Color Field Research Articles

Tunable white light emission from Dy3+/Eu3+ doped LaAlO3 nanophosphors via hydrothermal method

A sequence of Dy3+/Eu3+ co-doped LaAlO3 nanophosphors are synthesized by hydrothermal technique and their phase purity, particle nature and luminescence characteristics are investigated. All the prepared samples possess single-phased perovskite type rhombohedral structure of LaAlO3 and consist of polygonal natured particles with the mean size of 30 nm. Under the excitation with 351 nm, LaAlO3: Dy3+ nanophosphors shown characteristic emission peaks of Dy3+ ion and are positioned at 485, 576 and 665 nm. LaAlO3: 9 mol% Dy3+, y mol% Eu3+ nanophosphors exhibited emission bands of both Dy3+ and Eu3+ ions and are noticed at 485, 576, 590, 620 and 696 nm under 351 nm excitation. It can be perceived that the Dy3+ integrated luminescence intensity is reduced and the average lifetime of Dy3+ is decreased with the enhancing Eu3+ content, which is owing to energy migrates from Dy3+ ion to Eu3+ ion. Moreover, CIE coordinate values of LaAlO3: 9 mol% Dy3+, y mol% Eu3+ nanophosphors are altered from the bluish-white to white light and ultimately to the orange-white light location with increasing the Eu3+ ion content. This nature of color adjustable nanophosphors shows the excellent potential advantages in the fields of white light luminescent materials, optoelectronic devices and color displays.

Conveying colour research to design practice: Design and evaluation of aweb‐basedcolour tool

AbstractThis study presents a practice‐based research project to develop a colour tool prototype intended to convey colour research to design practice. Both the prototype design and its evaluation by experts are described. A web‐based prototype for a colour tool was cocreated with eight experienced designers and brand managers. The developed prototype is a visual and interactive website that predominantly provides research data on colour meanings in different product categories and cultures. In the evaluation study, an e‐mail survey of experts was conducted to assess the prototype. A senior manager at a leading US colour company and seven academics in the fields of colour, branding and graphic design participated in the survey. As for the results, the prototype generally was deemed useful for design practice. The outcome also emphasized that the prototype has strong potential to play a significant role in providing colour insights and supporting colour judgments, strategy and inspiration. However, the experts also raised several issues concerning the data's scope, an insufficient number of prototype web pages, product category choices, legal issues, data presentation method, data source clarity, and data management. The study's findings provide insight into how colour research can be delivered to design practice using a colour tool.

Diffusion of heavy quarks in the early stage of high-energy nuclear collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

We study the diffusion of charm and beauty in the early stage of high energy nuclear collisions at RHIC and LHC energies, considering the interaction of these heavy quarks with the evolving Glasma by means of the Wong equations. In comparison with previous works, we add the longitudinal expansion as well as we estimate the effect of energy loss due to gluon radiation. We find that heavy quarks diffuse in the strong transverse color fields in the very early stage (0.2-0.3 fm/c) and this leads to a suppression at low $p_T$ and enhancement at intermediate low $p_T$. The shape of the observed nuclear suppression factor obtained within our calculations is in qualitative agreement with the experimental results of the same quantity for $D-$mesons in proton-nucleus collisions. We compute the nuclear suppression factor in nucleus-nucleus collisions as well, for both charm and beauty, finding a substantial impact of the evolving Glasma phase on these, suggesting that initialization of heavy quarks spectra in the quark-gluon plasma phase should not neglect the early evolution in the strong gluon fields.

