• Composites Research
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• 제29권5호
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• pp.236-242
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• 2016

본 연구에서는 유리섬유/폴리프로필렌 기반의 열가소성 복합재의 열성형 시험 평가를 위해, 성형온도에서의 인장 및 면내 전단 물성 시험을 실시하였고, 이를 비직교 구성방정식을 이용하여 정량화 하였다. 이를 통해 실험값과 잘 일치하는 고온에서의 인장 및 전단 물성값을 수식화하여 얻을 수 있었다. 열성형 시험을 위해 반구돔 시험을 실시하였고, 이형제 사용 유무 및 홀더의 무게를 달리해가며 성형품의 최종형상을 비교하였다. 그 결과 이형제를 사용하면 성형품의 대칭성이 확보되고 주름 개선 효과에 유리하다는 것을 확인하였고, 적당한 힘의 홀딩력 제어가 필수적이라는 것을 알 수 있었다. 더 나아가 비직교 구성방정식이 고려된 열성형 수치해석을 실시하여 실험 결과와 유사한 양상을 확인할 수 있었고, 홀딩력이 낮을 수록 주름이 많아지고, 마찰력이 클수록 더 많은 펀치력을 필요로 함을 확인하였다.

• 한국안전학회지
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• 제24권5호
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• pp.21-27
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• 2009

Effective way of cooking oil fire extinguishment is using water mist system which has cooling and smothering effects. Low pressure water mist system has advantage because it is compatible with existing sprinkler systems. To increase the effectiveness of low pressure water mist system, additives can be used which increase the momentum of water particle and the chemical effect. In this experiment, aqueous film forming form(AFFF) agent is used as additive and the effect of additive concentration and water pressure are experimented. For the extinguishment of cooking oil fire such as soybean and olive oils, AFFF agent is effective and can decrease the fire extinguishing time and water consumption.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.69-72
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• 2009

This research is focused on the applying of the foaming agent which can make the independent pore in the concrete structure in order to make a lightweight concrete structure. This lightweight foamed concrete can satisfy both the required strength and the mechanical properties as structural members. In addition, anti freezing-thawing properties also required. As a result of the unit volume-weight measurement, when the foaming agent mixed at 0.5% to 1%, the lightweight foamed concrete can be applied for the structural member. Also the density and compressive strength measurement results reveals that it will be suitable as structural member with 21MPa strength, when the density is betweenity8 to 1.9 and foaming agent quantities are 0.5% to 1%. Finally the result of freezing-thawing experiment, the effect freezing-thawing damage reduced according to adding foaming agent because those foaming agent make micro-pores in the structure which are not seen in the ordinary concrete structure.

• 대한소아치과학회지
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• 제47권2호
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• pp.120-127
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• 2020

이 연구의 목적은 치면착색제인 10 - 20 mM erythrosine을 광감각제로 사용한 광역동 치료의 항균 효과를 평가하는 것이다. Streptococcus mutans, Lactobacillus casei, Candida albicans를 포함하는 다종 우식원성 세균막을 hydroxyapatite disc에 형성하였다. 광감각제로 20 μM, 10 mM, 20 mM erythrosine을 3분간 적용 후 24초 동안 광조사를 시행하였다. 각 실험군의 Colony-forming unit (CFU)을 측정하고 세균막을 Confocal laser scanning microscopy (CLSM)을 이용하여 관찰하였다. 10 - 20 mM erythrosine을 광감각제로 사용한 광역동 치료 실험군에서 CFU의 현저한 감소가 관찰되었고, 그 결과는 CLSM 관찰에서도 확인되었다. 이번 연구를 통해 치과 임상에서 사용되는 치면착색제를 광감각제로 이용한 광역동 치료의 높은 항균효과를 확인할 수 있었다.

• 한국식품위생안전성학회지
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• 제2권4호
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• pp.191-196
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• 1987

Erythrosine used as a colouring agent in drugs, cosmetics and foods in Korea, was examined for its effects on murine immune system and methemoglobin formation. As immunotoxicologic assay parameters, we adopted circulating leukocytes and immunoorgan weights for pathotoxicology, IgM plaque forming cells and arthus reaction for humoral immunity, delayed hypersensitivity reaction of cell mediated immunity and carbon clearacnce for macrophage function. Erythrosine's effects were observed as follows; 1. Ery throsine showed no significant effects on circulating leulocyte counts and relative immunoorgan weight. 2. Erythrosine diminished IgM plaque forming cells. 3. Erythrosine decreased arthus reaction, in the dose dependent manner. 4. Erythrosine had no significant effect on delayed hypersensitivity. 5. Phagocytic and corrected phagocytic index were not affected. 6. Methemoglobin content was similar in the test and control groups.

