Substantial quantities, meaning

The technique of the filtration of hot solutions has already been described in Section 11,28. The filtration of cold solutions will now be considered this operation is usually carried out when it is desired to separate a crystalline solid from the mother liquor in which it is suspended. When substantial quantities of a solid are to be handled, a Buchner funnel of convenient size is employed. The ordinary Buchner fimnel (Fig. 11,1, 7, a) consists of a cylindrical porcelain funnel carrying a fixed, flat, perforated porcelain plate. It is fitted by means of a rubber stopper or a good cork into the neck of a thick-walled filtering flask (also termed filter flask, Buchner flask or suction flask) (Fig. 11,1, 7, c), which is connected by means of thick-walled rubber tubing (rubber pressure tubing) to a similar flask or safety bottle, and the latter is attached by rubber pressure tubing to a filter pump the safety bottle or trap is essential since a sudden fall in water pressure may result in the water sucking back. The use of suction renders rapid filtration possihle... 

The Albright Goldman oxidation protocol is not a good choice as a standard oxidation procedure, because it tends to deliver substantial quantities of side compounds on simple substrates. On the other hand, it may succeed in hindered alcohols resistant to oxidation by other means. In those cases in which the Albright-Goldman oxidation delivers a useful yield of aldehyde or ketone, this oxidation protocol is hardly surpassed in terms of economy and experimental usefulness. Both DMSO and Ac20 are cheap solvents that are conveniently employed in this oxidation at room temperature or with some heating. 

Potassium is by far the mineral found in highest concentration in maple syrup, with a range from various studies of 541 031 ppm. Typically, the average values are around 2000-3300 ppm. Calcium is also found in substantial quantities, with a mean of 630-1470 ppm. The mean magnesium concentration is 130-375 ppm. Lesser amounts of manganese, sodium, and phosphorus are usually found. 

A number of plants and some trees contain a white, milky liquid that is released when the stem or bark is cut. The liquid is called a latex from the Latin meaning liquid. Common sources include dandelions, milkweed, goldenrod, and potted rubber plants. Rubber trees, from which substantial quantities of latex can be harvested, grow in some tropical areas of the world. A major constituent of this latex is a homopolymer of isoprene (2-methyl-1,3-butadiene), called polyisoprene. Polyisoprene, as well as a number of other elastomers, has a carbon-carbon double bond in every repeat unit. The properties of polyisoprene are the result of the presence of these double bonds. Just as stereochemistry plays a critical role in both proteins and polysaccharides, we will see its importance here. 

The Isua sedimentary beds, on the other hand, contain iron compounds that could have formed only in the absence of oxygen, which means that the Earth did not have an oxidizing atmosphere for hundreds of millions of years. Those same sediments, however, contain also many types of carbon compounds, and this shows that, by Isua s times, there were in the atmosphere substantial quantities of carbon dioxide (C02), and probably nitrogen (N2), two gases which are neither reducing nor oxidizing. 

The sulfur trioxide employed for the production of the mixed anhydride desirably is purified and freed from sulfuric acid since the use of sulfur trioxide containing sulfuric acid in any substantial quantity causes a reduction in yield of mixed anhydride as compared to that obtainable with pure sulfur trioxide. Any conventional means of securing pure sulfur trioxide can be employed, as for example, distillation from phosphorous pentoxide. The sulfur trioxide itself can... 

This approach can also be used for multichannel MSRs. Because of the small volumes of the individual channels, many channels have to be used in parallel to produce substantial quantities of product. A uniform distribution of the reaction mixture over thousands of microchannels is usually necessary to obtain adequate performance of a multichannel MSR [76]. Flow maldistribution will broaden the RTD in such a multitubular reactor and will lead to a reduced reactor performance, meaning reduced product yield and selectivity at a given space velocity [75,77]. Therefore, several authors have presented design studies of flow distribution manifolds [71,78-80]. 

Substantial quantities of soip- gasoline are being sweetened by oxidation of mercaptan Sulfur by means of oxygen and copper chloride solution. 

Meaning of"Substantial Quantities"or"Substantial Human Exposure"... 

Despite the fact that results of hardness tests are impossible to interpret in terms of any single fundamental mechanical property of materials, they are probably the simplest mechanical property tests to perform. Also, it is frequently the only mechanical test that can be employed when material is not available in substantial quantities as has been the situation in rare earth research. Nevertheless, carefully conducted hardness tests often are a sensitive means for detecting differences in impurity concentrations and for classifying metals. 

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