The hydrothermal reactivity of a Mg-vermiculite from Santa Olalla (Spain) was studied experimentally at 150 and 300ºC, 75 and 100 bars, respectively, in (Na,K,Ca,Mg) chloride and sulphate solutions (liquid/solid ratio = 10). The formation of mixed-layer clays is demonstrated by FT-IR spectroscopy, X-ray diffraction (XRD) and electron microprobe. The gradual decrease of the 3220 cm–1 infrared band intensity, characteristic of free water, is interpretated as the dehydration of the interlayer Mg cation of the vermiculite. The presence of ‘brucite type’ sheets is also observed by the increase of 3555 cm–1 and 3420 cm–1 band intensities. The XRD results show that run products are able to expand when glycolated. Microprobe analyses document the decrease of IVSi content and a significant enrichment in Mg in the run products. The formation of a mixed-layer clay comprising saponite and chlorite layers is proposed.

Alkali feldspar (Or64.5Ab34.8An0.6) in a granite pegmatite from Hanazono, Kosei Town, Shiga Prefecture, southwest Japan, consists of two types of regions observable with the naked eye: one is colourless and transparent, and the other is pale pink and opaque. The colourless regions are clear, cryptoperthitic and almost free of micropores, and the pale pink regions are turbid, vein microperthitic and with many micropores visible under a microscope. The latter regions may have been changed from the former by the catalytic action of water. Integrated absorbance values were calculated for both types of regions from Fourier-transform infrared microspectra in the range 2500–4000 cm−1. These values were used as semi-quantitative parameters of water contents. The turbid regions are much more enriched in water compared to the clear regions. The chemical states of water in both regions were also evaluated. Water in the turbid regions is estimated to be present mainly as H2O inclusions in micropores and to be present to a lesser extent as structural OH groups. A small amount of water in the clear regions may be present as structural OH groups. The water distribution in the feldspar records the cooling history of hydrothermal reactions causing the coarsening of cryptoperthites to microperthites.

On-farm instruments for assessing colostrum quality are needed in order to ensure that the calf is supplied with enough IgG to avoid failure of passive transfer. The aim of this study was to evaluate methods for estimating the IgG concentration in cows' colostrum. This research included 126 colostrum samples from 21 Danish farms with different breeds, ensuring a broad variation pattern in IgG, total protein and fat concentration. Approximately one third of the samples did not fulfil the recommendation of >50 g IgG/l colostrum, and the IgG concentration decreased with time from calving to milking. The ratio of IgG to total protein varied from 6 to 61%, however IgG and total protein were correlated with r2 = 0·70. The variation in fat was independent of variations in protein and IgG. The IgG concentration was measured by ELISA and compared to fast measurements by specific gravity by colostrometer, Brix by refractometer and prediction from infrared spectroscopy. The three fast methods were all correlated to the total protein concentration of colostrum; however specific gravity was also influenced by the fat concentration. Furthermore, specific gravity generally overestimated the IgG concentration, and the cut-off level should be raised to 1050 in order to ensure adequate IgG in colostrum. None of the methods estimated IgG concentration better than the correlation of total protein and IgG, meaning that they all depended on the indirect correlation between total protein and IgG. The results suggest that using a refractometer for quality control of colostrum is an easy and feasible method, and a cut-off level of Brix 22 seems sufficient to assure adequate IgG concentration in colostrum fed to the calf.

Ribonucleotides (RMPs) are the building blocks of genetic material consisting of a sugar group, a phosphate group and a nucleobase. Prussian blue (PB) is an ancient compound which is supposed to have formed under the conditions of primitive Earth. The interaction between nucleotides and mineral surfaces is of primary importance in the context of prebiotic chemistry. In the present work, the adsorption of RMPs on PB has been studied in the concentration range 0.4 × 10−4–3.0 × 10−4 M of RMPs at pH 7.5, T = 27°C and found to be 53.1, 41.7, 25.8 and 24.0% for adenosine 5′-monophosphate (5′-AMP), guanosine 5′-monophosphate, cytidine 5′-monophosphate and uridine 5′-monophosphate, respectively. Optimum conditions for the adsorption were studied as a function of concentration, time, amount of adsorbent and pH and data obtained were found to fit the Langmuir adsorption isotherm. Langmuir constants (KL and Xm) values were calculated. Fourier transform infrared spectroscopy, Raman spectroscopy, field-emission scanning electron microscopy and X-ray diffractometry techniques were used to investigate the interaction of RMPs on PB surface. Adsorption kinetics of 5′-AMP on PB has been found to be pseudo-second order. Results obtained from this study should prove valuable for a better understanding of the mechanism of RMP–PB interaction.

Ag nanoparticles dispersed SiO2 composite films were successfully prepared by a sol–gel method. The structural transition, formation, and optical property along with relevant band gap of Ag/SiO2 thin films during the annealing process were studied by Fourier transform infrared spectroscopy, thermogravimetry–differential thermal analysis, x-ray diffraction, and ultraviolet–visible spectroscopy, while the microstructure of thin films was revealed by transmission electron microscopy. The results indicate that the Ag spherical particles with the diameter of 10–20 nm were formed by breaking Si–O–Ag bonds above 200 °C and dispersed in the SiO2 matrix. The optical absorption property of Ag/SiO2 nanofilm in the visible range is enhanced, and the band gap (Eg) is widened with raising annealing temperatures, which is promising for the potential applications in nonlinear optical and related fields.