• Title/Summary/Keyword: measuring pH

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Optimal conditions of enzymatic hydrolysis for producing anti-inflammatory peptides from sandfish (Arctoscopus japonicus) hydrolysate (도루묵 가수분해물 유래 항염증 펩타이드 제조를 위한 효소 가수분해 최적 조건)

  • Jang, Hye Lim;Yoon, Kyung Young
    • Korean Journal of Food Science and Technology
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    • v.50 no.2
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    • pp.203-208
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    • 2018
  • In this study, the hydrolysis conditions for the production of anti-inflammatory peptides from meat and roe hydrolysates of sandfish (Arctoscopus japonicus) were determined by measuring the nitric oxide (NO) scavenging enzymatic activity, experimental pH, temperature, enzyme concentration, and hydrolysis time. The optimal conditions determined when using meat hydrolysate were a pH value of 5.0, at a temperature of $30^{\circ}C$, 1% enzyme concentration, and 4 h hydrolysis time. The optimal conditions when using roe hydrolysate were a pH of 5.0, a temperature of $70^{\circ}C$, enzyme concentration of 3%, and hydrolysis time of 3 h. The NO scavenging activities of meat and roe hydrolysate were determined to be 18.94 and 19.81%, respectively. In summary, this study determined the optimum enzymatic hydrolysis conditions for the production of anti-inflammatory peptides from sandfish.

Ion-Pair High Performance Liquid Chromatographic Retention Behavior of Salicylic Acid and Its Derivatives (살리실산 및 그 유도체들의 이온쌍 고성능액체크로마토그래피 머무름 거동)

  • Lee, Kangwoo;Chung, Yongsoon;Oh, Sangkeun
    • Analytical Science and Technology
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    • v.12 no.3
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    • pp.203-208
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    • 1999
  • The ion-pair high performance liquid chromatographic elution behavior of salicylic acid and its derivatives was studied with measuring capacity factor, k', changing the concentration of ion-pairing reagent (tetrabutylammonium chloride, TBACl) in mobile phase. As a result, it was found that k' of the samples increase at pH 7.2 as the TBACl concentration increases. The derivatives of salicylic acid were separated each other at an optimum mobile phase condition which was found from the observation of the retention behavior. The optimum mobile phase condition was methanol solution($MeOH:H_2O_2$ 30:70) containing 20 mM TBACl for the determination of salicylic acid and methanol solution($MeOH:H_2O_2$ 20:80) containing 40 mM TBACl for p-aminosalicylic acid at pH 7.2. The method has been applied for the analysis of the contents of salicylic acid derivatives in an aspirin tablet and a tuberculosis curing agent.

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Equilibrium, Kinetic and Thermodynamic Parameter Studies on Adsorption of Acid Black 1 Using Coconut Shell-Based Granular Activated Carbon (야자각계 입상 활성탄의 Acid Black 1 염료 흡착에 대한 평형, 동역학 및 열역학 파라미터의 연구)

  • Lee, Dong-Chang;Lee, Jong-Jib
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.590-598
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    • 2016
  • In this study, the adsorption behavior from aqueous solution as well as kinetic and thermodynamic parameters of Acid Black 1 were investigated through batch reaction using coconut shell based granular steam activated carbon. The effects of various adsorption parameters such as pH, initial concentration, contact time, temperature were studied. To confirm the effect of pH, pHpzc measurements were analyzed followed by measuring removal efficiencies of Acid Black 1 at the pH range from 3 to 11. Experimental equilibrium adsorption data were fitted using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherm. The conformity of adsorption reaction for pseudo first and second order model were evaluated through kinetic analysis. Values of enthalpy change and activation energy were also investigated through thermodynamic analysis and it was confirmed that the adsorption process was endothermic. The spontaneity of adsorption process was evaluated using the values of entropy and Gibbs free energy changes.

