Abstract The corrosion inhibition property of the Uncaria gambir extract (UGE) for the low-carbon steel was investigated in a prepared cooling-water solution using gravimetric analysis and potentiodynamic polarization measurements. Anticorrosive effectiveness was tested at the UGE concentrations of 0–1500 ppm and temperatures of 40–60°C. The CaCO3 scale inhibition performance was evaluated following

Abstract In this work, the porous structure of a carbon material and a crystalline structure of NiWO4 have been investigated. The electrochemical performance of symmetric and hybrid asymmetric supercapacitors was investigated by cyclic voltammetry and galvanostatic cycling methods. The processes occur mainly at the electrode-electrolyte interface have been analyzed. It was determined that at discharge

Abstract Different concentrations of Citrus aurantium with deoxyribonucleic acid as additive (Citrus aurantiumDNA) were co-deposited with nickel via electrodeposition. The coatings were formed in an aqueous nickel bath with the incorporation of Citrus aurantiumDNA concentrations at different temperatures, and the influence of the acid and the temperature on the microstructure of the coatings was studied

Abstract The use of a pulse picosecond laser with a wavelength of 532 nm and frequency of 15 Hz in the formation of holes with diameters up to 0.1 mm in nonmetallic substrates (silicon, ceramics, etc.) was proposed. It was found by modeling in MathCAD and COMSOL Multiphysics that the half-angle value of the light cone aperture that depends on the focusing of laser radiation exerts a significant effect

Abstract— The nano- and micro-indentation mechanical parameters of the AISI 316L stainless steel, such as nanohardness (НNI), microhardness (HMI), the Young modulus (E), the indices of plasticity (H/E) and resistance (H3/E2), and relaxation parameters hs, hres, he-p and their dependences on the value of P load applied to an indenter were studied. Hardness is shown to be slightly decreased in the microindentation

Abstract Electrochemically synthesized thin-layer NiS electrodes were studied in lithium perchlorate dissolved in 1.3-dioxolane or in a mixture of 1.3-dioxolane and tetrahydrofuran. In the 1.3-dioxolane 1 M LiClO4 electrolyte, the irreversible capacity was reduced by 20% сompared to the initial capacity. However, the stability of the electrochemical characteristics of NiS electrodes in redox reactions

Abstract The protection properties of (3-aminopropyl)trimethoxysilane (APTMS) incorporated epoxy coating on aluminum alloy were studied by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) analysis in seawater. The epoxy-APTMS coated Al alloy displayed higher charge transfer resistance (Rct) as well as film resistance (Rf)

Abstract In the present study, the corrosion behavior and microstructure changes of copper sheets joined with martensitic stainless steel AISI 410 in the salt environment after the explosive welding process have been investigated. An explosive loading and explosive material thickness were considered as variables. In the investigation, potentiodynamic polarization tests, electrochemical impedance spectroscopy

Abstract— The problem of determining initial conditions to ensure the uniqueness of the mathematical modeling of the electric discharge in water was formulated and solved. The method was developed for determining initial values of the discharge characteristics, which ensure their agreement between each other. The method efficiency was exhibited by the example of the electric discharge in water, whose

Abstract The paper reports that silicon with nanoclusters of manganese atoms has unique electrical, photoelectric, magnetic, and photomagnetic properties that are absent in ordinary doped semiconductor materials. The samples revealed an anomalously high impurity photosensitivity in the region of λ = 1–3 μm, a large negative magnetoresistance at room temperature, and new thermomagnetic and photomagnetic

Abstract This work deals with the preparation of biocomposites from low-density polyethylene modified by bio-fillers such as fish bones and fish scale and with the study of their dielectric permittivity and dielectric loss depending on the temperature and on the amount of bio-fillers, before and after irradiation with ultraviolet rays. The studies were carried out under the following conditions: a

Abstract It is shown that it is possible to obtain nanostructured layers with an increased thickness (up to 2 mm), suitable for the repair of worn surfaces of component parts made of aluminum alloys during electrospark alloying of the surface of the aluminum alloy (D1) by the processing electrode of an Al–Sn alloy (20% Sn) with the use of the high current density and two-phase technology for producing

