• Carbon letters
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• 제27권
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• pp.42-49
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• 2018

A citric acid functionalized graphene oxide nanocomposite was successfully synthesized and the structure and morphology of the nanocatalyst were comprehensively characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, X-ray diffraction patterns, atomic force microscopy images, scanning electron microscopy images, transmission electron microscopy images, and thermogravimetric analysis. The application of this nanocatalyst was exemplified in an important condensation reaction to give imidazole derivatives in high yields and short reaction times at room temperature. The catalyst shows high catalytic activity and could be reused after simple work up and easy purification for at least six cycles without significant loss of activity, which indicates efficient immobilizing of citrate groups on the surface of graphene oxide sheets.

• 대한본초학회지
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• 제24권1호
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• pp.1-7
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• 2009

Objectives : The purpose of this study is to investigate on storage characteristics of Herbal materials treated with Gamma-irradiation(10 KGy). Methods : This experiments were carried out by field survey and storage characteristics were carried out by physicochemical determination. Results : Antimicrobial activity of oriental medicine materials(Angelica dahurica Radix, Glehnia littoralis Radix) were examined, together with investigation of effects on gamma-irradiation. Oriental medicine materials contaminated in microbial cell were tend to be pinhole in packaging materials(polypropylene) by bug and Larva. At the same time, PVDC (polyvinylldichloride) package also was founded in bug and Larva by microbial contamination during storage in room temperature. Conclusions : In conclusion, it is very desirable to dose gamma-irradiation(10 KGy) in these oriental medicine materials in order to prevent microbial activity.

• 한국융합학회논문지
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• 제8권12호
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• pp.425-430
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• 2017

본 연구는 토복령 추출물의 여드름 균에 대한 항균활성 및 방부효과를 측정하여 최근 논란이 되고 있는 합성방부제의 대체 가능한 천연 항균 추출물의 개발을 위해 연구하였다. 토복령은 국내산으로 건조한 후 증류수와 95% EeOH 두 가지 용매를 각각 사용하여 실온에서 추출하였다. 그 결과 2종 P ropionibacterium acnes 3314, Propionibacterium acnes 3320의 여드름 균에 대한 항균 효과가 매우 우수하였으며, 특히 증류수 추출물의 clear zone이 16.61 mm로 가장 높은 활성을 나타내었다. 또 피부오염 군집을 채취한 결과에서는 24.48 mm의 clear zone을 보여 토복령 추출물은 여드름균에 대한 항균 활성뿐 아니라 그 외 피부 상재균에 대한 항균 활성도 높음을 알 수 있었다. 이 상의 결과로 토복령 추출물은 항균효능 및 방부 효능을 갖는 화장품 원료로서의 가능을 확인할 수 있었고, 향후 천연 방부제 개발을 위한 기초 연구 자료가 될 것으로 사료된다.

• 생명과학회지
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• 제17권10호
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• pp.1381-1386
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• 2007

황금에 대한 수 추출물의 열 변환에 의한 생리활성 변화를 보기 위하여 HPLC를 통한 peak분석과 기능성 평가를 하였다. 열처리 전의 시료 (CW)와 열처리 후의 시료 (CHW)간의 peak분석에서 CW와 CHW의 비교 시 A와 B가 없어지고 열처리 후에 C라는 다른 물질의 peak가 형성됨을 알 수 있었다. 또한, 전체적인 기능성 평가에서 항산화성에서는 CW와 CHW 별 차이가 없었고, 항고혈압 활성은 CW가 높았다. 항암성에 있어서 폐암에서는 CW가 높았고, 위암, 간암, 후두암 등에는 CHW가 높게 나왔다. 그리고, 멜라닌 생성세포의 멜라닌 생성 억제는 CHW에서 약 80%로 매우 높게 나타났다. 결론적으로 열처리를 통한 시료 내 구성성분의 변환이 기능성 차이를 보여주며, 이는 새로운 열 변환 물질의 생성 때문으로 판단된다. 이들 변화된 물질은 황금의 주성분인 Baicalin 외의 물질이 열 변환 된 것으로, 생성된 물질에 대한 구조분석이 필요한 것으로 사료된다.

