• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.289-299
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• 2003

Effects of various combinations of corn oil (CO) and perilla oil (PO) as respective dietary sources of ${\omega}$-6 and ${\omega}$-3 polyunsaturated fatty acids on fatty acid profiles of immune organs were studied in young chicks. Seventy-five 1-day-old male (ISA Brown) chicks were assigned to five treatments with three replications. Semi-purified-type diets containing glucose and soybean meal as major ingredients were added with 8% CO, 6% CO+2% PO, 4% CO+4% PO, 2% CO+6% PO and 8% PO and fed for 7 weeks. There were no significant differences in body weight gain, feed intake and relative weights of liver and immune organs (g/100g weight) among dietary groups. Dietary fatty acid patterns were generally reflected in the fatty acid compositions of all immune organs such as spleen, thymus and bursa of Fabricius. The levels of a-linolenic acid(LNA), eicosapentaenoic acid (EPA) and docosahexaenoic acid in various immune organs increased with increasing levels of perilla oil in the diets, whilet the levels of linoleic acid (LA) and arachidonic acid (AA) decreased. Thymus appeared to have capacity to retain remarkably higher (P<0.05) levels of LA and LNA up to 37 and 22%, respectively, compared to the other organs. Thymic tissue contained ${\omega}$-3 fatty acid and ${\omega}$-6 fatty acid 10~36 times and 3~5 times higher than the other organs, respectively. Spleen tissue was specifically higher (P<0.05) in the levels of AA and EPA and the ratios of AA/LA and EPA/LNA, compared to the other organs, suggesting that the tissue might have high desaturase activity to convert LA or LNA to AA or EPA, respectively. BSA antibody production tended to increase by 18 ~ 32% with higher levels of perilla oil in diet, although the increase was not statistically significant. In conclusion, fatty acid compositions of immune organs very depending on the lipid composition of the diets and each organ appears to respond differently for its fatty acid profile to dietary lipids. Considering AA and EPA are precursors of many important eicosanoids, further studies are required to clarify the responses of the immune organs to the dietary fatty acids.

• Journal of Environmental Science International
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• v.13 no.12
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• pp.1079-1088
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• 2004

In order to understand chemical characteristics and dewfall formation in western Busan area, we analysed monthly distribution of dewfall, and investigated the correlation between dewfall formation amount and meteoro­logical factors. This study used the modified teflon plate $(1m{\times}1m)$ at Silla university in Busan from August 2002 to April 2003. In order to estimate qualitatively water soluble components, IC, ICP and UV methods for water soluble ions are also used respectively. Dewfall amount of sampling periods (47 day) collected 3.8 mm. Meteorological conditions for the formation of dewfall above $50\;g/m^{2}$ showed that temperature diurnal $range(^{\circ}C)\;was\;5.6^{\circ}C$ above, cloud amounts (1/10) at dawn of the sampling day was 7/10 below, mean wind speed at dawn (0~6hr) of the sampling day was 4.4 m/sec below, and mixing ratio at 6hr of the sampling day was 3.2 g/kg above. Distribution of water soluble ions in dewfall founded the highest concentration (206.1\;{\mu}eq/{\ell}\;for\;SO_{4}^{2-},\;42.4\;{\mu}eq/{\ell}\;for\;NH_{4}^{+},\;249.2\;{\mu}eq/{\ell}\;for\;Ca^{2+},\;and\;42.0\;{\mu}eq/{\ell}\;for\;Mg^{2+})$ during the March, the lowest concentration $(73.0\;{\mu}eq/{\ell}\;for\;SO_{4}^{2-},\;4.6\;{\mu}eq/{\ell}\;for\;NH_{4}^+\;and\;72.7\;{\mu}eq/{\ell}\;for\;Ca^{2+})$ during the August. Monthly equivalent ratio of $[SO_{4}^{2-}]/[NO_{3}^-]$ showed the highest value (4.99) during the October, the lowest value (1.84) during the August, and the mean value was 3.45.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.35-41
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• 2008

