Application of analytical techniques to the unveiling of the glazing technology of medieval pottery from the Belgrade Fortress

Medieval glazed ceramics, dated to the early 15th century, excavated at the Belgrade Fortress, Serbia, were investigated by combining optical microscopy, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), micro-Raman spectroscopy and multivariate statistical analysis. The decoration and style of the investigated ceramics were characteristic of workshops from different areas of the medieval Serbian State: Ras, Krusevac and Belgrade/Smederevo. Comparison was made with ceramic samples from the same period excavated at the Studenica Monastery, the hitherto earliest workshop discovered, which were used as reference material for the Ras area. Ceramics from the Belgrade Fortress were covered with a transparent, lead-based glaze. The majority of the glazes were produced by application of mixture of lead oxide and quartz to the clay body, whereas only two samples were glazed by application of lead oxide by itself. The brown colours of the glaze originated from Fe-based spinel, whereas copper and iron were responsible for the colouring of the green and yellow glazes. The obtained results revealed glazing technology taken from Byzantine tradition

Spectroscopic Study of An Icon Painted on Wooden Panel

Russian icon painted on wooden panel analyzed in this work is interesting for art historians because there is no precise information in which workshops it was made or who the author was. Similar icons are often found in churches and monasteries in our region. In order to obtain information about materials used for creation of investigated icon two micro-analytical techniques were used: Energy-Dispersive X-Ray Fluorescence spectroscopy (EDXRF) and micro-Raman spectroscopy. Obtained results confirmed presence of following materials: lead-white, vermilion, minium, ultramarine, brown and green earth pigments and silver in combination with yellow organic varnish, which served to an iconographer for gilding. Ground layer was made of calcite. Blue pigment ultramarine was probably used for blue colour as well as for obtaining particulars hues in several parts of the paint layer. This can be important information for further research concerning particular workshop in which the icon was made. Identified materials are typical for Russian iconography of the 19th century

CONTROL OF GLYCEMIA AND CARDIOVASCULAR RISK FACTORS IN PATIENTS WITH TYPE 2 DIABETES IN PRIMARY CARE IN MONTENEGRO

Some observational studies have shown that only a small number of diabetic patients achieve optimum control of glycaemia and cardiovascular risk factors. The aim of this study was to analyze whether patients with type 2 diabetes mellitus treated in primary care achieve adequate control of glycemic levels and cardiovascular risk factors. This was a retrospective, record-based, cross-sectional study that included eligible patients from 35 to 90 years old with type 2 diabetes mellitus treated in Primary Health Care Center in Podgorica. We investigated electronic records of 531 diabetic patients. The observed prevalence of type 2 diabetes mellitus among individuals between ages 35 and 90 years, was 11,84 %. Half of the patients were female. The mean age was 65,88±9,86 years. The mean value of HbA1c was 7,56±1,71. Fifty-nine percents of patients achieved optimal levels of HbA1c ≤ 7 %. Also, more than half of patients achieved target levels of blood pressure while 27.9% achieved LDL ≤ 2.6 mmol/L. Fifty percent of patients were non-smokers and 45.1 % were obese. Among patients on primary prevention only 5.7 % had met all target levels while on secondary prevention that number was even smaller 3.7 %. Our study showed that control of HbA1c and blood pressure was similar to other studies but reaching target levels of LDL was challenging for our patients. Further analysis are needed in order to discover the reasons for poor control of certain CVRF and to develop strategies for its optimal management

Micro/mesoporous aluminosilicate materials via dual templating, Part 1: synthesis and characterization

In a quest for optimal synthesis procedure of hierarchically porous zeolite by dual template method, a series of materials was prepared starting from zeolite yielding precursor with an addition of surfactant as a mesoporogen. Characterization of the obtained materials showed that all samples possess micro and mesoporous structures, which ratio depends on the amount of surfactant present in the reaction mixture. However, in the most of the samples separation of phases occurred, and crystalline zeolite phase along amorphous MCM-41 like phase were detected, except for the sample obtained from the modified precursor, where only crystalline zeolite phase was obtained, with a specific and unusual morphology. Adsorption isotherm of that sample resembles the isotherms obtained for post synthesis modified samples

