• 한국세라믹학회지
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• 제39권3호
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• pp.245-251
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• 2002

깁사이트의 급속 열분해 산물인 비정질 알루미나로부터 γ-alumina bead를 제조하고, 이를 21.87%의 질산($HNO_3$)과 28.57%의 초산($CH_3COOH$)을 혼합한 용액에 침적시킨 다음 200$^{\circ}$C 온도로 3시간 수열처리하여 결정의 변화, 기공특성, $N_2$ 흡/탈착 등온선, 기계적강도 및 내열특성 등을 조사하였다. 0.1∼0.3${\mu}$m 크기의 침상 및 판상 의사베이마이트 결정은 같은 결정구조를 갖는 1∼2${\mu}$m 길이의 침상형 베이마이트 결정으로 변했고, 이를 통해 ${\gamma}$-alumina와 베이마이트 사이에는 수열반응에 기인한 가역적 상 변화가 발생한다는 사실을 알 수 있었다. 수열처리 전 ${\gamma}$-alumina bead에 비해 $N_2$ 흡착 용량이 450㎖/g에서 670㎖/g으로 증가하였고, 100∼1000${\AA}$ 범위의 기공부피는 0.15㎖/g에서 0.77㎖/g으로 증가하였으며, 기계적 강도가 1.4MPa에서 2.2MPa로 증가하였다. 또한 40vol%의 수증기를 포함한 1000$^{\circ}$C의 고온에서도 100∼1000${\AA}$ 범위의 기공을 유지하며 ${\theta}$-alumina 결정구조를 유지하는 높은 내열저항을 나타내었다.

• Journal of Ginseng Research
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• 제27권4호
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• pp.195-201
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• 2003

인삼 뿌리썩음병균 Cylindrocarpon destructans의 후막포자형태에 대해서 광학현미경 및 전자현미경을 사용하여 조사하였다. 전형적인 C. destructans의 후막포자는 균사로부터 형성되었으나 분생포자에서는 생성되지 않았다. 그러나 pH 4로 조절된 Czapek Dox broth에서 2$0^{\circ}C$, 12일간 배양하였을 때는 소형분생포자가 미성숙한 후막포자 유사세포로 변형되었다. 후막포자는 potato dextrose agar 및 V-8 Juice agar 그리고 질소원이 결제된 Czapek Dox broth배지에서 2$0^{\circ}C$, 16∼20일 배양으로 생성되었고, 생성된 후막포자는 황갈색 혹은 적갈색을 띄었으며 균사의 중간이나 말단 부위에서 한 개 혹은 사슬형태로 존재하였다. 후막포자는 직경이 11.3∼11.9 $\mu\textrm{m}$이었으며 외부에 1.5∼1.8 $\mu\textrm{m}$ 길이의 혹 같은 돌기가 여러 개 형성되어 표면이 울퉁불퉁 하였다.

• Advances in Traditional Medicine
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• 제5권4호
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• pp.294-300
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• 2005

Uncaria Tomentosa and Maytenus are known to have anti-inflammatory and anti-rheumatoidal effects after either a single application or application over a short-term period. We applied these natural products to Wister rats every day for two weeks and investigated the effects of this long-term application on inflammation. This was done by measuring footpad edema, which was induced by a locally injected carrageenan. There was a dramatic reduction in edema in both U. Tomentosa- and Maytenus-treated rats; furthermore, the reduction lasted as long as three days for rats treated with U. Tomentosa. When the Balb/C mice underwent similar treatment for one month, the level of IgM in the blood of U. Tomentosa-treated mice decreased while the level of IgG in Maytenus-treated mice increased. This suggests that the long lasting effects of U. Tomentosa may be related to a low level of IgM and the subclass switch from IgM to IgG. Since the anti-inflammatory effects of U. Tomentosa lasts for three days, it may prove useful in treating rheumatoid arthritis when applied for an extended period of time, especially since this product is known to have minimal side effects.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권6호
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• pp.518-526
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• 2019

Purpose: Limited means exist to assess gastrointestinal activity in pediatric patients postoperatively. Recently, myoelectric gastrointestinal activity recorded by cutaneous patches has been shown in adult patients to be predictive of clinical return of gastrointestinal function postoperatively. The aim of this case series is to demonstrate the feasibility of this system in pediatric patients and to correlate myoelectric signals with return of bowel function clinically. Methods: Pediatric patients undergoing abdominal surgery were recruited to have wireless patches placed on the abdomen within two hours postoperatively. Myoelectric data were transmitted wirelessly to a mobile device with a user-interface and forwarded to a cloud server where processing algorithms identified episodes of motor activity, quantified their parameters and nominally assigned them to specific gastrointestinal organs based on their frequencies. Results: Three patients (ages 5 months, 4 year, 16 year) were recruited for this study. Multiple patches were placed on the older subjects, while the youngest had a single patch due to space limitations. Rhythmic signals of the stomach, small intestine, and colon could be identified in all three subjects. Patients showed gradual increase in myoelectric intestinal and colonic activity leading up to the first recorded bowel movement. Conclusion: Measuring myoelectric intestinal activity continuously using a wireless patch system is feasible in a wide age range of pediatric patients. The increase in activity over time correlated well with the patients' return of bowel function. More studies are planned to determine if this technology can predict return of bowel function or differentiate between physiologic ileus and pathologic conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2146-2148
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• 2005