Controllable synthesis and luminescence properties of NaYF4@YOF composite microcrystals with multiform morphologies

A variety of α-NaYF4@YOF composites with diverse morphologies and particles sizes have been fabricated via an easy-to-operate approach. First of all, the YB(OH)4CO3 precursor was obtained by a urea-based homogeneous precipitation route. Subsequently, the uniform and well-dispersed β-NaYF4 microcrystals with a variety of crystal shapes were synthesized by a simple hydrothermal process. The morphology and particle size of the β-NaYF4 samples can be adjusted in a controlled manner by simply tuning the reaction temperature and time, feeding molar ratio of precursor/NaF, or total amount of the reactants. Finally, the β-NaYF4 microcrystals converted to α-NaYF4@YOF composites which inherited the morphology and dispersity of the hydrothermal products after an annealing process in air. Upon UV or NIR excitation, the as-synthesized lanthanide ions Ln3+ (Eu3+, Tb3+, Yb3+/Er3+, Yb3+/Ho3+) doped α-NaYF4@YOF samples show the intense characteristic down-conversion (DC) or up-conversion (UC) multicolor emissions. Moreover, the calcination process not only broadens the excitation range but also improves the emission efficiency of the phosphors due to the enhanced crystallintiy and formation of YOF shell. The as-synthesized Ln3+-doped luminescent materials may find potential applications in fields of color displays, optoelectronic devices, and light-emitting diodes (LEDs).

Substanzaktivität. Farbe als prima materia im Andachtsbild der Frühen Neuzeit

Abstract In devotional pictures of the Quattrocento by Giovanni di Francesco Toscani, Fra Angelico, Zanobi Strozzi, Benozzo Gozzoli, and Bartolomeo Caporali, floor and wall fields repeatedly appear as non-representational color grounds. They refer to a hitherto rather insufficiently analyzed multi-layered reflection of the design modes of the time. These surfaces only superficially resemble natural stone structures. Rather, they are coloristic protoforms of the pictorial figurations, which is why these color fields, apart from a theological sub-iconography, can also be understood as references to the substrate character of the color. By evoking spiral and snail shapes in addition to completely amorphous spots, they also seem to reflect the processes of rock formation as explored in Albertus Magnus’s De mineralibus. As a fluid matter that can develop spontaneously into any form in the sense of a painterly generatio spontanea, color finally approximates the Aristotelian concept of hylē. This contribution seeks to explore the exciting and dynamic relationship between matter and form in the quattrocentesque devotional picture. The color substance of the amorphous grounds is understood as an activated source material that is transformed into vivid forms by way of the respective artistic technē.

Breaking mirror twin color

We investigate simple extensions of the Mirror Twin Higgs model in which the twin color gauge symmetry and the discrete ℤ2 mirror symmetry are spontaneously broken. This is accomplished in a minimal way by introducing a single new colored triplet, sextet, or octet scalar field and its twin along with a suitable scalar potential. This spontaneous ℤ2 breaking allows for a phenomenologically viable alignment of the electroweak vacuum, and leads to dramatic differences between the visible and mirror sectors with regard to the residual gauge symmetries at low energies, color confinement scales, and particle spectra. In particular, several of our models feature a remnant SU(2) or SO(3) twin color gauge symmetry with a very low confinement scale in comparison to ΛQCD. Furthermore, couplings between the colored scalar and matter provide a new dynamical source of twin fermion masses, and due to the mirror symmetry, these lead to a variety of correlated visible sector effects that can be probed through precision measurements and collider searches.

83‐2: Reliability Characterization of Luminance Degradation of OLED Mobile Display Considering Color Difference Index Based on Usage Patterns

In this paper, we delve into reliability characterization for the luminance degradation of OLED device considering color difference index based on the usage patterns. Accelerated aging tests were conducted and then the usage patterns (viewing contents) were taken accounted for the power model to evaluate lifetime. This method enables to provide a practical lifetime prediction on color shifts induced display image degradation at different Gray levels, since different individual components of Red (R), Green (G), and Blue (B) have different degradation rate associated with the usage patterns. Using the color coordinate CIE 1931 (Δx, Δy), the just‐noticeable difference (JND) index is adopted to quantitatively assess color difference as an objective judgment with a perceivable recognition. Such approach will render a consistent management over color difference and, thus, facilitate product color performance and field reliability.

