Radiation bum

Pierre and Marie Curie called Becquerel s radiation radioactivity . They found that another heavy element, thorium, was also radioactive, and deduced that natural uranium ore (pitchblende) contained other radioactive elements, which they called polonium (after Marie s native country) and radium (because it glowed). After two years of sifting through tonnes of uranium ore, they isolated salts of these new elements. The work left both the Curies with hands badly scarred from radiation bums, and it no doubt hastened Marie s death from leukaemia in 1934. Pierre might have met the same fate had he not been tragically killed in a road accident in 1906. 

A volunteer who worked at a nearby plant died from bums received while helping to spray fire-water during the emergency. Four people suffered major bum injuries when the initial vapor cloud ignited. Many spectators who stood on an earthen mound on that warm early Sunday afternoon suffered intense radiation bums from the BLEVEs. [10]. 

Compared to thermal bums, radiation induced bums develop more than a week after exposure. Therefore, patients presenting with bum injuries immediately after exposure are suffering from thermal rather than radiation bums. Table 4.3 illustrates the relationship between exposure dose and cutaneous injury. 

In addition to his scientific discoveries, Becquerel may have been the first person to suffer radiation bums. In 1890, he carried a vial containing a small sample of radium in the breast pocket of his jacket. He developed a wound that looked like a burn but that did not heal for several months. The danger of radiation to cells would not be understood for many years and was probably a factor in the death by cancer of a number of scientists. 

The effect of radiation on the skin cells is the same as thermal bums, and Biere is no difference in die appearance of hums from thermal and radiation sources. Unless radioactive material is still present, radiation bums are not radioactive and there... 

Examples Cut, puncture, laceration, abrasion, fracture, bruise, amputation, insect bite, electrocution, or a thermal, chemical, electrical, or radiation bum. Sprain and strain injuries to muscles, joints, and connective tissues are classified as injuries when they result from a slip, trip, fall or other similar accidents. 

Radiation generates heat. This heat can destroy tissue, much like a sunburn does. In fact, the term radiation bum is commonly used to describe the destruction of skin and tissue due to heat. 

There are numerous other hazards which rely on protective clothing. Examples are bumping into sharp and pointed objects and radiation bums from welding and other activities. Loss of grip and slipping and dropping lifted items rely on clothing with slip-resistant properties. 

Metal fumes, infrared and ultraviolet radiation, bums, electrical, fire, noise, ozone, nitrogen dioxide... 

MicrobaUoons have been used for gap filling, where the spheres dampen sound or vibration in the stmcture. In the medical area, microbaUoons have been evaluated as a skin replacement for bum victims and phantom tissue for radiation studies. An important appHcation is in nitroglycerin-based explosives, in which microbaUoons permit a controUed sequential detonation not possible with glass spheres. 

Furnaces for Oil and Natural Gas Firing. Natural gas furnaces are relatively small in size because of the ease of mixing the fuel and the air, hence the relatively rapid combustion of gas. Oil also bums rapidly with a luminous flame. To prevent excessive metal wall temperatures resulting from high radiation rates, oil-fired furnaces are designed slightly larger in size than gas-fired units in order to reduce the heat absorption rates. 

Electric shock and bums can also lead to injury. Burns can occur touching hot surfaces. They can also occur from radiation. 

In general, when a flammable vapor cloud is ignited, it will start off as only a Are. Depending on the release conditions at time of ignition, there will be a pool fire, a flash fire, a jet fire, or a fireball. Released heat is transmitted to the surroundings by convection and thermal radiation. For large fires, thermal radiation is the main hazard it can cause severe bums to people, and also cause secondary fires. 

A flash fire is the nonexplosive combustion of a vapor cloud resulting from a release of flammable material into the open air, which, after mixing with air, ignites. In Section 4.1, experiments on vapor cloud explosions were reviewed. They showed that combustion in a vapor cloud develops an explosive intensity and attendant blast effects only in areas where intensely turbulent combustion develops and only if certain conditions are met. Where these conditions are not present, no blast should occur. The cloud then bums as a flash fire, and its major hazard is from the effect of heat from thermal radiation. 

The main hazard from a BLEVE fireball is its thermal radiation, which can cause secondary fires and can bum people severely. Rapid mixing, combustion, and... 

Consequently, if none of these conditions is present, no blast effects are to be expected. That is, under fully unconfined and unobstructed conditions, the cloud bums as a flash fire, and the major hazard encountered is heat effect from thermal radiation. 

Radiation heat flux is graphically represented as a function of time in Figure 8.3. The total amount of radiation heat from a surface can be found by integration of the radiation heat flux over the time of flame propagation, that is, the area under the curve. This result is probably an overstatement of realistic values, because the flame will probably not bum as a closed front. Instead, it will consist of several plumes which might reach heights in excess of those assumed in the model but will nevertheless probably produce less flame radiation. Moreover, the flame will not bum as a plane surface but more in the shape of a horseshoe. Finally, wind will have a considerable influence on flame shape and cloud position. None of these eflects has been taken into account. 

Sample problem 9.1.S demonstrated the calculation of thermal radiation from the BLEVE of a tank truck. This 6000-gallon (22.7 m ) tank was 90% filled with propane, and burst due to fire engulfment at an overpressure of 1.8 MPa (18 bar). The resulting thermal radiation was sufficient to cause third degree bums to a distance of 300 to 360 m. 

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