Nutrient Enrichment Bioassays (NEBs) were conducted in the laboratory during June $22{\sim}28$, 2006 in order to determine primary limiting factor on the phytoplankton growth. For the NEBs, the water was sampled using a 10L polyethylene-lined container and dispensed into 2.5L container in the laboratory. The algal growths response in the control (C) and three treatments of phosphorus (P), 2-fold phosphorus (2P), and nitrate nitrogen $(NO_3-N)$ were monitored during 7 days. In the cubitainers which were spiked as P (T1) and 2P (T2) Chl-${\alpha}$ concentrations were decreased during the test period and the final concentrations was low than initial values. However, Chl-${\alpha}$ in the cubitainers which were spiked as $NO_3$(T3) and $P+NO_3$(T4) showed significant increases compared to the initial values, indicating that in the short-term experiments, nitrogen seemed to be a primary limiting nutrient during the periods of NEBs experiment. Long-term ambient nutrient data of TP and TN, and TN:TP mass ratios, however, showed a potential phosphorus limitation on phytoplankton growth and previous other researchers showed a variations of limiting nutrients by nitrogen or phosphorus depending on the seasons sampled and locations. In this study nitrogen as primary limiting nutrient in the NEBs seem to be an seasonal effect rather than the consistent nitrogen limitation.

• Journal of the Korean institute of surface engineering
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• v.27 no.4
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• pp.207-214
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• 1994

In consideration of global environmental protection and fuel saving, aluminum alloy sheets for auto body panels such as hood, fender etc., are expected one of the most promising materials for weight saving of cars. The chemical conversion coating is required to prevent the filiform corrosion occurring on painted aluminum. However the conventional process for the composited material mixed with aluminum and steel is complexs; aluminum part is chromated and assembled to the body, and then the steel body undergoes Zn phosphating. In order to overcome the low productivity due to the complex process and the environmental problem with a conventional process, a simultaneous zinc phosphating process for alsuminum and steel in an assembled condition is demanded. Newly developed phosphate solution has been investigated to characterize the phosphating behavior under various conditions. The optimum conditions of the phosphating solution for the application of the paint treatment derived as follows : about 0.3 for the ratio of Zn to $PO_4$, , 200~500 ppm for the concentration of fluoride ion, and 2.5~4.0 for pH. The concentration of dissolved aluminum ion must be kept below 2--ppm and suitable accelerator is found to be a mixture of 1g/$\ell$ $NO_2\;^-$, and 6g/$\ell$ $NO_3\;^-$.

• Nutritional Sciences
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• v.4 no.1
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• pp.3-12
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• 2001

Long chain polyunsaturated fatty acids (LCPUFA) are important components of brain phospholipds and play important role (s) in brain function. In rats, the maximum brain growth occurs during the period of lactation even though it happens during the third trimester of gestation in human. Since milk contained docosahexaenoic acid (DHA) even through the maternal diet had no DHA and/or a very small amount of its precursor, $\alpha$-linolenic acid ($\alpha$-LnA), an emphasis was given to maternal adipose tissue as a reservoir of this fatty acid. We, therefore, investigated the mesenteric and subcutaneous adipose tissues for their fatty acid composition in dams reared with different fat diets. Diets containing various amounts of $\omega$6 and $\omega$3 fatty acids were given to adult female rats (200-250g) throughout the pregnancy and lactation periods. Diets were composed of 10% (wt/wt) corn oil (CO), soybean oil (SO), perilla seed oil (PO) containing about 60% $\alpha$-LnA, or fish oil (FO) rich in eicosapentaenoic acid (EPA) and DHA. The fatty acid ompositions of mesenteric and subcutaneous fat were measured and evaluated at Day-2 and Day-15 after parturition. In general, major characteristics of dietary fatty acid composition was reflected on the fatty acid composition of adipose tissues. Dietary fatty acid composition was reflected more on mesenteric fat as compared to subcutaneous fat. Mesenteric fat was found to contain less arachidonic acid (AA) and mesenteric fats of CO, SO and PO groups contained less DHA than did the subcutaneous fat. The P/M/S ratios of adipose tissues were similar between experimental groups while dietary P/M/S ratios differed significantly. It was noticeable that a small proportion of DHA was found in the adipose tissues of animals of CO, SO and PO groups (Day-2) and in SO and PO groups (Day-15), the groups which do not contain DHA in their diets. The percentage of DHA in mesenteric fat o CO, SO and PO groups decreased as lactation continues, while the proportion of DHA in FO group increased. Adipose tissues of FO group had higher DHA/EPA ratio as compared to the diet. Considering the fact that the body contains a large amount of adipose tissues, our present finding suggests that the adipose tissue can serve as a reservoir of DHA for pregnant and lactating rats.

