Color Measurements Research Articles

High-throughput color determination of red raspberry puree and correlation of color parameters with total anthocyanins

BackgroundRed raspberry fruit color is a key driver of consumer preference and a major target of breeding programs worldwide. Screening for fruit color typically involves the determination of anthocyanin content and/or the assessment of color through a colorimeter. However, both procedures are time-consuming when the analyses involve hundreds or thousands of samples. The objectives of this study were to develop a high-throughput method for red raspberry puree color measurement and to test the correlations between color parameters and total anthocyanin content. Color coordinates were collected with a colorimeter on 126 puree samples contained in Petri dishes and with the Tomato Analyzer Color Test (TACT) module to assess the same samples prepared in Petri dishes and in 96-well plates. An additional 425 samples were analyzed using only 96-well plates. Total anthocyanins were extracted from all 551 samples.ResultsRegression models for L*, a*, b* measured with the colorimeter and TACT using Petri dishes were all significant (p < 0.001), but very consistent only for L* (R2 = 0.94). Significant (p < 0.001) and very consistent regressions (R2 = 0.94 for L* and b*, R2 = 0.93 for a*) were obtained for color parameters measured with TACT using Petri dishes and TACT using plates. Of the color parameters measured with the colorimeter, only L*, a*/b*, and hue significantly correlated with total anthocyanins (p < 0.05), but, except for L* (R = − 0.79), the correlations were weak (R = − 0.23 for a*/b* and R = 0.22 for hue). Conversely, all correlations with total anthocyanins and color parameters measured with TACT were significant (p < 0.001) and moderately strong (e.g., R = − 0.69 for L* and R = 0.55 for a*/b*). These values were indicative of darker colors as total anthocyanin content increased.ConclusionsWhile the colorimeter and TACT-based methods were not fully interchangeable, TACT better captured color differences among raspberry genotypes than the colorimeter. The correlations between color parameters measured with TACT and total anthocyanins were not strong enough to develop prediction models, yet the use of TACT with 96-well plates instead of Petri dishes would enable the high-throughput measurement of red raspberry puree color.

СТАНДАРТИЗАЦІЯ ЛЛЯНОЇ СИРОВИНИ: ПОРІВНЯЛЬНИЙ АНАЛІЗ ДОСВІДУ США ТА УКРАЇНИ

The main problem in the primary processing of bast fiber raw materials is Ukraine's significant lag in the field of standardization compared to the USA, which negatively affects production efficiency, product quality, and competitiveness in the global market. The article aims to provide a comprehensive comparative analysis of flax raw material quality assessment systems in Ukraine and the USA, identify the key reasons for Ukraine's lag, and develop practical solutions to address these issues. The research found that while Ukraine still relies on outdated standards for flax fiber quality evaluation, which are primarily based on organoleptic methods and do not take into account modern requirements, the USA is actively developing and implementing innovative standards that regulate a wide range of quality indicators, such as fiber fineness, strength, color, shive content, and other important parameters. The main reasons for Ukraine's lag in the field of flax standardization include persistent economic difficulties, obsolete infrastructure and equipment, insufficient funding for scientific research, and weak integration with international standardization organizations. The authors propose a set of solutions to overcome these challenges, which involve increasing state support for the flax industry, intensifying research efforts aimed at developing new methods for assessing the quality of flax raw materials, harmonizing national standards with international ones, deepening international cooperation, and fostering the development of industry associations and clusters. The article emphasizes the necessity of introducing modern instrumental methods for assessing the quality of flax raw materials, such as spectrophotometry for color measurement, computer vision systems for analyzing fiber structure, and automated methods for determining fineness and shive content. The importance of developing standards for new and innovative flax products to expand the range, improve the competitiveness of domestic products, and enter promising markets is underlined.

Artificial Rainfall on Grain Quality and Baking Characteristics of Winter Wheat Cultivars in Korea.

