Improve Color Quality Research Articles

Hybrid White OLEDs with High Electroluminescence Efficiency and High Color Rendering Index Achieved by a Sandwich Interlayer Sensitizing Configuration

AbstractWhite organic light‐emitting devices (WOLEDs) exhibit promising applications as white illumination and background light, but achieving high efficiencies, and high color quality for the WOLEDs still remains difficult. Herein, to enhance exciton utilization and improve the color quality of WOLEDs, a new sandwich configuration of an ultrathin orange phosphorescent layer located between two blue thermally activated delayed fluorescence (TADF) layers is proposed, and the working mechanism is investigated. In this configuration, the interlayer sensitization from blue TADF layers to orange phosphorescent layer via efficient Förster energy transfer occurs, which effectively alleviates exciton quenching in emitting layers and thus results in excellent electroluminescence (EL) efficiencies and improved color quality. The obtained two‐color hybrid WOLED exhibits an external quantum efficiency (ηext) exceeding 27%, with Commission Internationale del'Eclairage (CIEx,y) coordinates of (0.335, 0.396) and a color rendering index (CRI) of 63. By further incorporating an ultrathin red phosphorescent layer between the orange phosphorescent layer and the blue TADF layer, the ηext maintains at 21.96% and the CRI increases to 91 (CIEx,y = 0.380, 0.366). These results demonstrate the proposed sandwich interlayer sensitizing configuration is an effective and feasible strategy for realizing high EL efficiencies and high color quality simultaneously for hybrid WOLEDs.

Improving color quality in goldfish (Carassius auratus) by giving of papaya seed flour (carica papaya) as a natural inhibitor in the gonad development process

Goldfish (Carassius auratus) is a freshwater ornamental fish growing fast and in demand in Indonesia. This study aimed to obtain the best dose for the treatment and determine the effect of papaya seed powder on gonadal infertility, thereby increasing the development of colour quality in Comet fish (Carassius auratus). This research was carried out from May to August 2023 which was carried out in the Aquatic Laboratory room of the Aquaculture Study Program, Faculty of Agriculture, Juanda University, Bogor, West Java Province. This study used comet fish weighing 14-17 g stocked with three fish/aquariums. The study used a completely randomized design with four treatments and three replications. Treatment P0 (without papaya seed flour), P1 treatment (5 g papaya seed flour), P2 treatment (10 g papaya seed flour), and P3 (15 g papaya seed flour). The parameters observed were colour, weight gain, body circumference, sperm volume and survival rate. The results showed significantly different (P<0.05) in colour, weight growth, body circumference, and sperm volume, with the best results in the P2 treatment with a colour scoring value of 24.93, weight growth of 15.78 grams, body circumference of 5.94 cm and a sperm volume of 0.06 ml. The range of water quality includes temperature 24 – 28.9 oC, pH 7 – 8.68, and DO 5 – 7.5 mg/L. The survival rate in adding papaya seed powder showed no significant difference (P>0.05) in survival results (SR) with a value of 100%.

Cross-domain colorization of unpaired infrared images through contrastive learning guided by color feature selection attention

In challenging lighting conditions, infrared detectors have become vital tools for enhancing visual perception, overcoming the limitations of visible cameras. However, inherent imaging principles and manufacturing constraints confine infrared imaging systems to grayscale, significantly impacting their utility. In comparison to visible imagery, infrared images lack detailed semantic information, color representation, and suffer from reduced contrast. While existing infrared image colorization techniques have made significant progress in improving color quality, challenges such as erroneous semantic color prediction and blurred depiction of fine details persist. Acquiring paired color images corresponding to real-world infrared scenarios poses substantial difficulties, exacerbating challenges in cross-domain colorization of infrared images. To address these critical issues, this paper introduces an innovative approach utilizing contrastive learning for unsupervised cross-domain mapping between unpaired infrared and visible color images. Additionally, we introduce a color feature selection attention module guiding rational infrared image coloring. The proposed method employs the Residual Fusion Attention Network (RFANet) as a generator, enhancing the encoder’s ability to represent color and structural features. Furthermore, to ensure structural content consistency and enhance overall color style matching accuracy, we design a comprehensive joint global loss function integrating both detailed content and color style. Experimental evaluations on publicly available datasets demonstrate the superior performance of the proposed unsupervised cross-domain colorization method for infrared images compared to previous approaches.

