• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.403-413
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• 2020

A mathematical model comprised with eight simultaneous quasi-linear partial differential equations was suggested to provide optimal chlorination strategy. Upstream weighted finite element method was employed to construct multidimensional numerical code. The code was verified against measured concentrations in three type of reactors. Boundary conditions and reaction rate were calibrated for the sixteen cases of experimental results to regenerate the measured values. Eight reaction rate coefficients were estimated from the modeling result. The reaction rate coefficients were expressed in terms of pH and temperature. Automatic optimal algorithm was invented to estimate the reaction rate coefficients by minimizing the sum of squares of the numerical errors and combined with the model. In order to minimize the concentration of chlorine and pollutants at the final usage sites, a real-time predictive control system is imperative which can predict the water quality variables from the chlorine disinfection process at the water purification plant to the customer by means of a model and operate the disinfection process according to the influent water quality. This model can be used to build such a system in water treatment plants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.542-549
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• 2021

The purpose of this study was to provide an economical and easy preparation method for recombinant human epidermal growth factor (rhEGF) without the need for an expensive enzyme to cleave the fusion part. However, the N-terminal fusion part is still useful for affinity chromatography. The hEGF is an important hormone in cell growth and proliferation in humans, and many studies on the expression and purification of this protein have been reported. In the present study, the hEGF gene was designed to be optimized with the E. coli codon usage preference and to contain Asn-Gly at the N-terminus of the protein. The gene was inserted into pRSET_A, an E. coli expression vector, and transformed into E. coli BL21 (DE3). The recombinant fusion protein was successfully co-expressed with pG-Tf2, a chaperone vector, in E. coli and purified by Ni-NTA column chromatography. The rhEGF was then released by hydroxylamine treatment and confirmed by SDS-PAGE. ELISA analysis showed that the activity of the free rhEGF was more than 92% similar to that of commercial EGF. The biological activity of the rhEGF was confirmed by a cell proliferation test with human skin fibroblasts.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.67-71
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• 2011

The cathodic active material of $Li/SO_2Cl_2$ battery is $SO_2Cl_2$, which is the solvent of an electrolyte. It is referred to as a catholyte, a compound word of cathode and electrolyte. As the battery discharges, the catholyte burns out. And thus, the characteristics of the $SO_2Cl_2$ in the battery determine the capacity. In addition, the transition minimum voltage (TMV) and the voltage delay deviation of $Li/SO_2Cl_2$ battery are due to the passivation film formed by the reaction between an electrolyte and Li. Impurities in the electrolyte, such as moisture or heavy metal ions, will accelerate the growth of the passivation film. Therefore, a technology must be established to purify an electrolyte and to ensure the effectiveness of the purification method. In this research, $LiAlCl_4/SO_2Cl_2$ was manufactured using $AlCl_3$ and LiCl. Its concentration, the amount of moisture, and the metal amount were evaluated using an ionic conductivity meter, a colorimeter, and FT-IR.

• Ecology and Resilient Infrastructure
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• v.8 no.1
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• pp.9-21
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• 2021

In this study, fish and flow surveys were conducted at 12 survey points to calculate the fish habitat suitability index of Miho Stream in the Geum River Water System. The field surveys were conducted four times from September 2019 to May 2020. The results show the presence of 8 families, 37 species, and 5,754 individuals. The number of water purification species that preferred waters with a low flow rate was the highest. The habitat suitability index was calculated according to the Washington Department of Fish and Wildlife method based on the populations collected at various water depths and flow rate sections and the flow rate survey results. For the dominant species, Zacco platypus and swimming species, the results were compared by calculating at Gasan Bridge and Palgye Bridge at the upper stream. The single species showed no significant difference between the upstream and downstream at water depths of 0.1 - 0.5 m and flow rates of 0.2 - 0.5 m/s. The species swimming ability was similarly calculated at water depths of 0.2 - 0.5 m and flow rates of 0.2 - 0.5 m/s. The dominant species, Pyramid, had a wide range of physical habitats. The habitat suitability index between the swimming species was similarly calculated. These results can be effectively used as basic data for calculating the environmental ecological flow rate and establishing a river restoration plan of the Miho Stream.

