Jo Dec 16, 2025
At present, rapid population growth, global warming, indiscriminate drain of industrial wastewater and oil spill incur dwindling resources of available fresh water, devastatingly affecting our living environment. Hence, oil/water separation has attracted considerable attention due to the serious water pollution caused by oil spill accidents and oily wastewater from industries, etc. This has led to active researches for the improvement of oil/water separation efficiency.
Superhydrophilic-superoleophobic membranes are not fouled by oil, which means high separation efficiency and long lifetime. Hence, they are a main target for the fabrication of oil/water separation membranes.
There are many superhydrophilic-superoleophobic materials available such as fabrics, metal meshes and polymer filtration membranes. Since they are usually hydrophobic, their wettability characteristics should be improved to be superhydrophilic-superoleophobic. Dopamine has attracted much attention recently due to its potent adhesion property. Based on the strong adhesion behaviour and the intrinsic capacity for facile secondary treatments, a great number of approaches have been put forward for surface modification of solid materials.
Kim Myong Hak, a researcher at the Faculty of Chemical Engineering, has proposed a novel method to improve the hydrophilicity of stainless steel mesh by coating a polydopamine (PDA) as a transition layer on the surface of a hydrophobic stainless steel mesh and modifying a hydrophilic triblock copolymer onto the surface.
The water contact angle on the triblock copolymer-modified mesh in the air is 0°, which proves the mesh to be superhydrophilic. The oil (dichloromethane) contact angle on the surface of the modified mesh in water is 155°, exhibiting greater underwater superoleophobicity than on the surface of mesh with only a polydopamine layer.
The triblock copolymer/polydopamine modified mesh could selectively separate oil from immiscible oil/water mixtures with high separation efficiency of above 96%.
...
Jo Dec 15, 2025
This is an era of Industry 4.0. The IoT is the core technology of Industry 4.0, which tags information such as the shape, position, property and history of all things including human beings and manages them in real time by connecting them with the Internet. Being tagged and connected with the Internet by the Radio Frequency Identification Device (RFID), all things are in real-time Smart management.
If the spindle unit which is the core unit of a machine tool is in real-time management through the Internet by introducing Internet of Things (IoT) from the design stage, the quality of design can be further improved and put on a scientific basis.
Kim Son Ho, a researcher at the Faculty of Mechanical Science and Technology, defined the tag content of machine parts, tagged spindle unit parts of "RT-350" CNC lathe and introduced a 3D modeling algorithm for them. In addition, he programmatically implemented an RFID by identifying the shape, position, property and history information of the parts using the IF-THEN-module of rule-based reasoning (RBR) of the expert system.
As a result, the design quality of a spindle unit has further increased and the time for design has been reduced by 1/5. In addition, the design has become more intelligent.
...
Jo Dec 14, 2025
Methanol is an important basic raw material for the chemical industry and it has many applications in organic synthesis, dyes, medicines, pesticides, etc. Methanol, which is chemically mass-produced from coal gasification and natural gas, is a feed ingredient of C1 chemical industry and organic chemical industry.
Low-pressure methanol synthesis using copper-based catalysts is widely used worldwide in the production of methanol by coal gasification. Since the methanol obtained from this process contains water and a mixture of various organic substances, it must be purified for the usage as a raw material for the organic synthesis industry. Distillation is the most matured separation process, which is widely used for the purification of methanol.
Ro Jin Hyok, a researcher at the Faculty of Chemical Engineering, has simulated a methanol distillation process for obtaining high-purity methanol from crude methanol produced from coal gasification, and investigated the influence of some factors on its purity.
The factors include the rate of extracted water in the pre-distillation column, and the reflux ratio, the amount of distillate and the temperature of feed in the main distillation column.
The results show that the optimum conditions for the process operation are as follows. The rate of extracted water in the pre-distillation column is 3 500kg/h and the reflux ratio, the rate of distillate and the feed temperature are 1.1, 17 000kg/h and 69℃, respectively, in the main distillation column.
Under these conditions, the purity of methanol is 99.93% and the recovery rate is over 98.9%.
...
Jo Dec 12, 2025
Lithium and its compounds have been widely used in several fields including battery, aerospace and light metal alloys due to their special properties. Recently, gradual exhaustion of lithium resources on land makes it important to extract lithium from seawater and salt lake brine which are rich in lithium.
There are several methods for recovering lithium from lithium resources including precipitation, solvent extraction and adsorption. Among them, adsorption method is suitable for recovering lithium from seawater and salt lake brine due to its simple process and high recovery.
Inorganic adsorbents are widely applied in the adsorption method. Among them, ion sieve materials are most widely used. At present, there are two types of lithium ion sieves―manganese type and titanium type. The ion sieve of manganese type has a disadvantage of big dissolution rate of manganese. Therefore, research on the titanium type with higher chemical stability is becoming more intensive.
Ri Song Ho, a section head at the Institute of Analysis, has prepared a titanium-type lithium ion sieve for recovering lithium from seawater and salt lake brine, and investigated its characteristics.
First, he prepared the precursor of lithium ion sieve (Li2TiO3) by the solid state reaction with lithium carbonate (Li2CO3) and titanium dioxide (TiO2) as raw materials. Then, he prepared a lithium ion sieve (H2TiO3) by extracting lithium from the precursor with HCl solution.
The extraction rate of lithium and the dissolution loss rate of titanium are 91.23% and 0.2%, respectively, during HCl treatment of the precursor. The equilibrium adsorption capacity of lithium on the prepared ion sieve is 38.8mg/g.
...
Jo Dec 11, 2025
Saenap (a Korean brass wind instrument) is a peculiar national wind instrument.
Hard woods like paktal tree, date tree, etc. were used for its hollow pipe.
It is basically the same as a flute in the way of playing. It is characterized by bright and gorgeous timbre, fluency and strong appeal, and it produces great volume.
It is used as a melodic instrument in holiday amusements, instrumental music of peasants and dance music boasting of the pleasure of rich harvest, and in mixed orchestra it usually appears in the parts stimulating the national interest.
...
Jo Dec 9, 2025
Currently, research on parameter tuning methods is active due to the widespread use of PID controllers in industrial practice. Many studies have been carried out on self-tuning methods to tune the parameters of PID controllers with varying plant parameters, bringing about remarkable successes.
Meanwhile, the Particle Swarm Optimization (PSO) algorithm is a kind of optimization method based on the theory of cluster intelligence, which has been widely applied in the field of function optimization, neural network learning, multiobjective optimization, fuzzy control system, etc. The population optimization algorithm is easily applicable to various types of problems because there are no complex crossover and mutation operations like in genetic algorithms. The greatest advantage of PSO algorithm is its fast convergence speed, simplicity of evolution operation, low computational cost and small number of parameters used in it.
The T-S fuzzy model approximates nonlinear characteristics, and inference using it can be used as a tool to implement controllers or fuzzy models with optimal and adaptive functions because it is simple and convenient for mathematical analysis and it can be easily combined with PID control or adaptive control.
Kim Yong Su, a researcher at the Faculty of Automatics, has proposed a method for designing a PID controller, based on the characteristics of PSO algorithm and T-S fuzzy model.
According to the proposed method, you first use the PSO algorithm to determine the position of a dominant pole which minimizes the judge function consisting of Integral of Absolute Error (IAE) and overshoot value and then express it as a T-S fuzzy model to determine the parameters of a PID controller using fuzzy inference.
The proposed method allows you to get both the optimal dominant pole and the exchanging frequency at the same time, and to get a good control result as the overshoot value is small.
...