• Korean Journal of Materials Research
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• v.24 no.2
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• pp.116-122
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• 2014

$Bi_2Sr_2CaCu_2O_x$(Bi-2212) and $Bi_2Sr_2Ca_2Cu_3O_y$(Bi-2223) high-Tc superconductors(HTS) have been manufactured by plasma spraying, partial melt process(PMP) and annealing treatment(AT). A Bi-2212/2223 HTS coating layer was synthesized through the peritectic reaction between a 0212 oxide coating layer and 2001 oxide coating layer by the PMP-AT process. The 2212 HTS layer consists of whiskers grown in the diffusion direction. The Bi-2223 phase and secondary phase in the Bi-2212 layer were observed. The secondary phase was distributed uniformly over the whole layer. As annealing time goes on, the Bi-2212 phase decreases with mis-orientation and irregular shape, but the Bi-2223 phase increases because a new Bi-2223 phase is formed inside the pre-existing Bi-2212 crystals, and because of the nucleation of a Bi-2223 phase at the edge of Bi-2212 crystals by diffusion of Ca and Cu-O bilayers. In this study the spray coated layer showed superconducting transitions with an onset Tc of about both 115 K, and 50 K. There were two steps. Step 1 at 115 K is due to the diamagnetism of the Bi-2223 phase and step 2 at 50 K is due to the diamagnetism of the Bi-2212 phase.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.528-532
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• 1997

A fermented squeezed-type paste was processed in order to highly effective utilization of cockle shell by-product, and improvement on rheological properties and texture of hydrolysate by used additives. The cockly shell by-products were homogenized with addition of water and enzymatically hydrolyzed at 5$0^{\circ}C$ for 8 hours added 4% Protease N.P.(Pacific Chemical Co.). And the hydrolysate was thermally treated for the purpose of flavor improvement, enzyme inactivation and pasteurization product at 10$0^{\circ}C$ for 1 hour, with 4% glucose. To make improvement of rheological properties, used complex additive with 0.5% alginic acid, 1% pectin and 0.2% agar were very effective. And stability of mixing was 98.1% after centrifuged at 10,000 rpm for 60 minutes. The chemical composition of moisture, total carbohydrate, total nitrogen and amino type nitrogen in the fermented squeeze-type cockle shell by-product paste were 57.7%, 20.6%, 1,458mg% and 1,187mg%, respectively. And the ratio of amino type nitrogen in total nitrogen was 81.4%.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1021-1027
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• 1997

We examined some properties of yeast cell wall lytic enzyme produced by Dicyma sp. YCH-37. Several metal ions, reducing reagents, and chemical modifiers have little effects on the lytic activity, except guanidine-HCl. Yeast cells of early log phase were more susceptible to the enzyme than those of stationary phase, and heat-treated cells were more easily lysed than intact living ones. Yeast cells pretreated with organic solvents such as butanol and acetone were more susceptible to the enzyme than intact living ones. Yeast cells cultured in Yeast extract-Malt extract medium containing 0.5 M ammonium sulfate were easily lysed by the lytic enzyme, and yeast cells cultured without shaking were more easily lysed by the enzyme than those with shaking. When SDS, ${\beta}-mercaptoethanol$, Triton X-100, sodium sulfite, and KCl were added to enzyme reaction mixture each, lysis of yeast cells was more effective.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.769-773
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• 2001

Protein content of okara and soybean were found to be 37.3% and 42.5%, respectively by micro-Kjeldahl analysis. Solubility of okara protein in phosphate buffer (pH 8) was 10% versus soy protein of 68.4%. Insolubilization of okara protein was mostly due to disulfide bonding between cysteine residues caused by excessive heat treatment during soymilk processing: hydrophobic interactions and hydrogen bondings were involved to lesser extent. Optimum extraction temperature and time were $60^{\circ}C$ and 40 min. Typical solubility profile of soy protein disappeared for okara protein though minimum solubility of the protein was around pH 3.0. Treating okara with protease was effective in solubilizing okara protein and solubility increased to 19.2%. Optimum reaction temperature and time were $80^{\circ}C$ and 50 min, respectively. Cell wall degrading enzyme did not increase solubility of the protein, however. Through enzymatic reaction okara protein could be effectively solubilized for uses as food ingredient.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.223-229
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• 1988

Bacillus subtilis K-4-3, which produces considerable amount of $\beta$-glucanase was selected among extracellular $\beta$-glucanase-producing bacteria isolated from soil. $\beta$-glucanase was purified by ammonium sulfate fractionation, Sephadex G-100 gel filtration and DEAE-sephacel ion exchange chromatography. The purified enzyme revealed a single band by polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. Its molecular weight was estimated to be 17000 dalton by SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature of the purified $\beta$-glucanase were 7.0 and $50^{\circ}C$, respectively. The enzyme was strongly inhibited by 1.0mM of $Fe^{3+}$, and activated by 1.0mm of $Li^{}47+$. The absence of glucose after thin layer chromatography of reaction products revealed that the purified enzyme contains no cellobiase or laminarinbiase activity. The loberation of ki, tri-and tetra-saccharide as reaction products can be explained by endoaction of the enzyme.

