• Journal of Periodontal and Implant Science
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• 제43권6호
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• pp.301-307
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• 2013

Purpose: This in vitro study was performed to assess the adherence of Porphyromonas gingivalis to a resorbable blast media (RBM) titanium surface pretreated with an ultrasonic scaler or toothbrush and to evaluate the effects of the treatment of the RBM titanium discs on the bacterial removal efficiency of brushing by crystal violet assay and scanning electron microscopy. Methods: RBM titanium discs were pretreated with one of several ultrasonic scaler tips or cleaned with a toothbrush. Then the titanium discs were incubated with P. gingivalis and the quantity of adherent bacteria was compared. The disc surfaces incubated with bacteria were brushed with a toothbrush with dentifrice. Bacteria remaining on the disc surfaces were quantified. Results: A change in morphology of the surface of the RBM titanium discs after different treatments was noted. There were no significant differences in the adherence of bacteria on the pretreated discs according to the treatment modality. Pretreatment with various instruments did not produce significant differences in the bacterial removal efficiency of brushing with dentifrice. Conclusions: Within the limits of this study, various types of mechanical instrumentation were shown to cause mechanical changes on the RBM titanium surface but did not show a significant influence on the adherence of bacteria and removal efficiency of brushing.

• 한국세라믹학회지
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• 제30권6호
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• pp.492-498
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• 1993

The pretreatment condition for uniform distribution of SiC whisker in A2O3-SiCw composites has been determined and the mechanical properties of the composites with various whisker contents have been measured. Good dispersion of the whisker can be obtained in a solution of pH=10.45 by ball milling and ultrasonic treatment. The relative density of hot pressed composites decreases with the whisker content up to 40vol%, but is found to be satisfactory, over 98% for all samples. The mechanical property of the composites is sensitive to the whisker dispersion. Uniform distributjion of the whisker is critical in order to guarantee good mechanical property.The samples containing 20~30vol% whisker show the best mechanical property within the studied range.

• 한국의류학회지
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• 제31권12호
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• pp.1754-1760
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• 2007

홍화 황색소의 면, 마, 레이온과 같은 셀룰로오스 섬유에 대한 염착량을 증진시키기 위하여 키토산 전처리를 행하였다. 키토산 전처리가 염착성, 색상, 염색견뢰도에 미치는 영향을 조사하였다. 섬유 종류에 관계없이 키토산 전처리는 염착성을 증진시켰으며, 농도가 증가함에 따라 계속 증가하였다. 2% 처리농도에서 미처리와 비교할 때 면은 5.6배, 모시는 7.2배, 레이온은 3.7배 염착량이 증가하였다. 키토산 전처리한 면과 모시는 YR 색상에서 Y 색상으로 변화하였으며, 레이온의 경우에는 전처리와 상관없이 Y 계열의 색상을 보였다. 키토산 전처리에 의해 색상은 노란색이 강하여졌으며 더 진하고 깊은 색상으로 변하였다. 키토산 전처리 직물은 염색온도에 따라 색상이 변화하였는데 공통적으로 50, $70^{\circ}C$에서는 YR 색상을 30, $90^{\circ}C$에서는 Y 색상을 나타냈다. 염색온도가 높을수록 색상은 진하고 칙칙하였다. 세탁견뢰도는 아주 낮았으며, 일광에 매우 약한 홍화 황색소의 특성을 고려할 때 일광견뢰도는 양호한 편이었다. 기존의 자동 염색기로 염색하는 경우와 비교할 때 초음파 염색법이 면과 모시의 염착량을 30% 이상 증진시키는 효과가 있음을 확인하였다. 레이온의 경우, 두 방법간의 염착량 차이는 없었다.

