• Journal of Korean Society of Environmental Engineers
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• v.39 no.8
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• pp.456-461
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• 2017

In this study, nano fibers with various physical properties were materialized by using a variety of polymers [PAN (Polyacrylonitrile), PU (Polyuretane), PSU (Polysulfone)] which are raw materials of dope solution manufactured for electrospinning and solvents [NMP (N-methyl-2 pyrrolidone), DMF (Dimethylformamide)] and evaluated characteristics of their flux and SS (Suspended Solids) separation and then ascertained application of manufactured fibers as separation membrane for water treatment. In this study, analysis of surface of manufactured material was carried out through SEM analysis to ascertain the cause of flux and SS separation performance by checking diameter, uniformity and straightness of fiber. If additive is used in manufacturing nano fiber water treatment separation membrane, it is expected to solve problems such as membrane fouling and mechanical strength and to be used as basic factor for manufacturing separation membrane with catalyst function added.

• Journal of the Korean Applied Science and Technology
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• v.21 no.3
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• pp.225-230
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• 2004

Synthesis gas is a high valued compound as a basic chemicals at various chemical processes. Synthesis gas is mainly produced commercially by a steam reforming process. However, the process is highly endothermic so that the process is very energy-consuming process. Thus, this study was carried out to produce synthesis gas by the partial oxidation of methane to decrease the energy cost. The effects of reaction temperature and flow rate of reactants on the methane conversion, product selectivity, product ratio, and carbon deposition were investigated with 13wt% Ni/MgO catalyst in a fluidized bed reactor. With the fluidized bed reactor, $CH_4$ conversion was 91%, and Hz and CO selectivities were both 98% at 850$^{\circ}C$ and total flow rate of 100 mL/min. These values were higher than those of fixed bed reactor. From this result, we found that with the use of the fluidized bed reactor it was possible to avoid the disadvantage of fixed bed reactor (explosion) and increase the productivity of synthesis gas.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.618-623
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• 2020

Spherical phenolic resin beads were synthesized by suspension polymerization at 98 ℃ from phenol, ortho-cresol, formaldehyde, with triethylamine as a basic catalyst, and spherical phenol-cresol copolymer resin beads with relatively low crosslinking density as well. Phenol reacts with formaldehyde at two ortho- and one para- positions to form a crosslinked structure, but ortho-cresol instead of phenol reduces the crosslinking density during copolymerization due to the methyl group at a ortho- position. As a result, spherical phenol-cresol copolymer beads showed more shrinkage with decreasing apparent density compared to the spherical phenol beads when carbonized at 700 ℃ under nitrogen. As the molecular weight of the cresol oligomer increases, the pore radius of the carbonized copolymer beads decreases, which is consistent with the density and shrinkage results. It was confirmed that the characteristics such as density decrease, shrinkage, yield and so on during carbonization can be controlled by controlling the degree of crosslinking of the spherical phenolic resin particles with cresol.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.639-644
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• 2011

A simple and highly sensitive chemiluminescence method to determine norfloxacin (NFLX) has been proposed by measuring the chemiluminescence (CL) intensities using a flow injection (FI) system. The CL intensity of the luminol-$H_2O_2$ system is strongly enhanced by the addition of Cu (II) in alkaline condition. The CL intensity is substantially increased after the injection of NFLX into the luminol-$H_2O_2$-Cu (II) system. The enhancement effect is attributed to a catalytic effect of Cu (II) due to the interaction with NFLX which forms a complex with the catalyst. Under the optimal conditions, the sensitizing effect of the CL intensity is proportional to the concentration of NFLX in the range of $1.5{\times}10^{-9}-5.9{\times}10^{-7}molL^{-1}$ (r = 0.9994) with a detection limit ($3{\sigma}$) of $2.98{\times}10^{-10}molL^{-1}$. The proposed method had good reproducibility with the relative standard deviation (RSD, n = 5) of 1.6% for $1{\times}10^{-7}molL^{-1}$ of NFLX. The possible reaction mechanism of the CL reaction is also discussed. This method has been successfully applied for the determination of trace amount of NFLX in pharmaceutical preparations and serum samples.

• Korean Journal of Human Ecology
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• v.15 no.5
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• pp.823-833
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• 2006

The globalization phenomenon of the 21st century has acted as the catalyst to accept diversity, and a new cultural code, ethnic, has emerged in the modem society by the pursuit of diversity throughout the whole society and culture. Unlike preceding studies focusing on ethnic concepts and design development, this study attempted comparative analyses on ethnic trends shown in the collections of two designers, Issey Miyake and Yohji Yamamoto, who have strong ethnic consciousness. It is considered the comparative analysis on the two designers' collections with ethic images will be a guide to indicate the fashion philosophy of the two designers in the category of Japan, and this will be useful as basic data for the establishment of the globalization identity which is needed in the future fashion industry. The study results are as follows. First, it was found that the ethnic code has been so widely accepted by the world designers in a very positive form to accept foreign cultures that the ethnic code is now showing an aspect of eclecticism. Second, designer Issey Miyake has been pursuing his own ethnic style based on his philosophy to liberate humans through continuous researches and efforts on clothes. Third, Yohji Yamamoto has been pursuing a Japanese ethnic style as a designer who has expressed the unique beauty of Japan from the characteristics of Japanese traditional clothes. Fourth, as a result of comparative analyses on collections, they both have pursued an ethnic style based on the unique national characteristics of Japan, but it was also found that their fashion philosophy has developed differently in the same category of ethnic trend.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.543-548
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• 2006

