Rainbow Research Articles

Retroreflective Multichrome Microdome Arrays Created by Single-Step Reflow.

Structural colors are known for their tunability, fade resistance, and eco-friendliness. Recent advancements have shown that such colors can be efficiently produced using total internal reflection (TIR) on high-refractive-index convex microstructures without the need for periodic nanostructures. However, a reproducible, fast, and programmable production strategy for these microstructures is essential for commercial applications. Here, a single-step method is reported for creating multicolor patterns by transforming photolithographically-patterned micropillars into microdomes through thermal reflow. These micropillars, uniform in height but varying in diameter, are converted into microdomes that differ in diameter and height, which display a full spectrum of structural colors, creating a versatile color palette. This process enables the production of high-resolution multicolor graphics using a rainbow color set, with high reproducibility. Additionally, by mixing distinct microdomes and adjusting their densities, a rich variety of color presentations can be achieved, enabling the recreation of arbitrary color images with microdome arrays. The variable heights of the microdomes also allow for dynamic discoloration or color changes through mechanical compression. The high reproducibility and scalability of this method hold significant commercial promise for various optical applications.

Rainbow Connection on Amal(Fn,xz,m) Graphs and Amal(On,xz,m) Graphs

Coloring graph is giving a color to a set of vertices and a set of edges on a graph. The condition for coloring a graph is that each color is different for each neighboring member graph. Coloring graph can be done by mapping a different color to each vertex or edge. Rainbow coloring is a type of rainbow connected with coloring edge. It ensures that every graph G has a rainbow path. A rainbow path is a path in a graph where no two vertices have the same color. The minimum number of colors in a rainbow connected graph is called the rainbow connection number denoted by rc(G). The graphs used in this study are the Amal(Fn,xz,m) graph and the Amal(On,xz,m) graph.

Monitoring ocular disease via optical nanostructures potentially applicable to corneal contact lens products

Ocular diseases can cause vision problems or even blindness if they are not detected early. Some ocular diseases generate irregular physical changes in the eye; therefore, reliable diagnostic technology for continuous monitoring of the eye is an unmet clinical need. In this study, a pulsed laser (Nd:YAG) was used to create optical nanostructures on a hydrogel-based commercial contact lens. Simulations were used to determine the spacing of the nanostructures, which were then produced and tested on the lens in ambient humidity and fully hydrated environments. The nanostructures produced a 4° diffraction angle difference in response to the environmental changes. Vision obstruction was considered while designing the nanostructure features on the lens. The curved nanostructures exhibited a series of visible rainbow colors with an average range of 8° under normal room light. A spherical surface was also used to simulate the human eye, and application of a force (curvature change) caused the nanostructure spacing to change, influencing the visible color of the contact lenses. A smartphone camera application was used to measure the progress of ocular diseases by analyzing the RGB color values of the visible color. The nanostructures were also responsive to K+ ion variations in artificial tear fluids, with a 12 mmol L−1 sensitivity, which may allow the detection of ocular ionic strength changes.

Visualizing Anthocyanins: Colorimertic Analysis of Blue Maize

Anthocyanin, vibrant pigments found in a wide range of plants, including maize, contribute to the red, blue, and purple hues observed in fruits, vegetables, and grains. The inherent color variations in maize, including natural shades of purple, red, blue, and even rainbow colors, pose a significant challenge in accurately assessing maize maturity. This study recognizes the importance of visualizing the distinct blue purplish anthocyanin coloration to determine the optimal harvest time for blue maize, particularly among small-scale producers. To address this crucial need, this research project presents the development of the MaizeMeter, an advanced colorimeter specifically designed to analyze maize color based on anthocyanin pigmentation. Leveraging the power of Internet of Things (IoT) implementation, the MaizeMeter provides real-time monitoring and interpretation of anthocyanin color values. The proposed methodology encompasses the calibration of the color sensor and the prototyping of the MaizeMeter, culminating in the establishment of a comprehensive database of anthocyanin color profiles in blue maize. The generated anthocyanin color database by the MaizeMeter will serve as a vital tool for small-scale farmers and researchers, enabling more efficient and accurate assessment of maize maturity in the future.