Abstract Recently, efficient coatings with excellent adhesion to the substrate have been applied to metals through the plasma electrolytic nitriding (PEN) method, which is a cathodic atmospheric plasma process with a high deposition rate. The structure, microhardness, and corrosion resistance of coatings after cathodic PEN with different critical and plasma-formation voltages were investigated. The

Abstract The electrical conduction of a magnetic fluid (MF) on kerosene, stabilized by oleic acid, is investigated in an external magnetic field. The analysis of the current-voltage characteristics with electric and magnetic fields crossed at different angles showed a change in the conductivity of the magnetic fluid. In the case of the same orientation of the fields, the conductivity is maximal, while

Abstract— The structure and dielectric properties of new hybrid polymer nanocomposites based on polyvinylidene fluoride (PVDF) and CdS and ZnS nanoparticles (NPs) have been studied. It was established that ZnS and CdS NPs, when added at low concentrations, define the structure of the host polymer matrix, and new polar groups and stable charge traps arise, which, in turn, leads to an increase in the

Abstract— The results from studying electrohydrodynamic (EHD) vortex flows in a 1-mm gap with different geometry of electrodes and under constant external electric fields are presented. The solution of a transformer oil with iodine was used as a working fluid in which the unipolar conductivity was formed owing to the electro-chemical injection of negative ions from the cathode. The EHD microvortex

Abstract Low-carbon steel (Type 20) is subjected to cathodic carburizing followed by quenching and anodic plasma electrolytic polishing. The structure of the surface layer and its elemental composition are established, and the microhardness distribution within the surface layer, as well as its surface roughness, are measured. The microhardness of the surface layer exceeds 900 HV after carburizing at

Abstract— Based on the results of earlier studies and technological recommendations, a design is made for the electro-discharge drilling (EDD) of small diameter holes using an ultrasonic application for the technology of manufacturing of a filter containing 580 rhombic holes with a 0.25-mm inscribed circle diameter. The parameters of dimensional and geometric precision of the holes that were obtained

Abstract— Experimental results on the effect of the length of the discharge gap during an underwater spark discharge and the length of the metal conductor at its underwater electrical explosion are presented. In both cases, the dependence of the pressure wave amplitude on the length of the interelectrode gap or the conductor length has an optimum at which the pressure wave with a maximum amplitude

Abstract— In the present study, M. buxifolia mediated silver nanoparticles (AgNPs) were synthesized by mixing different volumes of the plant extract and silver nitrate solutions. The prepared AgNPs were characterized by UV-spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray (XRD) analysis, thermal gravimetric analysis (TGA), energy dispersive X-ray (EDX) analysis, fourier

Abstract This study investigated the effects of temperature and the current density on the production of an Al–Li master alloy using electrolysis. The current efficiency and the specific energy consumption were calculated according to Faraday’s law to determine optimal conditions for production of the Al–Li master alloy. Solid aluminum and graphite were used as the cathode and the anode, respectively

Abstract Six new pyrazole derivatives were successfully prepared and investigated as corrosion inhibitors for mild steel in 1 M H2SO4 solution by weight loss measurements for 24 h at 30°C. It was observed that at higher inhibitor concentrations, the rate of corrosion decreases, the inhibition efficiency increases as well as the surface coverage degree. The values of the standard free energy of adsorption

Abstract The work is devoted to justifying the selection of a rational range of voltage pulse duration on the basis of comparing the time of the anodic dissolution start with the time of the electric double layer’s charging during electrochemical dimensional micromachining. The range of short circuit times as the limit of the maximum voltage pulse duration is justified. The simulation of dimensional

Abstract— Commercial polyethersulfone (PES) membrane was modified and evaluated for the removal of metal ions from an aqueous solution. Modifications were carried out by a radical polymerization technique, using acrylic acid as monomer. The grafting polymerization on the membrane was developed in an aqueous medium at 60°C. Two molar initiator/monomer (3 and 7%) ratios were used to study PES-grafted-polyaceylic

