• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.1-8
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• 2007

Extraction conditions were optimized using response surface methodology for preparing high-quality, hot water extracts from cultivated Chrysanthemum indicum L. petals. A fractional factorial design was applied to investigate the effects of added sample ratio ($X_1$), extraction temperature ($X_2$) and extraction time ($X_3$) variables on extract properties, such as, soluble solid contents ($Y_1$), sugar content ($Y_2$), ?E ($Y_3$), turbidity ($Y_4$), total phenol ($Y_5$) and DPPH ($Y_6$). Second-order models were employed to generate a 3-dimensional response surface for dependent variables and their coefficients of determination ($R^2$) ranged from 0.8408${\sim}$0.9914. The range of optimum conditions at $80^{\circ}C$ extraction for maximize characteristics of hot water extracts was 2.3${\sim}$2.7 g and 9.2${\sim}$11.2 hr.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.509-517
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• 2019

The birnessite (7Å manganate, δ-MnO₂) which is a manganese oxide and comprises manganese nodules, is a major manganese mineral on the earth surface and a precursor in the synthesis of todorokite. In this study birnessite was synthesized by three different methods: Feng et al. (2004) and Luo et al. (1998) based on redox reaction and Ma et al. (1999) based on reduction reaction. 12 birnessite samples were synthesized by different combinations of Na⁺ and K⁺ cations based on the base (OH^-) and permanganate (MnO₄^-) reagents in the synthesis. The mineral compositions of synthesized birnessite were identified by XRD, and the two cation ratio in the mineral was measured by ICP. The products obtained after hydrothermal treatment of Mg-buserite, by the precursor of birnessite, was examined by XRD, and then phase transition to todorokite and their characteristics were compared. Our results show that the byproducts and the characteristics of phase transition by each synthetic method have different trends. Hausmannite (γ-Mn₃O₄) and feitknechtite (β-MnOOH) were formed by both methods in the redox reaction mechanism. By Feng et al. (2004)'s method, manganite (γ-MnOOH) phase only appeared when cation was predominantly Na⁺. Two birnessite samples synthesized by redox reaction mechanism showed phase transition to todorokite (10Å manganate, OMS-1) when both NaOH and KMnO₄ were used together. However, single-phase birnessite was formed by Ma et al. (1999)'s method, and phase transition was confirmed only for the sample when the cation was only composed of Na⁺.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.25-39
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• 1994

The Deogbong napseok clay deposit which is composed mainly of dickite and pyrophyllite has been formed by hydrothermal alteration of the Late Cretaceous volcanic rocks consisting of andesitic tuff and andesite. The mineralogy of the napseok ores and the hydrothermal alteration processes have been studied in order to know the nature of the interaction between minerals and fluids for the formation of the deposit. Chemical distribution shows that alkali elements and silica were mobile but alumina was relatively immobile during the hydrothermal processes. It is evident that enrichment of alumina and leaching of silica from the host rock led to the formation of the napseok ore, whereas the enrichment of silica in the outer zone of the deposit gave rise to the silica zone. A large amount of microcrystalline quartz closely associated with dickite and pyrophyllite suggests the increasing activity of silica. Thus Si which was released away from the argillic zone by the increasing activity of silica. Thus Si which was released away from the argillic zone by the increasing activity of silica solubility moved out precipitating in the margin of the deposit to form the silica zone. Variation in dickite crystallinity implies the local change in the stability of the system. Thermodynamic calculation shows that the invariant point of pyrophyllite-dickite (kaolinite)-diaspore-quartz assemblages at 500 bars in the system $Al_{2}O_{3}-SiO_{2}-H_{2}O$ is about 300 $^{\circ}C$. Based on the mineral assemblages and the experimental data reported, it is estimated that the main episode of hydrothermal alteration occurred at least above 270 to 300 $^{\circ}C$ and $X_{CO_2}$ <0.025. Mineral occurrence and chemical variation indicate that the activity of Al is high in the upper part of the deposit, whereas the activity of Si is high in the lower part and the margin of the deposit. The nonequilibrium phase relations observed in the Deogbong deposit might be due to local change in intensive thermodynamic variables and fluid transport properties that resulted in the formation of nonequilibrium phases b of several stages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1708-1715
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• 2012

