The nanofabrication of long-range ordered metal nanostructures has garnered significant research attention in the advancement of plasmonic-assisted sensor development. In this study, we report efficient nanofabrication of silver arrays on Teflon (Tef/Ag) for fabricating a surface-enhanced Raman spectroscopy (SERS) sensor for detecting multiple pollutants. The number of laser pulses was systematically varied from 200 to 10000 to study its impact on the morphological features of Ag nanoarrays. Atomic Force Microscopy (AFM) and UV-visible spectroscopy were employed to study the morphological and optical characteristics, respectively. The physical properties were then correlated to their corresponding sensing activities. The number of laser pulses was optimized to achieve the highest SERS sensing efficiency. The sensor fabricated at 5000 laser pulses exhibited the highest SERS enhancement, attributed to the formation of a highly dense metal nano-island formation (Fig. 1a). Compared to silicon and quartz, Teflon provided the best substrate for achieving the highest SERS enhancement. An enhancement factor of 3.1 × 10 7 has been estimated for Teflon/Ag sensor, which showed superior efficiency of the fabricated sensor. The reproducibility of the sensor showed relative standard deviation values of 9.1%. The sensor was further validated for the detection of various environmental pollutants, demonstrating its potential as a flexible, reusable and efficient platform for environmental monitoring.
Composites are materials designed to achieve superior mechanical or physical properties, and understanding both their failure and dynamic behavior is essential. Despite numerous past studies on understanding this behavior of composite materials, information on the interrelationship between these two aspects remains limited. The study aims to conduct a process innovation and provide detailed understanding of the effect of fiber orientation on the Graphite epoxy and E-glass epoxy composite laminates failure behavior and natural frequency and the relationship between the failure and dynamic behavior of these two materials. To achieve this, a process innovation of the simulation of failure analysis and vibration analysis of these composite laminates under uniaxial tensile loading was conducted on 8-ply composite laminates under a lamination scheme of (-θ/45/-45/θ/-θ/45/-45/θ), where θ from 0° to 90°. Finite element models for simulation were developed and validated to ensure the reliability and validity of findings in this study are trustworthy and useful. The results show that both failures loads, and natural frequencies are not much affected by the fiber orientation under this lamination scheme. These two behaviors are also identified to be closely related under specific modes of natural frequency. The detailed effects of failure and natural frequency under fiber orientation and its relation are successfully acknowledged. The findings are expected to support the optimization of laminate design and enhance the structural performance of composite materials in engineering applications and contribute to more informed material selection.
This study investigates the effects of various cutting technologies on a 0.25 mm thick ferritic steel, a material widely used in packaging and other lightweight applications. The study provides a comprehensive comparison of four distinct cutting technologies: Laser Cutting, Milling, Electrical Discharge Machining (EDM), and Water Jet Cutting. The research focuses on the impact of these cutting processes on the material’s properties and its performance under uniaxial tension. X-ray diffraction is used to precisely measure the magnitude and distribution of residual stresses along the cut edge in order to correlate them with changes in the material's flow curve, which is critical for accurate mechanical characterization. Furthermore, a laser-scanning microscope was used for detailed morphological analysis of the cut edge and for roughness measurement. To quantify mechanical property changes, microindentation hardness testing was used to assess the degree of work hardening induced by each cutting method. Finally, Digital Imaging Correlation (DIC) was employed to track strain distribution and observe strain field variations.
Copper is a valuable industrial metal, extensively utilized in its pure form due to its excellent electrical and thermal conductivities. It plays a vital role in a wide range of applications, including refrigeration systems, coin and jewelry manufacturing, strain gauges, thermocouples, and more. However, in its ionic form, copper (particularly as Cu 2+ ) can be toxic, especially when present in industrial effluents and wastewater streams. Therefore, the effective adsorption of cupric ions (Cu 2+ ) is a critical environmental and technological concern addressed in this study. From this work, tissue paper pulp waste, chitosan derived from frozen food industry byproducts, and chitosan-coated pulp waste were developed as modified adsorbents for Cu 2+ removal from aqueous solutions. Brunauer–Emmett–Teller (BET) surface area analysis revealed that chitosan exhibited the highest porosity, while the chitosan-coated pulp provided a well-balanced structure with enhanced functional properties. Under controlled experimental conditions, all three materials demonstrated significant Cu 2+ removal efficiency, with the chitosan-coated pulp slightly outperforming the others. These findings highlight the potential of chitosan-coated pulp waste as a low-cost, sustainable, and highly effective adsorbent for the remediation of heavy metal-contaminated wastewater.
Various heat treatments were applied to reduce quench-induced residual stresses while improving the mechanical properties of particle-reinforced aluminum composite. The residual stress distribution of samples quenched in water with different cooling media was measured. The results showed that quenching with the 30% polyethylene glycol quenchant (PAG) yields up to an 86.8% reduction in residual stress magnitude compared with cold-water quenching (CWQ). Still, the tensile properties of samples quenched in 30% polyethylene glycol quenchant were low, with a 12.5% reduction in yield strength. The experimental results show that the uphill quench (UQ) method is an effective means of reducing residual stresses induced by quenching. At the same time, the effect on tensile properties is negligible. Moreover, the study found that combining uphill quenching with short-aging treatment can further improve the residual stress, strength, and fracture toughness of SiCp/Al-Cu-Mg composites.
