Blue Research Articles

Copper nanoparticle biosynthesis and characterization utilizing a bioflocculant from Kytococcus sedentarius

Abstract The application of microbial flocculants in nanoparticle synthesis is attracting scientists to utilize them due to their eco-friendliness. This study was mainly focused on biosynthesizing and characterizing copper nanoparticles from a non-pathogenic microorganism Kytococcus sedentarius to produce bioflocculant. The formed copper nanoparticles (CuNPs) were analyzed using UV–vis spectroscope (UV–vis), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD) and thermo-gravimetric analysis (TGA). After extraction and purification, 2.4 g was produced from bioflocculant in a 1 L culture fermentation mixture. During CuNP biosynthesis, a blue color change was obtained after 24 h of incubation indicating their successful formation. A variety of elements namely, C, O, Cu, P, Ca, Mg and Al were found in the as-synthesized CuNPs with 25.23 % (wt) carbon, 20.13 % (wt) of oxygen and 23.37 % (wt) of Cu element. SEM and TEM images of the product depicted it to be agglomerated with different size and shapes. The TGA showed the CuNPs to be thermal stable as 70 % weight was retained at 900 °C with 30 % weight lost. FT-IR spectrum of the biosynthesized CuNPs contains a variety of functional groups related to sugar and proteins namely, hydroxyl, amine, carboxyl groups and a typical Cu–O bond at 559 cm−1. The crystallite size was estimated to be 28.3 nm, which is in line with JCPDS card no. 89–5899 of copper standard confirming the correct peak orientation. UV–vis analysis revealed the absorption peak to be 275 nm which confirms synthesis of the CuNPs using a bioflocculant.

Evolution of Ni-induced orthorhombic phase in SnO2: Influence of Ni on the optical and photocatalytic properties

This paper presents the impact of nickel doping on the structural, optical and photocatalytic characteristics of Sn1-xNixO2 (x = 0, 0.3, 0.05, 0.07) nanoparticles. The samples are synthesized via the chemical co-precipitation method. Information on the structural properties of the samples is obtained via the Rietveld refinement technique. As the dopant concentration increases, a partially stable orthorhombic phase emerges and becomes prominent, indicating a correlation with the amount of Ni dopant. This orthorhombic phase arises during the transformation from the amorphous state to a more stable crystalline phase. The FESEM-EDAX analysis demonstrates the uniform distribution of agglomerated particles. Additionally, the Raman data provides information related to surface defects and vacancies. A minor increase in the band gap value is detected, and this observed blue shift can be attributed to the Burstein-Moss effect. The samples exhibit a strong blue emission, primarily attributed to surface defects and states, particularly due to the oxygen vacancies. The CIE coordinates show an increase in blue colour purity, making the samples suitable for blue components in white-light emitting diodes. However, the photocatalytic study reveals only partial degradation of methylene blue under visible light conditions.

Signs of colour symbolism in traditional Altaian culture

The study of the symbolism of traditional culture categories, including the symbolism of colour in folklore studies and toponymic names becomes very relevant due to the revival of many aspects of spiritual culture. Nowadays the symbolism of colour becomes important in the life of a modern person. It accumulates deep meanings. The extent of research done on the topic: In the Altaian folkloristics colour epithets were studied in detail in the research of M. A. Demchinova, V. P. Oinoshev, S. P. Tyukhteneva and others. Up to the present time colour symbolism in the traditional culture of the Altaian people has not been the object of special research. The aim of the study is to highlight some aspects of colour symbolism in folklore art and toponymy of the Altai Mountains. Theoretical comprehension of colour symbolism as a special category in Altaian folklore studies is based on the functional method and has been applied in the researches by S.S. Surazakov, S.P. Tyukhteneva and M.A. Demchinova. The genre symbolism of Altaian folklore seemed to be considered in those researches. The present study includes the usage of a complex of comparative and historical research methods. Being a characteristic and actively used component for a number of ethnonyms, toponyms, hydronyms and to designate religious names colour has a great semantic load in the traditions of Altaians. For example, many Altaian clans (seoki) are divided into smaller units and colours such as white, black and yellow are actively used to name them: ak (white) kobok [kœbœk], karа (black) kobok [kœbœk], kara todosh (black todosh), sary todosh (yellow todosh). There is also a large number of hydronyms and toponyms associated with black, white, yellow, blue and other colours: KaraArka, Sary-Chet, Karakol, Akkem, Karasuu etc. O.P. Molchanova, a researcher of the toponymy of the Altai Mountains, writes about the great importance of some adjectives that indicate colour in the construction of geographical names. The use of colour epithets in folklore works creates a colorful image. The sharply contrasting colours show the opposition of good and evil. There is a hierarchy of colours in traditional culture. Red colour shows the colorfulness of the object being described, also symbolizes health, wealth, a world of prosperity. Grey is typical for poor people, and it has semantics of unhealthiness. There are names with the formant “kan” in the toponymy of Altai. It turns out that the formant “kan” is added to the names of especially revered natural objects. The author of the article suggests that the word “kan” (in the meaning of “blood”) is present in the names of especially revered objects. Research perspectives: The results of the research of colour symbolism in folklore and toponymy of the Altai Mountains can be applied for further study of the characterization of artistic images in literature, folklore and ethnography. The topic requires further research.

