• Title, Summary, Keyword: pH

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A Study on the Validity of 'Hepa-S' Hepatitis B Antibody Detecting Reagent after Vaccination of 'Hepa-Vax' (B형 간염백신 'Hepa-Vax' 접종후 항체검사시약 'Hepa-S' kit의 정확도에 관한 연구)

  • Moon, In-Sook
    • Journal of Preventive Medicine and Public Health
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    • v.18 no.1
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    • pp.51-57
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    • 1985
  • To attempt to measure the effect of domestic product P.H.A. kit 'Hepa-S' after completion of 'Hepa-Vax' vaccination schedule, P.H.A. test and R.I.A. test on the 330 healthy adults were carried out. The results obtained were as follow ; 1. The positive anti HBs rate after completion of 'Hepa-Vax' vaccination were; in P.H.A. test with domestic product P.H.A. kit 81.2%, in P.H.A. test with foreign product P.H.A. kit 82.7%, and in R.I.A. test 95.8% 2. Using the result of R.I.A. test as the standard, sensitivity of P.H.A. test with domestic product P.H.A. kit was 84.8% and specificity was 100.0% 3. Using the result of R.I.A. test as standard, sensitivity of P.H.A. test with foreign P.H.A. kit was 86.4% and specificity was 100.0%. 4. The concordance rate of P.H.A. test with domestic product and foreign product kit was 98.5%. On the result of this study, there was no significant difference in the validity between the domestic product P.H.A. kit 'Hepa-S' and the foreign P.H.A. kit $'Hebsgencell^{TM}'$. So that it is recommendable to use domestic product P.H.A. kit instead of foreign product P.H.A. kit.

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Relationship Between pH and Temperature of Electroless Nickel Plating Solution

  • Nguyen, Van Phuong;Kim, Dong-Hyun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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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.

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Swelling Characteristics of a Hydrogel poly(N-isopropylacrylamide-co-N N'-dimethylaminopropyl methacrylamide) Sensitive to Both pH and Temperature (pH 및 온도에 동시에 민감한 하이드로젤의 팽윤 특성)

  • 손창규;정인식;박창호
    • KSBB Journal
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    • v.14 no.1
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    • pp.58-65
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    • 1999
  • A hydrogel, poly(N-isopropylacrylamide-co-N,N'-dimethylaminopropyl methacrylamide), sensitive to both pH and temperature was synthesized and characterized for its welling behavior, lower critical solution temperature (LCST), and its appearance. The hydrogel with 5 mol% of N,N'-diemthylaminopropyl methacrylamide (DMAPMAAm) increased its volume phenomenonally in a lower pH range (ph 1~8) even at temperature ($37^{\circ}C$ and $40^{\circ}C$) higher than LCST. This behavior was unique compared to the temperature -sensitive hydrogel which did not exhibit any swelling in the same pH range. The hydrogel with 20 mol% of DMAPMAAm was swollen significantly at a higher pH of 12. With pH decrease from 12 to 2 water content in the gel increased from 38.8 wt% and 60.6 wt%, and 90.8 wt% for 5 mol% and 20 mol% gel, respectively. The transition pH that pH effect overwhelmed temperature effect occurred at a lower pH for a higher temperature ($40^{\circ}C$) and a lower mol% (5 mol%) of DMAPMAAm. Transparency and LCST of the gel increased with higher DMAPMAAm mol%.

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Studies on the Production of Acid Resistant Amylase by Molds (part 1) -Isolation and its Cultural pH- (Asp, 속균(屬菌)에 의(依)한 내산성(耐酸性) Amylase 생산(生産)에 관(關)한 연구(硏究) (제 I 보) (第 I 報) -분리(分離) 및 배양(培養) pH에 대(對)하여-)

  • Park, Yoon-Choong;Lee, Suk-Kun
    • Applied Biological Chemistry
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    • v.9
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    • pp.91-96
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    • 1968
  • 1. Two strains of Aspergilli producing acid resistant amylase were isolated from air. The strain $U^{-1}$ and $U^{-2}$ were similar to Asp. usamii tan type mutant in the morphological characteristics. 2. The influence of cultural pH for production of amylase were investigated in the suface culture, it was different each other in the cultural optimum initial pH. The activity of acid resistant amylase produced by strain $U^{-1}$ was higher than that of strain $U^{-2}$. The acid resistance was increased by culturing in lower pH. 3. The lower initial pH ($U^{-1}$ pH 4.0, $U^{-2}$ pH 2.0) was better than neutral (pH 6.0) for the production of amylase and growth of them. The effect of low initial pH for the production of amylase was not to accelerate but caused by change of pH in the cultural process, in the range of this experiment.

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pH-Drift Characteristics of Sol-Gel-Deposited $Ta_{2}O_{5}$-Gate ISFET (Sol-Gel 법으로 형성한 $Ta_{2}O_{5}$ 게이트 ISFET의 pH 드리프트 특성)

  • Kwon, Dae-Hyuk;Cho, Byung-Woog;Kim, Chang-Soo;Sohn, Byung-Ki
    • Journal of Sensor Science and Technology
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    • v.5 no.2
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    • pp.15-20
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    • 1996
  • The diffusion of hydrogen ions into a sensing membrane causes the output voltage of pH-ISFET to vary with time, which might be considered to be drift in this sensor. We tried to deposit ultra-thin film for minimizing tile drift that has been considered to be main obstacle for putting pH-ISFET to practical use. In this paper, tantalum pentoxide, known as a good pH sensing membrane, was formed to about $70{\AA}$ thick by sol-gel method on $Si_{3}N_{4}/SiO_{2}$-gate of pH-ISFET. The fabricated $Ta_{2}O_{5}$-gate pH-ISFET showed good sensitivity(about 59mV/ pH) and good lineality in the range of pH $3{\sim}11$, and had relatively small average pH drift of about 0.06 pH/day.

