• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.11
• /
• pp.1014-1019
• /
• 2006

The influence of the number of solution coatings on the densification of the PZT thick films was studied. PZT powder and PZT precursor solution was prepared by a sol-gel method and PZT thick films were fabricated by the screen-printing method on the alumina substrates. The powder and solution of composition were (A) PZT(80/20)/PZT(20/80), (B) PZT(70/30)/PZT(30/70) and (C) PZT(60/40)/PZT(40/60), (D) PZT(52/48)/PT. The coating and drying procedure was repeated 4 times. And then the PZT precursor solution was spin-coated on the PZT thick films. A concentration of a coating solution was 0.5 moth and the number of coating was repeated from 0 to 6. The porosity of the thick films was decreased with increasing the number of coatings and the PZT thick films with 6-times coated showed the dense microstructure and thickness of about $60{\mu}m$. A grain size was increased with increasing the coating number. All PZT thick films showed the typical XRD patterns of a typical perovskite polycrystalline structure. The relative dielectric constant of PZT thick films was improved 30-100% as the number of coatings.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.9
• /
• pp.1347-1353
• /
• 2006

Effects of microencapsulated chitooligosaccharide addition in milk were evaluated by determination of the efficiency of microencapsulation, cholesterol removal, color, viscosity and sensory properties. Coating material was polyglycerol monostearate (PGMS) and the efficiency of microencapsulation was 88.08% at a 10:1 ratio of coating to core materials (w/w). When 0.5% of microencapsulated chitooligosaccharide was added into milk, the color values (L, a, and b) and viscosity were significantly different from those of noncapsulated chitooligosaccharide-added groups (p<0.05). The release of chitooligosaccharide from microcapsules was 7.6% in milk at $4^{\circ}C$ for 15-day storage. In both 0.5 and 1.5% microencapsulation addition, the scores of all sensory characteristics except for off-flavor were significantly different between encapsulated chitooligosaccharide and noncapsulated chitooligosaccharide-added groups during all periods of storage. The present study indicated that chitooligosaccharide microcapsules could be applicable into commercial milk with little adverse effects on physical and sensory properties.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.4
• /
• pp.1-9
• /
• 2016

The purpose of this study was to compare heat shading performance of various blind types in summer. 4 types of blinds were employed and the results are summarized as follows: 1) There were significant differences in indoor thermal environment and heat shading performance between different heat shading devices, and functional blinds demonstrated relatively superior heat shading performance. 2) Indoor long wave radiation influx measures were lowest for the coating roll blind (Blind B), followed by the coating venetian blind (Blind C), the venetian blind (Blind A), the roll blind, and not having any blinds at all. 3) Such examination results carry implications to reduce cooling load and enhance the indoor environment.

• Microbiology and Biotechnology Letters
• /
• v.23 no.2
• /
• pp.236-242
• /
• 1995

Biological control of soilborne plant pathogens by the addition of antagonistic microorganisms to the soil may offer a practical supplement or alternative to existing disease management strategies that depend heavily on chemical pesticides. Soil amendment with antagonistic microbes was non-effective because of high cost, low efficacy, and inconvenient usage on the treatment course. Therefore, seed coating formulation for the application of biological seed treatments has been being to apply successful disease suppression for many important crops. The objectives of this study were to investigate the optimal condition for the spore production of biocontrol agent Bacillus subtilis YBL-7 and the liquid coating formulation that contained a suspension of a proper aqueous binder, as well as a ground fine solid particulate material. The maximum yield has been obtained from 60 hrs-old culture at 30$\circ$C in spore forming (SF) medium containing 0.8% nutrient broth, 0.05% yeast extract, 10$^{-1}$ M MgCl$^{2}$, 10$^{-4}$ M MnCl$^{2}$, 10$^{-5}$ M dipicolinic acid, and pH 6.5. The optimal condition of dried spore preparation was achieved when cells of B. subtilis YBL-7 was heat-dried with 50$\circ$C for 2 hrs.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.12
• /
• pp.2019-2027
• /
• 2013

In this study, we tried to develop a coating agent for the fresh-cut fruits used in cakes. First, the coating agent mixing ratios of sugar, pectin, sodium alginate, carrageenan, xanthan gum, vitamin C, and purified water were selected to be 55, 2, 2, 0.04, 0.1, 0.05, and 40.81% (w/w), respectively. In a freeze-thaw stability of the coating agent, the viscosity remained constant for 3 cycles of freezing and thawing repetition process, but showed a slightly decreasing trend in the 4th repetition process (P<0.05). On the other hand, the sugar content, pH, and chromaticity remained constant even in the 4th repetition process. Pineapple coated with the coating agent had smaller weight loss, hardness changes, and total bacteria distribution compared to the uncoated pineapple (P<0.05). In the chromaticity, both of the two pineapples experienced browning with increasing storage duration, as L value decreases and b value increases. However, when the color difference was compared, the progress of browning for the uncoated pineapple was faster than the coated pineapple. Also, the progress of browning at $4^{\circ}C$ was found to be slower than the progress of browning at $25^{\circ}C$. Therefore, the storage stability of the fresh-cut fruits could be improved by coating the fresh-cut fruits for cakes with the coating agent and storing at a low temperature, which would contribute to extending the shelf-life of cakes.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.5
• /
• pp.1516-1522
• /
• 2014

