Mid-century

This whole field is an excellent illustration of the deep change in metallurgy and its inheritor, materials science, wrought by the quantitative revolution of mid-century. 

However, I believe that enough has been described to support my contention that modern methods of characterisation are absolutely central to materials science in its modern incarnation following the quantitative revolution of mid-century. That revolution owed everything to the availability of sensitive and precise techniques of measurement and characterisation. 

Why cocktails Why now Probably a couple of reasons. They ve had their heydays before, in the late nineteenth century, the early twentieth century, mid-century, and with the retrospective revivals of the 1980s and 1990s, when lounge culture and cocktail culture synonymously changed the way many people socialized. Cocktail drinking became a young, urban style of life unto itself—a martini culture that transcended gin and vermouth. 

In the late 1950 s two groups - one at ICI (ref. 1) and the other at the Mid-Century Corporation (ref. 2) - independently discovered that p-xylene is oxidized to terephthalic acid in almost quantitative yield when soluble bromides are used together with cobalt and manganese catalysts in acetic acid solvent at temperatures > 130 °C (ref. 3). This discovery formed the basis for what became known as the Mid-Century process and later, when the Mid-Century Corporation was acquired by Amoco, as the Amoco MC process for the commercial production of terephthalic acid. A large part of the ca. 6 million tons of the latter that are manufactured annually, on a worldwide basis, are produced via this method. This makes it the most important catalytic oxidation process (ref. 4). 

Amoco Amoco Chemicals Company, a subsidiary of Amoco Corporation, formerly Standard Oil Company (IN), is best known in the chemicals industry for its modification of the Mid-Century process for making pure terephthalic acid. /7-Xylene in acetic acid solution is oxidized with air at high temperature and pressure. Small amounts of manganese, cobalt, and bromide are used as catalysts. The modification allows the use of terephthalic acid, rather than dimethyl terephthalate, for making fiber. The process can also be used for oxidizing other methylbenzenes and methylnaphthalenes to aromatic carboxylic acids. See also Maruzen. 

LOR [Liquid-phase oxidation reactor] Not a process but a piece of equipment in which to conduct liquid-phase oxidations (e.g. the Mid-Century process) safely with oxygen rather than with air. The oxygen is introduced into the liquid phase and rapidly dispersed in the form of bubbles 1 to 5 mm. in diameter. Developed by Praxair and ABB Lummus Global in 1996. 

Mid-Century Also called M-C. A process for oxidizing p-xylene to terephthalic acid, using oxygen in acetic acid and catalyzed by a mixture of cobalt and manganese bromides. Developed in the 1950s by Halcon International and commercialized by Standard Oil Company (Indiana). The first plant was built at Jolet, IA, in 1938. The Amoco and Maruzen processes are improved versions. 

The move to fuel cells may not be pushed by declining oil supplies. The cost of developing new oil discoveries continues to fall and we may not see a forced drop in productivity. It was thought that there was 1.5 billion barrels of oil in the North Sea, but now there appears to be 6 billion barrels. We may not begin to reach the physical limits of oil production until mid-century. Supplies could tighten quickly from natural or manmade disasters and recent price rises are driven by increasing worldwide demands. Older oil fields are being pursued to meet this demand, but full development is expected to take years. 

Indeed these qualities have been developed since the mid-Century so that in a particular segment of the information industry such as telephones and communications, our volume of synthetic polymers used annually exceeds that of any other class of materials, although the actual tonnage of metallic and inorganic matter still leads. For the world of tomorrow, we find microelectronics, thin film circuitry and systems and, especially now photonics, with lasers and light guides, to be dominant components. All of these strongly use polymers, for their special physical-chemical as well as familiar mechanical and electro-optical qualities. 

Meanwhile attempts to find an air oxidation route directly from p-xylene to terephthalic acid (TA) continued to founder on the relatively high resistance to oxidation of the /Moluic acid which was first formed. This hurdle was overcome by the discovery of bromide-controlled air oxidation in 1955 by the Mid-Century Corporation [42, 43] and ICI, with the same patent application date. The Mid-Century process was bought and developed by Standard Oil of Indiana (Amoco), with some input from ICI. The process adopted used acetic acid as solvent, oxygen as oxidant, a temperature of about 200 °C, and a combination of cobalt, manganese and bromide ions as catalyst. Amoco also incorporated a purification of the TA by recrystallisation, with simultaneous catalytic hydrogenation of impurities, from water at about 250 °C [44], This process allowed development of a route to polyester from purified terephthalic acid (PTA) by direct esterification, which has since become more widely used than the process using DMT. 

We tend to think of race as being indisputable, real It frames our notions of kinship and descent and influences our movements in the social world we see it plainly on one another s faces. It seems a product not of the social imagination but of biology. Like some mid-century liberals who saw race as a myth or a superstition, however, scholars in several disciplines have recently shaken faith in this biological certainty. The conventions by which race mixing is understood, they point out, is one site where the unreality of race comes into view. Why is it that in the United... 

Whereas the first development in mid-century scholarship represented a thoroughgoing revision of the race concept, this latter development represented a shift in the locus of scholarly inquiry. An interest in various kinds of typology and in discovering essential traits or the paths of development of this or that race—interests that had shaped the scholarship from Blumenbach on down—now gave way to the more immediate question of social relations. Race relations now came into its own as a field, from the Chicago school s sociological studies of urban cultural ge-... 

The presumed immutability of the Jews became a staple of American science by mid-century as well, even though slavery and the question of Negro citizenship still dominated racial discussion. In Types of Mankind (1855) Josiah Nott remarked that the well-marked Israelitish features are never beheld out of that race The complexion may be bleached or tanned. . . but the Jewish features stand unalterably through all climates. In Natural History of the Human Races (1869) John Jeffries, too, argued that the Jews have preserved their family type unimpaired and though they number over five million souls, each individual retains the full impress of his primitive typical ancestors. 23 And of course we have already seen where these observations on Jewish racial integrity tended in the age of eugenics. 

But whether the exchange gives voice to a mid-century protest against LaFarge s rendering of race as myth, or a late-century objection to his... 

Prior to polymerization, p-xylene is first oxidized to terephthalic acid (TA) or dimethyl terephtalate (DMT). These diacid or dimethyl ester monomers are then polymerized via a condensation reaction with ethylene glycol to form the polyester. Prior to the development of a method to purify TA to make purified terephtahc acid (PTA, >99% pure) by the Mid-Century Corporation in the 1950s [10], DMT was the primary way to obtain the purified dicarboxylate. The Amoco Oil Company, now part of BP International, made several improvements to the PTA process since its inception [11]. Since the advent of the availability of PTA, it has become the monomer of choice over DMT. PTA avoids the complications of including methanol to enable purification and handling the methanol evolved during the polymerization to polyester. 

As new experiments were performed, the results sometimes seemed to contradict Berzelius s atomic weight determinations. Different chemists began to make different assumptions about how the weights should be calculated. There was confusion also about the terms atom and molecule themselves. At mid-century these two words were still used interchangeably. Even the discovery of simplicity sometimes proved to be confusing. In 1808 the French chemist and physicist Joseph Louis Gay-Lussac discovered a simple chemical law and chemists did not know how to explain it. 

Wheeler, D. Art Since Mid-Century 1945 to the Present. New York Vendome, 1991. White, ]. The Birth and Rebirth of Pictorial Space. London Tiranti, 1967. 

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