scholarly journals Evaluation of Applicability to Metofluthrin-based Termiticide for the Traditional Wooden Buildings

2021 ◽  
Vol 37 (6) ◽  
pp. 679-688
Author(s):  
Sae-Min Yoon ◽  
Yonggun Park ◽  
Jinyoung Chung ◽  
Wonjoung Hwang
Keyword(s):  
Mass Loss ◽  
Color Change ◽  
Color Difference ◽  
Dilution Ratio ◽  
Insecticidal Effect ◽  
Termite Control ◽  
Cultural Properties ◽  
Wooden Structures

In this study, we investigated the applicability of a termiticide based on metofluthrin for termite control on traditional wooden buildings. To evaluate their mortality, termites were exposed to the agent, diluted to various concentrations, for seven days; it was found that it had a sufficient insecticidal effect although there was a difference depending on the degree of agent dilution. Next, the effect on Dancheong, used in traditional wooden structures, was measured based on the color change according to the number of agent treatments. The results showed that only the color difference value of two pigments (i.e., Bun and Juhong) was measured as 3.0 or higher. However, there this varied according to the dilution ratio. Thus, it was found that most pigments had little effect on the color of Dancheong. Finally, the termiticidal efficacy of the agent when applied to wood was evaluated. We found that the specimens coated with 10-fold and 20-fold dilutions exhibited 2.83 and 6.28% mass loss, respectively. The 10-fold dilution satisfied the performance of termiticide as a mass loss of less than 3%. In conclusion, the metofluthrin-based agent used in this study has little effect on various Dancheong pigments and has a termiticidal effect against termites; it is therefore suggested that it may be used in preserving traditional wooden cultural properties in Korea.

Formation of the nitrogen-fixing enzyme system in Azotobacter vinelandii

1968 ◽  
Vol 14 (1) ◽  
pp. 25-31 ◽  
Author(s):  
G. W. Strandberg ◽  
P. W. Wilson
Keyword(s):  
Color Change ◽  
Azotobacter Vinelandii ◽  
Nitrogenase Activity ◽  
Color Difference ◽  
Potassium Nitrate ◽  
Whole Cells ◽  
System A ◽  
Growth System ◽  
A Cell ◽  
Enzyme Formation

The formation and activity of nitrogenase2 in Azotobacter vinelandii OP was examined using a cell-free assay system. A lag period of about 30 min occurred between the exhaustion of the combined nitrogen source and growth on N2. Cells grown on ammonium acetate or potassium nitrate had no detectable nitrogenase activity. Nitrogenase activity appeared in cells, grown under a flowing gas phase of 20% O2 – 60% He, about 45 min after the exhaustion of ammonia. Nitrogenase formation was inhibited in a closed system with an atmosphere containing 40% O2 but not by one containing 20% O2. Hydrogen did not inhibit enzyme formation. The question of whether N2 is required for the formation of the enzyme could not be answered as this gas could not be completely eliminated from the growth system. Chloramphenicol prevented the formation of the enzyme and inhibited nitrogen fixation in whole cells, but had no effect on cell-free enzyme activity. A brief rise in turbidity which occurred during nitrogenase formation appeared to be due to a color change in the cells from reddish brown to dark brown. Spectrophotometric examination of extracts from ammonia- and N2-grown cells did not reveal any components responsible for this color difference, but this result may reflect only the presence of interfering substances in the crude extract.

scholarly journals Influence of UV Radiation on the Color Change of the Surface of Steamed Maple Wood with Saturated Water Steam

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 217
Author(s):  
Ladislav Dzurenda ◽  
Michal Dudiak ◽  
Eva Výbohová
Keyword(s):  
Uv Radiation ◽  
Color Change ◽  
Color Space ◽  
Color Stability ◽  
Color Difference ◽  
Saturated Steam ◽  
Water Steam ◽  
Saturated Water ◽  
Red Color ◽  
Uv Lamp

