1 Nearly one-fifth (19%) of juvenile violent crimes occur in the 4 hours between 3 p.m. and 7 p.m. on school days. 2  A smaller proportion of juvenile violent crime (15%) occurs during the standard juvenile curfew hours of 10 p.m. to 6 a.m. (inclusive of both school and nonschool days).
Cause. Sooty mold is a fungal disease initiated by a combination of feeding insects, such as whiteflies and aphids, and fungi. Insects feed on the gardenia for the sap in the foliage and stems. The insects take in large amounts of sap and expel the leftover as a sticky liquid called honeydew.
This is called the tarnishing of silver and is a natural process. The notion that silver tarnish only occurs with silver jewelry made from low purity silver is not correct. What Causes Silver To Tarnish? The presence of Hydrogen Sulfide in any material that silver comes into contact with, is one of the prime reasons for silver tarnish. Sulfur containing materials generally cause silver to tarnish and Hydrogen Sulfide is just one of these. Materials like wool, rubber bands, fuels derived from fossils, a few types of paints and rubber (latex) gloves are some of the common materials that cause tarnishing of silver.