• Membrane Journal
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• v.26 no.2
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• pp.108-115
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• 2016

This study is to evaluate the performance of draw solutions in the water reuse of sewage discharge water using fertilizer drawn forward osmosis. Feed water used in all experiments was the effluent from secondary sedimentation tank in activated sludge process. Considering osmotic pressure, solubility, and pH, $NH_4H_2PO_4$, KCl, $KNO_3$, $NH_4Cl$, $(NH_4)_2HPO_4$, $NH_4NO_3$, $NH_4HCO_3$, and $KHCO_3$ were screened from a comprehensive lists of fertilizer. Their performances were evaluated in terms of water permeate flux and reverse solute flux. KCl showed the highest average water flux followed by $NH_4Cl$, $NH_4NO_3$, $KNO_3$, $KHCO_3$, $NH_4HCO_3$, $NH_4H_2PO_4$, and $(NH_4)_2HPO_4$. Using KCl as draw solution, the average water permeate flux was 13.49 LMH. There was no big difference in osmotic pressure between the effluent from secondary sedimentation tank and deionized water. $NH_4H_2PO_4$ showed the lowest reverse solute flux followed by $NH_4Cl$, $(NH_4)_2HPO_4$, $KNO_3$, $NH_4HCO_3$, and $NH_4NO_3$. Using $NH_4H_2PO_4$ as draw solution, the reverse solute flux was $4.96{\times}10^{-3}mmol/m^2{\cdot}sec$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.4
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• pp.135-139
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• 2004

The layered organic-inorganic hybrid compounds($C_6H_5CH_2NH_3)_2CuCl_4$ and ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$ have been directly synthesized. From the X-ray diffraction data and the organic guest size, the orientation of the intercalated organic amine was determined. The inorganic sheets consist of $CuCl_4^{2-}$layers of comer-sharing octahedra copper chloride. The protonated organic amine was intercalated into the $CuCl_4^{2-}$layers with bilayer structure for ($C_6H_5CH_2NH_3)_2CuCl_4$ and monolayer structure for ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.403-407
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• 2010

건축 구조재료로 사용되는 소나무의 화재조건을 알아보기 위하여 콘칼로리미터(ISO 5660-1)를 이용하여 연소성질을 분석하였다. 자연 건조된 소나무에 $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$ 등의 암모늄염을 이용하여 난연성을 부가하였다. 소나무의 함수율은 10.2%였으며 초기 열방출 곡선은 $(NH_4)_2HPO_4$인 경우 완만하게 증가하였으며 가장 좋은 난연성을 보였다. $HRR_{peak}$ 값은 무처리된 경우 $217\;kW/m^2$, $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$인 경우에는 각각 $190\;kW/m^2$, $188\;kW/m^2$, $166\;kW/m^2$로 나타났다. 즉 $(NH_4)_2HPO_4$로 처리된 경우 23.5%의 감소현상이 관찰되었다. $HRR_{peak}$ 도달 시간은 무처리된 시험편(290s) 및 $(NH_4)_2SO_4$, $NH_4H_2PO_4$, $(NH_4)_2HPO_4$으로 처리된 시험편은 각각 298s, 263s, 313s로 나타났다. 연기 발생속도는 사용한 암모늄염 중 $(NH_4)_2SO_4$로 처리된 시험편이 가장 작게 관찰되어 저발연성 감연제 역할을 하는 것으로 판단된다.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.188-194
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• 1995

This study was carried out to investigate the effect of NH$_4$H$_2$PO$_4$ on pH stabilization in deep flow culture system using tap water, and to determine the optimum range of NH$_4$H$_2$PO$_4$ in culture solution. The pH of tap water is 7.5. The higher the concentration of NH$_4$H$_2$PO$_4$ was, the more the pH of nutrient solution was decreased. In NH$_4$H$_2$PO$_4$ 4/3-5/3 me/$\ell$, the pH of nutrient solution was 6-7.5 during the experiment. The highest brix(%) was obtained in NH$_4$H$_2$PO$_4$ 5/3-6/3 me/$\ell$. Leaf length, leaf width and stem-base diameter were highest in NH$_4$H$_2$PO$_4$ 2/3 me/$\ell$. The L and b＊ values were highest and the a＊ value was lowest in NH$_4$H$_2$PO$_4$ 8/3 me/$\ell$. Toxicity symptom of ammonium appeared in NH$_4$H$_2$PO$_4$ 8/3 me/$\ell$. It suggests that there was the relationship between leaf color and growth condition. It was concluded that NH$_4$H$_2$PO$_4$ 2/3 me/$\ell$ was good before harvest stage and NH$_4$H$_2$PO$_4$ 5/3-6/3 me/$\ell$ at harvest stage.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.193-201
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• 2023