Abstract An analytical review of recent studies in the field of electrical explosion of conductors (EEC) has been performed to select modes and conditions of high-resistivity EEC, which is used to produce functional wear-resistant hard-alloy carbide coatings containing refractory metals, their carbides, and nanocarbon particles. The influence of the environment in which the EEC is carried out on the

Abstract Hybrid photochemical methods are considered for water disinfection in which treatment with ultraviolet (UV) and ultrasonic (US) radiations are combined (US/UV) and applied consecutively or simultaneously; the use of catalysts is also included. The literature survey shows that inactivation of pathogenic microorganisms in aquatic media by high-frequency US (>100 kHz) has not been studied adequately

Abstract The inhibitive action of cysteine was investigated against the corrosion of aluminium alloy 6061-T6 (AA6061-T6) in a 0.5 M hydrochloric acidic medium in the temperatures range of 303–323 K using potentiodynamic polarization as well as electrochemical impedance spectroscopy methods. The electrochemical results of the former were validated by the latter. Cysteine showed mixed inhibitor behavior

Abstract A corrosion inhibitor bis[[3,4-dihydroxyphenylmethylene]carbonothioicdihydrazide] (DCT) was synthesized and used to improve the corrosion resistance of an epoxy based primer coating on AA2024-T3 alloy in NaCl solution. The ability of DCT to inhibit the corrosion was evaluated by electrochemical studies. The compound exhibited an inhibition efficiency of 99%. The surfaces of the corroded specimens

AbstractElectroplating of zinc−nickel alloy coatings (3–16 at % Ni) on Type 17G1S-U steel from ammonium oxalate baths is studied. The effects that the ratio of alloy components has on the coating’s corrosion resistance and structure and the electroplating kinetic parameters are revealed. Applying zinc–nickel alloy coatings leads to a nearly sevenfold decrease in the corrosion rate compared to zinc-only

AbstractIt is shown that the formation of anodic oxides in the galvanostatic mode of electrolytic anodizing of Si, SiC, and Si3N4 proceeds with the activation control of the process. It is suggested that the limiting stage of the oxidation process of these materials is the anodic reaction of the formation of intermediate monoxide SiO.

Abstract—Methods of numerical modeling were used to study the electrophysical effects in the boundary zones of phases that are formed during the passage of an electric current through a metal melt volume with inclusions of conductivity other than the matrix conductivity. The possibility of changing the crystallization stimulus of the liquid-metal system was shown to be subject to the electric current

Abstract—A green compound, N,N′-bis(2,4,6-trihydroxybenzaldehyde)-2,2-dimethylpropandiimine, was studied as an acid corrosion inhibitor for X80 steel. Aqueous 15% HCl was utilized for simulating the oil well acidizing fluid at various temperatures. The inhibition performance was assessed using the weight loss method, the electrochemical impedance, the polarization, and the scanning electron microscopy

AbstractAn electric discharge micromachining experiment is described. The features of electroerosive cutting of parts by a wire electrode-tool with a diameter of 7–20 μm were studied. The results are interpreted using the developed mathematical model of the EDM cutting process, accumulating available experimental data on the EDM process dynamics with a nonrigid wire electrode. The problem of the stability

Abstract—Two new Mannich bases: 1-[(4-methylpiperazin-1-yl)(phenyl)methyl]thiourea and 1-[(4-ethylpiperazin-1-yl)(phenyl)methyl]thiourea were synthesised by a cost effective green method. The synthesised Mannich Bases were characterised and tested as corrosion inhibitors for the corrosion of a mild steel surface in 0.5 M hydrochloric acid solution using potentiodynamic polarization and electrochemical

AbstractThe stability of the membrane’s dynamic layer consisting of polystyrene (PS) microparticles is studied. To improve the stability, a nylon-PS membrane is subjected to thermal treatment at temperatures of 50 to 100°C for 10 min. The effect of heat treatment on the surface of the dynamic membrane is studied by scanning electron microscopy and wetting angle measurements. The stability of the dynamic

AbstractThe reasons for the fall in the discharge capacity of the LiMn2O4 spinel composition with a Norit carbon filler in the redox reaction with lithium at a temperature of 271 K were analyzed using cyclic voltammetry and impedance spectroscopy. A comparison is made between the electrochemical behavior of LiMn2O4–Norit compositions, LiMn2O4 compositions with carbon nanotubes, and LiMn2O4 compositions