The effects of moral context on the colours of guilt and pride

ABSTRACT There is little evidence on what colours are associated with moral emotions of guilt and pride and how a change in moral context alters colour-emotion associations. We have addressed this by manipulating the context of (im)moral vs. environmentally (un)friendly behaviours. This is because environmental behaviours are classified as moral, yet they are often driven by different moral motives. We wanted to find out whether this difference could be captured by colour-emotion associations with guilt and pride. We have used an online colour picker to examine over 400 UK participants. The results of the RGB colour model revealed that guilt was most commonly associated with red, black, green, and violet colours. However, the colours of immoral behaviours were much darker than the colours of environmentally unfriendly behaviours. In contrast, pride in moral behaviours was mostly associated with pink, violet, green and blue, whereas pride in environmentally friendly behaviours was mostly paired with green, suggesting that moral context, indeed, has an impact on colour-emotion associations of guilt and pride. In addition, our study has uncovered that colour-emotion associations of guilt and pride are comprised of a certain colour signature, rather than a single colour, and this signature varies with the alteration of context. Our study contributes to developing research in both colour and environmental fields.

Comprehensive metrological and content analysis of the public–private partnerships (PPPs) research field: a new bibliometric journey

Studies around public–private partnerships (PPPs) have shaped a complex and colorful research field. A series of review studies have been performed to explore the knowledge base of this field. Despite their significant contributions, bibliometric research on the PPPs literature is still needed to capture more comprehensive, diverse and detailed information in this area from a holistic perspective, for reducing subjectivity and one-sidedness. Under this situation, this paper continues the bibliometric journey by conducting a comprehensive metrological and content analysis of the PPPs research field. By applying a newly developed Bibliometrix R-package tool, the overview of PPPs research is presented via metrological analysis using a series of indexes. The intellectual structure of this domain is then explored via content analysis using the methods of keywords analysis and citation analysis from both static and dynamic perspectives. Consequently, the panoramic view including the overview, pivotal points of topics, thematic evolution and research focuses of this domain are depicted visually and intuitively via a set of science maps. This new attempt crystallizes out key findings and valuable information of PPPs research, which can consolidate and broaden the bibliometric findings of previous PPPs literature studies and act as a guidance for analyzing the knowledge base of other research fields.

Rapidity loss, spin, and angular asymmetries in the scattering of a quark from the color field of a proton or nucleus

We calculate the helicity amplitudes for scattering of a quark from both large and small $x$ gluons of a target proton or nucleus using spinor helicity formalism. We show that scattering from large $x$ gluons of the target results in non-zero spin asymmetry at intermediate $p_t$ as well as rapidity loss of the projectile quark. We comment on how this can also generate angular asymmetries in particle production in high energy collisions.

A completely parallel surface reconstruction method for particle-based fluids

We present a novel surface reconstruction pipeline that significantly improves reconstructing efficiency while preserves high-quality details for particle-based liquid simulation. Our surface reconstruction algorithm is a sort of completely parallel narrow band method. At the beginning of reconstruction, we develop a spatial hashing grid-based strategy to identify surface particles, which is much more precise and simpler than the smoothed color field. Consequently, those precise surface particles ensure accurate extraction of scalar field in the narrow band around surface without any redundancy, which brings great performance improvement for subsequent reconstruction stages. Furthermore, in order to obtain a better computation performance, we carefully analyze the potential race conditions and conditional branches of each reconstruction step between parallel threads and come up with a completely parallel reconstruction method combined with the exclusive prefix sum algorithm. Our method is pretty straightforward to implement. Experimental results demonstrate that our method runs up to dozen times faster than the state-of-the-art of narrow band-based fluid surface reconstruction, especially for large-scale particle-based fluid.

The confining color field in SU(3) gauge theory

We extend a previous numerical study of SU(3) Yang–Mills theory in which we measured the spatial distribution of all components of the color fields surrounding a static quark–antiquark pair and provided evidence that the simulated gauge invariant chromoelectric field can be separated into a Coulomb-like ‘perturbative’ field and a ‘non-perturbative’ confining field. In this paper we hypothesize that the fluctuating color fields not measured in our simulations do not contribute to the string tension. Under this assumption the string tension is determined by the color fields we measure, which form a field strength tensor pointing in a single direction in color space. We call this the ‘Maxwell picture of confinement’. We provide an additional procedure to isolate the confining field. We then extract the string tension from a stress energy-momentum tensor having the Maxwell form, constructed from the simulated non-perturbative part of the field strength tensor. To test our hypothesis we calculate the string tension for values of the quark–antiquark separation ranging from 0.37 fm to 1.2 fm. We also calculate the spatial distributions of the energy-momentum tensor surrounding static quarks for this range of separations, and we compare with the distributions obtained from direct simulations of the energy-momentum tensor.

