Forging Volumetric Methods

Abstract We studied the drying of polyacrylamide (PAAm)-multiwalled carbon nanotube (MWNT) composites, prepared by free radical crosslinking copolymerization in water, with a steady state fluorescence technique. Composite gels were prepared at room temperature with pyranine (Py) doped as a fluorescence probe. Drying experiments were performed in air at various MWNT contents by real time monitoring of the Py fluorescence intensity (I) which increased as the drying proceeded. The Stern-Volmer equation, combined with the moving boundary diffusion model, was used to explain the behavior of I during drying. It was observed that the desorption coefficient (D) increased as the temperature increased. Drying energies (ΔE) were measured for the drying processes for each MWNT content gel, by using fluorescence, gravimetrical and volumetric methods. It is understood that ΔE values decrease by increasing MWNT content, until 1 wt% MWNT, and then increase above the level of this threshold value. The energy of drying is strongly correlated with the MWNT content in the composite. ΔE drops to its lowest value, at which conducting cluster starts to appear.

Minimum convex hull mass estimations of complete mounted skeletons

Biology Letters ◽

10.1098/rsbl.2012.0263 ◽

2012 ◽

Vol 8 (5) ◽

pp. 842-845 ◽

Cited By ~ 43

Author(s):

W. I. Sellers ◽

J. Hepworth-Bell ◽

P. L. Falkingham ◽

K. T. Bates ◽

C. A. Brassey ◽

...

Keyword(s):

Convex Hull ◽

Body Mass ◽

Laser Scanning ◽

Regression Line ◽

The Body ◽

Alternative Approach ◽

Subjective Input ◽

Skeletal Reconstruction ◽

Volumetric Methods ◽

User Intervention

Body mass is a critical parameter used to constrain biomechanical and physiological traits of organisms. Volumetric methods are becoming more common as techniques for estimating the body masses of fossil vertebrates. However, they are often accused of excessive subjective input when estimating the thickness of missing soft tissue. Here, we demonstrate an alternative approach where a minimum convex hull is derived mathematically from the point cloud generated by laser-scanning mounted skeletons. This has the advantage of requiring minimal user intervention and is thus more objective and far quicker. We test this method on 14 relatively large-bodied mammalian skeletons and demonstrate that it consistently underestimates body mass by 21 per cent with minimal scatter around the regression line. We therefore suggest that it is a robust method of estimating body mass where a mounted skeletal reconstruction is available and demonstrate its usage to predict the body mass of one of the largest, relatively complete sauropod dinosaurs: Giraffatitan brancai (previously Brachiosaurus ) as 23200 kg.