scholarly journals Alexander Calder’s Half-Circle, Quarter-Circle, and Sphere (1932):A Complex History of Repainting Unraveled

2020 ◽  
Author(s):  
Federica Pozzi ◽  
Julie Arslanoglu ◽  
Eleonora Nagy
Keyword(s):  
New York ◽  
Cross Sections ◽  
Treatment Plan ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Drying Oil ◽  
Non Invasive ◽  
History Of ◽  
Titanium White

Abstract The Whitney Museum of American Art, New York, owns one of the largest motorized works made by the renowned American artist Alexander Calder, titled Half-Circle, Quarter-Circle, and Sphere. Created in 1932, and acquired by the Whitney in 1969, this seminal work was featured in an iconic exhibition held in 2017 and entitled Calder: Hypermobility. Prior to that, the object underwent a series of treatments in order to repair its main kinetic elements that had become compromised during its lifetime. While the work’s mechanism retained its creator’s ingenious engineering solutions, the motor, urethane belts, plug, and electrical wires turned out to be neither original, nor authentic to the period. The appearance of the piece had also been altered, as most surfaces displayed multiple layers of overpainting and, thus, did not deliver the proper gloss, hue, and texture. These observations prompted a first, comprehensive scientific study to investigate the stratigraphy of Calder’s painted surfaces on Half-Circle, Quarter-Circle, and Sphere, with the final goal to comprehend and restore its original appearance through careful removal of the overpaint. Non-invasive X-ray fluorescence (XRF) analysis was carried out to gain initial insight into the paints’ composition. After that, extensive microscopic sampling was performed to assess the possible presence of original layers below the repainting throughout the object’s surface. Cross sections were examined with optical microscopy and analyzed with Fourier-transform infrared (FTIR) and Raman spectroscopies, as well as scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), in order to identify pigments, colorants, and extenders located in the various paint layers. Scrapings were also investigated with pyrolysis – gas chromatography / mass spectrometry (Py-GC/MS) for a detailed characterization of the binding media. Scientific analysis revealed, in selected white and red areas, up to eleven layers of overpaint composed of a wide array of modern materials, including pigments (titanium white in the form of tetragonal rutile and a variety of synthetic organic red pigments) and binders (alkyd or late formulations of enamels based on ortho-phthalic acid / phthalic anhydride, glycerol and pentaerythritol, polyvinyl acetate with various plasticizers, and acrylics). On the other hand, the identification of materials that were available in the early 1930s, such as zinc white, calcite, and gypsum, as well as traditional drying oil binders, supported the hypothesis that a layer of original paint may still be present in certain areas. In addition to shedding new light on the stratigraphy of Calder’s painted surfaces, this study informed the optimization of a treatment plan tailored for the safe removal of the overpaint to uncover the original layer, wherever present.

scholarly journals Alexander Calder’s Half-Circle, Quarter-Circle, and Sphere (1932): A Complex History of Repainting Unraveled

2020 ◽  
Author(s):  
Federica Pozzi ◽  
Julie Arslanoglu ◽  
Eleonora Nagy
Keyword(s):  
New York ◽  
Cross Sections ◽  
Treatment Plan ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Drying Oil ◽  
Non Invasive ◽  
History Of ◽  
Titanium White

