q 2 - q 1
... Now if we consider the condensation process, i.e. if the cyclic process started by increasing the external pressure, which equals PH2O(T), by Δ P, it is possible to show that, for a cycle, the permanent change in the external energy of the heat reservoir is V ΔP. Thus, as ΔP approaches infinitesi ...
... Now if we consider the condensation process, i.e. if the cyclic process started by increasing the external pressure, which equals PH2O(T), by Δ P, it is possible to show that, for a cycle, the permanent change in the external energy of the heat reservoir is V ΔP. Thus, as ΔP approaches infinitesi ...
The first and second law of Thermodynamics - Ole Witt
... This work is, however, reversible, since it is the precisely equal to the work which has to be done to bring the gas back to its initial state, releasing the heat Q to the external reservoir. It is rather easy to convince yourself that Wirr < Wrev. Thus if we let the external pressure Pext be less t ...
... This work is, however, reversible, since it is the precisely equal to the work which has to be done to bring the gas back to its initial state, releasing the heat Q to the external reservoir. It is rather easy to convince yourself that Wirr < Wrev. Thus if we let the external pressure Pext be less t ...
SOLUTIONS: HOMEWORK #6
... (b) We take nozzle as the system, which is a control volume since mass crosses the boundary. The energy balance for this steady-flow system can be expressed in the rate form as E& − E& out ...
... (b) We take nozzle as the system, which is a control volume since mass crosses the boundary. The energy balance for this steady-flow system can be expressed in the rate form as E& − E& out ...
Thermal Ratings of Surface Mount Packages
... intent was to show a realistic rating for maximum power dissipation, but the dilemma was that the true rating depended on the printed circuit board as much as the device. The ratings shown on the first data sheets were optimistic for a standard PC board as they focused on the device, not the PC boar ...
... intent was to show a realistic rating for maximum power dissipation, but the dilemma was that the true rating depended on the printed circuit board as much as the device. The ratings shown on the first data sheets were optimistic for a standard PC board as they focused on the device, not the PC boar ...
Heat sink
A heat sink is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device into a coolant fluid in motion. Then-transferred heat leaves the device with the fluid in motion, therefore allowing the regulation of the device temperature at physically feasible levels. In computers, heat sinks are used to cool central processing units or graphics processors. Heat sinks are used with high-power semiconductor devices such as power transistors and optoelectronics such as lasers and light emitting diodes (LEDs), where the heat dissipation ability of the basic device is insufficient to moderate its temperature.A heat sink is designed to maximize its surface area in contact with the cooling medium surrounding it, such as the air. Air velocity, choice of material, protrusion design and surface treatment are factors that affect the performance of a heat sink. Heat sink attachment methods and thermal interface materials also affect the die temperature of the integrated circuit. Thermal adhesive or thermal grease improve the heat sink's performance by filling air gaps between the heat sink and the heat spreader on the device.