• Journal of Ceramic Processing Research
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• v.20 no.5
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• pp.464-469
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• 2019

In this study, the electrical conductivity of multi-walled carbon nanotubes (MWCNTs) and polyethylene synthesized by an extrusion process was evaluated. The MWCNTs used exhibited differences in their dispersion characteristics depending on the type of catalyst or synthesis gas used. Thus, the choice of catalyst or synthesis gas significantly affect the physicochemical state of the final MWCNTs and MWCNT-based composites. In this investigation, the characteristics of MWCNTs were analyzed in four cases by introducing ethylene and propylene gas to each catalyst synthesized using deposition precipitation and spray drying methods. The MWCNT-based composites synthesized using the catalyst prepared by deposition precipitation and the ethylene synthesis gas showed the best electrical conductivity. In principle, the morphologies of the MWCNTs indicate that the smaller the aggregate size and bundle thickness, the better the electrical conductivity of the MWCNT composites. This implies that the network is well-formed.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.118-131
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• 2020

It is necessary to add protective agents for protecting the probiotic viability in the preparation process of probiotics starter. In this study, we used whey protein concentrate (WPC), pullulan, trehalose, and sodium glutamate as the protective agent and optimized the proportion of protective agent and spray-drying parameters to achieve the best protective effect on Lactobacillus plantarum. Moreover, the viable counts of L. plantarum in starter stored at different temperatures (-20℃, 4℃, and 25℃) for 360 days were determined. According to response surface method (RSM), the optimal proportion of protective agent was 24.6 g/L WPC, 18.8 g/L pullulan, 16.7 g/L trehalose and 39.3 g/L sodium glutamate. The optimum spray-drying parameters were the ratio of bacteria to protective agents 3:1 (v: v), the feed flow rate 240 mL/h, and the inlet air temperature 115℃ through orthogonal test. Based on the above results, the viable counts of L. plantarum was 12.22±0.27 Log CFU/g and the survival rate arrived at 85.12%. The viable counts of L. plantarum stored at -20℃ was more than 10¹⁰ CFU/g after 200 days.

• Korean Journal of Materials Research
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• v.28 no.4
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• pp.201-207
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• 2018

Infrared(IR) heating has many advantages, such as energy efficiency, reduced heating time, cleanliness, equipment compactness, high drying rate and easy automation. These features of IR heating provide widely industrial applications, such as surface heat treatment in semiconductor fabrication, thermoforming of polymers, drying and disinfection of food products, heating to metal forging, and drying of wet materials. In this study, the characteristics of a protected gold mirror were examined by spectrophotometer and the lifetime of the coating layers were evaluated by a cross-cutting method and salt spray test. The effects of manufacturing conditions on the protected gold mirror were seen and remedies for these effects were noted in order to improve the properties of the protected gold mirror in the drying process. The reflectance and lifetime of the protected gold mirror was influenced by manufacturing conditions, such as surface roughness and forming conditions of the anti-oxide layer, the adhesion layer, the reflecting layer and the protection layer. The results of this study showed that the protected gold mirror manufactured using a buffing method for pre-treatment resulted in the most effective reflectance. In addition, $Al_2O_3$ coating on an Al substrate as an anti-oxide layer was more effective than the anodizing process in the test of reflectance. Furthermore, the protected gold mirror manufactured by layers forming of various materials resulted in the most effective reflectance and lifetime when coated with $Al_2O_3$ as the anti-oxide layer, coated Cr as the adhesion layer, and coated $MgF_2$ as the protection layer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.224-231
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• 2012

We investigated the effects of various washing methods on the quality of semi-dried Pacific saury Cololabis saira, known in Korea as Guamegi. We immersed samples for 5 min in seawater, tap water, chlorinated water (100 mg/kg), ammonia water (100 mg/kg), citric acid (0.1 M), butylated hydroxyanisole (BHA, 0.2 g/kg), or sesame oil (5 g/100 g), and then dried them in the sun for 3 days. The moisture and crude lipid contents after drying were 26.62-32.49 g/100 g and 26.40-33.01 g/100 g, respectively. The moisture content significantly decreased while the crude lipid content increased during drying. The different washing methods did not have a significant effect on the acidity, peroxide values, or levels of thiobarbituric acid or biogenic amine in Guamegi. The lightness of Guamegi during drying significantly decreased, but this decrease was not significantly different among washing methods. The degree of acceptance in a sensory evaluation was higher for Guamegi treated with sesame oil. Our results suggest that these washing methods should not be used to inhibit lipid oxidation, biogenic amine formation, or color changes in semi-dried Pacific saury, because effective components are extracted by the lipids during drying.