Design and implement of patch type wireless skin temperature measuring system (패치형 무선 피부 온도 측정 시스템의 설계 및 구현)

  • Woo, S.H.;Park, S.Y.;Din, Z. Mohy Ud;Won, C.H.;Lee, J.H.;Park, H.J.;Lee, J.W.;Hong, Y.G.;Suh, J.H.;Youm, Y.G.;Cho, J.H.
    • Journal of Sensor Science and Technology
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    • v.17 no.5
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    • pp.350-360
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    • 2008
  • In every large hospital, nurses must perform simple repetitive tasks such as measuring body temperature. Such tedious work reduces nurses' motivation to provide quality medical care, which is an important element of the medical services provided by a hospital. If a device were available to measure body temperature, nurses could focus on the more important aspects of providing quality medical care to the patients. However, body temperature is generally measured from the throat, anus, tympanum or armpit, where it is difficult to affix a patch type device. In addition, general body temperature measuring points shows moving artifact error; therefore, it is not good point to continually measure the temperature. In this paper, a patch type skin temperature measuring system was developed. To appropriately measure the skin temperature, a thermal transducer was implemented with a thin (0.5 mm) temperature sensor. The system is small and thin ($H6.6{\sim}5.3{\times}L35{\times}W24\;mm$), and weighs only 5 g including a battery, case and circuit; therefore, it is small and light enough to function as a patch type device. Moreover, the system worked for 5 days. To investigate differences between the experimental and conventional thermometer, simple clinical experiments were performed with 17 volunteers, and the result showed some correlation between the implemented system and conventional thermometer (Correlation coefficient = 0.647, P<0.1).

Precise Control of Nutrient Solution and Analysis of Ionic Contribution to EC Reading (양액의 정밀 제어 및 이온의 EC 기여도 분석)

  • Son, Jung-Eek
    • Horticultural Science & Technology
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    • v.16 no.3
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    • pp.352-354
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    • 1998
  • A soilless culture system with the precise control of nutrient solution was developed and the time changes of ionic contribution to EC reading was analyzed. The measuring device designed was able to wash electrodes cleanly and to measure the pH and EC of nutrient solution stably in the box. The nutrient supply system using metering device was also able to control the EC and pH within ${\pm}0.05mS/cm$ and ${\pm}0.05$, respectively. Under the EC control, activity coefficients of all ions decreased with time as ionic concentrations of $SO_4$, Mg and Ca increased due to the selective nutrient absorption by plants. Time changes of ionic contribution to EC reading could be calculated using equivalent ionic conductivities and activity coefficients obtained by numerical analysis.

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Quality Characteristics of Porridge Made from Rice Flour Processed into Rice Powder (쌀가루전용 품종으로 제조한 죽의 품질 특성)

  • Lee, Youn Ri;Song, Yu Ri;Kim, Ji Su;Jung, Hye Jin;Oh, Mi Reu
    • The Korean Journal of Food And Nutrition
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    • v.33 no.5
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    • pp.584-587
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    • 2020
  • The value of using rice flour processed into rice powder in preparing porridge was evaluated by measuring the moisture content, pH, total starch, reducing sugar, and color content. The moisture content of the rice flour and the pH of porridge made with rice flour were measured. Rice flour contained 77.55% moisture and the moisture content of the porridge made from rice flour processed into rice powder was 91.40 to 92.47%. The pH of rice flour porridge was acidic at 6.53 to 6.95. The color of the porridge was also measured. The L* values ranged from 82.62 to 97.55, the a* values ranged from -0.09 to 0.08, and the b* values ranged from -2.74 to 1.91.

Effect of Aspartame on the Quality and Fermentation of Baechu Kimchi (Aspartame이 김치의 숙성과 품질에 미치는 영향)

  • 이강자
    • Journal of the East Asian Society of Dietary Life
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    • v.6 no.1
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    • pp.77-84
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    • 1996
  • For the purpose of utilizing aspartame as sweetener of kimchi, the kimchi containing 0.01 to 0.08% aspartame was investigated by measuring pH, acidity, texture, color, sensory evaluation test during fermentation of 250days at 1$0^{\circ}C$, The pH of kimchi added aspartame was a little higher than that of control. The Hunter L-value of kimchi containing 0.01 to 0.04% aspartame was higher than that of control, and "a" and "b" values were also high in 0.06 to 0.08% and 0.01 to 0.08% treatments, respectively. The sweet taste and overall taste of kimchi containing 0.02% were suitable. In spite of the decrease of sweetener's degree by decomposition of aspartame during fermentation, the edible period of the kimchi by decrease of sour taste was also extended.e was also extended.

