Study on chemical and fatty acid modifications of cow's milk in relation to fat globules diameter

Studies regarding the range of values for variations in the size of milk fat globules have been conducted over the years by various Authors, based on objective observation and mathematical extrapolation. In 1969,Walstra calculated the existence of a population of globules smaller than 1 μm and identified a population of larger globules, distributed in a "Gaussian" manner and showing a peak at a diameter of around 3-4 micrometers; later Timmen e Patton (1988) separated the cream from the rest of the milk by centrifugation and classified the fat globules into small and large sizes

Soil vs. glass: an integrated approach towards the characterization of soil as a burial environment for the glassware of Cucagna Castle (Friuli, Italy)

This research is performed on a selection of archaeological glass finds with corresponding soil samples, excavated on the site of the High Medieval castle Cucagna in Friuli/Northern Italy. In the frame of understanding medieval glass technology and the chemical-physical conditions that influenced the state of preservation of the glass finds, this study uses a multi-analytical line-up of methods to characterize the composition of the glass and basic parameters of the soil including texture, mineralogical composition, pH, redox potential (Eh) and electric conductivity (EC). The results show that glass corrosion in soil not only depends on acidity, alkalinity or glass composition but also on the texture of the soil, measurable as grain-size distribution, and the mineralogical composition. The compositional groups of the glassware from Cucagna indicate the use of various raw material sources, pointing to Northern and Central Italian glass workshops with primary or secondary glass production.[GRAPHICS].FdA – Publicaties zonder aanstelling Universiteit Leide

SEM-EDX analysis of ancient gold leaf glass mosaic tesserae

Metal leaf (gold, silver or their alloys) glass tesserae began to be used in wall mosaics in the st century AD (the first examples are in Rome) and their use has been uninterrupted up to day. The metal leaf could be obtained from circulating coins, jewellery or refining. According to various techniques that have changed over the centuries, the leaf was hot fixed between two glass layers. From an archaeological point of view, it is interesting to know when and where these tesserae were made, if they were new made or if they were reused tesserae recovered from earlier dismantled mosaics. The determination of the glass composition of the tesserae is not of great help in this connection, for the same kind of glass was used over long periods. Available information is still scanter for glasses produced between the 1st to 8th centuries when the batch of raw materials (a natural soda called natron and a silica-lime sand) was melted in large tank furnaces and chunks of raw glass were transported all over the Mediterranean to be remelted and shaped into manufacts in small pot furnaces. The SEM-EDS analysis is proposed in this study as a useful tool to investigate the composition of both the glass and the gold alloy in leaf tesserae from mosaics of the 1st - 9th centuries. The comparison of the composition of the gold leaf of the tesserae with that of circulating gold coins (for which an important analytical data base is available), adds further information to the glass analysis, allowing us to improve the dating of the tesserae and increase the knowledge that may result from scientific analyses. The results demonstrate that good quantitative analyses of the metal leaf can be performed and that metal leaves made of pure gold or gold-silver alloys were used