Abstract—This work reports the synthesis and electrochemical performance of the nickel-doped lithium manganese oxide along with the surface modification of the mentioned oxide coated with the aluminum oxide via a solid state route. The structural and functional groups were confirmed by the X-ray powder diffraction and Raman spectroscopy studies, respectively. A pyramid-like structure of the pure lithium

Abstract—Micro texturing with dimples is one of the most established methods for the enhancement of lubrication and tribological performance. In this work, a novel approach of through-mask electrochemical micromachining is instigated to fabricate high-aspect-ratio circular micro-dimples utilizing a low-cost photoresist (AZ-4903) as mask. Experiments were performed to understand the influence of the

Abstract—The inhibiting effect of the expired meloxicam on the corrosion of mild steel (MS) in 1 M HCl was tested by the weight loss, electrochemical frequency modulation, potentiodynamic polarization (PP) and electrochemical impedance spectroscopy techniques. The PP curves showed that this drug acts as mixed type inhibitor. This drug was adsorbed chemically on the MS surface following the Temkin adsorption

Abstract—Based on experimental and theoretical data, thermodynamic analysis of possible chemical reactions occurring in the titanium–aluminum–hexamethylenetetramine system under conditions of self-propagating, high temperature synthesis (SPHTS) was performed. It was shown that, under the above conditions, the MAX-phase Ti3AlC2 can be predominantly formed at cooling down the material up to temperatures

Abstract—In this work, an electrochemical sensor based on a poly threonine modified graphite-carbon nanotube paste electrode was developed for the investigation of tyrosine. The modification of the electrode was characterized by field emission scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The modified electrode shows many advantages such as simple preparation

Abstract—In order to provide further evidence on the existence of the phenomenon of electro-chemical phase formation in metals and alloys via a supercooled liquid state stage, a set of experiments were carried out to reveal the predicted structural features in alloys during electrochemical phase formation at chemically identical solid or liquid cathode. In the third part of the research, the results

AbstractThe characteristics of an overstressed, high-current nanosecond discharge in atmospheric air between zinc, copper, and iron electrodes are given with a distance between the electrodes of 1–3 mm. It is established that this discharge is a point source of ultraviolet radiation in the spectral range of 200–300 nm and a nanoparticle stream of zinc, copper, and iron oxides. The optimization results

AbstractA bipolar nanosecond discharge with a voltage amplitude of one polarity of 15–40 kV and a current amplitude of 50–150 A in a pulse was ignited at an inter-electrode distance of 0.1 cm and the pressure of argon 101 or 202 kPa, at a frequency of the pulse voltage 40–100 Hz. The pulsed electric discharge power was in a range of 5–11 MW, with a plasma energy input of 0.40 and 0.44 J per pulse.

AbstractThe work specifies the distribution features of electromagnetic and hydrodynamic fields in the conductive electric-current treatment of melts by parallel electrodes via the methods of numerical experiments. It was shown that it is possible to create local areas of concentration of the electromagnetic field, to avoid the flow of current through the electrode walls, and to increase the treatment

Abstract—The paper presents the study results on the influence of the alternating current’s frequency on the value of active resistance. It has been revealed that the value of the active resistance increases to a minimum value with an increase in the frequency of the alternating field, and it increases sharply with a further increase in the frequency. It is shown that the cause of the growth of active

Abstract—This paper presents the results into the study of electret properties of composite materials based on ultrahigh molecular weight polyethylene (UHMWPE) and nano-dispersed amorphous silica filler α-SiO2 (aerosil) depending on the volume content of silicon dioxide and the absorbed dose D γ-irradiation at room temperature using the method of thermally stimulated depolarization (TSD). It was found

AbstractPowders of VT3-1 titanium alloy and VK-15 hard alloy have been obtained and investigated. A proposal is suggested for the possibility of their industrial use, especially for surface spraying. High efficiency methods and apparatuses are suggested to produce metal powders using an electric arc in the cross hydrodynamic flow of the working liquid that burns without a pause. They make it possible

