• 한국군사과학기술학회지
• /
• 제10권1호
• /
• pp.123-129
• /
• 2007

A 2-step process for the safe destruction of chemical wafare agents(agent hydrolysis followed by supercritical water oxidation) was studied to obtain kinetic data for the pilot plant design. This process is simple to operate by using commercial equipments and could be applied as an alternative technology to incineration. Sarin(GB) and sulfur mustard(HD) were hydrolysed in sodium hydroxide and water respectively and their hydrolysates and OPA, which is binary agent for GB were oxidized in a continuous flow supercritical water oxidation system. Destruction efficiencies of the materials were above 99.99% in supercritical water.

• 한국세라믹학회지
• /
• 제29권6호
• /
• pp.419-430
• /
• 1992

Fabrication possibility of low-shrinkage alumina without oxidation and wetting agent was presented on the basis of observation about oxidation behavior, microstructure and physical characteristics of such reaction agents free Al2O3-Al system. The composition less than Al 10w/o where Al can act as a sintering agent for Al2O3 was excluded. Under the condition of present experiments oxidation of Al2O3-Al system was dependent not on holding time but mainly on oxidation temperature. In thes case of Al powder not comminuted effectively during powder mixing of Al2O3-Al, columnar structure which would act as a hindrance to the densification during sintering developed more during oxidation with higher Al contents, and which made the fabrication of low-shrinkage Al2O3 ceramics impossible. If Al powder was comminuted effectively due to co-mixed Al2O3 characteristics, densification was improved because of no columnar structure and made the fabrication of sintered body with -2.7% dimensional change and 81% relative density possible. As a result, it is possible to fabricate dense low-shrinkage Al2O3 ceramics without oxidation and wetting agent under conditions such as smaller particle size of Al, Al contents below 50v/o, higher green density of Al2O3-Al compact and the use of Al2O3 powder used for high-density ceramics.

• 한국염색가공학회지
• /
• 제29권1호
• /
• pp.11-17
• /
• 2017

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that can not be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor(MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbenedisulfonic acid derivative by ozone oxidation were evaluated by $UV_{254}$ Scan, $COD_{Mn}$, T-N and color using a synthetic wastewater sample ($COD_{Mn}=433.0mg/{\ell}$) and paper and paper mill wastewater ($COD_{Mn}=157.2mg/{\ell}$).

• 한국표면공학회지
• /
• 제47권4호
• /
• pp.147-154
• /
• 2014

Formation behavior of PEO (Plasma Electrolytic Oxidation) films on AZ31 Mg alloy was studied in aqueous solutions containing various concentrations of hydroxide ion ($OH^-$) and silicate ion ($SiO_3{^{2-}}$) by voltage-time curves, and corrosion resistance of the PEO film-covered specimen was investigated by immersion test in 0.5 M NaCl solution. From the analyses of the voltage-time curves, it is suggested that two different types of anions are essentially needed for the formation of PEO films on AZ31 Mg alloy: film formation agent and local film breakdown agent. $SiO_3{^{2-}}$ ion acts only as a film formation agent but $OH^-$ ion acts not only as a film formation agent but also film breakdown agent. The PEO films prepared on AZ31 Mg alloy in alkaline silicate solution showed very good corrosion resistance without any pitting or filiform corrosions up to 480 h of immersion in 0.5 M NaCl.

• 한국염색가공학회지
• /
• 제30권1호
• /
• pp.51-61
• /
• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• 치위생과학회지
• /
• 제9권2호
• /
• pp.153-160
• /
• 2009

본 연구는 금속-도재 수복물 제작에 사용되는 Ni-Cr alloy와 Co-Cr alloy, 그리고 티타늄에 gold bonding agent를 도포하여 Au coating 층을 형성하였다. 각 시편의 절단면을 전자현미경으로 Au coating 층과 porcelain bonder, 그리고 불투명 도재간의 결합을 관찰하였고, 각 계면의 상태를 SEM/EDS 방법으로 조사하였다. 실험에서 사용된 재료와 방법의 범위 내에서 다음과 같은 결론을 얻었다. 1. Gold bonding agent를 사용하여 형성한 Au coating 층은 미세다공성을 가진 구조로 판단되었다. 2. Au coating 층과 porcelain bonder 그리고 불투명 도재간의 결합은 잘 일어나 보였다. 3. Au coating 층은 도재 소성과정에서 발생하는 산화층의 확산을 제한하는 것으로 관찰되었다.

