• Title/Summary/Keyword: Titration method

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Preparation of Poly(vinyl butyral) by Precipitation Method and Its Characterization (침전법에 의한 폴리비닐부티랄의 제조 및 특성분석)

  • 서광원;김덕준
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.168-173
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    • 2002
  • Poly (vinyl butyral) (PVB) was synthesized by acetalization of poly (vinyl alcohol) (PVA) PVB was prepared in particulate forms in water, and chemical and physical properties of the products were characterized using various techniques. The prepared PVB had size distribution from 100 to 700 $\mu\textrm{m}$ with mean diameter of about 380 $\mu\textrm{m}$. The chemical structure of PVB was characterized using FT/IR and NMR, and the average degree of acetalization was determined to be 77% from the titration measurement. DSC data showed that the crystalline structure of PVA vanished as acetalization reaction proceeded to produce PVB, and the glass transition temperature emerged at about $70^{\circ}C$. TGA data showed that PVB was much more thermally stable than PVA, and showed no degradation up to $300^{\circ}C$. Solubility test showed that PVB was soluble in alcohols but Insoluble in water, being totally different from PVA.

Synthesis of modified polyacrylamides and their applications for the retention system of papermaking (변성 폴리아크릴 아미드의 합성 및 제지공정의 보류시스템에 응용)

  • Son, Dong-Jin;Yoon, Ji-Hyun;Choi, Eun-Jeong;Kim, Bong-Yong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2009.04a
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    • pp.23-28
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    • 2009
  • The purpose of this study was to improve not only wet-end performances but also paper characteristics by the modification of various factors like molecular design and ionic characteristics of polyacrylamides First of all physical characteristics were observed after modify molecular design of the cationic polyacrylamides to linear, branched and cross-linked. In addition it was found analysis method to confirm branch degree of cationic polyacrylamides to combine ionic titration characteristics and spectroscopic behavior, After application of these structure modified polyacrylamides to the multiple retention systems with inorganic microparticles, it was found adjusting of branch degree of polyacrylamides was very important to optimize wet-end improvement. Second, After polymerization of amphoteric polyacrylamide to have both of cationic and anionic functional group in the polymer, we observed not only physical characteristics but also wet-end improvement to apply recycled pulp and found that the improvement of solution stability to prevent hydrolysis and increase of ash retention dramatically to compare traditional cationic polyacrylamide retention aid, Finally, After polymerization of anionic polyacrylamide, we observed not only wet-end improvement but also paper characteristics to apply preflocculation of PCC and it was found the improvements of flocculation efficiency, retention, ash retention, optical properties of the paper and bursting strength to compare traditional preflocculant of cationic polyacrylamide.

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Development of Chicken Immunoglobulin Y for Rapid Detection of Cronobacter muytjensii in Infant Formula Powder

  • Kim, Yesol;Shukla, Shruti;Ahmed, Maruf;Son, Seokmin;Kim, Myunghee;Oh, Sejong
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.706-712
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    • 2012
  • The present study was aimed to produce a chicken polyclonal antibody against Cronobacter muytjensii and to develop an immunoassay for its detection. Purification of anti-C. muytjensii IgY from egg yolk was accomplished using various methods such as water dilution and salt precipitation. As a result, sodium dodecyl sulfate-polyacrylamide gel electrophoresis produced two bands around 30 and 66 kDa, corresponding to a light and a heavy chain, respectively. Indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was performed to determine the effectiveness of the chicken IgY against C. muytjensii. The optimum conditions for detecting C. muytjensii by indirect ELISA and checkerboard titration of the antigen revealed an optimum average absorbance at the concentration of 18 ${\mu}g/mL$, having ca. $10^8$ coated cells per well. The anti-C. muytjensii IgY antibody had high specificity for C. muytjensii and low cross-reactivity with other tested pathogens. In this assay, no cross-reactivity was observed with the other genera of pathogenic bacteria including Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, Enterobacter aerogenes, Salmonella Enteritidis and Listeria monocytogenes. In addition, detection of C. muytjensii in infant formula powder showed a low matrix effect on the detection curve of IC-ELISA for C. muytjensii, with similar detection limit of $10^5$ CFU/mL as shown in standard curve. These findings demonstrate that the developed method is able to detect C. muytjensii in infant formula powder. Due to the stable antibody supply without sacrificing animals, this IgY can have wide applications for the rapid and accurate detection of C. muytjensii in dairy foods samples.

