scholarly journals Study of Pigments from the Colonial Convent of Actopan, Hidalgo, Mexico

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 852
Author(s):  
Jesús Benjamín Ortega-Lazcano ◽  
Demetrio Mendoza-Anaya ◽  
Eleazar Salinas-Rodríguez ◽  
Juan Hernández-Ávila ◽  
Otilio Arturo Acevedo-Sandoval ◽  
...  
Keyword(s):  
16Th Century ◽  
Wall Paintings ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Color Palette ◽  
Red Color ◽  
Palygorskite Clay ◽  
Complementary Analysis ◽  
Scanning Electron

In this work, scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR) techniques were used to study blue, red, and ochre pigments from wall paintings of the 16th century colonial convent of San Nicolás de Tolentino in Actopan, Hidalgo, Mexico. In the blue pigments, nanometric fibers with a chemical composition of mostly O, Si, Al, and Mg were identified. XRD and FTIR analysis indicated the presence of palygorskite clay, which suggests that these analyzed blue pigments are similar to Mayan blue. In the red pigment, structures with different morphologies (spines and flake shapes, for instance), with a composition of C, O, Al, Si, S, Ca, Na, Mg, and K and a higher concentration of Fe and Pb, were observed. Complementary analysis showed that the red color originates from hematite and lead. Finally, the ochre pigment showed a significant presence of O and Fe, which was associated with the goethite mineral, while calcite was a crystalline phase identified in all analyzed pigments; these show that these pigments are characteristic of the known Mexican Colonial color palette.

scholarly journals PREPARATION OF CHITOSAN-CELLULOSE COMPOSITE BEADS USING CELLULOSE ISOLATED FROM SUGARCANE BAGASSE

2019 ◽  
Vol 19 (2) ◽  
pp. 30-34
Author(s):  
Rahmi Rahmi ◽  
Alfahmizar Alfahmizar ◽  
Lelifajri Lelifajri
Keyword(s):  
Sugarcane Bagasse ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
H2so4 Concentration ◽  
Composite Beads ◽  
Hydrolysis Process ◽  
Xrd Patterns ◽  
Cellulose Composite ◽  
Scanning Electron

Chitosan-cellulose composite beads had been prepared using cellulose isolated from sugarcane bagasse. Sugarcane bagasse was hydrolyzed with H2SO4 with various concentrations (30, 40, and 50%). Cellulose obtained was characterized using Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). FTIR analysis results inform the existence of typical functional groups of cellulose in the sample. XRD patterns show H2SO4 concentration on the hydrolysis process influence the crystallinity of cellulose. Cellulose was used as a filler in the preparation of chitosan-cellulose composite beads. The results show that cellulose decrease the crystallinity of chitosan. 

scholarly journals Sintesis Komposit TiO2-Bentonit dan Aplikasinya untuk Penurunan BOD dan COD Air Embung UNNES

2016 ◽  
Vol 2 (2) ◽  
pp. 114-119
Author(s):  
Navela Rahma Aji ◽  
Emas Agus Prastyo Wibowo ◽  
Resti Ujiningtyas ◽  
Hestin Wirasti ◽  
Nuni Widiarti
Keyword(s):  
Fourier Transform ◽  
Water Reservoir ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Absorption ◽  
Composite Formation ◽  
Main Absorption Peak ◽  
Scanning Electron

Abstrak Telah disintesis komposit TiO2-bentonit untuk penurunan BOD dan COD. Penelitian ini bertujuan untuk mengetahui proses pembentukan komposit TiO2-Bentonit serta mengetahui katalis terbaik dalam proses fotodegradasi air embung. Penelitian diawali dengan preparasi TiO2-Bentonit. Hasil pembentukan komposit dikarakterisasi dengan menggunakan X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) dan Scanning Electron Microscope (SEM). Katalis yang diuji adalah TiO2, bentonit, TiO2-bentonit yang diaplikasikan ke air embung dengan waktu penyinaran selama 30 menit.Terbentuknya komposit TiO2-Bentonit ditunjukkan dengan refleksi TiO2 pada 2 25. Hasil analisis menggunakan FTIR yakni Ti-O antara range 400-700 cm -1 dalam hal ini ditunjukkan dalam peak 478.35 dan 594.08. Puncak serapan-serapan utama pada bentonit beradi di bilangan gelombang 3626.17 cm-1, 3448.72 cm-1 dan 1635.64 cm-1. Spektra TiO2-Bentonit tidak menunjukkan adanya pergeseran serapan pada bilangan gelombang 3448.72 cm-1 yang belum  menunjukkan ikatan O-H yang semakin lemah karena adanya TiO2 di dalam antar lapis bentonit.Penurunan nilai BOD dan COD terbesar diperoleh dengan menggunakan TiO2-Bentonit yakni untuk BOD 18.40 ppm dan COD 10.05ppm. Kemampuan komposit TiO2-Bentonit lebih besar dibandingkan katalis TiO2 dan bentonit.   Kata kunci: air embung, fotodegradasi, TiO2-bentonit Abstract   Have done synthesized composite TiO2-bentonite to decrease BOD and COD. This study aims to determine the process of form he composite TiO2-bentonite and determine the best catalyst in the process of photodegradation water reservoir. The study begins with the preparation of TiO2-bentonite. Results composite formation characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). The catalyst is tested TiO2, bentonite, TiO2-bentonite which is applied to the water reservoir with the exposure time for 30 menit.Terbentuknya composite TiO2-bentonite indicated by TiO2 reflection on the 2θ ≥ 25. FTIR analysis results using the Ti-O between the range 400-700 cm-1 in this case is shown in peak 478.35 and 594.08. The main absorption peak-absorption on bentonite beradi at wavenumber 3626.17 cm-1, 3448.72 and 1635.64 cm-1. TiO2-bentonite spectra did not indicate any shift in absorption at wavenumber 3448.72 cm-1 which has not shown the OH bond is weakened by the existence of TiO2 in between layers of bentonite. Impairment The BOD and COD obtained using the TiO2-bentonite for BOD 18.40 ppm and 10.05 ppm COD. TiO2-bentonite composite capability greater than TiO2 catalyst and bentonite.   Keyword: air embung, photodegradation, TiO2-bentonite DOI: http://dx.doi.org/10.15408/jkv.v0i0.3620

