Jo Oct 16, 2026
The use of ozone gas started about a century ago. Ozone has been used to purify water polluted by microorganisms. The chemistry of ozone in aqueous solutions is complex and the direct reaction with molecular ozone and the indirect reaction with radicals generated when ozone is dissolved in water are considered for the process of water treatment with ozone.
The authors calculated the first principles of the reaction between molecular ozone and water vapour, but no first principles study of the decomposition of ozone in water has been carried out.
Choe Un Hwa, a researcher at the Faculty of Online Education, has conducted a study to select the size of ozone bubbles used for water treatment using ozone microbubbles, considering the ozonolysis characteristics in water.
She quantitatively calculated the decomposition of ozone in water using the density functional method (DFT/6-31G*). Among the four possible reactions between O3 and H2O in gas and water, the possibility of obtaining H2O2+O2 is relatively high.
Considering that H2O2 and O2 are products of indirect reactions by ozone with OH- as an initiator and the rate of indirect reactions is very fast, the size of ozone bubbles used for water treatment can be as large as a micron size, which can increase the solubility of ozone gas in aqueous solution and improve the ozonation efficiency.
You can find more information in her paper “Ozone Micro Bubble Treatment: What is the Size of Ozone Bubble Suitable for Water Treatment?” in “Proceedings of KUTIC-2025”.
...
Jo Oct 15, 2026
Femoral head osteonecrosis is a disease affecting patients at the age of 30-50 that usually progresses to femoral head collapse and often leads to total hip arthroplasty. Femoral head osteonecrosis frequently progresses to the subchondral fracture of femoral head, eventually leading to complete joint destruction.
Joint-preserving surgical interventions are generally more successful at earlier stages of bone involvement than after the occurrence of subchondral fracture. It means that the optimal time to evaluate and treat osteonecrosis of femoral head is before the occurrence of subchondral fracture. Early diagnosis can facilitate the application of interventions that can avoid or delay arthroplasty to some extent. However, misdiagnoses and delayed diagnoses are common due to the lack of preliminary symptoms, typical features, and internal fixation interference on radiographs.
Kim Ju Hyang, a researcher at the Faculty of Information Science and Technology, investigated the problem of extracting significant features for detecting bone diseases such as avascular necrosis and osteoporosis of femoral head from radiographic images of femoral head, and classifiers. On this basis, he proposed a method for early diagnosis of femoral head osteonecrosis by feature extraction and classifiers.
She performed feature extraction by 2D Dual tree complex wavelet transform, and early detection by support vector machine (SVM). Using 2D Dual tree complex wavelet transform on femoral radiographs, she extracted high-frequency component features based on six-way complex wavelet coefficients of femoral head images. Then, she selected the most significant features for classification among the spatial domain features and other features significant for avascular necrosis detection to construct feature vectors and designed a support vector machine classifier.
The experimental results show that the proposed method is cost-effective due to the use of X-ray images and has excellent detection performance.
If further information is needed, you can refer to her paper “Dual Tree Complex Wavelet Transform-Based X-Ray Image Feature Extraction and Early Diagnosis of Femoral Head Osteonecrosis by Support Vector Machine” in “Proceedings of KUTIC-2025”.
...
Jo Oct 14, 2026
The annular centrifugal extractors (ACEs) are based on the principle of Taylor-vortex flow. They essentially consist of two co-axial cylinders where the outer one is stationary and the inner one is rotating. They provide very high values of mass transfer coefficient in the annular region because of high levels of power consumption per unit volume. What is more, the rotor separates two phases into the other without any carryover of one phase. With these two advantages, they are used for several applications of liquid-liquid extraction where low inventories are desired. They include metal recovery and purification in the mining industry, processing of uranium and high plutonium fuels, caustic side solvent extraction to remove cesium from nuclear waste, hydrochloric washing of polymer phases, bromination and subsequent efficient separation of brominated polymer from aqueous phase.
Ri Hui Myong, a researcher at the Faculty of Thermal Engineering, investigated the phase separation characteristics and extraction characteristics of TBP-NaNO3 system in a 50mm annular centrifugal extractor with respect to the rotational speed and the inlet phase ratio, and derived an empirical formula for the throughput of NaNO3 under a given operating condition.
The maximum throughput of TBP-NaNO3 system in the 50mm annular centrifugal extractor was 12.6kg/h at a rotational speed of N=2 500r/min and an inlet phase ratio of Ro/a=1.
You can find more information in his paper “Phase Separation and Extraction Characteristics of TBP-NaNO3 System in an Annular Centrifugal Extractor” in “Proceedings of KUTIC-2025”.