Abstract The Whitney Museum of American Art, New York, owns one of the largest motorized works made by the renowned American artist Alexander Calder, titled Half-Circle, Quarter-Circle, and Sphere. Created in 1932, and acquired by the Whitney in 1969, this seminal work was featured in an iconic exhibition held in 2017 and entitled Calder: Hypermobility. Prior to that, the object underwent a series of treatments in order to repair its main kinetic elements that had become compromised during its lifetime. While the work’s mechanism retained its creator’s ingenious engineering solutions, the motor, urethane belts, plug, and electrical wires turned out to be neither original, nor authentic to the period. The appearance of the piece had also been altered, as most surfaces displayed multiple layers of overpainting and, thus, did not deliver the proper gloss, hue, and texture. These observations prompted a first, comprehensive scientific study to investigate the stratigraphy of Calder’s painted surfaces on Half-Circle, Quarter-Circle, and Sphere, with the final goal to comprehend and restore its original appearance through careful removal of the overpaint. Non-invasive X-ray fluorescence (XRF) analysis was carried out to gain initial insight into the paints’ composition. After that, extensive microscopic sampling was performed to assess the possible presence of original layers below the repainting throughout the object’s surface. Cross sections were examined with optical microscopy and analyzed with Fourier-transform infrared (FTIR) and Raman spectroscopies, as well as scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), in order to identify pigments, colorants, and extenders located in the various paint layers. Scrapings were also investigated with pyrolysis – gas chromatography / mass spectrometry (Py-GC/MS) for a detailed characterization of the binding media. Scientific analysis revealed, in selected white and red areas, up to eleven layers of overpaint composed of a wide array of modern materials, including pigments (titanium white in the form of tetragonal rutile and a variety of synthetic organic red pigments) and binders (alkyd or late formulations of enamels based on ortho-phthalic acid / phthalic anhydride, glycerol and pentaerythritol, polyvinyl acetate with various plasticizers, and acrylics). On the other hand, the identification of materials that were available in the early 1930s, such as zinc white, calcite, and gypsum, as well as traditional drying oil binders, supported the hypothesis that a layer of original paint may still be present in certain areas. In addition to shedding new light on the stratigraphy of Calder’s painted surfaces, this study informed the optimization of a treatment plan tailored for the safe removal of the overpaint to uncover the original layer, wherever present.

scholarly journals Alexander Calder’s Half-Circle, Quarter-Circle, and Sphere (1932):A Complex History of Repainting Unraveled

2020 ◽  
Author(s):  
Federica Pozzi ◽  
Julie Arslanoglu ◽  
Eleonora Nagy
Keyword(s):  
New York ◽  
Cross Sections ◽  
Treatment Plan ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Drying Oil ◽  
Non Invasive ◽  
History Of ◽  
Titanium White

Abstract The Whitney Museum of American Art, New York, owns one of the largest motorized works made by the renowned American artist Alexander Calder, titled Half-Circle, Quarter-Circle, and Sphere. Created in 1932, and acquired by the Whitney in 1969, this seminal work was featured in an iconic exhibition held in 2017 and entitled Calder: Hypermobility. Prior to that, the object underwent a series of treatments in order to repair its main kinetic elements that had become compromised during its lifetime. While the work’s mechanism retained its creator’s ingenious engineering solutions, the motor, urethane belts, plug, and electrical wires turned out to be neither original, nor authentic to the period. The appearance of the piece had also been altered, as most surfaces displayed multiple layers of overpainting and, thus, did not deliver the proper gloss, hue, and texture. These observations prompted a first, comprehensive scientific study to investigate the stratigraphy of Calder’s painted surfaces on Half-Circle, Quarter-Circle, and Sphere, with the final goal to comprehend and restore its original appearance through careful removal of the overpaint. Non-invasive X-ray fluorescence (XRF) analysis was carried out to gain initial insight into the paints’ composition. After that, extensive microscopic sampling was performed to assess the possible presence of original layers below the repainting throughout the object’s surface. Cross sections were examined with optical microscopy and analyzed with Fourier-transform infrared (FTIR) and Raman spectroscopies, as well as scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), in order to identify pigments, colorants, and extenders located in the various paint layers. Scrapings were also investigated with pyrolysis – gas chromatography / mass spectrometry (Py-GC/MS) for a detailed characterization of the binding media. Scientific analysis revealed, in selected white and red areas, up to eleven layers of overpaint composed of a wide array of modern materials, including pigments (titanium white in the form of tetragonal rutile and a variety of synthetic organic red pigments) and binders (alkyd or late formulations of enamels based on ortho-phthalic acid / phthalic anhydride, glycerol and pentaerythritol, polyvinyl acetate with various plasticizers, and acrylics). On the other hand, the identification of materials that were available in the early 1930s, such as zinc white, calcite, and gypsum, as well as traditional drying oil binders, supported the hypothesis that a layer of original paint may still be present in certain areas. In addition to shedding new light on the stratigraphy of Calder’s painted surfaces, this study informed the optimization of a treatment plan tailored for the safe removal of the overpaint to uncover the original layer, wherever present.

scholarly journals Unmasking a wild man: scientific analysis of Bertoldo di Giovanni’s Shield Bearer in The Frick Collection