The wood of maple (Acer Pseudopatanus L.) was steamed with a saturated steam-air mixture at a temperature of t = 95 °C or saturated steam at t = 115 °C and t = 135 °C, in order to give a pale pink-brown, pale brown, and brown-red color. Subsequently, samples of unsteamed and steamed maple wood were irradiated with a UV lamp in a Xenotest Q-SUN Xe-3-H after drying, in order to test the color stability of steamed maple wood. The color change of the wood surface was evaluated by means of measured values on the coordinates of the color space CIE L* a* b*. The results show that the surface of unsteamed maple wood changes color markedly under the influence of UV radiation than the surface of steamed maple wood. The greater the darkening and browning color of the maple wood by steaming, the smaller the changes in the values at the coordinates L*, a*, b* of the steamed maple wood caused by UV radiation. The positive effect of steaming on UV resistance is evidenced by the decrease in the overall color difference ∆E*. While the value of the total color diffusion of unsteamed maple wood induced by UV radiation is ∆E* = 18.5, for maple wood steamed with a saturated steam-air mixture at temperature t = 95 °C the ∆E* decreases to 12.6, for steamed maple wood with saturated water steam with temperature t = 115 °C the ∆E* decreases to 10.4, and for saturated water steam with temperature t = 135 °C the ∆E* decreases to 7.2. Differential ATR-FTIR spectra declare the effect of UV radiation on unsteamed and steamed maple wood and confirm the higher color stability of steamed maple wood.

scholarly journals PENGARUH RESIN TERHADAP PERUBAHAN WARNA PADA CAT TEMBOK

2019 ◽  
Vol 5 (2) ◽  
pp. 132
Author(s):  
Nurlela Nurlela ◽  
Risnawati Risnawati
Keyword(s):  
Film Thickness ◽  
Vinyl Acetate ◽  
Polyvinyl Acetate ◽  
Color Change ◽  
Color Difference ◽  
Background Color ◽  
Color Changes ◽  
Synthetic Resins ◽  
Color Background

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.

scholarly journals Study on the Prediction of Surface Color Change of Cultural Properties Materials by Fog Occurrence

2016 ◽  
Vol 32 (4) ◽  
pp. 491-500
Author(s):  
Ye Bin Han ◽  
Sang Hyeon Park ◽  
Ji A Yu ◽  
Yong Jae Chung
Keyword(s):  
Color Change ◽  
Surface Color ◽  
Cultural Properties

scholarly journals COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

2014 ◽  
Vol 2 ◽  
pp. 345-352 ◽  
Author(s):  
Cristina Marinela Olarescu ◽  
Mihaela Campean
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Color Change ◽  
Treated Wood ◽  
Untreated Wood ◽  
Cost Effective ◽  
Assessment Procedure ◽  
Mathematical Correlation ◽  
Heat Treated ◽  
Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood.  For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective. 

scholarly journals Study on the effect of heat treatment on amethyst color and the cause of coloration

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Renping Cheng ◽  
Ying Guo
Keyword(s):  
Heat Treatment ◽  
Significant Relationship ◽  
Color Change ◽  
Heating Temperature ◽  
Visible Spectrum ◽  
Crystallinity Index ◽  
Color Difference ◽  
Cell Parameters ◽  
Initial Color ◽  
A Charge

Abstract The effect of heat treatment on amethyst color was studied from a new perspective of chromaticity of gemstones and the cause of amethyst coloration was discussed based on the results of X-ray diffraction, ultraviolet–visible spectroscopy. The results show that the amethyst color has no significant relationship with cell parameters but the crystallinity index decreases as temperature rises. The absorption band at 545 nm in the UV–visible spectrum can be related to a charge-transfer transition of Fe3+ and O2−, which has a significant relationship with amethyst lightness and chroma. The color at different temperatures can be divided into three stages: The amethyst stage with temperature below 420 °C, the prasiolite stage with temperature between 420 and 440 °C where the color center is the most unstable, the citrine stage with temperature above 440 °C. The color change degree of heated amethyst is related to its initial color. When the initial color is darker, the color difference of heated amethyst is larger, and the easier it is to change the color after heat treatment. A more appropriate heating temperature to obtain citrine by heating amethyst is about 560 °C.

scholarly journals Application of the Entropy Method and Color Difference Formula to the Evaluation of Round Brilliant Cut Diamond Scintillation

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1489
Author(s):  
Fukang Liu ◽  
Ying Guo ◽  
Shaojie Lv ◽  
Guange Chen
Keyword(s):  
Rotation Angle ◽  
Color Change ◽  
Color Difference ◽  
Entropy Method ◽  
Modeling Approach ◽  
Difference Formula ◽  
Main Factor

A modeling approach combining the entropy method and color difference formula is proposed in order to quantitatively evaluate diamond scintillation. The images of 66 diamonds were captured from 0° to 105° rotation at 15° intervals. The color difference of corresponding pixels in adjacent rotation angle images was calculated using a MatLab r2014a program, which indicated the diamond’s color change due to its scintillation. A threshold (10) was determined to divide the color difference into seven color difference intervals, the percentage of which indicated the color-change area. The color difference and the percentage were comprehensively analyzed using the entropy method to evaluate diamond scintillation objectively and quantitatively. Lightness was the main factor affecting the diamond scintillation while chroma and hue also significantly affected it.

