• 한국염색가공학회지
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• 제18권4호
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• pp.1-10
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• 2006

Tannin treatment has been used for improving the color fastness of dyed materials. In natural dyeing, the tannin treatment is highly effective in improving the fastness. The chitosan treatment also improves the fastness and depth of shade in natural dyeing. In this study, the effects of tannin and chitosan pre-treatment on the color and fastness in loess dyeing were investigated. Cotton woven fabric specimens and cotton knit fabric specimens were pre-treated with chitosan solution in acetic acid, and the specimens were then treated with or without tannin. The specimens were finally dyed with loess. The tannin treatment decreased the K/S values, while the chitosan treatment increased the K/S. Both the tannin treatment and the chitosan treatment increased the wash fastness and light fastness. In tannin treatment, tannin component and Fe component of loess may react together to decrease the lightness and develop dark color. For maintaining inherent color of the loess, it is much preferable to employ chitosan treatment rather than tannin treatment.

• 한국염색가공학회지
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• 제20권2호
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• pp.29-37
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• 2008

Polar amino groups of the waste SS(silk-sericin) were modified by two isocyanate compounds of MOI[2-(methacryloyloxy)ethyl isocyanate] and AOI [2-(acryloyloxy)ethyl isocyanate]. When the MOISS (MOI-modified silk sericin) or AOISS(AOI-modified silk sericin) was pressed hot, vinyl groups in the MOI or AOI were polymerized and then the flexible and transparent films were obtained. Tensile moduli and strengths of the MOISS films were significantly improved as the MOI contents increased. By the addition of the isocyanate compounds, silk sericin films exhibited lower solubility to the distilled water($80^{\circ}C$) and also lower swell ratio to the distilled water(room temperature). In the effect of tensile properties and restraining the water swelling, MOI was better than AOI. BOD(biochemical oxygen demand)/TOD(theoretical oxygen demand) of the pure sericin film was almost 100% perfect level after 10 days immersion into the activated sludge. With increasing isocyanate content reacted with polar amino groups, BOD/TOD decreased. When more than 50 mol% of polar amino groups remained unreacted, sericin films could retain more biodegradability. Comparing with MOI from the viewpoint of biodegradability, AOI was more effective.

• 한국염색가공학회지
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• 제22권2호
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• pp.83-87
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• 2010

Crystal structure of coumarin 6 has been solved by X-ray diffraction. The crystals are triclinic, space group P-1, with a=8.823(2) ${\AA}$, b=8.898(2) ${\AA}$, c=11.025(9) ${\AA}$, ${\alpha}$=86.41(3)$^{\circ}$, ${\beta}$=85.39(3)$^{\circ}$, ${\gamma}$=76.23(3)$^{\circ}$, Mr=350.42, V=837.1(3) ${\AA}^3$, Z=2 and R=0.0516. The molecules are packed parallel to each other by weaker ${\pi}{\cdots}{\pi}$ and C-H${\cdots}{\pi}$ interactions. The detailed geometry of C-H${\cdots}{\pi}$ interactions were discussed. The hydrogen bonds and non-traditional C-H${\cdots}O$ interactions join the no-parallel molecules together. All the molecules packed wall-like with the molecular brick.

• 한국염색가공학회지
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• 제29권4호
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• pp.276-283
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• 2017

The aim of this study is to develop an effective dyeing process for black color on the silk fabrics, using natural Indigo, Madder, Amur cork tree, Alder, Logwood, and Gallnut. All natural dye materials were water-extracted, concentrated, and freeze-dried. Seven different processes were carried out and the color differences(${\Delta}E$) of black color with each process from the chemical black dyed fabric were compared. The light, washing, and rubbing fastness were evaluated. The black dyeing of the silk fabrics was well carried and excellent black color was obtained in every methods. The profound black color could be obtained by the subtractive mixture of the three primary colors of red, yellow, and blue in the order of indigo(blue) - amur cork tree(yellow) - madder or lac(red). Black color was efficiently obtained by iron mordant when logwood or alder fruit was used. The color difference(${\Delta}E$) from the black color with chemical dyestuff was the lowest in the indigo - amur cork tree - lac - iron method. Light fastness and washing fastness were excellent in all dyeing processes, showing grade 5. The fastness to rubbing was excellent as shown grade 5 in the dry samples of logwood - iron process and alder fruit - iron process.

• 한국염색가공학회지
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• 제29권4호
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• pp.268-275
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• 2017

As the substitute of synthetic coloring materials for hair dyeing, we selected some natural ones of three primary colors such as sappan wood, logwood(red), gardenia blue(blue) and amur cork tree(yellow). Mixed colorants and metallic mordanting technique were used to widen the color space of dyed samples. In view of similarity in morphological and chemical structure, wool was adopted as the reference material for human hair to evaluate the color properties of hair dyeing. The color properties of the dyed samples were evaluated by using CIE $L^*a^*b^*$ and Munsell color systems. The addition of an alum or ferrous mordants was effective to expand the color space of hair and to increase the colorfastness to washing and light more than the rating of 1. Displaying the dyed samples by using Munsell color system, better linearity of hue values between the dyed samples of wool and human hair was shown when alum mordant was used.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.263-267
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• 2007

Even though Waterpower Generation as pollution-free has its own merit of contribution by supply of good quality electricity, due to the noise made at the time of its operation, a normal mutual communication among the workers and technicians engaging at the hydraulic turbine dynamo room is almost impossible, and since those finishing materials had been used mainly by reflection material, it is actual situation that when working for maintenance in the hydraulic turbine dynamo room, as counterpart's voice vibrates, its working efficiency is difficult to ensure. On such view point, this Research has conducted Psycho-acoustics Experiment about voice Definition using Auralizational Technique, on the object for the hydraulic turbine dynamo room that improved its acoustic performance by computer simulation. As the result of Study, it was known that the clearness of sound with regard to voice information transmission was apparently improved in all items than before improvement. Therefore, it is considering that these results would be utilized usefully when renovation on the hydraulic turbine dynamo room in the future.

