Home insulation, often referred to as cavity insulation, is a cast iron money saver during the winter months because it regulates the flow of heat from a warm area to a cold one.

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Once the home has been duly sealed, the flow of air, moisture and heat in and out of it can be carefully controlled.

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Richard Hamilton of Columbia University had previously realised the usefulness of this heat-flow model but became unstuck when he found that, under this transformation, the object may stretch out to form singularities spikes that could not be easily manipulated into a sphere.

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At Mach 4 or 5, the air flow would become dangerously hot but this heat exchanger - consisting of a dense and closely-guarded bundle of tiny tubes - would chill things down to a manageable temperature in milliseconds.

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The enormous heat generated by the radioactive fuel in the reactor core needs a constant flow of cold water.

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The problem is not only how to get rid of the heat, but how to cope with the very large electrical currents that must flow on and off the chip without melting the connecting leads.

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It was a necessary precaution, but it didn't help the flow of the game, particularly in the stop-start first half when both teams were coming to terms with the heat.

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