Composite Structures Research Articles

Multifunctional Bistable Ultrathin Composite Booms with Flexible Electronics

Small satellites such as CubeSats pose demanding requirements on the weight, size, and multifunctionality of their structures due to extreme constraints on the payload mass and volume. To address this challenge, we introduce a concept of multifunctional deployable space structures for CubeSats based on ultrathin, elastically foldable, and self-deployable bistable composite structures integrated with flexible electronics. The multifunctional bistable booms can be stored in a coiled configuration and self-deploy into a long structure upon initiation by releasing the stored strain energy. The boom demonstrates the capabilities of delivering power and transmitting data from the CubeSat to the flexible devices on the boom tip. The boom also shows the ability to monitor the dynamics and vibration during and after the deployment. A payload boom has been installed in a 3U CubeSat as flight hardware for in-space testing and demonstration. This effort combines morphable ultrathin composite structures with flexible electronics.

Active and Passive Infrared Emittance Tuning Using Optically Transparent Unpatterned ITO Thin Films

Tailoring of thermal emittance has applications in smart radiators, camouflage, infrared (IR) scene generation, stealth, and thermal management. Various studies have explored avenues to achieve both passive and active emittance tuning using methods such as meta-surfaces, phase change materials, composites, nanostructure arrays and multi-layer stacks. Most of these methods often involve complex fabrication processes like multilayer depositions and micro/nano patterning, limiting their scalability for large-scale applications. This study presents a straightforward and scalable approach for passive and active emittance tuning using Indium Tin Oxide (ITO) films deposited on a high emissivity flexible polyethylene terephthalate (PET) substrate. By changing the deposition time, the thickness of the ITO film is controlled which changes the observed emissivity of the ITO/PET composite structure over a wide range (0.2-0.94) while maintaining optical transparency. Using this approach for passive emittance tuning, we demonstrate an IR scene generation application. As the ITO film is conducting, by applying voltage to the ITO/PET sheet, its temperature is changed using which active emittance tuning is also achieved. Compared to existing methods of emittance tuning, the presented approach is simpler, gives flexible films with optical transparency, and has the potential for large-scale integration, enabling cost-effective and scalable manufacturing of emittance-tuned surfaces.

Composite Materials For Creation Of Anti-Icing Elements And Other Aircraft Systems

The relevance of the development is related to the safety of aircraft flights, which is significantly affected by aircraft icing. The reliability of the anti-icing system (AIC) is a prerequisite for all modern aircraft, as well as for high-altitude unmanned aerial vehicles (UAVs). Icing of aircraft and UAVs is a very urgent problem, as evidenced by a large number of foreign publications and patents on proposals for methods of removing ice from metal and composite structures using nanomaterials. Icing can lead to a decrease in the lifting power of the aircraft and an increase in drag, and also affects the operation of the aircraft controls, reduces visibility from the cockpit, increases vibration and load on individual elements of the airframe, and negatively affects the operation of engines

Synergistic Action of Rutin-Coated Zinc Oxide Nanoparticles: Targeting Biofilm Formation Receptors of Dental Pathogens and Modulating Apoptosis Genes for Enhanced Oral Anticancer Activity.

Oral diseases are often associated with bacterial and fungal pathogens such as Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans. This research explored a novel approach to addressing these pathogens by synthesizing zinc oxide nanoparticles (ZnO NPs) coated with rutin (RT), a plant-derived compound. The synthesized ZnO-RT NPs were comprehensively characterized using UV-Vis spectrophotometer, SEM, and EDAX techniques to confirm their structural composition. The antioxidant potential was assessed through free radical scavenging assays. Additionally, the antimicrobial activity of ZnO-RT NPs was evaluated using a zone of inhibition assay against oral pathogens. Molecular docking studies with the Autodock tool were performed to elucidate the interactions between RT and the receptors of oral pathogens. The findings demonstrated that ZnO-RT NPs exhibited robust free radical scavenging activity. Furthermore, they showed significant antimicrobial activity with a minimal inhibitory concentration of 40 μg/mL against oral pathogens. ZnO-RT NPs also displayed dose-dependent anticancer effects on human oral cancer cells at concentrations of 10, 20, 40, and 80 μg/mL. Mechanistic insights into the anticancer activity on KB cells revealed the upregulation of apoptotic genes. This study underscores the promising potential of ZnO-RT NPs for dental applications due to their strong antioxidant, anticancer, and antimicrobial properties. These nanoparticles offer a hopeful prospect for addressing oral pathogen challenges and enhancing overall oral health.