• Fisheries and Aquatic Sciences
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• v.24 no.7
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• pp.260-275
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• 2021

Aquaponics is a cultivation system that combines aquaculture and agricultural hydroponics. This study investigated the productivity of leafy vegetables cultivated in the hybrid biofloc technology-aquaponics (HBFT-AP) using Japanese eel fed two kinds of diets (Mash, commercial powdered feed and extruded pellet [EP]) and hydroponics (HP).The mash was fed to the fish in a type of a dough mixed with water for 6 weeks (Exp1) and switched to the EP containing 2.7% monobasic potassium phosphate (MKP) for subsequent 6 weeks (Exp2). Leafy vegetables of 8 cultivar were employed in the experiment and water quality [dissolved oxygen (DO, mg/L), pH, water temperature (℃), electrical conductivity (EC; ㎲/cm), turbidity (NTU), TAN (NH₃ + NH₄⁺) (mg /L), NO₂-N (mg/L), NO₃-N (mg/L) and PO₄-P (mg/L)] was measured 6 times a week. Leafy vegetable productivity (HBFT-AP vs HP) was compared in respective experiment, which was similar or somewhat higher in HBFT-AP. During the 12-week feeding trial, concentrations of nitrite (NO₂-N) and phosphorus (PO₄-P) were kept low in variability while total ammonia nitrogen (TAN) and NO₃-N levels increased with time in HBFT-AP. At the end of two feeding trials, values of weight gain (WG, %), feed efficiency (FE, %), specific growth rate (SGR, %) and protein efficiency ratio (PER) were higher in Exp2 than in Exp1. As well, higher values in hematocrit (PCV, %), plasma K (mEq/L) and inorganic phosphorus (mg/dL) were found (p < 0.05) in Exp2 where fish were fed the EP (EP: 38.60%, 2.80 mEq/L and 7.04 g/dL; Mash: 33.20%, 1.95 mEq/L and 5.50 g/dL). Leafy vegetables in HBFT-AP using Japanese eel fed the EP with MKP 2.7% had a productivity similar (4 kinds of cultivar) or somewhat higher (4 kinds of cultivar) compared to those in HP. Also, Japanese eel fed the EP showed higher values of Pi (m/dL) and K (mEq/L) in plasma compared to those fed commercial powder diet.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.578-584
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• 1990

A microorganism capable of producing high level of extracelluar cyclomaltodextrin glucanotransferase(EC 2.4.1.19; CGTase) was isolated ’rom soil. The isolated strain No. 239 was identified as Bacillusstearothermophilus. The maximal CGTase production (about 7.0 unitslml) was observed in medium containing2% soluble starch, 0.5% defatted soybean meal, 0.1% NaH_2PO_4.2H_2O$ and 0.015% $ CaC_l2 $ with initial pH 7.0. The strain was cultured at $55^{\circ}C$ for 48 hr with reciprocal shaking. At 0.83% substrated concentration potato starch was the optimum substrate with 50.1% conversion to cyciodextrin (CD)after the reaction at $65^{\circ}C$ for 24 hr (CGTase 10 unitlg starch). Using soluble starch as substrate (5% substrate concentration, CGTase 10 unitlg starch), the maximum conversion of 40% was obtained at11 hr reaction, and the ratio of $\alpha-, \beta-$ and $\gamma$-CD production at this time were 1.0:1.3:0.4, respectively., respectively.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.130-143
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• 1997

