Total Reflection Research Articles

Printing and dyeing of halloysite nano clay hybrid with natural chlorophyll dye on cotton fabric

This work deals with the synthesis of hybrids formed by the natural dye chlorophyll and halloysite for their subsequent application in the textile field. Once the pigments have been synthesised, with 98% adsorption, they are used for two textile colouring functions, namely printing and dyeing. In both cases, satisfactory and interesting results were obtained. The hybrids were characterised by FTIR, XRD, TGA, SEM-EDX, BET and all the appropriate colour measurements were carried out to obtain the coordinates in CIELAB space and also to know their total solar reflectance (TSR) 45.98%. In addition, statistical techniques were used with the use of ANOVA to evaluate the results obtained. The dyeing was carried out by exhaustion and its use was compared with the use of nibbled and non-nibbled fabrics. The textiles were tested for fastness and the results are presented in instrumentally obtained grey scale values, achieving in some cases values of 4-5. Thus, the chlorophyll adsorption capacity of halloysite and its stabilisation for subsequent application in printing and dyeing processes on textile substrates has been demonstrated. This process could be scalable at an industrial level.

Numerical investigation of various laser–waterjet coupling methods on spot power density distribution

This paper presents a numerical simulation study on the coupling of lasers and waterjets, focusing on the distribution of the spot power density. The analysis utilized a laser wavelength of 532 nm, chosen for its minimal energy attenuation in water. The key conditions for successful coupling were identified, including the necessity for the spot diameter of the laser beam to be smaller than the nozzle diameter of the waterjet fiber, the numerical aperture of the laser beam to be lower than that of the waterjet fiber, and the divergence angle of the laser to be smaller than the critical angle for total internal reflection. Using the ZEMAX simulation software, various coupling cases were explored, revealing that the radial displacement of the waterjet fiber relative to the laser axis has the most significant impact on the output power density, followed by angular deflection, whereas the axial displacement has the minimal effect. This study also investigates the combined effects of different influencing factors on the peak distribution of the output power density, uncovering distinct characteristics resulting from these deviations. Overall, the research findings provide theoretical insights for achieving effective coupling between fine waterjets and lasers as well as for the design of water-guided laser coupling devices.

Electromagnetic porous lignocellulosic matrix composites: A green electromagnetic shielding material with high absorption efficient electromagnetic interference

Electromagnetic interference (EMI) shielding materials play a vital role in human society, especially in light of the rapid development of electronic communication equipment. Therefore, it is urgent to develop green, high-efficiency EMI shielding materials. Wood, as a renewable raw material, possesses significant structural advantages in studying EMI materials due to its unique 3D pore structure. Herein, we report magnetoelectric lignocellulosic matrix composites derived from the delignified wood for efficient EMI shielding. The composite was fabricated by in-situ polymerization of PEDOT conductive coating and magnetic Fe3O4 in delignified wood. The conductive 3D pore structure of Fe3O4/PEDOT@wood could effectively cause dielectric loss and multiple internal reflections. Combined with the magnetic loss of Fe3O4, the material exhibited excellent EMI shielding effectiveness (SE), which could be attributed to the synergistic effect of dielectric and magnetic losses. The Fe3O4/PEDOT@wood showed excellent conductivity (103 S/m), good magnetism (26.7 emu/g), the EMI SE up to 59.8 dB, and high SEA/SET ratios of∼84.2 % to 95.7 % at 2 mm in X -band. Moreover, the material exhibited a high compressive strength and tensile strength of 100.8 MPa and 18.1 MPa, respectively. Therefore, this work provided a reference for the preparation of high-efficiency EMI shielding materials.

