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What is the history of sulfur usage

Sulfur, chemical symbol S, has beeen known since antiquity, and its occurrence in the natural state in Sicily insured its availability to the early Mediterranean civilizations. Homer mentioned its medicinal properties about 900 BC, and the fumes of burning sulfur (sulfur dioxide, SO2) have long been used for bleaching textiles and for fumigation.

The name can be traced to the Sanskrit word sulveni which was the basis of the Roman word sulphurium. It is also known as brimstone from the German word Brennstein meaning burning stone. To the alchemist sulfur, along with mercury, was an essential ingredient of all metals, and it was not until the work of the French chemist Antoine Laurent Lavoisier in the late eighteenth century that it was classified as a chemical element.

How do you refine sugar

Concentrated juice is then boiled to a supersaturated (highly concentrated) solution in vacuum pans. Crystallization is induced by seeding with a magnum of sugar and syrup to form a mixture of sugar crystals and liquor, known collectively as massecuite. The massecuite is discharged from the vacuum pans at 160° F (71° C) into water-cooled crystallizers where further sugar crystals are formed by reducing the temperature to about 100° F (37.8° C) over a 48-hour period. The raw sugar crystals are separated by reheating the massecuite to 122° F (50° C) to reduce the viscosity, followed by treatment in basket centrifuges operating at 1500 rpm. The residual syrup purged from the massecuite – a dark viscous liquid known as black-strap molasses – is used in the manufacture of rum, industrial alcohol and citric acid.

How is sugar produced for sale

Sugar beet processing is a relatively simple process. The beets are washed and sliced up. Sucrose is extracted from the slices with hot water, and the solution obtained is purified by precipitating calcium carbonate in it. Impurities are trapped in the precipitate and filtered out. The process is repeated several times to give a clear solution. Vacuum evaporation is used to concentrate the solution – which is seeded and cooled so that the sugar crystallizes out.
Much of the world's sugar cane is harvested by handcutting after burning the crop to remove the leaves. However, mechanical systems such as push-rake cutting and grab harvesting have come into use. The cane arriving at the raw sugar factory is washed on conveyers to remove field mud, sand and trash. The cane is nearly 90 per cent juice and it was traditionally extracted by a combination of shredders and three-roll crushers which squeezed out the juice.

What is the history of sugar refining

Sugar cane existed in New Guinea 12,000 years ago and was cultivated in Egypt and the coastal lands of the Mediterranean about 3000 BC. A soft, sweet and thin-stemmed variety, known as Criolla, was introduced into the West Indies in 1493 by the explorer Christopher Columbus. During the eighteenth century, sugar cane plantations developed rapidly in the colonies of many European countries as a result of the cheap supply of slave labor drawn from the African continent. The modern varieties of sugar cane are hybrids of Saccharum officinarum, S. robustum and S. spontaneum, which have been bred to resist Mosaic disease and to give high yields.

How do electric trains use power

Electric trains were first used in subways in 1890 (on the City and South London line in Britain), and all subsequent underground railways have been electrically worked. Subsurface cut-and-cover lines 'everywhere are also electrically worked. The early locomotives used on underground railways have given way to multiple-unit trains, with separate motors at various points along the train driving the wheels, but controlled from a single driving cab. With most subway systems, steel wheels running on steel track are used, but some systems have been developed using pneumatic tires running on tracks. These are claimed to offer a smoother ride and give greater traction that allows more rapid acceleration and braking.

What are the most famous ancient rivers in the mideast

Two famous rivers rise in the mountains of Armenia — the Tigris and the Euphrates. Flowing  southward, they approach each other to form a common valley, proceed in parallel channels for the greater part of their course, and unite shortly before reaching the Persian Gulf. In antiquity each river had a separate mouth.

The soil which the Tigris and Euphrates bring down every year fills up the Persian Gulf at the rate of about three miles a century. Their delta was therefore much less extensive five or six thousand years ago than it is to-day.

Should deep sea submersibles have a crew

Submersibles may or may not carry crew, but the relative merits of crewing such craft are still debated. An uncrewed submersible is easier to construct – it does not have a life support system. The only problem is to make the vessel sufficiently strong to withstand the pressures found at great depths in the sea.

Using an uncrewed submersible also has many advantages to those involved in the work. Because the vessel does not have to come up for air, there is no time limit to the mission. The controlling crew can be changed on the surface and the work can progress with little disruption. Potentially hazardous environments and materials can be tackled with little worry. Finally, with only one crew, there can be no arguments about operational decisions.

What are life support systems for deep sea vessels

At the start of the 1960s there were only four deep-sea research vessels in the world, but by 1970 there were 43, mainly funded by investment from the U.S. government. However, in the 1970s and 1980s the pace of new investment in these specialized vessels has slackened. Instead, submersibles have moved firmly into the commercial sphere and are now used for marine engineering projects and exploration.

Life support systems used in submersibles are generally simpler than those found in larger submarines. Cost, size and mission length have all had an influence on the design of these systems. Free-swimming submersibles usually have both oxygen supply and carbon dioxide removal systems, but those lowered from surface vessels often economize by only having an oxygen supply system. Consequently, dives are limited to only an hour or two. Oxygen is usually supplied from cylinders, and carbon dioxide removal is carried out by Barylyme or lithium hydroxide scrubbers. Air pressure is carefully maintained at that found at sea level, and normal Earth atmosphere gas constituents are aimed for, which is easier for the crew.

How to build a submersible

The bathyscaphe has two main sections – a large float and a spherical cabin slung beneath it. The float, which is lighter than water and filled with gasoline, gives the craft positive BUOYANCY. It also contains iron shot, held in hoppers by electromagnets. When on the surface, some of the compartments in the float are filled with air. For diving, these compartments are filled with water.

The gasoline-filled compartments are left open at the bottom. As the bathyscaphe dives deeper and the pressure increases, some water finds its way into the gasoline-filled compartments, equalizing the pressure inside and outside the float. This allows the float to be constructed from much lighter gauge materials than the crew sphere.

What are water cooled engines and help

Other types of engine produced at the time included the Spanish Hispano-Suiza, a design well ahead of its time with eight steel cylinders arranged in a V and screwed into an aluminum block. In the later years of the war this engine yielded, in successive versions, 150, 220 and 300 hp.

The Rolls-Royce Eagle, a V12 engine with a broadly similar layout adapted from an original Mercedes design, produced 360 hp in its Mark 8 version. This was the engine of the Vickers Vimy that carried Britons Alcock and Brown across the Atlantic in 1919.