Compositional and Morphological Comparison among Three Coeval Violins Made by Giuseppe Guarneri “del Gesù” in 1734

In the present work, we had the opportunity to study the coating systems of three different coeval violins, namely “Spagnoletti”, “Stauffer”, and “Principe Doria”, made by Giuseppe Guarneri “del Gesù” in 1734. These three violins were non-invasively investigated by reflection Fourier transform infrared spectroscopy and X-ray fluorescence. These two techniques were combined for the first time with a 3D laser scanner. The analytical campaign enabled the characterization of the materials and their distribution within the stratigraphy, mainly composed of varnish and, when present, of a proteinaceous ground coat. Some restoration materials were also identified, suggesting the application of different maintenance treatments undertaken during their history. The preliminary information about morphological and geometrical differences between the three coeval violins were acquired through the 3D laser scanner in order to observe similarities and differences in the design features among the three violins.

A Study of the effect of adding antimony oxide to the coating surfaces of steel and cast Iron by glass

The study included adding antimony oxide to mixtures of coating metal surfaces (Enameling), after it was selected ceramic materials used in the coating metal pieces of the type of steel and cast iron in two layers. The first is called a ground coat and the second is a cover coat.Ceramic materials layer for ground coat have been melted down inplatinum crucible at a temperature of 1200oC to prepare the glassmixture (Frit). It was coated on metals at a temperature of 780oC fortwo minutes, while the second layer was prepared glass mixture(Frit) at a temperature of 1200oC, but was coated at a temperature of760oC for two minutes.Underwent tests crystalline state of powders (Frits) and enameled samples using X-ray diffraction technique and found that the process of powders and ground coat layer is random, while the cover layer included having developed a silicon oxide and titanium oxide phases. It was measured density, coating thickness and Knoop hardness for each layer. As well as practical tests conducted dipping enameled samples in diluted and concentrated sulfuric acid, as well as diluted and concentrated hydrochloric acid for three days at a temperature of 100oC. The samples showed good resistance against these acids. The addition of antimony oxide reduced the presence of bubbles in the coated cast iron and enhancement physical and mechanical properties.

Neupräsentationen und Umdeutungen des Heiligen Kreuzes von Polling vom 13. bis zum 18. Jahrhundert

The center of the baroque altarpiece of the Augustinian Monastery of Polling in South Germany forms the so-called Holy Cross. Its current presentation, dated from 1763, is the last of a sequence of four well-documented presentations of a Romanesque wooden cross since 1230. This cross is an excellent example for analyzing and comparing several methods of re-presenting a historic art object as well as for understanding the motivation for such re-presentations, which are grounded on changes of the spiritual function of the object. In its first reframing, the cross received a covering of gilded parchment and a painting of the crucifix on this ground coat. In a fundamental publication from 1994, this covering was compared with a reliquary holding the old venerated wooden cross. However, looking at the context of medieval instructions for painters and the material evidence of extant contemporary paintings, this interpretation becomes questionable: the covering with parchment was a common and technically motivated procedure rather than a spiritually motivated one.