• 대한본초학회지
• /
• 제22권2호
• /
• pp.51-63
• /
• 2007

Objectives : For the congenital feeble, the Gongjindan is useful medicine. The experiment is to estimate the value of the Gongjindan as therapeutic agent preventing against aging with an analysis of the ingredients and the bio-activating effects by enzymologic methods. Methods : General ingredients' of the Gongjindan's extract were analyzed first and the quantitative analysis of a reducing sugar, a soluble protein, an amino acid and minerals was made. The Gongjindan, which is extracted, concentrated, and freeze drying with water, ethanol and chloroform, have got applied for the experiment. The effects on electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, whitening effect have been investigated in the physiological activity measurement of function experiment. Results : The contained amino acid, in order of high amount, is Arginine, Alanine, Glutamic acid, Proline and the contained free amino acid is Glutamic acid, Leucine, Lysine, Phenylalanine. The derivative of free amino acid is ${\gamma}-Aminoisobutyric$ acid, Phosphoserine, Taurine. And the Gongjindan is containing 13 species of minerals in order of Ca>K>Na>Mg>Fe>AI>Mn. Then, to assure of the Gongjindan's capability of anti-oxidation, these following subjects-polyphenol, electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, tyrosinase inhibition- are analyzed and show high activity especially the most in ethanol extracts. Conclusion : With this analysis of ingredients, the Gongjindan is containing many materials functioning as anti-oxidation, anti-aging, anti-fatigue, neurotransmitter and immune agent. Moreover, In every water, ethanol, chloroform extracts, the Gongjindan's capability of anti-oxidation is confirmed so that we can apply to patients' treatment clinically.

• 유기물자원화
• /
• 제13권4호
• /
• pp.107-117
• /
• 2005

본 연구에서는 펜톤산화 공정을 축산폐수의 전처리 시스템으로 활용하고자 초기 pH, $H_2O_2/Fe^{2+}$ 비율, $H_2O_2/Fe^{2+}$ 약품주입량, 응집 및 침전을 위한 중화제 등과 같은 펜톤산화의 적정 운영조건을 도출하는 실험적 연구를 실시하였다. 적정 조건을 도출하기 위해 교반시험기를 이용하여 120 rpm에서 2시간 동안 각 조건을 변화시키면서 펜톤산화 반응을 진행한 후 2시간 동안 침전시켜 그 상등액의 잔류 과산화수소, $COD_{Cr}$, SS 등을 분석하였다. 실험결과 도출된 최적조건은 초기 pH는 4, $H_2O_2/Fe^{2+}$비율은 10:1, $H_2O_2/Fe^{2+}$ 약품주입량은 5,000/500mg/L 그리고 중화제로는 $Ca(OH)_2$가 양호한 것으로 나타났다. 이러한 최적 조건에서 펜톤산화에 의해 축산폐수의 $COD_{Cr}$ 제거율은 43% 그리고 SS는 84%의 제거율을 나타내었다.

• Preventive Nutrition and Food Science
• /
• 제4권3호
• /
• pp.171-174
• /
• 1999

For monitoring lipid oxidation development in cooked ground pork during refrigerationm, malonaldehydethiobarbituric acid(MA-TBA) contents were measured using high performance liquid chromatography(HPLC). As the oxidation proceeded during refergeration, TBA-reaction substances(TBARS) absorbances increased and the corresponding HPLC peak areas also increased proportationately. The correlation coefficient between the HPLC peak areas and MA-TBA absorbance were 0.9979. The treatemtn of cetrimide, an ion pairing agent, gave a complete resolution of the MA-TBA complex and the butanol extraction of the complex increased its recovery by 37.8%. Both cetrimide treatment and butanol extraction are essential steps for analyzing MA-TBA complex in ground pork wiht HPLC. A reliable and specific measurement of NA-TBA in ground pork was successfully performed using HPLC.

• 한국염색가공학회지
• /
• 제28권4호
• /
• pp.253-270
• /
• 2016

In the wool textile industry, the necessity for technology development has been steadily raised to create improved fineness and yarn count of existing wool yarns with thick fineness for ensuring higher quality grades of wool yarn. Recently, through controlling fineness of wool yarn for making finer wool in relation with environmentally-friendly and high-sensitivity trend, a differentiated continuous drawing process where the quality of wool can be artificially manipulated has been suggested in the latest textile industry. This study investigated the basic conditions during the continuous drawing process which enable to manufacture wool yarn with fine count by controlling reducing agent treatment, physical drawing and drying after reducing agent treatment, and oxidizing agent post-treatment conditions. Furthermore, this study reviewed the drawing effects by applying the basic conditions for reduction and oxidation reaction in the drawing processes of wool/cashmere, wool/silk, wool/polyester blended yarns as well as such wool yarns. Also, in order to review the practicability, this study examined the physical properties and dyeability of drawn wool yarn applied textile materials in comparison with normal wool yarn applied textile materials.