• Korean Journal of Materials Research
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• v.4 no.6
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• pp.662-668
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• 1994

The physical and electrical characteristics of sub-l0nm thick capacitor dielectrics formed by wet oxidation of silicon nitride(oxide/nitride composite) and by removing the top oxide of oxidized silicon nitride(0xynitride) are described. For the capacitors with an oxide/nitride composite layer, the capacitance decreases sharply, but the breakdown field increases with an increase in the wet oxidation time at $900^{\circ}C$. For the capacitors with oxynitride layers, the values of both the capacitance and the breakdown field increase with increasing wet oxidation time. The reduction of effective thickness and the improved quality of oxynitride film are responsible for the improved capacitance and increased breakdown fields, respectively. In addition, intrinsic TDDB characteristics and early breakdown failure rate of oxynitride film are improved with increasing oxidation time. Consequently, the oxynitride film is suitable for dynamic memories as a thin dielectric film.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.777-785
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• 2010

The effect of two doses of different sources of zinc, inorganic (zinc oxide) or chelated (zinc glutamate chelate), on morphology and turn-over of the small intestine was assessed in early-weaned pigs orally challenged with enterotoxigenic E. coli K88 (ETEC). Sixty pigs weaned at 21 days were assigned to one of the following 5 diets: control (C); C+Zinc oxide (ZnO), either a 200 or a 2,500 mg Zn/kg dose; or C+zinc chelate with glutamic acid (Glu-Zn), either a 200 or a 2,500 mg Zn/kg dose. On d 2, the pigs were orally inoculated with 1.5 ml of a $10^{10}$ CFU/ml E. coli K88ac O148 suspension. Zinc supplements did not improve the performance of the pigs, but on d 5 faecal excretion of ETEC was reduced, and this was mainly due to high zinc doses (p<0.05). The villous height in the duodenum was improved by the zinc supplements (p<0.01) whatever the source and the level, whereas no effect was seen in the other two tracts of small intestine. The diet did not affect apoptosis and mitosis counts, while ETEC-susceptible pigs had more mitotic cells in the villi than non-susceptible pigs, particularly in the jejunum (p<0.01). The duodenum had fewer mitotic cells in the villi (p<0.05) and in the crypts (p<0.01) and more apoptotic cells in the villi. High dietary doses of ZnO or Zn-Glutamate improve villous height of the duodenum, but not of the jejunum and the ileum, and do not affect the epithelial proliferative activity and apoptotic index of intestinal mucosa of early-weaned pigs orally challenged with ETEC.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.341-341
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• 2012

Recently, oxide semi-conductor materials have been investigated as promising candidates replacing a-Si:H and poly-Si semiconductor because they have some advantages of a room-temperature process, low-cost, high performance and various applications in flexible and transparent electronics. Particularly, amorphous indium-gallium-zinc-oxide (a-IGZO) is an interesting semiconductor material for use in flexible thin film transistor (TFT) fabrication due to the high carrier mobility and low deposition temperatures. In this work, we demonstrated improvement of flexibility in IGZO TFTs, which were fabricated on polyimide (PI) substrate. At first, a thin poly-4vinyl phenol (PVP) layer was spin coated on PI substrate for making a smooth surface up to 0.3 nm, which was required to form high quality active layer. Then, Ni gate electrode of 100 nm was deposited on the bare PVP layer by e-beam evaporator using a shadow mask. The PVP and $Al_2O_3$ layers with different thicknesses were used for organic/inorganic multi gate dielectric, which were formed by spin coater and atomic layer deposition (ALD), respectively, at $200^{\circ}C$. 70 nm IGZO semiconductor layer and 70 nm Al source/drain electrodes were respectively deposited by RF magnetron sputter and thermal evaporator using shadow masks. Then, IGZO layer was annealed on a hotplate at $200^{\circ}C$ for 1 hour. Standard electrical characteristics of transistors were measured by a semiconductor parameter analyzer at room temperature in the dark and performance of devices then was also evaluated under static and dynamic mechanical deformation. The IGZO TFTs incorporating hybrid gate dielectrics showed a high flexibility compared to the device with single structural gate dielectrics. The effects of mechanical deformation on the TFT characteristics will be discussed in detail.

