• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.309-316
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• 2012

This study was performed to investigate the effects of forage cropping system and cattle slurry on productivity of whole crop rice, whole crop barley and Sorghum-Sudangrass hybrid and environmental pollution in paddy land. Forage cropping system used in this study was consisted of double-cropping whole crop barley followed by whole crop rice applied with cattle slurry (DWBRC) and double-cropping whole crop barley followed by Sorghum-Sudangrass hybrid applied with cattle slurry (DSSBC). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The field had been sown with whole crop rice 'Nampyung', Sorghum-Sudangrass hybrid 'Sordan79' and whole crop barley 'Younyang'. The yields of whole crop barley in DWBRC and DSSBC were 7,515 kg/ha and 8,515 kg/ha, respectively. The yields of whole crop barley in DSSBC significantly increased as compared with that of DWBRC (p<0.05). The contents of crude protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrient (TDN) of whole crop barley in DWBRC were not difference as compared with those of DSSBC. The pH, and contents of total nitrogen and organic matter in soil samples collected at the end of the experiment increased as compared with those at the beginning of the experiment (p<0.05). However, The content of phosphate in DWBRC was no difference as compared with DSSBC. In addition, after the end of experiment, the concentrations of exchangeable cations (Ca, Na, Mg and K) in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (p<0.05). The concentrations of $NH_4$-N, $NO_3$-N, $PO_4$-P, Cl, Ca, K, Mg and Na in leaching water were hardly influenced by the cropping system and application of cattle slurry.

• Restorative Dentistry and Endodontics
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• v.35 no.2
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• pp.80-87
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• 2010

The purpose of this study was to compare the different canal irrigation methods to prevent the formation of precipitate between sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Extracted 50 human single-rooted teeth were used. The root canals were instrumented using NiTi rotary file (Profile .04/#40) with 2.5% NaOCl and 17% EDTA as irrigants. Teeth were randomly divided into four experimental groups and one control group as follows; Control group: 2.5% NaOCl only, Group 1: 2.5% NaOCl + 2% CHX, Group 2: 2.5% NaOCl + paper points + 2% CHX, Group 3: 2.5% NaOCl + preparation with one large sized-file + 2% CHX, Group 4: 2.5% NaOCl +95% alcohol+ 2% CHX. The teeth were split in bucco-lingual aspect and the specimens were observed using Field Emission Scanning Electron Microscope. The percentages of remaining debris and patent dentinal tubules were determined. Statistical analysis was performed with one-way analysis of variance (ANOVA). Energy Dispersive x-ray Spectroscopy was used for analyzing the occluded materials in dentinal tubule for elementary analysis. There were no significant differences in percentage of remaining debris and patent tubules between all experimental groups at all levels (p > .05). In elementary analysis, the most occluded materials in dentinal tubule were dentin debris. NaOCl/CHX precipitate was detected in one tooth specimen of Group 1. In conclusion, there were no significant precipitate on root canal, but suspected material was detected on Group 1. The irrigation system used in this study could be prevent the precipitate formation.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.743-760
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• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• Economic and Environmental Geology
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• v.8 no.3
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• pp.117-124
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• 1975