• 한국수산과학회지
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• 제34권5호
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• pp.483-487
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• 2001

갑오징어 가공 부산물인 갑으로부터 유용 칼슘을 효율적으로 추출하기 위하여 소성처리 ($800^{\circ}C$, 2시간), 고온가압처리 ($121^{\circ}C$, 10시간) 및 초음파처리 ($60^{\circ}C$, 10시간)와 같은 전처리 방법에 대하여 검토하였다 소성처리에 의한 칼슘 추출 분말의 경우 백색이었으나, 기타 추출법으로 처리되어진 칼슘 분말의 경우 연노랑색을 나타내었다 소성처리에 의한 갑 분말의 칼슘함량은 $70.5\%$로 원료 및 다른 전처리 방법에 비하여 약 2배정도 증가하였다 전 처리 방법에 따른 칼슘의 가용화율은 원료에 비하여 초음파처리 및 고온가압처리의 경우 약간 감소하였으나, 소성처리한 경우 약 22배가 증가하였다. 이상의 칼슘제로서 가장 중요한 품질지표인색조, 칼슘 가용화율 및 순도 둥으로 미루어 보아 전처리 방법으로는 소성처리가 가장 우수하였다. 소성처리 시료를 RED 상분석한 결과 주성분은 산화칼슘이었다. 그러나, 소성처리에 의한 칼슘 추출 분말의 경우 pH가 12.9로 강알칼리를 나타내어 안전성 측면에서 식품품질 개선제 둥으로 사용하기에는 다소 문제가 있었다. 이상의 결과로 미루어 보아 갑오징어갑으로부터 칼슘을 추출하는 방법으로는 소성처리가 가장 우수하였으나, 강알칼리로 인해 식품 품질개선제 등과 같이 효율적으로 이용하기 위하여는 반드시 중성부근의 pH로 조정이 이루어져야 하리라 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.846-853
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• 2024

Adzuki bean (Vigna angularis), which provides plant-based proteins and functional substances, requires a long soaking time during processing, which limits its usefulness to industries and consumers. To improve this, ultrasonic treatment using high pressure and shear force was judged to be an appropriate pretreatment method. This study aimed to determine the optimal conditions of ultrasound treatment for the improved hydration of adzuki beans using the response surface methodology (RSM). Independent variables chosen to regulate the hydration process of the adzuki beans were the soaking time (2-14 h, X₁), treatment intensity (150-750 W, X₂), and treatment time (1-10 min, X₃). Dependent variables chosen to assess the differences in the beans post-immersion were moisture content, water activity, and hardness. The optimal conditions for treatment deduced through RSM were a soaking time of 12.9 h, treatment intensity of 600 W, and treatment time of 8.65 min. In this optimal condition, the values predicted for the dependent variables were a moisture content of 58.32%, water activity of 0.9979 a_w, and hardness of 14.63 N. Upon experimentation, the results obtained were a moisture content of 58.28 ± 0.56%, water activity of 0.9885 ± 0.0040 a_w, and hardness of 13.01 ± 2.82 g, confirming results similar to the predicted values. Proper ultrasound treatment caused cracks in the hilum, which greatly affects the water absorption of adzuki beans, accelerating the rate of hydration. These results are expected to help determine economically efficient processing conditions for specific purposes, in addition to solving industrial problems associated with the low hydration rate of adzuki beans.

• 한국표면공학회지
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• 제50권4호
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• pp.244-250
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• 2017

Effects of plating conditions (dispersant concentration, plating time, and ultrasonication) on electroless Cu plating on SiC fabric woven by crossing of SiC continuous fibers vertically were studied. The ultrasonic dispersion treatment not only did not improve the dispersion of the SiC fibers, but also did not change the plating thickness. The ultrasonication in the pretreatment step of electroless plating did not improve the dispersion of the fibers, while the ultrasonication in the plating step enhanced the dispersion of the fibers and decreased the thickness of the Cu films. It was possible to control the thickness of the Cu coating layer as well as the dispersion of the fibers in the fabric by changing the plating conditions such as dispersant concentration, plating time, and ultrasonication, but it was very difficult to coat copper on the intersection of vertical fibers in the fabric.

