• Journal of the Korean Applied Science and Technology
• /
• v.37 no.6
• /
• pp.1619-1626
• /
• 2020

In this study, the physical properties of water-dispersible polyurethane resins synthesized with polyammonium phosphate and HMDI were studied by coating film samples and full-grain surfaces. Solvent resistance was found to be unchanged in all samples, and in terms of tensile strength, DPU-AP3 (1.887 kgf/㎟) containing the most ammonium polyphosphate showed the lowest physical properties. The elongation rate was measured as 54 8% in the sample containing a large amount of ammonium polyphosphate. Abrasion resistance was measured as 548 mg.loss of a sample containing a lot of ammonium polyphosphate, and it was confirmed that the physical properties of the blended resin of ammonium polyphosphate and water-dispersible polyurethane were changed.

• Microbiology and Biotechnology Letters
• /
• v.38 no.1
• /
• pp.112-115
• /
• 2010

In this study, the antibacterial activity and the moisturizing effect of cream contaning Persicaria hydropiper L. extract were investigated by clinical trial. MIC values of ethyl acetate fraction from Persicaria hydropiper on P.acnes, S.aureus, P.ovale were 0.13~0.25%. The results showed that the antibacterial activity of the ethyl acetate fraction was higher than or equal to the methyl paraben and quercetin. The cream containing the ethyl acetate fraction of Persicaria hydropiper L. extracts was formulated for skin hydration effect. Also, the transepidermal water loss (TEWL) and the water contents in skin were measured. The cream containing Persicaria hydropiper L. extract was applied to the right lower arm. After 180 min, TEWL of parts was decreased as $6.5\;g/m^2h$ (experimental cream) and $7.5\;g/m^2h$ (placebo cream) respectively. And the water contents in skin were increased by 2~4% than the placebo cream. These results indicate that extract/fractions of Persicaria hydropiper L. can function as high potential as bactericide against the skin pathogenic bacteria and the increase of skin hydration of the cream containing extract could be applicable to new functional cosmetics for antiaging.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.36 no.4
• /
• pp.315-321
• /
• 2010

In this study, we investigated the antibacterial activity and the skin moisturizing effect of cream contaning Cedrela sinensis A. Juss shoots extracts. MIC values of ethyl acetate fraction from Cedrela sinensis A. Juss shoots extracts on P. acnes and S. aureus were 0.13 %, 0.03% respectively and P. ovale and E. coli were 0.25 % equally. The results showed that the antibacterial activity of the ethyl acetate fraction on P. acnes and S. aureus were higher than the methyl paraben. The cream containing the ethyl acetate fraction from Cedrela sinensis A. Juss shoots extracts was formulated and its skin moisturizing effect was evaluated in a clinical trial. The skin hydration and transepidermal water loss (TEWL) were investigated after topical application of the cream. The skin hydrating effect of the cream containing Cedrela sinensis A. Juss shoots extract was 10 ~ 15 % higher than the placebo cream, and transepidermal water loss was decreased to 6.7 g/$m^2h$ in the subjects applied with cream containing the ethyl acetate fraction of Cedrela sinensis A. Juss shoots extracts. These results indicate that ethyl acetate fraction from Cedrela sinensis A. Juss shoots extracts could be applicable to new functional antibacterial cosmetics.

• Analytical Science and Technology
• /
• v.16 no.4
• /
• pp.277-282
• /
• 2003

The amount of water for the cultivation of citrus is different based on the growing period. The effect of water stress induces to enhance of sugar accumulation in citrus. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine the water content of citrus leaves non-destructively by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from 'Okitsu' Satusuma mandarin leaves (Citrus unshiu Marc.) ranging from 20.80 to 69.98% of water content by loss on drying method, and NIR reflectance spectra of citrus leaves were acquired by using a fiber optic probe. It was found that the variation of absorbance band 1450 nm from OH vibration of water depending on the water content change. Partial least squares regression (PLSR) was applied to develop a calibration model over the spectral range 1100-1700 nm. The calibration model predicted the water content for the validation set with a standard errors of prediction (SEP) of 0.97%. In order to validate the developed calibration model, routine analyses were performed using independently prepared citrus leaves. The NIR routine analyses showed good results with those of loss on drying method with a SEP of 0.81%. The rapid and non-destructive determination of the water content in citrus leaves was successfully performed by portable NIR system.