Phosphorus-Doped Silicon for Li-ion Battery Applications: Studied with Electrochemical Isothermal Microcalorimetry, ATR-FTIR and XPS

Silicon (Si) has garnered significant attention as a potential anode material for lithium-ion batteries due to its high theoretical specific capacity. However, there are considerable challenges to address before practical implementation, primarily stemming from issues such as very large volume changes upon Li insertion/extraction, poor electrical conductivity, and an unstable solid-electrolyte interphase (SEI). We report here investigations on P-doped Si (SiPx) using electrochemical isothermal micro-calorimetry (EIMC), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS) techniques. The EIMC measurements on SiPx revealed decreased parasitic reaction heat flows during the lithiation/de-lithiation cycles. The first cycle cell voltage profiles show decreased electrochemical reactivity for the SiPx. Analyses using ATR-FTIR and XPS on cycled electrodes suggest that the parasitic reaction products originate from solvent and electrolyte salt decomposition, with significantly lower amounts observed on the SiPx. Collectively, these findings endorse P-doping of Si as a promising strategy for Li-ion battery applications and demonstrate the unique advantages of performing EIMC measurements by focusing on the intrinsic losses from parasitic reactions, regardless of the electrode and cell configurations being optimized. In contrast, fully optimized configurations are necessary when using coulombic efficiency as the metric for cycle stability of the battery chemistry.

Insight into in situ enzymatic transesterification modification of polyethylene terephthalate fibers with polyethylene glycol

Polyethylene terephthalate (PET) fabric was enzymatically modified with polyethylene glycol (PEG). Lipase from Aspergillus oryzae was used as a catalyst. The wetting behavior of the modified PET fabric was characterized by the water contact angle, water adsorption dynamics and moisture regain. The initial water contact angle of the modified fabric decreased from 129.3° to 74.9°. The water absorption dynamics results indicated that the equilibrium water absorption amount of the modified fabric was approximately 10 times greater than that of the untreated sample. The initial absorption rate (Vinit) of the modified fabric was almost 30 times higher than that of the untreated fabric. The moisture regain reached 3.52% after modification. Scanning electron microscopy revealed granular and sheet coatings on the surface of the modified fabric. Chemical linkage of PEG onto the PET fibers was confirmed by attenuated total reflection–Fourier transform infrared spectroscopy. The modification had no significant effect on the thermal properties of the PET fabrics according to the thermogravimetric curve and differential scanning calorimetry results. The mechanical properties of the modified fabric were slightly improved. Therefore, in situ enzymatic transesterification between PET and PEG could be a potential novel modification approach for adding value to PET fiber textiles.

Electrodeposition of myristate based superhydrophobic coatings on steel with enhanced corrosion resistance and self-cleaning property

In recent decades, superhydrophobic (SHP) coatings have gained significant attention because of their versatile applications. Superhydrophobic coating is considered as a promising solution to combat corrosion and biofouling issues encountered by steel components in various industries. Using a one-step electrodeposition technique, a superhydrophobic coating with strong corrosion resistance and anti-biofouling property was fabricated on carbon steel in this work. With a water contact angle (WCA) of 170.3 ± 4.2° and a sliding angle (SA) of ∼1°, the wettability of the surface was optimized by varying the electrodeposition potential and deposition time. The as-developed superhydrophobic carbon steel surfaces were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), laser Raman spectroscopy (LRS), Energy dispersive X-ray (EDS) spectroscopy and X-ray diffraction (XRD). Employing field emission scanning electron microscopy (FESEM), the morphology of the superhydrophobic coatings was examined. Potentiodynamic polarization (PDP) technique was used to study the anti-corrosion property of SHP coating and bare sample in 3.5 wt% NaCl solution. The superhydrophobic coating was found to exhibit 99 % corrosion inhibition efficiency. In addition, the biofouling resistance of the coating was evaluated in both gram-negative and gram-positive bacterial cultures and compared with the uncoated sample. Total viability count (TVC) for the SHP coated samples was 5 orders less as compared to the uncoated sample exposed to gram-negative bacterial culture. Similarly, 4 orders reduction in TVC was estimated for the SHP coated sample as compared to the uncoated sample in gram-positive bacterial culture. The impact of superhydrophobic coating on the corrosion performance and biofouling properties of carbon steel was investigated along with the self-cleaning property and robustness of the coating.

