Conventionally, waveguide terminals formed in a plurality of dielectric substrates are joined together by mounting the dielectric substrates on carriers and fastening them to a waveguide adapter with screws. The cooking apparatus includes a cooking cavity that contains food to be cooked and water therein, and a heating unit that heats the food and the water. The LED package can be coupled to a heat sink for dissipating heat from the LEDs. Some embodiments describe methods and apparatus for adjusting, along a length of the device, the porosity of the occluding device. Based on routing information associated with the query IP address, the content delivery network service provider routes the DNS query. The device determines an inter-atrial conduction time and compares the IACT to a threshold.