Metallic Color Research Articles

Silver to Gold Metallic Luster Changes in Stimuli-Responsive Diacetylene Derivatives Uniquely Arranged within Crystals.

Eye-catching metallic luster materials, especially those whose colors can be controlled by external stimuli, have many potential applications. Here, we present a silver luster material that changes color to gold upon UV irradiation. Diacetylene (DA) derivatives with stilbenes introduced via linkers at both ends (DS-DAn (n = 1-6)) exhibited significantly different metallic luster and color change behaviors depending on the linker carbon number (n). The results revealed that the stacked structure of platelet crystals consisting of DS-DA1 with the shortest linker carbon chain exhibited a silver luster and changed its appearance to gold upon UV irradiation; this was an exceptional property of this material. More importantly, we found a unique crystal structure formed by DS-DA1, where the two assembled states coexisted. Partial topochemical polymerization of DA within this unique crystal structure dramatically changed its color from silver to gold. The findings of this study not only contribute to the development of the basic science of DA polymerization but also facilitate the development of new applications of metallic luster materials due to their attractive features that are adaptable to photomask patterning and UV laser lithography.

Assessing the Physiochemical and Sensorial Quality of Pea Sauce Canned in Plastic Trays vs. Metal Cans

Metal cans, while boasting excellent barrier properties, raise concerns about leaching and environmental impacts. This study explored plastic trays, a potential alternative for canned food packaging. First we delved into the plastic tray’s characteristics, including its composition and permeability to oxygen and water vapor. Secondly, we conducted a comparison between the newly introduced plastic packaging and traditional metal cans, focusing on their interactions with food during the sterilization process and their effects on the quality of Tunisian pea sauce. The composition analysis revealed that the plastic tray was composed of polypropylene (PP) (with a single endothermic peak at 168 °C), while the film was found to have a mixture of PP internally and polyethylene terephthalate (PET) externally (with two endothermic peaks at 161.96 °C and 243.81 °C). Plastic trays showed good results in water vapor permeability (0.832 g/m2.d) but exhibited higher oxygen permeability (190 g/m2.d), raising oxidation concerns. Migration testing confirmed plastic packaging safety (<10 mg/dm2), while some simulants exceeded limits in metal cans. pH levels remained consistent between both packaging types, but varied significantly over a 28-day storage. Total Volatile Basic Nitrogen (TVBN) levels differed significantly between plastic and metal packaging, with notable variations observed over time with maximums of 0.3 mg/100 g for plastic trays and 0.17 mg/100 g for metal cans. Sensory evaluation revealed that tasters were adept at differentiating between canned pea sauce in plastic trays and metal cans (83%, 10/12), with taste and color exhibiting significant differences (p < 0.05). This underlines the impact of packaging material on canned food quality and consumer preference, with minimal influence on other sensory aspects. This data empowers manufacturers to make informed packaging decisions for a diverse range of canned foods.

A reference quality genome assembly for the jewel scarab Chrysina gloriosa.

The jewel scarab Chrysina gloriosa is one of the most charismatic beetles in the United States and is found from the mountains of West Texas to the Southeastern Arizona sky islands. This species is highly sought by professional and amateur collectors worldwide due to its gleaming metallic coloration. However, the impact of the large-scale collection of this beetle on its populations is unknown, and there is a limited amount of genetic information available to make informed decisions about its conservation. As a first step, we present the genome of C. gloriosa, which we reconstructed using a single female specimen sampled from our ongoing effort to document population connectivity and the demographic history of this beetle. Using a combination of long-read sequencing and Omni-C data, we reconstructed the C. gloriosa genome at a near-chromosome level. Our genome assembly consisted of 454 scaffolds spanning 642 MB, with the 10 largest scaffolds capturing 98% of the genome. The scaffold N50 was 72 MB, and the BUSCO score was 95.5%. This genome assembly will be an essential tool to accelerate understanding C. gloriosa biology and help make informed decisions for the conservation of Chrysina and other species with similar distributions in this region. This genome assembly will further serve as a community resource for comparative genomic analysis.

Living jewels: iterative evolution of iridescent blue leaves from helicoidal cell walls.

