• Journal of Environmental Science International
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• v.19 no.8
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• pp.941-949
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• 2010

The three electrode system was used to detect the pesticide fenitrothion ($C_9H_{12}NO_5PS$. MW=277.24) using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The working electrode was mercury immobilized on a carbon nanotube paste electrode (Hg-CNTPE). At the optimized condition, the limit of detection (LoD) was 0.6 ppt ($2.16{\times}10^{-12}\;M$), and the relative standard deviation was 0.035% (n=15). And there is more sensitive in detecting fenitrothion than common type carbon nanotube paste electrode. When it was implanted into the brain of live fish (carp), the existence of fenitrothion was measured without any destruction or damage of tissue.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.99-105
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• 2018

In this paper, we present fortified instructional methods that contributed in improving students' interest toward the expository organic chemistry laboratory course. Reformed TA (Teaching assistant) training and allocation method, a thorough course orientation session, text-light/graphics-heavy results PPT reports, and journal article templated-term papers have improved students' satisfaction in the organic chemistry laboratory course. These methods could be implemented while maintaining the traditional organic chemistry laboratory instruction styles and hence could be broadly applicable.

• Korean Journal of Materials Research
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• v.15 no.7
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• pp.480-485
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• 2005

Sc has been known to be an very effective ppt-hardening element in Al and Al alloys and also to be effective in modification of eutectic Si in hypoeutectic Al-Si alloys. The modification mechanism of Sc is different from that of the traditional modifier Sr in Al-Si alloys. In the present study the effects of Sc on the primary and eutectic Si in hypereutectic Al-Si alloys were investigated with evaluating the microstructures with OM, EPMA and EBSD methods. The results represent that Sc has only a small effect on primary Si when added less than $0.8wt\%$. However, when Sc addition leading to the precipitation of metallic Sc within primary Si reaches $1.6wt\%$, very coarse primary Si occurs.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.619-624
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBS) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.307-318
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• 2002

To provide a guideline for the development of a web-based sport biomechanics class in undergraduate program, thirty web sites, searched via search engines in May 2002, were analyzed intensively. In terms of requirement of log-in, only one site of 30 sites required user name and password. Seventeen(57%) sites provided the lecture note, which had various file formats such as 59% if PDF, 29% of HTML, and 12% of PPT. Fourteen(47%) sites provided the assignment and grade information on web. Eleven(37%) sites provided various resource and links which were related in sports biomechanics. Only four(13%) sites provided discussion or online digitizing or kinematic analysis program. Based on above results, a guideline for the development of a virtual classroom for college level sport biomechanics. A web-based sport biomechanics class should be developed with consideration of several functions as follows; homepage design, lecture note, measurement of class attendance, collaborative research system, and web-based data collection and analysis software for biomechanics laboratory.

• Asian Journal of Turfgrass Science
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• v.18 no.3
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• pp.141-148
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• 2004

In this report, several factors such as infection time and concentration of bacterial suspension, influencing on transient gene expression in Agrobacterium-mediated transformation were evaluated. An appropriate concentration (O.D 600nm = 1.0-1.2) of bateria and 30 min of infection time showed a higher level of GUS expression. To improve transformation efficiency (TE), friable embryogenic calli (FEC) were bombarded by tungsten particles without plasmid DNA, and then co-cultivated with A. tumefaciens LBA4404 which contains pTOK233 super binary vector, carrying neomycin phosphotransferase (NPTII), hygromycin phosphotransferase (hpt) and$\beta-glucuronidase$ (GUS) genes. Three days after co-cultivation with A. tumefaciens and particle bombardment, FEC cultures were transferred to the selection medium (SM: MS medium supplemented with BA 1mg/l, hygromycin 100mg/l, cefotaxime 250 mg/l and vancomycin 200mg/l). They were cultured for 2 weeks and then transferred to the second SM containing hygromycin 50mg/l, cefotaxime 200 mg/l and vancomycin 100mg/l. Later, stable GUS expression was detected 4 to 6 weeks after transfer to the SM. Further, TE from Agrobacterium-mediated transformation after particle bombardment increased to about 3-folds compared with Agrobacterium-mediated transformation without particle bombardment. In the present study, we established an efficient transformation protocol of zoysiagrass by using A. tumefaciens in the combination with particle bombardment for the first time.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.281-287
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• 1999

Codonopsis lanceolata ("Deoduck" in Korea) is a perennial herb, and belongs to family, Campanulaceae. Its taproot is used a good source of a wild vegetable as well as an herbaceous medicine. In this study, to develop a bialaphos-resistant transgenic Codonopsis, seed germination mechanism and somatic embryogenesis of the plant were investigated, and Agrobacterium-mediated transformation with bar gene encoding phosphinothricin acetyltransferase (PAT) was performed. Attempt were made to regenerate plant from cells via somatic embryogenesis. When the cotyledons, nodes and leaf disks were cultured on MS medium containing 2,4-D and zeatin, embryogenic calli were induced. Upon transferring the somatic embryos to N6 solid medium without plant growth regulators, they developed into plantlets under continuous illumination. All plants were dead on MS basal medium containing 10 mg/L phosphinothricin (PPT) and Basta, respectively. The explants did not produce calli in the medium containing 200 mg/L kanamycin. The explants were cocultured with Agrobacterium tumefaciens for 2 days, and transformants were selected in MS basal medium containing 1.0 mg/L 2,4-D, 100 mg/L kanamycin and 500 mg/L carbenicillin. After the selection, embryogenic calli were induced and then somatic embryos were produced by subsequent subculturing. The somatic embryos were germiated on N6 basal medium containing 200 mg/L kanamycin and 500 mg/L carbenicillin. PCR analysis showed that nptII and bar genes were introduced in the Deoduck transformants. After the confirmation of bar gene expression in RNA and protein level, the transgenic Deoduck will be used to study the genetics of filial generation with the herbicide control gene, bar.gene, bar.

