Maximum Color Research Articles

Comparative Evaluation of Surface Roughness and Colour Stability of Four Different Composite Resins after Application of Desensitising Agents: An In-vitro Study

Introduction: Dentinal Hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. Desensitising agents are regularly used by patients experiencing hypersensitivity, which can affect the physical properties of the existing restorative material. Aim: To evaluate the surface roughness and colour stability of four different types of composite resin restorations after exposure to a desensitising agent. Materials and Methods: The in-vitro study was conducted in the Department of Conservative Dentistry and Endodontics at Ranjeet Deshmukh Dental College and Research Centre, Nagpur, Maharashtra, India from January 2024 to March 2024. Total 56 standardised composite resin discs of size 8×2 mm thickness were prepared using four different types of composites: microhybrid, nanofilled, nanohybrid, and flowable. They were further divided into control and experimental groups based on the application of a desensitising agent, with seven samples in each subgroup. The desensitising agent was applied twice a day for three minutes for one month. Surface roughness was evaluated using a surface profilometer, and colour stability was assessed using a spectrophotometer with the Commision on Ilumination (CIE) L*a*b* formula. The data were analysed using Student’s t-test for pair-wise comparison and One-way Analysis of Variance (ANOVA), with Tukey post-hoc tests for intergroup comparison. Results: The application of a desensitising agent on the samples resulted in a significantly greater effect on the surface roughness of the experimental subgroup than their control counterparts (p≤0.05). Among all groups, the nanofilled group exhibited the lowest surface roughness (0.418±0.047), and the colour change (1.87±0.00) was clinically acceptable. However, the flowable group had the maximum colour change amongst all the other groups (3.16±0.00). Conclusion: Within the limitations of the study, nanofilled composite resin restorative material has minimal surface roughness and colour change after exposure to the desensitising agent. It can be considered the material of choice for restoration in patients with DH.

TREATMENT OF LEACHATE FROM ERBIL LANDFILL SITE BY ELECTRO- AND CHEM-ICAL COAGULATION METHODS

Landfill leachate is commonly heavily contaminated wastewater. and consists of a high number of organic compounds, inorganic salts, toxic gases and heavy metals that exert a serious threat to the environment and public health. Thus, it requires treatments before direct release into receiving waters. This paper presents the results of electrocoagulation (EC) and chemical coagulation (CC) treatment of leachate from the Erbil landfill site. The removal efficiency of chemical oxygen demand (COD), phosphate (PO43-), total suspended solids (TSS), total organic compound (TOC), and color of leachate was studied using iron and aluminum electrodes. The removal percentages were also compared to those produced by electrochemically generated Fe2+ and Al3+ dosages. The effect of different pH values on the removal efficiency of these parameters was evaluated at optimal conditions. The removal percentages for chemically added coagulants were lower than those for electrochemically generated Fe2+ and Al3+. In EC, the highest COD removal efficiency of 92% and 87% was achieved at the original concentration (C1) for iron and aluminum electrodes, respectively. The iron and aluminum electrodes also showed a maximum color removal of 90% and 95%, respectively, for the original undiluted leachate solution. Both Fe and Al electrocoagulation methods were not effective in removing TOC from the leachate of municipal solid waste. The highest removal efficiency of 78% was achieved at a 1:4 diluted solution (C2) using the Al-electrocoagulation method. The maximum removal percentage for PO43- was 94% at C1 using the Fe-electrocoagulation system. However, both systems were not very effective in removing TSS.

Mannitol improves Monascus pigment biosynthesis with rice bran as a substrate in Monascus purpureus.

