scholarly journals The historical glazed tiles from Nossa Senhora da Soledade Cemetery, Northern Brazil: microstructural, physical and mineralogical characterization

Cerâmica ◽  
2018 ◽  
Vol 64 (369) ◽  
pp. 141-147
Author(s):  
S. A. M. Gasparetto ◽  
T. A. B. C. Sanjad

Abstract During the nineteenth century, historical glazed tiles were used in the mortuary architecture of Nossa Senhora da Soledade Cemetery, in Belém. These ceramic pieces are an extraordinary part of Brazilian cultural heritage but are at a high deterioration stage due to conditions to which they are subjected. The aim of this research was the microstructural, physical and mineralogical characterization of glazed tiles from Nossa Senhora da Soledade Cemetery. The samples consisted of Portuguese fragments from the nineteenth century, decorated by stamping. The characterization was performed by optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, water absorption test, and X-ray diffractometry. The results indicated that glazed and ceramic layers have manufacturing defects and a heterogeneous character due to the handmade production process. The porosities vary from 13.3% to 22.9%. The ceramics are composed of quartz, gehlenite, calcite, rutile, cristobalite, diopside, anorthite, hematite and wollastonite. According to the results, despite many similarities (country of origin, century of production, decorative technique), the samples have variations in their microstructure and mineralogy. Information regarding the compositions of the tiles and their variation is important to support future restorative interventions.

Cerâmica ◽  
2020 ◽  
Vol 66 (380) ◽  
pp. 483-495
Author(s):  
V. M. J. Salgado-Campos ◽  
L. C. Bertolino ◽  
F. J. da Silva ◽  
J. C. Mendes

Abstract This study reports the mineralogical characterization of kaolin occurrences in the State of Rio de Janeiro, Brazil, to identify new kaolinite and halloysite deposits. Samples were collected in 10 pegmatites with varying sizes for X-ray diffractometry, chemical analysis by X-ray fluorescence, and scanning electron microscopy studies. The results indicated that the kaolin occurrences were of weathered origin, wherein some places there were occurrences of tubular halloysite. Concerning the regolith stratigraphy, samples located in the saprock zone were found to contain kaolinite and/or halloysite contents from 0 to 10.1%, while those located in the saprolite zone contained kaolinite and/or halloysite contents from 16.3% to 34.9%. Kaolinite and/or halloysite-7Å were formed from plagioclase weathering instead of K-feldspar or mica, and the halloysite-7Å occurrence was related to samples in regions with a higher degree of weathering.


2021 ◽  
Vol 14 (3) ◽  
pp. 1787
Author(s):  
Rafaela Teixeira Paula ◽  
Geraldo César Rocha

Materiais saprolíticos constituem importantes seções no recorte vertical da paisagem. São materiais ainda pouco conhecidos e demandam maior dedicação. Para caracterização destes materiais pode-se fazer uso de técnicas mineralogia e micromorfologia como a difração de Raios-X (DRX) e o Microscópio Eletrônico de Varredura (MEV). O DRX é uma técnica de caracterização de estruturas cristalinas. O MEV é um tipo de microscópio capaz de produzir imagens de alta resolução da superfície de materiais sólidos. O objetivo é caracterizar amostras de materiais intemperizados de diferentes rochas. Foram selecionados cinco perfis de intemperismo  em Juiz de Fora - MG. Os parâmetros utilizados para a análise física e mineralógica foram os seguintes: cor, textura, consistência, rocha de origem e grau de alteração, mineralogia e micromorfologia. A cor é variável entre e intra amostras, é dependente dos minerais constituintes e do grau de alteração. A textura está ligada aos minerais constituintes e seus tamanhos, que são dependentes de seus graus de alteração. A consistência é dependente da resistência dos minerais constituintes e da alteração. As rochas de origem são o quartzito ou o gnaisse. Os principais minerais encontrados foram quartzo, biotita, muscovita e caulinita. Quanto maior a porcentagem de argila, menor a consistência e maior o grau de alteração. A presença de minerais mais resistentes tende a dificultar a pedogênese, resultando em perfis mais arenosos, com poucos minerais de argila e sem atividade biológica. Nos perfis em que predomina o quartzo, apesar da presença desse mineral, o grau de alteração é elevado. Physical and Mineralogical Characterization of Weathering Materials in the Urban Area of Juiz de Fora - MG through Macroscopic Analysis, X-Ray Diffractometer and Scanning Electron Microscope ABSTRACTSaprolitic materials are important sections in the vertical cutout of the landscape. These materials are still little known and demand greater dedication. To characterize these materials, we can use mineral and micromorphological techniques such as X-ray diffraction, a technique for characterizing crystalline structures and the Scanning Electron Microscope, a type of microscope capable of producing high-resolution images of the surface of solid materials. The objective is to characterize weathered colors of different stones. Five weathering profiles were selected in Juiz de Fora - MG. The parameters used for physical and mineralogical analysis were as follows: color, texture, consistency, original rock and degree of change, mineralogy and micromorphology. The color is variable, depends on the constituent minerals and the degree of change. The texture is linked to the constituent minerals and their sizes, which depend on their degree of change. The consistency is dependent on the strength of the constituent minerals and the degree of change. The original rocks are quartzite and gneiss. The main minerals found were quartz, biotite, muscovite and kaolinite. The higher the clay percentage, the lower the consistency and the greater the degree of change. The presence of more resistant mineralsmakes pedogenesis difficult, resulting in more sandy profiles, with few clay minerals and without biological activity. In profiles that predominate quartz, despite the presence of this mineral, the degree of change is high.Keywords: Mineralogy; Micromorphology; Weathering material.


