Conservation of Volcanic Tuffs Bearing Rock Paintings at La Pintada, Sonora Archaeological Site

2014 ◽  
Vol 1618 ◽  
pp. 195-205
Author(s):  
S. Cruz ◽  
N. A. Pérez ◽  
J. Cárdenas ◽  
J. R. Vidal-Solano ◽  
L. Alatorre
Keyword(s):  
Color Change ◽  
Archaeological Site ◽  
X Ray Diffraction ◽  
Volcanic Tuff ◽  
Weathering Processes ◽  
Conservation Treatment ◽  
Indigenous Groups ◽  
Petrographic Analyses ◽  
Alumino Silicate ◽  
Rock Paintings

ABSTRACTThe Archaeological Site La Pintada is located near Hermosillo, Sonora, Mexico; this is one of the most important sites in the region due to its extension and wide archaeological evidence. This site was a gathering point for various indigenous groups since the pre-Hispanic age to the first contacts with the Spanish conquerors; they left their live experiences and worldview in the form of rock paintings along a wide natural canyon. Several of these paintings are in risk due to weathering processes of their rock support: the volcanic tuff.In order to preserve these paintings the characterization of the volcanic tuff was made with petrographic analyses and X-Ray Diffraction, and among with the results obtained from environmental monitoring, different degrees of alteration were established. According to these results, the conservation treatment proposed was the consolidation of the tuff.The consolidants used for this treatment were alkoxysilanes in two variations: Silicate and alumino-silicate which were developed in Mexico for volcanic tuff consolidation. The consolidants were synthetized in the laboratory, and afterwards were tested on powders and cubic probes of the rock in Hermosillo’s environmental conditions (24°C, 45%RH).The consolidants were tested in two different types of application: aspersion and injection. The consolidated probes were evaluated for hardness, water absorption and color change. Afterwards, in situ tests were performed. The results of this evaluation showed that the Silicate consolidant was the best for this treatment, since it was easy to manipulate, improved the rock’s properties and did not cause a change appearance; making this Mexican material suitable for the conservation of the rock paintings.

scholarly journals Green Synthesis and Characterization of Copper Nanoparticles Using Fortunella margarita Leaves

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4364
Author(s):  
Rutaba Amjad ◽  
Bismillah Mubeen ◽  
Syed Shahbaz Ali ◽  
Syed Sarim Imam ◽  
Sultan Alshehri ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Color Change ◽  
Metal Oxide Nanoparticles ◽  
Visual Observation ◽  
X Ray Diffraction ◽  
Synthesis Of Nanoparticles ◽  
Characteristic Absorption Peak ◽  
Bluish Green ◽  
Dark Green

The use of biomaterials in the synthesis of nanoparticles is one of the most up-to-date focuses in modern nanotechnologies and nanosciences. More and more research on green methods of producing metal oxide nanoparticles (NP) is taking place, with the goal to overcome the possible dangers of toxic chemicals for a safe and innocuous environment. In this study, we synthesized copper nanoparticles (CuNPs) using Fortunella margarita leaves’ extract, which reflects its novelty in the field of nanosciences. The visual observation of a color change from dark green to bluish green clearly shows the instant and spontaneous formation of CuNPs when the phytochemicals of F. margarita come in contact with Cu+2 ions. The synthesis of CuNPs was carried out at different conditions, including pH, temperature, concentration ratio and time, and were characterized with UV-Vis absorption spectra, scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis analysis reveals the surface plasmon resonance property (SPR) of CuNPs, showing a characteristic absorption peak at 679 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm.

scholarly journals Análise e Avaliação dos Problemas Existentes na Fachada de Arenito do Museu Júlio de Castilhos, Porto Alegre, RS