Hydrogen peroxide (H₂O₂) is a type of active oxygen species (ROS) that causes oxidative stress in cells and affects cell growth, proliferation, senescence, and death. The purpose of this study is to find active peptides that attenuate cytotoxicity of H₂O₂. A positional scanning synthetic tetrapeptide combinatorial library was screened to predict the sequence of potentially active peptides. As a result of comparing the effect of peptide pools on H₂O₂-induced death of human keratinocytes (HaCaT cells), various active peptide sequences were predicted. Especially, peptides containing cysteine (C) residue were predicted to be active. In follow-up experiments, the cytotoxicity and activity of cysteine-containing peptides of different lengths, such as C-NH₂, CC-NH₂, CCC-NH₂, and CCCC-NH₂ were examined. C-NH₂ and CC-NH₂ showed no significant cytotoxicity up to 1.0 mM, but CCC-NH₂, and CCCC-NH₂ showed relatively strong cytotoxicity. C-NH₂ and CC-NH₂ alleviated H₂O₂-induced cytotoxicity. CC-NH₂ was more cytoprotective compared to C-NH₂, C, N-acetyl cysteine (NAC), and glutathione (GSH). When intracellular ROS was measured by flow cytometry, H₂O₂ increased ROS production, and CC-NH₂ suppressed ROS production more effectively than C-NH₂, and it was as effective as C, NAC, and GSH. This study suggests that CC-NH₂ of the cysteine-containing peptides of different lengths has an antioxidant property that safely and effectively alleviates H₂O₂-induced cytotoxicity and ROS production.

• Korean Journal of Materials Research
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• v.9 no.9
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• pp.872-877
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• 1999

The purpose of this research was to investigate the characteristics and the cleaning efficiency on HN(sub)4OH solutions added with H(sub)2O(sub)2 and surfactants. NH(sub)4OH solutions added with surfactants did not show much changes in pH and redox potential (Eh) as a function of NH(sub)4OH concentration compared with NH(sub)4OH solution. However H(sub)2O(sub)2 added NH\ulcornerOH solutions showed the decrease of pH and the increase of Eh as the concentration of NH(sub)4OH increased. The decrease of surface tension from 72 dynes/cm to 38 dynes/cm was observed in solutions added with surfactant but not in H(sub)2O(sub)2. The etch rates of silicon in NH(sub)4OH solutions(NH(sub)4OH:H(sub)2O= 1 : 5) showed at least 50 times higher than those in H(sub)2O(sub)2 and surfactant added NH(sub)4OH solutions(NH(sub)4OH:H(sub)2O(sub)2= 1 : 1 : 5) solution removed the PSL particles (0.67$\mu\textrm{m}$ in diameter) on Si wafers effectively at all temperatures investigated. NH(sub)4OH solution added with a surfactant could not remove particles at room temperature, however it was possible to remove particles at higher temperatures, 5$0^{\circ}C$ and 8$0^{\circ}C$.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.120-130
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• 1996

Crisphead lettuce(Lactuca sativa L.) was grown in NFT to investigate the effects of NO$_3$-N and NH$_4$-N ratio in nutrient solution and elevated $CO_2$ treatment in the crisphead lettuce growth. This experiment has been conducted under three different ratios of NO$_3$-N:NH$_4$-N(100:0, 75:25, 50:50) with two $CO_2$ concentration (control, 1500ppm ). The results are as follows; 1. In the case of not controlling pH and EC in nutrient solution, pH was gradually increased in NO$_3$-N:NH$_4$-N=100:0 treatment but rapidly decreased in the nutrient solution 2. Daily changes of NO$_3$-N and NH$_4$-N were observed without controlling the nutrient solution. In the treatments of NO$_3$-N:NH$_4$-N ratios were 75:25 and 50:50, NO$_3$-N absorption rates were 27.7% and 26.1%, while NH$_4$-N absorption rates were 87.9% and 71.2%, respectively. 3. There was little differences in total nitrogen of leaves. However phosphorus, potassium, calcium and magnesium contents were highly shown in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. 4. Higher $CO_2$ assimilation rate was shown in plants grown under $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. It dropped significantly with the increase of NH$_4$- N rates in nutrient solution. 5. Fresh weight, leaf number, root length and root weight of crisphead lettuce were far better in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. Growth differences by $CO_2$ elevation were not shown in other NO$_3$-N:NH$_4$-N treatments. 6. The highest nitrate contents of leaves were shown in NO$_3$-N single treatment but shown the lowest vitamin C contents. Nitrate contents of leaves were decreased by $CO_2$ but the effect was slight treatment.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.552-558
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• 1995

