From the late

The earliest examples of analytical methods based on chemical kinetics, which date from the late nineteenth century, took advantage of the catalytic activity of enzymes. Typically, the enzyme was added to a solution containing a suitable substrate, and the reaction between the two was monitored for a fixed time. The enzyme s activity was determined by measuring the amount of substrate that had reacted. Enzymes also were used in procedures for the quantitative analysis of hydrogen peroxide and carbohydrates. The application of catalytic reactions continued in the first half of the twentieth century, and developments included the use of nonenzymatic catalysts, noncatalytic reactions, and differences in reaction rates when analyzing samples with several analytes. 

Micro-Turbines. These turbines are in the range from 20kW-350kW. The growth of these turbines has been dramatie from the late 1990s, as there is an upsurge in the distributed generation market. 

It is no exaggeration to claim that it was the extensive worldwide body of research on semiconductors from the late 1930s onwards that converted physicists to the recognition that scrupulous control of purity, stoichiometry and crystal perfection, together with characterisation methods that could check on these features, are a precondition of understanding the nature of semiconductors and thus also a precondition of exploiting them successfully - indeed, not only semiconductors but, by extension, many kinds of materials. 

Carbon dioxide, considered a wanning gas, comprises about 0.036 percent of the atmosphere by volume. As Figure 1 shows, carbon dioxide levels have increased as a component of the atmosphere by nearly 30 percent from the late eighteenth century to the end of the twentieth century, when the level was close to 365 parts per million by volume. Prior to the period of industrialization, carbon dioxide levels were largely stable, at about 280 parts per million, though fluctuations as low as 200 parts per million or as high as 300 parts per million have been observed through analysis of air bubbles trapped in arctic ice cores. 

NUCLEAR ENERGY AND NUCLEAR DEFENSE FROM THE LATE 1970S TO THE PRESENT... 

From the late 1850s to the turn of the ccntui-y, the major interest in petroleum was as a source of kerosene, as both a fuel and illuniinant. As early as the 1820s, it was generally known from chemical experiments that illuminants, heating fuels, and lubricants could be obtained relatively cheaply from the distillation of crude oil. 

The gross flux of carbon from atmosphere to ocean is thus ca. 80 Pg C/yr. There are several complications with the above calculation. The isotopic ratios must be steady-state values, which are unavailable due to the changes resulting from atmospheric atom bomb testing. The few available pre-bomb measurements from the late 1950s (Broecker et ah, 1960) together with determinations in corals (Druffel and Linick, 1978) are invaluable tools for determin-... 

In Section 9.1 it was noted that this cement was the only important zinc oxide cement other than the ZOE cement. Its invention and development is largely associated with Brauer who, with coworkers, has been carrying out a programme of research and development from the late 1950s to the present day. 

However, it is not only knowledge transfer on the technology itself which impacts on society microchemical processing wiU have repercussions on our wealth, health, and environment. From the late 1960s (first prognoses on limits of production... 

Valuable contributions were made by two Canadian agencies, particularly by the National Research Council Canada (NRCC) who, from about 1976, provided marine and marine biological CRMs certified for metals, metal species and organic constituents (Berman 1984 Willie 1997). More recently their Halifax laboratories have issued a highly respected range of CRMs for the determination of shellfish toxins. Another Canadian producer, the National Water Research Institute (NWRI) specialized in marine (water and sedimentary) CRMs, and from the late 1980 s their matrix materials certified also for organic compounds (Chau et al. 1979 Lee and Chau 1987). 

Increasing activities for the production and certification of biological, environmental and geological CRMs from the late 1980 s have been also reported from Poland (Dybczyhski 1995) and the Czech Republic (Kucera et al. 1995,1998). 

Jones CE, Halliday AN, Lohmann KC (1995) The impact of diagenesis on high-precision U-Pb dating of ancient carbonates An example from the Late Permian of New Mexico. Earth Planet Sci Lett... 

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