Highest Color Index Research Articles

Multi-sites induced ultra-broadband luminescence based on Eu2+ doped whitlockite-type phosphor for full-spectrum WLEDs

Ultra-broadband-emitting phosphors are crucial for achieving high-quality full-spectrum WLEDs. However, it is difficult to achieve ultra-broadband emission by doping a single luminescent center. In this work, we propose a strategy to achieve ultra-broadband orange-red emission through utilizing Eu2+ selective occupation in multi-cation sites whitlockite-type phosphate Sr8Mg2Na(PO4)7. The result indicates that Eu2+ can occupy Sr1Mg1, Sr2Mg2, and Sr3Mg3 sites, and generate an ultra-broadband emission ranging from 400 to 800 nm with dominant emission at 620 nm and a FWHM of 220 nm upon 385 nm excitation. Interestingly, a new emission shoulder at 430 nm is obtained, which is demonstrated to ascribed to Eu2+ occupying the Mg4Na1 site in a weak crystal field. As an ultra-broadband-emitting and red-light abundant phosphor, the full-spectrum WLEDs shows much higher color index than that of YAG: Ce3+. Moreover, an ultraviolet light pumped full-spectrum WLED with a high Ra (∼92) and low CCT (∼4275 K) is fabricated by mixing the Sr8Mg2Na(PO4)7: Eu2+ and commercial phosphors BAM: Eu2+, Mn2+. In summary, this work deeply investigated the luminescence properties of Eu2+ in whitlockite-type phosphor Sr8Mg2Na(PO4)7 and is expected to guide the design of novel broadband-emitting phosphors with multi cationic sites for emerging full-spectrum WLED applications.

Er3+-activated Na0.5La0.5MoO4 multifunctional molybdate phosphors for optical thermometers and white LEDs

In this report, we have successfully prepared a series of Er3+-activated Na0.5La0.5MoO4 green molybdate phosphors by solid-state reaction. The X-Ray diffraction patterns confirmed that all diffraction peaks of Na0.5La0.5MoO4:Er3+ phosphors matched well with the standard data card with orthorhombic phase and the Rietveld refinement results indicated that the space group of the crystal structure was I41/a. Under 379 nm excitation, Na0.5La0.5MoO4:3%Er3+ phosphor exhibited strong green emission, with two strong emission peaks at 530 nm, 551 nm and a weak one centered at 656 nm, corresponding to the transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2, respectively. The experimental results showed that the optimal doping concentration of Er3+ was x = 3%, and electric dipole-dipole interaction was the major mechanism for the concentration quenching according to Dexter theory. Surprisingly, the optimal Na0.5La0.5MoO4:3%Er3+ phosphor presented thermal enhancement to the ratio of 2H11/2 → 4I15/2 transition to 4S3/2 → 4I15/2 transition in the elevated temperature range of 300–475 K. The maximum Sa and Sr were 1.79 × 10−2 K−1 and 1.094% K−1 respectively, which were applied to optical thermometers based on fluorescence-intensity-ratio technique. Furthermore, Na0.5La0.5MoO4:3%Er3+ phosphor had excellent thermal quenching performance (I425K/I300K = 93.47%) and high activation energy (Ea = 0.366 eV). Finally, the prepared Na0.5La0.5MoO4:3%Er3+ green phosphor, commercial BaMgAl10O17:Eu2+ blue phosphor and CaAlSiN3:Eu2+ red phosphor were combined with the 365 nm near-UV chip to produce a warm white LED device with high color index (Ra = 86.4) and low correlation color temperature (CCT = 4328 K). The above results suggested that the Er3+-activated Na0.5La0.5MoO4 multifunctional phosphors had considerable potential in the field of optical temperature measurement and phosphor-converted white light emitting diodes.

