• 한국가시화정보학회지
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• 제10권2호
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• pp.20-24
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• 2012

Increasing the active catalyst surface area is important in improving a converter's efficiency. In addition, uniform flow is advantageous in that it produces more efficient catalytic conversion. This results in the ability to use a smaller catalytic converter with uniform flow as opposed to a larger converter requirement for non-uniform flow. Therefore, it is important to characterize the internal flow of the catalytic converter. To characterize the system's flow patterns, velocity measurements were taken at the mid and exit planes of a ceramic honeycomb catalytic converter at flow rates of 37.8 l/s and 94.4 l/s. Measurements were conducted using LDV. The profiles were measured along both the major and minor axis of the planes. Primary flow direction velocities measured along the minor axis, at both flow rates, varied greatly at the mid plane and somewhat at the exit plane. The areas of greatest air flow were seen near the edges of the walls and on the side of the converter opposite the flow's entrance region. It also appears that the high velocities opposite the intake are due to the design of the entrance region. The entrance region is possibly too small to properly redirect the vertically entering fluid into an evenly distributed flow in the primary flow direction.

• 대한한방소아과학회지
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• 제22권1호
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• pp.113-121
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• 2008

Objectives In human myeloid leukemia cells, there are no specific features of apoptosis compared with apoptosis in other cell types. Solanum nigrum L.(SNL) is a deciduous tree, which is widely distributed in Korea with reported anti-tumor, anti-inflammatory and non-specific immune-enhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are unknown and its mode of action potential has never been investigated. Thus anti-tumor property of methanol extract was investigated. Methods In this study, anti-tumor property of methanol extract was investigated by determining its in vitro growth-inhibitory effects on human myeloid leukemia cells. XTT proliferation assay, DNA fragmentation, immunoblot analysis, densitometric analysis were used. Results 1. The methanol fraction of the extracts of SNL induced mitochondria-mediated apoptosis in human myeloid leukemia cells. 2. The methanol fraction exhibited relatively higher cytotoxic activity in a dose-dependent manner than chloroform, and hexane fraction. 3. Typical ladder profile of Oligonucleosomal fragments were appeared. 4. The secreted cytosolic cytochrome C level was increased by treatment of methanol fraction. Conclusions Methanol fraction of SNL is capable of inducing apoptosis in human myeloid leukemia cells.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.279-283
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• 2013

We tested the effects of various distillers dried grains (DDGs) in a formulated diet on growth and body composition of juvenile sea cucumber Apostichopus japonicus. DDG is a solid residue obtained by filtering an aqueous mixture of fermented rice with Aspergillus oryzae and yeasts. Six isonitrogenous and isocaloric diets (DDG0, DDG-G, DDG-C, DDG-K, DDG-W, and DDG-P) were formulated to contain 20% DDG obtained from different Makgeolli factories. Juvenile sea cucumber (average weight, $2.1{\pm}0.02$ g) were randomly distributed in eighteen 50-L rectangular plastic tanks (40 L of water each) in a seawater flow-through system at a density of 50 juveniles/tank. Three replicate groups of sea cucumber were fed each of the six experimental diets at a feeding rate of 5% body weight per day for 22 weeks. At the end of the feeding experiment, survival and weight gain of the juvenile sea cucumber were not affected by the type of dietary DDG (P > 0.05), and the proximate and amino acid compositions of the whole body were not affected by dietary DDG diets (P > 0.05). These results indicate that rice-based DDG is a potential dietary ingredient that could be used at dietary concentrations of up to 20% for growth of juvenile sea cucumber.

• 한국초등과학교육학회지:초등과학교육
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• 제33권3호
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• pp.597-606
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• 2014

The purpose of this study is to survey and analyze difficulties in teaching and learning elementary school science on the chapter titled 'electric circuit'. 28 elementary school teachers who teach 5th grade science and 73 5th grade students in elementary school were taken part in this survey. The pilot questionnaire was distributed to find out both the degree and the reason of difficulties in teaching and learning. The answers are analyzed with four areas to extract elements which make class difficult; Learner factors (L), Instruction factors (I), Curriculum & textbooks factors (C), and Environment factors (E). The results are as follows. (1) It can be seen that both students and teachers feel the highest difficulty in 7th lesson 'the direction of current', while they felt little difficulty in lesson 3 'conductor and nonconductor' and lesson 8 'the safety of electricity'. (2) The most mentioned reason of difficulties in teaching and learning was Learner factors (L). (3) Teachers felt many difficulties in experimental environment. On the other hands, students didn't think experimental failures as serious trouble. (4) Students felt many difficulties in new terms and hazy concepts or expressions. (5) Teachers felt a lot of difficulties in those from Curriculum & textbooks factors.