Structural colour is responsible for the remarkable metallic blue colour seen in the leaves of several plants. Species belonging to only ten genera have been investigated to date, revealing four photonic structures responsible for blue leaves. One of these is the helicoidal cell wall, known to create structural colour in the leaf cells of five taxa. Here we investigate a broad selection of land plants to understand the phylogenetic distribution of this photonic structure in leaves. We identified helicoidal structures in the leaf epidermal cells of 19 species using transmission electron microscopy. Pitch measurements of the helicoids were compared to the reflectance spectra of circularly polarised light from the cells to confirm the structure-colour relationship. By incorporating species examined with a polarising filter, our results increase the number of taxa with photonic helicoidal cell walls to species belonging to at least 35 genera. These include 23 monocot genera, from the orders Asparagales (Orchidaceae) and Poales (Cyperaceae, Eriocaulaceae, Rapateaceae) and 17 fern genera, from the orders Marattiales (Marattiaceae), Schizaeales (Anemiaceae) and Polypodiales (Blechnaceae, Dryopteridaceae, Lomariopsidaceae, Polypodiaceae, Pteridaceae, Tectariaceae). Our investigation adds considerably to the recorded diversity of plants with structurally coloured leaves. The iterative evolution of photonic helicoidal walls has resulted in a broad phylogenetic distribution, centred on ferns and monocots. We speculate that the primary function of the helicoidal wall is to provide strength and support, so structural colour could have evolved as a potentially beneficial chance function of this structure.

Harnessing the Synergetic Effects of Ag, Mn Dopants in Eco-Friendly Ultraviolet Selective Quantum Dots for Luminescent Solar Concentrators.

Quantum dots (QDs) are promising building blocks for luminescent solar concentrators (LSCs), yet most QD-based LSCs suffer from toxic metal composition and color tinting. UV-selective harvesting QDs can enable visible transparency, but their development is restricted by large reabsorption losses and low photoluminescence quantum yield (PLQY). The developed here Ag, Mn: ZnInS2/ZnS QDs show a high PLQY of 53% due to the passivating effect of ZnS shell. These QDs selectively absorb UV light and emit orange-red light with a large Stokes shift of 180nm. A LSC of 5×5×0.2cm3, fabricated using a poly(lauryl methacrylate) (PLMA) as a matrix, maintains 87% of integrated PL after 7h of UV exposure. The QD-PLMA achieved 90.7% average visible transparency (AVT) and a color rendering index (CRI) of 95.8, which is close to plain PLMA (AVT=90.8%; CRI=99.5), yielding excellent visible light transparency. Incorporating Si-PVs at LSC edges, the Ag, Mn: ZIS/ZnS QD-LSC achieved an optical efficiency of 1.42%, ranking competitively among high-performing UV-harvesting LSCs.

Indolocarbazole Derivatives for Highly Efficient Organic Light‐Emitting Diodes

AbstractSince the discovery of the organic light‐emitting diode (OLED), scientists worldwide have dedicated extensive efforts to enhance the efficiency and reliability of devices, striving for superior performance. Various molecular structures have undergone structural modifications to assess their suitability in achieving the desired outcomes. This review focuses on indolo[3,2,1‐jk]carbazole (ICz), a building block that has garnered considerable attention within the OLED community. The rigid and fused ICz core induces a multiresonance effect through an alternating distribution of frontier molecular orbitals. Notably, ICz‐based thermally activated delayed fluorescence emitters exhibit a full width at half maximum below 20 nm, ensuring high color purity, and boast an external quantum efficiency above 30%, comparable to state‐of‐the‐art narrow‐emitting boron–nitrogen‐type materials. Furthermore, the ICz core is a building block in host and metal complexes, enhancing stability, efficiency, and color purity. Consequently, the ICz core is promising as a central component in host and emitters, improving OLED device performance. This review aims to succinctly summarize studies on ICz‐based organic materials within the OLED field, offering insights into future perspectives regarding developing and applying ICz‐derived organic compounds.

