• 한국염색가공학회지
• /
• 제19권1호
• /
• pp.45-52
• /
• 2007

Polyacrylonitrile(PAN) fiber was treated with low-temperature plasmas of argon and oxygen for surface modification, and its surface chemical structure and morphology were examined by a field emission scanning electron microscope(FESEM) and a Fourier-transform infrared microspectroscopy(IMS). The argon-plasma treatment caused the only mechanical effect by sputtering of ion bombardment, whereas the oxygen plasma brought about a chemical effect on the PAN fiber surface. The experimental evidences strongly suggested that cyclization of nitrile group and crosslinking were likely to occur in the oxygen-plasma treatment. On the other hand, with the argon-plasma treatment, numerous my pits resulted in ranging from several tens to hundreds nanometers in radius. The plasma sensitivity of functional groups such as C-H, $C{\equiv}N$, and O-C=O groups in the PAN fiber was dependent on their chemical nature of bonding in the oxygen-plasma, in which the ester group was the most sensitive to the plasma. Vacuum-ultraviolet(VUV) radiation emitted during plasma treatment played no substantial role to alter the surface morphology.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
• /
• pp.711-714
• /
• 2001

A new technology to make fluoride gas such as NF$_3$contained in the exhaust gas from semiconductor manufacturing plants convert directly into a harmless substance have been established and new concept on the disposal treatment of global warming gases were presented. Experimental results verify that the chemical reactions can be take place at substantially lower temperature of 80-40$0^{\circ}C$ as compared with the combustion treatment method. Reaction product is mainly metal fluoride which is a harmless and a valuable chemical material as one of new resources. The other favorable characteristics are that the continuous treatment is possible at a low temperature under atmospheric pressure. Furthermore this process is compact, easily controllable and safely operable at low running cost. This paper concerns with a new harmless disposal treatment of toxic global warming gas.

• 한국세라믹학회지
• /
• 제29권5호
• /
• pp.341-346
• /
• 1992

The effects of CaO addition on the low temperature degradation behavior of 2.5Y-TZP ceramics were investigated. Y2O3-CaO-ZrO2 ceramics were prepared from the commercial Y-TZP powder added within 1 mol% of CaO. Fully tetragonal phase could be obtained at each composition under sintering condition of 1500$^{\circ}C$ for 1 hour. As the amount of CaO increased, grain size was decreased. From the result of heat treatment at 200$^{\circ}C$, volume fraction of monoclinic phase formed on the surface of each specimen was decreased with higher CaO amount. Stability of tetragonal ZrO2 phase for low temperature heat treatment was increased by CaO addition without the degradation of mechanical properties.

• Fibers and Polymers
• /
• 제7권3호
• /
• pp.262-269
• /
• 2006

In this paper, the effects of low temperature plasma (LTP) treatment on the dyeing properties of the wool fiber were studied. The wool fibers were treated with oxygen plasma and three types of dye that commonly used for wool dyeing, namely: (i) acid dye, (ii) chrome dye and (iii) reactive dye, were used in the dyeing process. For acid dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased but the final dyeing exhaustion equilibrium did not show any significant change. For chrome dyeing, the dyeing rate of the LTP-treated wool fiber was also increased but the final dyeing exhaustion equilibrium was only increased to a small extent. In addition, the rate of afterchroming process was similar to the chrome dyeing process. For the reactive dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased and also the final dyeing exhaustion equilibrium was increased significantly. As a result, it could conclude that the LTP treatment could improve the dyeing behavior of wool fiber in different dyeing systems.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 1994년도 특별강연 및 춘계학술발표 개요집
• /
• pp.39-43
• /
• 1994

The effects of ageing treatment on the mechanical properties of two Cu-bearing HSLA(High Strength Low Alloy) steels, HSLA-A and HSLA-B ,were studied by means of SEM, TEM, tensile, charpy impact and hardness tests. These steels showed excellent combination in strength and toughness at an ageing of $650^{\circ}C$ by the precipitation of $\varepsilon$-Cu and low carbon alloying. The peak strength was achieved at an ageing of 50$0^{\circ}C$ in both steels, while the impact energy was very low in this peak strength. With ageing temperature above this temperature, strength was decreased whereas impact energy increased. A marked increase in hardness above 675$^{\circ}C$ was associated with the formation of “M-A constituents” which forms during cooling from austenite-ferrite two phase region. The impact transition temperature of HSLA-A and HSLA-B steels were -l$25^{\circ}C$ and -145$^{\circ}C$, respectively.

• 원예과학기술지
• /
• 제31권6호
• /
• pp.726-731
• /
• 2013

저온암흑처리가 국내 육성 신품종 딸기의 화아분화에 미치는 영향을 구명하고자 실험을 수행하였다. 3월 29일에 모주를 정식하여 8월 2일에 런너를 절단하여 육성시킨 자묘를 7일간, 14일간, 그리고 21일간 $13^{\circ}C$ 저온저장고에서 저온암흑처리를 하였는데, 정식일인 2010년 9월 20일을 기준으로 역산하여 8월 21일에 3주간 처리, 9월 5일에 14일간 처리, 9월 12일에 7일간 처리를 각각 개시하였다. 처리 후에는 각각의 처리구별로 실체 현미경을 사용하여 형태적인 화아분화를 확인하였다. 또한, 저온암흑 처리한 딸기묘를 9월 20일에 고설수경재배 시스템에 일제히 정식하고 야마자키 조성딸기배양액을 EC $0.8dS{\cdot}m^{-1}$로 공급하여 재배하면서 처리별로 출뢰 및 개화를 조사하였다. 현미경으로 화아분화를 검경한 결과, 7일간의 저온암흑처리에서 '싼타'와 '매향'이 현저하게 빠른 화아분화를 나타내었다. 14일간의 처리구에서는 '설향'을 제외한 '싼타', '대왕', 그리고 '매향'은 현저하게 화아분화가 촉진되었다. 21일간의 처리구에서는 품종간에 유의성 있는 차이가 없었으며 다른 처리구에 비하여 화아분화의 진행이 늦었다. 정식 후의 개화율은 '설향'과 '매향'은 대조구인 무처리구와 큰 차이를 나타내지 않았다. 그러나, '싼타'와 '대왕'은 대조구에 비하여 현저하게 빠른 개화와 높은 개화율을 나타내어서 저온암흑처리 방법이 이들 두 품종에서는 조기수확 및 수량증대에 기여할 수 있는 기술로 기대된다.

