• Title/Summary/Keyword: lightness index difference

Search Result 34, Processing Time 0.034 seconds

Effects of UV Absorber and HALS(Hindered Amine Light Stabilizer) Addition in Water-soluble Acrylic Resin on Discoloration of Larix leptolepis (S. et Z.) Gordon (수용성(水溶性) 아크릴 수지(樹脂)의 자외선(紫外線) 흡수제(吸收劑)와 HALS 첨가(添加)가 일본잎갈나무의 변색(變色)에 미치는 영향(影響))

  • Kang, Kyoung-Taek;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.24 no.4
    • /
    • pp.47-55
    • /
    • 1996
  • UV transmission spectra of water-soluble acrylic resin films containing hydroxybenzophenolic, hydroxyphenylbenzotriazolic UV absorber and HALS(hindered amine light stabilizer) were investigated by exposure time(before exposure weathered for 160 and 320hours) in QUV Weather-Ometer. Also the YID(yellowness index difference), LID(lightness index difference) and CD(color difference) of dried water-soluble acrylic resin films and the coated woods of Larix leptolepis were analyzed by addition level of UV absorber(0, 1, 2 and 3%) and HALS(0, 0.5, 1 and 1.5%) and by exposure time in QUV Weather-Ometer. They showed no significant effects on UV transmission spectra of dried water-soluble acrylic resin films in the range of 300 to 400nm irrespective of exposure time. However, UV transmission decreased as increase of exposure time. UV transmission spectra were lower in dried water-soluble acrylic resin films containing hydroxybenzophenolic UV absorber and HALS than in these containing hydroxyphenylbenzotriazolic UV absorber and HALS in the range of 350 to 400nm. The least YID, LID and CD in the coated woods of Larix leptolepis appeared at the addition level of 3%, based on non-volatile content, in hydroxybenzophenolic and hydroxyphenylbenzotriazolic UV absorber, and of 1.5% in HALS to water-soluble acrylic resin.

  • PDF

The survey on the skin color and pigmentation index in Korean adult subjects

  • Cho, Joon-Hwan;Yun, Ju-An;Bae, Ji-Yeon;Ha, Jea-Hyon
    • Proceedings of the SCSK Conference
    • /
    • 2003.09b
    • /
    • pp.438-447
    • /
    • 2003
  • We selected 113 subjects (male:59, female:54) in 20 to 29 age and observed the skin color difference between female and male. Also we measured the minimal persistent pigment darkening dose (MPPD) in same subjects. The skin colors of upper inner arm and back were measured with chromameter (CR10, Minolta, Japan) which represents skin color as $L^{*}$, $a^{*}$, and $b^{*}$ in value. MPPD was measured with solar simulator multi-port 601(Solarlight Co. USA). All statistical analysis was performed on the computer software package SPSS 8.0. The skin colors between male and female was significant difference in back and upper inner arm. There was significant difference of skin colors between back and upper inner arm in both male and female. There was no relationship existed between the values of MPPD and skin color ( $L^{*}$ $a^{*}$ $b^{*}$) of back in both male and female. As a result of survey, we knew that there was apparent difference of skin color between back and upper inner arm due to gender. Also we hope these data will be helpful to study on the correlation of the pigmentation index and skin color.(omitted)omitted)ted)

  • PDF

A STUDY ON THE COLOR CHANGES OF DISCOLORED NONVITAL TEETH BY THE NONVITAL BLEACHING TECHNIQUES (표백방법에 따른 번색된 무수치의 색조 변화에 관한 연구)

  • Park, Hyun-Hee;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
    • /
    • v.19 no.1
    • /
    • pp.169-179
    • /
    • 1994
  • The purpose of this study was to compare and evaluate the bleaching efficacy of three nonvital bleaching techniques: Walking bleaching, Walking bleaching and heat application, and Walking bleaching and bleaching light application. 36 extracted anterior teeth with intact crowns were immersed in 5 % sodium hypochlorite solution for twenty-four hours to loosen extrinsic debris. Lingual access openings were prepared in all teeth and the pulps were extirpated. The teeth were stored in 5% sodium hypochlorite for twenty-four hours to open the dentinal tubules and they were stained via whole blood. Once the teeth were stained, they were evaluated with Colorimeter. The teeth in each group were ranked from lightest to darkest and divided equally into three experimental groups in which the following bleaching techniques were used. Intracoronal base was placed 2mm below cementoenamel junction. Group 1 Walking bleaching (Superoxol + Sodium perborate) Group 2 Heat application + Walking bleaching (Superoxol+Sodium perborate) Group 3 Light application+Walking bleaching (Superoxol+Sodium perborate) The bleaching agents were changed every 3 days and the teeth were bleached for a total of 14 days. The teeth were evaluated with Colorimeter before the start of any bleaching and on day 14. The results were as follows: 1. At the end of 14 days, all the sample teeth demonstrated the increase of Lightness Index at cervical 1/3 of crown (p<0.05) Lightness Index was significant difference in group 2 and 3, but there were some minor differences among groups (p>0.05). 2. In all groups, there was significant difference in red chromacity (p<0.05), but there were some minor differences among groups (p>0.05). 3. In all groups, there was no significant difference in yellow chromacity (p>0.05).

