• 한국초지조사료학회지
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• 제25권3호
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• pp.185-190
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• 2005

본 연구는 2000년 7월부터 12월까지 충남대학교 생명과학대학 내 부속 환경조절축사에서 수행하였다. 공시된 혼파유형별 목초는 관행 혼파초지(orchardgrass 50+tall fescue 20+perennial ryegrass 10+ Kentucky bluegrass 10+white clover $10\%$), 다초종 혼파초지(orchardgrass 40+tall fescue 20+perennial ryegrass 10+Kentucky bluegrass 10+redtop 10+alfalfa 5+red clover $5\%$) 및 단순 혼파초지(orchardgrass 80+red clover $20\%$)의 3처리를 두어 1999년 9월 7일 경운초지조성 방법에 의해 조성된 기존초지에서 수확한 1번초(4월 20일)를 재래산양에 급여하여 목초의 이용성을 비교 분석하였다. 얻어진 결과는 다음과 같다. 건물섭취량은 다초종 혼파초지(30.2g/BWkg/day)가 관행(26.5g/BWkg/day)이나 단순 혼파초지(26.9/BWkg/day)에 비하여 다소 높은 결과를 보였으나 유의적인 차이는 없었다(p>0.05). 건물소화율과 세포내용물질(cellular constituents)의 소화율은 다초종 혼파초지가 관행이나 단순 혼파초지에 비하여 높은 결과를 보였으나 (p<0.05), NDF와 ADF 소화율은 혼파유형간에 유의적인 차이가 인정되지 않았다(p>0.05). 외관상 생물가는 다초종 혼파초지$(55.1\%)$가 관행 $(54.0\%)$이나 단순 혼파초지$(53.3\%)$에 비하여 높은 편이었으나 유의적인 차이는 인정되지 않았다.(p>0.05). 외관상 대사에너지 축적률은 다초종 혼파초지$(60.2\%)$가 관행$(56.9\%)$이나 단순 혼파초지$(55.9\%)$에 비하여 높았다(p<0.05). 이상의 결과로 보아, 재래산양에 의한 초지 유형별 목초의 질소 및 에너지의 이용성은 대체적으로 다초종 혼파초지가 다른 혼파유형에 비하여 개선되는 결과를 보였다.

• Journal of Animal Science and Technology
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• 제47권6호
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• pp.1081-1086
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• 2005

본 시험은 혼파유형별로 초지의 건물수량과 품질을 비교 검토하여 집약적인 경운초지에 적합한 혼파유형을 제시하고자 1999년 9월부터 2002년 12월까지 충남대학교 생명과학대학내 부속 초지시험포장에서 수행하였다. 공시된 혼파유형은 관행 혼파초지(orchardgrass 50%+tall fescue 20% + perennial ryegrass 10% + Kentucky bluegrass 10% + white clover 10%), 다초종 혼파초지(orchardgrass 40% + tall fescue 20% + perennial ryegrass 10% + Kentucky bluegrass 10% + redtop 10% + alfalfa 5% + red clover 5%) 및 단순 혼파초지(orchardgrass 80% + red clover 20%)의 3유형을 두어 시험하였다. 얻어진 시험결과는 다음과 같다. 3년 평균 ha당 건물수량은 혼파유형에 따라 차이를 보여, 다초종 혼파초지가 13,070kg/ha로 다른 관행(11,206kg)이나 단순 혼파초지(11,291kg)에 비하여 높은 결과를 나타내었다(p<0.05). 화학적성분 및 건물소화율(DMD)은 혼파휴형에 따라 차이를 보였는데, CP 함량은 다초종과 단순 혼파초지가 관행 혼파초지에 비하여 높았으며(p<0.05), 섬유소 물질의 함량은 대체적으로 관행 혼파초지에서 높은 결과를 나타내었다. 그러나 DMD는 다초종 혼파초지가 다른 혼파초지에 비하여 높은 결과를 나타내었다(p<0.05). 3년 평균 조단백질CPDM) 수량과 가소화건물(DDM) 수량은 다초종 혼파초지가 관행이나 다른 혼파초지에 비하여 높은 결과를 나타내었다(p<0.05). 이상의 결과를 종합해 볼 때, 혼파유형에 따라 건물수량과 품질이 달라지고 있음을 확인할 수 있었으며, 다초종 혼파초지가 관행이나 단순 혼파초지에 비하여 건물수량과 품질을 높이는데 효과적이라 하겠다.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.376-378
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• 1992

