The Study Of Agar Binder And Super P Additive In Porous Zinc Anode For Zinc-Air Batteries

A zinc-air (Zn-air) battery was fabricated using porous Zn anode, an air cathode, and 6 M KOH-sago gel electrolyte. The porous Zn anode was prepared by mixing Zn powder and agar binder at different concentrations to achieve the desired conductivity and physical properties. Agar is an abundant natural polymer that does not require tedious and costly processing or preparation. Agar is also a gel-forming environmental friendly material. Meanwhile, the presence of KOH causes the growth of ZnO needle structures to cover the Zn-active material. Zn-agar binder without KOH produced the highest discharge capacity of 505 mAhg1. By contrast, the addition of KOH reduced the discharge capacity. The introduction of Super P improved the electrochemical performance of the batteries. The advantages of using Super P in batteries include high purity, large area, and highly structured body. The use of Super P additive in porous Zn anode enhanced the Zn-air battery discharge capacity because of the efficient and better voltage stability obtained from such an anode. The specific discharge capacity and power density of Zn anode with 2 wt% Super P were 776 mAhg1 and 20 mWcm2, respectively. Morphological images and structural properties were also analyzed to support these observations. Super P acted as a bridge in the Zn powders and improved the electrochemical performance of the Zn-air batteries

Effects of Soil Properties to Corrosion of Underground Pipelines: A Review

A b s t r a c t This review concentrates on corrosion properties that expose to soil environment. Forms of corrosion classified with respect to outward appearance and altered physical properties are uniform attack, galvanic corrosion, erosion corrosion, stress corrosion, crevice corrosion, pitting and inter-granular corrosion. A porous soil may retain moisture for a longer period for optimum aeration and indirectly increase the initial corrosion rate. External corrosion is corrosion attack upon the outside of the pipe soil medium and the most failure mechanisms experienced by buried steel pipelines. Many systems possibly in contact with soil have risk to be corroded such as storage tanks and pipelines

Review of Manufacturing Process of Natural Fiber Reinforced Polymer Composites

Lately, natural fibers have been gaining consideration in development of composites due to its biodegradability, availability and low-cost compared to synthetic fibers. Natural fibers are renewable sources, biodegradable, environmentally friendly and effortless in machinery. In this paper, the manufacturing of production for natural fiber reinforced polymer composite (NFRC) will be reviewed. These including injection molding, resin transfer molding (RTM), pultrusion, sheet molding compound (SMC) and compression molding processing technique. Injection molding and compression molding are mostly used in the industry. This is due to the machines give a good finishing surface of the products and low cos

Study on dimensional stability of particleboard made using glutardialdehyde modified corn starch as the binder at various relative humidity

The objective of the study was to evaluate the dimensional stability of experimental particleboard panels made from rubberwood (Hevea brasiliensis) using modified starch as binder. Panels were manufactured using 15% corn starch modified with glutardialdehyde and 13% modified starch with 2% Urea Formaldehyde resin as improvement. The particleboards were tested for their dimensional stability towards moisture. Results found that the 2% replacement of modified starch with urea formaldehyde resin showed a little increased in dimensional stability compared to using glutardialdehyde modified corn starch only as the binder. Therefore, this study indicated that combination of modified corn starch and urea formaldehyde resin can have a potential to be used as an improved binder to produce particleboard panels with accepted properties

The impact of COVID-19 on students’ anxiety and its clarification: a systematic review

IntroductionSince the emergence of COVID-19 in 2019, every country in the world has been affected to varying degrees. Long-term psychological pressure and anxiety will inevitably damage the physical and mental health of students. This study aimed to examine the effects of the COVID-19 pandemic on students who experienced stress and anxiety and to clarify which intervention was more effective.MethodsA comprehensive literature search was conducted between January 2020 and December 2022 using online databases such as PubMed, Web of Science, Scopus, and Google Scholar by using the following keywords in combination: “COVID-19,” “stress,” “anxiety,” “depression,” and “intervention.” The retrieved literature was screened and reviewed.ResultsA total of 2,924 articles were retrieved using subject and keyword searches. After screening through the titles and abstracts, 18 related studies were retained. Their review revealed that: (1) most studies did not use medication to control stress and anxiety; (2) the standard methods used to reduce stress and anxiety were religion, psychological counseling, learning more about COVID-19 through the media, online mindfulness courses, improving sleep quality, and physical exercise; (3) the most effective interventions were physical activity and raising awareness about COVID-19 through the media and online mindfulness programs. However, some studies show that physical activity cannot directly relieve psychological stress and anxiety.ConclusionLimited interventions are effective, but learning more about COVID-19 and using active coping strategies may help reduce stress and anxiety. The implications of COVID-19 are also discussed

Effect of milling time on alumina-titania-carbon nanotube by powder metallurgy method

