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Quantitative/qualitative data/measurements

Spectrophotometric and spectrofluorimetric methods provide a wealth of information concerning structural determinations (identification, purity and precise measurement of concentration) and chemical changes in alkaloids. These techniques yield both quantitative and qualitative data on the effect of solvents, pH and other physiological conditions [141-143]. X-ray crystallography, H and NMR spectroscopy, infrared spectroscopy (IR) and circular dichroic spectroscopy were also used to study the physical properties... [Pg.173]

The qualitative data on the absorption, distribution, metabolism, and excretion of hydrogen sulfide in humans and animals are well known. Quantitative data are generally lacking. Additional animal data through collection by quantitative measurements are collected are needed, as well as data on changes in these parameters with exposure. [Pg.129]

Antibody-based detection methods include immuno-cytochemistry, which gives qualitative data but has very good spatial resolution. Radioimmunoassays provide a quantitative measure of release or content. One of the major limitations of all antibody-based methods is the potential for cross-reactivity among the many peptides. For example, some of the most sensitive gastrin antisera also detect CCK, since the peptides share a common COOH-terminal tetrapeptide sequence. Methods for detection of the mRNAs encoding neuropeptides include Northern blots, which provide quantitative data and information on splice variants, but lack fine anatomical resolution. The more commonly used polymerase chain reaction, which can be quantitative but often is used in a more qualitative manner, provides great sensitivity. Alternatively, in situ hybridization preserves anatomical relationships and can be used to obtain both qualitative and quantitative data. [Pg.328]

In most experiments, scientists collect quantitative data, which is data that can be measured with instruments. They also collect qualitative data, descriptive information from observations other than measurements. [Pg.5]

Dihydroisoquinolines can often be detected by the red coloration that develops when they are exposed to air or to mineral acids, and also by the ease with which they reduce silver nitrate solution.7 The most convenient method, however, is by UV spectral measurement. Due to the instability of simple 1,2-dihydroisoquinolines, reliable quantitative spectral data have been difficult to obtain, although some have been reported.20,64,87 Nevertheless, the qualitative UV absorption curve characteristically contains a medium-intensity broad band at 330-340 nm (in ethanol) 75,144,145, and this is extremely useful for the detection of 1,2-dihydroisoquinoline structures. [Pg.294]

The results of the two methods complemented one another. Whole-body autoradiography is a qualitative detection method with a very high local resolution which includes all organs and many small substructures, whereas measurement after dissection yields quantitative concentration data for a limited, preselected number of organs. [Pg.593]

The energy dispersive x-ray fluorescence spectrometer, which had been developed recently as a qualitative analysis instrument, showed promise of meeting the goals of the new laboratory (1). Its unique features, which earned it the name, The Curators Dream Instrument, are The measurements require neither sampling nor alteration of the object in any way. Systems for obtaining quantitative analysis data are now operational (I). Concentrations of up to thirty elements above chlorine (Z = 17) can now be printed out simultaneously. Techniques have been developed that minimize errors caused by sample size, shape, position, overlapping spectral peaks, matrix effects, and baseline compensation. Interpretative procedures have been established that recognize the shallow depth of penetration of the excitation radiation (2). [Pg.143]

Process data is either quantitative or qualitative in nature. Quantitative data, or variable data, is measured along a continuous scale (i.e., 1 to 60 seconds). Qualitative data, or attribute data, is measured in categories, like pass/fail, yes/no, blue/green, and so on. Both types of data have value, but usually variable data is preferred over attribute data because it tells you more about the process. [Pg.219]

Measurement Systems Analysis starts with translating customer and process requirements into metrics (measurable outcomes). These metrics can be based on subjective qualitative data (taste, appearance, etc.), or objective quantitative data (e.g., seconds, number of defects). The type of data determines the type of MSA ... [Pg.287]

The introduction of GC as an analytical technique has had a profound impact on both qualitative and quantitative analysis of organic compounds. Identification of compounds by GC can be accomplished by their retention times on the column as compared to known reference standards, by inference from sample treatment prior to chromatography, " or by the concept of retention index. " The latter method and tables of retention indices " with associated conditions have been reported. " Although qualitative data and analytical techniques for identification of compounds are well-established " and relative retention data for over 600 substances also have been published, " the main utility of GC undoubtedly lies in its powerful combination of separation and quantitative capabilities. Use in quantitative analysis involves the implementation of two techniques being performed concurrently, i.e., separation of components and subsequent quantitative measurement. [Pg.463]

