Flame spread along a fuel rod in the absence of gravity
An analysis is carried out of the steady spread of a flame with infinitely fast kinetics over a thermally thin solid rod in the absence of gravity. Due to the radial convergence on the solid surface of the heat flux heating and vaporizing the fuel, the spread rate is found to be higher than for a flame spreading over a slab, and the region of the gas around the flame which is affected by molecular transport is large compared with the radius of the rod. The effects of radiation, of a buoyancy force opposing flame propagation and of axial heat conduction in the solid are discussed briefly
On the dominant mode of heat transfer in downward flame spread
The dominant mechanism by which heat is transferred to the unburnt fuel ahead of the flame is analyzed by measuring the heat transfer parameters involved in the process of downward propagation of flames over two extreme thicknesses of a solid fuel. Measurements of the gas velocity fields and temperature fields for both fuel thicknesses are reported. Experimental techniques employed include Laser Doppler Velocimetry (LDV) and thermocouple probing. Qualitative information from the measurements as well as quantitative calculations of the pathways of heat transfer indicate that for thick fuels heat conduction through the solid phase is the dominant mechanism of heat transfer, and that as the thickness of the fuel decreases heat conduction through the gas is of increased importance. It is also shown that convective effects due to the entrainment of air by the flame plume play an important role in the ability of the heat to be conducted through the gas from the flame.
Accumulation of Bone-Seeking Radionuclides in Liver Metastasis from Colon Carcinoma
Fifteen colon cancer patients with metastasis to the liver were examined by both liver and bone scans. Seven of these showed accumulation of bone seeking radionuclides in the liver at the site of a defect in the scan. Such accumulation was found in two diphosphonate, in one pyrophosphate and in six 18F scans. To our knowledge, this is the first series to report localization of 18F in intrahepatic metastasis from colon cancer. The precise mechanism for this non-skeletal accumulation is unknown.