Early years

About 1820 the Scotsman Macintosh rediscovered the process of dissolving rubber and placed the solution between two fabrics which as a result became united, impermeable and without the stickiness of earlier products. His name, or rather a mild corruption of it, mackintosh, has become perpetuated to cover a variety of rainproof outer garments. 

Whilst Faraday had shown in 1826 that rubber was a hydrocarbon of empirical formula CsHg few further important developments occurred until the closing years of the 19th century when the structure of natural rubber began to be progressively revealed, a process which only became substantially complete about 1930 and which is considered in the next chapter. 

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As introduced in Section 14.2, bottlenecks in the process facilities can occur at many stages in a producing field life cycle. A process facility bottleneck is caused when any piece of equipment becomes overloaded and restricts throughput. In the early years of a development, production will often be restricted by the capacity of the processing facility to treat hydrocarbons. If the reservoir is performing better than expected it may pay to increase plant capacity. If, however, it is just a temporary production peak such a modification may not be worthwhile. 

I may have some talent for coping with administrative duties and dealing with people, but it never affected me in the ways I have sometimes observed it did others. When in my early years in Hungary I was helping to start a small research institute of the Academy of Sciences,... 

During the early years of this century, organic chemists were enjoying success in determining the structures of ordinary-sized organic molecules, and this probably contributed to their reluctance to look beyond structures of convenient size. Physical chemists were interested in intermolecular forces at this period, and the idea that polymers were the result of some sort of association between low molecular weight constituent molecules prevailed fora long while. 

In the early years of reactor development, electricity from nuclear sources was expected to be much cheaper than that from other sources. Whereas nuclear fuel cost is low, the operating and maintenance costs of a nuclear faciHty are high. Thus on average, electric power from coal and nuclear costs about the same. 

In early years the contact process frequentiy employed only two or three catalyst stages (passes) to obtain overall SO2 conversions of approximately 95—96%. Later, four pass converters were used to obtain conversions of from 97% to slightiy better than 98%. For sulfur-burning plants, this typically resulted in sulfur dioxide stack emissions of 1500—2000 ppm. 

In the early years of ground water and soil remediation, pump and treat was the conventional technology. Contaminated ground water is pumped to the surface where it is treated and reinjected or discharged to surface waters or wastewater treatment plants. Reinjection maybe used to stimulate in situ... 

Chemical analyses of stream water that have been pubhshed since the early years of this century generally include deterrninations for four positively charged ions (cations)—calcium (Ca ), magnesium (Mg ), sodium (Na ), and potassium (K )—and five negatively charged ions... 

In the early years of the chemical industry, use of biological agents centered on fermentation (qv) techniques for the production of food products, eg, vinegar (qv), cheeses (see Milk and milk products), beer (qv), and of simple organic compounds such as acetone (qv), ethanol (qv), and the butyl alcohols (qv). By the middle of the twentieth century, most simple organic chemicals were produced synthetically. Fermentation was used for food products and for more complex substances such as pharmaceuticals (qv) (see also Antibiotics). Moreover, supports were developed to immobilize enzymes for use in industrial processes such as the hydrolysis of starch (qv) (see Enzyme applications). 

The modem history of the military use of toxic chemical agents (1,3—5) dates from the first full-scale (chlorine) gas attack on April 22, 1915, near Ypres, Belgium in World War I. There were a few reports of the limited use of toxic chemicals since that time. The Italians employed mustard, a bUster agent, during the Ethiopian war in 1935 and 1936 the Japanese used toxic chemicals in a number of small-scale engagements in the early years of their war with China and Iraq purportedly employed both mustard and nerve gases in the 1980s. 

The sum-of-years-digits depreciation allows equipment or plant to be depreciated by a greater amount during the early years than during the later years. 

Thus, cash flow in the early years of a project has a greater value than the same amount in the later years of a project. Therefore, it pays to receive money as soon as possible and to delay paying out money for as long as possible. 

An (NPV) or (DCFRR) estimation will be no better than the accuracy of the projec ted cash flows over the life of the project. Clearly, one is likely to predict cash flows more accurately for 2 or 3 years ahead than, say, for 9 or 10 years ahead. However, since the cash flows for the later years are discounted to a greater extent than the cash flows for the earher years, the latter have less effec t on the overall estimation. Nevertheless, the difficulty of predicting cash flows in later years and the inherent lack of confidence in these predictions are serious disadvantages of the (DCFRR) method. In this respec t (NPV)s are more usefm since they are calculated for each year of a project. Thus, a project with a favorable (NPV) in the early years is a promising one. 

