• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.606-613
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• 2005

The badge-type diffusive sampler for the measurement of formaldehyde in indoor air using three types of colorimetric methods such as chromotrophic acid(CTA), 3-methyl-2-benzothiazolinone hydrazone(MBTH), and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole(AHMT) method. The washing of the collection filter with several cleaning solution was effected with satisfactory results, regardless of the types of cleaning solutions. The concentrations of absorbance solution in each colorimetric method were experimentally determined by considering the sampling rates. The variation blank values in each colorimetric method was below 15%. As compared with CTA and AHMT methods, the reproducibility of MBTH method was excellent and was below 10% relative standard deviation. The collected formaldehyde mass and time-weighted concentration had a good correlation (correlation coefficient > 0.93). The limit of detection and limit of quantitation, and minimum sampling time were closely correlated to the sampling rates for the measurement of formaldehyde in each method.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.549-552
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• 2012

This report presents a mobile instrumentation platform based on a smartphone using its built-in functions for colorimetric diagnosis. The color change as a result of detection is taken as a picture through a CCD camera built in the smartphone, and is evaluated in the form of the hue value to give the well-defined relationship between the color and the concentration. To prove the concept in the present work, proton concentration measurements were conducted on pH paper coupled with a smartphone for demonstration. This report is believed to show the possibility of adapting a smartphone to a mobile analytical transducer, and more applications for bioanalysis are expected to be developed using other built-in functions of the smartphone.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.794-801
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• 2003

As it is important to measure the degree of the deterioration and predict service life caused by chloride in concrete structure the methods of measuring chloride in the concrete is raised important problems. This study is to set a new standard for using of the colorimetric method through grasping the character of the colorimetric distinction method, and measuring the chloride content at the place discolored. Also, to predict chloride content around embeded bar and time reaching limit chloride concentration through measuring the chloride content of concrete surface by colorimetric distinction method and this study presents the new concept of concrete degradation and diagnosis of the durability by salt damage. According the results, it is possible to use colorimetric distinction method as simplified measurement to measure the fixed quantity of the chloride concentration. What is more, it would make calculation of concrete surface chloride had a wide fluctuation at the general environment extended. Also, it would be make estimating durability of reinforced concrete structures applied to the basic data.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.332-336
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• 2005

Epoxide hydrolase activities of various microbial cells were analyzed by colorimetric assay based on alkylation of epoxides with 4-(p-nitrobenzyl)pyridine (NBP). The epoxide hydrolase activity was determined by measuring the decrease of color intensity at 560 nm due to the decrease of styrene oxide substrate by epoxide hydrolase-catalyzed hydrolysis reaction. The experimental conditions of NBP colorimetric assay were optimized for the efficient measurement of epoxide hydrolase activities from various microbial cells.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.4
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• pp.33-42
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• 2009

This study was performed to evaluate the hexavalent chromium content in flexography inks and organic pigments used as colorants for the ink. The digestion of sample was carried out under alkaline condition, and the content of soluble hexavalent chromium extracted from samples was determined by UV-visible colorimetric analysis method after alkaline digestion. Duplicate sampling system to obtain two digested samples, was applied in this study. To determine the hexavalent chromium content in the flexography ink and organic pigment colorimeteric analysis was employed. Because the organic pigment is the main ingredient of flexography ink it is important to remove the errors associated with the colorant of the ink in colorimetric determination. The duplicate sampling system allowed us to correct the errors associated with the colorimeteric measurement. The additional filtration was found an essential step to exclude colorimeteric error derived from the various precipitates. The soluble hexavalent chromium content in flexography inks was generally less than 5 ppm. Yellow, violet and some magenta colors showed higher soluble hexavalent chromium contents. The content of hexavalent chromium in organic pigments was greater than flexography inks, and yellow, violet and some magenta pigments contained greater amount of hexavalent chromium, which indicated that the hexavalent chromium in inks derives from the colorants. The soluble hexavalent chromium content in linerboards were below 1 ppm, and no hexavalent chromium was detected in UKP. Results suggested that flexography ink is the main factor to cause hexavalent chromium in linerboard and organic pigments.

