scholarly journals ELECTROCHEMICAL PERFORMANCES AND CORROSION INHIBITION OF AA6061 IN TROPICAL SEAWATER

2017 ◽  
Vol 25 (2) ◽  
pp. 251-259
Author(s):  
R. Rosliza ◽  
H.B. Senin ◽  
W.B. Wan Nik
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Electrochemical Performances ◽  
Double Layer Capacitance ◽  
Sem Images ◽  
Corrosion Rates ◽  
Current Densities ◽  
Scanning Electron

The corrosion performances of AA6061 aluminum alloy in tropical seawater was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and their morphology was characterized by the scanning electron microscopy (SEM). The results showed that the presence of sodium benzoate as an inhibitor significantly decrease the corrosion current densities (i corr ), corrosion rates and double layer capacitance (C dl ), whilst increasing the polarization resistance (R p ). The scanning electron microscopy (SEM) images indicated that the mechanism of charge transfer and the formation of thin film have been taken place on the specimens. 

scholarly journals Microscopy Methods for Biofilm Imaging: Focus on SEM and VP-SEM Pros and Cons

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Michela Relucenti ◽  
Giuseppe Familiari ◽  
Orlando Donfrancesco ◽  
Maurizio Taurino ◽  
Xiaobo Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ion Beam ◽  
Ruthenium Red ◽  
Variable Pressure ◽  
Sem Images ◽  
Advantages And Disadvantages ◽  
Pros And Cons ◽  
Microscopy Techniques ◽  
Scanning Electron

Several imaging methodologies have been used in biofilm studies, contributing to deepening the knowledge on their structure. This review illustrates the most widely used microscopy techniques in biofilm investigations, focusing on traditional and innovative scanning electron microscopy techniques such as scanning electron microscopy (SEM), variable pressure SEM (VP-SEM), environmental SEM (ESEM), and the more recent ambiental SEM (ASEM), ending with the cutting edge Cryo-SEM and focused ion beam SEM (FIB SEM), highlighting the pros and cons of several methods with particular emphasis on conventional SEM and VP-SEM. As each technique has its own advantages and disadvantages, the choice of the most appropriate method must be done carefully, based on the specific aim of the study. The evaluation of the drug effects on biofilm requires imaging methods that show the most detailed ultrastructural features of the biofilm. In this kind of research, the use of scanning electron microscopy with customized protocols such as osmium tetroxide (OsO4), ruthenium red (RR), tannic acid (TA) staining, and ionic liquid (IL) treatment is unrivalled for its image quality, magnification, resolution, minimal sample loss, and actual sample structure preservation. The combined use of innovative SEM protocols and 3-D image analysis software will allow for quantitative data from SEM images to be extracted; in this way, data from images of samples that have undergone different antibiofilm treatments can be compared.

scholarly journals Corrosion Inhibitive Action and Adsorption Behaviour of Justicia Secunda Leaves Extract as an Eco‐Friendly Inhibitor for Aluminium in Acidic Media

2021 ◽  
Vol 11 (5) ◽  
pp. 13019-13030
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weight Loss ◽  
Electrochemical Impedance ◽  
Physical Adsorption ◽  
Charge Transfer Resistance ◽  
Aluminum Surface ◽  
Protective Film ◽  
Transfer Resistance ◽  
Scanning Electron

The extract of Justicia secunda (JS) leaves was investigated as an eco‐friendly corrosion inhibitor of aluminum in 0.5 M HCl using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and scanning electron microscopy (SEM) techniques. The inhibitor concentrations used ranged from 50 to 250 ppm at 30, 40, and 50oC. Results show that Justicia secunda acts as a good inhibitor for aluminum. Its efficiency increased with increasing inhibitor concentration but decreased with increasing temperature. Maximum inhibition efficiency as high as 94.3% was found at 30°C for 250 ppm of the inhibitor with the weight loss technique. Tafel polarization results show that the extract acts as a mixed-type inhibitor. The Nyquist plots indicated decreasing double-layer capacitance and increasing charge transfer resistance on increasing JS concentration. The inhibition action occurred through the physical adsorption of the extract on the aluminum surface. The adsorption process was found to follow Langmuir adsorption isotherm. The formation of a protective film on the metal surface was confirmed by scanning electron microscopy.

Fabrication of Ultra Thick Ferromagnetic Structures in Silicon

2004 ◽  
Author(s):  
Debbie G. Jones ◽  
Albert P. Pisano
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Saturation Magnetization ◽  
Silicon Wafer ◽  
Fabrication Process ◽  
Sem Images ◽  
Deep Reactive Ion Etching ◽  
Scanning Electron

A novel fabrication process is presented to create ultra thick ferromagnetic structures in silicon. The structures are fabricated by electroforming NiFe into silicon templates patterned with deep reactive ion etching (DRIE). Thin films are deposited into photoresist molds for characterization of an electroplating cell. Results show that electroplated films with a saturation magnetization above 1.6 tesla and compositions of approximately 50/50 NiFe can be obtained through agitation of the electrolyte. Scanning electron microscopy (SEM) images show that NiFe structures embedded in a 500 μm thick silicon wafer are realized and the roughening of the mold sidewalls during the DRIE aids in adhesion of the NiFe to the silicon.

