Authors:A. Smallwood, P. Thomas, A. Ray, and P. Šimon
The dehydration of samples of a Coober Pedy, South Australian sedimentary
white opal, displaying play of colour, was investigated using TMA by heating
the samples of the specimen to a range of temperatures between room temperature
and 1000 at 200C intervals followed by cooling to room temperature. Etched
fracture surfaces of the samples were then examined using SEM. The samples
showed the typical expansion at low temperature up to 210C before contraction
was observed. The contraction of the opals was ascribed to both sintering,
supported by morphological change observed in the SEM micrographs, and dehydroxylation
of the silanol groups producing silicon-oxygen-silicon bridges resulting in
a more dense silica network.
Authors:G. Della Gatta, E. Badea, R. Ceccarelli, T. Usacheva, A. Maši?, and S. Coluccia
Environmental impact on parchment was investigated by differential scanning calorimetry (DSC) and scanning electron microscopy
(SEM). Parchments subjected to accelerated ageing and old parchments were compared to evaluate quality and extent of deterioration.
Stability of fibrillar collagen within parchment was determined from the changes in thermodynamic parameters associated with
thermal denaturation. Parchment surface was characterised, and specific morphological criteria were selected for damage assessment.
The thermodynamic and morphological changes of collagen induced by deterioration are discussed, and their correlations are
proposed as a means of ranking damage in old parchments.</o:p>
Authors:V. Hill, N. Passerini, D. Craig, M. Vickers, J. Anwar, and L. Feely
Poly(d,l-lactide) microspheres with progesterone loadings of 0, 10, 20, 30 and 50% w/w were manufactured using an interrupted
solvent evaporation process. Spherical microspheres with loadings close to the theoretical values were produced. The glass
transition of the polymer could be identified by a step change in the heat capacity measured by TMDSC. Progesterone was found
to plasticise the glass transition temperature at contents of 20% w/w or less. At a 30% loading, cold crystallisation of progesterone
was seen indicating that an amorphous form of the drug was present; these microspheres were found to exhibit a pitted surface.
TMDSC of the 50% progesterone samples suggested that most of the drug was present as crystals. This was supported by the SEM
and PXRD results.
Authors:Elena Badea, Lucreţia Miu, P. Budrugeac, Maria Giurginca, A. Mašić, Nicoleta Badea, and G. Della Gatta
A comprehensive investigation has been made of a set of 14th to 16th-century parchment bookbindings from the Historical Archives of the City of Turin. Advanced physico-chemical techniques, such
as thermal analysis (DSC, TG and DTA), spectroscopy (FTIR and UV-Vis-NIR), scanning electron microscopy (SEM) and unilateral
nuclear magnetic resonance (NMR-ProFiler) were employed to assess specific deterioration processes occurring at different
levels in the hierarchical structure of parchment. Changes in the measured physical and chemical parameter values of parchment
due to interaction with the environment were used to identify possible deterioration pathways.
Authors:M. Roy, Praniti Dave, Shiv Barbar, Sumit Jangid, D. Phase, and A. Awasthi
The polycrystalline ferroelectric compounds of general formula Pb1−XBaXTiO3 with X = 0.00, 0.1, 0.2 and 0.5 were prepared by high temperature solid-state reaction technique using high purity oxides and carbonates.
The compounds formation was confirmed by X-ray diffraction and all the X-ray peaks were indexed with tetragonal structure
of space group P4mm. Morphology and particle size of the compounds were obtained using scanning electron microscopy. Ferroelectric phase transition,
enthalpy change, and specific heat of the compounds were obtained using modulated differential scanning calorimetry. It was
observed that the phase transition temperature decreased linearly with the increase of substitution concentration.
Authors:D. Dias, Marisa Crespi, M. Kobelnik, and C. Ribeiro
PHB [poly (3-hydroxybutyrate)], post-consumer soft-drink bottles poly (ethylene terephthalate) PET (herein named PET-R) and
PHBPET-R (blends of PHB and PET-R in several compositions) samples were evaluated by differential scanning calorimetry (DSC)
and scanning electronic microscopy (SEM) in order to verify their thermal properties and porosity according to amounts of
PET-R added the blends. The DSC curve showed that the solvents used to solve the polymer mixture cause changes in the thermal
behavior of PET-R films and in PHBPET-R blends. SEM studies of the PHBPET-R blends show that with a gradual mass increase
of PET-R, there are gradual increases in the porosity of the films.
Authors:A. Ould-Abbas, M. Bouchaour, D. Trari, and N. E. Chabane Sari
samples was examined by scanning electron microscopy (SEM). The thicknesses were evaluated by the cross-sectional SEM analysis and the porosity was measured by gravimetric method. To determine the size of the pores we use the technique of adsorption and
Authors:V. Rodríguez-Lugo, L. Ortiz-Velázquez, J. Miranda, M. Ortiz-Rojas, and V. Castaño
The characterization of samples of painted plasters obtained from the archaeological site of Xochicalco, in Central Mexico,
is presented. Elemental concentrations of the painted layers were obtained by using proton induced X-ray emission (PIXE).
The main crystalline structures of the samples are identified with the help of X-ray diffraction (XRD), while the microstructure
is studied by scanning electron microscopy (SEM). The information resulting from the application of these three techniques
is used to achieve more accurate values for the elemental concentrations. Additional data regarding organic components of
the paintings was obtained through Fourier transform infrared spectrometry (FTIR). Although the latter results only provided
reliable data on inorganic components, they help to clarify the results from XRD and confirm those of SEM.
Authors:A. Skaropoulou, G. Kakali, and S. Tsivilis
form of sulphate attack (TSA) concerns cements and concretes containing limestone
and is attributed to the formation of thaumasite. This work deals with the
confirmation of thaumasite formation in cement mortars. Three types of cement
were examined: Portland cement and Portland limestone cement containing 15
and 30% mass/mass limestone. The specimens were cured at 5C, for 12 months,
in a 1.8% MgSO4 solution. The formation of thaumasite
was checked and confirmed by XRD, TG and SEM. It was concluded that mortars
containing limestone suffer from TSA at low temperature. The combination of
XRD, TG and SEM leads to the positive identification of thaumasite and resolves
the well known problem of thaumasite and ettringite confusion.