• Korean Journal of Medicinal Crop Science
• /
• 제15권5호
• /
• pp.346-351
• /
• 2007

An efficient somatic embryogenesis and plant regeneration protocol was developed for Schisandra chinensis Baill, using embryogenic cell suspensions and optimized media conditions. Friable embryogenic callus was induced from cotyledonary leaf and hypocotyl explants of 7 days old seedlings on MS agar medium supplemented with 1.0 to $4.0\;mg\;l^{-1}$ of 2,4-dichlorophenoxyacetic acid (2,4-D). Fast growing and well dispersed embryogenic cell suspensions were developed within two months when embryogenic calli were transferred to MS liquid medium containing $1.0\;mg\;l^{-1}\;2,4-D$. One third strength of MS medium was the best for both overall growth and development of somatic embryos in liquid culture. Over 3400 viable somatic embryos were produced from each 150 ml flask with an initial cell density of 30 mg in 30 ml medium. Germinated somatic embryos developed in liquid medium converted into plantlets after transferred to half-strength MS semi-solid medium. Approximately 90% of the converted plantlets were successfully transplanted to soil and grew into fertile plants.

• Polymer(Korea)
• /
• 제28권4호
• /
• pp.298-304
• /
• 2004

We fabricated a polymer dispersed liquid crystal (PDLC) cell using LC with negative dielectric anisotropy and UV curable monomer exhibiting transparent state initially (called normally transparent (NT)) and studied the electro-optic characteristics. The NT PDLC cell made with the ratio of LC : monomer = 70/30 wt%, curing temperature of 20 $^{\circ}C$ and strong UV intensity of 198 ㎽/$\textrm{cm}^2$ had high contrast ratio and showed good electro-optic characteristics. In this condition, LC is aligned vertically on the substrate due to the vertical alignment layer and the polymer made with the UV exposure does not influence the alignment of the LC much. Therefore, the transmittance at the zero voltage is very high and the scattering state of the cell is good after applying the voltage because LC with negative dielectric anisotropy tries to align perpendicular to the field. And also, the NT PDLC cell showed better viewing angle characteristics than that in the normally scattering (NS) PDLC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
• /
• pp.61-62
• /
• 2009

Electro-optical properties of liquid crystal display (LCD) using fringe-field switching (FFS) devices depend on many parameters such as cell retardation, electrode structure, magnitude and sign of dielectric anisotropy, rubbing angle and cell gap. In this paper, the light efficiency of FFS device depending on magnitude of positive dielectric anisotropy with other cell parameters such as rubbing angle and angle and cell gap have been explored compared with FFS device using LC with negative dielectric anisotropy.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 1997년도 하계학술대회 논문집 C
• /
• pp.1585-1587
• /
• 1997

We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in the cell with slanted non-polarized ultraviolet (UV) light irradiation on two kinds of the polyimide (PI) film. It was shown that the monodomain alignment in NLC is obtained in the cell with slanted non-polarized UV light irradiation on PI surface. The pretilt angle of NLC is generated about 3 degrees in the cell with slanted non-polarized UV light irradiation with 70 degrees on PI surface without side chain. But, the pretilt angle of NLC is generated about 1 degree in the cell with slanted non-polarized UV light irradiation with 80 degrees on PI surface with side chain. We consider that the pretilt angle generation in NLC is attributted to anisotropic dispersion force between the LC molecular and the PI surface.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.614-615
• /
• 2009

For the high reflectance under the ambient light condition, a highly efficient diffractive reflector has been proposed, based on a micro grating structure.[1] This reflector was designed to show highly concentrated distribution of the reflected light to the normal direction of the reflector under specific incident conditions of the light. In order to apply a diffractive reflector to a reflective liquid crystal display, the coupling between the viewing angle characteristics of a liquid crystal (LC) cell and the reflective distribution of the reflector should be considered. Under the optimum configuration confirmed through the analysis of the coupling between a LC cell and a reflector, a reflective vertical alignment (VA) cell with a diffractive reflector shows contrast ratio and brightness much higher than that with a conventional bumpy reflector.

