scholarly journals The role of the under-layer in the coloured perception of gildings in mediaeval mural paintings

2013 ◽  
Vol 1 (1) ◽  
pp. 16 ◽  
Author(s):  
Aurélie Mounier ◽  
Floréal Daniel
Keyword(s):  
Electron Microscopy ◽  
16Th Century ◽  
Absorption Properties ◽  
Gold Leaf ◽  
X Ray ◽  
Mural Paintings ◽  
Application Techniques ◽  
Analysis System ◽  
Scanning Electron

A study of the gildings used in mural paintings from the 12th to 16th century showed rather limited types of application techniques (essentially mixtion techniques, but also in rare examples distemper techniques) and a higher variety of employed metals. Samples have been taken off from mural paintings in the southwest of France as in the Bordeaux Cathedral, Meyrals Castle, Ste-Marie Church of Audignon. Samples analyses have been carried out by scanning electron microscopy coupled with an energy dispersive X-ray analysis system, Raman spectroscopy and Fourier transform infrared spectroscopy. Depending on the metal used for the gilding, the under-layer could be different in terms of material and colour. Under the gold leaves, the layer is usually red or yellow. That can be explained by the absorption properties of light by the gold leaf. Under tin leaves, which are thicker and opaque, the usefulness of the under-layer is less obvious. An experimental study illustrates the role of the coloured under-layer.

Effect of Zn on the intermetallics formation and reliability of Sn-3.5Ag solder on a Cu pad

2007 ◽  
Vol 22 (7) ◽  
pp. 1879-1887 ◽  
Author(s):  
Y.K. Jee ◽  
Y.H. Ko ◽  
Jin Yu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Isothermal Aging ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drop Tests ◽  
Joint Microstructures ◽  
Role Of Zn ◽  
Scanning Electron

Varying amounts of Zn (1, 3, and 7 wt%) were added to Sn–3.5Ag solder on a Cu pad, and the resultant solder joint microstructures after a reflow and isothermal aging (150 °C, up to 500 h) were investigated using scanning electron microscopy, energy dispersive x-ray, and x-ray diffraction, which were subsequently correlated to the results of microhardness and drop tests. Zinc was effective in improving the drop resistance of Sn–3.5Ag solder on the Cu pad, and an addition of 3 wt% Zn nearly doubled the number of drops-to-failure (Nf). The beneficial role of Zn was ascribed to suppression of Cu6Sn5 and precipitation of Zn-containing intermetallic compounds (IMCs). However, the Zn effect was reduced as Cu6Sn5 and Ag3Sn precipitated in a joint IMC layer after prolonged aging. The interface between Ag5Zn8 and Cu5Zn8 was resistant to drop impact, but two other layered IMC structures of Cu6Sn5/Cu3Sn and Cu5Zn8/Cu6Sn5 were not.

Effect of Seedings on the Microstructure of Hydrated Alumina

2012 ◽  
Vol 554-556 ◽  
pp. 709-713
Author(s):  
Yan Hong Liu ◽  
Hong Wen Ma ◽  
Mei Tang Liu
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Decisive Role ◽  
Mechanism Study ◽  
Hydrated Alumina ◽  
Crystal Nucleus ◽  
X Ray ◽  
Intrinsic Mechanism ◽  
Scanning Electron

The morphology and particle size of boehmite play a decisive role on the application of alumina that derived from it. In this paper, we employed pseudoboehmite that produced from Al2 (SO4)3•18H2O and NH3•H2O at 70 °C, pH 7.5 as precursor to synthesize boehmite, and utilized different seeding when preparing pseudoboehmite and boehmite. To identify the influence of seeding on the microstructure of pseudoboehmite and boehmite, the products were characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and BET. The results indicate that the pseudoboehmite seeding has a significant influence on the morphology and particle size of pseudoboehmite to which we should pay high attention. However, the boehmite seeding does not play the role of crystal nucleus as expected. The further intrinsic mechanism study is ongoing.

