• Natural Product Sciences
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• 제25권3호
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• pp.222-227
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• 2019

Quantitative nuclear magnetic resonance (qNMR) is a well-established method adopted by international pharmacopoeia for quantitative and purity analyses. Emodin is a type of anthraquinone, well known as the main active component of Fabaceae, Polygonaceae and Rhamnaceae. Purity analysis of emodin is usually performed by using the high-performance liquid chromatography (HPLC)-UV method. However, it cannot detect impurities such as salts, volatile matter, and trace elements. Using the qNMR method, it is possible to determine the compound content as well as the nature of the impurities. Several experimental parameters were optimized for the quantification, such as relaxation delay, spectral width, number of scans, temperature, pulse width, and acquisition time. The method was validated, and the results of the qNMR method were compared with those obtained by the HPLC and mass balance analysis methods. The qNMR method is specific, rapid, simple, and therefore, a valuable and reliable method for the purity analysis of emodin.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.880-894
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• 2010

고속철도교의 기초로 많이 사용되고 있는 매입말뚝에서 천공으로 이완된 지반과 말뚝 사이의 충전재로서 기존 포틀랜드 시멘트계는 쏘일시멘트 강도가 낮고 시멘트 용출로 인한 지하수 오염, 희석 및 일수현상으로 인한 지표부 지반의 이완, 수평 저항성의 감소 및 내구성의 저하, 하중분담효과의 저하 등 안정성 확보 문제와 환경오염 문제를 내포하고 있었다. 특히, 고속철도교의 경우 열차진동, 급정거시 충격수평력 작용, 지진 등 일반 구조물 기초와는 달리 다양한 측면에서 안정성 확보가 필요하며, 기초 시공 분야도 저탄소 녹색성장이라는 친환경 기조의 시대적 요구사항을 고려해야 하는 실정이다. 더불어 경제성 및 공기 단축 등 시공성 확보까지 가능한 새로운 미래형 친환경 기초공법의 개발이 필수적이다. 따라서 기존 공법의 내구성 및 내진성, 내수평성을 개선하고, 환경오염을 최소화 할 수 있도록 새로운 충전재료의 개발과, 시공방법의 개선을 통해 구조적 안전성과 환경적 저해요소를 최소화하기 위한 다양한 시험 및 기초연구를 실시하였다, 이를 위해 수중불분리성과 고유동성, 고점성, 고침투성, 조강성 등을 동시에 가지는 신개념의 고성능 다기능의 충전재를 활용하여 기존의 시멘트계 충전재와의 적용성 비교시험을 실시하였다. 그 결과 기존 매입말뚝 공법 및 마이크로 파일 기초에 적용하였을 경우 연직지지력, 수평저항력 등 많은 측면에서 뛰어난 적용성을 보이고 있어 향후 다양한 추가 연구를 통해 새로운 친환경 기초로의 개발도 기대할 수 있을 것으로 판단된다.

• 치위생과학회지
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• 제17권1호
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• pp.46-55
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• 2017

본 연구는 치과 의료진에 의해 실시된 치과불안 감소에 대한 인지행동치료의 효과를 검증하고 이를 통해 치과 진료 과정에서 적용 가능한 효과적인 개입방법 제안을 연구의 목적으로 하였다. 연구대상과 방법은 임상치과의원에 내원한 치과불안 증세를 보이는 환자중, 연구에 동의한 1인을 대상으로 DFS, 심층인터뷰, 그리고 SUD를 이용하여 환자의 치과불안 정도를 측정하고 불안의 종류와 수준에 따라 인지행동치료를 3월 2일부터 5월 20일까지 2주 간격으로 5회기 실시하였으며 연구의 결과는 다음과 같다. 첫째, 치과에 관련하여 왜곡된 인지의 변화는 이와 연결된 불안들과 함께 짧은 기간 동안 급성호전 현상을 나타내며 감소하였다. 둘째, 환자 개개인의 특성과 심리적 상태에 따라 주요 개입법과 보조적인 개입법을 함께 사용하는 것이 효과적이며, 호흡이완법은 신체적 긴장감과 심리적 안정화를, 수신호 사용은 진료과정 중의 소통에 효과적으로 나타났다. 공감적 관계맺기는 의료진과의 신뢰성 형성을 통한 원활한 소통과 지속적인 치료에 대한 동기부여 및 치료적 퇴보를 완화시켰다. 불안목록 작성, 점진적인 둔감법, 직접적인 노출법, 진료과정 리허설은 문제에 대한 직접적이고 점진적인 도전을 경험함으로써 적응력강화 및 자기 조절 능력을 향상시키고 왜곡된 인지 변화를 유도하였다. 셋째, 인지행동치료를 훈련한 치과 의료진이 치료과정 중에 실시한 단시간 심리적 개입이 환자의 치과불안 감소에 유의미한 효과가 있음을 도출하였다. 본 연구는 단일사례연구라는 제한점에도 불구하고 단기간의 인지행동치료 개입법이 치과와 연계된 왜곡된 인지를 재구조화함으로써 환자의 치과진료 회피행동과 치과불안을 감소시키는 것에 효과적인 접근법이며 지속적인 연구가 필요함을 확인하였다.

