• Journal of Life Science
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• v.25 no.3
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• pp.329-335
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• 2015

This study was performed to determine the optimal ratio of Petasites japonicus, Luffa cylindrica, and Houttuynia cordata, all of which are supposed to have anti-respiratory disease effects, such as against rhinitis. The experiment incorporated a mixture design and included 12 experimental points with center replicates for three different independent variables (Petasites japonicus 30~70%; Luffa cylindrica 10~30%; and Houttuynia cordata 10~30%). Based on this design, the mixture was extracted in hot water at 121℃ for 45 min and anti-allergy and anti-microbial activities were observed. The response surface and trace plot described for the anti-allergy activity showed Petasites japonicas was a relatively important factor. The correlation coefficient (R²) value 82.10% for the inhibition effect of degranulation was analyzed by the regression equation. The analysis of variance showed the model fit was statistically significant (p<0.05). The optimal ratio of the mixture was Petasites japonicus 0.75%, Luffa cylindrica 0.11%, and Houttuynia cordata 0.14%. The anti-microbial activity for each extraction of the mixture was valid on gram-positive, such as Staphylococcus aureus (KCCM 40881) and Staphylococcus epidermidis (KCCM 35494), while it was less effective on gram-negative, such as Escherichia coli (KCCM 11234) and Pseudomonas aeruginosa (KCCM 11328).

• The Journal of Engineering Geology
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• v.7 no.2
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• pp.127-137
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• 1997

Bentonites that are used currently for the civil engineering puppose in our country were investigated to reveal their physico-chemical properties such as viscosity, swelling volume, cation exchange capacity (CEC) and chemical composition, and to compare the content of their constituting minerals and their characteristics using the X-ray diffraction and infrared spectrum methods. The content of montmorillonite in the hentonites ranges from 50 to 79%. As the content of montmorillonite in the hentonites increases, the viscosity, swelling volume, water content, methylene blue adsorption, CEC, and the amount of clay-size particles tend to increase in general. Because these properties also show good correlation within them, the results can he used to infer the characteristics of hentonites indirectly. However, a few samples do not show this correlation hetween the properties. This is probably due to the characteristics of constituting minerals of raw ore and manufacturing process. A saraple with lowest content of rnontrnofiiionite was shown to be inferior in the physico-chemical properties that are needed for the civil engineering-purpose bentonites.

• Korean Journal of Pharmacognosy
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• v.51 no.3
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• pp.222-229
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• 2020

Recently, consume for functional cosmetics containing natural products has been greatly increased. In order to develop it as a natural cosmetic material, we selected Ixeridium dentatum (Thunb.) Tzvelev, Plantago asiatica L. and Rumex crispus L. that have antioxidant and anti-inflammatory effects. In this study, simultaneous quantitative analysis of the isolated compounds and natural product complexes (Mix.) were validated using high performance liquid chromatography (HPLC). The isolated six compounds were shown in a large linearity with a correlation coefficient (R²) of 0.99. The limit of detection (LOD) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 0.36 ㎍/mL, 0.36 ㎍/mL, 0.37 ㎍/mL, 0.30 ㎍/mL, 0.22 ㎍/mL and 0.12 ㎍/mL, respectively. The limit of quantification (LOQ) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 1.10 ㎍/mL, 1.08 ㎍/mL, 1.12 ㎍/mL, 0.99 ㎍/mL, 0.66 ㎍/mL and 0.35 ㎍/mL, respectively. Content analysis showed chlorogenic acid (0.19 ± 0.02%), plantamajoside (0.48 ± 0.01%), acteoside (0.65 ± 0.01%), emodin (1.15 ± 0.11%), chrysophanol (0.73 ± 0.01%) and physcion (0.69 ± 0.09%). Therefore, the results of this study may provide for basic data of standardization research natural cosmetic material development on the I. dentatum, P. asiatica and R. cripus.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1114-1118
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• 1999

Barrier rib for the plasma display panel(PDP) was made by photolithographic process utilizing photosensitive barrier rib paste. The barrier rib paste was prepared by first dissolving ethylcellulose(binder polymer) in butyl carbitol(BC)/butyl carbitol acetate(BCA) =30/70 wt % mixture solvent at 15 wt % concentration. To this solution a mixture of functional monomers consisted of tripropyleneglycol diacrylate/ pentaerythritol triacrylate = 50/50 wt %, Irgacur 651 photoinitiator, and barrier rib powder were added and then the whole mixture was mixed in the three roll mill for 2 hr. The effect of component and concentration of photosensitive barrier paste on the photolithographic process was studied. After optimization of the paste formulation and photolithographic process, barrier rib could be obtained with good resolution up to $100{\mu}m$ height.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.636-642
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• 2007

Software program to predict the packing density of multi-sized and multi-component particulate system was developed. For this purpose, the experiment to measure the packing density of AP (ammonium perchlorate) and Al (aluminum) particles with different sizes and their mixtures was carried out. The packing densities obtained from various experiments were compared with the predicted data from the developed software program. In the case of the packing density of the binary system, which is comprised of two different size particles and/or two different components, the relative errors were ranged 0.25~13.13%, and in the same venue the relative errors of the ternary system were 0.25~13.13%. Agreement between experimental data and the predicted results is reasonably accurate. In order to achieve the targeted packing density, the software program calculated the contour of the component particles and this will contribute the formulation of optimal packing systems.

