• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.324-330
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• 2015

When diagnostic ultrasounds are used, an ultrasonic transmission media is used to effectively transmit the ultrasonic energy. Types of ingredients of polymer hydro gel, emulsion, and oil gel were compared with commercialized products by measuring characteristics of ultrasonic transmission media such as skin lubricity, skin moisturizing, and dryness speed which were contained in each different media. The mean friction coefficient measured to investigate skin lubricity showed high in the agent containing a large amount of oil, whereas the mean friction coefficient of the low viscosity emulsion did not show a significant difference with that of the polymer hydro gel. The moisture evaporation measured to investigate the dryness speed of the agent showed highest in polymer hydro gel. This showed that the larger amount of oil it had, the less moisture evaporation occurred. For skin moisture measured to investigate moisturizing characteristics of skin, low viscosity emulsion showed high in moisture content, whereas it showed slowest reduction in moisture content. As a type of emulsion appropriately containing water and oil is superior in skin moisturizing and skin tenderness, it is expected to serve as a dosage form of new ultrasonic transmission media.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.632-636
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• 1993

Gel strength of fish protein at various processing conditions such as heating temperature, heating time and salt content was determined by using compressive stress and residual delay time of ultrasonic wave. The compressive stress, interpreted as indicating the relative gel strength, was increased with increasing the heating temperature and heating time, and with decreasing the salt content, while the delay time of ultrasonic wave reduced, indicating that the gel strength and the delay time are inverse proportion. The result of the multiple regression analysis with factorial design showed that the model equation consisted with delay time and processing condition variables gave the good prediction of the gel compressive stress which was coincided with compressive stress measured.

• Polymer(Korea)
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• v.30 no.5
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• pp.412-416
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• 2006

The superparamagnetic nanoparticles were prepared by coprecipitation of $FeCl_3$ and $Na_2SO_3$ with $NH_4OH$ and the surface charge on hydroxyl group by chemisorption was changed depending on pH. We studied correlation between surface charge of magnetite and pH. Using this correlation the properties of poly (acrylic acid) (PAAc) hydrogel embedded with magnetite was studied. The magnetite was characterized by XRD, AFM. and FTIR. The zeta-potential of magnetite was influenced by pH: great positive charge was shown high under the pH 4 and isoelectric point was found at pH 7. The hydrogen bond formed by combining oi PAAc hydrogel and magnetic colloid under pH 4 caused tensile strength to increase, while swelling and elongation at break to decrease. The result confirmed that the magnetic moment was increased proportionally to the content of magnetite.

• KSBB Journal
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• v.15 no.6
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• pp.548-555
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• 2000

A hydrogel, poly(N-isopropylacrylamide-co-N, N-dimethylaminopropylmethacrylamide), sensitive to both pH and temperature, was synthesized and characterized at $^13∼23{\circ}C$ and pH of 10.3∼12.3. The gel was more transparent and mechanically stronger at lower preparation temperature and pH. Large pores observed in scanning electron microscope seem to be responsible for the lower biomolecular separation efficiency. The lower critical solution temperature (LCST) decreased at a higher polymerization temperature. At $25^{\circ}C$, which is lower than the LCST, the gel was swollen regardless of the solution pH. At $40^{\circ}C$, however, the gel was swollen at neutral and acidic pHs even though the temperature was higher than the LCST. The gel collapse pH, defined as the point at which the gel made its largest volume decrease per unit pH increment, increased as the gel preparation temperature increased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.377-382
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• 2010

The Present study uses non-Newtonian simulant gel propellant mixed by Water, Carbopol 941, and NaOH solution in order to analyze the gel propellant flow behavior. Rheological data have been measured and obtained prior to the analysis of flow characteristics where water-gel propellant as well as water-gel propellant with $Al_2O_3$ nano particles are both used. The critical Dean number were examined by numerical simulation of gel propellant in the U-shape duct flow. It is found that though gel-nano propellants have higher apparent viscosity, the critical Dean number did not showed notable difference with respect to the water-gel propellant. It is believe that this is due to the fact that the power law index of both propellants have close value, as was demonstrated by Fellouah et al.[1]

• Polymer(Korea)
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• v.29 no.5
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• pp.518-521
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• 2005

Biodegradable polymers and hydrogels have been increasingly applied in a variety of biomedical applications including current drug delivery system and tissue engineering field. ${\alpha},\;{\beta}-Poly$(N-2-hydroxyethyl-DL-aspart-amide), PHEA. is one of poly(amino acids) with hydroxyethyl pendants, which is hewn to be biodegradable and potentially biocompatible. So that, the utilization and various chemical modifications of PHEA have been attempted for useful biomedical applications. In this wort chemical gels based on PHEA were prepared by crosslinking with diisocyanate compound in DMF in the presence of catalyst. Here, the PHEA was prepared from polysuccinimde, the thermal polycondensation product of aspartic acid, via ring-opening reaction with ethanolamine. The preparation of gels and their swelling behavior, depending on the different medium and pH, were investigated. Also the morphology by SEM and simple hydrolytic degradation were observed.