2018 ◽  
Vol 24 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Susana Coentro ◽  
Rui C. da Silva ◽  
Cátia Relvas ◽  
Teresa Ferreira ◽  
José Mirão ◽  
...  

AbstractThis work explores the combination of µ-Raman spectroscopy and scanning electron microscopy with X-ray energy dispersive spectrometry (SEM-EDS) for the study of the glazes in 15th–16th century Hispano-Moresque architectural tiles. These are high lead glazes that can be tin-opacified or transparent, and present five colors: tin-white, cobalt-blue, copper-green, iron-amber, and manganese-brown. They are generally homogenous and mineral inclusions are mostly concentrated in the glaze-ceramic interface. Through SEM-EDS, these inclusions were observed and chemically analyzed, whereas µ-Raman allowed their identification on a molecular level. K-feldspars, wollastonite and diopside were the most common compounds, as well as cassiterite agglomerates that render the glaze opaque. Malayaite was identified in green glazes, and andradite and magnesioferrite in amber glazes. Co–Ni–ferrites were identified in blue glazes, as well as Ni–Fe–olivines. Manganese-brown is the color where most compounds were identified: bustamite, jacobsite, hausmannite, braunite, and kentrolite. Through the µ-Raman analysis of different areas in large inclusions previously observed by SEM, it was possible to identify intermediate phases that illustrate the reaction process that occurs between the color-conferring compounds and the surrounding lead glaze. Furthermore, the obtained results allowed inference of the raw materials and firing temperatures used on the manufacture of these tiles.


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.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Liu Liu ◽  
Decai Gong ◽  
Zhengquan Yao ◽  
Liangjie Xu ◽  
Zhanyun Zhu ◽  
...  

Abstract Historically, sutras played an important role in spreading Buddhist faith and doctrine, and today these remain important records of Buddhist thought and culture. A Mahamayuri Vidyarajni Sutra with polychrome paintings was found inside the cavity on top of the Nanmen Buddhist pagoda, built in the early Tang dynasty (618–627 CE) and located in Anhui Province, China. Textile was found on the preface which is strongly degraded and fragile. Unfortunately, the whole sutra is under severe degradation and is incomplete. Technical analysis based on scientific methods will benefits the conservation of the sutra. Optical microscopy (OM), micro-Raman spectroscopy combined with optical microscope (Raman), scanning electron microscopy in combination with energy dispersive X-ray analysis (SEM–EDS) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the pigment and gilded material, as well as the paper fiber and textile. Pigments such as cinnabar, minium, paratacamite, azurite, lead white were found. Gilded material was identified as gold. A five-heddle warp satin, made of silk, was found as the textile on the preface of the sutra. The sutra’s preface and inner pages were made of paper comprised of bamboo and bark. As a magnificent yet recondite treasure of Buddhism, the sutra was analyzed for a better understanding of the material. A conservation project of the sutra will be scheduled accordingly.


2021 ◽  
Vol 13 (9) ◽  
pp. 4840
Author(s):  
Fatai Arolu Ayanda ◽  
Mohd Firdaus Mohd Anuar ◽  
Syaharudin Zaibon ◽  
Shamshuddin Jusop

The physical, chemical and mineralogical characterization of the constituents of magnesium-rich synthetic gypsum produced in a rare earth-refining plant located in Gebeng, Pahang, Malaysia was conducted through elemental chemical analysis, scanning electron microscopy with Energy Dispersive X-ray (EDX)-analyzer, thermal analysis, X-ray fluorescence and X-ray diffraction. The crystalline nature of the by-product was studied using FTIR spectroscopy. Elemental analysis confirmed the presence of Ca and Mg, which are essential macronutrients required by plants and this Ca alongside the high pH (9.17) of MRSG may confer on the material a high acid neutralization capacity. From the result, it was observed that the studied by-product is a heterogeneous crystalline material comprising of gypsum (CaSO4.2H2O) and other major components such as calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate) and sulfur. These aggregates may contribute to give an acid neutralization capacity to MRSG. The XRD study of MRSG indicated a high content of gypsum (45.4%), shown by the d-spacing of 7.609 Å (2-theta 11.63) in the diffractogram. The infrared absorption spectra of MRSG indicate close similarities to mined gypsum. The results of the characterization indicated that MRSG has valuable properties that can promote its use in amending soil fertility constraints on nutrient-deficient tropical acid soils.


2012 ◽  
Vol 620 ◽  
pp. 314-319
Author(s):  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
Saadah Abdul Rahman

Hardwood is wood from angiosperm trees. The characteristic of hardwood include flowers, endosperm within seeds and the production of fruits that contain the seeds. This paper aims to discuss the preparation and characterization of cellulose obtained from hardwood. The hardwood Merbau (Intsia bijuga) was chosen as raw material in this study. Alkaline treatment and delignification methods were used for the preparation of cellulose. Acid hydrolysis was employed to produce cellulose nanocrystal (CNC). The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The final product, from both trated and untreated samples were then compared.


2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).


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