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Titles and Abstracts for Issue No. 13, Summer 2001
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Evaluation
of Lithium Compounds as Color Agents for Pyrotechnic Flames |
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Ernst-Christian Koch [Morlauterer
Straße 103a, D-67567 Kaiserslautern, Germany] |
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Abstract: The obstacles to producing
red colored pyrotechnic flames with lithium compounds are discussed.
The principle emitter of red light in such flames is atomic lithium.
Hydrogen and halogens in the flame gases are expected to have a
substantial effect on the concentration of atomic lithium. The development
of effective Li-based red color compositions therefore depends primarily
on the proper control of the concentrations of hydrogen and halogens
in the flame to maximize the formation of atomic Li. Some possible
ways of doing this are proposed and are supported by thermodynamic
calculations.
Keywords: lithium, pyrotechnics,
red flame, color agent
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Pyrotechnic
Delays and Thermal Sources |
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M. A. Wilson and R. J. Hancox [Pains
Wessex Australia P/L, Melbourne, Australia] |
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Abstract: The technology associated
with pyrotechnic delays, together with the many factors, both physical
and chemical, that affect the performance of delay compositions
and influence the design of delay elements have been outlined. The
production of heat by thermite and thermate systems is similarly
discussed.
Keywords: pyrotechnics, gassy
delays, black powder, gasless delays, thermites, thermates, incendiaries,
Goldschmidt reaction
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Fireworks
Shell Drift due to Shell-to-Bore Clearance |
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Randall K. Norton [Pittsburg,
CA 94565, USA] |
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Abstract: For fireworks aerial
shells, decreasing shell-to-bore clearance and increasing mortar
length appear to have the effect of increasing the predictability
of fireworks aerial shell trajectories, and thus dud aerial shell
impact points. Some geometrical considerations are given to the
influence of mortar length and shell-to-bore clearance on apparent
aerial shell drift.
Keywords: fireworks aerial
shell drift, mortar length, shell clearance
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Pressure,
Plume Flicker, and Acoustic Data Correlation in Labscale Hybrid
Rockets |
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Mary Fran. Desrochers, Gary
W. Olsen, Chris Luchini, and M. Keith Hudson [Department
of Applied Science and The Graduate Institute of Technology, University
of Arkansas at Little Rock, Little Rock, AR 72204 USA] |
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Abstract: The development of the
hybrid rocket motor has been plagued by combustion instabilities.
These are usually monitored as fluctuations in chamber pressure and
are on the order of tens of Hz in frequency. Previous work using our
labscale hybrid system has also indicated instabilities at these frequencies.
These have been attributed to fuel chuffing or other phenomena. Additional
studies, in areas such as IR and other spectral monitoring, have indicated
that these oscillations are also present in the plume as light emission
flicker. However, they were not investigated in the previous work.
This paper presents a study of these specific phenomena and attempts
to correlate plume flicker, acoustic data, and higher speed chamber
pressure monitoring. It was found that the plume flicker frequencies
match those found using high speed pressure transducers, although
these light intensity fluctuations demonstrate greater amplitude.
Acoustic data could not be correlated, as it appears as a form of
white noise. The authors feel that flicker data offers an inexpensive
but sensitive alternative to high-speed pressure transducer use.
Keywords: hybrid rocket, exhaust
plume, plume diagnostics, combustion diagnostics, engine health
monitoring, optical emissions, acoustic emissions
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Pyrotechnic
Reaction Residue Particle Identification by SEM / EDS |
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K. L. & B. J. Kosanke [PyroLabs,
Inc., 1775 Blair Rd., Whitewater, CO, USA] and
Richard C. Dujay [Mesa State College,
Electron Microscopy Facility, Grand Junction, CO, USA] |
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Abstract: Today the most reliable
method for detecting gunshot residue is through the combined use
of scanning electron microscopy (SEM) and energy dispersive spectroscopy
(EDS) of the resulting X-rays. In recent years, this same methodology
has found increasing use in detecting and characterizing pyrotechnic
reaction residue (PRR) particles. This is accomplished by collecting
particulate samples from a surface in the immediate area of the
pyrotechnic reaction. Suspect PRR particles are identified by their
morphology (typically 1 to 20 micron spheroidal particles) using
a SEM, which are then analyzed for the elements they contain using
X-ray EDS. This will help to identify the general type of pyrotechnic
composition involved. Further, more detailed laboratory comparisons
can be made using various known pyrotechnic formulations.
Keywords: pyrotechnic reaction
residue, gunshot residue, scanning electron microscopy, energy dispersive
spectroscopy, morphology, X-ray elemental analysis, forensics
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Commercial
Developments in Red Phosphorus Performance and Stability for Pyrotechnics |
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Sebastian Hoerold and Andrew Ratcliff
[Clariant GmbH, Division PA, BU-Additive,
D-65840 Sulzbach am Taunus, Germany] |
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Abstract: Red phosphorus has become
an essential ingredient in the production of modern smoke and obscurant
devices. Nearly all multi-spectral developmental projects are being
based on the new versions of red phosphorus available from Clariant.
In pyrotechnics and munitions, phosphine liberated by the traditional
red phosphorus- based smoke compounds may diffuse through the device
and can give rise to corrosion of essential working parts. It is
shown in this paper that surface modification treatment of red phosphorus
can dramatically reduce the formation of decomposition products.
New developments in coating the surface are presented and the long-term
stability of various pre-treated red phosphorus powders are discussed.
The best stabilization results are found by using special combinations
of precipitated inorganic salts together with special micro encapsulation
systems. The use of dust suppression agents is also discussed.
The newly developed materials reduce the potential hazards that
arise during the manufacturing process whilst improving the shelf
life of the smoke composition.
Keywords: red phosphorus, stability,
smoke, microencapsulation
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Summary
Report on Tests on Display Fireworks Conducted by the Bureau of
Mines for the U.S. Department of transportation Relative to Hazard
Classification of Display Fireworks (Reprint) |
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J. Edmund Hay [Formerly:
Supervisory Physical Scientist, Pittsburgh Research Center, U.S. Department
of the Interior, Bureau of Mines, Pittsburgh, PA, USA] |
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Introduction: The U.S. Department
of Transportation (DOT) requested the U.S. Bureau of Mines to conduct
tests on explosive substances and articles in support of the involvement
of both agencies with the United Nations (UN) Group of Experts on
Explosives pursuant to the development of an international classification
system for explosive substances and articles. As a sub-set of the
work performed under this agreement, DOT requested the Bureau to
conduct special tests on samples of display fireworks (classified
as class B fireworks at the time that the tests were done) in their
normal shipping cartons. These tests included tests conducted according
to the specifications of UN test series 6, and an additional test
to determine the consequences of a fire involving a truck loaded
with 500 pounds of class B Fireworks. Test procedures and results
are reported herein. These tests were performed at a site leased
by the Bureau from Consolidation Coal Co. in Harrison County, Ohio,
during the period May 28–31, 1985.
Keywords: display fireworks,
UN tests, hazard classification
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Communications
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Brief
Survey of Chromium Toxicity by Monona Rossol
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