• Macromolecular Research
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• 제11권5호
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• pp.387-392
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• 2003

The ablation effects of Ar-plasma treatment and alkali-decomposition behavior in NaOH solution of polyethylene terephthalate (PET) film were investigated. The modifications were evaluated by analysis of atomic force microscopy topographical changes, and by the measurement of decomposition yield in conjunction with heats of formation and electron densities of acyl carbon calculated by Parameterization Method 3 method. It has shown that the alkali-decomposition is hampered by plasma treatment and its decomposition yield is closely related with plasma treatment conditions such as exposure time to plasma. Plasma-treated PET films exhibited lower decomposition yield, compared to that of virgin PET. Increasing plasma exposure time contributes positively to decrease the decomposition yield. It has also shown that the topography of PET surface was affected by the base-promoted hydrolysis as well as Ar-plasma treatments. These behaviors are attributed to the decreased nucleophilicity of acyl carbon damaged by the ablation of Ar-plasma.

• 한국염색가공학회지
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• 제14권4호
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• pp.214-222
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• 2002

In order to give a silk-like touch to PET fabrics, the PET fabrics were treated with NaOH alkaline solution in various conditions. In alkaline treatment, the liquor flow type pilot weight reduction apparatus with magnetostrictive ultrasonic transducer was used for the study. The weight loss of PET fabrics hydrolyzed in 4% and 6% NaOH solution, at $95^\circ{C}$ and $99^\circ{C}$ for 60min. with ultrasonic application showed 3.7~4.6% higher than that of treated fabric without ultrasonic application. From the difference of specific weight loss, the treatment condition of the maximum of hydrolyzation effect appeared at $95^\circ{C}$ in $4^\circ{C}$ and at $90^\circ{C}$ in 6% NaOH solution, respectively. During the alkali hydrolysis of PET fabrics, the decomposition rate constant(k) increased exponentially with the treatment temperature and were not related with ultrasonic cavitation. The activation energy$(E_a)$ in decomposition of PET fabrics were 21.06kcal/mol with ultrasonic application and 21.10kcal/mol without ultrasonic application. The ultrasonic application gave a little higher value of the activation entropy$(\Delta{S}^\neq)$ and a little lower value of Gibbs free energy$(\Delta{S}^\neq)$ compared with not used ultrasonic apparatus.

• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.59-66
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• 2012

This study is interested in identifying the effectiveness of alkali-activated fire protection material compounds including the alkali-activator such as potassium hydroxide, sodium silicate and fly ash as the fire resistant finishing materials. Also, this paper is concerned with change in compressive strength and pore structure of the alkali-activated fire protection material at high temperatures. The testing methods of fire protection materials in high temperature properties are make use of TG-DSC and mercury intrusion porosimetry measurements. This study results show that compressive strength is rapidly degraded depending on a rise of heating temperature. Porosity showed a tendency to increase irrespective of specimen types. This is due to both the outbreak of collapse of gel comprising the cement and a micro crack by heating. However, alkali-activated fire protection material composed of potassium hydroxide, sodium silicate and fly ash has the thermal stability of the slight decrease of compressive strength and porosity at high temperature. These thermal stability is caused by the ceramic binding capacity induced by alkali activation reaction by the reason of the thermal analysis result not showing the decomposition of calcium hydrate.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2867-2872
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• 2010

Two new energetic organic alkali metal salts, 1,1-diamino-2,2-dinitroethylene rubidium salt [Rb(FOX-7)${\cdot}H_2O$] and 1,1-diamino-2,2-dinitroethylene cesium salt [Cs(FOX-7)${\cdot}H_2O$], were synthesized by reacting of 1,1-diamino-2,2-dinitroethylene (FOX-7) and rubidium chloride or cesium chloride in alkali methanol aqueous solution, respectively. The thermal behaviors of Rb(FOX-7)${\cdot}H_2O$ and Cs(FOX-7)${\cdot}H_2O$ were studied with DSC and TG methods. The critical temperatures of thermal explosion of the two compounds are 216.22 and $223.73^{\circ}C$, respectively. Specific heat capacities of the two compounds were determined with a micro-DSC method, and the molar heat capacities are 217.46 and $199.47\;J\;mol^{-1}\;K^{-1}$ at 298.15 K, respectively. The adiabatic times-to-explosion were also calculated to be a certain value of 5.81 - 6.36 s for Rb(FOX-7)${\cdot}H_2O$, and 9.92 - 10.54 s for Cs(FOX-7)${\cdot}H_2O$. After FOX-7 becoming alkali metal salts, thermal decomposition temperatures of the compounds heighten with the rise of element period, but thermal decomposition processes become intense.