Intense Continuous Wave Laser to Synthesize Luminescent Solution of Carbon Dots

Biocompatible Carbon dots (CDs) were obtained by the laser irradiation of vegetable carbon placed in a Phosphate-Buffered Saline (PBS) solution. The carbon nanoparticles were generated by a visible and continuum wave (CW) He-Ne laser beam at a 632.8 nm wavelength with 1 mm2 spot, irradiating the carbon target for times of the order of some hours. The CDs generation might be due to thermal effects induced by the prolonged laser irradiation inducing carbon atoms ejection bounded by weak van de Walls forces. Ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR) transmittance and luminescence measurements were employed to study the CDs synthesize. The UV excitation at a 365 nm wavelength induces visible CDs luminescence mainly at about 474 nm wavelength, giving the emitted light a characteristic blue color. The CDs luminescence in biocompatible solutions is presented and discussed in anticipation of possible applications in various sectors, such as radiation detector and material physics, engineering, microelectronics, sensors and, above all, in relation to bio-images from cell cultures and biological tissue as possible applications to the bio-medical field.

Parallel biosensor platform for the detection of carbapenemase-producing E. coli in spiked food and water samples

The rise of carbapenem-resistant E. coli, specifically carbapenemase-producing (CP) strains, in biological samples needs attention. Early detection is crucial in minimizing and controlling their detrimental impact. However, their rapid identification directly from contaminated samples has not been documented well. This study presented an affordable and rapid platform for extraction and detection of CP E. coli, particularly Klebsiella pneumoniae carbapenemase (KPC)-producing E. coli from spiked food and water samples. Glycan-coated magnetic nanoparticles (gMNPs) were utilized to extract the bacteria from contaminated buffer solution, tap water, romaine lettuce, ground beef, and chicken breast samples. The bacterial cell concentration by gMNPs was achieved in the presence of food microparticles and natural microflora. Transmission Electron Microscopy (TEM) illustrated the successful isolation of bacteria and their interaction with gMNPs. For detection, a parallel plasmonic biosensor using dextrin-coated gold nanoparticles (dGNPs) was developed. The biosensor successfully detected KPC-producing E. coli from pure culture by targeting uidA and blaKPC genes and did not require any PCR amplification. The stability of dGNPs, shown by their red appearance, indicated the presence of target DNA. In contrast, their agglomeration, given by their blue or purple color, indicated the absence of target DNA. This stability and agglomeration of the dGNPs were confirmed by TEM and quantified by absorbance spectrum measurements. Further, the designed biosensor platform successfully identified the DNA extracted from water and food samples contaminated with KPC-producing E. coli, with no false positives for the samples contaminated with non-target bacteria. The biosensor successfully detected the target organism, where the original concentration prior to magnetic extraction was 103 CFU/mL. The biosensor results were further confirmed with the standard PCR assay. As a proof-of-concept, these findings indicate promising applications of the integrated platform for cost-effective and rapid bacterial detection from complex matrices within <7 h. The gained insights may facilitate future application of this platform for its complete validation study to improve real-world applicability.