Hollow SiO2 photonic crystal - graphene quantum dots composite and its application in multi-level intelligent anti-counterfeiting through regulation synergistic effect of structural color and fluorescence

The research on composite materials with rainbow color (structural color) and ultraviolet excitation characteristics (fluorescence) is the development direction of the new generation of functional photonic engineering materials. Herein, composite materials composed of hollow SiO2 photonic crystals (PCs) with nanometer thickness and PEGDA gel containing graphene quantum dots (GQDs) were prepared to achieve fluorescence regulation effect and thus apply in multi-level intelligent anti-counterfeiting. Due to the SiO2 shell thickness of 20–41 nm, the Bragg diffraction law explained that the material underwent secondary refraction, resulting in a wide photonic band gap (PBG). On the other hand, due to the comparison of refractive index between air (n = 1) and composite material (n = 1.46), the transmittance of the composite materials were only 21 %–26 %, indicating strong refractive ability. Therefore, we constructed a PC structure with a wide photonic bandgap (PBG) to provide better wavelength selectivity and coverage range, which would significantly increase the effect of structural color on fluorescence. Based on the unique quantum dot size effect of GQDs, we also investigated the fluorescence enhancement effect with 157 nm FWHM located on PC materials. Therefore, artificial design and control of both fluorescence enhancement and fluorescence suppression had been achieved through multi-level regulation of structural color. We further utilized these properties to create multi-level anti-counterfeiting verification patterns, such as a 3 × 3 digital encoding matrix. The authenticity of the product information must be verified through stepwise identification under specified conditions. This intelligent anti-counterfeiting technology offers a novel approach to safeguard information security.

Ascendancy of Mass Media in Achieving Gender Equality

For centuries, marginalisation has affected the niches and nooks of the world on a different level. Identities like caste, creed, religion, language, race and gender have been practiced with a hierarchy and hegemony. Women are one of the largest marginalized communities along with LGBTQIA+. OTT platform plays a crucial role in displaying voices from the margins in order to showcase socio-cultural inequality and inhumanity. The present paper deals with the Indian patriarchal mindset that refuses to accept women as a major contributor and creator of society. Accepting all weak gender identities as a part of the main stream is almost like mission impossible. Desmond Tutu’s ‘rainbow colour society’ is a far reaching-goal in India. Thanks to social media of the 21st century for transmitting these minority voices to the public’s attention and awareness. The media of the 21st century has aided a lot in conditioning society’s mindset into accepting an egalitarian society. The present paper deals with marginalized married Indian women’s voices from a film called The Great Indian Kitchen on OTT and a television series based on Manju Kapoor’s novel Married Woman and Jhumpa Lahiri’s novel, Namesake. The house wives have been portrayed as searching for identities and are rebellious against the stereotypical roles. The issues of identities of the women protagonists have been powerfully depicted through these channels. The research is based upon qualitative and quantitative data analysis with statistical evidence wherever necessary. The paper is divided into four parts, namely the role of media in the 21st century, issues of identities as a theoretical background, application of the identity issues of Ashima , protagonist of book , Namesake Nimisha, the protagonist, in the film The Great Indian Kitchen and in the tele-series The Married Woman and last but not the least conclusions. This is a study and critique to highlight how the media aids in re-conceptualization of societal norms and traditions for the queer and female community to gain their self-esteem and dignity with special reference to GEM (Gender Empowerment Measure).

Improving the Taste of Robusta Coffee by Fermentation with Yeast Inoculum and Its Effect on Caffeine Content