Simultaneously enhancing the EMI shielding performances and mechanical properties of structure–function integrated CF/PEEK composites via chopped ultra-thin carbon fiber tapes and interfacial engineering with MXene

The functionalization of carbon fiber reinforced poly(ether-ether-ketone) (CF/PEEK) structural composites with high electromagnetic interference shielding efficiency (EMI SE) has important engineering application in the fields of aviation and aerospace. However, the simultaneous enhancement of interfacial properties and EMI SE in the CF/PEEK composite remains a significant concern. To address this issue, we have employed a continuous impregnation approach that involved synthesizing PFEEK as a binder and then utilizing mechanical spreading technology to prepare chopped ultra-thin CF tapes as the reinforcement phase. Subsequently, we deposited 2D MXene (Ti3C2Tx) on the CF tape surface to endow the interface properties and EMI SE for the CF/PEEK composites. As a result, when the MXene content was 1.0 mg/ml, the flexural strength, flexural modulus, and interlaminar shear strength (ILSS) of the obtained CF/PEEK composites achieved 17.6 %, 13.3 % and 36.6 % enhancement higher than that of the virgin CF/PEEK composites, respectively, which may be owing to the elevated interfacial properties via the hydrogen bonds, physical entanglement, π-π interactions, and mechanical interlocking with the incorporation of PFEEK and MXene. The optimal ILSS value and specific EMI SE/t value of the CF/PF-M1/PEEK composites can reach 113.7 MPa and 80.8 dB/mm, respectively. The enhancement in the EMI SE can be attributed to the enhancive reflection, the increased polarization losses, and multiple interlayer reflections of EM waves facilitated by the incorporation of MXene and multi ultra-thin CF/PF-MXene layers. This approach resulted in a structure–function integrated CF/PEEK composite, which holds promising application prospects across various cutting-edge domains.

Minilateralism and pathways to institutional progression: alliance formation or cooperative security governance?

ABSTRACT Even as essential definitional and conceptual issues related to ‘minilateralism’ remain unresolved, conjecture has arisen as to the future trajectories of established institutions, such as the Trilateral Strategic Dialogue (TSD), AUKUS, and the Quad. – Could they evolve into formal military alliances over time, or serve as the foundation of a new organisation aimed at providing regional security governance? To systematically evaluate such contingencies this article traverses a set of interrelated conceptual issues relating to minilateral institutionalisation. It seeks to differentiate minilaterals in terms of their ‘hybridity’ both in structural composition and functionality, and ascertain what this implies for their institutional progression. This process assists us in identifying on what grounds minilaterals might potentially evolve into a more formalised institutional paradigm – either (i) a military alliance or (ii) a cooperative security governance organisation. This foregoing conceptual apparatus is then brought to bear of on the case studies above to draw out clues as to their prospective institutional development pathways. The article concludes that, while such putative institutional transformations remain conceivable, in none of the cases is a particular pathway preordained. Instead, minilaterals may simply continue to adapt within the parameters of their present institutional boundaries.

Tree species selection for optimizing soil carbon storage: Insights from litter decomposition and bacterial community analysis in coastal ecosystems

Coastal wetland ecosystems are critical sinks for atmospheric carbon dioxide, playing a vital role in global carbon cycling and climate regulation. The decomposition of leaf litter plays a crucial role in the formation and stability of soil organic carbon (SOC) in these environments. This study investigated the impact of leaf litter decomposition from five tree species (Populus deltoids, Ligustrum lucidum, Taxodium 'Zhongshanshan', Hibiscus hamabo, and Nerium oleander) on SOC dynamics, humus composition, and soil bacterial community structure in a tidal flat. Litterbags were used to monitor the mass loss and changes in litter chemical composition over 270 days. The results revealed significant differences in decomposition rates among the tree species, with Nerium oleander exhibiting the fastest decomposition and Populus deltoids the slowest. Surprisingly, initial litter chemistry did not correlate with decomposition rates; however, changes in lignin and hemicellulose content during decomposition were significantly related to mass loss. Despite its rapid decomposition, Nerium oleander litter resulted in the highest accumulation of SOC, total humus, and humin compared to the other species, challenging the conventional view that slower decomposition leads to greater SOC storage. The soil microbial community structure was significantly influenced by SOC, humus, and litter components, with distinct microbial assemblages associated with each tree species. A random forest model identified key bacterial taxa, predominantly Proteobacteria, as important predictors of SOC content, highlighting the role of bacterial diversity in regulating SOC dynamics. These findings underscore the importance of considering litter quality, decomposition dynamics, and bacterial community composition in strategies aimed at enhancing soil carbon sequestration. This study suggests that selecting tree species with rapidly decomposing litter, such as Nerium oleander, in coastal plantations can be an effective management tool for optimizing soil carbon storage, offering valuable insights for mitigating climate change impacts.