Wheat (Triticum aestivum L.) stands as a significant cereal crop globally, including in Korea, where its consumption reached 35.7 kg per capita in 2023. In the southern regions of Korea, wheat cultivation follows paddy rice, with harvesting typically occurring during the rainy season in mid-June. This timing, coupled with the high humidity and unpredictable rainfall, often leads to pre-harvest sprouting and subsequent deterioration in flour quality. To assess the impact of rain on flour quality, an artificial rain treatment was administered 45 days after heading in an open field greenhouse, followed by flour quality analysis. The color measurement revealed an increase in the L* parameter, indicative of enhanced kernel vitreousness, attributed to endosperm starch degradation via alpha-amylase activation induced by water absorption. Moreover, significant changes were observed in ash content and the gluten index within the wetted group, resulting in decreased dough strength and stability, ultimately leading to a reduction in loaf volume. Consequently, it is recommended that wheat be harvested 4-7 days after reaching the physiological maturity stage to avoid the rainy season and ensure the production of high-quality wheat.

Color variation between composite and vita classical shade guide

The correct replication of color and translucency of the tooth structure is one of the biggest challenges in esthetic and restorative dentistry and mistakes in tooth shade selection may lead to failures in treatment. Objective: This study aim to evaluate, through CIEL * C * h * and CIEL * a * b * color systems, the difference between color of composite and Vita Classical shade guide, using the Vita EasyShade spectrophotometer. Material and methods: Four composite (Forma, Opallis, Oppus and Vittra) shade A2 were used. The specimens (n=6) were obtained using a steel matrix (4x2mm), then hydrated for 7 days and submitted to the finishing and polishing procedures; for subsequent color measurement with spectrophotometer. The color variation was calculated by measuring both color systems values of each material and comparing them with the Vita A2 shade guide results. The statistical analysis used was one-way ANOVA / Tukey test, considering a significance level of 5% (p≤0.05). Results: All materials showed color variation when compared to the shade guide. By the analysis of L*C* h*, all materials demonstrated a color variation greater than what is considered clinically unacceptable, whereas in the analysis of L*a*b* only Vittra APS resin composite showed a clinically acceptable color variation. Conclusion: The analyzed materials showed a great variation of color and the Vita Classical shade guide might not be in accordance to composite shade.

Analysis of Fatty Acid Composition and Volatile Profile of Powder from Edible Crickets (Acheta domesticus) Reared on Apple By-Products.

Edible crickets have recently been used as a new alternative protein source with high nutritional value. The nutritional and flavor-related value of edible crickets varies greatly depending on the species, growth conditions and processing conditions. However, few studies have investigated the effects of the diet fed to crickets during their growth phase on flavor. Therefore, in this study, we characterized the flavor-related factors of powder from crickets reared on apple by-products (ACP) by comparing them with those of powder from crickets reared on a control diet (CCP). The fatty acid composition and volatile compounds of each powder were determined using gas chromatography and mass spectrometry, followed by sensory analysis and color measurement. A decrease in unsaturated fatty acids, specifically γ-linolenic acid, α-linolenic acid, arachidonic acid and docosahexaenoic acid, was observed in ACP. A total of 50 volatile compounds were identified, of which 11 were present in only ACP, while 39 were found in both powders. The sensory analysis showed that the overall balance score of ACP was higher than that of CCP, and according to the color measurements, ACP was darker than CCP. These differences between CCP and ACP might have been due to the differences in the chemical composition of the diets fed to the crickets during their growth phase. The results of this study suggest that one of the factors determining the food value of edible crickets, especially in terms of flavor, is the diet they are fed during their growth phase.

Waterless Dyeing of Polyamide 6.6.

Waterless dyeing of polyamide 6.6 using scCO2 (supercritical carbon dioxide) was investigated. PA (polyamide) fibers can be dyed with various dyes, including disperse dyes. The conventional aqueous dyeing process uses large amounts of water and produces polluted water. Considering these environmental issues, waterless dyeing of fibers is a forefront issue, and utilization of supercritical carbon dioxide (scCO2) is a commercially viable technology for waterless dyeing. This study tested PA6.6 (polyamide 6.6) dyeing in scCO2 at 100 °C 220 bar pressure for 45 min. Color measurements and color fastness tests were performed, as well as tensile strength, scanning electron microscope (SEM) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. PA6.6 fabrics yielded higher K/S (color strength, the Kubelka-Munk equation) values with larger molecular weight dye and almost the same color strength with medium and small-sized dyes, demonstrating the ability of dyeing in a supercritical environment without water as a more environmentally friendly dyeing option compared to conventional dyeing.

