Extensive facial damage caused by a blast injury arising from a 6 volt lead accumulator.
Low-voltage electrical injuries are relatively uncommon. Injury caused by flow of heavy current due to short-circuiting a low-voltage battery has not been described in the English literature. A 9-year-old boy connected two thin household electrical wires to the two terminals of a 6 volt (lead accumulator) battery and pressed the other two ends between his teeth. This resulted in a blast causing a compound comminuted fracture of the mandible and extensive tissue damage in the oral cavity. The low internal resistance of a lead accumulator (approximately 0.03 ohms) permits the flow of a heavy current (approximately 200 amps) when short-circuited. This instantaneously vaporises a minuscule portion of wire at approximately 2000 K resulting in a sudden rise of intraoral pressure to 30 kg cm-2 leading to tissue damage.
Experimental Electrical Burns: Low Voltage
Low-voltage electrical burns were studied in 25 pigs submitted to bilateral thigh burns using 500 volts AC for 10 seconds. In a group of 6 animals, the wounds were observed and histologic specimens obtained at different intervals during the first week. The burn measured approximately 4 cm in diameter and extended through two muscle layers. This tissue underwent further necrosis during the first 48 hours. After 2 days there was no further necrosis. In a second group, the wounds were debrided and covered with either a split-thickness skin graft or a rectus abdominis musculocutaneous flap. All wounds with flap coverage healed primarily and there was no deep necrosis. From our findings we conclude that debridement and definitive closure can safely be performed 2 days after low-voltage electrical burns.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.