To reduce the production cost of Monascus pigments (MPs), the utilization of rice bran (RB), an agricultural waste product, as a substrate in submerged fermentation was conducted in this study. To improve MP production, different nutritional ingredients including mannitol (Man), NH4NO3 (AN), ZnSO4 (Zn), and optimization (Opti), which was a synthesis of the three above ones, were added in rice bran (RB) medium. The yields of MPs, pigment constituents, and growth and development of Monascus purpureus M9 were investigated in this study. Man had the maximum color value of 3,532 U/g, which was 18.69 times more than that of RB and reached up to 76.65% of the value of rice (Rice) fermentation. Man significantly increased the production of two orange pigments, monascorubrin and rubropunctatin, of which the yields were 69.49 and 95.36% of the counterpart of Rice. The biomass and colony diameter of Opti presented the maximum value among different groups. AN and RB induced more asexual spore formation, whereas Opti and Man promoted sexual spore production. Comparative transcriptomic analysis showed that different nutritional ingredients led to changes in pigment production, promoting the growth and development of M. purpureus M9 through the regulation of related gene expression. Man and Opti improved MP production by regulating the primary metabolism, including the Embden-Meyerhof pathway (EMP), the pentose phosphate (PP) pathway, the tricarboxylic (TCA) cycle, fatty acid degradation (FAD), fatty acid biosynthesis (FAB), amino acid metabolism (AAM), and fructose and mannose metabolism (FMM), to provide the precursors (acetyl-CoA and malonyl-CoA) for MP biosynthesis. This study presents a low-cost method for increasing MP production and explains the molecular mechanisms of different nutritional ingredients for enhancing MP biosynthesis.

Electrochemical degradation of reactive industrial textile dye using graphite as potential catalytic electrode

In recent years, the indirect electrochemical degradation of industrial effluents has gained popularity. This study examines the electrochemical aqueous solution degradation of reactive azo dyes employing graphite carbon electrodes as a possible catalyst. The findings suggested that the degradation of dyes was significantly influenced by the starting pH and the supporting electrolytes. Studies on chemical oxygen demand (COD) and UV-Vis were used to assess the effectiveness of the degrading process. Reactive dye may be used to obtain maximum colour removal efficiencies of 99% and chemical oxygen demand (COD) removal efficiencies of 88%. The LC-MS investigation indicated the breakdown of reactive dye and verified that the azo groups and aromatic rings were eliminated.

Optimization of clothing style and color design mode and innovation of technique under symbiosis mode

Abstract In this paper, we combine the thesaurus matching through the clothing style feature mining method, get the conditional probability index through great likelihood estimation, use iterative scale training parameters, and calculate the similarity mean of the belonging feature values. To identify and classify clothing styles, texture features are extracted from clothing styles, and the optimal training sample set of popular clothing colors is selected. The highest data mining algorithm in symbiotic mode has an accuracy rate of 96.4% for short-skirt clothing styles, a statistical result of 82.61 for tie-dye clothing techniques, and a maximum color threshold of 0.14. Symbiotic mode achieves a visual effect of distinctive features, which leads to optimal clothing styles and color innovations.

A biological cleaning agent for removing mold stains from paper artifacts

Efficient removal of mold stains becomes an important research topic for paper conservation. In this study, a cleaning scheme based on the combination of bioenzymes and biosurfactants was explored. Morphological and molecular biology identifications were first jointly applied to identify the dominant strains sampled from five ancient books that are stored in the same environment. Cellulolytic experiments were then conducted to evaluate the cellulose degradation ability of the strains according to the cellulolytic digestive index. Finally, paper Mockups for the ancient books were constructed to investigate the most effective combination of bioenzymes and biosurfactants in removing mold stains as well as its effect on the paper’s physical properties. The result concluded that the combination of 3% papain, 7% of sophorolipid or 7% of betaine, and distilled water, achieved optimal stain removal effect with over 50% cleaning rate at 35 °C, after 30 min of infiltration. The maximum color difference of the paper material after cleaning was around 0.60, pH was between 7.45 and 7.79, and no significant changes in tensile strength were observed. At the same time, Sophorolipid and Betaine both have superior deacidification, anti-acidification, anti-aging, and reinforcement capabilities, which can provide extra support to the fibrous structure in addition to cleaning the paper materials. The microbial contamination cleaning agent proposed in this study shows promising application prospects in conserving mold-contaminated paper artifacts.