Functional traits mediate the elevational patterns of functional diversity and community structure of mosses in a tropical mountain area

Functional diversity refers to the value, range, and distribution of functional traits within a community, such as the morphological, physiological and behavioral characteristics of species that determine the role a species plays in an ecosystem. Assessing the drivers of elevational pattern of functional diversity is crucial to predict the effects of global change on functional diversity and community structure. In our research, we collected mosses species data from 65 sampling sites and measured 11 functional traits that are related to their ecological functions. We applied double canonical correspondence analysis (DCCA) to analyze species responses to environmental conditions based on their traits. We applied generalized additive models with a Gaussian function of variance to determine the elevational patterns of functional trait composition, diversity and community structure. We applied and compared boosted regression trees (BRT) without considering functional traits and piecewise structural equation modelling (SEM) mediated with functional traits to relate environmental variables with functional diversity and functional community structure, respectively. We found the first DCCA axis accounted for the largest dissimilarities between the two groups of species and correlated mainly with the water-utilization traits. Although both functional diversity and community structure displayed negatively skewed pattern along the elevational gradient, habitat complexity and climatic variables contributed differently to their respective patterns. The SEM approach consistently outperformed the BRT approach in explaining the variations in both functional diversity and community structure. Our findings highlight the important role of functional traits in mediating the relationship between the environment and functional diversity metrics. Both biotic and abiotic processes play a significant role in shaping the community assemblages, with environmental variables having distinct impacts. Traits related to structure maintenance, water absorption, cell hydration, and nutrient acquisition were found to be key drivers of functional diversity, while water-utilization traits were mainly responsible for regulating functional community structure.

Nanostructure-induced functional combination of vanishing magnetostriction and magnetic softness in ferromagnetic (GaNi)xCoCrFe (x = 0.4–1.6) high-entropy alloys

Searching for high-entropy alloys with functional properties that emerge from their multi-scale structure, we have investigated the (GaNi)xCoCrFe (x = 0.4–1.6) system. We have characterized structure, microstructure, nanostructure and chemical composition of the individual phases in the multi-phase alloys and determined their magnetic, magnetostrictive and electrical properties. We found that the alloys are ferromagnetic and exhibit functional combination of magnetic softness and vanishing magnetostriction, classifying them as energy-efficient “supersilent” materials (inaudible to a human ear) for alternating-current (AC) electromagnetic applications in the audio-frequency range. The alloys develop a two-phase structure, a face-centered cubic (fcc) and a body-centered cubic (bcc), where the fcc phase fraction decreases, while the bcc fraction increases with the increasing (GaNi)x content. Ferromagnetism of the alloys originates from the highly nanostructured bcc phase, with the ferromagnetic Curie temperatures in the range TC = 750–700 K, depending on x. The fcc phase is not nanostructured and is paramagnetic at room temperature, but undergoes a spin glass transition at Tf≈6.4 K. The magnetic softness and vanishing magnetostriction of the alloys are both nanomagnetic phenomena. The magnetic-softness and magnetostriction parameters of the x = 1.3 and 1.6 alloys make them relevant for supersilent AC applications at low frequencies.

Evolution of pore structure and cement composition during weathering of conglomerate at Mogao Grottoes in alkaline and arid regions, NW China

Numerous conglomerate grottoes have been excavated and preserved in the arid and alkaline regions of NW China. After millennia of weathering, these conglomerate grottoes have suffered from various weathering issues (such as seepage and collapse) that are internally governed by the distribution of pore networks and the degree of cementation. However, studies on conglomerate weathering have mostly been reported in humid and tropical climates, where intensive chemical weathering occurs. Additionally, characterizations of pore evolution during conglomerate weathering have been restricted due to limitations in detecting pore size and pore type using a single pore characterization method. To fill this gap, this study jointly used mercury intrusion porosimetry (MIP) and computed tomography (CT) to characterize the pore evolution process during conglomerate weathering at Mogao Grottoes, a world heritage site in NW China. Mineralogical, hydrological, mechanical and microscopic characterization were also conducted to understand the changes in compositions of bulk samples and cements during weathering. Results revealed that the majority of pores in conglomerate are concentrated in macropores > 5 μm, followed by mesopores and micropores. During weathering, volume fraction of macropores significantly increases and that of micropores decreases, with median/average pore diameters experiencing an 8- to 10-fold increase. Permeability, porosity and fractal dimension exhibited strong positive linear correlations with median/average pore diameters. Throughout weathering, the abundances of calcite and clay minerals show notable decrease, particularly in cements, resulting in an enrichment of feldspars. Frequently occurring sand-carrying wind activities and salt weathering in arid regions are inferred to be responsible for the major cement loss and porosity generation through physical processes. Our combined MIP-CT method for pore network characterization is also applicable to other lithologies with a wide range of pore sizes. The proposed mechanism of pore evolution and cementation failure provides a scientific base for protecting stone heritages in arid zones.