Influence of Color Therapy in Alleviating Academic Stress in High School Students

Aim: Color Therapy as a powerful communication tool possesses the potential to impact emotions, moods, and psychological reactions. This study delves into the significance of colors and their influence on academic stress levels. The research aims to investigate the efficacy of color therapy, specifically utilizing blue and yellow, in alleviating academic stress among high school students. Study Design: Purposive sampling method of research was used. Place and Duration of Study: Saket MGM Senior Secondary School, Vidisha, near Bhopal (MP). The study took almost three months including data collection, one month 8 hours daily (excluding Saturday and Sunday) intervention. Methodology: The sample comprised 150 high school students whose academic stress levels were initially measured by Academic Stress Scale by Kim. Subsequently, students exhibiting moderate to extreme stress levels were exposed to a color intervention and again the stress level was observed. The data was analyzed through Student’s t-test. Results: The findings of the study revealed a substantial reduction in academic stress levels among students after exposure to blue and yellow color therapy. The accompanying statistical analysis, with a significant p-value of less than 0.01, underlines the robust evidence of this positive change. Conclusion: The results suggest that employing specific colors in educational settings may offer a viable and non-intrusive approach to addressing academic stress among high school students. Implications of the study are discussed.

Monitoring of water Quality to assess Seasonal Color Changes of Lunar-Lubha River in East Jaintia Hills, Meghalaya (India)

The Lunar-Lubha River is a significant river in Meghalaya, India, flowing through the Jaintia Hills and eventually reaching Bangladesh’s Surma valley. During winter, the river undergoes a remarkable transformation, changing its color from turquoise to a vibrant sky-blue hue. This study investigated the reason behind this color change by examining the physicochemical characteristics of the river water during pre-monsoon, post monsoon and winter season of the year 2020 to 2022. Chemical properties of the white-powdery sediment (which acts as light reflecting media) found on the riverbed of the color-changing stretches of the river were also investigated. The analysis revealed the presence of high levels of Iron (Fe) and Alumina (Al) in sediments of the Lunar-Lubha River beds. The water quality in stations located at Lunar River can be designated below-E as per Central Pollution Control Board (Govt. of India) guidelines as the water in those stations is not fit for drinking, bathing, propagation of marine life as well as irrigation or agricultural uses. The blue coloration is more prominent in the deeper sections of the river compared to the shallow stretches. This observation aligns with the argument that shorter wavelengths of light scatter more as the depth increases. The presence of light scattering effect due to variation in water depth and the white-colored sediments at the riverbed could explain the intensified blue color in the river. The apparent blue color of the Lukha River is most likely an illusion induced by the scattering effect rather than the genuine blue color of the water.

First Report of Tuff in Neoproterozoic Bhima Basin: Field Evidence, Petrography and Geochemical Studies

Abstract We report here the presence of tuffs from the Neoproterozoic Bhima basin unreported hitherto. These are exposed near Hotpet, Hulkal, Kanchankavi, and Ukinal area along two different stratigraphic horizons (1) within carbonates of Shahabad Formation and (2) above shale of Hulkal Formation. Tuffs are of two types: 1. Ash fall tuff and 2. Lapilli tuff, occurring as beds, matrix of a conglomeratic unit and patchy discontinuous layers. Physically ash fall tuff is thinly bedded (2-6 cm) and light-weight, lapilli tuff is hard, compact and individual beds are not discernible in the field. Presence of petrological features like bipyramidal quartz, fiamme structures, embayed quartz grains, blue CL colours of quartz grains, volcanic layering and banding, altered glass, and stretched and elongated volcanic glasses, are clear indications of its volcanic affinity. The tuff is anomalously high in silica content ranging from 71.4-91.2wt% and have low alumina value ranging from 0.75-4.11 wt % compared with that of the normal felsic tuffs, rhyolites and high silica rhyolites. REE in the tuffs can be grouped into two types, 1. Ash fall tuff with enriched LREE and fractionated HREE, 2. Lapilli tuff with flat LREE and HREE pattern. Tuff shows high Hf, overall enrichment of large ion lithophile elements (LILE Rb, Th, K and Pb) and depletion in HFSEs (Nb, Ta, Ti, P). The tuff is probably generated from continental crust source and the depositions are episodic and have more than one eruptive pulses of volcanic activity.

