• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.133-138
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• 1991

Several quality indices of Shiitake mushroom (Lentinus edodes) were measured during storage at modified atmosphere (MA) conditions made by plyethylene film bag with different thicknes. IN the mushrooms kept in the thicker film bag, larger amounts of ethyl alcohol and acetaldehyde were produced during storage. The lowest weight loss was marked by the mushrooms kept in 0.06mm thick film bag. Protein content of the mushrooms was increased with the storage period without any storage period without any significant trend depended on the storage treatments and electrophoresis pattern of protein was changed little in the mushrooms kept in 0.04mm thick P.E. film bag during storage.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.432-439
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• 2004

Increase in water vapor barrier properties of sodium alginate films was studied by preparing composite films with fatty acids, i.e., lauric, palmitic, stearic, and oleic acids, and by treatment with 3% $CaCl_{2}$ solution for 3 min. Film thickness, surface color, microstructure, tensile strength (TS), elongation at break (E), water vapor permeability (WVP), water solubility (WS), and sorption isotherm of films were investigated. Microstructure of films observed with SEM was changed by fatty acid and $CaCl_{2}$ treatments. TS decreased 25-70% depending on fatty acid used, and increased 1.5- to 2-fold by $CaCl_{2}$ treatment. E decreased by both fatty acid and $CaCl_{2}$ treatments. Except oleic acid, WVP decreased significantly (p<0.05) by forming composite films with fatty acids, particularly with stearic acid, WVP decreased more than two-fold. WS also decreased by fatty acid and $CaCl_{2}$ treatments. In stearic acid, WS decreased about 30-fold by combined treatment of fatty acid and $CaCl_{2}$. Sorption isotherm showed typical biphasic pattern with deliquescent point of 0.75. Results of isotherms and BET monolayer moisture content indicated hydrophilicity of film decreased by $CaCl_{2}$ treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.71-74
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• 1996

Ta$_2$O$_{5}$ film ale recognized as promising capacitor dielectric for future DRAM\`s. The electrical properties of Ta$_2$O$_{5}$films greatly depend on the heating condition. In the practical fabrication process, several annealing process, such as the annealing of Al in H$_2$(about 40$0^{\circ}C$) and reflow of BPSG (borophosphosilicate glass) film in $N_2$(about 80$0^{\circ}C$), exist after deposition of Ta$_2$O$_{5}$ film. In this paper, we describe the temperature effect on the electrical properties of W/Ta$_2$O$_{5}$/Si structure. The thin film of Ta$_2$O$_{5}$ and tungsten have been deposited on p-si(100) wafer using the sputtering system. The heating temperature was varied from 500 to 90$0^{\circ}C$ in $N_2$for 30min and The degree of temperature is 100\`C. In a log(J/E$^2$) Vs 1/E plot of typical I-V data, we find a linear relationship for the temperature of 500, $600^{\circ}C$ and as deposition. This could indicate Fowler-Nordheim tunneling as the dominant mode of current transports. However, we can not find a linear relationship for the temperature above $700^{\circ}C$. This could not indicate Fowler-Nordheim tunneling as the dominant mode of current transport. The high frequency (1MHz) capacitance-voltage (C-V) of W/Ta$_2$O$_{5}$/Si Capacitor were investigated on the basis of shift in the threshold voltage and dielectric constant. The magnitude of the threshold voltage and dielectric constant depends on the heating temperature, and increases with heating temperature.temperature.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.134-140
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• 1997

PbTiO$_{3}$-PbZrO$_{3}$-Pb(Ni$_{1}$3/Nb $_{2}$3/O$_{3}$)(PZT-PNN) thin films were prepared from corresponding metal organics partially stabilized with diethanolamine by the sol-gel spin coating method. Each mol rates of PT:PZ:PNN solutions were #1(50:40:10), #2(50:30:20), #3(45:35:20) and #4(40:40:20), respectively. The spin-coated PZT-PNN films were sintered at the temperature from 500.deg. C to 600.deg. C for crystallization. The P-E hysteresis curve was drawn by Sawyer-Tower circuit with PZT-PNN film. The coercive field and the remanent polarization of #4(40:40:20 mol%) PZT-PNN film were 28.8 kV/cm and 18.3 .mu.C/cm$^{2}$, respectively. Their dielectric constants were shown between 128 and 1120, and became maximum value in MPB(40:40:20 mol%). The leakage currents of PZT-PNN films were about 9.4x 10$^{-8}$ A/cm$^{2}$, and the breakdown voltages were about 0.14 and 1.1 MV/cm. The Curie point of #3(45:35:20 mol%, sintered at 600.deg. C) film was 330.deg. C.

