Color Light Research Articles

78‐1: Invited Paper: Gamut Rings Color Scope for Use with Wide Gamut Display Systems

Traditional chromaticity scopes and vectorscopes have limited ability to visualize color appearance attributes, which limits color grading and color correction. A new tool based on gamut rings can monitor the lightness, chroma, and hue distributions of the pixel colors of input images in a single 2D diagram. The perceptually intuitive visualization is expected to facilitate more efficient and effective color grading, thereby broadening the market's understanding of the benefits of wide gamut displays.

On-chip integrated metasystem for spin-dependent multi-channel color holography.

On-chip integrated metasurface driven by in-plane guided waves is of great interests in various light-field manipulation applications such as colorful augmented reality and holographic display. However, it remains a challenge to design colorful multichannel holography by a single on-chip metasurface. Here we present metasurfaces integrated on top of a guided-wave photonic slab that achieves multi-channel colorful holographic light display. An end-to-end scheme is used to inverse design the metasurface for projecting off-chip preset multiple patterns. Particular examples are presented for customized patterns that were encoded into the metasurface with a single-cell meta-atom, working simultaneously at RGB color channels and for several different diffractive distances, with polarization dependence. Holographic images are generated at 18 independent channels with such a single-cell metasurface. The proposed design scheme is easy to implement, and the resulting device is viable for fabrication, promising plenty of applications in nanophotonics.

Experimental Analysis of the Light Wavelength’s Impact on the Performance of a Silicon Solar Cell

The main aim of this article is to analyse the Si solar cell’s behaviour when it is exposed to light of different colours. An experimental work, with 100 experimental tests, was carried out, using an RGB LED. In order to obtain better fitting of the characteristic curves’ results, we used a novel discrete model, d1MxP. The obtained results showed that all experimental points of the tests were inside the two triangles that connected the three theoretical primary colours and the three experimental primary colours in the chromaticity diagram. With this diagram, the colour purity could be determined, which presented values between 20% and 60%. The primary colours of the three different LEDs of the light source presented a dominant wavelength that corresponded to the peak wavelengths of the light source spectrum, which showed high purity. However, the obtained results show that mixing colours may not lead to an increase in the cell’s output power. Additionally, an increase in the cell’s temperature was observed, due to the surplus absorbed energy, which was converted into heat, being one of the causes of the cell’s efficiency reduction.

Coprecipitation routed MWCNT/CdMn2O4 nanocomposite for high performance aqueous hybrid supercapacitor

A facile coprecipitation approach is used to synthesize CdMn2O4 and a multi-walled carbon nanotube/CdMn2O4 composite. The prepared CdMn2O4 nanoparticles and multi-walled carbon nanotube/CdMn2O4 composite are characterized by numerous characterization techniques and discussed. The TEM characterization reveals that CdMn2O4 nanoparticles are attached with the multi-walled carbon nanotubes (MWCNTs). Further, the supercapacitive performance of CdMn2O4 and MWCNT/CdMn2O4 is investigated. High specific capacities (Qs) of 124.25 and 202 mAh g-1 are obtained at 1 A g-1 from CdMn2O4 nanoparticles and MWCNT/CdMn2O4 composite, correspondingly. The performance of cyclability of MWCNT/CdMn2O4 indicates the long durability of the material for commercial application. Further, an aqueous hybrid supercapacitor (HSC) is assembled by MWCNT/CdMn2O4 and activated carbon (AC). MWCNT/CdMn2O4//AC delivers an energy density of 36.80 W h kg-1 at the power density of 775 W kg-1 with the current density of 1 A g-1. Further, two yellow, two blue, two green, two red and two white color light emitted diodes (LEDs) are easily and separately lighted by two MWCNT/CdMn2O4//AC connected in series. As well, a kitchen timer and toy motor fan were powered by two MWCNT/CdMn2O4//AC connected in series.

Tactile, Auditory, and Visual Stimulation as Sensory Enrichment for Dairy Cattle.

