• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.619-624
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• 2015

This study experimentally determined the effect of titanium tetrachloride (TiCl₄) concentration ([TiCl₄]) (0.25-0.55 mM) and initial pH (3-11) on phosphorus (P) removal in synthetic wastewater (2 mg P/L). The P removal efficiency increased when [TiCl₄] increased. The P removal efficiency showed a parabolic trend with an inflection point at pH 7. At the molar ratio of TiCl₄ and P>6.2, the P removal efficiency was over 90% and the residual P concentration was less than 0.2 mg/L. Within the design boundaries, the complete P removal could be achieved at 7.0≤initial pH≤8.5 and 0.43≤[TiCl₄]≤0.55 mM. The final pH was over 5.8 at initial pH≥7.7 and [TiCl₄]≥0.35 mM. The results showed that TiCl4 was effective in P removal in water so that it could be an alternative chemical for P removal.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1131-1136
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• 2003

Forty-eight individually fed Angus steers (body weight $220kg{\pm}9.1$) were utilized to investigate the effects of copper (Cu) source and concentration on lipid metabolism and carcass quality. Steers were stratified by body weight and initial liver Cu concentration and randomly assigned to one of five groups. Groups were then randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 10 mg Cu/kg DM from $CuSO_4$; 3) 10 mg Cu/kg DM from a Cu amino acid complex (Availa Cu) 4) 20 mg Cu/kg DM from $CuSO_4$; and 5) 20 mg Cu/kg DM from Availa Cu. Steers were fed a corn-alfalfa-based growing diet for 56 d. Steers were then switched to a high concentrate finishing diet for 145 d. On day 74 of the finishing phase subcutaneous adipose tissue biopsies were obtained from three steers/treatment to determine basal and stimulated lipolytic rates in vitro. Steers were then slaughtered after receiving the finishing diet for 145 d. Control steers tended (p<0.12) to have lower ceruloplasmin (Cp) activity than Cu supplemented steers. Steers receiving 20 mg Cu/kg DM from Availa Cu had higher (p<0.03) Cp activity than steers receiving 20 mg Cu/kg DM from $CuSO_4$. Plasma non-esterified fatty acids were similar across treatments. Steers receiving 10 mg Cu/kg DM from Availa Cu had higher (p<0.02) total plasma cholesterol concentrations relative to steers receiving 10 mg Cu/kg DM from $CuSO_4$. Steers receiving 20 mg Cu/kg DM from Availa Cu had lower (p<0.03) plasma triglyceride concentrations than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Fatty acid profile of longissimus muscle was similar across treatments. Backfat depth tended (p<0.18) to be lower in Cu supplemented steers relative to controls. Steers supplemented with 20 mg Cu/kg DM from Availa Cu had heavier (p<0.03) hot carcass weights and a greater (p<0.02) dressing percentage than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Furthermore, in vitro basal (p<0.06) and epinephrine stimulated (p<0.04) lipolytic rates of subcutaneous adipose tissue were higher in Cu supplemented steers relative to controls. The results of this study suggest that Cu supplementation has minimal effects on blood and lean tissue lipid profile. However, it appears that Cu may play a role in lipid metabolism in subcutaneous adipose tissue.

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.281-285
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• 2000

• Korean Membrane Journal
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• v.5 no.1
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• pp.10-17
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• 2003

1,3,5-Sustitituted polyphenylene type dendrimers were synthesized. The dendrimer was heated in cone. H$_2$SO$_4$ at 120$^{\circ}C$. The reaction mixture was precipitated to ether after simple filtration to get para-sulfonated dendrimer as the chief product. To give mechanical properties to the sulfonated dendrimer, it was partially cross-linked with phenyl ether in the medium of P$_2$O$\sub$5/ and CH$_3$SO$_3$H.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.256-256
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• 2012

SoP용 재료에 응용하기 위하여 NiCuZn 페라이트계 이용한 이종접합의 관한연구를 하였다. NiCuZn 페라이트계와 유전체의 이종접합특성은 XRD, Dilatometer, LCR meter, FE-SEM, EDS 이용하여 물리 화학적 특성을 조사하였다. NiCuZn 페라이트계는 일반적인 세라믹 제조공정을 이용하여 분말을 제조하였으며, 이종접합은 모든 시편에서 잘 진행되었으며 일부 유전체의 이온들이 페라이트 쪽으로 확산이 진행되었으며 NCZF700계는 $900^{\circ}C$ 소결 시편에서 확산이 진행되지 않은 현상이 나타났다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.2
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• pp.83-90
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• 1997

