Conceptual Relevance

Conceptual relevance. Is the indicator relevant to the assessment question (management concern) and to the ecological resource or function at risk ... 

Should the indicators have conceptual relevance to a more detailed biogeochemical process Explain. 

Several other principles should guide the construction of a battery. Importantly, the tests should be reliable and of clear biologic significance ( ). This means that they should truly measure what they purport to measure and that the end point should have conceptual relevance to mutagenicity or carcinogenicity. Secondly, a battery should seek to maximize the metabolic parameters provided by all tests. As an example, tests with intact cell metabolism should be included to extend the metabolism obtained with the commonly used exogenous subcellular preparations. This may be of particular importance in view of the artifactual enhancement of activation over detoxification that is known to be characteristic of enzyme preparations ( 5, ). Moreover, the DNA adducts formed by activation through mic-... 

This book exposes the current status of aqueous synthesis through the most comprehensive one-volume coverage of the field to date. In this book we have made the important distinction between reactions that are performed in the presence of water and reactions that are run in water alone or in water with only a small amount of co-solvent. Unless there is some conceptual relevance that warrants discussion, examples of reactions performed with less than 50% water content are not within the scope of this book and thus not included. 

Direct use of equation (2) or equation (4) to study primitive hydrophobic effects started in 1990 with the realizations that these formula can be directly feasible for atomic-sized solutes in water at the moderate conditions of greatest interest and that when feasible these results give information of direct conceptual relevance to molecular theories. We anticipate later discussion by asserting here that insights drawn from these direct calculations have recently lead to new theories that promise to the extend the range of applicability of molecular ideas beyond the primitive hydrophobic effects that is the topic of subsection 4.1.3. 

Simulated Annealing-based solutions [19] are conceptually the same as Genetic Algorithm-based approaches. However, the SA-based techniques, in our experience, are more sensitive to the initial settings of the parameters. Nevertheless, once the correct ones are found, the method can achieve the efficiency of GA-based solutions. We must point out that SA-based solutions have never outperformed the GA-based ones in our studies. Much of what has been mentioned regarding the GA-based solutions is also relevant for the SA technique, particularly, with respect to the cost functions. 

Quantum mechanics is cast in a language that is not familiar to most students of chemistry who are examining the subject for the first time. Its mathematical content and how it relates to experimental measurements both require a great deal of effort to master. With these thoughts in mind, the authors have organized this introductory section in a manner that first provides the student with a brief introduction to the two primary constructs of quantum mechanics, operators and wavefunctions that obey a Schrodinger equation, then demonstrates the application of these constructs to several chemically relevant model problems, and finally returns to examine in more detail the conceptual structure of quantum mechanics. 

Conceptual Flowsheet for the Extraction of Actinides from HLLW. Figure 5 shows a conceptual flowsheet for the extraction of all the actinides (U, Np, Pu, Am, and Cm) from HLLW using 0.4 M 0< >D[IB]CMP0 in DEB. The CMPO compound was selected for this process because of the high D m values attainable with a small concentration of extractant and because of the absence of macro-concentrations of uranyl ion. Distribution ratios relevant to the flowsheet are shown in previous tables, IV, V, VI, and VII and figures 1 and 2. One of the key features of the flowsheet is that plutonium is extracted from the feed solution and stripped from the organic phase without the addition of any nitric acid or use of ferrous sulfamate. However, oxalic acid is added to complex Zr and Mo (see Table IV). The presence of oxalic acid reduces any Np(VI) to Np(IV) (15). The presence of ferrous ion, which is... 

The considerations presented above were based on the specific assumption that the catalytic reaction of the serine proteases involves mechanism a of Fig. 7.2. However, one can argue that the relevant mechanism is mechanism b (the so-called charge-relay mechanism ). In principle the proper procedure, in case of uncertainty about the actual mechanism, is to perform the calculations for the different alternative mechanisms and to find out which of the calculated activation barriers reproduces the observed one. This procedure, however, can be used with confidence only if the calculations are sufficiently reliable. Fortunately, in many cases one can judge the feasibility of different mechanisms without fully quantitative calculations by a simple conceptual consideration based on the EVB philosophy. To see this point let us consider the feasibility of the charge-relay mechanism (mechanism b) as an alternative to mechanism a. Starting from Fig. 7.2 we note that the energetics of route b can be obtained from the difference between the activation barriers of route b and route a by... 

