• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.194-201
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• 2009

To evaluate the exposure of non-point source pesticide pollution in agricultural watershed and to investigate pesticide distribution and runoff from agricultural land, paddy field, upland and orchard, this experiment was carry out during crop growing seasons. The pesticide were detected twenty pesticides fungicide 4, insecticide 10, herbicide 6) in water of Neungchon agricultural watershed and detection concentrations were range 0.008${\sim}$7.59 ppb. Most of the detection pesticides were using pesticides to rice paddy fields to control fungi, insects, weeds. During the crop cultivation, the pesticide were detected total thirty pesticides by pepper field soil 6, orchard soil 4, sesame field soil 3 and rice paddy field soil 5, and pesticide concentrations were range 0.001${\sim}$0.109 ppm. Especially the herbicides were detected mainly in May and June in the stream water. The pesticide were detected thirty pesticides by fungicide 2, insecticide 6, herbicide 5 in water of Jungam Koseong agricultural watershed and detection concentrations were range 0.01${\sim}$7.21 ppb. In regard to the detected pesticides, the concentration of individual pesticides measured in surface water of the study areas never exceeded guidelines for agriculture chemicals concerning water quality-effluent from paddy fields in Japan (Katayama, 2003). Runoff rate of pesticides was range 0.07${\sim}$3.06 % from Kongju agricultural land to watershed after applied pesticides.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.33-40
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• 2009

From 2006 to 2008, natural habitat of Sparassis crispa were surveyed for investigating ecological conditions at sixteen different sites in Korea. The investigated sites showed very wide altitudinal distribution ranged from 240 meters to 1,100 meters above the sea level. In general, S. crispa showed distinct feature of heart-rot fungi as it occurs on soils around the stems of larch (Larix kaempferi) and Korean white pine (Pinus koraiensis). But it also could be found on stems or on the stumps of dead trees, which indicated that the fungus might have several invasion routes and capabilities to grow on various ecological conditions. All of the sixteen sites were pure stands consisted with conifers such as larch or Korean white pine. The dominant tree layer showed $15.3{\sim}38.0$ meters for tree heights, thicker than twenty centimeters for the diameter at breast height (DBH), and all of them were older than thirty years. Since the stands were pure stand, species diversity of trees in the sites was extremely low. While the dominant tree layer showed only pure coniferous stand, the co-dominant tree layer, shrub layer and herbaceous layer showed more diverse features with higher Shannon-Wiener (H') indices. Soil texture of thirteen sites among sixteen investigated sites were loamy soils, and the contents of organic matter in soil were more or less higher than general forest soils in Korea with $3.79{\sim}14.32%$. The cation exchange capacity (CEC) was also relatively higher than general forest soils with $16.1{\sim}27.2$ cmol+/kg. The data indicated that the cauliflower mushroom occurring sites were relatively fertile than general forest soils. The soils were acidic with pH ranged from 4.2 to 5.2, which were typical features for conifer stands in Korea.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.70-80
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• 2005

To evaluate the exposure of molinate in agricultural environment and its effect against the non-target crop in air, this experiment was conducted to elucidate volatilization characteristics of molinate in aquatic condition and to determine critical concentration of molinate in the air causing phytotoxicity to Chili pepper. Cumulative volatilized rate of molinate from water was 22.7% at $35^{\circ}C$ for water temperature and 20 L/min for air velocity while 3.2% at $25^{\circ}C$ and 10 L/min within 47 hour after applied under closed system, respectively. The molinate concentrations in air above 60 cm height from soil surface of valley and open paddy rice field were reached the highest value of 18.17 and $11.59{\mu}g/m^3$, respectively within 24 hours after applying granular formulation at dose rate of molinate 150 g/1,000 $m^2$. However, their concentrations were drastically diminished to around 0.18 and $0.51{\mu}g/m^3$ level in 20 days after application, which volatilization pattern were similar to both regions. Also, the concentration of molinate in air above 60 cm height from soil surface was distributed higher 2 times than that above 180 cm height. Meanwhile, a phytotoxic symptom against the nearby chili pepper was revealed within three days after applied and molinate was detected $0.004{\sim}0.006$ mg/kg level from severe damaged leaves. The dose and exposure relations of molinate in the air against the non-target crop was also investigated in lab trial. The phytotoxic symptom, shriveled leaves, of the chili pepper was encountered by exposing two days with concentration of $13.6{\mu}g/m^3$, three days with $6.8{\mu}g/m^3$ or four days with $3.4{\mu}g/m^3$. The symptom was still recovered within four weeks after the plants had received fresh air. On the other hand, the phytotoxic response through root uptake of the herbicide in water culture was relatively insensitive, in which the symptom is observed ten days with the concentration of 300 ${\mu}g/L$.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.35-38
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• 1979

