Micro-analytical Evidence of Copper-Based Pigment and Fungal Contamination of Medieval Mural Paintings in Beram, Croatia

2019 ◽  
Vol 25 (6) ◽  
pp. 1471-1481
Author(s):  
Tea Zubin Ferri ◽  
Emina Pustijanac ◽  
Ines Kovačić ◽  
Josipa Bilić

AbstractThe aim of the present study was to map the painting materials, degradation processes, and biological features present on the mural painting in the church of St. Mary in Beram (Croatia) to study their possible interaction and produce information helping the preservation of this valuable painting. The research was conducted on micro samples of painting materials taken from different sites along the painting and the characterization of the present fungal species was carried out. The painting samples, together with observable patinas and degradation products, were studied by optical microscopy (OM), scanning electron microscopy, energy-dispersive spectroscopy (SEM/EDS), Fourier-Transform Infrared spectroscopy, and powder X-ray diffraction. Fungal diversity was studied using cultivation methods followed by OM and SEM analyses in addition to molecular analysis. The results contribute to the characterization of the original painting materials, successively added materials and occurred interventions, to the understanding of degradation progressions and fungal biotransformation processes. A mineral, cumengite, a copper-based pigment extremely rarely used in art, was found. Its occurrence together with barium sulfate, gypsum, and calcium oxalate possibly produced by microbiological activity was studied and information was added regarding the composition of painting materials in St. Mary church mural cycle.

2018 ◽  
Vol 782 ◽  
pp. 129-135 ◽  
Author(s):  
Bogdan Istrate ◽  
Corneliu Munteanu ◽  
Ștefan Lupescu ◽  
Vasile Iulian Antoniac ◽  
Eusebiu Sindilar

In recent years, researchers have been able to identify new materials with special properties that can be used in major medical fields. Magnesium-based materials used in orthopedics are an important alternative, being the third generation of biocompatible materials. A biodegradable magnesium-based material has the ability to degrade at a certain rate, is biocompatible, and together with other alloying elements ensures osteointegration. Mg-0.5Ca-xY biodegradable alloys will be developed in an induction melting furnace using ceramic crucibles, melting at 710-720 °C in the controlled atmosphere of 5.0 Ar. SEM analyses and X-ray diffraction reveals the size distribution of Mg-sized grains, with a hexagonal lattice and formation of compounds with the two alloying elements: Mg2Ca, Mg2Y, Mg24Y5uniformly arranged in the α-Mg matrix. The alloying elements influence the microstructure, the size of the α-Mg grains decreasing considerably.


Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Andrea Gil-Torrano ◽  
Auxiliadora Gómez-Morón ◽  
José María Martín ◽  
Rocío Ortiz ◽  
Mª del Camino Fuertes Santos ◽  
...  

The archaeological site of Cercadilla (Cordoba, Spain) includes a complete chronological sequence from the 3rd to 12th centuries. The most relevant monument is a Roman palace dated between the end of the 3rd century and the beginning of the 4th century AD. It is believed that it was the headquarters of the Emperor Maximiano Herculeo. A bathtub with mural paintings has been found in the thermal zone of the palace. Regarding the occupation of the archaeological site in the medieval period, it should be pointed out that two houses with mural paintings were found; these belong to the Caliphal era (10th-11th centuries). During the Caliphal era, the archaeological site was mostly occupied by one of the large suburbs surrounding the walled city. Cercadilla was gradually abandoned; this process starts at the beginning of the 11th century. This study is focused on the analysis of pigments and preparatory layers of red and white mural paintings of the Roman period in the bath zone and on the analysis of pigments in mural paintings in two houses of the Caliphal era. In the thermal zone, the walls have a white mural painting with vertical and horizontal red bands, while the walls in the two Caliphal houses present the red mural painting decorated with white stripes. Techniques such as Optical Microscopy (OM), Scanning Electron Microscopy in combination with Energy Dispersive X-ray Microanalysis (SEM-EDX), X-ray Diffraction (XRD), micro X-ray Diffraction (μ-XRD), Wavelength Dispersive X-ray Fluorescence (WD-XRF), and Fourier Transform-Infrared Spectroscopy (FT-IR) have been used to study the mural paintings of this archaeological site. The results allowed to determine the composition of the materials used and to understand the differences between the technologies employed in Roman and Caliphal remains studied.


