• Smart Structures and Systems
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• v.18 no.5
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• pp.865-884
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• 2016

We have previously demonstrated a microfluidic elastomer, which changes apparent color and could have potential applications in smart windows. The practical use of such functional microfluidic systems requires rapid and uniform fluid displacement throughout the channel network with minimal amount of liquid supply. The goal of this simulation study is to design various microfluidic networks for similar applications including, but not limited to, the color-switching windows and compare the liquid displacement speed and efficiency of the designs. We numerically simulate and analyze the liquid displacement in the microfluidic networks with serpentine, parallel and lattice channel configurations, as well as their modified versions with wide or tapered distributor and collector channels. The data are analyzed on the basis of numerical criteria defined to evaluate the performance of the corresponding functional systems. We found that the lattice channel network geometry with the tapered distributors and collectors provides most rapid and uniform fluid displacement with minimum liquid waste. The simulation results could give an important guideline for efficient liquid supply/displacement in emerging functional systems with embedded microfluidic networks.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.497-501
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• 1997

Kinetic parameters on heat-induced color changes of anthocyanin pigment from purple sweet potato were determined in the temperature range of $121{\sim}141^{\circ}C$. Color change determined by a browning index $(A_{532}\;nm/A_{420}\;nm)$ followed second order reaction kinetics. Activation energy values of purple sweet potato pigment solutions of pH 2.0, 3.0, 4.0 and 5.0 were 69.57, 76.68, 81.07 and 92.98 kJ/mol, respectively, indicating that temperature dependency of the reaction increased with pH. Apparent kinetic compensation effect between preex-ponential factor and activation energy value was observed.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1218-1223
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• 2003

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.413-418
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• 2001

The moire phenomena, which are induced by mask vibration due to the excitation of speakers, degrades the color purity of CRT. So it is important to eliminate this phenomena to obtain a good CRT design. In this study we analyze the mask vibration by experiment as well as finite element method. To obtain the finite element solutions efficiently, an equivalent model was employed. The experimental and analysis results show reasonable agreements. An enhanced design configuration of mask welding points are suggested through this study.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.444-449
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• 2010

The aim of this study was to measure the hair melanins of various colors and to find the relationship between the quantity of melanins and hair color phenotypes in alpacas. According to the Munsell color system, 3 healthy alpacas were selected for each of the 22 different hair color phenotypes (66 alpacas altogether). Alpaca hair was taken from the lateral thoracic region and then dissolved with different solutions to obtain melanins. The values of alkali-soluble melanins (ASM), eumelanin (EM) and pheomelanin (PM) were measured by spectrophotometric assay, and labeled as Sp.ASM, Sp.EM and Sp.PM, respectively. Data were analyzed using SPSS11.5 software. Results showed that average Sp.ASM and Sp.PM were increased as the color deepened from white to black, ranging from 0.500 to 4.543 for Sp.ASM and from 0.268 to 1.457 for Sp.EM. However, average Sp.PM had no such apparent relationship with color. Based on the value of Sp.ASM and EM, 7 hues were produced and gray was a single hue. Most of the data were in a normal distribution (p>0.10). ANOVA analysis showed that mean values of Sp.ASM, Sp.EM and Sp.PM were significantly different (p<0.05). The results also showed that Sp.ASM was positively correlated with Sp.EM but the correlation between Sp.ASM and Sp.PM was not significantly different from 0. It is concluded that EM is the major constituent of alpaca hair melanin; there is a significant correlation among ASM, EM and alpaca hair colors, and EM is the most reliable parameter for distinguishing these groups.