Effect of Carbon Nanotube Content on Properties of Ethylene Propylene Diene Rubber/CaCO3/ Carbon Nanotube Composites

2017 ◽  
Vol 1142 ◽  
pp. 206-210
Author(s):  
Jun Su ◽  
Cai Hong Li
Keyword(s):  
Tensile Strength ◽  
Carbon Nanotube ◽  
Color Change ◽  
Color Difference ◽  
Ethylene Propylene ◽  
Nanotube Composites ◽  
Total Color Change ◽  
Carbon Nanotube Composites ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber

This paper studies how the addition and various content of Carbon nanotube (CNT) affecting the properties, especially the color difference of ethylene propylene diene rubber (EPDM)/ CaCO3 composites. The results show that the increased content of CNT can turn EPDM/CaCO3 composites from lighter, greener, and bluer to darker, redder and yellower, respectively. The total color change (ΔE) of EPDM/CaCO3 composites is acceptable, when the content of CNT is less than 2wt%. The optimum tensile strength of EPDM composites can be gained, when the content of CNT is 3%.

Comparison of Two At-home Whitening Products of Similar Peroxide Concentration and Different Delivery Methods

2012 ◽  
Vol 37 (4) ◽  
pp. 333-339 ◽  
Author(s):  
JB da Costa ◽  
R McPharlin ◽  
T Hilton ◽  
JL Ferracane ◽  
M Wang
Keyword(s):  
Soft Tissue ◽  
Color Change ◽  
Color Difference ◽  
Delivery Methods ◽  
Tooth Color ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Tissue Sensitivity ◽  
The Right ◽  
At Home

SUMMARY Purpose This study compared the whitening efficacy, side effects, and patients' preferences/perceptions of two whitening systems of similar peroxide concentration but different formulation and delivery methods. Methods The tooth color change of 24 participants was measured using a shade guide (BSG) and a spectrophotometer (ES). Color difference was calculated: ΔE* = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2. One whitening treatment was randomly applied to the right or left maxillary anterior teeth and the other was applied to the contralateral teeth, at-home with 35% carbamide peroxide in a tray (TW) or with 14% hydrogen peroxide in strips (WS). The tooth color was evaluated at baseline, 15 and 30 days (15 days postwhitening). Participants rated their tooth and soft tissue sensitivity (1–10 scale) and completed a questionnaire on their preferences. Results were analyzed by repeated measurement regression analysis/Tukey and Mann-Whitney (p<0.05). Results At 15 days, the teeth treated with TW and WS presented ΔE* = 7 and 6, respectively (ΔBSG=3 for both), and at 30 days, they presented ΔE* = 7.5 and 6.5, respectively (ΔBSG=3 for both). There was no significant difference in tooth and soft tissue sensitivity between treatments. No participant reported tooth and gingival sensitivity at the postwhitening appointment. Of the participants, 83% preferred the TW over WS. Conclusion Both ΔE* and ΔBSG showed no significant difference in tooth color change between TW and SW at either time point. By the end of the study no participants reported tooth and gingival sensitivity. Participants preferred TW over SW.

scholarly journals Pengaruh Kualitas dan Kuantitas Pakan (Daun Bawang) terhadap Kejadian Polimorfisme Warna pada Larva Spodoptera exigua Hubner (Lepidoptera: Noctuidae)

2019 ◽  
Vol 8 (2) ◽  
pp. 129
Author(s):  
LATIZIO BENI DA COSTA CRUZ ◽  
I WAYAN SUPARTHA ◽  
I WAYAN SUSILA
Keyword(s):  
Spodoptera Exigua ◽  
Defense Mechanism ◽  
Color Change ◽  
Block Design ◽  
Color Difference ◽  
Color Polymorphism ◽  
Test Method ◽  
Developmental Phase ◽  
Color Changes ◽  
Lepidoptera Noctuidae

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.

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