Existing knowledge, application

Although the mechanism of corrosion is highly complex the actual control of the majority of corrosion reactions can be effected by the application of relatively simple concepts. Indeed, the Committee on Corrosion and Protection concluded that better dissemination of existing knowledge was the most important single factor that would be instrumental in decreasing the enormous cost of corrosion in the U.K. 

Transfer of existing knowledge into application in industry... 

Applications of the method to w-amino acids were discussed and existing knowledge was summarized by Marik et al. [258]. Silylation was executed at 80°C for 1— 2 h or at 90°C for 0.5-1 h, with the use of BSA either alone or with the addition of triethylamine or acetonitrile. BSA alone was recommended as tris-TMS derivatives were produced in practically 100% yield. The presence of amine and solvent led to the formation of bisand tris-derivatives in various ratios, changing with time. However, these conclusions were valid only if the reaction was started with amino acid hydrochlorides. The presence of... 

Table 1.2 Parameters relevant to sensor applications that are difficult or impossible to quantitatively predict and calculate using existing knowledge and rational approaches...

Data massaging. By this we mean the application of a filter based on existing knowledge to enhance the quality of unknown information. Primary examples are signal averaging or smoothing. 

Successful syntheses of a wide variety of zeolite and zeotype materials have been developed over the last 50 years. Much is known about the way in which these structures are formed, particularly from recent detailed studies using advanced techniques of microscopy (HRTEM and AFM). However, a number of issues surrounding the mechanism of synthesis remain incompletely resolved. This is partly due to experimental difficulty but is also a reflection of the fact that not all systems arc the same. Nevertheless, in the foregoing account an attempt has been made to review our existing knowledge in terms of basic similarities between one reaction regime and another. In this way, it is hoped to establish some overall principles which, with appropriate modification, may be found to be generally applicable, or at least to provide a framework for further analysis. 

The above observations and discussions indicate that HEU frameworks behave differently compared to most synthetic zeolites with disordered or partly disordered Si, A1 distribution. Even for a given Si/Al ratio the exact exchange behavior of a HEU framework can not be predicted based on the existing knowledge. One of the reasons is the low topological symmetry (C2/m) of the HEU framework compared to the cubic frameworks of e.g. LTA or FAU. In low symmetry structures the distribution of Si and Al, or the existence of numerous polymorphs, plays a much more important role than in a high symmetry framework. In summary, we have to accept the conclusion [14] that for any sophisticated practical application of natural clinoptilolites specific studies on representative samples from the deposit that is being examined for its exploitation potential have to be carried out. 

To be usefully applicable, a QSAR model must be able to learn from available data and reproduce them (goodness of fit, verified by R ), be stable and robust (verified by internal cross-validations leave-one-out, leave-many-out or bootstrap) and, most importantly, by extracting the maximum information from the limited existing knowledge, it must be able to reliably predict data for new chemicals not involved in model development (external validation). 

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