• Journal of Korean Society of Steel Construction
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• v.22 no.3
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• pp.271-280
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• 2010

This study was programmed to fabricate a beam-to-column connection that is limited to a steel-welded moment connection with full-scale members, using SN steel. A cyclic seismic test was conducted of the nine specimens that were fabricated by choosing the test variable for the weld access hole geometry, connection design method, and RBS. From the test results, failure modes, the moment-drift behavior, and the strain distribution were provided. From the specimen material properties, the beam's nominal plastic flexural capacity and classified qualified connection as a special moment flame were calculated. By analyzing the skeleton part and the baushinger part, a range of strength-raising effects, and deformation ratios were provided, with which the seismic performance of the specimens were evaluated. The test results showed that the specimens eliminated their weld access holes that demonstrated higher seismic performance than the specimens' existing weld access holes, and that the WUF-W connection that was reinforced by the supplemental fillet weld around the shear tap that was fastened by five bolts demonstrated superior seismic performance.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.21-22
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• 2009

최근, 헵타메틴 시아닌색소(heptamethinecyanine)는 그 적용 범위가 넓기 때문에 많은 연구자들의 관심을 받고 있다. 특히, photo-sensitizers, dye lasers, optical recordings와 storage media 등 다양한 분야에 적용이 가능하다. 헵타메틴 시아닌색소의 주된 특징은 polymethine 사슬에 연결된 cyclohexene 고리에 의하여 근적외선 부근에서 흡수가 이뤄진다는 것이다. 근적외선 색소의 흡수 특성을 HOMO와 LUMO 에너지 전위를 사용하여, 수치화 함으로써 분자간, 분자내 상호작용을 분석 할 수 있다. 따라서, 본 실험은 헵타메틴 시아닌 색소의 치환체에 따른 전기화학적 특성을 순환 전압-전류법(Cyclic voltammetry)과 분자 모델링을 통하여 HOMO와 LUMO의 에너지 준위를 구하고, 치환체 효과가 헵타메틴 시아닌색소에 미치는 전기화학적 특성을 UV-Vis와 계산으로부터 얻어진 에너지준위를 분석하고자 한다. 본 실험에 사용된 Uv-Vis 스펙트럼 측정은 Agilent 8453 UV-Vis spectrophotometer를 사용하였고, 전기화학적 분석 방법인 순환 전압-전류법은 Versa STAT 3 (Princeton allied research in USA)를 사용하였다. 순환전압-전류법의 측정은 Acetonitrile 용액에 $TBAPF_6$ (Tetrabutylammonium hexafluorophosphate)를 전해질로 하고, Ag/$Ag^+$을 기준전극으로 사용하여 주사 속도를 50mV/s로 하여 측정 하였다. 치환체에 의한 영향을 알아보기 위하여 분자구조 최적화 모델링을 사용하였다. 3차원 분자입체 특성 및 에너지 준위 상태는 Materials studio 4.2를 사용하여 특성을 예측 하였다. 본 연구에서는, 헵타메틴 시아닌 색소의 기본 골격에 각기 다른 치환체를 치환 시켜 치환체에 의한 영향을 전기화학적인 방법인 순환 전압-전류법(Cyclic voltammetry)와 분자 모델링 방법을 사용하여, HOMO와 LUMO에너지 준위 값을 구함으로써 치환체에 의한 영향을 알아보았다. 치환체로는 Dye 1과 Dye 2로 치환된 헵타메틴 시아닌 색소를 사용하였다. 이렇게 얻어진 HOMO/LUMO 에너지 준위 값으로부터 이온화 에너지($I_p$)와 전자 친화도($E_a$) 또한 구할 수 있는데, $I_p$와 $E_a$는 분자 오비탈과 전자전이에 관련된 값들이고, 이는 계산을 통하여 얻을 수 있다. 순환 전압-전류법의 계산 방법은 봉우리 전위(peak postential)와 (onset potential)방법이 있는데, 이 계산을 통한 전위 값들이 봉우리 전위 계산 방법이 onset potential 방법에 비하여 작은 전위 값으로 나타난다. 하지만 이 두 가지 방법 모두 현재 순환 전압-전류법을 사용하여 HOMO/LUMO 에너지 준위를 측정하는 방법에 쓰이고 있으며, 어떠한 계산 방법이 더 정확하다고는 말 할 수 없지만, 본 실험 결과를 통하여 비교 분석한 결과 onset potential 계산 방법이 봉우리 전위 계산 방법에 비하여 정확하다고 판단된다. Dye 1과 Dye 2를 순환 전압-전류법으로 측정한 결과 각기 다른 전위를 나타내고 이것을 계산을 통하여 정량화하면 Dye 2가 Dye 1에 비하여 높은 전위 값을 갖음을 알 수 있는데, 이것은 ethyl 에 비하여 surful 원자의 전자공여성이 더 크다고 할 수 있다.

