Color Phenomena Research Articles

Mechanical Grinding-Induced Intermolecular Charge Transfer for Near-Infrared Photothermal Conversion.

In this study, charge-transfer-type compounds comprising synthesized naphthalenediimide derivative (H4NDISA) or its Pb-based coordination polymer (Pb-NDISA) and suitable primary or secondary amine organic molecules were prepared by the solvent-free mechanical grinding method. The coloration phenomenon arising from charge transfer during grinding serves as a discriminative tool for distinguishing various organic guest molecules. The porous structure of Pb-NDISA crystals facilitates the infiltration of guest molecules and contributes to the preservation of the intermolecular charge transfer state. Moreover, the intermolecular charge transfer induced by grinding exhibits remarkable stability in an ambient atmosphere, underscoring the pivotal role of well-ordered molecules in the mechanical grinding procedure. This mechanochromic phenomenon holds promise for the detection and sensing of organic molecules, while the exceptional charge-transfer absorption characteristics offer the potential for efficient near-infrared photothermal conversion.

Psychophysics of neon color spreading: Chromatic and temporal factors are not limiting

Neon color spreading (NCS) is an illusory color phenomenon that provides a dramatic example of surface completion and filling-in. Numerous studies have varied both spatial and temporal aspects of the neon-generating stimulus to explore variations in the strength of the effect. Here, we take a novel, parametric, low-level psychophysical approach to studying NCS in two experiments. In Experiment 1, we test the ability of both cone-isolating and equiluminant stimuli to generate neon color spreading for both increments and decrements in cone modulations. As expected, sensitivity was low to S(hort-wavelength) cone stimuli due to their poor spatial resolution, but sensitivity was similar for the other color directions. We show that when these differences in detection sensitivity are accounted for, the particular cone type, and the polarity (increment or decrement), make little difference in generating neon color spreading, with NCS visible at about twice detection threshold level in all cases. In Experiment 2, we use L-cone flicker modulations (reddish and greenish excursions around grey) to study sensitivity to NCS as a function of temporal frequency from 0.5 to 8 Hz. After accounting for detectability, the temporal contrast sensitivity functions for NCS are approximately constant or even increase over the studied frequency range. Therefore there is no evidence in this study that the processes underlying NCS are slower than the low-level processes of simple flicker detection. These results point to relatively fast mechanisms, not slow diffusion processes, as the substrate for NCS.

An apparent motion color illusion.

We introduce a new illusory color phenomenon. The illusion is evoked by two alternating displays comprising various colored disks. Although the colors in the alternating displays are the same, the color appearance of the two displays are quite different. We suggest that apparent motion of the disks modulates the color percepts.

Formation of Three-Dimensional Thinking as one of the Significant Professional Qualities of an Architect

The article touches upon the problems of the professional formation of an architect, the development of his three-dimensional thinking in the process of studying the disciplines of the artistic cycle. The architect's vision must meet the strict requirements imposed by the specifics of visual activity, the laws of figurative literacy and the tasks of a particular stage of work, correlate with the ultimate ideals and purpose of creative activity. In the study of light as a means of artistic expression, an important role must be given to the psychology of the perception of light in nature and in the image. Only having a developed three-dimensional thinking a student can convincingly and accurately convey the character of a three-dimensional shape, its plasticity and movement.The recognition of three-dimensional forms, including natural objects based on three-dimensional vision of images, through an accurate assessment of light and shadow gradations, adequate transfer of color phenomena of reality to the possibilities of the visual sphere and skillful modeling of forms depicted by light and shadow, becomes an emphasis in the training of an architect. The position of color in the image of shapes in space is no less significant.Pedagogical techniques for the formation of three-dimensional thinking of students and the development of their graphic skills in drawing three-dimensional objects, including architectural ones, are based on scientific discoveries of scientists, scientists and artists since the Renaissance.The integrity of perception, attention to detail, the study of space, understanding of form, possession of means of shaping and the image of a three-dimensional object in a two-dimensional format are becoming universal criteria that allow us to talk about the high-quality training of future architects.