2007 ◽  
Vol 34 (1) ◽  
pp. 63
Author(s):  
VERÔNICA DI BENEDETTI ◽  
RUY PAULO PHILIPP ◽  
ROBERTO SACKS DE CAMPOS
Keyword(s):  
Chemical Deposition ◽  
Alkali Feldspar ◽  
Mineralogical Composition ◽  
Granitic Rocks ◽  
Porto Alegre ◽  
Urban Architecture ◽  
Weathering Processes ◽  
Military Engineer ◽  
Petrographic Analyses ◽  
The City

The Júlio de Castilhos museum of Porto Alegre, formerly used as residence, was built in 1877 by a military engineer Catão Roxo. This building is one of the few examples of urban architecture from the last part of the nineteenth century. Its façade is covered by arenitic and granitic rocks quarried near the city. The covering shows the effects of weathering processes occurred during many years. Some of these were observed during a façade mapping as loss of rocky materials, discoloration, chemical deposition, desintegration and fracturing. Petrographic analyses of the arenite indicate an arcosean composition, rich in quartz, with plagioclase and alkali-feldspar (microcline) and opaque minerals in lesser amounts. The grains have a fine layer of iron oxide (hematite) clad, with a fringe of siliceous cement. The remained pores are filled by clay minerals, mainly illite. The elevated degree of compactation and diagenesis are responsible for the high coherence of the rock, allowing its use as covering rock. The petrographic features (textures and mineralogical composition) indicate that the arenites used on the façade’s museum, comes from the Botucatu Formation. The recognition of the mineral constituents and the knowledge of regional geology allow the façade’s recuperation through the replacing of unrecoverable pieces by new ones.

Comparative Spectroscopic Analysis of Maya Wall Paintings from Ek’Balam, Mexico

2014 ◽  
Vol 1618 ◽  
pp. 63-72 ◽  
Author(s):  
A. Alonso ◽  
N. A. Pérez ◽  
J. L. Ruvalcaba Sil ◽  
E. Casanova ◽  
P. Claes ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Analytical Techniques ◽  
Archaeological Site ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Invasive ◽  
Yellow Orange ◽  
Pigment Distribution ◽  
The Rich ◽  
Invasive Techniques

ABSTRACTThe Maya archaeological site of Ek’Balam is located in Yucatán, Mexico. This place is known for its artistic tradition of reliefs modeled in stucco as well as the rich pictorial and hieroglyphic texts. Although the mural played a key role in the artistic program architectural of elite groups, most of these remains have not been studied, either by its incomplete or fragile condition, or by localization in inaccessible substructures.In this study, technical aspects of the mural paintings from rooms 12 and 50 of the main building of the site are addressed by the spectroscopic analysis of its materials. Optical microscopy was used to observe the layers superposition and pigment distribution, while the stucco and rock support were characterized by X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). Moreover, the chromatic palette composed of different colors and tones of red, yellow, orange, green, blue and black were analyzed mainly with non-invasive techniques using Raman and FTIR spectroscopies as well as XRF.The information obtained from the combination of these analytical techniques, allowed a better understanding of the similarities and differences between these two rooms that were built during the last construction stage of the Acropolis. These results were also compared with previous analyses of mural painting of this site and other Maya paintings.

scholarly journals Archaeometric Characterisation of Decorated Pottery from the Archaeological Site of Villa dei Quintili (Rome, Italy): Preliminary Study

Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 172 ◽  
Author(s):  
Michela Ricca ◽  
Giuseppe Paladini ◽  
Natalia Rovella ◽  
Silvestro Antonio Ruffolo ◽  
Luciana Randazzo ◽  
...  
Keyword(s):  
Multidisciplinary Approach ◽  
Raw Materials ◽  
Archaeological Site ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geochemical Study ◽  
Renaissance Period ◽  
Preliminary Study ◽  
Materials Used