Effects of Microwave Utilization on the Color Properties of Food: A Review

AbstractThis review discusses the importance of food coloring in determining consumer food preferences and the factors that can affect the color of food. It emphasizes the significance of preventing the degradation of pigments during food preparation and highlights the role of microwave ovens in preserving these pigments by reducing processing time and improving color quality. The review delves into the scientific principles underlying microwave heating and its effects on Maillard browning, caramelization, and other chemical reactions responsible for color changes in food. The potential benefits of microwave cooking (MWC) in preserving the natural color of certain foods are highlighted, along with challenges and considerations in maintaining color stability. The review synthesizes findings from diverse studies, providing a comprehensive overview of the current state of knowledge on the effects of microwave utilization on food color. Insights from this review contribute to a better understanding of the intricate relationship between microwave technology and the visual appeal of food, paving the way for informed culinary practices and the development of innovative MWC strategies.

125 Relationship of electrical conductivity to color variables (chroma, hue, L*, a*, b*) of fresh beef loins

Abstract Appraisal of beef color and overall quality assessment by consumers may be variable. In this study, Prime Grade beef strip loins were used to determine if electrical conductivity measurements (ECM) are correlated with color variables (chroma, hue, L*, a*, and b*) and could be used to improve color quality assessment and evaluation. An experimental design consisting of 6 full strip loins x 6 steaks per loin x 2 locations per steak was used and provided 72 total observations for analysis. Electrical conductivity measurements (ECM) procedures developed in our lab consisted of using emulsified meat samples concealed in silicon vessel connected to copper electrodes leading to a digital multimeter. ECM was measured in microsiemens (µS) over 60 sec with a sampling rate of 2/sec. Color variables were measured using a Varian Cary 50 Series Spectrophotometer following procedures of AMSA to ensure standardization. Data were analyzed using ANOVA and Pearson correlation coefficients. ECM means in microsiemens (µS) were 14.37, 42.52, 34.86, 22.89, 16.05, and 24.70 for the six groups of fresh steaks and were not different (P > 0.05). However, ECM values for cooked steaks differed (P < 0.05). Mean values for chroma, hue, L*, a*, and b* were different (P < 0.05) across fresh loin steaks. Correlations of ECM to all five of the color variables were different and negative (P < 0.05): chroma -0.013, hue -0.050, L* -0.009, a *-0.031, b* -0.110. These data show that ECM provide another analytical procedure that may be used in evaluating the color of fresh beef loins, and in the overall assessment and evaluation of beef products.

A magnetically responsive photonic crystal of graphene oxide nanosheets.

Magnetically responsive photonic crystals of colloidal nanosheets hold great promise for various applications. Here, we systematically investigated the magnetically responsive behavior of a photonic crystal consisting of graphene oxide (GO) nanosheets and water. After applying a 12 T magnetic field perpendicular and parallel to the observation direction, the photonic crystal exhibited a more vivid structural color and no structural color, respectively, based on the magnetic orientation of GO nanosheets. The reflection wavelength can be modulated by varying the GO concentration, and the peak intensity can be basically enhanced by increasing both the time and strength of the magnetic application. To improve color quality, we developed a novel approach of alternately applying a magnetic field to two orthogonal directions, instead of using a rotating magnetic field. Finally, we achieved color switching by changing the direction of applied magnetic fields.

Pengaruh Tingkat Pemberian Pakan Buatan Berbahan Dasar Tepung Daun Kelor (Moringa oleifera) Terhadap Kecerahan Warna Ikan Mas Koi (Cyprinus carpio)

One way to improve color quality is by feed nutrition engineering. This study aimed to determine the effect of the level of artificial feeding made from moringa (Moringa olefera) leaf flour on the color brightnees level of koi crap. The material used was moringa leaf flour, wich contains protein and caratenoids that can increase fish’s color brightnees and growth. The study employed an experimental method using a completely randomized design with four treartments and three replications. Furthermore, the treatments consisted of treatments A (5%); treatment B (10%); treatment C (15%); and treatment D (20%). The stocking density was ten fish/aquarium, and the feeding frequency was twice daily. The findings indicated that the provision of moringa leaf flour as the main igredient of artificial feed had a significant effect (p< 0.05) on color improvement and a highly significant effect (p<0.01) on weight gain. Moreover, the result signified that the highest increase in color was in treatment C from 11.69 to 16.95, the highest increase in absolute length growht was in treatment C with a value of 1.35 cm, and the highest increase in absolute weight gain was in treatment C manely 2,29 gr.

