• 생명과학회지
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• 제11권2호
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• pp.153-158
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• 2001

To investigate the effects of soil acidification on growth of Impatiens balsamina L. plants were transplanted to acidified soils with H$_2$SO$_4$ solution. The concentrations of soluble Ca, Mg, K, Al and Mn in the acidified soils increased with increment of H$^{+}$ addition to the soil. In both species, the plant height and root length were inhibited by soil acidification, showing much severer inhibition in Impatiens balsamina L. than in Tagetes patula L., As the soil pH decreases, the growth of underground parts decreased greatly than that of above ground parts in both species. Total dry weight decreased with increased Al concentration as well as lowered soil pH in both plants. There was a strong positive correlation between relative total dry weight and molar (Ca+Mg+K) / Al ratio of the soil. The results suggest that molar(Ca+Mg+K)/ Al ratio of the soil may be useful indicator for assessing the critical load of acid deposition in herb species.s.

• 약학회지
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• 제19권1호
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• pp.30-35
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• 1975

pKi values and sensitivity of acid-base indicators in the mixed solvent systems of water-alcohols and water-acetone at differential pH and in concentration media were determined by spectrophotometric method. When the concentration of the organic solvents were increased, the pKi values of sulfophthalein indicators, thymol blue and bromcresol purple, became larger whereas those of an axo indicator, methyl yellow, became smaller nad the pH values of the equivalent points of acids became smaller and the pH values of the equivalent points of acids became higher than those in the aqueous solution. potassium bicarbonate, a standard compound used in the organic solvent systems without a prerequisite procedure of expelling carbon dioxide by boiling.

• Journal of Yeungnam Medical Science
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• 제8권1호
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• pp.98-106
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• 1991

본 연구에서 정상적인 분만 산모의 제대동맥혈의 pH와 신생아의 Apgar score및 질병의 이환유무를 관찰하였고, 또한 분만시 제대결찰 시간의 경과가 태아의 혈중가스농도의 변화 및 신생아의 건강에 미치는가를 분석해 보였다. 본 연구의 결과, 불량한 Apgar score를 보인 많은 신생아에서 산성증을 보인 경우가 적음으로 제대동맥혈의 pH와 Apgar score의 상관관계는 미약한 것으로 생각되며, 제대동맥혈의 분석이 Apgar score보다는 태아의 건강상태의 파악에는 좀더 도움이 되리라 생각한다. 그러나 제대동맥혈의 pH와 Apgar score등, 단독적인 지표만으로 초기 신생아의 건강 상태 및 평가 및 관리에 임상적 의의를 부여하기는 어려웠다. 또한 분만시 제대혈관의 결찰의 시간의 결정은 대부분의 산과의들의 토론의 대상처럼 어느 시간이 태아의 건강에 도움이 되는가는 결정할 수가 없었다. 그러나 신생아의 건강 상태를 파악하기 위해서 제대동맥혈을 채취할 경우는, 조기결찰의 특별한 적응증이 없는 한 분만직후에는 제대결찰을 시행하지 않고 즉시 제대동맥혈을 채취하는 것이 바람직하다고 할 수 있다. 이는 분만직후의 제대동맥혈이 분만진통이나 분만자체가 태아에 미치는 영향을 가장 잘 반영하기 때문으로 생각되어지기 때문이다. 태아의 건강의 지표로서 Apgar score, 제대혈관내의 pH와 가스농도의 분석이 그 정확도와 감수성을 더하기 위해서는 좀 더 많은 대상군과 좀 더 다양한 대조군으로 연구를 하여야 할 것 으로 사료된다.

• 한국물환경학회지
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• 제18권4호
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• pp.401-409
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• 2002

In this study, to evaluate the applicability of ORP and pH as process control parameters for an intermittent aeration process, a 200L/d bench-scale plant was installed and operated for 90 days. It was fed with synthetic wastewater which contained $COD_{Cr}$ : 400mg/L, TN : 40mg/L and TP : 7mg/L. ORP & pH were measured on-line and compared with the variation of nutrient concentrations. As the results, both of the ORP and pH were able to monitor successfully nitrification and denitrification. Bending-points on the ORP curve and peak points on the pH curve corresponded to the termination of nitrification and denitrification. For P uptake and release, pH was the best indicator for performance evaluation. The aerobic pH apex was appeared when P uptake was accomplished and there was a relationship between the P release and pH variation. But the pH curve needed filtering because there were many noises on it. In this study, the shape of the ORP & pH curves were varied as the operating conditions such as aeration rates and organic loads were changed. It allowed the operating states of biological systems to be effectively evaluated. If it is properly managed to show the bending points and peak points clearly, the on-line monitoring of ORP & pH will be a reliable and effective technique for process control of intermittent aeration processes.

