• 한국자기공명학회논문지
• /
• 제11권2호
• /
• pp.115-121
• /
• 2007

A new quantitative analysis of chloride by the HERETIC NMR method which does not need internal or external references was described. The results showed that the use of HERETIC peak corresponding $500\;{\mu}g/mL$ of chloride calibration showed less than 4 % standard deviations from 50 to $5000\;{\mu}g/mL$ range of chloride concentrations.

• Bulletin of the Korean Chemical Society
• /
• 제27권7호
• /
• pp.972-973
• /
• 2006

• Journal of Preventive Medicine and Public Health
• /
• 제17권1호
• /
• pp.245-250
• /
• 1984

Reciprocal exchanges of DNA in sister chromatids (SCEs) are induced by various carcinogens and mutagens, although the quantitative relationship between the number of mutations and SCEs induced varies among chemicals. Nevertheless, the analysis of SCEs production by various agents often proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity. Mercury, even if which has no evidences for mutagenicity and carcinogenicity, is reported to exert some cytotoxic effects, such as chromosomal aberrations or bad influences to ovulation and reproduction in experimental animals, etc.. In this study, tests for sister chromatid exchanges have been carried out on normal human lymphocytes in whole blood culture to add mercury chloride ($HgCl_2$) or methylmercury chloride ($CH_3\;HgCl$) for 72 hr. The results indicate the dose-dependent relationship between the frequencies of SCEs and the concentrations of $HgCl_2,\;CH_{3}HgCl$ and 5-bromo-2'-deoxyuridine (BrdU). Lymphocyte proliferation has depressed in the higher concentration of mercury.

• 콘크리트학회논문집
• /
• 제12권1호
• /
• pp.33-44
• /
• 2000

Since the mechanism of chloride diffusion and its ratio in concrete depend on structural conditions and concrete as a micro-structure, if these are analyzed quantitatively, the long-term ageing of structures can be predicted. Although, a quantitative analysis of concrete micro-structure, in which the results are affected by various parameters, is very difficult, this can be done indirectly by the durability test of concrete. In this study, the compressive strength, void ratio and air permeability of concrete. In this study, the compressive strength, void ratio and air permeability of concrete are chosen as the parameters in concrete durability test, and these effects on test results are analysed according to changes of mixing properties. The relationships between parameters and chloride diffusion velocity is used for prediction models of chloride diffusion. The developed prediction models for the chloride diffusion according to mixing and physical properties, can be used to estimate the service life and corrosion initiation of reinforcing bars in marine structures.

• 대한화학회지
• /
• 제9권3호
• /
• pp.148-151
• /
• 1965

Benzyl chloride 및 bromide와 chloride 및 bromide ion 간의 반응을 90% ethanol 용액에서반응속도론적으로 연구하였다. 반 정량적인 결과의 해석은 bond-formation 이 bond-breaking보다 더 중요하고 또 결합형성 과정에서는 형성으로 얻은 energy보다는 nucleophile의 electron affinity의 증가로 인한 차이가 더 중요함을 보여주고 있다.

• 분석과학
• /
• 제25권6호
• /
• pp.395-401
• /
• 2012

본 연구에서는 PVC 제품에 잔류하는 염화비닐 단량체(VCM)에 대한 정량분석방법을 제시하였다. 용출용매의 경우, 에탄올, THF, 아세톤에서 유사한 추출효율을 나타내었으나, 노말헥산을 이용한 경우에는 상대적으로 낮은 추출효율을 보였다. 분쇄 PVC 시료에 VCM 표준용액을 주입한 분석시료에 대한 VCM 함유량 측정 결과, GC/MS를 이용한 직접주입법이나 헤드스페이스법 모두 양호한 결과를 나타내었다. PVC 제품의 중간물질인 스펀지에서의 VCM 분석과 관련하여 5 개 시험전문기관의 시험소간 비교시험 결과, 각 시험소간 결과 편차가 크지 않은 것으로 나타나 본 연구에서 제시한 전처리 및 분석방법에 대한 플라스틱 제품내의 VCM 정량방법이 유효한 것으로 판단되었다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
• /
• pp.263-268
• /
• 1997