In practice most distribution cuiwes are not symmetrical about the median but are inherently skewed. The effect of an advertising campaign is usually to increase the rate of sales in the early years. It may also increase the level of mature demand for the product, but this mature demand must be asymptotic to a finite upper Emit of sales c. Such a cui ve is positively skewed since xm — xd) < x(j —x ). This situation can often be approximated by the Gompertz cui ve defined by Eq. (9-96) ... 

Filter Press The filter press, one of the most frequently used filters in the early years or the chemical industry, is still widely employed. Often referred to genetically (in error) as the plate-and-frame filter, it has probably over 100 design variations. Two basic popular designs are the flush-plate, or plate-and-frame, design and the recessed-plate press. Both are available in a wide range of materials metals, coated metals, plastics, or wood. 

In determining the protection current required, the surfaces of the objects to be protected in the water and on the seabed, as well as those of foreign constructions that are electrically connected to the object to be protected, should be isolated. The protection current densities derived from experience and measurements for various sea areas are given in Table 16-3. In exceptional cases measurements must be carried out beforehand at the location of the installation. Such investigations, however, provide little information on the long-term development of the protection current. By using a suitable coating [4], the protection current density in the early years of service will be only about 10% of the values in Table 16-3. For a planned operational lifetime of 30 years, about 50% of these values is necessary. 

Applying two important tax credits would improve the early years cash flow and shorten the payback period. A 10% investment tax credit and a 10% energy tax credit applied to the incremental capital costs for the expanders yields nearly 1.0 million additional first-year cash... 

As in Europe, air pollution research activity expanded tremendously in the United States during these three decades. The headquarters of federal research activity was at the Robert A. Taft Sanitary Engineering Center of the PHS in Cincinnati, Ohio, during the early years of the period and at the National Environmental Research Center in Triangle Park, North Carolina, at the end of the period. 

As can be seen in Table 2 all revenues less expenses associated with selling are summed in Row 17. All expenses including noncash expenses such as depreciation, amortization, and depletion are summed in Row 30. The net profit before tax, Row 32, is obtained by subtracting Row 30 from Row 17 and making any inventory adjustment required. Row 34 is the cash taxes that are to be paid unless offset by investment or energy tax credits in Row 36. The deferred income tax is shown in Row 35. The deferred tax decreases the net profit after tax in the early years and increases the net profit after tax in later years. The impact on cash flow is just the other way around as discussed later. Row 37, profit after tax, is obtained as foliow s ... 

Polybutadiene was first prepared in the early years of the 20th century by such methods as sodium-catalysed polymerisation of butadiene. However, the polymers produced by these methods and also by the later free-radical emulsion polymerisation techniques did not possess the properties which made them desirable rubbers. With the development of the Ziegler-Natta catalyst systems in the 1950s, it was possible to produce polymers with a controlled stereo regularity, some of which had useful properties as elastomers. 

Regarding a historical perspective on carbon nanotubes, very small diameter (less than 10 nm) carbon filaments were observed in the 1970 s through synthesis of vapor grown carbon fibers prepared by the decomposition of benzene at 1100°C in the presence of Fe catalyst particles of 10 nm diameter [11, 12]. However, no detailed systematic studies of such very thin filaments were reported in these early years, and it was not until lijima s observation of carbon nanotubes by high resolution transmission electron microscopy (HRTEM) that the carbon nanotube field was seriously launched. A direct stimulus to the systematic study of carbon filaments of very small diameters came from the discovery of fullerenes by Kroto, Smalley, and coworkers [1], The realization that the terminations of the carbon nanotubes were fullerene-like caps or hemispheres explained why the smallest diameter carbon nanotube observed would be the same as the diameter of the Ceo molecule, though theoretical predictions suggest that nanotubes arc more stable than fullerenes of the same radius [13]. The lijima observation heralded the entry of many scientists into the field of carbon nanotubes, stimulated especially by the un-... 

Fine, M.E. (1990) The First Thirty Years, in Tech, The Early Years a History of the Technological Institute at Northwestern University from 1939 to 1969 (privately published by Northwestern University) p. 121. 

During the early years of physieal ehemistry, Ostwald did not believe in the existence of atoms... and yet he was somehow ineluded in the wild army of ionists. He was resolute in his scepticism and in the 1890s he sustained an obscure theory of energetics to take the place of the atomic hypothesis. How ions could be formed in a solution containing no atoms was not altogether clear. Finally, in 1905, when Einstein had shown in rigorous detail how the Brownian motion studied by Perrin could be interpreted in terms of the collision of dust motes with moving molecules (Chapter 3, Section 3.1.1), Ostwald relented and publicly embraced the existence of atoms. 

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