• Analytical Science and Technology
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• v.37 no.2
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• pp.87-97
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• 2024

The appropriate intake of fluoride (F^-) is beneficial to human health; however, the over-consumption can result in various potentially harmful effects. This study compared different colorimetric reagents, i.e., aluminium-xylenol orange (Al-XO), zirconium-xylenol orange (Zr-XO), and zirconium-alizarin red S (Zr-ARS), for fluoride measurements by the UV-Vis, in terms of reaction mechanisms, method sensitivity, and interferences from aluminium and ferric ions. The colorimetric procedures were optimized, and the analytical methods were evaluated. The goodness of linearity (R² > 0.998) was obtained for all three assays within the concentration range of 1.0-20.0 mg/L fluoride in deionized water, in which the method sensitivity followed the descending order of Zr-XO > Al-XO > Zr-ARS. The Zr-XO was applied for determining the fluoride in different tea extracts in water (90 ℃ and 60-minute-brewing) and black tea demonstrated the highest fluoride content (3.0-3.6 mg/L). The effects of brewing time and temperature on the release of fluoride in the tea extracts were also investigated, indicating these are critical factors for the fluoride extraction. This study highlighted the application potentials of the UV-Vis measurement as a simple, convenient, and cheap analytical approach and discussed different colorimetric reagents used for fluoride determination in tea extracts in the context that the UV-Vis spectrophotometers are commonly equipped in most laboratories.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.188-194
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• 2000

Thermochromic liquid crystal reflect a unique color at even temperature. Therefore, they have been successfully applied to non-intrusive heat transfer research. Hue capturing method is widely used in the quantitative measurement from the TLC image. However it is affected by several measurement conditions. The distances of camera and light source have little influence on the color, but the value of hue is seriously affected by the measurement angle. In this study, the hue capturing method is improved by considering the effect of measurement angle. This improved calibration method can diminish the misreading of temperature caused by curvature of test surface.

• Toxicological Research
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• v.8 no.1
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• pp.119-129
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• 1992

Present study was carried out to investigate the cytotoxicity of cadmium, chromium and mercury on cultured rat fibroblasts. The colorimetric assays of neutral red (NR) and tetrazolium MTT, the measurement of total content of protein and electron microscopic studies were performed on the fibroblasts cultured in the media containing various concentrations of cadmium, chromium and mercury. The results are as follows' 1. In cadmium-treated group, the NR and MTT values were dose-dependent increase. The NR90, NR50, MTT90 and MTT50 values of cadmium were 0.2mM, 19.5mM 1.0mM and 60.0mM, respectively.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.45-57
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• 2006

Offset lithography is the most widely used printing process in domestic printing industry, but there are no industry-wide specifications for press control to assure consistent quality across printing plants. As printing becomes more of a commodity and less of an art, it is necessary to develop a print quality specification standard suitable for Korea offset printing field. This study aims to contribute to improving the quality of domestic offset color prints by comparative study on color reproduction properties of 2 kinds of domestic process color ink composed of C(cyan), M(magenta), Y(yellow) and K(black) and of 3 kinds of domestic coated paper, using colorimetric color measurement method.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.904-911
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• 2006

Passive sampler is simple and inexpensive measuring equipment for air pollution. In this study we developed colorimetric ozone passive sampler which was coated a colorimetric reagent to a filter substrate. Interference of criteria all pollutant ($SO_2,\;NO_2,\;CO$) on ozone passive sampler was investigated through experimental chamber. Field measurement of developed ozone passive samper was compared automatic sampler result in Suwon area. The results shows interference of $SO_2$ gas is larger than other gases. Developed passive sampler can be roughly applicable to wind speed range from 0.8 to 3.3 m/s, temperature range from 3.9 to $27.5^{\circ}C$ and relative humidity range from 48 to 84%.