• Title/Summary/Keyword: , absorbance

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Changes in color value of salt-fermented fish sauces during fermentation and storage (숙성 및 저장 중 액젓의 색도 변화)

  • IM Yeong Sun;CHOI Yeung Joon;CHO Young Je
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.383-387
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    • 2000
  • To investigate availability of color value as quality standard for grading of salt-fermented fish sauces, the effect of storage period, dilution ratios, additives (glucose, MSG, IMP) and pigments (caramel and tar) on the changes of color value were measured by spectrophotomeky. The highest absorbance was scanned at 453 nm in fish sauces (anchovy and northern sand lance) without regard to storage periods, dilution ratios, pigments and additives. Absorbance at 453 nm was gradually increased during storage in fish sauces, and absorbance of northern sand lance sauce was higher than that of anchovy sauce during fermentation. There were almost no differences according to concentration of additives in fish sauces added additives during storage. But in case of fish sauces added pigments, absorbance increase of fish sauces added tar pigment was faster than that of caramel pigment during storage. The results suggest that color value is inadequate as quality standard for grading of salt-fermented fish sauces.

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Optimization of Parameters for Simultaneous Multielemental Analysis by Atomic Absorption Spectrometry (원자흡수분광법에 의한 다원소 동시분석시 조건의 최적화)

  • Kim, Hyo Jin;Kang, Jong Seong
    • Analytical Science and Technology
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    • v.6 no.4
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    • pp.359-362
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    • 1993
  • To find compromise experimental conditions that will allow a group of elements to be run on flame atomic absorption spectrometer without changing the burner height or gas flow rates, measurements were carried out. The optimum absorbance for simultaneous analysis of ten elements was observed at high flow rate of air-$C_2H_2$ as fuel and at 2mm of burner height. At the condition, 73% of mean relative absorbance were achieved.

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A Spetrophotometric Cyanmethemoglobin Method for the Estimation of Serum Hemoglobin Levels (혈청(血情)해모구로빈 측정(測定)에 관(關)한 연구(硏究))

  • Tchai, B.S.;Cho, K.H.;Lee, C.K
    • Journal of Nutrition and Health
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    • v.7 no.4
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    • pp.30-32
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    • 1974
  • Hemoglobinemia is found in hemolytic anemia, paroxysmal nocturnal hemolobinuria and paroxysmal hemoglobinuria. Recently increasing use of extracorporeal circulation in cardiac surgery has stimulated the development of more precise methods for rapidly evaluating the formation and clearance of extracoporeal hemoglobin. A spectrophotometric method of analysis seemed to offer the best solution to the requirements. The method presented is on the basis of hemoglobin derivatives converted to cyanmethemoglobin, and the absorbance is measured in a spectrophotometer at 540 and 680 nm. The blank value ismeasured at 680 nm while the absorbance at 540 nm measures the hemoglobin derivatives. This method estimates all the hemoglobin derivatives such as oxyhemoglobin, carboxyhemoglobin, methemoglobin, sulfhemoglobin and hemialbumin. The method was tested in recovery experiments, which is given table 1. A good degree of correlation was obtained in a comparision with the method described by Crosby and Furth for non-hemolyzed serum. The spectrophotometric technique described offers many advantages in speed and simplicity over the chemical procedure.

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Spectrophotometric Determination of Trace Lead(II) After Extraction of Lead-Thiosulfate Complex into Aliquat336-CHCl$_3$ and Replacement by Cu (납-티오황산 착물생성과 구리치환에 의한 미량 납(II)의 비색분석에 관한 연구)

  • Lee, Seok-Ki;Joung, Chang-Ung
    • Journal of Environmental Health Sciences
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    • v.24 no.3
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    • pp.1-5
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    • 1998
  • A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

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Measurement of Spray Deposit Amount Using Spectrophotometer and Food Dye as Tracer

  • Rhee, J.Y.;Ahn, S.Y.
    • Agricultural and Biosystems Engineering
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    • v.1 no.1
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    • pp.16-21
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    • 2000
  • Measurement of spray deposit is necessary for evaluation of a chemical application technology. However it is not easy and time consuming. A simple method for measuring the deposition amount of spray using a tracer and a spectrophotometer was developed. Various materials were tested to determine an adequate tracer. Food dye was selected as a tracer, because it was cheep and easily treatable. Using NIRS(Near Infrared Reflection Spectrophotometer), a regression curves between maximum absorbance of a solution and concentration of the tracer were obtained. Yellow food dye solution showed a peak of spectrum at 452 nm, and absorbance of peak showed a tendency to increase as concentration increased. Green or pink food dye were tested and judged to be good tracers. However, tracer concentration should not exceed certain limits in order to measure maximum absorption. Using spraying liquid with known tracer concentration and known amount of washing liquid, spray deposit amount on real targets on leaves could be estimated at less than 13% error level.

