• KSBB Journal
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• v.21 no.2
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• pp.133-139
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• 2006

In 'solid-phase' PEGylation, the conjugation reaction occurs as the proteins are attached to a solid matrix, and thus it can have distinct advantages over the conventional, solution-phase process. We report a case study: rhIFN-${\alpha}$-2a was first adsorbed to cation exchange resin and then N-terminally PEGylated by aldehyde mPEG of 5, 10, and 20 kD through reductive alkylation. After the PEGylation, salt gradient elution efficiently recovered the mono-PEGylate in a purified form from the unwanted species such as unmodified IFN, unreacted PEG, and others. The mono-PEGylation and its purification were integrated in a single chromatographic step. Depending on the molecular weight of the mPEG aldehyde used, the mono-PEGylation yield ranged 50-64%. We could overcome the major problems of random, or uncontrollable, multi-PEGylation and the post-PEGylation purification difficulties associated with the solution-phase process. N-terminal sequencing and MALDI-TOF MS confirmed that a PEG molecule was conjugated only to the N-terminus. Compared with the unmodified IFN, the mono-PEGylate showed the reduced anti-viral activity as measured by the cell proliferation assay. The bioactivity was reduced more as the higher molecular weight PEG was conjugated. Immunoreactivity, evaluated indirectly by antibody binding activity using a surface plasmon resonance biosensor, also decreased. Nevertheless, trypsin resistance as well as thermal stability was considerably improved.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.4
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• pp.402-409
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• 2006

This study was performed to investigate the effects of Capsosiphon fulvescens (CF) extract on serum and liver lipid metabolism in rats. Male Sprague-Dawley rats were administered 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia and were divided into six groups. Experimental groups were administered with following diets; normal diet group (NC), high cholesterol diet group (HC), normal diet and CF extract (200 mg/kg) administered group (NC-CFL), normal diet and CF extract (400 mg/kg) administered group (NC-CFH), high cholesterol diet and CF extract (200 mg/kg) adwlinistered group (HC-CFL), and high cholesterol diet and CF extract (400 mg/kg) administered group (HC-CFH). The body weight gain and feed efficiency ratio were increased by high cholesterol diet, but gradually decreased to the corresponding level of the normal diet group by administered CF extract. The serum total cholesterol concentration of normal diet group was significantly higher than those of NC-CFL group and NC-CFH group. The concentrations of serum total cholesterol LDL-cholesterol and triglyceride and the atherogenic index .were tended to decrease in the CF extract administered groups compared with the high cholesterol diet group. However, HDL-cholesterol and phospholipid concentrations in serum decreased in the high cholesterol diet group and markedly increased by the CF extract administered groups. There were no differences in the concentrations of serum triglyceride, phopholipid, LDL-cholesterol, HDL-cholesterol and free cholesterol in normal diet groups. Concentrations of total cholesterol and triglyceride in liver and kidney were also markedly decreased in the CF administered groups. Total cholesterol and triglyceride concentrations of adipose tissue in the CF administered groups were also decreased compared with the high cholesterol diet group. In addition, there were no differences in the concentrations of liver, kidney and adipose tissue total lipid, triglyceride and total cholesterol in normal diet groups. The activities of heparin-releasable lipoprotein lipase (LPL) and total-extractable LPL in adipose tissue were increased in the high cholesterol diet group compared with the CF extract administered groups, but those of the NC -CFL group and NC-CFH group were similar to the normal diet group. Taken together, it is suggested that the extract of CF have an antiatherosclerotic effect by reducing cholesterol level of serum and liver. Furthermore, the extract of CF decreased LPL activity and triglyceride concentration, resulting in less lipid storage.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.768-774
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• 2014

