• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.381-385
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• 2009

A basic objective is the preparation and surface studies of supported molten salt catalysts because molten salts can stay as the liquid phase in the range of the ordinary reaction temperature. Many kinds of metal salt mixtures for the formation of molten salt phase are appliable but CuCl and KCl were selected in this study because Cu is considered catalytically reactive in many reactons. The loading of the molten salt was selected as 25 vol% of the total pore volume of ${\gamma}-alumina$ to provide reasonable exposed surface area. The surface structure of catalysts containing molten salts in the ${\gamma}-alumina$ was studied using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). CuCl and KCl were added into the ${\gamma}-alumina$ using concentrated hydrochloric acid solution by the impregnation technique. The surfaces of the prepared catalysts before and after heat treatments were compared and they suggested that the heat treatment of catalysts helped the formation of molten-salt although the surface compositions of CuCl and KCl were not uniform.

• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.113-118
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• 1973

In this study, the several chemical compositions, which include general components (moisture, fat, protein, sugar, fiber, ash, acid insoluble ash), minor components (sesamol, sesamolin, sesamin), the characteristics of oil (specific gravity, refractive index, iodine value, saponification value, unsaponificable matter, insoluble impurities), fatty acid components (analyzed by GLC), amino acid patterns (analyzed by autoanalyzer), of Korean whole white Sesamum indicum were investigated and were compared with decuticled sesame samples. The results were summarized as follows: 1) The crude fiber, total ash and acid insoluble ash contents of the decuticled sesame seed and it meal were significantly lower as compared to the whole sesame samples. 2) The specific gravity, refractive index, iodine value, unsaponificable matter and insoluble impurities contents of the whole sesame oil were greater than the decuticled samples. 3) The fatty acid contents of the whole and decuticled sesame oil were approximatly equal amounts. But unsaturated fatty acid contents of the decuticled sesame oil was significantly lower than the whole sesame oil. 4) The decuticled sasame meal was concentrated higher protein than the whole sasame meal. But amino acid contents of the protein in their was approximatly equal amounts and sesame proteins are found to be rich in methionine, cystine and tryptophan, they are deficient in lysine. 5) The sesamol, sesamolin and sesamin contents of the whole and decuticled sesame oil were approximatly equal amounts. 6) The oxalate and calcium contents of the decuticled sesame seed and its meal were also significantly lower as compared to the whole sesame samples.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.289-304
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• 2016

The $PM_{10}$ and $PM_{2.5}$ aerosols were collected at the Gosan site of Jeju Island in 2013 and analyzed, in order to examine the variation characteristics of the chemical compositions in relation to the haze, Asian dust, and mixed haze-Asian dust episodes. Volume concentrations obtained from the Aerodynamic Particle Sizer (APS) were high in the range of $0.6{\sim}1.0{\mu}m$ particles for haze event, and in the range of $2.0{\sim}10.0{\mu}m$ particles for Asian dust event. For the haze event, nitrate concentrations increased highly as 8.8 and 25.1 times for $PM_{10}$ and $PM_{2.5}$, respectively, possibly caused by the inflow of air mass stagnated in eastern parts of China into Jeju area. For the Asian dust event, the concentrations of nss-$Ca^{2+}$, $NO_3{^-}$ and nss-$SO_4{^{2-}}$ increased 6.0, 1.5, 1.8 times for $PM_{10}$, and 2.3, 1.3, 1.6 times for $PM_{2.5}$, respectively. Meanwhile, for the mixed haze-Asian dust event, the concentrations of nss-$Ca^{2+}$ and $NO_3{^-}$ increased 13.4 and 3.2 times for $PM_{10}$, and 1.8 and 3.4 times for $PM_{2.5}$, respectively. The $NH_4NO_3$ content was higher than that of $(NH_4)_2SO_4$ during the haze event, however it was relatively low during the mixed haze-Asian dust event. The aerosols were acidified mostly by inorganic acids, and especially the nitric acid contributed highly to the acidification during both the haze and the mixed haze-Asian dust events. Meanwhile, the neutralization by ammonia was noticeably high during haze event when the stagnated air mass moved from China.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.146-151
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• 2011

Essential oil was extracted from cones of metasequoia (Metasequoia glyptostroboides) by steam distillation, fragrance was determined by sensorial analysis and chemical compositions were analyzed by gas chromatography-mass spectrometry with solid-phase microextraction apparatus. Metasequia contained 0.40% of essential oil in the cone. Major impact fragrances of the essential oil were woody, coniferous and herbal, and minor impact fragrances were minty, spicy and oily. There were nine constituents in the essential oil : 8 hydrocarbons and 1 oxide. Constituents were limonene (66.18%), ${\delta}$-3-carene (11.11%), ${\beta}$-caryophyllene (6.66%), ${\beta}$-myrcene (5.92%), ${\beta}$-pinene (4.14%), caryophyllene oxide (2.39%), camphene (2.32%), ${\alpha}$-caryophyllene (0.85%), and tricyclene (0.43%). Herbal and minty frangrances could be due to limonene and ${\delta}$-3-carene, spicy frangrance to caryophyllene, woody and coniferous frangrances to ${\alpha}$-pinene and ${\beta}$-pinene, and oily fragrance to camphene.

