scholarly journals INVESTIGATION OF THE OPTICAL PROPERTIES OF FLEXOPRAPHIC PRINTS ON PVC AND PET FILMS / FLEKSOGRAFINIŲ ATSPAUDŲ ANT PVC IR PET PLĖVELIŲ OPTINIŲ SAVYBIŲ TYRIMAS

2017 ◽  
Vol 8 (6) ◽  
pp. 577-582
Author(s):  
Jana Valauskaitė ◽  
Rimantas Stonkus
Keyword(s):  
Optical Properties ◽  
Color Difference ◽  
Color Matching ◽  
Color Changes ◽  
Color Characteristics ◽  
Yellow Color ◽  
Color System ◽  
Pet Films

An optical properties of the flexographic prints on the shrink sleeve has been experimentally investigated. Two main materials of shrink sleeve: PVC and PET were used for the research. Films were printed using UV flexographic inks. The color changes arised during shrinking of the films were analysed. Investigations were done using CMYK and PANTONE color matching systems. Color characteristics CIE L*a*b* and color difference DE at different shrink level of the film was estimated. It was found that colors become darker during the shrinking of the film. In the case of rasterize image it is related to the deformation of the raster dots, decrease of the spaces between the raster dots and other factors. The biggest changes in the CMYK color system was determined in the Yellow color, while in the tested PANTONE color system – in the blue (P 290) color. The smallest changes in the CMYK color system was determined in the Cyan color, while in the PANTONE color system – in the white color. Eksperimentiškai ištirtos fleksografiniu spaudos būdu atspausdintų atspaudų ant susitraukiančių plėvelių optinės savybės. Tyrimui naudotos dvi pagrindinės susitraukiančioms plėvelėms naudojamos medžiagos: PVC ir PET, užspausdintos ultravioletiniais (UV) dažais. Išnagrinėti spalviniai pokyčiai, atsirandantys plėvelei besitraukiant. Tyrimai atlikti su CMYK ir PANTONE sistemų spalvomis. Nustatytos spalvinės charakteristikos CIE L*a*b* ir spalvų skirtumas DE, plėvelei susitraukiant skirtingai. Nustatyta, kad, plėvelėms besitraukiant, spalvos tamsėja. Rastruotuose vaizduose tai susiję su rastrinių taškelių deformacija, tarpų tarp rastrinių taškelių sumažėjimu ir kitais veiksniais. Didžiausi spalviniai pokyčiai CMYK spalvinėje sistemoje nustatyti Yellow (geltonoje) spalvoje, o tarp tirtų PANTONE sistemos spalvų – mėlynoje (P 290) spalvoje, mažiausi pokyčiai CMYK sistemoje nustatyti Cyan spalvoje, o PANTONE sistemoje – baltoje spalvoje.

Evaluation of Microwave and Ozone Disinfections on the Color Characteristics of Iranian Export Raisins Through an Image Processing Technique

2019 ◽  
Vol 82 (12) ◽  
pp. 2080-2087
Author(s):  
REZA SADEGHI ◽  
ESMAEEL SEYEDABADI ◽  
RAHIL MIRABI MOGHADDAM
Keyword(s):  
Image Processing ◽  
Color Difference ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Storage Pests ◽  
Color Changes ◽  
Color Characteristics ◽  
Hue Angle ◽  
Total Color Difference ◽  
Ozone Treatments

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

Optical Stability of High-translucency Resin-based Composites

2019 ◽  
Vol 44 (5) ◽  
pp. 536-544
Author(s):  
YB Piccoli ◽  
VP Lima ◽  
GR Basso ◽  
VE Salgado ◽  
GS Lima ◽  
...  
Keyword(s):  
Optical Properties ◽  
Calculated Data ◽  
Color Difference ◽  
Storage Condition ◽  
Color Variation ◽  
Dental Resin ◽  
Large Variability ◽  
Color Differences ◽  
Color System ◽  
The Stability

