• YAKHAK HOEJI
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• v.35 no.1
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• pp.15-21
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• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.38-43
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• 1980

The spectrophotometric determination oi reducing sugar in the tobacco leaves was carried out by employing blue tetrazolium chloride as a color developing reagent. The absorption maximum of formazan dye which is the product of the reaction between blue tetrazolium chloride and fructose was shown to be $530^{nm}$. In the fructose concentration range of 0.02mg/ml-0.14mg/ml the calibration curve was well coincided to the law of Beer-Lambert. In order to take a look at the accuracy and/or recovery rate of fructose determination, the standard fructose was added to the tobacco leaves and the concentration of this standard fructose was estimated. A tittle lower concentration of the standard fructose compared with the pure one in solution was observed. However, an excellent analytical recovery was revealed under the -2% of relative error limit. When we carried out the quantitative determination of this reducing sugar by the method of visual read-out (without using the spectrophotometer), the relative error was obtained to be $\pm$10%.

• Journal of the Korean Chemical Society
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• v.39 no.2
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• pp.87-93
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• 1995

The amount of Cr(Ⅲ) and Cr(Ⅵ) in a chromium plating solution could be determined simultaneously within five minutes using UV/VIS spectrophotometer coupled with a flow-through analysis(FTA) setup. The λmax's at 580 nm and 440 nm which correspond to Cr(Ⅲ) and Cr(Ⅵ), respectively, well obey the Beer-Lambert law in the range over 0.05 g/L for Cr(Ⅲ) and 0.005 g/L for Cr(Ⅵ). when the pH of the sample is less than 4.0, the absorption extinction coefficients of those peaks are not much dependent on the proton concentration. The amount of Cr(Ⅲ) and Cr(Ⅵ), and the total chromium in post treatment chromium plating solution, which normally has few g/L of Cr concentration, could be easily measured using UV/VIS spectrophotometry after the sample had been diluted with sulfuric acid of pH=1.0 in the flow-through analysis setup; this method is far more convenient and faster than the common redox titration (which requires at least 40 min/sample) method, while the accuracy of the method is highly comparable to conventional titrimetric method. Since the implementation of an PTA-UV/VIS setup in any plating industry is cost effective and easy to operate, the analytic method described in this paper may be applied directly for in situ analysis of plating solutions.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.14-19
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• 1980

The spectrophotometric determination of nictotine content with barbituric acid buffer solution was carry out. Absorption maximum for the proposed solution appeared at 505 nm and the absorbance remained stable for 15 minute at pH 4.2. Lambert-Beer law was proved to be applicable in the range of nicotine concentration of $7.5\mu{g}/ml$~$25\mu{g}/ml$. According to the analysis of nicotine contents in Burley and Flue-cured tobacco leaves by this method, the relative deviation was obtained to be 2.8% in comparision with the Griffith method.

• Journal of Powder Materials
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• v.24 no.6
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• pp.483-488
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• 2017

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of $WO_3$ nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of $WO_3$ are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on $WO_3$ nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert's law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

• Journal of The Korean Digital Architecture Interior Association
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• v.5 no.1
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• pp.9-16
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• 2005

In Interior design, light is the most important factor in deciding color, texture and illumination level which are the basic factors of spatial design. To apply rendering technologies on prediction of illuminating effect, it is important to understand and analyse the basic properties of the illumination models that are local illumination model and global illumination model. The illumination models in computer graphics express the factors which determine the surface color, texture and light distribution through the reflection. The purpose of this study is to propose the best way of shading algorithm in interior space provided by the computer, based on the experimental analysis that 5 shading methods are applied to the interior space. The results of this study were as followed. 1) Local illumination models that are Lambert shading, Ground shading and Phong shading are not suitable to the prediction of interior illumination effect. 2) Ray tracing that is global illumination model could be adopted to interior illumination effects. Ray tracing is a very versatile algorithm because of the large range of lighting effects it can model. 3) Neither radiality nor ray tracing offers a complete solution for simulating all interior illumination effects. 4) Radiosity excels at rendering diffuse-to-diffuse inter-reflections and ray tracing excels at rendering specular reflections. By merging both shading techniques, that offers the best of both. Using computer technologies to simulate lighting in preliminary design stage which will provide information for designers and occupants to determine the effect of using artificial light sources at each stage of their design process. Further study in illumination analysis, prediction of illumination effect, and lighting calculation is required as computer media expands.