• KSBB Journal
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• 제28권3호
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• pp.202-207
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• 2013

In this study, saponin content of extract from modified preconditioning process was investigated in Saponaria officinalis L. for cosmetic natural surfactant. Saponin content in steamed leaves from S. officinalis L. was about three times more than that in dried leaves (tea saponin and quillaja saponin). And saponin extracts from steamed leaves was excellently shown in both forming force and forming stability. In emulsion activity, saponin extracts from steamed leaves had a similar level to quillaja saponin and tea saponin. Saponin extracts from steamed leaves in S. officinalis L. showed nontoxic effect below in $1,000{\mu}g/mL$ of concentration and dose-dependent inhibition of NO production. From the experiment, the extracts of S. officinalis L. showed good cosmetic agent.

• 한국표면공학회지
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• 제35권5호
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• pp.279-288
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• 2002

Zinc phosphating for cold forming of steel was studied with emphasis on decreasing phosphating temperature. To lower phosphating temperature, some techniques, such as adding Cu ion into bath, using activator in the form of pre-dip, and aeration in bath, instead of using conventional accelerator, namely oxidizing agent, have been tried. It was revealed that phosphating, leading to coatings of Improved uniformity and fine crystal size, can be carried out using above techniques at lower temperature ($55^{\circ}C$) compared to conventional phosphating temperature ($80 ~ 90^{\circ}C$ ). Under present condition, it was seen that optimum concentrations of Cu ion in phosphating bath and activator in pre-dip are 0.015% (w/w) and 2.0 g/1, respectively. The coating weight was within the range of 15 ~ 20 g/$\m^2$. When lubricant was applied into phosphating coatings, the amount of lubricating component (total soap) was found to be 6 ~ 10 g/$\m^2$ and the lubricated panel revealed excellent lubricating properties.

• 한국식품영양학회지
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• 제1권2호
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• pp.95-101
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• 1988

In order to produce lactic acid and calcium lactate very useful for foods and medical supplies, lactic acid fermentation was studied by Lactobacillus sporogenes, a spore forming lactic acid bacterium. When this bacterium was cultured aerobically in the spore forming medium, the spore forming rate was 96.0% as total cell number 20$\times$108/ml, spore number 19.2$\times$108/ml. One minute agitating every 1 hour in the flask culture, or agitation of 100rpm in the fermenter was most efficient to continue to ferment at 45$^{\circ}C$ for 4days in the fermentation medium containing 10% glucose as carbohydrate and CaCO3 as a neutralizing agent. This homofermentative lactic acid bacterium showed fermentation yield of 99.3% and more than 98.2% of the yield was L(+)-lactic acid.

• 한국표면공학회지
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• 제36권1호
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• pp.59-68
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• 2003

Zinc phosphating for cold forming of steel was studied with emphasis on decreasing phosphating temperature. To lower phosphating temperature, some techniques, such as adding Cu ion into bath, using activator in the form of pre-dip, and aeration in bath, instead of using conventional accelerator, namely oxidizing agent, have been tried. It was revealed that phosphating, leading to coatings of improved uniformity and fine crystal size, can be carried out using above techniques at lower temperature (55$^{\circ}C$) compared to conventional phosphating temperature ($80∼90^{\circ}C$). Under present condition, it was seen that optimum concentrations of Cu ion in phosphating bath and activator in pre-dip are 0.015 % (w/w) and 2.0 g/1, respectively. The coating weight was within the range of $\15∼20 g/m^2$. When lubricant was applied into phosphating coatings, the amount of lubricating component (total soap) was found to be$ 6∼10 g/\m^2$ and the lubricated panel revealed excellent lubricating properties.

• 한국세라믹학회지
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• 제53권1호
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• pp.13-17
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• 2016

It is highlighted that increasing the adsorbent surface area on volumetric basis is very important in providing an easy access for gas molecules. Fine particles around $3{\mu}m$ of soft-burned dolomite kiln dust (SB-DKD) were hydrated to wet slurry samples by ball mill process and then placed in a chamber to use spray dryer method. Spherical granules with particle size distribution of $50{\sim}60{\mu}m$ were prepared under the experimental condition with or without addition of a pore-forming agent. The relationship between bead size of the pore-forming agent and size of SB-DKD particles is the most significant factor in preparation of spherical granules with a high porosity. Whereas addition of smaller beads than SB-DKD resulted in almost no change in the surface porosity of spherical granules, addition of larger beads than SB-DKD contributed to obtaining of the particles with both 15 times larger average pore volume and 1 order of magnitude larger porosity. It is considered that spherical granules with improved $N_2$ gas adsorption ability may also be utilized for other atmospheric gas adsorption.