THE SYMBOLIC AND PSYCHOSEMANTIC POLYVALENCE OF COLORS

Color and shape, being inseparable, are the essential elements of human optical perception. In painting, color is the main tool of expression and the most significant element. The meaning of colors depends on a complex of physiological, psychological and cultural-social factors. Psychologists see color not as a simple sensation, but as a complex and multilateral perception, inextricably linked to socio-cultural and aesthetic aspects. The phenomenon of color has been studied by many artists, painters, researchers, psychologists, philosophers, physicists, who over time, through various researches regarding the influence of colors on the human psyche, have come to the conclusion that color exists both in the external, objective world of reality, as well as in the inner, subjective world of human, generating multiple emotional, psychological and intimate effects in the human personality.

The red color in Russian, French and Chinese linguistic cultures on the example of phraseology and proverbs

The research conducted in this article is aimed at analyzing color symbols in Russian, French and Chinese linguistic cultures using the analysis of phraseology and proverbs. The research methodology is based on a comparative analysis of phraseological units and proverbs containing color components in these languages. In the course of the study, both common and unique features in the color symbolism of each of the linguistic cultures under consideration were identified. Through a comparative analysis of phraseology and proverbs in different languages, it was possible to better understand how color embodies cultural norms, worldview and historical contexts in each nation. This allowed us to see which aspects of color are particularly significant for each culture and what associations and symbolic meanings are associated with them. Special attention is paid to the analysis of differences and similarities in the interpretation of color in the idiomatic expressions of each language. This allows us to understand which cultural and historical factors form unique views and ideas about color in each of the linguistic cultures under consideration. The study also highlights that the interpretation of color symbols in idiomatic expressions depends on the cultural and historical contexts of each language. Idioms are a reflection of the collective consciousness and worldview of the people, and the study of color phenomena in idioms helps to better understand national identity and linguistic evolution. In addition, the study found that the red color can acquire different meanings and connotations in different languages, despite common dictionary definitions. This indicates that the use and attitude towards the color red depends on the cultural and historical characteristics of each language group. The scientific novelty of the work lies in the fact that it combines linguistic analysis with the analysis of cultural characteristics and uses the methodology of synergetic symbolism. This approach allows us to understand how the interaction of different colors creates new symbolic meanings and associations specific to each culture.

The birth of zinc anode-based electrochromic devices

Since the discovery of electrochemical coloration phenomenon, electrochromic devices capable of monitoring transmittance, reflectance, and absorption at designated wavelengths have embraced great achievements. The marriage of electrochemistry and optical modulation has infused fascinating properties in electrochromic devices, which find applications in thermal management, display, smart windows, and camouflage. Inspired by the multipronged advancements in electrochemical devices, the incorporation of multivalent metal ions having rich electrochemistry into electrochromic devices is bloomed in recent years. Zinc, distinguished by its high crustal abundance, suitable standard redox potential, and inherent safety, has facilitated the assembly of highly efficient electrochromic devices. Zinc anode-based electrochromic devices with dual-band (visible and near-infrared) tunability, energy retrieval functions, multi-color options, multiple working modes (transmittance mode and reflectance mode), and scalability have been prominently showcased. Here in this review, the birth of zinc anode-based electrochromic devices will be systematically narrated, starting from the discovery of electrochromic phenomenon, to the evolution of electrochromic devices, and to the latest achievements in zinc anode-based electrochromic devices. Additionally, this review delves into the future development trends and perspectives of zinc anode-based electrochromic devices. This review serves as a handbook, which summarizes the history of electrochromism, introduces the physics behind it, highlights the development in zinc anode-based electrochromic devices, and aims to inspire future endeavors into this field, particularly those focused on developing energy-efficient electrochromic devices.

A teaching-learning sequence on colour in the context of a motivational stage for high school students

In this article we present a Teaching-Learning Sequence (TLS) on colour performed in the non-formal setting of a vocational stage with a sample of N=38 18-year-old high school students. Based both on previous educational research and the analysis of the characteristics of the Italian high school curriculum, the TLS adopts cooperative experimental investigation activities with low-cost equipment which help students distinguish different physical situations involving the combination of colours; furthermore, it focuses on developing a solid understanding of the connection between the physics and physiology of colour phenomena. The TLS was highly appreciated by students and, thanks in part to the inclusion of advanced topics such as photonic crystals and plasmons, it may have a significant motivational value.

