• Journal of Korean Society of Water and Wastewater
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• v.37 no.4
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• pp.187-202
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• 2023

This study focuses on the application of a new measurement method that quantifies the residual color of filtered water using a spectrocolorimeter after filtering the discolored substances. It was confirmed through the color and turbidity cross-test that the discolored substances cannot be measured effectively with the current legal color and turbidity test method. Therefore, the National Institute of Environmental Research's filter testing method, which involves filtering the sample through 0.45 ㎛ filter and visually inspecting the color, was improved. A membrane filter colorimetry (MFC) method was established by measuring the color difference (ΔE*ab(65)) of the filtered filter using a spectrophotometer and expressing it as filter color unit (FCU). Using the MFC method, the FCU for reference materials such as iron and manganese, as well as field samples, was measured. The results showed a high correlation with turbidity, and the color difference patterns varied depending on the type of reference materials and field samples. This indicates that the MFC method is an effective new measurement method of discolored tap water.

• The Journal of the Korean dental association
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• v.9 no.4
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• pp.151-157
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• 1971

Freshly extracted permant teeth were examined by electron microscope according to the Filmy replica method. Preparatory method with hydrochloric acid or proteolytic enzyme treatment was used in order to injure the structural composition of enamel surface to compare between the natural carious defects and the etched samples used in this study. The natural carious defects were chalky white or brown discolored portions at the smooth enamel surface without having visible loss of enamel substances. The findings were as follows: 1. The first caries attact initiated from the mineralized portion of rod sheath which is located at the top of enamel rod. 2. The caries developed downward along the rod sheath interprismatic substances and enamel rods subsequently. However, the caries involvement of interprismatic substances and enamel rods occured almost at the same time. 3. The rod sheath attached to the remineralized smooth emael surface was located at the top of enamel rod.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.343-351
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• 2016

The objective of this study was to evaluate the effects of a short-term/extreme temperature abuse (STA) on color characteristics and oxidative stability of aged beef muscles during simulated retail display. Two beef muscles (longissimus lumborum, LL and semitendinosus, ST) were aged for 7 (A7), 14 (A14), 21 (A21), and 28 d (A28), and further displayed at 2℃ for 7 d. The STA was induced by placing steak samples at 20℃ for 1 h on the 4th d of display. Instrumental and visual color evaluations, ferric ion reducing capacity (FRC) and 2-thiobarbituric acid reactive substances (TBARS) assay were performed. Initially, redness, yellowness and hue angle of all beef muscles were similar, regardless of aging time before display (p>0.05). An increase in postmortem aging time increased lipid oxidation and caused a rapid discoloration after STA during display (p<0.05). ST muscle was more sharply discolored and oxidized after STA, when compared to LL muscle (p<0.05). The FRC value of beef muscles was decreased after 7 d of display (p<0.05). The results from the current study indicate adverse impacts of postmortem aging on color and oxidative stabilities of beef muscles, particularly under temperature abusing conditions during retail display. Thus, developing a specific post-harvest strategy to control quality attributes in retail levels for different muscle types and aging conditions would be required.

• KSBB Journal
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• v.28 no.5
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• pp.287-294
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• 2013

Stained and discolored hair will be damaged by the shampooing, daily UV disposal, and the use of hair dryer. Thus many studies about the effect of various natural substances on the re-secure the skin and scalp are recently reported. This study was carried out to investigate the effect of green tea (Camelloia sinensis) seed oil on colored (dyed) and decolored (bleached) hair. The beneficial effects of green tea seed oil are already well known, but little research has been done about the hair treatment and fade-resistant effect. Dyed and bleached hair was pretreated with green tea seed oil to determine the tensile strength and elongation of the hair, to analyze the hair surface using SEM, and to compare the color fade using spectrocolormeter. The results showed that the tensile strength increased with green tea seed oil pretreatment samples for virgin, dyed, and bleached hairs. Elongation showed the reverse results showing the presence of hair treatment effect. The results of the surface pre-treatment in all groups analyzed by SEM, the hair cuticle became sharper, so coating effect were identified with all samples. The value of the $L^*$, $a^*$, $b^*$ decreased with washed hairs damaged by UV irradiation and the values were decreased also in dyed and bleached hair. In summary, green tea seed oil prevent reinjury to the heat and UV rays for colored and decolored hairs. Cosmetic practice effects of the oil were identified in the field to be appropriate to the customer's skin and scalp that natural cosmetic oils would like to offer.