Necking regime

The existence of the two lengthscales in the intermediate regime has a simple physical interpretation and can be explained in terms of the LCA theory, which links the velocity of the interface with its local curvature. Namely, one can show [223] that the quantity p(t) = (LH(t)/LK(t))2 estimates the average number of necks piercing the surface of a sphere of radius LH(t) [LH(t) is the characteristic... 

Clinical signs of neurotoxicity (tremors and ataxia) have been observed in sheep, dogs, and rats dining or immediately after both oral and inhalation exposure. Sometimes tremors developed early in the treatment regime and other times the tremors became apparent only after repeated exposures. Fluke-infected sheep experienced tremors of the facial muscles, neck, and forelimbs and were unable to stand after treatment with hexachloroethane. They were successfully treated with calcium borogluconate. This suggests that the neurological action of hexachloroethane may be the result of interference with the availability of calcium within excitable cells. 

The regimes combining Orzel and capecitabine with radiation therapy have become the focus of increasing interest in the management of patients various malignancies including rectal, anal, locally advanced head and neck, esophageal, and pancreatic cancers. 

An important finding of the analysis is the way in which an initially inhomo-geneously distributed liquid will redistribute itself in the two-dimensional array. For low liquid content where the liquid is situated at isolated necks, tha-e is always a force driving the liquid to redistribute itself homogeneously. In the second regime, where some of the pores are filled, it is immaterial which pores fill with liquid as long as the correct fraction of pores is filled. Consequently,... 

Work hardening is the reason why the flow curve of metals increases in the plastic regime (see chapter 3). If the material is unloaded after plastic deformation, the stress-strain curve follows a line parallel to the elastic line. If the load is raised again, the yield strength has increased and the stress-strain curve follows the same line as on unloading. The strain until the material starts to neck or fracture is reduced the material has lost ductility. 

Figure 6.23 Experimental data and predicted lifetimes based on the necking model (Eq. (6.4), short-term lifetimes) the Riedel model (Eq. (6.6), intergranular damage), and finally a combination of the Riedel model and the measured strain rates in the low stress regime (Fig. 6.7). A test result corresponding to a test which is in the tertiary stage after 25 years is shown by the range of possible lifetime [48], Steel grade 91, 600°C.

Figure 6.32 Comparison between experimental lifetimes and predicted ones. The necking model is used at high stress whereas the Riedel intergranular damage is used at low stress (high-stress regime of strain rates) and very low stress (low-stress regime of strain rates), (a) Material A (b) material B. Experimental data found in Ref [103]. Advanced austenitic stainless steel, Fe35Ni25CrNb, 980°C.

Necking and intergranular damage modelings allow rather fair predictions of lifetimes up to 25 years, provided the low-stress regime of strain rates is taken into account. 

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