The tetranuclear complexes, $X_2[M_{O4}O_12{R'C(NH_2)NO}_2](X= n-Bu_4N^+$, $R'=(CH_3)_2CH$, $CH_3CH_2CH_2$, $CH_3SCH_2$; $X=(CH_3)_2CHC(=NH_2)NH_2^+$, $R'=(CH_3)_2CH$; $X = CH_3CH_2CH_2C(=NH_2)NH_2^+$, $R'=CH_3_CH_2CH_2$; $X=CH_3SCH_2C(=NH_2)NH_2^+$, $R'=CH_3SCH_2)$ have been synthesized by the reactions of monomeric and polynuclear complexes with isobutyl-, butyl- and thiomethylacetamidoxime. The prepared complexes were identified by elemental analysis, infrared, $^1H$ NMR and $^{13}C$ NMR spectroscopy. The structure of complex ${(CH_3)_2CHC(NH_2)_2}_2[M_{O4}O_{12}{(CH_3)_2CHC(NH_2)NO}_2]$ was determined by X-ray single crystal diffraction. Crystal data are follows: Monoclinic, $P2_{1/c}$, $a=10.168(3){\AA}$, $b=11.768(1){\AA}$, $c=13.557(1){\AA}$, ${\beta}=102.08(1)^{\circ}$, $V=1586.2(5){\AA}^3$, Z=2, final R=0.026 for 2951($F_0>3s(F_0)$). This complex is composed of a planar cyclic $[Mo_4({\mu}-O)_4]$ and two ${\mu}_4$-amidoximate.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.386-392
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• 1989

The adsorption of $NH_4\;^+$ and $Zn^{2+}$ by four Korean zeolites, the major species of which are clinoptilolite, clinoptilolite with mordenite, mordenite with clinoptilolite, and mordenite was measured in different concentrations of solutions of $NH_4\;^+$ and $Zn^{2+}$, and their mixtures. The adsorption of $NH_4\;^+$ was greater than that $Zn^{2+}$ far all samples at the concentrations of the added solutions from $1\;to\;7{\times}10^{-3}N$ and this difference was greater at the higher concentrations. Also, $Zn^{2+}$ adsorption by samples was decreased by the presence of $NH_4\;^+$, but that of $NH_4\;^+$ by the presence of $Zn^{2+}$ was not. The extent of $NH_4\;^+$ selectivity among samples was increased in order of clinoptilolite with mordenite$NH_4\;^+$ adsorbed by six successive equilibrations with the solution containing both $NH_4\;^+$ and $Zn^{2+}$ each at a concentration of $3{\times}10^{-3}N$ were in range from 43.7 to 50.4 me/100g, whereas those amounts of $Zn^{2+}$ were in the range from 6.6 to 17.0 me/100g. It was suggested from these results that mordenite and clinoptilolite, particularly the former, can be used for removal of $NH_4\;^+$ from municipal wastewater and those zeolites treated with wastewater can be applied to agricultural land.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.37-45
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• 1989

Voltammetric behavior of alkylammonium ion was studied in the absence and in the presence of crown ether in propylene carbonate as solvent. The peak potentials and the peak currents, their dependency on the concentrations, the reversibility of the electrode reactions are described. In the presence of crown ether chemical reaction might be preceeded before the electron-transfer process, the peak potential for the reduction shifts at the negative direction as the concentration of crown ether to the electrolyte solution increases. The addition of crown ether(20mM 18CR6)to the electrolyte solution made it possible to determine voltammetrically the dialkylammonium ions($Me_2NH^{+}_{2};O.6{\sim}0.8mM$) in the presence of the monoalkylammonium ions ($EtNH^{+}_{3} ;1.6mM$) and the monoalkylammonium ions ($EtNH^{+}_{3} ; 0.5{\sim}2.5mM$) in the presence of the dialkylammonium ions($Me_2NH^{+}_{2};0.5mM$)