Wet chemical analysis (for $MnO_2$, MnO, and $H_2O$(+)) and electron microprobe analysis (for $Fe_2O_3$ and PbO) give $MnO_2$ 74.91, MnO 11.33, $Fe_2O_3$ (total Fe) 4.19, PbO 0.03, $H_2O$ (+) 9.46, sum 99.92%. 'Available oxygen determined by oxalate titration method is allotted to $MnO_2$ from total Mn, and the remaining Mn is calculated as MnO. Traces of Ba, Ca, Mg, K, Cu, Zn, and Al were found. Li and Na were not found. The existence of (OH) is verified from the infrared absorption spectra. The analysis corresponds to the formula $Mn^{4+}{_{4.85}}(Mn^{2+}{_{0.90}}Fe^{3+}{_{0.30}})_{1.20}O_{8.09}(OH)_{5.91}$, on the basis of O=14, 'or ideally $Mn^{4+}{_{5-x}}(Mn^{2+},Fe^{3+})_{1+x}O_{8}(OH)_{6}$ ($x{\approx}0.2$). X-ray single crystal study could not be made because of the distortion of single crystals. But the x-ray powder pattern is satisfactorily indexed by an orthorhombic cell with a 9.324, b 14.05, c $7.956{\AA}$., Z=4. The indexed powder diffraction lines are 9.34(s) (100), 7.09(s) (020), 4.62(m) (200, 121), 4.17(m) (130), 3.547(s) (112), 3.212(vw) (041), 3.101(s) (300), 2.597(w) (013), 2.469(m) (331), 2.214(vw)(420), 2.098(vw) (260), 2.014 (vw) (402), 1.863(w) (500), 1.664(w) (314), 1.554(vw) (600), 1.525(m) (601), 1.405(m) (0.10.0). DTA curve shows the endothermic peaks at $250-370^{\circ}C$ and $955^{\circ}C$. The former is due to the dehydration: and oxidation forming$(Mn,\;Fe)_2O_3$(cubic, a $9.417{\AA}$), and the latter is interpreted as the formation of a hausmannite-type oxide (tetragonal, a 5.76, c $9.51{\AA}$) from $(Mn,\;Fe)_2O_3$. Infrared absorption spectral curve shows Mn-O stretching vibrations at $515cm^{-1}$ and $545cm^{-1}$, O-H bending vibration at $1025cm^{-1}$ and O-H stretching vibration at $3225cm^{-1}$. Opaque. Reflectance 13-15%. Bireflectance distinct in air and strong in oil. Reflection pleochroism changes from whitish to light grey. Between crossed nicols, color changes from yellowish brown with bluish tint to grey in air and yellowish brown to grey through bluish brown in oil. No internal reflections. Etching reactions: HCl(conc.) and $H_2SO_4+H_2O_2$-grey tarnish; $SnCl_2$(sat.)-dark color; $HNO_3$(conc.)-grey color; $H_2O_2$-tarnish with effervescence. It is black in color. Luster dull. Cleavage one direction perfect. Streak brownish black to dark brown. H. (Mohs) 2-3, very fragile. Specific gravity 3.59(obs.), 3.57(calc.). It occurs as radiating groups of flakes, flower-like aggregates, colloform bands, dendritic or arborescent masses composed of fine grains in the cementation zone of the supergene manganese oxide deposits of the Janggun mine, Bonghwa-gun, southeastern Korea. Associated minerals are calcite, nsutite, todorokite, and some undetermined manganese dioxide minerals. The name is for the mine, the first locality. The mineral and name were approved before publication by the Commission on New Minerals and Mineral Names, I.M.A.

• Journal of Life Science
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• v.18 no.10
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• pp.1377-1383
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• 2008

A bacterium producing non- or partially digestible dextran was isolated from kimchi broth by enrichment culture technique. The bacterium was identified tentatively as Leuconostoc sp. strain SKY. We established the response surface methodology (Box-Behnken design) to optimize the principle parameters such as culture pH, temperature, and yeast extract concentration for maximizing production of dextran. The ranges of parameters were determined based on prior screening works done at our laboratory and accordingly chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 1, 5, and 9 g/l yeast extract. Initial concentration of sucrose was 100 g/l. The mineral medium consisted of 3.0 g $KH_2PO_4$, 0.01 g $FeSO_4{\cdot}H_2O$, 0.01 g $MnSO_4{\cdot}4H_2O$, 0.2 g $MgSO_4{\cdot}7H_2O$, 0.01 g NaCl, and 0.05 g $CaCO_3$ per 1 liter deionized water. The optimum values of pH and temperature, and yeast extract concentration were obtained at pH (around 7.0), temperature (27 to $28^{\circ}C$), and yeast extract (6 to 7 g/l). The best dextran yield was 60% (dextran/g sucrose). The best dextran productivity was 0.8 g/h-l.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.339-347
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• 2000

An algicidal bacterium, Micrococcus sp. LG-5 against the harmful dinoflagellate, Cochlodinium polykrikoides was isolated. The optimal conditions for the highest algicidal activity of bacterial culture filtrate showed in the range of $20{\~}30^{\circ}C$, at pH 7.0 and $3.0{\%}$ of NaCl concentration. In addition, $IC_(50)(mean of 50{\%} inhibitory concentration)$ of the culture filtrate against C. polykrikoides after incubation of 5 days was $0.482{\%}$. To investigate heat and pH stability of the culture filtrate of Micrococcus sp. LG-5, the culture filtrate ($pore size, 0.1 {\mu}m$) was heated to $121^{\circ}C for 15 min$ and adjusted pH from 2.0 to 10.0. There were no significant changes in algicidal activity by heat treatment and the pH change between pH from 5.0 to 10.0. The algicidal substances produced from Micrococcus sp. LG-5 were mainly detected in the fraction of $10,000{\~}1,000$ MWCO (molecular weight cut-off). The culture filtrate of Micrococous sp. LG-5 showed antimicrobial activity against Enterococcus faecalis, Escheiichia coli, Uebsiella pneunioniae and Vibrio altinolyticus, but did not show against Pseudomonas aeminosa, P. Buorescens, Salmonella typhi, Staphylococcus aureus, V. cholerae and V parahaemolyicus. The culture filtrate of Micrococcus sp. LG-5 was examined against 16 phytoplankton species and showed the algicidal activity against Ajexandzium tuarense, Eutreptiella Drnnastin, Gymnodinium catenatum, G. mikimotoi, G. sanguineum, eyodinium impuaicum, Heterocapsa triquetra, Heterosipa akashiwo, Prorocentrum micans and Pyraminonas sp.. However no algicidal effects of Micrococcus sp. LG-5 were observed against Chlamydomonas sp., Cylindrotheoa closterium, P. mininum, P. triestimum, Pseudonieschia sp. and Sczipuiella trochoidea. On the other hand, algicidal activity on the tested marinelivefood was not detected except for Isochrysis galbana. In addition, physiological responses of cultured olive flounder (Paralichthys oliraceus) exposed to $1 and 10{\%}$ of the culture filtrate of Micrococcus sp. LG-5 were measured. There were no clear changes in AST, GGT, creatinine, urea, total cholesterol, total protein, albumine, $Mg^(+2), Ca^(+2), Na^+, K^+, and Cl^-$. These results indicate that olive flounders were not affected when they were exposed to the culture filtrate of Micrococcus sp. LG-5.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.808-815
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• 2007

