Measurement ranked

As unifying, underlying concepts, type and rank certainly can be employed to envision why coals have the properties that they do. However, it is time for a reevaluation of coal classification concepts. How can we measure rank when we analyze coals of different types and when there is no simple rank progression even when vitrinite or vitrinite-rich coals are compared And how can we assess type when maceral identification criteria are highly subjective, except for reflectance measurements that routinely are not even applied to the liptinite and highly variable inerti-nite macerals And, finally, how can coals be classified scientifically when empirical and derived properties like calorific value and fixed carbon yield are employed as classifying parameters ... 

Ordinal scale of measurement Ranked information with an ordered relationship between numbers. 

Each of the following solutions was prepared by dissolving enough of the compoimd to make a solution that is 0.1 OM weak acid. The pH of each solution is measured. Rank the acids from weakest to strongest. Suppose a strong acid had been prepared like the others. What pH would you predict for a O.IOM solution of a monoprotic strong acid ... 

The first three searches compared the performance of different similarity measures with the full INBS frequency data. When the performance of the frequency Tanimoto measure and the city block metric was compared, it was found that the hits ranked to the top using the Tanimoto measure were not as similar to the query structure as those ranked top by the city block metric. Generally it was found that the city block and Euchdean distance measures ranked the hits equally well, however in two cases the city block ranking was better than the Euclidean ranking, so use of the city block metric may be preferred. The fourth search used only the paths from the most connected atom in the structure in a city block metric calculation. A comparison of the performance of the INBS search for individual query structures using the city block metric for all paths and for the Morgan root atom alone is discussed below. 

The multipole moment of rank n is sometimes called the 2"-pole moment. The first non-zero multipole moment of a molecule is origin independent but the higher-order ones depend on the choice of origin. Quadnipole moments are difficult to measure and experimental data are scarce [17, 18 and 19]. The octopole and hexadecapole moments have been measured only for a few highly syimnetric molecules whose lower multipole moments vanish. Ab initio calculations are probably the most reliable way to obtain quadnipole and higher multipole moments [20, 21 and 22]. 

Similarity is often used as a general term to encompass either similarity or dissimilarity or both (see Section 6.4.3, on similarity measures, below). The terms "proximity" and distance are used in statistical software packages, but have not gained wide acceptance in the chemical literature. Similarity and dissimilarity can in principle lead to different rankings. 

In general, different similarity measures yield different rankings, except when they are monotonic. Improved results are obtained by using data fusion methods to combine the rankings resulting from different coefficients. 

Following the similar structure - similar property principle", high-ranked structures in a similarity search are likely to have similar physicochemical and biological properties to those of the target structure. Accordingly, similarity searches play a pivotal role in database searches related to drug design. Some frequently used distance and similarity measures are illustrated in Section 8.2.1. 

The development of a new drug is both a time-consuming and a cost-intensive process. It takes 12 to 15 years and costs up to 800 million to bring a new drug to the market. As measured by the market capitalization, the pharmaceutical companies play a pivotal role in the global economy. In February 2003 Pfizer was ranked at position five worldwide, with a market capitalization of 163 billion. Ranking third as far as the market capitalization in Europe is concerned was GlaxoSmithKline, with a current value of 101 billion. Novartis was number five in Europe with 82 billion. 

A measure of sophistication is necessary in order to obtain a reasonable set of parameters. The following steps are recommended in order to address the concerns above. They are ranked approximately best to worst, but it is advisable to use all techniques for the sake of doublechecking your work. Step 9 should... 

Table 7.4 lists the Q and e values for an assortment of common monomers. The extremes in the column of e values in Table 7.4—which are listed in order-quantify the range of donor-acceptor properties which is used as the basis for ranking in Fig. 7.2. The Q values perform a similar ranking with respect to resonance effects. The eight different Q-e combinations in Table 7.4 allow the estimation of ri and values for 28 different copolymers. Of course, in these systems Q and e values were assigned to give the best fit to r values which had already been measured. As an illustration of the predictive values of the Q-e scheme, consider the following example ... 

MohsAn early (1822) hardness comparison test involved assigning a relative number to aH known materials (usuaHy minerals and pure metals) by virtue of their relative abHity to scratch one another. The results of this classification are not relatable to other properties of materials or to other measures of hardness. As a result of this limited useflilness, the Mohs hardness test is primarily used for mineral identification. Some examples of the Mohs hardness scale, which ranks materials from 1 to 10, are Hsted in Table 6. 

To obtain the WeibuU parameters, the strengths of n > 30 samples are measured and ranked from lowest to highest. The probabUity of faUure is then calculated using an estimator ... 

Vitrinite Reflectance. The amount of light reflected from a poHshed plane surface of a coal particle under specified illumination conditions increases with the aromaticity of the sample and the rank of the coal or maceral. Precise measurements of reflectance, usually expressed as a percentage, ate used as an indication of coal rank. 

Seam correlations, measurements of rank and geologic history, interpretation of petroleum (qv) formation with coal deposits, prediction of coke properties, and detection of coal oxidation can be deterrnined from petrographic analysis. Constituents of seams can be observed over considerable distances, permitting the correlation of seam profiles in coal basins. Measurements of vitrinite reflectance within a seam permit mapping of variations in thermal and tectonic histories. Figure 2 indicates the relationship of vitrinite reflectance to maximum temperatures and effective heating time in the seam (11,15). 

Electron spin resonance (esr) (6,44) has had more limited use in coal studies. A rough estimate of the free-radical concentration or unsatisfied chemical bonds in the coal stmcture has been obtained as a function of coal rank and heat treatment. For example, the concentration increases from 2 X 10 radicals/g at 80 wt % carbon to a sharp peak of about 50 x 10 radicals/g at 95 wt % carbon content and drops almost to zero at 97 wt % carbon. The concentration of these radicals is less than that of the common functional groups such as hydroxyl. However, radical existence seems to be intrinsic to the coal molecule and may affect the reactivity of the coal as well as its absorption of ultraviolet radiation. Measurements from room... 

Coke Production. Coking coals are mainly selected on the basis of the quaUty and amount of coke that they produce, although gas yield is also considered. About 65—70% of the coal charged is produced as coke. The gas quaUty depends on the coal rank and is a maximum, measured in energy in gas per mass of coal, for coals of about 89 wt % carbon on a dry, mineral matter-free basis, or 30% volatile matter. 

The UL flammability ratings describe the relative ease of ignition and combustibiUty of plastics. Tests include the measurement of flame propagation, time to self-extinguish, melt and drip with and without flame, and oxygen indexes. Some engineering plastics, eg, polyetherimides, are, as ranked by this test, inherently nonflammable. Others can be made nonflammable by compounding with flame retardants (ERs) such as bromine... 

Experimental mea.surement of relative volatility. Rank candidate solvents by the increase in relative volatility caused by the addition of the solvent. One technique is to experimentally measure the relative volatility of a fixed-composition key component-solvent mixture (often a 1/1 ratio of each key, with a 1/1 to 3/1 solvent/key ratio) for various solvents. [Carlson et al., Jnd. Eng. Chem., 46, 350 (1954)]. The Oth-... 

Mag., 25(1), 131 (1972)] conclude that these measurements are valid when 50 percent corrections are added for the bending energy of the crystal. Kuznetzov ranks other materials by a relative wear test. His results substantiate the efficiencies given earlier. Attempts to measure efficiency of the grinding process by calorimetiy involve errors that exceed the theoretical surface energy of the material being ground. 

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