• 한국식생활문화학회지
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• 제16권4호
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• pp.316-322
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• 2001

This study was performed to investigate flavor modification effects of ${\beta}-cyclodextrin$ $({\beta}-CD)$ inclusion complex on the flavor of Doenjang (Korean traditional fermented soy paste) with various substitution levels of 10, 20, and 30%. Water and protein contents of the substituted samples showed significantly lower values compared to those of control(p<0.05). Results of DSC(Differential Scanning Calorimetry) showed that significantly higher ${\Delta}H$ values (386.03 and 304.23) in the 20 and 30% substituted samples represented the stabilized internal cell structures(p<0.05). Internal structures observed with the scanning electronic microscope tended to be less rough and organized making even and ordered internal cell structures as the substitution levels were increased. Results of sensory evaluation showed significantly higher savory flavor and significantly lower bitter and astringent flavors with the substituted samples compared to those of control(p<0.05). Results from this study showed the substitutions of ${\beta}-CD$ could possibly modify unfavored flavors of Doenjang while keeping the unique, nutritional and functional properties when ${\beta}-CD$ was used as a flavor modifier.

• Archives of Pharmacal Research
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• 제23권2호
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• pp.163-166
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• 2000

The effects of modifiers such as methanol, water diethylamine in methanol (10 v/v %), and diethylamine in water (10 v/v %) were investigated at three different concentrations (1, 5, and 10 v/v %) of the modifiers in supercritical $CO_2$ (SC-$CO_2$) in order to enhance the supercritical fluid extraction (SFE) efficiency of cephalotaxine from Cephalotaxus wilsoniana Leaves. Among the modifiers employed, methanol basified with diethylamine was found to greatly enhance the extraction efficiency relative to any other modifiers employed. The results suggest that cephalotaxine in plant matrices may be readily changed from SC-$CO_2$-insoluble salt to SC-$CO_2$-soluble free base by basified modifiers. In addition, SC-$CO_2$modified with basified methanol could enhance the extraction efficiency of cephalotaxine more than 30% when compared to the conventional organic solvent extraction.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1023-1028
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• 2014

Protonated caffeine ($CH^+$) and glucosamine ($GH^+$) overlapped in an analysis with ion mobility spectrometryquadrupole mass spectrometry. Ethyl lactate vapor (L) at different concentrations from 0 to 22 mmol $m^{-3}$ was added as a buffer gas modifier to separate these signals. The drift times of $CH^+$ and $GH^+$ increased with L concentration. The drift time increase was associated to clustering equilibria of $CH^+$ and $GH^+$ with one molecule of L and the equilibrium of $GH^+$ was more displaced to the formation of $GLH^+$ than that of $GLH^+$. $GH^+$ clustered more to L than $CH^+$ because $GLH^+$ formed more stable hydrogen bonds (26.30 kcal/mol) than $GLH^+$ (24.66 kcal/mol) and the positive charge in $GH^+$ was more sterically accessible than in $CH^+$. The aim of this work was to use theoretical calculations to guide the selection of a buffer gas modifier for IMS separations of two compounds that overlap in the mobility spectra and predict this separation, simplifying that empirical process.

• 한국재료학회지
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• 제30권11호
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• pp.609-614
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• 2020

3 mol% yttria-doped stabilized zirconia (3YSZ) is synthesized by a solvothermal process, and its characteristics are investigated using various methods. Also, the dispersibility of synthesized 3YSZ nanoparticles is observed with the species of surface modifier. The 3YSZ nano sol prepared with an optimum condition is employed in prism coating and its properties are evaluated. The synthesized 3YSZ nanoparticles show a globular shape with about 10 to 20 nm crystallite size. The mixed phases with the nano sol show a high specific surface of 178 ㎡/g. The prism sheet coated with the 3YSZ nano sol present an excellent refractive index, transmittance, and luminance; refractive index is 1.603, transmittance is 90.2 %, and luminance of coating film is improved by 5.9 % compared to that of the film without 3YSZ nano sol. It is verified that the surface modified 3YSZ is suitable as the prism sheet for optical displays.

• 폴리머
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• 제27권1호
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• pp.75-83
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• 2003

다이시아네이트-점토 나노복합재료(dicyantate-clay nanocomposite)를 개질제의 종류와 cation exchange capacity (CEC)의 차이에 따라 용융 in-situ법에 의하여 제조하였고 이들의 물성과 분산을 측정하였다. 다양한 층간 삽입물을 함유하여 다양한 층간거리와 적층밀도를 갖는 montmorillonite (MMT)에 따라 다양한 구조의 나노복합재가 제조되었다. 사용된 다이시아네이트와 점토는 각각의 친화성에 따라 실리케이트 내부로의 삽입정도가 달라졌다. 다이시아네이트-점토 나노복합재료의 분산은 CEC와 개질제의 지방족 사슬길이에 의존하였으며 더 낮은 CEC를 가지고 지방족 사슬의 길이가 짧은 것이 좀 더 분산된 구조를 가지는 것으로 측정되었다. 또한 사용된 개질제에 고분자와의 반응성이 부여되면 층간 삽입이 더욱 용이한 것으로 나타났다. 다이시아네이트 나노복합재료의 전단탄성율은 반응성을 가지며 박리된 구조를 가지는 경우에 더 향상된 물성을 가지는 것으로 나타났다.

