• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1129-1134
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• 2001

In the point of the Eco-concrete(Environmentally Friendly Concrete), it is very important to reduce the pH of high porous concrete by the pH to be able to grow plants, because the pH of concrete is l1~13. But the method of measuring the pH of high porous concrete is not well-defined, yet. Therefore, first, this paper report the method of measuring the pH of high porous concrete. Secondly this paper reports the pH reduction of high porous concrete to grow plants.

• Journal of Oral Medicine and Pain
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• 제39권4호
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• pp.127-132
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• 2014

Purpose: Many substances in saliva or oral health care products interact with each other. The aim of this study was to investigate interactions between hyaluronic acid (HA), lysozyme, peroxidase, and glucose oxidase (GO) in enzymatic activities at low pH levels. Methods: HA (0.5 mg/mL), hen egg-white lysozyme (HEWL, $30{\mu}g/mL$), bovine lactoperoxidase (bLPO, $25{\mu}g/mL$), and GO ($50{\mu}g/mL$) were used. The influences of HA, bLPO, and GO on HEWL activity were determined by measuring the turbidity of a Micrococcus lysodeikticus suspension. The influences of HA and HEWL on bLPO activity were determined by the NbsSCN assay, measuring the rate of oxidation of 5-thio-2-nitrobenzoic acid (Nbs) to 5,5'-dithiobis(2-nitrobenzoic acid) $(Nbs)_2$. The influences of HA and HEWL on GO activity were determined by measuring oxidized o-dianisidine production. All experiments were performed at pH 4, 5, and 6. Results: HA and GO did not affect the enzymatic activity of HEWL at pH 4, 5, and 6. bLPO enhanced the enzymatic activity of HEWL at pH 5 (p<0.05) and pH 6 (p<0.05) significantly. The enzymatic activity of bLPO was not affected by HA and HEWL at pH 4, 5, and 6. HA and HEWL did not affect the enzymatic activity of the GO at pH 4, 5, and 6. Conclusions: Peroxidase enhances lysozyme activity at low pH, otherwise there were no significant interactions in enzymatic activities between HA, lysozyme, peroxidase, and GO at low pH levels.

• 한국식품영양학회지
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• 제11권6호
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• pp.657-661
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• 1998

Green tea powder (3%, 6%, 9%) was added to green tea bread and physicochemical characteristics of green tea bread were investigated. As the result of measuring the pH of the dough, the pH of control was 5.6 and the pH of the investigated. As the result of measuring the pH of the dough, the pH of control was 5.6 and the pH of the samples were 5.34, 5.29 and 5.26 each. As it is seen above, there is no big difference in the pH of the three different dough. Therefore, it could be that the pH of the dough doesn't really affect on the volume of the bread. As the amount of the green powder was changed, the weight of bread, volume of bread, baking loss rate, the color of the surface, the tenderness of the crumb were affected. The 9% of the green powder gave the most distinguishable affect on these factors. As the amount of thee green tea green tea powder caused the change of color. The result of the sensory evaluation showed that the addition of the green tea powder affected significantly on the quality of the bread. Considering the result of the test, 3% of the green tea powder bread is the best for the production of the bread.

• 한국환경보건학회지
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• 제19권4호
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• pp.44-50
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• 1993

This paper has concentrated on estimating the improvement of sludge dewaterability for the application of ozone in sewage treatment plant sludge. The experiment for the study was conducted by batch reactor, contacting ozone (5.0 g O$_3$/hr/l) to waste sludge and measured the Specific Resistance to Filtrate (SRF) varying pH, pressure and reaction time of ozone. And then checked the dissolved solids concentration of flitrate. The results of experiment were as follows: 1. When the total solids concentration of excess sludge was 9, 000 mg/l, the optimum injection rate of ozone was 5.0 g O$_3$/hr/l, and then pressure was 50 cm Hg for the measuring SRF. 2. In the range of pH 3~5, the effect of ozone injection was excellent, but it was unsatisfactory in the range of pH 9~11. Therefore, the ozone injection by acidifying pH level was effective in improving the dewaterability of sludge. 3. It was estimated that the dissolved solids concentration of flitrate was increased in proportion to the injection rate of ozone.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.1032-1036
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• 2006

In this study, we implement the potable blood gas analyzer measuring pH, $pCO_2\;and\;pO_2$ of the arterial blood. The implemented system by this study is divided into hardware and software part and also the hardware portion is parted by mechanism and electronic circuit mit. The system program is composed of operating, washing, correcting and measuring program. And to correct the system, two-point calibration method is used, one-point calibration method is also added for more accuracy, and system program is coded. For verifying the implemented system, We examine to response property of each electrode. And evaluate accuracy of the system using standard reagent and was construed as statistical.