• 한국미생물·생명공학회지
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• 제49권1호
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• pp.45-56
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• 2021

Improved amylases were developed from protoplast fusants of two amylase-producing Aspergillus species. Twenty regenerated fusants were screened for amylase production using Remazol Brilliant Blue agar. Crude enzyme extracts produced by solid state fermentation of rice bran were assayed for activity. Three variable factors (temperature, pH and enzyme type) were optimized to increase the amylase activity of the parents and selected fusants using rice bran medium and solid state fermentation. Analysis of this optimization was completed using the Central Composite Design (CCD) of the Response Surface Methodology (RSM). Amylase activity assays conducted at room temperature and 80℃ demonstrated that Aspergillus designates, T5 (920.21 U/ml, 966.67 U/ml), T13 (430 U/ml, 1011.11 U/ml) and T14 (500.63 U/ml, 1012.00 U/ml) all exhibited improved function making them the preferred fusants. Amylases produced from these fusants were observed to be active over the entire pH range evaluated in this study. Fusants T5 and T14 demonstrated optimal activity under acidic and alkaline conditions, respectively. Fusants T13 and T14 produced the most amylase at 72 h while parents TA, TC and fusant T5 produced the most amylase after 96 h of incubation. Response surface methodology examinations revealed that the enzyme from fusant T5 was the optimal enzyme demonstrating the highest activity (1055.17 U/ml) at pH 4 and a temperature of 40℃. This enzyme lost activity with further increases in temperature. Starch hydrolysis using fusant T5 gave the highest yield of glucose (1.6158 g/100 ml). The significant activities of the selected fusants at 28 ± 2℃ and 80℃ and the higher sugar yields from cassava starch hydrolysis over their parental strains indicate that it is possible to improve amylase activity using the protoplast fusion technique.

• The Korean Journal of Physiology
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• 제1권2호
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• pp.199-213
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• 1967

Circulatory and respiratory activities were observed in men exposed to the environment of engine room of a cruising Republic of Korea Navy ship and compared to the control values obtained in an ordinary laboratory room on land. The environment of an engine room of cruising navy ship was presumed to be a multiple stress acting on men. The environment of the engine room included high temperature $(35-42^{\circ}C)$, low relative humidity (20-38% saturation), vibration (about 7 cycles per second), rolling and pitching of ship and noises. Sixteen men were divided into two groups consisted of each 8 subjects. Subjects of sea duty group had experience of continuous on board duty averaging 3.5 years. Men of land duty group had no experience of on board activity. On land observations were made on one day prior to the boarding and leaving the port and four days after landing. In between observations in the engine room were made on the first, 5 th, 9 th, 12 th, and 14 th day of on board activity. The whole experimental period lasted for 20 days. Measurements on circulatory and respiratory parameters were at standing resting state (after 30 minutes standing in the case of on land study and 15 minutes in engine room study) and within one minute after cessation of on the spot running of which rhythm was 30/min. and lasted for 5 minutes. Oxygen consumption and pulmonary function test were done in the period of two minutes from the 3rd to 5th minutes of running. The following results were obtained. 1. Body temperature showed no change regardless of group difference or on land or on board measurements. 2. Pulse rate increased markedly after boarding the ship id both groups. Pulse rate increased from the first day on board at rest and after exercise as compared to the on land control value. This increase in pulse rate was more marked after exercise. Sea duty group showed less increase in pulse rate at rest than the land duty group. Standing and resting pulse rate of sea duty group on lam was 81 and increased to 87 at the 5th day on board and remained smaller than the land duty group throughout the period on board. Control standing and resting pulse rate of land duty group on land was 76 and reached 89 at the 9th day on board and thereafter decreased a little. Pulse rate of land duty group at rest on board remained greater than that of sea duty group throughout the period on board. 3. Systolic blood pressure of sea duty group increased after boarding the ship and remained higher than the control value on land. In the land duty group, however, systolic blood pressure decreased during the period on board the ship. Diastolic blood pressure decreased in both groups. 4. Resting breathing rate of land duty group increased and remained higher than the control value on land. In sea duty group, however, resting breathing rate showed a transient increase on the 1st day on board and decreased thereafter to the control value on land and kept the same level throughout the period of cruise. Absolute value of breathing rate in the sea duty group was greater than the land duty group both at rest and after exercise. 5. There was a lowering of breathing efficiency in both groups. Thus, increases in tidal volume and minute ventilation volume and decreases in maximum breathing capacity, vital capacity, capacity ratio and air velocity Index were observed after boarding the ship. An increase in ventilation equivalent was also observed in both groups. The lowering of breathing efficiency was more marked in the land duty group than the sea duty group. 6. Energy expediture increased in both groups during their stay on the ship and was more marked in the sea duty group. 7, Lactate concentration in venous blood at rest and after exercise increased after boarding the ship and no group difference was observed.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권3호
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• pp.132-138
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• 2010

