• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.253-253
• /
• 2008

Recently, high performance microelectronic devices are designed in multi-layer structure in order to make dense wiring of metal conductors in compact size. For making dense wiring of metal conductors, we investigated CTE and peel strength of dielectric materials for next generation PCB. It is an object of this research to develop an epoxy resin composition for an interlayer insulating material exhibiting low CTE and high peel strengnth and making an insulating layer thinner.

• Applied Microscopy
• /
• 제45권3호
• /
• pp.144-149
• /
• 2015

Nothobranchius guentheri and Nothobranchius patrizii have special life cycle to sustain the dry season. So, we investigated the fertilized eggs morphology, and compared ultrastructures of surface structures and the cross section of fertilized egg envelopes using light and electron microscopes to determine whether these fertilized eggs and egg envelopes show the species specificity or have special structure to sustain the dry season. These fertilized eggs were spherical, yellowish, demersal and adhesive, and had a one-sided large oil droplet. The whip-like structures, adhesive filament were distributed throughout egg envelope in both species. But, that of N. guentheri was covered with fibrous structures, and that of N. patrizii was smooth. The egg envelope consisted of two distinct layers: an outer, electron-dense layer containing adhesive filaments and an inner layer of 16 to 17 horizontal electron-dense lamellae alternating with 15 to 16 interlamellae of lower electron density in both species. The external shapes of fertilized egg and section of fertilized egg envelope were same, but ultrastructure of adhesive filaments on the outer surface was concluded to show species specificity. Our data indicate that the ultrastructural differences of adhesive filament and outer surface of fertilized egg envelope show species specificity although these species belong to same genus.

• Nuclear Engineering and Technology
• /
• 제52권1호
• /
• pp.115-122
• /
• 2020

A promising method for removal of Cs ions from water and their incorporation into stable crystal structure ready for safe and permanent disposal was described. Cs-exchanged X zeolite was hot-pressed at temperature ranging from 800 to 950 ℃ to fabricate dense pollucite ceramics. It was found that the application of external pressure reduced the pollucite formation temperature. The effect of sintering temperature on density, phase composition and mechanical properties was investigated. The highest density of 92.5 %TD and the highest compressive strength of 79 MPa were measured in pollucite hot-pressed at 950 ℃ for 3 h. Heterogeneity of samples obtained at 950 ℃ was determined using scanning electron microscopy. The pollucite hot-pressed at 950 ℃ had low linear thermal expansion coefficient of ~4.67 × 10^-6 K^-1 in the temperature range from 100 to 1000 ℃.

• The Plant Pathology Journal
• /
• 제27권1호
• /
• pp.8-13
• /
• 2011

The induced resistance of cucumber leaves treated with oligochitosan to the infection of the cucumber powdery mildew, Sphaerotheca fuliginea, was investigated using transmission electron microscopy. The results showed that when the plants were treated with oligochitosan and challenged with inoculum, a significant decrease of the disease occurred. The mycelial development in the treated leaves was markedly inhibited. The cytoplasm of the powdery mildew mycelium was aggregated, with its organelles disintegrated and the cytoplasm collapsed. The protoplasm in haustoria became electron-dense. Haustoria became malformed, their organelles disintegrated, the hausterial wall thickened and eventually the whole complex necrotized. The host cells produced defence structures and materials associated with infection and a hypersensitive response. The host cell wall was thickened and deeply stained; several layers of papilla structure were produced under the cell wall; dark materials were deposited between the cell wall and plasmalemma; extrahaustorial plasmalemma was deeply stained and extrahaustorial matrix appositions had large deposits of electron-dense material; the cytoplasm was disordered, host organelles disintegrated and eventually the whole host cell disintegrated and necrotized.

• Parasites, Hosts and Diseases
• /
• 제31권4호
• /
• pp.315-320
• /
• 1993

Fibricola seoulensis 조직융해구(tribocytic organ)의 미세구조를 알기 위하여, 전자현미경으로 관찰하였다. 조직응해구의 표피에서 미세응모가 관찰되었다. 조직융해구에는 3가지 형태의 세포들이 관찰되는 데, 첫째는 방추형이고, 핵 및 원형질이 전자밀도가 낮고, 원형질내 직경 $0.1-0.2{\;}\mu\textrm{m}$의 과립이 소수 관찰된다 둘째는 방추형이고, 핵 및 원형질이 전자밀도가 높고, 직경 $0.1-0.2{\;}\mu\textrm{m}$의 미립자로 구성된 과립을 포함한다 셋째는 원형질이 전자밀도가 높고, 직경 $0.3-1.2{\;}\mu\textrm{m}$의 과립을 다수 포함한다. 위의 세포들 중, 첫째와 둘째 세포는 표피세포로, 셋째는 조직응해구의 특 이 분비세포로 추정한다. 이것은 조직융해구의 분비 기능을 설명할 수 있는 또 다른 소견이라고 할 수 있다.

• 천문학회보
• /
• 제44권1호
• /
• pp.70.3-70.3
• /
• 2019

Understanding how the filamentary structure affects the formation of the prestellar cores and stars is a key issue to challenge. We use the Heterodyne Array Receiver Program (HARP) of the James Clerk Maxwell Telescope (JCMT) to obtain molecular line mapping data for two prestellar cores in different environment, L1544 in filamentary cloud and L694-2 in a small cloud isolated. Observing lines are $^{13}CO$ and $C^{18}O$ (3-2) line to find possible flow motions along the filament, $^{12}CO$ (3-2) to search for any radial accretion (or infalling motions) toward the cores of gas material from their surrounding regions, and $HCO^+$ (4-3) lines to find at which density and which region in the core gases start to be in gravitational collapse. In the 1st moment maps of $^{13}CO$ and $C^{18}O$, velocity gradient patterns implying the flow of material were found at the cores and its surrounding filamentary clouds. The infall asymmetry patterns of HCO+ and $^{13}CO$ line profiles were detected to be good enough to analyze the infalling motions toward the cores. We will report further analysis results on core formation in the filamentary cloud at this meeting.