Dental Students Knowledge in Colour Determinationaccuracy of Fixed Partial Denture in RSGM Usu

The aesthetics of fixed denture treatments are important factors that determine the success of the treatment. The optimal esthetic results in the manufacture of crowns and bridges require several considerations such as the size, shape, and color of the denture. The right color is one of the factors that influence the success of fixed bridges (GTJ) from an aesthetic aspect. In this descriptive survey research, the author examined the color of the ceramic metal that would be attached to the patient and compared it to the color guide and then the author distributed a questionnaire to assess the level of knowledge from clinical clerkship students at Prosthodontics Department Universitas Sumatera Utara regarding the procedure in determining the color of dentures. A colorimeter is used as a tool in determining the color accuracy of fixed dentures. The mean difference in color between the fixed denture and the color guide was tabulated and univariate analysis was performed. The results showed no significant color difference between the fixed denture and the color guide. 80,95% of respondents had a good knowledge level in the determining color procedure.

Callainireinwardtia Savage (Diptera, Muscidae) is a Cyrtoneurininae of uncertain position: Systematics and description of a new species from Brazil

Callainireinwardtia Savage is a genus of Neotropical Cyrtoneurininae known from Callainireinwardtia woodi Savage, a species only known from six specimens collected in Costa Rica. Considering the combination of a bare anepimeron, metallic blue-green color, and the morphology of the post-abdomen, the original author proposed that the genus belongs to Reinwardtiini, whose taxa are considered to belong to Cyrtoneurininae or Reinwardtiinae in more recent classifications. Here, we have described Callainireinwardtia papaveroisp. nov. isolated from Brazil. For the first time, we also tested the phylogenetic position of the genus using molecular markers (AATS, CAD, EF1-α) based on a taxonomic sample of Muscidae. We could amplify EF1-α from C. papaveroisp. nov. and analyzed the dataset using maximum likelihood. Although different analytical strategies yielded different results for the sister group of the genus, we recovered its position among Cyrtoneurininae in all cases, corroborating the previous hypothesis. Depending on the partitioning scheme, Callainireinwardtia is either a sister group of Synthesiomyia, the clade (Synthesiomyia nudiseta + Neomuscina), or a clade composed of eight Cyrtoneurininae genera (Synthesiomyia, Neomuscina, Chaetagenia, Eginia, Muscina, Passeromyia, Philornis, and Pseudoptilolepis). Considering the limitations of our dataset, the sister-group hypothesis should be carefully considered. We have also provided a key for the identification of the genus and its species, a distribution map, and an updated taxonomic catalog of the genus.

Period–Luminosity–Metallicity–Color Relations of Late-type Contact Binaries in the Big Data Era

Binary stars ubiquitous throughout the Universe are important. Contact binaries (CBs) possessing period–luminosity (PL) relations could be adopted as distance tracers. The PL relations of CBs are influenced by metallicity abundance and color index, which are connected to both the radius and luminosity of stars. Here we propose fine relations of the period–luminosity–metallicity–color (PLZC) from the ultraviolet to infrared bands based on current surveys. The accuracy of the distance estimation is 6% and 8%, respectively, depending on the PLZC relations of the CBs in the infrared and optical bands of the collected data. PLZC models are still more accurate than PLC models in determining intrinsic luminosity, notwithstanding their limited improvement. Meanwhile, these relations based on synthetic photometry are also calibrated. On the basis of the synthetic photometry, a 6% accuracy of distance is estimated. The measured or synthetic data of PLZC or PLC relations in infrared bands comes first in the list of suggestions for distance estimations and is followed by the measured data of optical bands.

A Possible Correlation between Metallicity and Near-IR Color for Late-M and L Dwarfs

We examine the relationship between metallicity and J − K color for 64 benchmark late-M and L dwarfs, all of which are wide companions to higher-mass stars, and six of which are new discoveries. We assess the correlation between the Δ(J − K) color anomaly (the difference in an object’s J − K color from the median color for field objects of the same spectral type) and the metallicity of the host star to investigate how metallicity affects ultracool photospheres. Using Spearman’s rank correlation test and Student’s t-test, the late-M dwarf (L dwarf) sample’s Δ(J − K) and metallicity show a positive correlation at the 95% (90%) confidence level. A linear fit to color anomaly as a function of metallicity finds a slope of 0.17 ± 0.07 for the late-M dwarfs and a slope of for the L dwarfs. We also computed the Δ(J − K) versus metallicity relationship predicted by multi-metallicity model spectra generated using Drift-Phoenix. The modeled late-M dwarfs show a slope of 0.202 ± 0.03, which is close to our observational results, but the modeled L dwarfs show a slope of 0.493 ± 0.02, steeper than our observational results. Both our empirical results and the models indicate that more metal-rich objects should appear redder photometrically. We speculate that higher metallicity drives more condensate formation in these atmospheres, thus making these ultracool dwarfs appear redder.

