• Journal of Electrochemical Science and Technology
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• 제5권2호
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• pp.58-64
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• 2014

The surface of an ordered mesoporous silica (OMS) was functionalized using 1H,1H,2H,2H-perfluorooctyltrimethoxysilane at $20^{\circ}C$ and $60^{\circ}C$. It was shown that only elevated temperature allows lyophobic properties on the walls of OMS, eventually preventing pore flooding with nonaqueous electrolytes. The functionalized OMSs (OMS-F) were characterized with various techniques: wettability test, $N_2$ sorption measurement, high-resolution transmission electron microscopy (HR-TEM). Cathodes of $10mg/cm^2$ loading were prepared with a commercial Pt/C catalyst and polyvinylidene fluoride (PVDF, 2.5 wt.%) binder using a typical doctor blade method on a commercial gas diffusion layer (GDL) in the presence or in the absence of OMS-F additives. Subsequent discharge-charge curves were taken in a 1M LiTFSI-TEGDME electrolyte at 60oC in pure oxygen atmosphere. It was found that the discharge capacity was significantly affected by OMS-F: 5 wt.% of additive extended discharge capacity by a factor 1.5. On the other hand, a similar OMS material but synthesized at $20^{\circ}C$ did not show lyophobic properties and deteriorated cathode capacity.

• 한국지반신소재학회논문집
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• 제9권3호
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• pp.67-75
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• 2010

본 연구에서는 생분해성 수지를 이용한 연직배수재에 대해 다양한 성능 평가방법을 적용하여 생분해성 플라스틱배수재의 공학적 특성을 분석하였다. 생분해성 플라스틱으로 제작한 연직배수재는 기존 합성수지 연직배수재에 비해 낮은 인장변형률을 가지며 상대적으로 낮은 인장강도를 갖지만, 연직배수재로서 가져야 할 최소한의 인장강도는 발휘하는 것으로 나타났다. 생분해성 플라스틱으로 제작한 필터는 투수성이 좋고 유효구멍크기가 작아 필터의 성능으로 매우 적합한 것으로 나타났다. 또한 생분해성플라스틱 배수재의 통수능은 필터의 강성을 개선하는 경우 국내 시방기준에도 만족할 수 있는 성능을 갖는 것으로 나타났다.

• 전기화학회지
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• 제13권2호
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• pp.145-152
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• 2010

본 연구에서는 organophosphate를 기반으로 한 과불소화된 아크릴레이트 가교제를 사용하여 제조한겔 고분자 전해질의 이온 전도도 및 전기화학적 특성을 평가하였다. 과불소화된 아크릴레이트 가교제를 사용하여 만든 겔 고분자 전해질은 액체전해질의 함량이 최대 97 wt%까지 안정한 겔 상태를 유지하였다. 본 연구에서 제조한 겔 고분자 전해질의 이온전도도는 $30^{\circ}C$에서 $1.0\;{\times}\;10^{-2}\;S/cm$의 값을 가졌다. 또한 전기화학적 안정성 테스트에서도 약 4.5V로 이상까지 산화에 의한 열화가 없이 안정하였다. 합성된 겔고분자 전해질을 리튬이온 고분자 전지에 적용하여 그 활용성을 평가하였다. 양극으로는 $LiCoO_2$를 사용하였으며 음극으로는 카본을 사용하였다. 이렇게 만든 리튬이온 고분자 전지는 0.1C에서 136.11 mAh/g의 용량으로 이론용량과 거의 비슷한 값을 나타내었으며, 2C 방전에서도 초기 용량의 91%를 유지하였다. 또한 500번의 충방전 후에도 초기 용량의 70%정도의 용량을 유지하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.119-122
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• 2009

The gravel compaction pile method has been used as a soft foundation improvement method because bearing capacity and discharge capacity is excellent. But the discharge capacity decreased when the clogging was generated because the clay penetrate into a void of gravel compaction pile. Accordingly, the purpose of this study is to reduce the clogging generation in gravel compaction pile constructing in the soft ground and take a step to minimize a void of gravel compaction pile. And the proper mixing ratio was determined with the large scale direct shear test performed to get strength and permeability with mixing ratio of crushed stone and sand(100:0, 90:10, 85:15, 80:20, 75:25). As a result of the test, it was showed that internal friction angle was the highest at 85:15 mixing ratio of crushed stone and sand and we can make sure a tendency of internal friction angle's decrease when the mixing ratio of crushed stone and sand passed 15%.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.449-456
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• 2009

As soft grounds have complex engineering properties that the load bearing capacity is low and high compressibility, it needs to solve this problems prior to structures are constructed by the method of improvement of soft ground. Generally, the sand mat is used to as a horizontal drain material and loading base for soft ground improvement work. However, as the natural environment can be damaged by sand pickings of large quantity and the volume which is enormous and an amount of demanded sand is increased, it is state of short in supply. This paper presents the result of field experimental test to use Precious Slag Ball to solve these issues instead of sand mat as the replacing material. This study evaluated the performance of Precious Slag Ball as a sand mat in terms of discharge capacity, settlement, and settlement through the K-Embank program.