• Herbal Formula Science
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• v.13 no.1
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• pp.1-7
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• 2005

Objective : Okchun-San(OCS) is known as an effective herbal medicine on Type 2 diabetes. We performed to change OCS formulation for freeze drying capsulation. Methods The mixtures of OCS were extracted with water. finally, the filtered solution were evaporated and lyophilized to dry granules. The various ratio of excipients were studied to determine the formation for capsulizing. The samples were inspected for any difference in color, taste and appearance. Results: The prepared form of OCS were dried and weighted 260kg. The lyophilized dry powder yielding 40kg. The suitable ratio of OCS-dry powder and excipient was 10:1. The average weights of On and placebo capsules were $440{\pm}5.28mg$, $465{\pm}7.95mg$, respectively. There was no notable change in color and appearance for both capsuled samples throughout the study period. Conclusions: Therefore in can be concluded that freeze drying capsulation is appropriate form of OCS.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.425-429
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• 1989

Functional relationships of carotenoid destruction and nonenzymatic browning during red pepper drying were established by the dynamic test using the moisture-temperature-quality history curve in actual drying experiments. The dependence of the rate constants on temperature and moisture content was established and analysed assuming that carotenoid destruction and nonenzymatic browning are the first order and the zero order reaction, respectively. Carotenoid destruction rate constant was high at high moisture and high temperature, and had a minimum value at some intermediate moisture content. As dependence of rate constant on temperature, activation energy of carotenoid decolorization ranged from 7.7 to 27.4 kcal/mol, showing higher value at higher moisture content. Nonenzymatic browning showed higher rate at higher temperature and higher moisture content. Activation energy of browning was in the range of 7.5-20.2 kcal/mol with higher value at higher moisture level.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.7-16
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• 2017

BACKGROUND: Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea. METHODS AND RESULTS: To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processing methods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This finding was more pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreased with increasing treatment time. Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111. CONCLUSION: The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at $90^{\circ}C$ for 5 min, and roasting.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.17-24
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• 1989

Effects of cooking and drying methods on the lipids content and neutral lipid component of shrimp, Metapenaeus joyneri, were investigated. Total lipid content of the fresh shrimp was 6.0%(dry basis), which was not changed significantly depending on the cooking and drying methods. Lipid of the fresh shrimp was composed of 36.8% of neutral lipids, 21.5% of glycolipids, and 41.7% of phospholipids. Freeze dried shrimp was substantially higher in neutral lipid contents but lower in glycolipid and phospholipid contents than hot air dried one. Main components of the neutral lipids were triglycerides, free sterols, free fatty acids and esterified sterols. Freeze dried shrimp contained higher triglycerides contents than hot air dried shrimp, whereas free fatty acids content in hot air dried shrimp was greater than that of freeze dried one due to the decomposition of triglycerides to free fatty acids during hot air drying. Major fatty acid composition of the total lipid were palmitoleic acid, eicosapentaenoic acid and docosahexaenoic acid, and that of neutral lipid were palmitic acid, palmitic acid, oleic acid, eicosapentaenoic acid and docosahexaenoic acid in fresh shrimp.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.25-30
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• 1989

Effects of cooking and drying methods on the composition of glycolipids and phospholipids of shrimp, Metapenaeus joyneri, were investigated. Major components of the glycolipids were esterified steryl glycosides, monogalactosyl diglycerides and steryl glycosides. Hot air drying enhanced the esterified steryl glycosides content substantially with the reduction of the monogalactosyl diglycerides content. However, reversed pattern was shown for freeze drying. Main components of the phospholipids were phosphatidyl ethanolamines, phosphatidyl cholines, phosphatidic acids, phosphatidyl inositols and phosphatidyl serines. Phosphatidic acids content for hot air and freeze dried shrimp without tooting was 8.3% and 5.9%, respectively. On the other hand, freeze dried shrimp with microwave heating was higher in phosphatidyl ethanolamines contents but lower in phosphatidyl cholines contents than hot air dried shrimp. Major fatty acids of the glycolipids and phospholipids fractions were pentadecanoic acid, palmitic acid, oleic acid, nervonic acid and eicosapentaenoic acid in fresh shrimp.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.104-109
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• 2013

PURPOSE. Among the surface treatment methods suggested to enhance the adhesion of resin cement to fiberreinforced composite posts, conflicting results have been obtained with silanization. In this study, the effects of silanization, heat activation after silanization, on the bond strength between fiber-reinforced composite post and resin cement were determined. MATERIALS AND METHODS. Six groups (n=7) were established to evaluate two types of fiber post (FRC Postec Plus, D.T. Light Post) and three surface treatments (no treatment; air drying; drying at $38^{\circ}C$). Every specimen were bonded with dual-curing resin cement (Variolink N) and stored in distilled water for 24 hours at $37^{\circ}C$. Shear-bond strength (MPa) between the fiber post and the resin cement were measured using universal testing device. The data were analyzed with 1-way ANOVA and by multiple comparisons according to Tukey's HSD (${\alpha}$=0.05). The effect of surface treatment, fiber post type, and the interactions between these two factors were analyzed using 2-way ANOVA and independent sample T-tests. RESULTS. Silanization of the FRC Postec Plus significantly increased bond strength compared with the respective non-treated control, whereas no effect was determined for the D.T. Light Post. Heat drying the silane coupling agent on to the fiberreinforced post did not significantly improve bond strength compared to air-syringe drying. CONCLUSION. The bond strength between the fiber-reinforced post and the resin cement was significantly increased with silanization in regards to the FRC Postec Plus post. Bond strength was not significantly improved by heat activation of the silane coupling agent.