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Buried metal objects in seawater may undergo corrosion because of the corrosive ions such as chloride ions present in seawater. However, a paint coating may control the corrosion of the metal objects such as robots. Corrosion resistance of mild steel in 3.5 % sodium chloride solution before and after coating with Asian guard red paint has been evaluated by polarization study and AC impedance spectra. In presence of Asian guard red paint, the linear polarization resistance increases, corrosion current decreases, charge transfer resistance increases, double layer capacitance decreases and impedance value increases. That is corrosion resistance of mild steel objects in 3.5 % sodium chloride solution increases after coating with Asian guard red paint.

Due to the importance of underwater exploration in the development and utilization of deep-sea resources, underwater autonomous operation is more and more important to avoid the dangerous high-pressure deep-sea environment. For underwater autonomous operation, the intelligent computer vision is the most important technology. In an underwater environment, weak illumination and low-quality image enhancement, as a pre-processing procedure, is necessary for underwater vision. In this paper, introduced the Deep learning based Underwater Metal object detection using input Image data by using several step to improve the model performance. In this experimentation we are using TURBID dataset 100 images to validate the performance. And also we compare the performance result by given the input images in different validation level. In first input image is initially preprocessed and that images is given to the KFCM-Segmentation. The segmented images are given to the DWT Extraction to extract the features from those images. And finally the Convolution Neural Network (CNN) is used to classify the images to detect the objects. Also this proposed model attained the classification accuracy of 98.83%. This method is much suitable for detect the objects in underwater robotically. Metallic parts of machines of ships or aero planes may submerge in sea water. They may undergo corrosion when they come in contact with sea water which contains 3.5% sodium chloride. This is most commonly responsible for the corrosive nature of the sea water. The robots made of materials such as mild steel may also undergo corrosion when they come in contact with sea water, while is search. If a paint coating is given, it will control the corrosion of these proposed materials. Hence this work is undertaken. Mild steel is coated with Asian guard red paint. Corrosion resistance of mild in3.5% sodium chloride solution is measured before coating and after coating by electrochemical studies such as such as polarization study and AC impedance spectra. The corrosion inhibition efficiency offered by red paint to mild steel in 3.5% sodium chloride is 99.98%.

The corrosion performance of α-brass in 1 M HNO3 and in the presence of polyethylene glycol (PEG) has been investigated using AC impedance spectra (EIS), potentiodynamic polarization (PP), electrochemical frequency modulation (EFM), and mass reduction (MR) techniques. The outcome data of EIS showed a rise in the resistance charge transfer (Rct) and a decrease in the capacitance double layer (Cdl). Protection efficiency (IE) of PEG has been obtained by varying the dose of the PEG and temperature. PEG adsorbed on α-brass in acidic solution follows isotherm Langmuir. The polarization curves displayed that PEG acts as a mixed-kind inhibitor. The parameters obtained from thermodynamic activation of corrosion α-brass in 1 M HNO3 were obtained and debated. The results obtained from all tests were in excellent agreement.

Corrosion resistance property of mild steel immersed in simulated concrete pore solution (SCPS) prepared in well water has been evaluated by weight loss method, in the absence and presence of an aqueous extract of Turmeric (Curcuma longa L), The main constituent of the plant extract is curcumin It is observed that in the presence of an aqueous extract of turmeric corrosion inhibition efficiency increases. The mechanistic aspects of corrosion inhibition have been studied by weight loss method, polarisation study and AC impedance spectra. In the presence of the Turmeric extract, the inhibition efficiency increases, linear polarisation resistance value increases; corrosion current decreases; charge transfer resistance value increases and double layer capacitance decreases. Thus it is observed that in the presence of turmeric inhibitor the corrosion resistance of mild steel incorporated in concrete structure increases. Thus the corrosion resistance of mild steel incorporated in concrete structure can be improved by addition of an aqueous extract of turmeric.

