• 상하수도학회지
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• 제37권4호
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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.

• 대한치과의사협회지
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• 제9권4호
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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.

• 한국축산식품학회지
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• 제36권3호
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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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• 제28권5호
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• pp.287-294
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• 2013

염색 및 탈색된 헤어는 일상생활 중의 자외선, 열기구 사용수세 (샴푸)에 의해 재손상되며, 이의 해결을 위해 최근 피부와 두피에 안전한 각종 천연물질의 연구가 활발하다. 이 연구는 녹차씨 오일의 광퇴색 방지와 모발 트리트먼트 효과를 확인하고자 수행되었다. 그러나 녹차의 기능은 이미 많이 알려져 있으나 녹차씨 오일을 이용한 모발 트리트먼트 및 퇴색 방지의 연구는 미비하다. 염색 및 탈색된 헤어에 녹차씨 오일을 이용한 전처리 트리트먼트 효과를 알아보기 위해 인장 강도 및 신장율을 측정하고 모발표면을 SEM으로 분석하였으며 색차계를 이용한 모발 광퇴색을 비교하였다. 실험결과 모발의 인장강도와 신장율의 측정에서 녹차씨 오일 전처리 시료는 버진헤어, 염색헤어, 탈색헤어에서 모두 증가하였고 신장율은 염색헤어와 탈색헤어에서 낮아져 염색헤어와 탈색헤어에서 트리트먼트 효과가 있었다. 모발표면을 촬영한 결과 모든 군에서 전처리된 모발 큐티클의 문리가 더 선명하고 코팅효과가 확인되었다. 모발의 광퇴색 값은 열과 수세의 반복 실험에서 전처리된 각 시료 모두 $L^*$, $a^*$, $b^*$값이 감소하였고 자외선 조사 실험에서는 염색과 탈색헤어에서 $L^*$, $a^*$, $b^*$값이 각각 감소하였다. 위의 실험결과에 의해 녹차씨 오일은 염색 및 탈색모발의 재손상 방지와 열과 자외선에 의한 색상의 퇴색방지 효과를 확인하였으며 앞으로 미용 실무현장에서 고객의 피부와 두피에 적합한 천연화장품 오일로 사용이 가능하리라 사료된다.