• 대한치과의사협회지
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• 제18권5호통권134호
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• pp.355-359
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• 1980

64 dental students who had brushed their teeth with scrubbing method, using 'W' dentifirice for a long lime, were made to practise either scrubbing or Bass method. using one of the 'W','X','Y','Z' toothpaste instead of only 'W' paste for recent 3 weeks. Dental plaque on the teeth of every students were carefully examined compared the results. The simplified oral hygiene index was applied for this purpose and following conclusions were achieved. 1) The Scrubbing method of tooth-paste 'X', Bass method of tooth-paste 'X', and the Bass method of tooth-paste 'Z' had an obvious effect to inhibition of accumulation of plaque. 2) In the tooth brushing method, the scrubbing and Bass are both effective in reducing the plaque accumulation 3) The tooth paste 'X' has the most effectiveness in reducing the plaque accumulation among four tooth pastes 4) The difference in the value of plaque index between the tooth pastes, 'W' and 'X' was only significant statisticallay

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.97-97
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• 2009

산업용 온수관련용 자동차용 등의 다양한 용도로 응용이 가능한 고기능성 세라믹 히터 제작을 위해 후막공정 기술을 적용한 적층형 세라믹 히터의 수요가 증가하고 있으며, 고열로 인한 변형의 우려가 있는 내열성 기판 제작에도 적층형 HTCC 세라믹 기판 적용이 확대되고 있다. 이러한 고내열성 세라믹 기판 제작을 위해서는 paste의 균일성, Low TCR 특성 및 세라믹과 paste 매칭성 확보가 중요한 요소이다. 본 연구에서는 W/Mo 함량비를 변화시켜가며 paste를 제조하여 비저항과 TCR 특성을 비교한 후 가장 낮은 값을 나타내는 조성을 선정하였다. 이 조성에 $Al_2O_3$, $Ta_2O_5$ 등의 첨가제를 사용하여 비저항 특성 개선을 위한 실험을 통해 우수한 고내열성 기판용 paste 조성을 확보하고자 하였다. 그리고 이 Paste를 적용하여 HTCC 그린시트와 매칭성 조건을 확인하고자 하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.311-316
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• 2001

This study analyzed the influence of paste fluidity and vibration time for fundamental properties of porous concrete. Results of this study were shown as follows; 1) Even if target void ratio is same, void ratio and compressive strength of porous concrete is different according to w/c, paste flow and vibration time. So, In case of target void ratio, we must consider the influence of w/c, paste flow, and vibration time. 2) Though w/c and vibration time are same, as paste flow increase, all void ratio, continuous void ratio, and compressive strength decrease and difference between upper and lower void ratio increase. 3) Though w/c and paste flow are same, as vibration time increase, all void ratio and continuous void ratio decrease and difference between upper and lower void ratio increase. Also, compressive strength increase by 10 seconds and decease after 10 seconds. 4) As types of superplasticizer is different, all void ratio, continuous void ratio, and compressive strength are different. So, we must give consideration to paste fluidity and vibration time in order that increase of strength of porous concrete and distribution of uniform void.

• 한국세라믹학회지
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• 제45권6호
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• pp.336-344
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• 2008

Rheological properties of cement pastes containing blast furnace slag (BFS: 3,900, $7,910\;cm^2/g$) or fly ash powder (FA: 4,120, $8,100\;cm^2/g$) according to the ratio of water/binder (W/B) and the dosage of polycarboxylate type superplasticizer (PC) were investigated by a mini slump and a coaxial cylinder viscometer. In this experiment, the ratio of replacing OPC with BFS or FA was 30 wt%, the W/B was from 30 to 70 wt%. As a result, the fluidity of cement paste containing BFS or FA was improved with increasing W/B and the dosage of PC. BFS or FA replaced cement paste with W/B 70% and PC 0.3% showed the highest fluidity. The segregation range of cement paste was occurred below $10\;d/cm^2$ of the yield stress and below 50 cPs of the plastic viscosity by the coaxial cylinder viscometer. And also it was formed that the plastic viscosity and the yield stress of FA replaced cement paste were higher than them of BFS replaced cement paste.