• Journal of Conservation Science
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• v.22
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• pp.43-60
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• 2008

This study is investigated the characteristics and the comparison on blackware and whiteware at Gilmyeong-ri kilns, located Poncheon-si, Geonggi province at AD 19c using scientific analysis. It is measured by scientific analysis classified as microstructure observation, physical methods which involved chromaticity, specific gravity, absorption ratio and porosity, and chemical analysis of components of body and glaze. As a result, a particle and a pore of body surface appeared differently by the degree of vitrification. In glaze, Blackware have better on good vitrification than whiteware in the microstructure observation. The physical characteristics of chromaticity, specific gravity, absorption ratio and porosity differed according to degree of vitrification rather than porcelain types. In composition, body of blackware have higher ratio of $Fe_2O_3$ and $TiO_2$ than of whiteware. Also glaze of blackware have higher ratio of $Fe_2O_3$ and $TiO_2$, and lower ratio of $SiO_2$ and $Al_2O_3$ than whiteware. Especially, blackware have higher ratio in the composition of CaO and $P_2O_5$ by which ash is used or not.

• Journal of the Korean earth science society
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• v.34 no.4
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• pp.289-302
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• 2013

In order to determine the provenance of the Huksan Mud Belt sediments in the southeastern Yellow Sea, the major and rare earth elements of the same sediments were analyzed. The surface sediments were sampled from top of piston-cores and box-cores taken at 51 sites within the Huksan Mud Belt. With the mean grain size of $5-6{\phi}$, the sediments of the study area are mud-dominated. The spatial distribution patterns show that silt content is high in the northern Mud Belt, whereas clay content increases as it moves toward the southern Mud Belt. Interestingly, the geochemical compositions both of major and rare earth elements have resulted in differences of sediment provenance. Among the major elements, plots of Fe/Al vs. Mg/Al ratios, $Al_2O_3$ vs. MgO ratios, and $Al_2O_3$ vs. $K_2O$ reveal that the Huksan Mud Belt sediments are dominated by the Korean river-derived sediments. However, the characteristics of rare earth elements infer sediments originating from the Chinese rivers. This discrepancy between the above provenances is attributed to the different contributory factors in the content of chemical elements. Considering strong correlation between major elements with grain sizes, the contents of the major elements are thought to be influenced by the grain size. However, there is a weak correlation between rare earth elements and grain sizes. The behaviour of rare earth elements may be controlled by heavy minerals, rather than grain sizes. Further study requires to solve the discrepancy arose from the difference in applied chemical tracers.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.457-468
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• 2018

To improve understanding of the physico-chemical characteristics of aerosols in the national park and comparing the air pollution between national park and the urban area nearby national park, the aerosol characterization study was conducted in Bukhansan National Park, Seoul, from July through September 2017. Semi-continuous measurements of $PM_{2.5}$ using PILS (Particle Into Liquid System) coupled with IC (Ion Chromatography) and TOC (Total Organic Carbon) analyzer allowed quantification of concentrations of major ionic species($Cl^-$, $SO_4{^{2-}}$, $NO_3{^-}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg{^{2+}}$ and $Ca{^{2+}}$) and water soluble organic carbon (WSOC) with 30-minute time resolution. The total mass concentration of $PM_{2.5}$ was measured by T640 (Teledyne) with 5-minute time resolution. The black carbon (BC) and ozone were measured with a minute time resolution. The timeline of aerosol chemical compositions reveals a strong influence from urban area (Seoul) at the site in Bukhansan National Park. Inorganic aerosol composition was observed to be dominated by ammoniated sulfate at most times with ranging from $0.1{\sim}32.6{\mu}g/m^3$ (6.5~76.1% of total mass of $PM_{2.5}$). The concentration of ammonium nitrate, a potential indicator of the presence of local source, ranged from below detection limits to $20{\mu}g/m^3$ and was observed to be highest during times of maximum local urban (Seoul) impact. The total mass of $PM_{2.5}$ in Bukhansan National Park was observed to be 10~23% lower than the total mass of $PM_{2.5}$ in urban area (Gireum-dong and Bulgwang-dong, Seoul). In general, ozone concentration in Bukhansan National Park was observed to be similar or higher than urban sites in Seoul, suggesting additional biogenic VOCs with $NO_x$ from vehicle emission were to be precursors for ozone formation in Bukhansan National Park.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.277-284
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• 1998