Evaluation of the effects of different photosensitizers used in antimicrobial photodynamic therapy on tooth discoloration: spectrophotometric analysis.

Tooth discoloration is a common concern in antimicrobial photodynamic therapy (aPDT) using various photosensitizers (PS). Toluidine Blue (TB), Methylene Blue (MB), Phthalocyanine (Pc), and 2-mercaptopyridine-substituted zinc phthalocyanine (TM-ZnPc) are among those studied, but their relative impacts on tooth discoloration remain unclear. This study aimed to compare the effects of TB, MB, Pc, and TM-ZnPc in aPDT on tooth discoloration, utilizing a controlled experimental setup. The study comprised seventy-five single-rooted incisors with root canals. Following meticulous preparation, a standardized area on the crown surface was designated for examination, and precise measurements of the initial tooth colors were recorded. Samples were randomly divided into five groups: Negative control, MB, TM, Pc, and TM-ZnPc. Photoactivation was performed using LED light, and color measurements were taken at multiple time points up to 90 days. Data were converted to Lab* color values of the CIE Lab* color system (International Commission on Illumination, Vienna, Austria), and ΔE values were calculated. Statistical analysis was performed using Two-way ANOVA and Post-Hoc Tukey tests (p < 0.05). At day 7 and 30, TM-ZnPc and Pc caused less discoloration compared to MB and TB. TM-ZnPc caused more tooth discoloration compared to Pc (p < 0.05). Compared to baseline, MB and TM-ZnPc caused more tooth discoloration at 30 days and TB caused more tooth discoloration at 90 days (p < 0.05). No significant difference was observed in terms of tooth discoloration at all periods evaluated after Pc application (p > 0.05). All photosensitizers tested in the study caused tooth coloration. All PS induced clinically detectable tooth discoloration, with TB and MB causing more significant discoloration compared to Pc and TM-ZnPc at certain time points. TM-ZnPc and Pc demonstrated more stable coloration levels over time, suggesting their potential reliability in aPDT applications. This study highlights the importance of selecting appropriate PS to minimize tooth discoloration in aPDT, with Pc showing promise in this regard.

Enhancing wood coatings with red beetroot-derived pigments: Investigating synergy with UV absorber and composite filler for improved durability and aesthetics

The objective of this study is to assess the synergy among a specific bio-based pigment derived from red beetroot, a composite filler, and a UV absorber as additives for wood paints. The composite filler aims to enhance the mechanical properties of the coating, while the UV absorber is selected to improve the pigment's color stability under solar radiation. The impact of these additives on sample aesthetics is evaluated through color, gloss, and roughness measurements. Mechanical properties are analyzed using Buchholz surface hardness and Taber abrasion resistance tests. The protective role of the UV absorber is further examined through accelerated degradation tests in a UV-B chamber. To ensure that the additives do not compromise the coating's barrier properties, water uptake tests, resistance to liquids, and contact angle measurements are conducted. Overall, the study demonstrates how each additive serves a distinct purpose and their combined application offers benefits such as enhanced color retention and improved mechanical durability of the coating. It highlights the potential of using bio-based pigments to enhance color durability without sacrificing the protective performance of wood coatings.

