• 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.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.119-128
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• 2008

Laboratory analytical results of 22 sets of hydrophobic adsorbent coils containing surface soil-vapor and two soil samples collected by conventional intrusive method from each boring location at two active dry cleaning facilities in the State of Illinois, U.S.A, were presented to evaluate the performance of soil-vapor survey. The most critical factor to determine the effectiveness of soil-vapor survey is the distance from the soil-vapor sampling device to the actual contamination, which is a function of soil porosity, permeability, primary lithology, and other geological and hydrogeological site-specific parameters. Also this factor can be affected by the history of contaminant-generating operations. The laboratory analytical results in this study showed longer dry cleaning operation history (i.e., 50 years) and presence of fine sand at the beneath Site B allow the contaminants to migrate farther and deeper over a fixed time compared to Site A(i.e., 35 years and silty clay) so that the soil-vapor survey is not likely the most effective environmental site investigation method alone for Site B. However, for Site A, the soil-vapor survey successfully screened the site to identify the location reporting the highest soil concentration of chlorinated solvents.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.218-218
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• 2013

We report a simple and cost-effective method to fabricate transparent superhydrophobic surface on various substrates. The surface was fabricated by coating hydrophobic PDMS (polydimethylsiloxane) film on the silica nanoparticle and subsequent fixing of the hydrophobic silica nanoparticles onto substrates. The water contact angle for the prepared surface was determined to be over $150^{\circ}$, whichindicates that the surface is highly repellent to water. The hierarchical structure and roughness of the surface were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Additionally, transparency of the prepared surface was measured with UV-VIS spectrometer. The transmittance of the superhydrophobic surface was ~80%, which is lower than that without PDMS-coated silica by only 5 to 10%. It is also notable that the superhydrophobic surface fully recovers its original transmittance after self-cleaning process. Also the PDMS coating is stable under a wide range of pH conditions, UV radiation and salinity conditions, which is essential for the practical use. Moreover, our fabrication method is applicable in large scale production.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.2
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• pp.11-20
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• 1986

This study is to examine the colorfastness of leathers which has been tested for concentration of dyestuff and method of dyeing. This study Particularly attempts to solve some problems of colorfastness in wearing and treating leather goods. The finding of this study can summarized as follows: 1. In dyeing garment leathers classified by concentration, the colorfastness to light improves as concentration increases. 2. As the result the more concentration increases, the more the colorfastness to rubbing declines. 3. In colorfastness to dry cleaning, the grade of color fading has been to be high but that of staining to be bad as concentration increases. 4. In assessing change in colorfastness, grades to light and rubbing after coating have been found to be better than that before coating. 5. In colorfastness to dry cleaning after coating, both grades of color fading and staining have been found to be bad.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.3
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• pp.7-14
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• 2003

Fabrics dyed with artemisia extract have quite natural and elegant tones of color. This study purposed to find the best one for dyeing among artemisia collected in the four seasons in order to develop a more efficient method of dyeing with artemisia. As for the method of research, the researcher dyed wool fabric and silk fabric with artemisia, and measured dyeability according to the number of repeats of dyeing, coloration by post-mordant, color fastness to washing, color fastness to dry cleaning and color fastness to light. The results are as follows. 1. In dyeing with artemisia, dyeability was improved as the number of repeat of dying increased, and it was higher in wool fabric than in silk fabric. 2. Among artemisia collected in the four seasons, autumn artemisia had dyeability much inferior to that of artemisia from the other seasons, and winter artemisia had the best dyeability. 3. According to the result of treating fabric with post-mordant, the dyeability was improved significantly, and coloration was most remarkable when copper and iron mordant were used. 4. The color fastness to washing and color fastness to dry cleaning of fabric mordanted with artemisia were as high as grade 4-5 and grade 5 respectively. The color fastness to light was highest in winter artemisia as grade 4.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.215-221
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• 2017

The electroless plating process largely consists of substrate cleaning, seed formation (activator formation), and electroless plating. The most widely used activator in the seed formation step is Pd, and Sn ions are used to facilitate the formation of this Pd seed layer. This is problematic because the Sn ions interfere with the reduction of Cu ions during electroless plating; thus, the Sn ions must be removed by a hydrochloric acid cleaning process. This method is also expensive due to the use of Pd. In this study, Cu electroless plating was performed by forming a seed layer using a silver nanosol instead of Pd and Sn. The effects of the Ag nanosol concentration in the pretreatment solution and the pretreatment time on the thickness and surface morphology of the Cu layer were investigated. The degrees of adhesion to the substrate were similar for the electroless-plated Cu layers formed by conventional Pd activation and those formed by the Ag nanosol.

