Qualitative differences

The dynamics begin to take on a qualitatively different nature as the number of components, capable of mutual... 

The simplest condensed phase VER system is a dilute solution of a diatomic in an atomic (e.g. Ar or Xe) liquid or crystal. Other simple systems include neat diatomic liquids or crystals, or a diatomic molecule bound to a surface. A major step up in complexity occurs with poly atomics, with several vibrations on the same molecule. This feature guarantees enonnous qualitative differences between diatomic and polyatomic VER, and casts doubt on the likelihood of understanding poly atomics by studying diatomics alone. 

Unbinding processes can be viewed as taking place in several qualitatively different regimes (Izrailev et al., 1997 Marrink et al., 1998). These regimes can be illustrated by considering the simplest binding potential... 

The time for classical simulated annealing increases exponentially as a function of the ratio of the energy scales /AU. However, for 5 > 1 the situation is qualitatively different. As a result of the weak temperature dependence in the barrier crossing times, the time for simulated annealing increases only weakly as a power law. 

In eontrast, if the eleetron is eonstrained to remain within a fixed area in the x,y plane (e.g., a reetangular or eireular region), then the situation is qualitatively different. Constraining the eleetron to any sueh speeified area gives rise to so-ealled boundary eonditions that impose additional requirements on the above A and B funetions. 

Conjugare is a Latin verb meaning to link or yoke together and allylic carbocations allylic free radicals and conjugated dienes are all examples of conjugated systems In this chapter we 11 see how conjugation permits two functional units within a molecule to display a kind of reactivity that is qualitatively different from that of either unit alone... 

EXAFS spectra of platinum metal, having a face-centred cubic crystal stmcture, have been obtained at 300 K and 673 K. Explain what qualitative differences you might expect. How many nearest-neighbour atoms are there in this stmcture Illustrate your answer with a diagram. 

Research for an antidepressant among non-tricyclic compounds with pharmacological effects qualitatively different from those of the conventional tricyclic compounds led to the preparation and testing of a series of indazole derivatives for reserpine-like activity in mice. l-[3-(Dimethylamino)propyl]-5-methyl-3-phenyl-l//-indazole (FS-32 692) antagonizes reserpine-induced effects and potentiates amphetamine-induced self-stimulation and l-Dopa-induced increase in motor activity. FS-32 produces an anticholinergic action mainly on the central nervous System, while the action of imipramine occurs centrally as well as peripherally (79AF511). 

Studies on the mechanism of action of /3-lactam antibiotics have shed considerable light on how these agents kill bacteria. They also help explain qualitative differences between various agents and why there is a correlation between the reactivity of the /3-lactam and antibacterial activity. However, it is also clear that reactivity is only one factor in determining how effectively a given /3-lactam antibiotic will inactivate bacterial enzymes (82BJ(203)223). 

As there now exists a large body of laboratory studies on each of the variable systems, for example the effect of die lime/silica ratio in the slag on the desulphurization of liquid iron, the most appropriate phase compositions can be foreseen to some extent from these laboratory studies when attempting to optimize the complex indusuial process. The factorial uials are not therefore a shot in the dark , but should be designed to take into account die laboratory information. Any qualitative difference between die results of a factorial uial, and the expectations predicted from physico-chemical analysis might suggest the presence of a variable which is important, but which was not included in the nials. 

The harmful effects of industrial emissions are not confined to the workers but extend beyond the plant boundary line. Chemically-induced diseases among workers exposed to industrial chemicals are a warning sign of the risks to which a larger population is also being exposed usually the chemical hazards are in principle similar in the occupational and general environment. However, occasionally environmental exposures can be qualitatively different from the occupational environment and may also cause deleterious health effects in the general population. 

The shock-modified composite nickel-aluminide particles showed behavior in the DTA experiment qualitatively different from that of the mixed-powder system. The composite particles showed essentially the same behavior as the starting mixture. As shown in Fig. 8.5 no preinitiation event was observed, and temperatures for endothermic and exothermic events corresponded with the unshocked powder. The observations of a preinitiation event in the shock-modified mixed powders, the lack of such an event in the composite powders, and EDX (electron dispersive x-ray analysis) observations of substantial mixing of shock-modified powders as shown in Fig. 8.6 clearly show the first-order influence of mixing in shock-induced solid state chemistry. 