Structural and morphological features of MgO powders. The key role of the preparative starting compound

1998 ◽  
Vol 13 (8) ◽  
pp. 2218-2223 ◽  
Author(s):  
S. Ardizzone ◽  
C. L. Bianchi ◽  
B. Vercelli
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Starting Compound ◽  
Scanning Electron

The present paper reports data concerning magnesia samples obtained by calcination of different precursor salts at different increasing temperatures (873–1253 K). The oxides are characterized by x- ray diffraction, scanning electron microscopy, and N2 adsorption at subcritical temperatures. The samples appear to be composed, at any temperature, of pure periclase with a degree of crystallinity which increases with the temperature of calcination. Morphologically, the products have the shape either of lamellas or of cubes of variable dimensions, depending on the nature and route of preparation of the precursor salts. The variation of the specific surface area and the degree of porosity with the nature of the precursors and the temperature is discussed.

scholarly journals Intracellular Siderophore Detection in an Egyptian, Cobalt-Treated F. solani Isolate Using SEM-EDX with Reference to its Tolerance

2017 ◽  
Vol 66 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Farrag M. Rasha
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Fusarium Solani ◽  
X Ray ◽  
Cobalt Uptake ◽  
Molecular Studies ◽  
Control Regime ◽  
Co Concentrations ◽  
Scanning Electron

An Egyptian, plant pathogenic Fusarium solani isolate was grown on cobalt concentrations of 0, 50, 200, 500, 800, and 1000 ppm. The isolate survived concentrations up to 800 ppm, however failed to grow at 1000 ppm. Morphology and elemental analysis of the isolate under the investigated Co concentrations were studied using Scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX). The isolate reserved its morphology up to a concentration of 200 ppm. Morphological distortions were dramatic at 500 and 800 ppm. EDX detected Co uptake through the hyphae, microconidia, macroconidia, and chlamydospores. Iron, calcium, and potassium were also detected. EDX results showed a linear relationship between Co% and Fe% up to a concentration of 500 ppm reflecting the possible ability of the isolate to synthesize intracellular siderophores storing iron and their release out of the vacuoles. The participation of such siderophores in conferring tolerance against cobalt is discussed. At 800 ppm, the % of Fe was greatly reduced with an accompanying increase in morphological distortions and absence of microconidia. Increasing the implicated cobalt concentrations resulted in increasing the percentages of the chelated cobalt reflecting the possible implication of the cell wall as well as extracellular siderophores in the uptake of cobalt. The current results recommend the absence of cobalt in any control regime taken to combat the investigated F. solani isolate and highlights the accomplishment of biochemical, ultrastructural, and molecular studies on such isolate to approve the production of siderophores and the role of cell wall in cobalt uptake.

Synthesis of Coal Dust Depressor and its Application in Preventing Coal Dust

2012 ◽  
Vol 482-484 ◽  
pp. 2301-2306 ◽  
Author(s):  
Fang Qin Cheng ◽  
Shu Yan Cheng ◽  
Yan Xia Guo ◽  
Li Qiong Cao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Coal Dust ◽  
Raw Material ◽  
Surface Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stock Pile ◽  
Scanning Electron

A novel coal dust depressor was prepared by alkalization and etherficayion reactions using wastepaper as raw material. The sample was characterized by means of FTIR spectroscopy (FTIR)、scanning electron microscopy (SEM)、X-ray diffraction (XRF) and viscometer measurements. The coal dust inhibitor was developed to suppress flying dust over coal dump and conveyor. The result shows that flying coal dust was prevented by intrinsic viscosity of coal dust depressor which was sprayed on the surface stock pile can make the surface material bond with each other to form layer of crust, having a role of dust prevention. Application of the coal dust depressor can reduce the losses of coal and protect the environment from being polluted.

scholarly journals Study of the Painting Methods of Mural Paintings in Ancient Tombs of Goguryeo Using Scanning Electron Microscope

2013 ◽  
Vol 19 (S5) ◽  
pp. 157-161 ◽  
Author(s):  
Kyeongsoon Han ◽  
Sangjin Lee ◽  
Hwasoo Lee
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Elemental Mapping ◽  
The West ◽  
X Ray ◽  
Mural Paintings ◽  
Scanning Electron