• KSBB Journal
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• 제15권5호
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• pp.452-457
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• 2000

Buffer의 특성에 맞는 체류인자에 관한 모텔식을 얻기 위 해서는 buffer 9} 양이온의 농도에 관한 관련식을 실험으로 결 정해야 한다 또한 model 식에서 비이온과 음이온의 체류인 자를 나타내는 ko와 k의 값이 일정한 경향을 나타내고 있기 때문에 buffer의 농도와 modifier의 농도를 동시에 고려한 model 식이 가능하게 된다. 본 연구에서 제안한 모델식을 이용하여 임의의 buffer의 농도에 따른 시료의 체류시간을 예측할 수 있다. 이러한 모텔식을 이용하여 buffer를 이 용한 RP-HPLC의 분석 및 분리조건을 예측할 수 있고 시행 오차적인 방법보다 빠른 시간 내에 최적의 분석 및 분리조건 을 얻을 수 있다

• 한국세라믹학회지
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• 제52권2호
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• pp.128-132
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• 2015

In this study, we prepared cadmium phosphate glasses with various compositions, given by $xCdO-(100-x)P_2O_5$ (x = 10-55 mol%), and analyzed their Fourier transform infrared spectra, dissolution rate, thermal expansion coefficient, glass transition temperature, glass softening temperature, and optical band gap. We found that the thermal expansion coefficient and dissolution rate increased while the glass transition temperature and glass softening temperature decreased with increasing CdO content. These results suggest that CdO acts as a network modifier in binary phosphate glass and weakens its structure.

• 정보처리학회논문지B
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• 제15B권1호
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• pp.69-72
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• 2008

본 연구는 한국어 의존 구조를 결정하는 단계적 의존 구조 분석기를 제안한다. 각 단계에서는 주어진 문법관계의 후보열에서 올바른 문법관계를 결정하는데, 대상문법관계의 종류에 따라 독립적으로 수행된다. 문법관계의 후보열은 미리 학습된 지지벡터기계를 이용하여 주어, 목적어, 보어, 부사어 등 7가지의 문법관계로 추정한다. 각 단계에서는 지지벡터기계 분류기와 어절 간의 거리, 교차 구조 금지, 격 제한의 원칙 등의 한국어 언어 특성을 이용하여 대상문법관계를 결정하며, 모든 단계를 거쳐 최종적으로 전체 의존 구조와 문법관계가 결정된다. 트리 및 문법관계 부착 말뭉치를 이용하여 제안된 시스템을 구현 및 실험하였으며 약 85.7%의 정확률을 얻었다.

• 펄프종이기술
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• 제39권3호
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• pp.41-51
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• 2007

In order to elucidate the effects of types and mixing ratio of GCC and clay, coating color concentration, and types of rheology modifiers on high solid coating, various coating colors were prepared, high shear viscosity was measured and then rheology of the coating colors was analyzed. Coating color concentration was able to be increased from 67% to 69% and from 68% to 71% with a higher GCC ratio and with the rheology modifier instead of the synthetic thickener, keeping similar or improved coating color rheology and coated paper quality. The rheological properties of high solid coating color were superior with smaller average particle sizes of clay and latex, wider size distribution of GCC and higher added amount of latex.

• Bulletin of the Korean Chemical Society
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• 제21권1호
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• pp.56-60
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• 2000

The mechanism of a matrix modification for the trace determination of volatile lead and bismuth by an electro-thermal atomic absorption spectrophotometry was studied by a X-ray diffractometry (XRD). For the investigation of structures, the ash products of the elements were produced by using a palladium as a matrix modifier with or without aluminum or nickel as an auxiliary modifier. The same charring conditions as in the analysis of samples were applied together with much concentrated solution of analytical elements and modifiers in a graphite furnace to get a large amount of the product for XRD. The XRD patterns showed PbPd3 for lead and BiPd3 for bismuth. These mean that the reaction procedures through the charring and atomization were changed from $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}$$Pb^0$ to $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}PbPd_3$ ${\rightarrow}$ Pb o for lead and from $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ Bi o to $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ $BiPd_3$ ${\rightarrow}$ $Bi^0$ for bismuth by the addition of modifiers. The volatile elements were stabilized by the formation of palladium alloys through a charring process. Charring temperatures were raised about 500 $^{\circ}C$ by the alloying and the atomization was also stabilized for the enhancement of sensitivities.