• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.555-558
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• 2008

Trapping efficiency of various sex pheromone blends of the peach pyralid moth, Dichocrocis punctiferalis was compared by field study to develop monitoring system with its sex pheromone at chestnut orchards in Korea. Five candidates of the sex pheromone blends used for the field trapping of D. punctiferalis males were 70:30, 75:25, 80:20, 85:15 and 90:10 mixture of (E)-10-hexadecenyl aldehyde (E10-16:Al) and (Z)-10-hexadecenyl aldehyde (Z10-16:Al). All lures were treated with 1 or 2 mg of each blends. During 2 years of field survey, the 75:25 blend was usually the most effective in attracting males among 5 blends tested. For the 2nd generation, the best capturing activity for D. punctiferalis male was observed by lure with 75:25 blend. Both 90:10 and 75:25 blends showed highest efficiency for the 3rd generation. In most cases. lures treated with 1 mg of blend caught more male moths than these treated with 2 mg of blend.

• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.257-261
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• 2003

Population of small mammals (Apodemus agrarius and Crocidura lasiura) was monitored to identify the bioaccumulation of heavy metals in Gumho river basin around Daegu city. The small mammals were captured during 28 of May~12 of June, 2002. The techniques of live-trapping and snap-trapping were applied to capture the animals. A total of 39 animals were captured among which 53.3% (16130) of population were reached to breeding. Heavy metals (Cu, Pb, Zn, Cd) were analyzed. According to the analysis of heavy metal elements, Zn was more accumulated in kidney (6.83 mg $kg^{-1}$) than in liver (3.66). However, the accumulation of Cu was higher in liver than in kidney. Even though this site was relatively away from major industrial zones, heavy metals were wide spread along the stream of Gumbo River. This is the first quantitative study of small mammal bioaccumulation of heavy metals in Korea so that further research should be followed in other industrial areas that heavy metals were widely dispersed.

• Korean Journal of Materials Research
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• v.20 no.7
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• pp.345-350
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• 2010

For the present paper, we prepared MgO/MWCNT/$TiO_2$ photocatalyst by using multi-walled carbon nanotubes (MWCNTs) pre-oxidized by m-chlorperbenzoic acid (MCPBA) with magnesium acetate tetrahydrate $(Mg(CH_2COO)_2\cdot4H_2O)$ and titanium n-butoxide $(Ti\{OC(CH_3)_3\}_4)$ as magnesium and titanium precursors. The prepared photocatalyst was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. The decomposition of methylene blue (MB) solution was determined under irradiation of ultraviolet (UV) light. The XRD results show that the MgO/MWCNT/$TiO_2$ photocatalyst have cubic MgO structure and anatase $TiO_2$ structure. The porous structure and the $TiO_2$ agglomerate coated on the MgO/MWCNT composite can be observed in SEM images. The Mg, O, Ti and C elements can be also observed in MgO/MWCNT/$TiO_2$ photocatalyst from EDX results. The results of photodegradation of MB solution under UV light show that the concentration of MB solution decreased with an increase of UV irradiation time for all of the samples. Also, the MgO/MWCNT/$TiO_2$ photocatalyst has the best photocatalytic activity among these samples. It can be considered that the MgO/MWCNT/$TiO_2$ photocatalyst had a combined effect, the effect of MWCNT, which could absorb UV light to create photoinduced electrons $(e^-)$, and the electron trapping effect of MgO, which resulted in an increase of the photocatalytic activity of $TiO_2$.

• Composites Research
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• v.35 no.6
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• pp.402-411
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• 2022

In this study, the channels-contained hybrid membranes have been fabricated through the incorporation of glass fibers and GO sheets (GO/glass fibers, GG), or a mixture of chitosan/GO (CS/GO/glass fibers, CGG), as hybrid membranes using in organic dye removal. The material properties are well investigated the terms in the morphological, chemical, crystal, and thermal characterizations for verifying interactions in their formed structure. These hybrid membranes have been fitted well in pseudo-second order and Langmuir models that are associated with chemical adsorption and a monolayer approach, respectively. The highest adsorption ability of methylene blue and methyl orange reached 59.40 mg/g and 229.07 mg/g (GG); and 287.47 mg/g and 252.91 mg/g (CGG), which is more enhanced than that of previous GO-based other adsorbents. Moreover, the dye separation on these membranes could be favorable to superb sealing and trapping dye molecules from water instead of only the dye connection occurring on their surface, regarding the physically sieving effect. The membranes can also be reused within two and three adsorbing-desorbing cycles on the GG and CGG ones, respectively. These membranes can become future adsorbents to be applied for wastewater treatment due to their structural features.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.280-285
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• 1996

