• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.375-381
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• 2006

In this sturdy, spherical activated carbon(SPAC) contained $TiO_2$ was made by ion-exchanged treatment and heat treatment for applying fluidizing bed system. The ion-exchange resin was treated by $TiCl_3$ aqueous solution. The treated resin and raw resin were heat-treated under nitrogen condition to convert into Ti-SPAC. During the heat-treatment, burn-off weight amounts and the element were measured by means of TGA and TGA/MS, individually. The physicochemical properties of Ti-SPAC was characterized by means of XRD, SEM, EDS, BET, EPMA, ESR, intensity and titanium content. The Ti-SPAC had spherical shape with diameter size about $350{\mu}m{\sim}400{\mu}m$ and $617m^2/g$ specific surface area. Structure of $TiO_2$ in Ti-SPAC was anatase and rutile form. Also, $TiO_2$ on SPAC were found that the $TiO_2$ were uniformly distributed through EPMA analysis. Moreover, the Ti-SPAC showed indirect photocatalyst activity estimation through ESR analysis, characteristics of photocatalyst potentially. Over all results, Ti-SPAC was used in fluidizing bed UV/photocatalyst system to remove HA(Humic Acid). That results were HA removal efficiency was about 70％ and Ti-SPAC intensity was preserved during reaction. Ti-SPAC showed practical possibility as photocatalyst in fluidizing bed system.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1169-1175
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• 2011

The soil chemical properties, microbial community structures and biochemical properties of lettuce or cucumber-cultivated greenhouse soil samples were analyzed to assess soil health and characterize microbial distribution in 8 locations in Korea. Although most of chemical properties were within the soil management guidelines, the available phosphate, and the contents of exchangeable potassium and calcium were higher than those of recommended levels. In the culture-dependent analysis, 841 bacterial strains were isolated from the greenhouse soils and were identified at the genus level by 16S rRNA gene sequences analysis. The dominant bacterial genera were Bacillus (35.7%), Microbacterium (9.3%), Arthrobacter (5.7%) and Lysobacter (5.1%). The abundance of pseudomonads was highly variable depending on the soil samples. In the culture-independent analysis, soil microbial community was investigated by using phospholipid fatty acid (PLFA) method. Principal component analysis (PCA) showed that a specific grouping for microbial community structure in the greenhouse soils was not observed based on cultivated crops and investigated sites. The results revealed that the greenhouses soils examined are relatively sound managed in terms of soil chemical contents and microbial properties.

• Journal of the Korean Society of Combustion
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• v.19 no.1
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• pp.17-28
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• 2014

In this study, the laminar burning velocity of syngas fuel($H_2/CO$) and flame structure with various hydrogen contents were studied using both experimental measurements and detailed kinetic analysis. The laminar burning velocities were measured by the angle method of Bunsen flame configuration and the numerical calculations including chemical kinetic analysis were made using CHEMKIN Package with USC-Mech II. A wide range of syngas mixture compositions such as $H_2$ : CO = 10 : 90, 25 : 75, 50 : 50, 75:25 and equivalence ratios from lean condition of 0.5 to rich condition of 5.0 have been considered. The experimental results of burning velocity were in good agreement with previous other research data and numerical simulation. Also, it was shown that the experimental measurements of laminar burning velocity linearly increased with the increment of $H_2$ content although the burning velocity of hydrogen is faster than the carbon monoxide above 10 times. This phenomenon is attributed to the rapid production of hydrogen related radicals such as H radical at the early stage of combustion, which is confirmed the linear increase of radical concentrations on kinetic analysis. Particular concerns in this study are the characteristics of burning velocity and flame structure different from lean condition for rich condition. The decrease of OH radicals and double peaks are observed with $H_2$ content in rich condition once $H_2$ fraction exceeds over threshold.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.2
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• pp.75-91
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• 1991

This study is one of studies on the analysis of vegetation spatial image and visual preference of roadside slopes in Chi-Ri Mt. national park. In this article, we analized the soil characteristics and the actual vegetation within slopes and forest lands contiguous to those. The results obtained were summarized as follows; The physical and chemical properties of soil in forest lands were better than slopes and Cheoneun temple - Seongsam pass was the best fertilized among 3 sector. In the structure of woody plants in forest lands, the high importance value species were Pinus denciflora, Quercus aliena within Ukmojeong-Deokdong sector, Q. aliena, Q. varabilis, Q. serrata within Banseon-Seongsam pass sector, and P. denciflora, Q. dentata within Cheoneun temple-Seongsam pass sector. And also, Aster scaber, Arundinella hirta, Pteridium aquilinum were the high importance value herbs within all sector. In slopes, the species diversity indices of woody plants were low, but that of herbs showed slightly high. By the cluster analysis used in similarity index, it was observed that woody plants structure between slopes and forest lands made little, but the herbs made slightly higher than woody plants.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.13-21
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• 2005

