SUBJECTS 191 spark

The minimum ignition energy of Hquid acetylene under its vapor, when subjected to electrostatic sparks, has been found to depend on the temperature as indicated in Table 3 (86). Ignition appears to start in gas bubbles within the Hquid. 

The rapid growth and expansion of the chemical industry has been accompanied by a spontaneous rise in human, material, and property losses because of fires, explosions, hazardous and toxic spills, equipment failures, other accidents, and business interruptions. Concern over the potential consequences of catastrophic accidents, particularly at chemical and petrochemical plants, has sparked interest at both the industrial and regulatory levels in obtaining a better understanding of the subject of this book Health, Safety, and Accident Management (HS AM). The writing of this book was undertaken, in part, as a result of this growing concern. 

Aluminium alloys are susceptible to thermite sparking when dropped on to rusty surfaces. Consequently their use may be subject to restrictions. For example, in ships tanks the weight of the anode and the height that it is suspended are strictly controlled. This is because thermite sparking is dependent on the kinetic energy of the anode. 

Combusts in contact with air if it is subjected to friction or a flame or sparks. Ignition can also take place if it is really dry and submitted to a temperature of 275°C. Finally, in the powdered state, it can detonate when air is present. 

Bottles and vials are not subjected to such a vacuum test because of the flexibility of the rubber closure. However, bottles that are sealed under vacuum may be tested for vacuum by striking the base of the bottle sharply with the heel of the hand to produce a water hammer sound. Another test is the spark test, in which a probe is applied outside the bottle. When it reaches the air space of the bottle, a spark discharge occurs if the headspace is evacuated. 

More recent work shows that the amino acid yield (in particular of glycine) in a CO-N2-H2O atmosphere subject to irradiation with high energy particles is much higher than if spark discharges are used (Kobayaski et al., 1998). These authors thus assume that cosmic radiation could have been an important source of energy for prebiotic syntheses on Earth. 

Sparks resulting from static charge and discharge continue to cause major fires and explosions within the chemical industry. The examples and fundamentals developed in these sections were designed to emphasize the importance of this subject. Hopefully this emphasis on the fundamentals will make the subject less elusive and destructive. 

If the two gases are mixed in equal proportions in a diffused light and are subjected to an electric spark, the above reaction takes place with explosive violence. If a glass tube containing a mixture of the gases is heated, the same reaction takes place with violence. 

From Acetylene.—If acetylene is compressed and then subjected to an electric spark it undergoes dissociation into its elements. 

The acetylene produced is then compressed in very trong cylinders and subjected to an electric spark, when be following reaction takes place —... 

The attention-getting, humorous story starters in this book wiii sureiy spark the imagination of the most reiuctant story writer. The antics of characters with unusuai names wiii motivate young writers to compiete the stories and even create their own stories about the subjects. Reading Levei is 3.5-4.S. 

It may be that the relay switches the ac through so long after the HV pulse that it accidentally provides the ac for the following HV spark pulse. If so, it is not something I would be keen on relying on. Any thoughts on the subject ... 

Subjecting phosphorus trifluoride to an electric spark in the absence of air (a disproportion reaction occurs) ... 

Another type of substance, which is less sensitive than primaries, is the class called propellants. They are explosive but formulated with different intention than HE s. Their function is to burn in a controllable fashion and, ideally, not to detonate under any circumstance. An important property of propellants is their sensitivity to ignition, which can be determined by subjecting them to sparks or flames... 

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