• Parasites, Hosts and Diseases
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• 제55권3호
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• pp.341-345
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• 2017

The metacercariae of Artyfechinostomum malayanum (Leiper, 1911) Mendheim, 1943 were discovered in Pila sp. snails purchased from a market in Phnom Penh, Cambodia. They were isolated from the snails using the artificial digestion technique and were orally fed to 2 hamsters, 1 rat, and 2 mice to obtain the adult flukes. The metacercariae were round, $145-165{\mu}m$ in diameter, having a cyst wall of $6-10{\mu}m$ in thickness, a head collar and collar spines, and characteristic features of excretory granules. Adult flukes were recovered in the small intestines of the animals at days 14 and 32 post infection and were morphologically observed using a light microscope and a scanning electron microscope. They were plump or elongated, ventrally curved, $6.0-8.1{\times}1.6-2.0mm$ in size, and characterized by the head collar bearing 43 collar spines, including 5 end group ones on each side, a long cirrus sac extending beyond the posterior margin of the ventral sucker, a submedian ovary, and 2 deeply lobed testes. Eggs in uteri were operculate, ovoid to ellipsoid, and $120-135{\times}68-75{\mu}m$ in size. In scanning electron microscopy, the head collar was prominent with collar spines looking like horns. Scale-like tegumental spines were densely distributed on the ventral surface between the head collar and ventral sucker. Sensory papillae were distributed mainly on the tegument around suckers. By this study, it has been first confirmed that the life cycle of A. malayanum exists in Cambodia.

• 대한기계학회논문집
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• 제11권5호
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• pp.828-836
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• 1987

본 연구에서는 유동장과 입자의 부착율과의 관계에 대해 고찰하기 위하여 부 착되는 고체 벽면의 형상을 원통형으로 하여 비등온 유동에서 열확산에 의한 미소입자 의 원주방향으로의 부착율을 측정하고, 원통 내부의 냉각장치를 이용하여 벽면과 고온 가스와의 온도 차이를 크게하여(약 400∼700˚K), 높은 온도구배 영역에서의 열확산 효과에 대해 실험적인 연구를 확장시킴으로써 폭넓은 온도구배 영역에서의 열확산 이 론의 타당성을 검토한다. 그리고 이러한 실험결과들은, 원통주위의 미소입자 전달에 관한 종래의 Levich 등의 해와 입자의 미소한 관성의 영향을 동시에 고려한 Fernandez de la Mora 등의 점근적인(asymptotic)이론과 비교될 것이다.

• Journal of Plant Biology
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• 제35권2호
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• pp.143-153
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• 1992

한국산 왕벚나무(Prunus yedoensis Matsumura) 화외밀선의 미세구조 및 당액 분비기작을 규명하기 위하여 광학현미경, 주사형 및 투과형 전자현미경을 이용하여 관찰하였다. 밀선은 secretory layer와 subsecretory layer로 구성되어 있었으며 엽병의 유관속은 subsecretory layer에 있는 유관속과 연결되어 있었다. Secretory cell에서는 cristae가 잘 발달되지 않은 다수의 mitochonidria가 관찰되었으나 소포체는 소수 나타났고 골지체가 전혀 관찰되지 않았다. 색소체는 thylakoid가 거의 발달되지 않았으며, 소수가 관찰되었고 $0.2-0.3\;\mu\textrm{m}$ 크기의 소포를 특징적으로 갖고 있었다. subsecretory cell에서는 원형질 연락사가 잘 발달해 있었고 다수의 Calcium oxalate 결정이 관찰되었는데 이는 당투과에 간접적으로 관여하는 것 같다. 당액 전구물질은 사부에서 subsecretory layer를 거쳐 secretory layer까지 이동하는 것을 원형질 연락사를 통한 symplastic transport에 의하여 일어나는 것으로 생각되며 secretory layer에서 당액으로 재합성되어 외부로 배출되는 것 같다. Secertory cell의 맨 바깥쪽 세포벽은 cuticle 에 의하여 덮여 있었으며 secretory cell에서 당액은 원형질막, 세포벽, cuticle을 차례로 통과하는 누출상 분비(eccrine secretion)에 의하여 분비되는 것으로 사료된다.

