• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.20-30
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• 1993

Liquid Chromatographic behavior of Pd(II) in Isonitosoethylacetoacetate imine IEAA-NR: R=H, CH3, C2H5, n-C3H7, n-C4H9, C6H5-CH2) Chelates were investigated by reversed phase high performance 1iquid chromatography on Micropak MCH-5 Column using Methanol /water as mobile phase. The optimum condition for the separation of Pd-Isonitrosoethylacetoacetate imine chelates were examined with respect to the flow rate, mobile phase strength. It was found that Pd(IEAA-NR)2 chelates were eluted in an acceptable range of the capacity factor value (0 $\leq$ log k' $\leq$ 1), The dependence of the logarithm of capacity factor(k') on the volume fraction of water in mixture with in the binary mobile phase was examined. Also, the dependence of k'on the liquid-liquid extraction distribution constant in methanol-water / n-alkane extraction system was on system was invert tigated for Pd(IEAA-NR)2. Both kinds of dependence are linear, which suggests that the retention of the electroneutral metal chelates be largely due to the solvophobic effect.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.62-79
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• 1994

The quanttative and structural analysis of the binary standard mixtures of albite and quartz, and microcline and albite were carried out using the Rietveld refinement method in order to investigate the accuracy and precision of the method. The quantitative analysis using the Rietveld method results in a standard deviation of 4 wt % for the albite-quartz standard mixtures and 1 wt % for the microcline-albite standard mixtures, suggesting that its accuracy is far better than that of the conventional XRD method in which only a few selected peaks are utilized. Furthermore, the unit-cell parameters of component minerals in mixtures were also estimated accurately during the analysis. It was observed that the refined weight fractions deviate systematically from their measured values when the method is applied to the mixtures that contain minerals with different degrees of preferred orientation, such as albite-quartz mixtures. The preferred orientation parameters and R-values suggest that the systematic deviation is caused as a result of the preferred orientation effect of feldspar crystallites. It is evident that the preferred orientation corrections are of help for the accurate determination of unit-cell parameters, although they may not improve the result of quantitative analysis significantly. The refined weight fraction of the mineral with higher degree of preferred orientation in mixture is greater than the measured one. This is apparently caused by the effect of geometry of feldspar crystallites in the surface of the mounted sample. The Rietveld refinement method minimizes the problems inherent in the traditional XRD methods, such as the line overlap, primary extinction, and preferred orientation effect, by fitting every data point in a whole pattern explicitly. Furthermore, accurate unit-cell parameters as well as scale factors that can be obtained from the Rietveld refinement are used for the quqantification. The present stdudy demonstrates that the Rietveld method yields far more accurate analytical result than the conventional XRD quantitative analysis method does.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.65-72
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• 2006

Recent technical advances in the biorecognition engineering and the microparticle fabrication may enable us to develop the single step purification using magnetic particle, because of its simplicity, efficacy, ease of automation, and process economics. In this study, we used commercial magnetic particles from Seradyn, Inc. (Indianapolis, USA). It was ca. 2.8 micron in diameter, consisted of polystyrene core and magnetite coating, and its surface had carboxyl groups. The model, capture protein was IgG and anti-IgG was used as the ligand molecule. We studied the different surfaces ('nude', ester-activated, and anti-IgG coated) for their biorecognition of IgG. At a high pH condition, we could reduce non-specific binding. Also anti-IgG immobilized magnetic particle could capture IgG more selectively. We attempted 'oriented immobilization' of anti-IgG, in which the polysaccharides moiety near the C-terminus was selectively oxidized and linked to the hydrazine-coated MP, to improve the efficacy of biorecognitive binding. Using this method, the IgG capturing ability was improved by ca. 2 fold. From the binary mixture of the IgG-insulin, IgG could be more selectively captured. In summary, the oriented immobilization of oxidized anti-IgG proved to be as effective as the streptavidin-biotin system and yet simpler and cost-effective. This immobilization method can find its applications in protein biochips and biotargeting.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.489-495
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• 2020

Whereas the control of the hydration heat in mass concrete has been important as the concrete structures enlarge, many conventional strategies show some limitations in their effectiveness and practicality. Therefore, In this study, as a solution of controling the heat of hydration of mass concrete, a method to reduce the heat of hydration by controlling the hardening of cement was examined. The reduction of the hydration heat by the developed Phosphate Inorganic Salt was basically verified in the insulated boxes filled with binder paste or concrete mixture. That is, the effects of the Phosphate Inorganic Salt on the hydration heat, flow or slump, and compressive strength were analyzed in binary and ternary blended cement which is generally used for low heat. As a result, the internal maximum temperature rise induced by the hydration heat was decreased by 9.5~10.6% and 10.1~11.7% for binder paste and concrete mixed with the Phosphate Inorganic Salt, respectively. Besides, the delay of the time corresponding to the peak temperature was apparently observed, which is beneficial to the emission of the internal hydration heat in real structures. The Phosphate Inorganic Salt that was developed and verified by a series of the aforementioned experiments showed better performance than the existing ones in terms of the control of the hydration heat and other performance. It can be used for the purpose of hydration heat of mass concrete in the future.