• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.101-109
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• 2007

In situations of spatio-temporal perception about visuo-auditory stimulus, researches propose optimal integration hypothesis that perceptual process is optimized to the interaction of the senses for the precision of perception. So, when the visual information considered generally dominant over any other sense is ambiguous, the information of the other sense like auditory stimulus influences the perceptual process in interaction with visual information. Thus, we performed two different experiments to certain the conditions of the interacting senses and influence of the condition. We consider the interaction of the visuo-auditory stimulation in the free space, the color of visual stimulus and sex difference of testee with normal people. In first experiment, 12 participants were asked to judge the change in the frequency of audio-visual stimulation using a visual flicker and auditory flutter stimulation in the free space. When auditory temporal cues were presented, the change in the frequency of the visual stimulation was associated with a perceived change in the frequency of the auditory stimulation as the results of the previous studies using headphone. In second experiment, 30 male and 30 female were asked to judge the change in the frequency of audio-visual stimulation using a color of visual flicker and auditory flutter stimulation. In the color condition using red and green. Both male and female testees showed same perceptual tendency. male and female testees showed same perceptual tendency however, in case of female, the standard deviation is larger than that of male. This results implies that audio-visual asymmetry effects are influenced by the cues of visual and auditory information, such as the orientation between auditory and visual stimulus, the color of visual stimulus.

• Textile Coloration and Finishing
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• v.16 no.5
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• pp.8-18
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• 2004

In order to study on the color change of silk dyed with natural colorant due to light fading, and find out the effect of combination dyeing, colorant extracts of safflower red, safflower yellow and amur cork tree were used, either singly or in combination. In combination dyeing, safflower yellow or amur cork tree dyeing process was added on the top of the silk fabric was dyed with safflower red. Color change and light fastness were investigated by $L^*,\; a^*,\; b^*$ H, V/C, and Color difference. Brightness of silk fabric dyed with safflower red and safflower yellow increased gradually with increasing the radiation time of UV light, but amur cork tree was decreased and turned to dull. Color difference of dyed with Amur cork tree showed higher than the others. Combination dyeing of safflower red and amur cork tree provided better light fastness than the one of safflower red and safflower yellow.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.315-325
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• 2020

Boron compound had many advantages as wood preservative, but it was prone to leaching. Improving boron preservation was required to extend the service life of fast growing and low durability red jabon (Antochephalus macrophyllus) hardwood. This study aimed to evaluate the dimensional stability, color change and durability of modified red jabon wood by double impregnation with boron and methyl methacrylate (MMA) and heat treatment. Impregnation I used boric acid or borax, and impregnation II used MMA, while heat treatment used temperatures of 90 ℃ or 180 ℃ for 4 hours. The dimensional stability, leachability, water absorption, color change and decay resistance of modified red jabon wood were tested. The results showed that MMA impregnation increased the dimensional stability of red jabon wood, while the leaching and water absorption in the wood significantly reduced. Heating at 180 ℃ caused less water absorption and higher dimensional stability of the wood than that of heating at 90 ℃. Impregnation with boric acid and MMA followed by heating at 90 ℃ resulted in the highest wood ASE, 89.9%. The color change (∆E^*) of wood increased significantly after MMA impregnation and heating at 180 ℃. Boric acid impregnation caused more resistant wood than borax impregnation against decay fungi and termites. Impregnation with boric acid and MMA followed with heating at 180 ℃ increased significantly the wood resistance against decay fungi and termites.

• Textile Coloration and Finishing
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• v.7 no.3
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• pp.1-10
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• 1995

The optical behavior of coloring matter extracted from onion's coats, the depression effects of destruction, yellowing and W transmittance of silk treated with color solution of onion's coats color difference of silk fabrics dyed with acid dyes and drycleaning fastness of silk treated with color solution has been investigated. The results are as follows : 1) The coloring matter extracted from onion's coats by alkali-acid method appeared properties of aglycon type. 2) &{\lambda}_{max}&of color solution extracted by distilled water was found at 280 and 327nm. 3) The decrease of tensile strength and the elongation of the silk treated with color solution were depressed but those of untreated silk were increased by irradiation of UV light. 4) The yellowness index of silk treated with color solution showed a little change by irradiation. 5) The UV transmittance of silk treated with color solution was decreased as increasing concentration of color solution. 6) The color difference after dyeing with several acid dyes on treated and untreated silk fabrics showed remarkable changes. 7) Drycleaning fastness of silk treated by color solution was excellent.

• Restorative Dentistry and Endodontics
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• v.46 no.4
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• pp.47.1-47.9
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• 2021

