Qualitative investigation

Nicoll, G. (2003). A qualitative investigation of undergraduate chemistry students macroscopic interpretations of the submicroscopic structure of molecules. Journal of Chemical Education, 50(2), 205-213. 

Therefore the lattice-gas model has proved most useful for the study of those processes in which the ionic double layer plays a major role, and there are quite a few. So it has been used to investigate the interfacial capacity, electron and ion-transfer reactions, and even such complex processes as ion pairing and assisted ion transfer. Because of its simplicity we carmot expect this model to give quantitative results for particular systems, but it is ideally suited to qualitative investigations such as the prediction of trends and orders of magnitude for various effects. 

Tube erosion has been observed in both atmospheric and pressurized bed combustors. The scaling analysis presented earlier can be used to construct an accurate hydrodynamic simulation of the commercial bed. This can be used to qualitatively investigate factors related to tube wear such as the location of highest wear around the circumference of an individual tube and the location within the bed of the tube experiencing the highest wear. Quantitative wear rates cannot be obtained from model tests... 

For qualitative investigations there is considerable latitude in experimental procedure. There are few limitations on solvent for reactions studied in the liquid phase, although standard considerations of susceptibility to radical attack must obviously be taken into account. With polar solvents it may be desirable to replace the normal silica sample tube with a flat cell, although spin-adduct concentrations are usually sufficiently great for this to be circumvented by the use of capillary tubes. 

The qualitative investigation of copolymers is considerably more difficult when the homopolymers cannot be distinguished by their solubility. In this case other physical data of the supposed copolymer can be compared with the corresponding data for various physical mixtures of homopolymers, for example, softening point and melting range, density, and crystallinity. Copolymers can frequently be distinguished from physical mixtures of homopolymers by the qualitative and quantitative composition of their pyrolysis products. 

The calculations presented in the previous sections ignore the influence of molecular rotation on the efficiency of vibrational population transfer. This approximation defines useful models that permit qualitative investigation of the influence of background states on the efficiency of energy transfer within an embedded subset of states but is inadequate for the quantitative description of energy transfer in the corresponding real molecules. We expect the rotation... 

The metalloporphyrin complexes and their derivatives have been studied from the standpoint of model compounds of hemoglobin. The polymer-metalloporphyrin complexes are also formed by the reaction in Scheme 8, and a few qualitative investigations have been made with poly(L-lysine)9,10, poly(L-histidine)11, and poly(vinylimidazole)12 as the polymer ligand. Blauer9 has studied the complex formation of heme with poly(L-lysine) and has discussed the effects of the molecular weight and secondary structure of poly(L-lysine) on complex formation. 

Examination of these products comprises firstly the technical tests relating to intensity, fastness and behaviour in mixtures, and further, qualitative analysis for the determination of the nature of the product and of any adulterations, and also certain quantitative determinations. The qualitative investigation is carried out as in paragraph 1 and the quantitative determinations as in paragraphs 2 and 3... 

Qualitative Investigation.—A little of the substance is treated with hot dilute hydrochloric acid the chrome green does not dissolve, whereas several of the extraneous substances which it may contain pass into solution at any rate partially, e.g., calcium and magnesium compounds, yellows with a chromium or iron basis, and greens with a copper basis these substances may be detected in the solution by the ordinary methods. 

Qualitative Investigation.—The aqueous solution of logwood extract is deep red if the extract is neutral, reddish-violet if alkaline, or yellowish if acid (extracts containing tanning substances are always acid) it is turned reddish-yellow and yellow by acids and reddish-violet and then brown by alkalies. 

Qualitative Investigation of the Nature of the Weighting. The following tests are made ... 

Nevertheless even now it is possible to apply the qualitative investigation of kinetic models corresponding to simple model mechanisms, not only for a description of the established experimental kinetic curves, but also for the prediction of kinetic regularities in the parametric region that has not been examined by experiment [165]. 

N.N. Bautin and E.A. Leontovich, Qualitative Investigation Methods for Dynamic Systems on the Plane, Nauka, Moscow, 1976 (in Russian). 

However, the observed consistency of the experimental and theoretical appraisals can be considered as surprisingly satisfactory. Both these results and the results of the previous section point to the possibility of employing the Vinogradov constitutive equations (9.58)-(9.60) for qualitative investigations of non-uniform flows of polymer liquids. 

The developed mathematical model has been applied for calculation of processes in MHHP intended for vehicle air conditioning [4, 7]. Study of influence of the basic heat pump parameters (pressure of hydrogen charging, temperatures and coolant consumption, cycle time) on its power characteristics has been carried out. It was shown that the estimated data well agreed with experimental results. It was found that the developed model could be used for qualitative investigation of various parameters influence and approximate quantitative assessments. 

In an attempt to modify the observed droplet behavior, a brief qualitative investigation was carried out with blends of SRC-II heavy distillate and pure heptane. The objective was to enhance droplet disruptive combustion as a means of reducing effective droplet size and hence soot formation. With these fuels visible droplet fragmentation was found to occur throughout the droplet stream. The fragmentation produced new droplets on different trajectories these in turn were terminated by small disruptions, as described above. Three blends were used 60/40, 80/20, and 90/10. Secondary atomization was observed for all three, although the violence of the activity was noticeably reduced as the heptane content of the blend became smaller. This secondary atomization was a completely different process than the... 

Strickmann et al. [126] used on-line coupling of CEC with electrospray ionization (ESI) mass spectrometry (MS) for the qualitative investigation of the biotransformation of the NSAID etodolac. The drug and its metabolites were analyzed in urine extracts. This hyphenated technique proved to be a useful tool for bioanalytical investigations. 

According to qualitative investigations, cyclobutane carboxaldehyde decomposes into acrolein and ethylene at 350-450 °C. The reaction was studied in... 

The qualitative investigations of Baumann, Heinicke, Kaiser and Bethge if they can be repeated successfully, should be extended to provide quantitative studies of the pressure effects upon the formation and decomposition of the species. Thus, the order of Reactions (30) and (32) might be determined. This would provide additional information about the mechanisms of these processes. 

This activating influence by the azido group was predicted on electronic grounds by Miller and Parker in 1958. Both the susceptibility of aromatic azides to electrophilic substitution and the orthopara directing effect could perhaps be inferred from earlier qualitative investigations of the nitration of aromatic azides which are summarized in Table 5. These conclusions have since been placed on a... 

While recent, although not numerous, studies4,33,34 36-38 42 8 of spiropyrans and spirooxazines have addressed the mechanistic aspects of the degradation of these photochromes and elucidated the structure of the intermediates and photooxidation products, only qualitative investigations have been reported regarding the stability of other classes of organic photochromes. 

The enantiomeric composition of the sulfur containing compounds in yellow and purple passion fruit is still unknown. The results of quantitative and qualitative investigation of sulfur containing components showed the best correlation to the organoleptic properties of pas-sionfruit concentrates. 

In the apparatus of the second type, in which the diffraction pattern is observed on a fluorescent screen, the inelastically scattered electrons are excluded by a grid placed between the inner grid and the fluorescent screen (5). This method is being used in certain qualitative investigations in this laboratory but it does not furnish quantitative measurements of intensity which compare with those of the electrical method. 

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