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A diagram of the vertical zone refining process used to grow single-crystal ice from an initially polycrystalline material. The convection in the melt is a result of water's density maximum at 4 °C. Silicon crystal in the beginning of the growth process Growing silicon crystal A high-purity ( 5N ) tantalum single crystal, made by the floating ...
Float-zone silicon is very pure silicon obtained by vertical zone melting. The process was developed at Bell Labs by Henry Theuerer in 1955 as a modification of a method developed by William Gardner Pfann for germanium. In the vertical configuration molten silicon has sufficient surface tension to keep the charge from separating.
The methods involve heating polycrystalline material above its melting point and slowly cooling it from one end of its container, where a seed crystal is located. A single crystal of the same crystallographic orientation as the seed material is grown on the seed and is progressively formed along the length of the container.
The image below is a schematic flow diagram of a typical oil refinery that depicts the various unit processes and the flow of intermediate product streams that occurs between the inlet crude oil feedstock and the final end products. The diagram depicts only one of the literally hundreds of different oil refinery configurations.
William Gardner Pfann (October 27, 1917 – October 22, 1982) was an inventor and materials scientist with Bell Labs.Pfann is known for his development of zone melting which is essential to the semiconductor industry.
In metallurgy, refining consists of purifying an impure metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining the final material is chemically identical to the raw material. Refining thus increases the purity of the raw material ...
Flames could be seen where a military helicopter made an emergency landing at Camp Pendleton on Friday, causing police to warn drivers of potential traffic delays along Interstate 5. All four crew ...
The image below is a schematic flow diagram of a typical petroleum refinery that depicts the various refining processes and the flow of intermediate product streams that occurs between the inlet crude oil feedstock and the final end-products. The diagram depicts only one of the literally hundreds of different oil refinery configurations.