SI process is a thermochemical process producing hydrogen by decomposing water while recycling sulfur and iodine. Various technologies have been developed to improve the efficiency on Section III of SI process, where iodine is separated and recycled. EED(electro-electrodialysis) could increase the efficiency of Section III without additional chemical compounds but a substantial amount of $I_2$ from a process stream is loaded on EED. In order to reduce the load, a crystallization technology prior to EED is considered as an $I_2$ removal process. In this work, $I_2$ particle sinking behavior was modeled to secure basic data for designing an $I_2$ crystallizer applied to $I_2$-saturated $HI_x$ solutions. The composition of $HI_x$ solution was determined by thermodynamic UVa model and correlation equations and pure properties were used to evaluate the solution properties. A multiphysics computational tool was utilized to calculate particle sinking velocity changes with respect to $I_2$ particle radius and temperature. The terminal velocity of an $I_2$ particle was estimated around 0.5 m/s under considered radius (1.0 to 2.5 mm) and temperature (10 to $50^{\circ}C$) ranges and it was analyzed that the velocity is more dependent on the solution density than the solution viscosity.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.25-35
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• 2018

This study presents microstructural characteristics and strength properties of alkali-activated kaolin(K)-fly ash(FA) blends binders. The compressive strength, X-ray diffraction(XRD), thermogravimetric(TG) analysis and SEM/EDS were measured for hardened samples. The results were shown that all the samples had developed the compressive strength over time, regardless of replacement levels of K. It was found that when the amount of K increased, the strengths of samples decreased. In XRD result, no new crystalline phases were observed in all the hardened samples other than the crystalline components of raw FA and K, whereas TG analysis showed that N-A-S-H gel was formed as a reaction product in all the samples. Samples did not have the typical microstructure of dense, and there is little significant difference between the microstructures of the samples despite the differences in the strength testing results with replacement ratios of K. This study showed that the strength of sample was larger for lower Si/Al ratio of reaction product formed in sample. According to the correlation between Si/Al ratio and strength in this study, it is expected that if a chemical additive is used for lowering the Si/Al ratio of reaction product(i.e., increasing the $Al_2O_3$ solubility) in alkali-activated K-FA blends binders, strength improvement in K-FA blends binders could be achieved.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.185-190
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• 2021

Cement has been used as a main material in the modern construction industry. However, it has been pointed out as a main cause of global warming due to carbon dioxide generated during manufactured. Recently, research that replacing cement substitute to industrial by-products such as Blast Furnace Slag which is by-producted in steelworks. When Blast Furnace Slag is used as a cement substitute, it shows a problem of lower initial strength, which is caused by glassy membrane on the particle surface. In this study, we used Electrolysis Alkaline Aqueous to improve the usability and problem of lower initial strength. As a result of the experiment, cement matrix using Blast Furnace Slag and Alkaline Aqueous showed initial strength and hydrate product were developed than that using general mixing water. Also, as a result of porosity analysis, It was confirmed that cement matrix using Alkaline Aqueous and Blast Furnace Slag has a tighter structure in internal porosity and porosity distribution than using general mixing water.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.332-340
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• 2023

This study investigated the effects of nanoparticles on the fracture toughness of cement mortar. Three-point bending tests, compressive tests, and slump tests were conducted on cement mortars reinforced with carbon nanotubes(CNTs), nanosilica(NS), and nano calcium carbonate(NC), respectively. Cement mortar with a water-to-cement ratio and a sand-to-cement ratio of 0.45 and 1.5, respectively, and reinforced with 0 and 2 vol.% of 19.5 mm steel fibers, respectively, was used. Reinforcement with nanoparticles partially improved the fracture toughness and compressive strength of the cement mortar. However, in the case of cement mortar reinforced with steel fibers, the reinforcement with nanoparticles was found to reduce the flowability of the mortar, adversely affecting the dispersion of steel fibers, and ultimately leading to a decrease in fracture toughness, contrary to the intended enhancement. Additional research is needed to improve the decrease in mortar fluidity caused by the reinforcement with nanoparticles.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.145-152
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• 2020