Abstract 17285: Impact of Baseline Yellow Plaque Assessed by Coronary Angioscopy on 11-month Vascular Response After Stent Implantation

Background: In-stent yellow plaque (YP) evaluated by coronary angioscopy (CAS) 1 year after stent implantation is associated with the future adverse cardiac event. However, the impact of baseline YP on vascular response has not been fully investigated. Methods: This was a sub-analysis of the Collaboraiton-1 study (multicenter, retrospective, observational study). A total of 88 lesions from 80 patients with chronic coronary syndrome who underwent percutaneous coronary intervention with polymer-free biolimus A9-coated stent or durable-polymer everolimus-eluting stent implantation were analyzed. Optical coherence tomography (OCT) and CAS were serially performed immediately and 11 months after stent implantation. YP was defined as the stented segment with yellow or intensive yellow color assessed by CAS. Neoatherosclerosis was defined as a lipid or calcified neointima assessed by OCT. Neointimal coverage (NIC) over the stent was classified into 4 grades by CAS: grade 0, stent struts fully visible; grade 1, stent struts bulging into the lumen, although covered; grade 2, stent struts embedded in the neointima, but translucently visible; and grade 3, stent struts fully embedded and invisible. OCT and CAS findings at 11 months were compared between the lesions with baseline YP (YP group) and those without YP (Non-YP group). Results: Baseline YP was detected in 37 lesions (42%). OCT findings at 11 months showed that the incidence of neoatherosclerosis was significantly higher in YP than Non-YP groups (11% versus 0%, P=0.028) and mean neointimal thickness tended to be lower (104±43 μm versus 120±48 μm, P=0.098). CAS finding at 11 months demonstrated that dominant and minimum NIC grades were significantly lower (Figure) and maximum yellow color grade was significantly higher in YP than Non-YP groups. Conclusions: Baseline YP affected the incidence of neoatherosclerosis as well as poor neointimal coverage at 11 months after stent implantation.

Electrocoagulation technique and statistical analysis for treatment of real effluent from the pulp and paper industry

The electrochemical treatment of Organic Pollutants is a promising technique for substances with biodegradability resistance. In this research, the black liquor effluent originating from the Rakta Paper and Paper Company's mill, which employs rice straw as a raw material for paper fiber production, was subjected to treatment using the electrocoagulation method utilizing monopolar aluminum electrodes. The experiments were carried out using a 2.5 L electrochemical cell equipped with monopolar aluminum electrodes connected in parallel. The study examined the impact of operating parameters such as initial pH, current density, number of plates and electrolyte concentration on percentage removal and power consumption. The results revealed a positive correlation between the percentage of color removal and the duration of electrolysis, current density, sodium chloride concentration, and the number of electrodes used. The maximum color removal was observed at initial solution pH 6.5, experimental time 120 min, current density 61.8 A m−2, initial NaCl solution concentration 2 g L−1 and six aluminum plates. The statistical and mathematical data based on experimental results were analyzed using the central composite design from response surface methodology (RSM). The quadratic model is deemed appropriate owing to its substantial coefficient of determination (R2 = 0.99) and statistically significant p-value (≤ 0.0002), suggesting the model's significance. The experimental results indicate that the utilization of electrocoagulation as a treatment method for paper mill effluents has demonstrated superior efficacy compared to the adsorption technique.

One-Step Microwave Synthesis of New Hybrid Phosphor (CSSC) for White Light-Emitting Diodes

The possibility of synthesizing a new hybrid phosphor CSSC (mixture of 0.5 CaSrSiO4:Eu2+: 0.29 Ca6Sr4Si6O21Cl2:Eu2+: 0.21 Ca10Si6O21Cl2:Eu2+) using a one-step microwave synthesis method is demonstrated. The concentrations of europium and calcium in the synthesized phosphors were optimized at 1 and 10 mol. %, respectively, to achieve maximum brightness and color rendering index. The optimal conditions for the synthesis of phosphors in a microwave furnace were determined as 750 °C for 10 min. The resulting phosphor exhibited a wide luminescence spectrum that covered the entire visible region, resulting in a high color rendering index and a warm white luminescence when used as a light source. It is shown that the sol–gel method for preparing the charge mixture for the new phosphor allows for a 35% higher luminescence brightness compared to the solid-phase method, due to a more uniform distribution of the activator.