Biomimetic Crack Sensors Using Electrohydrodynamic Technology

2021 ◽  
Vol 21 (7) ◽  
pp. 3773-3778
Author(s):  
Keon-Young Kim ◽  
Se-Min Jeong ◽  
Chang-Yull Lee
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crack Initiation ◽  
Health Monitoring ◽  
Grid Structure ◽  
Sem Images ◽  
Impact Tester ◽  
Microscopic Damage ◽  
Pet Substrate ◽  
Scanning Electron

This paper proposes a new mechanism for detecting microscopic damage of structures based on imitating the sensory organs of spiders. Therefore, it is essential to manufacture sensors that can react sensitively to the micro deformations of structures. Numerous cracks were intentionally generated to improve the sensitivity of the proposed sensor, and an increase in the gap of the crack was observed by scanning electron microscopy (SEM) observation. Electrohydrodynamic technology is used to detect deformations in a structure of depositing Ag nano paste on a polyethylene terephtha-late (PET) substrate. Ag nano lines are also observed by SEM images. The sensor is constructed as a grid structure, by forming layers patterned horizontally and vertically. An impact tester is used to verify the mechanism for structural health monitoring using the developed sensor. The resistance changes of the sensors are applied to estimate the structure’s damaged location. The intersections of the lines with varying resistance can be used to accurately detect crack initiation. The proposed mechanism is a powerful methodology for estimating and detecting microscopic deformations and damage to structures.

Effect of moisturized air on magnetoimpedance response of Fe-based ribbons

2020 ◽  
Vol 34 (24) ◽  
pp. 2050249
Author(s):  
L. Yoosefi ◽  
V. Setoodeh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Conditions ◽  
Surface Condition ◽  
High Sensitivity ◽  
Response Ratio ◽  
Sem Images ◽  
Weak Magnetic Fields ◽  
Magnetic Elements ◽  
Scanning Electron

High sensitivity and response ratio of magnetoimpedance (MI) sensors have raised interest for using them in different environments for detection of weak magnetic fields of magnetic elements even though the high dependence of the MI response to the surface condition of the MI sensor has limited its application in some environments. In this study, we investigate the effects originating from the MI measurement in moisturized air. Using scanning electron microscopy (SEM) images, it is observed that the surface of an Fe-based MI sensor has become rough and granular after the presence of moisture on its surface. Results can be useful for developing MI sensors for use in different environmental conditions.

scholarly journals Influence of Monomer Concentration on the Morphologies and Electrochemical Properties of PEDOT, PANI, and PPy Prepared from Aqueous Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Shalini Kulandaivalu ◽  
Zulkarnain Zainal ◽  
Yusran Sulaiman
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Monomer Concentration ◽  
Lithium Perchlorate ◽  
Sem Images ◽  
Eis Measurements ◽  
Scanning Electron

Poly(3,4-ethylenedioxyhiophene) (PEDOT), polyaniline (PANI), and polypyrrole (PPy) were prepared on indium tin oxide (ITO) substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.

scholarly journals C-S-H Pore Size Characterization Via a Combined Nuclear Magnetic Resonance (NMR)–Scanning Electron Microscopy (SEM) Surface Relaxivity Calibration

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1779 ◽  
Author(s):  
Christoph Naber ◽  
Florian Kleiner ◽  
Franz Becker ◽  
Long Nguyen-Tuan ◽  
Christiane Rößler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ion Beam ◽  
New Method ◽  
Sem Images ◽  
Surface Relaxivity ◽  
Scanning Electron ◽  
Nuclear Magnetic

A new method for the nuclear magnetic resonance (NMR) surface relaxivity calibration in hydrated cement samples is proposed. This method relies on a combined analysis of 28-d hydrated tricalcium silicate samples by scanning electron microscopy (SEM) image analysis and 1H-time-domain (TD)-NMR relaxometry. Pore surface and volume data for interhydrate pores are obtained from high resolution SEM images on surfaces obtained by argon broad ion beam sectioning. These data are combined with T2 relaxation times from 1H-TD-NMR to calculate the systems surface relaxivity according to the fast exchange model of relaxation. This new method is compared to an alternative method that employs sequential drying to calibrate the systems surface relaxivity.

Study on Corrosion Behavior of Al-Zn-In and Al-Zn-Ga Alloys in NaCl Solution

2011 ◽  
Vol 284-286 ◽  
pp. 1701-1704
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Gao Lin Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
X Ray ◽  
Inductive Loop ◽  
Capacitive Loop ◽  
Scanning Electron

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.

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