Glass historic

SOL-GEL PREPARATION OF BULK SILICA GLASSES Historical Badiground... 

ASTM defines crystal as (1) colorless, highly transparent glass, which is frequently used for art or tableware. (2) colorless, highly transparent glass historically containing lead oxide. In Europe, lead crystal must contain at least 24 wt% PbO waAfull lead crystal at least 30 wt%. Steuben glass has traditionally contained about 30 wt% PbO. 

A parallel but more historically comprehensive discussion of glass stmcture and composition has been given (36). Prediction of stmctural parameters and consequent properties from theoretical principles has increased with the advent of supercomputers. Of particular interest to glass scientists... 

Disk thermistors can be produced to close limits of iaterchangeabihty, eg, 0.1 and 0.05° C. Disks cannot be made as small as the smallest beads 2 mm diameter seems an approximate practicable limit. Disks historically have been considered to be less stable than good beads. They are commonly protected with a coatkig of epoxy reski, which provides less compressive support than the glass coatkig of bead thermistors. More recent developments have resulted ki kiterchangeable glass-encapsulated disk thermistors which have the stabihty characteristics of the best beads. 

Besides readings of Earth s surface temperatures taken with standard glass thermometers, direct readings of atmospheric temperatures have been taken with satellites and weather balloons. In addition to direct measurements of Earth s recent temperatures, proxy measurements of temperatures from farther in the past can be derived from borehole temperature measurements, from historical and physical evidence regarding the e xtent and mass of land and sea ice, and from the bleaching of coral reefs. 

Energy and bottle An interesting historical (1950s) example is the small injection blow molded whiskey bottles that were substituted for glass blown bottles in commercial aircraft continues to be used in all worldwide flying aircraft. At that time, just in USA, over 500 x 1012 Btu or the amount of energy equivalent to over 80 x 106 barrels of oil was reduced. 

Romich, H. (1999), Historic glass and its interaction with the environment, in Tennent, N. H. (ed.), The Conservation of Glass and Ceramics Research, Practice and Training, James and James, London. 

Turner, W. E. S. and H. P. Rooksby (1961), Further historical studies based on X-ray diffraction methods on the reagents employed in making opal and opaque glass, Jahrbuch des Romisch-Germanischen Zentralmuseums (Mainz) 8, 1-6. 

Because of their brittleness, glass dewars have nowadays only an historical interest [3], We shall hereafter describe only metal dewars (or cryostat). 

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