Identification of the optical emission detected by Gaia with radio structures in parsec-scale active galactic nucleus jets

Aims. We investigated the location of the optical emission with respect to the parsec-scale radio structure and attempted to identify whether the optical centroid is coincident with the radio core or a radio component of the jet. Methods. We used optical Gaia DR3 and 8 GHz ICRF3 positions and a model fitting of 15 GHz imaging by the MOJAVE VLBA survey for 422 sources, mostly blazars. We searched for possible associations between optical centroids and radio components. We also compared the astrometric and photometric properties of each category, looked for trends between the various source parameters, and discussed possible biases. Results. Sources can be separated into four categories based on whether their optical centroid (i) falls onto the radio core (category C), (ii) lies close to the base of the jet (category B), (iii) coincides with a radio component downstream in the jet (category J), or (iv) is not found to coincide with a detected radio component (category O). Due to a number of random and systematic errors, the number of sources falling into each category remains approximate but close to 32%, 36%, 22%, and 10%, respectively. The family of quasars, mostly flat spectrum radio quasars (FSRQs), clearly dominates the C and B categories, with their percentage decreasing from categories C to O. Conversely, the family of BL Lacs is spread over the four classes and dominates the category O. Radio galaxies are mainly in classes O and J, and the radio-loud narrow-line Seyfert 1 all belong to class C. An individual analysis of O sources shows that, despite the absence of a direct association with a specific radio component, the optical Gaia centroid is globally related to the radio VLBI jet structure. Conclusions. Our study shows that the spatial distribution of the optical counterparts seen by Gaia below the 0.2-arcsec scale around the radio cores appears in the vast majority of cases to be related to the AGN core or to its jet, with most of them located downstream in the jet. Those associated to the core also exhibit a bluer color index, suggesting a possible contribution of the accretion disk to the optical emission, while those associated to a radio knot in the jet appear redder and tend on average to be found in more polarized radio sources. Most BL Lacs have their optical emission coincident with the jet base or a knot in the jet, while sources with an optical emission on or close to the radio core are mostly FSRQs. Radio components associated with the optical centroid at the jet base or along the jet are mainly stationary or quasi-stationary features, with low apparent MOJAVE velocities. There are indications that the apparent proper motion of the Gaia centroids may be higher than the speed of the associated radio components, but the significance of this trend requires further investigation.

TADF deep-blue OLED with color index approaching Rec.2020 standard blue gamut achieved by a boron-based D–A type molecular skeleton

The ultra-high definition (UHD) displays in the market require organic light-emitting diodes (OLEDs) to meet the Rec.2020 color gamut standard, while it is still challenging to exploit ultra-deep-blue emitters that satisfy such blue standard. Herein, by substituting tCz (3,6-di(tert-butyl)carbazole) donor unit on the robust BOC (8,8,12,12-tetramethyl-8,12-dihydro-4-oxa-3a2-boradibenzo[cd,mn]pyrene) acceptor unit with high structural rigidity and appropriate energy levels, a novel boron-based D–A type thermally activated delayed fluorescence (TADF) ultra-deep-blue emitter, namely, tCz-BOC, was readily designed and synthesized. Inheriting from its rigid organoboron core, the emitter presents ultra-deep-blue emission with narrow spectral full width at half maximum (FWHM) of 54 nm and high photoluminescence quantum yield up to 73.7%. Additionally, tCz-BOC can effectively harvest T1 excitons through high-lying T2 mediated reverse intersystem crossing process. As a consequence, the fabricated OLED based on tCz-BOC exhibits a satisfactory ultra-deep-blue emission with λEL of 424 nm, narrow emission bandwidth with FWHM of 47 nm, excellent maximum external quantum efficiency (EQEmax) of 13.9%, as well as the CIEy coordinate of 0.047, which is fairly close to the Rec.2020 blue color gamut.

Multiband reflectance and shadowing of the protoplanetary disk RX J1604.3-2130 in scattered light

Context. A spatially resoved circumstellar disk spectrum and composition can provide valuable insights into the bulk composition of forming planets and into the mineralogical signatures that emerge during and after planet formation. Aims. We systemically extracted the RX J1604.3-213010 (J1604 hereafter) protoplanetary disk in high-contrast imaging observations and obtained its multi-band reflectance in the visible to near-infrared wavelengths. Methods. We obtained coronagraphic observations of J1604 from the Keck Observatory NIRC2 instrument and archival data from the Very Large Telescope SPHERE instrument. Using archival images to remove star light and speckles, we recovered the J1604 disk and obtained its surface brightness using forward modeling. Together with polarization data, we obtained the relative reflectance of the disk in R, J, H (H2 and H3), K (K1 and K2), and L′ bands spanning 2 yr. Results. Relative to the J1604 star, the resolved disk has a reflectance of ~10−1 arcsec−2 in R through H bands and ~10−2 arcsec−2 in K and L′ bands, showing a blue color. Together with other systems, we summarized the multiband reflectance for nine systems. We also identified a varying disk geometry structure, and a shadow that vanished between June and August in 2015. Conclusions. Motivated by broadband observations, the deployment of the latest technologies could yield higher-resolution reflection spectra, thereby informing the dust composition of disks in scattered light in the future. With multi-epoch observations, variable shadows have the potential to deepen our insight into the dynamic characteristics of inner disk regions.

