• Journal of Adhesion and Interface
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• v.22 no.3
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• pp.91-97
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• 2021

By introducing an organic interlayer on the Parylene C dielectric surface, the electrical device performances and the operating stabilities of organic field-effect transistors (OFETs) were improved. To achieve this goal, hexamethyldisilazane (HMDS) and octadecyltrichlorosilane (ODTS), as the organic interlayer materials, were used to control the surface energy of the Parylene C dielectrics. For the bare case used with the pristine Parylene C dielectrics, the field-effect mobility (μ_FET) and threshold voltage (V_th) of dinaphtho[2,3-b:2',3'-f ]thieno[3,2-b]- thiophene (DNTT) FET devices were measured at 0.12 cm²V^-1s^-1 and - 5.23 V, respectively. On the other hand, the OFET devices with HMDS- and ODTS-modified cases showed the improved μ_FET values of 0.32 and 0.34 cm²V^-1s^-1, respectively. More important point is that the μ_FET and V_th of the DNTT FET device with the ODTS-modified Parylene C dielectric presented the smallest changes during a repeated measurement of 1000 times, implying that it has the most stable operating stability. The results could be meaned that the organic interlayer, especially ODTS, effectively covers the Parylene C dielectric surface with alkyl chains and reduces the charge trapping at the interface region between active layer and dielectric, thereby improving the electrical operating stability.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.681-692
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• 2021

Vegetation processes have a significant impact on rainfall runoff processes through evapotranspiration control, but are rarely considered in the conceptual lumped hydrological model. This study evaluated the model performance of the Hapcheon Dam watershed by integrating the ecological module expressing the leaf area index data sensed remotely from the satellite into the hydrological partition module. The proposed eco-hydrological model has three main features to better represent the eco-hydrological process in humid regions. 1) The growth rate of vegetation is constrained by water shortage stress in the watershed. 2) The maximum growth of vegetation is limited by the energy of the watershed climate. 3) The interaction of vegetation and aquifers is reflected. The proposed model simultaneously simulates hydrologic components and vegetation dynamics of watershed scale. The following findings were found from the validation results using the model parameters estimated by the SCEM algorithm. 1) Estimating the parameters of the eco-hydrological model using the leaf area index and streamflow data can predict the streamflow with similar accuracy and robustness to the hydrological model without the ecological module. 2) Using the remotely sensed leaf area index without filtering as input data is not helpful in estimating streamflow. 3) The integrated eco-hydrological model can provide an excellent estimate of the seasonal variability of the leaf area index.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.63-72
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• 2011

The aim of this study, a traditional residential area in the environmentally friendly design techniques to identify the techniques and principles that have been carried out to reestablish the principles. To do this, through literature review environmental performance is reflected in the traditional residential area side of resources conservation, locational aspects, spatial configuration, and how cases were selected looking for ways to apply modern. Are examples of upper class housing in the Chosen Dynasty Period period construction relatively well-preserved round and a good building with a clear housing Dokrakdang year were selected. Locational aspects of the terrain with minimal changes to the building and construction techniques were entirely in terms of environmental conservation and environmental temperature was adjusted to regulate the room temperature technique could be seen. In terms of cycling in natural materials were recycled. and water make used of positive through water cycling technique & water control. In addition, the importance of landscape views overlooking the landscape from inside to outside through the regulation of the various internal and external space technique was used to attract and expand. Traditionality in the pursuit of modern space, simply cut off because of tradition rather than to restore or recover the organizing principle inherent in the traditional space, and extraction of the contemporary social, cultural and environmental understanding of space is acceptable in basis. Environmentally-friendly design techniques in a traditional residential area for a long time to be developed by the experience of its application of modern environmental and energy problems and pleasant environment to the creation of human life and are subject to significant swings in that.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.133-137
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• 2011

In this study, illite was size-reduced using a wet-ball-milling treatment to improve its dispersion. Changes in illite particle size, size distribution, and dispersion characteristics after varying the treatment period were investigated. And the dispersion and dispersion stability of illite solution after 2 h wet ball milling treatment with different pH conditions were also evaluated. The illite particle size significantly decreased as the treatment time increased and the size reduction effect of wet ball milling deteriorated above 2 h treatment time. In addition, illite particle size was more evenly distributed as the treatment time increased. X-ray diffraction (XRD) analysis showed that no crystal structural changes of illite were induced, but the characteristic peak of illite the weaker due to the size reduction and exfoliation, as the treatment time increased. Zeta potential analysis showed that the illite dispersion improved, as the treatment time increased. The illite wet-ball-mill treated at pH 2 had the lowest dispersion stability. Illite dispersion and dispersion stability increased as pH increased, due to the increase in surface ionization. Hence, the results showed that as the treatment time increased, the illite particle size decreased, and dispersion and dispersion stability improved due to the increase in surface energy and repulsion force between particles.

