• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2002년도 춘계총회 및 학술발표회
• /
• pp.27-27
• /
• 2002

• 대한화장품학회지
• /
• 제11권1호
• /
• pp.32-52
• /
• 1985

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 1998년도 춘계학술발표회 초록집
• /
• pp.86-86
• /
• 1998

• Bulletin of the Korean Chemical Society
• /
• 제17권10호
• /
• pp.949-951
• /
• 1996

• 한국환경과학회지
• /
• 제14권10호
• /
• pp.919-928
• /
• 2005

This study introduces the development of new supercritical water oxidation(SCW)(multiple step oxidation) to destruct recalcitrant organic substances totally and safely by using sodium nitrate as an oxidant. This method has solved the problems of conventional SCW, such as precipitation of salt due to lowered permittivity, pressure increase following rapid rise of reaction temperature, and corrosion of reactor due to the generation of strong acid. Destruction condition and rate in the supercritical water were examined using Polyvinyl Chloride(PVC) and ion exchange resins as organic substances. The experiment was carried out at $450^{\circ}C$ for 30min, which is relatively lower than the temperature for supercritical water oxidation $(600-650^{\circ}C)$. The decomposition rates of various incombustible organic substances were very high [PVC$(87.5\%)$, Anion exchange resin$(98.6\%)$, Cationexchange resin$(98.0\%)$]. It was observed that hetero atoms existed in organic compounds and chlorine was neutralized by sodium (salt formation). However, relatively large amount of sodium nitrate (4 equivalent) was required to raise the decomposition ratio. For complete oxidation of PCB was intended, the amount of oxidizer was an important parameter.

• 약학회지
• /
• 제34권3호
• /
• pp.215-218
• /
• 1990

An ion chromatographic method based on indirect photometric detection of UV transparent anions was developed. Separation of anion was accomplished on strong anion exchange column (Waters SAX) using UV detector at 254 nm. Among examined UV-active additives (Dns-H, Dns-glu, Dnsser, Dns-val), Dns-glu showed the highest sensitivity. Studies on the effects of the pH and ionic strength of eluent revealed that the increase of pH and ionic strength of the eluent decreased capacity factor. The best eluent for the separation of acetate, fluoride, chloride, nitrate and bromide was $1\;{\times}\;10^{-4}M$ Dns-glu in 5 mM phosphate buffer (pH 6.30). The detection limit of chloride ion was 2.1 ng in this condition.

• Bulletin of the Korean Chemical Society
• /
• 제26권1호
• /
• pp.51-56
• /
• 2005

A PVC membrane electrode for lead ion based on 1-phenyl-2-(2-quinolyl)-1,2-dioxo-2-(4-bromo) phenylhydrazone (PQDBP) as ionophore was demonstrated. The optimum composition of the membrane was 30 wt% poly(vinyl chloride), 60 wt% dibutyl phthalate as a plasticizer, 4 wt% ionophore and 6 wt% sodium tetraphenylborate as additive. The electrode exhibits a Nernstian response (28.7 mV decade$^{-1}$) for Pb$^{2+}$ over a wide concentration range (1.0 ${\times}$ 10$^{-1}$ to 1 ${\times}$ 10$^{-6}$ M) with a detection limit of 6.0 ${\times}$ 10$^{-7}$ M. This sensor has a short response time and can be used for at least 2 months without any divergence in potentials. The proposed electrode could be used in a pH range of 3.0-6.0 and revealed good selectivities for Pb$^{+2}$ over a wide variety of other metal ions. It was successfully applied as an indicator electrode for the potentiometric titration of lead ion with potassium chromate and for the direct determination of lead in mine.

• 한국식품과학회지
• /
• 제48권4호
• /
• pp.341-346
• /
• 2016

HPA는 식품으로 섭취되는 녹말을 분해하는데 있어서 매우 중요한 역할을 수행하는 효소이기 때문에 HPA 효소 활성의 억제는 당뇨와 비만과 같은 질환의 예방과 치료에 있어서 의미를 가진다. 따라서 HPA는 당뇨병 치료와 비만 예방을 위한 새로운 식 의약품 소재 개발을 위한 주요 타깃 효소 중 하나이며, 새로운 소재의 개발을 위해서는 HPA의 반응 메커니즘을 비롯하여 천연 기질 분해 특성에 대한 이해가 반드시 필요하다. 본 연구에서는 HPA의 동질효소 중 연구가 거의 진행되지 않은 HPA II에 대한 효소 특성화를 진행하고자 P. pastoris 시스템을 이용하여 재조합 HPA II를 생산하였으며, 녹말 분해와 관련된 효소적 특성을 분석하였다. HPA II는 10 mM NaCl까지 농도 의존적으로 효소활성이 증가하였으며, 최적 활성을 위한 pH는 0 mM NaCl 조건에서 pH 6.5이었으나 10 mM NaCl조건에서 pH 7.5로 이동하는 특성을 보였으며, 이는 HPA I을 포함하는 염소이온 의존형 아밀레이스가 나타내는 전형적인 특징이다. 염소이온 존재 시 최적 pH가 염기성 pH 영역으로 이동하는 것은 염소 이온과 효소의 결합에 의해 HPA II의 산/염기 촉매 잔기의 $pK_a$값이 커진다는 것을 의미하며, 염소이온을 첨가하였을 때 녹말에 대한 가수분해 활성의 증대 정도가 산성 pH 영역보다 염기성 pH 영역에서 두드러지게 나타났다는 점이 이를 뒷받침하였다. 반응속도론적 분석 결과에 따르면 염소이온 존재 시 효소활성의 증대는 대부분 전환수(turnover number)의 증대에 의한 것으로 나타났으며, 가용성 녹말 보다 곡류 녹말에 대한 전환수의 증대가 크게 나타났다. 염소이온은 활성의 증대뿐만 아니라 고농도의 기질 조건에서 기질에 의한 효소 활성 억제 양상을 심화시키는 것으로 나타났다. 결론적으로 HPA II의 특징은 HPA I과 거의 유사한 경향을 나타내었으며, 염소이온 첨가여부에 따른 HPA II의 가수분해활성 결과를 바탕으로 향 후 HPA에 대한 곡류 녹말 가수분해 활성 억제제 개발을 위한 연구를 추진할 계획이다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
• /
• pp.751-754
• /
• 1999

Corrosion inhibitors are widely used to protect chloride-induced corrosion of reinforcement in concrete. However, the number of researches on the corrosion of reinforcement, when corrosion inhibitor is used, is not enough for actual application in the field. In addition, on corrosion of reinforcement a quantitative standard about corrosion inhibitor does not exist and the data about its influencing concrete are relatively rare. In this study, the effectiveness of rebar corrosion protection, setting time, compressive strength, chloride ion's penetration, and diffusion test were performed using with three different kinds of corrosion inhibitors.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
• /
• pp.1233-1237
• /
• 2000

In this study, we measured and assay the analysis of chloride ion in cement hydration by the standard method of JCI and understand the mutual relation between added contents and result. The purpose of this research is to provide fundamental information for the deterioration of the reinforcing concrete on account of steel of reinforced steel to repress.