• 한국환경복원기술학회지
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• 제3권2호
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• pp.10-23
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• 2000

The purpose of this research was to investigate water spaces such as marshes and watercourses, especially focusing on methods to establish eco-ponds. Many aqua-ecosystems have been filled up or destroyed in the process of rapid industrialization and urbanization in the cities. This inquiry was done by comparing, studying and analyzing existing ponds and studying documents on the introduction and methods of making eco-ponds. Existing ponds were put into three categories as the either eco-pond, man-made/natural ponds, or man-made ponds. Three instances were selected for each category, totaling nine. Data on the size and shape, depth, waterproofing techniques, water supply, plants and planting plan, and the maintenance of the ponds was collected and compared. The following are conclusions based on comparing, studying and analyzing these existing ponds, and studying documents on the introduction and methods of making eco-ponds. ${\cdot}$ It is noteworthy that different environments and depths must be provided because these are main variants contributing to attracting plants in the ponds. ${\cdot}$ In these places plants emerged, such as, floating-leaved plants, free-floating planktonic plants, submerged plant etc, in the different water level zones, once these various conditions were provided. ${\cdot}$ Various spaces can be used for shelter, places for relaxation and habitation. ${\cdot}$ After establishing a pond, routine maintenance is necessary for preventing eutrophication. However the minimal possible management should be done to maintain a natural status.

• 대한치과교정학회지
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• 제46권2호
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• pp.65-72
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• 2016

Objective: The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation. Methods: Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks. Results: Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5. Conclusions: The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner.

• Korea-Australia Rheology Journal
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• 제19권4호
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• pp.191-199
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• 2007

Precision injection molding process is of great importance since precision optical products such as CD, DVD and various lens are manufactured by those process. In such products, birefringence affects the optical performance while residual stress that determines the geometric precision level. Therefore, it is needed to study residual stress and birefringence that affect deformation and optical quality, respectively in precision optical product. In the present study, we tried to predict residual stress, final shrinkage and birefringence in injection molded parts in a systematic way, and compared numerical results with the corresponding experimental data. Residual stress and birefringence can be divided into two parts, namely flow induced and thermally induced portions. Flow induced birefringence is dominant during the flow, whereas thermally induced stress is much higher than flow induced one when amorphous polymer undergoes rapid cooling across the glass transition region. A numerical system that is able to predict birefringence, residual stress and final shrinkage in injection molding process has been developed using hybrid finite element-difference method for a general three dimensional thin part geometry. The present modeling attempts to integrate the analysis of the entire process consistently by assuming polymeric materials as nonlinear viscoelastic fluids above a no-flow temperature and as linear viscoelastic solids below the no-flow temperature, while calculating residual stress, shrinkage and birefringence accordingly. Thus, for flow induced ones, the Leonov model and stress-optical law are adopted, while the linear viscoelastic model, photoviscoelastic model and free volume theory taking into account the density relaxation phenomena are employed to predict thermally induced ones. Special cares are taken of the modeling of the lateral boundary condition which can consider product geometry, histories of pressure and residual stress. Deformations at and after ejection have been considered using thin shell viscoelastic finite element method. There were good correspondences between numerical results and experimental data if final shrinkage, residual stress and birefringence were compared.