• Textile Coloration and Finishing
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• v.6 no.2
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• pp.40-46
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• 1994

In order to study the properties of cochineal color, variation of uv, visible spectra by pH, dyeing properties on the silk in several dyeing conditions and thermodynamic parameter were investigated. Cochineal colors had an unusual to pH, especially had instability in alkali condition. An increase in the dyeing temperature and in time resulted in an increase in the dye content of silk fibers. Concentration of cochineal color in the silk fiber was related to pH and the maximum exhaustion of cochineal colors showed at about pH 3. The value of apparent diffusion coefficients and standard affinities of dyeing increased with the increase of dyeing temperature. The standard heats of dyeing(ΔH°), variation of entropy(ΔS°) and activation energy(E/sub act/) were caculated to be -1.72kcal/mo1, -3.77cal/mo1ㆍdeg and 1.26kcal/mo1, respectively. Silk fabrics were dyed bright red by tin chloride, reddish purple by copper sulfate, and bluish gray by iron sulfate, respectively. Lightfastness of silk fabrics mordanted by metal ion was weak.

• The Korean Journal of Food And Nutrition
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• v.6 no.1
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• pp.31-36
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• 1993

Strawberry pulp was separated into serum and insoluble pulp by centrifugation and the serum was concentrated in vacuo to five folds at 55~58$^{\circ}C$ and 30~60mmHg. Concentrated strawberry pulp was prepared by mixing of concentrated serum and insoluble pulp. To evaluate the quality changes of straw-berry pulp, color, physicochemical and sensory properties were analyzed after concentration and during 18 weeks storage at -18'2. The results obtained from the study were as follows : during 18 weeks storage at - l8$^{\circ}C$, soluble solid, browning, reducing sugar content were increased and total anthocyanin, vitamin C, apparent viscosity were decreased. The result of sensory evaluation indicated that texture of concentrated pulp was inferior to that of control but flavor, color intensity and overall acceptance were not different from each other.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3621-3625
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• 2010

Colored cubic-zirconia specimens made by skull melt process were annealed in vacuum at the temperature of $1200^{\circ}{\sim}1400^{\circ}C$ for 10~60 minutes to enhance the color. The three different colored specimens become darker and eventually are black as annealing temperature and time increase. Conventional gem stone grading method and XPS were employed to quantify the property change and to reveal the mechanism of the color change. Color was changed apparently but the hardness and apparent density did not vary with annealing. Based on XPS result, we concluded that the main cause of the color change in cubic zirconia might be the change of Y-O bonding energy state of $Y2_O_3$ phase-stabilizer by vacuum annealing.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.57-65
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• 2004

Digital photographs of 16 pork chops were each modified to give 16 treatments, such as two levels each of fat cover, color, marbling and drip, giving a total of 256 images. Consumers from three locations in France and six locations in Korea selected their preferred chop from 16 treatments in different chops and repeated this selection process eight times from different groups of chops, respectively. Respondents were asked to complete a questionnaire on socio-demographic information. Both the results of the French and Korean surveys gave four clusters of consumers, but they were not the same in terms of the choice strategies used, or in terms of their relationships with the socio-demographic items. The interesting apparent similarities (such as, both color levels being equally important to consumers in both countries) and differences(such as, the strong preference for lean meat in France; no fat preference in Korea) suggest a need to compare the results from the two countries. However, due to the difference of the socio-demographic make-up of the consumer panels from the two countries, a simple and direct comparison of the clusters based on choice and their relationships with the questionnaire items is not possible, but is currently being explored.

• Textile Coloration and Finishing
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• v.19 no.2
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• pp.36-43
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• 2007

Dyeing and fastness properties of a dyeable PP fiber were examined with four different types of disperse dyes. It was found that the dyed PP fiber could be cleared by soaping without using sodium hydrosulphite, and that the heat setting above $140^{\circ}C$ resulted in the melting of the PP fiber. The rates of dyeing and the extents of exhaustion of three primary E type dyes were different with each other, the apparent color strength did not increase with increasing dye concentration, and color fastness to washing was not satisfactory. In the cases of both high wash fastness and high light fastness dyes, the rates of dyeing were slow and the extents of exhaustion were very low. On the other hand, the dyeing rates of three primary S type dyes were similar and the build-up properties were good with good color fastnesses. It might be concluded that the best disperse dyes for the dyeable PP fiber were S type dyes.