A novel impact approach based on electromagnetic loading technology: A case study on CFRP/Al riveted structures

To investigate the mechanical response and damage behavior of aircraft fuselage composite structures under out-of-plane impact loads more efficiently and flexibility, this paper proposed a novel impact approach and testing platform based on inductive coils to yield electromagnetic impact force. The influence of system key parameters on the electromagnetic loading waveforms were analyzed using an electromagnetic field finite element model. Single/repeated impact tests on CFRP/aluminium alloy (Al) riveted structures were conducted at different voltages (energies) based on this approach. The results indicate that the electromagnetic impact (EMI) approach exhibits significant advantages in both variable strain rate loading and continuous impact loading scenarios. This device can efficiently achieve multi-point and multiple impact loading. The electromagnetic impact forces with various amplitudes and pulse-widths can be accurately obtained by altering voltage and capacitance values, which can demonstrate the good experimental consistency of such test approach. Besides, with this test method, the load threshold for damage formation can be clearly defined: once the impact force exceeds the damage threshold load, the delamination area of the CFRP laminates expand as the impact energy increases. Note that when the provided out-of-plane impact load is slightly higher than the damage threshold load by changing the voltage, significant delamination damage may suddenly manifest in any one impact event of the repeated impacts.

Structural regulation of 1T-MoS2/Graphene composite materials for high-performance lithium-ion capacitors

Heterogeneous composite structures are considered an effective strategy by utilizing the advantages of heterogeneous components. However, the relationship between structural modifications and electrochemical performance remains inadequately understood. In this study, we leveraged DFT calculations to elucidate the key advantages of the 1T-MoS2/Gr heterostructure, including its exceptional electrical conductivity, enhanced Li+ adsorption capabilities, and improved Li+ diffusion kinetics. To synthesize the 1T-MoS2/Gr composite, we developed a facile, one-step hydrothermal method using glucose as a reducing agent, achieving an optimal heterostructure that maximized the synergistic properties of the components. By comparing different levels of graphene content, the relationship between structural regulation and electrochemical performance has been studied, and a remarkably significant heterostructure composite material (1T-MoS2/Gr-0.8) was identified. As the anode material for lithium-ion batteries (LIBs), 1T-MoS2/Gr-0.8 presents excellent cycle performance with 467 mAh g−1 under the condition (0.5 A g−1, 600 cycles). Simultaneously, when assembling the lithium-ion capacitor (LIC) device with an activated carbon (AC) cathode, even at a high power density of 11.7 kW kg−1, the energy density of the 1T-MoS2/Gr-0.8//AC LIC is as high as 137.0 Wh kg−1. Moreover, the capacity retention rate remains at 89.9 % even after 2000 cycles at 2 A g−1, demonstrating its candidacy as a high-performance anode material for LICs.

Experimental and numerical study on behavior of UHPC-filled circular stainless steel tube stub columns under eccentric compression

Ultra-high performance concrete (UHPC) filled stainless steel tube (UFSST) is a newly proposed composite structure specifically designed to withstand harsh natural environments. To study the behavior of the UFSST column, 3 axial compression and 9 eccentric compression UFSST stub columns were tested respectively. And a comprehensive parametric analysis was conducted by employing a refine finite element model validated by the test data. The results show that the thickness (t) of stainless steel tubes is a key parameter affecting the eccentric compression performance of UFSST stub column. The increase in t can significantly improve the performance of UFSST stub columns, including the ultimate bearing capacity (Nu), ultimate bending moment (Mu), and ductility (DI). Finally, a modified computational model for the bearing capacity of UFST and UFSST stub columns under eccentric compression was proposed and showed a higher prediction accuracy. For UFST and UFSST stub columns, the prediction model yielded mean values of 0.99 and 1.00 for the ratio of predicted to experimental results, with standard deviations of 0.06 and 0.08, respectively.