The solubility variations of Abies koreana Wilson wood and their correlations ammong the factors which effect the extraction were investigated. In hot water solubility for 10 hours, extracted contents were 2.33% in heart wood, 12.30% in sapwood. In base solubility (here, used NaOH), the solubility content was 8.23% only for 1 hour. In organo-soluble fractions, there was not any variation between the content 4.00% for 1 hour and 4.44% for 10 hours, about the temperature effect, in the neutral solvent, at temperature $25{\pm}3^{\circ}C$, $50{\pm}3^{\circ}C$ and $97{\pm}3^{\circ}C$ and the solubility contents were 2.73%, 3.29%, 7.32% respectably. In the pH variations, initinal pH of solution, 6.5 became as low 5.4 after 10 hours extraction. Generally, the correlation coefficients between solubility and hour, solubility and temperature, solubilities' pH and hours, solubility and part, were r=0.890, r=0.986, r=-0.955, r=0.840 respectably. It is suggested that the most serious factor of the extraction in this material is the temperature.

• Journal of Forest and Environmental Science
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• v.8 no.1
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• pp.21-33
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• 1992

This study was performed to investigate the hardness of wood related to the wood surface, sap and heartwood, early and latewood, specific gravity, annual ring width and moisture content on major Korean tree species such as Pinus koraiensis, Abies holophylla, Larix leptolepis and Quercus valiabilis. The results were summarized as follows: 1. The arithmetic mean values of wood hardness on cross section were respectively $8.0kg/mm^2$ on Quercus valiabilis, $7.4kg/mm^2$ on Larix leptolepis, $5.1kg/mm^2$ on Pinus koraiensis and $4.7kg/mm^2$ on Abies hollophylla. 2. Generally hardness of wood on cross section was greater than the others and the proportion of cross section hardness to radial was respectively 2.8 on Quercus valiabilis, 2.6 on Larix leptolepis, 3.8 on Pinus koraiensis, and 4.1 on Abies holophylla and that proportion was tend to be decrease as specific gravity increased. 3. It was recognized that the hardness of sap and heartwood was different from each of the tree species and generally heartwood hardness was somewhat greater than sapwood. 4. Generally latewood hardness with in a ring was greater than earlywood and the proportion of earlywood hardness to latewood decreased as specific gravity increased. 5. The relations between hardness of wood and specific gravity show a high positive correlation on all sample tree species. 6. The values of hardness decreased with increasing annual ring width. 7. Hardness of wood on Abies holophylla was greatest in oven dried wood and it was decreased as moisture content increased, but not changed with moisture content abve F.S.P.. The proportion of oven dried wood hardness to green are respectively 3.0 on cross, 2.4 on radial and 1.9 on tangential section.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1248-1254
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• 1997

To measure antioxidative activities, the various extracts from RVS (Rhus Verniciflua Stokes) were tried out with either DPPH or thiocyanate method. Also we used the GO (Glucose Oxidase) 20 mU/mL hydroxyl radical system in mouse whole brain cell culture. Chloroform, n-hexane or ethanol were used as extract solutions which had different polarity respectively. In DPPH and thiocyanate method, the antioxidative activities of the crude ethanol extracts were stronger than other extracts. The crude ethanol extracts were fractionated 5 peaks by glass column. Among of them, antioxidative activity of peak II $(P_{II})$ was shown stronger than other fractions, a little for peak III $(P_{III})$ and peak IV $(P_{IV})$, and none for peak I $(P_I)$ and Peak V $(P_V)$. In the antioxidative effects of crude ethanol extracts (30 mg/mL), cell viabilities were evaluated $1\;{\mu}L\;(297\;{\mu}g/mL)$, $2\;{\mu}L\;(588\;{\mu}g/mL)$ of crude ethanol extracts 59%, 68% respectively. $10\;{\mu}L\;(2,727\;{\mu}g/mL)$ addition of crude ethanol extracts had 95% cell viabilities, 0.01% significant, comparing control. In addition, the compounds related to antioxidative effect of crude ethanol extract might be glycoproteins by means of SDS-PAGE. Comparison to antioxidative effects between several antioxidants (ascorbic acid, ${\alpha}-tocopherol$, catalase) $273\;{\mu}L/mL$ addition of crude ethanol extracts corresponds to $1\;{\mu}g/mL$ catalase in antioxidative effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.862-873
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• 2015

In this study, we investigated the physiochemical properties and biological activities of Gangwon-do endemic Makjang (MJ) products (12 types). The pH levels of all samples were in the range of 4.43 to 5.69, and MJ5 showed the highest pH (5.69). The salinities of all samples ranged from 11.1% to 16.9%. Hunter color values for L (lightness), a (redness), and b (yellowness) ranged from 26.2 to 36.9, 3.9 to 11.5, and 6.5 to 16.6, respectively. The amino nitrogen content of MJ2 was highest, whereas the total content of free amino acids of MJ11 (4,657.7 mg%) was highest. Total fatty acid contents of all samples ranged from 1,598.6 mg% to 2,874.4 mg%, with MJ10 showing the highest fatty acid content. The content of total polyphenolic compounds ranged from 401.48 to $746.67{\mu}g$ tannic acid equivalent/mL, with MJ11 showing the highest content. The 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiozoline-6-sulfonic acid) radical scavenging effects of MJ11, MJ8, and MJ4 were 51.30% and 82.5%, 41.29% and 67.0%, and 49.88% and 87.7%, respectively. MJ12 showed the strongest growth inhibitory effect on lung cancer A549 cells, whereas MJ5 showed the strongest growth inhibitory effect on AGS gastric cancer cell and MCF-7 breast cancer cell. MJ7 showed greater lipid accumulation inhibitory activity in HepG2 cells than the others. ACE inhibitory activity of MJ11 was the highest among the samples.

