scholarly journals CHATODOLUMINESCENCE MICROSCOPIC ANALYSIS TO INTERPRET THE REDOX CONDITION DURING THE FORMATION OF CARBONATE VEIN

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
I Wayan Warmada ◽  
Retno Hartati
Keyword(s):  
Microscopic Analysis ◽  
Optical Microscope ◽  
Electron Gun ◽  
Coarse Grained ◽  
Bright Orange ◽  
Luminescence Pattern ◽  
Calcite Deposition ◽  
Reducing Environment ◽  
Red Luminescence ◽  
Growth Zoning

Cathodoluminescence (CL) is generated by an electron gun coupled to an optical microscope. There are two types of chatodoluminescence, i.e., cold CL and hot CL. In the cold cathode microscopic equipment, the electrons are generated by an electric discharge between two electrodes under a low gas pressure, whereas in the hot CL microscope, the electrons are generated by heating a filament (2000–3000°C). In this paper we utilize cold CL combine with electron microprobe analysis (EMPA). The CL microscopy of carbonate shows at least three carbonate generations, i.e., rhodochrosite with dull or no luminescence, Mg-rich calcite with dark red luminescence, manganese-bearing calcite with up to 0.04 wt.% Mn with bright orange luminescence, and pure calcite and Mn-rich calcite (> 0.15 wt.% Mn) with dull or no luminescence. The result also suggests that the luminescence pattern of calcite is controlled by the amount of Mn2+. Sectoral zoning and chevron-shape growth zoning exist in some coarse-grained calcite aggregates. The sectorial zoning of calcite as reflected by dull to bright CL color indicated that slightly to more reducing environment during calcite deposition. Keywords: Chatodoluminescence, rhodochrosite, calcite, sectorial zoning

A correlation of CL emissions from Penrith sandstone with elemental distributions obtained by simultaneous SEM-CL and EDS analysis

1995 ◽  
Vol 53 ◽  
pp. 392-393
Author(s):  
Paul J. Wright
Keyword(s):  
Optical Microscope ◽  
Electron Gun ◽  
High Electron ◽  
Collection System ◽  
Electron Hole ◽  
Depositional Processes ◽  
Eds Analysis ◽  
Distribution Mapping ◽  
Backscattered Electron ◽  
Electron Imaging

Most industrial and academic geologists are familiar with the beautiful red and orange cathodoluminescence colours produced by carbonate minerals in an optical microscope with a cold cathode electron gun attached. The cement stratigraphies interpreted from colour photographs have been widely used to determine the post depositional processes which have modified sedimentary rock textures.However to study quartzose materials high electron densities and kV's are necessary to stimulate sufficient emission. A scanning electron microscope with an optical collection system and monochromator provides an adequate tool and gives the advantage of providing secondary and backscattered electron imaging as well as elemental analysis and distribution mapping via standard EDS/WDS facilities.It has been known that the incorporation of many elements modify the characteristics of the CL emissions from geological materials. They do this by taking up positions between the valence and conduction band thus providing sites to assist in the recombination of electron hole pairs.

The Effect of Grain Size on Superplastic Deformation of Ti-6Al-4V Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 387-392 ◽  
Author(s):  
Wen Juan Zhao ◽  
Hua Ding ◽  
D. Song ◽  
F.R. Cao ◽  
Hong Liang Hou
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Superplastic Deformation ◽  
Initial Strain Rate ◽  
Deformation Mode ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Transmission Electron ◽  
Grain Growth Model

In this study, superplastic tensile tests were carried out for Ti-6Al-4V alloy using different initial grain sizes (2.6 μm, 6.5μm and 16.2 μm) at a temperature of 920°C with an initial strain rate of 1×10-3 s-1. To get an insight into the effect of grain size on the superplastic deformation mechanisms, the microstructures of deformed alloy were investigated by using an optical microscope and transmission electron microscope (TEM). The results indicate that there is dramatic difference in the superplastic deformation mode of fine and coarse grained Ti-6Al-4V alloy. Meanwhile, grain growth induced by superplastic deformation has also been clearly observed during deformation process, and the grain growth model including the static and strain induced part during superplastic deformation was utilized to analyze the data of Ti-6Al-4V alloy.

