• Title/Summary/Keyword: pH measurement

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Analysis of naturally Dyed Textile Fabrics by using Aronia Extract (아로니아 추출물에 의한 직물의 천연염색과 염액의 Spectrum 분석)

  • Won, Ah Young;Kim, Jongjun
    • Journal of Fashion Business
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    • v.22 no.1
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    • pp.124-134
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    • 2018
  • This study examined the dyeing characteristics and spectrum of cotton and silk by using dyeing solution extracted from aronia. The value $L^{\ast}$ which indicates the brightness of cotton regardless of mordant increases with increasing pH from pH 3.5 to pH 10.5. The color difference value(${\Delta}E$) of the cotton was generally high in pH 3.5 regardless of mordant existence. The silk showed the highest ${\Delta}E$ value in pH 3.5 dye solution as cotton did. On the other hand, the silk with mordant dyed showed the highest ${\Delta}E$ value in pH 7. Silk fabrics dyed with Aronia solution turns out red in pH 3.5, blue in pH 7 and yellow in pH 10.5. This is because of the amino acid, one of the silk ingredients, combines with a part of anthocyanin to show blue. As the result of the spectrum measurement, the maximum absorption wavelength of Aronia solution was increased in the order of pH 10.5, pH 3.5 and pH 7, regardless of extraction temperature and mordant. The measurement results of color fastness to washing and color fastness to light are generally low. Therefore, there is a need for further study to improve color fatness in the future.

On-line Measurement of Buffer Capacity of a Fermentation medium and Estimation of Organic Aicd Production (발효배지의 완충용량의 온라인 측정 및 유기산 생산 추정)

  • Hur, Won;Jung, Yoon-Keun
    • KSBB Journal
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    • v.13 no.4
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    • pp.461-467
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    • 1998
  • A fermentation system was supplemented with a device for the measurement of the durations of alkali pump feeding for automatic pH control and an A/D convertor for precise monitoring of pH value by computer. A software program was developed to measure buffer capacities from the pH signal and the pH control signal during fermentation. By measuring the buffer capacity on-line, levels of acetic acid were estimated by a software sensor using pH signal in a fermentation process of E.coli growing in a minimal medium. The measured values of acetic acid showed correlation to those of estimated by the software sensor. Lacitic acid production was also successfully estimated by the values of buffer capacities measured on-line.

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A Study on the Electrometric Measurement of the pH of Acid Rain (산성비의 pH 측정에 대한 연구)

  • Lee, Hwa-Shim;Kim, Myung-Soo
    • Journal of the Korean Chemical Society
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    • v.44 no.1
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    • pp.10-16
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    • 2000
  • In general, acid rain is unbuffered solution with low ionic strength and high resistance. Therefore during the pH measurement of acid rain, error can be occurred due to the liquid junction potential difference between the sample and the standard solution. Actually the average conductivity of rain in Taeduk Science Town during 1998 is 12.8 ${\mu}S/cm$, while that of pH standmd solutions is about 5,980 ${\mu}S/cm$. There is a large difference in ionic strength. To compensate the bias due to residual liquid junction potentials, a quality control standard(QCS) of dilute sulfuric acid, which has the conductivity and pH values simikw to rain, was prepared. The pH of QCS solution was determined using the hydrogen electrode system without liquid junction, and compensation has been made for the bias terms by performing the pH measurements with glass electrode. On the basis of this compensation method, the pH vaiues of rain in Taeduk Science Town during 1998 were measured.

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pH Sensor Application of Printed Indium-Tin-Oxide Nanoparticle Films (Indium-Tin-Oxide 나노입자 인쇄박막의 pH sensor 응용에 대한 연구)

  • Lee, Changhan;Noh, Jaeha;An, Sangsu;Lee, Sangtae;Seo, Dongmin;Lee, Moonjin;Chang, Jiho
    • Journal of Sensor Science and Technology
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    • v.31 no.2
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    • pp.85-89
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    • 2022
  • We investigated a pH sensor using an Indium tin oxide (ITO) nanoparticle (NP) film printed on a flexible substrate. First, the printing precision and mechanical stability of the ITO-printed film were investigated. In particular, the factors that influence the crystallinity of ITO films were studied using X-ray diffraction pattern analysis. The response of the ITO pH sensor was calibrated using a series of standard pH solutions (pH 3-11). The pH values of various specimens were measured using an ITO pH sensor, and the results were compared with those of various pH measurement methods. As a result of the experiment, the maximum error was approximately ± 0.04 pH (0.4 %) at pH 9, which indicated that the ITO pH sensor is highly suitable for pH measurement. Finally, we used the ITO pH sensor to the measure of general specimens such as solvents and beverages and compared the results in comparison with those obtained from several conventional methods.

