• Horticultural Science & Technology
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• v.29 no.3
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• pp.211-216
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• 2011

This study was carried out to clarify precise $CO_2$ demands of paprika plants (Capsicum annumm L.) by measuring photosynthesis rates of the leaves in high, low positions, and the $CO_2$ consumption of a whole plant in a large sealed chamber. A photosynthesis measuring system (LI-6400) was used to measure the photosynthetic rates of the leaves located in different positions. A large sealed chamber that can control inside environmental factors was developed for measuring $CO_2$ consumption by a whole paprika plant. With increase of radiation, photosynthetic rates of the leaves in higher position became larger than those in lower position. The $CO_2$ consumption by the plant was estimated by using decrement of $CO_2$ concentration from initial level of 1500 ${\mu}mol{\cdot}mol^{-1}$ in the chamber with increase of integrated radiation. A regression model for estimating $CO_2$ consumption by the plant (leaf area = 7,533.4 $cm^2$) was expressed with integrated radiation (x) and was suggested as $y=-0.06234+3.671^*x/(2.589+x)$ ($R^2=0.9966^{***}$). The photosynthetic rate of the whole plant measured in the chamber was 3.4 ${\mu}mol\;CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ under 300 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity, which is in-between photosynthetic rates of the leaves in high and low positions. For this reason, some differences between required and supplied $CO_2$ amounts in greenhouses might occur when depending too much on photosynthetic rates of leaves. Therefore, we can estimate more accurately $CO_2$ amount required in commercial greenhouses by using $CO_2$ consumption model of a whole plant obtained in this study in addition to leaf photosynthetic rate.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.329-334
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• 2004

The objective of this study was to determine the effect of herb and bio ceramic complex supplementation on growth performance and meat quality characteristics in finishing pigs. Seventy-two crossbred (Landrace ${\times}$ Yorkshire ${\times}$ Duroc) pigs (78.98kg average initial body weight) were used in a 45 days growth assay. Dietary treatments included 1) Control (basal diet). 2) HBC (Herb and bioceramic complex) 0.1 (basal diet + 0.1％ Herb and bioceramic complex) and 3) HBC 0.2 (basal diet +0.2％ Herb and bioceramic complex). For overall period, ADG (Average Daily weight Gain), ADFI (Average Daily feed Intake) and ADG/ADFI increased in Control with no significant difference (p>0.05). Backfat thickness was not significantly different among the treatments (p>0.05). The total cholesterol, HDL (High Density Lipoprotein) cholesterol, LDL (Low Density Lipoprotein) cholesterol, LDL + VLDL (Very Low Density Lipoprotein) cholesterol, Triglyceride and Atherogenic index concentrations of serum in pigs fed HBC 0.2 diet were lower than those of pigs fed Control and HBC 0.1 diets without significant difference (p>0.05). L$\^$*/-, a$\^$*/-, and b$\^$*/- values of M. longissimus dorsi muscle were not significantly different among the treatments (p>0.05). The pH of pigs fed HBC 0.2 diet was significantly lower than that of pigs fed Control and HBC 0.1 diets (p<0.05). In conclusion, growth performance, cholesterol concentration in serum and meat quality were not affected by supplemental herb and bioceramic complex.

• Food Science of Animal Resources
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• v.23 no.4
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• pp.342-349
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• 2003

