainless steels. Finally, suggestions are provided for future testing necessary to ensure the safety of hydrogen storage at 700 bar. (C) 2010 Published by Elsevier Ltd on behalf of Professor T. Nejat Veziroglu.

In 2006, seventeen Universities across the United States competed in the United States Department of Energy's "Challenge X," a project based on reengineering a General Motors Equinox vehicle to minimize energy consumption and emissions while meeting or exceeding the performance of the original vehicle. The team from Texas Tech University used National Instruments CompactRIO Programmable Automation Controller (PACs) and the LabVIEW Real-Time Operating System to monitor H2 tank pressure, temperature and deionized water status. National Instruments PACs were also used to monitor and trigger the emergency stop system within the vehicle, if alarming levels of hydrogen are sensed anywhere within the vehicle.

An in situ, easy, and versatile method to decorate a polymer substrate with uniformly spaced centimeter- long arrays of 5 - 10 nm palladium nanoparticles is reported. The electrochemical deposition of palladium nanoarrays is described as well as results from various microscopic and spectroscopic characterizations, such as transmission electron microscopy, scanning electron microscopy, optical microscopy, and electron spectroscopy for chemical analysis for their size, morphology, chemical constituent, and chemical state, respectively. The Pd nanoarrays were synthesized using a special kind of active template from an electrolyte solution of ionic strength 0.10626 mol g(-1). The effect of curvature on the active template is discussed briefly. Understanding of the preferentially deposited Pd nanoparticles to form nanoarrays longitudinally under controlled conditions can lead to the preparation of low- cost, lightweight, reliable hydrogen sensors for safety monitoring applications. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.1945667] All rights reserved.

The strength of materials and structural elements operating in contact with high-pressure gaseous hydrogen is studied as applied to the problems of hydrogen power-generating industry. The requirements to the design of structural elements operating in hydrogen are formulated. We propose a model of influence of high-pressure gaseous hydrogen on the strength and plasticity characteristics of structural materials and apply this model to the development of the corresponding procedures of strength analysis and evaluation of the cyclic fatigue life and durability of strucrural elements of hydrogen power-generating equipment taking into account the dislocation and diffusion mechanisms of hydrogen transport in the metal. The data on the properties of materials in hydrogen, the choice of the proper safety and durability margins, and the evaluation of admissible stresses in the structures are presented. The analysis of strength, cyclic fatigue life, and the number of cycles to failure are illustrated by special examples.

{This paper evaluates the performance of the NIOSH draft method 5525 for analysis of monomeric and TRIG aliphatic isocyanates in autobody repair shops. It was found that an optimized pH gradient enhanced noticeably the resolution and, therefore, identification of aliphatic isocyanates. Samples proved to be very stable for at least a year when stored at -13 degreesC in the freezer, and no major stability problems were found for the MAP reagent. The detector response factor RSD for selected MAP ureas was 40%2in the fluorescence (FLD), 3%2in the UV at 254 nm (UV254), and 1%2in the UV at 370 nm (UV370). The mean FLD/UV254 and UV254/UV370 detector response ratios of standards were 31.7 (RSD = 37.8) and 17.1 (RSD = 5.4), respectively. The FLD/UV254 ratio in bulks varied from 0.41 to 1.97 times the HDI monomer ratio. The mean UV254/UV370 ratio in bulks was 16.1 (range 14.1 to 19.2

This paper explores the public's understanding of 'sustainable energy', focusing upon hydrogen, which for most is unfamiliar. We report reactions to a first tour of the recently established 'Hydrogen Research and Demonstration Centre' in the Valleys of South Wales, which was guided by its scientists and engineers. The visitors lived within 50 miles and fell into three age-categories: 14-year old Baccalaureate students; 18-19 year old students at Tertiary College; and adult- members of a Citizens' Panel. They took part in six focus groups which were facilitated, recorded and then analysed thematically by independent sociologists. The paper examines themes on which the groups agreed or disagreed, and how clear or ambiguous their discourse was. While broad consensus was reached on benefits, costs and safety of hydrogen, there were differences in how groups imagined incorporating it into their lives. In conclusion, we draw lessons for securing wider public commitment to sustainable energy. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.