Microstructure of Omani expansive soils

1999 ◽  
Vol 36 (2) ◽  
pp. 272-290 ◽  
Author(s):  
Amer Ali Al-Rawas ◽  
A McGown
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Clay Minerals ◽  
Expansive Soils ◽  
Microstructure Characteristics ◽  
Three Samples ◽  
Two Samples ◽  
Scanning Electron

The fundamental factors controlling the expansive nature of Omani soils are their characteristics with respect to geology, mineralogy, engineering, and microstructure. The first three factors have been extensively studied, however, the fourth has not yet been fully investigated and no work has been published on this aspect. Therefore, this paper deals with the microstructure characteristics of these soils. The scanning electron microscope was employed in this investigation. Three samples selected from different sites where expansive soils problems were known (Al-Khod, Al-Murtafa'a, and Duqm) were investigated. Two specimens from each sample, representing the vertical and horizontal planes, were tested. In addition, two samples that were subjected to swelling were tested to investigate the microfabric changes caused by swelling. The fabric of the Omani expansive soils studied generally consists of dense clay matrices, although clay-granular matrices are occasionally observed. In addition, no connectors have been observed and only few aggregations have been seen. Pore spaces are mainly of the intra-assemblage and intra-elemental types. Significant microfabric changes were induced by swelling.Key words: microstructure, microfabric, SEM, expansive soils, Oman, clay minerals.

Comparative evaluation of surface roughness and texture of polished nanofill and nanohybrid composites using profilometer and scanning electron microscope: in - vitro study

2017 ◽  
Vol 9 (2) ◽  
pp. 4-10
Author(s):  
Krishna Prasada L ◽  
Jyothsna S Jathanna ◽  
Naveen Kumar ◽  
Ramya M.K ◽  
Elizabeth Issac
Keyword(s):  
Surface Roughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Resin Composite ◽  
In Vitro Study ◽  
Average Value ◽  
Three Samples ◽  
Group B ◽  
Scanning Electron

BACKGROUND: To determine the effectiveness of three polishing systems on three different composite materials by evaluating surface roughness using a Profilometer and Scanning electron microscope. METHODOLOGY: A total of Sixty-three resin composite disks were prepared in rectangular acrylic mould of 8×2mm dimension, with 4mm thickness. Specimens were made of light activated resin composite Filtek Z-250-XT, Tetric-N-Ceram bulkfill, Ceram X Duo. The sixty-three samples were divided into three groups of twenty-one samples each i.e. Group A (Filtek Z-250-XT), Group B (TetricN-Ceram bulkfill) and Group C (Ceram-X-Duo).Out of 21 samples of each of the material, 7 specimens were polished with multi enhance polishing agents, 7 specimens were polished with super snap polishing agents and 7 specimens were polished with sof-lexdiscs.Surface roughness of each sample after polishingwasevaluatedusingProfilometer and Scanning electron microscope. RESULTS: One-way anova and kruskalwallis test was used for statistical analysis. Ceram-X-Duo gave least roughness average value with Super snap polishing system when compared to multi enhance and sof-lex polishing system. CONCLUSION: Super snap polishing system is a better polishing system than multi enhance and soflex and Ceram-X-Duo composite material offers better polishability compared to Filtek Z-250-XT and Tetric-N-Ceram bulk fill.

Characterization of Thai Amulets: A PIXE Study

2011 ◽  
Vol 324 ◽  
pp. 505-508 ◽  
Author(s):  
Krit Won-In ◽  
Songtam Suksawang ◽  
Sawet Intarasiri ◽  
Chom Thongleurm ◽  
Teerasak Kamwanna ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Emission Spectroscopy ◽  
Energy Dispersive ◽  
X Ray ◽  
Two Samples ◽  
Fluorescence Spectrometer ◽  
First Time ◽  
Scanning Electron

The Thai amulets that created in an image of Lord Buddha meditation were made to explain the Dharma of Buddha and believed to bless every life in this world for good karma. Phra Somdej Wat Rakhang amulet is the top of the five most famous Thai amulets. There are many molds with various compositions. In this work, it was the first time that X-ray fluorescence spectrometry methods; scanning electron microscope cooperated with energy dispersive X-ray fluorescence spectrometer (SEM/EDS) and particle induced X-ray emission spectroscopy (PIXE) were carried out to analyze their compositions. Two samples were collected from different molds. Results revealed C, Ca and Si were main composition. The differences in their compositions have been used to identify and characterize for each molds.

scholarly journals Experimental study of petrophysical properties of a tight formation by considering the clay minerals and flow sensitivities

2016 ◽  
Vol 20 (2) ◽  
pp. 1 ◽  
Author(s):  
Guangfen Liu ◽  
Shoujun Li ◽  
Daihong Gu ◽  
Yang Lu ◽  
Emmanuel Asamoah
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Clay Minerals ◽  
Field Emission ◽  
Petrophysical Properties ◽  
X Ray Diffraction ◽  
Acid Sensitivity ◽  
X Ray ◽  
Scanning Electron ◽  
Tight Formation