Several types of enrichment can be used to improve animal welfare. This review summarizes the literature on the use of mechanical brushes, tactile udder stimulation, music, and visual stimuli as enrichment methods for dairy cows. Mechanical brushes and tactile stimulation of the udder have been shown to have a positive effect on milk yield and overall behavioral repertoire, enhancing natural behavior. Classical music reduces stress levels and has similarly been associated with increased milk yield. A slow or moderate tempo (70 to 100 bpm) at frequencies below 70 dB is recommended to have this positive effect. Evidence on the impacts of other types of enrichment, such as visual stimulation through mirrors, pictures, and color lights, or the use of olfactory stimuli, is equivocal and requires further study.

Enhancing Foundation Shade Suggestions through Skin Tone Identification

As we concentrate on addressing the challenges in responsible beauty product recommendation, particularly when it involves comparing the product’s color with a person’s skin tone, similar as for foundation and robe p conditions. The features uprooted using the prints from illuminated terrain can be largely deceiving or indeed be inharmonious to be compared with the product attributes. Hence bad illumination condition can oppressively degrade quality of the recommendation. We introduce a machine learning frame for illumination assessment which classifies images into having moreover good or bad illumination condition. We also make an automatic stoner guidance tool which informs a stoner holding their camera if their illumination condition is good or bad. This way, the stoner is handed with rapid-fire feedback and can interactively control how the print is taken for their recommendation. Only a many studies are devoted to this problem, substantially due to the lack of dataset that's large, labeled, and different both in terms of skin tones and light patterns. Lack of similar dataset leads to neglecting skin tone diversity. Thus, we begin by constructing a different synthetic dataset that simulates colorful skin tones and light patterns in addition to a being facial image dataset. Next, we train a Convolutional Neural Network (CNN) for illumination assessment that outperforms the being results using the synthetic dataset. Eventually, we dissect how the work improves the shade recommendation for colorful foundation products

Study on the dyeing properties of Chinese fir with Cinnamomum camphor pigment by premordant dyeing

ABSTRACT Wood staining can improve the quality of Chinese fir. In this study, Cinnamomum camphora natural plant pigment was used as a substitute for synthetic dyes to stain Chinese fir, and the staining performance was enhanced through pre-mordanting with alum. The dyeing effects of direct dyeing and mordant dyeing were compared, and the factors and levels influencing color difference, wash fastness, and light fastness were investigated through an orthogonal experimental design. The results showed that mordanting time had the greatest influence on color difference and lightfastness, while mordanting temperature had the greatest influence on washfastness. After pre-mordanting, the washfastness of Chinese fir improved to a level of 2–3, while the improvement in lightfastness was not significant. Pre-mordanting increased the dye uptake rate by 6.67%. Scanning electron microscopy revealed that NaOH pretreatment opened the wood pores and increased the flow channels for dye liquor. Infrared analysis indicated that O-H in wood fibers formed complexes with Al3+ in the mordant, resulting in a decrease in the characteristic peak intensity of O-H. X-ray diffraction analysis showed that the attractive effect of Al3+ vacant orbitals on O-H partially influenced the ordered arrangement structure in the crystalline region.

Chromatic Wavelengths Luminescence: It’s Impact to Growth Response of Tsitsirika (Catharanthus Roseus)

This study seeks to analyze the complex interactions between color psychology, lighting technology, and the cultivation of Tsitsirika (Catharanthus roseus) in the Philippine agricultural environment. The study is organized around three main goals: first, to investigate the effect of several LED wavelengths, specifically red, blue, and green, on the overall growth parameters of Tsitsirika. Second, it intends to conduct a rigorous comparative analysis, carefully comparing the development patterns shown by various colored LEDs to those detected in natural solar irradiation. This comprehensive analysis seeks to identify significant differences and explain potential benefits or drawbacks related with the use of artificial lighting. Ultimately, the study aims to explain the physiological characteristics induced by red, blue, and green LED wavelengths on Tsitsirika, revealing their subtle effects on the plant's physiological and morphological aspects, including leaf pigmentation and stomatal behavior. By thoroughly addressing these objectives, this study hopes to provide nuanced and academically valuable insights on the prudent application of color psychology and lighting technology, ultimately influencing optimal cultivation practices for Tsitsirika. This scholarly endeavor is positioned to support sustainable and efficient agricultural practices, not just in the Philippines but also with potential for broader application.

