Within same system

If there are more than two subsystems in equilibrium in the large isolated system, the transfers of S, V and n. between any pair can be chosen arbitrarily so it follows that at equilibrium all the subsystems must have the same temperature, pressure and chemical potentials. The subsystems can be chosen as very small volume elements, so it is evident that the criterion of internal equilibrium within a system (asserted earlier, but without proof) is unifonnity of temperature, pressure and chemical potentials tlu-oughout. It has now been... 

Note The speed of the motor ean be varied by vai-ying the frequeney alone but this docs not provide satisfactory performance, A variation in frequeney causes an inverse variation in the flux, for the same system voltage. The strength of magnetic field, p, develops, the torque and moves the rotor, but at lower speeds. / would be reduced, which would raise 0 , and lead the magnetic circuit to saturation. For higher s )ccds, / would be r.nised, but that would reduee which would adversely diminish the torque. Hence frequency variation alone is not recommended practice for speed control. The recommended practiee is to keep V/fas constant, to maintain the motor s vital operatin.c parameters, i.e. its torque and 0 ,. within acceptable limits. 

When it becomes essential to discriminate between a fault within the circuit to be protected from one outside the circuit, this scheme may be adopted. While doing so, it must be ensured that adequate ground fault protection is available to the remaining feeders, if connected on the same system. 

If the feed to a system is switehed instantaneously from one supply to another, a step-ehange residenee time experiment ean be performed. The seeond feed must be distinguishable from the first, but both should have die same density and viseosity and behave in die same manner within die system. A step signal is often performed by switehing from undyed to dyed feed, unless die traeer is expensive or unpleasant (e.g., radioaetive traeers) in sueh a ease, an impulse traeer is used. 

Sometimes it is necessary to convert within the same system, for example changing grams (g) to milligrams (mg) or milligrams to grams. Proportion and a known equivalent also may be used for this type of conversion. 

The double-headed arrow is intended to imply the existence of a resonance hybrid a stmcture with an electronic distribution intermediate between the two shown. Every instmctor knows the hazards of this portrayal. Firstly, the doubleheaded arrow is misinterpreted by some students to mean either (i) that there is an equilibrium condition involving the two different species, or (ii) that flipping occurs between the two species. A second problem is demonstrated by those students who ask Are these not the same If we rotate one of the molecules by 60°, we see that they are identical . We can hypothesise that the latter problem may be exacerbated by the tendency of textbooks (and probably teachers) to talk about these two different resonance stmctures as though we are referring to two different molecules - when, in fact, we are talking about different electron distributions in just one molecule. It seems so important for instractors to refer to just one set of six carbon atoms joined by ct bonds, and then to discuss alternative distributions of the six TT electrons within that system. 

The industrial case study was centred on the four mixers found in the toiletries area, as described above. Due to the multiple products found in the area, the residues within the system were not all the same (Table 6.7). This coupled with compatibility considerations between the various contaminants in the wastewater meant that the multiple contaminant wastewater minimisation methodology was suited to the problem. 

Fig. 7.19 Illustration of the additivity of conformational geometry functions for the -ro-tation in (CH3CO)(H)N-C(CH3)(H)(CONHCH3) (ALA). During the torsional motion about the N-C(a) bond of ALA, the interactions within the system are the same as those encountered during the N-C torsion in N-ethyl acetamide (NEA), plus those encountered during the N-C(a) torsion in N-acetyl N -methyl glycine amide offset by 120° as shown (GLY), minus those encountered during the N-C torsion in N-methyl acetamide (NMA).

For the Ni-Al2C>3 system [27] there was little effect of pH on the amount of incorporation above a pH of 2. However, decreasing the pH below 2 resulted in a sharp decrease in the amount of incorporation. Below a pH of 2.0, reportedly no particle incorporation was obtained for copper plating with SiC or AI2O3 [27], Other researchers [25] found no effect of pH on amount of BaS04 incorporated within a copper matrix, in the presence of tetraethylene pentamine, although in the presence of thallous ions incorporation for the same system was found to increase with pH. 

Consider a small region in phase space, At, sufficiently small that the density is essentially constant within this region. The number of system points An = qAt. If the surface of the element is always determined by the same system points originally in the surface, the behaviour of the element can be followed as a function of time. None of the points within the surface may escape and there are no sources or sinks of system points. Consequently... 

Implications of the prototypic classification method are that categories within the system will possess fuzzy boundaries. Individuals within a category will be somewhat heterogeneous and may not share any common features. In our depression example, a prototypic classification scheme may yield a diagnosis of depression in one patient who shows agitation, anhedonia, and suicidal ideation and the same diagnosis in another patient who shows sadness, fatigue, worthlessness, and decreased appetite. 

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