• Journal of the Korean institute of surface engineering
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• v.48 no.6
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• pp.260-268
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• 2015

The thermal barrier coating (TBC) for inner wall of liquid-fuel rocket combustor consists of NiCrAlY as bonding layer and $ZrO_2$ as a top layer. In most case, the plasma spray coating is used for TBC process and this process has inherent possibility of cracking due to large difference in thermal expansion coefficients among bonding layer, top layer and metal substrate. In this paper, we suggest crack-free TBC process by using a precise electrodeposition technique. Electrodeposited Ni-P/Cr double layer has similar thermal expansion coefficient to the Cu alloy substrate resulting in superior thermal barrier performance and high temperature oxidation resistance. We studied the effects of phosphorous concentrations (2.12 wt%, 6.97 wt%, and 10.53 wt%) on the annealing behavior ($750^{\circ}C$) of Ni-P samples and Cr double layered electrodeposits. Annealing temperature was simulated by combustion test condition. Also, we conducted SEM/EDS and XRD analysis for Ni-P/Cr samples. The results showed that the band layers between Ni-P and Cr are Ni and Cr, and has no formed with heat treatment. These band layers were solid solution of Cr and Ni which is formed by interdiffusion of both alloy elements. In addition, the P was not found in it. The thickness of band layer was increased with increasing annealing time. We expected that the band layer can improve the adhesion between Cr and Ni-P.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.50-54
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• 2005

Antimicrobial activities of ethanol extracts of marta rosemary (Rosemarinus officinalis L.) against Bacillus subtilis and Salmonella typhimurium were investigated under conditions similar to processing of general food materials to develop natural food preservatives. The strongest antimicrobial activities were shown against the tested organisms at pH 7. In B. subtilis, the herbal extract extended the lag phase at low concentrations, and reduced the specific growth rate during logarithmic phase at high concentrations. In S. typhimurium the herbal extract reduced the specific growth rate even at lower concentrations. These trends were obtained at low pHs of culture solution. Antimicrobial substances of herbs were efficiently extracted with low polar solvents. The thermal stability of antimicrobial substances decreased with heating time at $100^{\circ}C$. S. typhimurium was more sensitive to herbal extracts at $100\;and\;121^{\circ}C$ than B. subtilis.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.50-55
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• 1990

Differences in the major components between non-greening and greening garlic bulbs were compared, and the several factors to be affected on the greening were investigated to study on the greening phenomenon occured in garlic puree made from stored garlic bulbs. From the several chemical analyses it was found that the contents of total nitrogen and lipid were lower in the greening than in the non-greening bulb but the contents of pyruvic and succinic acid were not. The content ratio of glutamic acid to total amino acid and the composition ratios of linoleic and linolenic acid were high in the greening bulb in comparsion with the non-greening. The protein pattern of the greening bulb by SDS-PAGE was significantly differed from that of the non-greening, especially in molecular weight ranges of 45.0-66.2 Kd. From the studies on the effects of pH, temperature and duration on the development of green color in the garlic powder solution, the optimum pH for the greening was 5.5 and maximum degree of the greening in the pH adjusted solution was shown after 30 min at $50^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.99-104
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• 2012

The co-precipitation technique has been applied to synthesize biphasic calcium phosphate (BCP). $Ca(NO_3)_2{\cdot}4H_2O$ and $(NH_4)_2HPO_4$ as the starting materials was used. X-ray diffraction (XRD) and Fourier transformed infrared (FT-IR) spectroscopy were used to characterize the structure of as-synthesized and calcined BCP powders. After immersion in Hanks' Balanced Salt Solution (HBSS), for 1 week a precipitation started to be formed with individual small granules on the specimen surface. An MTT assay indicated that BCP powders have no cytotoxic effects on MG-63 cells, and that they have good biocompatibility.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.172-178
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• 2002

Vitamins are bio-active materials and essential elements in our body but some of them are very low in milt Various vitamin-fortified milks are developed by the help of milk processing technology. However, heat treatments can affect vitamins contents in milk. Total loss of vitamins during the UBT(ultra high temperature) treatment was investigated. UHT treatment caused 60∼70% loss for vitamin C, and 30∼40% loss for vit. D3 and vit. E which are well-known as heat stable materials. On the contrary, degradation of water-soluble vitamins is relatively very low in the capsule-coated state. The capsule could reduce the loss of vitamins by protecting vitamins from the degradation factors such as heat, oxygen, lights etc. The fortification method using capsule can be thought as a new way to reduce the loss of vitamins during milk processing. Further study about heat treatment time and temperature, and capsule coating and materials will be required to minimize the loss of vitamins in milt.