• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.12-18
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• 2016

This study was carried out to investigate the change on soil $CO_2$ efflux rates, soil temperature, soil water content and soil pH by thinning intensity treatments (heavy thinning, light thinning, control) of a black pine (Pinus thunbergii Parl.) stand disturbed by pine wilt disease in Wola National Experimental Forests in Jinju, Gyeongnam province. Monthly variations of soil $CO_2$ efflux rates were not significantly different between the thinning and the control treatments (P>0.05). The annual mean soil $CO_2$ efflux rates were $0.58g\;CO_2m^{-2}h^{-1}$ for the light thinning, $0.49g\;CO_2m^{-2}h^{-1}$ for the heavy thinning and $0.45g\;CO_2m^{-2}h^{-1}$ for the control treatments, respectively. There was a significant exponential relation between soil $CO_2$ efflux rates and soil temperature, but no correlation between soil water content or soil pH and soil $CO_2$ efflux rates. The values of $Q_{10}$ were 3.40 for the light thinning, 3.20 for the heavy thinning and 3.06 for the control treatments, respectively. The results indicate that soil $CO_2$ efflux rates in a black pine stand disturbed by pine wilt disease could be affected by thinning treatments.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.299-305
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• 1987

In the polythylene film mulching(P.E. mulching) culture, soil temperature ranked in the order of clear P.E.-, black P.E.-, and non-mulching. The difference in temperature between P.E mulching and non-mulching conditions was greatest in maximum temperature in fine day. Under the dry season, soil water content ranked in the order of black P.E.-, clear P.E.- and non-mulched soil. Under the rainy season, however, the content in non-mulched soil was higher than in the mulched soils, while there was little difference between the two colored films. In three phases of soil, liquid phase ratio was higher and gaseous phase ratio was lower in mulched soil than in non-mulched soil under the dry season. However, the opposite result was observed under the rainy season. The content of soil organic matter in red pepper field applied with the compost and mixed-fertilizer ranked in the order of black P.E.-, clear P.E.- and non-mulching conditions. However, the content between mulching and non-mulching differed little in peanut field applied with mixed-fertilizer. In red pepper field, soil nitrogen content in mulching conditions slightly differed from that in non-mulching conditions during the dry season. The soil nitrogen content decreased rapidly 86 days after fertilizer application during the rainy season. In peanut field, there was little difference in the content between the two conditions. The nitrogen content in the leaves of red pepper and peanut was much higher in P.E mulching than in non-mulching.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.544-550
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• 2012

This study was conducted to investigate the characteristic factors which have been influenced on nitrous oxide ($N_2O$) emissions related to the environment change of nitrogen application level, rainfall and temperature during the potato cultivation at black volcanic ash soil from 2010 to 2011. During the potato cultivation, the more amount of nitrogen fertilizer applied, $N_2O$ emissions amounts were released much. $N_2O$ emissions with the cultivation time were released much at the first and middle of cultivation with heavy rainfall, but it was released very low until the end of cultivation and drought season. $N_2O$ emissions mainly were influenced by the rainfall and soil water content. The correlation (r) with $N_2O$ emissions, soil wate, soil temperature in 2010 were very significant at $0.6251^{**}$ and $0.6082^{**}$ respectively, but soil EC was not significant to 0.10824. In 2011, soil temperature was very significant at $0.4879^{**}$, but soil water and soil EC were not significant at 0.0468 and 0.0400 respectively. Also, $NH_4$-N was very significant at $0.7476^{**}$, but $NO_3$-N and soil nitrogen ($NO_3-N+NH_4-N$) were not significant at 0.0843 and 0.1797, respectively. During the potato cultivation period, the average emissions factor of 2 years released by the nitrogen fertilizer application was presumed to be 0.0040 ($N_2O-N\;kg\;N^{-1}\;kg^{-1}$). This factor was lower about 2.5 times than the IPCC guideline default value (0.0100 $N_2O-N\;kg\;N^{-1}\;kg^{-1}$).

