• Journal of Ceramic Processing Research
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• 제20권5호
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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.

• 한국축산식품학회지
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• 제40권1호
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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.

• 한국재료학회지
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• 제28권4호
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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.

• 한국수산과학회지
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• 제45권3호
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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.

• 대한한의학방제학회지
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• 제13권1호
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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.

• 한국식품과학회지
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• 제21권3호
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• pp.425-429
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• 1989

고추의 건조 중 중요한 품질요소인 carotenoid 파괴 및 비효소적 갈변의 kinetics를 건조 중 품질측정을 이용한 dynamic test에 의하여 평균 수분함량과 온도의 함수관계를 결정하였다. 1차반응으로 가정된 carotenoid 파괴 속도상수는 고온 고수분에서 높았으며 수분의존성에 있어서 건조중간의 어떤 수분함량에서 최소치를 보여주고 있었다. 온도의존성에 있어서 활성화 에너지는 7.7-27.4kcal/mol로 나타났고 수분함량이 높을수록 높았다. 0차반응으로 분석된 비호소적 갈변은 온도와 수분함량이 높을수록 쉽게 일어났으며 활성화에너지는 7.5-20.2kcal/mol로서 수분함량이 높을수록 높았다.

• 한국환경농학회지
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• 제36권1호
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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.

• 한국식품과학회지
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• 제21권1호
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• pp.17-24
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• 1989

가열처리 및 건조방법이 새우의 지방질 함량과 중성지방질에 미치는 영향을 밝히고자 하였다. 생새우의 총지방질 함량은 건물기준으로 6.0%였으며, 가열 및 건조방법에 따라 총지방질의 함량은 유의적인 변화가 없었다. 생새우의 중성, 당 및 인지방질의 함량비는 각각 36.8:21.5:41.7% 이었고 동결건조한 것은 열풍건조한 것보다 중성시방질의 함량이 유의적으로 많은 반면에 당 및 인지방질의 함량은 적었다. 중성지방질의 주요성불은 triglyceride, free sterol, free fatty acid 및 esterified sterol이었으며, 동결건조한 것은 열풍건조한 것보다 triglyceride 함량은 유의적으로 많았고 free fatty acid 함량은 적었는데, 이는 열풍건조중 triglyceride가 분해된 것으로 생각되었다. 생새우의 총지방질의 구성 주요지방산은 palmitoleic acid, eicosapentaenoic acid 및 docosahexaenoic acid이었고, 중성지방질의 구성 주요 지방산은 palmitic acid, palmitoleic acid, oleic acid, eicosapentaenoic acid 및 docasahexaenoic acid이었다.

• 한국식품과학회지
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• 제21권1호
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• pp.25-30
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• 1989

가열처리 및 건조방법이 새우의 극성지방질에 미치는 영향을 밝히고자하였다. 새우중의 당지방질의 주요성분은 esterified steryl glycoside, monogalactosyl diglyceride 및 steryl glycoside 이었으며, 열풍건조한 것은 동결건조한 것보다 esterified steryl glycoside 함량은 유의적으로 많은 반면에 monogalactosyl diglyceride 함량은 적었다. 새우중의 인지방질의 주요성분은 phosphatidyl enthanolamine, phosphatidyl choline phosphatidic acid, phosphatidyl inositol, phosphatidyl serine 이었으며, phosphatidic acid 함량은 가열처리 하지 않고 열풍건조한 것은 8.3%, 동결건조한 것은 5.9%로서 전자가 후자보다 유의적으로 많았고, phosphatidyl ethanolamine 함량은 마이크로파 처리 할 경우 동결건조한 것은 열풍건조한 것보다 그 함량이 많은 반면에 phosphatidyl choline함량은 적었다. 생새우의 당 및 인지방질 획분의 주요 지방산은 pentadecanoic acid palmitic acid oleic acid, nervonic acid 및 eicosapentaenoic acid 이었다.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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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.