Dentin Caries Recording with Schiff's Reagent, Fluorescence, and Back-scattered Electron Image

1993 ◽  
Vol 72 (12) ◽  
pp. 1588-1592 ◽  
Author(s):  
E.-L. Hietala ◽  
L. Tjaderhane ◽  
M. Larmas
Keyword(s):  
Ultraviolet Light ◽  
Scattered Electron ◽  
Mineral Contents ◽  
Mandibular Molar ◽  
Electron Image ◽  
Back Scattered Electron Image ◽  
Tetracycline Labeling ◽  
Normal Light ◽  
Carious Process ◽  
Caries Lesions

After being weaned, the Wistar rats (12) were fed on a sucrose diet for five weeks to induce dental caries. Tetracycline was injected intraperitoneally into 7 of them to label the mineralizing dentin front. Five rats without tetracycline injection were used to verify spontaneous fluorescence. The evidently carious area under one prominent fissure from each mandibular molar hemisected sagittally in the midline was photographed under ultraviolet light so that autofluorescence would be revealed. The jaws were then stained with Schiff's reagent and photographed under normal light and again under ultraviolet light. The areas of all the lesions were quantified planimetrically as they appeared on the photographs. The mineral contents of the areas were verified with the back-scattered electron images. The caries lesions revealed with Schiff's reagent also exhibited a change in the color of the dentin fluorescence regardless of the tetracycline labeling. The areas of these lesions followed the shapes of the lesions stained by Schiff's reagent but they were greater. Staining with Schiff's reagent was repeatable after the specimen was washed with ethanol for a few weeks. The loss of minerals was seen in the areas stained with Schiff's reaction but was also related to the change in dentin fluorescence, which seems to be a more sensitive indicator of the caries progression than Schiff's reagent, especially in the early phase of the carious process.

scholarly journals Hf-Zr interdiffusion in single crystal zircon II: determination by back-scattered electron image.

1995 ◽  
Vol 29 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Hiroshi Nagasawa ◽  
Hisayoshi Yurimoto ◽  
Masana Morioka
Keyword(s):  
Single Crystal ◽  
Scattered Electron ◽  
Electron Image ◽  
Back Scattered Electron Image

The effect of specimen tilt on back-scattered electron image contrast in scanning electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 506-507
Author(s):  
X. Meng-Burany ◽  
A.E. Curzon
Keyword(s):  
Electron Beam ◽  
Image Contrast ◽  
Reference Specimen ◽  
Scattered Electron ◽  
Simple Method ◽  
Sputtered Films ◽  
Electron Image ◽  
Backscattered Electron ◽  
Back Scattered Electron Image ◽  
Image Position

The present work concerns the back-scattered electron image contrast of a thin film of Cu64Mo36 on a silicon substrate. The contrast is defined by the ratio(1)where If and Ib are the backscattered electron signals from the film and from an adjacent bulk reference specimen. In previous work on thin sputtered films of Cu-Mo, Cu-W and Cu-Al both the film and the bulk reference specimen were perpendicular to the incident electron beam. It was found that the dependence of r on the accelerating voltage of the electron beam could be used to obtain both the thickness and the composition of the films. It is the purpose of the present work to determine whether the simple method previously used to extract the required information can be extended to include tilted specimens. As will be seen the method can be adapted to films tilted by less than 50°.

scholarly journals The failure process of mortars during sulfate attack

2019 ◽  
Vol 39 (3) ◽  
pp. 221-228
Author(s):  
Kaiwei Liu ◽  
Aiguo Wang ◽  
Daosheng Sun ◽  
Yan Li ◽  
Jinhui Tang
Keyword(s):  
Failure Process ◽  
Surface Damage ◽  
Scattered Electron ◽  
Transition Zones ◽  
Strength Failure ◽  
Wide Range ◽  
Deterioration Process ◽  
Damage Process ◽  
Electron Image ◽  
Back Scattered Electron Image

External sulfate attacks on concrete structures may cause serious damage and it has attracted a wide range of attention from numerous researchers over the past decades. However, many studies have been concentrated on the sample which has been already destroyed. This paper investigated the entire deterioration process of mortars that were immersed in Na2SO4 solution containing 3 gSO4 2-/L and 33.8g SO4 2-/l at 20 o C up to 600 days. The study on time-varying regularity of expansion, cracks, compressive strength and mineral phases was investigated. Back scattered electron image was used to further examine the evolution of microstructures of the mortars during the attack process. The results showed that damage process of mortars can be described as induction stage, surface damage, bulk damage and then completely damage stage. Fine ettringites that were formed in restricted spaces, approximately 2-5 μm, result in surface damage. At the bulk damage stage, cracking was the main characteristic of mortar which leads to obvious expansion. In this stage, some large ettringite crystals (>20μm) were just deposited in the formed cracks. At the later stage, gypsum can be easily formed at interfacial transition zones as the consumption of calcium hydroxide, which mainly contributed to completely strength failure rather than expansion.