• 콘크리트학회논문집
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• 제15권4호
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• pp.529-540
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• 2003

최근 콘크리트 내구성설계에 관한 연구가 활발히 진행되고 있으며, 사용수명 예측이 핵심인 내구성 평가모델 개발이 그 좋은 예이다. 본 연구에서는 콘크리트 구조물의 잔존수명예측 모델을 개발하여 적정시기의 유지보수를 통한 경제적 구조물 사용을 목적으로 하였다. 육지 콘크리트 구조물인 저수지의 콘크리트 구조물 부분을 대상으로 전국 70개 지구를 선정하고, TG/DTA 법과 페놀프탈레인 지시약법으로 중성화를, pH메타법으로 pH 값을 측정하여 탄산칼슘함량 대비 사용연수, pH값, 콘크리트 피복 두께의 관계함수를 각각 유도한 후 가능한 최소의 자료측정으로 잔존수명을 예측할 수 있는 모델을 개발하였다. 개발된 잔존수명예측 모델은 탄산가스등의 고정변수에 의한 실내촉진실험 자료기반 모델과 달리 동결융해작용, 중성화, 철근 부식 등 복합적인 열화작용이 동시에 일어나는 현장의 환경적 영향을 받은 구조물에서 측정한 자료를 기반으로 개발되었다. 이러한 점에서 그 신뢰성을 높게 평가 받을 수 있을 것이며, 시설물 유지관리자에게 적정 보수보강 시점을 제공하여 경제적인 구조물 사용에 도움을 줄 수 있을 것으로 판단된다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권3호
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• pp.159-167
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• 1999

This study performed experiments for measuring corrosion potential and current density variations in the polarzation curves of polyvinylchloride. The results were examined to identify particular influences affectingthe corrosion potential such as temperature, pH, enzyme, and salt. The lines representing active anodic dissolution were only slightly shifted in the potential direction by temperature, pH, enzyme and salt. The Tafel slope for the anodic dissolution was determined using the polarization effect with varying conditions. The slope of the polarization curves describing the active-to-passive transition region was noticeably shifted in the potential direction. In addition, using the variation in conditions, the best temperature and pH were determined for the corrosion rate, and resistance of corrosion. The second anodic current density peak and maximum passive current density were designated as degraded(IP/I0). The value of IP/I0 was used in measuring the extent of the degradation of the polyvinychloride. The potentiodynamic parameters of the corrosion were obtained using a Tafel plot.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.33.1-33.1
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• 2018

pH is expressed mathematically as $pH=-{\log}[H^+]$, is a measure of the hydrogen ion concentration, [$H^+$] to specify the acidity or basicity of an aqueous solution. The pH scale usually ranges from 0 to 14. Every aqueous solution can be measured to determine its pH value. The pH values below 7.0 express the acidity, above 7.0 are alkalinity and pH 7.0 is a neutral solution. The solution pH can be determined by indicator or by measurement using pH sensor, which measuring the voltage generated between a glass electrode and a reference electrode according to the Nernst Equation. The pH value of solutions depends on the temperature and the activity of contained ions. In nickel electroless plating process, the controlled pH value in some limited ranges are extremely important to achieve optimal deposition rate, phosphorus content as well as solution stability. Basically, nickel electroless plating solution contains of $Ni^{2+}ions$, reducing agent, buffer and complexing agents. The plating processes are normally carried out at $82-92^{\circ}C$. However, the change of its pH values with temperatures does not follow any rule. Thus, the purpose of study is to understand the relationship between pH and temperature of some based solutions and electroless nickel plating solutions. The change of pH with changing temperatures is explained by view of the thermal dynamic and the practical measurements.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.82-87
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• 1997

Ion-Sensitive Field-Effect Transistors(ISFETs) with LPCVD silicon nitride as a sensitive gate were fabricated on the basis of a CMOS process. The silicon nitride was deposited directly on a poly silicon gate-electrode. Using a specially designed measuring cell, the hydrogen ions sensing properties of the ISFET in liquid could be investigated without any bonding or encapsulation. At first, th sensitivity was estimated by simualtions according to the site-binding theory and the experimental results were analysed and compared with simulated results. The measured dta were in good agreement with the simulated results. The silicon nitride based ISFET has good linearity evaluated from correlation factor ($\geq$0.9998) and a mean pH-sensitivity of 56.8mV/pH. The maximum hysteresis width between forward(pH=3\longrightarrowpH=11)- and backward(pH=11\longrightarrowpH=3) titration was 16.7mV at pH=6.54.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.1-9
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• 2024

As part of monitoring technology aimed at verifying the stability of CO₂ geologic storage and mitigating concerns about leakage, a method for measuring the pH and alkalinity of high-pressure fluid samples was established to obtain practical technology. pH measurement for high-pressure samples utilized a high-pressure pH electrode, and alkalinity was measured using the Gran titration method for samples collected with a piston cylinder sampler (PCS). Experimental samples, referencing CO₂-rich water and CO₂ geologic storage studies, were prepared in the laboratory. The PCS controls the piston, preventing CO₂ degassing and maintaining fluid pressure, allowing mixing with KOH to fix dissolved CO₂. Results showed a 6.1% average error in high-pressure pH measurement. PCS use for sample collection maintained pressure, preventing CO₂ degassing. However, PCS-collected sample alkalinity measurements had larger errors than non-PCS measurements, limiting PCS practicality in monitoring field settings. Nevertheless, PCS could find utility in preprocessing for carbon isotope analysis and other applications. This research not only contributes to the field of CCS monitoring but also suggests potential applications in studies related to natural analogs of CCS, CO₂-rock interaction experiments, core flooding experiments, and beyond.