• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.62-70
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• 2009

The objective of this study was to measure the leaching of filler (Si, Ba) from nanofiller-contained composites (Palfique Estelite $sigma^{{R}}$ (Tokuyama Dental Corp., Tokyo, Japan), $Z-350^{{R}}$ (3M ESPE, USA), Ceram X duo $E3^{{R}}$, $D3^{{R}}$ (Dentsply, Konstanz, Germany)) under different conditions. The samples used for the study of leachable components were made by insertion of the material into a circular mold, 10 mm in diameter and 3.0 mm high. Each specimen was placed in a disposable polystyrene vial containing 5 mL of distilled water, artificial saliva or 0.1N NaOH and kept in an oven at $37^{\circ}C$. ; water and artificial saliva - 150 days, 0.1N NaOH - 15days. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to determine the amount of Si and Ba in the test solutions. 1. Filler leaching was significantly great in 0.1N NaOH among all samples(p<.0.001). 2. When samples were stored in the distilled water, Estelite showed the lowest amount of Si leaching. When samples were stored in the artificial saliva, Z-350 showed the lowest amount of Si leaching. 3. There were significant differences in filler leaching between 3 storage medias and composite resins(p<.0.001). 4. Si and Ba leaching occurred in greater proportion when samples were stored in the artificial saliva than distilled water. 5. There were significant interactions in monthly filler leaching between leaching in artificial saliva and in distilled water, as well as the interaction between storage medium and filler(p<.0001). These results indicate that a continuous filler leaching of nanofiller-contained composite resins was in storing aqueous solutions under over time.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.111-116
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• 2001

This study was carried out to evaluate the irritant potential of P-toothpaste in hamster cheek pouch. The test materials were applied once at the beginning of this study into right pouches of hamsters and maintained for 14 days. Animals were administered with P-toothpaste, Bamboo salt toothpaste, D.W. and control solution, respectively. In order to evaluate the irritant potential in mucosa of hamster cheek pouch, we observed clinical signs, morality, body weights and gross and histopathological findings for 14 days. In all groups, there were neither dead animals nor significant changes of body weights. In addition, there were no differences between D.W. and P-toothpaste treated group in gross and histopathological findings. Therefore, these results suggest that there was little irritant potential of P-toothpaste in hamster cheek pouch.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2003.07a
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• pp.81-81
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• 2003

우리 민속전통주의 참나무 oak통을 이용한 저장주의 가능성을 규명하기 위하여 상법에 의하여 쌀로 제조한 증류주를 용량 10L의 수입 참나무(oak)통에서 실온 25로 5개월부터 9개월까지 숙성한 숙성주와 숙성하지 않은 증류주의 성분함량 변화를 측정하여 다음과 같은 결론을 얻었다. 1) 유기산은 검출되지 않았으며 다만 7개월 이상 숙성주에서 acetic acid 가 0.023 ∼ 0.033%로 미량 검출되었다. 2) 총 유리아미노산의 함량은 숙성 기간이 경과할수록 감소하였다. ) 휴젤유 함량을 측정한 결과 숙성 기간이 길수록 감소하였으며 휴젤유 중 가장 많은 성분은 isopropyl alcohol이었다. 4)휘발성 향기성분은 숙성기간이 경과함에 따라 이취를 생성할 수 있는 aldehyde나 ketone류가 감소하였고 신선한 과실향이나 꽃향기 등의 향기 성분인 ester류가 증가하여 숙성 5개월째에는 oak 숙성주로서 가장 독특한 향을 갖는다고 예측할 수 있었다. 5) Gas chromatography-olfactometry를 이용하여 각각의 시료들의 향기특성을 관능 평가하여 동정한 결과 전반적으로 green 및 herb note가 우세한 숙성기간 8개월 숙성주가 가장 우수한 것으로 판단되었다. 6) 전체적인 색상 비교 결과 기준값이 되는 oak 숙성을 하지 않은 증류주보다 숙성기간이 오래 경과된 숙성주일수록 점점 높아지는 경향을 보였다. 또한 UCS graph에서 보면 기준값 보다 숙성된 시료가 탁하다는 것을 나타냈고 색상 선에서는 기준시료보다 R(red)에 가까웠다. 숙성기간이 긴 발효주일수록 명도는 낮았다.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.172-177
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• 2002

Photodegadation rates of carbofuran in aqueous solution were measured under various test conditions mainly following the guidelines of U.S. EPA and OECD. Half-lives of carbofuran in distilled water were 9.7 days. 3.3 days, and 1 hr under natural sunlight, SUNTEST with UV filter, and SUNTEST without UV filter, respectively. Waters from a paddy field accelerated the decomposition by factor of 6. It was confirmed that the use of SUNTEST could shorten the test period of photodegradation.