The usage of the colour name зялёны (green) in the texts of Belarusian healing spells

Сolour names in any language create certain lexico-semantic fields of colour, which can be analyzed in different aspects: formal, functional, semantic etc. The defined words in the language are constantly in development and change. The result of their semantic development is the combination of direct, indirect and symbolic meanings of the revealed words, it was actively used and it is used in different kinds of linguistic and literary works.In the texts of Belarusian spells the vocabulary of colour name is represented by a range of colour names, which are grouped in certain colour codes according to their specific features. The article deals with the functioning peculiarities of the colour name green in the texts of Belarusian healing spells. The colour name зялёны (green) is quite rarely used, it stands out as the essential element of nature or an open space, inhabited by evil spirit.The authour defines that the semantics if this colour name is not singled-valued. In Belarus the зялёны (green) colour is an ambivalent symbol: on the one hand it symbolizes the vital force of nature, on the other hand it can symbolize the illnesses and the place of their reference.This colour is neutral, soft, calming, making an impression of some marked space. This colour name has a very restricted word-combinability in the analyzed texts. These peculiarities are closely connected with the national and cultural traditions of Belarusians and underline the features of their mentality.

Ultrarelativistic quark-nucleus scattering in a light-front Hamiltonian approach

We investigate the scattering of a quark on a heavy nucleus at high energies using the time-dependent basis light-front quantization (tBLFQ) formalism, which is the first application of the tBLFQ formalism in QCD. We present the real-time evolution of the quark wave function in a strong classical color field of the relativistic nucleus, described as the Color Glass Condensate. The quark and the nucleus color field are simulated in the QCD SU(3) color space. We calculate the total and the differential cross sections, and the quark distribution in coordinate and color spaces using the tBLFQ approach. We recover the eikonal cross sections in the eikonal limit. We find that the differential cross section from the tBLFQ simulation is in agreement with a perturbative calculation at large $p_\perp$, and it deviates from the perturbative calculation at small $p_\perp$ due to higher-order contributions. In particular, we relax the eikonal limit by letting the quark carry realistic finite longitudinal momenta. We study the sub-eikonal effect on the quark through the transverse coordinate distribution of the quark with different longitudinal momentum, and we find the sub-eikonal effect to be sizable. Our results can significantly reduce the theoretical uncertainties in small $p_\perp$ region which has important implications to the phenomenology of the hadron-nucleus and deep inelastic scattering at high energies.

Оцінка впливу колірного і графічного оформлення контенту сайту на його конверсію

Показана фізіологія впливу колірної палітри сайту на психологію користувача і, як наслідок, на його конверсію. Показано, що оптичні, геометричні ілюзії і колірний контраст є основними факторами, які спотворюють колірну палітру сайту. Запропоновано алгоритм оцінки кольорової палітри сайтів на основі теоретико-множинного підходу і сформульовані рекомендації по її корекції.

Image encryption with cross colour field algorithm and improved cascade chaos systems

In this study, the critical factor of the chaos system has been analysed to improve the randomicity of the encryption keyspace. Several chaos systems have been integrated together with a linear function to form a much more efficient key sequence generator. This study also presents the cross colour field confusion method which scrambles the pixels among the R G B colour matrixes. In this way, the range of the pixels scrambling map is extended to three matrixes compared to the traditional pixels scrambling schemes which do pixels scrambling in its own colour matrix. The experiment results show that the improved cascade system has better bifurcation diagrams. The cross colour field diffusion algorithm makes the encrypted image has little pixel correlation and no information leakage. The experiment results justify that the novel cross colour confusion scheme with improved chaos systems has a good ability to resist brute force attack, known plain attack, chosen plain text attack, chosen ciphertext attack and differential attack. The security analysis demonstrates that the proposed approach has satisfactory properties in image encryption.