Design of colon-targeted drug delivery of dexamethasone: Formulation and in vitro characterization of solid dispersions

Colon-targeted drug delivery continues to generate increasing attention for its prospects in treating inflammatory bowel disease (IBD). This study aimed to develop and evaluate colon-targeted solid dispersions of dexamethasone (DEX-SDs) in vitro to reduce its systemic exposure. This would ultimately improve the therapeutic efficacy of DEX while minimizing its adverse effects. Different DEX-SDs formulations were prepared utilizing Eudragit S100 (EU S100) and a combination of hydroxypropyl methyl cellulose (HPMC) and EU S100 to tune its drug release profile suitable for colonic delivery. The fabricated formulations were extensively characterized via Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and polarized light microscopy (PLM). The different characterization techniques strongly suggest preparing solid solution-type solid dispersions of DEX with the other polymers (DEX-SDs). In addition, the in vitro dissolution of DEX-SDs was evaluated using two dissolution media (pH 1.2 and 7.4). The in vitro release of DEX-SDs was low in the acidic media and higher and sustained in the basic medium, leading to the conclusion that the developed DEX-SDs may represent an effective technology can overcome challenges related to poor drug solubility and bioavailability.

Evidence of microplastic contamination in the food chain: an assessment of their presence in the gastrointestinal tract of native fish

This research study focused on the primary freshwater surface sources of Khyber Pakhtunkhwa (KP) province, Pakistan—Swat and Kabul rivers. The study aimed to assess microplastic (MP) contamination of fish in the Swat and Kabul rivers. Understanding this contamination is vital for evaluating the environmental and health risks associated with consuming contaminated fish and contributing to the ongoing conservation efforts. The study’s objective was to investigate the presence of MPs in the gastrointestinal tracts (GIT) of fish and to delineate the identified MP types. Samples of local dominant fish (Schizothorax plagiostomus [Swatay] and Racoma labiata [Chunr], Cyprinus carpio [Common Carp], and Clupisoma naziri [Sher Mayai]) were collected, and their body weight and length assessed to gauge the overall health. The GIT samples were processed, digested and filtered before microscopic examination to detect MPs. Subsequently, the identified MPs were subjected to attenuated total reflectance–Fourier transform infrared spectroscopy for characterization by analyzing their absorption bands. Results of the study showed the presence of MPs in fish samples, predominantly identified as polyethylene (PE), with polypropylene (PP) being the subsequently prevalent plastic type, which manifested fish contamination with MPs. The study revealed MP pollution in both Swat and Kabul rivers, with fish ingesting these particles. This poses potential health risks for fish and health of the ecosystem.

Role of UV radiation and oxidation on polyethylene micro- and nanoplastics: impacts on cadmium sorption, bioaccumulation, and toxicity in fish intestinal cells

This study investigated the role of ultraviolet (UV) radiation and oxidation in high-density polyethylene microplastics (2–15 μm) and nanoplastics (0.2–9.9 μm) (NMPs) on particle chemistry, morphology, and reactivity with cadmium (Cd). Additionally, toxicity of NMPs alone and with Cd was evaluated using RTgutGC cells, a model of the rainbow trout (Oncorhynchus mykiss) intestine. The role on NMPs on Cd bioaccumulation in RTgutGC cells was also evaluated. Dynamic light scattering indicated that after UV radiation NPs agglomerated size increased from 0.8 to 28 µm, and to 8 µm when Cd was added. Oxidized MPs agglomerated size increased from 11 and 7 to 46 and 27 µm in non-UV- and UV-aged oxidized MPs when adding Cd, respectively. Cd-coated particles exhibited generally significantly higher zeta potential than non-Cd-coated particles, while attenuated total reflectance–Fourier transform infrared spectroscopy showed that the functional chemistry of the particles was oxidized and modified after being exposed to UV radiation. Presence of NMPs resulted in a significant decrease in Cd bioaccumulation in RTgutGC cells (100.5–87.9 ng Cd/mg protein) compared to Cd alone (138.1 ng Cd/mg protein), although this was not quite significant for co-exposures with UV-aged NPs (105.7 ng Cd/mg protein). No toxicity was observed in RTgutGC cells exposed to NMPs alone for 24 h. Moreover, co-exposures with Cd indicated that NMPs reduce the toxicity of Cd. Altogether these results show that UV aging enhances NMP surface reactivity, increasing Cd absorption in solution, which resulted in a reduction in Cd bioavailability and toxicity.

Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO2 nanocomposites and tuning the dielectric relaxation, optical, and photoluminescence performances

Nanocomposite films consisting of carboxymethyl cellulose, polyethylene oxide (CMC/PEO), and anatase titanium dioxide (TO) were produced by the use of sol-gel and solution casting techniques. TiO2 nanocrystals were effectively incorporated into CMC/PEO polymers, as shown by X-ray diffraction (XRD) and attenuated total reflectance fourier transform infrared (ATR-FTIR) analysis. The roughness growth is at high levels of TO nanocrystals (TO NCs), which means increasing active sites and defects in CMC/PEO. In differential scanning calorimetry (DSC) thermograms, the change in glass transition temperature (T g) values verifies that the polymer blend interacts with TO NCs. The increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites, as observed. The electrical properties of the CMC/PEO/TO nanocomposite undergo significant changes. The nanocomposite films exhibit a red alteration in the absorption edge as the concentration of TO NCs increases in the polymer blend. The decline in the energy gap is readily apparent as the weight percentage of TO NCs increases. The photoluminescence (PL) emission spectra indicate that the sites of the luminescence peak maximums show slight variation; peaks get wider, while their intensities decrease dramatically as the concentration of TO increases. These nanocomposite materials show potential for multifunctional applications including optoelectronics, antireflection coatings, photocatalysis, light emitting diodes, and solid polymer electrolytes.

Goos–Hänchen shifts on spin representation

We analyze the Goos–Hänchen (GH) shift and longitudinal spin splitting (LSS) at a planar interface between two optical media in the spin representation. While these optical effects have been studied previously, we examine the direct and cross-reflected light fields, and their interference from the spin representation to reveal the physical mechanism of the GH shift and establish a quantitative relationship between it and LSS. Furthermore, we show that angular asymmetric spin splitting occurs under the spin representation when linearly polarized light with a phase difference of 180° and an amplitude ratio angle deviating from 45° impinges on the air–glass interface at Brewster’s angle. Finally, we reveal that the spin component field of the reflected light field for the total reflection case is different from that of the Brewster angle reflection, the most typical manifestation is that the intensity of the two spin component fields is not equal.

Surface crystallized supramolecular to achieve highly dispersed ultrafine nano-palladium in-situ deposition to promote thermal/electrocatalytic reduction

To promote the greening and economization of industrial production, the development of advanced catalyst manufacturing technology with high activity and low cost is an indispensable part. In this study, nitrogen-doped hollow carbon spheres (NHCSs) were used as anchors to construct a supramolecular coating formed by the self-assembly of boron clusters and β-cyclodextrin by surface crystallization strategy, with the help of the weak reducing agent characteristics of boron clusters, highly dispersed ultra-small nano-palladium particles were in-situ embedded on the surface of NHCSs. The deoxygenation hydrogenation of nitroaromatics and the reduction of nitrate to ammonia were used as the representatives of thermal catalytic reduction and electrocatalytic reduction respectively. The excellent properties of the constructed Pd/NHCSs were proved by the probe reaction. In the catalytic hydrogenation of nitroaromatics to aminoaromatics, the reaction kinetic rate and activation energy are at the leading level. At the same time, the constructed Pd/NHCSs can also electrocatalytically reduce nitrate to high value-added ammonia with high activity and selectivity, and the behavior of Pd/NHCSs high selectivity driving nitrate conversion was revealed by density functional theory and in situ attenuated total reflection Fourier transform infrared (ATRFTIR) technique. These results all reflect the feasibility and superiority of in-situ anchoring ultra-small nano-metals as catalysts by surface crystallization to build a supramolecular cladding with reducing properties, which is an effective way to construct high-activity and low-cost advanced catalysts.