Study on Rate-Limiting Factors with a Heavy Loaded Biofilter

  • Son, Hyun-Keun
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.E2
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    • pp.74-81
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    • 2007
  • Feasibility test for a biofilter was performed to treat VOCs. The applied loading rate to the biofilter was calculated between 60 to $3,700\;kg\;COD/m^3$. Trimethyl-pentene and trimethyl-hexene were the two most dominant compounds and they occupy about 85 percent. During the acclimation period, it is desirable for a biofilter to receive relatively lower VOCs concentration and flow rate, until it can adjust to new substrate and operational environment. Temperature at various points inside the biofilter reactor was observed with more than 23 temperature sensors. With steam heating, temperatures of the top sections of the media were greater than those of bottom sections. Without steam heating, intermediate stages generally had higher temperature measurement than those of bottom and top stages. Because the pH values for different biofilter materials vary significantly, measurement of the pH for the mixture of different combinations of biofilter materials is necessary. Based on the types and brands of media, the measured pH ranged from 5.38 to 9.10. The range of measured pH of different mixtures with perlite, compost, saw dust, peat moss, limestone, vermiculite was 7.05 to 8.62.

A Study on the Body Composition, Physical Activity Level, Basal Metabolic Rate, and Daily Energy Expenditure of Elderly in Busan (부산지역 일부 노인들의 신체조성, 신체활동수준, 기초대사량 및 에너지소비량실태에 관한 연구)

  • Lim, Hwa-Jae
    • Korean Journal of Community Nutrition
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    • v.21 no.2
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    • pp.178-189
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    • 2016
  • Objectives: The objectives of the study were to assess body composition, physical activity level (PAL), basal metabolic rate (BMR), and daily energy expenditure (DEE) and to examine associations between PAL and body composition, BMR, and DEE of elderly in Busan. Methods: A cross-sectional study was conducted among 226 elderly aged 65-93 years. Body composition was measured by Inbody 720. PAL was calculated by daily activity diary. BMR was calculated by Harris-Benedict (H-B) formula, Dietary Reference Intakes (DRI) formula, and Inbody 720 measurement. DEE was calculated by H-B formula, DRI formula, Inbody 720 measurement, and estimated energy requirements (EER) formula. Results: The mean fat free mass (FFM) in elderly men was significantly higher than that in elderly women (p<0.001). The mean percent body fat and fat mass (FM) in elderly women were significantly greater than those in elderly men (p<0.001, p<0.001). The mean PAL in elderly men (1.59) was significantly higher than that in elderly women (1.53) (p<0.001). The mean DEEs calculated by 3 methods except for H-B formula in elderly men were higher than EER for elderly men (2000kcal). The mean DEEs calculated by 4 different methods in elderly women were higher than EER for elderly women (1600kcal). Age showed significantly negative correlations with height (p<0.001, p<0.001), FFM (p<0.001, p<0.001), BMRs calculated by H-B formula (p<0.001, p<0.001), DRI formula (p<0.001, p<0.001) and Inbody 720 measurement (p<0.05 p<0.01) and DEEs calculated by H-B formula (p<0.001, p<0.001), DRI formula (p<0.001, p<0.001), Inbody 720 measurement (p<0.05, p<0.05), and EER formula (p<0.001, p<0.001) in elderly men and elderly women. PAL showed significantly positive correlations with FFM (p<0.05), BMR by Inbody 720 measurement (p<0.05) in elderly men and negative correlations with FM (p<0.05) in elderly women. Conclusions: Based on the results, PAL was associated with greater FFM in elderly men and lesser FM in elderly women. Therefore, nutritional education to increase physical activity for health promotion in late life is needed in the elderly.

Characteristics and Fabrication of Dissolved Oxygen and pH Measurement System based on the Optical Sensor for Analysis of Cell Metabolic Functions (세포대사 기능 분석을 위한 광학센서 기반 용존산소와 pH 측정 시스템의 제작 및 특성 분석)

  • Jang, Jiwoon;Hwang, Insook;Lee, Jongmok;Lee, Sunmin;Kang, Sora;Kim Pak, Youngmi;Kim, Nayoung
    • Journal of Sensor Science and Technology
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    • v.25 no.1
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    • pp.51-56
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    • 2016
  • This study evaluates the performance of an optical sensor and measurement system (CMA-24) which can analyze the fluctuation of dissolved oxygen and pH simultaneously. In the optical sensor system, the fluorescent materials, Rudpp and HPTS which are sensitive to dissolved oxygen and pH, respectively, are coated on the bottom of a 24-well -plate by the sol-gel technology. The detection times of the emission light of the oxygen sensor were $4,186{\pm}13.90{\mu}s$ and $4,452{\pm}36.68{\mu}s$ for the dissolved oxygen of 17% $O_2$ and 7.6% $O_2$, respectively. On the other hand, the detection times of the pH sensor were $6,699.43{\pm}14.64{\mu}s$, $6,722.24{\pm}6.21{\mu}s$, and $6,748.52{\pm}2.63{\mu}s$ using pH 6, 7, and 8, respectively. When we determined cellular respiration levels of C2C12 myocytes with CMA-24, $O_2$/pH measurement system, the ratio of the uncoupled to coupled OCR (oxygen consumption rate) was 1.41. The results mean that this CMA-24 system shows almost the same sensitiveness as the commercial system.

