• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.729-734
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• 2002

Radiorespirometric analysis revealed that Pseudomonas sp. strain KKI isolated from a soil contaminated with petroleum hydrocarbons was able to catabolize polycyclic aromatic hydrocarbons such as phenanthrene and naphthalene. The rate and extent of phenanthrene mineralization was markedly enhanced when the cells were pregrown on either naphthalene or phenanthrene, compared to the cells grown on universal carbon sources (i.e., TSA medium). Deduced amino acid sequence of the Rieske-type iron-sulfur center of a putative phenanthrene dioxygenase (PhnAl) obtained from the strain KKI shared significant homology with DxnAl (dioxin dioxygenase) from Spingomonas sp. RW1, BphA1b (biphenyl dioxygenase) from Spingomonas aromaticivorans F199, and PhnAc (phenanthrene diokygenase) from Burkholderia sp. RP007 or Alcaligenes faecalis AFK2. Northern hybridization using the dioxygenase gene fragment cloned from KKI showed that the expression of the putative phn dioxygenase gene reached the highest level in cells grown in the minimal medium containing phenanthrene and $KNO_3$, and the expression of the phn gene was repressed in cells grown with glucose. In addition to the metabolic change, phospholipid ester-linked fatty acids (PLFA) analysis revealed that the total cellular fatty acid composition of KKI was significantly changed in response to phenanthrene. Fatty acids such as 14:0, 16:0 3OH, 17:0 cyclo, 18:1$\omega$7c, 19:0 cyclo increased in phenanthrene-exposed cells, while fatty acids such as 10:0 3OH, 12:0, 12:0 2OH, 12:0 3OH, 16:1$\omega$7c, 15:0 iso 2OH, 16:0, 18:1$\omega$6c, 18:0 decreased.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1869-1873
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• 2008

An isolate from holothurians was identified as an eicosapentaenoic acid (EPA)-producing bacterium KMG427, which is characterized by EPA synthesis efficiency, by thin layer and gas chromatographic analyses. The EPA production was maximized to more than 10% of the total fatty acids by incubation at $4^{\circ}C$ after cell proliferation at $20^{\circ}C$. The isolated bacterium was categorized as Gram-negative, rod-shaped, aerobic, and motile with a single polar flagellum. According to phylogenetic analysis based on morphological and physiological specificities as an EPA-producing bacterium, the isolate KMG427 was found to belong to the genus Shewanella. The 16S rDNA of KMG427 was revealed to have 100% of sequence identity to that of S. hanedai CIP $103207^T$. Therefore, the isolate might be classified and identified as Shewanella sp. KMG427.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.71-80
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• 2012

To improve the $NO_X$ conversion over a SCR (selective catalytic reduction) catalyst, the DOC (diesel oxidation catalyst) is usually placed upstream of the SCR catalyst to enhance the fast SCR reaction ($4NH_3+2NO+2NO_2{\rightarrow}4N_2+6H_2O$) using equimolar amounts of NO and $NO_2$. Here, a ratio of $NO_2/NO_X$ above 50% should be avoided, because the reaction with $NO_2$ only ($4NH_3+4NO+O_2{\rightarrow}4N_2+6H_2O$) is slower than the standard SCR reaction ($4NH_3+4NO+O_2{\rightarrow}4N_2+6H_2O$). In order to accurately predict the performance characteristics of SCR catalysts, it is therefore desired to develop a more simple and reliable mathematical and kinetic models on the oxidation kinetics of nitric oxide over a DOC. In the present work, the prediction accuracy and limit of three different chemical reaction kinetics models are presented to describe the chemicophysical characteristics and conversion performance of DOCs. Steady-state experiments with DOCs mounted on a light-duty four-cylinder 2.0-L turbocharged diesel engine then are performed, using an engine-dynamometer system to calibrate the kinetic parameters such as activation energies and preexponential factors of heterogeneous reactions. The reaction kinetics for NO oxidation over Pt-based catalysts is determined in conjunction with a transient one-dimensional (1D) heterogeneous plug flow reactor (PFR) model with diesel exhaust gas temperatures in the range of 115~$525^{\circ}C$ and space velocities in the range of $(0.4{\sim}6.5){\times}10^5\;h^{-1}$.

• Analytical Science and Technology
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• v.15 no.2
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• pp.115-119
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• 2002

The formation of inclusion complexes between cyclodextrin(CD) and Congo red was studied by spectrophotometric methods at various temperatures. The cavity sizes are 0.49 nm, 0.62 nm for $\alpha$-and $\beta$-CD, respectively. Therefore, $\alpha$-CD was not found to form an inclusion complex with Congo red due to steric hinderance. In the $\beta$-CD use two $\beta$-CD molecules formed an inclusion complex with one molecule of Congo red, from the slope of the S-shaped curve increased. Two prominent isosbestic points appear at 346 nm and 478 nm. The formation constants were decreased with the increasing temperatures, due to low binding energy between $\beta$-CD and Congo red. The thermodynamic parameters were calculated from the plot of $lnK_f$ vs 1/T. The $\Delta$H, $\Delta$S and $\Delta$G were -50.73 kJ/mol, $-108.96J/K{\cdot}mol$ and -18.26 kJ/mol, respectively.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.143-150
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• 2009

