Prognostic capability

ABSTRACT Condition based maintenance is an advanced maintenance strategy able to achieve both cost reduction and high availability and reliabihty performance. It is based on the system health monitoring whose issues are diagnostic and prognostic capabilities. 

The next steps of the project wdl be an extension of the model to implement a wider set of failure modes and a development of the prognostic capability. 

In infants who have suffered perinatal hypoxic-ischaemic brain injury (birth asphyxia), P spectra obtained within a few hours of birth show no abnormalities. However, in many cases a delayed secondary energy failure (SEP) develops within 24 h. The Pi signal increases, accompanied by reduced PCr and, in severe cases, low NTP. Furthermore, in contrast to the profound acidosis seen during acute hypoxia-ischemia, an intracellular alkalosis may be detected. Additionally, localized spectroscopy shows elevated lactate levels for several weeks following SEE. Both PCr/Pi and lactate/N-acetylaspartate (Lac/NAA) ratios have proved to be extremely useful indices of the severity of hypoxic-ischaemic injury, with strong prognostic capabilities. 

Application of Analysis at Studying THE Prognostic Capability of the Kinetic Model OE Reaction System... 

Prognostic capability is an important feature of the kinetic model. It is determined by the range of change of parameters, which describe the conditions of a reaction progress (concentrations of reagents, catalyst, promoter, conversion of the initial reagents, pressure, temperature, etc.) outside of which the prognostic capability of the model fails. 

Definition of the applicable range of the kinetic model of a chemical reaction is of special importance for its control. Theoretical methods for the optimal control of chemical processes will be considered in the next chapter. It is expedient to perform the controlling impact on a reaction by using a proper kinetic model, within the limits of change of the controlling parameters u(t), where it maintains its prognostic capability. 

Besides, as is already known (see Seetion 3.4) the value analysis of the kinetic model promotes increasing its prognostic capability, thus broadening possible interval of the adequate effect of the control parameter u(f) (equation 4.26). 

Certainly, when solving the problems of targeted influence on a complex reaction we deal with the extremality task. A similar situation arises when the problem is set to describe the behavior of a chemical reaction system, namely, in the identification of the kinetic model, which describes experimental results to the best advantage and possesses a maximum of prognostic capability. To attain this end the following approaches highlighted in the above are usually used ... 

Reduction of Mechanism for Oxidation of Ethylbenzene Inhibited by BHT. Prognostic Capability of the Kinetic Model... 

A saticfactoiy coincidence for the dominant steps is observed at 120 °C. Such a coincidence in the base mechanisms may be somewhat considered as an indicator of good prognostic capability of the kinetic model. 

Construction of kinetic models conforming to experimental data and having prognostic capability enables the successful control of one of the major problems of chemical kinetics of complex reactions. Meanwhile, in solving this problem the broad application of conventional analytical methods is a challenge. 

The evaluation and improvement of prognostic capability of the kinetic model of a multistep reaction. 

Cat B is an abundant and ubiquitously expressed cysteine peptidase of the papain family and makes up a major fraction of lysosomal enzymes that is capable of degrading components of the extracellular matrix in various diseases [30-32]. Cat B is also a prognostic marker for several types of cancer [33], and increased expression and secretion of cat B has been shown to be involved in the migration and invasion of various tumours [34—36], The precise role of cat B in solid tumours is not fully understood, but it has been proposed to participate, along with other cysteine cathepsins, in metastasis, angiogenesis, and tumour progression [37], Indeed, cat B inhibitors reduce both tumour cell motility and invasiveness in vitro [38], Recently, metal complexes based on rhenium, gold and palladium were shown to be effective inhibitors of cat B [39-44],... 

Summarizing the above, it may be assumed that the value analysis together with examination of the parametric sensitivity may beeome a very effective tool to improve the prognostic reliability of kinetic models and to eontrol the capabilities of such models. 

Development of theoretical principles of goal-directed influence on a complex chemical process, similar to the described cases of optimal control, is based on the detailed mechanism of the process. Such an approach is the most fundamental with a relatively wide prognostic range. Hence, the principles of goal-directed influence do not interpret the reaction mechanism passively, but allow also correcting the ideas on the mechanisms, making them more realistic. Here a quite simple principle is applicable if the kinetic model is accurate and reliable, then it has heuristic capabilities, that is, it describes correctly the behavior of a reaction system when varying the conditions of the reaction. 

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