• 한국식품과학회지
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• 제48권5호
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• pp.454-460
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• 2016

본 논문에서는 E. coli O157:H7, S. Typhimurium, S. aureus와 B. cereus에 대한 ddPCR의 검출 효율과 검출한계를 측정하였으며 동시 검출을 위한 multiplex 검출 가능성을 타진하였다. ddPCR은 PCR mix를 포함한 시료를 15,000-20,000개의 droplet으로 분할하여 PCR 하는 방법으로 droplet reader를 이용하여 droplet의 형광 신호를 계수하였다. 식중독 세균의 표적 DNA를 검출하기 위해 2가지 색의 형광 probe (TaqMan)를 제작하였다. ddPCR은 표적 유전자의 형광 신호를 $100fg/{\mu}L$부터 $10ng/{\mu}L$까지의 DNA를 검출 할 수 있었다. 이후에 두 종류의 식중독 세균에서 프라이머 농도를 달리하여 표적 DNA 증폭 크기의 분포가 서로 다르게 구별할 수 있음을 확인하여 multiplex PCR의 가능성이 있음을 알 수 있었다. ddPCR은 비교적 낮은 검출한계를 가지기 때문에 식품에 적은 농도로 존재하는 식중독 세균의 검출에 활용이 가능할 것으로 생각되었다. 또한 식품의 전처리 조건 확립과 반응조건 확립을 통하여 향후 복잡한 matrix effect를 가지는 식품에서 극 미량의 균 검출도 가능할 것으로 생각되었다.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.203-209
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• 2014

Candelilla wax-in-water nanoemulsions stabilized by Span 80/Tween 80 were prepared by the phase inversion composition (PIC) method. Stable nanoemulsions with droplet diameters below 50 nm could be formed when the hydrophilic-lipophilic balance (HLB) values were between 13.5 and 14.5, surfactant concentration was 5.0 wt%, and the surfactant-wax ratio was 1:1. Increased emulsification temperature and cooling rate were found to improve the emulsion properties. Process of PIC (adding aqueous phase to the wax phase) produced smaller droplet size nanoemulsion compared to the process of adding wax phase to the aqueous phase. The stability of these nanoemulsions was assessed by following the change in droplet diameters with time of storage at room temperature (${\sim}25^{\circ}C$). The size remained constant during 2 months storage time.

• 한국응용과학기술학회지
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• 제20권2호
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• pp.101-109
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• 2003

Provitamin $B_5$ liquid crystal ($PVB_5$-LC) was the new emulsion system to enhance moisturizing activity on the skin. In this study, it should be mentioned that PVB5-LC could be prepared with the main compound of hydrogenated lecithin (HL) in oil-in water (O/W) emulsion. The key ingredient of humectants was contained 2% of provitamin $B_5$ ($PVB_5$) into the $PVB_5$-LC. The best suitable compositions of $PVB_5$-LC were made from 4.0 wt% of HL, 4.0 wt% of cetostearyl alcohol (CSA) as emulsifier and gelling agent, 3.0 wt% of 1,3-butylene glycol (1,3-BG) and 2.0 wt% of glycerin as moisturizers, 3.0 wt% of cyclomethicone (CMC), 3.0 wt% of isononanoate (ININ), 3.0 wt% of capric/caprylic triglyceride (CCTG), 3.0 wt% of macadamia nut oil (MNO) as emollients. As the analytical result of $PVB_5$-LC, it could know that the distribution range of particle size was 0.14 to 12.37 m level (mean size 3.24 m). It was certified the multi lamellar phase around the droplet of liquid crystal when observed the droplet particles through a polarization microscope. And it clinically was tested the effectiveness of moisturizing activity (in-vivo) compared with control sample (O/W emulsion). The effectiveness of moisturizing activity of $PVB_5$-LC with Skincon-200EX after 6 hours went up 49.0% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 25.7% (p<005, n=20). Also, in case of Comeometer CM-825, the moisturizing activity of $PVB_5$-LC after 6 hours rose 36.6% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 10.8%. Therefore, it was known that the effectiveness moisturizing activity of $PVB_5$-LC with HL was remarkably superior compared with O/W emulsion cream.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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• pp.91-98
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• 2000

The fuels of water-in-oil emulsion have a potential of reducing PM(Particulate Matter) and NOx emissions, and increassing combustion efficiency in the furnaces and the burners. For making the most of the beneficial of the secondary atomization due to the microexplosion, the water droplets distributed in the oil must have the optimal sizes. The purpose of this paper is to investigate the water droplet size distribution characteristics of the different types of the static mixers. For analysing the size distribution characteristics efficiently, image analysis system was constructed and an appropriate image processing algorithm was developed. Two kinds of static mixers: Kenics type and RF type, were tested. As a results, RF type static mixer shows a better characteristics in the mean drop sizes, particularly in the condition of high water content.