Escherichia coli O157：H7, Staphylococcus aureus and Salmonella enteritidis are food borne pathogens involved in food poisoning in numerous countries. This study aimed to obtain knowledges on the survival of Esc coli O157：H7, Sta aureus and Sal. enteritidis in the yoghurt added with water extract of Omija(Schizandra chinensis). The growth inhibition of Schizandra chinensis extract on the food borne pathogens were measured by total microbial count and effect of growth inhibition was correspondent to the concentration of Schizandra chinensis extract. The highest growth inhibition effect of Schizandra chinensis extract was shown on the Sta aureus followed by Sal. enteritidis and Esc. coli O157：H7. The number of surviving Esc. coli O157：H7 cell(3.55${\times}$10$\^$5/ CFU/mL) was decreased to 1.00${\times}$10$^1$∼3.00${\times}$10$^1$ CFU/mL after 24 hours incubation by the addition of 0.4∼l.0％ of Schizandra chinensis extract in the yoghurt. And also the viable cell counts of surviving Sta. aureus cells (initial inoculum 1.24${\times}$10$\^$5/ CFU/mL) were decreased gradually to 4.00${\times}$10$^2$∼8.50${\times}$10$^2$ CFU/mL after 48 hours of incubation, but the viable cells of Sal. enteritidis were not detected after 24 hours of incubation. Growth of the food borne pathogens was strongly inhibited by the addition and incubation of Schizandra chinensis extract for 48 hours in the yoghurt.

• Journal of Life Science
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• v.26 no.1
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• pp.68-74
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• 2016

Perchlorate (ClO₄⁻) is an emerging pollutant detected in surface water, soil, and groundwater. Previous studies provided experimental evidence of autotrophic ClO₄⁻ removal with elemental sulfur (S⁰) particles and activated sludge, which are inexpensive and easily available, respectively. In addition, ClO₄⁻ removal efficiency was shown to increase when an enrichment culture was used as an inoculum instead of activated sludge. PCR-DGGE was employed in the present study to investigate the microbial community in the enrichment culture that removed ClO₄⁻ autotrophically. Microorganisms in the enrichment culture showed 99.71% or more ClO₄⁻ removal efficiency after a 7-day incubation when the initial concentration was approximately 120 mg ClO₄⁻/l. Genomic DNA was isolated from the enriched culture and its inoculum (activated sludge), and used for PCR-DGGE analysis of 16S rRNA genes. Microbial compositions of the enrichment culture and the activated sludge were different, as determined by their different DGGE profiles. The difference in DGGE banding patterns suggests that environmental conditions of the enrichment culture caused a change in the microbial community composition of the inoculated activated sludge. Dominant DGGE bands in the enrichment culture sample were affiliated with the classes β-Proteobacteria, Bacteroidetes, and Spirochaetes. Further investigation is warranted to reveal the metabolic roles of the dominant populations in the ClO₄⁻ degradation process, along with their isolation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.469-475
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• 2002

The rotating biological contactor (RBC) was tested for treatment of aquacultural water in a pilot-scale recirculating aquaculture system. Performance of RBC on the treatment of nitrogen source such as total ammonia nitrogen (TAN), nitrite nitrogen and nitrate nitrogen and chemical oxygen demand (CODcr.) was evaluated. A system was stocked with nile tilapia at an initial rearing densities of $5\%$ and $7\%$ over 30 days. As increasing rearing density from $5\%$ to $7\%$, the TAN removal rates was increased from $39.4 g/m^3{\cdot}day$ to $86.0 g/m^3{\cdot}day$. But TAN removal efficiency was decreased from $24.5\%$ to $16.0\%$. The removal rate of $COD_Cr$ was higher than TAN. The RBC as an aerator was also evaluated for increasing dissolved oxygen concentration. For $5\%$ and $7\%$ of rearing density, the average aeration rate were $280 g/m^3{\cdot}day$ and $255 g/m^3{\cdot}day$, respectively.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.192-199
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• 2010

