Power, concept

Suffice it to say that Dobereiner s research established the notion of triads as a powerful concept, which several other chemists were soon to take up with much effect. Indeed, Do-bereiner s triads, which would appear on the periodic table grouped in vertical columns, represented the first step in fitting the elements into a system that would account for their chemical properties and would reveal their physical relationships. 

A powerful concept for improving the chemo- and stereoselectivity of metal catalysts is their modification by co-adsorbed auxiliaries. This concept should be particularly useful for... 

Our previous two chapters based on references [1,2] describe how the use of the power concept for a hypothesis test allows us to determine a value for n at which we can state with both a- and / -% certainty that the given data either is or is not consistent with the stated null hypothesis H0. To recap those results briefly, as a lead-in for returning to our main topic [3], we showed that the concept of the power of a statistical hypothesis test allowed us to determine both the a and the j8 probabilities, and that these two known values allowed us to then determine, for every n, what was otherwise a floating quantity, D. 

One learns from these molecular complexes that equivalent synthons can lead to virtually identical crystal structures. Synthons in, V and VI are chemically and geometrically equivalent though they originate from different molecules, a nitrile, an N-oxide and a nitro compound. These three synthons are used in crystal design in almost the same way. So, different molecules may yield similar crystal structures if they are capable of forming equivalent synthons. This is a powerful concept because it establishes a many-to-one correspondence between molecular and crystal structures. 

In GM s Hy-wire hydrogen powered concept vehicle, there is a fuel cell for the power source and electronics replace mechanical parts in the steering and braking systems. The driver looks through a large, sloped windshield that covers space usually taken up by an engine. There is no dashboard, instrument panel, steering wheel or pedals, only a set of adjustable footrests. 

Finally, the molecular approach, which has been adopted for many years by research groups in heterogeneous catalysis, appears to be a powerful concept to tackle the CVD preparation of nanostructures. 

Discuss what is meant by the bond order. Why is it a powerful concept ... 

The powerful concepts of matrix algebra can also be further extended to partitioned matrices, whose elements are themselves matrices rather than scalars [cf. (9.7)] ... 

This looks like a powerful concept, but its value is limited due to uncertainty in estimating hGa. Both hG and a are difficult to estimate due to dependence on power dissipation as discussed below. The primary value of the NG concept is in estimating an expected change from baseline data as in the comparison of Example 19 with Example 20. 

Generation and release of polymer-supported reactive intermediates or activated reactants have been demonstrated as a powerful concept leading to several novel... 

Exergy, or availability, is a quite powerful concept to be able to deal in a unified manner with many kinds of energy, such as heat, mechanical work, chemical energy, and so on (i,2,3,4). 

Fig. 3. (a) Hierarchy of deterministic, continuum models. Dimensional analysis and symmetry are powerful concepts in reducing the dimensionality of complex models, (b) Hierarchy of stochastic models for chemically reacting well-mixed systems. 

There are two exciting newer developments of biologically relevant enamines that may also exemplify some of the future directions in which the field is moving. Only a few of the many published examples will serve to illustrate the potential of these powerful concepts. 

One of the most fruitful areas of research in solid-state synthesis is the synthesis of doped materials. Here the solid-state chemist takes advantage of a powerful concept in... 

Based on such comparisons and taking into account typical uptakes of aromatic solutes (of the order of 0.005 mol/g under most favorable conditions), it is tempting to postulate that the dispersion interactions—which allow a much more effective utilization of the carbon surface—may be the dominant driving force for the adsorption of organic solutes. In particular, aromatic solutes have a natural affinity for the graphene layers on the carbon surface (see Fig. 3) because of the possibility of 7i-7t overlap. Indeed, 7C-7t interactions and 7t-cation complexation are currently very powerful concepts and popular re.search topics [75-77,714,88,715-717,89,90,718,719]. (Thus, for example, the landmark paper by Hunter and Sanders [74] currently has close to 800 citations in the Science Citation Index.)... 

We construct the attainable region by noting that the concentration space is a vector field with a rate vector (e.g., in Fig. 1, dC /dC/ = RB/R ) defined at each point. Moreover, we are not restricted to concentration space, but can consider any other variable that satisfies a linear conservation law (e.g., mass fractions, residence time, energy, and temperature—for constant heat capacity and density). The attainable region is an especially powerful concept once it is known, performance of the network can often be determined without the network itself. 

Residence time is the fundamental quantity that describes systems in steady state. It is a very powerful concept that plays a central role in much of environmental chemistry. Compounds with long residence times can accumulate to relatively high concentrations compared with those with shorter ones. However, even though gases with short residence times are removed quickly, their high reactivity can yield reaction products that cause problems. 

In addition to conventional modeling concepts for predetermined procedures, which comprise activities in a well-defined order or with explicit conditions for their execution, a modeling language for design processes must provide powerful concepts for temporal and structural abstraction. Temporal abstraction refers to the freedom to omit information about the temporal relations between activities (e.g., by permitting a partial overlap of two subsequent activities). An even stronger structural abstraction allows to create process models which do not determine whether an activity is performed at all. 

The idea of an associated equilibrium state is thus quite general it is a very powerful concept that can be used more accurately and more confidently than the concept of local equilibrium. Confidence comes fi om two sources first we can see that the real nonequilibrium state and the imagined equilibrium state are closely similar, and second, we can bring the exact differences to light—even, in some circumstances, express them quantitatively and demonstrate their smallness. It is the second aspect that brings confidence, and allows us to use associated equilibrium states to define potentials and predict material responses, even in situations where the exact magnitude of the small differences cannot actually be worked out in numbers. 

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