Phosphazenes provide a wide range of research opportunities in inorganic chemistry because of their structural characteristics and various applications. Therefore, it is a rapidly developing subject in inorganic chemistry. The reticulated polyphosphazenes are cyclomatrix type polyphosphazene compounds that contain excess crosslinking. One of the cyclophosphazenes, octachlorocyclotetraphosphazene (tetramer) is of great importance as it is used as the main component of many phosphazene compounds. A distinct class of polymers noted for its remarkable mechanical strength, chemical versatility, and thermal stability are cyclomatrix polyphosphazenes. The biologically active amines octopamine and isoprenaline were selected as the organic monomers to investigate their effects on the structural and functional characteristics of the resultant polyphosphazenes.In this study, octopamine and isoprenaline monomers were used in a reaction with cyclic linker compound octachlorocyclotetraphosphazene (tetramer) to create various cyclomatrix polyphosphazenes. The produced cyclomatrix polyphosphazene nano/microspheres were characterized.utilizing SEM, FT-IR, 31P-NMR, XRD and TGA techniques.
Olive tree leaves are renewable sources and the main byproducts of olive oil production industry having high production quantity. Hydrothermal carbonization (HTC) is one of the commonly used and promising methods to produce chemical, material and energy. However, carbonization stage of HTC process is complicated and uncomprehended and different methods have been proposed to enhance this stage. One of the current and/or green methods for this is salt addition during the HTC process. Therefore, in this study, the effects of two different Na-based salts (NaCl and Na2CO3) on HTC process of olive tree leaves were revealed based on both characteristics of hydrochars and process liquid products. HTC experiments were carried out at 180°C and 200°C, 5 hours and 1/7 (w/w) mixing ratio. Additionally, Na-based salts were added to the reactor at 10% and 20% of the weight of olive tree leaves and HTC experiments were carried out at the same experimental conditions. The 10% and 20% salt addition resulted lower hydrochar yields as comparing to the without salt addition conditions for both HTC temperatures. Carboxyl groups and intermolecular bonded -OH groups in hydrochars decreased with the addition of 20% Na2CO3 salt, indicating increment of the dehydration and decarboxylation reactions with salt addition. Process liquids composed of mostly organic acid compounds, such as acetic acid and benzeneacetic acid 3,4-dihydroxy. The total area percentages of organic acids decreased with the addition of Na-based salts, which indicating enhancement of decarboxylation reactions. Consequently, NaCl and Na2CO3 can successfully be used in HTC process of lignocellulosic biomasses to change and/or enhance byproducts of HTC process quantity and quality.
In this study, the recovery of dry soap-based (calcium/sodium) lubricants used and discarded in wire drawing processes was investigated. The chemical structure of the waste soaps was analyzed using FT-IR, XRF, TG/DTA, and SEM techniques. While no significant chemical degradation was observed in the soaps after use, a considerable increase in metallic contaminants, particularly iron, was detected. Therefore, chemical cleaning with HCl at various concentrations was applied to remove iron from the waste soaps. The optimal recovery conditions were achieved with 0.5 M HCl treatment for 8 hours at 60 °C. Under these conditions, the chemical structure of the soap was preserved, the iron content was significantly reduced, and the morphology closely resembled that of the original soap. The findings demonstrate the reusability of the waste soaps and offer a sustainable recovery approach for industrial applications.
Novel ceramic pigments containing B, Al, Cu, Ti, and Si oxides were prepared via the sol–gel method. Dark green ceramic pigments were obtained by varying the B/Cu molar ratio while maintaining constant ratios of other metal oxides. The structural and morphological characteristics of the ceramic pigments were investigated using XRD, FTIR, SEM and EDX analyses. UV–vis analyses were conducted in three different solvents to examine the effect of the solvent on the light absorption properties of the pigments. The CIELAB colorimetric system was employed to quantify the colour of the synthesized ceramic pigments. Variations in the metal ratios and the different molecular arrangements of all metal oxides within the pigment structure led to changes in the colour parameters (L*, a*, b*). In the visible-light region, the absorption band of the ceramic pigments shifted away from the centre of the green region toward the blue region, which is attributed to the acidic nature of the prepared solutions (pH = 1). The increase in proton concentration in the solution caused the absorption bands to shift toward shorter wavelengths.
There is a need to improve the mechanical, optical and physical properties, as well as identify alternative sources of raw materials for paper in order to decrease deforestation, costs of manufacturing paper, and eventually lower the costs of paper. This study therefore explores the development and characterization of kaolin-infused paper using recycled paper pulp and kaolin as basic raw materials. Kaolin, a locally abundant clay mineral, was incorporated at varying levels to evaluate its influence on the mechanical, optical, and physical properties of paper. Paper sheets were produced with recycled pulp and different variations of kaolin and tested for tensile strength, grammage, water absorption, and microstructural characteristics using SEM, EDS, and XRD. The results show that moderate kaolin addition (3–6 wt%) improved tensile strength from 5.69 to 6.65 MPa before reducing as percentage of kaolin increased , stiffness also improved , and water absorption reduced from 286.6 to 196.65 g/m2. Excessive filler levels caused agglomeration and reduced mechanical integrity. XRD confirmed crystalline phases such as quartz and feldspar, indicating the mineral contribution of kaolin to the composite matrix. The findings demonstrate kaolin’s potential as a sustainable filler for improved paper properties when used at optimal levels. Combined with recycled pulp, this approach supports eco-friendly, cost-effective, and sustainable paper production.
