Cloud seeding

This use may some day become of practical importance if it can complete economically with silver iodide. 

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Cloud Seeding. In 1947, it was demonstrated that silver iodide could initiate ice crystal formation because, in the [ -crystalline form, it is isomorphic with ice crystals. As a result, cloud seeding with silver iodide has been used in weather modifications attempts such as increases and decreases in precipitation (rain or snow) and the dissipation of fog. Optimum conditions for cloud seeding are present when precipitation is possible but the nuclei for the crystalliza tion of water are lacking. 

Pollution can cause opposite effects in relahon to precipitation. Addition of a few particles that act as ice nuclei can cause ice particles to grow at the expense of supercooled water droplets, producing particles large enough to fall as precipitation. An example of this is commercial cloud seeding with silver iodide particles released from aircraft to induce rain. If too many particles are added, none of them grow sufficiently to cause precipitation. Therefore, the effects of pollution on precipitation are complex. 

On a smaller scale, the largest producer of iodine is Japan where it is extracted from. seaweed containing more than 0.05 parts per million. The most important industrial iodine compound is silver iodide used with silver bromide in photography. Iodine is important in medicine for treating thyroid problems by adding it to table salt. It is used directly as a disinfectant, and a component of d vs. Crystalline silver iodide is used for cloud seeding. 

Rainmaking while the term invokes images of primitive rituals to influence the rain gods, modern day meteorologists have sound chemical principles to induce precipitation. What chemistry fundamentals are instrumental in cloud seeding ... 

The discovery of cloud seeding, United States Bureau of Reclamation Environmental Education, http //www.rsgis.do.usbr.gov/html/history.htm... 

Alpine lake, Colorado, 1973-74. Silver iodide (43 kg), equivalent to 19.7 kg silver, released into system from local cloud seeding practices between 1963 and 1973 Lake water, 1973 vs. 1974... 

Cloud point (CP), 75 207 24 126 Cloud seeding, silver iodide in, 22 685 Clove bud oil, 24 542 Clove buds, 23 166 Clove leaf oil, in perfumes, 78 367 Cloverite, 76 820 Cloves, 23 155 Cloxacillin, 3 33 Cloxyfonac, 73 4 It, 48 C1S03H, fatty alcohol sulfation with, 23 541. See also Chlorosulfonic acid Clupanodonic acid, physical properties, 5 33t... 

Silver iodide, 14 370, 22 671 in cloud seeding, 22 685 natural occurrence of, 22 668 Silver ion activity, in photographic crystal growth, 19 179 Silver-ion reduction... 

The iodide salt is used as a source of dietary iodine in table salt and animal feed in cloud seeding as a coating in cathode ray tubes as a temperature indicator and as a catalyst in organic reactions. 

Silver iodide is used in cloud seeding for artificial rain making and in photography. Its colloidal suspension is used as a local antiseptic. 

Sodium iodide is an iodine supplement in food, an expectorant, cloud seed to cause rain, and solubilizes iodine in aqueous solution for analytical work. The radioactive iodide salt of sodium, Na(I-131) is used to diagnose thyroid function. 

Aerosols, fog and smog, foams, water purification and sewage treatment cloud seeding and clean room technology (see also Vignettes 1.1 and VIII)... 

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