Sunlight exposure caused yellowing and increased mineral content in wool

2010 ◽  
Vol 50 (4) ◽  
pp. 300 ◽  
Author(s):  
M. R. Fleet ◽  
K. R. Millington ◽  
A. L. King
Keyword(s):  
Trace Metals ◽  
Ultraviolet Light ◽  
Mineral Content ◽  
Kojic Acid ◽  
Sunlight Exposure ◽  
Aqueous Alcohol ◽  
Mineral Contents ◽  
Base Level ◽  
Copper Chelator ◽  
Chelating Compounds

This study determines how levels of various trace metals in wool and the colour of the fibre change as a result of sunlight exposure and treatment with chelating compounds during wool growth. Twenty-four yearling Merino sheep were clipped on the shoulders and rumps and fitted with sheep coats modified with transparent patches. Patches over the shoulder wool (one per sheep) were either polyethylene (PE) that transmits ultraviolet light or polyvinyl chloride (PVC) that excludes ultraviolet light. The rump wool on each sheep was treated either with a copper chelator treatment (kojic acid or methyl gentisate in aqueous alcohol) or aqueous alcohol only. For 12 of the sheep the rumps were exposed to sunlight through PE patches while rump wool on the other sheep was covered by the sheep coat. Wool was harvested after 11 weeks’ growth with yellowness (Y-Z) and individual mineral contents measured using the same clean wool sample. Sunlight exposure through PE patches caused a mean increase in Y-Z to 9.1 (shoulder) or 9.5–10.1 (rump) from a base level of 7.1–7.2 (shoulder) or 7.0–7.6 (rump) in wool protected by the sheep coat. In contrast, there was no significant change in Y-Z for the PVC patch (shoulder). Therefore, it appears that ultraviolet light damage caused the increased Y-Z. Most of the trace metals analysed increased in the shoulder wool exposed to sunlight but the paired differences for PVC were lower than PE. It appears that changes in fibre caused by sunlight exposure (especially ultraviolet light) facilitate adsorption of minerals from the environment, including the animal’s own suint. Application of the chelating compounds to the rump wool caused pronounced yellowing of the wool with Y-Z increase being most pronounced for kojic acid. Copper levels in the wool were reduced by kojic acid and methyl gentisate while calcium levels were increased by kojic acid and reduced by methyl gentisate. It is not clear from these findings whether minerals and copper in particular contribute to yellowing of wool. However, the different effects of sunlight and chelation on mineral contents in wool shown may well relate to alternative mechanisms of discoloration (i.e. photoyellowing versus bacterial).

Melting study of a peridotite KLB-1 to 6.5 GPa, and the origin of basaltic magmas

1993 ◽  
Vol 342 (1663) ◽  
pp. 105-120 ◽  
Keyword(s):  
Partial Melting ◽  
Mantle Peridotite ◽  
Quantitative Information ◽  
Scattered Electron ◽  
Continental Flood Basalts ◽  
Image Technique ◽  
Electron Image ◽  
Partial Melts ◽  
Institute Of Technology ◽  
Source Materials

With a newly established multi-anvil press in the Tokyo Institute of Technology, we have carried out a series of melting experiments on peridotite KLB-1 up to 6.5 GPa. Melt fractions of the peridotite were determined in a wide P-T range using extensive X -ray mapping analysis of run products by EPMA and a digitalized back-scattered electron image technique. Compositions of partial melts and solid residues were determined in the whole melting range up to 6.5 GPa. Given quantitative information on mantle melting, we discuss conditions of melting of various basalt magmas and the nature of their source materials. Our conclusions are consistent with the hypothesis that typical mid oceanic ridge basalts represent low pressure ( ca . 1 GPa), low temperature ( T p ≈ 1300 °C) partial melting products of mantle peridotite. Island arc picritic tholeiites may also be regarded as partial melts of a peridotitic source, at 1-2 GPa pressures and T p ranging from 1400 to 1500 °C. However, proposed primary magmas for Hawaiian tholeiite are difficult to produce by partial melting of typical mantle peridotite at any depth under anhydrous conditions. Source materials for magmas in large hotspots (e.g. Hawaii, Iceland and some continental flood basalts (CFBS)) may be anomalously enriched in FeO and TiO 2 relative to typical upper mantle peridotites such as KLB-1.

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