scholarly journals Assessment of Corrosion Performance of Steel Rebar in Snail Shell Ash Blended Cements under Marine Environments

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7286
Author(s):  
Raghav Muralidharan ◽  
Karthick Subbiah ◽  
Taejoon Park ◽  
Han-Seung Lee

An attempt has been made on a constructive approach to evaluate the performance of snail shell ash (SSA) for its corrosion performance under marine environments. Corrosion performance of steel rebar in chloride-contaminated SSA with (0% to 50%) replacement levels of cement extract medium was examined through electrochemical and weight loss techniques. Initially, snail shell powder (SSP) is made by pulverizing and subsequently SSA is by thermal decomposition methods. Both SSP and SSA were characterized by X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscopy, and energy dispersion X-ray spectroscopy. Concrete cubes with 0% to 50% replacement levels of cement by SSA were evaluated for their mechanical properties. A critical level of 20 to 30% SSA improved both corrosion resistance and strength of concrete. Extrapolation modeling for the strength and corrosion rate with respect to later age were made. SSA is a suitable replacement material for natural limestone in cement productions.

Author(s):  
M. Abd Elkodous ◽  
(Dr.) Ahmed Hassaan ◽  
Prof (Dr.) KAUSHIK PAL ◽  
(Dr.) A I Ghoneim ◽  
(Dr.) Zizi Abdeen

Synthesis of macro-mesoporous Titania (Titanium dioxide-TiO2) nanospheres was successfully achieved using a modified template-free methodology to incorporate macroporous channels into a mesoporous TiO2 framework to form mixed macro-mesoporous TiO2 spheres (MMPT), which were doped with carbon dots (C-dots) to form improved nanocomposites (C-dots@MMPT). Elemental composition, surface bonding and optical properties of these nanocomposites were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and ultraviolet-visible absorption spectroscopy (UV-VIS). Evaluation of photocatalytic activity for each (C-Dots@MMPT) sample was performed via degrading the Methylene Blue (MB) dye compared with bare samples (MMPT) under visible light irradiation using 300 Watt halogen lamp.


NANO ◽  
2009 ◽  
Vol 04 (03) ◽  
pp. 165-170 ◽  
Author(s):  
XIAO-JUN HU ◽  
JIN-KU LIU ◽  
XIAO-YAN QIN ◽  
JIA HUANG ◽  
YI YI

The hydroxylapatite nanostructures with different morphologies have been synthesized by a facile solution approach. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) technologies, and Fourier transforms infrared spectroscopy (FT-IR). The control mechanism of the hydroxylapatite with various morphologies nanostructures was investigated. Some practical experimental conclusions could be obtained, which were expected to have potential values in crystal engineering research and practical applications.


2009 ◽  
Vol 283-286 ◽  
pp. 250-255 ◽  
Author(s):  
Abdurrahman Bahadir ◽  
Celaletdin Ergun ◽  
Murat Baydogan

Not many studies have been found in the literature on the effect of Ag ions on the structure and phase stability of hydroxylapatite which may be recognized as important information in the scaffold fabrication. The objective of the current study is to develop a better understanding on the structure and behavior of the antibacterial Ag incorporated hydroxylapatite. In order to do this, Ag doped hydroxylapatite was made by a precipitation method, and sintered in air at 1300oC. The materials were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), density measurements and scanning electron microscopy (SEM).


2014 ◽  
Vol 1078 ◽  
pp. 20-24
Author(s):  
Jiang Jie Wang ◽  
Xiao Hong Yang ◽  
Jing Wang ◽  
Qin Tong ◽  
Jin Ku Liu

Zinc phosphate materials which have different morphologies, particle size and good crystalline were prepared via an effective template method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FT-IR). The control mechanism of the zinc phosphate was investigated. Some practical experimental conclusions could be obtained, which were expected to have potential values in synthesis of functional materials.