Achieving the conversion from Room-Temperature phosphorescence to photothermal properties by Carbon-Regulated bandgap

Bandgap tunability plays an important role in controlling the photophysical properties of semiconductor material. In this work, we propose a powerful carbon component engineering strategy for regulating the optical bandgap of scandium/cysteine functional materials (Sc/Cys-FMs) that are synthesized by a facile one-pot hydrothermal method. The band structure of Sc/Cys-FMs is closely related to the Cys ligands. As Cys amount rises, the obtained Sc/Cys-FMs exhibit the red-shifted room-temperature phosphorescence (RTP) emission from Sc/Cys-FMs-50 (3.01 eV) to Sc/Cys-FMs-150 (2.14 eV), accompanied by a decrease in quantum efficiency and an increase in lifetime. Meanwhile, the Sc/Cys-FMs show a unique time-dependent phosphorescence color (TDPC) phenomenon, with a dynamic transition of RTP color from yellow to green as the decay time prolongs because of the emission-dependent lifetime. As the amount of Cys further increases, the bandgap can be continuously reduced to 1.88 eV (Sc/Cys-FMs-300) and 1.56 eV (Sc/Cys-FMs-600), causing the quenching of RTP emission and significantly enhanced photothermal properties. The continuously decreasing bandgap has been proven to be directly ascribed to the increase of carbon component in Sc/Cys-FMs. Considering the TDPC properties, Sc/Cys-FMs can be well used for dynamic phosphorescent anti-counterfeiting. This work not only develops a scalable method for preparing functional materials with superior RTP and photothermal properties, but also proposes the carbon component engineering strategy to achieve bandgap tunability of materials.

A new electric-blue tarantula species of the genus Chilobrachys Karsh, 1892 from Thailand (Araneae, Mygalomorphae, Theraphosidae).

The enchanting phenomenon of blue coloration in animals arises from the fact that blue is one of the rarest colors found in nature, and it is a structural color that is produced by the arrangement of biological photonic nanostructures, rather than pigments. This unique coloration has evolved independently in many different species, adding to the fascination and diversity of coloration patterns in the animal kingdom. This study describes a new species of Chilobrachys Karsch, 1892 from southern Thailand that exhibits a blue-violet hue resembling the color of electrical sparks. Photographic illustrations, a morphological description, and the natural habitat of the new species are given. The diagnosis, palpal-bulb structures, spermathecae, and stridulatory organ morphology of related species are discussed.

Comparative evaluation of the effects of lighting conditions on the shade selection of maxillary central incisor using visual methods

Background: The selection of shade of a tooth is a routine practice for a dentist, especially a prosthodontist, to make esthetically pleasing prostheses. The phenomenon of colour is a matter of perception by the eye. Every opaque object receives light, absorbs some of it and reflects the rest. A tooth being an opaque object, reflects some amount of light. The dominant wavelength of this reflected light is discerned by us as the colour of the tooth. Light has variable properties that influence our perception. Daylight is regarded as the standard source for the selection of the colour of a tooth. Conversely, the lack of optimal circumstances during different times of the day necessitates using artificial illuminants to select shade of a tooth. This study was carried out to compare the accuracy of a shade-matching light (SMILE LINE) to that of standard daylight. Methods: This study followed the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for cross-sectional studies. The study comprised 125 participants of ages ranging from 20 to 30 years. Five observers from the Department of Prosthodontics, Sharad Pawar Dental College (SPDC), Wardha selected the shade of the maxillary central incisor of 125 subjects under sunlight, dental operatory light, and shade-matching light. The statistical analysis was performed using the SPSS software, and Kappa statistics were used to compare the shades selected by the shade-matching light and dental operatory light with sunlight. Results: A strong correlation was discovered between the shades of tooth selected under the shade matching light and shades selected under sunlight for four out of five observers. Conclusions: The shade correcting device gives shades comparable to those selected under sunlight in ideal conditions making it useful as an alternative to sunlight for shade selection.

A model of colour appearance based on efficient coding of natural images.

