scholarly journals Color Characteristics of Red False Heartwood and Mature Wood of Beech (Fagus sylvatica L.) Determining by Different Chromacity Coordinates

2019 ◽  
Vol 11 (3) ◽  
pp. 690 ◽  
Author(s):  
Ivan Klement ◽  
Tatiana Vilkovská

Structure of wood can affect intensity of color change in remarkable ways. This article was focused on the analysis of the color changes red false heartwood and mature wood by different methods such as ΔE* (Total color difference), h* (Hue angle), C*ab (Color saturation) and Sab (Saturation). The aim of this study was to evaluate the color properties of red false heartwood and mature wood by using different chromacity coordinates. Our observations suggested that the density in the absolute dry state was equal between the red false heartwood and mature wood. The biggest difference was in the area of the free water domain, thus from an initial MC value to the fiber saturation point (FSP). The shorter drying time of the red false heartwood samples was caused by their lower initial MC. Due to the different MC, the temperature created a different color intensity of the compared samples. Mature wood samples achieved more saturated color in the drying process than did the samples of red false heartwood.

2020 ◽  
Vol 328 ◽  
pp. 04004
Author(s):  
Ladislav Dzurenda

The paper presents a mode for drying steaming maple timber of thickness h = 38 mm from moisture W1 = 50 % to W2 = 10 %, while preserving the color of wood obtained by the steaming process. The drying process is divided into two parts. Evaporation of free water from wet wood at drying medium temperatures td = 35 - 40 °C and evaporation of water from wood below the hygroscopicity limit W ≤ 25 % at drying medium temperatures td = 70 - 80 °C. Total color difference ΔE* determined by the difference in values on the CIE L*a*b* color space coordinates dried by the proposed mode for steaming maple timber and the reference values ΔE* = 1.03. According to the categorization of wood color changes in thermal processes by work (Cividini et al. (2007), this change belongs to the category of small color changes. A negative aspect of this drying mode is the approx. 25 % increase in timber drying time.


2019 ◽  
Vol 5 (2) ◽  
pp. 132
Author(s):  
Nurlela Nurlela ◽  
Risnawati Risnawati

The Influence of Resin against the Change of Color on the Wall PaintThe quality of the paint is determined by the resin used. Synthetic resins for polymer paints are made by combining several monomers to achieve various characteristics. The incorporation of some monomers such as polyvinyl acetate resin, acrylic vinyl resin and acrylic styrene resin which act as a binder can affect the quality of the paint especially the color change. The purpose of this study is to find the color changes that occur on the wall paint by using Poly Styrene Acrylic , Poly Vinyl Acetate and Poly Vinyl Acrylic. From the results of the measurement of color difference, significant color change occurs in the Poly Vinyl Acetate (PVAc) + Poly Vinyl Acrylic (PVA) and Poly Styrene Acrylic (PSA). The results of the quality test of the three resins based on pH test, scrub test and viscosity test, PSA has better quality compared to PVA + PVAc and PVA resin. From the color difference measurement test, some things need to be considered, are temperature, film thickness, substrate color/background color and measurement conditions (measured in wet sample/in plate/dry surface) and test on resin added additive according to the type of each resin.Keywords: Paint, Resin, Color Changes, Poly Vinyl Acetate, Poly Styrene.ABSTRAK Kualitas dari cat sangat ditentukan oleh resin yang digunakan. Resin sintetis untuk cat berupa polimer yang dibuat dengan menggabung beberapa monomer untuk mencapai berbagai karakteristik. Penggabungan dari beberapa monomer seperti resin poli vinil asetat, resin vinil akrilik dan resin stirena akrilik yang berfungsi sebagai pengikat mampu mempengaruhi kualitas cat terutama dari perubahan warna. Tujuan dari penelitian ini adalah untuk mengetahui perubahan warna yang terjadi pada cat tembok dengan menggunakan Poli Stirena Akrilik, Poli Vinil asetat dan Poli Vinil Akrilik. Dari hasil pengukuran perbedaan warna, perubahan warna cukup signifikan terjadi pada resin Poli vinil Asetat (PVAc) + Poli Vinil Akrilik (PVA) dan resin  Poli Stirena Akrilik (PSA). Hasil uji Kualitas cat dari ketiga resin berdasarkan uji pH, uji scrub dan uji viscositas, PSA memiliki kualitas yang lebih baik dibandingkan dengan resin PVA+PVAc dan PVA. Dari pengujian pengukuran perbedaan warna, beberapa hal yang perlu di perhatikan, yaitu suhu, film thickness, warna substrat/background color dan kondisi pengukuran (diukur dalam keadaan wet sample/dalam bentuk plate/dry surface) dan pengujian terhadap resin yang ditambahkan zat aditif yang sesuai dengan tipe masing-masing resin tersebut.Kata Kunci: Cat, Resin, Perubahan Warna, Poli Vinil, Poli Stirena.