• Computers and Concrete
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• 제16권6호
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• pp.847-864
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• 2015

This study aimed to develop models of sulfate diffusion and ettringite content profile in cement paste for the predication of the damage behavior in cement paste subject to external sulfate. In the models, multiphase reaction equilibrium between ions in pore solution and solid calcium aluminates phases and the microstructure changes in different positions of cement paste were taken into account. The distributions of expansive volume strain and expansion stress in cement paste were calculated based on the ettringite content profile model. In addition, more sulfate diffusion tests and SEM analyses were determined to verify the reliability and veracity of the models. As the results shown, there was a good correlation between the numerical simulation results and experimental evidences. The results indicated that the water to cement ratio (w/c) had a significant influence on the diffusion of sulfate ions, ettringite concentration profile and expansion properties in cement paste specimens. The cracking points caused by ettringite growth in cement paste specimens were predicted through numerical methods. According to the simulation results, the fracture of cement paste would be accelerated when the specimens were prepared with higher w/c or when they were exposed to sulfate solution with higher concentration.

• 한국건축시공학회지
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• 제6권3호
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• pp.75-82
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• 2006

This study investigates the influence of various blending factors on cement paste fluidity and find out the most effective evaluation method of cement paste flow, comparing flow test apparatuses such as ring flow(R-F), flow cone(F-C) and mini slump(M-S). A viscometer also measures the rheology coefficients to secure faithful numerical data. Firstly, series I examines cement paste, affected by several cement products and mineral admixture types in the range of W/B 40%, ordinary fluidity, and W/B 30%, high fluidity. In this series, the three types of cement product depended on companies, are randomly used and the mineral admixture, such as fly ash, blast furnace slag and silica fume, are incorporated in the cement paste, in response to the ratio of 10, 20, to 30%, respectively. In addition, series II studies various chemical admixture types, affecting the cement paste. This series is carried out with manufacturing companies and component types in the range of W/C 30%, high fluidity. For the manufacturing companies, randomly four products are used and for the component types, polycaboxylate, melamine, naphthalene and lignosulfonate type are chosen. Test results showed that in the fluidity test of cement paste considering various types of blending factors, R-F exhibited similar tendency with F-C and M-S. In the analysis of consistency curves measured by viscometer, the fluidity evaluation method using flow test apparatuses was significantly effective, except for the some of the low fluidity specimens. In conclusion of this study, R-F was the most convenient, faithful and effective fluidity evaluation method of cement paste.

• 한국식품위생안전성학회지
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• 제21권4호
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• pp.218-222
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• 2006

본 연구의 결과 각 깻잎 유산균(Bifidobacterium animalis DY 64) 바이오 된장은 실온에서 저장 30일 동안 Salmonella spy, Staphylococcus aureus 및 Escherichia. coli균에 대해 음성반응을 나타내었다. 호기성 미생물의 집락은 균일한 모양을 형성하였으며 잡균의 오염이 없고 콩 메주 속의 Bacillus spp.에 의해 숙성이 진행된 것으로 사료되었다. 또한 상온에 유지한 기능성 된장의 외관과 냄새에 대한 관능적 평가에서도 초기 제조 직후의 외관과 냄새를 유지하므로 서 품질열화에 영향을 나타내지 않았다. 깻잎 기능성 바이오 된장의 풍미에 대한 관능평가 결과는 3-5% 깻잎 처리군은 깻잎 특유의 풍미생성으로 높게 등급 되었으며, 파란 색조는 외관상 신선미를 느낄 수 있었다고 기록하였다 깻잎은 특유의 독특한 향미 생성으로 저 농도의 수준에서 냄새와 풍미에 대해 높게 등급 되었다. 본 연구의 결과 고정화 유산균(Bifidobacterium animalis DY 64)등을 이용하여 제조한 유자와 깻잎 바이오 된장은 상온 저장 동안 미생물학적 저장 안정성과 냄새, 외관 및 풍미에 대한 기호성 향상을 가능하게 하였다. 이전 연구에서 본 바이오 유가된장 및 깻잎 된장은 항산화 효과 및 고혈압억제 효과가 있음을 규명하였으며, 전통 발효식품인 재래된장의 기능적 품질향상 뿐만 아니라 관능적 품질에 대한 기호성 향상으로 내수 촉진을 가능하게 할 수 있을 것으로 검토되었다.

