• Resources Recycling
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• v.5 no.3
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• pp.31-36
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• 1996

The metallic copper was recovered from sludge of the copper electro-plating plant by pyrometallurgical process. The reducing agent was Pyrolysized from waste tires and the flux was a mixture $Na_2CO_3$, $NaB_4O_7$, and glass. The green sludge contained 87.5% moisture and 12.5% solid with 56.5% Cu and 1.59% Fe. The sludge dried at $100^{\circ}C$ was analyized to be $Cu_4SO_4(OH)_6{\cdot}2H_2O$ and CuO by XRD analysis. The former was 84% and the latter 16%, However, the calcined sludge at $500^{\circ}C$ was 49% $Cu_2O(SO_4)$ and 51% CuO. The sludge could by smelted at $1100^{\circ}C$ for two hours with 6 to 8 moles carbon with respect to copper to produce metallic copper (>90%) with recovery of 9% above.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.198-204
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• 1988

This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.185-191
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• 1999

An air-conditioning system based on the chemical heat storage principle was considered. $H_2O$ was chosen as the reaction gas and the working fluid as well. Na$_2$S, CaCl$_2$, MnCl$_2$, BaCl$_2$, MgCl$_2$, Fe$_2$(SO$_4$)$_3$ and MnSO$_4$ were tested as the solid reactants by using Cahn pressure balance. Na$_2$S was superior to other salts in respect of high capability of absorption of water gas, 5 moles of $H_2O$ per unit mole of Na$_2$S, and adequate temperature of adsorption, $65^{\circ}C$ at 7torr, and of desorption, 13$0^{\circ}C$ at 76torr. Clausius-Clapeyron diagram of Na$_2$S was obtained via adsorption experiments at several vapor pressures of water gas. To enhance heat and mass transfer characteristics, usually below 1W/m K, of the reactor bed of general adsorption systems, expanded graphite block was adapted as the support of Na$_2$S salt. Expanded graphite blocks had thermal conductivity values of 20~80W/mK with respect to 100~400kg/㎥ of block bulk density. Permeability values of expanded graphite blocks were 10$^{-13}$ ~ 10$^{-14}$ $m^2$ with respect to 100~300kg/㎥ of block bulk density showing highly decreasing values of permeability, below 10$^{-l4}$$m^2$, in the range of above 150kg/㎥ of block bulk density.y.

• Journal of Plant Biology
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• v.29 no.3
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• pp.197-205
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• 1986

Leaf mesophyll protoplasts from five cultivars of tobacco (N. tabacum L.) were cultured. The protoplasts did not survive in culture medium containing Murashige and Skoog inorganic salts for over 6 days. NH4NO3 and FeSO4.Na2EDTA concentration of Murashige and Skoog medium were toxic in tobacco leaf mesophyll protoplast culture. Therefore we investigated optimum condition in Murashige and Skoog medium. High plating efficiency was obtained by reducing the concentrations of NH4NO3 and FeSO4.Na2EDTA to 1/3 and 1/10, respectively, on the supplemented with 5$\mu$M IAA, 0.5 $\mu$M 2.4-D 5 $\mu$M BAP. Plants were regenerated from protoplast-derived calluses.

• 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 $SO_4\;^{2-}$.

• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.56-64
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• 1991

The destructed chips(Pinus rigida Mill) were sulfonated under different conditions and defiberated. The yields and strengths of pulp, fatty acid and resin acid in sulfonated chips were determined. The results of this work were as follows: 1) A sulfonation caused a yield reduction to 97.9~88.2% at single stage. and to 94.9~88.2% at two stage pretreatment. The pulp yields were rapidly draped with increasing cooking temperature from $130^{\circ}C$ to $150^{\circ}C$ 2) Pulp strengths were improved with iacreasing cooking temperature. A sulfonation with 5% $Na_2SO_3$/NaOH(8/2) at single stage and 2% NaOH-5% $Na_2SO_3$ at two stage were most effective and gave the best combination of strength properteis. 3) Fatty acid esters in chips were mostly consisted of palmitic and olleic acid. During a sulfonation the former increased extensively, and the latter was lost with increase of cooking times. The amount of pimaric type in the chips was relatively decreased by the pretreatnent and abietic-type increased. But the changes between two resin acid types were insignificant. 4) The effciency of pitch removal was dependant upon cooking liquor pH. To remove sufficiently the resinous substance, the chips must be sulfonated at over pH 12. Therefore, taking account of pitch removel, two stage sulfonation is considered suitable as reinforcement pulp for newsprint manufacture from pitch pine chips : 2% NaOH($60^{\circ}C$ 1 hr) at first stage and 5% $Na_2SO_3$ ($130^{\circ}C$, 1hr) at secund stage.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.233-236
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• 2008