Abstract—This work formulated and solved the problem of determining the specific electrical conductivity of plasma in the channel of the electrical discharge in water as well as that of the discharge channel resistance taking into account the deviation in its shape from that of a straight circular cylinder. The closing ratios and empirical functions whose parameters agree with the experimental data

AbstractUsing the atomic force microscopy method, the surface of thin, copper-containing polyacrylonitrile (PAN) films is studied. The distribution function over the height of the surface profile is analyzed by the method of multifractal detrended fluctuation analysis (MFDFA). The fractal dimension, correlation dimension, scaling exponent, and Hurst exponent (H) are used as parameters in this analysis

AbstractThe investigation results for the fine dispersion of the prerefined oxides of rare-earth elements using electric discharges in an aqueous medium are presented. A possibility of producing oxide particles with a size less than 1 μm is shown, including the generation of those particles from large blocks of previously coagulated oxide particles. It is shown to be reasonable to choose such an interposition

Abstract—The work highlights the results of application of a bio polymer glycogen as a green inhibitor for the corrosion control of 6061Al-15%(V)SiC(P) composite material in 3.5% NaCl medium. The corrosion rate measurements were done by electrochemical methods such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Kinetic and thermodynamic parameters were calculated

AbstractThe paper reports the oxidative decolorization of the direct blue 14 (DB-14) dye in an aqueous phase via an ecologically friendly electrochemical advanced oxidation process. The investigation of several experimental conditions such as the solution pH, initial concentrations of the oxidant, the dye, and current density was carried out in a single-compartment electrolytic cell with the use of

Abstract—The dispersion equation is derived analytically and in a linear approximation using the dimensionless amplitude of oscillations for capillary waves on the charged surface of a layer of viscous conductive liquid on a metal wire. The metal wire is shown to stabilize the capillary waves. The wire effect becomes substantial only at high values of the wire radius. The appearance of the electric

AbstractAn electrochemical study of three API steels: X52, X65, and X80, exposed to seawater and sediment from seabed is presented. Two seabed samples were collected at 60 meters depth near a platform (seabed A) and at a distance of 500 m (seabed B) from the same platform of the Sonda of Campeche, México. In both samples, the seawater and sediment were separated in order to characterize their corrosiveness

AbstractThe purpose of this study was to investigate the role of different welding techniques: laser and tungsten inert gas (TIG) on the corrosion behavior of commercially pure titanium (cp-Ti) frameworks in dentistry. Electrochemical tests were conducted in artificial saliva at pH 7.2, 37°C. The surfaces were examined using scanning electron microscopy. The received data were analyzed by one-way ANOVA

Abstract—Commercially pure titanium Cp-Ti and Ti6Al4V alloy were liquid borided using a borate bath consisting of 70% borax and 30% SiC at 1000°C for 3, 6, and 12 h. The borided materials were characterized by scanning electron microscopy to reveal the produced microstructures. Two kinds of titanium borides were identified by the X-ray diffraction analysis (TiB2 on the top of the surface followed by

Abstract—The existence of the phenomenon of electrochemical phase formation in metals and alloys via a supercooled liquid state stage has been discussed. In the second part of the research, the results of the precision X-ray phase analysis for the interface between electrodepositing alloy in the form of a substitutional solid solution and a cathode of Wood’s alloy that persisted in either a solid or

Abstract—In order to better integrate 316 L stainless steel implants, in this study, hydroxyapatite/chitosan (HA/CS) nanocomposite coatings, barium titanate/chitosan (BT/CS), and hydroxyapatite/barium titanate/chitosan (HA/BT/CS) were applied on the mentioned steel via electrophoretic deposition at 10 V for 150 s. Tri-ethanolamine was used as a dispersant to create a stable suspension. The microstructure

Abstract—This research is done with the purpose of revealing an increase in the fatigue performance of carbo-nitrided powertrain shafts followed by the second tempering. The fatigue test was conducted at a bi-directional torsional cyclic load using an MTS torque tester. Various investigations were carried out to find out the effect of surface roughness, second tempering, inter granular oxidation, retained