A series of 20 wt % $(NH_4)_2SO_4$ and 3 wt % $Al_2O_3$ surface treatments were applied to $Li[Li_{0.2}Mn_{0.54}Co_{0.13}Ni_{0.13}]O_2$ substrates. The $Li[Li_{0.2}Mn_{0.54}Co_{0.13}Ni_{0.13}]O_2$ substrates were synthesized using a co-precipitation method. Sample (a) was left pristine and variations of the 20 wt % $(NH_4)_2SO_4$ and 3 wt % $Al_2O_3$ were applied to samples (b), (c) and (d). XRD was used to verify the space group of the samples as R$\bar{3}$m. Additional morphology and particle size data were obtained using SEM imagery. The $Al_2O_3$ coating layers of sample (b) and (d) were confirmed by TEM images and EDS mapping of the SEM images. 2032-type coin cells were fabricated in a glove box in order to investigate their electrochemical properties. The cells were charged and discharged at room temperature ($25^{\circ}C$) between 2.0V and 4.8V during the first cycle. The cells were then charged and discharged between 2.0V and 4.6V in subsequent cycles. Sample (d) exhibited lower irreversible capacity loss (ICL) in the first charge-discharge cycle as compared to sample (c). Sample (d) also had a higher discharge capacity of ~250 mAh/g during the first and second charge-discharge cycles when compared with sample (c). The rate capability of the $Al_2O_3$-coated sample (b) and (d) was lower when compared with sample (a) and (c). Sample (d), coated with $Al_2O_3$ after the surface treatment with $(NH_4)_2SO_4$, showed an improvement in cycle performance as well as an enhancement of discharge capacity. The thermal stability of sample (d) was higher than that of the sample (c) as the result of DSC.

• Journal of Powder Materials
• /
• v.18 no.5
• /
• pp.430-436
• /
• 2011

Joining of NiO-YSZ to 316 stainless steel was carried out with B-Ni2 brazing alloy (3 wt% Fe, 4.5 wt% Si, 3.2 wt% B, 7 wt% Cr, Ni-balance, m.p. 971-$999^{\circ}C$) to seal the NiO-YSZ anode/316 stainless steel interconnect structure in a SOFC. In the present research, interfacial (chemical) reactions during brazing at the NiO-YSZ/316 stainless steel interconnect were enhanced by the two processing methods, a) addition of an electroless nickel plate to NiO-YSZ as a coating or b) deposition of titanium layer onto NiO-YSZ by magnetron plasma sputtering method, with process variables and procedures optimized during the pre-processing. Brazing was performed in a cold-wall vacuum furnace at $1080^{\circ}C$. Post-brazing interfacial morphologies between NiO-YSZ and 316 stainless steel were examined by SEM and EDS methods. The results indicate that B-Ni2 brazing filler alloy was fused fully during brazing and continuous interfacial layer formation depended on the method of pre-coating NiO-YSZ. The inter-diffusion of elements was promoted by titanium-deposition: the diffusion reaction thickness of the interfacial area was reduced to less than 5 ${\mu}m$ compared to 100 ${\mu}m$ for electroless nickel-deposited NiO-YSZ cermet.

• Journal of the Korean Vacuum Society
• /
• v.4 no.S2
• /
• pp.131-138
• /
• 1995

The broad beam ion sources of hot filament plasma type have widely used for modifications of materials and thin films, and the new type intensive current broad beam metal ion source including reactive gaseous ion beams is needed for preparing the hard coating films such as DLC, $\beta-C_3N_4$ Carbides, Nitrides, Borides etc. Now a electorn beam evaporation(EBE) broad beam metal ion source has been developed for this purpose in our lab. CN film has been formed by the EBE ion source. Study of the CN film shows that it has high hardness(HK=5800kgf/$\textrm {mm}^2$)and good adhesion. This method can widely changes the ratio of C/N atom's concentrations from 0.14 to 0.6 and has high coating rate. The low energy pocket ion source which was specially designed for surface texturing of medical silicon rubber was also developed. It has high efficiency and large uniform working zone. Both nature texturing and mesh masked texturing of silicon rubbers were performed. The biocompatibility was tested by culture of monocytes, and the results showed improved biocompatibility for the treated silicon rubbers. In addition, the TiB2 film synthesized by IBED is being studied recently in our lab. In this paper, the results which include the hardness, thickness of the films and the AES, XRD analysis as well as the tests of the oxidation of high temperature and erosion will be presented.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.942-945
• /
• 2006

The picture quality of a plasma display panel is very sensitive to the phosphor characteristics such as luminescence, decay time, surface properties, and even longevity of phosphor material in itself. In our previous work, the discharging characteristics in green cell of PDP were demonstrated to be enhanced by coating $Zn_2SiO_4:Mn^{2+}$ phosphors with positively charged metal oxide such as MgO. Here, $Zn_2SiO_4:Mn^{2+}$ phosphors were coated by various metal oxides for examining the coating effect on the picture quality. Specially, longevity while fabricating the panel was investigated for panel application in this work. Also the effects of ion and electron bombardment on the phosphor surface will be discussed in this work.

• Korean Journal of Materials Research
• /
• v.14 no.2
• /
• pp.110-114
• /
• 2004

High velocity oxy-fuel sprayed NiCoCrAlY coatings were oxidized between 1000 and $1200^{\circ}C$ in air, and the oxide scales were examined by XRD, SEM/EDS, and EPMA. The unoxidized coatings consisted mainly of ${\gamma}$'$-Ni_3$Al, with some ${\gamma}$-Ni. The major oxide formed on the coatings was $\alpha$ $-Al_2$$O_3$. Additionally, (CoCr$_2$$O_4$, $CoAl_2$$O_4$) spinels and $Al_{5}$ $Y_3$$O_{12}$ coexisted. NiO was not found, despite of high amount of Ni in the coating. Below the oxide layer, internally formed $Al_2$$O_3$ existed.