Investigation of Dyeing Synthetic Fabrics by Using Bacterial Colorants for More Sustainable Textile Production

Polyester and polyamide fibers are the most commonly used textile fibre globally. For this reason, studies conducted on the production and dyeing of synthetic fabrics, especially polyester fabrics, have a significant environmental impact. In this study, it was aimed to put forward a more sustainable way to dye synthetic fabrics. Even if plant dyes are a good alternative for sustainable dyeing in the absence of synthetic dyestuff, the usage amount of plant dyestuffs is high and consistency is low. Bacterial dyeing can be a good alternative for more sustainable synthetic fabric dyeings due to consistent production and free of petroleum-based dyestuffs. Within the scope of this study, 100% polyester and %100 polyamide woven fabric were dyed using 3 different receipts with 3 different bio-colors, the most suitable dyeing methods were determined for both polyester and polyamide fabric. Quality control parameters were checked regarding color depth, washing and rubbing fastness. The findings reveal that polyamide fabrics have higher K/S values compared with polyester fabrics while dyeing with the same receipt and process. pH adjustment and adding salt are necessary to get better results for dyeing pink and brown polyester. Only adding dyestuff to the dyeing bath is enough to dye polyester in blue color. On polyamide fabrics, most suitable dye bath includes salt and pH is 4 to dye pink and brown. But for the blue color, adding salt and adjusting pH to 4 gives better results in polyamide fabric.

Extraction of natural dyes from tarum leaves (Indigofera Tinctoria L.) using the Ultrasound-Assisted Extraction (UAE) method

The rapid development of the textile industry has led to increased use of synthetic dyes. Although synthetic dyes are more practical and economical, their use can have adverse effects on health and the environment. Natural dyes are utilized as alternatives with indigo leaves (Indigofera tinctoria L.) being one source known for producing a blue color. However, the commonly used extraction methods require long extraction times and significant solvent consumption. Given the limitations of current methods, innovation is needed for an efficient extraction method that produces safe and environmentally friendly natural dyes, one of which is ultrasound-assisted extraction (UAE). Therefore, this study aims to determine the extraction process of indigo leaves using UAE method, then identify the parameters influencing the extraction process using the UAE, determine the extraction yield using UAE, assess the dyeing results of the extracted dye from indigo leaves on cotton fabric, and compare the extraction results of indigo dye through the UAE method with the addition of CaO and NaOH solutions. The results of this study indicate that the natural dye from Indigofera tinctoria obtained the best conditions at extraction time of 90 min, feed-to-solvent ratio of 0.05 g/ml, and CaO-to-solvent ratio of 0.005 g/ml. Furthermore, the addition of CaO solution obtained the highest yield at 4.25 %, while the addition of NaOH solution resulted in 4.8 %. Additionally, the analysis and test results of the application of natural dye from Indigofera tinctoria on cotton fabric revealed a darker color with the addition of NaOH solution compared to the addition of CaO solution.

Red–Green–Blue Light Emission from Composition Tunable Semiconductor Micro‐Tripods

AbstractMicro/nanoscale lasers that span the entire visible spectrum, especially those in red, green, and blue colors, are not only essential for a variety of optical devices but also have important applications in visible color communication, multi‐color fluorescence sensing, and wavelength division multiplexing. Despite the great efforts made to achieve multi‐color lasing using a variety of approaches, on‐chip white light emission and even red, green, and blue multi‐color lasers still suffer from considerable challenges in micro‐nano structures. Here, CdSxSe1−x, CdS, and ZnS micro‐tripod structures are successfully prepared using chemical vapor deposition approaches. The micro‐photoluminescence (µ‐PL) spectra and PL‐mapping of these micro‐tripods reveal various emissions at 630, 508, and 460 nm, respectively. Additionally, white‐light emissions based on these composition‐tunable tripods are realized through an end‐coupling structure system. Moreover, room‐temperature modes tunable lasers are observed clearly from three legs of these micro‐tripods, with a low threshold of ≈48.39 µJ cm−2 and a high quality factor of 1227.3. The realization of micro‐tripods‐based lasers may provide an innovative way for highly integrated photonic circuits and communications.