This paper is to be researched into ozone generation character of Bi-Ti-Si type high dielectric ceramic catalyst discharge tube. And conditions of basic experiment are the outside diameter of discharge tube : 52 mm, the length of discharge tube : 350 mm, the frequence : 900 Hz, the temperature of cooling water : $25^{\circ}C$, quantity of flow : 5, 10, 20 L/min, pressure : 1.2, 1.4, 1.6 atm, and distance of discharge gap : 0.4, 0.6, 0.8 mm. Ozone generation characteristics were measured to consumption power. At quantity of flow : 20 L/min, discharge gap : 0.6 mm, pressure : 1.6, and consumption power : 150 W, Maximum ozone generation efficiency of 175 g/kWh was obtained. And a range of maximum ozone generation efficiency was measured below the flow quantity of 20 L/min at below pressure of 1.6 atm. However, Maximum ozone generation efficiency was measured over the flow quantity of 20 L/min at over pressure of 1.6 atm.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.1-6
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• 2010

Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were synthesized in high yields by the reduction of the corresponding chlorosilanes with $LiAlH_4$ in diethyl ether. The dehydrocoupling of 1 and 2 was performed using group IV metallocene complexes generated in situ from $Cp_2MCl_2$/Red-Al and $Cp_2MCl_2$/n-BuLi (M = Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 ($M_w$ vs polystyrene using GPC) and from 500 to 900 ($M_w$ vs polystyrene using GPC). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble network polymer.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.559-571
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• 2012

Dimethyl ether (DME) is a new clean fuel as an environmentally-benign energy resource. DME can be manufactured from various energy sources including natural gas, coal, and biomass. In addition to its environmentally friendly properties, DME has similar characteristics to those of LPG. The aim of this article is to represent the development of new DME process with KOGAS's own technologies. KOGAS has investigated and developed new innovative DME synthesis process from synthesis gas in gaseous phase fixed bed reactor. DME has been traditionally produced by the dehydration of methanol which is produced from syngas, a product of natural gas reforming. This traditional process is thus called the two-step method of preparing DME. However, DME can also be manufactured directly from syngas (single-step). The single-step method needs only one reactor for the synthesis of DME, instead of two for the two-step process. It can also alleviate the thermodynamic limitations associated with the synthesis of methanol, by converting the produced methanol into DME, thereby potentially enhancing the overall conversion of syngas into DME. KOGAS had launched the 10 ton/day DME demonstration plant project in 2004 at Incheon KOGAS LNG terminal. In the mid of 2008, KOGAS had finished the construction of this plant and has successively finished the demonstration plant operation. And since 2008, we have established the basic design of commercial plant which can produce 3,000 ton/day DME.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.317-323
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• 2006

This paper deals with High Stacking System(HSS) development to develop a next generation port handling system for accommodating mega-sized container ships. It aims to develop the HSS that maximizes handling capacity within the limited space of the port. The system is expected to resolve the problem of yard space shortage as well as utilize innovative technology to ensure high-performance and automation at the terminal so as to enhance stevedoring productivity. The main objectives of this paper is suggesting the design concept drawing the HSS terminal and simulation analysis was undertaken taking into consideration performance of handling equipment, and port handling system Design concept drawing of the HSS terminal and will be used as base data for basic design and detailed design in actual operations of the terminal in the future. The HSS, to be applied to both conventional and new terminals, is expected to act as a catalyst for enhancing the value-added at ports.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.252.2-252.2
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• 2013

ZnO nanostructures have a lot of interest for decades due to its varied applications such as light-emitting devices, power generators, solar cells, and sensing devices etc. To get the high performance of these devices, the factors of nanostructure geometry, spacing, and alignment are important. So, Patterning of vertically- aligned ZnO nanowires are currently attractive. However, many of ZnO nanowire or nanorod fabrication methods are needs high temperature, such vapor phase transport process, metal-organic chemical vapor deposition (MOCVD), metal-organic vapor phase epitaxy, thermal evaporation, pulse laser deposition and thermal chemical vapor deposition. While hydrothermal process has great advantages-low temperature (less than $100^{\circ}C$), simple steps, short time consuming, without catalyst, and relatively ease to control than as mentioned various methods. In this work, we investigate the dependence of ZnO nanowire alignment and morphology on si substrate using of nanosphere template with various precursor concentration and components via hydrothermal process. The brief experimental scheme is as follow. First synthesized ZnO seed solution was spun coated on to cleaned Si substrate, and then annealed $350^{\circ}C$ for 1h in the furnace. Second, 200nm sized close-packed nanospheres were formed on the seed layer-coated substrate by using of gas-liquid-solid interfacial self-assembly method and drying in vaccum desicator for about a day to enhance the adhesion between seed layer and nanospheres. After that, zinc oxide nanowires were synthesized using a low temperature hydrothermal method based on alkali solution. The specimens were immersed upside down in the autoclave bath to prevent some precipitates which formed and covered on the surface. The hydrothermal conditions such as growth temperature, growth time, solution concentration, and additives are variously performed to optimize the morphologies of nanowire. To characterize the crystal structure of seed layer and nanowires, morphology, and optical properties, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and photoluminescence (PL) studies were investigated.