An unbleached hardwood kraft pulp was bleached in vitro with partially purified manganese peroxidase (MnP) from the fungus Phanerochaete sordida YK-624 without the addition of MnSO$_4$ in the presence of oxalate, malonate or gluconate known as manganese chelator, When the pulp was treated without the addition of MnSO$_4$, the pulp brightness increased by about 10 points in the presence of 2 mM oxalate, but the brightness did not significantly increase in the presence of 50 mM malonate. Residual MnP activity decreased faster during the bleaching with MnP without MnSO$_4$ in the presence of malonate than in the presence of oxalate. Oxalate reduced MnO$_2$ which already existed in the pulp or was produced from $Mn^{2+}$ by oxidation with MnP and thus supplied $Mn^{2+}$ to the MnP system. Thus, bleaching of hardwood kraft pulp with MnP, using manganese originally existing in the pulp, became possible in the presence of oxalate, a good manganese chelator and reducing reagent. Properties of partially purified MnPs from liquid cultures of white rot fungi, Ganoderma sp. YK-505, Phanerochaete sordida YK-624 and Phanerochaete chrysosporium were compared. MnP from Ganoderma sp. YK-505 was superior to MnPs from P. sordida YK-624 and P. chrysosporium in stabilities against high temperature and high concentration of $H_2O$$_2$. The MnP from Ganoderma sp. YK-505 differed in pH-activity profile from other MnPs. These data suggest that MnP from Ganoderma sp. YK-505 has different structure from those of other fungi. Bleaching of hardwood kraft pulp using the MnP from ganoderma sp. YK-505 is now in progress.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.38-39
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• 2001

The seasonal changes in pH, Fe, Al and SO$_4$$\^$2-/ contents of acid drainage released from coal mine dumps play a major role in precipitation of metal hydroxides in the Taebaek coal field area, southeastern Korea. Precipitates in the creeks underwent a cycle of the color change showing white, reddish brown and brownish yellow, which depends on geochemical factors of the creek waters. White precipitates consist of Al-sulfate (basaluminite and hydrobasaluminite) and reddish brown ones are composed of ferrihydrite and brownish yellow ones are of schwertmannite. Goethite coprecipitates with ferrihydrite and schwertmannite. Ferrihydrite formed at higher values than pH 5.3 and schwertmannite precipitated below pH 4.3, and goethite formed at the intermediate pH range between the two minerals. With the pH being increased from acid to intermediate regions, Fe is present both as schwertmannite and goethite. From the present observation, the most favorable pH that basauluminte can precipitate is in the range of pH 4.45-5.95. SEM examination of precipitates at stream bottom shows that they basically consist of agglomerates of spheroid and rod-shape bacteria. Bacteria species are remarkably different among bottom precipitates and, to a less extent, there are slightly different chemical compositions even within the same bacteria. The speciation and calculation of the mineral saturation index were made using MINTEQA2. In waters associated with yellowish brown precipitates mainly composed of schwertmannite, So$_4$ species is mostly free So$_4$$\^$2-/ ion with less AlSo$_4$$\^$+/, CaSo$\sub$(aq)/, and MgSo$\sub$4(aq)/. Ferrous iron is present mostly as free Fe$\^$2+/, and FeSo$\sub$4(aq)/ and ferric iron exists predominantly as Fe(OH)$_2$$\^$+/, with less FeSo$\sub$4(aq)/, Fe(OH)$_2$$\^$-/, FeSo$_4$$\^$-/ and Fe$\^$3+/, respectively Al exists as free Al$\^$3+/, AlOH$_2$$\^$-/, (AlSo$_4$)$\^$+/, and Al(So$_4$)$\^$2-/. Fe is generally saturated with respect to hematite, magnetite, and goethite, with nearly saturation with lepidocrocite. Aluminum and sulfate are supersaturated with respect to predominant alunite and less jubanite, and they approach a saturation state with respect to diaspore, gibbsite, boehmite and gypsum. In the case of waters associated with whitish precipitates mainly composed of basaluminite, Al is present as predominant Al$\^$3+/ and Al(SO$_4$)$\^$+/, with less Al(OH)$\^$2+/, Al(OH)$_2$$\^$+/ and Al(SO$_4$)$\^$2-/. According to calculation for the mineral saturation, aluminum and sulfate are greatly supersaturated with respect to basaluminite and alunite. Diaspore is flirty well supersaturated while jubanite, gibbsite, and boehmite are already supersaturated, and gypsum approaches its saturation state. The observation that the only mineral phase we can easily detect in the whitish precipitate is basaluminite suggests that growth rate of alunite is much slower than that of basaluminite. Neutralization of acid mine drainage due to the dilution caused by the dilution effect due to mixing of unpolluted waters prevails over the buffering effect by the dissolution of carbonate or aluminosilicates. The main factors to affect color change are variations in aqueous geochemistry, which are controlled by dilution effect due to rainfall, water mixng from adjacent creeks, and the extent to which water-rock interaction takes place with seasons. pH, Fe, Al and SO$_4$ contents of the creek water are the most important factors leading to color changes in the precipitates. A geochemical cycle showing color variations in the precipitates provides the potential control on acid mine drainage and can be applied as a reclamation tool in a temperate region with four seasons.