Development of Micro Wired pH Electrode for Real-Time Monitoring for Gastroesophageal Reflux (위식도 역류 실시간 모니터링 마이크로 와이어 pH 전극 개발)

  • Kim, Eung-Bo;Lee, Kyu-Jin;So, Sang-Kyun;Joung, Yeun-Ho;Park, Jung Ho;Kim, Nam Hee
    • Journal of Biomedical Engineering Research
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    • v.38 no.6
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    • pp.277-284
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    • 2017
  • This paper presents an implantable pH measurement electrode for wireless gastroesophageal reflux measurement. Usually, gastroesophageal reflux is diagnosed by a catheter-type wire connection between the esophagus and the diagnostic device which brings many side effects such as restriction of daily living, pain, and discomfort in the nasal cavity and pharynx of patients. In order to solve these issues, researchers have been studied a wireless measurement method and a micro-sized pH electrode for human body insertion is necessary. Commercial glass packaged pH meter is formed by a sensing and a reference electrodes in a KCl solution. However, if the glass meter is inserted into the human body, there are risks of leakage of the solution, breakage of the glass package, injury of the body elements. Therefore, the solution should be solidified on the micro-sized noble metal wire which has a characteristic of biocompatible. After solidified wire fabrication, the designed meter was tested for feasibility of measurement and the result was well agreed with pH values of commercial pH meter. Potentials in pH 1 to 12 solution was measured to obtain the sensitivity of the sensor with linearity. And we have designed a simulation of gastroesophageal reflux with symptom frequency, interval, and duration time in pH 2 solution. The proposed sensor has capable to get the same potential for 24 measurements in 3 days, and it has sensed same pH values of 2 for one hour with every 10 minutes. Furthermore, the sensor was survived for 48 hours with reasonable potentials in the acid solution.

Uncertainty evaluation in electrochemical noise resistance measurement (전기화학적 노이즈 저항 측정에서의 불확도 평가)

  • Kim, Jong Jip;Kang, Su Yeon
    • Corrosion Science and Technology
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    • v.12 no.5
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    • pp.220-226
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    • 2013
  • The uncertainty in statistical noise resistance measurement was evaluated for a type 316 stainless steel in NaCl solutions at room temperature. Sensitivity coefficients were determined for measurands or variables such as NaCl concentration, pH, solution temperature, surface roughness, inert gas flow rate and bias potential amplitude. The coefficients were larger for the variables such as NaCl concentration, pH, inert gas flow rate and solution temperature, and they were the major factors increasing the combined standard uncertainty of noise resistance. However, the contribution to the uncertainty in noise resistance measurement from the above variables was remarkably low compared to that from repeated measurements of noise resistance, and thus, it is difficult to lower the uncertainty in noise resistance measurement significantly by lowering the uncertainties related with NaCl concentration, pH, inert gas flow rate and solution temperature. In addition, the uncertainty in noise resistance measurement was high amounting to 17.3 % of the mean, indicating that the reliability in measurement of noise resistance is low.

Investigation of the mechanism of Ni-P alloy deposition using by in-situ surface pH measurement during electrodeposition (음극표면 pH 측정에 의한 Ni-P합금의 전착기구 고찰)

  • 이규환;장도연;김동수;이상열;권식철;강성군
    • Journal of the Korean institute of surface engineering
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    • v.35 no.2
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    • pp.93-100
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    • 2002
  • To better understand the codeposition mechanism of phosphorous, surface pH and potential of cathode were measured during electrodeposition of Ni-P alloys. The pH of cathode surface was measured using a flat-bottom glass pH electrode and a 500 mesh gold gauze as cathode. The cathode surface pH was increased with increasing the current density and always higher than the pH in the bulk solution. As a result of overplotting the surface pH and cathode potential on the Pourbaix diagram, it was found that cathode surface shift to the domain of predominant of $H_2$$PO3$-or $H_2$$PO_2$-. Additionally, new deposition mechanism was suggested that $H_2$ $PO_2$- and $H_2$$PO_3$- play important roles in the deposition reaction of Ni-P alloys.