The present study describes the energy absorption and damage analysis of the spherical core sandwich structures (SCSS) fabricated using woven Glass Fibre Reinforced Plastic (GFRP) by hand- layup method. Based on the core orientation, the spherical cores are categorized as stagger (S), regular (R), inverted (I), and interlock (L). The pitch distance and diameter of the models considered for the study are 24 mm and 16 mm, respectively. The specimens are subjected to a low velocity impact test (LVIT) at three different energy levels 9.9, 27.5, and 53.9 J respectively. Evaluations are carried out on the different kind of parameters namely coefficient of restitution (COR),energy absorption ratio, and energy loss percentage maximum displacement, maximum force, absorbed energy, and rebound energy. Among the models at every impact velocity it is found that the model R sustains a maximum force of 3078 N at 7 m/s impact velocity. The stagger model has recorded a maximum displacement of 34.4 mm among all velocities, whereas the regular model reveals a minimum displacement of 4.9 mm based on the analysis of maximum displacement. Similarly, the regular model has a maximum energy absorption ratio at 5 and 7 m/s respectively, whereas at 3 m/s the interlock model absorbs more energy. The failure pattern of the specimens is analyzed through visual inspection and ultrasound testing. Matrix cracking and fibre breakage are the typical failures seen in the model at 3 m/s, while core crushing and perforation are seen at 5 and 7 m/s impact velocities. The damage area is minimum for the interlock model whereas it is maximum for the stagger model.

In this work, Al2O3:xEu3+ red phosphor powders were produced by the combustion synthesis technique with different x molar percentage concentrations of doping of x = 1.5, 3.0, 5.0, and 7.0 mol% of Eu. X-ray diffraction analysis demonstrated that the powders present the Al2O3 crystalline phase. Scanning electron microscopy discovered a sheet-like morphology in the Al2O3:xEu3+ phosphor samples. The sheet particle sizes are in the range of 40 – 280 mm and with an average thickness of 4.8 mm. Photoluminescence measurements of the samples under 254 nm excitation, showed two main red emission peaks at 615 nm and 700 nm attributed to Eu3+ luminescent transitions, 5D0-7F2, 5D0-7F4, respectively. The Al2O3:xEu3+ red phosphors were applied for fingerprint revealing application on different surfaces and in crime scenes. The fingerprints were successfully revealed on steel, plastic, and ceramic surfaces, and photographs of the revealed fingerprints were taken. Several fingerprint features, such as short ridges, eyes, bifurcations, cores, and right loop elements, were clearly detected and sharply defined in the photographs. Therefore, the Al2O3:xEu3+ red phosphors show potential as an effective material for fingerprint detection in forensic science applications.

Cerium oxide (CeO2) doped with zinc oxide (ZnO) nanoparticles were synthesised using sol-gel method. The impact of CeO2 doping on the microstructure, optical, photocatalytic, and antibacterial properties of ZnO nanoparticles (NPs) were investigated. XRD results showed the presence of both CeO2 and ZnO phases. The ZnO sample crystallizes into a hexagonal wurtzite structure and CeO2 with a cubic structure. The crystallite sizes were estimated and found to be 18 nm and 29 nm for the CeO2 and ZnO, nanoparticles respectively. FTIR spectrum reveals the formation of chemical bonds. The FESEM studies showed the formation of dense crystallites with aggregation. The EDX studies confirmed the presence of cerium, zinc, and oxygen in the sample, and no additional peaks have been detected. The UV-Visible spectroscopy analysis revealed the bandgap of 3.15 eV. The photodegradation activity of the nanoparticles with methylene blue (MB) dye was carried out using visible light irradiation and the degradation efficiency was found to be 75.81 % in 1 h duration. The antibacterial susceptibility test was conducted using the agar well diffusion method to investigate the activity of CeO2 doped ZnO nanoparticles against E. coli, Salmonella typhimurium, Bacillus cereus, and Shigella flexneri, and the results showed significant antibacterial activity as compared to the control drug penicillin.

With the advancement of social science and technology and the escalating demand for resources, the utilization rate and load of mechanical equipment in diverse industries have become increasingly prominent. Mechanical malfunctions occur frequently, especially in material transportation, causing substantial economic losses. Mechanical wear has emerged as the principal cause of mechanical equipment failure; hence, studying the wear of particles and transportation machinery is of paramount importance. This paper utilizes the discrete element method and numerical simulation approach to investigate the influence of mechanical structure alterations on the wear of discharge chutes in coal conveyor systems. The results reveal that in terms of speed, reducing the conveyor belt speed has negligible effects on the falling trajectory and distribution characteristics of the materials but reduces the frequency of contact between the materials and the chute surface, thereby diminishing the tangential force exerted by the materials on the chute. The tangential cumulative force plays a crucial role in the wear of the chute by granular particles and can effectively alleviate the wear of the chute. With respect to the inclination angle of the conveyor belt, when increasing the angle clockwise, the influence on the falling trajectory and distribution characteristics is relatively minor, and the falling speed of the materials will accelerate. Nevertheless, the wear of the chute will decrease as the inclination angle increases. When increasing the inclination angle counterclockwise, the falling trajectory and distribution characteristics are significantly affected, and the materials will tend to concentrate, and the falling speed will decelerate, resulting in a substantial reduction in chute wear. These discoveries provide theoretical underpinnings for reducing equipment wear and optimizing coal transportation equipment.

Metallic plasmonic nanostructures can achieve nanoscale light-matter interactions and have a wide range of applications in spectral modulation and optical sensing fields stemming from their rich and tunable optical properties. Herein, we propose a composite nanostructure consisting of a gold nanodisk array and a GaAs thin film, which achieves symmetric and asymmetric configurations by adjusting the nanodisk radius of the array structure. We systematically investigate the relationship between plasmonic modulation and asymmetric/symmetric coupling modes. The results indicate that the two configurations correspond to single resonance and dual resonance, respectively. The short wavelength of the dual-resonant mode is jointly excited by the local surface plasmon polariton (LSP) mode of the nanodisk itself and the waveguide-hybridized lattice mode of the bottom GaAs film. And the long wavelength corresponds to the LSP mode of the array nanostructure which strongly depends on its size. Improving structural symmetry leads to different trends in resonance wavelength. Furthermore, we investigate the sensing performances for asymmetric/symmetric nanodisk arrays. This work is of great significance for applications such as multi-resonance sensing, plasmonic modulation, etc.