• Journal of the Korean Chemical Society
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• v.50 no.2
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• pp.99-106
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• 2006

The electronic absorption spectra of [3-(2-thenoyl) 3-(p-NO2-phenylhydrazone) ethyl pyruvate] (I), p-Br (II) and p-CH3 (III) were studied in ethanol and the spectra comprise four absorption bands which assigned to the corresponding electronic transition. The pK values of these compounds have been determined spectrophotometrically and pH-metrically, the results shown that the interval range for color change of compound (I) is (8-10) similar to that of phenolphethalin indicator, indicating that this compound can be used as acid-base indicator. The successive stability constants of the compounds under study with some transition elements (Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO2(II), La(III) and Zr(IV) have been determined pH- metrically. Stoichiometric complexes with ratios 1:1 and 1:2 (M: L) were formed for all metals. The pK of the three derivatives and the values of the stability constant (logK) of the complexes have the order; III > II > I. Also conductometric titrations have been carried out and the results show that this titration can be used for determination of both the metal ion and the ligand concentrations by each others.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.452-456
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• 1987

Acidic strength of benzenesulfonic acid (HBs) and it's derivatives, p-toluenesulfonic acid(HTs), p-chlorobenzenesulfonic acid(HCs) and m-nitrobenzenesulfonic acid(HNs), were measured in the anhydrous acetic acid medium by spectrophotometry. p-naphtholbenzein (PNB) was used as an indicator base and the ionization constants of HTs, HBs, HCs and HNs were $3.5{\times}10^2,\;4.1{\times}10^2,\;19.3{\times}10^2\;and\;50{\times}10^2$, respectively, at 20.0${\pm}$0.1$^{\circ}$C.

• Korean Journal of Pharmacognosy
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• v.20 no.2
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• pp.88-95
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• 1989

Traditional Chinese herbal drugs, namely, Atractylodes Rhizome and Atractylodes Rhizome White were identified by means of chemical analysis such as TLC and GC/MS. In Korea, the old-grown and the newly-grown rhizomes of Atractylodes japonica Koidzumi (Compositae) are used as the Atractylodes Rhizome and the Atractylodes Rhizome White, respectively. Both rhizomes contain the atractylon asa major spot on TLC. The content of atractylon in a newly-grown rhizome of A. japonica (Atractylodes Rhizome White called in Korea) appears to contain much larger quantity in comparison with that of an old-growon one (Atractylodes Rhizome). The TLC spot pattern analysis showed that rhizomes of A. japonica and A. macrocephala contain the atractylon as a major indicator spot, but no atractylodin (extreamly small amount). However, rhizomes of A. lancea De Candolle and A. koreana Kitamura contain the atractylodin as a major indicator spot.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.540-544
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• 2012

During heat treatment and storage of milk, deteriorative reaction takes place, which consequently influence on the milk quality. In this study, formation of lactulose and furosine under different thermal conditions and storage conditions, and the ratio of lactulose and furosine (LU/FU) in presence of reconstituted milk powder were determined to establish chemical indicators for heat damages of milk and the adulteration of fresh milk in dairy field. The lactulose and furosine contents linearly increased with increased heating temperature and heating time. It showed high correlation between the formation of lactulose and furosine, and the treatment temperature and time (p<0.05). The lactulose and furosine concentration of HTST milk and UHT milk noticeably increased during storage at $30^{\circ}C$, but there was no noticeable increase of lactulose and furosine concentration at lower storage temperature. In the raw milk, the lactulose and furosine contents greatly increased with the addition of reconstituted milk. The increase level of furosine was much higher than that of lactulose, which consequently resulted in the lower LU/FU ratio in milk as increase of added reconstituted milk amounts. As comparing with raw milk, there was more than twice reduction in LU/FU ratios after the addition of reconstituted milk (p<0.05). It can be concluded that lactulose and furosine are suitable milk quality indicators of heat damage and for demonstrating improper addition of reconstituted milk powder.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.279-288
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• 2013

Objectives: Effectiveness and conditions of vapor-phase hydrogen peroxide (VPHP) system on decontamination of Geobacillus stearothermophilus(GS) spores, Escherichia coli (E.coli) and Enterobacteria phage felix01 (felix01) were determined. Methods: The VPHP system was designed to vaporize 35% (w/w) solution of hydrogen peroxide, continuously to inject and withdraw VPHP. The system and VHP 1000ED (Steris) were operated such that dehumidification and conditioning were initiated without samples in the chamber. Then the samples were loaded into and removed. Coupons (glass, anodizing, silicon, viton) with GS spores ($1{\times}10^6$ colony forming unit/mL [CFU/mL]), E.coli ($1{\times}10^7$ CFU/mL) and felix01 ($1{\times}10^7$ plaque forming unit/mL[PFU/mL]), and Biological Indicator (BI) with GS spores ($1{\times}10^6$ CFU/mL) on stainless steel coupons were used. The tested samples were sonicated and vortexed, and then were plated for enumeration, followed by incubation at $55^{\circ}C$, 24 hr for GS spores, and at $37^{\circ}C$, 24 hr for E.coli and felix01. BI analysis in broth culture was only qualitative. Results: The efficacy of the VPHP system on decontamination was almost equivalent to that of VHP 1000ED. The conditions for complete decontamination with the VPHP system was as follows: concentration; 700~450 ppm, relative humidity; approximately 55%, and temperature; $34{\sim}32^{\circ}C$. When comparing the decontamination efficiency among different kinds of coupons, glass was the most effective, however, all kinds of coupons were decontaminated completely after 60 min exposure in both systems. Conclusion: The VPHP system can be recommended as an alternative system for traditional system using ethylene oxide, formaldehyde or chlorine dioxide.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.58-66
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• 1997

