Jo May 19, 2026
Compared to monochannel membranes, multichannel membranes have the advantage of being able to generate higher permeate flux per unit volume of membrane elements by providing higher mechanical strength and larger filtration area within a given volume. However, the permeability of multichannel membranes is not directly proportional to the filtration area because the contributions of the middle and central channels and wall channels to the permeate flux are not the same. Since the permeated flow through the inner channels is not drained well towards the outer surface, proper placement of exit channels can increase permeate flux.
Through previous studies, it is found that permeate flux is mainly controlled by the permeability ratio of skin layer to porous support, and the geometry, and that proper arrangement of exit channels can increase permeate flux.
Kim Un Ok, a researcher at the Faculty of Applied Mathematics, has investigated the effect of exit channel placement on permeate flow in square 64-channel ceramic membranes which are now in wide use, and determined proper placement for various cases.
She assumed permeate flow to be two-dimensional potential flow and solved the mathematical model by finite element method.
The numerical simulation results show that the placement of exit channels affects permeate flux and it is possible to determine reasonable placement of exit channels according to the permeability ratio of skin layer to porous support.
For more information, you can refer to her paper “Effect of Exit Channel Placement on Permeate Flow in Square 64-Channel Ceramic Membrane” in “Proceedings of KUTIC-2025”.
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Jo May 18, 2026
Several computational methods have been applied to the research to develop new materials. For example, according to the considered scale, they are divided into finite element methods, Monte Carlo methods, molecular dynamics methods, etc. In addition, the experimental data analysis methods include experimental design, neural network, genetic algorithm, etc., which require high-performance computing devices, long computational time and a considerable amount of experimental analysis.
In contrast, grey models are widely used in data analysis as they can improve prediction accuracy from a small amount of poor data. Grey models are mainly applied in various fields such as energy consumption and prediction and CO2 gas emission, attracting a great deal of interest of many researchers. This has led to active research into grey models but few of the results have been applied to the study of material properties.
Pang Chol Ho, a researcher at the Faculty of Material Science and Technology, proposed a hybrid exponential smoothing method, developed a grey model combined with a structural adaptive discrete grey Bernoulli model, and predicted some properties of material.
The comparison analysis with other grey models showed that the proposed model has the highest predictive accuracy.
He used the proposed model to predict various properties of material. The results showed that the predictive accuracy (MAPE) was 0.007 65 for tensile strength, 0.016 52 for Branell hardness and 0.025 15 for the thermoelectric performance parameters of high-entropy alloy AgSnSbSe1.5. This means that the proposed model is effective for predicting material properties.
You can find more information in his paper “Application of Hybrid Grey Bernoulli Model in Material Research” in “Proceedings of KUTIC-2025”.
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Jo May 17, 2026
Selective laser melting (SLM) is the most popular AM technique that enables production of complicated metal products with high precision, flexibility, acceptable surface finish and material efficiency by melting metal powders using laser energy.
Since SLM process parameters affect the multiple quality attributes of SLM parts, it is very important to perform optimization and effect assessment of SLM process parameters. AlSi10Mg alloy is widely used in the industrial fields such as automotive and aerospace industries, and it is suitable for SLM processes due to its good castability, good strength, lower thermal expansion coefficient, and excellent wear and corrosion resistance.
Yang Ji Yon, a post-graduate student at the Faculty of Material Science and Technology, performed an analysis of the relationship between the properties (tensile strength, hardness and relative density) and process parameters (laser power LP, scan speed SS, and overlap rate OR) of SLM-manufactured AlSi10Mg alloy using Taguchi and TOPSIS methods.
For the individual properties, the optimal process parameters were LP 320-360W, SS 600mm/s and OR 35%, and the effect rankings varied according to the properties. For the TOPSIS-based overall quality index, the optimal process parameters were LP 320W, SS 600mm/s and OR 35%, and the effect ranking was SS, OR and LP.
For further details, you can refer to her paper “Relationship between Properties and Process Parameters for AlSi10Mg Alloy Manufactured by Selective Laser Melting” in “Proceedings of KUTIC-2025”.
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Jo May 15, 2026
Recently, PbO2 electrodes with high oxygen overpotential, good electrical conductivity and electrocatalytic property have been widely used as anode in electrochemical industries such as electrowinning of metals, lead acid batteries, analytical sensors, electrochemical synthesis of peroxides and electrochemical treatment of wastewater, etc.