The 2.5GeV linac of the Pohang Light Source(PLS) is planed to be converted to a XFEL. The PAL XFEL requires a new 1.2-GeV linac that will be combined to the existing linac to increase a beam energy upto 3.7GeV. This stability is mainly determined by a low level RF drive system and klystron-modulators. The stability level of the modulator has to be improved 10 times better to meet the pulse stability of 0.02 %. The regulation methods such as traditional de-Qing and precision inverter charging technology are reviewed to find out suitable upgrade scheme of the modulators. In order to obtain electron beam of the consequently stability for XFEL linac, the pulse-to-pulse beam voltage regulation is less than +/-0.5%. To get the reliable stability of the modulator which is less than +/-0.2%, a charging section is improved in a modulator which has been operated with inverter power supply and de-Q'ing.

• Current Research on Agriculture and Life Sciences
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• 제10권
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• pp.11-17
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• 1992

탈지 가자박으로 부터 free, soluble 및 insoluble bound phenolic acids를 추출하여 식용대두유 기질에서 항산화효과률 0.02%(w/w)의 BHA, BHT의 항산화 효과와 비교하고자 각 기질과 대조구를 $60{\pm}1^{\circ}C$에서 35일간 저장하면서 매 7일 간격으로 과산화물가, TBA가를 측갱하였다. BHA, BHT와 free, soluble 및 insoluble hound phenolic acids를 첨가한 시험구와 대조구의 과산화물가는 21일의 경우 60, 30, 14, 11, 10, 100이었다. 같은 조건하에서 추출물의 TBA가는 0.150, 0.108, 0.105, 0.073, 0.078, 0.185이었다. 이것으로 보아 phenolic acids는 식용대두유 기질에서 우수한 항산화력을 나타내었다. 분리확인된 phenolic acids는 p-coumaric acid, ferulic acid, phloroglucinol, pyrogallol, vanillic acid, caffeic acid으로 확인되었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.269-274
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• 2003

본 논문에서는 2대의 다이오드 정류기에 부스트 컨버터를 이용하여 전류의 파형을 능동적으로 만들어 정현파의 입력전류를 얻는 새로운 방식의 고조파 저감방식을 제안한다. 제안한 당식으로 역률 1의 전원 품질을 얻을 수 있으며 입력측의 변동에 대한 출력전압의 조정도 가능하다. 또한 저감된 용량을 갖는 3상 오토 트랜스포머의 사용으로 기존의 $\Delta$-Y 변압기에 비해 KVA정격이 80$\%$ 절감되며 상간변압기도 필요 없다. 본 방식을 소형화와 고품질의 전원이 요구되는 통신용 정류기등에 적용하면 효과적이다. 제안한 방식의 동작원리, 제어 및 설계방법을 기술하고 1.5KW급 시작품으로부터의 실험결과를 제시한다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.522.3-523
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• 1986

A Screening test was carried out for chitin-decomposing bacteria. In 100 samples from soil, fesh water and sea water, 7 strains of Chitinolytic bacteria were isolated. 5-3K which exhibited the highest chitinase activity was identified as Aeromonas hydrophila and cultural conditions from maximum chitinase production were determined. Optimum Chitinase production was obtained at pH 7, 33eC and with chitin concentration greater tham 0.2% Under optimal conditions, high yields of Chitinase were obtained in 16-30 hours. Chitinase was purified by ammonium sulfate precipitation and sephadex G-100 gel-filtration from the culture filtrgte.

• 한국자기학회지
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• 제5권5호
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• pp.631-635
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• 1995

Longitudinal magnetic recording process of thin film media was simulated by the 2-D finite element method (FEM). To describe precisely the hysteresis behavior of thin film media, scalar Preisach model was used. In this paper, we discussed the formation of bit patterns and importance of modeling of minor loops in high density recording. The effects of the media coercivity and film thickness on the remanent magnetization and transition shape were investigated.

• 한국공간구조학회논문집
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• 제16권1호
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• pp.85-94
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• 2016

In this study, an acceleration sensor that has optical fibers to measure the inclination and acceleration of a structure through contradictory changes in two-component FBG sensors was examined. The proposed method was to ensure precise measurement through the unification of the deformation rate sensor and the angular displacement sensor. A high sensitivity three-axis accelerometer was designed and prepared using this method. To verify the accuracy of the accelerometer, the change in wavelength according to temperature and tension was tested. Then, the change in wavelength of the prepared accelerometer according to the sensor angle, and that of the sensor according to the change in ambient temperature were measured. According to the test results on the FBG-based vibration sensor that was developed using a high-speed vibrator, the range in measurement was 0.7 g or more, wavelength sensitivity, 2150 pm/g or more, and the change in wavelength change, $9.5pm/^{\circ}C$.