• Title/Summary/Keyword: Research and Development Department

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Effects of Physicochemical/Mineralogical Characteristics of Limestones and Porosity after Calcination on Desulfurization Reactivities

  • Baek, Chul-Seoung;Seo, Jun-Hyung;Cho, Jin-Sang;Cho, Kye-Hong;Han, Choon
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.34-42
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    • 2016
  • Characteristics of wet flue gas desulfurization and in-furnace desulfurization of domestic and overseas limestone with different crystallinity and crystalline size are studied in this article. Properties of desulfurization were evaluated in relation to physicochemical/ mineralogical characteristics, degree of pore formation for different calcination temperatures and TNC(total neutralizing capability). TNC of domestic high crystalline limestone was lower than that of overseas one. On the other hand, the porosity after calcination was shown to be relatively high for domestic limestone, which had high initial rates of desulfurization reactions in-furnace. Based on low pore formation and porosity with high TNC of crystalline high-Ca limestones compared to macrocrystalline ones, the former are preferred for wet desulfurization processes.

Abnormal Oceanic Conditions Caused by Typhoons Around the Korean Peninsula (태풍에 의해 발생하는 한국근해 해황이상변동)

  • SUH Young-Sang;GU Ji-Young;HWANG Jae-Dong;LEE Na-Kyung;KIM Bok-Kee;JANG Lee-Hyun;KANG Yong-Q;LEE Dong-In
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.4
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    • pp.417-429
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    • 2003
  • Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature (SST) in range of 5 to $8^{\circ}C$ was observed. The areas of SST decrease were an order of 100-200 km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30 m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.

Structural and Optical Properties of GaN Nanowires Formed on Si(111)

  • Han, Sangmoon;Choi, Ilgyu;Song, Jihoon;Lee, Cheul-Ro;Cho, Il-Wook;Ryu, Mee-Yi;Kim, Jin Soo
    • Applied Science and Convergence Technology
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    • v.27 no.5
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    • pp.95-99
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    • 2018
  • We discuss the structural and optical characteristics of GaN nanowires (NWs) grown on Si(111) substrates by a plasma-assisted molecular-beam epitaxy. The GaN NWs with high crystal quality were formed by adopting a new growth approach, so called Ga pre-deposition (GaPD) method. In the GaPD, only Ga was supplied without nitrogen flux on a SiN/Si surface, resulting in the formation of Ga droplets. The Ga droplets were used as initial nucleation sites for the growth of GaN NWs. The GaN NWs with the average heights of 60.10 to 214.62 nm obtained by increasing growth time. The hexagonal-shaped top surfaces and facets were observed from the field-emission electron microscope images of GaN NWs, indicating that the NWs have the wurtzite (WZ) crystal structure. Strong peaks of GaN (0002) corresponding to WZ structures were also observed from double crystal x-ray diffraction rocking curves of the NW samples. At room temperature, free-exciton emissions were observed from GaN NWs with narrow linewidth broadenings, indicating to the formation of high-quality NWs.

Calculations of Storm Surges, Typhoon Maemi (해일고 산정 수치모의 실험, 태풍 매미)

  • Lee, Jong-Chan;Kwon, Jae-Il;Park, Kwang-Soon;Jun, Ki-Cheon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.1
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    • pp.93-100
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    • 2008
  • A multi-nesting grid storm surge model, Korea Ocean Research and Development Institute-Storm surge model, was calibrated to simulate storm surges. To check the performance of this storm surge model, a series of numerical experiments were explored including tidal calibration, the influence of the open boundary condition, the grid resolutions, and typhoon paths on the surge heights using the typhoon Maemi, which caused a severe coastal disasters in Sep. 2003. In this study the meteorological input data such as atmospheric pressure and wind fields were calculated using CE wind model. Total 11 tidal gauge station records with 1-minute interval data were compared with the model results and the storm surge heights were successfully simulated. The numerical experiments emphasized the importance of meteorological input and fine-mesh grid systems on the precise storm surge prediction. This storm surge model could be used as an operational storm surge prediction system after more intensive verification.

Soil Acclimatization of Regenerated Plants by Gibberellic Acid Treatments of Panax ginseng C. A. Meyer (GA3 처리에 의한 인삼 재분화 식물체의 토양 순화)

  • Kim, Young Chang;Park, Hong Woo;Kim, Ok Tae;Bang, Kyong Hwan;Kim, Jang Uk;Hyun, Dong Yun;Kim, Dong Hwi;Cha, Seon Woo;Choi, Jae Eul
    • Korean Journal of Plant Resources
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    • v.26 no.1
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    • pp.84-89
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    • 2013
  • We established that regenerated plants of Panax ginseng were directly transplanted into the soil without the acclimatization process. When regenerated plants were treated at the concentration of $0.4mg\;l^{-1}$ for 9 hr before transplantation into the soil, our results showed that the survival rate of them was the highest. The optimal size of the root was above 4 cm in length and 0.4 g by weight before transplantation into the soil. The highest survival rate increased to 59.6%. After 4 years of cultivation in the fields, our results showed that there were no significant morphological differences between regenerated plants and wild-type ginseng. Also, we obtained healthy seeds from regenerated plants. This study provides the basis for a relatively rapid multiplication of selected genotypes and will allow a much more rapid evaluation of the germplasm of the unexplored and unstudied Korean ginseng.