This work focused on the study of decorated pottery dated back to the 16th century from the Roman archaeological site of Villa dei Quintili, a monumental complex located in the south-eastern part of Rome (Italy). A minero-petrographic and geochemical study was undertaken to analyse five archaeological samples in order to define textural features and raw materials used for their production, along with the chemical and physical composition of the superficial decorative glazed coatings. For this purpose, different analytical methods were used, such as polarising optical microscope (POM), X-ray diffraction (XRD), micro-Raman spectroscopy, X-Ray fluorescence (XRF), and electron microprobe analysis coupled with energy dispersive spectrometry (EMPA-EDS). The results of such a multidisciplinary approach allowed us to achieve important results crucial to recognise the shards as majolica of the Renaissance period, improving knowledge about manufacturing processes of these renowned painted ceramic artefacts.

scholarly journals Effect of Various Parameters on Bio-Synthesis of Copper Nanoparticles Using Citrus Medica Linn (Lemon) Extract and Its Antibacterial Activity

2020 ◽  
Vol 1 (1) ◽  
pp. 51-58
Author(s):  
Sharmila Pradhan ◽  
Rajeswori Shrestha ◽  
Khuma Bhandari
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Color Change ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Crystalline Nature ◽  
Bio Synthesis

This research is focused on bio-synthesis of Copper nanoparticles (CuNPs) using lemon extract to study the effect of various parameters on synthesis and to explore antibacterial activity. The biomolecules present in lemon extract act as self reducing and stabilizing agent. The synthesis of CuNPs was found to be affected by various parameters like volume of the lemon extract, concentration of the precursor and the temperature etc. Preliminary characterization of formation of nanoparticles were done by color change and UV-visible (UV-vis) spectroscopy. Elemental composition of the prepared sample was determined via Energy Dispersive X-ray (EDX) Spectroscopy. Presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM ) revealed the formation agglomerated CuNPs of different shape and sizes and the X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs. Finally, agar well diffusion method showed that CuNPs have potential antibacterial activity against Gram-ve bacteria compared to Gram +ve bacteria.

scholarly journals Hybrid nanocomposites made of diol-modified silanes and nanostructured calcium hydroxide. Applications to Alum-treated wood

2017 ◽  
Vol 89 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Fabrizio Andriulo ◽  
Rodorico Giorgi ◽  
Calin Constantin Steindal ◽  
Hartmut Kutzke ◽  
Susan Braovac ◽  
...  
Keyword(s):  
Calcium Hydroxide ◽  
Structural Integrity ◽  
Treated Wood ◽  
Single Step ◽  
Hybrid Nanocomposites ◽  
Viking Age ◽  
X Ray Diffraction ◽  
Conservation Treatment ◽  
Starting Point ◽  
Gas Chromatography Mass Spectroscopy

AbstractThe alum-treated Viking Age archaeological wooden objects from the Oseberg find have undergone extensive chemical deterioration due to the original conservation treatment, based on alum salts (KAl(SO4)2·12H2O), done in the early 1900s. Today, the artifacts are highly acidic (pH≤2) and fragile; in some cases wood has almost completely lost its structural integrity. Research on conservation methods for these finds is currently underway. In the present study, organic/inorganic multi-functional ‘hybrid systems’ – using propylene glycol modified TEOS and alkaline nanoparticles (Ca(OH)2) – have been engineered to deacidify and consolidate alum-treated wood in a single step. The advantage of using silicon monomer and nano-materials as a starting point resides in their ease of penetration into the wood structure, where silicon monomers subsequently undergo polymerization. Treated samples were investigated using thermal analysis (DTG), X-Ray Diffraction (XRD), infrared spectroscopy (ATR-FTIR), SEM/EDX and Gas Chromatography Mass Spectroscopy (GC-MS). Results suggest that in addition to consolidating the wood, alkoxysilanes could act as a bridging agent between remaining lignin and calcium hydroxide nanoparticles.

scholarly journals Effect of Recycled Ceramic Waste Content on the Properties of Unsaturated Polyester Resin

2019 ◽  
Author(s):  
Mohamed Farsane ◽  
Abdellah Anouar ◽  
Souad Chah ◽  
Miloudi Bouzziri
Keyword(s):  
Polyester Resin ◽  
Mechanical Performance ◽  
Color Change ◽  
Filler Content ◽  
Unsaturated Polyester ◽  
Unsaturated Polyester Resin ◽  
Physical Parameters ◽  
X Ray Diffraction ◽  
Ceramic Waste ◽  
Waste Particles