Exploring Alkali Hydroxide Influence on Calcium Titanate Formation for Application in Biodiesel Catalysts

Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.

Spatial‐Dependent Coupling of Electrochemistry, Mass Transport, and Stress in Silicon‐Graphite Composite Electrodes for Lithium‐Ion Batteries

AbstractThe commercialization of high‐capacity silicon materials in lithium‐ion batteries is hindered by significant volume changes. Composite anodes made from silicon and graphite, which increase battery capacity and maintain electrode structural stability, are receiving considerable attention. However, the spatial configuration of the active particles in the electrode is few investigated due to the complexity of experiments at the microscopic scale. Herein, this work focuses on electrochemical, mass transport, and stress coupling mechanisms by considering different spatial configurations of silicon and graphite. In situ electrochemical and stress measurements are first conducted to demonstrate the impact of the active material arrangement. Then, a 2D electrochemical‐mechanical model is developed considering the heterogeneity of electrochemical processes at the particle‐electrolyte interface. The results show that placing silicon in the upper active layer significantly reduces the ion transport resistance, while the graphite layer near the current collector provides a good conductive network for electron transport in the silicon layer, enhancing the performance of the composite electrode structure. By combining electrochemical and mechanical field models with experimental verification, this study deepens the understanding of composite electrode structure design, offering practical guidance for optimizing the spatial configuration of electrode materials to significantly improve battery performance.

Innovative Multielement Modification of Pitch-Derived Two-Dimensional Carbon Nanosheets as Anodes for Superior Performance Sodium-Ion Batteries.

The development of advanced anode materials for sodium-ion batteries (SIBs) using pitch-based carbon materials has the advantages of low cost, high electrical conductivity and easy structural modification. In this research, various well-established modification techniques for petroleum pitch are integrated, including the use of recrystallized NaCl as molten salt template, pretreatment and high-temperature carbonization under a pure oxygen atmosphere, and the introduction of heteroatoms (N and S) by hydrothermal methods. The resulting two-dimensional carbon nanosheets with multielement modification exhibit enhanced Na+ storage properties, thereby bringing higher cycling stability and superior rate performance. Due to its specific structure and chemical composition, NS-P-OPDC exhibited a high reversible capacity of 406.77 mAh g-1 at a current density of 100 mA g-1 and a superior rate performance of 193.20 mAh g-1 at a current density of 3 A g-1 after being applied to the anode of SIB half-cell. Especially, a capacity retention of 97.7% was still achieved after 4000 cycles. Meanwhile, the full-cell assembled by Na3V2(PO4)3 (NVP) cathode and NS-P-OPDC anode could provide a reversible capacity of 235.30 mAh g-1 at a current density of 300 mA g-1. This application proves to advance petroleum pitch-based high-performance electrodes toward greater efficiency in electrochemical energy storage.

Degradation of Concrete Cement Stone Under the Influence of Aspergillus niger Fungi

The concepts of physical and chemical transformations occurring in cement concrete under conditions of microbiological deterioration can be used to control the processes of the destruction of cement concretes in order to ensure the required durability and to predict the service life of products. The study of changes in the structural and phase composition of cement stone made of Portland cement grade CEM I 42.5N in the process of fungal deterioration for 6 months when moistened, as well as a sample of a concrete wall exposed to fungal microorganisms for 20 years, was carried out. Diffractograms of the studied cement stone samples contain a large number of pronounced narrow peaks and indicate a highly crystalline structure of phases with the presence of an X-ray amorphous phase of calcium hydrosilicates and tobermorite gel in the cement stone. Changes in the structure of cement stone under the influence of fungi are confirmed by the data of a derivatographic analysis. A decrease in the content of calcium hydrosilicates and ettringite, as well as other crystalline phases in cement stone, leads to a decrease in compressive strength by about 15% over 6 months of fungal degradation. Similar changes after 20 years of exposure to microorganisms suggest deterioration in the strength characteristics of concrete.

Microbial Surface Confined Growth Strategy for the Synthesis of Highly Loaded NiCoP Nanoparticles with Hollow Derived Carbon Shells for Sodium Ion Capture.