Detector saturation can effect both quantitative and qualitative data analysis, and each of these effects should be appreciated. The effect on sample quanti-tation is intuitive, where for instance a twofold increase in sample concentration produces a less than twofold increase in response. This will cause a flattening of calibration curves at higher concentrations. For API techniques, source saturation (or ion suppression) is another source of response saturation independent of detector saturation. Detector saturation can also effect qualitative measurements such as mass accuracy and isotope ratio calculations. In the former, when a mass spectral peak that has some finite resolution stalls to saturate the detector the peak-top calculations that provide the m/ measurement of the peak will become ambiguous. Likewise, it is possible that as one isotope of an ion starts to saturate the detector, adjacent isotopes in the distribution will still provide a linear response. The result of this is that incorrect isotope ratios will be obtained. Changes in relative isotope ratios of individual spectra across a chromatographic peak is an indicator of possible detector saturation. [Pg.78]

The choice of an appropriate statistical method is important, and a method suitable for the comparison of two groups in terms of an ordinal outcome measurement is the Mann-Whitney/Wilcoxon rank-sum test (not to be confused with the Wilcoxon matched-pairs signed ranks test, which is appropriate for paired data - see later). It is both inefficient and inappropriate to use a qualitative data test (such as a simple chi-square) for such a measurement, and the application of quantitative data tests (such as one of the f-tests) is also invalid. [Pg.360]

Because of its advantage in terms of study size over qualitative data, and usually over ordinal data, it is often attempted to obtain outcome measures in clinical studies on a quantitative scale. Two approaches used in an attempt to achieve this aim are the visual analogue scale (VAS) and summated ratings. ... [Pg.361]

In most experiments, scientists collect quantitative data, which is data that can be measured with instruments. They also collect qualitative data, descriptive information from observations other than measurements. Interpreting data and analyzing observations are important. If data is not organized in a logical manner, wrong conclusions can be drawn. Also, other scientists may not be able to follow your work or repeat your results. [Pg.2]

Finally, it should be evident that the principal utility of electrokinetic data is qualitative and comparative. The demonstration that an electrokinetic phenomenon exists is a demonstration that an electrified interface exists. This broad implication is conclusive. In a quantitative sense, however, measurements of electrokinetic phenomena on the same kind of interface under different conditions have only a comparative value. Changes in the zeta potential as the composition of the interfacial region is varied through adsorption can be a useful guide to molecular interpretation even though C itself has little objective significance. [Pg.106]

Interpretation. The results of concrete resistivity measurements can be used for a quantitative or qualitative interpretation. Resistivity data measured on a structure and corrected for the temperature effect can be compared to reference data of similar concrete types (Table 2.4). Usually additional information is necessary. If, for example, a wet structure made with OPC has a mean resistivity value of 50 fl m, it means that the water-to-cement ratio and the porosity must be quite high. Consequently, the corrosion rate after depassivation will be high. [Pg.286]

The first one may be called a "point" model (67,69). Here only the absorption-reaction interaction (that is, microscopic scale phenomena) is simulated so that gas absorption rate per unit interface (R) may be measured for a variety of combinations of bulk gas and bulk liquid compositions. Then, these results are inserted into an appropriate two-phase contactor model (for example, those listed in Tables 3-6), to yield the required capacity. It is clear that the method eliminates theoretical modeling at the microscopic level and none of the quantitative process specific data (i.e. Stage 1 of Figure 1) is needed. However, some qualitative data are required as the model is applicable only to reactions which are fast enough to take place in the diffusion film near the interface so that there is no unreacted dissolved gas, and no reaction in the bulk of the liquid (inappropriate considerations of bulk reactions may result in vast design errors (70)). It is also confined to the case where a single gas is being absorbed. The reason for these limitations is mainly that, in these cases, there is a simple stoichiometric relationship... [Pg.308]

The social pillar of sustainabihty, nevertheless, requires creating a unit system to convert qualitative data into quantitative data. The human health impact is measured on the number of healthy life years lost because of premature mortality and disability/ person/year, or so-called disabihty-adjusted hfe year (DALY)/person/year [15]. For social weU-being, the result is obtained based on 11 midpoint impacts, which are divided... [Pg.332]

Evaluation is often equated and confused with assessment, but the two concepts are different. Evaluation is defined in education as the formal determination of the quality, effectiveness, or value of a program, project, process, objective, or curriculum. Assessment, conversely, is defined as a systematic process for collecting information in the form of quantitative and qualitative data, usually in measurable terms, about students performance. Assessment provides important information for... [Pg.35]

In addition to the use of qualitative and quantitative accident data when identifying and evaluating risk (see sections 10.1.2 and 10.1.3), there is a need to consider the relative occurrence of different accident types, in order that effective accident control measures may be implemented throughout an organisation. [Pg.180]

This study is about the fault diagnosis by the hybrid method of qualitative model-based method and quantitative history data-based method. The diagnosis is performed by the observation of measured value and predicted value by DPLS model built on the local causal relationships of SDG The proposed method has the advantages to improve diagnosis accuracy and resolution, and facilitate diagnosis of masked multiple-fault. [Pg.448]


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See also in sourсe #XX -- [ Pg.219 , Pg.288 ]




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