Line of sight emitters can use IR diodes. Clouds are excellent emitters of infrared radiation. Single photons are routinely generated using single emitters (atoms, Nitrogen-vacancy center, Quantum dot ). EPA has issued standards for alpha particles, beta particles and photon emitters, radium and uranium. Radioactive medical waste tends to contain beta particle and gamma ray emitters. Deforestation also makes Indonesia one of the biggest emitters of greenhouse gases. Emissions trading works by setting a quantitative limit on the emissions produced by emitters. Making small ensembles and crystals could act as a single photon emitters. Therefore, California, is one of the highest greenhouse gases emitters in the United States. Water exits from tape through emitters or drippers. LaB and CeB are thermionic emitters, used, for example, in scanning electron microscopes. Tri-color LEDs contain three different LED emitters in one case. Bi-color LEDs contain two different LED emitters in one case. Drip irrigation systems distribute water through a network of valves, pipes, tubing, and emitters. Event channels are conduits in which events are transmitted from event emitters to event consumers.