Decentralised Coordination in Swarm Robots Through XGBoost-Enhanced Colour Light Communication

Decentralised Coordination in Swarm Robots Through XGBoost-Enhanced Colour Light Communication

Developing an Automated Spectrophotometer with RGB LED and Light Sensor Using Arduino Microcontroller

This research used RGB LED (Red Green Blue Light Emission Diode), LDR (Light Dependent Resistant) sensors, 3D printed sampling cartridge, and Arduino Mega to create a spectrophotometer with automation software to select wavelength, calculate calibration parameters, and report the concentration of the materials being studied. Spectrophotometers are finding applications across many fields, including clinical laboratories, pharmaceuticals, molecular biology, biochemistry, and even the medical realm. This study assembled an Arduino mega system coupled with software for the automatic selection of best-fit color light, calibration curve, and actual concentration interpolation processes. Dilution solutions from multiple chemical materials were evaluated to examine their linearity of calibration curves. Our study demonstrated that the tested chemical samples revealed a significant regression coefficient of up to 0.9945 for serial dilution solutions. Relative concentrations were measured with remarkable precision, exhibiting less than 5.0 % error compared to a commercial spectrophotometer. These findings highlight the viability of the RGB spectrophotometer and emphasize its potential with the promise of further refinement in development.

How does Coloured Lighting Influence the Affective Processes of Pupils?

Nowadays, the progressive incorporation of technological elements in classrooms adds new possibilities to be explored in the field of colour and environment. In this sense, LED lighting as a source of “coloured light” is a resource that has not yet been analysed. The present quasi-experimental design had a pre-test and was carried out for a single group in a primary school for two months, focusing on the dependent variables “energy level”, “enjoyment level” and “feeling”, whose values were collected by means of a self-perception survey. The results obtained are significant in the post hoc analysis of variance for some scenarios of the variable “feelings”, but less so for the others. The disparity of results according to the colour analysed, with violet sometimes having a greater impact than orange at other times, also leads us to consider the need for dynamism positively.

Morphological Characterization of Elite Indian Bean Genotypes of Bundelkhand Region

The morphological characterization of Indian bean genotypes of Bundelkand region was conducted at Vegetable Research Farm, RLBCAU, Jhansi during kharif season 2020-21. A total of 21 genotypes of Indian bean were collected from various districts of Uttar Pradesh. The randomized block design with two replications was used and morphological characterization was conducted. Observations were recorded on ten morphological characters selected from DUS. Dolichos bean germplasm exhibits significant diversity in various qualitative traits, including plant growth habit (ranging from pole to bush), stem colour variations (green, dark green, and purple), diverse flower colours (purple, white, and dark purple), leaf vein colours (light green, green, and purple), distinct leaf densities (sparse, intermediate, and dense), pod colours encompassing green, light green, white, purple, and dark purple, as well as pod characteristics such as curvature (straight, curved, and highly curved) and shape (straight, intermediate, and curved).

Psychophysical determination of boundaries and smoothness of color gradients.

Color gradients constitute an important component in the evaluation of the color quality of multicolored patterns that contain color transitions. A two-part psychophysical study was designed and employed to test the appearance of a set of hue-, chroma-, or lightness-based color gradients. The influence of several parameters on the visual determination of gradients' boundaries and perceived smoothness was tested. These parameters included gradient type, e.g.,transitions based on hue, chroma, lightness or their combination, orientation, slope, and quantization step size of color transitions. The influence of these parameters on intra- and interobserver variability in responses was calculated using the standardized residual sum of squares metric. In the first part of the experiment, the perceived boundaries of color gradient stimuli as well as observer confidence ratings in performing these visual tasks were determined. In the second part, the perceived smoothness ratings of the stimuli and visual confidence ratings in assessments were examined. Four binary color transition images, i.e.,brown-green, brown-tan, green-olive, and light sage-olive, were generated. Three different linear-gradient slopes were applied to each transition, and each stimulus was shown to observers, separately, in four orientations: horizontal, vertical, right diagonal, and left diagonal. Results indicate that the gradient slopes influence perceived boundaries and smoothness ratings. When determining smoothness ratings, observers were found to be more tolerant to changes in chroma and lightness than in hue.

