“The Shell of Anomia Simplex: Structural and Nanomechanical Investigations”
In this thesis focus has been on the inorganic part of the shell of Anomia simplex. The investigations with different methods have revealed that both shells contained calciumcarbonate in the form of calcite and aragonite. Right shell had around three times as much magnesium as the left shell. This was also reflected in the amount of magnesium in their calcite structures. Aragonite was placed were the muscle was attached (moystracum) in the left shell, but the structure remains unidentified. The rest of the left shell was made of calcite in a foliated structure following the shell. Right shell had aragonite in a crossed lamellar structure, thickest near the hole for the byssus and gradually thinner away from it until it disappeared. The rest of the right shell contained a prismatic structure of calcite, which wrapped around the aragonite structure at the hole for the byssus, covering the edge there the shell could touch the byssus.
”31P MAS NMR studies of Potassium Ortho- and Pyrophosphates”
The focus in this project has been on the solid state 31P NMR charaterization of K2HPO4 and K4P2O7. Originally it was only meant to focus on K4P2O7. Due to the complexity of K4P2O7‘s structure, the focus was widenend to also include studies of K2HPO4 because K4P2O7 can be made from K2HPO4 by heating it.
”Characterization of Sodium-Alumino-Silicate Glasses by Solid-state NMR Spectroscopy”
The purpose of this project has been to characterize and compare different sodium-alumino-silicon glasses with solid-state NMR spectroscopy. All the glasses have been made via batch melting and data have been obtained with MAS single-pulse experiments. The glasses have been divided in three group depending on which relationships which were varied. One with fixed Na/Al and changed Si/Al relationship, one with changed Si/Al and a small change in Na/Al and one with changed Na/Al and opposite changed Si/Al.
No significant difference was seen in the 23Na spectrums obtained at 4,7T and about 11,000 Hz, except a small tendency of higher frequency for the center of gravity, δcg, with a raised amount of aluminum. For the 27Al spectrums, obtained at 9,4T and 12,000Hz, it was seen what most of the aluminum was in tetrahedral coordination in the area for Al(-O-Si)4 and partly Al(-O-Si)3. Only a small fraction was in sex coordinated environment. A raised amount of aluminum leads to a lower frequency for δcg, but the differences is small. The 29Si spectrums, obtained at 4,7T and 10,000 Hz, shows what both the Si/Al and the Na/Al relationship affects δcg, both a higher amount of aluminum and a higher Na/Al relationship move δcg towards higher frequency. The broad peakshape, and for the quadruple nucleuses, the missing singularities, supports the glasses are of amorphous character.