• Journal of Aquaculture
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• v.8 no.2
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• pp.117-131
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• 1995

In order to improve the present running seawater system for seedling production of marine fishes, rearing experiments with the juveniles of black seabream (Acanthopagrus schlegeli) and oblong rockfish (Sebastes oblongus) were conducted. The recirculating seawater system (F) equipped with the rotating biological contactors and the running seawater system (R) were used. Environmental factors, growth, survival rate and rearing density of the fish were compared between two systems during the experimental period. In the rearing experiment of black seabream, water temperature in F was fluctuated with surrounding air temperature and was higher than that in R. Specific gravity of the rearing seawater in F was relatively stable in the range of 1.0252 to 1.0266, while that in R was greatly fluctuated. pH in F turned out to be 7.51, but pH in R was similar to that in the natural seawater. Dissolved nitrite and nitrate in F were higher than those in R. While no significant differences in the growth of black seabream juveniles were recognized between two systems, survival rates of fishes in F were higher than those of fishes in R. In the rearing experiment of oblong rockfish, water temperature in F was higher than that in R. Specific gravity in F was slightly higher than that in R which showed relatively less fluctuation in the range of 1.0253 to 1.0270. pH in F turned out to be 7.96, but pH in R was similar to that in the natural seawater. Dissolved nitrite and nitrate in F were higher than those in R, but ammonia was lower in F. The juveniles of oblong rockfish reared in F grew significantly faster in their total length and body weight than those in R (P<0.05). However, survival rates of fishes between two systems showed no significant differences.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.35-63
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• 1989

Geochemical characteristics of the Guryongsan (Ogcheon) uraniferous black slate show that this is an analogue to the conventional Chattanooga and Alum shales in occurrences. Whereas, its highest enrichment ratio in metals including uranium, among others, is explained by the cyclic sedimentation of the black muds and quartz-rich silts, and the uniform depositional condition with some what higher pH condition compared to the conditions of the known occurrences. The cyclic sedimentation, caused by the periodic open and close of the silled basin, has brought about the flush-out) of the uranium depleted water and the recharge with the new metal-rich sea water, which consequently contributed to the high concentration of metals in mud. The metal-rich marine black muds, which mostly occur in the early to middle Palaeozoic times, is attributed by the geologic conditions which related to the atmospheric oxygen contents, and these are scarcely met in the late Precambrian and/or with the onset of Palaeozoic era in the geologic evolution of the earth.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.317-322
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• 2022

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA), a chronic contagious disease in small ruminants. The prevalence of CLA has been reported to be >50% in Korean black goats. CLA is difficult to control due to a lack of efficient vaccines and treatment methods. Effective disinfection of the farm environment may be an alternative strategy for reducing the spread of C. pseudotuberculosis. The objective of this study was to evaluate the efficacy of commercial disinfectants against CLA. The six commercial disinfectants, largely composed of sodium dichloroisocyanurate, sodium hypochlorite, potassium monopersulfate triple salt, quaternary ammonium, citric acid, and copper sulfate, were tested against five different genotypes of C. pseudotuberculosis isolated from goat farms in Korea. Efficacy tests were performed in accordance with the disinfectant efficacy test guidelines recommended by the Animal and Plant Quarantine Agency of Korea with slight modifications. All disinfectants except for copper sulfate exhibited >99.99% killing efficacy under hard water conditions following 30 min of incubation, which is the recommended standard treatment time according to guidelines. The minimum bactericidal treatment time was evaluated by employing treatments for durations of 1, 5, and 15 min. The most effective compounds under hard water conditions were sodium dichloroisocyanurate, potassium monopersulfate triple salt, and sodium hypochlorite, exhibiting >99.99% killing efficacy after 1 min of treatment. In the aqueous solution forms, citric acid and the quaternary ammonium compound were the most effective, but required at least 5 min to kill >99.99% of the bacteria. The current study characterizes the killing efficacy of six commercial disinfectant active compounds against C. pseudotuberculosis. Thus, this study provides essential information regarding the efficacy of the disinfectants used to control CLA in goat farms.

• Korean Journal of Organic Agriculture
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• v.5 no.1
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• pp.101-110
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• 1996

Inorder to minimize the daily intake amount of nitrate by chinese cabbage, the favorate vegetable for Korean, the influences of storage conditions at different temperature and light or dark treatments after post-harvest and effects of cooking temperature and infrared rays on changes of nitrate contents in edible parts of chinese cabbage were determined. The nitrate contents on midrib and leaf blade in chinese cabbage during post-harvest were decreased steeply in 2 days and decreased slowly again in 5 days. The temperature treatment to decrease the nitrate contents in midrib and leaf blade of chinese cabbage were effective as the following of $25^{\circ}C$> $15^{\circ}C$ > $-4^{\circ}C$ > $-10^{\circ}C$. The nitrate contents of midrib and leaf blade were decreased in the timecourse of post-harvest. It is more effective to store in $4^{\circ}C$ than in $15^{\circ}C$, and is more effective in transparent vinyl package than in black vinyl package, but the treatment of light is more effective than the treatment of temperature. The nitrate contents of midrib decreased rapidly by 17.9% in the treatment of 5 days at$ 15^{\circ}C$. By treatment of $80^{\circ}C$, $90^{\circ}C$, $100^{\circ}C$ water, the nitrate contents of midrib were increased slightly, but decreased in leaf blade. It reached 68.5%, 50.6%, 45.9% in the leaf blade respectively by treatment of 80%, 90%, 100% water at 1 min. By infrared rays treatment, the nitrate contents of midrib did not change in 3 min but increased rapidly after 6 min, and in the leaf blade it increased continually after 1 min.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.6
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• pp.633-641
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• 2016