Mattel's ©Barbie: Preventing Plasticizers Leakage in PVC Artworks and Design Objects through Film-Forming Solutions.

The main conservation problem of p-PVC artworks is phthalate-based plasticizer migration. Phthalate migration from the bulk to the surface of the materials leads to the formation of a glossy and oily film on the outer layers, ultimately reducing the flexibility of the material. This study aimed to develop a removable coating for the preservation of contemporary artworks and design objects made of plasticized polyvinyl chloride (p-PVC). Several coatings incorporating chitosan, collagen, and cellulose ethers were assessed as potential barriers to inhibiting plasticizer migration. Analytical techniques including optical microscopy (OM), ultraviolet/visible/near-infrared spectroscopy (UV/Vis/NIR), Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), and scanning electron microscopy (SEM) were utilized to evaluate the optical and chemical stability of selected coating formulations applied to laboratory p-PVC sheet specimens. Subsequently, formulations were tested on a real tangible example of a design object, ©Barbie doll, characterized by the prevalent issue of plasticizer migration. Furthermore, the results obtained with the tested formulations were evaluated by a group of conservators using a tailored survey. Finally, a suitable coating formulation capable of safeguarding plastic substrates was suggested.

Triple notched MIMO antenna for S and C band applications

ABSTRACT A hexagon-shaped fractal multiple-input multiple-output (MIMO) antenna for WLAN, WiMax, and C band applications is proposed. The antenna consists of two hexagon-shaped self-similar fractal structures placed at a 6 mm gap with a reduced ground plane along with a ground stub at the centre. The proposed design covers the 2.37–7.82 GHz band with band rejections at 2.54–2.87 GHz, 3.56–3.83 GHz and 6.26–7.13 GHz. The notches are introduced to avoid interference between different application bands. The parametrically optimised reduced height of the ground plane and the strategical placement of a stub at the centre of this ground plane provide notch bands and reduce the mutual coupling below −17 dB throughout the operating bands. The proposed antenna gain varies between 2–3 dBi in the operating bands. The diversity parameters like envelope correlation coefficient (ECC) and diversity gain, channel capacity loss (CCL) and Total Active Reflection Coefficient (TARC) are calculated and found to be well below the acceptable range. A prototype of the proposed design is fabricated and measured. The measurement results are in good agreement with their simulated counterparts.

Performance of Chitosan/Carbon Nanotube-Coated Ultrafiltration Membranes for Natural Organic Matter Removal from Drinking Water

The objective of this study is to improve the filtration efficiency of commercially available polyethersulfone (PES) ultrafiltration (UF) membranes, with a specific focus on removing natural organic matter (NOM) and preventing membrane fouling. The modification of UF membranes was accomplished by utilizing chitosan/multi-walled carbon nanotubes (CS/MWCNT-OH) and employing both dip and spin coating techniques. The membrane surface morphologies were evaluated using the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and Energy-Dispersive X-ray Spectroscopy (EDX) techniques. Tests were carried out to assess the effectiveness of the membranes in a laboratory-scale system using two primary water sources from Istanbul, specifically the Melen River and Terkos Lake. Total organic carbon (TOC), UV254 absorbance, turbidity, and trihalomethane formation potential (THMFP) were all measured as part of a thorough analysis. The surface morphology investigations verified the effective deposition of MWCNT-OH nanoparticles onto the membrane surface. This was corroborated by the reduction in the water contact angle, showing an improvement in the hydrophilicity of the membrane. The modified membranes demonstrated much higher TOC removal rates compared to the original membranes. Specifically, the removal efficiencies for Melen River and Terkos Lake were 37.14% and 56.86%, respectively. Nevertheless, the alteration of the surface led to a decline in membrane flux as a result of the concurrent drop in pore size. To summarize, the results of this work highlights the considerable capability of surface modification using CS/MWCNT-OH to improve the performance and antifouling characteristics of commercial PES UF membranes.