...
Jo Oct 13, 2026
The fixed point theory provides a very powerful tool in mathematics and many other scientific fields such as nonlinear analysis, integral equations and differential equations. What is interesting in a recent study on the fixed point theory is the generalization of metric space (MS).
By generalizing the concept of MS in the fixed point theory, many mathematicians presented new concepts such as b-metric space, triple controlled metric type space and triple-composed metric space. Some other authors defined a new notion called S-metric space (S-MS). Later, some mathematicians introduced new concepts for generalizing S-MS by using the ideas of earlier space concepts. Sb-MS and triple controlled S-metric type space (TC-S-MTS) are typical examples.
Kil Chol Jin, a lecturer at the Faculty of Applied Mathematics, proposed a new concept of triple-composed S-metric space (TCS-MS). He got motivation from the concepts of TCMS and S-MS while analyzing the recent research results on S-MS.
TCS-MS is a new concept that uses the composition of three functions rather than the multiplication of three functions, unlike the recently introduced TC-S-MTS.
He presented some meaningful examples showing that triple-composed S-metric space is a real generalization of S-metric space and Sb-metric space. In addition, he proved a fixed point result for Proinov-type contractive mappings in triple-composed S-metric spaces.
For more information, please refer to his paper “Triple-Composed S-Metric Spaces and Related Fixed Point Results” in “Proceedings of KUTIC-2025”.
...
Jo Oct 12, 2026
Due to the frequent occurrence of accidents in the sea, it is an important requirement to predict accidents in advance and take safety measures from an early stage.
At present, assessment of accident risks is referred to as the question of how to predict risks and take measures. Intensifying research on the global regulatory tool, the Formal Safety Assessment (FSA), is important in finding and reducing ship accident risks from early stages by taking safety measures.
Jon Kwang Sik, a researcher at the Faculty of Naval Architecture and Ocean Engineering, proposed a methodology for evaluating ship safety and providing safety measures with a focus on the risk of possible collision accidents by applying the FSA method, which has been widely adopted.
He established a measure scheme for avoiding or minimizing damage by predicting damage results based on the identification of many risk indexes associated with collision accidents, and conducted a comparative analysis to propose the most appropriate measures to prevent collision accidents.
The proposed method will play an important role in planning regulations for assessing the safety of ships and taking safety measures in relation to possible marine accidents as well as collision accidents in all ships in the future.
...
Jo Oct 11, 2026
Tantalum and niobium are the most important materials for various sectors of the national economy. They are used for structural steel, superconducting, electron tubes, cemented carbide, steel modifiers, scientific lens additives, dental prosthetic materials, etc.
Tantalum and niobium are found in over 130 kinds of minerals, composed of tantalate and niobate or complex oxide of titanium-niobium-tantalate. The widely used minerals in the production of metallic tantalum and niobium are tantalum-columbite, pyrochlore, rare-earth perovskite, etc. Among them, pyrochlore is a very valuable mineral due to its high content of rare earth elements as well as tantalum and niobium.
The separation methods of tantalum and niobium include fractional crystallization of fluoride complexes, solvent extraction, ion exchange, distillation of chlorides, and selective reduction of NbCl5. Among them, those that have been commercialized for many years are fractional crystallization and solvent extraction.
Recently, the development of inexpensive and efficient solvent extractants by many researchers has led to the separation of tantalum and niobium by solvent extraction methods. Although the use of neutral extractants such as MIBK and TBP in hydrofluoric or hydrofluoric-sulfuric acid media is common for the separation of tantalum and niobium, the separation of tantalum and niobium from sulfuric acid decomposition has been rarely studied so far.
Kang Chung Su, a section head at the Faculty of Chemical Engineering, conducted a study to separate the impurities from the aqueous leachate of pyrochlore sulfate decomposition product and to separate tantalum and niobium with octanol as the extractant.
After keeping the pH of the sulfate leaching solution at 2 and mixing 100% octanol to an aqueous phase/organic phase ratio (A/O) of 1:1, the extraction at room temperature for 15min resulted in more than 99% tantalum extraction, but no niobium extraction. After stripping of the tantalum-loaded octanol with distilled water at room temperature for 20min at a phase ratio of 1:1, more than 99% tantalum was stripped. When ammonia solution is added to the tantalum pregnant strip solution to pH 4.5-5.5, tantalum hydroxide is precipitated and when ammonia solution is added to the raffinate to pH 6-7, niobium hydroxide is precipitated.
...