• Journal of Adhesion and Interface
• /
• v.22 no.2
• /
• pp.39-46
• /
• 2021

Waterborne polyurethanes (WPU) was synthesized using polyester polyol and polycarbonate polyol containing 3-Methyl-1,5-pentanediol (MPD) in a branched structure. To compare physical properties, WPUs were synthesized using polyester polyol obtained from 1,4-butanediol (BD) and adipic acid and polycarbonate polyol obtained from 1,6-hexane diol (HD)/ 1,4-butanediol (BD). This study investigated the effect of polyol molecular structure (molecular structure in soft segments) on the physical properties of WPUs. In the case of WPUs synthesized using polyols containing MPD, 100% modulus and tensile strength were lower than that without MPD, and elongation was higher. The transparency of WPU films with MPD were slightly better than WPU films without MPD.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.12 s.115
• /
• pp.1172-1180
• /
• 2006

The backscattering coefficients of a bare soil surface were measured using an R-band polarimetric scatterometer, which were used to verify the validities of scattering models and inversion algorithms. The soil moisture contents and the surface roughness parameters (the RMS height and correlation length) were also measured from the soil surface. The backscattering coefficients were obtained from several scattering models with these surface parameters, and the computation results were compared with the measured backscattering coefficients. The soil moisture contents of the surface were retrieved from the measured backscattering coefficients, and compared with the measured surface parameters. This paper shows how well the scattering models agree with the measurements, and also shows the inversion results.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.4
• /
• pp.1243-1249
• /
• 2018

Ceramides are commonly studied and developed in the cosmetics industry as ingredients that help a moisturized skin and strengthen a skin barrier. In this study, we determined how much great effects the moisturing cream containing a ceramide, obtained from evening primrose oil instead of using a common synthetic ceramide, made on the changes in moisturizing and transdermal water loss of skin. The result showed that the cream with a ceramide showed much better results than the cream without a ceramide at the skin moisture resistance and transdermal water loss of skin.

• Journal of Adhesion and Interface
• /
• v.22 no.1
• /
• pp.22-28
• /
• 2021

Products using diatomaceous earth, which are used in various fields, are optimized for moisture absorption, but have problems such as high hardness, powder flying, and rough surface feel. To improve this, an olefin-based foam having low hardness and high elasticity was prepared by adding an excessive amount of inorganic material using EVA (Ethylene vinyl acetate) having low hardness and excellent elasticity. Diatomaceous earth was added to impart moisture absorption characteristics of the foam, and the moisture absorption/drying characteristics showed a moisture absorption rate of about 10 to 15% and a moisture drying rate of 10 to 70% depending on the content of the diatomaceous earth. Through this study, it was possible to manufacture a water-absorbing olefin-based foam with diatomaceous earth added, and it was confirmed that the diatomaceous earth added to the foam had a great influence on water absorption and dissipation due to its microstructure and characteristics.

• KSBB Journal
• /
• v.8 no.5
• /
• pp.417-423
• /
• 1993

The effect of moisture content of biocatalyst on the performance of a gas phase continuous bioreactor was investigated along with study on the mass transfer limitation. The biocatalysts whose moisture contents are 46.2% and 37.2%, respectively were prepared by immobilization of alcohol oxidase on Amberlite IRA-400, following by slow dehydration method, and packed into a column. Relative production rate (RPR), acetaldehyde composition ($X_p$) and conversion (X) of biocatalysts (37.2%) are better than those of biocatalysls (46.2%), and it was considered that these are attributed to the mass transfer enhancement in the gas phase compared with the aqueous phase.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1997.10a
• /
• pp.73-74
• /
• 1997

1. 서론 : 공기중의 산소와 질소를 분리하여 공기 중에 21% 함유된 산소를 보다 높은 농도(21%이상)로 농축하기 위한 기초자료로서 건조 산소(dry O$_2$)와 건조 질소(dry N$_2$)의 투과도를 측정하였다. 그러나 공기중에는 항상 수분이 포함되어 있으므로 공기 중에 함유된 수분(water vapour)에 의한 산소 투과도와 질소 투과도의 변화를 측정하기 위하여 상대숩도 및 압력차이에 따른 영향을 고찰하였다. 그리고 분리막공정에서 순수기체의 막에 대한 투과도를 알 수 있다면 기체 혼합물에 대한 이상분리인자(ideal separation factor)를 알 수 있으며, 이를 이용하여 분리막의 분리 성능 예측이 가능하므로 투과도 예측식을 얻는다는 것은 매우 중요하다. 본 연구에서는 counter-current model을 이용하여 기체 혼합물의 투과도를 예측하고 실험치와 비교하였다.