Comparison of ELISA and HI titers in broiler chicks vaccinated with infectious bronchitis virus and Newcastle disease virus (전염성기관지염 및 뉴캣슬병 백신을 접종한육계에서 ELISA 및 HI 항체가 비교)

  • 고원석;이정원;곽길한;권정택;송희종
    • Korean Journal of Veterinary Service
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    • v.24 no.1
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    • pp.21-29
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    • 2001
  • To compare of serum antibody titers using ELISA and HI, serum samples were collected from 100 breeders and their progeny 550 broilers. The breeders and broilers were vaccinated with infectious bronchitis(IB)- and Newcastle disease(ND)-viruses according to general vaccination program. The antibodies in serum samples against IB and ND viruses were detected by enzyme-linked immunosorbent assay(ELISA) using commercial ELISA kit and hemagglutination inhibition(HI) test. Geometric mean titer(GMT) of ELISA and In titers were monitored from 1-day-old to 35-day-old broilers and compared to those of breeder chickens. The antibody titers of breeders vaccinated with ]B virus showed 47,800, ELISA and 7.2, HI, respectively. Progeny chicks, 1-day-old, vaccinated with IBV showed high antibody titers than those of breed chickens. Those chicks were maintained protective antibody levels until 11-day-old. From 14-day-old, the antibody level decreased below protective levels. In ND, breeders serum antibody titers ELISA and Eiu were 30,200 GMT and 8.7 HI titer, respectively. On 1-day-old chicks, antibody levels was decreased to half in ELISA(16,270) compared with those of breeders, but In titers was 7.4. Progeny broilers, protective antibody level was maintained until 14- day-old by ELISA, but at 11-day-old by HI titers. After then, ND antibody titer was continuously decreased underdefense level. These result indicated that the ELISA method be more sensitive than HI titration to detect serum antibody level for IBV and NDV.

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Thermal Stability of Photo-produced H3O+ in the Photolyzed Water-ice Film

  • Moon, Eui-Seong;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.192-192
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    • 2011
  • Hyperthermal ion scattering experiments were conducted with low kinetic energy (<35 eV) cesium ion beams to analyze the UV-photolyzed water-ice films. Neutral molecules (X) on the surface were detected as cesium-molecule ion clusters ($CsX^+$) which were formed through a Reactive Ion Scattering (RIS) process. Ionic species on the surface were desorbed from the surface via a low energy sputtering (LES) process, and were analyzed [1]. Using these methods, the thermal stability of hydronium ion ($H_3O^+$) that was produced by UV light was examined. As the thermal stability of $H_3O^+$ is related with the reaction, $H_3O^+$ + OH + $e^-$ (or $OH^-$) ${\rightarrow}$ $2H_2O$, which is similar or same with the reverse reaction of the auto-ionization of water, the result from this work would be helpful to understand the auto-ionization of $H_2O$ in water-ice that has not been well-understood yet. However, as $H_3O^+$ was not detected through a LES method, the titration experiment of $H_3O^+$ with methylamine ($CH_3NH_2$, MA), MA + $H_3O^+\;{\rightarrow}\;MAH^+$ + $H_2O$, was conducted. In this case, the presence of $MAH^+$ indicates that of $H_3O^+$ in the ice. Thus the pristine ice was photolyzed with UV light for a few minutes and this photolyzed ice was remained at the certain temperature for minutes without UV light. Then MA was adsorbed on that surface so that the population of $H_3O^+$ was found. From the calibration experiments, the relation of $MAH^+$ and $H_3O^+$ was found, so that the thermal stability of $H_3O^+$ can be investigated [2].