• 식물조직배양학회지
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• 제27권2호
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• pp.133-136
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• 2000

미생물에서 분리한 dykellic acid가 식물세포에 미치는 생리적 영향을 평가하기 위하여, 담배 광혼용영양배양세포(photomixotrophic cultured cells, PM세포)에 dykellic acid를 다양한 농도로 처리하여 세포의 생장과 단백질 함량 및 superoxide diamutase (SOD)활성에 미치는 영향을 조사하였다. 담배 PM세포는 0.7 mg/L 2,4-D, 0.3 mg/L kinetin, 30g/L sucrose, 200 mM NaCl를 함유한 MS배지에서 $25^{\circ}C$, 광조건에서 현탁배양 (100 rpm) 하였다. 계대배양시 화합물을 처리한 후 12일째의 세포생장 억제와 배지의 이온 전도도를 측정한 세포막손상의 결과는 일치하였으며, 화합물은 세포생장을 강하게 억제시켰다 ($IC_{50}$/, 약 20 $\mu$M). Dykellic acid 처리농도가 증가함에 따라 단위세포 무게당 단백질 함량과 SOD 비활성도를 현저히 증가시켰다. 이상의 결과로 dykellic acid는 식물세포 생장을 저해하는 활성을 가지고 있으며, 담배 PM세포는 적은 양으로도 천연물의 생리활성을 평가할 수 있는 유용한 생물소재임이 확인되었다.

• 한국어류학회지
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• 제27권3호
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• pp.228-232
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• 2015

빙어의 심실 구조를 광학현미경과 주사전자현미경으로 관찰하였다. 빙어의 심장은 정맥동, 심방, 심실 및 동맥구가 연속적으로 배열되어 있었다. 심실의 외벽은 심내막, 심근층, 심외막하층 및 심외막으로 구분되었고, 심방과 심실 사이의 방실판막 및 심실과 동맥구 사이의 구실판막이 관찰되었다. 심실은 주머니 모양이었으며, 심근층은 해면성 심근으로만 구성되어 있었고 관상혈관은 분포하지 않았다. 심실에서 소주들은 중심 내강과 작은 내강들을 형성하였으며, 소주는 원기둥 모양이었다. 심외막하층, 방실판막 및 구실판막에서 아교질의 분포가 관찰되었으나 소주에서는 심실의 기저부에서 부분적으로 관찰되었다. 특히 소주들 사이에서는 심내막교가 관찰되었다. 이와 같은 결과는 육봉형 빙어가 서식환경 및 생활양식에 적응한 결과로 생각된다.

• 전기학회논문지
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• 제58권12호
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• pp.2446-2452
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• 2009

A Ceramic Metal-halide lamp is achieved by adding multiple metals to a basic mercury discharge. Because the vapor pressure of most metals is very much lower than mercury itself, metal-halide salts of the desired metals, having higher vapor pressures, are used to introduce the material into the basic discharge. The metal compounds are usually polyatomic iodides, which vaporize and subsequently dissociate as they diffuse into the bulk plasma. Metals with multiple visible transitions are necessary to achieve high photometric efficiency and good color. Compounds of Sc, Dy, Ho, Tm, Ce, Pr, Yb and Nd are commonly used. The maximum visible efficacy of a Ceramic Metal Halide lamp, under the constant of a white light source, is predicted to be about 450lm/W. This is controlled principally by the chemical fill chosen for a particular lamp. Current these lamps achieve 130lm/W and these life time are the maximum 16,000[hr]. So factors of performance lower are necessary to improve lamp performance. In this paper, we analyzed factors of performance lower by accelerated deterioration test. The lamp was operated with short duration turn-on/turn-off procedure to enhance the effect due to electrode sputtering during lamp ignition. The tested lamp that was operated with a longer turn-on/off(20/20 minutes) showed blackening, changed distance between electrodes and lowered color rendering & color temperature by losses of Dy at 421.18nm, I at 511nm, T1 at 535nm and Na at 588nm compared with the new lamp.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.21-31
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• 2004

There are probably no architects of the 20th Century who had more influence on modern architecture than Mies van der Rohe and Le Corbusier. Although the two architects share one thing in common, namely, both are master of modernism, each has developed unique architecture of his own. The objective of this study is to investigate the characteristics of their works through a comparison analysis of the Ideas, design principles and architectural language reflected in the works, focusing on the houses. this study will also aim to provide a foundation for a new design that harmonizes the design principles and architectural language of the two. Through the study the following common points and differences were found between the houses of the two. A) Common points: Both architects avoided ornamentation In houses while placing weight on the functions of houses and they tried to plan rational floor plans by separating the wall from the structure. B) Differences: \circled1 The houses of Mies express the structure in a straight forward manner, while those of Corbusier are formative houses focusing more on shapes. \circled2 The shapes of the houses of Mies are limited to basic shapes, quadrangle while those of Corbusier employ various geometric curves. \circled3 Using steel and glass, the houses of Mies are light and transparent. On the contrary, using concrete, the houses of Corbusier are somewhat bulky with Three-dimensional changes. \circled4 The houses of Mies show the value of moderation based upon the classical principles of design, while the houses of Corbusier show the value of moderation based upon geometry. \circled5 The houses of Mies feature horizontal intoners with flexibility. However, Corbusier's houses have vertical interiors with some changes in the cross sections. \circled6 In terms of material, the interiors of Mies' houses employ materials with various tones and textures, while interiors of Corbusier's houses are painted in simple white. Summing up these characteristics, it could be said that the houses of Mies have logical and rational beauty, whereas the houses of Corbusier have more emotional beauty.