Harvesting coffee process by farmers generally executed entirety, resulting rainbow harvest. Coffee fermentation with yeast starter cultures Saccharomyces cerevisiae Y612, Candida parapsilosis Y207 and Torulospora delbrueckii Y594 was executed separately to determine the role of starter cultures on caffeine and robusta coffee taste at different maturity levels. The study was conducted at the Indonesian Industrial and Beverage Crops Research Institute in Sukabumi,, from June to November 2022. The experiment used a factorial complete randomized design. The first factor was the maturity level of the coffee and starter culture as the second factor. Fermentation was implemented for 48 hours inoculated with 108 cells/mL starter culture. The results showed that the temperature fluctuated, the pH value always decreased to 4.50 and T. delbrueckii was the starter culture with the highest activity during fermentation. Inoculum-fermented robusta coffee caffeine content was higher than non-inoculum. The lowest caffeine content was found in spontaneously fermented red fruit of 1.39%, while the highest caffeine content was produced by red fruit samples inoculated with C. parapsilosis of 2.7%. Robusta coffee with S. cerevisiae inoculation brought the best taste of robusta coffee with 82.10%, there was no significant difference between the red harvest coffee fruit and the fermented rainbow color with a starter culture. Keywords: Caffeine, Harvest, Inoculation, Maturity level, Starter cultures

Recent Progress on Photonic Cellulose Nanocrystal Films for Sensing Applications

Abstract: Cellulose nanocrystals (CNCs) have triggered considerable research interest in the last few years owing to their unique optical, biodegradation, and mechanical behavior. Herein, recent progress on the sensing application of photonic CNC films is summarized and discussed based on the analyses of the latest studies. We briefly introduce the three approaches for pre-paring CNCs: mechanical treatment, acid hydrolysis, and enzymatic hydrolysis, recapitulating their differences in preparation and properties. Then, when the aqueous suspension of cellu-lose nanocrystals (CNCs) reaches a specific concentration, it will self-assemble to form a left-handed nematic liquid crystal structure, and this structure can be maintained in films after water evaporation, which has strong photonic crystal properties. The periodic layered structure in the film interferes and diffracts with light, showing a rainbow color. Photonic CNC com-posites that combine CNCs and functional materials have good properties and broad prospects. Finally, we highlight the advanced applications of photonic CNC films, including mechanical sensing, thermal sensing, and humidity sensing. The prospects and ongoing challenges of pho-tonic CNC films were summarized.

Digital visualization in graduate transport phenomena

AbstractThe use of contour flood plots and color digital movies is investigated for teaching fluid mechanics, heat transfer, and mass transfer at the first‐year graduate student level. The color visualizations are intended to not only stimulate curiosity but also encourage enthusiasm and determination in learning difficult material. Although there is a significant amount of finite‐difference material, the focus is on analytical solutions. In particular, the mathematical problems involve error functions and Fourier series, which generally prove uninteresting and unpopular. Students are encouraged to produce the visualizations themselves, in addition to being provided with digital results in various forms. Excel can be used to generate both the analytical and finite difference calculations, but Python or another computer language can be employed. While software, such as Matplotlib with Python, Gnuplot, or Tecplot, can create excellent contour flood plots, results from Excel are also good, and Powerpoint will produce movies from individual frames. Student response is positive, although quantifying their reaction is difficult based on the small class sizes. Not surprisingly, the use of color appeals to students and adds to their interest. In addition, students claim increased understanding with contour plots and movies, but the visualizations should be used in conjunction with more traditional graphs, perhaps augmented with consistent use of color. However, the impact on motivation due to color presentation is harder to establish. Interestingly, both graduate and senior undergraduate students showed about equal preference for the rainbow and viridis color palettes.

Star Rainbow Coloring in Graphs

Star Rainbow Coloring in Graphs

On the study of rainbow antimagic connection number of comb product of tree and complete bipartite graph

Rainbow antimagic coloring is the combination of antimagic labeling and rainbow coloring. The smallest number of colors induced from all edge weights of antimagic labeling is the rainbow antimagic connection number of [Formula: see text], denoted by [Formula: see text]. Given a graph [Formula: see text] with vertex set [Formula: see text] and edge set [Formula: see text], the function [Formula: see text] from [Formula: see text] to [Formula: see text] is a bijective function. The associated weight of an edge [Formula: see text] under [Formula: see text] is [Formula: see text]. A path [Formula: see text] in the vertex-labeled graph [Formula: see text] is said to be a rainbow [Formula: see text] path if for any two edges [Formula: see text] it satisfies [Formula: see text]. The function [Formula: see text] is called a rainbow antimagic labeling of [Formula: see text] if there exists a rainbow [Formula: see text] path for every two vertices [Formula: see text]. When we assign each edge [Formula: see text] with the color of the edge weight [Formula: see text], we say the graph [Formula: see text] admits a rainbow antimagic coloring. In this paper, we show the new lower bound and exact value of the rainbow antimagic connection number of comb product of any tree and complete bipartite graph.

