scholarly journals Non-Invasive Study on the Sinope Gospels

Heritage ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 1269-1278
Author(s):  
Maurizio Aceto ◽  
Elisa Calà ◽  
Angelo Agostino ◽  
Gaia Fenoglio ◽  
Maria Labate ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Pure Gold ◽  
Late Antique ◽  
Reflectance Spectrophotometry ◽  
Purple Colour ◽  
X Ray ◽  
Non Invasive ◽  
Ultramarine Blue ◽  
Uv Visible

The 6th century Codex Sinopensis or Sinope Gospels (Paris, Bibliothèque nationale de France) is one of the most precious purple codices that survive from the Late Antique period. Together with the Vienna Genesis (Wien, Österreichische Nationalbibliothek) and the Rossano Gospels (Rossano Calabro, Museo Diocesano), it has an unusually rich decorative apparatus with scenes representing biblical episodes. It can be, therefore, considered one of the most important preserved artistic productions of the early medieval era. The manuscript has been subjected to a non-invasive diagnostic campaign to evaluate the quality of the colourants used in its decoration, to understand how the parchment was coloured, and to carry out a comparison with the Vienna Genesis and the Rossano Gospels. The techniques used were UV-visible diffuse reflectance spectrophotometry with optical fibres (FORS), X-ray fluorescence spectrometry (XRF), spectrofluorimetry, and optical microscopy. Analyses highlighted the presence of ultramarine blue, which, besides the use of pure gold for the ink and paint, certifies the high value of the manuscript. In addition, this must be seen as one of the earliest examples of its use in paintings. The purple colour of the parchment was identified as orchil, a dye extracted from lichens, similar to the results of analytical investigations carried out on other purple codices, and not the expected Tyrian purple dye.

scholarly journals Synthesis and Optimization of Visible Light Active BiVO4Photocatalysts for the Degradation of RhB

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Rong Ran ◽  
Joanne Gamage McEvoy ◽  
Zisheng Zhang
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Reflectance Spectrophotometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Range ◽  
Excellent Photocatalytic Activity ◽  
Visible Light Active ◽  
Uv Visible

Monoclinic BiVO4powders were synthesized via a novel route using potassium metavanadate (KVO3) prepared by calcination of K2CO3and V2O5as a starting material and followed by hydrothermal treatment and were investigated for the degradation of Rhodamine B (RhB) under visible light irradiation. The synthesized BiVO4particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The synthesis produced pure monoclinic BiVO4particles with multimorphological features containing flower-like, flake-ball, flake, cuboid-like, and plate-like shapes and exhibited strong absorption in the visible light range. The BiVO4prepared via KVO3possessed excellent photocatalytic activity for the degradation of RhB under visible light. The performance of this catalyst was found to be superior to other BiVO4photocatalysts prepared via ammonium metavanadate (NH4VO3) using coprecipitation, combustion, and calcination methods reported in literature, respectively.

scholarly journals Preparation and Characterizations of In0.1SnxZn0.85-2xS Powder Photocatalysts for Hydrogen Production under Visible Light Irradiation

2011 ◽  
Vol 364 ◽  
pp. 238-242 ◽  
Author(s):  
Kimi Melody ◽  
Yuliati Leny ◽  
Mustaffa Shamsuddin
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Solid Solutions ◽  
Visible Light Irradiation ◽  
Diffuse Reflectance ◽  
Average Rate ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible

A series of In0.1SnxZn0.85-2xS solid solutions was synthesized by hydrothermal method and employed as photocatalyst for photocatalytic hydrogen evolution under visible light irradiation. The structures, optical properties and morphologies of the solid solutions were studied by X-ray diffraction, diffuse reflectance UV–visible spectroscopy and field emission scanning electron microscopy. From the characterizations, it was confirmed that In0.1SnxZn0.85-2xS solid solution can be obtained and they have nanosized particles. The highest photocatalytic activity was observed on In0.1Sn0.03Zn0.79S photocatalyst, with average rate of hydrogen production 3.05 mmol/h, which was 1.2 times higher than the In0.1Zn0.85S photocatalyst.