State Visualization Design of AI Speakers using Color Field Painting

State Visualization Design of AI Speakers using Color Field Painting

The Impact of Color Palettes on the Prices of Paintings

We emphasize that color composition is an important characteristic of a painting. It impacts the auction price of a painting but it has never been considered in previous studies on art markets. By using Picasso's paintings, we demonstrate the method to analyze color compositions. In the case of Picasso's paintings sold at Chrisite's and Sotheby's auctions between 1998 and 2014 in New York, our econometric analysis shows that [controlling for all conventional painting and sale characteristics] some colors are associated with high prices. We also find that contrastive paintings (defined as works with colors that are distant from each other in the RGB color space) get high prices. We also analyse the works of Color Field Abstract Expressionists and find that, in the case of this school, the more distant the work's color composition is from the black/gray spectrum, the higher work's market price.

Visual Status of HIV and Non-HIV Infected Children in Relation to Anti-retroviral Drug Use and CD4+ Count in Jos, Plateau State Nigeria

In immunodeficiency diseases such as Human Immunodeficiency Virus (HIV) infection, various body functions may be affected; visual function could be one of them. In a child, there are predictable adverse outcomes of the disease that bother physical and mental development. This study sought to investigate any potential compromise of visual function amongst HIV-infected children on anti-retroviral drugs known as Highly Active Antiretroviral Therapy (HAART) use by comparing the visual acuity, colour sense and field of vision in infected and non-infected children. One hundred (100) children aged between 5 to 15 years consisting of fifty (50) HIV infected and fifty (50) non-HIV infected were selected through random sampling. Visual acuity test (Snellen’s method), colour sense test (Ishihara chart method) and field of vision test (confrontational method) were carried out. Latest Cluster of Differentiation 4 (CD4+) count of the HIV infected subjects also was collected. Statistical analysis was carried out using the Student T Test and ANOVA. The mean visual acuity of Human Immunodeficiency Virus (HIV) infected children was slightly low compared to the negative group (94.2±4.61and 96.4±12.58 respectively) but was not statistically significant (p>0.05). The mean of Ishihara colour sense test and that of the field of vision test also showed no statistically significant change between infected and non-infected children. Mean CD4+ count of the HIV infected children increased with age and use of anti-retroviral drugs. From 11 to 15 years, percentage defect in visual acuity increased amongst the HIV infected children, compared to the other ages but not statistically significant (p>0.05). It was concluded that visual acuity decreases slightly with improving CD4+ count and increasing age, for HIV positive children on anti-retroviral drugs. These parameters could be observed in subsequent years and subjects monitored for further investigation.

Exploring the initial stage of high multiplicity proton-proton collisions by determining the initial temperature of the quark-gluon plasma

Recently, the CMS Collaboration has published identified particle transverse momentum spectra in high multiplicity events at LHC energies $\sqrt s $ = 0.9-13 TeV. In the present work the transverse momentum spectra have been analyzed in the framework of the color fields inside the clusters of overlapping strings, which are produced in high energy hadronic collisions. The non-Abelian nature is reflected in the coherence sum of the color fields which as a consequence gives rise to an enhancement of the transverse momentum and a suppression of the multiplicities relative to the non overlapping strings. The initial temperature and shear viscosity to entropy density ratio $\eta/s$ are obtained. For the higher multiplicity events at $\sqrt s $ =7 and 13 TeV the initial temperature is above the universal hadronization temperature and is consistent with the creation of de-confined matter. In these small systems it can be argued that the thermalization is a consequence of the quantum tunneling through the event horizon introduced by the confining color fields, in analogy to the Hawking-Unruh effect. The small shear viscosity to entropy density ratio $\eta/s$ near the critical temperature suggests that the matter is a strongly coupled Quark Gluon Plasma.