Sulfur-Bridged Asymmetric CuNi Bimetallic Atom Sites for CO2 Reduction with High Efficiency.

Double-atom catalysts (DACs) with asymmetric coordination are crucial for enhancing the benefits of electrochemical carbon dioxide reduction and advancing sustainable development, however, the rational design of DACs is still challenging. Herein, we synthesize atomically dispersed catalysts with novel sulfur-bridged Cu-S-Ni sites (named Cu-S-Ni/SNC), utilizing biomass wool keratin as precursor. The plentiful disulfide bonds in wool keratin overcome the limitations of traditional gas-phase S ligand etching process and enable the one-step formation of S-bridged sites. X-ray absorption spectroscopy (XAS) confirms the existence of bimetallic sites with N2Cu-S-NiN2 moiety. In H-cell, Cu-S-Ni/SNC shows high CO Faraday efficiency of 98.1% at -0.65V versus RHE. Benefiting from the charge tuning effect between the metal site and bridged sulfur atoms, a large current density of 550mAcm-2 can be achieved at -1.00V in flow cell. Additionally, in situ XAS, attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), and density functional theory (DFT) calculations show Cu as the main adsorption site is dual-regulated by Ni and S atoms, which enhances CO2 activation and accelerates the formation of *COOH intermediates. This kind of asymmetric bimetallic atom catalysts may open new pathways for precision preparation and performance regulation of atomic materials toward energy applications. This article is protected by copyright. All rights reserved.

Biogenic Calcium Carbonate: Phase Conversion in Aqueous Suspensions

Powdered biogenic calcium carbonate from butter clams shows variations in its tendency to convert from aragonite to calcite when suspended in water, depending on whether the suspension has additional calcite or not. Our investigations treat these biogenic samples as complex hierarchical materials, considering both their mineral and organic components. We assess the mineral composition from Attenuated Total Reflection Fourier Transform Infrared spectroscopy peak shifts, as well as quantitative assessments of lattice constant refinements (powder X-ray diffraction). To isolate the mineral portions, we compare results from samples where the periostracum is removed mechanically and samples that are heated to temperatures that are sufficient to remove organic material but well below the temperature for thermal phase conversion from aragonite to calcite. The results show that the total organic content does not play a significant role in the aqueous mineral phase conversion. These results have potential implications for understanding carbonate mineral interactions in ocean sediments.

Eco friendly functional finishes of polyester fabric using keratin from wool and feather wastes

This research showcases the use of hydrothermally extracted solutions from poultry feathers and wool as eco-friendly and versatile textile finishes. These solutions, derived from waste biomass containing the keratin biopolymer, were obtained through environmentally conscious hydrothermal degradation processes. Initially, the study focused on analysing the chemical parameters and properties of both dialysed and non-dialysed solutions extracted from feathers and wool. The investigation tracked primarily the presence of keratin within these solutions. Upon application to polyester textiles as the reference material, the presence of these solutions on the fabric surface was confirmed successfully. A thorough physicochemical analysis of the treated textiles involved various analytical techniques. These encompassed surface composition analysis via X-ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), assessment of wettability through Contact Angle measurements, determination of surface charge using surface zeta potential, and examination of the thermal and flame-retardant properties via Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and calorimetric tests. In addition, the colour, UV radiation transmission and antioxidant activity were evaluated using standard tests.The remarkable effects of the treatment have been observed in the exceptional antioxidative action, fire resistance, UV protection and enhanced hydrophilicity of these innovative multifunctional textiles. This approach holds significant implications across research, economics and society, enriching Material Science by deepening the understanding of materials and their multifaceted properties. Moreover, it promotes resource efficiency, opens new sustainable textile market prospects, and contributes to social impact by supporting environmental sustainability, engaging communities and ensuring health and safety benefits.