• Korean Journal of Materials Research
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• v.17 no.3
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• pp.125-131
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• 2007

[ $TiO_{2}-solution$ ] was aaded in $SiO_{2}-solution$ by various composition. $SiO_{2}-TiO_{2}$ thin films were obtained by the dip-coating method on the $SiO_{2}$ glass substrates, and then heat-treated at various temperature. Nano-size $TiO_{2}$ particles dispersed $SiO_{2}-TiO_{2}$ films showed absorption peak by quantum size effect at short wavelength region $350{\sim}400nm$, which made them good candidates for non-linear optical materials and photo-catalytic materials. The thickness of $SiO_{2}-TiO_{2}$ films were $300{\sim}430nm$. The contact angle of $SiO_{2}-TiO_{2}$ films for water was $5.3{\sim}47.9^{\circ}$, and therefore it is clear that $SiO_{2}-TiO_{2}$ films have super hydrophilic properties and the self-cleaning effects.

• Explosives and Blasting
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• v.27 no.1
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• pp.1-6
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• 2009

The strainer can be clogged by dusts in a well. As a result, the permeability of a strainer is extremely reduced. This paper is intended to propose a cleaning method of strainer using blasting pressure of the detonating cords and to examine the applicability of this method. The pressure range that was not expected to affect the strainer was estimated. Test results of $3,000\;kg/cm^2$ pressure with a diameter of 12 cm without damage to the strainer was found to be appropriate. The mortar attached to the strainer was almost completely eliminated.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.34-39
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• 2004

Dyeing properties of Glycyrrhizae Radix was investigated with silk fabrics. Dyeing water is a type of chalcone, it showed yellow in IR spectrum. K/S value showed high in following conditions; Glycyrrhizae Radix $200g/1\ell4 water, $80^{\circ}$ of dyeing temperature, 90 minute of dyeing time. Glycyrrhizae Radix dyeing water has higher K/S value in alkalinity(pH9) than in neutrality(pH7) or acidity(pH3) conditions. K/S value showed highest in pH5 premordant method of alkalinity dyeing water condition. The color of silk fabric dyed with Glycyrrhizae Radix is yellow. The change of color did not show by mordant treatment. K/S value showed higher in mordant treatment than nonmordant. Light fastness showed over 3 degree in nonmordant, premordant, simmordant(Al,Cu,Fe) and postmordant(Cu). Water fastness showed over 3 degree in dyeing water(pH3, pH5, pH7). Dry cleaning fastness showed over 3 degree in all dyeing methods. Washing fastness is showed in 2-3 degree; Al in nonmordant, premordant, simmordant and Cu in simmordant are 2-3 degree. Perspiration fastness is nearly 3-4 degree in premordant and simmordant. Perspiration fastness shows high in premordant, simmordant than postmordant. The fastness of light, water, dry cleaning, washing, perspiration shows better nonmordant, premordant, simmordant than postmordant method.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.424-432
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• 2000

The plasma surface treatment, using hydrogen gas, of the silicon wafer was investigated as a pretreatment for the application to silicon-on-insulator (SOI) wafers using the silicon direct bonding technique. The chemical reactions of hydrogen plasma with surfaces were used for both the surface activation and the removal of surface contaminants. As a result of exposure of silicon wafer to the plasma, an active oxide layer was formed on the surface, which was rendered hydrophilic. The surface roughness and morphology were estimated as functions of plasma exposing time as well as of power. The surface became smoother with decreased incident hydrogen ion flux by reducing plasma exposing time and power. This process was very effective to reduce the carbon contaminants on the silicon surface, which was responsible for a high initial surface energy. The initial surface energy measured by the crack propagation method was 506 mJ/m2, which was up to about three times higher than that of a conventional RCA cleaning method.