The purpose of this study was to investigate whether water extracts of Sparassis crispa (SC) have anti-obesity effects. Treatment of mature adipocytes with SC caused a decrease in lipid accumulation (assessed by Oil Red O staining) and an increase in glycerol release. Mice were induced to obesity by a high fat diet (45% fat in total kcal) and experimental groups were treated with two different dosages of SC extracts, a low SC (LSC, 100 mg/kg/day) or high SC (HSC, 300 mg/kg/day). SC extracts were administered by gavages for 10 weeks in the experimental groups, while the control group was fed with distilled water. The body weight gain of mice fed SC was significantly reduced (11.88% lower in LSC, 14.54% lower in HSC) compared to the control group. Additionally, there were significantly reduced serum levels of triglycerides (13.57% lower in LSC, 19.46% lower in HSC), total cholesterol (32.22% lower in LSC, 24.67% lower in HSC) and glucose (28.85% lower in LSC, 25.82% lower in HSC) in mice fed SC compared to the control group. Hepatic triglycerides in mice fed SC were lower (9.68% lower in LSC, 14.24% lower in HSC) than the control group and total cholesterol levels were also lower in mice fed SC (38.72% lower in LSC, 35.20% in HSC). These results demonstrate that the water extract of SC may enhance lipolysis and up-regulate the expression of lipolytic enzymes in vitro and reduce body weight in vivo. These significant effects were found for both low and high doses of SC treatment, and suggest SC can be used as potential therapeutic substances for the prevention and treatment of obesity.

• Journal of Life Science
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• v.18 no.12
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• pp.1745-1751
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• 2008

This study was to investigate of characteristics and antioxidant function of yuza from 4 different area. The hot-water extracts of yuza peel extracts from Geoje, Goseong, Goheung and Namhae(Changseon, Seolcheon) were tested for antioxidant activity in different reaction systems. Contents of total phenolic compounds and flavonoids were $122.18{\pm}1.44$ mg/100 g and $114.39{\pm}0.94$ mg/100 g in hot water extracts from Namhae-Seolcheon, respectively. The highest contents of hesperidin and naringin were $55.45{\pm}1.36$ mg/100 g and $28.41{\pm}0.64$ mg/100 g in hot water extracts from Geoje, respectively. Antioxidant activity of yuza peel hot-water extracts were significantely increased as the increament of sample adding concentration ($500{\sim}10,000{\mu}g$/ml). Reducing power was $6{\sim}9$ folds higher in 10,000 ${\mu}g$/ml concentration than 500 ${\mu}g$/ml and it's O.D. value showed $0.68{\pm}0.012{\sim}0.97{\pm}0.021$. ABTs scavenging activity was more than 80% in 10,000 ${\mu}g$/ml concentration samples, except from Goseong ($78.13{\pm}1.30%$). Hydroxyl radical scavenging activity was higher in Namhae-Seolcheon ($31.36{\pm}1.36%$) and Namhae-Changseon ($30.28{\pm}1.60%$) at 10,000 ${\mu}g$/ ml concentration, others activity were below 30%. At 10,000 ${\mu}g$/ml concentration, NO radical scavenging activity and antioxidant activity in ${\beta}$-carotene linoleic acid system were $26.49{\pm}1.77{\sim}40.85{\pm}0.95%$ and $24.40{\pm}1.91{\sim}38.17{\pm}0.56%$, respectively.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.49-60
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• 2021

The Geumhwa Au-Ag deposit is located within the Cretaceous Gyeongsang basin. Mineral paragenesis can be divided into two stages (stage I and II) by major tectonic fracturing. Stage II is economically barren. Stage I, at which the precipitation of major ore minerals occurred, is further divided into three substages(early, middle and late) with paragenetic time based on minor fractures and discernible mineral assemblages: early substage, marked by deposition of pyrite with minor wolframite; middle substage, characterized by introduction of electrum and base-metal sulfides with Cu-As and/or Cu-Sb sulfosalts; late substage, marked by hematite and Bi-sulfosalts with secondary minerals. Changes in vein mineralogy reflect decreases in temperature and sulfur fugacity with a concomitant increase in oxygen fugacity. Fluid inclusion data indicate progressive decreases in temperature and salinity within each substage with increasing paragenetic time. During the early portion of stage I, high-temperature (≥410℃), high-salinity fluids (up to ≈44 equiv. wt. % NaCl) formed by condensation during decompression of a magmatic vapor phase. During waning of early substage, high-temperature, high-salinity fluids gave way to progressively cooler, more dilute fluids associated with main Au-Ag mineralization (middle) and finally to ≈180℃ and ≥0.7 equiv. wt. % NaCl fluids associated with hematite and sulfosalts (± secondary) mineralization (late substage). These trends are interpreted to indicate progressive mixing of high- and medium to low-salinity hydrothermal fluids with cooler, more dilute, oxidizing meteoric waters. The Geumhwa Au-Ag deposit may represent a vein-type system transitional between porphyry-type and epithermal-type.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.11-21
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• 2014