• Korean Journal of Materials Research
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• v.9 no.3
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• pp.274-281
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• 1999

Usually sputtering and electroless plating methods were used for manufacturing metal-alloy thin film magnetic memory devices. Since electroless plating method has many merits in mass production and product variety com­pared to sputtering method, many researches about electroless plating have been performed in the United State of America and Japan. However, electroless plating method has not been studied frequently in Korea. In these respects the purpose of this research is manufacturing Co-Mn-P alloy thin film on the corning glass 2948 by electroless plating method using sodium hypophosphite as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction 0$\alpha$urred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of $80^{\circ}C$. Also magnetic charac­teristics was found to be most excellent at the pH of 9 and the temperature of $70^{\circ}C$, resulting in the coercive force of 8700e and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was $0.216\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand,(1010), (0002), (1011) orientation of hcp for a-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-Mn-P alloy deposition, coercive force was about 1000e more than that of Co P alloy, but squareness had no difference. For crystal orientation, (l01O) and (lOll) orientation of $\alpha$-Co was dominant as same as that of Co- P alloy. Likewise we could confirm the formation of longitudinal magnetization.

• Food Science and Preservation
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• v.11 no.4
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• pp.565-568
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• 2004

To investigate the effect of soy protein film packaging on the quality of beef, the rate of weight loss, pH, 2-thiobarbituric acid reactive substance (TBARS), and microbial (total bacterial count) Salmonella spp., E. coli changes were determined during storage. Beef samples were packaged with soy protein film containing rosemary extract and then stored at $4^{\circ}C$. Soy protein film was effective on prevention of weight loss, compared with the control, regardless of addition of rosemary extract. Change in pH of soy protein films containing the rosemary extract (RPF) was less during storage, compared with the control. Packaging of beef products with RPF inhibited lipid oxidation by $86\%$ at day 8 of storage, compared to the control. RPF packaging also affected the microbial growth, resulting in retardation of total bacteria by more than 1 log cycle. These results indicate that storage of beef packaged with RPF should be appropriate in terms of quality as well as shelf-life.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.341-344
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• 1999

The effects of post annealing treatments of ferroelectrlclty in PZT(P $b_{1.05}$(Z $r_{0.52}$, $Ti_{0.48}$) $O_3$ thin film deposited on Pt/ $SiO_2$/Si substrate by RF-Magnetron sputtering methode was Investigated. Analyses by RTA(Rapid Thermal Annealing) treatments reveled that the crystallization process strongly depend on the healing temperature. The Perovskite structure with strong PZT (101) plan was obtained by RTA treatments at 75$0^{\circ}C$ With increasing RTA temperature of PZI thin films, the coercive field and remanent Polarization decreased, while saturation polarization( $P_{r}$) was decreased. P-E curves of Pt/PZT/Pt capacitor structures demonstrate typical hysteresiss loops. The measure values of $P_{r}$,. $E_{c}$ and dielectric constants by post annealed at 75$0^{\circ}C$ were 38 $\mu$C/$\textrm{cm}^2$ 35KV/cm and 974, respectively. Switching polarization versus fatigue characteristic showed 12% degradation up to 10$^{7}$ cycles.s.s.s.s.s.s.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1169-1174
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• 2011