Occurrence and antimicrobial resistance patterns of bacterial and fungal pathogens from patients with urinary tract infections in Ojo, Lagos Nigeria

Urinary tract infections (UTIs) is a common bacterial and fungal infection affecting millions of people globally. The aim of this study was to investigate the distribution and antimicrobial susceptibility patterns of bacteria and fungi from patients with UTI. Urine samples were collected aseptically from patients with symptoms of UTI in sterile universal containers from five hospitals in a period of three months. A total of 200 urine samples from 75 males and 125 females were analyzed and subjected to culture, biochemical identification and antimicrobial susceptibility testing using the Kirby-Bauer technique. Fungal isolates were identified based on cultural characteristics, lactophenol cotton blue stain, chlamydospore formation, and colony colour on CHROM agar Candida medium. Most samples were positive for one microorganism each and a few had two isolates, thus giving a frequency of 210 microbial isolates. The most commonly isolated bacteria were Escherichia coli, 71(34%), followed by Staphylococcus aureus, 63(30%), Enterobacter spp., 32(15.2%), Klebsiella spp., 17(8.1%), Proteus mirabillis, 15(7.1%) and Candida albicans 12(5.7%), being the only fungus isolated. Antimicrobial susceptibility testing showed that Escherichia coli showed 57.7% susceptibility to streptomycin. Klebsiella spp. were 70.5% susceptible to septrin, but with susceptibility as low as 47.1% to chloramphenicol. Enterobacter spp. showed 71.9% susceptibility to septrin, 68.8% to gentamycin, 59.4% to streptomycin and chloramphenicol, 53.1%. Proteus spp showed 53.5%, and 66.7% to pefloxacin, septrin and streptomycin respectively. Staphylococcus aureus showed susceptibility of 56(88.9%), 55(87.3%), and 47 (74.6%) to gentamicin, ciprofloxacin. and pefloxacin respectively. Candida albicans was highly susceptible to nystatin, fluconazole and miconazole by 7(58.3%) but was highly resistant to ketoconazole, 41.7%. The findings of this study provide valuable information on the distribution of bacterial and fungal agents that are common etiology of UTIs, and likely antimicrobial drugs for the treatment of UTIs.

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.

JWST NIRCam Photometry: A Study of Globular Clusters Surrounding Bright Elliptical Galaxy VV 191a at z = 0.0513

James Webb Space Telescope NIRCam images have revealed 154 reliable globular cluster (GC) candidates around the z = 0.0513 elliptical galaxy VV 191a after subtracting 34 likely interlopers from background galaxies inside our search area. NIRCam broadband observations are made at 0.9–4.5 μm using the F090W, F150W, F356W, and F444W filters. Using point-spread-function-matched photometry, the data are analyzed to present color–magnitude diagrams and color distributions that suggest a relatively uniform population of GCs, except for small fractions of reddest (5%–8%) and bluest (2%–4%) outliers. GC models in the F090W versus (F090W–F150W) diagram fit the NIRCam data well and show that the majority of GCs detected have a mass of ∼106.5 M ⊙, with metallicities [Fe/H] spanning the typical range expected for GCs (−2.5 ≲ [Fe/H]≲ 0.5). However, the models predict ∼0.3–0.4 mag bluer (F356W–F444W) colors than the NIRCam data for a reasonable range of GC ages, metallicities, and reddening. Although our data do not quite reach the luminosity function turnover, the measured luminosity function is consistent with previous measurements, suggesting an estimated peak at m AB ∼ −9.4 ± 0.2 mag in the F090W filter.

Approach to the "Missing" Diarylsilylene: Formation, Characterization, and Intramolecular C-H Bond Activation of Blue Diarylsilylenes with Bulky Rind Groups.

The treatment of the bulky Rind-based dibromosilanes, (Rind)2SiBr2 (2) [Rind = 1,1,7,7-tetra-R1-3,3,5,5-tetra-R2-s-hydrindacen-4-yl: EMind (a: R1 = Et, R2 = Me) and Eind (b: R1 = R2 = Et)], with two equivalents of tBuLi in Et2O at low temperatures resulted in the formation of blue solutions derived from the diarylsilylenes, (Rind)2Si: (3). Upon warming the solutions above -20 °C, the blue color gradually faded, accompanying the decomposition of 3 and yielding cyclic hydrosilanes (4) via intramolecular C-H bond insertion at the Si(II) center. The molecular structures of the bulky Eind-based 3b and 4b were confirmed by X-ray crystallography. Thus, at -20 °C, blue crystals were formed (Crystal-A), which were identified as mixed crystals of 3b and 4b. Additionally, colorless crystals of 4b as a singular component were isolated (Crystal-B), whose structure was also determined by an X-ray diffraction analysis. Although the isolation of 3 was difficult due to their thermally labile nature, their structural characteristics and electronic properties were discussed based on the experimental findings complemented by computational results. We also examined the hydrolysis of 3b to afford the silanol, (Eind)2SiH(OH) (5b).