Four different herbs, including rosemary, oregano, basil and sage, along with green tea were individually added to ground beef at different percentages: 0.5, 1.0, and 1.5, respectively. The sensory qualities of the five natural herbs and their antioxidant effects were evaluated using Beef-Yukwonjeon. For the sensory evaluation results, the 0.5% herb addition and the control group generally showed higher acceptability scores than the 1.0% or 1.5% herb addition groups. In particular, the Yukwonjeon made with 0.5% green tea showed higher preferences in the acceptance tests and ranking tests. However, the sensory differences among samples were reduced after 3 days of storage at $6^{\circ}C$. For the results of lipid oxidation without storage, the TBARS values of the herb addition groups were slightly lower than the value of the control group, but not significantly(p>0.05). However, the antioxidant effects of each herb showed higher values over a longer storage period as well as at the higher herb concentrations. The antioxidant effects of the herbs during 7 days' of storage at $6^{\circ}C$ were evaluated as $10.0{\sim}38.5%$ reductions in TBARS values as compared to the group without herbs. Furthermore, the antioxidant effects of the herbs during 30 days' of storage at $-20^{\circ}C$ were shown as $16.8{\sim}27.8%$ reductions in the TBARS value. The green tea showed the highest antioxidant activity against lipid oxidation, because it was acceptable at higher concentrations in the sensory evaluation. These results indicate the potential to produce better quality beef-Yukwonjeon, with herbs, especially green tea.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1529-1535
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• 1999

This study was done for the extraction of carotenoid from Phaffia rhodozyma in combination with PEF and other methods. PEF treatment conditions were $30{\sim}80\;kV/cm,\;100{\sim}1000\;Hz\;and\;100{\sim}1000\;{\mu}s$. In order to increase permeability of yeast cell wall, various methods such as freezing-thawing, mechanical treatment, solvents, permeabilizing agents, and yeast cell wall lytic enzyme were used before PEF treatment. The combination of PEF $(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ and conventional methods such as solvent and freezing-thawing pre-treatment had no effects on the extraction of carotenoid pigments. The extent of extracted carotenoid by the PEF $treatment(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ combined with yeast cell wall lytic enzyme and mechanical pre-treatment increased 52% and 69.8% more than the sum of that by each treatment, respectively. Permeabilizing agents, especially Tween 20 and capric acid, enhanced the extraction efficiency of carotenoid pigments from P. rhodozyma cells. These results indicated the feasibility for the continuous extracting carotenoid pigments from P. rhodozyma by PEF combined with other permeabilizing methods.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.456-464
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• 2014

Kimchi was prepared with three types of salt (4-year-aged solar salt, FS; 1-year-aged solar salt, OS; and purified salt, PS), using Leuconostoc citreum GJ7 as the starter culture. The prepared kimchi was fermented (up to 0.5-0.6% of acidity) and stored for 5 months at $-1^{\circ}C$. During the storage period, the acidity of FS kimchi increased gradually, whereas that of PS kimchi increased sharply. The yellowness (b) color value of PS kimchi (63.4) was higher than that of other kimchis with solar salts (55.6-60.3). Hardness of FS kimchi (1,912.6 gf) was greater than that of the other kimchis (1,554.4-1,650.2 gf) during the storage period. Moreover, sensory evaluation showed higher scores for FS kimchi than for other kimchis. These results suggest that FS is more suitable salt than PS for long-term storage of kimchi.