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Simultaneous Analysis of Ethanol and Harmful Components by GC in Alcoholic Liquors (GC를 이용한 주류중 에탄올 및 유해 성분의 동시 분석법)

  • 정의한;이명자;강금자;문혜성;유병옥;황정구;장준식
    • Journal of Food Hygiene and Safety
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    • v.7 no.1
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    • pp.45-48
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    • 1992
  • In Food revolution of Korea, colorimetries or a titration methods are introduced for the analysis of alcoholic liquors. But, these wet analyses have disadvantages such as individual errors, long process time, and sometimes tedious pretreatments. In the process of making alcoholic liquors, fusel oils are produced as by products. Five main fusel components that could be produced are 2-propanol, n-propanol, iso-butanol, n-butanol, and isoamyl alcohol. Also acetaldehyde and methanol could be produced as by-products of ethanol. With using capillary FFAP column in GC or GC/MSD, we analysed these five fusel components as well as internal standard (acetonitrile) including methanol, acetaldehyde and ethanol simultaneously. We obtained excellent mass spectra as qualitative data of all species. We also took excellent quantitative data with GC by using the internal standard method.

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The Effects of Laundering Conditions on Calcium Deposition on the Fabric (세척조건이 직물에의 Calcium 침착에 미치는 영향)

  • Moon Young Ae;Kahng He Won;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.5 no.1
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    • pp.9-14
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    • 1981
  • The influence of laundering conditions on calcium deposition on the fabric was studied by repeated laundering the cotton fabric with soap in the hard water of 200 P.P.M. $CaCO_3$. The experimental variables were: 1) soap concentrations ($0.06\%$, $0.13\%$, $0.25\%$), 2) water contents in the fabric after hydroextraction. ($65\%$, $150\%$, $315\%$), 3) builders (Na-EDTA, sodium carbonate, sodium metasilicate), 4) washing cycle (5, 10, 15, 20 cycles). The fabric was washed for 15 minutes at $23\pm1^{\circ}C$ in a washing machine (Model; Gold Star Wp-2005) under the similar conditions with those of home laundering, and rinsed 5 times for 5 minutes. The amount of calcium deposits on the fabric was determined by the EDTA-Back titration method described by Wasserman and Basch. Results of this study were follows: 1) The amount of calcium deposits on the fabric increased with increasing wash cycles. 2) During the rinsing process, residual calcium content on the fabric increased with water content in the fabric after hydroextraction. 3) The amount of calcium deposits on the fabric decreased with the increasing soap concentration above the equivalent amount of calcium ion content in the water. 4) Sequestering agents and alkaline builders influenced the amount of calcium deposits on the fabric. The amount of calcium deposits on the fabric was in the order of sodium metasilicate, sodium carbonate, nonbuilder, and EDTA.

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Nonstoichiometry and Electrical Properties of the $Er_{1-x}Sr_xFeO_{3-y}$Systems ($Er_{1-x}Sr_xFeO_{3-y}$계의 비화학양론과 전기적 성질)

  • Chul Hyun Yo;Jung Sung Tae;Pyun Woong Bum;Lee Seung Hyun
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.445-451
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    • 1989
  • A series of solid solutions with formula $Er_{1-x}Sr_xFeO_{3-y}, where x is from 0.0 to 1.0, has been synthesized by heating at $1200^{\circ}C$ for 24 hours. X-ray diffraction shows these samples to be orthorhombically distorted perovskites for compositions up to x = 0. 6 and apparantly simple cubic perovskite structures from $0.8{\leq}x{\leq}1.0$. Lattice volumes are increased with the introduction of Sr. The mixed valence state of two kinds of Fe ion in these ferrite systems is analyzed by the Mohr salt titration method. Mossbauer spectra measured at room temperature for x = 0.0 and 0.5 compositions shows hyperfine splitting for iron (III) due to magnetic ordering and indicates that these samples contain octahedrally and tetrahedrally coordinated iron sites. Electrical conductivity measurements indicate that conduction in these samples apparantly occurs over the octahedral sites by a hopping mechanism.