• Clean Technology
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• v.23 no.2
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• pp.196-204
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• 2017

CdZnS/ZnO composite was prepared through low-temperature precipitation and drying method. The property of CdZnS/ZnO as a recyclable photocatalyst for the degradation of rhodamine B (RhB) under visible light irradiation was examined. The sample was characterized by XRD, FE-SEM, XPS, UV-vis DRS and photoluminescence techniques before and after repeated reaction to investigate the change of properties during the photocatalytic reaction. During repeated reaction, the CdZnS/ZnO showed an improved photocatalytic activity and recycle stability. Among two feasible reaction pathways for photocatalytic degradation of RhB, the cleavage of conjugated chromophore was found to predominate over N-dealkylation of chromophore skeleton in the present work. The results indicate that the CdZnS/ZnO, prepared by a simple precipitation method, can be used as a visible-light driven photocatalyst with enhanced cycle stability and activity.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.237-244
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• 2009

The purpose of this study was to investigate the changing plantar foot pressure and muscle activation of neck, lumbar and low limb by different way of the using carrier during walking. Twenty healthy and young females who brought up infants and had no musculoskeletal disorders of neck, lumbar and low limb were instructed to perform plantar foot pressure and muscle activation of neck, lumbar and low limb during different ways of the using the carrier and walking. Plantar foot pressures were recorded by RS-scan system(RS scan Ltd, German), muscle activation were recorded by ProComp infinitiTM(Thought Technology Ltd, Canada). The data collected by each way of the using carrier and One-way ANOVA was used to analyze. The results indicated that there was a significant increase on erector spinae muscle activation and pressure of great toe zone by using anterior carrier and there was a increase on activation of paraspinal muscle and metatarsal zone by using posterior carrier. Therefore, the way of using carrier could be influenced upon structure and function of the foot and muscle activation.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.893-897
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• 2002

The chloroform layer from 75% ethanol extract of Dalbergia odorifera T.CHEN showed strong antioxidative activity on lard and palm oil as tested by Rancimat method. Antioxidative active compound isolated and identified by silica gel column chromatography, thin layer chromatography, mass spectrophotometer, $^1H-NMR$ and $^{13}C-NMR$ was identified as mucronulatol (3(R&S)-3,7-Dihydroxy-2',4-dimethoxyisoflavan). Results of Rancimat method revealed the induction period of Mucronulatol increased longer than those of synthetic antioxidant, BHA and BHT, at the same concentration. Mucronulatol combined with ${\delta}-tocopherol(200ppm)$, and with ascorbic acid (200 ppm) and citric acid (200 ppm) on lard and palm oil, respectively, showed strong synergistic effects.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.27-51
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• 2009

This study looked for ways to carry out development projects in a sustainable manner by generating improvement plans, and focused on reviewing the status and problems associated with the environmental and ecological planning that is currently applied to new town and large-scale development projects. Improved methods were suggested based on differences between urban development and housing development projects. Based on principles set for the introduction of environmental and ecological planning, the size of the projects subject to environmental and ecological planning was set. With regard to the procedural improvements for environmental and ecological planning, nine problems were singled out from the development planning phases. Solutions were suggested by separating the problems into the site and district designation phase, development planning phase, implementation planning phase, and post-management phase based on a literature review and the opinion of experts. In consideration of improvements to the planning system, the scope of environmental and ecological planning was set after looking at information related to environmental and ecological planning, literature review, expert interviews, and the relevance of related plans. The scope of the environmental and ecological planning was divided into the overview of planning, environmental and ecological conception, conception of spatial structure and framework, and urban environment regeneration and impact reduction plans. By synthesizing the above-described results, the functions of environmental and ecological planning, development planning, and environmental assessment and their inter-relations were defined. The defined inter-relations seem likely to be developed into a form that would enable sustainable land development.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.553-559
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• 2009

