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This study investigates the performance of vinyl ester composites reinforced with areca fruit fiber, microcrystalline cellulose, and silane coupling-grafted recycled PET bottle waste foam under conditions of water and heat-accelerated aging. The reinforcement, areca fiber and recycled PET foam were surface-modified using 3-aminopropyltrimethoxysilane (3-APTMS) to enhance interfacial bonding. The composites were fabricated using a manual hand layup process and subjected to aging tests. According to results the APS2 composite had enhanced heat conductivity at 0.17W/mk and decreased flame propagation speed at 10.99mm/min after being exposed to saltwater. Similarly, after being exposed to rainwater, the ARP2 composite developed a temperature conductivity of 0.16W/mk, a flexural strength of 80.3MPa, a tensile strength of 37.4MPa, and a flame propagation speed of 10.97mm/min. SEM analysis of silane-treated vinyl ester composites reinforced with areca fibers and microcrystalline cellulose reveals improved interfacial bonding and filler dispersion, enhancing the composite’s mechanical integrity. These findings confirm that the application of silane coupling agents significantly enhances the thermal stability, water resistance, and overall durability of the composites, making them suitable for demanding applications requiring high mechanical strength, effective thermal management, and robust fire resistance, particularly under challenging environmental conditions.

A nickel superalloy such as IN625 is widely employed in the oil, chemical processing, nuclear, and aviation industries due to its exceptional high-temperature strength, hardness, and corrosion resistance characteristics. These industries often require components with intricate and complex geometries that must adhere to close tolerances with adequate surface finish. Fiber laser beam machining (FLBM) has emerged as a significant advancement in fabrication technology, creating intricate forms and structures, especially in superalloys. This work aims to analyze the effect of laser frequency ($L_F)$, number of passes ($N_P$), laser power ($L_P)$, and scanning speed ($S_S$) in the machining of IN625 to achieve minimum surface undulation ($S_U$) and maximum erosion quantity ($E_Q$). The responsive surface methodology (RSM) was employed to model and optimize the parameters. The optimal condition was identified as $L_P$= 10.5W, $N_P$= 18, $S_S$= 283mm/min, and $L_F$= 18kHz; confirmation trials showed an improvement of 8.0% in $S_U$ and 19.75% in $E_Q.$ The influence of scanning speed on surface undulation and erosion quantity is significant. Analysis of variance (ANOVA) indicates that scanning speed contributes the most to surface undulation (70.48%) and erosion quantity (72.90%), followed by the number of passes with contributions of 13.94% to surface undulation and 14.41% to erosion quantity. Additionally, the surface topography and morphology of the machined surface are analyzed using 3D topography images and scanning electron microscopy (SEM) images.

This study investigates the mechanical, fatigue, water absorption, and flammability properties of polyethylene terephthalate (PET) core-pineapple fiber sandwich composites reinforced with silane-treated neem fruit husk (NFH) biosilica additives. The novel approach includes modifying the fiber’s surface and incorporating biosilica to enhance environmental resistance. The composites were prepared using a hand layup method, followed by silane treatment of the biosilica, pineapple fiber, PET core and vinyl ester resin. Subsequently, to evaluate environmental impacts on composite’s performance, sandwich composites were subjected to temperature aging at 40^∘C and 60^∘C in a hot oven for 30 days and warm water aging at the same temperatures in tap water with pH 7.4. According to the results, adding 1%, 3%, and 5 vol.% silane-treated biosilica significantly improved the mechanical properties. The composite with 3% biosilica (L2) showed a tensile strength of 120.8MPa, flexural strength of 194.4MPa, compression strength of 182.4MPa, rail shear strength of 20.21MPa, ILSS of 23.14MPa, hardness of 85 Shore-D, and Izod impact strength of 6.56 J. Even under temperature and water aging conditions, the composites showed only minimal reductions in properties, highlighting the efficacy of the silane treatment. The temperature-aged L2 composite had a tensile strength of 104MPa, flexural strength of 172.8 MPa, compression strength of 164MPa, and ILSS of 22.5MPa, while the water-aged L2 composite exhibited a tensile strength of 96MPa, flexural strength of 152.8MPa, compression strength of 146.4MPa, and ILSS of 21.4MPa. Scanning electron microscope (SEM) analysis confirmed uniform dispersion of biosilica particles, critical for improved performance, though higher concentrations led to agglomeration and stress points. The composites also demonstrated excellent flame retardancy, maintaining a UL-94 V-0 rating with decreased flame propagation speeds, specifically 9.05mm/min for L2. These findings underscore the potential of silane-treated biosilica as a reinforcing additive to enhance the durability and performance of composites in adverse conditions.

There are two conventional boundary treatment methods in molecular dynamics (MD) simulation for particle suspension or fiber in cross flow. One is that the fiber is represented by evenly spaced atoms, the other is that the fiber is treated as one mass point. The calculations with the two boundary treatment methods have been compared, it is found that, with the same properties, both methods could generate slip boundary condition on the fiber surface, however the one mass point method could result in very large slip boundary condition on the fiber surface, and the discrepancy could be as high as 2600%.

In this article, two possible applications of prism-based probes for liquid-switching, level-sensing, and as a refractometer are described. Theoretical formulation is developed for the emergent intensity for each system and possible range of operation for each system is reported. By comparing the theoretical investigations, some hints are given in optimum usage of prism in each case. Variation of the beam divergence, incident angle, and prism glass index are major parameters that are considered in this investigation. The obtained results are compared with some available experimental results and practical points concerning the effective application of each geometry is reported. Theoretical expressions developed here are in good agreement with the experimental measurements.