Evaluating Color Stability of Three Different Provisional Crown Materials: A Short Study

Purpose: To evaluate and compare the colour stability of three different provisional restorations using three different pigmented solutions Material and Methods: Total six samples of each material for each group ( Self-cure PMMA, Revotek LC, and CAD-CAM milled ) with the following specifications 2mm occlusal reduction, 1.5 axial reduction, 1mm round chamfer finish line, 6° convergence angle. This prepared tooth will be used as a guide for the metal die. After immersion in a staining solution of synthetic saliva (control), synthetic saliva and tea, synthetic saliva, and turmeric, on the 1st, 7th and 30th-day color measurement was done using a Spectrophotometer. Results: Mean values were compared using one-way analysis of variance (ANOVA) (statistically significant when P &lt; 0.05). Post hoc test using Tukey’s honestly significant difference was employed to identify significant groups (statistically significant when P &lt; 0.05). Repeated measures of ANOVA were performed to analyze the color stability of the different specimens at different periods of storage. Significant groups were identified using the Bonferroni test. Conclusion: Maximum discoloration was seen in synthetic saliva &amp;turmeric solution for all the two materials. CAD-CAM is the best material out of both if the provisional restoration has to be given for a longer duration in the esthetic region.

Comparative analysis of meat products made from various chicken meat raw material

Animal food, especially meat, has played an important role in the history of mankind. Different meats can be used in the production of meat products. In addition to lean meats, mechanically deboned meat (MDM) and mechanically separated meat (MSM) can also be used in meat products. However, the latter does not qualify as meat due to damage to the muscular structure due to the high pressure applied during the separation, therefore cannot be included in the meat content of products. The aim of our research work was to compare the characteristics of Bologna sausages made from chicken fillet, chicken MDM and poultry MSM. After evaluating our measurements (cooking loss, colour measurement, instrumental chemical composition measuring, stock measurement, determination of water activity, pH measurement, and sensory evaluation), we concluded that in the case of production with MSM, we produced a lower quality product using the same amount of meat raw material, which can be improved by using more additives (e.g. carminic acid, tetrasodium-pyrophosphate).

Light consistency correction for the liquid crystal tunable filter hyperspectral imaging system

In hyperspectral images, every pixel encompasses continuous spectral information. Compared with traditional colorimeters, using hyperspectral imaging systems (HIS) for fabric color measurement can result in obtaining richer color information. However, measuring fabric colors with liquid crystal tunable filter HIS can lead to challenges related to light consistency. In this paper, we adopted an innovative approach, integrating gradient boosted decision trees with a sliding window algorithm to develop a uniformity calibration model addressing the illumination uniformity issue. To address the consistency issues across various light sources, we further adopted a deep neural network (DNN) model to correct the reflectance measurements under different light sources. Subsequently, this model was merged with the uniformity calibration model to form a light-consistency correction model. Through calibration, we successfully reduced the color difference of the corrected samples from 3.636 to 0.854, an enhancement of 76.51%. This means that after calibration we can achieve consistency in fabric color measurements under nonuniform lighting and different light sources.

Color stability of CAD-CAM hybrid ceramic materials following immersion in artificial saliva and wine.

To examine the color stability of 3D-printed and milled, interim, and definitive, restorative materials after immersion in artificial saliva and wine for 1, 3, and 6 months. The study used a 2 × 5 factorial design with 10 subgroups, including 2 immersion liquids (artificial saliva and wine) and 5 manufacturing technology and restorative material combinations (n = 10). Color measurements were taken using a contact-type digital spectrophotometer (CM-2600d Spectrophotometer; Konica Minolta Healthcare Americas Inc) before immersion and at 1 month (T1), 3 months (T3), and 6 months (T6) after immersion. The CIE2000 system was used to calculate quantitative measurements of color differences in ΔE00, and comparisons were made to the acceptability threshold (AT) and perceptibility threshold (PT). Repeated measures of ANOVA (α = 0.05) were used to compare differences in color changes between manufacturing technology/restorative material-immersion liquid combinations at T1, T3, and T6. To compare the effect of immersion liquid and time on the manufacturing technology/restorative material groups, the ΔE00 values were compared to the PT of 0.8 and the AT of 1.8. Wine caused significant color changes in ΔE00 values beyond the PT and AT values in all groups at all time intervals, except for the AT value of milled definitive crowns (hybrid nano-ceramic material). Wine immersion caused significant ΔE00 for all manufacturing technology/restorative material groups at all time intervals (1 month, 3 months, and 6 months) when compared to artificial saliva immersion (all p < 0.001). Upon exposure to artificial saliva, 80%-100% of samples from all groups remained within the acceptable and perceptible color change thresholds. The wine had significant chromogenic effects on all tested restorative materials, however, the milled definitive crowns (hybrid nano-ceramic material) showed the greatest color stability. For patients with heavy wine consumption, 3D-printed definitive crowns (hybrid ceramic-filled material) may show discoloration exceeding acceptable and perceptible color change limits.

