Qualitative and Quantitative Definitions

Particle shapes influence properties such as surface area, bulk density, flow, and so on. A number of methods are available for describing shape from simpler qualitative descriptions, through property ratios, to techniques that employ fast Fourier transformations to describe the projected perimeter of the particle. The measurement of the shape and the relevance of the data obtained are generally the two difficulties associated with particle shape. Fortunately, in the processing of materials physically unlike those in chemical processing, shape is perhaps is less significant and is more often than not inherently accounted for in the nominal diameter. 

Some of the common terms used for defining or describing particle shapes in a qualitative way are presented in Table 2.1. It is by now quite clear that particle shape cannot be very precisely defined. However, it is fortunate that mineral particles occur in a variety of generally simple shapes some are acicular, several are plate-like, most are convex, others are mildly concave, and in this manner a phraseological descriptive list is built for the different shapes that are formed or produced or generally encountered of powders of fragments of 

Granular having approximately equidimensional but inegular shape 

Angular sharp-edged or having roughly polyhedral shape 

Crystalline of geometric shape, freely grown and developed in a fluid medium 

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Sala was also an important champion of the introduction of the chemical medicines. Sala s description of fermentation, as an intimate movement of elementary particles which tend to group themselves in a different order to make new compounds, is evidence of a concept doubtless derived from the atomic theory of the Greeks, and differs from the concept of chemical action in the nineteenth century mainly by lacking qualitative and quantitative definition. 

Remember that British Standard BS 5532 [CAULCUTT and BODDY, 1983] provides qualitative and quantitative definitions of both reproducibility and repeatability. The determination of repeatability and reproducibility for a standard test method by interlaboratory tests is given in [ISO 5725]. 

From the point of view of structural analysis of nitrogen containing polymers, simultaneous application of both 13C and 15N NMR techniques will result in a more complete qualitative and quantitative definition of the polymer system, because the two nuclei/spectroscopies behave complementarily. 

All of the above illustrations are outside the realm of analytical chemistry and instrumental analysis, which are vital for qualitative and quantitative definition or description of scenarios in environment, agriculture, civil engineering, medicine, and similar fields of scientific and technological endeavor. Since chemical data derived by analytical methods are critical for decision-making in these fields, many examples of the applications of MCDM can be found in such fields. One important common element in decision-making in these fields is that it is becoming more and more multidisciplinary, i.e., several disparate stakeholders, such as administrators, scientists. 

We have examined onion fly paragonial extract by matrix-assisted laser desorption-ionization time-of-fli t (MALDI-TOF) mass spectrometry (70). Figure 4 A reveals the components in the molecular weight range suspected of containing onion fly sex peptide. We speculate that onion fly sex peptide will turn out to be a peak conunon to the onion fly and seedcom fly extract (Figure 4 B), since extracts of paragonia from these two very closely related species are cross-reactive (J. L. Spencer and J. R. Miller, unpublished), antitative analyses of behavioral effects of these sex peptides await better qualitative and quantitative definition of stimuli. 

Envlroiunental testing Is a critical element In this process since It enables the qualitative and quantitative determination of toxic chemicals In the environment and the definition of environmental pathways which may lead to human exposure This paper briefly reviews the overall process of health risk assessments and the particular role which environmental testing plays Recent efforts to assess environmental health risks In relation to Love Canal Illustrate both the usefulness and the limitations of environmental testing In risk assessment ... 

In order to evaluate the extent of attrition and its impact on the particle size distribution, there is a need of a qualitative and quantitative characterization. This, however, is not as simple as it may seem at first. There are many different properties, parameters and effects that manifest themselves and could be measured. In addition, as will be shown, the choice of the assessment procedure is strongly connected with the definition of attrition which, on its part, depends on the degradation mechanism that is considered to be relevant to the process. Hence there are a lot of procedures and indices to characterize the process of particle attrition. Section 3 deals with those which are relevant to fluidized beds and pneumatic conveying lines. 

The definition of an atom and its surface are made both qualitatively and quantitatively apparent in terms of the patterns of trajectories traced out by the gradient vectors of the density, vectors that point in the direction of increasing p. Trajectory maps, complementary to the displays of the density, are given in Fig. 7.1c and d. Because p has a maximum at each nucleus in any plane that contains the nucleus (the nucleus acts as a global attractor), the three-dimensional space of the molecule is divided into atomic basins, each basin being defined by the set of trajectories that terminate at a given nucleus. An atom is defined as the union of a nucleus and its associated basin. The saddle-like minimum that occurs in the planar displays of the density between the maxima for a pair of neighboring nuclei is a consequence of a particular kind of critical point (CP), a point where all three derivatives of p vanish, that... 

The quadrupole/time-of-flight analyzer (QToF) has become a key option in the qualitative and quantitative analytical arena. Instruments with resolving power of 20000 (50% valley definition) can provide <5ppm mass accuracy for parent and product ion identification and for 20mda mass selection windows quantitation. While the triple quadra-pole retains the lead in sensitivity for quantification, the QToF has a decided edge on specificity (Micromass, 1999) and qualitative analysis. 

The PARCC parameters are meaningful only if compared to certain standards as a means to determine their acceptability. The EPA gives the following definition to these qualitative and quantitative standards, which are called acceptance criteria (EPA, 1997a) ... 

DQIs are usually thought of as attributes of a laboratory measurement system. However, a broader definition of primary DQIs will enable us to assess the entire measurement system that includes not only the laboratory measurements but also the sampling design and field procedures. Such broad interpretation of the primary DQIs will allow us to evaluate all components of total error and with it the overall, not just the analytical, data quality. The DQI definitions (EPA, 1999a) presented in this chapter are interpreted in a manner that encompasses all qualitative and quantitative components of total error. 