A chemical tool was developed for the analysis of complex mixtures such as crude drugs by the method of pattern recognition. Pattern recognition was accomplished by a multiple reference peak identification method and three kinds of outlier statistics. This tool was tested on the analysis of synthetic mixtures.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.718-724
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• 2006

The heterogeneous association behaviour of various concentration binary mixtures of mono alkyl ethers of ethylene glycol with ethyl alcohol were investigated by dielectric measurement in benzene solutions over the entire concentration range at 25 ${^{\circ}C}$. The values of static dielectric constant $\epsilon_0$ of the mixtures were measured at 1 MHz using a four terminal dielectric liquid test fixture and precision LCR meter. The high frequency limiting dielectric constant $\epsilon_\infty$ values were determined by measurement of refractive index $n_D$ ($\epsilon_\infty\;=\;n_D\;^2$). The measured values of $\epsilon_0$ and $\epsilon_\infty$ were used to evaluate the values of excess dielectric constant $\epsilon^E$, effective Kirkwood correlation factor $g^{eff}$ and corrective correlation factor $g_f$ of the binary polar mixtures to obtain qualitative and quantitative information about the H-bond complex formation. The non-linear behaviour of the observed $\epsilon_0$ values of the polar molecules and their mixtures in benzene solvent confirms the variation in the associated structures with change in polar mixture constituents concentration and also by dilution in non-polar solvents. Appearance of the maximum in $\epsilon^E$ values at different concentration of the polar mixtures suggest the formation of stable adduct complex, which depends on the molecular size of the mono alkyl ethers of ethylene glycol. Further, the observed $\epsilon^E$ < 0 also confirms the heterogeneous H-bond complex formation reduces the effective number of dipoles in these polar binary mixtures. In benzene solutions these polar molecules shows the maximum reduce in effective number of dipoles at 50 percent dilutions. But ethyl alcohol rich binary polar mixtures in benzene solvent show the maximum reduce in effective number of dipoles in benzene rich solutions.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.255-265
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• 2018

The huge amount of solvents used in the semi-conductor and display industry typically result in waste of valuable solvents which often form complex azeotropic mixtures. This study explored a recovery process of a quaternary waste solvent, comprising methyl 2-hydroxybutyrate, propylene glycol monomethyl ether acetate, ethyl lactate, and ethyl-3-ethoxy propionate. In this study, a novel shortcut column method with a graphical approach was exploited for the distillation column design of complex quaternary azeotropic mixtures. As a result, the proposed shortcut method and design procedure solved the complex separation paths successfully with less computational efforts while achieving all requirements for component purity.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1403-1407
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• 2004

Dielectric relaxation measurements on 3-nitrotoluene (3-NT) mixture of dimethylacetamide (DMA), dimethylformamide (DMF) and dimethysulphoxide (DMSO) have been carried out across the entire concentration range using Time domain reflectometry technique at 15, 25, 35 and $45^{\circ}C$ over the frequency range from 10 MHz to 20 GHz. For all the mixtures, only one dielectric loss peak was observed in this frequency range and the relaxation in these mixtures can be well described by a single relaxation time using Debye model. Bilinear calibration method is used to obtain complex permittivity ${\varepsilon}^{*}({\omega})$ from complex reflection coefficient ${\rho}^{*}({\omega})$ over frequency range 10 MHz to 20 GHz. The excess permittivity, excess inverse relaxation time, Kirkwood correlation factor, molar energy of activation are also calculated for these mixtures to study the solute-solvent interaction.

