• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.888-893
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• 2016

In this study, the solution plasma process was utilized with the aim of degrading synthetic dyes in water at atmospheric pressure. The experiments were conducted in a batch-type reactor consisting of a symmetric wire-wire electrode configuration with rhodamine B (RhB) as the target synthetic dye. The effects of the plasma treatment time and initial dye concentration on the RhB degradation were investigated by monitoring the change in absorbance of RhB solutions. The RhB solutions turned lighter in color and finally colorless with prolonged plasma treatment time, indicating the destruction of dye molecules. The RhB solutions were found to have degraded, following the first-order kinetic process. However, for high initial RhB concentrations, another kinetic process or factor seems to play a dominant role at the initial degradation stage. The fitted first-order rate constant decreased as the initial concentration increased. This result suggests that the degradation behavior and kinetic process of the RhB solution strongly depends on its initial concentration. The RhB degradation is considered to be due to a combination of factors, including the formation of chemically oxidative species, as well as the emission of intense UV radiation and high-energy electrons from the plasma. We believe that the solution plasma process may prove to be an effective and environment-friendly method for the degradation or remediation of synthetic dye in wastewater.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.53-61
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• 2024

This study explores the effects of X-ray irradiation for biological control and high-temperature degradation on dye stability in dyed textiles with Gardenia. To evaluate this study, optimal extraction solvents for these textiles were identified by comparing them with a crocin standard solution. Extraction using pyridine closely matched crocin. The study then assessed the stability of X-ray irradiation and high-temperature degradation on these textiles. Transparent yellow dyes were observed in all samples. Color differences were found to increase at higher irradiation doses and longer degradation periods. While UV spectroscopy spectra showed broadening and lowering trends with higher irradiation doses and longer degradation periods, suggesting a reduction in colorant transition, mass spectrometry revealed minimal chemical changes. In conclusion, both X-ray irradiation and high-temperature degradation induced spectral changes without complete dye decomposition. Major colorants were consistently detected.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.735-742
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• 2007

We propose an effective packet marking algorithm for video streaming in DiffServ network. Because legacy packet markers such as srTCM(single rate three color marker) cannot distinguish the importance of packet, these markers can cause quality degradation of streaming during the network congestion period. Recently proposed TMS (Two Marker System) [4] shows effectiveness in such scenario that video streaming service is struggling with other types of service traffic. However, if many video streaming services co-exist in DiffServ network and result in competition among themselves, then both legacy packet markers and even TMS cannot prevent drastic streaming quality degradation. To cope with this, we suggest A-TCPM (Adaptive time sliding window Three Color Marker) algorithm. In this algorithm, an A-TCPM module decides the color of a racket based upon the probability which is lead by current channel status and frame importance ratio. Simulation results show that proposed A-TCPM algorithm can enhance streaming service quality especially when overbooked video streaming sessions struggle with themselves.

• Journal of Conservation Science
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• v.31 no.2
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• pp.87-94
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• 2015

Plastic artwork can be appeared crack, change of color and whitening event by various environment conditions. A large scale plastic artwork often exhibits in outside it will be directly degraded by physical and chemical degradation factor such as strong sunlight, high humidity and rainfall. We should know degradation characteristic of plastics to prevent these damages. In this study, we studied degradation characteristic of plastics (5 types of wide use plastics; polypropylene, polystyrene, polyethylene, polyvinyl chloride, polyurethane) depending on various artificial degradation conditions such as high temperature, ultraviolet and these complex conditions (high temperature and ultraviolet). As a result, polypropylene, polystyrene and polyethylene show the most visible change especially polypropylene, polystyrene. Polypropylene didn't show a great change degree of tensile strength and contact angle, on the other hand polystyrene did. Polypropylene and polystyrene weakened by photo degradation, polyvinyl chloride and polyurethane had relatively good light stability. Also the high temperature and complex conditions were most degradation characteristic. High temperature worked for degradation catalyst because its energy can not enough worked for cut off binding energy of plastics while ultraviolet condition effected as directly degradation condition. Though following results, we expect it can be applied to investigation of degradation factor depending on plastic artwork materials and basic result of plastic artworks conservation.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.681-695
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• 2014

In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 ${\mu}m$, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were $7.5{\times}10^4$ and $1.25{\times}10^5$ cells/ml, respectively, and dominant species were Entosiphon sulcatus var sulcatus in PEMT A and Chlamydomonas reinhardtii in PEMT B, respectively. Flask experiments using the two media revealed that the percentages of color removal were 25.8% in PEMT A and 27.1% in PEMT B after 72-h cultivation, indicating the necessity of bioaugmentation. Experiments for bioaugmentation effect on color removal were carried out in the pilot-scale treatment for 75 d by three-step operation under the control of wastewater loading rate and microbial input rate. Dye degradation occurred mainly in the second reaction tank, and the attachment of augmented dye-degrading microorganisms to media took at least 35 d. Final value of chromaticity in effluent was 227, meeting the required standard. Therefore bioaugmentation onto media was good for color treatment. In summary, thickness of biofilm formed on the media depended upon the size of media, resulting in different ecosystem inside the media. Hence, this affected microbial community and color treatment further. Accordingly, the reduction of operation cost is expected by efficient color-treatment process using bioaugmented media.