High Temperature Polymer Electrolyte Membrane Fuel Cells, (HT-PEMFCs), are one of the most promising alternatives of clean power production by converting chemical energy to electrical energy. Even though the operating principles of an HT-PEMFC are understood, the overall system’s behavior is determined by a number of strongly coupled processes, each proceeding at a different rate.In a HT-PEMFC the elusive multistep Oxygen Reduction Reaction, (ORR), taking place at the cathodic electrode takes a major fraction of the open circuit potential. Thus, in order to optimize fuel cell performance by minimizing ORR power losses, an in depth understanding of the various processes and their interactions is necessary. One of the most powerful electrochemical characterization methods is the Electrochemical Impedance Spectroscopy technique, (EIS). It is a very powerful and sensitive in situ technique that has the ability to separate potential losses corresponding to different processes which proceed at different rates, (have different timescales), [1]. Our research revealed that ORR impedance spectrum consists of two arcs, a high frequency arc attributed to the charge transfer reactions across the interface and a low frequency arc due to the hysteresis phenomena between the oxygenated intermediate species coverage and the current dynamic response, (ORR relaxation impedance), [2]. Thus, by simulating the AC impedance spectra through the development of an appropriate physical model, valuable information on the electrochemical and chemical process at the electrode can be drawn. In order to demystify the multistep ORR kinetics a 1-D dynamic mathematical model has been developed in order to simulate AC impedance spectra at the low current linear activation region while at the same time a Monte Carlo type algorithm was used to estimate the values of the respective kinetic constants by simultaneously fitting polarization-dc bias and the corresponding galvanostatic AC Spectra. The model incorporates a three-step proposed mechanism for the ORR as well as a detailed macroscopic description of mass and charge transfer across the various parts of the Membrane Electrode Assembly, (MEA). The low current activation regime of operation was chosen because there the ORR overpotential dominates the AC spectra, the effect of the finite electrolyte conductivity and mass transport limitations are minimized and the adsorbed intermediate relaxation impedance is prominent while it diminishes at higher current densities as can be seen in Figure 1. As a result, the cathodic overpotential is constant throughout the cathodic electrode which may be well considered to operate under ideal kinetic conditions allowing thus an analytic expression for the HT-PEMFC impedance to be developed and used in the identification of the ORR kinetics. As far as validation of our approach is concerned, synthetic AC Impedance Spectra with known kinetic constants where produced and utilized by the Monte Carlo fitting algorithm at the low current operation regime. Figure 2 shows the histograms of the fitting algorithm for the OH intermediate reduction kinetic constant, by employing different number of bias points (I-V) and their respective AC spectra the algorithm successfully converges to the set value for k3+ , (k3+ =2*10-6 mol/(m2s)). By decoupling the various processes of the simulated AC impedance spectra, information was successfully extracted on the various kinetic and equilibrium constants related with the interaction of the reacting gases in the catalytic layer and the electrochemical interface. [1] O. Antoine, Y. Bultel, and R. Durand, Journal of Electroanalytical Chemistry, vol. 499, no. 1, pp. 85–94, Feb.2001. [2] X. Yuan, H. Wang, J. Colinsun and J. Zhang. 2007. International Journal of Hydrogen Energy, Volume:32, 4365-4380. This work has been conducted and supported within the framework of DeMStack, (DEMSTACK 325368, FCH-JU-2012-1). Figure 1

Solid electrolytes with high Mg-ion conductivity are required to develop solid-state Mg-ion batteries. The migration energies of the Mg2+ ions of 5,576 Mg compounds tabulated from the inorganic crystal structure database (ICSD) were evaluated via high-throughput calculations. Among the computational results, we focused on the Mg2+ ion diffusion in Mg0.6Al1.2 Si1.8O6, as this material showed a relatively low migration energy for Mg2+ and was composed solely of ubiquitous elements. Furthermore, first-principles molecular dynamics calculations confirmed a single-phase Mg2+ ion conductor. The bulk material with a single Mg0.6Al1.2Si1.8O6 phase was successfully prepared using the sol-gel method. The relative density of the sample was 81%. AC impedance measurements indicated an electrical conductivity of 1.6 × 10−6 Scm−1 at 500°C. The activation energy was 1.32 eV, which is comparable to that of monoclinic-type Mg0.5Zr2(PO4)3., GRAPHICAL ABSTRACT

