• Journal of Wetlands Research
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• v.21 no.4
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• pp.384-391
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• 2019

Nutrients in stormwater runoff have raised concerns regarding water quality degradation in the recent years. Low impact development (LID) technologies are types of nature-based solutions developed to address water quality problems and restore the predevelopment hydrology of a catchment area. Two LID facilities, infiltration trench (IT) and infiltration planter (IP), are known for their high removal rate of nutrients through sedimentation and vegetation. Long-term monitoring was conducted to assess the performance and cite the advantages and disadvantages of utilizing the facilities in nutrient removal. Since a strong ionic bond exists between phosphorus compounds and sediments, reduction of total phosphorus (TP) (more than 76%), in both facilities was associated to the removal of total suspended solids (TSS) (more than 84%). The efficiency of nitrogen in IP is 28% higher than IT. Effective nitrification occurred in IT and particulate forms of nitrogen were removed through sedimentation and media filters. Decrease in ammonium- nitrogen (NH₄-N) and nitrite-nitrogen (NO₂-N), and increase in nitrate-nitrogen (NO₃-N) fraction forms indicated that effective nitrification and denitrification occurred in IP. Hydrologic factors such as rainfall depth and rainfall intensity affected nutrient treatment capabilities of urban stormwater LID facilities The greatest monitored rainfall intensity of 11 mm/hr for IT yielded to 34% and 55% removal efficiencies for TN and TP, respectively, whereas, low rainfall intensities below 5 mm resulted to 100 % removal efficiency. The greatest monitored rainfall intensity for IP was 27 mm/hr, which still resulted to high removal efficiencies of 98% and 97% for TN and TP, respectively. Water quality assessment showed that both facilities were effective in reducing the amount of nutrients; however, IP was found to be more efficient than IT due to its additional provisions for plant uptake and larger storage volume.

• Journal of Life Science
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• v.22 no.9
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• pp.1187-1193
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• 2012

This study was conducted to evaluate effects of halogenated compounds on in vitro rumen fermentation characteristics and methane emissions. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Five kinds of halogenated compounds (bromochloromethane (BCM), 2-bromoethane sulfonic acid (BES), 3-bromopropanesulfonic acid (BPS), chloroform (CLF), and pyromellitic diimide (PMDI) known to inhibit methyl-coenzyme M reductase activity were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, protozoa, and fungi were enumerated, and gas production including methane and fermentation characteristics were observed in vitro. The pH values ranged from 6.25 to 6.72 in all the treatments, and these showed a similar level at 48 hr. The total gas production in the treatments showed a similar pattern with C at 48 hr, whereas methane production in the treatments was lower (p<0.05) than C. Concentrations of total volatile fatty acids (VFAs) and propionic acid were higher (p<0.05) in the treatments than in C at 12 hr. Therefore, halogenated compounds (BCM, BES, BPS, CLF, and PMDI) inhibited in vitro methane emissions by inhibiting methanogens in the rumen. Further studies on safety are needed.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.393-401
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• 2013

The objectives of this study were to analyze structures of fish community and the ecological health using a multi-metric fish model, the Index of Biological Integrity (IBI) in the Backje Weir of Geum River during two periods namely before-the-fishkill ($B_f$) and after-the-fishkill ($A_f$). The total number of fish species observed were 32 and among them 10 species (35%) were Korean endemic species. The exotic species observed were 3 which decreased by 0.4% after-the-fishkill ($A_f$). The dominant species were Opsariichthys uncirostris amurensis (13%) at the Bf period and Squalidus japonicus coreanus (17%) at the Af period in the Backje Weir. At after the fishkill ($A_{f-I}$) total biomass was about 10 times lower than the biomass before-the-fishkill ($B_f$). The biomass of Carassius auratus decreased 98% after-the-fishkill and as time passed by the biomass recovered to nearly 100%. Similar decrease in the biomass occurred in the population of Opsariichthys uncirostris amurensis, while Rhinogobius brunneus population increased. According to the structure analysis of fish community, species richness index, evenness index and species diversity index were high but after-the fishkill, the values of indices decreased. Tolerant species (64%) dominated the fish community, and the sensitive species (2%) were rare, indicating the degradation of the ecosystem. According to analysis of the multi-metric model (IBI), the mean model value of the fish community in Backje Weir was estimated as 17.5 indicating a "fair condition".