2019 ◽  
Vol 8 (2) ◽  
pp. 129
Author(s):  
LATIZIO BENI DA COSTA CRUZ ◽  
I WAYAN SUPARTHA ◽  
I WAYAN SUSILA

The Effect of Feed (Onion Leaves) on the Event of Color Polymorphism on Larvae Spodoptera exigua HUBNER (Lepidoptera: Noctuidae). Color polymorphism is a form of color difference that appears morphologically and genetically in the same insect species. The existence of these changes in shape has to do with the defense mechanism of the species concerned for disguise, avoiding natural enemies and adjusting to the new environment. The occurrence of color polymorphism is often found in S. exigua larvae that attack the onion crop in the field. The purpose of the study was to determine the effect of the quality and quantity of feed (onion) on the color changes of S. exigua larvae. This research was carried out in the laboratory using adaptation test method and comparative test with randomized block design. The results of the study show that decreasing the quality and quantity of feed (onion) encourages color changes from green to dark. In addition, green to dark color changes are also triggered by the developmental phase of the larvae. The development of larvae from the 3rd instar phase has shown symptoms of color change from green to dark even though the quantity and quality of the food is fulfilled.


2019 ◽  
Vol 82 (12) ◽  
pp. 2080-2087
Author(s):  
REZA SADEGHI ◽  
ESMAEEL SEYEDABADI ◽  
RAHIL MIRABI MOGHADDAM

ABSTRACT Raisins are one of the most important Iranian export products but are threatened by various storage pests. Because of the disadvantages of fumigants, we evaluated alternative microwave and ozone methods for their disinfection and the side effects on raisin qualities. To perform microwave disinfection, the studied raisin samples were exposed to microwave powers of 450, 720, and 900 W for 20, 30, 40, and 50 s. Also, ozone treatments included various combinations of ozone concentrations (2, 3, and 5 ppm) and exposure times (15, 30, 45, 60, and 90 min). An image processing technique was implemented to determine the color changes of raisins in terms of lightness, redness, yellowness, total color difference, chroma, and hue angle. The results revealed that increasing the microwave power and exposure time might lead to further changes of the previously mentioned color characteristics. Compared with the microwave treatments, ozone treatments had fewer effects on those features. Generally, microwave and ozone methods could successfully disinfect Oryzaephilus surinamensis in raisins, with acceptable changes in all the color characteristics. Hence, the previously mentioned methods are proposed as alternative chemical fumigants. HIGHLIGHTS


2013 ◽  
Vol 07 (01) ◽  
pp. 110-116 ◽  
Author(s):  
Emine Sirin Karaarslan ◽  
Bulbul Mehmet ◽  
Ertas Ertan ◽  
Mehmet Ata Cebe ◽  
Aslihan Usumez

ABSTRACTObjective:To examine the amount of change in color and color parameters of a composite resin (Filtek P60) polymerized by five different polymerization methods.Methods: A Teflon mold (6mm in diameter, 2mm in height) was used to prepare the composite resin discs (n=10). G1: Polymerization with inlay oven; G2: Polymerization with HQTH and autoclave; G3: Polymerization with LED and autoclave; G4: Polymerization with HQTH; G5: Polymerization with LED. Colorimetric values of the specimens before and after polymerization were measured using a spectrophotometer. The CIE L*a*b color system was used for the determination of color difference. Analysis of variance (ANOVA) was used to analyze the data for significant differences. Tukey’s HSD test and paired two-tailed tests were used to perform multiple comparisons (α=.05).Results: There were no significant differences in total color change (ΔE*ab) among the polymerization groups (P>.05). However, the lowest color change (ΔE*ab) value was 3.3 in LED and autoclave; the highest color change (ΔE*ab) value was 4.6 in HQTH. For all groups, CIE L*, C*ab and a*values decreased after polymerization (P<.05). The highest Δb* and ΔC*ab values were observed in specimens polymerized in an inlay oven (P<.05).Conclusion: Composite resin material showed color changes above the clinically accepted value in all study groups (ΔE*ab≥3.3). All specimens became darker during investigation (ΔL*< 0). Specimens polymerized with inlay oven presented the highest Δb* values which means less yellow color in specimens. (Eur J Dent 2013;7:110-116)


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 404D-404
Author(s):  
K.S. Kleeberger ◽  
B.C. Moser

A number of deciduous woody ornamental plants experience seasonal changes in stem pigmentation. The resulting coloration yields plants desirable for use as cut branches in the florist trade. The dynamics of color change are particularly important in identifying harvest periods based on optimum color. The characterization of this process has been investigated for Cornus (Cornus baileyi, Cornus sericea `Cardinal', Cornus sericea `Flaviramea', Cornus alba `Bud's Yellow') and Salix (Salix matsudana `Tortosa', Salix `Golden Curls', Salix `Scarlet Curls') cultivars. Seasonal color changes are presented in relation to date. These data were compared to chlorophyll and anthocyanin levels to further characterize pigmentation change. Because size and round stem shape are not conducive to traditional tristimulus color measurement techniques, L*a*b* measurements were obtained from images imported via computer scanner as CIELAB images. L*a*b* values then were used to determine hue angle and chromaticity for each sample date. Postharvest storage duration and conditions are evaluated with regard to moisture content and color retention in cut branches.