• The Journal of Korean Philosophical History
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• no.41
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• pp.9-38
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• 2014

Hanhweon-dang Kim Goeng-pil(1454~1504) sublimated ethics whose lead was opened up by Jeong Mong-ju in late Goryeo as one scholarly tendency. Kim Goeng-pil was called 'the father of ethics in Joseon' and has been respected as a model of ethicist for 400 years since then. Following Kim Goeng-pil, Confucian scholars of Joseon cultivated perseverance through Xiaoxue and the perseverance was sublimated to Confucian scholars' energy and then that of state, which served as driving force to keep the national legacy. Kim Goeng-pil suggested how to study with Xiaoxue and sought moral human beings and ethically ideal societies based on strong practicability which is required in Xiaoxue. Individuals' cultivation and social reform are not at a different dimension. Spirit of 'self-cultivation' that Kim Goeng-pil himself demonstrated advanced to pursuit of ethical, ideal state when reaching a level of Jo Kwang-jo. Kim Goeng-pil thought that teaching in Xiaoxue could be achieved through 'Gyeong (敬, respect).' It is the key of Neo-Confucianism in Joseon to control one's mind through the cultivating method of 'Gyeong.' Kim Goeng-pil settled Joseon's Confucianism as 'practical ethics(心學).' Before Kim Goeng-pil, no scholars had well presented the aspects of practical ethics. After King Myeongjong and Seonjo, Confucianism in Joseon worked as the cornerstone of practical ethics. Since mid-17th century, the system of practical ethics had been firmly established with focus on 'Gyeong. Literary men of Kim Goeng-pil and scholars they fostered led the academic and political world of Joseon after mid-16th century. They played the lead in Sarim faction's(士林派) ruling after King Seonjo came to throne. The very foundation which sublimated Joseon to the ethically ideal state and made the Dynasty a 'state of Sarim' was actually laid by Kim Goeng-pil.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.60-67
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• 2021

This study presented techno-economic analysis of a 500 MWe oxy-coal power plant with CO2 capture. The power plant included a circulating fluidized-bed (CFB), ultra-supercritical steam turbine, flue gas conditioning (FGC), air separation unit (ASU), and CO2 processing unit (CPU). The dry flue gas recirculation (FGR) was used to control the combustion temperature of CFB. One FGR heat exchanger, one heat exchanger for N2 stream exiting ASU, and a heat recovery from CPU compressor were considered to enhance heat efficiency. The decrease in the temperature difference (ΔT) of the FGR heat exchanger that means the increase in heat recovery from flue gas enhanced the electricity and exergy efficiencies. The annual cost including the FGR heat exchanger and FGC cooling water was minimized at ΔT = 10 ℃, where the electricity efficiency, total capital cost, total production cost, and return on investment were 39%, 1371 M$, 90 M$, and 7%/y, respectively.

• Membrane Journal
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• v.31 no.3
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• pp.228-240
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• 2021

The organic solvent robust polybenzimidazole (PBI) membranes were prepared as organic solvent nanofiltration (OSN) membrane for the recycling of alcoholic solvents using non-solvent induced phase separation with different dope solution concentration and coagulant composition of water/ethanol mixtures to control the membrane morphology and permeation performance. Investigation on crosslinking of polybenzimidazole indicated that the membrane crosslinked with dibromoxylene (DBX) had enough mechanical strength and solvent resistance to be applied as a OSN membranes. The crosslinked PBI membrane prepared by more than 20wt% dope concentration coagulated in water showed a rejection of > 90% to Congo Red (MW of 696.66 g/mol) while pure ethanol permeances was more than 22.5 LMH/bar at 5 bar. Investigation on coagulant composition indicated that ethanol permeance through crosslinked PBI OSN membrane increased with increasing of ethanol concentration in water/ethanol mixture coagulants.