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.154-162
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• 2017

The purpose of this study was to investigate the microbial reduction effect of chlorine dioxide and sodium hypochlorite in Korean chive. Korean chive inoculated with foodborne pathogens at the level of approximately 7~8 log CFU/g was treated with various concentration of chlorine dioxide (3, 4, 10, 25 and 100 ppm and sodium hypochlorite (100, 150 and 200 ppm) for 5, 10, 30 and 60 minutes. The treatment of 150 ppm sodium hypochlorite and 50 ppm chlorine dioxide for 30 min reduced the number of total bacteria in Korean chive up to 2.0 log CFU/g. Reduction of microbial levels was observed for all concentrations of sanitizers but their effectiveness did not correspond to their concentration. Due to the quality degradation, 50 ppm chlorine dioxide was not appropriate for Korean chive. Most effective reduction of microbial levels was observed when Korean chive were treated with 9 times more sanitizer in volume. For field application, the treatment of 150 ppm sodium hypochlorite showed 2.7 and 4.0 log CFU/g reductions for numbers of total bacteria and coliforms, respectively. Therefore, washing with sodium hypochlorite of a ratio of 1:9 (Korean chive : 150 ppm sodium hypochlorite (w/v)) for 30 minutes can reduce the number of foodborne pathogen in Korean chive.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.49-61
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• 2019

Swine manure has been recognized as a organic sources for composting and many research was conducted to efficiently utilize and treat. This study was to evaluate a feasibility for producing swine manure compost under various treatment with mixture of swine manure and saw dust. Treatments were designed as follows; non aerated composting pile(REF), aerated composting pile of $100L/m^3$(EXP1), and aerated composting pile of $150L/m^3$(EXP2). The total days of fermentation were 28 days and each samples were collected at every 7 days from starting of composting. Temperature sensors were installed under 30~40cm from the surface of composting pile. Inner temperature in composting piles of EXP1 and EXP2 was rapidly increased to $67{\sim}75^{\circ}C$ within 1~2 days. The elevated temperatures found during the thermophilic phase are essential for rapid degradation of organic materials. While swine manure composted, moisture content, total nitrogen, EC of EXP1, EXP2 in sample at 28 days were lower than those of REF. But, pH and organic matter of EXP1, EXP2 in sample at 28 days were higher than those of REF. After finishing fermentation experiment, maturity was evaluated with germination test. Calculated germination index(GI) at REF, EXP1 and EXP2 were 23.49, 68.50 and 51.81, respectively. The values of germination index were higher at EXP1 and EXP2 which is aerated composting piles than REF which is non aerated composting pile. According to the results, composting process by aerated static pile compost had significant effect on the reduction of required period for composting. Supplying adequate amount of air to compost swine manure will greatly reduce composting period.

• Journal of Science Education
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• v.45 no.3
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• pp.292-303
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• 2021

This study identifies the terms frequently used together with energy in online science news articles and topics of the news reports to find out how the term energy is used in everyday life and to draw implications for science curriculum and instruction about energy. A total of 2,171 online news articles in science category published by 11 major newspaper companies in Korea for one year from March 1, 2018 were selected by using energy as a search term. As a result of natural language processing, a total of 51,224 sentences consisting of 507,901 words were compiled for analysis. Using the R program, term frequency analysis, semantic network analysis, and structural topic modeling were performed. The results show that the terms with exceptionally high frequencies were technology, research, and development, which reflected the characteristics of news articles that report new findings. On the other hand, terms used more than once per two articles were industry-related terms (industry, product, system, production, market) and terms that were sufficiently expected as energy-related terms such as 'electricity' and 'environment.' Meanwhile, 'sun', 'heat', 'temperature', and 'power generation', which are frequently used in energy-related science classes, also appeared as terms belonging to the highest frequency. From a network analysis, two clusters were found including terms related to industry and technology and terms related to basic science and research. From the analysis of terms paired with energy, it was also found that terms related to the use of energy such as 'energy efficiency,' 'energy saving,' and 'energy consumption' were the most frequently used. Out of 16 topics found, four contexts of energy were drawn including 'high-tech industry,' 'industry,' 'basic science,' and 'environment and health.' The results suggest that the introduction of the concept of energy degradation as a starting point for energy classes can be effective. It also shows the need to introduce high-tech industries or the context of environment and health into energy learning.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.191-199
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• 2007

Seasonal variation in species composition of fish in the Saemangeum Reservoir was determined using seasonal samples collected by an otter trawl from April 2006 to February 2007 after the dike construction, and compared with the data obtained during the dike construction in 2001-2002. A total of 35 species, 8,960 individuals and 53,084.4 g of fish were collected during the study. Of the fish collected, brackish and coastal fishes such as Konosirus punctatus, Synechogobius hasta and Repomucenus lunatus, and migrant fishes such as Engraulis japonicus and Scomberomorus niphonius predominated in abundance accounting for 95% in the total number of individuals. Fish species composition and abundance showed a similar seasonal trend to those in the other western coastal waters of Korea. The resident species were mainly collected in spring and in autumn. The number of species and biomass were high in summer by the large amount of catch of migrating species. Catch was low in winter and only 2 species were collected. A brackish and coastal fish, K. punctatus and two migrant fishes, E. japonicus and S. niphonius were abundantly collected after the dike construction. However, the dominant fishes during the dike construction such as Leiognathus nuchalis, Neosalanx jordani and Chaeturichthys stigmatias were rarely collected. Fish density was $1,149\;inds./10,000m^2\;and\;12,644g/10,000m^2$ during the dike construction, and increased 6 times in the number of individuals ($7,467\;inds./10,000m^2$) and 3 times in biomass ($44,237g/10,000m^2$) after the dike construction. Annual species richness (R) and species diversity (H') decreased from R=0.0160 and H'=2.47 during the dike construction in 2001-2002 to R=0.0038 and H'=1.11 after dike construction in 2006-2006, respectively. These changes seemed to be related to the reduction of the saline area and degradation of water quality in Semangeum Reservoir after the dike construction.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.71-80
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• 1978

