Geopolymer Microstructure and Hydration Mechanism of Alkali-Activated Fly Ash-Based Geopolymer

2011 ◽  
Vol 374-377 ◽  
pp. 1481-1484 ◽  
Author(s):  
Yao Jun Zhang ◽  
Hai Hong Li ◽  
Ya Chao Wang ◽  
De Long Xu
Keyword(s):  
Electron Microscope ◽  
Fly Ash ◽  
Scanning Electron Microscope ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Alkaline Condition ◽  
Average Particle ◽  
Hydration Mechanism ◽  
Alkali Activated ◽  
Scanning Electron

The microstructure and hydration mechanism of alkali-activated fly ash-based geopolymer were studied by means of scanning electron microscope (SEM) coupled with energy dispersive X-ray analysis (EDXA) and field emission scanning electron microscope (FESEM). The FESEM photomicrographs indicted that the fly ash-based geopolymer showed three dimensional frameworks with an average particle size of 50 nm. EDXA results demonstrated that the Na-PSS type geopolymer was produced via the disintegration of Si-O-Al and Si-O-Si chemical bonds and the polycondensation reaction between [SiO4]4-and [AlO4]5- tetrahedrons in spherical fly ash particles under alkaline condition.

Preparation of Cr2O3 Nanoparticles via Hydrothermal Reduction of CH3OH

2012 ◽  
Vol 463-464 ◽  
pp. 760-763
Author(s):  
Zhen Zhao Pei ◽  
Hong Bin Xu ◽  
Yi Zhang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Average Particle Size ◽  
Average Particle ◽  
Calcination Temperatures ◽  
Cr2o3 Nanoparticles ◽  
Average Size ◽  
Hydrothermal Reduction ◽  
Scanning Electron

Nanoparticles of Cr2O3 were successfully obtained via hydrothermal reduction of CH3OH. The oxidant and chromium source was CrO3. The process needs no stirrer or surfactant and the CrO3 concentration was 0.83mol/L. The obtained products were loosely agglomerated Cr2O3 nanoparticles with the average size of 29 to 79 nm. Influences of reactant ratios and calcination temperatures on the specific surface area and average particle size were discussed. And the morphology of nanoparticles was investigated by use of field-emission scanning electron microscope.

Control of the Crystal Morphological Characteristic and Size of Nano-PCC via Turbo-Mixing Reactive Precipitation

2015 ◽  
Vol 754-755 ◽  
pp. 770-774
Author(s):  
Mohd Darus Daud ◽  
Aimi Noorliyana Hashim ◽  
Azmi Rahmat ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Ahmad Hadzrul Iqwan Jalauddin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Rotation Speed ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Mixing Conditions ◽  
Precipitated Calcium Carbonate ◽  
Novel Technology ◽  
Scanning Electron

An innovative and novel technology method of processing called Turbo-Mixing Reactive Precipitation (TMRP) design proposed as an alternative to this current processing or conventional productions of fine precipitated calcium carbonate (nanoPCC) in turbo-mixing conditions. In this paper, the effect of the stirring rate onto morphology, particle sizes and reaction time of the precipitated CaCO3 particles was discussed. CaCO3 nanoparticles with an average particle size of approximately 15.75 nm were successfully obtained by stirring rotation speed at 900 rpm. The structural analysis was conducted using a Scanning Electron Microscope (SEM) and a Field Emission Scanning Electron Microscope (FESEM). The results showed that the increasing of the multiple’s impeller stirring rotation speed is in favor of the formation of the spherical vaterite.

Microstructures of Low Angle Boundaries of the Second Generation Single Crystal Superalloy DD6

2011 ◽  
Vol 284-286 ◽  
pp. 1584-1587
Author(s):  
Zhen Xue Shi ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Single Crystal ◽  
Second Generation ◽  
Three Dimensional ◽  
Single Crystal Superalloy ◽  
Transition Electron ◽  
Scanning Electron

The specimens of low angle boundaries were machined from the second generation single crystal superalloy DD6 blades. The microstructures of low angle boundaries (LAB) were investigated from three scales of dendrite, γ′ phase and atom with optical microscopy (OM), scanning electron microscope (SEM), transition electron microscope (TEM) and high resolution transmission electrion microscopy (HREM). The results showed that on the dendrite scale LAB is interdendrite district formed by three dimensional curved face between the adjacent dendrites. On the γ′ phase scale LAB is composed by a thin layer γ phase and its bilateral imperfect cube γ′ phase. On the atom scale LAB is made up of dislocations within several atom thickness.