Synthesis and characterization of α-(4-(2,3-hydroxylpropoxy)phenylimino)-o-cresol Schiff base as an effective UV-absorber for ink systems

Schiff base is a diverse group of organic compounds and has potential as a UV absorber for ink systems due to its high UV protection, simple synthesis, and high dispersion in organic matrices. In this work, a novel Schiff base α-(4-(2,3-dihydroxylpropoxy)phenylimino)-o-cresol (named GMA-I) was synthesized and investigated as a UV absorber for ink system. The UV-protection of GMA-I was evaluated on ink-coated duplex substrate samples via color measurement using an accelerated UV test chamber. The results showed that the GMA-I exhibited strong absorption in both UVA and UVB regions with an extra high molar absorption coefficient of 43,554 M−1 cm−1, and high thermal stability of 271.4 °C. Interestingly, the GMA-I showed high UV protection for ink platform at low content of 2 wt% thank to the intramolecular proton transfer mechanism and therefore potential as a UV absorber additive for ink systems.

Hybrid meat batter system: effects of plant proteins (pea, brown rice, faba bean) and concentrations (3–12%) on texture, microstructure, rheology, water binding, and color

A lean meat batter system was mixed with four plant proteins at 3, 6, 9, and 12% (w/w): pea protein A (PA), pea protein B (PB), brown rice protein (BR) and faba bean protein (FB). Texture profile analysis (TPA) revealed that increasing plant protein levels hardened the hybrid meat batters, with PA and PB leading to the hardest gels. TPA results were supported by micrographs, demonstrating that the two pea proteins formed large aggregates, contributing to a firmer hybrid meat gel. Dynamic rheology showed that the incorporation of plant proteins lowered the storage modulus (G') during the heating stage (20 to 72°C), yet the 6% PA treatment produced a final G' (after cooling) closest to the control (CL). Nuclear Magnetic Resonance (NMR) T2 relaxometry also demonstrated that plant proteins reduced the water mobility in hybrid meat batters. Results were in line with the cooking loss, except for a higher cooking loss in the BR formulation compared to the CL. Color measurement showed that increasing plant protein levels led to darker and yellower meat batters; however, the effect on redness varied among treatments. Overall, the findings suggest that pea proteins have superior functionality and compatibility within a lean poultry meat protein system, compared to BR and FB tested here.

Anomalous trends in global ocean carbon concentrations following the 2022 eruptions of Hunga Tonga-Hunga Ha’apai

We report on observed trend anomalies in climate-relevant global ocean biogeochemical properties, as derived from satellite ocean color measurements, that show a substantial decline in phytoplankton carbon concentrations following eruptions of the submarine volcano Hunga Tonga-Hunga Ha’apai in January 2022. The anomalies are seen in remotely-sensed ocean color data sets from multiple satellite missions, but not in situ observations, thus suggesting that the observed anomalies are a result of ocean color retrieval errors rather than indicators of a major shift in phytoplankton carbon concentrations. The enhanced concentration of aerosols in the stratosphere following the eruptions results in a violation of some fundamental assumptions in the processing algorithms used to obtain marine biogeochemical properties from satellite radiometric observations, and it is demonstrated through radiative transfer simulations that this is the likely cause of the anomalous trends. We note that any future stratospheric aerosol disturbances, either natural or geoengineered, may lead to similar artifacts in satellite ocean color and other remote-sensing measurements of the marine environment, thus confounding our ability to track the impact of such events on ocean ecosystems.

Characterization of Lipid Extracts from Different Colors of Peach Palm Fruits-Red, Yellow, Green, and White-Obtained through Ultrasound-Assisted Green Extraction.