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Natural Dyeing of Silk Fabric Dyed with Rubus Coreanus Miquel Extract (복분자 열매를 이용한 천연염색)

  • Bai, Sang-Kyoung
    • Fashion & Textile Research Journal
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    • v.8 no.4
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    • pp.476-480
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    • 2006
  • For the purpose of application to new natural dyestuff, the dyeability of Rubus coreanus Miquel extract was analyzed. It was dyed in silk fabric according to various dye concentration, dyeing temperature, dyeing time, and dyeing repetition. And the effects of mordanting conditions were examined as color differences and color fastnesses. The maximum absorbance of Rubus coreanus Miquel extract was at 521 nm. The dyeaffinities were increased gradually as were increased dye concentration, dyeing temperature, dyeing time, and dyeing repetition. The dyeaffinity was increased at pre-mordanted condition, and color difference was increased distinctly at post mordanted condition. The hues of mordanted silk fabrics were RP, P, PB, BG where as non mordanted silk fabric was R. Lightfastness was the best at pre-Sn mordanted and the worst at Post-Al mordanted. Washing and perspiration fastnesses were improved on pre and post-Sn mordanted.

Enzymatic Determination of Glucose Using Soybean Sprouts Peroxidase. (콩나물 Peroxidase를 이용한 포도당의 효소적 분석)

  • 이민경
    • Journal of Life Science
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    • v.8 no.4
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    • pp.416-420
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    • 1998
  • Soybean sprouts peroxidase can be used for enzymatic determination of glucose. Peroxidase from soybean sprouts was purified by ammonium sulfate precipitation and DEAE Sephacel column chromatography. The glucose could be quantitatively assayed by using glucose oxidase and soybean sprouts peroxidase. The optimum pH and temperature for glucose assay were of pH 5.5 and $40^{\circ}C$, respectively. The relationship between absorbance and glucose concentration was linear. And also the relationship between absorbance and reaction time was linear. The reducing agents such as L-cysteine, dithiothreitol inhibited the glucose assay by glucose oxidase and soybean sprouts peroxidase.

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Red Pigment Overproduction by Fed-Batch Culture of Monascus anka (Monascus anka로부터 유기배양에 의한 적색소의 대량생산)

  • 김희구;박근태;손홍주
    • The Korean Journal of Food And Nutrition
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    • v.11 no.6
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    • pp.617-621
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    • 1998
  • The production of red pigment from glucose by fed-batch culture of Monascus anka was investigated. In batch culture using fermentor, 200 rpm of agitation speed, 1vvm of aeration volume, and 10% (v/v) of inoculum size were optimal, respectively. The red pigment production was increased by removal of wall-attached mycelium. In an intermittent feeding fed-batch culture, dry cell weight increased to 30 g/l, adn the red pigment content reached 350 of absorbance at 495nm. In a continuous feeding fed-batch culture, dry cell weight increased to 22g/l, and the red pigment content reached 190 of absorbance at 495nm.

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Electroluminescence and Electronic properties of multi1ayer organic Thin Film (다층구조를 갖는 유기박막의 발광 및 전자물성)

  • Lee, Cheong-Hak;Kim, Jeong-Tae;Park, Bok-Kee;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.792-794
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    • 1998
  • The TPD and the $Alq_3$ film are widely used as a hole transport layer and an emitter layer respectively, in organic electroluminescent(EL) device (ITO Glass/TPD/$Alq_3$/metal). In this structure, we fabricated two models. Model(1) having ITO glass/$Alq_3$/Al structure and model(2) having ITO Glass/TPD/$Alq_3$/Al structure were fabricated by the vacuum evaporation. The comparison between model(1) and model(2) was made about the absorbance, the wave length, the current-voltage characteristic and the ln I - $V^{(1/2)}$characteristic respectively. Electroluminescence of green and wavelength of 510[nm] were observed in both model. We observed absorbance from 320[nm] to 430[nm] in $Alq_3$ material and from 250[nm] to 400[nm] in TPD material.

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