In order to evaluate the exact effect of detergency it is necessary both to measure the actual soil content by chemical analysis and to determine the degree of soil removal visually. Since it takes considerable time and effort to use both methods, usually one of the two methods is used. Many studies have been carried out through increasing the visibility of oily soil to evaluate detergency by measuring reflectance of fabrics. In this study Sudan Black B, an oil soluble dye was used as an indicator to increase the visibility of oily soil on cotton and polyester fabrics. The condition of artificially soiled fabrics and the method of evaluating detergency were investigated which represent the actual detergency of oily soil by measuring the reflectance only. Also the detergency of Sudan Black B and that of oily soil were compared with each other under various washing conditions, As a result, the K/S values converted from the reflectances showed a good correlation with the actual soil content. Linear relationship between K/S value and the actual soil content was obtained. The K/S values of washed fabrics were higher than those of unwashed fabrics which included same content of soil since the soil visibility changed during washing. But the difference was small when Sudan Black B was used. With the increase of soil content, detergency of cotton fabric decreased, but detergency of polyester fabric increased gradually. With regards to soiled fabrics, detergency of cotton fabric measured by K/S value was close to that of actual oily soil when Sudan black B was used as an indicator.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.2
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• pp.92-97
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• 2002

One of the important roles of a DNA chip is the capability of detecting genetic diseases and mutations by analyzing DNA sequence. For a successful electrochemical genotyping, several aspects should be considered including the chemical treatment of electrode surface, DNA immobilization on electrode, hybridization, choice of an intercalator to be selectively bound to double standee DNA, and an equipment for detecting and analyzing the output signal. Au was used as the electrode material, 2-mercaptoethanol was used for linking DNA to Au electrode, and methylene blue was used as an indicator that can be bound to a double stranded DNA selectively. From the analysis of reductive current of this indicator that was bound to a double stranded DNA on an electrode, a normal double stranded DNA was able to be distinguished from a single stranded DNA in just a few seconds. Also, it was found that the peak reduction current of indicator is proportional to the concentration of target DNA to be hybridized with probe DNA. Therefore, it is possible to realize a sim71e and cheats DNA sensor using the electrochemical measurement for genotyping.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.31-38
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• 2013

If the time-temperature indicator (TTI) experienced a different temperature than the accompanied packaged food, influenced by heat transfer between the TTI, package, and ambient air, TTI would incorrectly predict the food quality changes with temperature. Temperature distributions of a finite slab with different sizes, representing beef packaged with TTI, were estimated by the finite element method (FEM). The thermal properties of the beef and TTI, such as heat capacity, density, and heat conductivity, were estimated from the relevant equations using their chemical compositions. The FEM simulations were performed for three cases: different locations of TTIs on the beef, different thicknesses of beef, and non-isothermal conditions of ambient air. The TTIs were mounted in four different locations on the beef. There was little difference in temperature between four locations of the TTI on the package surface. As the thickness of the slab increased, the temperature of the TTI changed faster, followed by the corner surface, as well as middle and bottom parts, indicating the possible error for temperature agreement between the TTI and the slab. Consequently, it was found that any place on the package could be selected for TTI attachment, but the package size should carefully be determined within a tolerable error of temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.167-180
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• 2018

Interest in the use of smart packaging systems for food products has increased in recent years. Therefore, food researchers are focusing on the development of new indicator based smart packaging technologies by using anthocyanin-based natural dye. Anthocyanins are one of the plant constituents known as flavonoids and responsible for the bright and attractive orange, red, purple, and blue colors of most fruits, vegetables, flowers, and some cereal grains. Indicators of natural dyes such as anthocyanins could express the quality and shelf life of perishable food products. However, the sensitivity and stability for their use in smart food packaging should be established to reach the market proposals. This review article focuses on recent studies related to use of natural dyes based on anthocyanin for smart food packaging applications. This study offers valuable insight that may be useful for identifying trends in the commercialization of natural dyes or for identifying new research areas. This review also provides food and packaging scientists with a thorough understanding of the benefits of anthocyanin-based natural dyes for shelf life indicator when applied to package material specific foods and hence can assist in accelerating commercial adoption.

• Textile Coloration and Finishing
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• v.18 no.5 s.90
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• pp.53-60
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• 2006

The 1,3-bis(4-aminoaryl)squaraines showed color, change behavior, they were found to undergo reduction with sodium borohydride in solution to give colorless leuco compounds, which oxidized readily in air back to the colored squaraine dye. We have shown that initial observations indicated that the derivatives synthesized gave new donor-acceptor chromophores. It is also interesting to note than the oxidation of the leuco squaraines did initially produce a species absorbing about 630-680 wavelengths. The 1,3-squaraines have found many uses as near-infrared absorbers, laser dyes and photoconductive materials. Furthermore their color-change redox behavior has potential in the area of peroxidase-based bioassaysas oxidation sensitive indicator systems were investigated.