<
| |
<
|
Titles
and Abstracts for Issue 24, Winter 2006
|
|
Vojtech Pelikan (Institute
of Energetic Materials (IEM), University of Pardubice, Czech Republic
) |
|
Abstract: The electrical properties
of bridgeless fuseheads were examined. A conducting composition based
on the mixture lead styphnate, Viton binder and conductive admixture
was used as the fusehead priming mixture. Several types of conducting
admixtures, namely two types of natural finely milled graphite and
special conducting carbon black, of varying particle size and origin,
were used. To produce fuseheads the standard dipping technology for
application of the pyrotechnic mixture was used. Fuseheads equipped
with a safety shroud and leading wires were installed in a standard
aluminum body No. 8 detonator to test the electrical and firing characteristics
and determine how these fuseheads will affect the detonator’s
properties in particular regarding reaction time. The measurements
further included determination of electric sensitivity (All-fire energy)
and resistance.
It was found that for production of this type of fusehead is possible
to use standard dipping technology without significant change in
the technological process, but the presence of binder in the pyrotechnic
composition has a considerable influence on the electrical properties.
Determination of the reaction times of detonators showed that is
possible to reach very short reaction times less than 1 ms.
This is approx. 20 times less compared with a detonator (or fusehead)
equipped with a standard bridge wire fusehead. This could be advantageous
for the many applications where a fast response of the electro-explosive
system is required together with low cost and ease of use. Typical
of such applications are firework displays and special pyrotechnic
effects.
Keywords: conducting composition,
initiator, lead styphnate, electric detonator, fusehead |
|
|
|
|
Ernst-Christian Koch
(Diehl BGT Defence GmbH & Co. KG, Fischbachstr. 16, D-90552 Röthenbach a.d. Pegnitz, Germany) |
|
Abstract:A mixture of magnesium,
potassium perchlorate, KClO4, and polytetrafluoroethylene,
(-C2F4-)n, displays an audible crackling
effect with nice sparks.
Keywords: crackling
effect, magnesium, potassium perchlorate, polytetrafluoroethylene,
Teflon™ |
|
|
|
|
Kazuomi Itoh, Dayu Ding and Tadao Yoshida
(Ashikaga Institute of Technology, 268-1Omae-cho, Ashikaga-shi, Tochigi 326-8558, Japan) |
|
Abstract: Spectra and color values of the light from LEDs and liquid colors were measured using the PMA-11C7473-36 spectrometer as a preliminary study of the color of firework flames. The light from LEDs was stable and reproducibly measured. The color values of the light from LEDs did not vary with change in the exposure time of the spectrometer and the distance between the light and the incident point. The color values of the flames of liquid colors were less stable than those from LEDs owing to the flickering of the flame, but nearly constant with the change of exposure time and distance. The peak heights of the flame spectra of the liquid colors were proportional to the exposure time, but when the highest peak was saturated the proportionality changed. The red and yellow spectra of the liquid colors consisted of the single peaks from Li and Na atoms, respectively, with high excitation purity. The green and blue spectra consisted mainly of the molecular spectra of BO2 and CuCl, respectively, with moderate excitation purity. The concentrations of the principal color emitters of the flames of alcohol colors were calculated using a computer program for chemical thermodynamics.
Keywords: flame spectra,
liquid colors, LED, spectroscopic measurement, thermodynamic
modeling |
|
|
|
|
Kazuomi Itoh, Dayu Ding,
Hiroshi Tajima and Tadao Yoshida
(Ashikaga
Institute of Technology, 286-Omae-cho, Ashikaga-shi, Tochigi 326-8558,
Japan) |
|
Abstract: The spectroscopic
measurement of burning stars has been carried out in order to examine
the spectra of the stars, the peak intensity profiles of the spectra,
the burning time and behavior, and the effect of filters on the
attenuation of peak intensity and the excitation purity
.
Keywords: firework stars,
spectroscopic measurement, burning time, emission spectra,
three dimensional
expression, peak intensity profile, excitation purity, filter
|
|
|
|
|
John Wraige (Rosemundy, Leigh Road, Hildenborough, Kent, UK TN119AH ) |
|
Abstract: This report presents the results of experiments carried out spasmodically over 14 years to investigate the glitter phenomenon. Various glitter compositions are disclosed. Some of these show that the use of sulphur in either elemental or combined form is unnecessary. Others show that similar considerations apply to antimony or any other heavy metal. It is further shown that the potassium ion may be replaced by either the caesium, rubidium, or sodium ion. Speculative broad mechanisms involved in the production of the glitter effect are discussed.
Keywords: fireworks, glitter, sulfur-free, nitrate, metals, nitro-compounds |
|
|
|
|
K. L. Kosanke and B. J. Kosanke (PyroLabs, Inc., Whitewater, CO, USA
) |
|
Abstract: Lightning Thermo Tube (LTT) is a recently introduced type of shock tube with characteristics that make it highly suitable for use with common pyrotechnics. LTT is reliably initiated by reasonably energetic electric matches and reliably ignites most pyrotechnic compositions. LTT is physically strong, easily spliced and branched, and highly weather resistant. LTT produces a bright flash of light upon functioning, which may be useful in itself. This paper presents the results of a series of tests performed to determine some of the more important capabilities and characteristics of LTT as it relates to use with pyrotechnics in general and fireworks in particular.
Keywords: thermo tube,
shock tube, pyrotechnic ignition system |
|
|
|
|
L. T. Briscoe, K. L. Kosanke*, and R. C. Dujay (Mesa State College, Center for Microscopy, PO Box 2647, Grand Junction, CO 81501) |
|
Abstract: A study was conducted
to determine the potential for being able to identify primer
gunshot residue (PGSR) within the substantial quantities of particulate
residues produced during the firing of a revolver using Black
Powder propellant and a percussion cap primer. Samples of gunshot
residue (GSR) were collected from the shooter’s hands, from surfaces
to the side of the shooter, from surfaces near the muzzle of
the weapon, and from various locations on the weapon itself (both
inside and outside). It was found to be relatively easy to identify
PGSR from the hand of the shooter, from surfaces to the side
of the weapon, and from most locations on the weapon. However,
using the methods of this study, no PGSR was identified within
the large amount of Black Powder residue projected out the muzzle
of the weapon and on the inside of its barrel.
Keywords: gunshot residue,
GSR, Black Powder, percussion cap primer, scanning electron microscopy,
SEM, energy dispersive spectroscopy, EDS |
|
|
|