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Titles and Abstracts for Issue 18, Winter 2003
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Color
Values and Spectra of the Principal Emitters in Colored Flames |
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W. Meyerriecks [702
Leisure Avenue, Tampa, FL 33613] and
K. L. Kosanke [PyroLabs, Inc., 1775
Blair Rd, Whitewater, CO 81527, USA] |
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Abstract: The emission spectra
of many of the more important emitters in pyrotechnic flames were
collected. For this purpose solutions and suspensions of sodium,
potassium, calcium, strontium, barium and copper salts were aspirated
into a propane gas flame as the excitation source. Performing instrument
corrections and using appropriate data reduction strategies allowed
the isolation of the individual spectra. Among these are the monochlorides
and monohydroxides of strontium, calcium, barium and copper. The
CIE color coordinates of the principal emitters were calculated
from the isolated spectra. In addition, a table of normalized band
and line intensities was produced for each of the successfully isolated
emitting species.
Keywords: flame spectra, flame
color, color emitter, color coordinate, monochloride, monohydroxide,
barium, calcium, copper, strontium
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Thermal
Characterization of Smoke Composition |
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Z. Abdel-Qader, Q. S. M. Kwok, R. C. Fouchard,
P. D. Lightfoot and D. E. G. Jones [Canadian
Explosives Research Laboratory, 555 Booth Street, Ottawa, Ontario,
K1A 0G1 Canada] |
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ABSTRACT: The present work includes
the thermal characterization of a smoke composition, the smoke components,
as well as a potassium chlorate–lactose mixture using differential
scanning calorimetry (DSC), thermogravimetry (TG), simultaneous
thermogravimetry-differential thermal analysis-Fourier transform
infrared spectrometry-mass spectrometry (TG-DTA-FTIR-MS), and accelerating
rate calorimetry (ARC). The DSC results for the smoke composition
show a sharp exotherm at 140–210 °C, and the ARC results show one
rapid exotherm with an onset temperature of 118 + 5 °C. These
exotherms result from the rapid and energetic reaction between lactose
and potassium chlorate. Kinetic studies conducted separately in
heat-wait-search and isothermal experiments in the ARC yielded substantially
different results for the activation energy. Simultaneous TG-DTA-FTIR-MS
was used to investigate the thermal behavior of the smoke composition
and to analyze the evolved gases during the heating process. Carbon
dioxide (CO2), water vapour and carbon monoxide (CO)
were detected with a significant intensity using FTIR-MS. Further
DSC and TG work was performed for 1-aminoanthraquinone (1-AAQ),
a dye that is the main component of the smoke composition. DSC and
TG results for the 1-AAQ dye are compared with those for a high
purity 1-AAQ dye from a different source. The DSC and TG results
indicate that the 1-AAQ dye sample had a significant nonvolatile
residual mass compared to the high purity one.
Keywords: smoke composition,
orange dye, aminoanthraquinone, thermal analysis, DSC, TG, DTA,
FTIR, MS, ARC
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Control
Systems for the Storage of Explosives, Including Fireworks |
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M. J. Bagley [Health
and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, SK17 9JN,
UK] |
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Abstract: This paper gives an account
of the use of a questionnaire to obtain up-to-date information on
control systems for the storage of fireworks and other types of explosives.
The study showed that control systems for the storage of explosives
based on quantity-distance schemes are used in many countries. In
most of these schemes, fireworks are treated in the same way as other
types of explosives.
The classification of fireworks is seen to be a particular problem
because of the large number of different types that are on the market.
There are also concerns about the accurate classification of fireworks
stored in steel transport containers or in magazines constructed
from brick or concrete. For the storage of mixed fireworks, several
countries assign the fireworks to the same hazard division as the
most hazardous type of firework in the store.
Keywords: explosives, storage,
fireworks, control
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Studies
of the Thermal Stability and Sensitiveness of Sulfur/Chlorate Mixtures
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Part 5: Application of Self-Heating Theory to the Prediction of
Ignition Temperatures |
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J. E. Fletcher [Health
and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, SK17 9JN,
UK] |
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Abstract: The self-heating models
of Frank-Kamenetskii and Thomas have been applied to predict self-ignition
temperatures for sulfur-chlorate mixtures in spherical and cylindrical
geometries of varying size. The models were validated by comparison
to experimental cardboard tube test data previously reported. It
was found that the Frank-Kamenetskii model, combined with kinetic
data from differential scanning calorimetry, gave the best agreement
with the experimental results. However, careful selection of the
kinetic parameters proved critical and, in this study, DSC data
provided more relevant predictions than ARC data. By appropriate
selection of size and geometry, the models could be further applied
to predict self-ignition temperatures for other mixtures and geometries
or systems that can be related to actual fireworks.
Keywords: sulfur, chlorate,
fireworks, thermal stability, self-heating, Frank-Kamenetskii, Thomas
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Assessing
the Risks — Suggestions for a Consistent Semi-Quantified Approach |
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Tom Smith [Davas
Limited, 8 Aragon Place, Kimbolton, Huntingdon, Cambs., PE28 0JD,
UK] |
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Abstract: Assessing the risks
of an operation, the operation of a whole factory, or the consequences
of firing a firework display has become a way of life. Much modern
legislation, certainly in the UK, is based less on “prescription”
and more on “goal setting”, which requires the risk creator to determine
the nature of the risk and to allow him to control it adequately.
Everyone involved in almost any activity, be it sport, driving,
or managing a pyrotechnic production facility, has always assessed
the risks—normally in their head and on the job. Modern legislation
demands that these informal processes, accurate as they may have
been, be documented, monitored and revised as appropriate, partly
at least to “prove” in any post-accident enquiry that adequate steps
had been taken to identify the particular circumstances that caused
the accident. Failing to identify a particular risk is as negligent
as failing to control a risk that had been identified.
Keywords: risk assessment,
consequence, hazard management
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Communications
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Particle Size Effect in Pyrotechnic
Compositions Containing Potassium Chlorate by M. Fathollahi, S.
G. Hosseini, S. M. Pourmortazavi, and F. Farahani
Review by B. E. Douda of: Pyrotechnics by A. P. Hardt
Review by S. D. Poehlein and S. K. Wilharm of: Pyrotechnics
by A. P. Hardt
Review by B. Sturman of: Pyrotechnics by A. P. Hardt
Review by J. Bergman of: Black Powder Manufacturing, Testing,
and Optimizing by Ian von Maltitz
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