• Korean Chemical Engineering Research
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• 제55권5호
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• pp.718-722
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• 2017

마이크로파 공정으로 제조된 순수한 $LaCoO_3$와 금속이온이 첨가된 $LaCoO_3$ 페롭스카이트 산화물에서 메틸오렌지의 광촉매 분해반응의 활성을 조사하였다. 순수한 $LaCoO_3$와 세슘 이온이 첨가된 $LaCoO_3$ 산화물들은 제조법과 무관하게 페롭스카이트 구조를 보여주었다. UV-Vis DRS 결과에 의하면 모든 촉매들은 가시광 영역에서 흡수스펙트럼을 나타내었다. 화학흡착된 산소종은 메틸오렌지의 광촉매 분해반응에서 중요한 역할을 하였으며, 화학흡착된 산소의 비율이 높을수록 더 높은 광촉매 활성을 보여주었다.

• 한국작물학회지
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• 제38권1호
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• pp.31-37
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• 1993

우리나라 주요 벼 재배품종 및 신육성계통(자포니카: 25품종, 통일형:8품종)에 대한 쌀 알칼리 붕괴성의 품종적 특이성을 분시검토하여 보고자 KOH 농도를 0.8-1.8까지 0.2% 간격으로 처리하여 농도별 쌀의 알칼리 붕괴반응을 조사하고 주성분분석법을 적용하여 품종적 유형을 분류하였다. 주성분분석에서 상위 2개 주성분치의 변이가 전변이량의 92%을 차지하였고 제1 및 제2 주요분치 좌표상의 품종분포에 따라 크게 4개 유형으로 군집화 시킬 수 있었다. 제 I 군에서는 전 KOH 농도에 걸쳐 거의 비슷하게 알칼리 붕괴성(ADV)가 낮은 도봉벼만 유일하게 분포하였고, 제 II군에는 1.4% KOH 농도에서 중간정도의 ADV 이면서 고-저 알칼리 농도 ADV간차가 중도인 백운찰벼, 신선찰벼 및 수원 34002 등 찰벼가 포함되어 있었다. 제 III군에는 1.4% KOH 농도에서 중-중고의 ADV 이면서 저-고 KOH 농도간 ADV 변화가 심했던 대부분의 통일형 품종과 자포니카 조생계가 분포되어 있었고 육도농림찰 001와 한강 찰벼등은 이 유형에 포함되어 있었다. 제 IV군에는 1.4% KOH 농도에서 ADV가 중고이상으로 높으면서 고-저 알칼리 농도 ADV간차가 중-중고인 중생 및 중만생 자포니카 품종들이 주로 분포 하였으며 조생인 금조벼가 이 유형에 속하였다. 여기서 제 1 주성분은 전 알칼리 농도에서 평균적으로 표현되는 붕괴성 정도였고 제 2 주성분은 저-고 KOH 농도의 ADV간 차 또는 KOH 농도에 따른 ADV 변화의 회귀계수와 밀접하게 관련된 요소였다. 1.2%-1.4% KOH 농도에서의 ADV는 저-고 KOH 농도간 ADV차와 2차 곡선 회귀계수를 나타내었다.