Accurate aerodynamic probe calibration requires a flow environment with high mean flow uniformity. This study presents the experimental characterization and topological mapping of the potential core in a 70 mm diameter subsonic free jet facility developed for multi-hole probe calibration. Using a custom-designed automated traverse system with a positioning repeatability of
In this study, chitosan-based composite coatings modified with calcium titanate particles were investigated in terms of their microstructural characteristics and corrosion resistance. Chitosan gels containing 0–2 wt.% calcium titanate were prepared, and the morphology of the resulting composites was examined using scanning electron microscopy. Fourier transform infrared analysis showed that the incorporation of calcium titanate particles into the chitosan matrix caused changes in the intensity of the characteristic hydroxyl, amine, and ether bands, indicating physical interactions between the particles and the polymer chains without the formation of new chemical bonds. The results demonstrated that calcium titanate particles were more uniformly dispersed within the chitosan matrix at low filler contents, while higher particle concentrations led to pronounced agglomeration. Among the investigated compositions, the composite containing 0.05 wt.% calcium titanate exhibited the most homogeneous microstructure with minimal particle aggregation. Based on these findings, the optimized composite formulation was applied onto metal substrates using the layer-by-layer deposition method to produce two-layer coatings. The corrosion behavior of uncoated and coated metal samples was evaluated by immersion in a saline solution for one week. Severe corrosion was observed on the uncoated metal surface, whereas no significant corrosion or surface degradation was detected on the coated samples containing calcium titanate. In addition, the particles were uniformly distributed on the coating surface without noticeable aggregation. Particle size analysis of calcium titanate powders revealed an average particle size of 1.81 micrometers, consistent with particle size distribution measurements. Overall, the results indicate that calcium titanate-modified chitosan coatings form an effective protective barrier and significantly enhance corrosion resistance in saline environments.
Early detection of thermal anomalies in photovoltaic (PV) panels is crucial for minimizing energy losses and improving maintenance planning. However, thermal images acquired under real-world field conditions often suffer from low contrast, non-uniform illumination, and noise, which significantly hinder the detection of small-scale faults. In this study, the effects of two image enhancement approaches Zero-Reference Deep Curve Estimation (Zero-DCE) and Swin Transformer for Image Restoration (SwinIR) on a YOLOv11-based object detection model are comparatively analyzed. The Zero-DCE method optimizes illumination and contrast without requiring reference images, whereas the SwinIR model focuses on noise suppression and preservation of structural details. To quantitatively evaluate the impact of both enhancement strategies on YOLOv11 performance, a series of experiments were conducted using identical training and testing protocols. The YOLOv11m model trained on raw thermal images achieved mean mAP@0.5 and mAP@0.5:0.95 scores of 0.849 and 0.748, respectively. When Zero-DCE-enhanced inputs were used, the mAP@0.5 increased to 0.943, while the mean recall reached 0.934, indicating an improvement in anomaly detection sensitivity. In contrast, the SwinIR-enhanced model achieved mean mAP@0.5 and mAP@0.5:0.95 scores of 0.843 and 0.755, respectively, demonstrating a limited improvement at higher IoU thresholds. The experimental results clearly indicate that different image enhancement strategies have a significant influence on fault detection performance. Moreover, the selection of an appropriate enhancement method plays a critical role in reliably identifying small and low-contrast anomalies in thermal PV imagery.
Companies are increasingly tending to replace their conventional fleets with electric vehicles (EVs), primarily driven by carbon policies. However, EVs face challenges such as limited driving range and the necessity for dedicated charging infrastructure. Given that the requirements of linehaul and backhaul customers are relatively consistent over time, the long-term operational costs of weekly routing often outweigh the one-off investment of installing charging stations. Furthermore, since EV charging is time-consuming, performing this process during loading or unloading operations offers a significant advantage by minimizing route completion time. To address this, this study proposes a two-stage mathematical modeling approach designed to prioritize operational efficiency. In the first stage, routes are constructed solely to minimize total travel costs, ensuring the most lean logistics operation. The second stage then determines the optimal locations for charging stations by minimizing their total number based on the pre-established routes. This hierarchy allows decision-makers to focus on routing stability before committing to infrastructure. To validate this framework, an integrated approach encompassing both routing and station determination was also developed. Both methodologies were applied to a case study in Turkey. The results provide evidence suggesting that the two-stage approach yields more encouraging outcomes, offering a practical and effective strategy for transitioning to electric fleets.