• 대한간호학회지
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• 제37권3호
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• pp.343-352
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• 2007

Purpose: The purpose of this study was to examine the effects of an inpatient pulmonary rehabilitation program on dyspnea, exercise capacity, and health related quality of life in inpatients with chronic lung disease. Method: This quasi experimental study was designed with a nonequivalent control group pre-post test time series. Twenty three patients were assigned to the experimental group and nineteen to the control group. The inpatient pulmonary rehabilitation program was composed of upper and lower extremity exercise, breathing retraining, inspiratory muscle training, education, relaxation and telephone contacts. This program consisted of 4 sessions with inpatients and 4 weeks at home after discharge. The control group was given a home based pulmonary rehabilitation program at the time of discharge. The outcomes were measured by the Borg score, 6MWD and the Chronic Respiratory Disease Questionnaire(CRQ). Results: There was a statistically significant difference in dyspnea between the experimental group and control group, but not among time sequence, or interaction between groups and time sequence. Also significant improvements in exercise capacity and health related quality of life were found only in the experimental group. Conclusions: An Inpatient pulmonary rehabilitation program may be a useful intervention to reduce dyspnea, and increase exercise capacity and health related quality of life for chronic lung disease patients.

• 한국전문물리치료학회지
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• 제9권2호
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• pp.145-156
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• 2002

The objectives of this study were to investigate the effects of thoracic flexibility exercise on chest function and mobility and to provide the information of physical therapy for patients with idiopathic scoliosis. Forty female subjects who were diagnosed with scoliosis participated in this study and were divided into the experimental and control groups. The experimental group consisted of 20 patients who were treated with thoracic flexibility exercise program during the admission (10 days) ad one month after discharge. The control group consisted of 20 patients who were not treated with thoracic flexibility exercise program. Vital capacity was measured using a respirometer. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration measured under armpits, at the junction between the sternum and xyphoid process, and at the waist. All subjects were measured two times: before the admission and at one month after discharge. Data were compared by groups using independent t-test, Vital capacity and chest expansion values (the armpit, chest and waist values) were significantly higher for the experimental group compared to those of the control group (p<.05). The findings of this study show that thoracic flexibility exercise program can lead to an increase in vital capacity and chest expansion and has a positive effects in relieving symptoms and restoring thoracic mobility.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.350-351
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• 2005

The electrochemical behavior of Si-C material synthesized by heating the mixture of silicon and polyvinylidene fluoride (PVDF). Coin cells of the type 2025 were made using the synthesized material and the electrochemical studies were performed. Si-C/Li cells were made by using the developed Si-C material. Charge/discharge test was performed at 0.1C hour rate. Initial charge and discharge capacities at Si-C material derived from 20 wt.% of PVDF was found to be 1,830 and 526 mAh/g respectively. Initial charge/discharge characteristics of the electrode were analyzed. The level of reversible specific capacity was about 216 mAh/g at Si-C material derived from 20 wt.% of PVDF, IIE, intercalation efficiency at initial charge/discharge, was 68 %. Surface irreversible specific capacity was 31 mAh/g, and average specific resistance was 2.6 ohm*g.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.95-98
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• 2006

Many LNG ships will be constructed in Korea and the demand of safety valves is increasing. The most important performance of the developed safety relief valves for LNG ship is flow capacity. Flow capacity tests for 8 sizes of developed safety valves were conducted in the high pressure gas flow standard system in KRISS. The initial spring force adjustment was important for setting pressure of the safety valve. The procedure of data reduction and evaluation of the safety valve performance are suggested. This procedure was approved by French Bureau Veritas and Lloyd's Register.

• 한국지반공학회논문집
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• 제25권8호
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• pp.33-45
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• 2009

단일코어 연직 배수재 공법은 현재까지 폭넓게 사용되는 연약지반 개량공법이다. 그러나 얇은 플라스틱 보드 형태의 PBD 구조로 인해 압밀 도중 큰 횡 방향 토압과 이에 따른 necking 현상이 발생하고 이는 PBD의 통수능을 감소시킨다. 본 연구 대상인 부산신항만 조성 공사현장은 대심도의 연약지반으로서 PBD 설치 시, 큰 횡 방향 토압에 의한 통수능 감소를 예상되어 통수능 감소현상을 극복하기 위하여 이중코어 PBD를 도입, 시공하고, 기존 형태의 단일코어 PBD를 동시에 설치한 후, 현장에서의 배수재 성능을 비교분석하였다. 실내실험으로는 개량 델프트 실험을 수행하여 연직배수재의 통수능을 측정하고, 현장에서 채취한 시료를 이용해 기본 물성실험 및 CRS 압밀시험을 수행하여 수치 해석 프로그램인 ILLICON에 적용하여 침하거동 양상을 파악하였다. 개량 델프트 실험에서는 이중코어 PBD의 통수능이 단일코어 PBD보다 높게 측정되었으나, 현장 계측 및 수치해석에서는 차이가 나타나지 않았다. 이는 일발전인 대심도 지반에서 압밀시 발생되는 물의 배수량은 상대적으로 작은 단일코어 PBD의 통수능 범위 보다도 작기 때문에 실제 현장에서는 단일코어 PBD와 이중코어 PBD의 성능차이가 없음을 확인하였다.