NiCoP is considered to be a very promising material for sodium ion (Na+) capturing, however, the volume expansion and poor cyclic stability of NiCoP during the storage limit its application. In response to these limitations, Finite element simulations are used to help in the rational design of the NiCoP structure. A novel microbial surface confined growth strategy is employed to synthesize highly loaded NiCoP nanoparticles (NiCoP NPs) supported on hollow derived carbon shells (NPC), constructing a stable composite structure known as NiCoP@NPC. The highly loaded and uniformly dispersed NiCoP NPs are anchored in-situ and fully exposed, enabling enhanced electron and ion transport efficiency and thereby boosting pseudocapacitance. The NPC from yeast played a crucial role in mitigating the volume expansion of NiCoP NPs, thereby enhancing the structural stability of the electrode. Consequently, NiCoP@NPC demonstrated a high Na+ storage capacity of 59.70 ± 1.51 mg g-1 at 1.6 V and maintained good cycling stability, retaining over 73.3% of its capacity after 80 cycles at 1.6 V. Scanning transmission X-ray microscopy (STXM) analysis confirmed the reversible conversion reaction mechanism and the robust structure of NiCoP@NPC before and after the reaction; Density function theory (DFT) and electrochemical quartz crystal microbalance (EQCM-D) further confirmed that the structural design of NiCoP@NPC promoted electron transport, Na+ adsorption as well as improved cycling stability. This study is intended to provide a new idea for the in-situ confined synthesis of metal phosphides electrodes with stable performance and structure.

Machinability characteristics study on hibiscus rosa-sinensis reinforced polymer composites using soft computing techniques

Abstract Understanding the drilling behaviour of composite materials is crucial for optimizing their manufacturing processes and enhancing their applicability across various industries. In this study, the drilling process of Hibiscus Rosa-Sinensis Polymer matrix composites is investigated due to the significance of investigating such advanced and sustainable composite materials for their potential applications. Hibiscus Rosa-Sinensis Fibers are extracted and processed from the outer bark of the hibiscus plant, are incorporated into polymer matrices in varying weight percentages (0 Wt%, 10 Wt%, 20 Wt%) to form discontinuously reinforced polymer composites. Samples with uniform dimensions of 150 × 75 × 15 mm, are used for the drilling operation using Ace Micromatic DTC-400 instrument. The project focuses on analysing the influence of key drilling input parameters such as Spindle speed, Feed rate and HRS (Hibiscus Rosa-Sinensis) Fiber weight percentage on the Thrust Force (N) and Torque (N-m) generated during drilling operations. Taguchi’s Design of Experiments with L27 orthogonal array is used to systematically optimize the input parameters to gain insights into the drilling behaviour of these composite materials. Further a second order mathematical model has been generated for Thrust Force and Torque using Response Surface Methodology (RSM). Thrust Force and Torque during drilling are measured using 9257 BA KISTLER Dynamometer coupled with DynoWare 2825 A software. The findings of this study not only contribute to a deeper understanding of the drilling process but also hold significant implications for industries reliant on composite materials. From aerospace to automotive sectors, where lightweight and durable materials are essential, to construction and renewable energy industries seeking sustainable alternatives, the application potential of hibiscus Rosa-Sinensis Fiber-reinforced composites is vast. By elucidating the intricate dynamics of drilling operations on these materials, this research paves the way for enhanced manufacturing processes and the development of advanced composite structures tailored to meet the demands of diverse industrial applications.

Adsorptive Removal of Dyes: A Comparison of Graphene Oxide to Granular Activated Carbon and Zeolite NaY

Synthetic carbon-based compounds are a prevalent wastewater contaminant that can adversely impact water resources due to their potential carcinogenic and toxic effects on aquatic biota and human health. This research investigates the versatility of graphene oxide (GO) as an alternative to commonly used adsorbents (zeolite NaY (NaY) and granular activated carbon (GAC)) for removal of synthetic cationic dyes. Rhodamine B (RhB) and methylene blue (MB), were selected as the target contaminants to represent cationic synthetic dyes with differing molecular sizes and structural compositions. Batch experiments using GO, NaY, and GAC as adsorbents were used to assess both physicochemical interactions between adsorbent surfaces and contaminants, and removal efficiency. GO demonstrated the highest removal efficiency for both target contaminants—at 99% and 86%, respectively—while the lowest removal efficiency was observed for NaY. Langmuir, Freundlich, Temkin, and BET isotherm models were used to describe the adsorption isotherms. Overall, GO demonstrated a more robust and higher removal efficiency of cationic dyes compared with GAC and NaY, indicating the potential of graphene oxide for the removal of complex structured organic contaminants in wastewater treatment.