Damaging Processes

Deterioration processes, especially caused by soluble salts interacting with moisture and microbial colonisation, will be presented in this chapter, in relation to restoration/consolidation treatments and their effects. Damage will also be considered that has occurred as a later consequence of extended ingress of moisture through damaged parts of the building or the use of unsuitable building materials. 

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Slifkin, L.M. (1975) in Radiation Damage Processes in Materials, ed. Dupuy, C.H.S. (Noordhoff, Leiden). 

Investigate ways to reduce the potential tor external impacts to damage process piping while the alkylation unit is operating... 

Therefore, the more the system is inhomogeneous the more considerable the damaging process is. 

Another class of methods such as Maximum Entropy, Maximum Likelihood and Least Squares Estimation, do not attempt to undo damage which is already in the data. The data themselves remain untouched. Instead, information in the data is reconstructed by repeatedly taking revised trial data fx) (e.g. a spectrum or chromatogram), which are damaged as they would have been measured by the original instrument. This requires that the damaging process which causes the broadening of the measured peaks is known. Thus an estimate g(x) is calculated from a trial spectrum fx) which is convoluted with a supposedly known point-spread function h(x). The residuals e(x) = g(x) - g(x) are inspected and compared with the noise n(x). Criteria to evaluate these residuals are Maximum Entropy (see Section 40.7.2) and Maximum Likelihood (Section 40.7.1). 

Has the potential for using alternative, less damaging processes been considered Identify changes already introduced and identify the potential for further change. 

A somewhat related situation can be used to explain the well-publicized lung-cancer inducing effects of P-carotene in heavy smokers. This subpopulation will have low vitamin C levels and hence damage due to smoke components, such as N02 can produce P-CAR which will reach the lung and initiate damage. In nonsmokers, the vitamin C (or other water-soluble antioxidant) is likely to be present in sufficient concentration to preclude this damaging process. Indeed, this speculation has been promoted by the American Chemical Society as the subject of a press release in 1997 (Bohm et al. 1997). 

Iron-Stimulated Free Radical-Mediated Damaging Processes... 

Reaction of nitric oxide with superoxide is undoubtedly the most important reaction of nitric oxide, resulting in the formation of peroxynitrite, one of the main reactive species in free radical-mediated damaging processes. This reaction is a diffusion-controlled one, with the rate constant (which has been measured by many workers, see, for example, Ref. [41]), of about 2 x 109 1 mol-1 s-1. Goldstein and Czapski [41] also measured the rate constant for Reaction (11) ... 

It is known that the toxic effects of some solid particles and fibers (latex, zeolite, asbestos fibers, etc.) depend on the stimulation of free radical production. Therefore, the inhibitory effects of flavonoids on particle-mediated damaging processes might be expected. Thus, rutin... 

Chelators of transition metals, mainly iron and copper, are usually considered as antioxidants because of their ability to inhibit free radical-mediated damaging processes. Actually, the so-called chelating therapy has been in the use probably even earlier than antioxidant therapy because it is an obvious pathway to treat the development of pathologies depending on metal overload (such as calcium overload in atherosclerosis or iron overload in thalassemia) with compounds capable of removing metals from an organism. Understanding of chelators as antioxidants came later when much attention was drawn to the possibility of in vivo hydroxyl radical formation via the Fenton reaction ... 

In agreement with the above consideration of the role of oxidative stress in cancer development, it was found that tumor cells (thymocytes) are more sensitive to oxidative stress than normal thymocytes [178], There are apparently the other free radical-mediated damaging processes, which can be more intensive in tumors. For example, it has been found that metHb formation was significantly elevated in cancer patients [179]. 

Replacement cost What are the costs of replacement of damaged processing equipment and loss of business with and without the level of emergency response being considered ... 

The analytical solutions derived in Sections 4.3 and 4.4 for the stress distributions in the monotonic fiber pull-out and fiber push-out loadings are further extended to cyclic loading (Zhou et al., 1993) and the progressive damage processes of the interface are characterized. It is assumed that the cyclic fatigue of uniform stress amplitude causes the frictional properties at the debonded interface to degrade... 

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