A new automatic sugarcane seed cutting machine based on internet of things technology and RGB color sensor.

Egypt is among the world's largest producers of sugarcane. This crop is of great economic importance in the country, as it serves as a primary source of sugar, a vital strategic material. The pre-cutting planting mode is the most used technique for cultivating sugarcane in Egypt. However, this method is plagued by several issues that adversely affect the quality of the crop. A proposed solution to these problems is the implementation of a sugarcane-seed-cutting device, which incorporates automatic identification technology for optimal efficiency. The aim is to enhance the cutting quality and efficiency of the pre-cutting planting mode of sugarcane. The developed machine consists of a feeding system, a node scanning and detection system, a node cutting system, a sugarcane seed counting and monitoring system, and a control system. The current research aims to study the pulse widths (PW) of three-color channels (R, G, and B) of the RGB color sensors under laboratory conditions. The output PW of red, green, and blue channel values were recorded at three color types for hand-colored nodes [black, red, and blue], three speeds of the feeding system [7.5 m/min, 5 m/min, and 4.3 m/min], three installing heights of the RGB color sensors [2.0 cm, 3.0 cm, and 4.0 cm], and three widths of the colored line [10.0 mm, 7.0 mm, and 3.0 mm]. The laboratory test results s to identify hand-colored sugarcane nodes showed that the recognition rate ranged from 95% to 100% and the average scanning time ranged from 1.0 s to 1.75 s. The capacity of the developed machine ranged up to 1200 seeds per hour. The highest performance of the developed machine was 100% when using hand-colored sugarcane stalks with a 10 mm blue color line and installing the RGB color sensor at 2.0 cm in height, as well as increasing the speed of the feeding system to 7.5 m/min. The use of IoT and RGB color sensors has made it possible to get analytical indicators like those achieved with other automatic systems for cutting sugar cane seeds without requiring the use of computers or expensive, fast industrial cameras for image processing.

Ternary anthocyanin-iron ion-pectin interactions: Structure-dependent formation and spectral properties as potential Tools for more stable blue colorants

Anthocyanins, while known for their color and suggested health benefits, face limited use as natural food colorants due to poor stability. The focus of the presented work is to study ternary pectin-metal ion-anthocyanin interactions (PIrA) as a function of anthocyanin structure and the impact of such interaction on the spectral properties, as a potential avenue for utilization as colorants. Apple pectin, an anionic polysaccharide, was enriched with iron ions to form molecular anchoring sites for anthocyanins. The complexation of selected anthocyanins, differing in the number of hydroxyls and size of the conjugated sugar, with the iron-enriched pectin was studied in single and multi-component models in comparison to systems without iron enrichment or enriched simultaneously with iron and anthocyanins. Anthocyanins with three hydroxyl groups on their B-ring, as delphinidin-3-glucoside (D3G) and delphinidin-3-rutinoside (D3R), resulted in higher wavelength of the maximal absorbance (λmax) upon PIrA complexation compared to anthocyanins with two hydroxyl groups on their B-ring, as cyanidin-3-glucoside (C3G) and cyanidin-3-rutinoside (C3R) (578, 574, 560, 566 for D3R, D3G, C3R and C3G, respectively). The anthocyanins affinity to the iron-enriched pectin was also structure dependent. Dissociation constants (Kd) presented significantly higher values for cyanidins than delphinidins (0.9, 0.5, 27.0, and 10.8 μM for D3R, D3G, C3R, and C3G, respectively). Finally, PIrA complexation improved anthocyanin stability. Empiric color degradation rates (K [1/day]) for PIrA complexes were also structure dependent (−2.5 ± 0.1*10−2, −4.7 ± 0.4*10−2, −4.8 ± 0.5*10−2 for D3G, D3R, and blackcurrant extract, respectively). PIrA complexation was found to be structure-dependent and to improve blue color stability.