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Titles and Abstracts for Issue No. 17, Summer 2003
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Color
Purity Measurements of Traditional Pyrotechnic Star Formulas |
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Brian V. Ingram [Sandia
National Laboratories, PO Box 5800–MS 1452, Albuquerque, NM 87185,
USA] |
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Abstract: Pyrotechnic formulas
designed to produce colored flames are well known, but the trends
in color quality due to individual formula components are less well
understood. This paper presents spectrometer work done to record
spectra and processes them into chromaticity coordinates. Major
formulas of the basic additive colors of red, green, and blue were
tested and compared. Impact sensitivities were gathered for those
major formulas. Then single suitable formulas were chosen for the
basic colors, which were then systematically altered and measured
for color quality performance. The formulas were altered to investigate
the role of oxidizer to fuel ratio, chlorine donor content, colorant
content, and colorant source.
Keywords: color purity, chromaticity
diagram, chromaticity coordinate, star formula, flame emission
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A
Study of the Combustion Behaviour of Pyrotechnic Whistle Devices
(Acoustic and Chemical Factors) |
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M. Podlesak [Weapons
Systems Division, System Sciences Laboratory, DSTO, PO Box 1500, Edinburgh
5111, Australia] and M. A. Wilson
[ Pains Wessex (Australia) Pty Ltd,
PO Box 90, Lara 3212, Australia, Formerly of Weapons Systems Division,
Aeronautical and Maritime Research Laboratory, DSTO, Melbourne, Australia] |
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ABSTRACT: Pyrotechnic whistles
have long been used in both civilian and military applications.
It is known that, under certain conditions, these compositions burn
in an oscillatory manner and have exhibited a tendency occasionally
to explode with great power during combustion. Based on the results
of experimental work and a study of the thermochemical properties
of whistle fuels, a hypothesis is proposed that attempts to account
for the observed high levels of explosive and acoustic power of
pyrotechnic whistles. The formation of < 10 mm diameter
hollow carbon spheres was observed in laboratory experiments involving
the thermal decomposition of potassium benzoate (a whistle fuel)
in a reducing atmosphere. At the moment of formation, the spheres
may possibly be filled with combustible hydrocarbon gases and would
be extremely reactive. If formed during the quiet cycles of an operating
whistle device, their existence may explain the higher than expected
acoustic power of pyrotechnic whistles. Such a hypothesis may also
lead to an understanding of other hitherto unexplained explosions,
where under conditions such as ‘cook-off’, the thermal decomposition
of organic fuels used in some other pyrotechnics would result in
the formation of new substances which are more reactive than the
parent chemicals.
Keywords: whistle, combustion,
acoustics, oscillating burning, pyrotechnics
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Reasons
for Fuse Failure and Drift Distance of Spherical Fireworks Shells |
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Marc Speer [Speer
Pyrotechnik, Hans-Böckler-Allee 51, 52074 Aachen, Germany / www.speerpyro.de] |
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Abstract: This work investigates
the reasons for the ignition-failure of spherical (round) shells.
It further statistically assesses the probability that the resulting
blind (dud) shells will fall within a certain range from the launch
point.
Keywords: fuse failure, shell
drift, Magnus effect, interior ballistics, exterior ballistics,
shell ballistics, blind shell, dud shell
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Some
Properties of Explosion Generated Toroids |
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Fred Ryan and Joe Daugherty
[PO Box 406, New Alexandria, PA 15670
USA] |
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Abstract: The mechanism of sound
production from explosion-created toroids is discussed, as well
as progress in rendering them more visible. The toroids, or “smoke
rings”, are easily formed by exploding a small charge at the bottom
of a cylindrical barrel that is open at the top. The stability,
self propulsion, velocities, visibility, and sound frequencies are
discussed. The dependency of these properties on the toroid production
parameters is experimentally compared with theoretical predictions.
Keywords: toroid, vortex, smoke
ring, explosion generated, sound emission, velocity, stability,
frequency, visibility
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Feasibility
Study on the Use of Nanoscale Thermites for Lead-Free Electric Matches |
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Darren L. Naud, Michael A. Hiskey, Steven
F. Son, James R. Busse, [ Los Alamos
National Laboratory, High Explosives Science and Technology, DX-2,
MS C920 Los Alamos, NM 87545, USA] and
Ken Kosanke [PyroLabs, 1775 Blair
Road, Whitewater, CO 81527, USA] |
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ABSTRACT: Electric matches are
used in the pyrotechnic industry to electrically initiate devices
remotely and with precise timing. Unfortunately, most current commercial
electric matches contain lead compounds, which when burned produce
lead reaction products that may cause environmental pollution and
contamination of firing areas. These lead compounds, namely lead
thiocyanate, lead nitroresorcinate and lead tetroxide, are used
in electric match pyrotechnic formulations because a small diameter
resistive bridgewire can reliably initiate them. A possible alternative
to lead-containing compounds is nanoscale thermite materials, otherwise
known as Metastable Intermolecular Composite (MIC) materials. These
super-thermite materials can be formulated to be sensitive to thermal
stimuli, such as resistive heating. In the effort to produce a lead-free
electric match, a feasibility study was performed using nanoscale
aluminum and molybdenum trioxide mixtures in electric match formulations.
Keywords: nanoscale, thermite,
lead-free, electric match, metastable intermolecular composite,
performance test, sensitiveness test
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Communications
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A Curious Observation during
the Burning of Bulk Whistle Composition by L. Weinman
Review by S. Miller of Proximate
Special Effects Familiarization and Safety by J. L. Mattingly,
D. A. Opperman and F. Pinkerton
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