Ru:Sn:Sb 전극의 성능에 영향을 미치는 인자에 대하여 조사하여 다음의 결과를 얻었다. 0.5-3 A로 전류를 변화시켰을 때 최적 전류는 2 A로 나타났다. 실험에 사용한 전해질의 RhB 분해 성능은 NaCl > KCl > HCl > Na$_2$SO$_4$로 나타났다. 최적 NaCl 농도는 1.75 g/L로 나타났다. 최적 공기 공급량은 2 L/min으로 최적 pH는 3으로 나타났다.

• Journal of Life Science
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• v.9 no.5
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• pp.596-603
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• 1999

The effects of anti-stress mind tonic (ASMT) drink (ASMT-0.1% and ASMT-0.5% concentration) were tested for the anti-stress action. ICR male mice (20$\pm$2 g) were fed with basic experimental diets free access to water containing these ingredients for 18 days. Psychological stress/sociopsychological stress were exposed by foot-shock for 1 hour for 3 days. Both ASMT-0.1 and ASMT-0.5 groups in the sociopsychological stress resulted in a significant decrease of 19.1% and 41.9% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretions in the brain were significantly increased 23.4% and 35.9%, respectively, in ASMT-0.1 and ASMT-0.5 groups compared with control group. MHPG-SO4 (3-Methoxy-4-hydroxyphenylethyleneglycol sulfate) levels in the brain resulted in a marked decreases of 27.1% and 19.6%, respectively in ASMT-0.1 and ASMT-0.5 groups. NA/MHPG-SO4 ratios in the brain of ASMT-0.1 and ASMT-0.5 groups resulted in a significantly increase of about 70% compared with control group. These suggest that mind tonic anti-stress drink can effectively ridded the sociopsychological stress.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.2.1-2.4
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• 2016

Objectives In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. Methods Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). Results While $C_8F_{17}SO_3Na$, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for $C_{15}F_9H_{21}S_2O_8Na_2$, 8.4% for $C_{17}F_9H_{25}S_2O_8Na_2$, 22.6% for $C_{23}F_{18}H_{28}S_2O_8Na_2$, and 23.6% for $C_{25}F_{17}H_{32}O_{13}S_3Na_3$. Conclusions $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, $C_{23}F_{18}H_{28}S_2O_8Na_2$, and $C_{15}F_9H_{21}S_2O_8Na_2$ were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.

• Journal of Life Science
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• v.21 no.9
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• pp.1205-1213
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• 2011

The optimal concentrations of salts in medium for cell growth and the production of carboxymethylcellulase (CMCase) by a recombinant E. coli JM109/DL-3 were established using two statistical methods: orthogonal array method (OAM) and response surface method (RSM). The analysis of variance (ANOVA) of data based on OAM indicated that $K_2HPO_4$ gave maximum sum of square (S) and percentage contribution (P) for cell growth as well as production of CMCase. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ in medium for cell growth extracted by Qualitek-4 (W32b) Software were 10.0, 1.0, 0.2, and 0.6 g/l, respectively, whereas those for the production of CMCase by E. coli JM109/DL-3 were 5.0, 1.0, 0.4, and 0.6 g/l. The analysis of variance (ANOVA) resulting from RSM indicated that a highly significant salt for cell growth was $K_2HPO_4$ ("probe>F" less than 0.0001), whereas $K_2HPO_4$ and $MgSO_4{\cdot}7H_2O$ were significant for the production of CMCase. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ for cell growth extracted by Design Expert Software were 7.44, 1.08, 0.22, and 0.88 g/l, respectively, whereas those for production of CMCase were 5.84, 0.69, 0.28, and 0.54 g/l. The optimal concentrations of salts and their influences on cell growth and production of CMCase extracted by OAM were almost the same as those by RSM. Production of CMCase by a recombinant E. coli JM109/DL-3 under optimized concentration of salts was 1.93 times higher than that by Bacillus amyloliquifaciens DL-3.