Hot Spot Effect Research Articles

The effect of hot spots on the oceanic age‐depth relation

Hot spots located both midplate and on midocean ridges can bias the empirical age‐depth relation. Ocean floor bathymetry for seafloor greater than 80 m.y. B.P. in age has been previously used to determine if the oceanic lithosphere behaves as a cooling half space or as a cooling plate. However, large areas of the ocean basins do not fit a simple age‐depth relation. Anomalously shallow swells, approximately 1000 km wide and 1 km high surround hot spots such as Iceland, the Azores, and the Cape Verde Islands. By sorting seafloor depth data by distance to the nearest hot spot track, we show that the along‐isochron variation in depth in the North Atlantic correlates with distance from a hot spot track. Due to the absence in the North Atlantic of seafloor both old and far from hot spots, we compare depth versus age at constant distance and do not observe flattening of the age‐depth relation in any distance range. The age‐depth relation, depth (meters) = 2700 + 295 t(m.y.)1/2, derived for seafloor 1200 to 1800 km from a hot spot track represents our best estimate of the age‐depth relation appropriate to seafloor unaffected by a hot spot track. In the North Atlantic the previously inferred flattening of the age‐depth relation appears to be caused by the inclusion of hot spot swells. This implies that hot spots may be the primary means of heat transfer from the deeper mantle to the base of the lithosphere.

U Cephei - Effects of disk, hot spot, and stream on primary eclipse light curves

U Cephei - Effects of disk, hot spot, and stream on primary eclipse light curves

Reply to the ’’Comment on ’The significance of the distribution of hot spots on the interpretation of laser-produced plasma experiments’ ’’

We disagree with the conclusion reached by Goel, Gupta, and Bhatnagar that the effect of hot spots is not significant in analyzing scaling laws using transformed variables. We believe they have overlooked the main points of our analysis.

The effect of hot spots on the noise characteristic of large-area bipolar transistors

Measurements indicate that when hot spots are formed in large-area silicon power transistors, the 1 f noise increases and a new noise component with a 1 f 2 spectrum shows up. The increase in 1 f noise is attributed to the decrease in effective device area when the hot spot is formed. The noise with a 1 f 2 spectrum is attributed to a thermal feedback effect in the hot spot.

The effect of hot spots on the noise characteristic of large-area bipolar transistors : S. B. Shacter, A. van Der Ziel, E. R. Chenette and A. D. Sutherland. Solid-St. Electron.21, 599 (1978)

The effect of hot spots on the noise characteristic of large-area bipolar transistors : S. B. Shacter, A. van Der Ziel, E. R. Chenette and A. D. Sutherland. Solid-St. Electron.21, 599 (1978)

Consideration of ``Spherical Hot Spots'' Arising from Pion Capture in Explosives Using Thermal Initiation Theory

The process whereby relatively high energy density, ``spherical'' zones of radiation heating may arise from slow π—-meson irradiations is described, and the effects of such microscale hot spots on six explosives (lead azide, lead styphnate, mercury fulminate, RDX, TNT, and PETN) was investigated. No explosions or signs of thermal decomposition were observed with any of the explosives. Analysis of these results by the hot-spot model of explosive initiation and thermal growth was attempted. The conclusions were (1) that this model can not explain the experimental results observed for RDX, in that it predicts initiation, and (2) that the previous experiments attempting explosive initiation by the microscale thermal effects of ionizing radiation have not investigated those explosives most susceptible to initiation by this mechanism.

High-temperature effects on flashover in air

Paschen's law has been confirmed experimentally for millimetric gaps at temperatures up to 1100° C, and the flashover voltages obtained were independent of electrode material.The effect of electrode hot spots at temperatures up to 1200° C was investigated in different electric fields, the bulk of the test gap being at room temperature. Under uniform-field conditions, hot spots caused a substantial lowering of flashover voltage, but their effect decreased with increase in the divergence of the field. A hot spot in the region of least electric stress had no significant effect when the ratio of maximum to minimum stress exceeded a value of the order of, but greater than, the ratio of hot spot to ambient temperature.Evidence is advanced in support of the view that the operation of Trigatron gaps can be explained in terms of hot-spot formation.