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 ◽  
...  

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.

2013 ◽  
Vol 544 ◽  
pp. 105-109
Author(s):  
Hua Fan ◽  
Ruo Yu Liu ◽  
Dong Dong Jing ◽  
Liang Jiao Chen ◽  
Yao Kun Zhang ◽  
...  

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.


2017 ◽  
Vol 8 (6) ◽  
pp. 577-582
Author(s):  
Jana Valauskaitė ◽  
Rimantas Stonkus

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.


2013 ◽  
Vol 726-731 ◽  
pp. 456-462 ◽  
Author(s):  
Yan Hua Dong ◽  
Ruo Yu Zhang ◽  
Zhen Tao Zhang ◽  
Lu Wei Yang ◽  
Chang Hu Xue ◽  
...  

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.


2011 ◽  
Vol 214 ◽  
pp. 531-534 ◽  
Author(s):  
Qiang Shi ◽  
Fu Cheng Bao ◽  
Jian Xiong Lu ◽  
Jing Hui Jiang

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.


Author(s):  
Yuchun Yan ◽  
Hayan Choi ◽  
Hyeon-Jeong Suk

It is difficult to describe facial skin color through a solid color as it varies from region to region. In this article, the authors utilized image analysis to identify the facial color representative region. A total of 1052 female images from Humanae project were selected as a solid color was generated for each image as their representative skin colors by the photographer. Using the open CV-based libraries, such as EOS of Surrey Face Models and DeepFace, 3448 facial landmarks together with gender and race information were detected. For an illustrative and intuitive analysis, they then re-defined 27 visually important sub-regions to cluster the landmarks. The 27 sub-region colors for each image were finally derived and recorded in L ∗ , a ∗ , and b ∗ . By estimating the color difference among representative color and 27 sub-regions, we discovered that sub-regions of below lips (low Labial) and central cheeks (upper Buccal) were the most representative regions across four major ethnicity groups. In future study, the methodology is expected to be applied for more image sources.


Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  

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.


1992 ◽  
Vol 76 (2) ◽  
pp. 242-242
Author(s):  
Nizard Carine ◽  
Schoëvërt Damien ◽  
Adolphe Monique ◽  
Decloître Françoise

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.


2010 ◽  
Vol 21 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Danilo Bonadia Catani ◽  
Livia Maria Andaló Tenuta ◽  
Fernanda Alcântara Andaló ◽  
Jaime Aparecido Cury

Considering that blood fluoride concentration varies according to fluoride exposure and that dental fluorosis is related to the amount of enamel formed under a given fluoride dose, the present study investigated whether the fluorosis produced by an oscillating chronic fluoride dose would be similar to that caused by exposure to a constant dose, representing the mean of the oscillation during a given time. Rats received during 78 days water with fluoride concentrations of 0, 12.5, 25 or 37.5 µg F/mL, or oscillating concentrations of 12.5 and 37.5 µg F/mL every 72 h (mean exposure=25 µg F/mL). The concentrations of fluoride in the plasma, femur and incisors of the rats were determined at the end of the experimental period. Also, the enamel dental fluorosis index was determined in the incisors using a quantitative method developed by our research group named Dental Fluorosis by Image Analysis (DFIA). Fluoride concentrations in plasma, femur and teeth, and DFIA increased linearly for constant fluoride concentrations in water (p<0.0001, r values=0.87-0.98). The results of the oscillating group and the groups receiving 25 µg F/mL did not differ significantly (p>0.05). The findings of this study suggest that in animals chronically exposed to symmetrically oscillating fluoride doses, the resulting dental fluorosis reflects the metabolic effect of the mean of the oscillating doses.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2106 ◽  
Author(s):  
Amalia Mazilu (Moldovan) ◽  
Codruta Sarosi ◽  
Marioara Moldovan ◽  
Filip Miuta ◽  
Doina Prodan ◽  
...  

The novelty of this study consists of the formulation and characterization of three experimental bleaching gels with hydroxylapatite oxides and fluorine (G28®, G29®, G30®) based on natural fruit extracts compared to the commercial Opalescence 15% (GC, Ultradent, South Jordan, UT, USA). Studies have been conducted on the effect that the experimental bleaching gels have on the color and morphology of different restorative materials (Nanofill®-Schulzer, P.L. Superior Dental Materials GmbH, Hamburg, Germany, and experimental nanocomposites (P11®, P31®, P61®)), immersed in coffee and artificial saliva (for 10 days and 30 days). The study also includes a cytotoxicity test on the gels and nanocomposites after bleaching, with ISO 109993-5 protocols on human dental follicle stem cells. UV-VIS spectroscopy, computerized measurement, and fluorescence spectrometry were used in order to observe the color changes, while the microstructure of the surface was investigated by Scanning Electron Microscopy (SEM). All of the samples immersed in coffee showed the highest color shift in comparison to the baseline. The color difference ΔE values obtained using the two methods (UV-Vis, computerized based on digital images) both after coloring and bleaching, respectively, were different for all four types of nanocomposites stored in the coffee, while no difference was observed in those stored in artificial saliva. The studied experimental gels and nanocomposites had a low cytotoxic effect on cell cultures after bleaching.


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