Self-limiting processes

The formation of the white spots was not linked to the use of lead white but to other lead pigments, namely red lead and lead-tin yellow which are thought to be much more chemically reactive. So does all this mean that eventually all the oils of oil paintings will slowly decompose The answer is no and the experts now believe that while some white spotting is inevitable it is a self-limiting process which will eventually cease before any real visual changes take place. 

Atomic layer epitaxy (electrochemical) — Electrochemical atomic layer epitaxy (ECALE) is a self-limiting process for the formation of structurally well-ordered thin film materials. It was introduced by Stickney and coworkers [i] for the layer by layer growth of compound semiconductors (CdTe, etc.). Thin layers of compound semiconductors can be formed by alternating - underpotential deposition steps of the individual elements. The total number of steps determines the final thickness of the layer. Compared to flux-limited techniques... 

The defect creation is a self-limiting process. As the defect density increases, the additional recombination through the new states reduces the concentration of band edge carriers and suppresses the creation... 

Terephthalic acid (TA) (diacid) is now the major monomer used in the production of PET. It is produced on a world-wide scale and is available in a number of purities. These can be generally referred to as PTA (pure TA), MTA (medium purity TA) or CTA (cmde TA). These descriptions are subjective and used in different ways by manufacturers. The purity of TA is the self-limiting process in PET manufacture. The major impurity in any TA grade is 4-carboxybenzaldehyde and it is a chain growth inhibitor. As the level of impurity increases less reaction can take place. From a food contact point of view the purity or impurities in the TA is important. Both US and EU law state that monomers should be of good technical quality but do not define what that technical quality should be. If no other information is available the... 

The activity of triacetin is due to the acetic acid released by hydrolysis of the compound by esterases present in the. skin. Acid release is a self-limiting process because the esterases are inhibited below pH 4. 

We have shown that, in order to exhibit intense PL, the Si nanocrystals must be perfectly passivated. A simple way to achieve this is through natural aerial oxidation. We have followed this process by measuring the photoluminescence as a function of time. Stable conditions are achieved after approximately 6 months. This indicates that the oxidation of Si nanoparticles is a self-limiting process. 

Several experiments have shown that electrokinetically mediated iron mineralization is, in essence, a self-limiting process in which the current falls as an essentially impermeable (1 x 10" m/s or less) iron-rich lithilied soil mass develops (e.g. Hopkinson and Cundy, 2003 Cundy and Hopkinson, 2005). In the context of Cr(VI) stabilization, the generation of low-permeability zones, in which chemically stabilized Cr(III) is locked in iron-rich mineral phase(s), means that stabilized zones are likely to be resilient to reactive flow, with the low permeability also serving to limit potential loss of adsorbed Cr(VI) residue on the iron mineral phase(s). 

Fig. 1.74). Luminal narrowing and ascites may be significant. Some transient small bowel intussusceptions can be observed. SchOnlein-Henoch syndrome, in general, is a self-limited process with a very good clinical outcome. 

Epiploic appendices are pedunculated adipose structures protruding from the serosal surface of the colon. An epiploic appendix might incidentally undergo infarction because of torsion or spontaneous venous thrombosis. The condition has been called epiploic appendagitis (van Breda Vriesman and Puylaert 2002). It is considered, as with omental infarction, a self-limited process, and the appropriate management is conservative. The inflamed mass is often delineated hy a hypoechoic ring on US. 

This gas-solid reaction is a self-limiting process that leads, at most, to a monolayer of CO gas coverage on the catalyst. Once all of the available Pt surface sites have reacted, no further CO will adsorb on the surface of the Pt. This is expressed by the fact that when the CO surface coverage (O) goes to 1, the reaction rate (dO/df) goes to zero. 

Passive oxidation occurs when the oxide layer that forms on the surface provides a protective coating that inhibits further oxide growth. Passive oxidation is therefore a self-limiting process that gradually slows down (or eventually completely stops) as the oxide grows thicker. 

Sutphin M, Midelton AW (1984) Eosinophilic cystitis in children a self-limited process. J Urol 132 117-119 Talarico HP, Ruhens D (1990) Gallbladder wall thickening in acute pyelonephritis. J Clin Ultrasound 18 653 -657 Talner LB, Davidson AJ, Lebowitz RL et al (1994) Acute pyelonephritis can we agree on terminology. Radiology 192 297-305... 

The chemisorption process is limited by the number of hydroxyl groups present on the substrate surface, or for monolayer formation. In this way, it is a self-limiting process, much like ALD, thereby providing good thickness control. The... 

Flatt, J. P., 1970, Conversion of carbohydrate to fat in adipose tissue An energy-yielding and, therefore, self-limiting process, /. Lipid Res. 11 131. 

UPD is a self limiting process. Deposition is terminated as soon as a complete monolayer has been formed. This statement should be qualified. There are a few cases reported in the literature where more than a monolayer is formed, but rarely more than two atomic layers. However, even in such cases, the process is self-limiting... 

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