• The Korean Journal of Rheology
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• v.7 no.3
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• pp.181-191
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• 1995

점탄성유체의 물성치들 중 정압열팽창계수 및 밀도는 자연대류 열전달 연구에 전단 속도 0에서의 점도는 점탄성유체에 대한 모델들 사용 시 필요하다. 본 연구에서는 점탄성유 체이며 마찰 감소 첨가제, 유전자 분리용액동으로 사용하는 Separan AP-273 용액의 정압열 팽창계수, 밀도 및 전단속도 0에서의 점도에대한 농도 및 온도의 영향을 조사하였다. 작동유 체의 물성치들은 10~6$0^{\circ}C$의 온도범위와 100~20,000wppm의 농도범위에서 측정되었다. 작 동유체의 물성치들에 미치는 열주기와 노화의 영향을 조사하기 위해서 정압열팽창계수와 전 단속도 0에서의 점도를 교대로 두 번씩 측정했다. 정압열팽창계수 및 밀도를 측정하는 장치 의 측정 정밀도는 증류수에 대한 측정치와 문헌에 나타난 자료를 비교하여 얻었고 이는 $\pm$ 2%이내였다. Separan AP-273용액의 정압열팽창계수 및 밀도는 증류수의 값들로 대치될수 있다. 작동유체의 정압열팽창계수와 밀도는 열주기와 노화의 영향을 받지 않았다. 낙하식 점 도계를 사용해 측정한 겉보기점도 값들을 나타내느 flow curve에서 전단속도가 0이 되는방 향으로 겉보기점도를 외삽시켜 Separan AP-273용액에 대한 전단속도0에서의 점도를 얻었 다. 정압열팽창계수 측정 전후에 측정한 작동유체에 대한 전단속도 0에서의 점도는 열주기 와 노화로 인해 퇴화되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.189-189
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• 2012

염료-감응형 태양전지 응용을 위하여 $TiO_2$ nanorods를 autoclave를 이용하여 FTO 기판위에 수열합성법으로 합성 하였다. $TiO_2$ nanorods는 증류수와 염산, Titanium tetra isopropoxide (TTIP) 전구체의 혼합 용액을 이용하여, $150-200^{\circ}C$의 온도에서 합성하였다. 합성된 $TiO_2$ nanorods의 두께와 길이, 밀도는 성장시간과 성장온도, 전구체의 양, 염산과 증류수의 비율 등의 성자조건 변화를 통하여 조절하였다. $TiO_2$ nanorods의 결정성과 표면형태를 관찰하기 위해 XRD, SEM 그리고 TEM을 이용하였으며, 광학적 특성을 관찰하기 위해서 UV-Vis을 측정하였다. 합성된 $TiO_2$ nanorods 형태는 수직으로 서장된 단결정 구조의 rutile 상으로 관찰되었으며, 길이는 약 $4-6{\mu}m$로 관찰되었다. 고온($200^{\circ}C$)에서 짧은 시간동안 성장시킨 $TiO_2$ nanorods가 태양전지에 응용이 유용한 샘플로 성장되었다. 또한, 반응시간과 전구체의 양이 증가할수록 $TiO_2$ nanorods의 밀도가 증가하였다.

• Membrane Journal
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• v.25 no.3
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• pp.216-222
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• 2015

The method measuring LEP (liquid entry pressure) was optimized to evaluate the wettabilities of hydrophobic membranes which might affect long-term durability of membrane in MD (membrane distillation) process. Conductivity of the permeate was monitored to measure the LEPs of PE (polyethylene) and PVDF (polyvinylidene di-fluoride) hollow fiber membranes from highly concentrated synthetic feed water of 20 wt% NaCl. Holding time over 5 min and the ratio of membrane area to the tank volume more than $10m^2/m^3$ were required to ensure LEP value.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.558-562
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• 1988

The ethanol-and water-extracts of curled tops and stalks of young bracken (Pteridium aquilinum) fronds in raw and cooked states were examined for their mutagenicity by Ames test using Salmonella typhymurium mutants. Even a small amount of water extract from raw bracken was mutagenic to TA 1538 strain without addition of $S_9$ mix whereas a strong toxicity appeared at higher levels of the extractive. With $S_9$ mix, the water-extract from raw bracken was not mutagenic at all and not toxic to all strains tested, The amount of water-extract from cooked bracken was one-tenth of the amount from raw bracken and the water-extract showed no mutagenic effect to all strains tested. Ethanol-extract of bracken showed no mutagenicity in any case.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.274-279
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• 2016

Purpose: The purpose of this study was to evaluate the transmission of candida in denture by dental polishing lathe. Materials and Methods: Maxillary complete dentures made from the same model were infected with Candida albicans. Polishing wheels were keep in various chlorhexidine solution and distilled water for an hour. The infected dentures were polished by prepared dental polishing lathe with sterile pumice and distilled water. And then sterile maxillary complete dentures were polished with same method. Polishing surface was wiped with a cotton swab and the sample was regrown for checking Candida albicans. Results: All polishing wheel with chlorhexidine resist fungal infection. But the polishing wheel with distilled water is infected with Candida albicans. Conclusion: A chlorhexidine is highly efficient in fungal infection prevention on dental polishing lathe.

• Resources Recycling
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• v.10 no.4
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• pp.3-9
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• 2001

The Sericite Powder W3S Comminuted in 1 M $KNO_3$solution for 0.5, 1, 2, 5 and 10 h, compared with the addition of distilled water. It has been found that the mean diameter of the ground particles decreases until the comminuting for 1 h, however, increases after 1 h due to the agglomeration between fine particles. The sericite powder comminuted with 1 M $KNO_3$solution for 1 h shows the mean particle size of $1.9\mu$m, and it also shows the mean particle size of 2.4 $\mu$m in case of comminution in distilled water for 1 h.