Whistle effect

A reaetion that produces a whistling effect is burning intermittently from layer to layer in the pressed composition. A whistling reaction is on the verge of an explosion, so these mixtures must be cautiously prepared and carefully loaded into tubes. Large quantities of bulk powder should be avoided, and they should never... 

Water, vaporization of, 113 Whistle effect, 176, 178 White light... 

Strontium nitrate Dextrin Red gum Polyvinyl chloride White sparks aluminum, magnesium, aluminum-magnesium alloy, titanium Whistle effect potassium benzoate or sodium salicylate White smoke mixture of potassium nitrate and sulfur Colored smoke mixture of potassium chlorate, sulfur, and an organic dye... 

Formulation A (Whistle) Formulation B (Blue) Effect A (Whistle) Effect B (Blue)... 

A unique whistling phenomenon can be produced by firmly pressing certain oxidizer-fuel mixtures into cardboard tubes and igniting the compositions. A detailed analysis of this phenomenon, from both a chemical and a physical view, has been published by Maxwell, and a more recent review of the whistle literature has also been published. Further whistle research has continued in efforts to fully understand the phenomenon. Without consolidation of the powder in a tube, whistle composition produces a rapid flash of light (in an explosive manner) and no whistlelike effect. The whistle effect is produced by compositions consisting of potassium chlorate or potassium perchlorate as the oxidizer, with a salt of benzoic acid or a substituted benzoic acid (e.g., potassium benzoate, sodium salicylate). 

Whether radiation is being absorbed or emitted the frequency at which it takes place depends on the velocity of the atom or molecule relative to the detector. This is for the same reason that an observer hears the whistle of a train travelling towards him or her as having a frequency apparently higher than it really is, and lower when it is travelling away from him or her. The effect is known as the Doppler effect. 

Liquid-driven transducers (i.e. a liquid whistle) can be used to produce efficient homogenization. The majority of the chemical effects observed using whistle-type transducers for the sonication of non-homogeneous reactions can be attributed mainly to the generation of very fine emulsions leading to increase in the interfacial phenomena rather than the ultrasonic irradiation itself. 

Chand et al. [64] have investigated the use of ozone treatment assisted by a liquid whistle reactor (LWR), which generates hydrodynamic cavitation, for water disinfection using a simulated effluent containing Escherichia coli. A suspension having an E. coli concentration of approximately 10s to 109 CFU mL 1 was introduced into the LWR to examine the effect of hydrodynamic cavitation alone... 

The underlying mode of action, involving as it does the flow induced vibration of a steel blade, immediately suggests the problem of erosion by particulate matter - the sand blasting effect. Despite this apparent drawback a whistle has been used in this Scott Bader process over several years without blade replacement. 

Aspects of special effects described in this chapter include fuses (quickmatch and plastic fuse), lances (small coloured flares), set-pieces and devices (assemblies consisting of various types of fireworks linked together), flash, bang and whistle compositions and daylight fireworks (smoke puffs and coloured smokes). Finally, the electrical firing of firework displays is discussed. 

Two basic audible effects are produced by explosive and pyrotechnic devices a loud explosive noise (called a "report" or "salute" in the fireworks industry) and a whistling sound. 

Under the effect of the mushrooms, the lost spirit is whistled for through space for the spirit is alienated, but by means ofthe mushrooms one can call for it with a whistle. If the person... 

Whistles, Pyrotechnic. US projectile ground-burst and booby-trap flash simulators precede their flash and expin with a whistling sound. The fact that certain compns whistle when compressed into a tube and ignited has been used in the fireworks industry for many years. The active substance most often used in pyrot whistles is gallic acid (3,4,5-trihydroxybenzoic acid). The K salts of benzoic acid of 2,4-dinitrophenol and of picric acid (2,4,6-trinitrophenol) and the Na salt of salicylic acid (o-hydroxybenzoic acid) are also effective. They are combined with K chlorate,... 

Fig 1 Effect of Open Tube Length on Whistle Frequency... 

Fig 4 Effect of Whistle Composition on Acoustic Output and Burning Rate... 

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