scholarly journals The Influence of Salt Solution on Morphological Changes in a Geosynthetic Clay Liner

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mochamad Arief Budihardjo
Keyword(s):  
Salt Solution ◽  
Morphological Changes ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Distilled Water ◽  
Nacl Solution ◽  
Geosynthetic Clay Liner ◽  
Clay Liner ◽  
Morphological Variations ◽  
Crystal Deposit

Morphological variations of geosynthetic clay liner (GCL) samples, hydrated with two different permeates, distilled water and NaCl solution (100 mM concentration), were observed in detail using microscopic analysis. After the GCL samples were hydrated with the NaCl solution, they were observed with an optical microscope. While the surface of the treated GCL samples was similar to the surface of the untreated GCL, a crystal deposit was found on the surface of the treated samples. Using a scanning electron microscope (SEM), a more solid appearance was observed for the bentonite particles contained in the GCL after the sample was hydrated with distilled water in comparison to the GCL sample that was hydrated with the NaCl solution. It appears that salt solution hydration results in less swelling of the bentonite particles. Furthermore, the energy-dispersive X-ray spectrometer (EDS) results showed that distilled water hydration had no effect on the distribution of the elements contained in the GCL samples. However, bound chlorine was observed, which demonstrated that the bentonite particles had absorbed the NaCl solution. In addition, changes in the hydraulic conductivity of the hydrated GCL samples were also observed.

Influence of Grain Size on Mechanical Properties in a Fe-9Ni-12Mn-2.5Si-1.0C TWIP Steel

2011 ◽  
Vol 197-198 ◽  
pp. 655-661
Author(s):  
Ze Bin Yang ◽  
Ding Yi Zhu ◽  
Wei Fa Yi ◽  
Shu Mei Lin ◽  
Cheng Mei Du
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Strain Hardening ◽  
Twip Steel ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Microstructure Observation ◽  
Transmission Electron ◽  
Average Grain Size

We investigate the influence of grain size on mechanical properties in a Fe-9Ni-12Mn-2.5Si-1.0C TWIP steel by unidirectional tensile. Meanwhile the microstructures of the TWIP steel were observed and analyzed by optical microscope (OM) and transmission electron microscope (TEM). The experimental results show that the TWIP steel’s yield strength and tensile strength decrease with the increasing of grain size, whereas the plasticity increases with it. When the average grain size reaches to 27μm, the tensile strength is 1080MPa, the elongation percentage is 77%, and the strength-plasticity product achieves the 83160MPa•%. Steel’s strain hardening rate can be changed from three-stage to four-stage with the increasing of grain sizes, the areas of strain hardening by twin deformation mechanism are expanded. Through the microstructure observation we found that, coarse-grained TWIP steel conducts to twinning formation, the high density twins can increase the alloy’s ductility by splitting the grain.

The Degradation of Microstructure of AlCu4Ni2Mg Aluminium Alloy after Prolonged Annealing at Elevated Temperature

2012 ◽  
Vol 186 ◽  
pp. 315-318 ◽  
Author(s):  
Małgorzata Wierzbińska ◽  
Jan Sieniawski
Keyword(s):  
Heat Treatment ◽  
Microscopic Analysis ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Soaking Time ◽  
Al2cu Phase ◽  
Phase Size ◽  
Electron Microscopes ◽  
Prolonged Holding

The influence of long term annealing on microstructure of Al-Cu4-Ni2-Mg aluminum alloy was investigated. The castings were subjected to T6 heat treatment followed by annealing at 523 K and 623 K for 100, 150, 300, 500 and 750 hours. The soaking time and temperature was adjusted by corresponding to real service conditions of the elements of an aircraft and motor engines from investigated alloys. Microstructural examination of the alloy was carried out with optical microscope, as well as scaning and transmissiom electron microscopes. The result of microscopic analysis showed that applied heat treatment caused an increasing in the particles of hardening (θ’-Al2Cu) phase size. The significant growth of the length and changing the value of shape factor of hardening phase precipitations was observed. The phenomenon of the increase in size and change in shape of precipitations of hardening phases continually change with the prolonged holding time at high temperature. The microstructure degradation is connected to a decrease of mechanical properties of alloy, confirmed by the result of tensile tests.

