• 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.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.303-311
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• 2020

Nondispersive infrared CO₂ gas sensor was developed after the simulation of optical cavity structure and assembling the optical components: IR source, concave reflectors, Fresnel lens, a hollow disk, and IR detectors. By placing a hollow disk in front of reference IR detector, the output voltages are almost constant value, near to 70.2 mV. The absorbance of IR light, F_a, shows the second order of polynomial according to ambient temperatures at 1,500 ppm. The differential output voltages and the absorbance of IR light give a higher accuracy in estimations of CO₂ concentrations with less than ± 1.5 % errors. After implementing the parameters that are dependent upon the ambient temperatures in microcontroller unit (MCU), the measured CO₂ concentrations show high accuracies (less than ± 1.0 %) from 281 K to 308 K and the time constant of developed sensor is about 58 sec at 301 K. Even though the estimation errors are relatively high at low concentration, the developed sensor is competitive to the commercial product with a high accuracy and the stability.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2032-2038
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• 2009

The amount of phenol and NaOH for the colorimetric determination of ammonia in Korean standard methods (KSM) is found to be highly excessive compared to the standard methods of several other countries. The absorbance of indophenol formed by the Berthelot reaction for ammonia analysis was measured under the various reaction conditions classified in experiment groups 1, 2, 3, 4 and KSM and American standards methods (ASM), and the relationships between the absorbance of indophenol and concentration of ammonia were compared. The amount of phenol can be reduced to 10 g (current 25 g in KSM) and NaOH can be reduced to 1.76 g (current 11 g in KSM) for the preparation of 200 mL phenate solution, and the absorbance sensitivity increased. The concentration of the phenol and NaOH correlatively affect the pH of the solution, which is a critical variable in achieving the maximum sensitivity and rapid and stable color development.

• Journal of Biosystems Engineering
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• v.24 no.6
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• pp.479-486
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• 1999

A measurement method for the deposition amount of spray, using tracer and spectrophotometer was developed. Food colors was selected as tracer, because it was cheep and easily treatable. Using NIRS(Near Infrared Reflection Spectrophotometer), regression curves between absorbance spectrum and concentration of the tracer were obtained. Yellow food colors showed the peak of spectrum at 452nm, and absorbance of peak showed a tendency to increase as concentration increased. Also, the possibility of concentration control by heating was investigated.

• YAKHAK HOEJI
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• v.30 no.4
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• pp.185-192
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• 1986

Authors developed the computer application program (language: APPLE SOFT BASIC) for derivative spectrophotometry. By means of this program, derivative of spectral absorbance with respect to wavelength is recorded versus wavelength. To try this program in connection with spectrophotometer system, the authors have done the simultaneous quantitation of pyridoxine center dot HCl and nicotinamide in the mixture, and the result was compared with that of absorbance method.

• YAKHAK HOEJI
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• v.29 no.4
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• pp.220-222
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• 1985

Rifampicin reacts with cupric ion to produce rifampicin-Cu(II) chelate (2:1) at pH 6.5, which can be extracted with methylisobutylketone (MIBK). Therefore, rifampicin can be quantitatively, determined by measuring the quantity of Cu(II) in the organic phase by atomic absorption spectrophotometry. Because higher absorbance ratio was obtained in pH 6.0~7.0, buffer solution at pH 6.5 was used in this measurement. Linear relationship was found between absorbance and concentration in the range of 1.0~4.0${\times}10^{-4}M$. This method might be applicable to the determination of rifampicin in the preparations.

• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.101-104
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• 1971

The dye-binding method based on the reaction of acidic orange-G dye with basic groups of protein molecule was investigated to observe its applicability to the determination of protein, basic amino acid and lysine contents in brown rice of several high-protein rice lines. The protein content of rice samples ranged from 7.91 to 10.53% and from 8.93 to 11.96% in terms of wet and dry bases, respectively. The correlation between dye-binding absorbance and protein content in terms of both dry and wet bases was highly significant; their correlation coefficients being $-0.955^{**}\;and\;-0.975^{**}$, respectively. The correlation of dye-binding absorbance lysine and basic amino acids were highly significant and their correlation coefficients were similar. Dye-binding absorbance-lysine showed a lower correlation than dye-binding absorbance-protein but a higher correlation than protein-lysine.

• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.88-96
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• 2008

Thermal evaporated 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films were deposited to examine the energy saving properties of silicides formed by rapid thermal annealing at temperature ranging from 500 to $1,100^{\circ}C$ for 40 seconds. Thermal evaporated 10 nm-Ni/(70 nm-poly)Si films were also deposited as a reference using the same method for depositing the 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films. A four-point probe was used to examine the sheet resistance. Transmission electron microscopy (TEM) and X-ray diffraction XRD were used to determine cross sectional microstructure and phase changes, respectively. UV-VIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were used to examine the near-infrared (NIR) and middle-infrared (MIR) absorbance. TEM analysis confirmed that the uniform nickel-cobalt composite silicide layers approximately 21 to 55 nm in thickness had formed on the single and polycrystalline silicon substrates as well as on the 25 to 100 nm thick nickel silicide layers. In particular, nickel-cobalt composite silicides showed a low sheet resistance, even after rapid annealing at $1,100^{\circ}C$. Nickel-cobalt composite silicide and nickel silicide films on the single silicon substrates showed similar absorbance in the near-IR region, while those on the polycrystalline silicon substrates showed excellent absorbance until the 1,750 nm region. Silicides on polycrystalline substrates showed high absorbance in the middle IR region. Nickel-cobalt composite silicides on the poly-Si substrates annealed at $1,000^{\circ}C$ superior IR absorption on both NIR and MIR region. These results suggest that the newly proposed $Ni_{50}Co_{50}$ composite silicides may be suitable for applications of IR absorption coatings.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1851-1853
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• 1996

In this paper the criteria for insulating oil condition of pole transformer were suggested by applying the UV-Visible spectrophotometric method. Ageing of insulating oil caused the change in absorbances of oil os well os the deterioration of electrical properties of oil. By comparing the electrical properties such as $tan{\delta}$ and breakdown voltage with the UV-Visible absorbances of oil, criteria for absorbance values determining oil condition were established. This UV-Visible spectrophotometric method might be applied in ageing analysis of oil and be expected to replace the current method.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.1-7
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• 2005

Although the Fourier Transform Infra-Red spectrophotometric Direct on Filter(FTIR-DOF) method is a useful analytical technique for quantifying quartz content in respirable dust samples, a number of analytical problems must be taken into consideration such as, to name only a few, inhomogeneous deposition of particles, level of environmental humidity, uneven surface of the filter, and interfering minerals in the sample. This study was designed to select the most suitable wavelength and proper filter material for the method, and to investigate effects of humidity and inhomogeneous deposition of particles on the filter. Samples of respirable dust, created in a dust chamber containing standard material of quartz, were collected using a cyclone equipped with a 25mm filter as a collection medium. The results were as follows; 1. Among seven (7) commercially available filters tested for the FTIR-DOF method, the DM 800 filter showed the best analytical performance having the lowest background absorbance bands and no overlapping peaks at 799, 779, and $695cm^{-1}$. 2. The variations of absorbance due to humidity ranged from 1.0% to 3.3% for $799cm^{-1}$, 1.0% to 3.3% for $779cm^{-1}$, and 8.9%~20.9% for $695cm^{-1}$ peaks, respectively. The $699cm^{-1}$ peak was proved to be most vulnerble to environmental humidity for quantitative analysis of quartz. 3. As for effects of inhomogeneous deposition of samples, the highest variation of absorbance of 10.9% ($13.5{\mu}g$) was observed when using the 695cm-1. The variations of absorbance from the other two peaks, 799 and $779cm^{-1}$, ranged from 1.2 to 3.2%, and 1.4 to 4.1%, respectively. Therefore, the $799cm^{-1}$ peak was considered to be most reliable for quantitative analysis of quartz. The results of this study suggest that, for quantitative analysis of quartz in the respirable dust samples, use of the $799cm^{-1}$ peak can minimize the influence of environmental humidity and inhomogeneous deposition of particles on the filter. The FTIR-DOF method, if adopted for routine analysis of quartz in the respirable dust samples, could save sample preparation time and efforts substantially and also could increase analytical throughputs. Since use of the $799cm^{-1}$ peak is prone to be affected by interferences in the sample, further research on minimizing the effects is needed.