One of zeolitic imidazolate framework materials (ZIF), ZIF-8, has been synthesized with microwave irradiation and conventional electric heating at $140{\sim}180^{\circ}C}$. ZIFs are porous crystalline materials and are similar to metal organic framework (MOF) materials because both ZIFs and MOFs are composed of both organic and metallic components. ZIFs are very stable and similar to zeolites because ZIFs have tetrahedral networks. ZIF-8, with a decreased crystal size, can be synthesized rapidly with microwave irradiation. The microwave synthesis of ZIF-8 is completed in 4 h at $140{^{\circ}C}$ and the reaction time is decreased by about 5 times compared with the conventional electric heating. The ZIF-8 obtained by microwave heating has larger surface area and micropore volume compared with the ZIF-8 synthesized with conventional electric heating. It can be confirmed that ZIF-8s show type-I adsorption isotherms, explaining the microporosity of the ZIF-8s. Based on FTIR and TGA results, it can be understood that the ZIF-8s have similar bonding and thermal characteristics irrespective of heating methods such as microwave and conventional heating.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.377-382
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• 2021

Oriental melon (Cucumis melo L.) is generally cultivated on the ground by creeping culture. A farmer has a higher workload for training stems. This study was conducted to find out a new cultivation of oriental melon to reduce a workload and improve the quality of fruit. There were three treatments for training stem of oriental melon; upward stem growing, downward stem growing, control (creeping stem growing). The results of the plant growth and the net photosynthesis showed higher in upward stem growing. The root activity was higher in downward stem attract. The yield was not significant as 4,055kg/10a in upward stem attract and 3,983kg/10a in downward stem attract. According to the results of the ergonomic agricultural workload evaluation, in the case of the working posture, the working posture of creeping cultivation methods (squatting, bending) showed a higher risk level than the upward and downward cultivation methods. Therefore, it is recommended the upward stem attract of oriental melon is a new cultivation as well as an alternative method for creeping stem attract in terms of improving the plant growth and yield, and reducing the workload.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.395-403
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• 2022

In the fracture operation of pan facial fracture, there are many cases where the shape and position of the occlusal and oral structures are abnormally changed because the index for repositioning to the original position is insufficient. And trismus and gag reflex in patients with pan facial fractures increase the difficulty of dental treatment, and the difference in the position of the jaw bone makes it difficult to restore aesthetically and functionally. In this case, digital workflows for minimal intraoral work could be selected to reduce patient discomfort and the difficulty of dental treatment. This case is using a digital workflow from implant planning to final prosthesis production in a patient with acquired skeletal grade III, trismus, and gag reflex due to pan facial fracture 15 years ago. In this case report, the use of digital workflow in a patient who has difficulty in dental treatment was able to minimize patient discomfort and obtain esthetic and functionally appropriate results.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.213-220
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• 2023

Mixed-matrix membranes (MMMs), which are composed of a polymer matrix filled with high-performance fillers as a dispersed phase, have been intensively studied for gas separations for the past 30 years. It has been demonstrated that MMMs exhibit superior gas separation performance compared to polymer membranes and are more scalable than polycrystalline membranes. Despite their potential, the commercialization of MMMs has yet to be reported due to several challenging issues. One of the major challenges of MMMs is the non-ideal interface between the continuous polymer phase and dispersed phase, which can result in defect formation (i.e., interfacial voids, etc.). With respect, many MMM studies have focused on addressing the issues through scientific approaches. The engineering approaches for facile and effective large-scale fabrication of MMMs, however, have been relatively underestimated. In this review paper, a novel strategy for fabricating MMMs in a facile and scalable manner using in situ metal-organic framework (MOF) formation is introduced. This new MMM fabrication methodology can effectively address the issues facing current MMMs, likely facilitating the commercialization of MMMs.