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Elena Basso ◽  
Federica Pozzi ◽  
Julia Day ◽  
Linda Borsch
Keyword(s):  
New York ◽  
Current Knowledge ◽  
Analytical Techniques ◽  
Gas Chromatography Mass Spectrometry ◽  
Italian Renaissance ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Select Group ◽  
Scientific Analysis ◽  
Wild Man

Abstract Bertoldo di Giovanni (ca. 1440–1491) was the primary sculptor and medal worker for Lorenzo the Magnificent (1449–1492). Despite being one of the most prominent Italian Renaissance artists working in Florence, little is known about his workshop and practice. The Frick Collection, New York, owns a Shield Bearer, one of a small number of bronze statuettes attributed to Bertoldo predominantly based on stylistic grounds. This article presents the results obtained from the scientific analysis of The Frick statuette, including a detailed technical characterization of the casting alloy, gilding, solder, organic coatings, and other later alterations. An array of analytical techniques was employed, including X-radiography, micro- and portable X-ray fluorescence (μXRF and pXRF) spectroscopies, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), Raman and Fourier-transform infrared (FTIR) spectroscopies, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). This work supported a larger technical study of Bertoldo’s statuettes and reliefs related to an exhibition organized by The Frick, which brought together a select group of medals, as well as eleven bronzes ascribed to the artist, including the museum’s statuette. Close collaboration between conservators, curators, and scientists was critical throughout the study of the Shield Bearer, which also included extensive visual examination of the object in order to understand details of manufacture, identify sampling sites, and interpret the collected data. This study confirmed that The Frick figure was cast from the same brass alloy as a second very similar Shield Bearer in the Liechtenstein Collection, Vienna, suggesting that the two are a pendant pair that was likely cast simultaneously. In addition, analysis supported the assertion that the copper base on The Frick sculpture is original and assisted in identifying later alterations in both works. This focused research has expanded the current knowledge of the sculptor’s materials and methods, enabling scholars to better contextualize his artistic production within the framework of Italian Renaissance sculpture.

scholarly journals Maximizing Anhydrosugar Production from Fast Pyrolysis of Eucalyptus Using Sulfuric Acid as an Ash Catalyst Inhibitor

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 609 ◽  
Author(s):  
Dongyan Zhang ◽  
Yuyang Fan ◽  
Anqing Zheng ◽  
Zengli Zhao ◽  
Fengyun Wang ◽  
...  
Keyword(s):  
Rank Order ◽  
Maximum Yield ◽  
Fast Pyrolysis ◽  
Value Added ◽  
Gas Chromatography Mass Spectrometry ◽  
Cellulose Content ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Theoretical Yield ◽  
Pure Cellulose

Anhydrosugars, such as levoglucosan (LG), are high value-added chemicals which are mainly derived from fast pyrolysis of pure cellulose. However, fast pyrolysis of raw lignocellulosic biomass usually produces a very low amount of levoglucosan, since alkali and alkaline earth metals (AAEM) present in the ash can serve as the catalysts to inhibit the formation of levoglucosan through accelerating the pyranose ring-opening reactions. In this study, eucalyptus was impregnated with H2SO4 solutions with varying concentrations (0.25–1.25%). The characteristics of ash derived from raw and H2SO4-impregnated eucalyptus were characterized by X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). The pyrolysis behaviors of raw and H2SO4-impregnated eucalyptus were performed on the thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG analysis demonstrated that the H2SO4-impregnated eucalyptus produced less char than raw eucalyptus. Py-GC/MS analysis showed that even small amounts of H2SO4 can obviously improve the production of anhydrosugars and phenols and suppressed the formation of carboxylic acids, aldehydes, and ketones from fast pyrolysis of eucalyptus. The rank order of levoglucosan yield from raw and impregnated eucalyptus was raw < 1.25% H2SO4 < 1% H2SO4 < 0.75% H2SO4 < 0.25% H2SO4 < 0.5% H2SO4. The maximum yield of levoglucosan (21.3%) was obtained by fast pyrolysis of eucalyptus impregnated with 0.5% H2SO4, which was close to its theoretical yield based on the cellulose content. The results could be ascribed to that H2SO4 can react with AAEM (e.g., Na, K, Ca, and Mg) and lignin to form lignosulfonate, thus acting as an inhibitor to suppress the catalytic effects of AAEM during fast pyrolysis of eucalyptus.