The corrosion resistance of 18 K gold in artificial saliva, in the absence and presence of Gemer-2 Tablet (orally taken by type 2 Diabetes) has been evaluated by polarization study and AC impedance spectra. Polarisation study reveals that in the presence of Gemer-2, LPR value increases and corrosion current decreases. That is in presence of Gemer-2, the corrosion resistance of 18K Gold in artificial saliva increases. AC impedance study reveals that in the presence of Gemer-2, R t value increases and C dl decreases. That is in the presence of Gemer-2 the corrosion resistance of 18 K Gold in AS increases. It is concluded that people clipped with orthodontic wire made of 18K Gold need not hesitate to take Gemer-2 orally.

The influences of trace water on electrochemical performances for lithium ion batteries are investigated by adjusting the trace water in the electrolyte. Electrochemical performances and AC impedance spectra are tested after the first process of lithiation. Results indicate that the battery comprehensive electrochemical properties change little when the water content is less than 211.3 ppm in electrolyte, however, the battery capacity attenuates wh en the water content is more than 211.3 ppm, results that the impedance increases sharply.

The properties of interfaces of water-stable lithium electrode have been investigated by EIS in Li–air batteries and four-electrode test-cells. The water-stable lithium electrode was prepared with the protection of NASICON-type glass–ceramic plate [0.8Li 2 O·0.25Al 2 O 3 ·1.5GeO 2 ·1.5P 2 O 5 glass–ceramic (LAGP)]. The glass–ceramic plates are water-stable and 200–500 μm thick with ion-conductivity of 4 × 10 −4 S cm −1 . In Li–air batteries, the AC impedance spectra of LAGP protected lithium electrode contained two semicircles and became three after one week. The composition of impedance of LAGP protected lithium electrode was analyzed, by comparison on the impedance spectra of LAGP protected lithium electrode and bare Li metal electrode in organic electrolyte. Furthermore, in four-electrode test-cell which excluded the LAGP|aqueous-solution interface, the interface impedance of LAGP plate was analyzed. And then by the analysis of impedance, the Li|organic-electrolyte interface caused the main impedance of the water-stable lithium electrode during the discharge. The impedance of water-stable lithium electrode should be decreased by the study of new electrolyte and interface modification.

The inhibition efficiency of the formulation consisting of Triisopropanol amine (TIPA) and Zn 2+ in controlling the corrosion of mild steel in aqueous solution containing 60 ppm Cl - has been evaluated by the weight loss method. The formulation consisting of 100 ppm TIPA, and 50 pm Zn 2+ has 62.5% inhibition efficiency TIPA alone has 46% efficiency. The nature of the protective film has been analyzed by polarization study, AC impedance spectra. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from the weight loss method, polarized study, AC impedance spectra and FTIR spectra. Keywords: Synergism, TIPA, Polarization study, AC impedance and FTIR spectra.

The inhibition efficiency (IE) of an aqueous extract of Hibiscus rosa-sinensis (white) in controlling corrosion of aluminium at pH 12 has been evaluated by weight loss method in the absence and presence of Zn 2+ . The formulation consisting of 8 mL flower extract (FE) and 50 ppm of Zn 2+ had 98% inhibition efficiency. Polarization study revealed that this formulation functioned as cathodic inhibitor. AC impedance spectra revealed the presence of a protective film formed on the metal surface. FTIR spectra revealed that the protective film consisted of a complex formed between the active principle of the flower extract and Al 3+ .