Molecular mechanism of antimicrobial co-resistance Colistin (mcr-1) and ESBLs genes among Escherichia coli isolates from commercial chickens in Pakistan.

Emergence of plasmid mediated colistin and extended spectrum β-lactamases (ESBL) resistant genes has been impacted the efficacy of colistin and β-lactams drugs like 3rd, 4th generation cephalosporin. Current study was aimed to investigate antimicrobial resistance genes (ARGs) among Escherichia coli isolates from meat producing commercial broilers in Pakistan. Two hundred (n=200) fecal samples were collected during January-2018 to August-2019. For isolation of E. coli, pink colonies on MacConkey agar were transferred to EMB agar. Metallic sheen color colonies were tested biochemically using API-20E kit. The molecular identification of E. coli (n=153) was targeted by amplification of uid gene through polymerase chain reaction (PCR) and different ARGs i.e. gentamicin, streptomycin, tetracycline, colistin, β-lactams drugs, quinolone and ampicillin followed by sequence analysis. Genotypically, followed by phenotypically of resistant ARGs of isolated PCR-confirmed E. coli (153) shoed resistant against gentamicin (aac(3)-IV), streptomycin (aadA1), tetracycline (tetA), colistine (mcr-1), ampicillin (bla-TEM) and bla-CTX-M were 86%, 88%, 86%, 88%, 83% & 77% respectively. 33/38 (86%) of the isolate was positive for quinolone resistance. Colistine (mcr-1), ESBLs (bla-TEM) and (bla-CTX-M) resistance genes were 88%, 83% and 77% respectively. About 33 isolated E. coli harbored the both mcr-1 and ESBLs genes. All of E. coli isolates were found sensitive to ceftriaxone (CTX-30) and imipenem (IMP-10). The Isolated E. coli showed single or multi clade decadency. The E. coli and ARGs sequences showed single or multi clade decadency. This is first comprehensive study from Pakistan that described the molecular evidences of ARGs and their co-existence in single isolates originated from commercial poultry. Commercial chicken (Broilers) can act as melting pot of antibiotic resistance genes for human being. It is alarming situation for surveillance of antibiotic resistance program because of more regulated prescription of antimicrobial agents in Pakistan.

Durable multicolor electrochromic fibers based on metal oxidecoated steel tapes

Electrochromic devices (ECDs) have the ability to selectively change color under the influence of electric current or potential and can keep the selected color after disconnection. They are used as smart windows, e-ink displays and even as flexible tapes. Most multicolor ECDs incorporate traditional “sandwich” architecture, which requires at least one electrode to be made of a transparent conductive polymer or thin film ceramics, and can be quite fragile and sensitive. In this paper, a flexible and durable multicolor ECD tape is reported, which uses advanced architecture, steel foil electrodes, and multiple coloration systems, for example intercalation used in tungsten and vanadium oxide based electrochromic systems, as well as a redox dye, for example methyl orange. The presented ECD tapes can utilize different metal oxides and color mechanisms with coloration efficiency around 10 cm2 C−1 for V2O5 and WO3 in both visible and IR range, and more than 30 cm2 C−1 for ZnO with added methyl orange dye. Due to the use of stainless-steel foil as a substrate, the assembled ECD tape has excellent durability properties, withstanding more than 39 MPa of pressure, and could therefore be used even in the most adverse conditions, for applications such as adaptive camouflage, color changing clothes, or other applications

Rapid and reversible humidity-dependent colour change by water film formation in a scaled springtail.

Colour is often not a static trait but can change over time either through biotic or abiotic factors. Humidity-dependent colour change can occur through either morphological change (e.g. to feather barbules in birds) or by the replacement of air by water causing a shift in refractive index, as seen in arthropod multi-layer cuticles or scales. The scaled springtail Lepidocyrtus cyaneus has scales that produce colour largely via thin film interference from their lamina. We observed a marked colour change from golden to violet/purple coloration in humid conditions. Light microscopy, micro-spectrophotometry, contact angle goniometry and optical modelling indicate that the formation of a thin film of water on top of the hydrophilic scales increases their laminar thin film thickness, causing a shift towards violet/purple colour. Evaporation of the water film causes the metallic golden colour to return. This constitutes a remarkably rapid colour change (in the order of seconds), only limited by the speed of water film condensation and evaporation, that may serve as inspiration for new dynamically coloured materials and sensors.