Effect of Blanching Pre-Treatments on Sensory Quality of Dragon Fruit Peel Pickle

Present investigation entitled effect of blanching pre-treatments on quality of dragon fruit peel picklewas aimed to evaluate sensory quality of dragon fruit peel pickleduring storage. For preparation of dragon fruit peel pickle, an experiment was laid out with six blanching pre-treatments [without blanching (T1), water blanching (T2), 0.5% citric acid blanching (T3), 1.0% citric acid blanching (T4), 0.5% alum (potassium aluminium sulphate) blanching (T5) and 1.0% alum (potassium aluminium sulphate) blanching (T6)]. The prepared pickle was stored for a period of 6 month to analyse the sensory quality attributes at three month intervals. The results of the investigation revealed that dragon fruit peel pickle prepared from peel blanched in 1 per cent citric acid (T4) observed to have maximum colour, taste, flavour, texture and overall acceptabilityscore. Overall findings of investigation revealed that best sensory quality dragon fruit peel pickle can be prepared from peel when blanched in 1 per cent citric acid followed by curing in 8 per cent salt and addition of ingredients. The dragon fruit peel pickle can be successfully stored for a period of six months with minimum changes in sensoryquality.

A Stearns–Noechel colour prediction model reconstructed from gridded colour solid of nine primary colours and its application

AbstractA full gamut colour solid model consisting of three lightness planes, 18 colour mixing units and 360 grid points is constructed from nine primary coloured fibres: red (R), yellow (Y), green (G), cyan (C), blue (B), magenta (M), dark grey (O1), medium grey (O2) and light grey (O3). Subsequently, the 213 coloured yarns and fabrics containing different lightness, hue and saturation were prepared according to the mixing ratio parameters in the colour solid. The Stearns–Noechel colour prediction algorithm, which predicts reflectance using coloured fibre mixing ratios, was improved and applied according to the requirements of colour prediction; and the Stearns–Noechel proportion prediction algorithm, which predicts coloured fibre mixing ratios by reflectance, was refined and employed in accordance with the demands of proportion prediction. Then, the 12 additional coloured fabrics were fabricated and their corresponding measurement data were used on the algorithm for validating its forecasting capabilities. The final experimental results reveal that the maximum colour difference for colour prediction is 5.5, the minimum is 1.7, and the average is 3.7; the maximum colour difference for proportion prediction is 3.3, the minimum is 0.3, and the average is 1.6. Therefore, this approach is promising to improve the colour reproduction issues encountered in the processing of three‐channel computer numerical control (CNC) spinning.

Investigation of photochromic behavior of biodegradable MoO3/Sg-St nanocomposites

Now a days, the synthesis of α-MoO3 based photochromic materials are a subject of many investigations as they can modulate solar light transmittance automatically, according to wavelength, in response to UV irradiation and hence can adjust the indoor atmosphere to reduce the consumption of energy. In the present work, an attempt has been made to investigate the relation between coloring/bleaching rates of self-supporting, highly flexible α-MoO3/Sg-St (Sago-Starch) nanocomposites (NCs) fabricated via solution casting technique. The prepared samples were characterized using FESEM, XRD, FTIR, and UV–Vis–NIR spectroscopy. Nano-sheet morphology of the synthesized sample was ascertained using FESEM while XRD reveals the orthorhombic structure of MoO3 with an average crystallite size of 135 nm. The average thickness of nanosheets comes out to be 111.57 nm (using FESEM). FTIR spectroscopy depicts the strong interaction between α-MoO3 and Sg-St polymer confirming the successful incorporation of α-MoO3 in the Sg-St matrix. The value of Eg for virgin Sg-St comes out to be 4.56 ± 0.12 eV and decreases to 2.54 ± 0.07 eV for 10 wt% α-MoO3/Sg-St NC while the refractive index (n) increases from 1.53 for virgin Sg-St to 2.11 for 10 wt% α-MoO3/Sg-St NC at 450 nm wavelength. The value of tensile strength for virgin Sg-St is found to be 9.54 which increases to 17.07 after incorporation of 1 wt% of α-MoO3 suggesting the strong interfacial interaction of nanofiller with polymer matrix. The prepared NCs exhibited a fast response to UV exposure (<30 s) with high coloration efficiency; which makes them a highly acceptable material for photochromic smart windows. The maximum coloration efficiency ∼0.6071 and RDR (%) value of 75.29 corresponds to 1 wt% α-MoO3/Sg-St NC.