• Journal of Environmental Health Sciences
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• v.16 no.2
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• pp.11-20
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• 1990

To investigate ionic characteristics of acid rain by the succeeding rainfall. bulk precipitation was collected every each 5mm rainfall from march to october 1990 at Dae Jeon area. pH, sulfate nitrate, chloride, ammonium ion was measured and analyzed. The result was as follows: 1. The weighted average pH of rain was 5.1$\pm$ 0.72(4.15~7.6) and rain pH less than 5.5 was appeared 51.3% 2. Average ion concentrations of sulfate, nitrate, chloride and ammonium ion was 125.12 $\mu$eq/l, 62.38 $\mu$eq/l, 31.95 $\mu$eq/l, 66.6 $\mu$eq/l and rates of each anions was 57%, 28.4%, 14.6% and rate of sulfate by nitrate was 2 times. 3. There is no correlations time interval of rainfall and Ion concentration change. 4. From initial to 15mm rainfall, each ion concentrations were decreased. and average concentration of pH, SO$^{-2}_{4}$, Cl ion concentration was increased in the succeeding rainfall 5. Only sulfate ion was correlated by the simple regression analysis with pH except NO$^{-}_{3}$, Cl$^{-}$ and NH$_{4}^{+}$ Cl$^{-}$ correlation coefficient was very high at the multiple regression analysis with pH. 6. Simple & multiple correlation coefficient among anions and NH$^{+}_{4}$ was very high especially N$^{+}_{4}$ and SO$^{2-}_{4}$ at simple regression analysis and SO$^{-2}_{4}$ and NO$_{3}^{-}$, Cl$^{-}$, NH$_{4}^{-}$ at multiple regression analysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.533-534
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• 2012

Colloidal III-V semiconductor nanocrystal quantum dots (NQDs) have attracted attention as they can be applied in various areas such as LED, solar cell, biological imaging, and so on because they have decreased ionic lattices, lager exciton diameter, and reduced toxicity compared with II-VI compounds. However, the study and application of III-V semiconductor nanocrystals is limited by difficulties in control nucleation because the molecular bonds in III-V semiconductors are highly covalent compared to II-VI compounds. There is a need for a method that provides rapid and scalable production of highly quality nanoparticles. We present a new synthetic scheme for the preparation of InP nanocrystal quantum dots using new phosphorus precursor, P(SiMe2tbu)3. InP nanocrystals from 530nm to 600nm have been synthesized via the reaction of In(Ac)3 and new phosphorus precursor in noncoordinating solvent, ODE. This opens the way for the large-scale production of high quality Cd-free nanocrystal quantum dots.

• Journal of the Korean institute of surface engineering
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• v.24 no.2
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• pp.103-113
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• 1991

Electroless Ni-Cu-P alloy plating of Al base hard disk was performed to investigate some properties according to the change of composition. It was found that the composition of Ni and Cu in deposits changed linearly with increasing the mole ratio of NiSO4.6H2O/CuSO4.5H2O. The increase in hardness by heat - treatment was confirmed to be associated with small size grained crystallization of the amorphous deposits. Acid resistance of all deposits layer. which had been heated up to 30$0^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, and it showed more superior acid resistance with decreasing Cu content and with increasing P. The resistivity of the deposits heat treated became smaller at temperature more than 50$0^{\circ}C$, and it became largerly with increasing P content. Cu 44.1wt% alloy(C bath) showed the most superior non-magnetically stable characteristics after heat treatment. It was superiorly with higher temperature and with decreasing P content.