In this study, the properties of unsaturated polyester resin were studied in the presence of recycled ceramic waste particles. Herein, composites were created that contained 28.5-50 wt% porcelain particles (particle size <180 µm). High filler contents increased the gel time and decreased the exotherm temperature of unsaturated polyester resin during curing. The obtained results showed that physical parameters, such as the resin density and porosity, increased as the filler content increased. In addition, the X-ray diffraction results indicated that the produced samples were a combination of ceramic waste particles and unsaturated polyester resin, resulting in semi crystalline structure. The results showed that the maximum water absorption at 40°C increased from 0.97 to 1.5% as the filler content increased from 28.5 to 50 wt%; in this process, the materials experienced a color change but did not lose mechanical performance. Finally, the samples were characterized by thermogravimetric analysis (TGA) to study the effect of porcelain powder on the thermal degradation of the resin. The TGA scans were analyzed with the Friedman method. The results indicated that the samples with porcelain powder exhibited substantially better thermal stability than unsaturated polyester resin.

scholarly journals Effect of Recycled Ceramic Waste Content on the Properties of Unsaturated Polyester Resin

2021 ◽  
Vol 58 (3) ◽  
pp. 174-185
Author(s):  
Mohamed Farsane ◽  
Khalid Saadouni ◽  
Soufia Lhasnaoui ◽  
Aziz Akhiate ◽  
Abdellah Anouar ◽  
...  
Keyword(s):  
Polyester Resin ◽  
Mechanical Performance ◽  
Color Change ◽  
Filler Content ◽  
Unsaturated Polyester ◽  
Unsaturated Polyester Resin ◽  
Physical Parameters ◽  
X Ray Diffraction ◽  
Ceramic Waste ◽  
Waste Particles

In this study, the properties of unsaturated polyester resin were studied in the presence of recycled ceramic waste particles. Herein, composites were created that contained 28.5-50 wt% porcelain particles (particle size [180 �m). High filler contents increased the gel time and decreased the exotherm temperature of unsaturated polyester resin during curing. The obtained results showed that physical parameters, such as the resin density and porosity, increased as the filler content increased. In addition, the X-ray diffraction results indicated that the produced samples were a combination of ceramic waste particles and unsaturated polyester resin, resulting in semi crystalline structure. The results showed that the maximum water absorption at 40�C increased from 0.97 to 1.5% as the filler content increased from 28.5 to 50 wt%; in this process, the materials experienced a color change but did not lose mechanical performance. Finally, the samples were characterized by thermogravimetric analysis (TGA) to study the effect of porcelain powder on the thermal degradation of the resin. The TGA scans were analyzed with the Friedman method. The results indicated that the samples with porcelain powder exhibited substantially better thermal stability than unsaturated polyester resin.

scholarly journals A INFLUÊNCIA DOS MICRORGANISMOS NA DEGRADAÇÃO DA ROCHA DE BENS TOMBADOS DO PARQUE NACIONAL DA TIJUCA

2016 ◽  
Author(s):  
Roberto Carlos da Conceição Ribeiro ◽  
Barbara Nunes Santana Tasca ◽  
Joedy Patrícia Cruz Queiroz ◽  
Maria Inês Sarquis
Keyword(s):  
Rio De Janeiro ◽  
National Park ◽  
Color Change ◽  
Central Area ◽  
Second Empire ◽  
X Rays ◽  
Cultural Significance ◽  
Stone Monuments ◽  
Weathering Processes ◽  
Structural Parts