Neither tropine nor 4-tropine is mydriatic, though the former is stated to produce mydriasis in cats when injected in large doses. The pharmacological properties of these two bases have been compared by Hazard, who points out that these cis-trans isomerides show qualitative differences in pharmacological action, whereas among optical isomerides there are usually only quantitative differences in activity. It has been stated that rabbits are immune from poisoning by belladonna and, in that connection,... 

To start the review of the PIMC results [328], we note that the detailed study of the quantum APR model (Eq. (41)) was partly motivated by the strong changes in shape of the orientational order parameter as a function of temperature as the rotational constant was increasing from its classical value 0 = 0 (see Fig. 3 in Ref. 327). For small enough 0 it was found that the order parameter decays monotonically with increasing temperature, similarly to the classical case. This is qualitatively different for larger 0, where T ) becomes a non-monotonic function of temperature. 

A qualitative difference in the type of solvation (not simply in the strength of solvation) in a series of nucleophiles may contribute to curvature. Jencks has examined this possibility. " " An example is the reaction of phenoxide, alkoxide, and hydroxide ions with p-nitrophenyl thiolacetate, the Br insted-type plot showing Pnuc = 0.68 for phenoxide ions (the weaker nucleophiles) and Pnu = 0.17 for alkoxide ions. It is suggested that the need for desolvation of the alkoxide ions prior to nucleophilic attack results in their decreased nucleophilicity relative to the phenoxide ions, which do not require this desolvation step. 

Qualitative difference in pharmacological effect Opposite enantiomer may cause unwanted effects... 

PET fibers in final form are semi-crystalline polymeric objects of an axial orientation of structural elements, characterized by the rotational symmetry of their location in relation to the geometrical axis of the fiber. The semi-crystalline character manifests itself in the occurrence of three qualitatively different polymeric phases crystalline phase, intermediate phase (the so-called mes-ophase), and amorphous phase. When considering the fine structure, attention should be paid to its three fundamental aspects morphological structure, in other words, super- or suprastructure microstructure and preferred orientation. 

Certain properties of the disordered alloy are qualitatively different from the properties of an intermetallic compound. A simple example of a property that demonstrates this qualitative difference is the finite residual resistivity of the disordered alloy, which is the resistivity in the limit as the temperature approaches zero. An ordered intermetallic compound will have a resistivity at T=0 that is essentially zero or infinity. A less simple example is Anderson localization. ... 

This can be described in terms of the Anderson proposition specialized for the present application, which states that certain properties of a macroscopic disordered alloy will be qualitatively different from those of an intermetallic compound. Specifically, the charges on a Cu or Zn atom in one of these alloys will take on a continuum of values. Once this is understood, it must be said that there will be applications in which it is a good approximation... 

The fact that jihysical systems having to decide between two qualitatively different... 

Surely no one could believe that the 1871 predictions were more definitive than those of 1869 just on the basis that Mendeleev was prepared to give the elements names (eka-silicon, etc.) in the 1871 paper, while he had been content with question marks in the relevant positions in 1869 But aside from this, it is difficult to discern any qualitative difference between the two papers that might count as significant in this regard.7... 

Data of Figs 8-10 give a simple pattern of yield stress being independent of the viscosity of monodisperse polymers, indicating that yield stress is determined only by the structure of a filler. However, it turned out that if we go over from mono- to poly-disperse polymers of one row, yield stress estimated by a flow curve, changes by tens of times [7]. This result is quite unexpected and can be explained only presumably by some qualitative considerations. Since in case of both mono- and polydisperse polymers yield stress is independent of viscosity, probably, the decisive role is played by more fine effects. Here, possibly, the same qualitative differences of relaxation properties of mono- and polydisperse polymers, which are known as regards their viscosity properties [1]. 

Variable, independent An experimental factor that can be controlled (temperature, pressure, order of test, etc.) or independently measured (hours of sunshine, specimen thickness, etc.). Independent variables may be qualitative (such as a qualitative difference in operating technique) or quantitative (such as temperature, pressure, or duration). Thus, if variable A is a function of variable B, than B is the independent variable. 

Fig. I. Effect of pressure on the melting temperature of argon, (a) Pure argon, (b) argon-helium, (c) argon-hydrogen.Qualitative difference between curves (b) and (c) is due to the effect of composition on the liquid-phase fugacity of argon (M6).

The qualitative difference between low-density and high-density rotational relaxation is clearly reflected in the Fourier transform of the normalized angular momentum correlation function ... 

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