Chiral Pearlescent Cellulose Nanocrystals Films with Broad-Range Tunable Optical Properties for Anti-Counterfeiting Applications.

Pearlescent materials are of technological importance in a diverse array of industries from cosmetics to premium paints; however, chiral pearlescent materials remain unexplored. Here, chiral pearlescent films with on-demand iridescence and metallic appearance are simply organized by leveraging vertical pressure to direct the self-assembly of cellulose nanocrystals. The films are formed with a bilayer planar anchored left-handed chiral nematic architecture, in which the bottom layer is featured with a vertical gradient pitch, and the top layer is featured with a uniform pitch. Simultaneous reflection of the rainbow colors and an on-demand color of left-handed polarized light with angle-dependent wavelength and polarization state accounts for the unique optical phenomenon based on experimental observation and theoretical analysis. Such chiroptical property can be readily tuned with architectural design, enabling reproducible optical appearance with high fidelity. Bringing the pearlescence, iridescence, and specular reflection together endows cellulose nanocrystal films with rich and tunable chiroptical properties that can be used for anti-counterfeiting applications. The current work marks the beginning of chiral pearlescent materials from renewable resources, while the pressure-directed self-assembly provides a step toward scalable production.

The mechanistic, genetic and evolutionary causes of bird eye colour variation

Birds display a rainbow of eye colours, but this trait has been little studied compared with plumage coloration. Avian eye colour variation occurs at all phylogenetic scales: it can be conserved throughout whole families or vary within one species, yet the evolutionary importance of this eye colour variation is under‐studied. Here, we summarize knowledge of the causes of eye colour variation at three primary levels: mechanistic, genetic and evolutionary. Mechanistically, we show that avian iris pigments include melanin and carotenoids, which also play major roles in plumage colour, as well as purines and pteridines, which are often found as pigments in non‐avian taxa. Genetically, we survey classical breeding studies and recent genomic work on domestic birds that have identified potential ‘eye colour genes’, including one associated with pteridine pigmentation in pigeons. Finally, from an evolutionary standpoint, we present and discuss several hypotheses explaining the adaptive significance of eye colour variation. Many of these hypotheses suggest that bird eye colour plays an important role in intraspecific signalling, particularly as an indicator of age or mate quality, although the importance of eye colour may differ between species and few evolutionary hypotheses have been directly tested. We suggest that future studies of avian eye colour should consider all three levels, including broad‐scale iris pigment analyses across bird species, genome sequencing studies to identify loci associated with eye colour variation, and behavioural experiments and comparative phylogenetic analyses to test adaptive hypotheses. By examining these proximate and ultimate causes of eye colour variation in birds, we hope that our review will encourage future research to understand the ecological and evolutionary significance of this striking avian trait.

Fast and Facile Etching of Gold Nanorods by N-Halosuccinimides: Toward Multicolorimetric Identification and Quantification of 20 Natural Amino Acids.