• 분석과학
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• 제16권4호
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• pp.333-338
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• 2003

Inclusion selectivity of a three-dimensional piperazine-ligated cyanocadmate host complex, $[Cd_x(CN)_{2x}\{HN(CH_2CH_2)_2NH\}_y]{\cdot}zG$, has been investigated for benzene (B), toluene (T), ethylbenzene (E), o- (O), m- (M), and p-xylene (P) isomers as the aromatic guest molecules. From the binary, ternary and quarternary guest mixtures of E and xylene isomer (X), the order of inclusion selectivity in the host complex is O>E>P>M. From the binary to quinary BTX mixtures, the order of preference in the complex is seen to be B>T>O${\gg}$P>M.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권5호
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• pp.18-28
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• 2009

다양한 물리화학적 특성을 지닌 12개의 유기오염물이 저표면적의 무기물 지반 수착제로 수착 시 12개의 유기오염물을 적은 수의 pseudocompound로 집략화하는 접근법(lumped approach)의 타당성과 정확성을 평가하였다. 집략화 접근법은 복잡한 혼합 유기오염물의 수착 거동을 근거로 통계적인 처리방법인 집략분석(cluster analysis)을 통해 개발되었다. 집략화 접근법을 이용해 수용액상에서 복잡한 혼합 유기오염물이 친수성 무기물로 수착 시 감소된 수의 집략화된 오염물(pseudocompound)과 집략화된 오염물의 수착 매개변수($K_f$, n)를 이용하여 복잡한 혼합 유기오염물의 수착을 설명할 수 있었다. 또한, 실험을 수행하지 않고(a priori) 복잡한 혼합 유기오염물 내 각 유기오염물의 특성(${\gamma_w}^{sat}$)을 근거로 pseudocompound를 예측할 수 있었다. 따라서 집략화 접근법은 복잡한 혼합 유기오염물의 수착거동을 단순화하여 반응관련 매개변수 산출에 필요한 시간과 비용을 감소시켜주고 통계적으로 정확성이 동일한 범위 내의 실용적인 수착 결과를 제공해 줄 수 있다. 향후 더 많은 반응 인자소결합크기, 수착제 내 반응 지점 수 및 반응성 그룹 등)를 고려한 다중회귀분석(multiple regression analysis)을 통해 집략화 접근법(lumped approach)의 정확도를 높일 필요가 있다고 판단된다.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2143-2147
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• 2013

Matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a very effective method for lipid mass fingerprinting. However, MALDI MS suffered from spectral complexities, differential ionization efficiencies, and poor reproducibility when analyzing complex lipid mixtures without prior separation steps. Here, we aimed to find optimal MALDI sample preparation methods which enable selective or class-wide mass fingerprinting of two totally different lipid classes. In order to achieve this, various matrices with additives were tested against the mixture of phosphatidylcholine (PC) and cerebrosides (Cers) which are abundant in animal brain tissues and also of great interests in disease biology. Our results showed that, from complex lipid mixtures, 2,4,6-trihydroxyacetophenone (THAP) with $NaNO_3$ was a useful MALDI matrix for the class-wide fingerprinting of PC and Cers. In contrast, THAP efficiently generated PC-focused profiles and graphene oxide (GO) with $NaNO_3$ provided Cer-only profiles with reduced spectral complexity.

• 약학회지
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• 제48권1호
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• pp.6-12
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• 2004

Near-infrared spectra of methanol-water mixtures and acetonitrile-water mixtures were acquired to find interactions between solvents widely used for reverse-phase liquid chromatography. Mixtures were prepared to give a series of increasing mole fractions of methanol or acetonitrile in water. Data matrices of acquired spectra were analyzed to determine the proper number of principal components of each mixture system using Malinowski's factor indicator function. Initial guess of score matrix and loading matrix were calculated by nonlinear iterative partial least squares (NIPALS) algorithm for faster computation. Iterative target transform factor analysis (ITTFA) was applied to convert the initial estimation of score matrix to true concentration profile and loading matrix to pure spectra of pure components of the mixtures. In case of methanol-water the number of principal components was found to be 4 and those initial guess of factors were converted to the pure spectra of water methanol and two kinds of complexes. In case of acetonitrile-water the number of pure components of the mixtures was found to be 3 and the pure spectrum of acetonitrile-water complex was found. The nonlinear characteristics of concentration profiles of complexes in the solvent mixtures may give a good criteria in understanding their elution characteristics in reverse-phase liquid chromatogrsphy.