• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.44-45
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• 2010

We are currently conducting studies on culturing and biocompatibility assessment of various cells such as neural stem cells and induced pluripotent stem cells(IPS cells) on carbon nanotube (CNT), on nerve regeneration electrodes, and on silicon wafers with a focus on developing nerve integrated CNT based bio devices for interfacing with living organisms, in order to develop brain-machine interfaces (BMI). In addition, we are carried out the chemical modification of carbon nanotube (mainly SWCNTs)-based bio-nanosensors by the plasma ion irradiation (plasma activation) method, and provide a characteristic evaluation of a bio-nanosensor using bovine serum albumin (BSA)/anti-BSA binding and oligonucleotide hybridization. On the other hand, the researches in the case of "novel plasma" have been widely conducted in the fields of chemistry, solid physics, and nanomaterial science. From the above-mentioned background, we are conducting basic experiments on direct irradiation of body tissues and cells using a micro-spot atmospheric pressure plasma source. The device is a coaxial structure having a tungsten wire installed inside a glass capillary, and a grounded ring electrode wrapped on the outside. The conditions of plasma generation are as follows: applied voltage: 5-9 kV, frequency: 1-3 kHz, helium (He) gas flow: 1-1.5 L/min, and plasma irradiation time: 1-300 sec. The experiment was conducted by preparing a culture medium containing mouse fibroblasts (NIH3T3) on a culture dish. A culture dish irradiated with plasma was introduced into a $CO_2$-incubator. The small animals used in the experiment involving plasma irradiation into living tissue were rat, rabbit, and pick and are deeply anesthetized with the gas anesthesia. According to the dependency of cell numbers against the plasma irradiation time, when only He gas was flowed, the growth of cells was inhibited as the floatation of cells caused by gas agitation inside the culture was promoted. On the other hand, there was no floatation of cells and healthy growth was observed when plasma was irradiated. Furthermore, in an experiment testing the effects of plasma irradiation on rats that were artificially given burn wounds, no evidence of electric shock injuries was found in the irradiated areas. In fact, the observed evidence of healing and improvements of the burn wounds suggested the presence of healing effects due to the growth factors in the tissues. Therefore, it appears that the interaction due to ion/radicalcollisions causes a substantial effect on the proliferation of growth factors such as epidermal growth factor (EGF), nerve growth factor (NGF), and transforming growth factor (TGF) that are present in the cells.

• Journal of Korean Society on Water Environment
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• v.38 no.2
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• pp.103-112
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• 2022

A gold amalgam voltammetric microelectrode (GAVM) system was developed for the quantification of dissolved biogeochemical species, such as O₂, Fe²⁺, Mn²⁺, and HS^- in sediment porewater. Commercially available Ag/AgCl and platinum electrodes were used as the reference and counter electrode, respectively, and a gold amalgam microelectrode was fabricated in the laboratory using 150-um diameter gold wire and a borosilicate capillary tube with a 1.6-mm diameter. A portable potentiostat (Metrohm, DropSens) was used for the application of voltage sweeping and to acquire the electric current. For sediment profiling, a commercially available actuator was customized and modified. The analysis method used in the system used the most widely used analysis method among the electrochemical analysis currently used The GAVM system was successively calibrated with the species and applied to estuarine sediments. The porewater analysis showed that the oxygen concentration was decreased to zero at a depth of 0.6 mm, and maximum Mn²⁺ and Fe²⁺ concentrations of 50 uM and 20 uM were detected at 2 and 3-cm depths, respectively. Maximum HS^- concentrations of 10 uM were detected at 4 cm in the deeper sediments. The GAVM system was successfully developed and applied to the sediment and can be used to better understand biogeochemical reactions.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1102-1110
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• 2008

This research was performed to analyze the characteristics of wood wastes from origin and to suggest grade-classification for them. Korean proximate analysis was conducted, and heating value, heavy metals and Cl concentrations were analyzed for gradeclassification. Wood wastes were sampled from forest, living, construction and demolition, and industrial areas with origin. Moisture content of most wood wastes was ranged in 5$\sim$10%. VS (volatile solids) and ash contents of them showed > 95% and < 5%, respectively. Most wood wastes except wood for growing mushroom permitted the standard (low heating value $\geq$ 3,500 kcal/kg) for refusederived fuel. CCA (Cr, Cu, As) concentration of wood wastes used in bench, wasted fishing boat, and railroad crosstie was higher than that of the other ones. Cl content showed approximately 1.3% in wood box for fish and $\leq$ 0.2% in the other wood wastes. Cl content of all wood wasted used in this research permitted the standard (Cl $\leq$ 0.2%, dry weight basis) for refuse-derived fuel. If the wood wastes were classified in 3-grade, plywoods would be in 2nd grade, and MDF (medium density fiber), wooden bench, painted electric wire drum, wasted fishing boat, and railroad crosstie be in 3rd grade.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.98-114
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• 2017

This study analyzed the commemorative landscapes of eight Holocaust concentration camp memorials(HCCM) of Germany and Poland from a landscape architecture point of view including historical landscape, places and remains, and monuments. A site survey was conducted at Dahau concentration camp memorial(CCM) and Bergen-Belsen CCM of Germany in September of 2015 and the Auschwitz-Birkenau extermination camp memorial(ECM), Majdanek ECM, Belzec ECM, Sobibor ECM, Treblinka ECM, Chelmno ECM of Poland in April of 2016. The results are as follows. First, the landscape of the concentration camp at Dahau CCM, Auschwitz ECM, and Majdanek ECM liberated by the Allied Forces was well conserved with the maintenance of camp facilities and the spatial structure of camps while monuments and memorials seized by sociopolitical argument were built with restriction. But Belzec ECM, Sobibor ECM, Treblinka ECM, and Chelmno ECM devastated and planted artificially to forest were overwhelmingly surrounded with natural landscape, and also, excavated relics and remains were preserved and the monuments were built at the place of memory. Second, gas chambers, crematoriums, guard posts, electric wire fences, railroads and ramps, barracks, and drainage ditches were considered to be typical facilities present in the camp structure and the gas chambers, crematoriums, human ashes, and mass graves demonstrated the horrible history of these camps and the railroad and ramp where Jewish prisoners arrived also had the strong sense of place. These remains were regarded as symbolic elements to create a memory of the tragedy and place. Third, commemoration of victims was applied as the basic concept and recalling the memory of the Holocaust was also considered very important content. Religious reconciliation and peace was represented at Dahau CCM and the Jewish identity was strongly expressed at Treblinka ECM and Belzec ECM representing the Jewish community and Judaism. Fourth, the monuments with semi-abstract styles and abstract sculptures represented the Holocaust symbolically and narratively and came into the conflict caused by the abstractness to the memorial landscape at Auschwitz-Birkenau ECM and Bergen-Belsen CCM. Fifth, remains for recalling the memory of tragedy and place and symbolic monuments to stand for public memory were juxtaposed at the same place and preserving on the authenticity of camp site had been conflicted with monumentalizing intentionally. Further study will required a concrete investigation of the monuments in the HCCM and an attempt to comparatively study the commemoration characteristics of memorials in Korea.