• ALGAE
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• 제36권1호
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• pp.13-24
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• 2021

The present-day genetic structure of macroalgal species reflects both geographical history and oceanic circulation patterns as well as anthropogenic introduction across native ranges. To precisely understand the genetic diversity and how the factors shape the current population structure of Gloiopeltis furcata sensu lato, we determined the mitochondrial 5' end of cytochrome c oxidase subunit I (COI-5P) sequences for 677 individuals sampled from 67 sites spanning almost the entire distribution range in Korea and Japan. Results from the phylogenetic analysis and haplotype distribution revealed eleven distinct lineages within G. furcata s.l. along the Korea-Japan coastal areas and displayed divergent phylogeographic patterns among lineages. Despite the closely related lineages distributed in same habitats as high rocky intertidal zone, they display different phylogeographic patterns among lineages. The populations from the south of Korea-Japan harbored the highest genetic diversity and unique endemism in comparison with other populations in the distribution range. This could be the evidence of southern refugia for G. furcata s.l. in the Northwest (NW) Pacific and the recent migration from native to introduced region. The reason is that an exceptional distribution pattern was found high genetic diversity in Hakodate of Japan where is the northern location in the NW Pacific. Our results imply the contemporary influence on the distribution due to current circulation pattern and anthropogenic effects. These phylogeographic findings provide the important insight into cryptic species diversity and the detailed distribution pattern of Gloiopeltis in the NW Pacific.

• 생물환경조절학회지
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• 제22권4호
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• pp.427-431
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• 2013

본 연구는 UVc 처리, 열수처리와 고 $CO_2$ 처리가 저온저장으로 인해 발생하는 저온장해 현상에 미치는 영향을 비교하고, 소량으로 다른 작물과 혼합 선적할 때 유지되는 $5^{\circ}C$ 이하의 저장 유통에 적용할 수 있는지 알아보기 위해 수행하였다. 각각의 처리 후 20일간 저온저장 후 상온에 5일간 저장하였다. 생체중은 MAP 조건이었던 고 $CO_2$ 처리구를 제외한 나머지 처리구에서 상온 저장후 급격히 감소하였으며, 에틸렌은 주기적으로 3% 내외의 수치를 보였다. 고 $CO_2$ 처리구는 저장 종료일인 25일에는 약 33%의 고 $CO_2$ 농도를 나타냈다. 저장 최종일에 측정한 경도는 통계적 유의성은 없었으나, 저온장해 현상이 완화되었던 열수처리에서 높았다. 저온장해 정도의 지표가 되는 전해질 용출량은 저온장해 발생온도인 $4^{\circ}C$에서는 고 $CO_2$ 처리구에서 가장 높았으며, 열수처리와 UVc처리구에서 가장 낮았는데, 비저온장해 대조구($7^{\circ}C$)와 유사한 수준이었다. 또한 저장최종일에 측정한 호흡률에서는 열수처리가 가장 낮아 저온장해가 완화되었음을 알 수 있었다. 이상의 결과로 보아 저온장해 완화 효과를 보인 열수처리와 UVc 처리는 소량으로 다른 작물과 혼합 선적할 때 유지되는 $5^{\circ}C$ 이하의 저장유통에 적용할 수 있을 것으로 판단되었다.