Near-infrared reflective coatings based on red-brown Ce1-xPrxO2 pigments

Red-brown Ce1-xPrxO2 pigments have high reflectance values over the entire NIR range, which recommend their use as NIR-reflective (cool) pigments. Ce0.99Pr0.01O2 pigment had the highest proportion of red and the lowest proportion of yellow (CIEL*/a*/b* = 60.1/19.7/13.1), corroborated with a total solar reflectance of 54.1 %. The pigments based on Ce1-xPrxO2 showed excellent behavior both in coloring an aqueous acrylic paint applied onto a metal substrate and a transparent glaze applied on a ceramic tile. The tile glazed with the Ce0.99Pr0.01O2 pigment had a significantly higher total solar reflectance (TSR = 45.0 %) than a commercial reference ceramic tile (TSR = 24.2 %), whilst the color of the two was comparable. In the case of metal substrates, the maximum temperature measured on the surface of the acrylic coating based on Ce1-xPrxO2 (54.0 °C) having a total solar reflectance of 51.4 %, was almost 10 °C lower than the temperature measured on the surface of the reference coating (63.7 °C), having a total solar reflectance of 35.7 %. These results demonstrate the extraordinary potential of Ce1-xPrxO2-based pigments to prevent overheating of metal/ceramic surfaces exposed to NIR radiation including, but not limited to, roofing applications.

Glass Defect Detection with Improved Data Augmentation under Total Reflection Lighting

To address the technical challenge of identifying tiny defects, especially dust and point defects, on mobile phone flat glass, an automatic optical inspection system is established. The system investigates algorithms including imaging principles, target detection models, data augmentation, foreground segmentation, and image fusion. The system builds an automatic optical inspection platform to collect glass defect samples. It illuminates the glass samples with a combined total reflection–grazing light source, collects the defect sample data, segments the background and defects of the collected data, generates the defect mask, and extracts the complete defects of the cell phone flat glass. The system then seamlessly integrates the extracted defects with a flawless background using Poisson editing and outputs the location information of the defects and the label output to automatically generate the dataset. The deep learning network YOLOv5 works as the core algorithm framework, into which the Constructive Block Attention Module and the small target detection layer are specifically added to enhance the capability of the model to detect small defects. According to the experimental results, the combined lighting effectively improves the precision of detecting dust and bright spots. Additionally, with the adoption of novel data augmentation techniques, the enhanced YOLOv5 model is capable of effectively addressing the challenges posed by inefficient sample data and non-uniform distribution, thus mitigating network generalization issues. Furthermore, this data augmentation approach facilitates the rapid adaptation of the same detection tasks to diverse environmental scenarios, enabling the expedited and efficient deployment of the model across various industrial settings. The mean average precision (MAP) of the optimal model in the validation set reached 98.36%, 2.62% higher than that of the original YOLOv5. In addition, its false acceptance rate (FAR) is 1.27%, its false rejection rate (FRR) was 2.47%, its detection speed was 64 fps, and its correct detection rate in the validation set was 98.75%, which meets the current industrial detection requirements by and large. In this way, this paper achieved the automated inspection of mobile phone flat glass with high robustness, high precision, and a low false acceptance rate and false rejection rate, significantly reducing material losses in the factories and the likelihood of error occurrence in follow-on products. This method can be applied to the multi-scale and multi-type detection of glass defects.