• Journal of Information Display
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• v.7 no.3
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• pp.13-18
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• 2006

Currently, the flexible organic light emitting devices (OLEDs) are investigated. They are very vulnerable to moisture, and thus have been found to show some problems. Thus, an effective barrier layer is needed to protect from moisture in air. We deposited thin films with magnesium oxide (MgO) and silicon oxide $(SiO_{2})$ compounds mixed at various mixture ratios on flexible polyether sulfone (PES) substrates by an electron-beam evaporator to investigate their applizability for transparent barrier applications. In this study, we found that as the MgO fraction increased, thin films comprised of MgO and $(SiO_{2})$ compounds became more amorphous and their surface morphologies become smoother and denser. In addition, zirconium oxide $(ZrO_{2})$ was added to the above-mentioned compound mixtures. $ZrO_{2}$ made thin mixture films more amorphous and made the surface morphology denser and more uniform. The water vapor transmission rates (WVTRs) of the whole films decreased rapidly. The best WVTR was obtained by depositing thin films of Mg-Si-Zr-O compound among the whole thin films. As the thin mixture films became more amorphous, and the surface morphology become denser and more uniform, the WVTRs decreased. Therefore, the thin mixture films became more suitable for flexible OLED applications as transparent passivation layers against moisture in air.

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.1-5
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• 2008

In this work, improvement of mechanical and electrical properties of gate dielectric layer for flexible organic thin film transistor (OTFT) devices was investigated. In order to increase the mechanical flexibility of PVP (poly(4-vinyl phenol) organic gate dielectric, a very thin inorganic $HfO_2$ layers with the thickness of $5{\sim}20nm$ was inserted in between the spin-coated PVP layers. Insertion of the inorganic $HfO_2$ in the laminated organic/inorganic structure of PVP/$HfO_2$/PVP layer led to a dramatic reduction in the leakage current compared to the pure PVP layer. Under repetitive cyclic bending, the leakage current density of the laminated PVP/$HfO_2$/PVP layer with the thickness of 20-nm $HfO_2$ layer was not changed, while that of the single PVP layer was increased significantly. Mechanical flexibility tests of the OTFT devices by cyclic bending with 5 mm bending radius indicated that the leakage current of the laminated PVP/$HfO_2$(20 nm)/PVP gate dielectric in the device structure was also much smaller than that of the single PVP layer.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.55-62
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• 2021

This study aims to reduce the rancid odor generated during the fermentation process of kimchi by inserting zinc oxide (ZnO) into an inorganic porous material with a high surface area to decompose or adsorb the fermentation odor. ZnO activated by the presence of moisture exhibits decomposition of rancid odors. Mixed with Titanium dioxide (TiO₂), a photocatalyst. To manufacture the packaging liner used in this study, NaOH, ZnCl₂, and TiO₂ powder were placed in a tank with diatomite and water. The sludge obtained via a hydrothermal ultrasonication synthesis was sintered in an oven. After being pin-milled and melt-blended, the powders were mixed with linear low-density polyethylene (L-LDPE) to make a masterbatch (M/B), which was further used to manufacture liners. A gas detector (GasTiger 2000) was used to investigate the total amount of sulfur compounds during fermentation and determine the reduction rate of the odor-causing compounds. The packaging liner cross-section and surface were investigated using a scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS) to observe the adsorption of sulfur compounds. A variety of sulfur compounds associated with the perceived unpleasant odor of kimchi were analyzed using gas chromatography-mass spectrometry (GC-MS). For the analyses, kimchi was homogenized at room temperature and divided into several sample dishes. The performance of the liner was evaluated by comparing the total area of the GC-MS signals of major off-flavor sulfur compounds during the five days of fermentation at 20℃. As a result, Nano-grade inorganic compound liners reduced the sulfur content by 67 % on average, compared to ordinary polyethylene (PE) foam liners. Afterwards SEM-EDS was used to analyze the sulfur content adsorbed by the liners. The findings of this study strongly suggest that decomposition and adsorption of the odor-generating compounds occur more effectively in the newly-developed inorganic nanocomposite liners.