Color Tunable Composite Phosphor Ceramics Based on SrAlSiN3:Eu2+/Lu3Al5O12:Ce3+ for High-Power and High-Color-Rendering-Index White LEDs/LDs Lighting.

Lu3Al5O12:Ce3+ phosphor ceramics were fabricated by vacuum sintering. On this basis, a bi-layer composite phosphor was prepared by low-temperature sintering to cover the phosphor ceramics with a layer of SrAlSiN3:Eu2+-phosphor-in-glass (PiG). The optical, thermal, and colorimetric properties of LuAG:Ce3+ phosphor ceramics, SrAlSiN3:Eu2+ phosphors and SrAlSiN3:Eu2+-PiG were studied individually. Combining the bi-layer composite phosphors with the blue LED chip, it is found that the spectrum can be adjusted by varying the doping concentration of SrAlSiN3:Eu2+-PiG and the thickness of Lu3Al5O12:Ce3+ phosphor ceramics. The maximal color rendering index value of the white LED is 86, and the R9 is 61. Under the excitation of a laser diode, the maximum phosphor conversion efficacy of the bi-layer composite phosphors is 120 lm/W, the Ra is 83, and the correlated color temperature is 4534 K. These results show that the bi-layer composite phosphor ceramic is a candidate material to achieve high color rendering index for high brightness lighting.

Valorization of bio-colorants extracted from Hypercium scabrum L. plant for sustainable and ecological coloration of wool yarns

Recently, natural dyes are being explored all over the world as safer and highly sustainable bio-based alternatives to synthetic dyes. Agricultural wastes and plant by-products are the most commonly explored alternatives with dual benefits of waste reclamation and sustainable dye production with extra value-adds. Hypercium scabrum plant contains interesting bio-dye molecules with high flavonoids and tannin contents. The present study aims at exploring the potential of H. scabrum plant extract to color wool textiles with a focus on sustainable bio-dye production and fastness properties. The extracted bio-dye was quantitatively (for total phenolic (2.733 mg per CE/g) and total flavonoid (1.140 mg per GAE/g) content using the Folin–Ciocalteu method) and qualitatively (UV–Vis, FT-IR, and EDX) characterized. The effect of dyeing parameters like pH (2–8), temperature (60–90 °C), dry-weight content of plant material as a dye (25–150% o.w.f.), and dyeing time (15–120 min) on color strength (K/S) values were assessed. Color fastness assays showed good resistance to light, washing, and rubbing. The effect of artificial aging (Xenon arc lamp) on the color strength of dyed wool yarns under different exposure times (0–48 h) was explored. The highest color fading occurred in control dyed samples with a first-order rate constant of 131.57 h−1 and a half-life period of 5.26 x 10−3 h. Color difference (ΔE) values suggested that mordanted samples showed less fading compared to control dyed samples at equal times of Xenon exposure. Additionally, the dyed samples were washed in double distilled water, tap water, and 4 g/L NaCl solution to check their effects on the corresponding K/S values while 4 g/L NaCl solution mimics the real conditions of perspiration. Maximum color leaching occurred in 4 g/L NaCl washing with a first-order rate constant of 11.57 min−1. Cost analysis of the dye extraction and dyeing procedure revealed that the process is sustainable and economical. Thus, the use of H. scabrum whole plant can provide a clean, economical, and sustainable source of alternative natural dyes that can be used to substitute synthetic analogs.