Latest Advances in Narrow‐Band Phosphors and Their Role in Color Management

Latest Advances in Narrow‐Band Phosphors and Their Role in Color Management

A TADF Emitter with Dual Para-Positioned Donors Enables OLEDs with Improved Efficiency and CIE Coordinates Close to the Rec. 2020 Red Standard

Developing red thermally activated delayed fluorescence (TADF) emitters concurrently with high efficiency and emission color close to the BT.2020 red standard is an ongoing challenge. Herein, we developed a new red TADF emitter BCN-TPA, in which two identical donors are attached at the para-positions of one fused phenyl ring in the acceptor framework. Such an arrangement mode can lead the donors with an obvious superimposed effect comparing the conventional arrangement with edge-capped donors on the acceptor. Thus, BCN-TPA yields enhanced overall donor strength with numerous superiorities, such as high oscillator strength and narrow singlet-triplet energy difference, thus giving rise to red-shifted emission with improved overall exciton utilization. In an organic light-emitting diode, BCN-TPA presents efficient deep-red electroluminescence with a maximum external quantum efficiency of 27.6% and a peak at 656 nm, corresponding to CIE coordinates of (0.686, 0.304), which are very close to the red primary in the BT.2020 standard. To the best of our knowledge, this is one of the topmost efficiencies in the field of deep-red TADF OLEDs. This work exemplifies an easy design principle for constructing high-performance deep-red TADF emitters, providing unique molecular-level insights toward improving color quality and elevating efficiency based on conventional D-A type molecular frameworks.

Improving Color Quality of Nanowire White Light-Emitting Diodes with Mn4+ Doped Fluoride Nanosheets.

A two-dimensional nanostructured fluoride red-emitting phosphor with an excellent quantum yield of ~91% is studied for cost-effective and high-color quality nanowire white light-emitting diodes (WLEDs). K2TiF6:Mn4+ phosphors are synthesized via an emulsification method using surfactants as sodium dodecyl sulphonate and oleic acid. The K2TiF6:Mn4+ phosphors in ultra-thin and nanosheet crystals are observed via scanning electron microscopy and high-resolution transmission electron microscopy. The surfactants are found to play a key role in inhibition of KTFM crystal growth process and stabilization of Mn4+ ions doping into the K2TiF6 host. The prepared phosphors exhibited intensive red emission at approximately 632 nm and excellent thermal stability in the range of 300–500 K upon 460 nm light excitation. Moreover, the K2TiF6:Mn4+ nanosheets were integrated on InGaN/AlGaN nanowire WLEDs for color quality study. The results show that the nanowire WLEDs with red-emitting phosphor exhibit unprecedentedly high color rendering index ~96.4, and correlated color temperature ~4450 K.

Improved color quality in double-EML WOLEDs by using a tetradentate Pt(ii) complex as a green/red emitter

Improved CRI of 81 and high EQE of 19.85% were achieved in simple structure WOLEDs with FIrpic as a blue emitter and a Pt(ii) complex as a green/red emitter.

On-Chip Depth and Image Sensing System With Offset Pixel Apertures

Depth sensing has been widely used in many applications over the past several decades. However, conventional depth sensing platforms are not suitable for mobile devices due to their large size and computation complexity. In this paper, we propose a compact system for depth and image sensing with offset pixel apertures (OPA). Specifically, we design an enhanced depth map processing (EDMP) and an OPA-dedicated image signal processing (OISP). The EDMP significantly improves the depth quality on excessively dark or light regions, greatly mitigates false depth aggregation at object boundaries, and increases depth precision with a very small overhead. Shot-noise-modeling and two-pass cost aggregation significantly reduce depth errors with reasonable hardware costs. Also, the OISP provides primary image processing while using white pixels to further improve color quality over conventional image sensors. Both EDMP and OISP are integrated on a single-chip. Our system shares the common hardware engine through time-multiplexing, taking advantage of the temporal margin caused by the sparsity of the OPA pixels. Compared to state-of-the-art OPA system, the proposed system reduces the depth error by 71.79%, increases the depth precision by 5.1 times, and reduces the angular error of color image by 54.08% on average.