Atractylodes macrocepala KOIDZ. (AmK) is a herbal medicine and resources of functional food which has been used for the treatment of indigestion, anorexia, diarrhea and digestive dysfunction. Recently AmK is frequently used as resources of functional food and whitening cosmetics. In this study was carried out to evaluate the acute oral toxicity of Amk in Sprague-Dawley(SD) rats. male and female rats were administered orally with Amk extract of 1,000 mg/kg (low dosage group), 2,000 mg/kg (middle dosage group) and 4,000 mg/kg (high dosage group). We daily observed number of deaths, clinical signs and gross findings for 7 days. No dead SD rats and no clinical signs were found during the experiment period. Also other specific changes were not found between control and treated groups in hematology and serum biochemistry. But we found out feeble histopathological changes in liver fat tissues. In addition no significant changes of gross bady and individual organs weight. These results suggest that water soluble extract of AmK has not acute oral toxicity and oral $LD_{50}$ value was over 4,000 mg/kg in SD rats.

• Journal of the Mineralogical Society of Korea
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• v.18 no.1
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• pp.11-17
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• 2005

Na-A zeolite were synthesized from melting slag of the incinerated ash by the alkaline activation processes. The experiments were performed in stainless steel vessels, with continuous stirring during the reaction periods. The silica-rich solution, a starting material, which was the waste of crystal growth factory, contains 5.7 wt% SiO₂ and 3.2 wt% Na₂O. And NaAlO₂ was made by the reaction of aluminium dross and NaOH solution and its molar ratios were Na₂O/Al₂O₃= 1.2 and H₂O/Na₂O=9. During the residence time of 7∼8 h at 80℃, the mixing of the silica-rich solution, NaAlO₂ and melting slag yields the production of homogeneous Na-A zeolite. The optimal reactant composition in molar ratio of Na₂O:Al₂O₃:SiO₂ was 1.3∼l.4 : 0.8∼0.9 : 2 and mixing ratio of solution and slag was 1/7∼10 (g/cc). Synthesized Na-A zeolite has cubic form uniformly and its size ranges about 1 ㎛. Ca/sup 2+/ ion exchange capacity of the Na-A was about 180∼210 meq/100g, corresponding approximately 80% to the commercial detergent builder.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.207-226
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• 1986

The skarn type tungsten deposits in Jechon area are developed in the contact aureole of Jurassic granodiorite and lower Paleozoic limestone beds. The Tong Myeong mine contains scheelitebearing skarns found at and near the contacts between crystalline limestone and hornfels. Although the skarns are heterogeneous, there are clear patterns in the preferred associations and nonassociations of minerals on all scales. The skarn show a zonal arrangement from limestone to hydrothermal vein as follow: wollastonite skarn, clinopyroxene skarn, clinopyroxene-garnet skarn, garnet skarn, and vesuvianite skarn. Scheelite, abundant in all skarn units except wollastonite skarn and also in quartz veins near orebodies, is everywhere strongly correlated with pyrrhotite. It is implied that it was a stable phase throughout the evolution of the zoned skarns, at least in pyrrhotite.forming environments. Deposition of scheelite was probably widely caused by increasing $a_{Ca^{2+}}$ in the fluid, resulting from associated and interrelated reactions: $FeCl_2\;aq+H_2S\;aq{\rightarrow}FeS+2H^{+}+2Cl^-$; and $CaCO_3+2H^+{\rightarrow}Ca^{+2}+H_2CO_3$. The spectral reflection powers of nine sulfide species were studied, for three mineralization stage. The shapes and characteristics of the spectral reflectivity profiles are significant in their control of other optical properties. The characteristics of the Vickers microhardness and the optical symmetry for the minerals studied are discussed. Broad radicle groupings of the sulfides can be made with regard to the reflectivity-microhardness values.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.33-40
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• 2008

Normally, cedar heartwood has a red color. However, it frequently changes black color (blackening phenomenon). It is reported that blackening phenomenon of cedar has been caused by oxidation of phenolics and norlignan extractives under weak alkaline conditions. In this study, heat treatment and UV irradiation were carried out to reduce the difference of color value between blackened wood and bright sap wood. Effects of temperature, moisture content, treatment time and light on decrease of color difference between blackened heartwood and sapwood were evaluated in each treatment. A decrement of different color value between blackened heartwood and bright sapwood by hot-water treatment was bigger than others. An effect of the vacuum drying was similar to that of the kiln drying. UV irradiation decreases the color difference between dried blackened heartwood and bright sapwood. It is suggested that UV irradiation could be used as final treatment to reduce the color difference on wood during drying process. Determination of optimum conditions and development of hybrid process for control of discoloration will be needed in a further study.