The sustained release dosage form which delivers melatonin (MT) in a circadian fashion over 8 h is of clinical value for those who have disordered circadian rhythms because of its short halflife. The purpose of this study was to evaluate the gelling properties and release characteristics of alginate beads varying multivalent cationic species $(Al^{+++}, \; Ba^{++}, \; Ca^{++}, \; Mg^{++}, \; Fe^{+++}, \; Zn^{++})$. The surface morphologies of Ca- and Ba-alginate beads were also studied using scanning electron microscope (SEM). MT, an indole amide pineal hormone was used as a model drug. The $Ca^{++}, \; Ba^{++}, \; Zn^{++}, \; Al^{++}\; and\; Fe^{+++}\; ions\; except\; Mg^{++}$ induced gelling of sodium alginate. The strength of multivalent cationic alginate beads was as follows: $Al^{+++}\llFe^{+++} the induced hydrogel beads were very fragile and less spherical. Fe-alginate beads were also fragile but stronger compared to Al-alginate beads. Ba-alginate beads had a similar gelling strength but was less spherical when compared to Ca-alginate beads. Zn-alginate beads were weaker than Ca- and Ba-alginate beads. Very crude and rough crystals of Ba- and Ca-alginate beads at higher magnifications were observed. However, the type and shape of rough crystals of Ba- and Ca-alginate beads were quite different. No significant differences in release profiles from MT-loaded multivalent cationic alginate beads were observed in the gastric fluid. Most drugs were continuously released upto 80% for 5 h, mainly governed by the passive diffusion without swelling and disintegrating the alginate beads. In the intestinal fluid, there was a significant difference iq the release profiles of MT-loaded multivalent cationic alginate beads. The release rate of Ca-alginate beads was faster when compared to other multivalent cationic alginate beads and was completed for 3 h. Ba-alginate beads had a very long lag time (7 h) and then rapidly released thereafter. MT was continuously released from Feand Zn-alginate beads with initial burstout release. It is assumed that the different release rofiles of multivalent cationic alginate beads resulted from forces of swelling and disintegration of alginate beads in addition to passive diffusion, depending on types of multivalent ions, gelling strength and drug solubility. It was estimated that 0.2M $CaCl_2$ concentration was optimal in terms of trapping efficiency of MT and gelling strength of Ca-alginate beads. In the gastric fluid, Ca-alginate beads gelled at 0.2 M $CaCl_2$ concentration had higher bead strength, resulting in the most retarded release when compared to other concentrations. In the intestinal fluid, the decreased release of Ca-alginate beads prepared at 0.2 M $CaCl_2$ concentration was also observed. However, release profiles of Ca-alginate beads were quite similar regardless of $CaCl_2$ concentration. Either too low or high $CaCl_2$ concentrations may not be useful for gelling and curing of alginate beads. Optimal $CaCl_2$ concentrations must be decided in terms of trapping efficiency and release and profiles of drug followed by curing time and gelling strength of alginate beads.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1717-1722
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• 2021

This study is devoted to the ability of carbon fiber material samples impregnated with various amounts of barium iodide and triethylenediamine to remove radioactive methyliodide from air streams. The main sorption characteristics of impregnated UVIS® carbon fiber were determined and the use of this material for purifying of technological gas flows at nuclear power plants was evaluated. The methyliodide trapping efficiency by samples impregnated with barium iodide, TEDA, and their mixture was 83.4 ± 0.8%; 93.1 ± 0.6% and 93.5 ± 0.7% respectively, under the same conditions. The study established a significantly higher capacity (8.3 ± 0.07 mg/cm²) of samples impregnated simultaneously with both chemical compounds toward methyliodide. Under the same test conditions, the values of this parameter for the samples impregnated separately with TEDA and BaI₂ were 2.85 ± 0.05 mg/cm² and 0.86 ± 0.04 mg/cm², respectively.

• Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.76-83
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• 2004

To supply fresh and quality quarantined seafood in live seafood specialty restaurants, facilities for short-term culture or holding of live marine fish and shellfish are a necessity. In this study, the performance of a simple recirculating aquarium system for the culture and holding of marine fish was evaluated. The aquarium system consisted of a culture tank, a foam fractionator for solids removal, and a Styrofoam bead filter for nitrification and solids trapping. In the first trial, the aquarium was stocked with a total of 12 kg Korean rockfish, which were fed approximately $0.5\%$ of the total fish body weight daily. During the 2-month culture period, total ammonia nitrogen (TAN) and nitrite nitrogen $(NO_2-N)$ concentrations remained below 1mg/L and 2mg/L, respectively. The chemical oxygen demand (COD) fluctuated between 13.6 and 31.2 mg/L on selected sampling days. The total suspended solids (TSS) removed by the foam fractionator was between 2.7 and 4.6g daily. The Styrofoam bead filter not only reduced TAN and $NO_2-N$ in the culture tank water, but also trapped solids equivalent to 8.3-26.7\% of the weight of feed supplied. In Trial 2, 30kg of live fish were held in the aquarium without feeding for a 24-hour period and the water quality parameters were monitored. TAN and $NO_2-N$ concentrations first increased and then decreased to around 0.3mg/L. These results demonstrate that the recirculating aquarium system is a functional option for the short-term culture or holding of marine fish.

• Korean Journal of Environmental Agriculture
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• v.10 no.2
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• pp.167-177
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• 1991

O-ethyl S-methyl ethylphosphonothioate [$LD_{50}$ (rat, oral) 4.6mg/kg ; $K_i$(bovine erythrocyte acetylcholinesterase) 303 $M^{-1\;min-1}$] was selected as a model compound to study the mode of action of O, S-dialkyl alkylphosphonothioates which have been hypothesized to be toxic via a bioactivation process. Two chemical oxidants, meta-chloroperoxybenzoic acid and monoperoxyphthalic acid, and rat liver microsomal oxidases were used to mimic the action of mixed function oxidases on the model compound. The formation of S-oxide, a very unstable active intermediate, was proposed based on the identification of metabolic products.Furthermore, a trapping experiment with ethanol showed that the unstable intermediate S-oxide had the ability to phosphorylate acetylcholinesterase which is an important enzyme in nerve systems. The S-oxide intermediates are presumed to be responsible for the toxicity of O,S-dialkyl alkylphosphonothioates.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.219-226
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• 2001

To identity the composition and ratio of the sex pheromone in the asiatic leafroller, Archippus breviplicanus (Walsingham), which is a major pest on apple leaves, and to develop a monitoring system using this sex pheromone, abdominal tips of their virgin female during the calling period were extracted and analysed. The GC/GC-MS analysis revealed the following three compounds; (E)11-tetradecenyl acetate (E11-14: Ac), (Z)11-tetradecenyl acetate (Z11-14: Ac), and tetradecyl acetate(14: Ac) with the ratio of 56:22:22. Electroantennogram (EAG) assay was also conducted to examine biological activity of the components. The three components evoked significantly higher responses than hexane or air but there was no significant differences between the mixtures made by components. Field trapping experiments for determining the optimum blend, seasonal fluctuation and the optimum amount for male attracting were carried out over 4 years from 1997 to 2000. Although male moths were attracted to 8:2 and 7:3 between E11-14: Ac and Z11-14: Ac, their 7:3 blend was found to be the most effective. Archippus breviplicanus appears to occur three times a year in Korea. The optimum amount for monitoring was found to be 1mg per trap. 14: Ac, the third component, did not show synergistic effect on male moth attraction.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3033-3038
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• 2013

Nanoscale Chevrel $Mo_6S_8$ powders are synthesized by molten salt synthesis. Synthesized $Mo_6S_8$ powders have different mean particle sizes which are dependent on a ratio of salt to precursor. The particle sizes of $Mo_6S_8$ powders changes along with the ratio increase. $Mo_6S_8$ (6:1) demonstrates the best electrochemical characteristics among the synthesized $Mo_6S_8$ powders although the $Mo_6S_8$ (4:1) has the smallest particle size. $Mo_6S_8$ (6:1) shows a reversible capacity of 83.9 $mAhg^{-1}$, which is 27.5% and 33% improved value over $Mo_6S_8$ (2:1) and $Mo_6S_8$ (4:1) at a current density of 0.2C, respectively. The superior electrochemical properties of $Mo_6S_8$ (6:1) are attributed to the balanced particle size which provides proper contact area with electrolyte and the shortened $Mg^{2+}$ diffusion length. The $Mo_6S_8$ (4:1) has the smallest particle size but further reduction of particle size from $Mo_6S_8$ (6:1) is not advantageous.