scholarly journals Influence of White Reference Measurement and Background on the Color Specification of Orange Juices by Means of Diffuse Reflectance Spectrophotometry

2006 ◽  
Vol 89 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Antonio J Melndez-Martnez ◽  
Isabel M Vicario ◽  
Francisco J Heredia
Keyword(s):  
Analysis Of Variance ◽  
Orange Juice ◽  
Diffuse Reflectance ◽  
The Other ◽  
Reflectance Spectrophotometry ◽  
Reference Measurement ◽  
Color Parameters ◽  
Color Differences ◽  
Color Specification

Abstract The color of citrus beverages, in general, is related to the consumers' perception of flavor, sweetness, and other characteristics related to the quality of these products, so it is important to develop suitable methods for accurately assessing this attribute. In this study, the color of 2 different kinds of orange juices (ultrafrozen orange juices and orange juices from concentrate) were measured using different white references in order to demonstrate the influence of white reference measurement on the color parameters obtained. The results of this work indicated that the election of a wrong white reference measurement can affect dramatically the accuracy of the objective specification of orange juice color. Thus, the application of analysis of variance ( = 0.01) revealed that, in most cases, the parameters obtained were significantly different. In terms of color differences, the change of the background for the same white reference affected the measurements less than the changes of white references for the same background. On the other hand, important chromatic differences between the 2 types of orange juices studied were found.

Sensing Nanoparticulate ZnO with Benzimidazole Derivative by Fluorescence

2013 ◽  
Vol 543 ◽  
pp. 63-67
Author(s):  
Jayabharathi Jayaraman ◽  
Jayamoorthy Karunamoorthy
Keyword(s):  
Diffuse Reflectance ◽  
Electrochemical Impedance ◽  
Fluorescent Sensor ◽  
Sol Gel ◽  
Benzimidazole Derivative ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible ◽  
Doped Zno ◽  
Scanning Electron

A sensitive benzimidazole derivative fluorescent sensor for nanoparticulate ZnO has been designed and synthesized. The nanocrystalline ZnO, Ag doped ZnO and Cu doped ZnO have been synthesised by sol-gel method and characterized by powder X-ray diffraction, scanning electron microscopy (SEM) and UV-visible diffuse reflectance, photoluminescence and electrochemical impedance spectroscopies. The synthesized sensor emits fluorescence at 360 nm and this fluorescence is selectively enhanced by nanocrystalline ZnO. This technique is sensitive to detect and estimate ZnO at micro molar level. Impurities such as Ag and Cu do not hamper the sensitivity of this technique significantly. Keywords: Sensor, SEM, EDX, Impedance, Fluorescence

Preparation of Nanoparticulate YFeO3 by Ultrasonic Assisted Method and its Visible-Light Photocatalytic Properties

2014 ◽  
Vol 636 ◽  
pp. 7-10 ◽  
Author(s):  
Pei Song Tang ◽  
Chao Wan Tang ◽  
Jia Ni Ying ◽  
Dong Jing Ni ◽  
Qian Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
Diffuse Reflectance ◽  
Optical Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
High Photocatalytic Activity ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasonic Assisted ◽  
Uv Visible

Using Fe (NO3)3⋅9H2O, Y(NO3)3⋅6H2O and citric acid as the main raw material, the YFeO3 nanoparticles were synthesized by ultrasonic assisted process and calcination. The YFeO3 nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that the perovskite structureYFeO3 (YFeO3-800) can be obtained through the calcination of ultrasonic processed YFeO3 precursors at 800 °C, and the resulting product has a particle size of 70 nm and an optical band gap of 2.0 eV. Consequently, the YFeO3-800 nanoparticles show high photocatalytic activity for decomposition of methyl orange under visible-light irradiation.

scholarly journals Effect of Electrolyte Composition on Structural and Photoelectrochemical Properties of Titanium Dioxide Nanotube Arrays Synthesized by Anodization Technique