Attentional Correlates of Colored Lights: Considerations for Cognitive Testing

Attention, an important index of cognitive function, can be affected amidst colored lights. This work investigated the effects of colored lights on the performance in attention task. Participants (N = 42) performed in one, two, and three letter cancellation task (LCT) during four lighting conditions. The order of LCT and the colored light sessions were randomized. The performance in LCT was evaluated through % accuracy, % omission, and % error. A repeated measures ANOVA showed a statistically significant difference in % accuracy in one LCT (F(2.46, 100.8) = 24.45, p < 0.001), two LCT (F(2.57, 105.4) = 20.53, p < 0.001), and three LCT (F(2.66, 109.22) = 17.96, p < 0.001) among the four colored lights. In addition, % omission revealed a statistically significant difference in one LCT (F(2.46, 100.8) = 24.43, p < 0.001), two LCT (F(2.57, 105.4) = 20.57, p < 0.001), and three LCT (F(2.66, 109.16) = 18.21, p < 0.001) among the four lights. There was no statistically significant difference in % error in one LCT (F(2.05, 84.1) = 1.23, p = 0.3), two LCT (F(2.66, 109.06) = 0.62, p = 0.971), three LCT (F(2.62, 107.53) = 0.97, p = 0.4) among the four lighting conditions. Colored lights affect attention-related cognitive processing. The attentional correlates of white and red lights are more compared to green, and blue lights. Lighting condition should be an important consideration for cognitive testing, for designing workspaces, educational settings, and other environments where attention plays a crucial role.

Optically Electroactive Polymer Synthesized in a Liquid Crystal with Cyclosporin A─Circularly Polarized Electron Spin Resonance.

Cyclosporine A (CsA), a naturally derived biomaterial and physiologically active substance, is commonly used as an immunosuppressant. In this study, CsA was revealed to function as a chiral inducer of cholesteric liquid crystals (CLCs) with a high helical twisting power. CsA induced helical structures in 4-cyano-4'-pentylbiphenyl, a synthetic liquid crystal (LC) used for general purposes. Electrochemical polymerization in CLC with CsA was also performed. The polymer prepared in CLC showed electro-optical activity via chiral induction by CsA. Synchrotron X-ray diffraction measurements indicated that the polymer film prepared in the CLC formed in the manner of LC molecular arrangement through molecular form imprinting from the LC order, although the polymer exhibited no liquid crystallinity. The polymer showed structural color and laser light oscillation diffraction derived from its periodic structure. The anisotropy of the circularly polarized electron spin resonance signals for the resulting polymer with respect to the magnetic field was observed.

Quantitative color analysis of burned bone to predict DNA quantity, quality, and genotyping success.

Badly burned skeletal remains are commonly submitted to forensic laboratories for victim identification via DNA analysis methods. Burned skeletal remains present many challenges for DNA analysis as they can contain low amounts of DNA which can also be damaged and degraded, resulting in partial or no STR profiles. Therefore, a simple, but effective screening method that identifies which samples may provide the most successful STR or mtDNA typing results for identification would enable forensic laboratories to save time, money, and resources. One metric that can be used and a screening method is the color of burned bone, as bone color changes with exposure to fire as temperature and length of exposure increase. This research developed a quantitative screening method based on the surface color of burned bone. The different visual bone colors (light brown, dark brown, black, gray, and white) were quantified using the Commission on Illumination L*a*b color space. These values were then compared to DNA yield, STR, and mtDNA profile completeness to identify whether the L*a*b values can predict genotyping success. A Bayesian network was constructed to determine the probability of STR typing success, given a set of L*a*b values. Results demonstrated that samples with an a* value greater than or equal to one and b* value greater than eight (light brown and dark brown burned samples) were the most predictive of STR typing success and mtDNA typing success. A decision tree for processing burned bones was constructed based on the color value thresholds.

