• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.966-972
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• 2007

A novel organoclay has been developed with aluminium-pillared clay modified with an amphoteric surfactant, N-Dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS). This novel organoclay is expected to have phosphorus removal capacity as well as organic and inorganic contaminant removal capacity, due to aluminum inside the clay structure. It also exhibited less surfactant desorption than conventional cation surfactant-based organoclays. Phosphorus in water can be decreased from 0.2 mg/L to 0.0012 mg/L in 27 hours with this organoclay. Also, cadmium could removed from water using this proposed organo-clay. Experiments were performed under various pHs and amphoteric surfactants sorption capability was the highest at pH 5 when more of the amphoteric surfactant head group took on positive charges.

• Textile Coloration and Finishing
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• v.26 no.1
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• pp.7-12
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• 2014

Nowdays, fluorescent rhodamine chemosensors have attracted a worldwide interest due to its ability to selectively detect heavy and transition metal cations. Due to the importance in environmental and biological toxic effects, the developments of fluorescent chemosensors have been received considerable attention in recent. Especially, a rhodamine-based chemosensor probes have been proved to be useful by exhibiting the efficient "off-on" fluorescence switching toward selected metal cations. This fluorophore can undergo the transformation from non-fluorescent and colorless spirolactam derivative to fluorescent ring-open form. In this study, a new fluorescent chemosensor was synthesized using rhodamine B through two-step procedures, and its selectivity and related optical property were characterized. Selectivity and sensitivity was found toward $Cu^{2+}$ guest molecules and then related optical properties of rhodamine B based fluorescent chemosensor compound were characterized using discussed. In addition, computational calculation was used to determine the HOMO/LUMO values.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.246-251
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• 1999

The purposed of this study was to investigate the efficient recycling of food waste according to the restaurants type. To the investigated of characteristic of food wastes in different types of restaurants we were collected the sample of 60 as Korean 35 Chinese 10 Japanese 5 Western 5 Flour 5 in Swoon. The average water content of food waste was 79.9% and Korean restaurant was 80.3% which was hig-her than that of any other serving type. On the examination of a organic matter content of food waste according to the season crude fiber was higher in may and July crude protein content was higher in January and march than that other seasons. The average pH of food waste was 4,74 C/N ratio was 15.8 and the average cation content was K 0.57% Ca 0.39% Mg 0.22% NaCl 3.36% respectively The aver-age concentration of Fe, Zn, Pb, Cu, Cr, Cd Ni were 154.37 mg/kg 24.79 mg/kg 0.27 mg/kg 5.63 mg/kg 5.49 mg/kg, 0.31mg/kg 1.07mg/kg respectively.

• Journal of Radiation Protection and Research
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• v.30 no.4
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• pp.167-174
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• 2005

The concentrations of natural and artificial radionuclides in soil and gamma ray dose rate in air at 233 locations in Korea have been determined. The national mean concentrations of $^{232}Th,\;^{226}Ra,\;^{40}K,\;^{137}Cs\;and\;^{90}Sr$ in soil were $60{\pm}31,\;33{\pm}14,\;673{\pm}238,\;35{\pm}9.3\;and\;5.0{\pm}3.4\;Bq\;kg^{-1}$, respectively. The mean gamma-ray dose rate at 1 m above the ground was $7918\;nGy\;h^{-1}$. $^{137}Cs$ concentration had highly significant correlation with organic matter content and cation exchange capacity. $^{90}Sr$ concentration had slightly coherent with pH. The results have been compared with other global radioactivity and radiation measurements.

• Membrane Journal
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• v.2 no.1
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• pp.49-58
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• 1992

Functionalized organic polymers have been used as supports for heterogenized homogeneous catalytic process[1]. Sprcific advantages of using these resins as support reagents have been reviewed[2-4]. These include: -ease of by-product separation from the main reaction product usuallyby simple filtration. -prevention of intermolecular reaction of reactive species or functional groups by simulating high dilution conditions[5]. -utility of the "fish-hook" principle in which a minor component in fished out of a large excess substrate by the insoluble polymer[6]. -the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances[7]. Catalysis by ion-exchange membranes is perhaps one of the latest examples of the use of a polymer-supported species. Conceptually, catalysts on membrane supports offer several possible advantages over traditional powder type systems. They are: (1) Membranes immobilize the catalyst, preventing agglomeration. (2) Filtration is unnecessary for the catalyst separation and so complete catalyst recovery is facilitated. (3) Catalytyic and separation processes can be combined, allowing membrane supported catalysts for the continous flow reactors. reactors.

