Blasting switch

Zundpille = squib 296 Ziindschalter = blasting switch 38 Ziindschnur = safety fuse 271, 276 Ziindschraube = fuze head 148 Ziindsicherung = igniter safety mechanism 184 Zundstrom = firing current 141 Ziindung = initiation 191 Ziindverzug = functioning time 77 147... 

With the availability of 3.3 and 6.6 kV vacuum contactors the control of HT motors up to 6.6 kV systems has now become easier and economical, compact and even more reliable. For 11 kV. systems, vacuum as well as SF (Sulphur hexafluoride) breakers can be used. The HT motor s switching and protection through a vacuum contactor provides a replica of an LT system. The earlier practice of using an HT OCB, MOCB, or an air blast circuit breaker for the interruption of an HT circuit is now a concept of the past. 

Figure 4.23 illustrates two common blast-generators chemical plants and rail-car switching yards (Baker et al. 1983), each blanketed in a large vapor cloud. The blast effects from each should be considered separately. 

While some drain cleaners contain concentrated sulfuric acid, many more contain sodium hydroxide. Mixing these two chemicals will not release chlorine gas, but the reaction between them does release a great amount of heat. Someone who makes the mistake of trying to undog their sink with one product and then switches to a different drain cleaner when the first does not clear the drain fast enough could create enough steam to blast the whole corrosive mess out of the sink right into their face. 

Before using the device in an operation, of course, the piece of test paper will have to be replaced by a fresh, unpunctured one of similar strength. Also, after the switch is positioned, and perhaps concealed, a further test with bulb and battery is necessary to be sure the switch is OPEN before the wires to the blasting cap and charge are connected. 

It was found that when the laser is operated in the Q-switched mode, the droplet (Propyl-nitrate or heptane) appears to break up or evaporate without ignition however, a blast wave due to energy addition via gaseous break down is always present. When the laser is operated in the pulsed mode with two pulses at 100 nsec apart, the first pulse serves to break up the drop and the second to ignite it. In this case explosive combustion is often observed in oxygen whereas a non-explosive ignition takes place if air is used. ... 

With the plethora of electronic timers and alarm watches on the market one would think it would be a simple task to adapt these units as demolition timers. Most of these devices do not put out sufficient energy to their alarm buzzers to reliably detonate an electric blasting cap. But it is not extremely difficult to modify them by using a Silicon-Controlled Rectifier (SCR) switching circuit. The PLO is known to have used timers adapted from a cheap digital alarm watch and a SCR in Lebanon. 

A great number of friends, bystanders, and inquisitive acquaintances watched as we hooked our 220-volt motor generator to the drop wires. We opened the throttle on the generator, blew a long blast on the car horn, and threw the switch. 

G. Stand behind the optional blast shield or to one side of the launcher, and fire the rocket motors by turning the switch to the launch position. 

A photosensitive triazene polymer with the structure shown in Scheme 8 was applied and a XeF excimer laser (351 nm) was used as irradiation source. Ejected plumes and blast waves were illuminated by fluorescence from a methanol solution of Rhodamine 101 which was excited by the second harmonic of a Q-switched Nd3+ YAG laser. The principles of this imaging method are the same as those reported previously for poly(methyl methacrylate) (PMMA) [94, 195, 199, 207] and liquid benzene [208]. 

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