This study represents a pioneering investigation and comparative analysis of lipid extracts from four different colors of peach palm (Bactris gasipaes Kunt) fruits-red, yellow, green, and white-by employing a green method based on ethanolic ultrasound-assisted extraction. This study examined the extraction yield, physico-chemical-quality attributes, chromatographic profiles (GC), color measurements, total carotenoid content, differential thermogravimetry (TG/DTA), and infrared spectroscopy (FTIR). The obtained lipid extracts displayed a high quality, considering the physico-chemical parameters of the Codex Alimentarius, and a fatty acids profile characterized by unsaturated fatty acids, notably omegas (ω-3, ω-6, and ω-9). The indices of atherogenicity (A.I.), thrombogenicity (I.T.), and hypocholesterolemic and hypercholesterolemic ratios revealed superior outcomes for the red peach palm lipid extract (approximately 0.35, 0.52, and 2.75, respectively), along with higher levels of β-carotene (748.36 µg of β-carotene per 100 g-1 of lipid extract) compared to the yellow, green, and white counterparts. Consequently, this research successfully demonstrates the efficacy of using a green extraction method in preserving the lipid's quality, which can display cardiovascular functionality and thermal stability. These findings underscore the considerable potential of peach palm lipid extract as a valuable raw material for diverse industrial applications across various sectors. The results support its utilization in the production of functional food products and nutraceuticals due to its favorable fatty acid composition, potent antioxidant properties exhibited by its high β-carotene content, and notable cardiovascular functionality indices.

Combining deep learning with physical parameters in POC and PIC inversion from spaceborne lidar CALIOP

POC and PIC are indispensable components in the global ocean carbon cycle, their transport and space distribution being driven by the biological carbon pump and the carbonate pump. However, passive ocean color remote sensing, usually employed for POC and PIC research, experiences serious shortcomings in polar winter conditions due to its reliance on sunlight, leading to scarce data coverage in the polar regions. In contrast, CALIOP has shown considerable promise in high-latitude ocean observing. Past approaches to estimate POC from CALIOP data relied on bbp measurements obtained through the application of algorithms that presume an empirical linear correlation between bbp and the backscatter coefficient measured at 180°. This method does not account for any spatiotemporal variability in the conversion coefficient. Furthermore, the potential of CALIOP to provide estimates of PIC has not been explored yet. Here, we developed an innovative Two-Branch-Two-Step (TBTS) model to estimate POC and PIC from CALIOP data, which effectively expands the spatial coverage of the MODIS products. This method exploits the strength of deep learning while encapsulating the generalizability of physical parameters. This method consists of two branches: (1) a deep learning branch based on lidar attenuated backscatter waveform and (2) a branch focusing on physical parameters, including the total column-integrated depolarization ratio and the subsurface cross-polarized component of column-integrated backscatter. The model’s generalizability and accuracy are confirmed through the evaluation of a test dataset and validation using in-situ measurements. Our model outperforms several other prevalent machine learning models. We also dissected the importance of different parts of the input data using SHAP tools, thereby providing insights into the black-box nature of deep learning models. Using CALIOP products, we put forth the inaugural estimation of interannually resolved PIC and POC standing stocks in polar regions. The implementation of CALIOP in polar regions bridges the gap inherent in passive ocean color measurements. Lidar-derived total global PIC standing stock is estimated to be 8% higher than that from MODIS, while the POC standing stock is boosted by 17.2%. The carbon standing stock in polar regions exhibits significant inter-annual variability and apparent seasonal periodicity. Hence, results from this research effort clearly reveal that the exploitation of the CALIOP-derived POC and PIC measurements, in combination with the application of new approaches and algorithms to future space lidar data, will undeniably enhance our comprehension of the polar ocean carbon cycle. However, it is important to acknowledge that the CALIOP products may inherit biases from the MODIS data used for training. Hence, where MODIS data is available, it’s still the “better” product to use, but where there isn’t MODIS data, the CALIOP product is extremely useful, especially in the polar regions.

