No abstract

This study examines the effects of particle sizes between 3-121µm on the fundamental vibrations of the [CO3

Mg-Ca carbonates are an important group of industrial minerals, which frequently occur intimately intermixed in natural settings and are traditionally assessed for phase purity by X‑ray diffraction (XRD). In this study Raman spectroscopy is employed to quantify the modal abundance of hydromagnesite [Mg 5(CO3)4(OH)2·4H2O], huntite [CaMg3(CO3)4], dolomite [MgCa(CO3)2], and magnesite [MgCO3], in powdered mixtures constructed from fabricated reference materials. Particle size distributions were assessed by scanning electron microscopy and laser diffraction. Raman analyses performed using a portable instrument were conducted at 25 °C and at atmospheric pressure. XRD was employed to validate the accuracy and precision of Raman measurements. Monovariable and multivariable methods were employed to provide quaternary quantification from the spectroscopic data. For monovariable calibration the amplitude of the peaks was plotted against the measured weight ratios of the four mineral phases. Overlapping bands were resolved using the Gaussian Lorentzian method. Chemometric methods were used to perform the multivariable calibration. The overall lowest error on component values was obtained by principal component regression with application of standard normal variate correction. The quantifications derived by Raman spectroscopy and XRD show close agreement. Hence, evidence suggests that a reliable four-way calibration program to screen the purity of carbonate assemblages can be constructed, providing particle size effects are constrained and spectroscopic operating conditions are uniform

The reaction kinetics and solid phase products following the dissolution of Mg(OH)2 by CO2 sparging in the presence of calcium salts at 35°C, over a thirty day period have been studied.

In recent years the delivery of practical laboratories classes has been subjected to debate, with regards to pedagogical efficiency. Our aim was to develop a prelaboratory online learning resource that enhances the preparedness and performance within laboratory classes. A study was conducted using second year Pharmacy students, in which the class was given access to an online learning resource that included visual information, quizzes, safety and theory and this was compared to the laboratory script as a preparative resource for class. Less advice was requested by students and reduced error in practical skills was observed when the online learning resource was used by students, when compared to the laboratory script. Students felt they were able to use the apparatus without requirement of support, and thus were more confident in the laboratory class. This online resource has the potential to overcome the pedagogical limitations associated with traditional delivery of laboratory classes.