• 한국식품과학회지
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• 제22권4호
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• pp.434-438
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• 1990

동결방지제를 첨가하여 붉은생고추 페이스트 및 딸기 펄프의 저온저장 실험을 한 결과, 붉은생고추 페이스트는 줄기만을 제거한 후 NaCl 15%, citric acid 0.5%를 첨가하면 $-9.6^{\circ}C$에서 미동결 상태로 저장할 수 있었고, 딸기펄프는 dextrose 25%, fructose 17%, sorbitol 8%, ascorbic acid 0.2%를 첨가했을 때 $-15^{\circ}C$까지도 미동결 상태로 저장할 수 있었다. 또한 동결방지제를 이용한 시료는 무처리한 시료에 비해 저장소요시간이 약 1/2 정도 걸리며, 소요에너지도 약 $70{\sim}80%$의 절감효과를 얻을 수 있었다. 따라서, 동결방지제를 이용하면 저온저장시 빙결정 생성에 따른 조직손상을 억제할 수 있을 뿐만 아니라 에너지 절감효과도 얻을 수 있는 것으로 사료되며, 이와 같은 결과를 일시에 다량 수확되는 과채류에 적용할시 농산물의 저장법 개선에 상당한 효과가 있을 것이다.

• 한국지반환경공학회 논문집
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• 제5권3호
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• pp.31-39
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• 2004

국내에서는 저소음, 저진동 말뚝공법으로 매입말뚝공법이 매우 활발하게 사용되고 있으나 설계시 마찰지지력을 과소하게 산정하는 경향이 있으며 시멘트풀의 배합비 및 품질관리에 대한 기준이 정립되지 않은 문제점이 있다. 본 연구에서는 시멘트풀에 대해 다양한 조건별로 시험을 실시하여 강도특성을 분석하였다. 시험결과 표준배합비(w/c=83%)의 시멘트풀의 압축강도는 최고 $156.0kgf/cm^2$를 나타내었고 w/c가 낮을수록, 재령이 길수록 압축강도가 커지는 경향을 나타내었고 토사의 혼입률이 높을수록 강도가 감소하여 일정량 이상이 혼입되면 제역할을 하지 못하는 것으로 나타났다. 또한 매입말뚝의 마찰특성을 분석하고 적합한 설계방안을 도출하기 위하여 시멘트풀의 경화 전후에 188회 동재하시험 결과를 분석하였다. 분석결과 극한단위 마찰력은 평균 $9.1kgf/cm^2$을 나타내어 매입말뚝의 통상적인 설계기준을 상회하는 것으로 나타났다.

• 한국수산과학회지
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• 제21권6호
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• pp.366-370
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• 1988

In Previous paper, an experimental equation for prediction of thermal diffusivity of white muscled fish meat paste products was suggested. In this paper, another experimental equation for red muscled fish meat paste products was derived. The thermal diffusivities of products with water contents of 44.74 to $82.83\%$ and lipid contents of 0.35 to $23.38\%$ could be deduced as following equations ; $$\alpha_{80.39^{\circ}C}=0.0759{\cdot}10^{-6}{\cdot}X_w+0.0836{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ $$\alpha_{100.63^{\circ}C}=0.0820{\cdot}10^{-6}{\cdot}X_w+0.0853{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ $$\alpha_{120.09^{\circ}C}=0.0830{\cdot}10^{-6}{\cdot}X_w+0.09140{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ The experimental equation derived from these equations was ; $$\alpha=(0.9795+.8996{\cdot}X_w){\cdot}\alpha_w-0.0709{\cdot}10^{-6}{\cdot}X_w-0.0779{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ The errors of the thermal diffusivities of red muscled fish meat paste products predicted with this equation were less than ${\pm}\;0.52\%$ compared with those measured. A new experimental equation for products of white and red muscled fish meat paste could be discribed as follow ; $$\alpha=(1.096+0.5318{\cdot}X_w){\cdot}\alpha_w-0.0057{\cdot}10^{-6}{\cdot}X_w-0.0992{\cdot}10^{-6},\;m^2{\cdot}s^{-1}$$ The errors of the thermal diffusivities predicted with this equation were less than ${\pm}\;0.13\%$ compared with those measured.