Study the Effect of Colored and White LED Light Radiation on the Biological Activity of Desmonostoc alborizicum Cultivated Under Modified BG-110 Medium Composition

Study the Effect of Colored and White LED Light Radiation on the Biological Activity of Desmonostoc alborizicum Cultivated Under Modified BG-110 Medium Composition

The Effect of Light on Negative Emotion and Cognitive Regulation in Individuals with Depressive Tendencies

ABSTRACT Light has been demonstrated to influence transient mood states in healthy populations and can be used as a treatment for clinical mood disorders. However, it is still interesting to know whether stimulus with relatively low light levels can moderate the transient mood state of people with depressive tendencies, and what are the effects respectively from light levels and light color. In this study, 10 subjects with depressive tendencies were recruited and screened to receive a typical lighting intervention, including five crossover conditions with the 300 l×-isoluminance groups (red, 6500 K-white, blue) and 6500 K-isospectral groups (50 lx, 300 lx, and 1500 lx). Negative cognitive bias, high-frequency heart rate variability, and subjective emotion were measured at different stages during the lighting intervention. Statistical results demonstrated that the lighting condition of 1500 lx-6500 K was associated with a transient positive mood state (p < 0.001) and had a significant positive moderating effect on the negative cognitive biases compared with the other groups (p = .017). Colored lights are more likely to trigger negative emotions and negative cognitive biases.

Modulation of the emission spectrum of rare-earth ions using inverse-designed photonic crystals cavities.

Rare-earth elements play an indispensable role in the optical communication and laser industries, due to their superior luminescent properties. Nevertheless, the selective enhancement and suppression of different emission bands during energy level transitions for multi-band emitting rare-earth ions presents a significant research challenge, which we aim to address. This study explores the potential of leveraging an inverse-designed dual-cavity photonic crystals structure to manipulate the emission spectrum, thereby facilitating the augmentation or suppression of distinct emission bands. We utilized a convolutional neural network model to establish the relationship between geometric parameters and the local density of states, forecasting the optimal cavity geometry parameters for achieving the desired modulation outcomes. This paper delineates the neural network's generalization capabilities, along with the modulation efficacy of the dual-cavity configuration, both confirmed through numerical validation. Our findings highlight the modulatory capacity of Dy3+ ions, which exhibit three emission spectrum in the visible range, to achieve pure color light emission within the devised cavity structure. Notably, our approach yielded enhancements of up to 2.79-fold and 2.81-fold in pure yellow and red light emissions respectively, compared to free space emissions. The single-sided emission enhancement reaches 16.28-fold for yellow light and 30.79-fold for red light. This emphasizes the transformative potential of this methodology in crafting rare-earth-based luminescent materials with meticulously engineered emission attributes.

Investigation of the Role of K2SO4 Electrolyte in Hole Transport Layer for Efficient Quasi-2D Perovskite Light-Emitting Diodes.

Quasi-two-dimensional (2D) perovskite light-emitting diodes are promising light sources for color display and lighting. However, poor carrier injection and transport between the bottom hole transport layer (HTL) and perovskite limit the device performance. Here we demonstrate a simple and effective way to modify the HTL for enhancing the performance of perovskite light-emitting diodes (PeLEDs). An electrolyte K2SO4 is used to mix with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as the hole transport layer. The K+ doping helped the quasi-2D perovskite phases grow vertically along the interface of the PEDOT:PSS, fine-modulate the phase distribution, and simultaneously reduce the defect density of quasi-2D perovskites. It also significantly reduced the exciton quenching and injection barrier at PEDOT:PSS and quasi-2D perovskite interface. The optimized green PeLEDs with the K2SO4 doped PEDOT:PSS HTL showed a maximum luminance of 17185 cd/m2 which is almost 4.7 times brighter than the control one, with a maximum external quantum efficiency of 18.64%.