In an attempt to elucidate the fate of 3,4-DCA and TCAB in various French soils, uniformly $^{14}C-ring-labeled$ 3,4-DCA and TCAB mere utilized and the following results obtained. 1) The rate of breakdown of $^{14}C-3,4-DCA$ into $^{14}CO_2$ was relatively higher in the early stage than that in the later stage. In 6 months of incubation in alkaline soil (pH 7.9), the rate was as high as 6.5% at dose 1 (1.5 ppm) and as low as 1.92% at dose 2(94 ppm), whereas in organic acid soil (pH 5.5) the rate was 4.91% at dose 1 and 4.24% at dose 2, respectively, without making any great difference between the two levels. 2) At dose 1, 47.70% of the initial radioactivity of $^{14}C-3,4-DCA$ was bound to soil in organic acid soil and 29.49% bound in alkaline soil, whereas at dose 2, 38.40% in organic acid soil and 20.30% in alkaline soil, respectively. 3) The amount of formation of $^{14}C-TCAB$ from $^{14}C-3,4-DCA$ seems to depend largely on the concentration of 3,4-DCA applied rather than on soil types. At dose 2, the amount was 50% of the total radioactivity extracted in organic acid soil and 30% in alkaline soil, corresponding to 1.8% and 1.4% of the initial radioactivity applied to soil, respectively. Cis-TCAB also seemed to be formed at dose 2 in both soils. Meanwhile, at dose 1, even though $^{14}C-TCAB$ was detected in trace on tlc and glc in both soils, the amount does not exceed 2 to 3% of the radioactivity extracted, corresponding to 0.05 to 0.1% of the initial radioactivity. 4) The rate of breakdown of $^{14}C-TCAB$ into $^{14}CO_2$ ranged from 0.05 to 0.20% in all the four soils. Most of the applied $^{14}C-TCAB$ remained intact after 3 months, not producing any detectable metabolites. 5) The fact that much more $^{14}C-TCAB$ was adsorbed to alkaline soil than to the other soils strongly indicates that in alkaline condition trans-isomer was converted tocisisomer which has the higher adsorption affinity than the former.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.241-248
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• 2009

Metabolic trial with 3 fistulated sheep was conducted in a 3 $\times$ 3 Latin square design and feeding trial with 24 Hanwoo steers in 12 month of age for 20 months was conducted to investigate the replacing effect of rice straw with fermented spent mushroom (Flammuliua velutipes) compost (FSMC) on fermentation characteristics, ruminal effective degradabilty and whole tract digestibility of nutrients in sheep, and to examine the growth performance of Hanwoo steers. Experimental diets for the metabolic trial with sheep were commercial concentrates and rice straw in the ratio of 70 : 30 (CON, DM basis). Same concentrate with 30% FSMC and 70% rice straw (FSMC-30) and 60% FSMC and 40% rice straw(FSMC-60). Diets for Hanwoo steers in three treatments were same as for metabolic trial in replacing ratio of rice straw with FSMC. pH of rumen fluid in sheep was not affected by FSMC. Ammonia-N content in the rumen fluid was highest in the sheep fed FSMC-60 at 3h (P<0.045). The CON diet increased (P<0.001) acetate proportion at 1h and 3h post feeding compared to FSMC-60 diet while propionate proportion was highest in the sheep fed FSMC-60 diet for all the sampling times (P<0.027~P<0.002). Increased proportion of butyrate was observed at 30 min prior to feeding (P<0.031), and 1h (P<0.011) and 6h(P<0.039) post feeding from sheep fed FSMC-30 diet compared to those from sheep fed other diets. Effective degradability in the rumen was not influenced by experimental diets. Whole tract digestibility of crude protein (P<0.031) and neutral detergent fiber (P<0.006) tended to be increased in the sheep fed CON diet while corresponding values were lowest in the sheep fed FSMC-60 diet. Total body weight gain of Hanwoo steers for 8 months was not different among diets, thus daily body gain was not influenced by the experimental diets.