Exposure assessment, however, is a highly complex process having different levels of uncertainties, with qualitative and quantitative consequences. Exposure assessors must consider many different types of sources of exposures, the physical, chemical and biological characteristics of substances that influence their fate and transport in the environment and their uptake, individual mobility and behaviours, and different exposure routes and pathways, among others. These complexities make it important to begin with a clear definition of the conceptual model and a focus on how uncertainty and variability play out as one builds from the conceptual model towards the mathematical/statistical model. 

The alkaloid contents in a single alkaloid cell from M. cordata roots of three different thicknesses (age 1-2 years) were determined as follows. The liquid from various numbers of alkaloid cells (Table II) was removed uniformly and collected in the microtrap. The liquid in the capillary and connection tubes was washed into the microtrap to make a certain definite volume for analysis. Quantitative analysis of each alkaloid was carried by preparing a calibration graph (4). Figure 3 shows the HPLC chromatogram of alkaloids from the alkaloid cells. The content of each alkaloid per single alkaloid cell in tissues from three different thickness of roots and its ratio are shown in Table II. The liquid in colorless cells contained only a minute amount of protopine and allocryptopine (Fig. 3). The thicker the roots, the more alkaloids were contained in a single alkaloid cell. In any thickness of root, the content of protopine-type alkaloids exceeded that of benzo[c]phenanthridine-type alkaloids. The ratio of the former to the latter was almost steady over 5 mm of root thickness (86-87%). The ratio of alkaloids in methanol extracts of the same fresh samples (thickness 5 mm) was determined by HPLC (Table III). The ratio of protopine-type alkaloids in the methanol extracts ( 80%) was less than that in the liquid from the alkaloid cells ( 87%). This was because the liquid in alkaloid cells near the cambium were picked up more than that in center cells (pith). Thus, intracellular components scattered in different places are analyzed qualitatively and quantitatively in situ by HC. 

Aromaticity is one of a number of remarkably important but fuzzy concepts in chemistry that does not lend itself easily to widely applicable clear-cut definitions. One of the more recent attempts to summarise what chemists with dilferent backgrounds see in this term was made by Schleyer. Valence bond theory has been, since Kekule s times, a major source of qualitative and quantitative interpretations of aromaticity, and it is surprising that it has not been mentioned, even once, in Schleyer s editorial. Of course, this omission does not diminish the importance that VB methods have had and still have in providing easy-to-understand ideas about aromatic behaviour which are often markedly superior to those coming from other theoretical sources. In order to justify this claim from a current perspective, in this section we look at the recent VB studies of the aromaticity of a series of benzenelike rings, and of clamped benzenes. 

A group of researchers in Budapest continued the line of Yoneda [16-21] but avoided the combinatorial explosion of the number of products by the preliminary definition of acceptable reaction products. Thus, the species to be included in the mechanism were fixed a priori, and the program provided the list of reactions. They used the matrix technique of Yoneda for the representation of reactions and species structures, but the number of generated reactions was limited by applying certain restrictions. The most important restriction was that bimolecular reactions were considered only with a maximum of three products. The number of generated reactions was kept low based on reaction complexity and thermochemical considerations. The mechanism obtained was reduced by qualitative and quantitative comparisons with experimental results, including contributions of elementary reactions to measured rates. The method proposed 538 reactions for the liquid phase oxidation of ethylbenzene. The reaction-complexity investigation approved only 272 reactions and the reaction heats were feasible in the cases of 168 reactions. This mechanism was reduced to a 31-step final mechanism. 

The feasibility of using FTIR-ATR spectroscopy for qualitative and quantitative analysis was investigated using the three known polymorphs of ganciclovir as a model system.65 Definitive identification of each polymorph was obtained from materials that did not need to be subjected to any sample handling or preparation. Quantitation of mixtures was carried out using a partial least-squares procedure, with mean absolute errors of less than 3% being reported for Form-I and Form-II, and about 6% for Form-Ill. 

In 1973, Tatro et al (11)examined the qualitative and quantitative changes in essential oil composition of leaf oils obtained from Juniperus occidentalis, J. osteosperma and J, californica, and found that neither growth medium or seasonal variation had a significant effect on oil composition. By contrast, they observed a definite diurnal cycling which they attributed to the fluctuation in air temperature over a twenty-four hour period. Six years later, Hopfinger et al (16) examined the diurnal variation in the leaf oil of Citrus sinensis (L.) Osbeck. The authors found that there was a two-fold diurnal change in oil... 

Definition of the API in terms of its critical quality attributes. Among the attributes that should be considered are chemical purity qualitative and quantitative impurity profiles physical characteristics such as particle size, bulk and tap density polymorphic forms moisture and solvent content homogeneity and microbial quality (if the product is susceptible to microbial contamination). 

Perhaps the most apt definition of analysis of adhesives is their qualitative and quantitative characterization. Since the early days of adhesive development, the elementary chemical analysis of adhesives has provided valuable information on the structure and purity of materials. Chemical methods of analysis are simple and cheap but labor intensive. The use of such techniques for analysis has been decreasing over the past 30 years. This is due to the complexity of the polymeric structures of adhesives as well as the development of much powerful and sophisticated instrumentation. More recently, advances in computer technology have been combined with analytical instruments to give speed, resolution, simplicity, and minimal sample requirements that were unimaginable two decades ago. 

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