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.39-45
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• 2011

This study presents the thermal behaviors of glass beads-rubber mixtures depending on the volumetric fraction of each constituent and relative size between them. The transient plane source method is used to measure the effective thermal conductivity of mixtures. The discrete element method (DEM) and the thermal network model are integrated to investigate the particle-scale mechanism of heat transfer in granular packings. Results show that 1) the effective thermal conductivity decreases as the rubber fraction increases, and 2) the relative size between two solid particles dominates the spatial configuration of inter-particle contact condition that in tum determines the majority of heat propagation path through particle contacts. For the mixtures whose volumetric fraction of rubber is identical, the less conductive materials (e.g., rubber particles) with a large size facilitate heat transfer in granular materials. The experimental results and particle-scale observation highlight that the thermal conduction behavior is dominated not only by the volumetric fraction but also the spatial configuration of each constituent.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.737-744
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• 2016

For electrolysis process using an insoluble electrode, electrochemical performance was greatly affected by the manufacturing method and procedure, such as the firing temperature, pre-treatment, type of precursor solution, coating method, electrode material, etc. Components of the electrode therein is one of the most important factors in electrochemical reaction. To achieve such characteristics, a appropriate ratio of the electrode material should be carefully chosen. The aim of this research was to apply experimental design method in the optimization of electrode component for the maximum generation of oxidants in electrochemical oxidation process. Mixture design, especially expanded simplex lattice design, in DOME (design of mixture experiments) with Design Expert - commercial software - was used to analyze the data. Analysis of variance (ANOVA) showed a high coefficient of determination ($R^2$) value of 0.9470, thus ensuring a satisfactory adjustment of the $3^{rd}$ order special cubic regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the TRO generation concentration and independent variables(mol ratio of 3 electrode components) in a real unit: TRO generation concentration $(mg/L)=TRO\;conc.=98.25{\times}[Ir]+49.71{\times}[Sn]+95.29{\times}[Sb]-16.91{\times}[Ir]{\times}[Sn]-29.47{\times}[Ir]{\times}[Sb]-22.65{\times}[Sn]{\times}[Sb]+703.19{\times}[Ir]{\times}[Sn]{\times}[Sb]$. The optimized formulation of the 3 component electrode for an high TRO (total residual oxidants) generation was acquired at mol ratio of Ir 0.406, Sn 0.210, Sb 0.384 (desirability d value, 1).

• Membrane Journal
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• v.7 no.2
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• pp.65-74
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• 1997

Pervaporation pilot tests for obtaining the anhydrous ethanol, which is an automobile fuel additive for reducing air pollution, were carried out in the production field of fermented ethanol by using a PVA composite membrane. In the pervaporation dehydration of the ethanol/water azeotropic mixture, the membrane performance is concluded to be enhanced with the heating temperature of feed. In the determination of the permeate condensation temperature from the viewpoint of energy cost, an Optimal temperature was found to be near $0{\circ}C$. The results on the dehydration of fermented ethanol were similar to those of synthetic ethanol, which indicates that the pervaporation performance is not influenced by impurities contained in the ethanol to be dehydrated. From a comparison of calculated energy needed in the system and measured value in the pilot test, it is confirmed that the latent heat for vaporization of permeant on the permeate side of membrane is supplied from the feed.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.615-619
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• 2019

Statistical design of experiments was performed to optimize MOF-235 synthesis process. Concentrations of terephthalic acid (TPA), iron (III) chloride hexahydrate, N,N-dimethylformamide (DMF) and ethanol were important factors to develop the crystal structure of MOF-235. MOF-235 was synthesized with various concentrations of the listed chemicals above and the crystallinity was measured by XRD. The effect of the composition on the synthesis of MOF-235 was evaluated using a statistical analysis. For the variance analysis using F-test, the concentration of ethanol showed the greatest effect on the crystallinity and TPA the least influential. A regression model for predicting the crystallinity of MOF-235 was derived and the prediction results for two synthetic variables were presented using contour plots. Finally, the crystallinity was predicted by a mixture method with $FeCl_3$, ethanol and DMF.

• Elastomers and Composites
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• v.40 no.2
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• pp.83-92
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• 2005

To develop an automotive fuel hose suitable to the international environmental regulation, FKM rubber materials as an inner material of fuel hole were prepared with different chemical compositions. Measurement of the properties of thermal resistance, oil resistance, fuel resistance, gas permeability including fundamental properties were performed to investigate compatibility for a fuel hose material. Fundamental properties, thermal resistance, oil resistance, fuel resistance and permeability of FKM rubber materials were improved with fluorine content. When the carbon content was 20 phr, FKM compounds with fluorine contents of 66%, 09% and 71% were shown to satisfy the specification oi fuel hose. The gas permeability of NBR and FKM compounds was measured on the mixed fuel oils prepared with isooctane-toluene and gasoline-methanol. FKM rubber materials showed a small difference in penetrated amount of fuel and showed a permeability superior to NBR material. he permeability of FKM rubber materials was not influenced by the contents of fuel oil. Thermal properties of 69% FKM rubber experienced by permeability testing were not variated.