scholarly journals Low molecular weight organic acid salts, markers of old fungi activity in wall paintings

2016 ◽  
Vol 8 (7) ◽  
pp. 1637-1645 ◽  
Author(s):  
Nati Salvadó ◽  
Salvador Butí ◽  
Trinitat Pradell ◽  
Victòria Beltran ◽  
Gianfelice Cinque ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Molecular Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Molecular Weight ◽  
Wall Paintings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synchrotron Light ◽  
Scanning Electron

Micro-Infrared Spectroscopy (μSR-FTIR) and X-ray diffraction (μSR-XRD) with synchrotron light, Gas Chromatography/Mass Spectrometry (CG/MS), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM/EDS) were used to obtain the distribution of calcium salts of low molecular weight organic acids (LMWOA) in micro-layered micro-samples.

REMOVAL ENHANCEMENT OF BASIC BLUE 41 BY RGO–TiO2 NANOCOMPOSITE SYNTHESIZED USING PULSED LASER

2018 ◽  
Vol 25 (01) ◽  
pp. 1850041 ◽  
Author(s):  
FATEMEH GHASEMI ◽  
SALIMEH KIMIAGAR ◽  
MOZHGAN SHAHBAZI ◽  
HOSSEIN VOJOUDI
Keyword(s):  
Pulsed Laser ◽  
Sem Analysis ◽  
Langmuir Model ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
Pulse Laser Irradiation ◽  
Nanocomposite Structure ◽  
X Ray ◽  
Optimum Ph ◽  
Scanning Electron

Graphene oxide (GO) and GO-TiO2 nanocomposite was produced then reduced under pulse laser irradiation (RGO–TiO[Formula: see text]. Basic blue 41 (bb41) dye was removed from aqueous solutions by using RGO–TiO2 nanocomposites. The UV–Vis absorption and FTIR analysis were utilized to confirm the reduction of GO-TiO2 to RGO–TiO2. The results showed complete reduction of GO. X-ray diffraction (XRD), Raman spectra and scanning electron microscopy (SEM) analysis were applied to approve the RGO–TiO2 nanocomposite structure. The effect of pH on the bb41 removal by RGO–TiO2 was studied varying the pH from 1 to 11. The optimum pH and adsorbent dosage were found to be 9 and 0.2[Formula: see text]g/L with 98% efficiency, respectively. The calculated coefficients demonstrated that the Langmuir model was fixed to the experimental data. The results indicated that RGO–TiO2 could be engaged as an exceptional sorbent to remove bb41 dye which is in aqueous solution.

scholarly journals Maya Blue Used in Wall Paintings in Mexican Colonial Convents of the XVI Century

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Luisa Straulino-Mainou ◽  
Teresa Pi-Puig ◽  
Becket Lailson-Tinoco ◽  
Karla Castro-Chong ◽  
María Fernanda Urbina-Lemus ◽  
...  
Keyword(s):  
Sixteenth Century ◽  
Clay Minerals ◽  
Wall Paintings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrf Scanning ◽  
Maya Blue ◽  
Indigo Blue ◽  
Continued Use ◽  
Scanning Electron

Maya blue is a well-known pre-Hispanic pigment, composed of palygorskite or sepiolite and indigo blue, which was used by various Mesoamerican cultures for centuries. There has been limited research about its continued use during the Viceroyalty period; therefore, the sixteenth century is the perfect period through which to study the continuity of pre-Hispanic traditions. The fact that the indigenous people were active participants in the construction and decoration of convents makes their wall paintings a good sampling material. X-ray fluorescence (XRF), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed in samples of blue found in convents across Puebla, Tlaxcala and Morelos in order to identify whether the numerous hues of blue were achieved with Maya blue or with other pigments. We found no copper (Cu) or cobalt (Co) with the XRF, so several pigments, such as azurite, smalt or verdigris, were discarded. With SEM, we discovered that the micromorphology of certain blues was clearly needle-shaped, suggesting the presence of palygorskite or sepiolite. In addition, we found silicon (Si), magnesium (Mg) and aluminum (Al) by using energy-dispersive X-ray spectroscopy (EDS) in all blue samples, which also suggests the presence of these magnesium-rich clay minerals. With the XRD samples, we verified that the blues were produced with these two clay minerals, thus confirming that several wall paintings were manufactured with Maya blue. These findings confirm that this particular manmade pre-Hispanic pigment, Maya blue, was an important pigment prior to the Viceroyal period.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

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.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Photocatalytic activity of TiO2 synthesized by anodization and anodic spark deposition

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Characteristics ◽  
Amorphous Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Anodic Spark Oxidation ◽  
Porous Surfaces ◽  
Scanning Electron

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

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