Crack Detection by Wavelet-Based Acoustic Emission Test In Vitro Cemented Implant

2010 ◽  
Vol 638-642 ◽  
pp. 558-563
Author(s):  
Nuno Eduardo Dias Gueiral ◽  
Elisabete Maria da Silva Marques Nogueira ◽  
Antonio Manuel de Amaral Monteiro Ramos
Keyword(s):  
Acoustic Emission ◽  
Wavelet Transform ◽  
Femoral Component ◽  
Crack Detection ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Cement Mantle ◽  
Monitoring Test ◽  
Acoustic Emission Test

One the mechanisms of failure in total hip arthroplasty in cemented prosthesis is cement fatigue. The main objective of this work is to use Acoustic Emission (AE) as a non-destructive and non-intrusive monitoring test in a cemented prosthesis. The femoral component was sinusoidally loading in a fatigue machine. Experimental data collected during acoustic emission test was treated and analysed by Wavelet Transform and allowed to locate a crack in cement mantle of femoral component. Other complementary diagnostic tests were used to confirm the existence of a fault (crack). One of them was penetrating liquids in different cut sections of femoral component. The other one was microscopic analysis that allowed observing the existence of a crack which location is pointed out by the results of AE answer. The AE sources locations are situated inside the crack observed in the optical microscope. The Wavelet Transform (WT) AE signals demonstrated the accuracy of damage location in bone cement and thus becoming useful in other orthopedics studies.

Effect of Nb Content on the Impact Toughness of Coarse-Grained Heat-Affected Zone of Pipeline Steels under Large Heat Input

2014 ◽  
Vol 1078 ◽  
pp. 3-7
Author(s):  
Feng Zhou ◽  
Zhou Gao ◽  
Kai Ming Wu
Keyword(s):  
Heat Affected Zone ◽  
Heat Input ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Electron Backscattered Diffraction ◽  
Pipeline Steels ◽  
Nb Content ◽  
Large Heat ◽  
Austenite Grains ◽  
The Impact

The effect of large heat inputs (200 kJ/cm) on the microstructures and toughness of heat-affected zone of Nb microalloyed X70 pipeline steels were simulated utilizing Gleeble-3800. The microstructures were observed by optical microscope, scanning electron microscope and electron backscattered diffraction technique. Results showed that when the large heat input welding was applied, big austenite grains and coarse microstructures were formed in the coarse-grained heat-affected zone, and thus the toughness of the coarse-grained heat-affected zone was seriously reduced. With the increase of Nb content, the toughness of the CGHAZ did not change remarkably under the large heat input welding.

scholarly journals Parasitism by a Digenea in Lucina pectinata (Mollusca: Lucinidae)

2017 ◽  
Vol 78 (1) ◽  
pp. 94-97
Author(s):  
M. M. Ribeiro ◽  
J. B. Oliveira ◽  
G. Boehs
Keyword(s):  
River Estuary ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Mangrove Sediment ◽  
Brazilian Coast ◽  
Economic Resource ◽  
Lucina Pectinata ◽  
Hematoxylin And Eosin ◽  
Chemical Conditions ◽  
Axis Length

Abstract Lucina pectinata is an important economic resource in the Brazilian coast. This study reports parasitism caused by a Digenea in this species. The specimens (n = 470) were collected in December 2012 in a mangrove swamp of the Cachoeira River estuary, Bahia, Brazil. They were measured along the anterior-posterior axis (length), and after macroscopic analysis for parasites and diseases cuts of 5 mm were fixated in Carnoy’s solution and processed by routine histology technique wherein sessions of 7 μm were stained with Harris hematoxylin and eosin (H&E). The tissues were examined using an optical microscope. The mean length of L. pectinata was 4.0 ± 0.53 cm. Microscopic analysis showed sporocysts containing both germ balls as cercariae of an unidentified Digenea (Platyhelminthes), these in various stages of development. The prevalence was 1.48% (7/470). In a parasitized specimen was macroscopic evidence of tissue densification of gills. The sporocysts were observed in mantle, gills, digestive gland and gonads, with evident alteration/destruction of tissues, including parasitic castration. There were no other parasites found, which is probably related to inaccessibility and chemical conditions in which lives L. pectinata, i.e., between 10 and 20 cm in mangrove sediment.