Pengaplikasian Material Aluminium Composite Panel pada Perancangan Apartemen dan Soho di Kota Surabaya

The demand for residential space continues to increase with the amount of growth in a city. This is something that is experienced by large cities such as Surabaya. The demand for residential and office space for local residents and migrants is due to the increasing number of national and multinational companies operating in the city of Surabaya. The use of technology in the creation of building materials is one of the positive impacts that can be felt due to the rapid influence of modernization and globalization. The use of ACP material with a variety of materials and colors and ease of application in workmanship. Aluminum composite panel (ACP) building facade is a combination of aluminum panels and composite materials. This building material is made of polyethylene coated with aluminum panels on both sides. Aluminum composite panel itself is a rigid and sturdy sheet but with a relatively light weight. This building material is used to line the exterior or interior walls of the building. Because this material is available in metallic and non-metallic colors, it can add an artistic and luxurious impression to the building facade. The use of ACP material used on the facade of this building has various advantages such as variations in thickness, strength and brightness and attractive facade patterns.

A novel plasmonic metal–semiconductor–insulator–metal (MSIM) color sensor compatible with CMOS technology

Color detection is one of the top interests in both biological and industrial applications. Specifically, the Determination of the light wave characteristics is vital in photonic technology. One of the features in the color sense that should be found out is its wavelength or color. In this work, we propose a structure that can be used to detect RGB colors separately in an efficient way. The proposed detector consists of the plasmonic filter sensing desired wavelength (red, green, and blue) and the PN diode to convert the received photons to the electrical current. At the input intensity of 1 mW × cm−2, the current density for blue, green, and red colors are 27, 35, and 48 µA × cm−2, respectively. It is shown that the intensities needed to obtain the current densities of 0.1 µA × cm−2 are 3.94, 2.98, and 2.25 µW × cm−2 for the blue, green, and red spectra respectively. It should mention that by using high-precision photodetector structures such as PIN diode, the minimum detectable level can be decreased. Simple adjusting for desired wavelength and linear operation for different input intensities are the characteristics of the designed structure. This detector is compatible with CMOS technology and can be easily utilized in numerous applications, such as charge-coupled devices, displays, and cameras.

Graphene coated copper in a one-year atmospheric corrosion and color preserving challenge

A one-year atmospheric corrosion study was conducted to evaluate the performance of transparent single-layer (SLG) and multilayer graphene (MLG) coating as a protective coating on copper substrate against atmospheric corrosion and color changing. Employing the CIE−L*a*b* color space, it was shown that the transparent SLG and MLG coatings can maintain the pure color of copper before exposure to the atmosphere. However, after 15 days the color change (∆E) in the SLG-coated copper (SLG/Cu) was found to be more than that in the bare copper. A scanning Kelvin probe (SKP) was used to measure the surface potential as well as corrosion behavior. The observed decrease of average surface Volta potential of SLG/Cu, from -312 mV to -830 mV, was supposed to be caused by corrosion and electron transfer during galvanic cell formation. Further examinations by Raman spectroscopy, OM, and AFM measurements were logically correlated with those from SKP. Moreover, it was revealed that the surface voltaic potential for MLG-coated copper (MLG/Cu) remains constant along one-year atmospheric exposure. The presented results strongly prove that the MLG coating could be considered an anti-corrosion coating that can fully preserve the color of copper metal after exposure to the environment for at least a year.

Deep learning-based optical authentication using the structural coloration of metals with femtosecond laser-induced periodic surface structures.

Structurally colored materials present potential technological applications including anticounterfeiting tags for authentication due to the ability to controllably manipulate colors through nanostructuring. Yet, no applications of deep learning algorithms, known to discover meaningful structures in data with far-reaching optimization capabilities, to such optical authentication applications involving low-spatial-frequency laser-induced periodic surface structures (LSFLs) have been demonstrated to date. In this work, by fine-tuning one of the lightweight convolutional neural networks, MobileNetV1, we investigate the optical authentication capabilities of the structurally colorized images on metal surfaces fabricated by controlling the orientation of femtosecond LSFLs. We show that the structural color variations due to a broad range of the illumination incident angles combined with both the controlled orientations of LSFLs and differences in features captured in the image make this system suitable for deep learning-based optical authentication.