Author(s):  
Risti Annisa ◽  
Yulian Fakhrurrozi ◽  
Sri Rahayu

Hoya coronaria found in heath forest of Air Anyir, Bangka has diverse colors. Flowers color diversity sometimes correlated varieties or the result of color changes during flowering process. The flowers development process observed from 5 H. coronaria varieties with different color from heath forest of Air Anyir, Bangka.The purpose of this research to know the flowering process and flower color change process some varieties of H. coronaria. This research done from September 2015-January 2016. This study used qualitative method to made detail and systematic description about flowering phase. H.coronaria flowering process consists of flower initation, flower estabilisment and flower development. Flower initation needs 13-15 days, flower estabilisment needs 10-12 days and flower development consists of early blooming process, full blooming and senescene. Early blooming process needs 1-3 days, full blooming needs 5-12 days and senescene needs 1-3 days. During the development process changes from rounded to pentagonal shape and there is a change in size. The observation result showed that 5 varieties are different from one another based on the difference between the colors of the flowers. Variety 1 has yellow corolla without honey line and deep pink corona. Variety 2 has light yellow green corolla with strong pink honey line and moderate red corona. Variety 3 has moderate red corolla with moderate red honey line and moderate red corona. Variety 4 has light yellow green corolla with moderate pink honey line and light yellow green corona. Variety 5 has moderate red without honey line and grayish red corona


Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 84 ◽  
Author(s):  
Soner Çelen

In this study, changes in the drying kinetics, color change, and the energy consumption for microwave energy were investigated for Trabzon persimmon. In addition to that, the microstructure of the persimmon was also investigated by considering its thermal changes. It is important to be aware of the purpose of the drying process for determining the drying system. Results of this research showed that 460 W for 7 mm slice thickness depending on energy consumption, 600 W for 5 mm slice thickness depending on drying time, and 600 W depending on color changes were found as suitable drying processes depending on drying conditions. The effective diffusion values varied between 2.97 × 10−8 m2 s−1 and 4.63 × 10−6 m2 s−1. The activation energy values for 5 mm, 7 mm and 9 mm slice thickness were estimated as 32.82, 18.64, and 12.80 W g−1, respectively. The drying time and energy consumption decreased, whereas drying rate increased with an increase in the microwave energy. The number of pores increased compared to structure of fresh sample, and the pores got to be larger for 5 mm slice thickness as the power level increased. Results showed that the applied microwave energy had an important effect on the heating of the material and the change in the microstructure.


2011 ◽  
Vol 474-476 ◽  
pp. 1638-1642 ◽  
Author(s):  
Hong Xia Zhao ◽  
Zhi Yang Luo ◽  
Xin Yuan ◽  
Yuan Li

The bad degree of meat and the color change have a close relation. Computer vision is not under the influence of physiological and psychological factor of person; Appraisement standard is objective and steady. Therefore, computer vision system has been established, which can do collection, management, display, and appraisement of porky color. The CIEL*a*b* and CIEDE2000 color difference formula were introduced into the classification of pork, the result was identical. Because the calculation course of CIEDE2000 color difference is complex, so the CIE1976L*a*b* color difference is still adopted to calculate color change at actual production.


2016 ◽  
Vol 86 (6) ◽  
pp. 900-904 ◽  
Author(s):  
Andrew Leland ◽  
Sercan Akyalcin ◽  
Jeryl D. English ◽  
Eser Tufekci ◽  
Rade Paravina

ABSTRACT Objective: To analyze the staining and color changes of a resin infiltrant system used for management of white spot lesions (WSLs). Materials and Methods: WSLs were artificially created on left buccal halves of 48 extracted human teeth. These sites were then treated with resin infiltration (RI) while the right halves of the teeth remained as nonresin (NRI) areas. Six groups were formed (n = 8 teeth/group) and were exposed to the following: red wine, coffee, orange juice, combined staining agents, accelerated aging, and distilled water for 1 week. The teeth were then polished with a prophy cup and polishing paste. Color properties were assessed using a spectrophotometer at baseline (T0), after each exposure (T1), and after polishing (T2). Color difference (ΔE*) was calculated between each time point for both halves of the teeth (RI and NRI). Data were analyzed with a two-way analysis of variance with presence of resin infiltration and staining agents as the main effects for each time point pair. Multiple comparisons were made with a Bonferroni post hoc test. The level of significance was set at P &lt; .05. Results: The red wine and combined staining agent groups caused the greatest color change between all intervals (P &lt; .05). Significant interactions were recorded between resin infiltration application and staining agents at all time periods (P &lt; .05). The presence of resin infiltration as a main effect did not affect color change between T0 and T2 (P &gt; .05). Conclusions: RI areas showed higher staining susceptibility than did NRI areas. However, prophylaxis had a strong effect on reversing the discoloration of both RI and NRI areas.


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