• Journal of Advanced Marine Engineering and Technology
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• 제25권4호
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• pp.904-911
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• 2001

The fuels of water-in-oil emulsion have a potential of reducing PM(Particulate Matter) and NOx emissions, and increasing combustion efficiency in the furnaces and the burners. For making the most of the beneficial of the secondary atomization due to the microexplosion, the water droplets distributed in the oil must have the optimal sizes. The purpose of this paper is to investigate the water droplet size distribution characteristics of the different types of the static mixers. For analysis the size distribution characteristics efficiently, image analysis system wes constructed and an appropriate image processing algorithm was developed. Two kinds of static mixers: Kenics type and RF type, were tested. As a results, RF type static mixer shows a better characteristics in the mean drop size, particularly in the condition of high water content.

• Food Science and Biotechnology
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• 제18권3호
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• pp.610-617
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• 2009

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey protein concentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oil because the majority of droplets were relatively small ($d_{32}=0.34$ and $0.35\;{\mu}m$, $d_{43}=0.65$ and $0.37\;{\mu}m$ for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was gradually dropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 types of emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated that WPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. It implies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.330-342
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• 2003

The formation of emulsions and micelles in water/ceramide PC104/CholE $O_{20}$/C$_{16}$E $O_{20}$ and water/ceramide PC104/CholE $O_{20}$ mixtures was investigated through the phase behavior studies. The phase diagrams showed the existence of micelle and emulsion regions in both systems. The mixed surfactant system (CholE $O_{20}$/C$_{16}$E $O_{20}$) showed the wider micellar and emulsion regions than the single surfactant system (CholE $O_{20}$). From FT-IR measurements, it was found that the polyoxyethylene (POE) groups of surfactants formed the hydrogen bonds with amido carbonyl group in ceramide PC104. This result indicated that the hydrophilic part (EO) of surfactants could stabilize the lamellar structure and emulsion of ceramide PC104. The mixed surfactant system (CholE $O_{20}$/C$_{16}$E $O_{20}$) resulted in the smaller emulsion droplet size due to the effect of curvature at the interface, thus further increasing emulsion stability. With the penetration of $C_{16}$E $O_{20}$into the interfacial layer of surfactants in emulsion, the curvature of the interface might be altered for the formation of smaller emulsion droplets. The mixed surfactant system could incorporate up to 4 wt. % of ceramide PC104 into emulsion more than single surfactant system.ystem.m.

• Journal of Pharmaceutical Investigation
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• 제41권4호
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• pp.249-253
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• 2011

To develop a sildenafil lactate-loaded solid self-emulsifying drug delivery system (SEDDS) with a fast onset of action and immediate action of erection, sildenafil lactate (0.3 g), which was prepared using a spray dryer, was dissolved in 4.7 g of the mixture of glyceryl monooleate/Transcutol/ Tween 20 (3/0.5/1, g). Its emulsion droplet size and pharmacokinetics in rabbits were evaluated compared with sildenafil citrate-loaded commercial tablet. The sildenafil lactateloaded SEDDS showed an emulsion droplet size of about 300 nm. In pharmacokinetics study, it gave significantly faster Tmax than did the commercial tablet. Thus, the sildenafil lactate-loaded SEDDS at the one-third drug dose compared to sildenafil citrate-loaded conventional tablet might induce a fast onset of action and immediate erection without enhanced bioavailability compared with the sildenafil citrate-loaded commercial tablet.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.815-820
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• 2009

Binary nanoemulsions which are defined as the, oil-droplet suspensions in binary solution ($H_2O$/LiBr), are developed to enhance the heat and mass transfer performance of absorption refrigeration systems. In this study, a novel two-step method is proposed to prepare the stable oil-in-binary solution (O/S) emulsion. Polymer is used as a steric stabilizer to stabilize the oil-droplets in a strong electrolyte ($H_2O$/LiBr). It is found that the thermal conductivity of the binary nanoemulsion is inversely proportional to the emulsion size while the concentrations of oil and $H_2O$/LiBr are less dominant for the thermal conductivity of binary nanoemulsions.

• 한국가시화정보학회지
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• 제20권3호
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• pp.10-18
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• 2022

We present an experimental investigation on emulsions created during the impact process between a surfactant-laden droplet and an oil layer on water. By varying the surfactant concentration and the viscosity of oil layer, we created emulsions and visualized them using multi-dimensional high-speed imaging. Our analysis shows that the emulsions are more likely to be unstable and decay within a minute if the impacting droplet contains more surfactant. We also found that there are three mechanisms of generation of emulsions depending on the concentration of surfactant and the viscosity of oil layer; the jet pinch-off, cavity pinch-off, and tearing of oil layer. Jet and cavity pinch-off turned out to be dominant mechanisms for high oil viscosities, while tearing of oil layer is dominant for low oil viscosities. Our result is potentially useful in designing optimal dispersant properties for offshore oil contamination.