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This report is a literature review of the current state of knowledge of fireworks
and fireworks hazards. It presents work to meet Deliverables D4-1 (types and compositions
of fireworks Articles), D4-2 (Functioning mechanism of and between fireworks
articles), D4-3 (Storage and transport regulations in EU countries) and D4-4 (The effect
of fireworks on health and the environment) of the CHAF work program.
Firework compositions are discussed in the first section. This leads to an understanding
of the variability in performance of various types of fireworks. Compositions
used in report effects are highlighted as being the most energetic while other compositions
are seen as providing a much lesser hazard in mass storage of fireworks. Individual
types of firework are examined. Large devices such as report shells are identified as
posing the largest hazard in bulk storage. Lesser, but still significant, hazards are predicted
for similar compositions in Roman candles and rockets. Gradations in hazard are
identified corresponding to UN hazard divisions 1.1, 1.3 and 1.4.
The second section reports the literature relating to the functioning mechanism of
and between fireworks articles. In this the major propagation mechanisms for fireworks
compositions are examined. The main stimuli identified are: fragment impact, heat and
shock wave, each of which can lead to the functioning of pyrotechnic composition in
the article or in an adjacent article leading to large-scale initiation. Consideration of the
pyrotechnic compositions leads to a different ranking for the three mechanisms with different
fireworks types. Thus with a report composition containing a metal/perchlorate
mixture shock initiation is seen to be the main propagation mechanism. Such a mechanism
is likely to afford a mass explosion. At a lesser hazard, blackpowder-based compositions
are reported to be more likely to propagate via a flame mechanism. This is less
likely to produce a mass explosion.
National legislation concerning the storage of fireworks for many European countries
is considered in the third section. Many of the national regulations are based on a
cube root of explosives content to determine "safety distances", often written as Q1/3.
Different multiplying factors are then applied depending on the type of adjacent site
(production buildings, residential housing, roads etc.). Commonly 22Q1/3 is used for residential
dwellings. Special provisions are enacted in many countries either to allow
lesser distances or in some cases to increase the safety distances depending on the
perceived hazard or extenuating circumstances.
The final section deals with the environmental hazards posed by the use of
fireworks. Toxic effects of the materials used in the manufacture and the likely reaction
products from functioning fireworks are highlighted. These range from heavy metal
poisoning from metals present for their colour effect to respiratory problems due to
pyrotechnic fume (both particulate and gaseous). Finally, noise pollution is considered.
While there is a short term problem from pyrotechnic fume at times of high usage
(national celebrations) there is no literature evidence, as yet, of long term detriment to
the environment.
IGUS is the International Group of Experts on the Explosion Risks of Unstable Substances. Today, the aim of the group is to exchange information on the behavior of unstable substances and to improve safety in production, storage, transport, and use of these substances. Full members of IGUS work for governments and independent research organizations. Experts from industry can and do attend meetings by invitation. IGUS's 50th anniversary in 2012 gives reason to have a closer look at the questions of how IGUS came to be, what IGUS's aims and objectives were, and how it is organized and working today.
In the present study, the impact of static traffic loading on the slight deflection effects in the concrete structure of an existing bridge has been investigated using distributed fiber optic sensors. In the face of increasing traffic density and severe traffic loading, the results of the load tests on the Amsterdam bridge 705 make an important contribution to the understanding of its structural behavior. The concept of the static loading was based on the use of two 36-ton trucks stopped on the bridge at multiple pre-determined locations. The load applied in this way led to location-dependent small deflection effects recorded as longitudinal strain of the sensing fiber embedded at the underside of the bridge. The measurements were performed with a commercially-available solution based on Tunable Wavelength Coherent Optical Time Domain Reflectometry with the measurement accuracy in the range of 0.5 µm/m.
Large-language models (LLMs) such as GPT-4 caught the interest of many scientists. Recent studies suggested that these models could be useful in chemistry and materials science. To explore these possibilities, we organized a hackathon. This article chronicles the projects built as part of this hackathon. Participants employed LLMs for various applications, including predicting properties of molecules and materials, designing novel interfaces for tools, extracting knowledge from unstructured data, and developing new educational applications. The diverse topics and the fact that working prototypes could be generated in less than two days highlight that LLMs will profoundly impact the future of our fields. The rich collection of ideas and projects also indicates that the applications of LLMs are not limited to materials science and chemistry but offer potential benefits to a wide range of scientific disciplines.