Visualising Iron Gall Ink Underdrawings In 16th Century Paintings In-Situ By Micro-XRF Scanning (MA-XRF) And LED-Excited IRR (LEDE-IRR)

Until today, iron gall ink is classified as an exceptional underdrawing material for paintings. A certain identification is always based on invasive analysis. This article presents a new non-destructive analysis approach using micro-X-ray fluorescence scanning (MA-XRF), LED-excited IRR (LEDE-IRR) using a narrow wavelength-range of infrared radiation (IR) and stereomicroscopy for visualising and identifying iron gall ink underdrawings. To assess possibilities and limits of this non-invasive approach, results were compared to invasive examinations on cross-sections using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). The approach is tested on panel paintings of Hans Holbein the Elder and Giovanni Battista Cima da Conegliano. The holistic setup could successfully visualise underdrawing lines made with iron gall inks, which formerly remained invisible by means of conventional IRR. For the first time, a direct access to a formerly invisible type of underdrawing is created, allowing to harness the whole iron gall ink underdrawing for interdisciplinary studies.

CHARACTERISTIC OF XONOTLITE SYNTHESIZED BY HYDROTHERMAL REACTION USING RICE HUSK ASH AND ITS APPLICATION TO ABSORB CHROME (III) SOLUTION

In this paper, we report on synthesizing xonotlite, calcium silicate hydrate (CSH), via a hydrothermal reaction using rice husk from the Mekong Delta, Vietnam. The rice husks were burnt at 1000 °C for 3 h. Grey rice husk ash was collected, then mixed with Ca(OH)2 at a Ca/Si molar ratio of 1 : 1. This was followed by a hydrothermal reaction at 180 °C for 24 h and 48 h to obtain the xonotlite mineral. Before and after adsorption, 3-mm xonotlite pellets were thoroughly characterized using X-ray diffractometry (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy. This material has potential application in chromium(III) removal during a chrome-plating process. The adsorption efficiency of the 3-mm pellet samples reached more than 76 % after 12 h.

Portrait of an Etruscan Athletic Official: A Multi-Analytical Study of a Painted Terracotta Wall Panel

The Getty’s Etruscan painted terracotta wall panel, Athletic Official, recently has been speculated to be associated with a Caeretan wall panel depicting a Discobolus based on a shared iconography. To better understand the materials and techniques used to create the Getty panel and investigate its relation to extant Etruscan painted terracotta panels, a multi-analytical study was conducted, using broadband visible, IR, and UV imaging, along with scanning MA-XRF, FORS, Raman, SEM-EDS, and XRD analytical techniques. The analytical results together with PCA analysis suggest the clay support of the Getty panel is most similar in composition to that of panels from Cerveteri. A manganese black was identified in the decorative scheme; not commonly employed, this appears to be an important marker for the workshop practice in Cerveteri. Most significantly, the use of MA-XRF scanning allowed for invisible ruling lines on the Athletic Official, presumably laid down at the earliest stages of the creation of the panel, to be visualized. Taken together, the results of this study provide new insights into Caeretan workshop practice as well as provide a framework for better understanding the design and execution of Etruscan polychromy.

Synergetic CT, XRF and Geoelectric Imaging for Non-Destructive Soil and Sediment Stratigraphic Study

This paper presents the application of three non-destructive techniques in the study of an agricultural area on the west coast of Peloponnese, Greece. The applied methods include (a) electromagnetic geophysical research using a handheld EM profiler (EMP-400 GSSI), (b) computed tomography (CT) with coring data, and (c) X-ray Fluorescence (XRF) scanning. As electrical conductivity is mainly influenced by the bulk soil, including water content, clay content and mineralogy, organic matter, and bulk density, a comparison of the three applied techniques indicates the same soil stratification and same soil properties with depth. Moreover, the ground-truthing by the undisturbed soil and sediments core retrieved in the centre of the site as well as the laboratory analyses of soil and sediment properties confirm the reliability of the geophysical research and the revealed soil/sediment stratification.

XRF Imaging (MA-XRF) as a Valuable Method in the Analysis of Nonhomogeneous Structures of Grisaille Paint Layers

Stained glass paint layers made with vitreous paints can be a challenging subject for analyses. Their heterogenic structure requires proper experimental methodology in order to obtain valuable data. The main goal of this paper is to present the advantages of macro-XRF scanning (MA-XRF) in the non-destructive investigation of historical grisaille paint layers on the basis of research conducted on seven stained glass panels from the Dominican Monastery in Kraków, the Diocesan Museum in Kielce and the National Museum in Poznań (Poland). The obtained results showed the capabilities of MA-XRF scanning in technology recognition, the legibility of damaged fragments of painted depictions, as well as with distinguishing the elemental composition between vitreous paints in different colours. Additionally, SEM-EDS measurements are presented so as to acquire quantitative results and additional information concerning light elements.

