• Korean Journal of Food Science and Technology
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• v.6 no.4
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• pp.199-208
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• 1974

An attempt was made to study on new method for the extraction of the regulatory proteins from myofibrils, and the procedures for the preparation of desensitized actomyosin and for complete extraction of troponin-tropomyosin complex were developed. When myofibrils were treated through the procedures developed in this study, actomyosin obtained had no Ca-sensitivity, indicating that Ca-sensitizing protein factor had been removed completely from myofibril. Consequently, it was concluded that the procedures developed in this study were convenient to test whether Ca-sensitizing proteins has been removed or not. When Mg-activated ATPase activity of myofibril were measured, the myofibrillar ATPase turned into the actomyosin type ATPase with the progress of the treatment. This result was interpreted to show that the regulatory proteins of the myofibril seems to play a cementing role on the structure of myofibril. When supernatant containing the regulatory proteins were fractionated with $(NH_4)_2SO_4$ saturation solution, regulatory proteins, ${\alpha}-actinin$ and troponia-tropomyosin complex, could be obtained and they showed their typical phyoislogical activity which modify the actin-myosin interaction. The amount of troponin-tropomyosin complex in myofibril was 72 mg per g myofibril. This result was in good agreement with the results reported by many investigators, and therefore it was concluded that our procedures for the extraction of troponin-tropomyosin complex were desirable to study on the quantitative analysis of troponin-tropomyosin complex.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.592-604
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• 1999

The steady state and dynamic characteristics of large cell area MCFC stacks were analyzed to solve the problems such as temperature difference generated in stacks and pressure difference between anode and cathode. Manipulated variables (current density, duel utilization rate, oxidant utilization rate) and controlled variables (temperature difference, anode and cathode pressure difference) which had an important effect on the MCFC stack performance were determined using operation results of two types of MCFC stacks (5kW (3,000 $\textrm{cm}^2$, 20 ea). 3kW (6,000 $\textrm{cm}^2$, 5ea)). The stability and transfer function representing system dynamics were obtained by steady state gain rate which showed the relative change between MVs and CVs. The transfer function was a 3$\times$3 matrix and a typical first order system without time delay. The optimal operating condition of large cell area MCFC stacks could be determined by analyzing dynamic characteristics. In case of a 5 kW MCFC stack, pressurized operation with recycle flow should be used to control the outlet temperature less than 68$0^{\circ}C$ and to control the MCFC system effectively. MIMO control or decoupler should be used to remove the interaction between MVs and CVs. This result will be used as important data in determining the control structure design and operation mode of large cell area MCFC systems in the future.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.35-44
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• 2013

In this study, a particle method without using grid was applied for analysing large deformation problems in soil flows instead of using ordinary finite element or finite difference methods. In the particle method, a continuum equation was discretized by various particle interaction models corresponding to differential operators such as gradient, divergence, and Laplacian. Soil behavior changes from solid to liquid state with increasing water content or external load. The Mohr-Coulomb failure criterion was incorporated into the particle method to analyze such three-dimensional soil behavior. The yielding and hardening behavior of soil before failure was analyzed by treating soil as a viscous liquid. First of all, a sand column test without confining pressure and strength was carried out and then a self-standing clay column test with cohesion was carried out. Large deformation from such column tests due to soil yielding or failure was used for verifying the developed particle method. The developed particle method was able to simulate the three-dimensional plastic deformation of soils due to yielding before failure and calculate the variation of normal and shear stresses both in sand and clay columns.

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.121-128
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• 2006

Recently, spillways are need to control stable water level for supporting main dams because of floods by unusual change of weather such as Typhoon Rusa. This study has been focused on the amount of leakage through the rock mass distributed fractures and joints under the opened emergency spillway. It is very important to evaluate the amount of leakage as these affect stability of spillway by interaction between effective stress and pore pressure. The commercial program MAFIC has been used for analyzing groundwater flow in fractured rock mass. The results showed that the values of range, average and deviation of leakage were 2.85∼ 3.79×10-1, 3.32×10-1 and 1.70×10-2 m3/day/m2 respectively. Secondary, we have estimated the effect of grouting after the transmissivity(Tf) of joint 1 as main pathway of leakage known from above results was changed from 1.78×10-7 to 1.59×10-9 m2/s. The results showed that the values of range, average and deviation of leakage were 7.80×10-4∼1.53×10-3, 1.18×10-3 and 1.32×10-4 m3/day/m2 respectively. As the result, the amount of leakage after grouting has been decreased by a ratio of 1 to 277.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.296-310
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• 2021

El Niño is a typical ocean and atmospheric interaction phenomenon that causes climate variability on a global scale, so it has been used as a very important teaching and learning material in the field of earth science. This study summarized the distribution and dynamics of the equatorial current system. The variability of the equatorial current system during the El Niño period and the associated misconceptions were also investigated. The North Equatorial Current, South Equatorial Current, and Equatorial Under Current significantly weaken during El Niño years. However, the variability of the North Equatorial Counter Current (NECC) during the El Niño period cannot be generalized because the NECC shows southward movement with weakening in the northern area and strengthening in the southern area, along its central axis. In the western Pacific, the NECC is further south during El Niño years, and thus, it has an eastward flow in the equatorial western Pacific. Our analysis of a mass media science article, a secondary school exam, and a survey for incumbent teachers confirmed disparate ideas about the equatorial current system's variability during El Niño periods. This is likely due to inaccurate interpretations of the existing El Niño schematic diagram and insufficient understanding of the equatorial current and wave dynamics.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.163-172
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• 2019