Improvement of wet rub fastness in continuous dyeing with c.i. Sulphur Black 1 by ultrasonic treatment

C.I. Sulphur Black 1 is among the most important dyes for cellulose textiles, as this dye offers a maximum colour depth at reasonable costs. In its final form the dye is present as solid pigment, thus limited wet rub fastness can be an issue. Controlled re-oxidation of the leuco form into the oxidised dye pigment and intensive washing and soaping are measures to achieve acceptable wet rub fastness. In this study pad-steam dyeing with C.I. Sulphur Black 1 was used to investigate the effects of an intensified washing process with use of ultrasonification on rub fastness. Ultrasound was applied following to steam fixation of the dye. Introduction of ultrasound into the following process steps was investigated: water seal, warm rinse, oxidation, soaping, cold rinse. Best results in rub fastness were obtained by combination of soaping and ultrasound processing. The high shear rate near to the fibre surface led to a reduction of the thickness of the stagnant diffusion layer and more intense removal of loosely bound dispersed dye. As a result of the treatment an improvement in wet rub fastness of the dyeings was achieved. Duration of 60 – 120 s was found sufficient to remove the major part of surface bound pigments which allows an integration into continuous pad-steam dyeing processing. The results demonstrate that ultrasound washing may lead to improved rub fastness of other dyeings where a pigment is the final form of the dye. The method thus could be extended to vat dyes including indigo, or naphthol dyes.

Treatment of real textile wastewater by coagulation/flocculation integrated with direct contact membrane distillation

ABSTRACT This study investigated the water recovery of real textile wastewater by Coagulation/Flocculation (CF) integrated with Direct Contact Membrane Distillation (DCMD). The proof-of-concept tests were studied with synthetic solutions of reactive and disperse black dyes at different concentrations, and real textile wastewater from the discharge machine and the equalization tank. Results showed that CF-DCMD exhibited higher permeate fluxes (up to 40%) than single DCMD and maximum color rejection rates (100%). Moreover, CF-DCMD enabled water reclamation from cotton and polyester dyeing wastewater which was not possible by MD (Membrane Distillation). The integrated system showed excellent chemical oxygen demand removal capacity, total suspended solids, turbidity, conductivity reduction, and removed any signs of toxicity from the tested wastewater. The coagulation/flocculation process prior to the MD reduced the fouling factor for all wastewater, highlighting the equalization tank where a reduction of around 72% was observed, achieving the goal of reducing fouling and increasing the efficiency of the MD. Membrane characterization indicated that CF-DCMD confirmed less fouling of membranes than single DCMD. Thus, this study allows to understand the potential and robustness of the CF-DCMD process in the treatment of textile wastewater and that it is possible to develop alternative technologies to treat complex wastewater effectively.

An Enhancement in Single-Image Dehazing Employing Contrastive Attention over Variational Auto-Encoder (CA-VAE) Method

Hazy images and videos have low contrast and poor visibility. Fog, ice fog, steam fog, smoke, volcanic ash, dust, and snow are all terrible conditions for capturing images and worsening color and contrast. Computer vision applications often fail due to image degradation. Hazy images and videos with skewed color contrasts and low visibility affect photometric analysis, object identification, and target tracking. Computer programs can classify and comprehend images using image haze reduction algorithms. Image dehazing now uses deep learning approaches. The observed negative correlation between depth and the difference between the hazy image’s maximum and lowest color channels inspired the suggested study. Using a contrasting attention mechanism spanning sub-pixels and blocks, we offer a unique attention method to create high-quality, haze-free pictures. The L*a*b* color model has been proposed as an effective color space for dehazing images. A variational auto-encoder-based dehazing network may also be utilized for training since it compresses and attempts to reconstruct input images. Estimating hundreds of image-impacting characteristics may be necessary. In a variational auto-encoder, fuzzy input images are directly given a Gaussian probability distribution, and the variational auto-encoder estimates the distribution parameters. A quantitative and qualitative study of the RESIDE dataset will show the suggested method's accuracy and resilience. RESIDE’s subsets of synthetic and real-world single-image dehazing examples are utilized for training and assessment. Enhance the structural similarity index measure (SSIM) and peak signal-to-noise ratio metrics (PSNR).

