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Nanoindentation of Shell and Scale: A Hard-Tough Layered Functionally Graded Hybrid Composite
Published in Arjun Dey, Anoop Kumar Mukhopadhyay, Nanoindentation of Natural Materials, 2018
Manjima Bhattacharya, Anoop Kumar Mukhopadhyay, Arjun Dey
The corneum forms the outermost layer and is mainly composed of conchiolin. The conchiolin is a protein material that aids in binding the calcium carbonate crystals together in the shell. The middle prismatic layer is primarily composed of the calcite crystals. The third nacre layer, which forms the innermost layer of shell, is mainly composed of the lamellar aragonite crystals [12]. The periostracum and prismatic layers are secreted by the band of cells that are located in the outer marginal regions, so that the shell grows at its outer edge. On the other hand, the nacreous layer develops from the inner mantle regions of the shell. The shells are made up of different crystalline polymorphs of calcium carbonate minerals such as calcite and aragonite, which are embedded in organic components [12].
Laboratory evaluation of seashells used as fine aggregate in hot mix asphalt
Published in International Journal of Pavement Engineering, 2020
Gaby Ruiz, Francisco Chávez, Stephanie Santamaría, William Araujo, Jorge Timaná, Robert Schmitt
Seashells are composed primarily of calcium carbonate (Wheaton 2007) and ionic species formed by calcium and magnesium appear to be less soluble with water, which can lead to greater adhesion with the asphalt than granitic aggregates. Research by Wheaton (2007) on oyster shells, in Eastern U.S. coastal waters, used photo-thermal infrared radiometry methods to measure thermal properties and internal composition. The oyster shells are composed primarily of calcium carbonate and a matrix of conchiolin. Calcium is primarily calcite with some presence of aragonite.