• 대한안전경영과학회지
• /
• 제24권1호
• /
• pp.73-80
• /
• 2022

The purpose of this study is to present the direction of the plan to transform the residential complex into a space that can provide an open residential environment that can lead to social communication and exchange without being closed to the urban residential environment, especially in the apartment complex environment, which is becoming more dense. As a result of the Openness analysis of the 'Codan Shinonome Canal Court', the overall accessibility was good in terms of space utilization, and the openness was low in terms of the spatial composition, which is a physical environment due to the dense block type. When looking at the overall openness of the Codan Sinonome complex in terms of analysis by block, the corrected openness index (C.O.I) for all six blocks was 0.245, the corrected accessibility index (C.A.I) was 1.447 and the openness composite index (O.C.I) was assessed at 1.692. This was due to the formation of high-density block-type urban dwellings and the introduction of S-shaped streets and the layout of low-rise urban support facilities and commercial facilities. The Codan Sinonome Canal Court, which is considered an "open city residence," quantitatively confirmed that it embodies macro-space structure and human-scale space environment even in high-precision environments.

• 한국세라믹학회지
• /
• 제52권6호
• /
• pp.395-402
• /
• 2015

The suspension plasma spray (SPS) technique has been used to obtain dense $Y_2O_3$ coatings and to overcome the drawbacks of the conventional air plasma spray (APS). SPS uses suspensions containing micrometer or sub-micrometer sized powders dispersed in liquid media. In this study, microstructure developments and mechanical properties have been investigated as functions of particle size of source material and plasma processing parameters such as plasma power and stand-off distance. The microstructure of the coating was found to be highly related to the particle size and the plasma processing parameters, and it was directly reflected in the hardness and the adhesion strength. When fine powder (BET $16.4m^2/g$) was used as a raw material in the suspension, there was, with increasing stand-off distance, a change from a dense structure with a slightly bumpy surface to a porous structure with a cauliflower-like surface. On the other hand, when a coarse powder (BET $2.8m^2/g$) was used, the coating density was lower, with microscopic splats on the surface. Using fine $Y_2O_3$ powders, the coating layer with an optimum short stand-off distance showed a high hardness of approximately 90% of that of sintered $Y_2O_3$ and an adhesion strength several times higher than that of the coating by conventional APS.

• 천문학회보
• /
• 제42권2호
• /
• pp.40.2-40.2
• /
• 2017

At local, majority of galaxies in the dense environment, such as galaxy cluster, are red and quiescent with little star-formation (SF) activity. However, a different picture emerges as we go to high redshift: (1) there exist non-negligible fraction of galaxies still forming stars actively even in dense environment, and (2) there is a significant cluster-by-cluster variation in the SF properties, such as quiescent galaxy fraction. In this presentation, we show the results of our study about the variation of quiescent galaxy fraction among high-redshift (z~1) galaxy clusters, based on the multi-object spectroscopic (MOS) observation with IMACS on the Magellan telescope. Our main result is that galaxy clusters which are connected with significant large-scale structure (LSS), well beyond the cluster scale, are more active in their SF activity, i.e., the quiescent galaxy fraction for these clusters is lower compared to the clusters which are detached from LSS.

• 한국패류학회지
• /
• 제4권1호
• /
• pp.1-16
• /
• 1988

The authors observed histochemical and ultrastructural characters on the osphradium of Rapana venosa Valenciennes using light microscope, scanning and transmission electron microscpes. The results were as follows:1)The basic structure of osphradium was bipectinated shape, which consisted of a septum situating in the center of osphradium and numerous osphradial leaflets. On the other hand, Epidermis of ospradial leaflets formed the structure of pseudostratified ciliated columnar epithelium which was composed of an epithelial cell layer, a basal cel layer and a neuropile. 2) Ciliated dpithelial cells:A large number of these cells were observed on the lateral and ventral regions but a small number of them were observed on the dorsal region. These cells had cylindrical microvilli, slender mitochondria and serve fibers.3) Supporting cells: These cells had cylindrical microvilli, spongy layer, electron dense granules, mitochondria and nerve fibers4) Four types secretory epothelial cells: Four distinct types of secretory epithelial cells were recognized and were arbitrily designated as Type I, Type II, Type III and Type IV.cell type I: These cells contained electron denwe granules(diameter, 0.94-1.56${\mu}{\textrm}{m}$), well developed Golgi apparatus and rough endoplasmic reticula, cell type II: These cills contained two types of granules of the different electron density. One was high electron density granules which were 0.4-1.0${\mu}{\textrm}{m}$ in diameter, The other was low electron density granules which were 0.75-1.2${\mu}{\textrm}{m}$ in diameter.cell type III:These cells had fibrous secretory materials and exhibited strongly positive reaction with Toluidine blue.cell type IV:A large number of this type of cells were observed on the ventral region of ospgradial leaflets and positively reacted with periodic acid Schiff reagent. 5)Dark cells contained several electron dense cillaty rootlets and unmerous granules but cellular organelles were not observed.6) Four types basal cells: Four distinci types of basal cells were recognized and arbitrarily designated as Type I, Type II, Type III and Type IV.Cell type I(light cell): These cells exhibited low electuon density and contained short smooth endoplasmic reticula, several vacuoles and granules.