Gold nanorods (AuNRs) have recently become fascinating chromophores in the field of colorimetric sensing because of their eye-catching rainbow colors along with the high dimensionality of their optical profile. The etching of AuNRs using an analyte-sensitive oxidizing agent is particularly an attractive tool not only for adjusting their plasmonic behavior through altering their aspect ratio but also for correlating the observed signal with the identity and concentration of the analyte. However, the deployment of this strategy in the field of sensing has been seriously hindered by various factors ranging from slow etching kinetics and the need for nonambient temperatures to low degrees of controllability along with the high toxicity of the etchants. To resolve these challenges, the present study aims to introduce the outstanding potentials of two inexpensive mild oxidants comprising N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) in the highly fast and controllable etching of AuNRs at room temperature. By controlling the concentration of the etchant and the pH of the medium, the longitudinal and transversal peaks could be well adjusted with nanometer precision. In an attempt to elucidate the etching mechanism, the effects of various parameters including the etchant concentration and pH, as well as the kinetics of the etching process were thoroughly investigated. After all, the capability of NBS in decarboxylating the amino acids was further exploited in the design of an all-inclusive multicolorimetric sensor array based on the etching of AuNRs for the sensitive quantification and highly accurate discrimination of all 20 amino acids in the micromolar range. To this end, the acquired data set was analyzed by two machine learning techniques including partial least-squares regression (PLSR) and linear discriminant analysis (LDA). The versatility of N-halosuccinimide reactions with various categories of organic compounds underlies ample opportunities for the design of diverse multicolorimetric sensors, further glamorizing the prospect of this approach.

ON RAINBOW ANTIMAGIC COLORING OF SNAIL GRAPH(S_n ), COCONUT ROOT GRAPH (Cr_(n,m) ), FAN STALK GRAPH (Kt_n ) AND THE LOTUS GRAPH(Lo_n )

Rainbow antimagic coloring is a combination of antimagic labeling and rainbow coloring. Antimagic labeling is labeling of each vertex of the graph with a different label, so that each the sum of the vertices in the graph has a different weight. Rainbow coloring is part of the rainbow-connected edge coloring, where each graph has a rainbow path. A rainbow path in a graph is formed if two vertices on the graph do not have the same color. If the given color on each edge is different, for example in the function it is colored with a weight , it is called rainbow antimagic coloring. Rainbow antimagic coloring has a condition that every two vertices on a graph cannot have the same rainbow path. The minimum number of colors from rainbow antimagic coloring is called the rainbow antimagic connection number, denoted by In this study, we analyze the rainbow antimagic connection number of snail graph , coconut root graph , fan stalk graph and lotus graph .

DESAIN MEJA BELAJAR ANAK BERGAYA TETRIS

Early childhood age is in a stage of growth and development both physically and mentally. In their activities at school, children who study at the kindergarten level need learning facilities, one of which is study tables and chairs. Sometimes these facilities do not meet the condition of the student's body, dealing with its terms of size, shape and parts. The impact of the mismatch between the school fascilities such asa tables and chairs with the body size of school children is one of the obstacles in the efforts of improving learning outcomes.
 Tetris is one of the most favorite games that prioritizes competition among players, but still the players have to follows the rules of the game. This toy is quite interesting and popular among young children. Based on this background, efforts are made to solve the problem, one of which is by making tables and chairs for kindergarten children with the concept of the Tetris game.
 In designing products so that are well directed, the Vinod Goel method is used with the stages of Preliminary Design, Design Development, and Final Design and Prototype.
 The results of this design are intended for children aged 5 - 6 years, with components of chairs, tables, Tetris cubes and Tetris puzzles, with configurations according to ergonomics and anthropometry. The connection system uses a butt joint with nail reinforcement and glue adhesive. The material used is multiplex, with a shape of a tetris concept, a retro fifties and colorful design style with rainbow colors

Simple Science Experiment at KB-TKIT Salman Al-Farisi 2 Yogyakarta

Early Childhood Education (PAUD) is essentially education that is held with the aim of facilitating the growth and development of children as a whole or emphasizing the development of all aspects of the child's personality. Therefore PAUD provides an opportunity for children to develop their personality and potential to the fullest. Children have a very high curiosity. This curiosity needs to be facilitated by adults, including parents/tutors/teachers who function as children's teachers. Children can learn anything from an early age, including learning science. Learning science from an early age begins by introducing nature and the environment. This will enrich the child's experience. Children learn to experiment, explore, and investigate their surroundings. This Community Service Activity (PkM) aims to improve children's skills in honing the ability to think about simple science events and provide education to children about simple experiments. This activity is carried out in the form of simulations and direct practical assistance to TK- KBIT Salman Al-Farisi 2 Yogyakarta. The first experiment was blowing up a balloon with a bottle. The second experiment is to make rainbow colors in a bottle and the third is a lava lamp. The result of this activity is that participants can carry out simple science experiments and gain scientific knowledge from the experiments carried out
 
 Keywords: experiments, childhood, science

Machine Learning-Assisted Colorimetric Assay Based on Au@Ag Nanorods for Chromium Speciation.