• Polymer(Korea)
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• v.32 no.5
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• pp.421-426
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• 2008

pH-responsive P(MAA-co-EGMA) hydrogel microparticles were synthesized via dispersion photo polymerization and the feasibility of the particles as the cosmetic formulation was investigated. Rh-B and the functional materials for the cosmetic application such as ascorbic acid, adenosine, EGCG, and arbutin were loaded in the P (MAA-co-EGMA) hydrogel microparticles in order to examine the interaction between the hydrogel and the loaded materials. In the loading experiments, Rh-B showed the highest loading efficiency to the P(MAA-co-EGMA) hydrogels due to the electrostatic attraction between the negative charge of the hydrogels and the positive charge of Rh-B at the ionized states. However, the functional materials showed relatively low loading efficiencies because of the electrostatic repulsions between the negative charges of both the hydrogels and the materials at the ionized states. In addition, P(MAA-co-EGMA) hydrogel microparticles showed pH-responsive release behavior of Rh-B according to the external pH changes.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09b
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• pp.166-169
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• 2003

유전자에 대한 정보를 획득하는 기술적인 문제가 해결되면서, 질병 진단을 위한 새로운 접근 방법으로 혈액 속에 있는 모든 단백질(proteome)의 구성을 분석하는 프로테오믹스(proteomics)에 대한 연구가 최근 들어 활발하게 진행되고 있다. 본 논문은 암 진단을 위하여 혈액 중의 단백질의 구성을 측정한 2차원 전기영동 (2D electrophoresis) 젤 데이터를 해석하는 새로운 방법을 제시하였다. 우선 측정된 많은 단백질 스팟(spot) 중에서 T-statistics 방법으로 단백질 스팟들을 선택하였다. 선택된 단백질 스팟들로 이루어진 암 환자와 정상인 두 샘플들의 확률 분포를 각 집단에 따로 적용된 PCA 영역에서 계산하였다. 최종적으로 조건부 확률의 차이에 근거한 베이즈 분류(Bayes classification) 이론을 적용하여 암 진단을 하였다.

• The Korean Journal of Nuclear Medicine
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• v.9 no.2
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• pp.47-54
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• 1975

난포자극호르몬(HFSH)을 클로라민 티를 사용하여 방사성요오드로 표지하였으며 평균 표지수율은 대략 65%이었다. 표지호르몬을 방사면역측정용으로 사용하기 위하여 전분젤 전기영동과 젤여과법으로 분리정제하고 그 분리정제효과를 분석한 결과 젤 여과법이 분리시간, 간편성, 항체와의 결합력 등으로 보아 우수함을 알 수 있었다. 한편 유리표지호르몬과 항체와 결합한 표지호르몬의 비율를 결정하기 위하여 이중항체법을 크로마토전기영동법과 비교하여 본 결과 이중항체법에 의해서만 효과적 비율결정이 가능하였다.

• Journal of the Korean Wood Science and Technology
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• v.18 no.2
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• pp.16-24
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• 1990

아세틸화(化) 고분자(高分子) 축합(縮合)탄닌의 젤침투 크로마토그래피 분석(分析)을 위해 일반적(一般的)으로 사용(使用)되고 있는 폴리스타이렌 표준물질(標準物質)은 부정확(不正確)한 교정(矯正)값을 준다. 한편 유도체화 하지않은 축합탄닌의 젤침투 크로마토그래피는 폴리스타이렌 디비닐벤젠 코폴리머 컬럼과 디메틸 포름아미드를 용매(溶媒)로 사용(使用)하여 매우 만족스럽게 분석(分析)될 수 있었다. 그 컬럼의 교정은 유도처리 되지않은 고분자(高分子) 축합(縮合)탄닌을 이용(利用)하여 수행되었으며 고분자 탄닌을 유도처리 할 필요가 없으므로 탄닌의 신속한 분자량(分子量) 결정(決定)이 가능하고 컬럼 크로마토그래피로 분리(分離)되어지는 탄닌을 연속적으로 분석(分析)할 수 있는 장점(長點)을 가진다.