• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.254-254
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• 2009

Single-walled carbon nanotubes (SWCNTs) have attracted much attention as promising materials for transparent conducting films (TCFs), thanks to their superior electrical conductivity, high mechanical strength, and complete flexibility. The CNT-based TCFs can be used in a variety of application fields as flexible, transparent electrodes, including touch panel screens, flexible electronics, transparent heaters, etc. First of all, this study investigated the effect of a variety of surfactants on the dispersion of SWCNTs in an aqueous solution. Following the optimization of the dispersion by surfactants, flexible TCFs were fabricated by spraying the CNT suspension onto poly(ethylene terephthalate) (PET) substrates. The sheet resistances of the TCFs having different surfactants were investigated with treatment in nitric acid ($HNO_3$) whose concentration and period of treatment time were varied. It seems that the $HNO_3$ removes the surfactants from and is simultaneously doped into the SWCNT network, reducing the contact resistance between CNTs. TCFs were characterized by UV-VIS spectroscopy, thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), and four-point probe.

• 한국대기환경학회지
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• 제24권6호
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• pp.674-681
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• 2008

Silver as a metal catalyst has been used to remove odorous compounds. In this study, silver particles in nano sizes ($5{\sim}30nm$) were prepared on the surface of $NaHCO_3$, the supporting material, using a sputtering method. The silver nano-particles were dispersed by dissolving $Ag-NaHCO_3$ into water, and the dispersed silver nano-particles in the aqueous phase was applied to remove inorganic odor compounds, $NH_3$ and ${H_2}O$, in a scrubbing reactor. Since ammonia has high solubility, it was removed from the gas phase even by spraying water in the scrubber. However, the concentration of nitrate (${NO_3}^-$) ion increased only in the silver nano-particle solution, implying that the silver nano-particles oxidized ammonia. Hydrogen sulfide in the gas phase was rapidly removed by the silver nano-particles, and the concentration of sulfate (${SO_4}^{2-}$) ion increased with time due to the oxidation reaction by silver. As a result, the silver nano-particles in the aqueous solution can be successfully applied to remove odorous compounds without adding additional energy sources and producing any harmful byproducts.

• Journal of Biosystems Engineering
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• 제20권3호
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• pp.288-298
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• 1995

In greenhouse vegetable, the automatic control in cultivating environment has been projected as a national business ; especially a countermeasure against the settlement of UR negotiation. Because it makes possible to manage a large greenhouse with family-hands and to expect the betterment of quality and the increasement of harvest in crops. In the course of carrying the workout, however, there are many problems with the overall control system with computers as well as the individual systems for environment control because of hardware and software problems : especially the shortage of data for development of the system is most serious. Among the many problems for development of the automatic control system, the automations of irrigation, liquefied fertilizer and chemical solution, mixing and ventilation, etc and the development of the general automatic controller system for environment control in greenhouse are studied, which requires a lot of tabors. The results are summarized as follows ; 1. In moisture control by the soil moisture meter, the error was shown 10 % in the beginning irrigation point and 19 % in the stop irrigation point. 2. The supply of liquefied fertilizers with the irrigation system was excellent by setting the operating time and the mixing ratio. 3. The developed chemical spraying system was operated well, but not perfect in nozzle positions. 4. The cucumber was cultivated properly with the trickle irrigation system. 5. The developed controller for the automatic control system in greenhouse was remarkable in the part of hardware, but more researches are needed in the part of software.

• 한국응용곤충학회지
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• 제42권4호
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• pp.345-352
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• 2003

논둑 불태우기의 당위성을 찾기 위하여 1995년부터 1997까지 2년동안 안동 지방 2개 지역 농가 포장에서 논둑을 태운 뒤의 잡초상, 곤충상 및 거미상과 아울러 다각적인 환경요인에 미치는 영향을 분석하였다. 분석 결과 및 기존자료들을 종합하여 볼 때 잡초상, 곤충상 및 도열병발생 등에는 별 영향이 없고 거미상 및 논둑 보존 등에는 불리하게 작용하며 더욱이 산불의 원인이 될 수 있는 등 뚜렷한 득은 없고 확실한 손실만을 초래하는 것으로 판단되어 논둑 불태우기를 절대 금하는 기초자료로 활용할 것을 건의한다.

• 한국기계가공학회지
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• 제19권8호
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• pp.88-93
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• 2020

The goal of this study is to determine the influence of major factors on the spiral surface microparticle injection machining of cylindrical specimens by the statistical method ANOVA. Before the experiment, rod-shaped test specimens and jigs for helical surface spraying were prepared, and the surface roughness was measured with a surface roughness meter. The injection particle, nozzle diameter, and injection pressure were the primary parameters of the experiment. Other factors that were considered were injection height, injection time, revolutions, and feed distance. The surface roughness after machining was measured, and the effects of the surface roughness data on the primary factors were determined with ANOVA.