Nitrogen Configuration of Polybenzoxazine Carbide

2015 ◽  
Vol 34 (3) ◽  
Author(s):  
Huachuan Zhang ◽  
Wu Gu ◽  
Rongqi Zhu ◽  
Qichao Ran ◽  
Yi Gu
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Carbon Materials ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Amine Nitrogen ◽  
X Ray ◽  
Pyrolysis Gas Chromatography ◽  
First Time ◽  
Pyridinic Nitrogen

AbstractCarbon materials should have specific centers for its functionalities. In this study, the specific centers of polybenzoxazine carbides were studied for the first time. Three classical benzoxazine monomers were chose as the object. The transformation of nitrogen configuration of polybenzoxazines carbides was characterized via pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and X-ray photoelectron spectroscopy (XPS). The results showed that the tertiary amine nitrogen converted to pyridinic nitrogen and pyrrolic nitrogen incorporated in graphene residuals during the carbonization, which were the specific centers for the functionality.

A nonlethal approach using strontium in scales to distinguish periods of marine and freshwater residency of anadromous species

2005 ◽  
Vol 62 (11) ◽  
pp. 2443-2449 ◽  
Author(s):  
David A Courtemanche ◽  
Frederick G Whoriskey, Jr. ◽  
Valerie Bujold ◽  
R Allen Curry
Keyword(s):  
Cross Sections ◽  
Electron Microprobe ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Cost Effective ◽  
Anadromous Fish ◽  
Migration Patterns ◽  
X Ray ◽  
History Of ◽  
Scale Surface

Spatiotemporal migration patterns of brook trout (Salvelinus fontinalis) and various other anadromous fish are poorly understood in many rivers of North America. A new, nonlethal approach to investigate these movements using analysis of scale microchemistry was developed that is relatively simple, cost effective, and potentially more accurate than other monitoring techniques. As fish grow, their scales incorporate in the calcified matrix different concentrations of trace elements present in ambient waters. Seawater Sr concentrations are 10–100 times higher compared with fresh water; thus, a higher Sr/Ca ratio in circulii corresponding to periods of life in seawater would be predicted. We used a wavelength-dispersive X-ray electron microprobe to assess Sr/Ca ratios along sagittal cross sections of scales, spanning the life history of a fish. We demonstrate that existing wavelength-dispersive X-ray electron microprobe studies using Sr analysis may suffer inaccuracies related to scale surface topography, and using the alternative embedding and cutting technique increases significantly the precision of Sr/Ca readings.

Study of Colonial Manuscripts from San Nicolás Coatepec, México, Through UV&IR Imaging and XRF

2012 ◽  
Vol 1374 ◽  
pp. 17-25
Author(s):  
Jocelyn Alcántara García ◽  
José Luis Ruvalcaba Sil ◽  
Marie Van der Meeren
Keyword(s):  
Imaging Techniques ◽  
High Sensitivity ◽  
X Ray ◽  
Historical Material ◽  
Qualitative And Quantitative ◽  
Non Invasive ◽  
History Of ◽  
Material Information ◽  
Non Destructive ◽  
Suitable Technique

ABSTRACTThe necessity of studying cultural heritage through non-invasive and non-destructive techniques has led to significant advances in the last decade. One of the most recent advancements in this theme in Mexico is the portable X-ray system SANDRA, which was used to study three manuscripts directly related to the history of “San Nicolás Coatepec”, Mexico. X-ray fluorescence was chosen as the suitable technique because it can provide a fast qualitative and quantitative multielemental high sensitivity analysis. The documents were examined globally, using imaging techniques with UV and IR lighting. This research evinced a change in the composition and evolution of writing materials (inks and pigments) and provided information concerning historical use of the documents and its actual legal value as a property document. It also stressed the need of spanning these results to an extensive research attaining other regions of Mexico, in order to fully understand the Mexican documents particularities, aging and deterioration. This, in turn, will provide not only historical material information but also an invaluable scoop to understand deterioration and conservation issues.

scholarly journals A pioneer of acrylic painting: new insights into Carmen Herrera’s studio practice