In the present study, the real-time monitoring system is developed based on the wireless sensor network (WSN) and power line communication (PLC) employed in the 3,000-ton-class training ship. The WSN consists of sensor nodes, router, gateway and middleware. The PLC is composed of power lines, modems, Ethernet gateway and phase-coupler. The basic tests show that the ship has rather good environments for the wired and wireless communications. The developed real-time monitoring system is applied to recognize the thermal environments of main-engine room and one cabin in the ship. The main-engine room has lots of heat sources and needs careful monitoring to satisfy safe operation condition or detect any human errors beforehand. The monitoring is performed in two regions near the turbocharger and cascade tank, considered as heat sources. The cabin on the second deck is selected to monitor the thermal environments because it is close to the heat source of main engine. The monitoring results of the cabin show the thermal environment is varied by the human activity. The real-time monitoring for the thermal environment would be useful for the planning of the ventilation strategy based on the traces of the human activity against inconvenient thermal environments as well as the recognizing the temperature itself in each cabin.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.275-278
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• 2002

The recognition of the natural background radiation is important not only for radiological education but also for the promotion of people's scientific view about radiation. We made a "room" on the web showing natural background radiation as part of a VRM (Virtual Radiation Museum). The "room" shows the video images of the tracks of charged particles from natural background radiation, alpha and beta ray track from known sources using a Large Scale Diffusion Cloud Chamber. The purpose of this study is to make clear the origin of a kind of track (named A-track) which is thick and easy to recognize with the length less than several cm in the cloud chamber, and to make numerical explanation of its counting rate. The study was carried out using a Large Scale Diffusion Cloud Chamber (Phywe, Germany) installed in the Niigata Science Museum. The Model RNC (Pylon Electronics, Canada) was used as Rn-222 source. Ra-226 activity in RNC was 111.6 Bq calibrated with NIST protocol. Rn-222 gas was injected into the cloud chamber. Continuous video recording with use of Digital Handycam (SONY, Japan) was carried out for 360 min. after injection of Rn-222 gas. The number of alpha-ray track (alpha track) in the video images was analyzed. The growth and decay curve of the total activity of Rn-222 and its alpha emitting progeny were calculated and compared with the count of the alpha tracks. As a result the alpha tracks formed by Rn-222 injection resemble A-Tracks. The relationship between A-track in the cloud chamber and atmospheric Rn is discussed.

• 한국동물학회지
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• 제31권2호
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• pp.133-141
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• 1988

본 연구는 polyacryiamide gel등을 전기영동을 응용, 보존시간에 따른 정액반, 질액반 등에서 PGM$_1$아형의 검출 및 효소활성의 안전성을 조사하여 다음과 같은 결론을 얻었다. (1). 정액반의경우, 실온에서 보존후 7일에는 85%,14일에는 15%의 PGM$_1$아형의 판정이 가능하였고, 21일에는 전혀 판정이 불가능 하였다. (2). 질액반의 경우, 실온에서 보존 후 7일에는 675의 PGM$_1$아형의 판정이 가능하였으나, 14일에는 전혀 불가능 하였다. 한편, 질액에 정액이 혼합된 경우, 질액의 PGM$_1$아형을 판정함으로서, 정액의 PGM$_1$아형의 추정이 가능하였다. 이 결과를 통하여 실제 법생물학 분야에 활용이 가능하다고 인정하였다.

• 한국주거학회논문집
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• 제15권2호
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• pp.1-9
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• 2004

This study aims to provide basic data for designing aged care residential facilities in Korea, based on the investigation and analysis of the aged care residential services and their communal living areas in Australia focusing on their types, scales, arrangement and the specific design of each compartment. -. A residential building with 10 beds is composed of private zones and communal ones, and their space arrangement depends on how to arrange bedrooms where residents mainly stay. -. A lounge, 26.7 m$^2$ of its average scale, is a main space for daily lives and an important place for making friends with neighboring residents. -. A dining hall is an important area for activity as well as a space for dining. The average scales of dining room, kitchen, and whole space are 42.7 m$^2$, 28 m$^2$, and 70.8 m$^2$ respectively, and those for person are 2.7 m$^2$: 1.7 m$^2$:4.4 m$^2$, although the scales depend on facilities. -. An activity room is used for promoting the social relationship between residents and visitors. Three of the investigated facilities have big rooms of 42 m$^2$, 39 m$^2$ and 51 m$^2$. -. If there is no lavatory in a bedroom, 2-6 bathrooms for residents are arranged near bedrooms and they are relatively big including shower baths. If there is a lavatory in a bedroom, 1 toilet for visitors is arranged in a communal living area and its scale is small.