• Journal of Powder Materials
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• v.5 no.3
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• pp.199-209
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• 1998

A new low melting inorganic binder, monoclinic $HBO_2$, has been developed for Selective Laser Sintering (SLS) of alumina powder by dehydration process of boron oxide powder in a vacuum oven at $120^{\circ}C$. It led to better green SLS parts and higher bend strength far green and fired parts compared to other inorganic binders such as aluminum and ammmonium phosphate. This appeared to be due to its low viscosity and better wettability of the alumina particle surface. A low density single phase ceramic, aluminum borate ($Al_{18}B_4O_{33}$), and multiphase ceramic composites, $A_{12}O_3-A_{14}B_2O_9$, were successfully developed by laser processing of alumina-monoclinic $HBO_2$ powder blends followed by post-thermal processing; both $Al_{18}B_4O_{33}$ and $A_{14}B_2O_9$ have whisker-like grains. The physical and mechanical properties of these SLS-processed ceramic parts were correlated to the materials and processing parameters. Further densification of the $A_{12}O_3-A_{14}B_2O_9$ ceramic composites was carried out by infiltration of colloidal silica, and chromic acid into these porous SLS parts followed by heat-treatment at high temperature ($1600^{\circ}C$). The densities obtained after infiltration and subsequent firing were between 75 and 80% of the theoretical densities. The bend strengths are between 15 and 33 MPa.

• Journal of the Korean institute of surface engineering
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• v.41 no.3
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• pp.102-108
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• 2008

In this paper, the LiF and polymer thin film as passivation layer have been evaporated on green OLED devices. HDPE, polyacenaphthylene, polytetrafluoroethylene, poly(2,6-dimethyl-1,4-pheneylene oxide), poly sulfone and poly(dimer-acid-co-alkyl poly-amine) have been used as polymer materials. The optical transmittance of evaporated polymer thin film was very good as an above 90% in visible range. The morphology of polymer thin film was measured by AFM. As a result of the measurement average roughness($R_a$) value of the polysulfone was very low as 2.2 nm. The green OLED devices with a structure of ITO/HIL/HTL/EML/Buffer/Al in series of various passivation films were fabricated and analyzed. It was observed that an OLED device with LiF as first passivation film has shown the good electrical and optical property, and all kind of polymer films did not influence on the I-V-L characteristics and the life time of OLED devices. Therefore, we found that polymer layer played a key role as a buffer layer between the inorganic passivation layers to relieve the stress of the inorganic layers.

• Composites Research
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• v.19 no.6
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• pp.32-37
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• 2006

This paper summarizes the processing inorganic continuous fibers from Korean minerals. Continuous filament fibers have been produced from two rocks, basalt and quartz diorite porphyry(QDP), by melting method. The essence of the method is that the vitrified materials was placed into the bushing, platinum/rhodium alloy crucible with a nozzle, and heated electrically to a temperature which allowed fiber spinning. Vitrified basalt without additive was suitable for producing continuous filament fiber. However doping quartz diorite porphyry with boric oxide yielded a material which could be pulled continuously.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.160-160
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• 2009

In recent years, the merging of nanomaterials and nano-technology into electro-optic (EO) device technology such as liquid crystal displays (LCDs) has attracted much attention because of their unique electro- and magneto-optic properties and novel display applications. One example of hybrid LC-inorganic systems is semiconductor nanorods added to LC for their strong reorientation effect and tunable refractive index. Doping of nanoparticles in LC or polymers can lead to changes in performance characteristics such as electro-optical, dielectric, memory effect, phase behavior, etc. Due to the tunability of LCDs with mixed inorganic materials, low voltage operation of a LC system can also be achieved using the significant electro-optical effect achieved through suspension of ferroelectric nanoparticles in NLC.