Quantitative X-ray diffraction analysis of rock, X-ray diffraction analysis of clay minerals types and components, Field Emission Scanning Electron Microscope (FESEM) and sensitivity flow experiments methods were used toresearch the effects of clay minerals on the porosity and permeability of Ordos Basin’s tight Chang 7 reservoir (Zhenbei area). These methods were also used to analyze the type, degree, and factors affecting reservoir sensitivity. The research showed that the reservoir possessed poor water, salt, and alkali sensitivity, poor to strong acid sensitivity and none to poor velocity sensitivity. Acid sensitivity among them had comparatively large differences, mainly because acid sensitivity was not only affected by chlorite but also by components of carbonate minerals. Stress sensitivity experiment results showed that the maximum degree of permeability damage in the rocks of this reservoir was median to very strong; irreversible damage level was weak to strong. Consequently, the experimental studies are favorable to not only determine the factor dominating the petrophysical properties of the tight formation, but also to optimize the follow-up development strategies, e.g. injection schedule and hydraulic fracturing implement. Estudio Experimental de las propiedades petrofísicas de una formación compacta al considerar las arcillas minerales y las respuestas de flujo ResumenEste trabajo utilizó análisis cuantitativos de rocas por difracción de rayos X, análisis de los tipos y componentes de arcillas minerales por difracción de rayos X, análisis con el microscopio electrónico de efecto de campo (FESEM, del inglés Field Emission Scanning Electron Microscope) y ensayos de respuesta de flujo para investigar los efectos de las arcillas minerales en la porosidad y permeabilidad del depósito Chang 7, en la cuenca del Ordos (región Zhenbei). Estos métodos también se utilizaron para analizar el tipo, el grado y los factores que afectan la respuesta del depósito. La investigación demuestra que el depósito posee poca agua, sal y respuesta alcalina, baja a fuerte respuesta de acidez, y ninguna a baja respuesta de velocidad. Entre estas características, la respuesta de acidez presentó grandes diferencias comparativas debido a que está afectada tanto por el clorito como por los componentes de minerales carbonatos. Los resultados de los ensayos de respuesta de tensión muestran que el máximo grado de daño por permeabilidad en las rocas del depósito es de mediano a muy fuerte; el nivel de daño irreversible va de débil hasta fuerte. Por lo tanto lo estudios experimentales son favorables no solo para determinar el factor dominante en las propiedades petrofísicas de la formación compacta sino también para optimizar las futuras estrategias de desarrollo, como una programación de las tareas de inyección y la implementación de la fractura hidráulica.

Effect of Corrosion on the Tensile Property of Austenised AISI 1040 Steel Exposed to Stagnant Seawater

2014 ◽  
Vol 12 ◽  
pp. 35-41 ◽  
Author(s):  
Unueroh Ufuoma Georgina ◽  
Basil Onyekpe
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Test ◽  
Tensile Properties ◽  
Tensile Property ◽  
Test Machine ◽  
Two Samples ◽  
The World ◽  
Scanning Electron

Corrosion is a major problem all over the world. A lot of researches on corrosion are ongoing all over the world and will continue to go on. This paper investigates the effect of corrosion on the tensile properties of AISI 1040 steel in seawater. The samples were austenised at 8300C, 9300C, and 10300C, while some were not. The austenised samples were quenched in water and tempered at 5000C. The samples were further machined into tensile test specimens and then exposed to stagnant aerated seawater. Two samples each from each austenised temperature were tested using a tensile test machine at every 15-days interval, for a duration of 90 days. Some of the fracture surfaces were examined using scanning electron microscope. The results shows a 25% decrease in tensile strength for as received sample, 20.1% decrease for samples austenised at 8300C, 20.9% decrease for samples austenised at 9300C and 22.4% decrease for samples austenised at 10300C at the end of the 90thday.

Preparation and Characterizations Cotton Coated Titanium Dioxide, TiO2

2013 ◽  
Vol 832 ◽  
pp. 739-743
Author(s):  
S.K.M. Maarof ◽  
Wahab Suhaida ◽  
M.F. Achoi ◽  
Mohamad Rusop ◽  
Saifollah Abdullah
Keyword(s):  
Titanium Dioxide ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystalline Phase ◽  
Cotton Fiber ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
X Ray ◽  
Three Samples ◽  
Scanning Electron

Cotton coated titanium dioxide, TiO2 was prepared by using immersion method. Three samples with different concentration which are 0.2 M, 0.5 M and 0.6 M of TiO2 solution with fixed value of temperature and time immersion has been used in this project. Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Ultraviolet/Visible (UV-Vis) Spectrophotometer have been used to determine the properties of samples. The surface morphology of the cotton, crystalline phase of TiO2 particles deposited on the cotton fiber and the amount of the TiO2 particles dispersed in the water has been investigated. The existence of TiO2 on the cotton fiber was identified by using SEM and XRD where the immersion method that has been used in this project contributed to the agglomerated TiO2 particles on the surface of cotton fiber. None of the samples showed the formation of anatase crystalline phase of TiO2 particle and UV-Vis showed the released of TiO2 in the water was higher in the first immersion and decreased exponentially for the second, third and fourth immersion.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

Characterization of Sputtered Films using the Scanning Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 44-45
Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Sputtered Films ◽  
Plasma Sputtering ◽  
Microelectronic Devices ◽  
Control Film ◽  
Scanning Electron

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.

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