CdTe thin-film solar cell technology is well known that it can theoretically improve its conversion efficiency and manufacturing costs compared to the conventional silicon solar cell technology, due to its optical band gap energy (about 1.45eV) for solar energy absorption, high light absorption capability and low cost requirements for producing solar cells. Although the prior studies obtained the high light absorption, CdTe thin film solar cell has not been come up to the sufficient efficiency yet. So, doping method was selected for the improvement of the electrical characteristics in CdTe solar cells. Some elements including Cu, Ag, Cd and Te were generally used for the p-dopant as substitutional acceptors in CdTe thin film. In this study, the sputtering-deposited CdTe thin film was immersed in $AgNO_3$ solution for ion exchange method to dope Ag ions. The effects of immersion temperature and Ag-concentration were investigated on the optical properties and electrical characteristics of CdTe thin film by using Auger electron spectroscopy depth-profile, UV-visible spectrophotometer, and a Hall effect measurement system. The best optical and electrical characteristics were sucessfully obtained by Ag doping at high temperature and concentration. The larger and more uniform diffusion of Ag ions made increase of the Ag ion density in CdTe thin film to decrease the series resistance as well as mede the faster diffusion of light by the metal ions to enhance the light absorption.

• Transactions on Electrical and Electronic Materials
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• v.4 no.2
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• pp.20-23
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• 2003

Piezoelectric powder with the composition of PbTiO$_3$-PbZrO$_3$-Pb(Mn$\_$1/3/Nb$\_$2/3/)O$_3$ and small particle size of 0.3 $\mu\textrm{m}$ was investigated for low-temperature firing of PZT thick films. PbTiO$_3$-PbZrO$_3$-Pb(Mn$\_$1/3/Nb$\_$2/3)O$_3$ ceramics showed dense microstructure and superior piezoelectric properties, electromechanical coupling factor (k$\_$p/) of 0.501 and piezoelectric constant (d$\_$33/) of 224. The PZT paste was made of the powder and organic vehicles, and screen-printed on Pt(450nm)/YSZ(110nm)/SiO$_2$(300nm)/Si substrates and fired at 800∼900$^{\circ}C$. Any interface reaction between the PZT thick film and the bottom electrode was not observed in the PZT thick films. The PZT thick film fired at 800$^{\circ}C$ showed moderate electrical properties, the remanent polarization(p$\_$r/) of 16.0 ${\mu}$C/$\textrm{cm}^2$, the coercive field(E$\_$c/) of 36.7 ㎸/cm, and dielectric constant ($\varepsilon$$\_$r/) of 531. Low-temperature sinterable piezoelectric composition and high activity of fine particles reduced the sintering temperature of the thick film. This PZT thick film could be utilized for piezoelectric microactuators or microsensors that require Si micromachining technology.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.145-150
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• 2004

Purpose: To compare three digital radiographic imaging sensors by evaluating the visibility of endodontic file tips with interobserver reproducibility and assessing subjectively the clarity of images in comparison with the x-ray film images. Materials and Methods: Forty-five extracted sound premolars were used for this study. Fifteen plaster blocks were made with three premolars each and #8, 10, 15 K-flexofiles were inserted into the root canal of premolars. They were radiographically exposed using periapical x-ray films (Kodak Insight Dental film, Eastmann Kodak company, Rochester, USA), Digora imaging plates (Soredex-Orion Co., Helsinki, Finland), CDX 2000HQ sensors (Biomedisys Co., Seoul, Korea), and CDR sensors (Schick Inc., Long Island, USA). The visibility of endodontic files was evaluated with interobserver reproducibility, which was calculated as the standard deviations of X, Y coordinates of endodontic file tips measured on digital images by three oral and maxillofacial radiologists. The clarity of images was assessed subjectively using 3 grades, i.e. plus, equal, and minus in comparison with the conventional x-ray film images. Results: Interobserver reproducibility of endodontic file tips was the highest in CDR sensor (p < 0.05) only except at Y coordinates of #15 file. In the subjective assessment of the image clarity, the plus grade was the most frequent in CDR sensor at all size of endodontic file (p < 0.05). Conclusion : CDR sensor was the most superior to the other sensors, CDX 2000HQ sensor and Digora imaging plate in the evaluation of interobserver reproducibility of endodontic file tip and subjective assessment of image clarity.