• Food Science and Preservation
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• v.19 no.4
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• pp.532-538
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• 2012

Seven rice varieties (Dasan, Keunseon, Goami, Baekjinju, Seolgaeng, Hangangchal and Heukseol) were used to study the physicochemical properties of dry milled (200-mesh) rice flour species. The moisture and crude protein contents of rice were 15.00-15.10% and 6.09-8.21%, respectively. The crude lipid and crude ash of rice were 0.21-1.02% and 0.37-1.62%, respectively. As for the Hunter's color value, the L value was highest in the Dasan flour (96.47); the a value was highest in the Heukseol flour (5.03); and the b value was highest in the Baekjinju flour (3.36). The water aborption index was highest in the Goami flour (1.45), and the water solubility index was highest in the Hangangchal flour (9.16%). The amylose contents of the rice flour species were highest in the Goami (26.42%) rice flour, followed by the Dasan (19.39%), Seolgaeng (19.24%), Keunseon (18.06%), Heukseol (15.52%), Baekjinju (9.16%), and Hangangchal (0.84%) rice flour. In the X-raydiffractin patterns of the diverse species, seven tice varieties showed A-type crystallinity. As for the amylogram properties, the initial pasting temperature was 58.00-$69.03^{\circ}C$. The maximum viscosity was highest in the Dasan flour. The Heukseol flour had the lowest maximum viscosity, breakdown, and setback. In terms of the thermal properties of the differential scanning calorimeter (DSC), the onset temperature was 59.03-$66.84^{\circ}C$; the peak temperature, 66-70-$72.82^{\circ}C$; and the end temperature, 74.06-$78.66^{\circ}C$. The enthalpy (${\Delta}H$) was lowest in the Heukseol flour (7.59 J/g) and highest in the Seolgaeng flour (11.36J/g).

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.4
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• pp.11-19
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• 2018

This study was conducted to develop the manufacturing method of biochar using pruned stems of pear tree and its application effect on the crop growth and soil physico-chemical properties. In this study, biochar derived from pruned stems of pear tree at heating temperature of $300^{\circ}C$, $500^{\circ}C$ and $700^{\circ}C$ in heating times of 2, 3 and 4 hours, were tested in the changes of their chemical properties during biochar processing. The pH, Exch. K, Exch. Mg and cation exchange capacity (CEC) increased as the pyrolysis temperature increased during the production of biochar, and the change of these properties rapidly occurred at $500^{\circ}C$. However, as the pyrolysis temperature increased, ash content increased and total carbon (T-C), yield decreased. And the change of the properties in response to the heating time was not shown. It was thought that it would be desirable to set the production conditions of biochar at $500^{\circ}C$ for 2 hours in consideration of the change of chemical properties and the ash content and yield. And also, were conducted the experiments to establish manufacturing method of farm-made biochar using drum biochar manufacturing machine and investigate the application effects of biochar on the cultivation of chinese cabbage and tomato. Application of biochar derived from pruned stems of pear tree could enhance pH, organic matter (OM), total carbon (T-C) of soil. On the other hand, soil electrical conductivity (EC), NO3-N were lowered compared to the control which has no application. The bulk density, porosity and aggregate formation of soil were improved by biochar application. The fresh matter yields of chinese cabbage and tomato were significantly increased in proportion to the application rate of biochar. This study demonstrated the effect of the biochar derived from agricultural byproduct to be as a low cost potential soil ameliorant by physico-chemical properties in eco-friendly greenhouse cultivation.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.228-238
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• 2021

The aim of this research was to develop a rapid and easy multi-residue method for determining dimethipin, omethoate, dimethipin, chlorfenvinphos and azinphos-methyl in agricultural products (hulled rice, potato, soybean, mandarin and green pepper). Samples were prepared using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Residual pesticides were extracted with 1% acetic acid in acetonitrile followed by addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. The extracts were cleaned up using MgSO₄, primary secondary amine (PSA) and octadecyl (C₁₈). The linearity of the calibration curves, which waas excellent by matrix-matched standards, ranged from 0.005 mg/kg to 0.3 mg/kg and yielded the coefficients of determination (R²) ≥ 0.9934 for all analytes. Average recoveries spiked at three levels (0.01, 0.1, 0.5 mg/kg) and were in the range of 74.2-119.3%, while standard deviation values were less than 14.6%, which is below the Codex guideline (CODEX CAC/GL 40).