• Resources Recycling
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• v.19 no.6
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• pp.86-92
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• 2010

In the many kind of construct-material, the concrete which has the high-strength and a durability is sufficient to use with structure-material. but the color of concrete is very monotony, so generally concrete isn't used the out surface. although color concrete is a method of expressing surface, the combination of pigment and cement cause many physical problem such as efflorescence phenomenon, strength degradation and so on. In this study, It attempt to develop the black mortar using the industrial granulated blast furnace slag and to evaluate basic physical properties compare with general color concrete to solve the color concrete problem. The result of experiment showed that the flow dropped mixing of pigment. but flow increased in proportion to the mixing rate in occasion of mortar that mix granulated blast furnace sla and black mortar which was made granulated blast furnace slag has more visible black color than any mortar.

• Journal of Conservation Science
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• v.33 no.3
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• pp.203-214
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• 2017

This study evaluated the degradation characteristics of FRP by ultraviolet (UV) rays and applied a UV-resistant coating to prevent the degradation of the surface of these sculptures. As a result of the degradation caused by UV rays, there were slight changes in the FRP surface and contact angle. The chromaticity sharply increased in the early phase of degradation. After applying the coating to the FRP, no significant surface changes were observed. However, it had lower changes in color as compared to the uncoated specimen, so it was verified that the control of discoloration could be possible. Some changes in the gloss and contact angle were observed depending on the extent of degradation, but the UV coating agent remained relatively stable. Analysis of the infrared light spectrum showed that there were almost no chemical changes, and it could be concluded that the coating treatment prevented degradation for a certain period. This study investigated the degradation of FRP used as materials in artwork exposed to UV rays, and it was found that there was a delay in the onset of degradation in the FRP with the UV-resistant coating when compared to the uncoated FRP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4590-4599
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• 2011

The Color shift phenomenon is becoming a major degradation factor of the emitting color purity in the organic emitting diodes which is generating a plurality of colors. In this study, the basic structure of organic light emitting diode device is comprised of ITO/${\alpha}$-NPD/$Alq_3$:DCJTB[wt%]/$Alq_3$/Mg:Ag, we have carry out numerical simulation of the electric-optical characteristics in organic light emitting diode device to estimate the mechanism of color shift phenomenon. We have investigated the causes of the color shift through the change of DCJTB doping concentration ratio. As the result, we have confirmed that the changes of the recombination rate which generated by trapped electrons and holes is one of the major factors for the color shift phenomenon.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.19-26
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• 2010

We found that saturated water vapor pressure is the most dominant stress factor for the degradation phenomenon in the package for high-power phosphor-converted white light emitting diode (high power LED). Also, we proved that saturated water vapor pressure is effective acceleration stress of LED package degradation from an acceleration life test. Test conditions were $121^{\circ}C$, 100% R.H., and max. 168 h storage with and without 350 mA. The accelerating tests in both conditions cause optical power loss, reduction of spectrum intensity, device leakage current, and thermal resistance in the package. Also, dark brown color and pore induced by hygro-mechanical stress partially contribute to the degradation of LED package. From these results, we have known that the saturated water vapor pressure stress is adequate as the acceleration stress for shortening life test time of LED packages.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.519-524
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• 1997

As an investigation for utilization of ascidian tunic carotenoids as a food color additives, we attempted to collect the volatile thermal degradation compounds from ascidian tunic carotenoids. Oxygenate volatile compounds were extracted by simultaneous distillation and extraction/concentration apparatus and analyzed by gas chromatography and mass spectrometery. Total 63 compounds were identified and some of them were caused by thermal degradation. They included 1,3,5-trimethylbenzene, 3,5,5-trimethyl-3-cyclohexen-1-ol, 3,5,5-trimethyl-3-cyclohexen-1-one, 1,1,2,3-tetramethyl-2-cyclohexen-5-ol, 1,1,2,3-tetramethyl-2-cyclohexen-5-one, 2,3,4,4-tetramethyl-6-hydroxy-2-cyclohexene-1-one, 1,2,3,8-tetrahydro-3,3,6-trimethyl-1-naphtol, dihydroacetinidolide, ${\beta}-ionone$, 2-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1-tolylethene, 2,6-dimethyl-8-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1,3,5-octatriene-7-yne. Proposed mechanism of formation of some compounds as thermal degradation products of ascidian tunic carotenoids are provided.