I consider the structure of steady wave system which is admitted by the continuum equations for materials that undergo phase transformations with exothermic chemical reaction. In particular, the dynamic phase front structures between liquid and gas phases, and solid and liquid phases are computationally investigated. Based on the one-dimensional continuum shock structure analysis, the present approach can estimate the nano-width of waves that are present in combustion. For illustration purpose, n-heptane is used in the evaporation and condensation analysis and HMX is used in the melting and freezing analysis of energetic materials of interest. On-going effort includes extension of this idea to include broad range of liquid and solid fuels, such as rocket propellants.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.3
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• pp.109-113
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• 2017

The hepatitis C virus (HCV) internal ribosome entry site (IRES) is an RNA structure located in the 5'-UTR of the HCV RNA genome. The HCV IRES consists of four domains I, II, III, and IV, where domains II - IV are recognized by 40S ribosomal subunit and the domain III is bound to eukaryotic initiation factor 3 (eIF3) for translation initiation. Here, we have characterized the tertiary interaction between an L-/K- rich peptide and the HCV IRES domain IV. To probe the peptide binding interface in RNA, we synthesized $^{13}C$- and $^{15}N$-double labeled RNA and the binding site was identified by using the chemical shift perturbation (CSP) NMR methods. Our results showed that the peptide binds to the upper stem of the IRES domain IV, indicating that the tertiary interaction between the IRES domain IV and the peptide would disrupt the initiation of translation of HCV mRNA by blocking the start codon exposure. This study will provide an insight into the new peptide-based anti-viral drug design targeting HCV IRES RNA.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.156-165
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• 2004

Concentrations of substrates, glucose, and ammionia in biological processes have been on-line monitored by using glucose-flow injection (FIA) and ammonia-FIA systems. Based on the on-line monitored data the concentrations of substrates have been controlled by an on-off controller, a PID controller, and a neural network (NN) based controller. A simulation program has been developed to test the control quality of each controller and to estimate the control parameters. The on-off controller often produced high oscillations at the set point due to its low robustness. The control quality of a PID controller could have been improved by a high analysis frequency and by a short residence time of sample in a FIA system. A NN-based controller with 3 layers has been developed, and a 3(input)-2(hidden)-1(output) network structure has been found to be optimal for the NN-based controller. The performance of the three controllers has been tested in a simulated process as well as in a cultivation process of Saccharomyces cerevisiae, and the performance has also been compared to simulation results. The NN-based controller with the 3-2-1 network structure was robust and stable against some disturbances, such as a sudden injection of distilled water into a biological process.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.189-190
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• 2018

KS standards mostly relate to single component material evaluation, so in cases of underground structure environments, most cannot predict the existing composite forms of deterioration, resulting in the applied waterproofing materials becoming unable to respond to these damaging factors. Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.2
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• pp.50-54
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• 2017

Cupin-superfamily proteins represent the most functionally diverse groups of proteins and include a huge number of functionally uncharacterized proteins. Recently, YaiE, a cupin protein from Escherichia coli has been suggested to be involved in a novel activity of pyrimidine/purine nucleoside phosphorylase (PPNP). In the present study, we achieved a complete backbone NMR assignments of YaiE, by a series of heteronuclear multidimensional NMR experiments on its [$^{13}C/^{15}N$]-enriched sample. Subsequently, secondary structure analysis using the assigned chemical shift values identified 10 obvious ${\beta}-strands$ and a tentative $3_{10}-helix$. Taken all together, the results constitute the first structural characterization of a putative PPNP cupin protein.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.130-136
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• 2008

$xTiO_2$-$ySiO_2$ system photocatalysts were developed by sol-gel method based on the change of production parameters, and their structure of crystallization and the specific surface area were measured. Considering the efficiency of the ethanol and phenol degradation using the catalyst, the conclusions were obtained as follows: By means of X-ray analysis of $xTiO_2$-$ySiO_2$ powder that is obtained from Titanium and Silicon alkoxide by sol-gel process, it is shown that crystal structure of anatase type is a dominating structure and, on the other hand, the structure of rutile also partly exists. The increase of $SiO_2$ contents causes the decrease of the degree of crystallization of the gel, whereas the specific surface area preferentially increases. It is shown that more than 90% of ethanol and phenol are degraded when reaction time is about three and an hours, and the maximum degradation rate of ethanol and phenol is shown in $60TiO_2$-$40SiO_2$ catalyst.