a submersible pump is a device which has a hermetically sealed motor close-coupled to the pump body. the whole assembly is submerged in the fluid to be pumped. the main advantage of this type of pump is that it prevents pump cavitation, a problem associated with a high elevation difference between pump and the fluid surface. submersible pumps push fluid to the surface as opposed to jet pumps which create a vacuum and rely upon atmospheric pressure. submersibles are more efficient than jet pumps.
a printing press, in its classical form, is a standing mechanism, ranging from 5 to 7 feet 1.5 to 2.1 m long, 3 feet 0.91 m wide, and 7 feet 2.1 m tall. the small individual metal letters known as type would be set up by a compositor into the desired lines of text.
aluminium production is highly energy-consuming, and so the producers tend to locate smelters in places where electric power is both plentiful and inexpensive. as of 2012, the world's largest smelters of aluminium are located in china, russia, bahrain, united arab emirates, and south africa.
china uses more than 4.5 billion liters of methanol per year as a transportation fuel in low level blends for conventional vehicles, and high level blends in vehicles designed for methanol fuels. other chemicals. methanol is the precursor to most simple methylamines, methyl halides, and methyl ethers.
aluminium is a chemical element with the symbol al and atomic number 13. it is a silvery-white, soft, non-magnetic and ductile metal in the boron group. by mass, aluminium makes up about 8% of the earth's crust, where it is the third most abundant element and also the most abundant metal. occurrence of aluminium decreases in the earth's mantle below, however. the chief ore of aluminium is bauxite. aluminium metal is highly reactive, such that native specimens are rare and limited to extreme redu
effective ignition source is a term defined in the european atex directive as an event which, in combination with sufficient oxygen and fuel in gas, mist, vapour or dust form, can cause an explosion. methane, hydrogen or coal dust are examples of possible fuels. effective ignition sources are: lightning strikes. open flames.
in geotechnical engineering, drilling fluid, also called drilling mud, is used to aid the drilling of boreholes into the earth. often used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells. one of the functions of drilling mud is to carry cuttings out of the hole. the three main categories of drilling fluids are: water-based muds, which can be dispersed and non-dispersed; non-aqueous muds, usua
human factors and ergonomics commonly referred to as human factors is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. the goal of human factors is to reduce human error, increase productivity, and enhance safety and comfort with a specific focus on the interaction between the human and the thing of interest.
description. the term uncontrolled decompression here refers to the unplanned depressurisation of vessels that are occupied by people; for example, a pressurised aircraft cabin at high altitude, a spacecraft, or a hyperbaric chamber.for the catastrophic failure of other pressure vessels used to contain gas, liquids, or reactants under pressure, the term explosion is more commonly used, or .