• 한국산업보건학회지
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• 제21권3호
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• pp.177-183
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• 2011

Occupational exposure to silicon carbide dust of manufacturing industries has seldom been evaluated in Korea. Accordingly, we evaluated various silicon carbide dust concentrations in the breathing zone of workers between May 2010 and July 2010. To compare silicon carbide dust concentrations, three dust samplers including the Institute of Occupational Medicine (IOM) sampler, 37mm cassette sampler, and Aluminum cyclone sampler were used. A total of 5 manufacturing industries producing abrasive and refractory materials using silicon carbide were investigated. The geometric mean concentrations were 2.04, 0.97, and $0.48mg/m^3$ in inhalable, total and respirable silicon carbide dust, respectively. The geometric mean concentrations of silicon carbide in abrasive material manufacturing industries were slightly higher than that of refractory manufacturing industries, and finishing operations were higher than that of other operations. It was found that the results of exposure assessment in airborne dust at manufacturing industries using silicon carbide in Korea showed exceeding rate to American Conference of Governmental Industrial Hygienists Threshold Limit Value ($3mg/m^3$) was 10% in respirable dust samples. Therefore, with the consideration of the close relationship between smaller dust size and the occurrence of occupational respiratory diseases, it is suggested to promulgate the new occupational exposure limit for respirable silicon carbide dust.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.629-632
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• 2005

ELID(ELectrolytic In-process Dressing) grinding is an excellent technique for mirror grinding of various advanced metallic or nonmetallic materials. A polishing process is also required for elimination of scratches present on ELID grinded surfaces. MAP(Magnetic Assisted Polishing) has been used as a polishing method due to its high polishing efficiency and to its resulting in a superior surface quality. This study describes an effective fabrication method combining ELID and MAP of nano-precision mirror grinding for glass-lens molding mould, such as WC-Co, which are extensively used in precision tooling material. And for the optics glass-ceramic named Zerodure, which is extensively used in precision optics components too. The experimental results show that the combined method is very effective in reducing the time required for final polishing. The best surface roughness of the polished glass-ceramic was within 1.7nm Ra in this study.

• 한국염색가공학회지
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• 제13권6호
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• pp.374-380
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• 2001

Cotton and ramie fabrics were dyed with artemesia and gardenia dyeing solutions. The chroma values of the fabrics dyed with gardenia were higher than that of artemesia. The ramie fabrics dyed with gardenia showed higher chroma values than the cotton fabrics. The colors of fabrics were deeper in shade but their chroma values were improved no more by repetition of dyeing process in artemesia dyebath. The two ways of dyeing processes were carried out. In the first wan, each fabric was dyed in 5 different concentration(1∼5%) of gardenia dyebath to get the fabrics dyed in different shades. After then the gardenia dyed fabrics were dyed again in the artemesia dyebaths. In the second way, the 5 fabrics were dyed in different shades by repetition of dyeing process in artemesia dyebath. After then the artemesia dyed fabrics were dyed again with the gardenia dyebaths. When the artemesia dyeing process was added on the fabrics dyed in five shades with gardenia, the color differences between five samples were slight. But when gardenia dyeing process was added on the fabrics dyed in five shades with artemesia, the samples showed different hue of colors between yellow and green of Munsell color circle. Like almost of fabrics dyed with Plants materials, the colorfastness to light and laundering of the dyed samples were poor But the colorfastness to drycleaning was good.

• 한국염색가공학회지
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• 제13권6호
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• pp.16-16
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• 2001

Cotton and ramie fabrics were dyed with artemesia and gardenia dyeing solutions. The chroma values of the fabrics dyed with gardenia were higher than that of artemesia. The ramie fabrics dyed with gardenia showed higher chroma values than the cotton fabrics. The colors of fabrics were deeper in shade but their chroma values were improved no more by repetition of dyeing process in artemesia dyebath. The two ways of dyeing processes were carried out. In the first way, each fabric was dyed in 5 different concentration(1∼5%) of gardenia dyebath to get the fabrics dyed in different shades. After then the gardenia dyed fabrics were dyed again in the artemesia dyebaths. In the second way, the 5 fabrics were dyed in different shades by repetition of dyeing process in artemesia dyebath. After then the artemesia dyed fabrics were dyed again with the gardenia dyebaths. When the artemesia dyeing process was added on the fabrics dyed in five shades with gardenia, the color differences between five samples were slight. But when gardenia dyeing process was added on the fabrics dyed in five shades with artemesia, the samples showed different hue of colors between yellow and green of Munsell color circle. Like almost of fabrics dyed with Plants materials, the colorfastness to light and laundering of the dyed samples were poor. But the colorfastness to drycleaning was good.