The use of stainless steel 304(SS) tanks to deposit thiourea in industry has been evaluated by studying the corrosion behaviour in 1% thiourea solution, before and after zinc plating. Weight loss method, 1% copper sulphate test, polarization study and AC impedance spectra have been used. The corrosion resistance of SS decreased when zinc was used for electrodeposition. Hence SS vessels electroplated with zinc should not be used to store thiourea solution, in industry.

At a weight ratio of n-C5H11OH/H2O=50/50, when the total content of sodium dodecyl sulfate (SDS) was less than 6.0%, the ternary mixture of SDS/n-C5H11OH/H2O coexisted in two immiscible microemulsions. The distribution and transfer of gatifloxacin (GTFX) between the two phases were studied using UV-Vis and electrochemistry AC impedance spectra. The results show that GTFX transferred from the upper phase (W/O) to the lower phase (O/W or bicontinuous microemulsion), but a small amount of SDS transferred from the lower phase to the upper phase correspondingly with the increase of the total SDS content at a total GTFX concentration of 1.0×10−5 mol/L. The addition of GTFX did not change the structures of the two different phases fundamentally, but resulted in the transfer and redistribution of GTFX and SDS, so the electric properties of the system were changed correspondingly.

WOS: 000243739700027, This study describes a laboratory investigation of the influence of thiosemicarbazide (TSC) on the corrosion of reinforcing steel and the compressive strength of concrete. The effect of TSC on the corrosion resistance of steel reinforced concrete was evaluated by carrying out electrochemical tests in NaCl and NaCl + TSC solutions for 60 days. Polarisation resistance (R(P)) values of TSC added reinforced concrete were much higher than those without TSC. Similarly, AC impedance spectra revealed that the resistance of TSC mixed electrodes were also quite higher than those without. The compressive strength of concrete specimens containing TSC was measured and an increase of 20-25% was observed. (c) 2005 Elsevier Ltd. All rights reserved.

The effect of acetate ions on the corrosion of reinforcing steel in chloride environments have been investigated. For this purpose, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and compressive strength techniques were used. In the presence of acetate ions polarization resistance (R p) values of reinforced concrete were higher than those without acetate ions. AC impedance spectra revealed the similar results with R p measurements. The compressive strength of concrete specimens containing acetate ions was measured and an increase of 14.7–38.9% was observed.

Inhibition of corrosion of carbon steel in dam water by hexanesulphonic acid as its sodium salt C6H13SO3Na (SHXS) in the absence and presence of a bivalent cation zinc ion (Zn2þ) has been investigated using weight loss method. Results of weight loss method indicate that inhibition efficiency (IE) increased with increase of inhibitor concentration. Polarization study reveals that SHXS-Zn2+ system controls the cathodic reaction predominantly. AC impedance spectra reveal that a protective film is formed on the metal surface. The nature of the metal surface has been analysed by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM).

Preliminary experimental results of the ac impedance spectra of a bipolar ion-exchange membrane are reported and interpreted on the basis of a previous theoretical model based on the Nernst–Planck/Poisson equations. It is shown that the experiments can provide valuable electrochemical information about the bipolar junction structure and the electric-field enhanced water dissociation phenomenon that occurs at this junction, although the high number of unknown parameters involved makes it difficult to obtain accurate values for the parameters characteristic of this phenomenon.

The environmental friendly inhibitor system DL-phenylalanine-Zn2+has been investigated by weight loss method. A synergistic effect exists between DL-phenylalanine and Zn2+system. The formulation consisting of 150 ppm of DL-phenylalanine and 5 ppm of Zn2+offers good inhibition efficiency of 90%. Polarization study reveals that this formulation functions as a anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. The surface morphology has been analysed by SEM and EDAX. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and electrochemical studies.