Stable All‐Fluorescence White Organic Light‐Emitting Diodes with High Efficiency and High CRI

AbstractWhite organic light‐emitting diodes (WOLEDs) have been regarded as the candidates for next‐generation flat‐panel displays and solid‐state lighting due to their low cost. However, it is still challenging to achieve two‐component WOLEDs with high efficiency, high color index (CRI), and long lifetime. Here, high‐performance all‐fluorescence WOLEDs based on a blue fluorescent emitter and an orange thermally activated delayed fluorescent (TADF) emitter are demonstrated. The optimized all‐fluorescence WOLED with two EMLs presents the maximum external quantum efficiency (EQE), current efficiency (CE), and power efficiency (PE) of 23.4%, 40.2 cd A−1, and 33.2 lm W−1, corresponding to a maximum CRI value of 83.1 and Commission Internationale de L'Eclairage (CIE) coordinate of (0.30, 0.31). To further improve the device stability, the all‐fluorescence WOLEDs with three EMLs and tandem structure are constructed, respectively. Under the premise of ensuring efficiency, in going from the two‐EMLs to the three‐EMLs and the tandem structure, the LT50 (time to 50% of the initial luminance) of all‐fluorescence WOLEDs increase from 601 to 714 h and 1622 h at an initial luminance of 1000 cd m−2. These strategies and results present new insight into the design of all‐fluorescence WOLEDs with high efficiency, high CRI, and extended lifetime.

Measuring Color Index of Transformer Oil–Enabling Single-Wavelength Spectroscopy With Artificial Neural Network-Fuzzy Logic Model

Conventionally, the color index of transformer oil is determined by a color comparator based on the American Society for Testing and Materials (ASTM) D 1500 standard. The equipment requires humans to operate, which leads to human error and limited number of samples tested per day. This work proposes the utilization of single-wavelength spectroscopy with 405 nm laser diode using artificial neural network (ANN) to determine the color index of transformer oil. Two ANN models were developed using data collected from 50 oil samples with different optical pathlengths of 1 to 10 mm, and laser output powers of 1 to 15 mW. The first model classified the input into different color indices and another model correlated the input parameters through regression analysis to determine the color index. A hybrid ANN-fuzzy logic model was also developed to improve the color index prediction. The root-mean-squared error (RMSE) obtained from the prediction by ANN regressor and ANN classifier are 0.5602 and 0.6416, respectively. The hybrid ANN-fuzzy logic model improves the RMSE especially for optical pathlengths <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt;$</tex-math> </inline-formula> 5 mm, which is required for measuring samples with high color index. This proposed method reduces the dependency on complex optoelectronic hardware to obtain highly accurate results. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —Unlike the conventional testing method for color index of transformer oil that requires human observation, the findings of this study enables the possibility of compact and smart portable device through the utilization of single wavelength spectroscopy with machine learning models. With no human involvement, more computational power with lesser hardware dependency, the maintenance cost and error can be reduced. This proposed method can potentially be applied to measure the color of other amber-colored liquid products such as olive oil, honey and others.

High‐Performance and Reliable White Organic Light‐Emitting Fibers for Truly Wearable Textile Displays (Adv. Sci. 11/2022)

Fiber-Based White Organic Light-Emitting Diodes In article number 2104855, Kyung Cheol Choi and co-workers develop first fiber-based white organic light-emitting diodes (WOLEDs) with high-performance and high reliable color index, using a dipcoatable single white-emission layer based on simulation and optimization of the white spectra. This pioneering work is believed to provide building blocks for realizing complete textile displays by complementing the lack of the core-technology.

Enzyme Aided Processing of Oil

Enzyme aided process (EAP) has been identified as a viable alternative for oil extraction. This paper reviews the recent trends in EAP of soybeans during degumming, transesterification, oil extraction, and demulsification. The “common protease effect” and the degree of demulsification of oil was also examined. EAP has improved overall oil yield to about 90% and high oil quality. EAP oils have high tocopherol content, decreased turbidity, higher color index, better oxidative stability, and drastic reduction in residual phosphorus content of oils thus contributing to enhanced oil quality. We conceptualize “Common enzyme effect” as the reason for degree of demulsification (oDem) occurring during enzyme aided extraction. The equation for rate of change of oDem have also been proposed. Few studies on simultaneous EAP have shown the efficacy of multifunctional enzyme to enhance oil recovery and quality. The use of immobilized enzyme has also received less attention, though, could potentially reduce EAP cost.