• Asian Journal of Atmospheric Environment
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• 제10권4호
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• pp.190-196
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• 2016

The objective of this study is to obtain the optimal conditions to remove hydrogen fluoride (HF) generated from a variety of F-gas treatment processes. First, we selected $Ca(OH)_2$ and $CaCO_3$ as a reactant among the various alkali salts which have a high removal efficiency and a competitive price by forming a calcium fluoride precipitate. Additionally, various factors were investigated to improve the removal efficiency of HF. The conditions such as the settling time, agitating time and intensity, reaction temperature, and pH were considered as main factors. As a result, in the treatment process to remove HF through Ca-based alkali salts, the optimal conditions were a 120 min settling time, 30 min of agitation at 100 rpm, a pH of 4-8, and a reaction temperature of $40^{\circ}C$.

• 한국안전학회지
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• 제4권1호
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• pp.75-81
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• 1989

The aim of this study is, by the Lime-Stabilization of decayed Organic Wastes, in preventing the reclaimed Waste from being another pollution due to reclaiming those things. 1. A perfect reaction is possible by the addition of poor Stabilization-Lime of 5 percent in a short time of 5 minute. 2. PH of the Stabilization-handled Wastes rise over 12. 3. Malodorant of Stabilized Wastes is slight because malodorant Volatilize in the course of the Stabilization or is captured in the handled subetance. 4. The second pollution scarcely brings about because a rapid decomposition is impossible on account of the coating of Alkali Substance.

• 한국염색가공학회지
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• 제14권6호
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• pp.305-312
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• 2002

In order to give a silk-like touch to PET fabrics, the PET fabrics were treated with NaOH alkaline solution in various conditions. In alkaline treatment, the liquor flow type pilot weight reduction apparatus with magnetostrictive ultrasonic transducer was used for the study. The effects of ultrasonic application, treatment time and temperature at NaOH 4% and 6"A solution on the decomposition rate of PET fabrics. From the results of the decomposition rate of PET fabrics, the qualitative and quantitative analysis of oligomer after decomposition of PET fabrics carried out by the HPLC. On the other hand, the surface pore characteristics of decomposition PET fabrics measured by porosimetery. The pore characteristics on the surface of treated PET fiber depended on the decomposition rate and did not depend on the ultrasonic cavitation. The pore diameter of alkaline untreated PET fiber were 15A and those of treated PET fibers were 5~6$\AA$ at the maximum pore volume. The average pore sizes of fiber before and after treatment were 141 h and 160h, respectively. Total amount of oligomer of the untreated PET fibers were 1.70wt% and 67.7% of total oligomer occupied with PET cyclic trimer and PET cyclic tetramer. Total amount of oligomer of fiber with 26.9% and 48.0% of weight loss without ultrasonic application were 1.78wt% and 1.79wt%, respectively. Also total amount oligomer of fibers which were reduced 27.7% and 48.2% of weight loss with ultrasonic application were 1.74wt%. This result showed that the removal rate of oligomer in the process of alkaline hydrolysis with ultrasonic higher than that of without ultrasonic application.tion.

• 암석학회지
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• 제3권1호
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• pp.41-48
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• 1994

암석의 용해 방법에 따른 미량원소 분석결과를 비교해 보기 위해 미국 지질조사소의 암석 표준시료 3종류 (G-2, W-2, BHVO-1)를 비이커-가열판법, 마이크로파 오븐법, 알칼리 용융법으로 용해 시켜 유도결합 플라즈마 질량분석기를 사용, 각각의 미량원소 농도를 측정하여 용해 방법에 따른 차이를 살펴보았다. 전체적으로 보아 비이커-가열판법으로 용해시킨 경우와 마이크로파 오븐법으로 용해시킨 경우는 비슷한 분석결과를 보인다. 알칼리 용융법을 사용하여 용해시킨 경우 높은 온도 때문에 Pb, Cu, Rb 등의 휘발성 원소 상당 부분이 손실된다. 산분해법의 경우 Zr, Hf 등의 원소가 저어콘 등의 불용성 광물에 농집되어 있을 때에는 광물들의 불충분한 용해로 인해 측정 농동가 낮게 나타난다. 회토류 원소 분석결과는 시료 용해 방법 사이에 차이가 없었으며 추천치와 대체로 일치하였으나 알칼리 용융법의 경우 큰 희석인자로 인한 측정상의 문제점이 일부 있었다.