Carbon Paste Electrode for Electrochemical Detectio...

Jo Mar 28, 2025

Nitrite is one of the toxic substances existing in foods such as fish, meat products and vegetables, which has a great impact on human life and health. When nitrite ions enter the body, they bind with blood hemoglobin to form metahemoglobin, causing it to lose its oxygen-carrying capacity. It also combines with amines and amides of the digestive organ to produce carcinogenic nitrosamine compound. Therefore, an accurate measurement of nitrite concentration is very important for protecting human life and health.

So far, various methods of detecting nitrite, such as chromatography, spectrophotometry, and electrochemical analysis, have been developed. Among these methods, the detection of nitrite ions by electrochemical sensing electrodes is a major candidate for nitrite detection due to its high sensitivity, selectivity and fast response. In particular, modified electrodes based on conducting polymers including polyaniline, polypyrrole and polyphenylene have received great attention in the development of sensing electrodes using them because of their ability to prevent surface contamination and improve the electrochemical properties of the electrodes.

Pak Jong Sung, a section head at the Faculty of Chemical Engineering, has developed a novel electrochemically modified carbon paste electrode based on PANI-TiO₂/Pt nanocomposites.

The experimental results demonstrate that the PANI-TiO₂/Pt electrode has pretty excellent electrocatalytic ability for oxidation of nitrite.

For more information, please refer to his paper “Electrochemical Detection of Nitrite on PANI-TiO₂/Pt Nanocomposite−Modified Carbon Paste Electrodes Using TOPSIS and Taguchi Methods” in “ACS Omega” (SCI).

Effects of Ultrasonic Power and Intensity of Mechan...

Jo Mar 27, 2025

Commonly, arsenic-bearing gold ore is very refractory. Therefore, it is necessary to break these ores up to the gold particle size or decompose them to make gold exposed before leaching. The process such as decomposition and crushing prior to leaching is called pretreatment of refractory gold ore. Recently, many researchers have studied the pretreatment of gold bearing arsenopyrite to expose gold and remove arsenic by changing the mineral composition, electrochemical and physicochemical properties of gold ore.

There are many pretreatment methods of refractory gold ores including roasting oxidation, bacterial oxidation, pressure oxidation and chemical pretreatment. Particularly, the chemical treatment methods are widely used due to its low cost. Among them, alkaline pretreatment is considered to be the most economical and eco-friendly. However, this method is not widely used due to the dependence of alkaline concentration, temperature and pressure.

Recently, ultrasound has been widely used to accelerate the speed of chemical reaction. Many researchers have already studied the effects of ultrasound on gold and zinc extraction, on copper extraction from copper ore, on leaching of phosphate using hydrochloric acid, and on sulfuric acid leaching of colemanite. However, the effects of ultrasonic power and intensity of mechanical agitation on leaching of minerals are rarely involved.

Hong Won Chol, a researcher at the Faculty of Mining Engineering, has investigated the effect of the ultrasonic power and mechanical agitation intensity of pulp on alkaline pretreatment of gold-bearing arsenopyrite.

He studied the effect of the pulp temperature on the leaching efficiency in alkaline pretreatment of arsenopyrite under both ultrasonic and non-ultrasonic conditions. Compared with the non-ultrasound condition at the temperature of 60℃, arsenic extraction and gold extraction increased by 20 % and 14.4 %, respectively, in the presence of ultrasound at ambient temperature.

You can find more information in his paper “Effects of Ultrasonic Power and Intensity of Mechanical Agitation on Pretreatment of a Gold-Bearing Arsenopyrite” in “Archives of Acoustics” (SCI).

Interactive E-learning System Equipped with Plagiar...

Jo Mar 26, 2025

Rapid development of computer network increases the applications of e-learning, which provides teachers and students with convenience and flexibility.

In the environment of distance education, interaction is a very important factor for raising the efficiency of teaching and self-study. Especially, in distance education of design project which deals with the designing of circuits or machinery, ensuring the interaction becomes more important since explicit and implicit knowledge hold large portion at the same time.

To raise the interaction in the distance learning, Jong Kum Sil, a lecturer at the Faculty of Distance Education, has proposed an e-learning system where a virtual board is introduced.

The main system consists of a teacher’s computer equipped with various exam and plagiarism-prevention tools, and client computers connected with the teacher’s by network. It also includes various tools for assessing the students’ design projects and the virtual board which is connected with teacher’s computer, so the students can ask questions online through the virtual board for teacher’s guidance. By inserting authentication to the students’ multi-media, she raised the fairness and objectiveness in assessing the students’ tasks.

For further details, please refer to her paper “An interactive e-learning system equipped with plagiarism detection tool for the distance education of the design course” in “INFORMATICA” (SCI).