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Organopalladium(II) Complexes as Ionophores for Thiocyanate Ion-Selective Electrodes

  • Kim, Dong-Wan;Lee, So-Hyun;Kim, Jung-Hwan;Kim, Jin-Eun;Park, Jong-Keun;Kim, Jae-Sang
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2303-2308
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    • 2009
  • A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium( II), [(dppe)$PdX_2$, X = Cl ($L^1$), X = I ($L^2$)] as active sensor has been developed. The diiodopalladium complex, [(dppe)$PdI_2](L^2$) displays an anti-Hofmeister selectivity sequence: $SCN^-\;>\;I^-\;>\;{ClO_4}^-\;>\;Sal^-\;>\;Br^-\;>\;{NO_2}^-\;>\;{HPO_4}^-\;>\;AcO^-\;>\;{NO_3}^-\;>\;{H_2PO_4}^-\;>\;{CO_3}^{2-}$. The electrode exhibits a Nernstian response (-59.8 mV/decade) over a wide linear concentration range of thiocyanate ($(1.0\;{\times}\;10^{-1}\;to\;5.0\;{\times}\;10^{-6}$ M), low detection limit ($(1.1\;{\times}\;10^{-6}$ M), fast response $(t_{90%}$ = 24 s), and applicability over a wide pH range (3.5∼11). Addition of anionic sites, potassium tetrakis[p-chlorophenyl] borate (KTpClPB) is shown to improve potentiometric anion selectivity, suggesting that the palladium complex may operate as a partially charged carrier-type ionophore within the polymer membrane phase. The reaction mechanism is discussed with respect to UV-Vis and IR spectroscopy. Application of the electrode to the potentiometric titration of thiocyanate ion with silver nitrate is reported.

A Solid-Contact Indium(III) Sensor based on a Thiosulfinate Ionophore Derived from Omeprazole

  • Abbas, Mohammad Nooredeen;Amer, Hend Samy
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1153-1159
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    • 2013
  • A novel solid-contact indium(III)-selective sensor based on bis-(1H-benzimidazole-5-methoxy-2-[(4-methoxy-3, 5-dimethyl-1-pyridinyl) 2-methyl]) thiosulfinate, known as an omeprazole dimer (OD) and a neutral ionophore, was constructed, and its performance characteristics were evaluated. The sensor was prepared by applying a membrane cocktail containing the ionophore to a graphite rod pre-coated with polyethylene dioxythiophene (PEDOT) conducting polymer as the ion-to-electron transducer. The membrane contained 3.6% OD, 2.3% oleic acid (OA) and 62% dioctyl phthalate (DOP) as the solvent mediator in PVC and produced a good potentiometric response to indium(III) ions with a Nernstian slope of 19.09 mV/decade. The constructed sensor possessed a linear concentration range from $3{\times}10^{-7}$ to $1{\times}10^{-2}$ M and a lower detection limit (LDL) of $1{\times}10^{-7}$ M indium(III) over a pH range of 4.0-7.0. It also displayed a fast response time and good selectivity for indium(III) over several other ions. The sensor can be used for longer than three months without any considerable divergence in potential. The sensor was utilized for direct and flow injection potentiometric (FIP) determination of indium(III) in alloys. The parameters that control the flow injection method were optimized. Indium(III) was quantitatively recovered, and the results agreed with those obtained using atomic absorption spectrophotometry, as confirmed by the f and t values. The sensor was also utilized as an indicator electrode for the potentiometric titration of fluoride in the presence of chloride, bromide, iodide and thiocyanate ions using indium(III) nitrate as the titrant.