Efficiency of chitosan nanoparticle with polyaluminum chloride in dye removal from aqueous solutions: Optimization through response surface methodology (RSM) and central composite design (CCD)

According to the widespread use of polyaluminum chloride (PAC) in wastewater treatment and residual aluminum left in treated water, there is an urgent need to use environmentally friendly natural coagulants with conventional chemical coagulants to reduce their consumption. In this investigation, chitosan (CS) nanoparticles prepared as natural coagulant by ion gelation were applied to remove anionic dyes from aqueous solutions. For the characterization of the synthesized CS nanoparticles, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and zeta analyzer were used. The effects of different parameters, including pH, initial concentration of dye in addition to CS nanoparticles, and PAC dosages on adsorption efficiency were studied via response surface methodology (RSM) to determine the optimum conditions for maximum color removal. Results of the tests indicate that the use of CS nanoparticles and PAC with an interval of 30 s effectively increases the efficiency of color removal. The usage of PAC (80 mg/L) and CS nanoparticles (150 mL/L) at pH = 6.6 reaches the maximum color removal efficiency of 92 %. Accordingly, the use of CS nanoparticles as coagulant aid reduced the amount of needed PAC and enhanced the color removal efficiency. Furthermore, the exclusive effect of CS nanoparticles in the adsorption of dye revealed that the adsorption followed the Langmuir type II model, with an adsorption capacity of 1100 mg/g. The resulting data from the kinetic study indicated that the pseudo-second-order type II model was the most suitable model to describe the adsorption process of dye on CS nanoparticles. Based on the results, the CS nanoparticles have adequate potential to reduce the amount of needed PAC dosage for the treatment of water contaminated with anionic dyes.

Deterministic rendering of structural color induced by atypical nano-gratings in ultra-precision diamond cutting

Ultra-precision diamond cutting (UPC) has been recently proposed for fast generation of nano-gratings to render diffractive structural color on various metallic surfaces. However, the complex nanoscale generation mechanism and atypical grating topography provide the significant challenges for deterministic rendering of structural color with standard representations. In this paper, an innovative diffraction prediction model is firstly proposed to describe the diffractive spectrum of atypical gratings under the full considerations of cutting process parameters, double working facets, material optical properties and environmental conditions. The standard CIE 1931 chromaticity diagram for grating-induced structural color is released for color gamut determination and optimization, where the color gamut range is defined by a novel concept of average saturation. The experimental results demonstrate the deterministic generation of three groups of nano-gratings with desired 3D topography, of which the measured angle-dependent diffractive spectrum and rendering color attributes show good agreements with theoretical results. Moreover, the new topography-modulation based strategies for achieving maximal color gamut and manipulating the ternary color attributes are clarified. The outcome of this paper lays the scientific foundations for deterministic rendering and performance enhancement of structural color enabled by UPC processes.

An eco-friendly ultrasound approach to extracting yellow dye from Cassia alata flower petals: Characterization, dyeing, and antibacterial properties

Using natural dyes in dyeing industries becomes an alternative to synthetic dyes, which are known to contain harmful chemicals that can pose risks to the environment and human health. This study involves the extraction of yellow dye from Cassia alata flower petals, optimization of the extraction process using an ultrasonic bath (40 KHz and an input power of 500), ultrasonic probe (390 W, 455 W, 520 W, 585 W, and 650 W), and conventional heating (heating mantle with 30 °C, 40 °C, 50 °C, 60 °C, and 70 °C), characterization of the dye, as well as dyeing (cotton, silk, and leather) without using a mordant. The extracted yellow dye was further evaluated to determine its antibacterial activity against skin bacteria. Dye extraction optimization using UV–Visible spectrophotometric analysis revealed that the maximum yellow color in methanol extract (287 and 479 nm) was obtained at 50 °C for 45 min using ultrasonic water bath extraction, followed by the ultrasonic probe and direct heating. Based on the FTIR spectra, it is evident that OH is present at approximately 3300 cm−1, while CH stretches at around 2900 cm−1. A characteristic peak at 1608 cm−1 bears a striking similarity to anthraquinonoid-based compounds. Also, using the ultrasonic water bath dyeing technique at 50 °C for 45 min, the yellow color of cotton, silk, and leather was dyed optimally. Due to effective color removal after two washings with boiling soap liquid, the dyed cotton and silk fabric displayed good washing and rubbing fastness. Regarding antibacterial activity, the dye was highly active against all pathogens after extraction in methanol. The maximum inhibition was observed against Pseudomonas sp. with a MIC value of 1.56 mg/ml.