Improving color quality and luminous flux of white LED utilizing triple-layer remote phosphor structure

In this manuscript, we presented a research that enhance the performance of WLED using the multi-phosphor configuration. The phosphor layers in the research are separated from each other to achieved better luminous efficiency, however, it makes controlling color light quality more complex. Another issue is finding out the whether two layers of phosphor or three layers of phosphor is better in improving color quality. The research addressed this issue by analyzing the optical aspects of the respective WLEDs that employ these structure. The studied aspects are quality indicators such as luminous efficacy (LE), and color uniformity, color rendering index (CRI), color quality scale (CQS). The results of the experiments in this research, which come from the employment of WLEDs with 2 color temperatures 5600 K and 8500, suggest that WLED with three phosphor layers is better in CRI, CQS, LE. This type of phosphor structure also limits the color deviation significantly, thus, improves the color uniformity. This results is verifies with Mie theory, therefore, can be applied as reference or guideline for production of better WLEDs

The options in remote phosphor structure for better white LEDs color quality

The WLEDs configuration with remote phosphor layers has higher luminescent performance than WLEDs with dispense coating or conformal coating and is applied for many modern devices. However, managing the chromatic performance of lighting structure with remote phosphor materials is a challenging objective that demands more research. This has inspired the usage of multi phosphor configurations with distance in between the layers to improve color quality. The results of this manuscript can support the manufacturers in choosing the optimal configuration for optical performance in LEDs devices with more than one phosphor material. The simulated model used in the experments is 6500 K CCT WLEDs, which results show the triple-layers structure is more favorable in terms of color quality and light output. Besides, a notable reduction occurs in color deviation means that chromatic stability is also enhanced in WLEDs with three phosphor layers. Through experimental results, which were confirmed by the Mie-scattering theory, this research offers valuable approach and details to produce better WLEDs.

Microfiltered red-purple pitaya colorant: UPLC-ESI-QTOF-MSE-based metabolic profile and its potential application as a natural food ingredient.

Complete characterization of microfiltered red-purple pitaya colorant (MRPPC) and its potential applications in foods is described. Using sensorial analysis, products that use carmine or beetroot dye as a food colorant in their formulations were compared. The effect of storage under refrigeration on the microbiological, physicochemical, and chemical changes of MRPPC were evaluated. The results showed that UPLC-ESI-QTOF-MSE was effective for the simultaneous determination of twenty metabolites, putatively identified as carbohydrates, flavonoids, and betalains. The MRPPC was shown to have microbiological and physicochemical stability through twelve weeks of storage, and chemometric analyses efficiently distinguished the metabolic profile in each storage period. Sensory analysis revealed that the MRPPC was useful as a food colorant in yogurt, where it improved color quality without affecting aroma and other characteristics. These results indicate that MRPPC is promising food ingredient as a natural red-purple colorant.

Color quality and antioxidant activity evaluation of clown loach juvenile, Chromobotia macracanthus Bleeker 1852 by addition of astaxanthin in diet

Botia or clown loach is the one of fishes was originated from Indonesia and as an ornamental fish commodity in the global market. Clown loach both nature and cultured have some problems when reared in aquaria that is the decrease of color quality. An innovation technology to improve color quality through diet formulates is needed. The aims of this research were to increase the color quality using astaxanthin in diet and to find out the role of astaxanthin as antioxidant in clown loach. The study consists of four treatments of astaxanthin dosages in the diet with isoprotein and isoenergy, namely 0, 50, 100 and 150 mg kg-1 with four replications. The fish juveniles with size of 3.44±0.51 cm and 0.56±0.02 g of weight with density of one fish per littre were used. The test diet was given three times a day during 60 days. The results showed that there were no significant differences antioxidant activity such as superoxide dismutase enzymes and malondialdehyde. However, there was a significant effect (P<0.05) to color quality of the chroma and total carotenoid, whereas no significantly different in lightness. The addition of astaxanthin was effective to improve the color quality of clown loach juvenile. Thus, 100 mg kg-1 of astaxanthin in diet is an optimal dose for clown loach juvenile.