One of the chief reasons for the recent extensive work in this field has been the recognition that ion-molecule reactions are highly relevant to radiation chemistry. The possibility that certain simple reactions, such as the formation of H3+, participate in the mechanism of product formation was appreciated much earlier 14), but wider applicability of this concept required that the generality of such reactions be demonstrated by an independent, unequivocal method. Mass spectrometry has been the predominant means of investigating ion-molecule reactions. The direct identification of reactant and product ions is appealing, at least in part, because of the conceptual simplicity of this approach. However, the neutral products of ion-molecule reactions cannot be determined directly and must be inferred. Gross chemical measurements can serve as an auxiliary technique since they allow identification of un-... 

We present a few basic ideas of structural mechanics that are particularly relevant to the design of telescopes and to the support of related optics. This talk only touches on a very rich and complex held of work. We introduce the ideas of kinematics and kinematic mounts, then review basic elasticity and buckling. Simple and useful mles of thumb relating to structural performance are introduced. Simple conceptual ideas that are the basis of flexures are introduced along with an introduction to the bending of plates. We finish with a few thoughts on thermal issues, and list some interesting material properties. 

The current undergraduate curriculum in chemical engineering, although it provides an excellent conceptual base for graduates who move into the electronics industries, could be improved by the introduction of instractional material and example problems relevant to the challenges outlined in this chapter. This would not require the creation of new courses, but rather the provision of material to emich existing ones. This theme is echoed, more broadly, in Chapter 10. 

Conditions two and three can only be fulfilled in iteration using Schwab s substmctures of a curriculum Phil - Ped - Sub). The main question is how to start the iteration. To work out a new vision on the learning of micro-macro thinking, there needs to be an interrelation between chosen philosophies on chemistry (education Phil) that is consistent with a pedagogical theory Ped). An example is extensively described by Meijer, Bulte, Pilot (2005 see also Pilot et al. in this book) chemistry is considered as a human activity in relevant communities of practice Phil), while learning Ped) is to take place as participation in such (situated) communities of practice. To avoid the use of the traditional conceptual stracture... 

Three analogous but theme-specific conceptual schemas have been constructed, with systems which have several nested sub-systems (Meijer et al., 2005). Relevant mi-crostractures at different meso-levels can be assigned to appropriate scales. In such conceptual schemas, structure can be defined as the distribution over space of the components in a system. Physical building blocks of such a system are regions that are bounded by a closed surface (Walstra, 2003), where at least some of the properties within such regions are different from those in the rest of the system. 

To summarise in authentic tasks, we have established that stmcture-property relations can be described by a dynamic system of stmctures, properties and their interrelations. Within the limits of our study we have derived a generalised conceptual schema, which we expect to be useful to teach macro-micro problems in which stmcture-property relations can be explicitly used (Figs. 9.2, 9.3 and 9.4). The system of nested stmctures, systematically assigned to appropriate scales, and the properties of the different stmctural components reveal a conceptual schema necessary for macro-micro thinking. The system of relevant nested stmctures and the explicit relations between stmctures and properties form the backbone of macro-micro reasoning. Depending on the task, a number of different meso-levels are relevant and... 

Very recent relevant observations reveal that the TCS approach albeit certainly significant as conceptual and operational tool in the issue of metal nanoclusters size control, requires a substantial further perfection. Resin sulfonated Bayer K1221 is a co styrene-divinylbenzene commercially available gel-type resin, in beaded form. Its cross-linking degree is ca. 4% mol and therefore K1221 is expectedly quite similar to DOMA-VP and MTEMA-DMAA 4-4 for example. In fact ISEC analysis reveals a nanoporosity featured by 4.0 and 2.0 nm nanopores only. The expectation is that a Pd°/K1221 nanocomposite obtained with a classic procedure [5,9,10] will exhibit diameters strictly ranging from 2 to 4 nm. 

The last state in Fig. 11.1 that has not yet been discussed is the state of the neat liquid compound X. For liquid compounds this is the relevant initial state for solubility, but almost aU drug-Uke compounds are solid at room temperature. In this case the neat liquid is a virtual state of a supercooled liquid which can hardly be accessed experimentally. However, it is an interesting intermediate state because it allows us to split the calculation of solubility into two separate steps, which are conceptually and for some methods computationally easier to handle than the complete step from the crystaUine state of the drug to the liquid state of the drug dissolved in water. In the first step we only have to transfer the compound from its neat crystalline state to its neat liquid state. The free energy of this fusion transfer is usually called AG s (or if considered in the opposite direction). 

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