AEROSOLS |
|
Aerosol spray is the name given to a type of canister containing liquid under pressure from pressurized vapor in equilibrium with another liquid, which often also dissolves the payload (see propellant below). When the can's valve is opened, the liquid is forced out of a small hole and emerges as an aerosol, or mist. As gas expands to drive out the payload, some propellant evaporates inside the can to maintain an even pressure. Outside the can, the droplets of propellant evaporate rapidly, leaving the payload suspended as very fine particles or droplets. Typical liquids dispensed in this way are insecticides, deodorants and paints. An atomiser is a similar device that is pressurised by a hand-operated pump rather than by stored gas.
|
AMBULANCE |
|
An ambulance is a vehicle designated for the transport of sick or injured people. The first ambulances called by that name were horse ambulances used in the American Civil War. The first practical ambulances were created by Dominique Jean Larrey, a French surgeon (17661842), for use in the Napoleonic Wars. Modern-day ambulances are typically large automobiles on a van or light truck chassis.
|
DEMOLITION |
|
Demolition is the opposite of construction: the tearing-down of buildings and other structures. It is contrasted with deconstruction, which is the taking down of buildings while carefully preserving valuable elements for re-use.
|
ENGINEERING - CHEMICAL |
|
Chemical engineering is the application of science, in particular chemistry, physics and mathematics, to the process of converting raw materials or chemicals into more useful or valuable forms.
|
MINERALS, OIL, GAS |
|
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace for the generation of heat or used in an engine for the generation of power, except oils having a flash point of approximately 40 °C (about 100 °F) and oils burned in cotton or wool-wick burners. In this sense, diesel is a type of fuel oil. Fuel oil is made of long hydrocarbon chains, particularly alkanes, cycloalkanes and aromatics. Factually and in a stricter sense, the term fuel oil is used to indicate the heaviest commercial fuel that can be obtained from crude oil, heavier than gasoline and naphtha.
|
PEST CONTROL |
|
Pest control refers to the regulation or management of another species defined as a pest, usually because it is believed to be detrimental to a person's health, the ecology or the economy.
|
POLLUTION |
|
Pollution is the release of environmental contaminants. Carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles are common air pollutants. Sunlight converts nitrogen oxides and hydrocarbons to ozone or smog. Water pollutants may consist of a wide range of organic and inorganic chemicals such as heavy metals, petrochemicals, chloroform, and bacteria. Water pollution may also occur in the form of thermal pollution and dissolved oxygen depletion. Soil contamination is an important aspect of environmental pollution; this phenomenon occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons. The U.S., Russia, China and Japan are the world leaders in air pollution emissions; however, Canada is the number two country on a per capita basis.
|
|