scholarly journals Three-dimensional Observation of the Rat Endocrine Pancreas by a Scanning Electron Microscope

1990 ◽  
Vol 12 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Masanori HISAOKA ◽  
Joji HARATAKE ◽  
Osamu YAMAMOTO ◽  
Akio HORIE
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Endocrine Pancreas ◽  
Three Dimensional ◽  
Scanning Electron

scholarly journals Ultrastructure of Human Fertile Hydatid Cysts Using a Scanning Electron Microscope (SEM)

2020 ◽  
Vol 1 (3) ◽  
pp. 52-55
Author(s):  
Hadi M. Hamza Al-Mayali ◽  
Hind A. Abdul Kadhim
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Zoonotic Diseases ◽  
Hydatid Cysts ◽  
Germinal Layer ◽  
Transmission Electron ◽  
The World ◽  
Laminated Layer ◽  
Scanning Electron

Introduction: Echinococcosis and hydatidosis caused by the metacestode of Echinococcus granulosus are among the most important zoonotic diseases in the world. This study aims to study the ultrastructure of fertile hydatid cysts that infect humans using a scanning electron microscope (SEM). Materials and Methods: Twenty samples of human fertile hydatid cysts were collected from the human liver and lung after performing surgery operations and examined with an SEM. Results: The results of the electron microscopy with different magnifications revealed that the laminated layer (LL) consists of sheets that appeared more compact and aligned. The brood capsules appeared, consisting of a net of finger-shaped structures that emerged from bulges of various sizes and shapes. Conclusion: Under a transmission electron microscope, it was found that the LL had a coherent and flexible structure, settling on a three-dimensional microscopic network of hydrophilic fibers, with high humidity. These fibers were arranged irregularly and had a diameter of about 10 nm; therefore, the fibers adjacent to the germinal layer (GL) were possibly attached to microtriches of tegument, which reached a thickness of 1 mm in the LL.

Highly sensitive compression sensors using three-dimensional printed polydimethylsiloxane/carbon nanotube nanocomposites

2019 ◽  
Vol 30 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Mohammad Charara ◽  
Mohammad Abshirini ◽  
Mrinal C Saha ◽  
M Cengiz Altan ◽  
Yingtao Liu
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Carbon Nanotube ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Multi Walled Carbon Nanotube ◽  
Highly Sensitive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This article presents three-dimensional printed and highly sensitive polydimethylsiloxane/multi-walled carbon nanotube sensors for compressive strain and pressure measurements. An electrically conductive polydimethylsiloxane/multi-walled carbon nanotube nanocomposite is developed to three-dimensional print compression sensors in a freestanding and layer-by-layer manner. The dispersion of multi-walled carbon nanotubes in polydimethylsiloxane allows the uncured nanocomposite to stand freely without any support throughout the printing process. The cross section of the compression sensors is examined under scanning electron microscope to identify the microstructure of nanocomposites, revealing good dispersion of multi-walled carbon nanotubes within the polydimethylsiloxane matrix. The sensor’s sensitivity was characterized under cyclic compression loading at various max strains, showing an especially high sensitivity at lower strains. The sensing capability of the three-dimensional printed nanocomposites shows minimum variation at various applied strain rates, indicating its versatile potential in a wide range of applications. Cyclic tests under compressive loading for over 8 h demonstrate that the long-term sensing performance is consistent. Finally, in situ micromechanical compressive tests under scanning electron microscope validated the sensor’s piezoresistive mechanism, showing the rearrangement, reorientation, and bending of the multi-walled carbon nanotubes under compressive loads, were the main reasons that lead to the piezoresistive sensing capabilities in the three-dimensional printed nanocomposites.

scholarly journals Preparation of ultrafine iron phosphate micro-powder from phosphate slag

2018 ◽  
Vol 238 ◽  
pp. 02002
Author(s):  
Fangjing Sun ◽  
Yi Zhang ◽  
Jiawei Zhang ◽  
Xixi Yan ◽  
Xiaoyu Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Electron Microscope ◽  
Average Particle Size ◽  
Iron Phosphate ◽  
Average Particle ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Phosphate Slag ◽  
Scanning Electron

In this experiment, ultrafine iron phosphate micro-powder was prepared by hydrothermal method which used phosphate slag as an iron source. The effects of reaction temperature, surfactants type and amount on its particle size were explored. The samples were characterized by using Malvern Laser Particle Size Analyzer (MS2000), X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX).The results showed that at 160 °C, 1 wt%CTAB, monoclinic iron phosphate micro-powder was obtained with an average particle size about 0.4 μm which also has a good dispersion in aqueous solution.

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