• 한국농림기상학회지
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• 제16권1호
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• pp.1-10
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• 2014

본 연구는 난과 희귀식물인 보춘화속의 제주도 분포범위와 자생지의 식생구조를 파악하기 위하여 실시되었다. 보춘화속은 전 세계적으로 아시아 및 호주 북부의 열대 및 아열대 지역에 분포하고 있다. 국내에서는 한란, 소란, 대흥란, 죽백란, 녹화죽백란, 보춘화 등 총 6종이 분포하고 있으며, 이들 6종은 모두 제주도에 분포하고 있다. 제주도 내 보춘화속은 해발 16-547m 사이에 분포하였는데, 이 중 대흥란은 해발 16-547m 사이에 분포하여 가장 넓은 해발 분포 범위를 나타냈다. 반면에 죽백란, 녹화죽백란, 소란 등은 한라산 남사면의 돈내코 계곡 및 효돈천계곡 등 좁은 해발 분포 범위를 나타냈다. 이들 종은 열대 및 아열대 지역에 분포하는 종으로서 기후온난화가 진행될 경우 제주도내에서의 해발 분포 범위 확대와 한반도 내륙으로의 자생지 확산이 예측된다. 한편, 제주도내에서 보춘화속자생지의 식생구조를 분석한 결과, 구실잣밤나무 군락과 구실잣밤나무-곰솔 군락, 곰솔-상수리나무 군락, 곰솔군락, 종가시나무-푸조나무 군락 등 5개 군락으로 구분되었다. 이들 군락내에서 자라는 보춘화속 중 한란과 소란 및 죽백란 등 3종은 구실잣밤나무 군락에서만 출현하였으며, 녹화죽백란은 구실잣밤나무-곰솔 군락에서 출현하였고, 대흥란은 곰솔-상수리나무 군락과 곰락 군락 및 종가시나무-푸조나무 군락 등 3개 군락에 분포하였다. 반면 보춘화는 구실잣밤나무-곰솔 군락, 곰솔-상수리나무 군락에서 출현하였다. 제주도에 분포하는 보춘화속은 불법 채취에 의해 개체수가 급격히 감소하고 있으며, 특히 한란, 죽백란, 녹화죽백란, 소란등은 식생학적으로 분포 범위가 매우 협소한 것으로 판단되며 이들 종에 대한 보전방안 마련이 필요할 것으로 사료된다.

• 환경생물
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• 제35권4호
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• pp.566-572
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• 2017

2015년 10월부터 2016년 7월까지 가을, 겨울, 봄, 여름의 계절별로 한강 하구의 시암, 성동, 공릉천, 산남, 장항습지 등 5개 습지에서 동물플랑크톤 채집을 실시하였다. 25종의 윤충류를 포함하는 총 46종류의 동물플랑크톤이 출현하였다. 기수종은 요각류 2종만이 출현하였고 10월에 성동과 장항습지에 출현한 15종류가 가장 다양하게 출현한 것이었다. 최대 출현량은 3월에 시암습지에서 윤충류의 대량 출현에 의해 $8,000indiv.\;L^{-1}$로 기록되었다. 3월에는 다른 정점에서도 $5,000indiv.\;L^{-1}$ 이상의 높은 출현량이 나타났지만 나머지 기간 중에서 수백 개체의 낮은 밀도가 지속되었다. 종다양성지수는 0.4~1.8 사이에서 변동하였다. 요각류 유생의 장내용물질 분석 결과 미동정물질들과 함께 규조류가 주먹이원인 것으로 밝혀졌다. 수온은 $10.1{\sim}28.2^{\circ}C$, pH는 7.1~8.6 용존산소량은 $4.5{\sim}11.0mg\;L^{-1}$ 사이에서 변동하여 정점에 따라 하계 수온상승에 의한 용존산소량 부족 가능성이 제기되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.47-51
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• 2000

A modified direct bonding technique employing a wet chemical deposition of $SiO_2$ film on a wafer surface to be bonded is proposed for the fabrication of Si-$SiO_2$-Si structures. Structural and electrical quality of the bonded wafers is studied. Satisfied insulating properties of interfacial $SiO_2$ layers are demonstrated. Elastic strain caused by surface morphology is investigated. The diminution of strain in the grooved structures is semi-quantitatively interpreted by a model considering the virtual defects distributed over the interfacial region.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.7-9
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• 2004

The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR. Quantifying water balance components is important to understand the basic hydrology. In this study, a simple method to estimate the ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data. The Morton's actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map. The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.