• 한국작물학회지
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• 제41권6호
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• pp.704-709
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• 1996

모시풀의 경편과 흡지의 배양을 통하여 완전한 식물체를 대량증식하기 위하여 소독방법과 생장조절제 처리 효과에 대한 기내배양을 실시하여 다음과 같은 결과를 얻었다. 1. 모시풀 경편 배양시 소독은 초음파세체기를 이용한 2% NaClO를 20분 동안 하였을때 오염률이 3.3%로 가장 낮았으며, 식물체도 79%가 생존하였고, 건실한 묘를 생산할 수 있었다. 2. 생장조절제 처리효과에서는 NAA(0.02mg/$\ell$)+ BA(1.5mg/$\ell$) + GA3(0.1mg/$\ell$) 혼합처리가 캘러스 형성이 안되고, 식물체 형성률이 96%였으며, 건실한 묘를 생산할 수 있었다. 3. 치상부위별로는 흡지보다 경편배양이, 품종별로는 개량종인 서방종보다 재래종인 보성종이 증식효률이 높았다. 4. 순화 효율은 상토 배합과 호르몬 처리에 있어서 버미큐라이트 : 모래 ：황토 =1 : 1 : 1의 배합과 NAA 1000ppm을 30분간 담근 후 이식한 순화율이 99%로서 건실하였으며, 식물체는 대부분 정상이었다.

• 유기물자원화
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• 제27권4호
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• pp.43-49
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• 2019

본 연구는 알칼리·초음파 전처리를 통한 하수슬러지의 가용화 정도를 확인하기 위해 슬러지 가용화율과 VSS 감량화율을 측정하였다. 또한 슬러지 가용화와 EPS간의 관계를 확인하기 위해 LB-EPS(Loosely-Bound EPS), TB-EPS(Tightly-Bound EPS)를 측정하였다. 실험 결과, TS 1.0%, pH 12 조건에서 슬러지 가용화율은 27.7% 증가하였고, LB-EPS as Carbohydrate와 Protein은 각각 14.6, 13.3 mg/L/g TS가 증가하여 가용화에 따른 유기물의 변화와 유사한 경향을 나타내었다. 또한 VSS는 26.7% 감량되었고, TB-EPS as Carbohydrate와 Protein은 각각 15.7, 21.9 mg/L/g TS 용출되어 가용화에 따른 고형물의 변화 역시 유사한 경향을 나타내었다.

• Restorative Dentistry and Endodontics
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• 제28권1호
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• pp.1-10
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• 2003

This study investigated the influence of IRM on marginal microleakage of 5th generation adhesives. Class V cavities with gingival margins in dentin were prepared on both buccal and lingual surfaces of 60 extract-ed human molar teeth. Prepared teeth were randomly divided into six groups. Group 1 and 4 received no temporary restoration with IRM. Group 2 and 5 were covered with IRM mixed at P/L ratio(10g/1g). Group 3 and 6 were covered with IRM mixed at P/L ratio(10g/2g). The temporary restorations were removed mechanically with an ultrasonic scaler after one-week storage in distilled water. The cavities were restored using one of two adhesives and composites ; Single Bond/Filtek Z 250(Croup 1, 2 and 3), UniFil Bond/UniFil F(Group 4, 5 and 6). Following one day storage in distilled water, the restored teeth were thermocycled for 500 cycles(between $5^{\circ}C{\;}and{\;}55^{\circ}C$) and immersed in 2 % methylene blue for dye penetration testing. The results were analysed using Kruskal-Wallis Test, Mann-Whitney and Wilcoxon signed ranked test at a significance level of 0.05. The results of this study were as follows 1. Ranking of mean microleakage scores at the enamel margins was Group 10.05) 4. At the dentin margins, the microleakage of the group not pretreated with IRM was lower than that of the group pretreated with IRM. And the microleakage of UniFil Bond was lower than that of Single Bond. 5. Compared with microleakages between the enamel and dentin margins of each groups, Group 1, 2, 3, 4, 5 and 6 at dentin margin were higher microleakage than those at enamel margin. There were significant difference between enamel and dentin microleakage of Group 2 and 3(p<0.05).