• Design & Manufacturing
• /
• 제14권2호
• /
• pp.1-6
• /
• 2020

Recently, research and commercialization related to the field of cell-based therapeutic drug development has been actively conducted. In order to maintain cell viability and prevent contamination, refrigeration preservation devices, such as CRF (controlled rate freezer) or vapor type LN2 tanks have been developed. On the other hand, the storage container for liquid nitrogen tanks currently on sale minimizes the flow structure to prevent structural defects when stored in a liquid nitrogen tank having a high thermal conductivity than vapor nitrogen. If the cell-based treatment drug is stored in the gaseous LN2 tank as it is, the cell survival after thawing is greatly reduced. It was estimated that the existing storage container structure was a factor that prevented the rapid entry and circulation of gaseous nitrogen into the container. Therefore, this study intends to propose a new supercellular storage container model that can maintain the mechanical strength while maximizing the fluid flow structure. To this end, we estimated that the structural change of the storage container effects on the equivalent stress formed around the through-holes of them when exposed to a cryogenic environment using thermal-structural coupled field analysis. As a result of storage experiments in the gas phase tank of the cell-based therapeutic agent using the developed storage container, it was confirmed that the cell growth rate was improved from 66% to 77%, which satisfied the transportation standards of the FDA(Food and Drug Administration) cell-based therapeutic agent.

• Journal of the Korean Wood Science and Technology
• /
• 제20권4호
• /
• pp.57-64
• /
• 1992

The unique cell wall micropores of pulp fiber can be utilized as loading site in variety of important practical application which could be the basis of new papermaking technologies. One of these includes the manufature of paper containing higher levels of in situ filler precipitated. Hardwood pulp fiber were first impregnated with the solution of sodium carbonate($Na_2CO_3$). The micropores in cell wall of pulp fibers were filled with the liquid salt solution. The second calcium nitrate($Ca(NO_3)_2$) solution formed an insoluble calcium carbonate($CaCO_3$) precipitate within the cell wall micropores by interacting with the first sodium carbonate solution. The effects of chemical concentration and dryness of pulp fibers on the retention of cell wall micropore loaded filler were investigated. The paper properties of cell wall micropore loaded pulp fibers were compared with those of conventionally loaded and lumen loaded pulp fibers. Also the presense of the fillers within the cell wall micropore was observed by SEM. Increasing the chemical concentration to generate the calcium carbonate increased the retention of filler in cell wall micropore loaded pulp fibers. The particle size distribution of precipitated calcium carbonate ranged from $0.1{\mu}m$ to $80{\mu}m$. But, the average particle size of cell wall micropore loaded calcium carbonate was $4{\mu}m$. The paper made from never dried pulp fibers, the cell wall micropores which were filled with calcium carbonate, had better mechanical and optical properties than those of conventionally loaded or lumen loaded pulp fibers.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.843-846
• /
• 2004

For the fast growing Liquid Crystal Display (LCD) TV market, it is essential to make the LCD panels to show moving images without any visual difficulties such as blurring or tailing. Owing to reduction of the cell gap and the improved Liquid Crystal (LC) mixtures with low viscosity, it is possible that our S-IPS TFT-LCDs feature a response time (R/T) as fast as 1-frame time (16ms) for a white-black operation and less than a 16rns in all gray levels without Over Driving Circuit (ODC) technology. Currently, mass production of the large size IPS panels with high speed has been successfully achieved. In order to achieve faster response time, new LC mixtures have been developed, optimizing the physical properties of rotational viscosity (${\gamma}$1) and elastic constants (Kii). Also, the LC mixtures with high elastic constant allow us to increase the cell gap. In this paper, realization of fast switching time in IPS mode with optimized '${\gamma}$1/Kii' parameter in the LC mixtures forms the core of this paper.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• 제16권2호
• /
• pp.109-115
• /
• 2023

In this paper, we demonstrated the orientation characteristics of liquid crystals using UV-treated FSAM as alignment layer. Moreover we confirmed the FSAM properties before and after UV treatment on indium tin oxide (ITO) glass substrates using physicochemical analysis. The hydrophobic property of the FSAM surface is change to hydrophilic through UV treatment. After UV treatment the LC molecules also were uniformly and horizontally aligned on the FSAM surfaces and the pretilt angle was obviously changed 90° degrees to 0° degrees. EO characteristic of TN cell which was fabricated with UV-treated FSAM was faster response time compare to conventional PI layer. The FSAM before and after UV treatment has a superior application potential as the LC alignment layer for LCD, potentially replacing the conventional polyimide layer.

• Proceedings of the IEEK Conference
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.515-516
• /
• 2008

We studied about new module technology to solve warpage problems that produce bending of cell in the LCD (Liquid crystal display). Characteristics of cell gap and glass bending of applying heat Panel's PAD part and cell at various temperature was investigated. When applies heat and compresses PAD party only in case of compressing COG(Chip on Glass), uniformity of cell gap that happen by glass bending by temperature of these compressing COG in the PAD party is decreased.