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Federica Pozzi ◽  
Elena Basso ◽  
Silvia A. Centeno ◽  
Isabelle Duvernois ◽  
Julie Arslanoglu
Keyword(s):  
New York ◽  
Treatment Plan ◽  
Scientific Study ◽  
Second Phase ◽  
Color Palette ◽  
Tetragonal Form ◽  
Studio Practice ◽  
Post War ◽  
Titanium White ◽  
Acrylic Paints

AbstractCarmen Herrera, born on May 30th, 1915, is a Cuban American abstract minimalist artist, whose first solo show was held at the Whitney Museum of American Art, New York, in 2016–2017. On this occasion, a scientific study of five paintings from the artist’s time in Paris (1948–1953) revealed her pioneering use of solvent-based acrylic paints in post-war Europe. This article presents a second phase of research into Herrera’s work aiming to shed light on her studio practice and ascertain the possible presence of other early acrylic paints in her pre-1963 artistic production. A selection of four paintings, namely Iberia #25 (1948), Iberic (1949), Flights of Colors #16 (1949), and Early Dynasty (1953), was subjected to an analytical campaign that relied on both non-invasive and micro-invasive techniques. Results confirmed the use of both oil and solvent-based acrylic paints, supporting our primary research and uncovering the first-known occurrence of acrylic binders in Herrera’s Iberia #25. In all cases, the ground layer consists of a mixture of titanium white in its tetragonal form of rutile, anhydrite, and talc, while the color palette was found to be based on both traditional and modern pigments. In most areas, several paint layers appeared to be overlaid on top of one another, revealing a creative process that developed through subsequent compositions. Remnants of earlier paint layers, which appeared to have been scraped off before new ones were applied, were observed directly above the ground in some of the samples examined. In addition, Iberia #25 and Iberic, with analogous geometric and chromatic schemes, underwent technical imaging, which exposed pencil lines and notes underneath the paint layers likely indicative of the intended design and polychromy. Besides corroborating a major alteration in the current scholarship on the availability and use of acrylic-based artists’ paints in post-war Europe, this research provides new insights into Herrera’s materials, techniques, and studio practice. In addition, the results of this scientific study assisted the development of a suitable treatment plan for Iberic in preparation for its display in The Metropolitan Museum of Art’s galleries as part of the museum’s 150th anniversary exhibition Making The Met, 1870–2020.

scholarly journals Organic Matter and Pigments in the Wall Paintings of Me-Taw-Ya Temple in Bagan Valley, Myanmar

2021 ◽  
Vol 11 (23) ◽  
pp. 11441
Author(s):  
Maria Letizia Amadori ◽  
Valeria Mengacci ◽  
Manuela Vagnini ◽  
Antonella Casoli ◽  
Parviz Holakooei ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Polarized Light ◽  
Pilot Project ◽  
Energy Dispersive ◽  
Gas Chromatography Mass Spectrometry ◽  
Environmental Scanning ◽  
Wall Paintings ◽  
X Ray ◽  
Non Invasive ◽  
Ancient City

Pagán is an ancient city located in Myanmar that is renowned for the remains of about 4000 pagodas, stupas, temples and monasteries dating from the 11th to 13th centuries. Due to a magnitude 6.8 earthquake in 2016, more than 300 ancient buildings were seriously damaged. As a part of the post-earthquake emergency program, a diagnostic pilot project was carried out on Me-taw-ya temple wall paintings to acquire further information on the materials and on their state of conservation. This article presents our attempts at characterising the painting materials at Me-taw-ya temple using non-invasive portable energy dispersive X-ray fluorescence (ED-XRF), portable Raman spectroscopy and micro-invasive attenuated total reflectance—Fourier transform infrared spectroscopy (ATR-FTIR), micro-Raman spectroscopy (µ-Raman), gas chromatography-mass spectrometry (GC-MS), polarized light microscopy (PLM) and environmental scanning electron microscope—X-ray energy dispersive system (ESEM-EDS) investigations with the aim of identifying the composition of organic binders and pigments. The presence of a proteinaceous glue mixed with the lime-based plaster was ascertained and identified by GC-MS. In addition, this technique confirmed the occurrence of plant-derived gums as binders pointing to the a secco technique. Fe-based compounds, vermillion, carbon black and As-compounds were identified to have been incorporated in the palette of the murals.

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