2015 ◽  
Vol 773-774 ◽  
pp. 1133-1137 ◽  
Author(s):  
Li Sze Lai ◽  
Yin Fong Yeong ◽  
Kok Keong Lau ◽  
Mohd Shariff Azmi

This paper presents the formation of highly crystalline ZIF-8 using microwave-assisted solvothermal method. The crystallinity of the ZIF-8 particles was characterized using X-ray diffraction. The lattice vibrations of the structure in the ZIF-8 framework were determined through Fourier transforms infrared spectroscopy. The morphology of the ZIF-8 particles was observed through scanning electron microscopy. The results showed that, 0.5 hour was sufficient for the formation of highly crystalline ZIF-8 particles using microwave-assisted solvothermal method under temperature 120 oC.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2040
Author(s):  
Munish Kumar ◽  
Ravi Kant ◽  
Suresh Chand ◽  
Ujjwal Prakash ◽  
Shankar Sehgal ◽  
...  

Corrosion behavior of FeAl-based alloys containing carbon produced through arc melting in argon atmosphere has been studied at 500 °C to 700 °C. The samples were tested in the aggressive environment of molten salts (80%V2O5/20%Na2SO4). The corrosion behavior was observed by weight change method and the layer products formed were examined by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The different phase components were observed in the surface layer after the test in Fe-22Al alloy. A protective Al2O3 layer was confirmed for Fe-22Al alloy containing carbon only. However, an additional TiO layer was also observed in Fe-22Al alloy containing carbon with Ti addition. The microstructural and XRD examinations revealed that this additional TiO layer protects better against penetration of corrosive media. The corrosion resistance behavior of FeAl-based alloys were addressed on the basis of microstructural evidence.


1989 ◽  
Vol 94 (3) ◽  
pp. 391-401
Author(s):  
R.W. Kensler ◽  
M. Stewart

A procedure has been developed for isolating gold-fish skeletal muscle thick filaments that preserves the near-helical arrangement of the myosin cross-bridges under relaxing conditions. These filaments have been examined by electron microscopy and computer image analysis. Electron micrographs of the negatively stained filaments showed a clear periodicity associated with the crossbridges, with an axial repeat every 42.9 nm. Computed Fourier transforms of the negatively stained filaments showed a series of layer lines confirming this periodicity, and were similar to the X-ray diffraction patterns of fish muscle obtained by J. Hartford and J. Squire. Analysis of the computed transform data and filtered images of the isolated fish filaments demonstrated that the myosin crossbridges lie along three strands. Platinum shadowing demonstrated that the strands have a right-handed orientation, and computed transforms and filtered images of the shadowed filaments suggest that the crossbridges are perturbed both axially and azimuthally from an ideal helical arrangement.


2019 ◽  
Vol 960 ◽  
pp. 3-8
Author(s):  
Hao Xu Wang ◽  
Yi Qin Cai ◽  
Zhuang Li ◽  
Qi Zhou

Atmospheric corrosion test of TRIP steels was conducted in laboratory. The surface morphologies of the specimens were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and electro-probe microanalysis (EPMA). Corrosion performance of TRIP steels under atmospheric environment was investigated by discussing the protective mechanism. The corrosion rates of steel A are significantly greater than steel B in atmospheric environment tests. The enhancement of corrosion performance of TRIP steel is attributed to the additions of alloying elements, such as P, Cr, Cu, and Ni etc.. The alloying elements increase the compactness and densification of rust layers. Electrochemical characteristic of TRIP steel is improved by means of the enhancement of the thermodynamic stability.


2020 ◽  
Vol 977 ◽  
pp. 195-200
Author(s):  
Hong Tham Thi Nguyen ◽  
Dao Thi To Uyen ◽  
Duy Chinh Nguyen ◽  
Van Thuan Tran ◽  
Tri Duc Lam ◽  
...  

We investigated the fabrication of Ca/Al layered double hydroxide (LDHs) via a one-step hydrothermal approach with slow hydrolysis of urea at a low temperature without further annealing required. The as-synthesized Ca/Al LDHs nanostructures obtained were defined using Fourier transforms infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that Ca/Al LDHs exhibit excellent adsorption performance on Congo red anionic dyes in aqueous solution. The adsorption capacity of the Ca/Al LDHs toward Congo red was found to be 59.41 mg/g.


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