MRS Advances ◽  
2017 ◽  
Vol 2 (63) ◽  
pp. 3973-3981 ◽  
Author(s):  
Marcie B. Wiggins ◽  
Jocelyn Alcántara-García ◽  
Karl S. Booksh

ABSTRACTCopper-based pigments are common in works of art that show signs of decay on green and blue areas and are frequently associated with the degradation of organic substrates and/or media (drying oils, cellulose, etc.). The exact causes of degradation remain unknown. This prompted us to study possible starting and degradation products of one especially reactive copper pigment, verdigris (copper acetate), as well as pigments of the same family (salt and soap greens). Preparation of pigments using historical methods was followed by spectroscopic and crystallographic characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Synthesis of verdigris and verdigris-like pigments resulted in a mixture of starting polymorphs of verdigris, including neutral and basic verdigris. With accelerated aging, pigments degraded to a polymorph of basic verdigris when not affected by organic media, whereas pigments on cellulosic substrates showed oxidized copper species. With this study, we are beginning to understand verdigris starting materials and highlight the complex interactions between pigments and substrates that influence pigment degradation pathways.


2002 ◽  
Vol 712 ◽  
Author(s):  
C. Montoya ◽  
J. Lanas ◽  
M. Arandigoyen ◽  
I. Navarro ◽  
P.J. García Casado ◽  
...  

ABSTRACTTen ancient mortars of dolomitic origin, used in the construction of the church of Santa María de Zamarce in Navarre, Spain, have been studied in order to define their composition and to characterize the type of binder employed. A complete characterization has been carried out including: morphological examination (visually and using optical microscopy); mineralogical studies (X-ray diffraction, XRD); chemical analysis (main components and soluble salts); grain size distribution and thermal studies (thermogravimetric and thermodifferential simultaneous analysis, TGA-DTA). Dolomite and calcite, as binders, and quartz, as aggregate, have been found as the main phases. The important variability of the studied samples has confirmed that the choice of the raw materials and their preparation were not taken carefully. Thermal behavior of the samples has shown the endothermic peaks related to calcite and dolomite decarbonations. No hydromagnesite phases have been detected. Finally, the approximate indications of the original composition of the raw materials mixtures are presented.


1974 ◽  
Vol 20 (10) ◽  
pp. 1379-1386 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths

Electron-dense particles of melanin were located in ultrathin sections of: the hyphal walls of Amorphotheca resume; the aleuriospore walls of Epicoccum nigrum and Humicola grisea; the sclerotial walls of Colletotrichum coccodes; and both within and between the microsclerotial cell walls of Verticillium dahliae. Melanin was extracted with KOH from each of the fungi, but, because of rapid oxidation of the pigment in air, extraction and analysis was carried out under nitrogen. The pigments were examined spectrophotometrically under UV and IR radiation and by means of x-ray diffraction. Characterization of the melanin in terms of its degradation products indicated it to be indolic in nature. These results are compared with published data on other melanins extracted from animal and plant sources.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Komal Prasad Malla ◽  
Sagar Regmi ◽  
Achyut Nepal ◽  
Sitaram Bhattarai ◽  
Ram Jeewan Yadav ◽  
...  

A novel natural hydroxyapatite (HAp) bioceramic was extracted from the ostrich cortical bone by the thermal decomposition method. HAp was characterized by different analytical tools such as thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Removal of organic impurities from the bone powder was confirmed by TGA analysis. FTIR spectra of HAp confirmed the presence of the major functional groups such as phosphate (PO43−), hydroxyl (OH−), and carbonate (CO32−) in the bioceramic. The XRD data revealed that the HAp was the crystalline phase obtained by calcination of the bone powder at 950°C, and the SEM analyses confirmed the typical plate-like texture of the nanosized HAp crystals.


1978 ◽  
Vol 22 ◽  
pp. 65-76 ◽  
Author(s):  
D. Chandra ◽  
C. O. Ruud ◽  
C. S. Barrett ◽  
R. E. Siemens

To assure an adequate supply of such critical metals as nickel and chromium, extraction procedures must be developed to process low grade domestic sources. In optimizing these procedures it is essential to use suitable analytical procedures to characterize the materials, identify phase transformations, and determine metal and mineral association of the critical metallic elements through all stages of the process. Evaluation of complex sources such as laterites requires special material handling techniques coupled with X-ray diffraction and with optical and SEM analyses of many individual particles. A joint study by the Bureau of Mines and the Denver Research Institute using these procedures has resulted in optimizing a new modification of an extraction process.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.


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