1 When the last tube is filling, remove the tourniquet. 2  Remove the needle from the patient's arm using a swift backward motion. 3  Place gauze immediately on the puncture site. 4  Apply and hold adequate pressure to avoid formation of a hematoma.
Thermal Diffusivity. a physical parameter of a substance that characterizes the rate of change of its temperature in transient thermal processes. Thermal diffusivity is a measure of the thermal-inertia properties of a substance. It is numerically equal to the ratio of the substanceâs thermal conductivity and the product of its specific heat (at constant pressure) and density. Thermal diffusivity is expressed in m 2 /sec.
Heat transfer occurs at a lower rate across materials of low thermal conductivity than across materials of high thermal conductivity. Correspondingly, materials of high thermal conductivity are widely used in heat sink applications and materials of low thermal conductivity are used as thermal insulation.The thermal conductivity of a material may depend on temperature. The reciprocal of thermal conductivity is called thermal resistivity.he reciprocal of thermal conductivity is thermal resistivity, usually expressed in kelvin-meters per watt (KÂ·mÂ·W â1). For a given thickness of a material, that particular construction's thermal resistance and the reciprocal property, thermal conductance, can be calculated.