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Titles and Abstracts for Issue 18, Winter 2003
Color Values and Spectra
of the Principal Emitters in Colored Flames
W. Meyerriecks and K. L. Kosanke [702
Leisure Avenue, Tampa, FL 33613, and PyroLabs, Inc., 1775 Blair Rd, Whitewater,
CO 81527, USA]
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
Reprint
Information: Number of pages = 22.
- Thermal Characterization
of Smoke Composition
- 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]
- 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
- Reprint
Information: Number of pages = 9.
- Control Systems for the
Storage of Explosives, Including Fireworks
- M. J. Bagley [Health
and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, SK17 9JN, UK]
- 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
- Reprint
Information: Number of pages = 11.
- Studies of the Thermal
Stability and Sensitiveness of Sulfur/Chlorate Mixtures — Part 5: Application
of Self-Heating Theory to the Prediction of Ignition Temperatures
- J. E. Fletcher [Health
and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, SK17 9JN, UK]
- 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
- Reprint
Information: Number of pages = 10.
- Assessing the Risks
— Suggestions for a Consistent Semi-Quantified Approach
- Tom Smith [Davas
Limited, 8 Aragon Place, Kimbolton, Huntingdon, Cambs., PE28 0JD, UK]
- 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
- Reprint
Information: Number of pages = 10.
Communications :
- 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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