An object's colour, brightness and pattern are all influenced by its surroundings, and a number of visual phenomena and "illusions" have been discovered that highlight these often dramatic effects. Explanations for these phenomena range from low-level neural mechanisms to high-level processes that incorporate contextual information or prior knowledge. Importantly, few of these phenomena can currently be accounted for in quantitative models of colour appearance. Here we ask to what extent colour appearance is predicted by a model based on the principle of coding efficiency. The model assumes that the image is encoded by noisy spatio-chromatic filters at one octave separations, which are either circularly symmetrical or oriented. Each spatial band's lower threshold is set by the contrast sensitivity function, and the dynamic range of the band is a fixed multiple of this threshold, above which the response saturates. Filter outputs are then reweighted to give equal power in each channel for natural images. We demonstrate that the model fits human behavioural performance in psychophysics experiments, and also primate retinal ganglion responses. Next, we systematically test the model's ability to qualitatively predict over 50 brightness and colour phenomena, with almost complete success. This implies that much of colour appearance is potentially attributable to simple mechanisms evolved for efficient coding of natural images, and is a well-founded basis for modelling the vision of humans and other animals.

Faces of the phenomenon of expectations

The article examines the vision of the phenomenon of expectations in the works of sociologists. For this purpose, an analysis of the works of M. Weber, T. Parsons, A. Schutz, V. Vroom, H. Heckhausen, N. Luhmann, P. Berger, Th. Luckmann, Y. Habermas, Z. Bauman, I. Hoffman, H. Garfinkel. The study showed that expectation is a complex and diverse phenomenon that cannot be reduced to a single denominator. The traditional method of organizing this colorful phenomenon by means of selection according to one or more criteria of classes and types of expectations has its limitations. After all, classification as a method of explanation can be the cause of false conclusions and interpretations, since the same manifestations of expectations can hide different reasons for their occurrence. K. Levin called this way of theorizing Aristotelian. The scientist saw a way out of this situation in the transition to the Galilean way of thinking. K. Levin called this transition the transition from the abstract-classifying to the constructive method. The latter means searching for the reasons for the existence of natural and social phenomena. This way of thinking is demonstrated in the works of the above-mentioned sociologists. Thanks to the analysis of their works, it was possible to distinguish four types of expectations. The first is pre-intentional expectations, the second is rational-activity expectations, the third is communicative-role expectations, and the fourth is background expectations. The essence of the pre-intentional type consists in unlimited dreams, fantasies, illusions, imaginations, which are concentrated in the consciousness of the subject of expectations, and which have no influence on the external world. The rational-activity type is an anticipatory reflection of object-transforming activity, processes of acquisition or appropriation of objects, which takes the form of intentions, plans, calculations, and the purpose of activity. The communicative-role type is manifested in the observance by interaction partners of standardized norms, rules, requirements, in the reproduction of status and role standards in behavior. The essence of background expectations lies in the presence of fixed attitudes in the behavior of the individual, in the standardized features of everyday processes, which are accepted by a person in everyday life on faith.

The Covariation of Color and Orange Fluorescence Instabilities in Yellow Sapphires

In recent years, some sapphires were found to fade in sunlight and to increase their color after UV irradiation. This unstable color phenomenon is attributed to the photochromism of corundum. The photochromic effect seriously affects the grading and evaluation of sapphires, although its mechanism is still uncertain. Here, we performed a set of photochromic experiments on sapphire specimens using a 254 nm shortwave UV light source and a D65 light source (which simulates sunlight) to generate different color states exhibiting characteristic absorption, emission, and excitation spectra. We observed that, for different color states, variation in the intensity of the absorption band at ~460 nm was consistent with that of orange fluorescence at 500–800 nm. This observation indicates a relationship between color instability and orange fluorescence. Peaks in excitation spectra at 320, 420, 490, 560, and 637 nm provide insight into the source(s) of excited orange fluorescence, which are related to different types of F-centers and Mg-trapped holes. We propose an explanation for the photochromic phenomenon: the color of photochromic yellow sapphire is the result of a variety of defects that release orange fluorescence simultaneously. Further, we hypothesize that the mechanism of photochromism in yellow sapphires is linked to electron transfer between F-centers and Mg-trapped holes.