AbstractDisputes on the painting methods of Goguryeo murals can mainly be categorized into whether the murals adapted eastern secco or western fresco; however, the murals have their own unique methods as well. There are different viewpoints among experts on interpreting the painting methods. This study involved the creation of research samples to discover the painting methods under dispute and may help discover the methods based on scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDX) studies. Goguryeo murals introduced pseudo-fresco rather than buon fresco methods. Unlike fresco techniques in the West, Goguryeo painters mixed traditional soft binders and adapted typical secco painting techniques for paintings, borders, and corrections after drying. The disputed issues may be resolved by these techniques, and samples may be produced based on the analyzed data. Therefore, many questions can finally be answered through SEM-EDX elemental mapping.

Surface Analysis of the Tarnishing Layer in Silver Alloys

MRS Advances ◽  
2017 ◽  
Vol 2 (63) ◽  
pp. 3983-3989 ◽  
Author(s):  
Janette Ortíz-Corona ◽  
José L. Ruvalcaba-Sil ◽  
Edgar Casanova-González ◽  
Francisco J. Rodríguez-Gómez
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Copper Content ◽  
Black Film ◽  
Silver Alloys ◽  
X Ray ◽  
Ammonium Sulfide ◽  
Sulfide Solution ◽  
Scanning Electron

AbstractAncient silver artifacts, when exposed to environments that contain sulfides (H2S), become tarnished and a black film is formed on the surface. The current study deals with the role of copper content and oxygen in the formation of tarnishing in the silver alloys 0.925, 0.800 and 0.720. An ammonium sulfide solution was used as an accelerator of the tarnishing process for different immersion conditions. The analysis of the tarnishing layer in silver alloys was performed by Raman Spectroscopy, Scanning Electron Microscopy - Energy Dispersive X-ray spectroscopy (SEM-EDS) and X-Ray Fluorescence (XRF). The formation of the tarnishing layer was found to be influenced by copper and oxygen contents. The corrosion products under the conditions studied were found to be mainly acanthite and jalpaite.

Synthesis and Characterization of Flower-Like Hematite Nanostructures

2011 ◽  
Vol 287-290 ◽  
pp. 169-172
Author(s):  
Hong Wang ◽  
Xi Yang He ◽  
Ying Wang
Keyword(s):  
Electron Microscopy ◽  
Average Length ◽  
Critical Role ◽  
Average Diameter ◽  
Synthesis And Characterization ◽  
Hydrothermal Route ◽  
X Ray ◽  
Scanning Electron

The flower-like α-Fe2O3superstructures were fabricated by a novel hydrothermal route and sequential annealing at 600 °C for 1 h using FeCl3×6H2O as the starting precursor. The structures and morphologies of the synthesized flower-like superstructures have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM). It is revealed that the flower-like α-Fe2O3nanostructures consist of nanorods with the average diameter of about 70 nm and an average length of about 200nm growing from the centers. The critical role of urea in the hydrothermal synthesis of the flower-like nanostructures is discussed.

scholarly journals Growth and Characterization of Ni Nano-Micro Structures in the Presence of Ethylenediamine

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Lingxiao Chen ◽  
Hang Liu ◽  
Linghao Liu ◽  
Yifan Zheng ◽  
Haodong Tang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alkaline Conditions ◽  
Naoh Solution ◽  
Micro Structures ◽  
Scanning Electron

Ni nano-micro structures have been synthesized via a solution reduction route in the presence of ethylenediamine (EDA) under strong alkaline conditions. The phase composition, morphology, and microstructure of the resulting products are investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The presence of EDA plays an important role in the formation of Ni nano-micro structures, and microflowers or microspheres assembled from nanosized horns can be produced by changing the amount of EDA. The size of Ni nano-micro structures is dependent on the NaOH concentration, and long chains assembled from Ni nano-micro structured microspheres can be obtained by reducing the amount of NaOH solution used. The role of both EDA and NaOH in the reduction of Ni (II) to Ni, as well as in the growth of Ni nano-micro structures, has been discussed, and a possible formation mechanism of these Ni nano-micro structures has been proposed based on the experimental results.

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