The linear and cross-sectional shapes of the natural river channel are subjected to continuous changes in time and space due to the interaction with the flow of water and sediment transport. This study aims to investigate the morphological characteristics and change patterns of river channel quantitatively for the middle reach of Nakdong River, which has undergone large scale riverbed dredging and construction work, as Four Major River Restoration Project. A series of bathymetry and near-river survey has been conducted to obtain the detailed terrain information for the study area. The properties related to the linear and cross-sectional characteristics of river channel have been calculated based on the filed survey data and analyzed with comparing the survey data obtained in 2012 for the project completion. Since there has not been enough time for meaningful terrain change to take place, it was not possible to extract special tendency in the degree and aspect of terrain change. However, it is necessary to make regular examinations to the patterns and degree of river channel change using the proposed methodology.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.1
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• pp.37-44
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• 2019

A bond-based peridynamic model has been reported dynamic fracture characteristic of brittle materials through a simple constitutive model. In the model, each bond is assumed to be a simple spring operating independently. As a result, this simple bond interaction modeling restricts the material behavior having a fixed Poisson's ratio of 1/4 and not being capable of expressing shear deformation. We consider a state-based peridynamics as a generalized peridynamic model. Constitutive models in the state-based peridynamics are corresponding to those in continuum theory. In state-based peridynamics, thus, the response of a material particle depends collectively on deformation of all bonds connected to other particles. So, a state-based peridynamic theory can represent the volume and shear changes of the material. In this paper, the perfect plasticity is considered to express plastic deformation of material by the state-based peridynamic constitutive model with perfect plastic flow rule. The elastic-plastic behavior of the material is verified through the stress-strain curves of the flat plate example. Furthermore, we simulate the high-speed impact on 3D granite model with a nonlocal contact modeling. It is observed that the damage patterns obtained by peridynamics are similar to experimental observations.

• Journal of Korea Water Resources Association
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• v.52 no.9
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• pp.615-626
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• 2019

Soil moisture and runoff have very close relationship. Especially the water retention capacity and drainage characteristics of the soil are determined by various factors of the soil. In this study, a total of 40 rainfall events were identified from the entire rainfall events of Sulma basin in 2016 and 2017. For each selected events, the constant-K method was used to separate direct runoff and baseflow from total flow and calculate the runoff coefficient which shows positive exponential curve with Antecedent Soil Moisture (ASM). In addition to that, the threshold of soil moisture was determined at the point where the runoff coefficient starts increasing dramatically. The threshold of soil moisture shows great correlation with runoff and depth to water table. It was founded that not only ASM but also various factors, such as Initial Soil Moisture (ISM), storage capacity of soil and precipitation, affect the results of runoff response. Furthermore, wet condition and dry condition are separated by ASM threshold and the start and peak response are analyzed. And the results show that the response under wet condition occurred more quickly than that of dry condition. In most events occurred in dry condition, factors reached peak in order of soil moisture, depth to water table and runoff. However, in wet condition, they reached peak in order of depth to water table, runoff and soil moisture. These results will help identify the interaction among factors which affect the runoff, and it will help establish the relationship between various soil conditions and runoff.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.160-170
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• 2019

The lactic acid bacteria species Lactobacillus plantarum (L. plantarum) has been used extensively for vaccine delivery. Considering to the critical role of dendritic cells in stimulating host immune response, in this study, we constructed a novel CD11c-targeting L. plantarum strain with surface-displayed variable fragments of anti-CD11c, single-chain antibody (scFv-CD11c). The newly designed L. plantarum strain, named 409-aCD11c, could adhere and invade more efficiently to bone marrow-derived DCs (BMDCs) in vitro due to the specific interaction between scFv-CD11c and CD11c located on the surface of BMDCs. After incubation with BMDCs, the 409-aCD11c strain harboring a eukaryotic vector pValac-GFP could lead to more efficient expression of GFP compared with wild-type strains shown by flow cytometry analysis, indicating the enhanced translocation of pValac-GFP from L. plantarum to BMDCs. Similar results were also observed in an in vivo study, which showed that oral administration resulted in efficient expression of GFP in both Peyer's patches (PP) and mesenteric lymph nodes (MLNs) within 7 days after the last administration. In addition, the CD11c-targeting strain significantly promoted the differentiation and maturation of DCs, the differentiation of $IL-4^+$ and $IL-17A^+$ T helper (Th) cells in MLNs, as well as production of $B220^+$ $IgA^+$ B cells in the PP. In conclusion, this study developed a novel DC-targeting L. plantarum strain which could increase the ability to deliver eukaryotic expression plasmid to host cells, indicating a promising approach for vaccine study.

• Clean Technology
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• v.27 no.2
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• pp.115-123
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• 2021

This study demonstrates a new method for the synthesis of organic-inorganic hybrid particles composed of an inorganic silica shell and organic core particles. The organic core particles are prepared with a uniform size using droplet-based microfluidic technology. In the process of preparing the organic core particles, uniform droplets are generated by independently controlling the flow rates of the dispersed phase containing photocurable resins and the continuous phase. After the generation of droplets in a microfluidic device, the droplets are photo-polymerized as particles by ultraviolet irradiation at the ends of microfluidic channels. The core particle is coated with a nano complex composed of polyallylamine hydrochloride (PAH) and phosphate ion (Pi) through strong non-covalent interactions such as hydrogen bonding and electrostatic interaction under optimized pH conditions. The polyamine nano complex rapidly induces the condensation reaction of silicic acid through the arranged amine groups of the main chain of PAH. Therefore, this method enabled the preparation of organic-inorganic hybrid particles coated with inorganic silica nanoparticles on the organic core. Finally, we demonstrated the synthesis of organic-inorganic hybrid particles in a short time under ambient and environmentally friendly conditions, and this is applicable to the production of organic-inorganic hybrid particles having various sizes and shapes.