TiO2 nanoparticles supported on natural zeolite clinoptilolite from Serbia for removal of bisphenol A from aqueous solution

Bisphenol A (BPA) is a well-known emerging contaminant that pose a severe threat to human health due to its negative effect on the body’s endocrine systems. BPA is widely used in the production of polycarbonate plastic and epoxy resins and therefore often detected in different water environments. Since the conventional wastewater treatments for BPA removal haven’t been proven efficient it is important to find a green and efficient method for its complete elimination. Therefore, the aim of this work was to prepare a cost-effective hybrid photocatalyst based on TiO2 nanoparticles and natural zeolite clinoptilolite and study its photocatalytic performance toward BPA. The TiO2/clinoptilolite, containing 20 wt% of TiO2, was prepared using ultrasound assisted solid-state dispersion method and characterized using a multi-technique approach by combining X-ray powder diffraction, FTIR, UV Vis DRS spectroscopy, atomic force microscopy (AFM), BET measurements and laser diffraction. The study showed complete removal of BPA (5 mg/L) after 180 minutes of simulated solar irradiation using 2 g/L of hybrid photocatalyst, at pH = 6.4. The addition of H2O2 led to a faster BPA removal after 120 minutes of irradiation. When BPA removal was tested in bottled drinking water a lower removal of 60 % after 180 minutes of irradiation was observed because of the presence of bicarbonate ions and its scavenger effect toward hydroxyl radicals. The reused photocatalyst showed good photocatalytic activity in repeated cycles (e. i. 70 % of BPA was still successfully removed at the end of the 4th cycle)

Spectroscopic investigation of two Serbian icons painted on canvas

A multianalytical study of two Serbian icons, The Virgin and Child and St. Petka, painted on canvas by unknown authors was performed in order to identify the materials used as pigments, binders and the ground layer. The investigated icons belong to the Museum of the Serbian Orthodox Church in Belgrade. Samples, collected from different parts of the icons, were analysed by: optical microscopy (OM), energy dispersive X-Ray fluorescence (EDXRF), Fourier transform infrared (FTIR) and micro-Raman spectroscopy. The obtained results revealed the presence of the following pigments: Prussian Blue, ultramarine, Green Earth, iron oxides, Lead White and Zinc White. Linseed oil was used as the binder. The materials used for the ground layers were gypsum, calcite, baryte and Lead White. The gilded surface of the icon The Virgin and Child was made of gold. The gilded surface on the frame of this icon was made of imitation of gold, i.e., Schlagmetal, since EDXRF spectroscopy showed the presence of copper and zinc, while gold was not detected. Based on the style and the consideration of an art historian, as well as on the obtained results for the corresponding pigments and binder, both icons were most probably made at the end of 19th or the beginning of the 20th century

Physicochemical characterisation of pottery from the Vinca culture, Serbia, regarding the firing temperature and decoration techniques

A study of decorated Neolithic pottery samples from the excavation site Plocnik, Serbia, was performed using X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) spectroscopy. The investigated samples belong to the era of the Vinca culture that existed in the central Balkan region from the mid VI until the first half of the V millennium BCE. The mineralogical composition of the pottery samples and comparison of the investigated pottery with thermally treated local clay indicated firing temperatures in the range from 600 to 800 degrees C. Two different types of white pigments were identified in white incrusted decorations: calcium carbonate and bone white (composed of crushed bones). This is the first evidence of the use of bones for decorations in pottery of the Vinca culture from the excavation site Plocnik. In addition to this, it was revealed that the potters used the iron reduction technique for obtaining black decorations

Spectroscopic investigation of milo milunović’s canvas painting “the inspiration of the poet”

A canvas painting by Milo Milunović “The Inspiration of the poet” was investigated in this work by multianalitical approach in order to identify pigments used by the artist as well as his painting technique. Results obtained by optical microscopy, fluorescence photography under UV light, energy dispersive X-Ray fluorescence (EDXRF) and FTIR Spectroscopy revealed following pigments on the painting: lead white, zinc white, cobalt blue, red pigment vermilion, green pigment viridian, as well as several earth colours. Optical micrographs show regions with no separation between layers, indicating that these areas were painted wet paint over wet paint