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.90-95
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• 2010

Blue devil (Pomacentrus caeruleus, also called Chrysiptera cyanea) is widespread in the Indo-Pacific Ocean and very popular all over the world as an aquarium fish because it is so easy to keep in a marine aquarium. However, tank-breeding techniques are not completely known. In this study, we reared blue devil and investigated its spawning ecology, as a necessary precursor for successful artificial-tank breeding. We investigated the spawning volume according to time with two types of calendars: solar and lunar. Rearing conditions were set at 30 ppt salinity, $27^{\circ}C$ water temperature, in two aquariums with water volumes of 80 and 125 L. We successfully bred P. caeruleus in this artificial-tank system. The aquarium fish formed a spawning harem with one male and more than two females. We harvested about 113,580 eggs in 44 spawning episodes by two spawning harems during the 11-month period from December to October. They showed a peak season of spawning volume and time in May and June. We confirmed the two peak points in spawning volumes and times, which coincided with the first quarter and last (third) quarter of the lunar phases of the moon.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.825-830
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• 2009

Pharmaceutical compounds enter the water environment through the diverse pathways. Because their concentration in the water environment was frequently detected in the level of ppt to ppb, the monitoring system should be optimized as much as possible for finding appropriate management policies and technical solutions. One Factor At a Time (OFAT) approach approximating the response with a single variable has been preferred for the optimization of LC-MS/MS operational conditions. However, it is common that variables in analytical instruments are interdependent. Therefore, the best condition could be found by using the statistical optimization method changing multiple variables at a time. In this research, response surface analysis (RSA) was applied to the LC-MS/MS analysis of emerging antibiotic compound, sulfamethoxazole, for the best sensitivity. In the screening test, fragmentation energy and collision voltage were selected as independent variables. They were changed simultaneously for the statistical optimization and a polynomial equation was fit to the data set. The correlation coefficient, $R^2$ valuerepresented 0.9947 and the error between the predicted and observed value showed only 3.41% at the random condition, fragmentation energy of 60 and collision voltage of 17 eV. Therefore, it was concluded that the model derived by RSA successfully predict the response. The optimal conditions identified by the model were fragmentation energy of 116.6 and collision voltage of 10.9 eV. This RSA can be extensively utilized for optimizing conditions of solid-phase extraction and liquid chromatography.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1422-1427
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• 2002

Fifteen crossbred cattle bulls of about 22-24 months age (mean body weight ranged from 291.0 to 298.1 kg) were randomly divided into 3 groups of 5 animals following randomized block design. Animals in group 1 were fed concentrate mixture containing wheat bran 97%, mineral mixture 2% and salt 1% plus ad libitum chopped green sugarcane tops (SCT) as a roughage source. Animals in group 2 were fed concentrate mixture containing lentil chuni 97%, mineral mixture 2% and salt 1% while group 3 concentrate contained wheat bran 48.5%, lentil chuni 48.5%, mineral mixture 2% and salt 1% plus ad libitum chopped green SCT to meet their maintenance requirements. During metabolism trial period, the mean total intake and digestibility of DM in groups 1, 2 and 3 was $8.09{\pm}0.41$, $8.41{\pm}0.49$ and $7.86{\pm}0.16kg/d$ and 60.24, 63.24 and 65.05%, respectively. The intake of CP (p<0.05) and EE (p<0.01) was significantly higher in group 2 and group 1, respectively as compared to remaining 2 groups, which were comparable. Digestibility of CP and EE was significantly (p<0.01) higher in group 3 and that of CP was comparable with group 2. The intake and digestibility of total carbohydrates, NDF, ADF, Hemi-cellulose and cellulose were similar among 3 groups. The mean body weight changes in group 1, 2 and 3 were 173.4, 253.4 and 203.4 g/d, respectively, which was significantly (p<0.05) higher in group 2. The total nitrogen (N) and phosphorus (P) intakes were significantly higher in group 2 and group 1, respectively. The total volatile fatty acids, ammonia-N, trichloro-acetic acid precipitable nitrogen (TCA ppt.-N; p<0.05), total-N concentrations and pH were significantly (p<0.01) higher in group 3, however, pH and TCA ppt.-N was comparable with group 2 and 1, respectively. From the results, it may be deduced that the feeding of chopped green SCT supplemented with a concentrate mixture having both wheat bran (48.5%) and lentil chuni (48.5%) has shown a better performance with respect to intake and digestibility of nutrients and growth as well.