Karakteristik Biometrik, Morfologi Telur, dan Habitat Ikan Padi Oryzias javanicus (Beloniformes, Adrianichthyidae) Asal Desa Linduk, Pesisir Teluk Banten

Information on the biometric characteristics, egg morphology, and habitat of O. javanicus are very important for its use as model fish in the laboratory, ornamental fish, and environmental bioindicators. Therefore, research is needed to analyze the biometric character, egg morphology, and habitat of ricefish O. javanicus in the brackish water pond of Banten Bay. This research was conducted non-eperimentally by observing biometric characters to examine meristic, morphometric, and sex dimorphism characteristics. Observations of egg morphology were macroscopic and microscopic characteristics. Habitat characteristics were observed by measuring water quality in situ. The results showed that O. javanicus from Linduk had meristic characteristics D.6–7; A.21–22; P.9-10; V.5–6 and sex dimorphism in the shape and size of the dorsal and anal fins. Blue metallic color pattern on the head and yellow color on the fins are potentially ornamental fish. O. javanicus eggs have a diameter of 1.08 ± 0.02 mm, are equipped with attaching filaments and non-attaching. The non-attaching filaments are 0.14 ± 0.03 mm in length. The percentage of yolk area was 73.7 ± 4.85%, and the oil droplet area was 8.3 ± 0.54% of O. javanicus at the gastrula stage with egg yolk volume 0.349 ± 0.048 mm3. Water quality in this study is a reference for rearing O. javanicus in the laboratory.

CHALCOLESTES COLORAENEUS (ODONATA, ZYGOPTERA, LESTIDAE) SP. NOV. FROM ROMANIA

This paper describes a new Chalcolestes species – Chalcolestes coloraeneus collected from Romania. This new species shows morphological similarities with Chalcolestes viridis by the metallic iridescent colour of the body and by the yellow to pale brown colour of the lower part of the head; it also shows similarities with Lestes dryas in the pruinosity of the last abdominal segments and with Lestes virens, Lestes sponsa and Lestes dryas by the long fringing hairs on the inferior male annal appendages. Chalcolestes coloraeneus can be separated by the other Lestes and Chalcolestes species by the male dark coppery metallic colour with green and reddish reflections and especially by the shape and colour of the male anal appendages.

Molecular, biochemical and micromorphological responses of cacao seedlings of the Parinari series, carrying the lethal gene Luteus-Pa, in the presence and absence of cotyledons

Investigations of the compatibility between cacao genotypes of the population of the Parinari series (Pa), resulting from the reciprocal crossing of Pa 30 × Pa 169 and Pa 121 × Pa 169, allowed the verification of the occurrence of the recessive lethal single character called Luteus-Pa. These genotypes have this gene in heterozygosity, which when intercross or self-fertilize, segregate in a 3:1 ratio. Normal (NS) and mutant (MS) seedlings grow normally and, after a period of approximately 30 days of age, MS leaves begin to show a metallic yellow color, followed by necrotic spots, and death of the entire seedling, approximately 40 days after the emergency. The work evaluate the molecular, biochemical and micromorphological responses in NS and MS, with and without cotyledons, resulting from the crossing of the Pa 30 × Pa 169 cacao genotypes, aiming to elucidate the possible lethal mechanisms of the homozygous recessive Luteus-Pa. The presence of the lethal gene Luteus-Pa in the seedlings of the cacao genotypes of the population of the Parinari (Pa), with and without cotyledons, resulting from the crossing of Pa 30 × Pa 169, in addition to regulating the synthesis of proteins related to the photosynthetic and stress defense processes, promoted an increase in the synthesis of proteins involved in the glycolic pathway, induced oxidative stress, altered the mobilization of cotyledonary reserves, the integrity of cell membranes, leaf micromorphology and induced the death of seedlings, soon after depletion of protein and carbohydrate reserves, especially in the absence of cotyledons.