• Journal of Soil and Groundwater Environment
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• v.27 no.spc
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• pp.99-112
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• 2022

From early 2000, many researchers in the groundwater and soil environment remediation project tried to calculate the pollution level and pollution remediation cost and reflect it in the design. In addition, by identifying the movement characteristics of oil pollutants in the underground environment, many researchers tried to derive design factors necessary for pollution purification. However, although the test should be conducted in an area contaminated with oil, the toxicity and risk are too great for testing by deliberately leaking pollutants that are harmful to the human body. And as oil-contaminated areas are promoted by military units such as returned US military bases, there is a limit to access by the general public. In addition, since the indoor simulation test and the field application test have been carried out separately from each other, it was difficult to compare and review various simulation tests Therefore, in this study, PITT (Partitioning Interwell Tracer Test) and analysis methods were specifically presented through actual tests so that field workers could easily use them with the help of the military base and the Korea Rural Community Corporation Soil Environment Restoration Team. However, in order to directly reflect the distribution tracer test results in the pollution remediation design, it is necessary to reduce the analysis errors by comparing the analysis results of the existing soil pollution survey, physical exploration, and numerical modeling. In addition, it is judged to be cautious in the analysis because errors can easily occur due to various factors such as the type of oil at the polluted site, the hydraulic conductivity of the aquifer, and the skill of the researcher.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.481-491
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• 2022

This study investigates the characteristics of the GAC adsorption behavior during the operation of a multi-stage cross-flow filtration and GAC adsorption process for the purpose of devising an advanced treatment of combined sewer overflows (CSOs) and evaluates the regeneration efficiency of spent GAC that has reached the design breakpoint. During the filtration process, suspended substances are easily removed, but dissolved organic substances are not removed, necessitating a process capable of removing dissolved organic substances for the advanced treatment of CSOs. In general, GAC adsorption has been applied under low-concentration organic conditions, such as for water purification and tertiary treatments of sewage, and has rarely been applied under conditions with high organic concentrations, such as with sewage or CSOs. Accordingly, this study will provide a new and interesting experience. Also in this study, the continuous operation and breakthrough characteristics of GAC according to the strength of the inflow organic matter were investigated, electrochemical regeneration was applied to the used GAC, and the regeneration efficiency was evaluated through desorption and re-adsorption tests. The results showed that the breakthrough period was 21 days under high concentration conditions, 28 days at medium concentrations, and 32 days under low concentration conditions. The desorption of adsorbed organic matter through electrolysis occurred in the range of 188 to 609 mgCOD/L depending on the electrolysis conditions, and the effect of the electrolyte type led to the finding that NaOH was slightly higher than H₂O₂.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.1-14
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• 2022

This study tried to suggest crisis management compliance to prevent personal information infringement accidents that may occur in the process because the data including personal information is being processed in the artificial intelligence (AI) service process. To this end, first, the AI service provision process is divided into 3 processes such as service planning/data design and collection process, data pre-processing and purification process, and algorithm development and utilization process. And 3 processes are subdivided into 9 stages following to personal information processing stages to infringe personal information. All processes were investigated with literature and experts' Delphi. Second, the investigated personal information infringement factors were selected through FGI, Delphi, etc. for experts. Third, a survey was conducted with experts on the severity and possibility of each personal information infringement factor, and the validity and adequacy of the 94 responses were verified. Fourth, to present appropriate risk management compliance for personal information infringement factors in AI services, a method for calculating the risk level of personal information infringement is prepared by utilizing the asset value of personal information, personal information infringement factors, and the possibility of infringement accidents. Through this, the countermeasures for personal information infringement incidents were suggested according to the scored risk level.

• Membrane Journal
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• v.33 no.4
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• pp.191-200
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• 2023

Polyethersulfone (PES) is a widely employed membrane material for water and industrial purification applications owing to its hydrophilicity and ease of phase separation. However, PES membranes and filters prepared using the nonsolvent induced phase separation method often encounter significant flux decline due to pore clogging and cake layer formation on the dense membrane surfaces. Our investigation revealed that tight microfiltration or loose ultrafiltration membranes can be subject to physical fouling due to the formation of a dense skin layer on the bottom side caused by water intrusion to the gap between the shrank membrane and the substrate. To investigate the effect of the bottom surface porosity on membrane fouling, two membranes with the same selective layers but different sub-layer structures were prepared using single and double layer casting methods, respectively. The double layered PES membrane with highly porous bottom surface showed high flux and physical fouling tolerance compared to the pristine single layer membrane. This study highlights the importance of physical optimization of the membrane structure to prevent membrane fouling.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.105-111
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• 2021