Objectives : South Korea has experienced unprecedented ups and downs in the sex ratio at birth(SRB), which has been a unique phenomenon in the last two decades. However, little is known about socioeconomic factors that influence the SRB. Employing the diffusion theory by Rogers, this study was undertaken to examine the trends in social variations in the SRB from 1981 to 2004 in Korea. Methods : The data was taken from Vital Birth Statistics for the period from 1981-2004. We computed the annual male proportion of live births according to the parental education(university, middle/high school, primary) and occupation(non-manual, manual, others). Logistic regression analysis was employed to estimate the odds ratios of male birth according to social position for the equidistant three time periods(1981-1984, 1991-1994, and 2001-2004). Results : An increased SRB was detected among parents with higher social position before the mid 1980s. Since then, however, a greater SRB was found for the less educated and manual jobholders. The inverse social gradient for the SRB was most prominent in early 1990s, but the gap has narrowed since the late 1990s. The mother's socioeconomic position could be a sensitive indicator of the social variations in the sex ratio at birth. Conclusions : Changes in the relationship of parental social position with the SRB were detected during the 1980-2004 in Korea. This Korean experience may well be explained by diffusion theory, suggesting there have been socioeconomic differences in the adoption and spread of sex-detection technology.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.397-405
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• 2006

Single crystal $AgGaSe_{2}$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_{2}$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_{2}$ thin films measured with Hall effect by van der Pauw method are $4.05{\times}10^{16}/cm^{3}$, $139cm^{2}/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $AgGaSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$=1.9501 eV-($8.79{\times}10^{-4}{\;}eV/K)T^{2}$/(T+250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_{2}$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $AgGaSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-$, and $C_{1}-$exciton peaks for n=1.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.747-749
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• 1999

Various methods for seed treatments have been devised to improve the rate and uniformity of seed germination of gourd (Lagenaria siceraria Standl.). Hydropriming and priming, the imbibition of seeds in distilled water and osmotic solutions respectively, are useful techniques for early establishment of uniform seedlings. In this study, the optimum conditions for hydropriming and priming were determined in gourd (Lagenaria siceraria Standl.) seeds. Effect of hydropriming was compared with those of osmotic priming. Seeds, hydroprimed or primed with 50 mM solution of $KH_2PO_4$ and $KNO_3$ at $30^{\circ}C$ for 2 days, showed shorter $T_{50}$ (number of days to 50% of the final germination percentage) and MDG (mean number of days to germination) than those unprimed. The relative effectiveness of hydropriming and priming in improving the germinability of gourd seeds was more evident when germinated at $20^{\circ}C$ than at $25^{\circ}C$ and $35^{\circ}C$.

• Convergence Security Journal
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• v.7 no.2
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• pp.9-16
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• 2007

In today's society, the paradigm is converted to information where both this and knowledge become the source of value added. In order to answer societies' needs school education is subject to a large change, that is 'from supplier-centered learners to demand-centered learners'. This study is the design and implementation of multimedia CAI program for learning about electricity in the meddle school the mechanics curriculum with a focus in generating electricity. Based on multimedia, software, educational utilization of the multimedia, CAI, learning theory and form, both technology and multimedia elements related to curriculum are analyzed. This title is composed of object, contents, evaluation and related sites every chapter for students to study. Also, it is designed for students to take interest and participate in the learning process actively by combining lots of media such as characters, sound, images and animation. Specially it is composed in a way of repetition according to the student's level.

• Convergence Security Journal
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• v.13 no.2
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• pp.195-202
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• 2013

Defense reform our military for the globalization of information. Scientific command structure, troop structure, unit structure, step-by-step into the power structure while promoting a history of quantitative-oriented structure, and structure of the quality of state-of-the-art technology-driven transition in the middle of the bottle numberplans about the current 3.3-fold increase in reducing the cadre(officers and NCOs). NCO groups in the executive, especially expanding the current level of 100% increase in the rate of long-serving, while ensuring a stable job and to superior resources to secure a stable policy through science. Military alliance is now underway. In the midst of this group, and urged the group at the University of the leading military and specialized resources to ensure each agreement required by subjects to reflect. Thus effectively improve the quality of education and the demands of the job analysis, DACUM curriculum development methods and procedures can be applied at the time of urgent need for foster an excellent resource for the discharge of curriculum development at the University of Selected as a core job, career, and job classification configuration inside of Duty according to KST derived from the group reflect on the training courses to meet the requirements in the curriculum through the development of curriculum, job definition, job model set to propose.

• Child Health Nursing Research
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• v.15 no.3
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• pp.271-281
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• 2009

Purpose: This study was conducted to develop an instrument to measure coping in emergency situations. Methods: The process included construction of a conceptual framework, generation 60 primary items, verification of construct validity and extraction of final items. The.60 preliminary items were reviewed for content validity by seven experts and were tested to evaluate inter-item correlation coefficient by three groups of elementary school students. From November 1 to December 10, 2008, data were collected from 920 elementary school students according to residential characters (major city, small town, rural area). Item analysis, factor analysis with rotation Varimax and Cronbach's alpha were used to analyze the data. Results: 1) There were 45 items in the final instrument categorized into 8 factors. 2) The factors were labeled as "Call for help and check" (8 items), "Care for common symptoms" (6 items), "Appropriate response for the situation" (5 items), "Evacuation" (6 items), "Care for tissue damage" (8 items), "Care for injury by heat, cold or foreign body" (6 items), "Offer help" (4 items) and "Rescue & escape" (2 items). 3) Cumulative percent of variance was 53.10% and eigen values ranged from 1.04 to 13.38. 4) Cronbach's alpha for the total was .943 and ranged from .527 to .869. Conclusion: Validity and reliability of the scale are confirmed in this study showing its utility for measuring coping in emergency situations with elementary school students. Utilization of the scale will also contribute to designing appropriate coping education programs for elementary school students.