PICTORIAL OVERTONES OF GEORGIAN POSTMODERNIST MINIATURE (ON THE EXAMPLE OF ROSTOM CHKHEIDZE'S MINIATURES)

The article describes the pictorial overtones of georgian postmodernist miniature. The phenomenon of color is not explained in the dictionary of Sulkhan-Saba Orbeliani, only a list of individual colors is presented (white, red, black, violet, blue) [1, p.188]. Viktor Nozadze dedicated a monumental monograph to the color language of «The Knight in the Panther’s Skin». Moses Gogiberidze especially discusses the music of Rustaveli's color in his monograph «Rustaveli, Petritsi, Preludes». Maya Jaliashvili, while analyzing the miniatures of Sandro Tsirekidze (in the words of the critic, the sleep-walker of the word), notes that the music and painting seemed to be combined and revealed verbally [2, p.60]. In the miniatures of Rostom Chkheidze, we find the border between the real and the unreal, which is also found in Georgian modernism. As an example, we cite Marine Revishvili's quote about Basil Melikishvili (whose life and work monograph is edited by Rostom Chkheidze, as mentioned above): Cosmic understanding of events is an important step in Basil Melikishvili's worldview and stylistic searches, to tangibly outline the boundary between the real and the unreal, wrapped in the web of the unknown, the mysterious. The real and the unreal merge and make us feel the eternity of the world, the unity of life and death... A symbolic key should open the door to the bosom of the unknown [3, p.189]. We think that t understand the essence of Rostom Chkheidze's collection of miniatures – «Steps of the Sun», «Sparks of the Moon» and «Paths of the Stars», we may think of the excerpt quoted above as a kind of key. Color is an important additional tone of the miniature. Eter Beriashvili writes about the miniatures of Olesia Tavadze, you read these small stories that are filled with sadness, and once again you 77 believe, together with the c o l o r s (the line is ours – K.K.), that we have gifted a word as an ordeal [4, p.8]. Rostom Chkheidze writes in the preface to the collection of Georgian miniature prose (we will use a conceptual phrase this time once again): A striking example of how philosophical thoughts grow out of sentiments, symbolic-metaphorical speech, painstakingly processed details and figurative images, are Vazha-Pshavela's miniatures (with heartache, he also adds that, as we mentioned above, Vazha's importance as a prose writer is still unexplored)

Multiscale models of plasmonic structural colors with nanoscale surface roughness.

Plasmonic coloration arises from resonant interaction between visible light and metallic nanostructures, which causes wavelength-selective absorption or scattering of light. This effect is sensitive to surface roughness that can perturb these resonant interactions and cause observed coloration to deviate from coloration predicted by simulations. We present a computational visualization approach that incorporates electrodynamic simulations and physically based rendering (PBR) to investigate the effect of nanoscale roughness on the structural coloration from thin, planar silver films decorated with nanohole arrays. Nanoscale roughness is modeled mathematically by a surface correlation function and parameterized in terms of roughness that is either out of or into the plane of the film. Our results provide photorealistic visualization of the influence of nanoscale roughness on the coloration from silver nanohole arrays in both reflectance and transmittance. Out-of-plane roughness has a significantly greater effect on coloration than in-plane roughness. The methodology introduced in this work is useful for modeling artificial coloration phenomena.

Evaluation of the Color Adjustment Potential of Single-Shade Composite Resin in Primary Teeth