Microstructures and Mechanical Properties of Bulk Nanocrystalline Fe3Al Materials With 5, 10 and 15 wt. % Cu Prepared by Aluminothermic Reaction

2011 ◽  
Vol 236-238 ◽  
pp. 2191-2196 ◽  
Author(s):  
Yu Peng Wei ◽  
Pei Qing La ◽  
Mei Dan Que ◽  
Wen Sheng Li ◽  
Yang Yang ◽  
...  
Keyword(s):  
Yield Strength ◽  
Optical Microscope ◽  
Matrix Phase ◽  
Coarse Grained ◽  
Compressive Yield Strength ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Aluminothermic Reaction ◽  
Transmission Electron ◽  
Bulk Nanocrystalline

Bulk nanocrystalline Fe3Al based materials with 5, 10 and 15 wt. % Cu were prepared by aluminothermic reaction in which the melts were superheated about 1600 K before solidification. Microstructures of those materials were investigated by optical microscope, electron probe microanalysis, X-ray diffraction and transmission electron microscope. It was shown that microstructures of the materials consisted of a nanocrystalline matrix phase and a little contamination Al2O3and Fe3AlCxfiber phases. The nanocrystalline matrix phase was composed of Fe, Al and Cu elements and disordered bcc which did not change with content of Cu. Average grain sizes of the nanocrystalline phase of the materials with 5, 10 and 15 wt. % Cu were 18, 24 and 25 nm respectively and that of the material with 5 wt. % Cu was the smallest. Compressive properties of the materials were tested. The material with 5 wt. % Cu has good ductility compared with the materials with 10 and 15 wt. % Cu. Yield strength of the materials was about two times higher than that of coarse grained Fe3Al material. The compressive yield strength of the material with 5 wt. % Cu was higher than those of the materials with 10 and 15 wt. % Cu and its flow stress in compression was up to about 1500 MPa.

Crude Oil and Outdoor Temperature Effects on the Tensile and Creep Properties of Glass Fiber Reinforced Vinylester Composite Pipes

2009 ◽  
Vol 83-86 ◽  
pp. 457-464
Author(s):  
S. Nizamuddin ◽  
Necar Merah ◽  
Z. Khan ◽  
F. Al-Sulaiman ◽  
Mauyed S. Mehdi
Keyword(s):  
Crude Oil ◽  
Environmental Conditions ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Outer Side ◽  
Outdoor Temperature ◽  
Creep Properties ◽  
Wide Range ◽  
Dual Curing ◽  
Composite Pipes

Composites are overtaking their traditional counterpart materials by prooving themselves to be superior alternatives even for their application in harsh environmental conditions. The technological innovations and developments in manufacturing processes, which lead to a wide range of new composite products, have made them attractive candidates for applications in oil & gas industry, with their application ranging from oil production to transportation. Lack of enough data regarding their long-term environmental and mechanical durability has been a major hinderance in their full-fledge application. This paper investigates the effect on the tensile and creep strength of filament wounded E-glass/vinylester composite pipes (GFRV) exposed to a combination of crude oil and outdoor temperature conditions of Dhahran. The variation in the tensile and creep properties is considered for exposure periods of 6, 12 and 24 months. The combined crude oil filled GFRV pipes exposed to outdoor environmental conditions for a periods of 6, 12 and 24 months have shown a constant increase in the tensile and creep strengths respectively, when compared with the as-received GFRV samples. This increase in the tensile and creep strengths may be attributed to the dual curing of the GFRV pipes i.e both the outer side and inner side of the pipes due to outdoor temperature and crude oil respectively. Microscopic analysis of fractured surfaces using optical microscope and SEM is used to characterize the failure mechanisms responsible.

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