• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.62-72
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• 2001

To elucidate the behaviors of alkali swelllng of woods. the dimensional change in cross section of cell elements of four major Korean woods during alkali swelling were examined by an optical microscory, an imaging analysis method and an X-ray diffrartion During alkali swelling, tracheid diameter of Larix kaempferi wood showed greater swelling property than that of Pinus koraiensis wood, and the cell wall swelled highly over 10% sodium hydroxide solution treatment. The radial diameter of vessel elements in earlywood shrunk, but it swelled slightly in tangential direction. When treated with 5% NaOH, the wall thickness of wood fiber increased about three times over the original one. The thickness of cell wall in all elements and the diameter of wood fiber and tracheid showed almost isotropic shrinkage. The diameter of cell elements during the mercerization process decreased, but cell wall thickness Increased. Crystal transformation of cellulose in wood was not occurred by alkali treatments. but relative crystallinity and crystallite width of the woods increased slightly. Consequently, it was demonstrated that the swelling properties of woods were dependant on wood species, cell elements and alkali concentration.

• Clean Technology
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• v.16 no.4
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• pp.297-303
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• 2010

Effect of interconnect structure on the cell performance in anode-supported tubular solid oxide fuel cell (SOFC) has been investigated in this study, employing the Fluent CFD solver. For the robust and reliable theoretical analysis corroborating experimental results, it is of great importance to elucidate the role of interconnect which is electrically connected with electrodes on the cell characteristics. From the fact that the thin interconnect provides the enhanced cell performance, it is revealed that the interconnect thickness is a key parameter that is able to effectively control the ohmic resistance. Under the constant thickness condition, the cell performance does not considerably change with the variation of interconnect width. This is because the current passage along with circumferential direction is not effectively altered by the change of interconnect width in tubular SOFC system.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1582-1584
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• 2001

In ac plasma display(PDP), an image quality mainly depends on the contrast ratio. And the contrast ratio is affected by the driving condition and size of discharge cell. In this study, the electrical and optical characteristics during reset, address and sustain discharge were investigated as the height and width of barrier rib were varied in order to obtain the highest contrast ratio. As a result, the optimum rib height and width were 140${\mu}m$ and 600${\mu}m$, respectively.

• ALGAE
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• v.22 no.3
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• pp.147-152
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• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.65-69
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• 2017

This paper presents a Technology-CAD (TCAD) simulation of the characteristics of crystalline Si pillar array solar cells. The junction depth and the surface concentration of the solar cells were optimized to obtain the targeted sheet resistance of the emitter region. The diffusion model was determined by calibrating the emitter doping profile of the microscale silicon pillars. The dimension parameters determining the pillar shape, such as width, height, and spacing were varied within a simulation window from ${\sim}2{\mu}m$ to $5{\mu}m$. The simulation showed that increasing pillar width (or diameter) and spacing resulted in the decrease of current density due to surface area loss, light trapping loss, and high reflectance. Although increasing pillar height might improve the chances of light trapping, the recombination loss due to the increase in the carrier's transfer length canceled out the positive effect to the photo-generation component of the current. The silicon pillars were experimentally formed by photoresist patterning and electroless etching. The laboratory results of a fabricated Si pillar solar cell showed the efficiency and the fill factor to be close to the simulation results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.851-856
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• 2017

Research on the edge isolation process of typical polycrystalline silicon solar cells was carried out using laser scribing equipment. The voltage-current characteristics of the solar cell before and after laser scribing were analyzed using a solar simulator. Current density and efficiency increased as the fill factor of the solar cell remained constant after the laser scribing process. The efficiency of the solar cell can be increased in a short time by the edge isolation process performed via a laser scribing process. The polycrystalline silicon solar cell was made into a series electrode, and the efficiency of the solar cell increased because the width of the solar cell was narrowed and the active region was widened by the laser scribing process.

• Journal of the Korean Society of Visualization
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• v.9 no.1
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• pp.29-35
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• 2011

In this paper, we applied various microfluidic chambers to visualize cell migration and measured the migration velocity in microchannels. Migration speed of B16 cell in a large channel was similar with that of wound healing experiment. However, the speed decreased gradually as the cell move inside of the channel. It is expected that this phenomenon is due to the shortage of oxygen or nutrition, whichare essential for cell growth. In the case of cell in the small channel whose size is smaller than the cell, its speed was slower than that in a larger channel.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.254-259
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• 1987

This paper describes the CMOS standard cell library implemented in double metal single poly gate process with 3\ulcornerm design rule, and its results of testing. This standard cell library contains total 33 cells of random logic gates, flip-flop gates and input/output buffers. All of cell was made to have the equal height of 98\ulcornerm, and width in multiple constant grid of 9 \ulcornerm. For cell data base, the electric characteristics of each cell is investigated and delay is characterized in terms of fanout. As the testing results of Ring Oscillator among the cell library, the average delay time for Inverter is 1.05 (ns), and the delay time due to channel routing metal is 0.65(ps)per unit length.

• Korean Journal of Veterinary Research
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• v.64 no.2
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• pp.9.1-9.7
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• 2024

Myxomatous mitral valve disease (MMVD) is a degenerative disease of the valve leaflets, causing left atrial dilatation and eccentric hypertrophy of the left ventricle by hemodynamic instability. Red cell distribution width (RDW) is a hematologic parameter that indicates the variation of red blood cell volume and size, reflecting anisocytosis. Human studies have found that anisocytosis is associated with poor prognosis in heart disease patients, and recent veterinary studies have also confirmed that the increase in RDW is associated with high mortality in MMVD patients. Medical records of 37 Maltese dogs with MMVD were retrospectively reviewed. When comparing RDW among the MMVD stage groups, there was a significant difference between stage B1, B2 and C. A significant and strong correlation between RDW and the left atrial-to-aortic ratio was identified. RDW was significantly correlated with the reticulocyte count independent of hematocrit, and the reticulocyte count exhibited a significant increase at stage C. This suggests that the congestive heart failure secondary to MMVD could be a contributory factor leading to an elevation in RDW. In conclusion, elevated RDW may associated with left atrial enlargement and progression of MMVD.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.137-142
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wildtype ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.