2020 ◽  
Vol 17 (4) ◽  
pp. 1183
Author(s):  
Tabarak Jafar Awaid ◽  
Asmaa Kadim Ayal ◽  
Ahlam Mohammed Farhan ◽  
Muna Sarhan Sando ◽  
Lim Ying Chin
Keyword(s):  
Ethylene Glycol ◽  
Diffuse Reflectance ◽  
Electrolyte Composition ◽  
Nanotube Arrays ◽  
Halogen Lamp ◽  
Photoelectrochemical Properties ◽  
X Ray ◽  
Photoelectrochemical Response ◽  
Titanium Dioxide Nanotube Arrays ◽  
Uv Visible

The present work involves studying the effect of electrolyte composition [@1= 0.5 wt.%  NH4F / 5% H2O / 5% Glycerol (GLY)/ 90%  Ethylene Glycol (EG)] and [ @2= 0.5 wt. % NH4F / 5% H2O / 95%  Ethylene Glycol (EG)]  on the structural and photoelectrochemical properties of titania nanotubes arrays (TNTAs). TNTAs substrates were successfully carried out via anodization technique and were carried out in 40 V for one hour in different electrolytes (@1, and @2). The properties of physicochemical of TNTAs were distinguished via an X-ray Diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), an Energy Dispersive X-ray (EDX), and UV–visible diffuse reflectance. The photoelectrochemical response of TNTAs was evaluated in 0.01M Na2S under the choppy light of a halogen lamp. TNTAs photoelectrode prepared at @1 electrolyte was not sufficient to increase the photocurrent response compared to TNTAs prepared at @2. The TNTAs photoelectrode prepared in the @2 electrolyte confirmed the highest photoconversion efficiency compared to the TNTAs photoelectrode prepared in the @1 electrolyte.

scholarly journals Au/TiO2Reusable Photocatalysts for Dye Degradation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Silija Padikkaparambil ◽  
Binitha Narayanan ◽  
Zahira Yaakob ◽  
Suraja Viswanathan ◽  
Siti Masrinda Tasirin
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Pollutants ◽  
Transmission Electron ◽  
Uv Visible

Nanogold doped TiO2catalysts are synthesized, and their application in the photodegradation of dye pollutants is studied. The materials are characterized using different analytical techniques such as X-ray diffraction, transmission electron microscopy, UV-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the strong interaction between the metallic gold nanoparticles and the anatase TiO2support. Au doped systems showed very good photoactivity in the degradation of dye pollutants under UV irradiation as well as in sunlight. A simple mechanism is proposed for explaining the excellent photoactivity of the systems. The reusability studies of the photocatalysts exhibited more than 98% degradation of the dye even after 10 repeated cycles.

Visible Light Photodegradation of Azo Dye by Cu/TiO2

2014 ◽  
Vol 917 ◽  
pp. 151-159 ◽  
Author(s):  
Nadia Riaz ◽  
Chong Fai Kait ◽  
Zakaria Man ◽  
Binay K. Dutta ◽  
Raihan M. Ramli ◽  
...  
Keyword(s):  
Visible Light ◽  
Azo Dye ◽  
Diffuse Reflectance ◽  
Orange Ii ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible

Cu/TiO2 photocatalysts with different metal loading were prepared via modified depositionprecipitation method with the intention to reduce the band gap for Orange II degradation and mineralization under visible light radiation. The photocatalysts were characterized using thermal gravimetric analysis, powder X-ray diffraction, diffuse reflectance UV-Visible spectroscopy and field-emission scanning electron microscopy. 10 wt% photocatalysts showed the best performance compared to the bare TiO2.

scholarly journals Pyrolysis Synthesized g-C3N4for Photocatalytic Degradation of Methylene Blue

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Gang Xin ◽  
Yali Meng
Keyword(s):  
Methylene Blue ◽  
Fourier Transform ◽  
Photocatalytic Activity ◽  
Carbon Nitride ◽  
Diffuse Reflectance ◽  
Photogenerated Electron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Uv Visible

Graphitic carbon nitride (g-C3N4) was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD), UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR), and elemental analyzer. The photocatalytic activity of g-C3N4was evaluated by the photodegrading experiments of methylene blue (MB). The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation over the C3N4photocatalyst is attributed to photogenerated electron impelled multistep reduction of O2.

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