The alone and combined effects of bacteriocin produced from Enterococcus faecalis MJ-213 and potassium sorbate against the food-borne pathogenic bacteria were studied. Bacteriocin minimal inhibitory concentration (MIC) values for Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076 were 50 and 100 ${\mu}g$/ml, respectively. Bacteriocin (100 ${\mu}g$/ml) alone was active against S. aureus and S. enteritidis, but it was lower in antimicrobial effectiveness than the combination of bacteriocin (100 ${\mu}g$/ml) with potassium sorbate (100 ${\mu}g$/ml), which reduced initial counts (6 log cycle) of S. aureus and S. enteritidis by 1 and 3 log cycle, respectively. The bactericidal activity of bacteriocin of E. faecalis MJ-213 heated at $100^{\circ}C$ for 30 min or $121^{\circ}C$ for 15 min was markedly decreased as compared with the control. Moreover, the activity of bacteriocin was completely abolished by pepsin or protease II, but not affected by ${\alpha}$-amylase or lipase. The activity of bacteriocin adjusted to pH 6.0-8.0 showed almost the same inhibition ratio compared with the bacteriocin unadjusted pH, and though the inhibition ratio against pathogenic bacteria was reduced than the control, the bacteriocin was stable at pH 4.0 or 10.0, relatively. Furthermore, the combined treatment of bacteriocin and potassium sorbate than the alone treatment of bacteriocin significantly decreased (p<0.05) the viable cell counts of S. aureus or S. enteritidis inoculated on grind beef during storage at $4^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.397-405
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• 2009

In this study, we investigated the potential of producing bioethanol from Liriodendron tulipifera by using oxalic acid pretreatment. Amounts of fermentable sugars, mostly xylose and glucose, in the liquid fraction (hydrolysate) was $40.22g/{\ell}$ after the biomass was pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$. Production amounts of ethanol was $8.6g/{\ell}$ from the 72 hours of simultaneous saccharification and fermentation (SSF) on solid fraction of the pretreated sample. At the same condition, when the reaction time increased to 40 minutes, $32.66g/{\ell}$ of fermentable sugars in the hydrolysate and $9.5g/{\ell}$ of ethanol was produced from the process of pretreatment and SSF. As a result of analyzing the fermentation inhibitors, such as acetic acid, 5-HMF, furfural and total phenolic compounds, as the reaction time increased, the amount of the fermentation inhibitors in the hydrolysate increased. Production of the fermentation inhibitors was more affected by initial concentration of oxalic acid rather than reaction time. $3.39{\sim}5.78g/{\ell}$ of acetic acid was produced by pretreatment with 0.013 g/g of oxalic acid, and the amount of furfural produced by decomposition of xylose was 2~3 times higher than the amount of 5-HMF produced by decomposition of glucose. All the hydrolysates contained more than $5g/{\ell}$ of total phenols considered as the degradation product of lignin. Therefore, by analyzing the amount of fermentable sugars and fermentation inhibitors in the hydrolysate, and producing ethanol from SSF of solid fraction of the pretreated sample, the biomass pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$ can be expected to produce the most ethanol.

• Journal of Korea Water Resources Association
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• v.41 no.12
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• pp.1219-1230
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• 2008

Stream inflows induced by flood runoffs have a higher density than the ambient reservoir water because of a lower water temperature and elevated suspended sediment(SS) concentration. As the propagation of density currents that formed by density difference between inflow and ambient water affects reservoir water quality and ecosystem, an understanding of reservoir density current is essential for an optimization of filed monitoring, analysis and forecast of SS and nutrient transport, and their proper management and control. This study was aimed to quantify the characteristics of inflow density current including plunge depth($d_p$) and distance($X_p$), separation depth($d_s$), interflow thickness($h_i$), arrival time to dam($t_a$), reduction ratio(${\beta}$) of SS contained stream inflow for different flood magnitude in Daecheong Reservoir with a validated two-dimensional(2D) numerical model. 10 different flood scenarios corresponding to inflow densimetric Froude number($Fr_i$) range from 0.920 to 9.205 were set up based on the hydrograph obtained from June 13 to July 3, 2004. A fully developed stratification condition was assumed as an initial water temperature profile. Higher $Fr_i$(inertia-to-buoyancy ratio) resulted in a greater $d_p,\;X_p,\;d_s,\;h_i$, and faster propagation of interflow, while the effect of reservoir geometry on these characteristics was significant. The Hebbert equation that estimates $d_p$ assuming steady-state flow condition with triangular cross section substantially over-estimated the $d_p$ because it does not consider the spatial variation of reservoir geometry and water surface changes during flood events. The ${\beta}$ values between inflow and dam sites were decreased as $Fr_i$ increased, but reversed after $Fr_i$>9.0 because of turbulent mixing effect. The results provides a practical and effective prediction measures for reservoir operators to first capture the behavior of turbidity inflow.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.68-75
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• 1985