This experiment was carried out to study the effects of lactic acid bacteria (LAB) inoculation and addition of cell wall degrading enzymes on the fermentation characteristics and chemical compositions of Italian ryegrass silage. An inoculant LAB with or without a cell wall degrading enzyme of Acremoniumcellulase (A), or Meicellulase (M) or a mixture of both (AM), was applied to 1 kg of fresh Italian ryegrass sample. The treatments were control untreated, LAB-treated (application rate $10^5$ cfu/g fresh sample), LAB+A 0.005%, LAB + A 0.01%, LAB+A 0.02%, LAB + M 0.005%, LAB + M 0.01%, LAB + M 0.02%, LAB+AM 0.005%, LAB + AM 0.01% and LAB+AM 0.02%. The sample was ensiled into 2-L vinyl bottle silo, with 9 silages of each treatment were made (a total of 99 silages). Three silages of each treatment were incubated at 20, 30 and $40{^{\circ}C}$ for an approximately 2-months storage period. All silages were well preserved as evidenced by their low pH values (3.79-4.20) and high lactic acid concentrations (7.71-11.34% DM). The fermentation quality and chemical composition of the control untreated and the LAB-treated silages were similar, except that for volatile basic nitrogen (VBN) content was lower (p < 0.05) in the LAB-treated silages. LAB + cellulase treatments improved the fermentation quality of silages by decreasing (p < 0.01) pH values and increasing (p<0.01) lactic acid concentrations, in all of cellulase types and incubation temperatures. Increasing amount of cellulase addition resulted in further decrease (p < 0.01) of pH value and increases (p < 0.01) of lactic acid and residual water soluble carbohydrate (WSC) concentrations. LAB + cellulase treatments reduced (p<0.01) NDF, ADF, hemicellulose and cellulose contents of silages compared with both the control untreated and LAB-treated silages. LAB + cellulase treatments did not affect the silage digestibility due to fact of in vitro dry matter digestibility (IVDMD) was similar in all silages. The silages treated with cellulase A resulted in a better fermentation quality and a higher rate of cell wall reduction losses than those of the silages treated with cellulases M and AM. Incubation temperature of $30{^{\circ}C}$ seemed to be more suitable for the fermentation of Italian ryegrass silages than those of 20 and $40{^{\circ}C}$.

• Journal of Conservation Science
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• v.28 no.3
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• pp.235-245
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• 2012

Nondestructive deterioration diagnosis has been carried out for the former ore dressing plant of the Yongwha mine in Yeongyang (Registered Cultural Property No. 255). Deterioration rates about organic contaminant and soil of the upper part (7 to 13 layer) indicate higher than the lower part (1 to 6 layer) of the ore dressing plants. By contrast, deterioration rates such as crack, break out and discoloration of the lower part indicate very higher than the upper part. It is estimated that the plants of the lower part that mechanical and chemical process had been done for flotation were damaged severely by physicochemical weathering with reaction of concrete and chemical solution. As results of ultrasonic velocity measurement, average p-wave velocity of plants were measured 2,462m/s (compressive strength $529kgf/cm^2$). As for the analytical results of surface contaminants and soil compositions using P-XRF, they were identical with major elements (Cu, Zn, Pb, Fe and As) of ore minerals from the Yongwha mine. Therefore, the ore dressing plant should be treated by phytoremediation with conservation because heavy metals could impinged upon plants and natural environment.

• Journal of Applied Biological Chemistry
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• v.52 no.2
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• pp.45-50
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• 2009

Antimicrobial activity and cell cytotoxicity of Korean Plum-yem (Cephalotaxus koreana) extract were evaluated for the development of a functional biomaterial. And the chemical compositions of Korean Plum-yem extract (KPE) were analyzed. KPE showed high antimicrobial activities against various microorganisms including gram-positive bacteria, gram-negative bacteria, yeasts and molds. KPE showed cytotoxic activity dose-dependently against blood cancer cell line K562. Additionally, the KPE showed no significant adverse effect in hemolysis and no mutagenicity. It was suggested that KPE could be used as a functional biomaterial for functional food and cosmetics