Utility of almond leaf (Terminalia cattapa) for improving growth and color quality of neon tetra fish (Paracheirodon innesi)

Ornamental fish farming is easy to stress, which results in fading colors and patterns of the body. The effort to maintain the color and pattern of the fish’s body are using Almond leaf. This study aims to obtain the optimum concentration of Almond leaf in the maintenance of neon tetra fish, which is expected to improve the color quality and growth of fish. Neon tetra fish seeds measuring 1 - 2 cm were maintained in an aquarium sizing 25 cm x 40 cm x 28 cm with a stocking density of 4 tails liter−1. The completely randomized design (CRD) was applied with four treatments and three replications. The different of Almond concentrations as a treatment i.e. 0 ppm, 250 ppm, 500 ppm, and 750 ppm. Parameters measured such as survival (SR), growth (absolute length and weight), color quality (lightness, chroma, hue a, and b) and glucose levels. Water quality measured such as DO, temperature, pH, conductivity, TDS, ammonia and nitrite. The results showed that Almond leaf affected the growth of absolute length and absolute weight. Almond leaf with a concentration of 500 ppm could improve color quality, especially for green-red colors.

Selecting a Suitable Remote Phosphor Configuration for Improving Color Quality of White Led

When compared with two conformal phosphor and in-cup phosphor structures, the remote phosphor structure has higher luminescent performance. However, it is difficult to control the color quality of the remote phosphor structure, so it has become a research target in recent years. So far, there are two remote phosphor structures used to improve color quality including dual-layer phosphor configuration and triple-layer phosphor configuration. This study suggests using those two configurations to make multi-chip white LEDs (WLEDs) that can achieve adequate values in color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE) and color uniformity. WLEDs with a color temperature of 5600 K are applied. Research results show that the triple-layer phosphor configuration is superior in CRI, CQS, LE. Besides, the color deviation decreases significantly, meaning that the color homogeneity increases with the triple-layer phosphor configuration. This can be demonstrated by analyzing the scattering characteristics of phosphor classes through Mie theory, thus making the research results more reliable and valuable for producing quality WLEDs. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Benefits of triple-layer remote phosphor structure in improving color quality and luminous flux of white LED

Remote phosphor structure has higher luminous efficiency comparing to that of both conformal phosphor and in-cup phosphor structures. However, it is hard to control the color quality of remote phosphor structure, and this issue has become one of the most researchable objectives to many researchers in recent years. Up to now, there are two remote phosphor structures applied to improve the color quality, including dual-layer phosphor configuration and triple-layer phosphor configuration. The purpose of this research is to select one of those configurations to have multi-chip white LEDs (WLEDs) achieved the highest color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE), and color uniformity. In this research, WLEDs with two correlated color temperatures (CCT) of 6600K and 7700K were applied. The obtained results showed that triple-layer phosphor configuration is more outstanding in CRI, CQS, and LE. Moreover, the color deviation has been significantly reduced, which means the color uniformity has been enhanced with the application of triple-layer phosphor configuration. These results can be proven by scattering properties of phosphor layers based on Mie theory. Thus, the researched results have become a reliable and valuable reference for manufacturing higher-quality WLEDs.

Evaluating tradeoffs between energy efficiency and color rendition

Color rendition and energy efficiency have long been considered characteristics of light sources that cannot be maximized simultaneously. The tradeoff has been studied extensively, but usually considering only average color fidelity. This work examines the color rendition versus energy efficiency tradeoff in the context of ANSI/IES TM-30-18, Method for Evaluating Light Source Color Rendition, which provides numerous measures beyond average color fidelity. The analysis demonstrates that color rendition criteria based on combinations of ANSI/IES TM-30-18 values can be used to improve color quality with less of an effect on luminous efficacy of radiation than increasing CIE Ra alone.