Laboratory experiments were conducted to investigate the effect of compost and humic acid treatment on adsorption of Cd, Zn, and Cu in soils. Three soils differing in physical and chemical properties used in this experiments were Bonyrang (Typic Udifluvents) SL, Gangseo (Aquatic Eutrochrepts) L, and Gyorae (Typic Distrandepts) SiL. Adsorption of Cd, Zn, ana Cu on the soils followed Langmuir isotherm up to 75 ppm of initial concentration. The adsorption maxima of Cd, Zn, and Cu for the Bonryang soil, the lowest in pH, organic matter content, and CEC, were the lowest of the three soils. Although the Gyorae soil derived from volcanic ash was the highest in organic matter content and CEC, the adsorption maxima of heavy metals for the Gyorae soil were lower than those for the Gangseo soil of which organic content and CEC were intermidiate. The adsorption maxima/CEC ratios for the Bonryang, the Gangseo, the Gyorae soils were found to be in the range of $23{\sim}27%,\;28{\sim}57%$, and $11{\sim}14%$ respectively The bonding energy constants of Cd, Zn, and Cu for the soils were in the order of Gangseo>Bonryang>Gyorae soils. The adsorption maxima of Cd, Zu, and Cu for the Bonryang soil increased with compost treatment by $100{\sim}210%,\;90{\sim}230%$, and $130{\sim}290%$ respectively, while little difference was observed when the soil was treated with humic acid Bonding energy constants of Cd, Zn, and Cu for the Bonryang soil increased significantly with compost treatment, and showed insignificant correlation with humic acid treatment.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.445-453
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• 2012

An investigation for removal of 1-indanone (1-ID), which were commonly produced from the biological and/or chemical treatment and natural weathering of the PAHs-contaminated soils, via oxidative transformation mediated by birnessite in the presence of various phenolic mediators is described. This study also examines the potential effect of the natural occurring substance humic acid (HA) on the oxidative transformation. The experiment was carried out in aqueous phase as a batch test (10 mg/L 1-ID, 0.3 mM phenolic mediators, $1.0g/L\;{\delta}-MnO_2$, at pH 5). All of the 11 tested phenoilic mediators belong to the group of natural occurring phenols and are widely used as model constituents of humic substances. From the results of HPLC analysis, it is demonstrated that 1-ID was not reactive to birnessite itself, but it can be effectively removed in birnessite-mediated cross coupling reactions in the presence of the phenolic mediators. The percent removals of 1-ID after 2 day incubation were ranged from 9.2 to 71.2% depending on the phenolic mediators applied. The initial rate constant ($K_{int}$, $hr^{-1}$) values for the 1-ID removals obtained from the pseudo-first-order kinetic plots also widely ranged from 0.18 to 15.0. Results of the correlative analysis between the removal efficiencies and structural characteristics of phenolic mediators indicate that the transformation of the 1-ID was considerably enhanced by the addition of electron-donating substituents (e.g., -OH, $-OCH_3$) at the benzne ring, and much less enhanced by the addition of electron-withdrawing substituents (e.g., -COOH, -CHO). The presence of HA showed that removal efficiencies of 1-ID in the birnessite-phenolic mediator systems decreased with increasing HA concentrations. However at low concentration of HA (< 2 mg/L), it caused some enhancement in the removals of 1-ID as compared to the control.