• Journal of the Korean Institute of Navigation
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• v.20 no.4
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• pp.111-128
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• 1996

This paper is focused on the desirable improvement schemes of the local network of information and telecommunication network. In this study, we examined whether polices of information and telecommunication of government have been carried out a desirable programme to meet the public interest, found out several problems in the these policies. Such problems as follows : (1) a system of local information & telecommunication is developing by a Model of Top-Down. In the present management system, an interest of the public of local society about the local telecommunication network is a much lower level, (2) there is no general controlling roll of the local information & telecommunication, (3) there is no service controlling system of local telecommuni-cation, and (4) there is no organic coordinating system of inter-departments in the central government level. In order to resolve these problems, this study suggests a few desirable sxhemes for the local telecommunication : (1) an establishment of middle-long range planning for the integrated future network of info-telecommunication, (2) an organizing of telecommunication network being suitable for the local characteristics toward B-ISDN.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.119-124
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• 2004

In this research montmorillonite intercalations complexes as organophilic clay compounds which have very different properties as the starting clay mineral were synthesized by the substitution of metal ions which exist in the montmorillonite layers with the organic cations which have long alkyl chain by the cation exchange reaction. Thereafter the obtained products dried in high vacuum were treated with the various swelling liquids such as dist. water, methanol, acetone, ether and acetonitrile in order to know the swelling behaviour of the synthesized complexes. Especially for this research Korean and Turkish clays were selected to compare the intercalations complexes of both clays and their swelling behaviour.

• Asian Journal of Turfgrass Science
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• v.5 no.2
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• pp.59-68
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• 1991

This experiment was carried out to investigate the mixing ratio of soil amending materials such as peat perlite, active carbon and zeolite for improvements of physiochemical properties of topsoil, of creeping bentgrass (Agrostis palustris var. Penncross). The results were as followed :1.Appropriate addition of soil improvement material was increased the soil porosity due to the decrease of bulk density. Over supplement of soil improvement material induced the decrease of infiltration of water into soil.2Content of organic matter was increased in treatment of peat and active carbon . Soil reaction was decreased in peat treatment, but increased in perlite, zeolite and active carbon. Exchangeable cation capacity was increased by the addition of all kinds of soil improvement materials used in this experiment.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.753-767
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• 2013

Soil contamination has continuously increased worldwide, thus the remediation for the contaminated soils has risen steadily. However, the consideration of ecological safety for the remediated soils and their agricultural uses has been very limited. Therefore, this study was to investigate the influences of selected environmentally-friendly agricultural materials, organic by-product fertilizer (OF), charcoal (CC), and biochar (BC), as soil conditioners for improving poor chemical properties of fuel-oil removed soil by land farming technique. Two different remediated soils, remediated soil A (RSA) and remediated soil B (RSB), were selected. Soil texture of both RSA and RSB was sandy loam. The chemical properties of RSA and RSB were as follows: soil pHs of 8.5 and 8.7, soil organic matter contents of 7.4 and 5.5g $kg^{-1}$, total nitrogen contents of 0.26 and 0.10g $kg^{-1}$, available phosphorus concentrations of 7.2 and 4.4mg $kg^{-1}$, and exchangeable calcium concentrations of 14.8 and $11.7cmol_c$ $kg^{-1}$, respectively. Results of the properties were not reached for the optimal values for cultivating crops that were recommended by National Academy of Agricultural Science at Rural Development Administration in Korea. However, after applying OF, CC, and BC, the chemical properties of soils were selectively improved, which were that soil organic matter content and available phosphorus concentration increased, whereas the soil pH were not changed. In particular, the chemical properties were positively changed more with the application of 5.0% biochar. Thus, continuous management of the remediated soils with applying the eco-friendly agricultural materials can improve the quality of reme-diated soils.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1745-1750
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• 2013

A novel green aqueous mobile phase modified with room temperature ionic liquids (RTILs) was employed in the absence of volatile organic solvents or ion-pairing reagents to analyze thiamine, a very polar compound, by reverse phase high performance liquid chromatography (RP-HPLC). Due to its strongly hydrophilic nature, thiamine was eluted near the column dead time ($t_0$) using a mobile phase without adding RTILs or ion-pairing reagents, even if a 100% aqueous mobile phase, which has weak elution power under reverse phase conditions, was used. Thus, 1-ethyl-3-methyl-imidazolium hexafluorophosphate ([EMIM][$PF_6$]), which has the strongest chaotropic effect, was selected as a mobile phase additive to improve retention and avoid baseline disturbances at $t_0$. Various mobile phase parameters such as cation moiety, chaotropic anion moiety, pH and concentration of RTILs were optimized to determine thiamine at the proper retention time. Method validation was performed to assess linearity, intra- and inter-day accuracy and precision, recovery and repeatability; all results were found to be satisfactory. The developed method was also compared to the current official United States Pharmacopoeia (USP) and Korean Pharmacopoeia (KP) methods using an organic mobile phase containing an ionpairing reagent by means of evaluating various chromatographic parameters such as the capacity factor, theoretical plate number, peak asymmetry and tailing factor. The results indicated that the proposed method exhibited better efficiency of thiamine analysis than the official methods, and it was successfully applied to quantify thiamine in pharmaceutical preparations.