SUMMARY This study investigated the stability of the optical properties of high-translucent shades of dental resin-based composites. Four commercial materials (Filtek Z350 XT, Opallis, Amelogen Plus, and IPS Empress Direct) and 14 non-Vita shades were tested. Disc-shaped specimens for each resin-based composite-shade combination (n=6) were evaluated at T0 (baseline), T1 (after 30 days of storage in water), and T2 (after 30 days of storage each in water and a coffee solution). Color measurements were performed according to the L′C′h′ color system. Translucency Parameter (TP) and CIEDE2000 color difference (ΔE00) were calculated. Data were statistically analyzed at α = 0.05. Baseline TP values varied from 43 ± 1 to 55 ± 1. Changes in TP at T1 varied from −3.0% (Opallis T-Neutral) to 4.2% (Amelogen Plus Trans Orange), with no major differences from T0. At T2, most resin-based composites showed significantly increased opacity, with changes varying between −15.0% (Empress Direct Trans 20) and −2.7% (Z350 XT Blue). However, the TP values were ≥40 throughout the study. Storage in water caused negligible color differences, with ΔE00 values at T1 ≤ 0.9 ± 0.6. At T2, all materials tested showed significant color difference, and ΔE00 ≥ 3.2 ± 0.2. The orange shades from Opallis and Amelogen Plus showed lower color variation than did the other shades. The most significant optical changes upon storage were detected in the hue and particularly the chroma color coordinate. In conclusion, the high-translucent resin-based composites showed large variability in the stability of their optical properties among the tested brands and different shades of the same material. Regardless of the storage condition, the tested resin-based composites retained their high-translucency character over time.

scholarly journals Image analysis for a microfluidic paper-based analytical device using the CIE L*a*b* color system

The Analyst ◽  
2016 ◽  
Vol 141 (24) ◽  
pp. 6507-6509 ◽  
Author(s):  
Takeshi Komatsu ◽  
Saeed Mohammadi ◽  
Lori Shayne Alamo Busa ◽  
Masatoshi Maeki ◽  
Akihiko Ishida ◽  
...  
Keyword(s):  
Image Analysis ◽  
Quantitative Method ◽  
Color Difference ◽  
Color Changes ◽  
System P ◽  
Color System ◽  
Analytical Device

A quantitative method based on image analysis of multiple color changes in microfluidic paper-based analytical devices using CIE L*a*b* color difference is presented.

Mathematical Model and Implementation of the Density-Based Gravure Spot-Color Matching

2010 ◽  
Vol 174 ◽  
pp. 56-59 ◽  
Author(s):  
Ru Bai Luo ◽  
Shi Sheng Zhou ◽  
Nan Jiang ◽  
Qiu Juan Yang
Keyword(s):  
Functional Module ◽  
Color Difference ◽  
Target Color ◽  
Color Matching ◽  
C Programming Language ◽  
C Programming ◽  
Color System ◽  
To Come ◽  
Matching Color ◽  
Spot Color

In the paper, the spot-color was divided into ten color areas based on the theory of Munsell color system, then, the model samples in IGT was produced according to each color area. After measuring and analyzing the data of the proofs, Gravure spot-color matching based on masking equation by the means of ten color areas was established. Finally, the paper validated the precision of Gravure spot-color matching model by the method of color difference. The functional module of Gravure spot-color matching in the commercial spot-color matching system was developed using C++ programming language and MySQL Database. The running result of spot-color matching software indicated that the Gravure spot-color matching system based on the proposed method is easy to come true by computer programming, and the color difference between matching color and target color is suitable range (△E≤6 ).

scholarly journals Assessment of changes in color and color parameters of light-cured composite resin after alternative polymerization methods

2013 ◽  
Vol 07 (01) ◽  
pp. 110-116 ◽  
Author(s):  
Emine Sirin Karaarslan ◽  
Bulbul Mehmet ◽  
Ertas Ertan ◽  
Mehmet Ata Cebe ◽  
Aslihan Usumez
Keyword(s):  
Composite Resin ◽  
Color Change ◽  
Color Difference ◽  
Study Groups ◽  
Color Parameters ◽  
Color Changes ◽  
Yellow Color ◽  
Before And After ◽  
Total Color Change

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)

Effect of Vitique Esthetic Cementation on Tetracycline Stained Teeth-Mask with Different Simulated Staining Levels Following IPS-Empress II Ceramic Veneers