Process Water Production for Oil and Gas Utility Systems at High Water Color Index Conditions

The article is devoted to the water treatment of high water color index waters for oil and gas utility systems at low temperatures conditions. The relevance of the article is justified by the development of pipeline transport in the regions of Eastern Siberia and the Far East. The purpose of the article is to provide an empirical presentation of the feasibility and efficiency of reactant treatment of high water color index waters at low temperatures by the example of real waters of the Lena River (Eastern Siberia) and the Zeya River (Far East).

A warm white light macromolecular complex phosphor containing Eu(III),Tb(III) and Zn(II) with low color temperature and high color index

This paper presented an approach warm white light macromolecular complex phosphor with low color temperature and high color index were synthesized with the copolymer as macromolecular ligand of 4-vinyl benzoate and methyl methacrylate and with Eu(III), Tb(III) and Zn(II) vacancy complexes. The structure and luminescent properties were characterized through infrared spectroscopy, ultraviolet–visible spectroscopy, thermogravimetry and fluorescence spectroscopy. The results show that polymethyl methacrylate functionalized by the carboxylic acid has the ability of coordination with metal ions. Under the excitation of near-ultraviolet light at 365 nm, the macromolecular complexes exhibit characteristic emission of Zn(II), Tb(III), and Eu(III) at 449 nm, 543 nm, and 613 nm, respectively. The CIE color coordinates (0.39, 0.35) calculated from the fluorescence emission spectra are located in the warm white region. The device was fabricated with a 365 nm near UV chip with a color temperature of 4237 K and a color rendering index of 83.

Determination of physicochemical characteristics, organic acid and sugar profiles of Turkish grape juices

This study investigated the physicochemical properties, sugar and organic acid profiles of 21 grape juice and 3 sour grape juice samples in Turkey. The pH, acidity and soluble solids were ranged from 2.64 to 4.19, 3.58 to 30.75 g L-1 and 5.45 to 25.45 °Bx, respectively. The turbidities varied between 1.59 and 109.50 NTU and the lowest value was in the Sultani Çekirdeksiz sour grape juices. The Denizli Karasi sample had the highest color index. The tartaric and malic acid amounts of the samples ranged from 0.53 to 13.16 g 100-1 g-1 and 0.45 to 30.80 g 100-1 g-1, respectively. The major acid was malic acid in the sour grape juice samples and tartaric acid in the grape juice samples. For all samples, glucose and fructose constituted a great part of total sugars. The glucose, fructose and total sugar contents changed from 28.45 to 48.00 g 100-1 g-1, 15.88 to 48.75 g 100-1 g-1 and 53.67 to 97.27 g 100-1 g-1, respectively. The highest sugar content was observed in Kara Erik and the lowest in Yediveren. As a result; some physicochemical characteristics, sugar and organic acid contents of the examined 24 grape juice samples were revealed by the current work.

Maturation and physiological quality of IAC-863 Rangpur lime seeds

There is a growing demand for high quality seeds to obtain citrus rootstocks. Normative Instruction 48 (MAPA) of September 24, 2013, requires minimum of 50% germination for the marketing of citrus seeds. Harvest season is one of the stages of seed production with great importance to ensure quality, which makes knowing its maturation process an important step. Thus, the objective of this study was to monitor physicochemical changes in IAC-863 Rangpur lime fruits in order to characterize the physiological maturity of seeds, and to define the ideal harvest point in order to obtain seeds with high physiological quality to obtain rootstocks. Physicochemical analysis of fruits (mass loss, color, soluble solids and acidity) and analysis of seeds (water content, germination and emergence) was performed. Higher germination results were observed in seeds obtained from fruits with higher color index and soluble solids content. The storage of IAC-863 Rangpur lime fruits after harvest increases germination rate, especially in mid-season fruits.