• Current Optics and Photonics
• /
• 제1권5호
• /
• pp.500-504
• /
• 2017

In this paper, we developed a temperature measurement system based on an infrared temperature imaging module for thermal safety verification of a plasma skin treatment device (PSTD). We tested a pilot product of the low-temperature PSTD using the system, and the temperature increase of each plasma torch was well-monitored in real-time. Additionally, through the approximation of the temperature increase of the plasma torches, a certain limitation of the plasma treatment time on skin was established with the International Electrotechnical Commission (IEC) guideline. We determined an appropriate plasma treatment time ($T_{Safe}$ < 24 minutes) using the configured temperature measurement system. We believe that the temperature measurement system has a potential to be employed for testing thermal safety and suitability of various medical devices and industrial instruments.

• 한국주조공학회지
• /
• 제40권2호
• /
• pp.16-24
• /
• 2020

The effect of a heat treatment on the microstructure and mechanical properties of Inconel 713C alloy vacuum investment castings were investigated. The microstructure of the as-cast state was observed, showing well-developed dendrite structures and distributed carbide particles and solidified massive precipitates in the grain or grain boundary during solidification, in this case the γ′ phase and MC particles. During a heat treatment, the γ phase matrix was reinforced by solid solution elements, carbide particles from the film morphology precipitated along the grain boundary, and many micro-precipitates of second γ′ phases 0.2 ㎛~2 ㎛ in size were newly formed in the γ phase matrix according to SEM-EDS analysis results. The tensile strength at a high temperature (850℃) decreased slightly becoming comparable with the room-temperature result, while the hardness value of the specimen after the vacuum heat treatment increased by approximately 19%, becoming similar to that of the as-cast condition. However, the impact values at room temperature and low temperature (-196℃) were approximated; this alloy was mostly not affected by an impact at a low temperature. In the observations of the fracture surface morphologies of the specimens after the tensile tests, the fractures at room temperature were a mix of brittle and ductile fractures, and an intergranular fracture in the inter-dendrite structure and some dimples in the matrix were observed, whereas the fractures at high temperatures were ductile fractures, with many dimples arising due to precipitation. It was found that a reinforced matrix and precipitates of carbide and the γ′ phase due to the heat treatment had significant effects, contributing greatly to the excellent mechanical properties.

• 한국재료학회지
• /
• 제15권8호
• /
• pp.496-502
• /
• 2005

Green-light emitting $BaMgAl_{10}O_{19}:Mn^{2+}$ (BAM:Mn) phosphor particles were prepared by spray Pyrolysis. The effect of reactor temperature and flow rate of carrier gas in the spray Pyrolysis on the morphology, crystallinity and photoluminescence characteristics under vacuum ultraviolet were investigated. The morphology of the as-Prepared Particles obtained by spray Pyrolysis had spherical shape and non-aggregation characteristics regardless of the reactor temperature. The spherical shape of the as-prepared Particles obtained by spray pyrolysis at low temperature disappeared after Post-treatment. On the other hand the as-Prepared Particles obtained by spray Pyrolysis at $1600^{\circ}C$ maintained spherical shape and non-aggregation characteristics after post-treatment at $1400^{\circ}C$ for 3 h under reducing atmosphere. The BAM:Mn Phosphor Particles Prepared by spray Pyrolysis at different reactor temperatures had pure crystal structure and high photoluminescence intensities under vacuum ultraviolet after post-treatment. BAM:Mn phosphor particles prepared by spray Pyrolysis at low How rate of carrier gas had complete spherical shape and filed morphology and high photoluminescence intensity after post-treatment under reducing atmosphere.

• 현장농수산연구지
• /
• 제20권1호
• /
• pp.67-74
• /
• 2018

본 실험은 우리나라 전역에서 5월에 개화하는 아까시나무 꽃을 이용하여 훈증, 저온건조, 덖음, 순간 침지를 하여 건강 꽃차를 개발하기 위해 수행하였다. 건조방법은 훈증처리 후 건조, 저온건조, 덖음, 순간침지로 하였다. 건강 차를 만들기 위한 실험을 다르게 한 후 꽃 무게의 변화, 꽃 색의 변화, 음료 색, 당도, 맛을 측정하였다. 이렇게 실험한 결과, 꽃차 무게의 변화는 생체대비 11%~12.5%로 나타났으며, 색의 변화는 덖음 처리에서 가장 연한 갈색으로 나타났고, 그 외 처리구는 탁한 백색으로 나타났다. 음료 색은 덖음 처리한 차에서 노란색이 강하게 나타났고 훈증, 저온건조, 순간침지에서는 연한 노란색으로 나타났으며, 당도는 덖음 차에서 가장 높은 2.9brix로 높게 나타났으며 다른 세처리구에서는 2.6~2.7brix로 나타났다. 맛은 덖음 처리에서 가장 좋았고, 순간 침지에서는 비릿한 맛이 났다.