Interpretation of Agronomic Traits Variation of Sesame Cultivar Using Principal Component Analysis

  • Shim, Kang-Bo;Hwang, Chung-Dong;Pae, Suk-Bok;Park, Jang-Whan;Byun, Jae-Cheon;Park, Keum-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.1
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    • pp.24-28
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    • 2009
  • This study was conducted to evaluate the growth characters and yield components of 18 collected sesame cultivars to get basic information on the variation for the sesame breeding using principal component analysis. All characters except days to flowering, days to maturity and 1,000 seed weight showed significantly different. Seed weight per 10 are showed higher coefficient of variance. Capsule bearing stem length and liter weight showed positive correlation with seed yield per 10 are. The principal components analysis grouped the estimated sesame cultivars into four main components which accounted for 83.7% of the total variation at the eigenvalue and its contribution to total variation obtained from principal component analysis. The first principal component ($Z_1$) was applicable to increase plant height, capsule bearing stem length and 1,000-seed weight. The second principal component ($Z_2$) negatively correlated with days to flowering and maturity by which it was applicable to shorten flowering and maturity date of sesame. At the scatter diagram, Yangbaek, Ansan, M1, M2, M4, M7 and M9 were classified as same group, but M10, Yanghuk, Kanghuk, M5, M6, M12 and M13 were classified as different group. This results would be helpful for sesame breeder to understand genetic relationship of some agronomic characters and select promising cross lines for the development of new sesame variety.

Estimation of the Efficiency of a Silt Screen using a Vessel-mounted ADCP

  • Jin, Jae-Youll;Park, Jin-Soon;Song, Won-Oh;Kim, Sung-En;Lee, Kwang-Soo;Yum, Ki-Dai;Oh, Jae-Kyung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.353-358
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    • 2003
  • As fur quantitative evaluation of the amount of sediments released into the ambient waters by various works fur coastal development, the instrument and method of the measurement of suspended sediment concentration (SSC) are critical for estimating the efficiency of a silt screen to reduce the spreading of sediment plumes generated by coastal works. (omitted)

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Establishing Rationale for the Clinical Development of Cell Therapy Products: Consensus between Risk and Benefit

  • Seunghoon Han;Hyeon Woo Yim;Hyunsuk Jeong;Suein Choi;Sungpil Han
    • International Journal of Stem Cells
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    • v.16 no.1
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    • pp.16-26
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    • 2023
  • Despite long-term research achievements, the development of cell therapy (CT) products remains challenging. This is because the risks experienced by the subject and therapeutic effects in the clinical trial stage are unclear due to the various uncertainties of CT when administered to humans. Nevertheless, as autologous cell products for systemic administration have recently been approved for marketing, CT product development is accelerating, particularly in the field of unmet medical needs. The human experience of CT remains insufficient compared with other classes of pharmaceuticals, while there are countless products for clinical development. Therefore, for many sponsors, understanding the rationale of human application of an investigational product based on the consensus and improving the ability to apply it appropriately for CT are necessary. Thus, defining the level of evidence for safety and efficacy fundamentally required for initiating the clinical development and preparing it using a reliable method for CT. Furthermore, the expertise should be strengthened in the design of the first-in-human trial, such as the starting dose and dose-escalation plan, based on a sufficiently acceptable rationale. Cultivating development professionals with these skills will increase the opportunity for more candidates to enter the clinical development phase.

Evaluation of Commercial Pheromones on the Population Dynamics of Spodoptera frugiperda (J. E. smith) and Mythimna loreyi (Duponchel) (Lepidoptera: Noctuidae)

  • Seo Yeon Hong;Hwi Jong Yi;Young Nam Yoon;Yun Woo Jang;Ki Do Park;Rameswor Maharjan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.67 no.4
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    • pp.285-295
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    • 2022
  • The trapping efficacy of five commercially available sex pheromones manufactured in Korea, the Netherlands, North America, China, and Costa Rica was evaluated to determine the population dynamics of Spodoptera frugiperda and Mythimna loreyi and their relationships with the weather parameters of maize fields in Miryang, Gyeongnam Province, Korea in 2019. The results show that the sex pheromone manufactured in Costa Rica were more efficient at capturing S. frugiperda and M. loreyi than those manufactured in other countries. The lowest number of S. frugiperda moths were captured using sex pheromones manufactured in the Netherlands. We noted that more than four population peaks of both the moth species and weather parameters influenced the moth population dynamics in Miryang. A positive relationship was observed between the population of S. frugiperda and weather parameters, such as mean temperature, rainfall, and relative humidity, for sex pheromones manufactured in Korea. Furthermore, a positive relationship was recorded between the population of M. loreyi and wind speed for the sex pheromone manufactured in Korea. The results of this study suggest that the sex pheromones manufactured in Costa Rica are the best solution for the efficient capture of S. frugiperda and M. loreyi under typical weather conditions in the southern parts of Korea. In addition, the outcomes of this study are discussed in terms of population dynamics and integrated pest management for S. frugiperda and M. loreyi as alternatives to chemical management by maize producers. Further studies related to the continuous improvement in the capture efficiency of both moth species using sex pheromones are now needed.