A new model accounting for the ac impedance spectra of synthetic ion-exchange bipolar membranes is presented. The theoretical approach is based on the Nernst−Planck and Poisson equations and applies some of the concepts used in the semiconductor pn junctions to the case of a bipolar membrane. The results presented are the current−voltage curves and the impedance spectra at electric currents above the limiting current. It is shown that the model is able to identify the main contributions to the bipolar membrane impedance and gives valuable information about the bipolar junction structure and its influence on the characteristic parameters involved in the field-enhanced water dissociation phenomenon.

The corrosion resistance of three stainless steel materials, namely, stainless steel (SS), stainless steel electroplated with zinc (SS-Zn) and stainless steel electroplated with zinc followed by blue passivation (BP), has been evaluated in an aqueous solution containing 3.5% NaCl. A potentiodynamic polarization study and AC impedance spectra have been used to investigate the corrosion behaviour of these metals. The corrosion resistance of these materials in 3.5% NaCl increased in the following order: SS>SS+Zn+BP >SS+Zn.

The inhibition efficiency (IE) of K 3[Fe(CN) 6] in controlling corrosion of carbon steel in aqueous solution containing 60 ppm of Cl - in the presence and absence of Zn 2+ has been evaluated by weight loss method. The formulation consisting of 100 ppm K 3[Fe(CN) 6] and 50 ppm Zn 2+ offers 98% inhibition efficiency to carbon steel immersed in aqueous solution containing 60 ppm Cl - . A synergistic effect exists between K 3[Fe(CN) 6] and Zn 2+ . As immersion period increases, the inhibition efficiency of K 3[Fe(CN) 6]� Zn 2+ system decreases. Polarization study reveals that this formulation controls the cathodic reaction predominantly. AC impedance spectra reveal that a protective film is formed on the metal surface. FTIR spectra reveal that the protective film consists of Prussian blue and Zn(OH) 2. The film is found to be UV fluorescent.

The high-temperature transformation of ${\mathrm{CsH}}_{2}{\mathrm{PO}}_{4}$ was studied by means of impedance spectroscopy, differential thermal analysis, and thermogravimetric methods. The dielectric constant showed a high-temperature anomaly around ${T}_{p}=230\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}.$ The thermal transformation which appears around ${T}_{p}=230\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ is endothermic in addition to showing weight loss. Our results show evidence that the high-temperature transformation of ${\mathrm{CsH}}_{2}{\mathrm{PO}}_{4}$ near ${T}_{p}$ is not a structural phase transition, but an onset of thermal decomposition of ${\mathrm{CsH}}_{2}{\mathrm{PO}}_{4}$ into ${\mathrm{Cs}}_{n}{\mathrm{H}}_{2}{\mathrm{P}}_{n}{\mathrm{O}}_{3n+1}$ [probably $n\ensuremath{\gg}1,$ $({\mathrm{CsPO}}_{3}{)}_{n}]$ at reaction sites at the surface of the crystal. From complex ac impedance spectra, we observed impedance consisting of two regions for measuring frequency: the low-frequency region may be due to the formation and migration of ${\mathrm{H}}_{2}\mathrm{O}$ molecules at the surface while the conduction mechanism of the high-frequency region seems to be Cole-Cole type and may be due to the proton migration in the bulk. Our results support that the phase of ${\mathrm{CsH}}_{2}{\mathrm{PO}}_{4}$ above ${T}_{p}$ is not a superionic conductor phase caused by a structural transition $(\mathrm{monoclinic}\ensuremath{\rightarrow}\mathrm{cubic})$ but rather a polymeric state caused by partial thermal decomposition. The possible origin of proton conduction for ${\mathrm{CsH}}_{2}{\mathrm{PO}}_{4}$ is considered to be the partial thermal decomposition of the crystal surface because the polymeric transition tends to increase breaking and reforming of the hydrogen bond at the surface.

This paper reports on studies into the AC impedance spectra and behaviour of field-aged VRLA batteries. The AC impedance spectra of "normal" and "abnormal" field-aged batteries are presented. Preliminary results indicating how the variation of the battery impedance with frequency might be used to identify aging characteristics are also shown.