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A Study on the Potency and Stability of the Cream Containing Cannabidiol Extracted Cannabis sativa L. from Korea (국내산 대마로부터 추출한 칸나비디올 함유 크림의 역가 및 안정성 평가)

  • Sung Dong, Yu;Hye Lim, Kim;Ki Jun, Seong;Jung Tae, Jeon;Ae Ri, Song;Jong Soo, Kang;Il Bum, Park
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.48 no.4
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    • pp.313-319
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    • 2022
  • In this study, the stability of cream containing 1% of cannabidiol (CBD) with more than 99% extracted from domestic Cannabis sativa was evaluated. The pH, hardness, content, and chromaticity were measured at intervals of 2 weeks under storage conditions for each temperature for 12 weeks (4 ℃, 25 ℃, 37 ℃, and 45 ℃). The pH of the experimental group containing 1% of CBD tended to decrease more than that of the control group. As a result of measuring the change in the content of CBD in the cream under each temperature for 12 weeks using HPLC, the difference in the amount of decrement according to temperature was confirmed. It was confirmed that as a result of measuring the chromaticity using color difference meter, the yellowness of the cream containing CBD increased according to the increase by the storage period and temperature compared to the control group. From the above results, it was confirmed that the content decrease and color change according to the temperature of the pH 5 ~ 6 cream formulation containing CBD. When CBD is applied to medicine and cosmetic formulations in the future, it is considered that research and development should be conducted in consideration of the change in the quantity and physicochemical quality of CBD under the temperature.

Erosive potential of several fruit-flavored liquors in Korea (국내 시판 중인 일부 과일 리큐어의 치아 부식능 평가)

  • Park, Seok-Woo;Kim, Sang-Kyeom;Jung, Eun-Ha;Kwon, Ho-Keun;Kim, Baek-Il
    • The Journal of the Korean dental association
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    • v.54 no.7
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    • pp.521-528
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    • 2016
  • Purpose: The aim of this study was to evaluate the erosive potential of several fruit-flavored liquors marketed in Korea by measuring pH, titratable acidity, and variations in pH utilizing an ISO method. Materials and Methods: Six fruit-flavored liquors were investigated. An orange juice and three kinds of soju were selected as the control beverage. The pH and titratable acidity of the beverages were determined by 1 M NaOH until the pH 5.5 and 7.0 (recorded as $TA_{5.5}$ and $TA_{7.0}$, respectively). All measurements were performed in triplicate. The process of ISO 28888 was used for measurement of the pH variation (${\Delta}pH$) using an under-saturated hydroxyapatite solution (screening solution) and determining the difference between the initial and final pH of the screening solution. The average ${\Delta}pH$ was determined based on 4 measurements. Results: All the fruit-flavored liquors tested in this study showed a pH lower than the critical pH for dental erosion (4.5). The average pH of the fruit-flavored liquors was 2.77 and was also lower than the pH of the soju and an orange juice (control drinks). $TA_{5.5}$ and $TA_{7.0}$ values of the fruit-flavored liquors were 4.92ml and 7.13ml, respectively. The fruit-flavored liquors showed an erosive potential capable of damaging the enamel surfaces, whereas the orange juice had the highest titratable acidity. The changes in pH determined using the screening solution confirmed that the fruit-flavored liquors had erosive potential, with ${\Delta}pH$ value of 1.53. Conclusions: The fruit-flavored liquors tested in this study might have a strong potential to erode dental hard tissues.

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The Usability of Zinc Electrode using Wireless Measuring System of Electric Potential (무선전위측정시스템에 사용하는 아연전극 활용성 검토)

  • Lee, Jong-Rark;Leem, Sa-Hawn;Kim, Sang-O
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.177-180
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    • 2006
  • This study is to make a basic study if solid zinc (Zn) can be used for buried reference electrode, so we examined the adequacy of zinc as reference electrode by using zinc which showed regular electrode for buried period. The deference of electric potential if zinc electrode for corrosion factor such as soil resistivity or pH didn't show fixed trend and there was no clear trend on the change of measurement period. From field test, it is known that the natural electric potential difference of CSE electrode and zinc electrode is 1,100mV, but the electric potential of zinc electrode for CSE electrode in the natural soil and copying soil was 1,094~1,158mV. There was no fixed trend on the change of measurement period and electric potential difference of zinc electrode for corrosion factors such as soil resistivity or pH. Consequently, there was 40~60mV of electric potential difference in every copying soil during the experiment measurement.

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