Characterization of three Arracacia xanthorrhiza Bancroft genotypes using morphological and color parameters

In Colombia, the arrachacha is a crop with high economic and nutritional value. Despite its agricultural importance, few studies have focused on characterizing morphological parameters between genotypes. Some arracacha genotypes have been classified based on their qualitative traits such as coloration of the root, stem and leaf. Because of the variability of this characteristic, it is necessary to use the colorimetric system for greater precision. Color characterization was performed using the CIELab colorimetric system and morphological parameters (plant height, root diameter and number of fleshy roots) on three different genotypes of A. xanthorrhiza Bancroft (Yema de huevo, Paliverde and Yucatana) in the municipalities of Boyaca and Somondoco in the Department of Boyaca, Colombia. The results showed differences in the morphological characteristics plant height, root diameter and number of fleshy roots. The Yema de huevo genotype had a greater root number and diameter and a higher height, closely followed by the Paliverde genotype. This response depended on the environmental conditions of each municipality. The root and stem coloration had differences between the three genotypes, meaning these morphological characteristics can differentiate these genotypes. The Yema de huevo and Paliverde genotypes had the highest color index, a response that depended on the characteristics of each municipality. This research provides information on the physical characteristics of each genotype, which allows for easier visual identification.

Complexity and online algorithms for minimum skyline coloring of intervals

Motivated by applications in optical networks and job scheduling, we consider the interval coloring problem in a setting where an increasing cost is associated with using a higher color index. The cost of a coloring at any point of the line is the cost of the maximum color index used at that point, and the cost of the overall coloring is the integral of the cost over all points on the line. A coloring of minimum cost is called a minimum skyline coloring. We prove that the problem of computing a minimum skyline coloring is NP-hard and initiate the study of the online setting, where intervals arrive one by one. We give an asymptotically optimal online algorithm for the case of linear color costs and present further results for some variations and generalizations of the problem. Furthermore, we consider the variant of the minimum skyline coloring problem where the intervals are already partitioned into color classes and we only need permute the colors so as to minimize the cost of the coloring. We show that this problem variant is NP-hard and present a 2-approximation algorithm for it.

The effect of olive fruit maturation in Spanish style fermentation with a controlled temperature

The influence of maturation of different olive fruit varieties and the effect of these olives fermented at room temperature in a spontaneous fermentation were studied. Also, table olives from Carrasqueña variety harvested in two consecutive weeks in green stage of maturation, were fermented at different thermal temperature by heat transfer to the brine. Initially, an olive growth characterization was carried out. The largest variety was “Manzanilla Cacereña” and presented less texture and the lowest total phenolic and antioxidant activity. However, “Carrasqueña” variety, which had the highest firmness, showed a slower size. The color index of “Manzanilla Sevillana” was rather higher than the color index of the other varieties. After fermentation process, the highest color index and free acidity in “Manzanilla Sevillana” table olive could be caused by the highest temperature of the brine achieved. In general, the varieties studied had a good texture during fermentation. On the other hand, the effect of thermal applications in table olive color was higher when the olives were harvested later and by thermal application. Finally, the effect of thermal application depended on initial maturation stage achieving an increase of phenols with determined temperatures and conditions.

Geneses of Two Types of Mafic Rocks to Carry Placer‐Magnetite Ores in the Sanin Granitic Belt, SW Japan

AbstractTwo types of mafic rocks from the central Sanin district, and their mafic minerals, were studied chemically and microscopically. They are classified into pyroxene‐containing gabbroid and hornblende–biotite quartz diorite. The gabbroid had higher color index but lower magnetite content; while the quartz diorite had lower color index, but higher magnetite content. The magnetite contents are also related to the amounts of hydrous mafic silicates. The gabbroic magma having pyroxene–amphibole assemblage, originated in the upper mantle, was considered essentially anhydrous, but became partly hydrous on the way to the site of solidification in the continental crust, and crystallized some magnetites with hypersthene and amphibole. The quartz dioritic magma was formed by partial melting of possibly subducting ocean‐floor basalts, once exposed to the sea‐floor then altered; thus the magmas became hydrous and oxidized originally, and precipitated abundant magnetite and hydrous mafic silicates from the early crystallization stage onward. Their weathered parts provided the most placer magnetite ores in the history.