Color Differences of Polimerized Resin-Based Composites and Corresponding Shade Guides

Objective: The purpose of this study is to analyze and compare the colors (A2, A3 and A3.5) of polymerized resin-based composites (RBCs) with respect to the shade numbers within each product line and the VITAPAN Classical® shade guide they purported to represent. Methods: Three A-shades (A2, A3 and A3.5) from four RBC products (Harmonize®, Empress® Direct®, Grandio® and Filtek® 500) were compared within the VITAPAN Classical® shade guide and within their own commercial shade guide. Nine disk-shaped specimens, 6 mm in diameter and 2 mm thick, were prepared for each RBC color (three of each color). The color measurements were made according to the CIE L*a*b* color scale (quantifying L*c*h*a*b* values) using a Vita Easyshade Compact IV® digital spectrophotometer. We calculated the CIEDE2000 color differences between polymerized composites and shade guides, as well as between composites. The values obtained from composites and samples of the color guides in the CIE L*a*b* space were represented by ICC3D software (Version 1.2.9) Results: The ANOVA test verified the existence of statistically significant differences between composites for the same shades (p &lt; 0.05) except for shade A2. CIEDE2000 color differences between composites and the VITAPAN Classical® shade guide ranged from 3.5 to 13.1 depending on the composite and the shade. Conclusions: There were color differences among the polymerized resin-based composites, between these and their own shade guides/manufacturer’s commercial guides, and between the former and the corresponding samples of the VITAPAN Classical® shade guide. Clinical significance: Color selection when performing an aesthetic dental restoration is essential for the clinician and the patient to obtain an optimal result. Taking into account the color difference (∆E00) for each composite with the VITAPAN Classical® shade guide or with the manufacturers’ commercial guide allows for more precision with shade selection in aesthetic dentistry.

The effect of knit structure on natural dyeing properties of cotton fabric

Natural dyeing of textile materials is gaining popularity all over the world since natural dyes are mostly eco-friendly, less toxic, and less allergenic as compared with synthetic dyes. Although synthetic dyes offer a broad range of color and color fastness and bright hues, they are nonbiodegradable and carcinogenic compounds and cause water pollution as well as waste disposal problems. This study presents the natural dyeing of cotton knitted fabric with three different structures using R. cordifolia root extract as a natural dye. Knitted fabrics with three different structures, interlock (350 g/m2), single jersey (145 g/m2) and rib (135 g/m2), were produced and dyed with madder (Rubia Cordifolia) in the presence of tannic acid as a mordant. The dyed samples were evaluated in terms of color measurement results (CIE L*,a*, b*, C*, h0, DE) and color fastness properties.

Preparation, characterization, and photocatalytic performance of atmospheric plasma-sprayed TiO2/Al2O3 coatings on glass substrates

Conventional methods for wastewater treatment are not always efficient in persistent organic pollutant degradation processes. Therefore, low-cost and effective methods of their removal from sewage are constantly sought. This study presents an attempt to fabricate thermally sprayed ceramic coatings on glass and their characterization. Granulation of TiO2, Al2O3, and their blends in different mass ratios was done. Assessment of actual density and specific surface area was performed, and TiO2, Al2O3, and TiO2/Al2O3 were then used as a coating material for the deposition on glass substrates in atmospheric plasma spraying. Surface analysis of coatings was done by evaluating their roughness and wettability. Both powder and coatings samples were characterized using the X-ray diffraction method and scanning electron microscopy. The photocatalytic activity was estimated in the Eosin Y degradation process under UV light. UV–Vis spectroscopy was applied to observe the changes in the dye concentration. Additional tests for color measurements before and after photodegradation were carried out using a sphere spectrophotometer in CIELab color space. Particle size distribution was examined for the powder samples after the granulation and d50 was stated at 48.42–63.28 µm. Characterization of coatings via roughness measurements showed the average roughness of a surface equal to 4.90–9.65 µm. Moreover, most of the coatings appeared to be hydrophobic with water contact angles between 100° and 130°. All of the coatings showed Eosin Y degradation ability and the highest efficiency was reached for 100T/C, A75T/C, and A50T/C samples and stated at 71%, 62%, and 51%, respectively.Graphical abstract