### residue | ash:

Volcanic ash
* Most volcanic ash consists of fine, dusty particles
  - falls to the surface and becomes welded together as rock called volcanic tuff
* can affect people hundreds of miles away from the cone of a volcano
  - away from the volcano
* can also affect aircraft operations
  - stops the sunlight from going in and out from the earth
* can be a serious hazard to aviation even thousands of miles from an eruption
  - aviation even thousands of miles from and eruption
  - hazardous over great distances
  - cause great damage to breathing passages and the respiratory system
  - contaminate water supplies, cause electrical storms, and collapse roofs
  - damage aircraft flying surfaces and electronics, and cause engine failure
  - travel hundreds to thousands of miles downwind from a volcano
* is an aviation hazard, as it can cause serious damage to aircraft engines
  - derived from a thick bed that crops out at the upper limit of dirt-covered ice
  - hot near the volcano, but it is cool when it falls at greater distances
  - often the source of the silica
  - present as both discrete ash layers and disseminated throughout the clay sequences
* is rock that has been exploded and shattered by steam inside the volcano
  - pulverized into dust or sand by volcanic activity
  - thought to be capable of providing a significant source of iron for phytoplankton
  - very durable and very ligth weight
* makes the island's soil rich and fertile.
* poses health problems
  - serious hazards to jet aircraft
* provides much needed nutrients for plants.
* serious hazard to aviation even thousand of miles from an eruption.
* serves as a fertilizer, returning important nutrients and minerals to the soil.
* severe threat to jet aircraft that fly over the North Pacific Ocean.
+ Global dimming, Causes and effects: Climate change :: Environmental issues
  * Volcanic ash can also stops the sunlight from going in and out from the earth. Decreases in the earth's temperatures are observed after large volcanic eruptions. Even for large eruptions, the ash clouds do not stay for a long time.

Conserved residue
* are functionally distinct within transketolases from different species
  - likely to be essential to protein function
* make similar contacts in two repressor-operator complexes.

### residue:

Crop residue
* Many crop residues are deficient in protein and minerals.
* Some crop residues provide food.
* can also help reduce wind erosion and can enhance snow entrapment
  - have allelopathic effects as they decay
* carries most corn diseases and insects to the next crop.
* cushions the impact of falling raindrops, which reduces soil detachment.
* decay faster when tilled into the soil than if left standing undisturbed.
* decompose in the soil to form soil organic matter.
* direct function of cropping intensity, fertilization, tillage, and sanitation.
* feed the animals and the animals' manure fertilizes the soil.
* has very low levels of vitamins and gestating ewes can become deficient.
* helps control and conserve water in ridge- tilled fields
  - erosion and conserve water in ridge-tilled fields
* is also vital to maintaining organic matter levels in soils.
* kill weeds.
* provide food and keep the soil surface cool and moist
  - shelter for small game and many species of songbirds
  - the raw materials for building soil organic matter
* reduce runoff from farm fields to improve water quality.
* reflects sunlight and insulates the soil from the air.
* works in a number of different ways to reduce runoff and erosion.

Drug residue
* Contain no Salmonella , etc.
* remain permanently entrapped in the hair.

Gunshot residue
* can indicate someone fired a gun.
* is normally a combination of gunpowder residues and lead residues.