Mn4+-activated BaSiF6 red phosphor: Hydrothermal synthesis and dependence of its luminescent properties on reaction conditions

In this work, a series of BaSiF6:Mn4+ red phosphors were synthesized through a hydrothermal route. The crystal structure and morphology were characterized by powder X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS) in detail. The influence of reaction conditions, including the concentration of KMnO4 and HF, reaction temperature and time, on the photoluminescence properties were investigated systematically. It can emit intense red light (∼636 nm) under blue light (∼458 nm) illumination. The white LED device based on YAG:Ce–BaSiF6:Mn4+ mixture shows warm white light with low color temperature and high correlated color index, which reveals its potential application in WLED.

Lycopene content and color index of tomatoes are affected by the greenhouse cover

The use of plastic or glass covers in greenhouses increases fruit yield and quality by controlling their environment. Color as well as lycopene content is the most important factors in the visual and nutraceutical quality of tomatoes, and they are factors affected by temperature and light inside the greenhouse. The objective of this study was to compare color development and lycopene accumulation in tomato fruits cv. ‘Geronimo’ at different maturity stages, grown in greenhouses covered with two types of covers (double-layer polyethylene K50 Clear+K50 IR/AC or flat glass 4mm thick coated with a 15% CaCO3 solution) in different periods of production. At 21, 25 and 29 weeks after transplanting, 24 clusters of tomatoes were labeled per experimental unit and three weeks after labeling, tomato fruits were harvested, classified by maturity, and analyzed for color index (a*/b*) and lycopene content. External and internal temperatures and light data were recorded through a meteorological station system with automatic control. Our results suggested that the season of production, temperature and lighting conditions in the greenhouse, affected the lycopene biosynthesis process. Lycopene content increased as the photoperiod was expanded and at the 32nd week, was higher in fruits collected in greenhouses with double layer of polyethylene (414μgg−1 freeze-dried fruit) than that in fruits grown under a covered with flat glass coated with CaCO3 (241μgg−1 freeze-dried fruit). The application of 15% CaCO3 solution helped to control the temperature but limited the lycopene biosynthesis. Tomato fruits that received greater amounts of light accumulated more lycopene and had the highest color index (1.22) which shows that it is possible that the accumulation of more lycopene is correlated to the transmittance of the cover. The temperature control through bleaching, washing and shading techniques could be improved if the light intensity needed to improve the fruit color development and lycopene accumulation is considered.

Optimum Application Amount, Timing, and Frequency of Slurry Composted and Biofiltered Liquid Fertilizer for Zoysia japonica 'Millock'

In Korea, slurry composted and biofiltered (SCB) liquid fertilizer is produced through the composting and biofiltering of animal waste. An appropriate guidelines involving proper treatment of SCB liquid fertilizer on turfgrass should be considered. An experiment was conducted to determine the optimum application amount, timing, and frequency of SCB liquid fertilizer for Zoysia japonica 'Millock'. The SCB liquid fertilizer was applied in low, medium, and high amount (N at 15, 25, and 40 <TEX>$g{\cdot}m^{-2}$</TEX> per year in 2010, and 10, 20, and 40 <TEX>$g{\cdot}m^{-2}$</TEX> per year in 2011, respectively) and treated during the growing season or dormancy period. During the growing season, SCB liquid fertilizer was applied twice or four times. The greatest improvement in turf quality for both years was in SCB plots applied four times with N at 40 <TEX>$g{\cdot}m^{-2}$</TEX> per year during the growing season (SH4). This treatment exhibited turf color retention in the fall, and enhanced clipping yield during the growing and fall seasons. SCB plots with four times during the growing season (SL4, SM4, and SH4) exhibited higher shoot density relative to the same amount of other SCB treatments. Plots treated during the dormancy period also showed a high turf color index during the next growing season in 2011. The results indicate that SCB with high amount up to N at 40 <TEX>$g{\cdot}m^{-2}$</TEX> per year applied four times during the growing season and dormant application produced high turf quality and growth, and could be recommended as an optimum application guide.