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Hydrogen ion-selective membrane electrodes based on arylamines as neutral carriers (아릴아민계의 중성운반체를 이용한 수소이온선택성 막전극)

  • Jeong, Seong-Suk;Cho, Dong-Hoe;Kim, Jae-Woo;Chung, Koo-Chun;Park, Myon-Yong
    • Analytical Science and Technology
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    • v.9 no.1
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    • pp.78-83
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    • 1996
  • Hydrogen ion-selective membrane electrodes based on tribenzylamine(TBA), tetrabenzylethylenediamine(TBEDA), pentabenzyldiethylenetriamine(PBDETA) as neutral carriers were shown good selectivity and linearity in the range of pH 1~pH 9, pH 2~pH 12, pH 4~pH 12. The pH selectivity of this membrane electrodes have nothing relation with the numbers of unshared electron pair in TBA, TBEDA, PBDETA and were shown a slope of 43.8mV/pH, 46.9mV/pH, 43.6mV/pH respectively. The selectivity coefficients were determined by the separate solution method for alkali($Li^+$, $Na^+$, $K^+$), alkaline earth metal($Ba^{2+}$, $Ca^{2+}$, $Mg^{2+}$) and transition metal ions($Mn^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, $Zn^{2+}$). The membrane electrode based on TBEDA appeared the best results as hydrogen ion electrode.

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Effect of pH Level on the Characteristics of a Landfill Clay Liner Material (pH에 따른 점토차수재의 특성)

  • Jung, Soo-Jung;Lee, Yong-Su;Kim, Tae-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.23 no.8
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    • pp.97-106
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    • 2007
  • In this study, experiments are conducted to find out the effect of waste leachate on landfill clay liner system. Tensile test, hydrometer analysis and crack pattern test were conducted on sand-bentonite mixtures with different pH values of water. The tensile strength of specimen compacted with pH 9 of water is smaller than that of specimen compacted with for pH 3 and 6 of water. That is, the higher the pH value, the smaller the tensile strength, because a higher pH solution decreases flocculation phenomenon. The percent finer also increased with high pH value in particle size distribution of fine grained soil (<0.075 mm), because the velocity of particles settling decreases. This trend becomes the clearer as the content of bentonite, becomes the larger, because the higher pH value decreases flocculation structure of fine soils. The results of the crack pattern tests also showed the effect of pH values of water.

A Fluorescent Sensor Film for Detecting pH of Acidic Solutions (산성 용액의 pH를 감지할 수 있는 형광 센서막)

  • Min, Jae Young;Kim, Hyung Jin
    • Journal of the Korean Chemical Society
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    • v.64 no.2
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    • pp.74-78
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    • 2020
  • A push-pull conjugated dye (DCMP) was covalently immobilized on a silanized glass surface to produce a high sensitivity pH sensor film for operating in the acidic region. A pH-sensitive sensor film was prepared by photo-initiating copolymerization of a modified DCMP (DCMA), 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate on the silanized glass surface. The absorbance of the sensor film increased with increasing pH between pH 2.0 and 5.0, and the fluorescence intensity of the film also increased about 50 times with increasing pH in the same pH range. The sensor film was reversible and reproducible under acidic conditions. The sensor film showed a relatively short response time between 20-50 seconds and high selectivity for proton in the presence of various metal ions.

Effect of pH-Sensitive P(MAA-co-PEGMA) Hydrogels on Release and Stability of Albumin (pH 감응성 P(MAA-co-PEGMA) 수화젤이 알부민의 방출과 안정성에 미치는 영향)

  • Yang, Juseung;Kim, Bumsang
    • Polymer Korea
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    • v.37 no.3
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    • pp.262-268
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    • 2013
  • pH-sensitive P(MAA-co-PEGMA) hydrogel particles were prepared and their feasibility as smart delivery carriers for cosmetic ingredients was evaluated. P(MAA-co-PEGMA) hydrogel particles having an average size of approx. $2{\mu}m$ were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-PEGMA) particles at a pH of around 5 due to the ionization of MAA in the hydrogel and as the amount of MAA in the hydrogel increased, the swelling ratio increased at a pH above 5. The P(MAA-co-PEGMA) hydrogel particles showed a pH-sensitive release behavior. Thus, at pH 4 almost none of the albumin permeated through the skin while at pH 6 relatively high skin permeability was obtained. The albumin loaded in the P(MAA-co-PEGMA) hydrogel particles was hardly degraded in the presence of pepsin and its stability was maintained.

pH-Sensitive Curdlan Acetate Microspheres를 이용한 Indomethacin의 방출 특성

  • Lee, Chang-Mun;Lee, Yeong-Jin;Lee, Gi-Yeong;Choe, Chun-Sun
    • 한국생물공학회:학술대회논문집
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    • pp.739-742
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    • 2003
  • Curdlan acetate was prepared from hydrophilic curdlan by chemical modification and it was used for pH-sensitive drug delivery system. Curdlan acetate microspheres were prepared by the solvent evaporation method. The size of the curdlan acetate microspheres was below $200\;{\mu}m$. The drug loading efficiency of microspheres was approximately 58.44%. In the swelling test, curdlan acetate microspheres were showed pH-sensitive behavior. The swelling capacity of microspheres at pH 7.4 was much greater than at pH 1.4. Also, Release rate of indomethacin (IND) at pH 7.4 from curdlan acetate microspheres was faster than that at pH 1.4. A pH-sensitive drug release pattern was due to the disintegrating after swelling.

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