Physicochemical and Electrochemical Characterization of Vanadium Electrolyte Prepared with Different Grades of V2O5 Raw Materials

The physicochemical and electrochemical performance of electrolytes prepared with different grades of V2O5 raw materials were investigated systematically for a vanadium redox flow battery. Physicochemical tests showed that the conductivity of electrolytes prepared with lower grades of V2O5 raw materials obviously decreased, while the viscosity increased. The results of electrochemical experiments showed that the electrochemical activity and reversibility of electrolytes decreased, and the solution resistance increased obviously, as the grade of V2O5 raw materials gradually decreased. In addition, the battery efficiency and charge–discharge capacity were negatively affected by impurities in the lower grade V2O5 raw materials, due to an increase of polarization on the charge–discharge voltage. Moreover, the performance of electrolytes was related to the total concentration of impurities in the electrolyte, and Na, K impurity ions were the main factors that adversely affected the electrochemical activity and reversibility, mass transfer, and capacity of the electrolytes. Based on the economic analysis, the impurities in V2O5 raw materials would not only reduce the performance of electrolytes, but also affect the production costs of electrolytes and the economic profits. Through this fundamental research, people can better understand the influence of V2O5 raw materials on electrolyte properties, and direct more attention to research how to effectively use lower grade V2O5 raw materials to reduce the costs of electrolyte preparation.

Scanning Electrochemical Impedance Microscopy in Redox-Competition Mode for the Investigation of Antibodies Labelled with Horseradish Peroxidase

Scanning electrochemical microscopy enhanced by electrochemical impedance spectroscopy (SEIM) was applied to detect immobilized antibodies labelled with horseradish peroxidase (Ab-HRP). The localized HRP activity was investigated by the SEIM redox competition (RC-SEIM) mode using hydrogen peroxide as a substrate and hexacyanoferrate as a redox mediator. Electrochemical impedance shows to be related to the consumption of hydrogen peroxide at the ultramicroelectrode. For the evaluation of impedimetric results, an equivalent electric circuit was applied with solution resistance, double-layer capacitance, and charge-transfer resistance. These equivalent circuit characteristics depend on the distance between the sample and ultramicroelectrode, and the concentration of substrate. From the gathered data, the charge-transfer resistance appeared to be the parameter describing the behavior of HRP catalyzed reaction as it showed a linear dependence on H2O2 concentration. The RC-SEIM mode suitability for the studying of HRP catalyzed reactions and for the evaluation of Ab-HRP bound to the surface was demonstrated. Additionally, the applicability of RC-SEIM mode for the determination of Ab-HRP affinity bound to the target analyte was discussed.

Novel method for scalable synthesis of wollastonite nanoparticle as nano-filler in composites for promotion of anti-corrosive property

This study is focused on novel anti-corrosive support. This coating is based on the mixed matrix (MM) including epoxy and its hardener as thermoset polymer, melamine–formaldehyde as the organic phase, activated graphite as both inorganic and conductive phases, as well as wollastonite nanoparticles as filler. The wollastonite nanoparticles are synthesized by the new and novel method as suitable etching using hydrofluoric acid, “HF” at room temperature (25 ℃). The synthesized wollastonite nanoparticles are then adapted as a suitable filler during the formation of a new type of MM anti-corrosive coating for the preservation of metals form any corrosion. According to the results, during coating the MM, significant positive characteristics such as enough positive open circuit potential (OCP), small enough (icorr), low cost, significant chemical/mechanical stability and acceptable flexibility are observed. Based on to the weight-loss analysis test on the MM-modified stainless steel during a 42-day time interval, the corrosion rate % is decreased from 74.86 to 0.34. In addition, the electrochemical impedance spectroscopy reveals major enhancements in the double-layer resistance and solution resistance of the cell system. Based on the electrochemical measurements, noticeable reduction and enhancement are observed in the correction rate and potential, respectively, during introducing hard corrosive conditions such as NaCl (3.0%, w/v) and HCl (1.0 mol L−1) environments that reveal the acceptable anti-corrosive behavior of the synthesized MM. The introduced MM is therefore considered as low cost, safe, eco-friendly, industrial-justified anti-corrosion support.