Objectives: This study aimed to use a laboratory model to evaluate the efficacy of an experimental bleaching agent. Materials and Methods: The model used human extracted molars that were treated and measured for bleaching efficacy. Teeth (n = 50) were distributed into 5 groups: Negative control (NC): immersion in water for 8 hours; Nanofibers (NFs): Experimental titanium dioxide nanofibers with stirring and light activation for 8 hours; Whitestrips (WS): Crest 3D White Glamorous White Whitestrips, 2 applications daily for 30 minutes, 14 days; 1% hydrogen peroxide (HP) standard: 1% hydrogen peroxide for 8 hours; and 30% HP standard: 30% hydrogen peroxide for 8 hours. Instrumental measurements were performed using a spectrophotometer. Results were recorded at baseline, 1-day post-bleaching, and 1-week post-bleaching. Kruskal-Wallis procedure was used to determine differences in color change. Pearson correlation was used to evaluate the relationship between visual and instrumental measurements. Tests of hypotheses were 2-sided with alpha = 0.05. Results: There was no significant difference in color parameters (L1, a1, b1, and shade guide units [SGU]) at baseline (p > 0.05). There was a significant difference among the groups for overall color change (ΔE^*ab) and change in shade guide units (ΔSGU) at 1-day and 1-week post-bleaching (p < 0.05). The higher the HP concentration, the higher the color change as expressed in ΔSGU and ΔE^*ab. The negative control exceeded the perceptibility threshold of ΔE^* = 1.2 regardless of time point. NFs showed a decrease in chroma, but were not statistically different compared to the negative control. Conclusions: The laboratory model was successful in screening an experimental bleaching agent.

• Tribology and Lubricants
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• v.24 no.1
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• pp.7-13
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• 2008

In this work, a simple and low cost sensor technique is proposed to test oil color in real time using in-line sensor. It is presented to use a ratio of intensity in red wavelength range to intensities of green and blue wavelength ranges (defined as a 'chromatic ratio') in order to estimate the oil color change. The proposed sensor technique is realized by irradiating a white LED as light source and a RGB color sensor as photoreceiver, and the chromatic ratio of various types of used oils are measured. The results show that chromatic ratio generally reflects chemical deterioration of oil, including oil oxidation and thermal degradation. It is concluded that the proposed sensor could be used for an effective oil monitoring technology.

• Journal of Power System Engineering
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• v.18 no.5
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• pp.55-59
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• 2014

This study performed experimental research to visualize the moisture content absorbed in R-22, refrigerant of refrigerator. Sulfuric acids were mixed with bromothylmol blue solution to make indicating solutions, and humidity papers were prepared by impregnation of the indicating solutions into solid supporters. Prior to the impregnation, small amount of lithium chloride was added into indicating solution. Moisture measuring cell was composed to test sensitivity of the humidity papers. Color changing characteristics of the humidity papers were also examined at various moisture contents in R-22. Color of the humidity paper varied linearly with the moisture content in R-22 in the range from 150 ppm to 300 ppm. The humidity papers showed complete color change to yellow at the moisture content of 300 ppm within 8 hours.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1998.11a
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• pp.138-141
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• 1998

To evaluate the color change of the opaque resin materials, a measuring system including PAS(photodegradation acceleration system) was constructed. Xenon lamp is used as a light source in the PAS, and the radiant energy from the lamp is irradiated to the samples through serveral high-pass filters with cut-off wavelength in UV and visible region. The color difference of the samples were measured by using the measuring system with a spectrophotometer(CM-2002) and a computer. The result showed that the opaque resin materials changed severely in their color in the wavelength of UV region and changed a little in the wavelength of visible region.

• Korean Journal of Human Ecology
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• v.9 no.3
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• pp.63-68
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• 2006

Walnut colorants were extracted from walnut hull and their dyeing properties on cotton were investigated. Effect of dyeing conditions on dye uptake and effect of mordanting on dye uptake, color change and colorfastness were explored. Walnut colorants showed low affinity to cotton compared with wool and its isotherm adsorption curve was Freundlich type. It was considered that hydrogen bonding and van der Waal's force were involved in the adsorption of walnut colorants onto cotton. The dyed cotton showed YR color and there was no significant color change as pH changed. The dyed cotton showed generally high colorfastness except fastness to washing and light. Mordanting did not improve dye uptake and colorfastness, and not affect color of the dyed cotton significantly.

• The Journal of Advanced Prosthodontics
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• v.16 no.3
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• pp.174-188
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• 2024

PURPOSE. The purpose of this study was to investigate the effects of surface treatments, liquids, and aging on color, translucency, and surface properties of monolithic ceramics. MATERIALS AND METHODS. Lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) ceramics (n = 135 each) were cut and divided into three groups [crystallization+glaze (single stage), crystallization-glaze (two stages), and crystallization-polish (two stages)]. One sample from each group was examined using scanning electron microscopy (SEM). Remaining samples were divided into four subgroups (distilled water, coffee, grape juice, and smoothie) (n = 11 each), stored for 12 d in the respective liquids, and thermally aged. One sample from each subgroup was analyzed using SEM. The color, gloss, and roughness values of the samples were analyzed after surface treatment (initial) and storage under different liquids+aging conditions. The initial data and both the aged data and data change values were analyzed using robust two- and three-way analyses of variance. RESULTS. The glazed groups exhibited smoother surfaces. Ceramic type and ceramic-surface treatment interactions affected the initial translucency parameter (TP) (P < .001) and the initial and aged roughness values (P ≤ .001). Surface treatment type affected the color change (P < .001), and ceramic type affected the aged TP values (P < .001). Type of ceramic, surface treatment, and their interactions affected both the initial and aged gloss (P ≤ .001) and TP change values (P ≤ .015). Surface treatment type and ceramic-surface treatment interactions affected the gloss change values (P ≤ .001). CONCLUSION. Although both ceramics and all surface treatments are clinically applicable, crystallization-glaze is recommended. When gloss and smoothness are important or when translucency is important, ZLS or LDS may be preferred, respectively.