Historical summary

Labs were able to make dramatic improvements in the methodology and consistently grow single crystals up to one kilogram in size [13]. Currently there are several dozen companies throughout the world that produce a-quartz commercially, and over 500000 kg are produced each year. 

Another historically important area involving inorganic chemistry in hydro-thermal fluids is related to the synthesis of zeolites and other microporous solids. It was recognized early on that naturally occurring zeolites (or boiling stones) are the result of natural hydrothermal activity. Thus, a fairly intense effort to prepare new zeolites from hydrothermal solutions in the laboratory was mounted, particularly in the petrochemical industry. Much of the early work is summarized in an excellent monograph by Barrer [29]. Most of the useful microporous solids are prepared at relatively low temperatures 

Most technology in this field was developed many years ago. To the knowledge of the authors, no significant new technical developments have been added by the more recent inorganic entrants. However, the rapid expansion and widespread use of any technique inevitably leads to useful innovations, and this process is now underway in the mainstream chemical community. 

The next level of containment is probably the fluoropolymer-lined digestion bomb. These autoclaves are sold by a number of vendors and are inexpensive (ca. 300 each), easy to handle, and require no special auxiliary equipment [31]. They are the vessels of choice for a number of workers doing some remarkable chemistry [32]. They also have the important advantage that they are inert to aqueous base and fluorides, making them a workhorse for the zeolite industry. However, they have the limitation that the fluoropolymer liner will deform and weaken above about 240 °C. Also, the autoclaves have simple screw top seats meaning they can rarely contain pressures exceeding 140 bar. Thus they cannot contain true supercritical aqueous fluids. Nonetheless their convenience makes them the vessel of choice for the large amount of hydro-thermal work done at 200 °C and below. 

It should be noted that the concept of the floating liner can be scaled for large commercial crystal growth. A platinum can is fabricated and welded 

In relation to lead refining major innovations have mainly occurred in the 70-year period from the late 1800s to the early 1900s, largely due to the quality demands for lead as the industrial age developed. 

Agricola, G, 1950. De Re MetaUica (1556), translation by H C and L H Hoover (Dover Pubbcalions Inc New York). Collins, H F, 1910. The Metallurgy of Lead (Charles Griffin and Co London). 

The extraction of lead from its ores by the iron-reduction process A historical perspective. Journal of Metals, October, pp 18-23. 

Eissler, M, 1891. Metallurgy of Argentfemus Lead A Practical Treatise on the Smelting of Silver - Lead Ores (Crosby-Lockwood and Son London). 

Hoffman, H O, 1899. The Metallurgy of Lead (The Scientific Publishing Company New York). Also revised edition, 1918 (McGraw Hdl New York). 

A high-pressure process was the first method used to manufacture polyethylene. 

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The production and properties of ethylene homo- and copolymer foams with densities less than 50 kg/cu.m. are reviewed. A brief historical summary is given, followed by a discussion of six key parameters as they relate to the properties and form of the foam. The diversity of the manufacturing processes available for foam production is illustrated by three distinct operating techniques. Stress-strain curves are used to demonstrate the wide spectrum of properties obtainable and examples of applications are given. 11 refs. 

A historic summary of the development of the product serves many purposes. The foremost purpose is to apprise the investigators of the scope of inspection. The investigators learn more about the product from the history of its development than from the analysis report of the finished product. This shows the awareness of the firm about the development process. This document should include a description of the API, the formulation, and the analytical methods. These sections should be clearly marked or presented in separate binders. The summary section should highlight how the biobatch is linked to the full-scale batch with respect to validation and scale-up of production. This section also offers an opportunity for the firm to address the issues that it considers critical. 

The past twenty-five years roughly match the development of the Division of Petroleum Chemistry, which was formed in 1921. In view of the fine historical summary recently prepared by Egloff and Alexander, there is no need to go into that story in any detail. 

It is well known that optical activity is induced for achiral species in the presence of chiral species, giving rise to ICD for the absorption band(s) of the achiral species. In the introduction Section, a historical summary is described in brief. The theory of ICD has been developed by Tinoco, Jr.46), Mason 47), and Schipper 48). 

After 1900 the direct determination of hydrate number was abandoned in favor of the second, indirect method. The indirect method is still in use today and is based on calculation of the enthalpies of formation of hydrate from gas and water, and from gas and ice. This method was originally proposed by de Forcrand (1902) who used the Clapeyron equation to obtain the heat of dissociation from three-phase, pressure-temperature data, as in the below paragraph. With this more accurate method many exceptions were found to Villard s Rule. The historical summary provided in Chapter 1 indicates that while the number of hydrated water molecules was commonly thought to be an integer, frequently that integer... 

The brief historical development in the last chapter noted that the early theoretical papers described chromatography in terms similar to distillation or extraction and were known as the plate theory. Useful as it may have been in the development of chromatography, the plate theory is of little value in modern chromatography and has been replaced by the rate theory. Any of the early books on gas chromatography can be consulted for a discussion of the plate theory, and Giddings1 has written a good historical summary of the concurrent development of the plate and rate theories. 

Today, virtually all biology books speak of the genetic code, but none mentions signal transduction codes or splicing codes. Why Perhaps a brief historical summary may help us to understand. In the 1950s it became clear that protein synthesis requires a transfer of information from nucleic acids to proteins, and people realised that such a process must necessarily use a code. The existence of the genetic code, in... 

Ammonium sulphate can be prepared by the general methods applicable to ammonium salts, and also by the action of sulphuric acid on ammonium chloride.12 It is manufactured by neutralizing with sulphuric acid the ammonia of coal or peat,13 and many other methods of manufacture have been worked and suggested.14 Veevers has written a historical summary of the methods employed in its manufacture.15... 

An historical summary of the PLC-based system validating an existing system... 

Historical summary of the development of industrial biocatalytic processes... 

The second part of the chapter deals with tides in the Baltic Sea, a much neglected subject in the author s opinion. The topic is introduced by a brief historic summary of Baltic Sea tidal theory, followed by an outline of present tidal theory for the Baltic Sea. The conclusion at the end of this chapter is that inclusion of the tides in numerical models of the Baltic Sea will lead to more realistic sea level forecasts. 

This brief historical summary of Permasep permeator developments introduces the subject of structure-property relationships for membranes from aromatic polyamides and derivatives. 

Bureau of the Census, Historical Statistics of the United States 1789-1945, 1949. Supplement and historical summary of Statistical Abstract of the United States. Continuation data, 1946 to date, given in appendices of Statistical Abstract of the United States. ... 

Cycloadditions A. Gilbert and J. Mattay, see above D. Bryce-Smith, A. Gilbert, J. Mattay, Tetrahedron 1986, 42, 6011 - 6014 (an historical summary) P. A. Wender,... 

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