We consider a family of fractal squares, denoted as ${{ℱ}}_{3,7}$. Each of them satisfies the set equation $K=\frac{1}{3}(K+{𝒟})$ for some ${𝒟}\subset {\{0,1,2\}}^2$ with $\#{𝒟}=7$. It is known that two of these fractal squares are Lipschitz equivalent if and only if they are isometrically equivalent. The aim of our study is to improve this by replacing Lipschitz equivalence with topological equivalence. To this end, we shall investigate the group $G_{\mathrm{\text{aut}}}(K)$ of all homeomorphisms of a fractal square $K\in {{ℱ}}_{3,7}$ that has a cut point and show that $\#G_{\mathrm{\text{aut}}}(K)=2$ or $8$.

We report on frequency doubling of 1.55-μm fiber oscillator-amplifier laser with conversion efficiency of 27% by using off-the-shelf nonlinear crystal. The system generates 135-femto-second (fs) pulses with average power of 110 mW at 80 MHz repetition rate. Frequency doubling efficiency as a function of pulse pre-chirp in front of a single mode erbium fiber amplifier was investigated.

Due to the increased use of composite materials in industrial applications, reliable and consistent finite element methods are required for the simulation and optimization of composite structures. In this paper, we presented the effect of finite element meshing in the modeling of degradation in composite structures under tensile stress; we have used an elastoplastic model to simulate the damage and plasticity behavior occurring in laminated composite structures carbon/epoxy: T300/914. This model works with different elements and the results obtained are not sensitive to mesh size. Thus, we have showed that two different meshes give the same results. Our findings are in good agreement compared to the experimental data.

Antimony doped ZnO (ZnO:Sb) fiber was grown by a simple thermal evaporation process of Zn powder and Sb₂O₃. Scanning Electron Microscopy (SEM) shows that the grown fiber reaches more than 70 μm, which is the longest ZnO fiber reported in literature. Electron Backscattered Diffraction (EBSD) study indicates that this crystal is composed of three main phases: antimony doped zinc oxide (ZnO:Sb), ordonezite (ZnSb₂O₆) and zinc antimony oxide (Zn₇Sb₂O₁₂). The current–voltage (I–V) characteristics demonstrate that the conversion efficiency of dye sensitized solar cell was greatly enhanced by ZnO:Sb fiber.

We report on a novel synthetic method of microwave processing with a domestic 2450MHz microwave synthesis system to prepare ZnO fiber using pure ZnO powder. We also studied and report on structure and morphology of the resultant products by XRD and SEM. XRD revealed that a single phase ZnO fiber can be synthesized quickly and easily by microwave processing. The results indicate that microwave processing is a promising method of processing ZnO fiber.

Alumina + zirconia (PRD-166) and Saphikon fibers reinforced glass matrix composites with and without a SnO₂ interphase were prepared by slurry infiltration and their mechanical characteristics were evaluated. Longitudinal bend strength increased with volume fraction of fibers in both PRD-166/glass and PRD-166/SnO₂/glass matrix composites. PRD-166/glass matrix composites failed in a brittle manner whereas PRD-166/SnO₂/glass matrix composites exhibited non-planar failure with crack deflection and fiber bridging as major toughening mechanisms. Saphikon/SnO₂/glass matrix composites failed in a tough manner with extensive fiber pullout. The difference in the failure mode between PRD-166/SnO₂/glass and Saphikon/SnO₂/glass matrix composites was due to fiber roughness.

Ceramic-polymer composite biomaterials were prepared by hot-pressing a mixture consisting of poly-L-lactic acid (PLA) and hydroxyapatite fibers (HAF). HAF can be prepared successfully by heating a compact consisting of β-calcium metaphosphate fibers (CPF) with Ca(OH)₂ particles in air at 1000 °C and subsequently treating the resultant compact with dilute aqueous HCl solution. HAF was 40 ~ 150 μm in length and 2 ~ 10 μm in diameter; HAF has almost the same dimensions as those of CPF. After PLA dissolved with methylene chloride was mixed with the fibers, the mixture was dried completely and subsequently it was hot-pressed uniaxially under a pressure of 40 MPa at 180 °C, resulting in fabrication of the PLA/HAF composite. The modulus of elasticity was improved effectively even by introducing a small amount of HAF; almost no degradation in the bending strength was observed and the modulus of elasticity showed high values of 5 ~ 10 GPa when the fibers of 20 ~ 60 wt.% were introduced. The stress-strain curves in the bending test of the PLA/HAF composites showed that very high energy is consumed for their fracture.

Self-similarity in optics, along with the soliton physics, recently attracts interest of the researchers of ultrafast and nonlinear fiber optics.¹ Both the parabolic similariton of active fibers, and nonlinear-dispersive similariton generated in passive fiber are of interest, especially for applications in ultrafast optics, such as pulse compression and shaping, similariton-based temporal lensing and spectrotemporal imaging, spectral interferometry, etc. However, the signal analysis-synthesis problems in a few femtosecond time scale demand the generation and study of broadband similaritons of ~100 nm bandwidth.

We generate the broadband similariton, and characterize it experimentally to reveal its nature and distinctive properties, and to describe it mathematically. We carry out the complete characterization of the broadband similariton by means of the chirp measurement through the technique of spectral compression and frequency tuning in the sum-frequency generation process. Our studies are of interest in view of applications of similariton to the signal analysis and synthesis problems in ultrafast optics, particularly for similariton-induced temporal lensing and similariton-based spectral interferometry. Our developed method of similariton chirp measurement can serve also for the fiber characterization.