ResumoO Parque Nacional da Tijuca, situado na zona central da cidade do Rio de Janeiro, protege uma das maiores florestas urbanas do mundo, embora sua vegetação resulte de reflorestamento durante o período do Segundo Reinado. É o Parque Nacional mais frequentado do Brasil, recebendo visitantes de diversos lugares que são atraídos pelas suas trilhas e paisagens. Distribuídas nele, existem seis banheiras esculpidas em mármore branco, segundo historiadores, proveniente de Carrara, na Itália, e teriam sido trazidas ao Parque durante o século XIX. A ação das intempéries associada à ação antrópica conduz à destruição de diversos monumentos pétreos de importante significado histórico e cultural. O caso das banheiras da Floresta da Tijuca não é diferente, a atuação desses agentes tem resultado em uma série de patologias e danos tanto na estética, quanto na integridade física das peças. Com base nestes fatores, foram realizados estudos com a finalidade da caracterização da deterioração do mármore que compõe as banheiras através do recolhimento de amostras e submissão destas á análise química, à difração de Raios-X, ao MEV, além de verificar o efeito da propagação microbiológica nesse processo. Por meio desse estudo foi possível identificar a predominância de cálcio, caracterizando o mármore como calcítico, além da presença de fungos dos gêneros Penicillium e Trichoderma. Que se proliferam devido à alta umidade do local e podem secretar ácidos que aceleram a degradação das rochas.Palavras Chave: mármore, banheiras, microrganismosAbstractTHE INFLUENCE OF MICRORGANISMS IN THE DEGRADATION OF THE ROCK OF CULTURAL HERITAGE ASSETS IN TIJUCA NATIONAL PARK. The Tijuca National Park is located in the central area of the Rio de Janeiro, protects stone of the largest urban forests in the world, although its vegetation results from reforestation during the period of the Second Empire. It is the most visited national park in Brazil. It receives visitors from many places, who are attracted by their trails and landscapes. Distributed through the park, there are six white marble carved bathtubs, according to historians, from Carrara, Italy, which probably were brought to the park during the nineteenth century. The weathering processes associated to anthropic action leads to the destruction of many stone monuments of historic and cultural significance. The case of the Tijuca Forest bathtubs is no different, the action of these agents resulted in a number of diseases and damages not only to the aesthetics aspects, but also to the physical integrity of some their structural parts. As an example, the color change caused mainly by the death of microorganisms. Based on these factors, studies have been conducted with the purpose of characterizing the deterioration of marble that make up the bath by collecting samples and submission of these will chemical analysis, the diffraction of X-rays, the SEM, and check the effect of the spread microbiological this process. Through these studied was possible to identify the prevalence of calcium, featuring marble as calcite, besides the presence of fungi Penicillium and Trichoderma.Keywords: marble, tubs, microorganisms

scholarly journals Green Approach for Synthesis of Manganese Nanoparticle using Banana Peel (Musa paradiasca) and its Characterization

2021 ◽  
Vol 2 (01) ◽  
pp. 75-82
Author(s):  
Sharmila Pradhan Amatya ◽  
Santu Shrestha ◽  
Yadav Aryal
Keyword(s):  
Color Change ◽  
Precursor Solution ◽  
Banana Peel ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Green Approach ◽  
Ft Ir ◽  
Crystalline Nature ◽  
Peel Extract

This research mainly aims at implementing green approach for synthesizing multifunctional manganese nanoparticles (MnNPs) using aqueous extract of banana peel (Musa paradiasca) and potassium permanganate (KMnO4) as the precursor. As synthesized MnNPs were confirmed initially by a color change and later on characterized by UV-visible (UV-vis) Spectrophotometer, Energy Dispersive Spectroscopy (EDX), X-ray Diffraction Spectroscopy (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Green approach was carried at various parameters like concentration of precursor solution, reaction time, temperature, etc for optimization. The formation of MnNPs was confirmed by the presence of surface plasmon absorbance band  (450 nm) and band at 6 and 6.5 keV of EDX spectrum. Likewise, so formed MnNPs were crystalline nature depicted from the sharp peak observed at 28.5º and 41° in X-ray diffraction pattern. Various types of biomolecules associated with the banana peel extract acting as natural reducer and stabilizer were analyzed from characteristic absorption bands present in the FT-IR spectrum.

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