  • PDF

Analysis of Surface Color Characteristics of Wood in Accelerated Weathering Test (촉진열화실험에 따른 목재 부재의 재색 특성 분석)

  • Kim, Gwang-Chul;Park, Chun-Young
    • Journal of the Korea Furniture Society
    • /
    • v.26 no.3
    • /
    • pp.262-266
    • /
    • 2015
  • This study was carried out to analyze the surface color change according to the weathering time. The surface color of material was one of evaluation indexes in exposure experiment. For the purpose, accelerated weathering test was performed with wood. The weathering time level was composed with 0, 500, 1000, 1500 and 2000 hours and color difference was estimated with the color difference meter. The surface color was changed to 500 hours that lightness and redness were decreased and yellowness was increased. However it did not changed after 500 hours. It means that the surface color could be the evaluation index of deterioration of the wood but it means very little after certain time.

Effect of Isocyanate Curing Agents on the Physical Properties and Flame Retardancy of Flame-Retardant PU Coatings (이소시아네이트 경화제 종류에 따른 PU 난연도료의 도막물성 및 난연효과)

  • Park, Hong-Soo;Shim, Il-Woo;Jo, Hye-Jin;Hahm, Hyun-Sik;Kim, Young-Geun
    • Journal of the Korean Applied Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.264-271
    • /
    • 2006
  • PU type flame-retardant coatings (TBAO/L-75, TBAOL ; TBAO/N-100, TBAON) were prepared by blending bromine-containing modified polyester (TBAO) which was synthesized in our earlier work. with two kinds of isocyanate curing agents, Desmodur L-75 and Desmodur N-100. Physical properties of the prepared flame-retardant coatings were tested. TBAOL shows better hardness than TBAON, while TBAON shows better viscosity, accelerated weathering resistance, yellowness index and lightness index difference than TBAOL. There were no remarkable differences in fineness of grind, $60^{\circ}$ specular gloss, cross-hatch adhesion, and abrasion resistance of TBAOL and TBAON. There was no discernable difference in flame-retardancy between the two flame-retardant coatings, TBAOL and TBAON. When the content of tribromo acetic acid, which is flame-retarding component, was 30wt% the LOI value was in a range of $29{\sim}30%$, which indicates that the two coatings are good flame-retardant coatings.

Early Postmortem Processing Conditions on Meat Quality of Hanwoo (Korean Native Cattle) Beef during Storage

  • Kim, B.C.;Rhee, M.S.;Ryu, Y.C.;Imm, J.Y.;Koh, K.C.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.12
    • /
    • pp.1763-1768
    • /
    • 2001
  • The combined effects of low voltage electrical stimulation (ES) and early short-term temperature conditioning on meat quality of Hanwoo beef (Korean native cattle) during storage were investigated. Shear force was influenced by ES and aging. Combination of ES and the $30^{\circ}C$ conditioning resulted in higher myofibril fragmentation index and improved lightness. There was no substantial difference in drip loss among treatments but ES samples showed higher cooking loss than control. Negative effect on shelf-life was not found by early short-term high temperature conditioning. Therefore, the meat quality of Korean native cattle was effectively improved by the combination of ES and the $30^{\circ}C$ conditioning.

2-Packaged Polyurethane Coatings(II);Preparation and Physical Properties of Polyurethane Coatings (2액형 폴리우레탄 도료에 관한 연구(II);폴리우레탄 도료의 제조와 도막물성)

  • Kim, Seon-Kil;Chung, Kyeng-Teak;Park, Hong-Soo
    • Journal of the Korean Applied Science and Technology
    • /
    • v.12 no.1
    • /
    • pp.19-27
    • /
    • 1995
  • The 2-packaged polyurethane coatings were synthesized, blending pheylmodified polyesters(of which synthetic methods were reported in the previous paper), Desmodur L-75(polyisocyanate wide1y used for coatings), wetting-dispersing agent, white pigment. etc. A variety of coating properties were tested for the coating treatment polyurethane coationgs. Compared with conventional 2-packaged polyure-thane coating, abrasion resistance and lightness index difference of the ones synthesized in the present work were somewhat decreased, but the coating properties such as hardness, gloss specular, cross hatch adhesion. etc. were improved. Especially, resistance against chemical reagents and salt were strikingly improved. In addition. the coationgs had short drying time and long pot-life. This shows that the coationgs are appropriate for rapid drying coatings.