Two identical Particle Into Liquid Samplers-Total Organic Carbon (PILS-TOC) were operated to measure fine particle Water Soluble Organic Carbon (WSOC) for one week on Feb. in 2016. The dual instrument operations provided validated WSOC concentrations to have a continuous WSOC measurement during the sample analysis period. Both PILS-TOC instruments were operated downstream of an carbon denuder to remove positive adsorption artifacts associated with semi-volatile organic compounds. Comparison of WSOC showed good agreement each other. The linear regression had a coefficient of determination ($r^2$) of 0.92 and a regression slope of 1.01 for the first period. The lower collection efficiency due to lower steam temperature is discussed. In addition, the potential primary source related to WSOC based on the comparison of black carbon (BC) concentrations is explained. The results of good agreement between two PILS-TOC measurements can provide the validation of WSOC cooperations and knowledge regarding the origins of WSOC and their behaviors.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.737-748
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• 2018

We evaluated the physicochemical and storage characteristics of Hanwoo Tteokgalbi treated with onion skin powder (OSP) and blackcurrant fruit powder (BFP). The experimental design included seven treatments: a control (ascorbic acid 0.1%), T1: OSP 0.3%, T2: OSP 0.6%, T3: BFP 0.3%, T4: BFP 0.6%, T5: OSP 0.15%+BFP 0.15%, and T6: OSP 0.3%+BFP 0.3%. The OSP was higher in both polyphenol and flavonoid contents compared to BFP (p<0.05). The moisture and ash contents of all Tteokgalbi samples with a large amount of added natural antioxidant powder (0.6%) were higher than those with small amounts of added antioxidant (0.3%). The cooking loss and water holding capacity were outstanding in the T2 treatment compared to the others (p<0.05). The lightness, redness, and yellowness values were reduced on the addition of 0.6% antioxidant powder (p<0.05). The springiness and cohesiveness values of the Tteokgalbi samples were higher for the 0.3% addition than the control and 0.6% addition (p<0.05). The Tteokgalbi samples with natural antioxidants showed similar sensory attribute scores compared to the control. The pH values reduced as the BFP increased (p<0.05), and the total microbial count increased after OSP addition. The 2-thiobarbituric acid reactive substance values of the samples treated with OSP were significantly lower than the control after day 10 (p<0.05). As a result, the addition of OSP or BFP did not have a significant negative influence on the quality characteristics of Hanwoo Tteokgalbi. In particular, the addition of 0.6% OSP was effective in increasing water retentivity and inhibiting lipid oxidation.

• Korean Journal of Clinical Pharmacy
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• v.22 no.2
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• pp.167-175
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• 2012

Different studies have been conducted regarding caffeine as psychostimulant drugs and its effects as well as determination in various materials. Since, coffee and tea are most drinkable beverage in the world and their major constituent is caffeine. So, analysis of the effect of equal amount of caffeine in coffee and tea with respect to SD rats was studied. The present methodology was purposed to determine and validate caffeine amount in different brands of coffee and tea, and canvass locomotor and behavioral patterns of SD rats after administrating coffee and tea orally consisting of same amount of caffeine (10, 30 mg/kg). Determination of caffeine in different brands of coffee and tea and validation of caffeine were evaluated using HPLC. Depending upon different brands of tea and coffee, caffeine amount was altered. Meanwhile, amount of caffeine in tea was directly proportional to the temperature of liquid. Coffee and tea (Instant Maxim original coffee$^{(R)}$ and earl grey black tea$^{(R)}$) consisting 10, 30 mg/kg of caffeine were studied in SD rats for locomotor activity and behavioral patterns using Tru Scan 99. The locomotor activities of SD rats were increased after administration of coffee and tea consisting caffeine compared to water. The coffee consisted of higher amount of caffeine exhibited steep movement of SD rats. Similarly, rearing and scratching of SD rats as frequency and duration were increased in coffee and tea consisting caffeine compared with water. The study revealed that coffee and tea had effects in locomotor activity and behavioral patterns of SD rats.