• The Korean Journal of Food And Nutrition
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• v.37 no.1
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• pp.48-56
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• 2024

Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.320-326
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• 2018

Background: Explosive puffing can induce changes in the chemical, nutritional, and sensory quality of red ginseng. The antioxidant properties of ethanolic extracts of red ginseng and puffed red ginseng were determined in bulk oil and oil-in-water (O/W) emulsions. Methods: Bulk oils were heated at $60^{\circ}C$ and $100^{\circ}C$ and O/W emulsions were treated under riboflavin photosensitization. In vitro antioxidant assays, including 2,2-diphenyl-1-picrylhudrazyl, 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid, ferric reducing antioxidant power, total phenolic content, and total flavonoid content, were also performed. Results: The total ginsenoside contents of ethanolic extract from red ginseng and puffed red ginseng were 42.33 mg/g and 49.22 mg/g, respectively. All results from above in vitro antioxidant assays revealed that extracts of puffed red ginseng had significantly higher antioxidant capacities than those of red ginseng (p < 0.05). Generally, extracts of puffed red and red ginseng had high antioxidant properties in riboflavin photosensitized O/W emulsions. However, in bulk oil systems, extracts of puffed red and red ginseng inhibited or accelerated rates of lipid oxidation, depending on treatment temperature and the type of assay used. Conclusion: Although ethanolic extracts of puffed red ginseng showed stronger antioxidant capacities than those of red ginseng when in vitro assays were used, more pro-oxidant properties were observed in bulk oils and O/W emulsions.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.407-416
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• 2003

In this study, we evaluate the correlation between in vitro and in vivo determination of SPF of sunscreen products containing various ingredients depending on emulsification system. For in vitro approach, we determined SPF by the method of Diffey and Robson using an TransporeTM tape(3M Health care, USA) and SPF 290-analyzer(Optometrics Co. USA). SPF values and standard deviations are calculated and displayed after completion of the run. In vivo SPF values are determined according to KFDA (the Korea Food and Drug Administration) method in panels of Fitzpatrick's skin type II or III. We investigated the difference in SPF data of sunscreen ingredient according to emulsification system. The in vivo SPF data is high in water-in oil(W/O) emulsion than in oil-in water(O/W) emulsion samples. The difference may be due to the particular behavior in each vehicles and its presence on skin surface may produce a different sunscreen film. We obtained the corrlation coefficient between in vitro and in vivo SPF data for O/W (R-squre=0.72 )and W/O emulsion(R-squre=0.77). From these results, we suggest the improvement of methodology using Transpore$^{TM}$ tape as substrate to increase the predictability of in vitro method.d.

• Economic and Environmental Geology
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• v.46 no.1
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• pp.51-61
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• 2013

Researches on the oil recovery enhancement using the nanotechnology has recently been studied in the United States. The previous researches has focused mainly on the flow characteristics of nanoparticles in porous media, and the stability of the nano-emulsion itself. However, the analysis did not deal with the size effects between a nano-emulsion and the pore size which has an important role when nano-emulsion flows in the porous media. In this research, nano-based emulsion was fabricated which is able to be applied for the enhanced oil recovery techniques and its characteristics was analyzed. In addition, in order to identify the characteristics of nano-emulsions flowing through the porous media, the size effect was analysed by filtering test. According to the results, when the emulsion was fabricated, SCA(Silane Coupling Agent) or PVA(Poly Vinyl Alcohol) are added to improve the stability of emulsion. As the ratio of the decane to water increased, the viscosity of emulsion and the droplet size also increased. For the filtering test at the atmospheric conditions, the droplet did not go through the filter; only the separated water from the emulsion was able to be filtered. This phenomenon occurred because the droplet was not able to overcome the capillary pressure. At the filtering test by suction pressure, most of the emulsion was filtered over the filter size of $60{\mu}m$. However, the ratio of filtration was rapidly degraded at less than $45{\mu}m$ filters. This is caused due to deformation and destruction of the droplet by strong shear stress when passing through the pore. The results from the study on the basic characteristic of nano-emulsion and filtering test will be expected to play as the important role for the fabrication of the stable nano-emulsion or the research on the recovery of residual oil in porous media.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.15-24
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• 1989

The transport of Chromium(Vl) ion from waste water throughl the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid parafnn oil were analyzed. Extraction euperiments were carried out to observe the effect of system variables, such as stirring speed, concentration of carrier, and NaOH in internal aqueous phase, and concentrations of H$_2$SO$_4$and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt. ％ and liquid parafnn oil concentration is 50 vol. ％. The transport of chromium(VI) ion in bacth extractor increased with increasing carrier concentration, the volume ratio of emulsion to external aqueous phases, and initial concentration of chromium(VI) ion under the optimum stirring speed of chromium(VI) ion below 2 ppm. The theoretical equation on the transport of chromium(Vl) ion agreed well with the experimental results.

• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.33-40
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• 2007

This study investigated the antioxidative and antimicrobial activities of nutmeg (water, ethanol extract and essential oil). The total phenol contents of water, ethanol extract and essential oil were 3.4%, 16.9%, and 3.2%, respectively. Hydrogen donating abilities of water, ethanol extract and essential oil at 1,000 ppm were 4.9%, 41.8% and 6.8%, respectively. The antioxidative activities in linoleic acid substrates were in the order of BHT > ethanol > extract > ${\alpha}$-tocopherol > essential oil > water extract. The antioxidative activities in linoleic acid emulsion substrates were in the order of BHT > water extract > essential oil > ethanol extract > ${\alpha}$-tocopherol. In antimicrobial activity, ethanol extract showed growth inhibition effect against Micrococcus luteus, Bacillus cereus and Salmonella enteritidis, and the essential oil showed growth inhibition effect against Micrococcus luteus. However, no antimicrobial activity of water extract was observed. The nitrite-scavenging abilities of water, ethanol extract and essential oil at 1,000 ppm were 4.5%, 28.8% and 98.8%, respectively, and the ACE inhibitory activities were 0.2%, 11.0% and 10.0%, respectively.

• Tribology and Lubricants
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• v.2 no.2
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• pp.27-31
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• 1986

By Bong Goo Rhee, College of Engineering, The Univ. of Won Kwang (344-2, Sinyongdong, Iri-shi, 510 Chunpuk-do, Korea), Yoshitsugu Kimura and Kazumi Okada, Institute of Interdisciplinary Research, Faculty of Engineering, The Univ. of Tokyo(4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan), Katsuyuki Hashizume, Taiho Kogyo(2-47 Hosoya-Cho, Toyoda-Shi 471, Japan) and Chang Heon Chi, The G. S of Chon buk N. Unv. It is empirically known that, in concentrated conjunctions lubricated with O/W emulsions, only the oil is entrained to form elastohydrodynamic films. In the present work, this phenomenon is studied experimentally and the result is compared with a theory Which employes a starved lubrication concept. The experiment is conducted in a four roller machine with 0/W emulsions of varying concentration of oil, i.e. beef tallow, in which the film thickness is determined by detecting the rate of X-ray transmission through the conjunction. Excellent agreement is found between the experimental and the theoretical results.

• Clean Technology
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• v.23 no.3
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• pp.325-330
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• 2017

This study presents the preparation of n-tetradecane-in-water emulsions with different weight ratios of n-tetradecane and water, and their potential application in packaging and shipping vaccines. The size and distribution of the n-tetradecane droplets are characterized using optical microscopy and light scattering methods, respectively. The thermal properties of the emulsions are determined using the T-history method. In the results, the emulsions, which are comprised of 17 ~ 30 wt% oil, 3 wt% surfactant, and 67 ~ 80 wt% water, are stable and have droplet sizes in the range of 100 to 800 nm. The thermal properties demonstrate that subcooling is prevented through increasing the droplet size. The results indicate that the n-tetradecane/water emulsions containing 25 ~ 35 wt% n-tetradecane, with a melting point of $2{\sim}8^{\circ}C$ and a latent heat of $227.0{\sim}250.8kJ\;kg^{-1}$, are good candidate materials for packaging and shipping vaccines.

• Geosystem Engineering
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• v.21 no.6
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• pp.335-343
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• 2018

Alkali-surfactant polymer flooding has become an important technique to improve oil recovery following the development of oil fields while the function of emulsification in enhanced oil recovery is rarely considered in the existing mathematical model for numerical simulation. In this paper, the mechanism of improving the recovery of the emulsification was analyzed in ASP flooding, and a relatively perfect mathematical model with deep filtration-theory was established, in which oil-water volume equation, saturation equation, viscosity equation, and permeability reduction equation are included. The new model is used to simulate the actual block of an oil field; the simulated results of the new model and an old model without considering the emulsification are compared with the actual well history. It is found that new model which is easy to be realized in numerical simulation has a high precision fitting, and the effect of adding oil and decreasing water is obvious. The sensitivity of emulsification was analyzed, and the results show that the water reducing funnel becomes wider and the rate of water cut decreases rapidly with the increase of emulsifying capacity, and then the rate of recovery slows down. The effect of increasing oil and decreasing water is better, and the degree of recovery increases. The emulsification of the ASP flooding is maintained at a moderate level, which corresponds to ${\Phi}=0.2$ in the new model, and the emulsification is applied to realize the general mathematical quantitative description, so as to better guide the oilfield development.

• Bulletin of Food Technology
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• v.24 no.3
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• pp.377-387
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• 2011