• Animal Bioscience
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• v.34 no.4
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• pp.603-612
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• 2021

Objective: We have tested our hypothesis that inclusion of purified glycerol as a replacer of portions of dried distillers grain with solubles (DDGS) would affect growth performance, rumen fermentation and blood parameters, carcass and sensory traits, reducing sugar and glycogen contents, and volatile compound profiles in longissimus thoracis (LT) in Korean cattle steers. Methods: A total of 20 Korean cattle steers (27.0±0.2 months old; 647±10.5 kg body weight [BW]) were assigned to a conventional control group or a glycerol group (3.17% purified glycerol addition as a replacement for DDGS and molasses). The steers were individually allowed to receive the experimental concentrate at the daily amount of 1.5% of their individual BW and a total 1.0 of kg/d of rice straw twice daily. The feeding trial was conducted for a period of 20 weeks. Results: Glycerol supplementation (GS) increased (p = 0.001) concentrate intake. However, GS did not affect (p>0.05) average daily gain, feed efficiency, and ruminal volatile fatty acid concentrations. GS tended to increase (p≤0.10) serum glucose concentrations at the 16th and 20th weeks. GS decreased (p = 0.001) LT pH. GS did not affect (p>0.05) carcass traits and the chemical or physicochemical compositions, reducing sugar or glycogen contents, sensory traits, and most of volatile compounds in the LT. Conclusion: The inclusion of purified glycerol as a replacement for DDGS in the finishing diet did not affect growth performance, rumen fermentation parameters, and carcass quality in Korean cattle. The purified glycerol could be used as a substitute for other energy sources such as DDGS in beef cattle, depending on the price.

• Journal of Radiation Protection and Research
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• v.46 no.1
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• pp.14-23
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• 2021

Background: For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides the nominal risk coefficients related to radiation exposure, which can be extrapolated using the excess relative risk and excess absolute risk obtained from the Life Span Study of atomic bomb survivors in Hiroshima and Nagasaki with the dose and dose-rate effectiveness factor (DDREF). Materials and Methods: Since it is impossible to directly estimate the radiation risk at doses less than approximately 100 mSv only from epidemiological knowledge and data, support from radiation biology is absolutely imperative, and thus, several national and international bodies have advocated the importance of bridging knowledge between biology and epidemiology. Because of the accident at the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station in 2011, the exposure of the public to radiation has become a major concern and it was considered that the estimation of radiation risk should be more realistic to cope with the prevailing radiation exposure situation. Results and Discussion: To discuss the issues from wide aspects related to radiological protection, and to realize bridging knowledge between biology and epidemiology, we have established a research group to develop low-dose and low-dose-rate radiation risk estimation methodology, with the permission of the Japan Health Physics Society. Conclusion: The aim of the research group was to clarify the current situation and issues related to the risk estimation of low-dose and low-dose-rate radiation exposure from the viewpoints of different research fields, such as epidemiology, biology, modeling, and dosimetry, to identify a future strategy and roadmap to elucidate a more realistic estimation of risk against low-dose and low-dose-rate radiation exposure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.59-69
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• 2021

Recently, large-scale offshore and coastal structures have been constructed owing to the increasing interest in eco-friendly energy development. To achieve this, precise simulations of waves are necessary to ensure the safe operations of marine structures. Several experiments are required in the field to understand the offshore wave; however, in terms of scale, it is difficult to control variables, and the cost is significant. In this study, numerical waves under various wave conditions are produced using a piston-type wavemaker, and the produced wave profiles are verified by comparing with the results from a numerical wave tank (NWT) modeled using the smoothed particle hydrodynamics (SPH) method and theoretical equations. To minimize the effect by the reflected wave, a mass-weighted damping zone is set at the right end of the NWT, and therefore, stable and uniform waves are simulated. The waves are generated using the linear and Stokes wave theories, and it is observed that the numerical wave profiles calculated by the Stokes wave theory yield high accuracy. When the relative depth is smaller than two, the results show good agreement irrespective of the wave steepness. However, when the relative depth and wave steepness are larger than 2 and 0.04, respectively, the errors are negligible if the measurement position is close to the excitation plate. However, the error is 10% or larger if the measurement position is away from the excitation location. Applicable target wave ranges are confirmed through various case studies.