2013 ◽  
Vol 544 ◽  
pp. 105-109
Author(s):  
Hua Fan ◽  
Ruo Yu Liu ◽  
Dong Dong Jing ◽  
Liang Jiao Chen ◽  
Yao Kun Zhang ◽  
...  
Keyword(s):  
Color Difference ◽  
Bonding Agent ◽  
Resin Adhesive ◽  
Color Changes ◽  
Color System ◽  
Abutment Teeth ◽  
Final Color

Abstract. To evaluate the color changes of tetracycline stained teeth after restored with IPS-EMPRESS Ⅱ ceramics. Simulated tetracycline stained teeth were divided according to staining degree into four groups: mild, moderate, severe, and very severe groups; each group had ten specimens which were repaired with IPS-EMPRESS Ⅱ ceramics veneers, bonded with Vitique Esthetic Cementation System. The ShadeEye-NCC color system was used to analyze the change in L, a and b. ΔE were calculated to compare color difference among the four groups.Before and after bonding, the values of L, a, b were significantly different (P <0.05). Mild tetracycline stained teeth bonded using resin adhesive without opaque bonding have a better effect than moderate and severe tetracycline stained teeth bonded with opaque resin adhesive; while, it is best to use other restorations to repair very severe tetracycline stained teeth. The IPS-EMPRESS Ⅱ ceramics can effectively improve the color of discolored tooth, however , the final color of the veneered teeth is easily influenced by the color of the abutment teeth. Aluting agent with color masking ability can do some improvements in the final color. An appropriate bonding agent should be chosen to perfect the final results of the veneered tooth.

Study on Kinetics of Color Changes in Thompson Seedless Grapes during Drying Process

2013 ◽  
Vol 726-731 ◽  
pp. 456-462 ◽  
Author(s):  
Yan Hua Dong ◽  
Ruo Yu Zhang ◽  
Zhen Tao Zhang ◽  
Lu Wei Yang ◽  
Chang Hu Xue ◽  
...  
Keyword(s):  
Color Difference ◽  
Order Kinetic ◽  
Thompson Seedless ◽  
Color Changes ◽  
Air Temperatures ◽  
Seedless Grape ◽  
Color System ◽  
Order Kinetic Model ◽  
Cie Lab ◽  
Kinetics Of

The aim of this study was to investigate the characteristic of color changes in Thompson seedless grape during drying at 30°C, 35°C and 40°C air temperatures. The CIE LAB color system was used to measure the surface color of the grapes. It was found that browning began at middle period of drying, where parameters L* and b* decreased and parameter a* increased during drying. Color changes during browning process were described as a first-order kinetic model, where the activation energies for the parameters L*, a*, b*, and total color difference were respectively 40.19, 24.29, 35.43, and 39.46 kJ·mol1.

Effect of Heat Treatment Temperature on the Color of Okan Wood

2011 ◽  
Vol 214 ◽  
pp. 531-534 ◽  
Author(s):  
Qiang Shi ◽  
Fu Cheng Bao ◽  
Jian Xiong Lu ◽  
Jing Hui Jiang
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Color Change ◽  
Treated Wood ◽  
Color Difference ◽  
Treatment Temperature ◽  
Strong Correlations ◽  
Color Changes ◽  
Color System ◽  
Effect Of Treatment

In this study the effect of high temperature on color change of okan wood was investigated. Wood specimens were subjected to heat treatment at 160°C, 180°C,200°C,220°Cfor 4 hours with the superheated steam as a heating medium and a shielding gas. Color changes were measured in the Minolta Croma-Meter CR-300 color system. The color parameters L*, a*, b* were determined by the CIEL*a*b* method on the surface of untreated and treated wood, and their variation with regard to the treatment (△L*,△a*,△b* ) were calculated. It was found that heat treatment resulted in a darkening of wood tissues, Color became dark with the temperature increases. The darkening accelerated when treatment temperature exceeded approximately 200°C. We found that heat treatment temperature were substantially important regarding the color responses. Strong correlations between total color difference and the treatment temperature were found. The effect of treatment temperature on color change in sapwood is more obvious than that in heartwood, the color of sapwood and heartwood tended to be more uniform when the temperature reaches more than 200°C.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

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