One of the principal causes of the deterioation of coastal concrete structures is the corrosion of reinforcing steel induced by the attack of chloride ions. An experimental study was performed to investigate the distribution of concentration of chloride ions in a coastal concrete structure and to measure the half-cell potential of embedded steel by using the copper-copper sulfate reference electrode. Quantitative analysis showed that the concentration of chloride ion in the aqueous phase near the surface of embedded steel exceeded a threshold value for corrosion, 0.05% by weight in concrete. The absolute value of half-cell potential at some members of embedded steel was measured to be higher than 350mV, indicating that the probability of corrosion is more than 90%. The prediction on corrosion based on the experimental measurements was confirmed by the observation of corrosion on the surface of steel bars in the concrete core taken out of the concrete structure.

• 한국대기환경학회지
• /
• 제15권3호
• /
• pp.327-333
• /
• 1999

Determination of chloride ion in concentrated NaOH solution by capillary electrophoresis has been studied. The analysis was performed by indirect UV absorption detection using chromate buffer at 254nm. The matrix effect of the sample has been observed so that the sensitivity in strong NaOH solutaion has decreased up to 10% of that in distilled water. The pH effect of the sample on the sensitivity of CE peaks has been investigated. The method for increasing the sensitivity have been investigated and the optimum pH and concentration of the buffer were 7.5 and 10mM, respectively. A cationic surfactant cetyltrimethylammonium bromide(CTAB), was added to a buffer solution in order to reverse the electroosmotic flow(EOF) in the capillary. This results in a short analysis time and better peak shapes. Using this optimum condition, the determination of chloride ion in real environmental sample has been performed, which is captured in strong NaOH absorbent prepared for absorbing gas from chimney. The standard addition method has been applied for the quantitative analysis, and it was obtained the good reproducibility.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.207-208
• /
• 2010

The building that supply tidal and splash zone was constructed near Seamangeum Gate Bridge. The specimens that will be tested for maintenance of gate bridge were exposed on the tidal and splash zone, totally about 650. The characteristics of strength, salt penetration profile, field application of surface repair material and section recover material will be acquired by periodical test. The program was developed to obtain optimal maintenance strategy of gate bridge as a marine concrete structure and to deposit experimental data, lab. test result, field test result, on its D/B. On this paper, the comparison of concrete and recover material in the salt penetration characteristics was expressed. The quantitative analysis of salt contents in concrete surface was most important so the improvement for the machine of gathering power of concrete and the apparatus of measuring chloride contents was proceeded at this time. The two conclusions were summarized like as - The resistance of chloride attack of concrete was appeared 2.5 times bigger than that of recover material - The resistance of chloride attack of polymer series was appeared more higher than that of others.

• Computers and Concrete
• /
• 제8권2호
• /
• pp.177-192
• /
• 2011

This research paper aims at computer based modeling of carbonation induced corrosion under extreme conditions and its experimental verification by incorporating enhanced electrochemical and mass balance equations based on thermo-hygro physics with strong coupling of mass transport and equilibrium in micro-pore structure of carbonated concrete for which the previous research data is limited. In this paper the carbonation induced electrochemical corrosion model is developed and coupled with carbon dioxide transport computational model by the use of a concrete durability computer based model DuCOM developed by our research group at concrete laboratory in the University of Tokyo and its reliability is checked in the light of experiment results of carbonation induced corrosion mass loss obtained in this research. The comparison of model analysis and experiment results shows a fair agreement. The carbonation induced corrosion model computation reasonably predicts the quantitative behavior of corrosion rate for normal air dry relative humidity conditions. The computational model developed also shows fair qualitative corrosion rate simulation and analysis for various pH levels and coupled environmental actions of chloride and carbonation. Detailed verification of the model for the quantitative carbonation induced corrosion rate computation under varying relative conditions, different pH levels and combined effects of carbonation and chloride attack remain as scope for future research.