• 생명과학회지
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• 제13권2호
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• pp.223-229
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• 2003

국내산 무의 추출물을 여러가지 Column과 HPLC를 이용하여 잿빛곰팡이 병원균에 대한 항 진균성 물질을 분리하였다. 투석튜브를 이용한 분리에서 이물질이 3.5kDa 이하의 저분자물질이며 또한 내열성 물질임을 확인하였다. 이물질들은 최소한 5종의 물질로 구성되어 있으며 이중 가장 항진균성이 강한 물질을 HPLC를 이용하여 순수 분리하였으며 잿빛곰팡이병에 감염된 식물에 적용한 결과 농약과 비슷한 효과를 나타내어 환경 친화적인 항진균 물질로서 사용가능성을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1373-1382
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• 2021

Plant growth promoting rhizobacteria (PGPR) are a group of bacteria that can increase plant growth; but due to unfavorable environmental conditions, PGPR are biologically unstable and their survival rates in soil are limited. Therefore, the suitable application of PGPR as a plant growth stimulation is one of the significant challenges in agriculture. This study presents an intelligent formulation based on Bacillus velezensis VRU1 encapsulation enriched with nanoparticles that was able to control Rhizoctonia solani on the bean. The spherical structure of the capsule was observed based on the Scanning Electron Microscope image. Results indicated that with increasing gelatin concentration, the swelling ratio and moisture content were increased; and since the highest encapsulation efficiency and bacterial release were observed at a gelatin concentration of 1.5%, this concentration was considered in mixture with alginate for encapsulation. The application of this formulation which is based on encapsulation and nanotechnology appears to be a promising technique to deliver PGPR in soil and is more effective for plants.

• 한국환경과학회지
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• 제32권1호
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• pp.25-35
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• 2023

The purpose of this study was to determine the optimal sound absorption conditions by comparing the sound absorption characteristics of fresh and air-dried leaves of Quercus glauca, the main species of evergreen broadleaf trees (EBLT) in southern Korea. The sound absorption coefficients (SACs) obtained under 18 conditions were comparatively analyzed. The SAC of air-dried leaves improved significantly with increasing leaf layer thickness. The highest average SAC in the fresh leaf group was 0.617, which was observed under the condition of a leaf specimen size of 0.5 × 0.5 cm² and a leaf layer thickness of 1.75 cm. In a group of air-dried leaves, this was 0.615 under the condition of a leaf specimen size of 0.5 × 0.5 cm² and a leaf layer thickness of 2.50 cm. The maximum value of SAC for each wavelength was observed under the condition of a leaf layer thickness of 2.50 cm consisting of 0.5 × 0.5 cm² leaf specimens, ranging from 1,400 Hz to 1,500 Hz.

• Journal of Chest Surgery
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• 제13권4호
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• pp.496-496
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• 1980

A 37 year old male patient was suffered from severe labored breathing caused by post tracheostomy stenosis, which was localized at the mediastinal trachea [cuffed tracheal stenosis] and ranged 1.5 cm in length and approximately 3 ram. in diameter on tracheogram. After dilation of tracheal stenosis with dilator, endotracheal intubation was tried for induction of anesthesia and control of respiration during operation. A tube was placed just beyond the tracheal stenosis without respiratory difficulty. Under the endotracheal anesthesia, circumferential resection of the mediastinal trachea containing the stenosis, approximately 2 cm in length [4 tracheal rings}, was carried out and primary direct end to end anastomosis was performed with interrupted submucosal sutures [3-0 Dexon] and mobilization of trachea Postoperative tracheostomy was not performed. The patient was completely relieved from dyspnea immediately after operation. Post-operative convalescence was entirely uneventful and at present, about 3 months after operation, he is now conducting a usual life. From the literature and our experience, the etiology and treatment of post-tracheostomy stenosis were discussed.