The oxidation state of an element significantly controls its toxicological impacts on biological ecosystems. Therefore, design of robust sensing strategies for multiplex detection of species with respect to their oxidation states or bonding conditions, i.e., chemical speciation, is quite consequential. Chromium (Cr) species are known as the most abundant inorganic groundwater pollutants and can be quite harmful to human health depending on their oxidation states. In the present study, a multicolorimetric probe based on silver-deposition-induced color variations of gold nanorods (AuNRs) was designed for identification and quantification of Cr species including Cr (III) and Cr (VI) (i.e., CrO42- and Cr2O72-) in water samples. In fact, the presence of Cr species leads to inhibition of the silver metallization of AuNRs to various degrees depending on the concentration and identity of the analyte. This process is accompanied by the blue shift of the longitudinal peak which results in sharp-contrast rainbow-like color variations, thereby providing great opportunity for highly accurate visual detection. The gathered dataset was then statistically analyzed using two pattern recognition and regression machine learning techniques. In particular, linear discriminant analysis was used as a classification method to discriminate the unicomponent and mixture samples of Cr species with 100% accuracy. Then, a well-known multivariate calibration technique called partial least-squares regression was employed for quantitative analysis of Cr species. Responses were linearly related to Cr species concentrations over a wide range of 10.0-1000.0, 1.0-200.0, and 1.0-200.0 μmol L-1 with detection limits of 37.7, 8.7, and 2.9 μmol L-1 for Cr3+, CrO42-, and Cr2O72-, respectively. The practical applicability of the multicolorimetric probe was successfully evaluated by analyzing Cr species in several water specimens comprising tap water, mineral water, river water, and seawater. Above all, the vivid rainbow color tonality of the proposed assay further improves the accuracy of the naked eye detection, making it a practical platform for on-site monitoring of Cr contamination.

What’s that stuff? Gel nail polish

Peruse the service menu at any nail salon, and you’ll be confronted with a staggering array of choices for your manicure: exfoliation, extensions, a rainbow of colors, tips, intricate nail art, and more. If you’re looking for a simple pop of color and a glossy finish, the first decision you’re likely to make is what kind of nail polish to get: regular or gel. Bottles of both types of polish are often lined up next to each other, with different-colored caps denoting at a glance which is which. The first difference you might notice between gel and regular polish is the price: gel polish is more expensive. But, your nail tech might tell you, it hardens in less than a minute with the help of a special curing lamp, and it’s much less likely to chip. The downside is that gel is more difficult to remove: it has to be

Photonic crystals with rainbow colors by centrifugation-assisted assembly of colloidal lignin nanoparticles

Photonic crystals are optical materials that are often fabricated by assembly of particles into periodically arranged structures. However, assembly of lignin nanoparticles has been limited due to lacking methods and incomplete understanding of the interparticle forces and packing mechanisms. Here we show a centrifugation-assisted fabrication of photonic crystals with rainbow structural colors emitted from the structure covering the entire visible spectrum. Our results show that centrifugation is crucial for the formation of lignin photonic crystals, because assembly of lignin nanoparticles without centrifugation assistance leads to the formation of stripe patterns rather than photonic crystals. We further prove that the functions of centrifugation are to classify lignin nanoparticles according to their particle size and produce monodispersed particle layers that display gradient colors from red to violet. The different layers of lignin nanoparticles were assembled in a way that created semi-closed packing structures, which gave rise to coherent scattering. The diameter of the lignin nanoparticles in each color layer is smaller than that predicted by a modified Bragg’s equation. In situ optical microscope images provided additional evidence on the importance of dynamic rearrangement of lignin nanoparticles during their assembly into semi-closed packing structures. The preparation of lignin nanoparticles combined with the methodology for their classification and assembly pave the way for sustainable photonic crystals.