Highways are characterized by high non-point pollutant emissions due to high traffic volumes and sections that cause abrupt change in driving speed (i.e. rest stations, ticketing office, etc.). Most highways in Korea were constructed with layers that do not allow adequate infiltration. Moreover, non-point pollution reduction facilities were not commonly installed on domestic highways. This study was conducted to evaluate a facility treating highway runoff and develop a cost-effective design for infiltration facilities by using soil amendment techniques. Performing soil amendment increased the hydraulic retention time (HRT) and infiltration rate in the facility by approximately 30% and 20%, respectively. The facility's efficiency of removing non-point pollutants (Total Suspend Soiled (TSS), Chemical Oxygen Demand(COD), Biological Oxygen Demand(BOD), Total Nitrogen (TN) and Total Phosphorus, (TP) were also increased by 20%. Performing soil amendment on areas with low permeability can increase the infiltration rates by improving the storage volume capacity, HRT, and infiltration area. The application of infiltration facilities on areas with low permeability should comply with the guidelines presented in the Ministry of Environment's Standards for installation of non-point pollution reduction facilities. However, soil amendment may be necessary if the soil infiltration rate is less than 13 mm/hr.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.65-75
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• 2019

The government is promoting recycling of waste resources through the enactment of Fundamental Law on Resource Circulation, the revision of the Wastes Control Act and zero-landfilling of untreated waste through improved processes such as recycling and diversification. As of 2015, the total amount of landfilled waste is 38,308 ton/day in Korea. The amount of landfilled waste from industrial sectors is 23,577 ton/day, accounting for 62 % of total landfilled waste. In the study, we investigated the characteristics of the thermal treatment residue among inorganic wastes and estimated the landfill reduction potential according to the relevant recycling criteria, which can go through recycling paths. As a result, it is estimated that about 5~42 % of the landfilled waste can be reduced in case mandatory recycling and landfill suppression policies such as recycling criteria for thermal processing residues and expansion of recycling obligation targets should be implemented. In order to minimize landfill disposal, it is necessary to expand the diversity of waste recycling type and the usage of recycled products.

• Journal of Korea Water Resources Association
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• v.54 no.2
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• pp.105-119
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• 2021

An increase in the frequency and intensity of both floods and droughts has been recently observed due to an increase in climate variability. Especially, land-use change associated with industrial structure and urbanization has led to an imbalance between water supply and demand, acting as a constraint in water resource management. Accurate rainfall-runoff analysis plays a critical role in evaluating water availability in the water budget analysis. This study aimed to explore various continuous rainfall-runoff models over the Soyanggang dam watershed. Moreover, the ensemble modeling framework combining multiple models was introduced to present scenarios on streamflow considering uncertainties. In the ensemble modeling framework, rainfall-runoff models with fewer parameters are generally preferred for effective regionalization. In this study, more than 40 continuous rainfall-runoff models were applied to the Soyanggang dam watershed, and nine rainfall-runoff models were primarily selected using different goodness-of-fit measures. This study confirmed that the ensemble model showed better performance than the individual model over different flow regimes.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.170-184
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• 2022

The Riparian Buffer Zone(RBZ) is a sustainable social-ecological system created in the middle zone between water and land. For the RBZ, close communication with the local community is important, and it is necessary to promote it as a communicative environmental planning process. In this study, for the RBZ project, three strategies are presented as a communicative act to understand and implement planning. First, government-led projects were avoided and improved to a process in which citizens and stakeholders participated together, centered on local partnership. Second, it was intended to introduce design criterias in terms of enhancing the function of ecosystem services that citizens can sympathize with, and to increase acceptance and awareness through the planning of preferred spaces and facilities. Third, after a balanced plan for habitats, water cycle-based ecological environment, ecological experience and open space, citizens felt the restoration effect and value as an ecological resources, and a system was prepared to participate in the operation and management. This study will work as a process model based on citizens's participation. In addition, it will be possible to provide lessons for the change of the policy paradigm for the RBZ and the implementation of similar projects in the future.