The Recent work discovers the evaluation on alumina-titania-carbon nanotube (Al2O3–TiO2–CNT) composite prepared by powder metallurgy method. The properties of Al2O3–TiO2–CNT composite have high hardness, chemical and thermal resistance, wear and corrosion resistance but lacking to low fracture toughness which lead to brittle properties. Hence, CNTwas added to the system due to attractive mechanical properties, low density and high fracture toughness. Elemental powders of Al2O3–TiO2–CNT were milling in low energy ball milling using different milling time at 15, 30, 45 and 60 hours. The peak XRD of TiO2 and CNT become diminished with increasing milling time. The powder that milled at 60 hour possible to has lowest crystallite size and highest internal strain due to finer and homogenous particle size deform during milling

Tapioca binder for porous zinc anodes electrode in zinc–air batteries

AbstractTapioca was used as a binder for porous Zn anodes in an electrochemical zinc-air (Zn-air) battery system. The tapioca binder concentrations varied to find the optimum composition. The effect of the discharge rate at 100mA on the constant current, current–potential and current density–power density of the Zn-air battery was measured and analyzed. At concentrations of 60–80mgcm−3, the tapioca binder exhibited the optimum discharge capability, with a specific capacity of approximately 500mAhg−1 and a power density of 17mWcm−2. A morphological analysis proved that at this concentration, the binder is able to provide excellent binding between the Zn powders. Moreover, the structure of Zn as the active material was not affected by the addition of tapioca as the binder, as shown by the X-ray diffraction analysis. Furthermore, the conversion of Zn into ZnO represents the full utilization of the active material, which is a good indication that tapioca can be used as the binder

Mechanisms of Microbiological Corrosion Employing Iron-Reducing Bacteria

Iron-reducing bacteria (IRB) seek to unravel iron corrosion for oil and gas steel pipeline failure. IRB continued to be dominating the microbiological corrosion of iron structures in steel by deteriorating steel surface via Fe(III) reduction. The mechanisms by IRB mediate Fe(III) reduction into Fe(II) for bacterial respiration to contribute to iron steel corrosion. However, the complexity of corrosion is not fully comprehended. It remains controversial due to the corrosion mechanisms proposed by IRB that may induce or inhibit corrosion when engaged with microbial biofilm. In this brief review, understanding microbiological corrosion mechanisms associated with IRB interactions may better understand microbiological corrosion and derive corrosion control

Corrosion characterization of Sn-Zn solder: a review

Yahaya, Muhamad Zamri/0000-0002-4750-4906; Mohd Nazeri, Muhammad Firdaus/0000-0003-4923-0184WOS: 000458380500006Purpose The purpose of this paper is to review and examine three of the most common corrosion characterization techniques specifically on Sn-Zn solders. The discussion will highlight the configurations and recent developments on each of the compiled characterization techniques of potentiodynamic polarization, potentiostatic polarization and electrochemical impedance spectroscopy (EIS). Design/methodology/approach The approach will incorporate a literature review of previous works related to the experimental setups and common parameters. Findings The potentiostatic polarization, potentiodynamic polarization and EIS were found to provide crucial and vital information on the corrosion properties of Sn-Zn solders. Accordingly, this solder relies heavily on the amount of Zn available because of the inability to produce the intermetallic compound in between the elements. Further, the excellent mechanical properties and low melting temperature of the Sn-Zn solder is undeniable, however, the limitations regarding corrosion resistance present opportunities in furthering research in this field to identify improvements. This is to ensure that the corrosion performance can be aligned with the outstanding mechanical properties. The review also identified and summarized the advantages, recent trends and important findings in this field. Originality/value The unique challenges and future research directions regarding corrosion measurement in Sn-Zn solders were shown to highlight the rarely discussed risks and problems in the reliability of lead-free soldering. Many prior reviews have been undertaken of the Sn-Zn system, but limited studies have investigated the corrosive properties. Therefore, this review focuses on the corrosive characterizations of the Sn-Zn alloy system

Extraction of Tannic Acid from Kenaf Bast Fibre using Ultrasonic Assisted Extraction

Tannic acid or tannin, type of phenolic compound contains in kenaf bast fibre. Conventional extraction has certain limitations in terms of time, energy, and solvent consumption. Ultrasound assisted extraction (UAE) can extract bioactive components in shorter time, low temperature, with lesser energy and solvent requirement. UAE as alternative extraction technique is better equipped to retain the functionality of the bioactive compounds. In this study, the conditions for ultrasound assisted extraction (UAE) of tannic acid from kenaf bast fibre by assessing the effect of sonication time and different duty cycles were optimized. The use of ultrasound to extract tannic acid from kenaf bast fiber was evaluated. Ultrasound-assisted extraction (UAE) was carried out using ethanol as solvent to intensify the extraction efficacy. Phytochemical screening was conducted to identify the presence of tannic acid in extracts. The extracts then were analyzed using High-Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM). It was found that 0.2429 mg/mL of tannic acid was obtained under the extraction conditions of extraction temperature of 40℃, sonication time of 20 minutes and duty cycle of 50%. From SEM analysis, it was found that the raw sample demonstrated rough surface and no porous but kenaf bast fibre display smoother surface with less impurities and few pores appeared after the extraction process using UAE. These results indicate that ultrasound-assisted extraction is an efficient method for extracting tannic acid from kenaf bast fibre with the advantages of lower extraction time and higher extraction yield