• Journal of Chest Surgery
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• 제13권4호
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• pp.503-506
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• 1980

A 37 year old male patient was suffered from severe labored breathing caused by post tracheostomy stenosis, which was localized at the mediastinal trachea [cuffed tracheal stenosis] and ranged 1.5 cm in length and approximately 3 ram. in diameter on tracheogram. After dilation of tracheal stenosis with dilator, endotracheal intubation was tried for induction of anesthesia and control of respiration during operation. A tube was placed just beyond the tracheal stenosis without respiratory difficulty. Under the endotracheal anesthesia, circumferential resection of the mediastinal trachea containing the stenosis, approximately 2 cm in length [4 tracheal rings}, was carried out and primary direct end to end anastomosis was performed with interrupted submucosal sutures [3-0 Dexon] and mobilization of trachea Postoperative tracheostomy was not performed. The patient was completely relieved from dyspnea immediately after operation. Post-operative convalescence was entirely uneventful and at present, about 3 months after operation, he is now conducting a usual life. From the literature and our experience, the etiology and treatment of post-tracheostomy stenosis were discussed.

• 소성∙가공
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• 제17권7호
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• pp.481-485
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• 2008

The subframe type rear suspension consisting of a side member and a front/rear cross member is widely used in a medium car and full car. In the small car case, the beam of tubular type without independent suspension system is used to reduce manufacturing cost. In this study, a subframe type rear suspension by hydroforming has been developed. In designing suspension, a driving stability and durability should be considered as an important factor for the performance improvement, respectively. Thus, we focus on increasing the stiffness of suspension and decreasing the maximum stress affecting a durability cycle life. Several optimization design techniques such as shape, size, and topology optimization are implemented to meet these requirements. The shapes of rear suspension obtained from optimization are formed by using hydroforming process. Through commercial software based on the finite element, the superiority of this design method is demonstrated.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.435-439
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• 2002

In the pneumatic system, pneumatic cylinder is wildly used to factory automation. In general, Pneumatic cylinder problems are occured with colliding to stroke end part at which piston collide to end-cap, head cap and tube when piston is loading. This appearances have a short life of cylinder and is due to system destruction. This study examines the dynamic characteristics of pneumatic cushioning cylinder and cushion sleeve design. At head part cushion chamber for the vertical experimental, The decisions of cushioning effect and the results of the experimental research are obtained to the followings: i) The cushioning effects could acqure to the reserch, if the compressible energy is more than kinetic ones. ii) The collision of piston and head cover could acqure to the research, if the kinetic energy is more than compressible iii) If the load increase to the rolling car, the cushion region pressures would increase and the dynamic force.

• 환경위생공학
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• 제20권1호
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• pp.40-54
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• 2005

This dissertation aims to develop adsorption tubes for measuring organic solvents in the working environment, by comparing and analyzing breakthrough condition and adsorption capacity with ACF. 1. In breakthrough characteristics, the raising velocity of breakthrough curve is increasing according to assault concentration, but $50\%$ breakthrough time is decreasing. As breakthrough curve of calculated data using this agrees with the one of experimental data both of them can be used on determining sampling time of adsorption tubes. It is predicted by theoretical that $10\%$ breakthrough time is increasing in the case of increasing filled adsorbent amount. 2. $10\%$ breakthrough time is regularly decreasing as much as assault concentration is increasing. As a result, we can predict the life of adsorbent within the range of the low concentration, and adsorption amount that ACF can sample during $10\%$ breakthrough time is increasing as much as assault concentration is increasing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1623_1624
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• 2009

The use of arc tubes made of ceramic material further enhanced some of the metal halide lamp’s properties. These properties translate into higher efficacy with better color rendering, stable color through lamp long life. Recently, due to an increase in the application of the ceramic metal-halide lamp, the study for the property etc. according to Ballast's driving scheme and the study for arc tube material, optimization of gas and so on are being proceeded to improve the property of the lamp. Especially, to control ceramic metal-halide lamp, the vigorous study and practical use with respect to Electronic Ballast, which has been improved in the disadvantages of the conventional Magnetic Ballast are made. In this paper, Electrical characteristics and gas insulation destroy time are analyzed by comparing magnetic ballast with electronic ballast.

• 산업기술연구
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• 제24권A호
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• pp.75-81
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• 2004

The metal halide lamps are now widely used in the application and commercial lighting due to their attracting properties such as good color rendering and high efficiency. But, they have the serious problem of acoustic resonance for high frequency operation and they need the high voltage to ignite. So, they have not been applied to indoors. Over the past few years, a considerable number of studies have been conducted on the electronic ballast together with hot restarting and resonance phenomenon. But, very few attempts have been made with the adaptive ignition method according to the lamp state. In this paper, electronic ballast is proposed for metal halide lamps with an igniter for adaptive ignition. The proposed electronic ballast can generate different ignition voltages according to the arc tube state.