3D volumetry CT scans accurately estimate GV after SG. A significant relationship between GV and EWL 6 months after SG was established, seeming that GV ≥ 100 ml at 6 months of SG is associated with poor EWL.

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a b s t r a c t The apparent molal volumes and compressibilities of Tris and Tris-HCl have been determined in water (5-45°C) and 0.725 m NaCl (5-25°C). The changes in the volume (ΔV) and compressibility (Δκ) for the dissociation of Tris-H þ Tris H Tris H − = + + + as functions of temperature in water and 0.725 m NaCl have been determined from these measurements. The values of ΔV and Δκ have been used to determine the effect of pressure on the dissociation constant for Tris-H þ (K P /K 0 ). K K RT P RT P ln / V/ 0.5 k/ P 0 2( )=− ∆ ( ) + ∆ ( ) These results will be useful in the calibration of pH systems making in-situ measurements at high pressure in seawater. In 0.725 m NaCl at 5°C and a pressure of 2000 bar, the dissociation constant is reduced by 29%.

The apparent molal volumes (V ϕ) of the trivalent rare earth (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) chlorides, nitrates and perchlorates have been calculated from the density measurements at 25 °C and (5 to 80) °C and 0.02 – 4 m. The values of V ϕ have been fitted to the Pitzer equations, V ϕ = V̅ 0 + (A v I/(1.2m) ln­(1 + 1.2I 0.5) + 2RTm(β V(0) + β V(1)  g(y) + mCV ), where V̅ 0 is the infinite dilution partial molal volume, A v is the Debye- Hückel slope, I is the ionic strength, and g(y) = (2/y 2)·[1 – (1 + y) exp­(−y)] where y = 2­(I 0.5). The Pitzer volume parameters β V(0), β V(1) and C V are functions of temperature. The values of V̅ 0, β V(0), β V(1), and C V for most of the rare earth chlorides are similar orders of magnitude. These results should be useful in estimating the effect of pressure on the equilibria of rare earths in natural waters over a wide range of temperature.