Characterization of Iranian Virgin Olive Oil from the Roodbar Region: A Study on Zard, Mari and Phishomi

AbstractThe aim of this study is to describe the physicochemical properties of Iranian virgin olive oil (Zard, Mari and Phishomi) cultivated in Roodbar, Gilan. There were statistically significant differences for most of the parameters (P &lt; 0.05). The acidity and peroxide value were in the limit established for classification as extra virgin olive oil. The oil of Zard had the highest amount of monounsaturated fatty acids followed by Mari and Phishomi oils. Mari oil proved to have the minimum value of polyunsaturated fatty acids, and the highest amount of phenolic compounds and oxidative stability. The oil of Phishomi had the maximum amount of chlorophylls and carotenoids and therefore it had the highest color index. There were no significant differences between the cultivars regarding the refractive index (1.469 at 20 °C for all three cultivars). According to the high content of monounsaturated fatty acids, the lowest amounts of polyunsaturated fatty acids and the highest amounts of phenolic compounds as well as the results of a Rancimat assay, it seems that the quality of the oil of Mari cultivar is better than Zard and Phishomi oils and is also more stable against oxidation.

AIR TEMPERATURE AND SUNLIGHT INTENSITY OF DIFFERENT GROWING PERIOD AFFECTS THE BIOMASS, LEAF COLOR AND BETACYANIN PIGMENT ACCUMULATIONS IN RED AMARANTH (AMARANTHUS TRICOLOR L.)

The objectives of this study were to determine the effects of daily air temperature and sunlight intensity variations on biomass production, leaf color and betacyanin accumulations in red amaranth (Amaranthus tricolor L.). For this purpose, two improved cultivars; BARI-1 and Altopati were grown in seven different period (from April to October, 2006) under vinyl house condition in the experimental facilities of Gifu University, Japan. The mean daily temperatures fluctuated from 18 (growing month- April) to 29oC (August), while the mean sunlight intensities varied from 850 (October) to 1257 μmol m-2 S-1 (August). The highest biomass yield and betacyanin accumulation was obtained in the warmer growing period (July and August) at 28 to 29oC mean air temperatures and 1240 to 1257 μmol m-2 S-1 sunlight intensity. At the warmer growing period red amaranth produced red leaves with high color index, which enhanced the betacyanin accumulations. The biomass yield and betacyanin accumulations were reduced significantly in the growing period/month April and October under low temperature regimes (mean air temperature 18 and 19oC, respectively). However, growing period’s air temperature contributed more for biomass and betacyanin accumulations in red amaranth than sunlight intensity. Comparing two cultivars the biomass yield of BARI-1 was higher biomass yield than that of Altopati and Altopati highlighted with the higher betacyanin accumulations than that of BARI-1 in all growing period. Quantification of the effects of daily air temperature and sunlight intensity on biomass and betacyanin accumulation is important for growers producing these crops for fresh market and also optimize the best growing period. Therefore the influence of air temperatures and sunlight intensity should be considered while grown red amaranth for maximum yield with bioactive compounds like betacyanin and should be grown in between 28 to 29oC air temperature and 1240 to 1257 μmol.m-2.S-1. of sunlight intensity.

A Novel Body Weight-loss Promoting Oil Prepared with Vegetable Protein

It has been reported that oil thermally processed with wheat gluten (gluten oil) exhibited safe weight-loss promoting effects in animal experiments. However, as the oil has a high color index, and its chemical properties and smell differ from those of fresh oil, it is uncertain if the oil will find market acceptance. In order to resolve the issue, frying oil was heated with soybean protein under reduced pressure (soybean protein oil), resulting in a product with an appearance, chemical properties and smell comparable to those of fresh oil. This improved oil was mixed (7 wt%) with powdered AIN93G no fat, defined standard diet and fed to 10-week-old Wistar rats ad libitum. The experimental rats grew normally, ingesting the same amount as that of the control rats; however, there was a negative correlation between body weight increases and fecal weight increases. After the 12-week feeding period, all the rats were sacrificed to obtain blood and organs. In the experimental group, liver weight, retroperitoneal fat tissue weight and serum triacylglycerol (TG) levels decreased significantly. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and histological analysis supported the safety of the improved oil. In conclusion, it was found that soybean protein oil inhibited body weight increases without any adverse effects in animal experiments. The oil holds promise as a novel dieting oil that steadily decreases body weight at an appropriate rate.