⁸⁹Zr is a positron-emitting radioisotope, which has known as well-suited radioisotope for use in a monoclonal antibody-based imaging agent for immuno-PET. The purpose of this study was to quantitatively evaluate the diagnostic ability of general trastuzumab and thio-trastuzumab as HER2 positive receptors based on Df hexadentate iron chelator. Desferrioxamine-p-SCN (Df-Bz-NCS) and desferroixamine-maleimide (Df-Mal) were purchased from Macrocyclics (Dallas, TX, USA). The trastuzumab was purchased from Roche (Schweiz), and thio-trastuzumab was obtained from professor Hyo-Jeong Hong group (Kangwon National University). The radioisotope ⁸⁹Zr was produced by domestic purification system and KIRAMS using medical cyclotron (50 MeV, Scantronix). The conjugates of Df-trastuzumab and Df-thio-trastuzumab were prepared with Df-Bz-NCS and Df-Mal under basic aqueous solution (pH 8-9) at room temperature, respectively. The conjugates purified by PD-10 column were mixed with dried ⁸⁹Zr chloride. ⁸⁹Zr-labeled conjugates were purified and concentrated by Amicon ultra centrifugal filter. The preparation step and time of ⁸⁹Zr-labeled conjugates was shorted as 4 steps within 2 hours. ⁸⁹Zr-labeled conjugates showed the highly radiochemical purity of over 98%, and were very stable until 7 days by the analysis of radio-ITLC method. Each radio-labeled conjugates were also exhibited the highly stability in both PBS buffer and mouse serum. Immuno-PET imaging of ⁸⁹Zr-labeled conjugates in mice bearing gastric cancer xenograft tumors with HER2 expression showed high tumor uptake in the NCI-N87 HER2-expressing. However, ⁸⁹Zr-Df-Mal-thio-trastuzumab showed a relatively lower tumor-to-background ratio than ⁸⁹Zr-Df-Bz-trastuzumab, as well as whole-body distribution. In the results, ⁸⁹Zr-Df-Bz-trastuzumab was evaluated to have a relatively higher HER2 diagnostic ability than ⁸⁹Zr-Df-Mal-thio-trastuzumab.

• Journal of the Daesoon Academy of Sciences
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• v.25_2
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• pp.103-136
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• 2015

The theory of post-heaven provided Korea's many emerging national religions with spiritual ground. The I Ching originated in China emphasizes the principles of change or static aspects of world, while Right I Ching, which Il-Bu Kim suggested, underlines dynamic aspects of world. Il-Bu Kim is perceived to open a new stage in the history of philosophy of I Ching in this regard. His most remarkable contribution is the view of Great Opening Era of Post-Heaven, according to which the clock of cosmos shows the era of great change from Pre-Heaven to Post-Heaven and in the world of Post-Heaven everything will take its proper place. As to human society, Il-Bu Kim foresaw the change from disharmony to harmony, imbalance to balance and era of xiaoren to that of junzi. The advent of such a new world, however, asks human's moral revolution as a prerequisite. In the tradition of East Asian thought, human is the center of the Samjae, Heaven-Earth-Human and the only being which could participate in the growth of Heaven and Earth. Without the change of human mind, however, human can neither participate in the growth of Heaven and Earth nor expect the right change of Heaven and Earth. Even though the world of nature changes according to the principle of cosmic harmony, as the Right I Ching predicts, the real change of Heaven and Earth can be achieved only with moral change of human. The human in the Right I Ching is a free man who sticks to nothing and communicates with cosmos with empty mind. This is the very image of perfect man(至人). The perfect man in the Right I Ching is the main agent of everything, that's to say, the main agent of the great opening to Post-Heaven Era. This is the reason why most leaders of Koran emerging religions concentrate on the change of human. In this regard, Jeung-San Kang encouraged people to become the perfect man through the purification of mind and body and the great opening of inner man, depending on the metaphysical principle of the Right I Ching. Cheok and Resolution of grievances for the mutual beneficence of all life are what he suggested as a method of the great opening of inner man. Such a view is based on the thought that the accumulated sinful behaviors are obstacles to cosmic change and the time of mutual beneficience opens with the removal of the obstacles. If such religious practices are so effective, as Jeung-San Kang says, that future world could consist of perfect men who have achived the great opening of inner man, moral change, and change of consciousness, we could expect that the activities of xiaoren will be shrinked and junzi will be welcomed, as the Right I Ching predicts.