• Rapid Communication in Photoscience
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• 제3권4호
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• pp.81-84
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• 2014

To examine the microenvironmental effect of DNA on the photosensitized reaction, the electron-donor-connecting porphyrin, meso-(9-phenanthryl)-tris(N-methyl-p-pyridinio) porphyrin (Phen-TMPyP), was synthesized. Phen-TMPyP can bind to oligonucleotides with two binding modes, depending on the DNA concentration. The fluorescence lifetime measurement of Phen-TMPyP shows a shorter component than that of the reference porphyrin without the phenanthryl moiety. However, the observed value is much longer than those of previously reported similar types of electron-donor-connecting porphyrins, suggesting that electron-transfer quenching by the phenanthryl moiety is not sufficient. The fluorescence quantum yield of Phen-TMPyP ($5{\mu}M$) decreased with an increase in DNA concentration of up to $5{\mu}M$ base pair (bp), possibly due to self-quenching through an aggregation along the DNA strand, increased with an increase in DNA concentration of more than $5{\mu}M$ bp and reached a plateau. The fluorescence quantum yield of Phen-TMPyP with a sufficient concentration of DNA was larger than that of the reference porphyrin. The singlet oxygen ($^1O_2$) generating activity of Phen-TMPyP was confirmed by the near-infrared emission spectrum measurement. The quantum yield of $^1O_2$ generation was decreased by a relatively small concentration of DNA, possibly due to the aggregation of Phen-TMPyP, and recovered with a sufficient concentration of DNA. The recovered quantum yield was rather smaller than that without DNA, indicating the quenching of $^1O_2$ by DNA. These results show that a DNA strand can stabilize the photoexcited state of a photosensitizer and, in a certain case, suppresses the $^1O_2$ generation.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2005년도 공동학술대회 논문집
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• pp.281-286
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• 2005

본 연구는 인공전류원 MT (CSAMT) 자료를 역산하기 위해 GRRI 알고리듬 분석을 실행하였다. 이 알고리듬은 MT 자료로부터 지반의 2차원 전도체 구조를 파악하기 위해 수정 RRI 알고리듬으로부터 독창적으로 개발된 것이나, 2.5차원 전진모델링을 결합시킬 수만 있다면, CSAMT자료까지 해석이 가능하다. 이러한 GRRI 근사감도는 정확한 1차원과 2.5차원의 감도와 비교함으로써 그 유용성을 검증할 수 있다. 그 결과, GRRI의 감도는 RRI 감도의 절반 정도이며 전반적으로 2.5차원의 감도와 매우 근사함을 보여준다. 비록 GRRI의 감도크기가 2.5차원의 감도보다 약간 크게 나타나고 있기는 하지만, 송신과 수신의 오프셋이 표피심도 1 보다 큰 경우의 감도는 유사하였다.

• 대한정형도수물리치료학회지
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• 제8권2호
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• pp.57-71
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• 2002

Cervical pain is a rapid increase that is owing to a flexion-extension whiplash injury, unappropriated posture, chronical repetition injury from abdominal position of head and neck, excessive repeating work, chronical deficiency of excercise. Because of that is bring about muscle unbalance, tightness of cervical extensor muscle, weakness of cervical deep flexor muscles, instability of cervical region and reduction of proprioceptive sensor. Recent the role of muscle is more emphasized for preservation of sine stabilization. And cognition of integrated muscular system, importance for the operation and relation is increased to maintain stability of the motor system and pertinent function. Therefore we are going to introduce the sling exercise and stabilization exercise method for advanced efficient of cervical and upper limb and for the muscle strengthening to importance cervical stabilization through neurological program as control the reaction of cervical stabilization. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensory-motor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovascular exercise, group exercise, personal exercise at home Sensory-motor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercise on an unstable surface, there by achieving optimum stimulation of the sensory-motor apparatus.

• 한국수소및신에너지학회논문집
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• 제26권2호
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• pp.120-126
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• 2015

Recently, the ever-increasing use of fossil fuels for rapid industrial development and population significantly caused an environment pollution and global warming such as climate change. So research and development of sustainable and eco-friendly energy have been performed. Especially the interest in nuclear fusion fuel was significantly increased from the developed countries. The system of fusion energy production was tritium separation, storage and delivery, and purification. Republic of Korea is in charge of Storage and Delivery System (SDS) in the International Thermonuclear Experimental Reactor (ITER). Welding part of the SDS bottles for storing the tritium is known to be susceptible to hydrogen embrittlement. In this study, conducted a study for the relaxation of the stability and hydrogen embrittlement of the weld area. The hydrogen heat treatment was processed through the Pressure-Composition-Temperature (PCT) device according to the time variation. Also mechanical properties such as impact test and hardness test according to using the alkaline cleaning liquid for hydrogen embrittlement relief and the fracture was observed by scanning electron microscopy (SEM) after the mechanical properties evaluation.