PbO2 is divided into two types, namely, α-PbO2 in the orthorhombic form and β-PbO2 in the tetragonal form. The anode material PbO2 is prepared by electrodeposition. α-PbO2, which is mainly electrodeposited in alkaline electrolyte, is used as an intermediate layer to enhance the performance of β-PbO2 on the substrate. β-PbO2 electrodeposited in acid solutions has good electrochemical properties such as electrical conductivity and active surface area, and it is considered as an alternative anode material for platinum or RuO2 electrodes. Pure β-PbO2 electrodes have not been durable when used at high voltages because they have low electrocatalytic activity. Therefore, many studies have been carried out to improve the stability, service life and adhesion of PbO2 electrodes. However, few papers have reported the changes in the stability, service life, electrochemical activity, etc. of electrodes depending on dispersants. Dispersants are often used in electrodeposition because they improve the surface property and adhesion of PbO2 layers.
Paek Yong Sok, a researcher at the Faculty of Chemical Engineering, prepared stainless steel (SS)/α-PbO2/β-PbO2 electrodes with improved surface states and electrocatalytic activity using cerium and dispersants sodium dodecyl sulfate (SDS) and polyvinyl alcohol (PVA), and evaluated the electrochemical properties of electrodes depending on the dispersants. He determined the service life of electrodes by accelerated life tests and electrooxidized Ce3+ in rare earth sulfate solution, using the prepared SS/α-PbO2/β-PbO2 electrodes.
The electrode prepared by the addition of SDS and PVA together had the longest life time 525h. Using the SS/α-PbO2/β-PbO2 electrode, 95% of cerium was oxidized at a current density of 20mA/cm2 for 37h. The current efficiency was more than 87% and the power consumption was the lowest, 1.8kW･h/kg.
For more information, please refer to his paper “Preparation of Stainless Steel/α-PbO2/β-PbO2 Electrode and its Application for Electrooxidation of Cerium” in “Proceedings of KUTIC-2025”.
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Jo May 14, 2026
Graphene is a very promising material for real applications due to its unique properties and special structure. The methods of graphene preparation include mechanical exfoliation, silicon carbide epitaxy, chemical vapor deposition, redox and laser-induced graphene (LIG). Among them, LIG is a very promising graphene preparation method due to its advantages such as low fabrication cost, simple fabrication and low environmental pollution.
Some researchers have conducted basic studies of LIG applications including hydrogen-generating electrodes, supercapacitors and various sensors. To date, however, no research has been published on the optimal parameter selection and the influence of these parameters on the properties of LIG.
Jang Il San, a researcher at the Institute of Nano Science and Technology, has investigated the effect of laser power and scanning speed on LIG formation when CO2 laser is irradiated on polyimide films.
First, he developed a theoretical model to get temperature field distribution on the film when CO2 laser is irradiated on a polyimide film. Then, he calculated the temperature distribution inside the laser beam focus spot at different laser powers and scanning rates using COMSOL Multiphysics. After that, he determined the laser power and scanning speed range for LIG formation, and prepared graphene samples accordingly.
The simulation of the temperature field on the polyimide film during LIG fabrication showed that the temperature at which graphene is formed is above 2 800K at the depth of about 0.025mm.
If further information is needed, you can refer to his paper “Effect of Laser Power and Scanning Speed on Properties of Laser-Induced Graphene” in “Proceedings of KUTIC-2025”.
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Jo May 13, 2026
As a kind of fibre, regular textile fabric is considered a porous medium composed of a lot of thread. Thread itself is also a porous medium. In other words, regular textile fabric corresponds to a large-pore porous medium composed of small-pore matrix (thread).
Heat and mass transfer problems in porous media have been studied in two categories: equilibrium and non-equilibrium. Some studies focused on the numerical simulation of the problems involving non-equilibrium heat and mass transfer.
Choe Song Gun, a section head at the Faculty of Thermal Engineering, has developed a mathematical model of fluid flow and non-equilibrium heat and mass transfer in porous media.
First, he presented governing equations for fluid, solid and porous regions and he paid special attention to moisture transfer from porous media to the surrounding moist air flow. Then, he described a CFD solution approach for spatially distributed temperature and moisture content in regular textile fabric during drying. User-Defined Scalar (UDS) and User-Defined Function (UDF) were used.
Finally, he conducted an unsteady simulation of drying of porous media placed in the 2D channel by using FLUENT, and analysed the effects of temperature and velocity at the inlet and the porosity and diffusion coefficient of porous media on drying.
For more information, please refer to his paper “CFD Simulation of Convective Drying of Regular Dual Porosity Media Under Local Non-Equilibrium” in “Proceedings of KUTIC-2025”.
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