Restoring composite resins with the optimal shades for all primary teeth is a great challenge for pediatric dentists. A newly developed single-shade composite resin can exhibit a color similar to that of the surrounding tooth structure based on the structural color phenomenon. This study aims to evaluate the color adjustment potential (CAP) of a single-shade composite resin compared to conventional multi-shade composite resins in primary teeth. A single-shade composite resin and two conventional multi-shade composite resins were included in this study. Two types of specimens, a single specimen and a dual specimen, were evaluated. For single specimens, duplications of the primary second molar denture teeth were made using experimental composite resins. For dual specimens, cavities were prepared on the buccal surfaces of extracted primary second molars and restored with experimental composite resins. The L*, a*, and b* values were measured using a colorimeter for the extracted teeth and specimens. The mean ΔE<sub>ab</sub><sup>*</sup> values for single and dual specimens and CAP were calculated. Bonferroni post-hoc analysis was performed to confirm the statistical significance between the ΔE<sub>ab</sub><sup>*</sup> and CAP values of the experimental resins. Among the single specimens, the single-shade composite resin showed significantly higher ΔE<sub>Single</sub> compared to other composite resins (<i>p</i> < 0.0167). There was no significant difference between ΔE<sub>Dual</sub> for all experimental resins. The single-shade composite resin showed highest CAP compared to other multi-shade composite resins. A single-shade composite resin exhibited the most prominent color adaptability compared to other conventional multi-shade composite resins for primary second molars. A single-shade composite resin can simplify shade matching and provide esthetic outcomes for the restoration of primary second molars.

АСПЕКТИ ВПЛИВУ КОЛІРНОГО РІШЕННЯ НА СПРИЙНЯТТЯ ЖИВОПИСНОГО ТВОРУ

The article examines the properties of color on which the essence of perception of the color component of a painting is based. It is clarified how with the help of color and color combinations the necessary atmosphere is created in the picture, the perception of the plot of this or that work is formed, how the viewer’s attention is focused on the main thing, the image of the general color composition is created, the techniques of color using are analyzed and their influence on the perception of the semantic component of the plot. Based on the theoretical analysis of literary sources, the physical, physiological, psychological, and emotional aspects of the influence of color on a person are considered, based on the conclusions of several sciences and scientific disciplines. The article highlights the most essential constituents of the phenomenon of color as the primary visual medium, and draws attention to the role of color science, as a science that systematizes knowledge about the nature of color and light, and types of color harmonies. The question of how local colors, tonal saturation, and intensity of color affect the perception of the composition of the work is clarified. The main characteristics of color as a tool capable of determining planning in a painting and providing subconscious information about phenomena or objects are considered, how the brightness of color shades affects the perception of the world in the picture, and why warm and cold colors of the color wheel are perceived differently in the compositional space of the work. The article raises the question of the color decision influence on the perception of the emotional coloring of a painting, why shades of one color sound different when combined with another, and how color combinations affect a person physically and psychologically on an associative level. The main aim of the article is to get acquainted with aspects of the color component understanding and types of color solutions, where color is considered the most effective means of creating a coherent artistic form and harmonizing space in visual art.

Colorization of images using soft colour capsule networks

Perceiving and interpreting color phenomena is a complex process for the human brain. Obtaining the true color of an object requires different experimental, physical, and theoretical results. By examining image features, color, and other aspects, individuals can study techniques for applying full-color images. In this context, color chemistry has been used in crime investigations to detect the time of death. It can be challenging for police to physically examine decomposed dead bodies, especially if they have been unknown for days, weeks, or even months. This makes the task much harder for law enforcement officials. An innovative approach has been developed to assist the police in investigating cases more efficiently. This approach enables them to solve crimes from the convenience of their offices, thereby enhancing their productivity.

Colour Strategies in Modern Brand Design

The purpose of the article is to identify current trends in contemporary colour strategy in brand design. The research methodology is defined by analytical, structural, empirical methods and a systemic approach to justify the role of colour as a multicomplex phenomenon in brand design. The scientific novelty consists in deepening the understanding of the content-functional nature of the colour phenomenon and strategies for its application in brand design; empirical detection of colours not associated with the design-product consumption categories, in particular in the preference of youth as an active category of consumers. Conclusions. The role and place of colour in the system of elements that create the visual image of a fashion company/product, which is an important factor in the economic sector, including the production and sale of goods/ services, is justified. It has been found that the brand’s idea is concentrated in the options of colour combinations, which help designers to choose by using or not using a particular color. The following has been empirically revealed: psycho-physiological, socio-psychological, aesthetic-emotional influence of a colour gamut balance and an optimal compositional solution of the design task on brand formation taking into account the age, gender, status characteristics of consumers, historical and ethnic traditions, fashion trends, against the background of economic, ecological, cultural and socio-political phenomena.