To investigate geochemical characteristics and the sources of the dissolved ion species in the river water in the Han river drainage basin, samples were collected at 60 sites from the Han river drainage basin. The data for. pH, conductivity, TDS (total dissolved solid), temperature, and concentrations of dissloved ions were obtained as follows : (1) The geochemical characteristics of the surface water in the South and North Han river drainage basins are mainly controlled by bed rock geology in the drainage basin and in the main stream of the Han river considerably affected by anthropogenic pollution. The South Han river water samples have high concentrations of $Ca^{2＋}$ (ave. 15.42 ppm), $Mg^{2＋}$ (ave. 2.74 ppm), HC $O_3$$^{[-10]}$ (ave. 51.9 ppm), which evidently indicates that the bed rock geology in a limestone area mainly controls the surface water chemistry. The concentration of S $O_4$$^{2-}$ is remarkably high (SHR10-2 : 129.9 ppm) because of acid mine drainage from the metal and coal mines in the upper reaches of the South Han river. (2) The South Han river and the North Han river join the Han river. in the Yangsuri, Kyounggido and flow through Seoul metropolitan city. The mixing ratio is about 60:40 at the meeting point (sample number HRl0). (3) The result of factor analysis suggests that the pollution factor accounts for about 79% and the bed rock type factor accounts for about 7% of the data variation. This means that the geochemical characteristics of the Han river water mainly controlled by anthropogenic pollution in the South Han river and main stream of the Han river drainage basin. (4) The chemical data for four tributaries such as the Wangsukcheon, the Tancheon, the Zunuangcheon, and the Anyangcheon show that the concentration of pollution elements such as N $O_2$, C $l^{－}$, P $O_4$$^{3-}$, S $O_4$$^{2-}$ and Mn are high due to municipal waste disposal.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2333-2337
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• 2007

Nanoporous TiO2 and ZrO2 thin films were spin-coated using a surfactant-templated approach from Pluronic P123 (EO20PO70EO20) as the templating agent, titanium alkoxide (Ti(OC4H9)4) as the inorganic precursor, and butanol as a the solvent. The control of the electronic structure of TiO2 is crucial for its various applications. We found that the band gap of the hybrid nanoporous thin films can be easily tuned by adding an acetylacetonestabilized Zr(OC4H9)4 precursor to the precursor solution of Ti(OC4H9)4. Pores with a diameter of 5 nm-10 nm were randomly dispersed and partially connected to each other inside the films. TiO2 and ZrO2 thin films have an anatase structure and tetragonal structure, respectively, while the TiO2-ZrO2 hybrid film exhibited no crystallinity. The refractive index was significantly changed by varying the atomic ratio of titanium to zirconium. The band gap for the nanoporous TiO2 was estimated to 3.43 eV and that for the TiO2-ZrO2 hybrid film was 3.61 eV.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.259-263
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• 1997

To investigate chemical changes of agricultural water in Nam river used for the basic information. Samples were collected from seven sites along the Nam river and were analyzed for inorganic content from April to September in $1994{\sim}1995$. Average value of analyzed inorganic concentrations at seven sampling sites were pH 7.9, COD 7.3mg/l, $NO_3-N$ 1.2mg/l, $Na^+$ 6.2mg/l, $Cl^-$ 14.8mg/l, EC 0.13dS/m, $PO_4\;^{3-}$ 0.21mg/l, $K^+$ 2.6mg/l, $Ca^{2+}$ 10.8mg/l,$Mg^{2+}$ 2.9mg/l, $SO_4\;^{2-}$ 10.5mg/l, $Fe^{3+}$ and $Zn^{2+}$ 0.02mg/l. The monthly average value of COD, $NO_3-N$, $Na^+$ and $Cl^-$ showed highest peak in July $8.4{\sim}11.6$, $1.1{\sim}1.7$, $5.4{\sim}13.1$ $18.9{\sim}27.9mg/l$. The highest region of average COD, $NO_3-N$, $Na^+$ and $Cl^-$ were Weola pumping station, $8.8{\sim}11.3$, $1.6{\sim}2.4$, $9.0{\sim}10.2$ and $21.7{\sim}23.0mg/l.$ The ionic $copmposition({\Sigma}A/{\Sigma}C)$ : ratio between total equivalant of anions and canon) of Nam river was higher at Weola pumping station than other topography. The EC was positively correlated with $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $Cl^-$ and $SO_4\;^{2-}$.