Effects of Acetic Acid Concentration on Rheological Characteristics and Emulsion Stability of Mayonnaise (마요네즈의 유동 특성과 유화 안정성에 미치는 초산 농도의 영향)

  • 배효미;오명숙
    • Korean journal of food and cookery science
    • /
    • v.5 no.1
    • /
    • pp.9-13
    • /
    • 1989
  • The effect of acetic acid concentration on the qualities of mayonnaise was studied. The rheological properties, emulsifying stability and color of the mayonnaise were determined by rotary viscometer, rotary shaker and centrifuge, and color and color difference meter, respectively. The rheological behavior of mayonnaise showed plastic behavior with yield stress and that of shear thinning. The yield stress and consistency index increased as the acetic acid concentration increased. The emulsion stability was lowest at 4% acetic acid concentration and highest at 1% acetic acid concentration. With the increase of the acetic acid concentration, lightness increased and yellowness decreased.

  • PDF

Effects of Young Barley Leaf Powders on the Quality Characteristics of Yellow Layer Cakes (보리순 분말의 첨가가 Yellow Layer Cake의 품질특성에 미치는 영향)

  • Kim, Yeoung-Ae
    • Food Science and Preservation
    • /
    • v.18 no.6
    • /
    • pp.830-835
    • /
    • 2011
  • This study was conducted to evaluate the effects of the substitution of flour with young-barley-leaf powder on the quality characteristics of yellow layer cake. The physical properties of the cakes (i.e., viscosity, specific gravity, specific volume, cake index, and color) were measured, and the changes in hardness during the three-day storage at $22^{\circ}C$ were measured. Sensory evaluation was done with five-scale acceptance test. Both the viscosity and specific gravity of the batter were significantly influenced by the substitution. Nonetheless, no significant difference was shown in the specific volumes of the cakes. The volume indices of the cakes containing young-barley-leaf powder were higher than those of the control. The lightness, redness, and yellowness values of the crusts decreased with the addition of young-barley-leaf powder. While the lightness values of the crumbs decreased, the redness and yellowness values increased. The substitution of more than 6% flour with young-barley-leaf powder kept the hardness of the cakes lower than that of the control during the three-day storage. The cakes containing 2, 4, and 6% young-barely-leaf powder showed no significant differences from the control in the acceptance test, except in the crumb color.

A Comparative Study on the Physiological Activities of Puffed Snack using Miscellaneous Cereals and Grain Crops (곡류 및 잡곡류를 이용한 팽화과자의 생리 활성 비교연구)

  • Yoon, Hyang-Sik;Yu, Ri;Noh, Jae-Gwan;Kim, Yee Gi;Kim, Sang Hee;Choi, Song Yi;Han, Nam Soo;Eom, Hyun-Ju
    • The Korean Journal of Food And Nutrition
    • /
    • v.27 no.5
    • /
    • pp.962-970
    • /
    • 2014
  • This study was performed to compare the physiological effects of puffed snack on diabetic and geriatric diseases using miscellaneous cereals and grain crops. The puffed snacks were prepared with different amounts of miscellaneous cereals and grain crops (in ratios of 10%, 20%, and 30% of brown rice). Changes in the water soluble index, water absorption index, color, antioxidant activity, total polyphenol content acidity, ${\alpha}$-glucosidase inhibition activity, and sensory evaluation were also determined. As the cereal and crop contents increased, the value of the water soluble index increased while the water absorption index decreased, with the exception of glutinous foxtail and barnyard millets. With respect to color, lightness and yellowness decreased in concert with increases in the cereal and crop contents, whereas redness increased. Furthermore, the antioxidant activity and total polyphenol content as well as ${\alpha}$-glucosidase inhibition activity increased remarkably with increasing concentrations of sorghum. There was no significant difference in the physiological activities depending on the addition of millet, barley and barnyard millets. In sensory evaluation, the puffed snacks containing sorghum, millet, and glutinous foxtail millet received higher values than other samples. Altogether, our results indicate that puffed snacks containing 10~20% sorghum could be suitable as ingredients for improving sensory and physiological activities in diabetic and geriatric diseases.