• 한국토양비료학회지
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• 제37권6호
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• pp.378-382
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• 2004

Soil pH is an important indicator for soil reactions and crop growth. pH buffer capacity and lime requirements are necessary to comprehend and manage soils well. The characteristics related with soil pH were analyzed and 5 field trials were conducted to elucidate pH buffer capacity of soil and lime requirements and liming factor for Korean acid soils. Soil minerals were analyzed for the soil of 2 years after treating $CaCO_3$ using X-ray diffraction. The amount of neutralized $H^+$ was regarded as the exchangeable aluminium overcoming ${\Delta}pH$, because pH buffer capacity of soil depended on exchangeable aluminium. Lime requirement was somewhat similar to the KCl exchangeable aluminium and it was also affected by the exchangeable cation by added lime. X-ray diffraction analyses revealed that an aluminium dissociation from Korean acid soils was equilibrated with kaolin minerals and changed into anorthite ($CaAl_2Si_2O_8$) by neutralizing with $CaCO_3$. Neutralizing process was composed of changing process of $Al^{3+}$ into $H^+$ and $Al(OH)_4{^-}$ ionic species and of neutralizing $H^+$ by, the amount of which was lime requirement. The fact that anorthite dissociates an aluminium ion higher than kaolinite does enabled to consider a liming factor (LF) the content of exchangeable cation and ${\Delta}pH$, $LF=1.5+0.2{\times}{\sum} Cations{\times}{\Delta}pH$.

• 한국수산과학회지
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• 제11권1호
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• pp.5-8
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• 1978

순환여과수조에 있어 수질 오염의 지표로서 대장균군의 수적인 변동을 측정하였다. 세균의 오염은 주로 어류의 먹이와 배설물 그리고 새로 교환되는 사육수의 기오염도에 원인이 있었다. 수조내의 세균량은 수질의 물리화학적인 요인에 의해서 조절되었으며, 이러한 요인들 중에서는 pH가 주된 것이었다. 수온 $20^{\circ}C$에 pH가 $5\~6$ 이하로 낮아질 경우에는 세균의 급격한 번식은 없었다. 수온이 $30^{\circ}C$ 이상 일 때 세균의 성장은 pH에 관계없이 현저하게 감소하였으며, 세균군은 그 이하의 온도에서 활발히 성장하는 것처럼 보였다.

• 한국식품영양학회지
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• 제30권1호
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• pp.9-18
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• 2017

As an indicator of skin health, acidified skin surface pH ranging from 5 to 7 is crucial for maintaining skin barrier. In this study, we evaluated the relationship between skin pH and dietary pattern (DP) as well as nutrient or food intake in 48 healthy middle aged adults. Skin pH was measured in the skin surface of the inner arm, and blood lipid profile was analyzed. Dietary intake data were obtained using 1 day 24 hour recall method, and DP was extracted using factor analysis. Results revealed that skin pH ranged from 5.15 to 6.88 in all subjects. There was no significant difference in skin pH between males and females. When subjects were grouped by tertile of skin pH, the food intake of fruit, and the nutrient intake of omega 6 fatty acid, potassium, vitamin A, vitamin C, ${\beta}$-carotene, and riboflavin in the first tertile group with skin pH ranging from 5.15 to 5.68 were significantly higher than in the third tertile group with skin pH ranging from 6.26 to 6.88. There was no difference in blood lipid profile between the first and the third tertile group. Among 5 DP extracted by factor analysis, DP5 characterized by a high intake of nuts and fruits as well as a low intake of beverages and alcohol was inversely correlated with skin pH after adjusting for gender and age. DP5 was positively correlated with nutrient intake of carbohydrate, fiber, potassium, iron, vitamin A, vitamin C, ${\beta}$-carotene, thiamine, and riboflavin but negatively correlated with sodium after adjusting for gender, age, smoking, and energy intake. Therefore, acidified skin pH could be maintained by these DP and nutrients.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.271-272
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• 2018

• 폴리머
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• 제29권6호
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• pp.593-598
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• 2005

Layer-by-layer(LbL) 자기 조립법에 의한 poly(ethylene-alt-maleic anhydride)(PEMAh)/poly(4-vinyl pyridine)(P4VP) 다층막의 염료 흡착 거동 및 pH 변화에 의한 염료 방출 거동을 Rodamine 6G(R6G)를 지시제로 사용하여 조사하였다. UV-vis 분광 분석을 이용하여 (PEMAh/P4VP)n 다층막의 두께 및 R6G의 흡착 및 방출 거동을 조사하였다. 다층막에 흡착되는 R6G의 흡착량은 필름의 두께 증가에 따라 선형적으로 증가하였다. (PEMAhAh/P4VP)n 다층막의 투과성은 pH 조건에 민감한 거동을 보였으며, 방출액의 pH가 감소할수록 R6G 방출 속도와 방출량은 증가하였다. PEMAh/poly(ethyleneimine)(PEI) capping layer를 (PEMAh/P4VP)n 다층막에 추가로 적층함으로써 흡착된 R6G의 방출 속도를 조절할 수 있었다.

• 센서학회지
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• 제18권5호
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• pp.365-371
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• 2009

In this study, we have fabricated a fiber-optic pH sensor which is composed of a light source, plastic optical fibers and a spectrometer. As an indicator, a phenol red is used, and a pH liquid solution is prepared by mixing of phenol red and various kinds of pH buffer solutions in these experiments. The emitting light from a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a light is changed in the pH liquid solution according to its color change. Therefore, we have measured the intensities and wavelength shifts of the modulated lights, which are changed due to the color variations of phenol red at different pH values, by using of a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of modulated light according to the change of color of phenol red are obtained.