• 미술이론과 현장
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• 제13호
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• pp.185-213
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• 2012

Charles Stankievech's 2011 installation LOVELAND includes a wall-sized screen depicting video footage of a barren arctic landscape in an enclosed room, painted and bathed in white light, that appears as an extension of the imaged environment. A melodic and industrial musical score emanates from multiple sound panels and as the music increases a cloud of purple smoke becomes visible on the horizon line in the distance and gradually advances toward the viewer until it completely fills the screen. The smoke then remains, rushing about madly and lapping at the border between the screen and the room before it suddenly subsides and the spectator is again left with the desolate landscape. The entire process takes a mere five minutes and then, fixed on an endless loop, begins again. This paper positions LOVELAND as an attempt to simulate a sublime experience of the end of the world through a transposition of the Arctic atmosphere into the gallery space. Encompassing a discussion of the historical and contemporary significance of the Arctic in popular culture, aesthetics and environmental politics, it is suggested that Stankievech employs an apocalyptic trope in reference to the unstable position of the North in the current political and ecological climate. Revisiting critiques of modernist exhibition practices and investigating the perceptual and temporal dimensions of the work, this analysis focuses primarily on the experience of the installation's spectator. Visually, aurally and phenomenologically immersed, the viewer is made subject to, and implicated in, the events unfolding on the screen and within the space. Due to the looping of the video footage, this paper argues that the apocalypse imaged in LOVELAND is presented as an endless event - incessantly enacted, yet infinitely deferred - and that the spectator is enveloped in an uncertain and unceasingly extended present moment.

• 한국습지학회지
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• 제7권4호
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• pp.81-88
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• 2005

2001년부터 2004년동안 4년간에 걸쳐 조사된 태화강하류의 겨울철새는 11목 21과 58종 최대 출현개체수는 14,034개체이다. 연도별로 출현 사항을 보면 종수의 경우 2001년 48종에서 2004년 31종으로 매년 줄어들고 있다. 한편 개체수의 경우 2002년에 11,991개체로 가장 많이 조사되었고 2004년이 3,476개체로 가장 적게 조사되었다. 5% 이상의 우점종은 흰죽지 Aythya ferina(6,946개체), 떼까마귀 Corvus frugilegus(1,643개체), 붉은부리갈매기 Larus ridibundus(1,193개체), 괭이갈매기 Larus crassirostris(805개체)로서 이들 4종의 개체수 합(10,587개체)이 전체 개체수의 75.4%를 차지한다. 태화강에 도래하는 조류를 보호하기 위해서는 강변 가까운 곳에 조류들의 먹이장소 조성, 쉼터 등 완충지대를 만들어주고 도로와 고수부지 사이는 수목대 또는 차광대와 방음벽을 설치할 필요가 있다. 무엇보다도 시민들의 철새에 대한 보호 의지가 강해야 한다. 또한 철새들이 많이 도래하는 태화강과 동천의 합수부 일대, 조류들의 번식지와 잠자리로 이용하는 대밭 지역($2{\times}0.1km^2$)의 서식지 보호 및 관리방안이 필요하다.

• 한국정밀공학회지
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• 제18권5호
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• pp.171-176
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• 2001

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. Mold for forming barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing process such as screen printing, sand-blasting and photosensitive glass methods. Mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper, Stripes of grooves of which width 48${\mu}{\textrm}{m}$ and 270${\mu}{\textrm}{m}$, depth 124${\mu}{\textrm}{m}$, pitch 274${\mu}{\textrm}{m}$ was acquired by machining hard and brittle materials of WC, Silicon, Alumina with dicing saw blade. Maximum roughness of the bottom and sidewall of the grooves was respectively 120nm, 287nm in grooving WC. Maximum tilt angle caused by difference between upper-most width and lower-most width was 2$^{\circ}$. Maximum Radius of bottom curvatures was 7.75${\mu}{\textrm}{m}$. This results satisfies the specification for barrier ribs of 50 inch XGA PDP if the groove form of mold was fully transferred to the barrier ribs. Barrier ribs were formed with Silicone rubber mold, which is transferred from grooved hard materials. Silicone rubber mold has elasticity accommodating the waveness of lower glass plate of PDP.