An Amazingly Simple, Fast and Green Synthesis Route to Polyaniline Nanofibers for Efficient Energy Storage

The major drawbacks of the conventional methods for preparing polyaniline (PANI) are the large consumptions of toxic chemicals and long process durations. This paper presents a remarkably simple and green route for the chemical oxidative synthesis of PANI nanofibers, utilizing sodium phytate as a novel and environmentally friendly plant derived dopant. The process shows a remarkable reduction in the synthesis time and usage of toxic chemicals with good dispersibility and exceedingly high conductivity up to 10 S cm−1 of the resulting PANI at the same time. A detailed characterization of the PANI samples has been made showing excellent relationships between their structure and properties. Particularly, the electrochemical properties of the synthesized PANI as electrode material for supercapacitors were analyzed. The PANI sample, synthesized at pre-optimized conditions, exhibited impressive supercapacitor performance having a high specific capacitance (Csp) (832.5 Fg−1 and 528 Fg−1 at 1 Ag−1 and 40 Ag−1, respectively) as calculated from galvanostatic charge/discharge (GCD) curves. A good rate capability with a capacitance retention of 67.6% of its initial value was observed. The quite low solution resistance (Rs) value of 281.0 × 10−3 Ohm and charge transfer resistance value (Rct) of 7.44 Ohm represents the excellence of the material. Further, a retention of 95.3% in coulombic efficiency after 1000 charge discharge cycles, without showing any significant degradation of the material, was also exhibited.

Procedure for Obtaining a Certificate of Title to the Land in the Semarang: Case Study in the National Land Agency Semarang

The background of this thesis-making by the problems that occur in the community, where people are still not or do not understand the procedures milik.Terbukti acquire rights to their land dispute or a state-owned building that happened because the people who inhabit this land are not applying for property rights and feel that the land itself. Scription this is made so that people understand about the procedures for securing property rights. Results: (1) Procedures of obtaining the certificate is property rights on state land through the National Land Agency, is generally set in the norm of the Minister of Agriculture No. 9 of 1999 on Procedures for Granting and Cancellation of State Land Property Rights and Rights Management. In Article 19 paragraph (2) BAL consisting of: bookkeeping land, registration of property rights, transfer of land rights, granting letters of proof of receipt of rights, (2) Barriers and solusiyang arising from applicant in the application process right (external): lack of accessories the proposed requirements of the applicant, not terselesainya application fee, the land dispute would be applied. Barriers arising from the Office of the (internal): lack of personnel in the service of the applicant carefully situations, employees who lack discipline, negligence of officers in performing their duties. Solution resistance of the applicant (external): more thoroughly before entering the application requirements, before making an application should first ask for details of funds in the process of granting the right, please check whether the land is in sengeketa or not. Solution barriers of Office (internal): officers should be more responsible in performing their duties, and provide a deterrent effect to employees who are lazy in performing their duties.Keywords: Procedures; Certificate of Property Rights; State land.

Preparation and Anticorrosive Property of Soluble Aniline Tetramer

Soluble aniline tetramer (AT) was successfully prepared by chemical oxidation method. Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-vis) were used to characterize its structure. The redox behavior of AT was identified through the electrochemical cyclic voltammetry studies. Then, the epoxy coating was prepared by using AT as inhibitor. Its anticorrosive property was evaluated by salt solution resistance test, polarization curve, and electrochemical impedance spectroscopy (EIS). Salt solution resistance test, polarization curves, and EIS measurements indicate that the obtained epoxy anticorrosive coating, containing 1.0% AT, exhibits remarkably enhanced corrosion protection properties on Q235 steel electrodes as compared to pure epoxy anticorrosive coating without AT. The significantly improved anticorrosion performance may be owing to the redox behavior of the AT, adsorption and inhibition effect of AT on Q235 steel surface, as well as synergistic curing effect by AT and polyamide.

Electrochemical Behavior of AISI 1020 Steel in Type C Commercial Gasolines

In the present paper, the corrosion behavior of 1020 carbon steel in commercial gasoline-ethanol blends was investigated. The composition of each gasoline-ethanol blend was evaluated by infrared spectroscopy, and the ethanol content was determined by the ABNT 13992 reference method. Electrochemical Impedance Spectroscopy (EIS) and polarization methods were employed to evaluate corrosion resistance and penetration rates. Statistical analyses revealed that the gasoline’s solution resistance governs the corrosion process, the RON (Research Octane Number) and MON (Motor Octane Number) numbers as well as the olefin content being more related to the corrosion rates. The polarization resistance had minor impact on the corrosion process.