Plasma Technology for Phosphogypsum Treatment

The phosphate industry generates a large amount of waste called phosphogypsum (PG). Generally, this waste is discharged without any treatment, and it causes considerable environmental problems. Hence, the objective of this study is the treatment of phosphate waste using thermal plasma technology. First, the waste is characterized using different techniques, such as X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and inductively coupled plasma (ICP). Such characterization shows that the waste contains different toxic elements, such as heavy metals, fluorine, chlorine, sulfur, and phosphorus. For this reason, a plasma reactor is used to separate toxic elements from metals, such as silicon, aluminum, and magnesium, with a pyrolysis/combustion plasma system. In this work, the influence of different parameters, such as time of treatment and plasma current, on the volatility of toxic elements is studied. The obtained results show that after 40 min of treatment and at a plasma current of 160 A, the phosphogypsum completely melts, and the most toxic elements, namely Pb, Cd, V, Cr, and As, are completely vaporized.

DE Fluoridation of Domestic Waste Water by using Activated Diatomaceous Earth in fixed Mattress Column Adsorption System

Study aims to eliminate fluoride from treated waste water or ground water through adsorption technique by using Activated Diatomaceous Earth as a sorbent. Study found that there is no change in pH and TDS, but the concentration of Fluoride ions reduced. The most elimination potential of 71.97 mg/kg turned into achieved for activated diatomaceous earth with particle sizes of 0.075-0.425 mm. The absorbance capability of diatomaceous earth (DE) is 20.73% when used as a filtration media. In this analysis, activated diatomaceous earth was used as an adsorbent in a fixed-mattress column adsorption system for DE fluoridation of water. The XRD, BET surface area, FTIR, XRF, Scanning Electron Microscopy (SEM), and pH Point of Zero Charges (pHPZC) evaluation had been executed for adsorbent to explain the mechanisms of absorption and fluoride elimination. The Bradley equation was used to calculate the isothermal data and adsorbent dose. The statistical analyses were performed using Langmuir and Freundlich equations.

Synthesis and Characterization of Biosilica from Rice Husks as a Catalyst for the Production of Biodiesel

The synthesis of silica particles from rice husk is a research based on natural materials and is classified as green material. Preparation of biosilica catalyst from calcined rice husk ash was carried out by the hydrothermal method using rice husk ash mixed with NaOH solution at a ratio of 1:5 (w/v) with the reaction temperature of 110-120°C, the pressure of 0.15-0.2 MPa for 15-30 minutes. Biosilica results are then continued with the calcination process at a temperature of 200-500°C for one hour. Biosilica with calcination is then compared to biosilica without calcination. These two kinds of biosilica are then characterized to determine their performance. The biosilica characteristic test that was carried out included X-Ray Fluorescence (XRF), Scanning Electron Microscopy(SEM), and Brunauer-Emmett-Teller (BET). The XRF test results show that biosilica with calcination process has higher silica and silica oxide content than that without calcination. The surface morphology of biosilica with calcination and without calcination gives an uneven surface and consists of lumps and with uneven distribution on the surface of the biosilica sample. Biosilica with calcination process has a larger surface area, pore volume, and radius than biosilica without calcination process.

Using CT scans to count varves in lake sediments. Application to Lake Sagtjernet, southeastern Norway

<p>Annually laminated sediments, also called varves, are valuable natural archives to reconstruct past environments and climate. Until now, the most common and reliable procedure to count varves has been to produce overlapping thin sections of the entire sediment sequence and counting in the microscope — a process that can take months to complete. Replacing this laborious method has been a long ongoing process within the varve community, and a task that we now may be getting with advancements in analytical tools. This study assesses the use of CT scanning to produce varve chronologies, applying it to the ferruginous sediments of Lake Sagtjernet in southeastern Norway — the first non-glacial varved lake sediment sequence in Norway continuously covering the last 4300 years.</p><p>Microfacies analyses of the sediments show that the varves are formed by cyclical deposition of iron and manganese. Oxygen measurements through 2013-2014 show permanent anoxic bottom waters while the seasonal turnover only reaching a depth of c. 6 m (out of a total 12 m depth). Combined with measurements of iron from the water column (highly enriched in the bottom waters) we suggest to classify Lake Sagtjernet as a ferruginous meromictic lake.</p><p>Varve counting on CT scans resulted in a 4300-year chronology, which we compared to an independent radiocarbon chronology (based on 17 <sup>14</sup>C dates, radionuclide and <sup>210</sup>Pb analyses). Our results show that all of the varve ages fall within the 95% confidence interval of the radiocarbon chronology. However, some sections of the sediments with lower concentrations of iron and manganese illustrate vague boundaries between laminae in the CT scans — increasing age uncertainties in the chronology. These age uncertainties can be reduced by using XRF scanning or thin sections in parallel with CT scans to evaluate the boundaries. Based on these results, we conclude that CT scanning is a fast and non-destructive method for producing varve chronologies.</p>