• Design & Manufacturing
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• 제14권1호
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• pp.36-41
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• 2020

Recently, due to the development of MEMS technology, researches for the production of effective micro structures and shapes have been actively conducted. However, the process technology based on chemical etching has a number of problems such as environmental pollution and time problems due to multi-process. Various processes to cope with this process are being studied, and one of the mechanical etching processes is the powder blasting process. This process is a method of spraying fine particles, which has the advantage of being an effective process in manufacturing hard brittle materials. However, it is also a process that adversely affects the material surface roughness and material properties due to the impact of the injection of fine particles. In this study, after fabricating micro-channels in fused silica glass with excellent optical properties among the hard brittle materials, we used the nano indentation system to analyze the micro parts using nano-particles as well as machinability and surface roughness analysis of the processed surface. The analysis was performed for the effective processing of powder blasting.

• 한국작물학회지
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• 제32권3호
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• pp.353-356
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• 1987

하우스 딸기 재배에 있어서 2, 4-D(아민감 40%)의 업면시용 효과를 알기 위하여 1 화방의 1번과 개화기(2월 11 일)에 10ppm 농도로 10 a당 120$\ell$를 처리하였던 결과, 1. 딸기는 엽병장 및 과경장이 길어지면서 상편생장을 하였고 잎과 과실로부터 에틸렌 생성이 증가되었다. 2 딸기는 에틸렌 생성 증가에 따른 수확최감기가 15일 정도 촉진되었고 과실비대로 1 과중이 증가되어 18 %의 증수 효과를 가져왔다.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.234-242
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• 2009

This study was attempted to develop surface washing-system of ginseng. The effect of sterilization, washing and keeping freshness of ginseng through analyzing unit process were examined to establish optimal condition for washing system. Surface washing method of fresh ginseng used two way and full cone spray type. Sterilization was used at $2^{\circ}C$ water with electrolysis water of 50 and 80 ppm. Ginseng was sterilized with electrolysis water during 30 and 60 s, dehydrated during 1 min and dried during 1min at 30 and $50^{\circ}C$. Hardness of surface-washed ginseng showed good result on 1 min spraying time with 80 ppm electrolysis water at $10^{\circ}C$ storage. Ginseng with 80 ppm electrolysis water was sterilized better with $1.05{\times}103$. There are no changes with 0% on appearance quality at 80 ppm electrolysis.

• 한국응용곤충학회지
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• 제7권
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• pp.53-55
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• 1969

본 시험은 1968년에 배나무 신초를 지사케 하는 배나무줄기벌을 구제하기 위하여 Dimecron, Lebaycid, Metayrtox, Endrin, Dieldrin, Sevin, Folidol, Dipterex, Fussol, Malathion, EPN, DDVP, D.S. Folithion, Cidial등의 약제를 사용하여 그 살충효과를 시험한 것이다. 1. 농약의 종류간과 처리일자간에는 모두 유의성이 있다. 2. 비교적 살충효과가 있는 것은 Dimecron, Lebaycid, D.S. Endrin, Metasystox, DDVP이며, 특히 Dimecron과 Lebaycid를 부화당일이나 부화후 4일에 살포하는 것이 가장 큰 방제효과를 보여주었다.

• 한국재료학회지
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• 제24권7호
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• pp.357-362
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• 2014

Thermal barrier coatings(TBCs) are being applied in many industrial fields such as thermal power generation, aviation and seasonal fields. $ZrO_2-Y_2O_3$(8%) thermal spray coating powders are commercially used as thermal-barrier coating materials to protect against oxidation and corrosion of heat-resistant alloys at elevated temperatures. Currently, $ZrO_2-Y_2O_3$(8%) thermal-spray powder is made using the industrial co-precipitation process, which is very complex and requires a lot of time. In this study, orthorhombic $ZrO_2$ and $Y_2O_3$ powders were fabricated by mechanical mixing, which is more economical than the co-precipitation process. A tetragonal, yttria-stabilized zirconia(YSZ) coating-layer was produced by plasma spraying, using orthorhombic $ZrO_2-Y_2O_3$(8%) powder. Our experimental results indicate that $ZrO_2-Y_2O_3$(8%) mixed powder can be used economically in industry because it is no longer necessary to make this powder by liquid and gas-phase methods.