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Carbon Nano Tubes (CNTs) are cylindrical structured rolled up sheets of graphene. The use of CNTs is observed as increasing immensely nowadays due to its tremendous characteristical properties. The low thermal expansion coefficient (CTE) of carbon nanotubes (CNTs), their high mechanical strength, high specific surface area (SSA), and high thermal conductivity strongly idealize them as a nanostructure for enhancing the physical properties of the fibre-reinforced polymer (FRP) materials for advanced applications such as microelectronic, chemical sensors, electromagnetic interference shielding (EMI), microwave absorption, hydrogen storage and aerospace. This review is comprised of the recent advancement in the fabrication of FRP by incorporated CNTs. Moreover, different functionalization techniques are analyzed to ensure uniform dispersion of CNTs and various fabrication routes were opted to enhance the overall performance of the CNTs incorporated FRPs composites. Common characterization techniques such as scanning electron spectroscopy (SEM), Differential scanning calorimetry (DSC), Thermal gravimetric analysis (TGA) and mechanical testing are discussed to study the influence of CNTs on physical and mechanical properties of CNTs incorporated FRP composite. Furthermore, comprehensive and descriptive overview of complex characterization techniques including Brillouin scattering, Raman spectroscopy, transmission electron microscopy (TEM), Dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), is also covered in the scope of this paper which are used for studying influence of CNTs on the properties of FRP composites. This review will facilitate upcoming researchers to choose the most appropriate functionalization method of CNTs, optimized fabrication route for composite synthesis, essential characterization techniques for evaluating the performance as per required applications.

Natural fibers, which are abundant, environmentally friendly, and biodegradable, are used as a replacement for synthetic fibers. The composite strength can be increased by treating the surfaces of natural fibers with suitable chemicals, which can also improve the interface interaction between fiber and matrix. Application of a coupling agent in chemical treatment is utilized to reinforce the bonding between fiber and matrix. The objective of the study is to determine the influence of silane concentration on the Sansevieria cylindrica fiber properties. The methods included fibers treatment using ethanol and coupling agent as dissolving and TiO2 with concentrations of 0 percent, 0.25 percent, 0.5 percent, 0.75 percent, and 1 percent. The mechanical strength testing was conducted through a single fiber test. Fiber morphology was observed using an electron microscope. FTIR analyzes the change in fiber chemical composition caused by TiO2 addition. As a result, the morphology of S. cylindrica fibers became rougher and showed a rougher surface after a silane concentration of 1 percent, but with the proper concentration, some fiber surfaces provided a good interface. Ti-O bonds are formed at a wavelength of 475 cm-1. The shift in a peak at 400–500 cm-1 indicates Ti-O-Ti group stretching vibrations believed to have originated from TiO2 particles. The mechanical strength increases as the concentration of TiO2 increases, with the highest fiber strength of 284.66 MPa observed at a TiO2 concentration of 1 percent. This represents a 26 percent higher tensile strength compared to the control specimen.

The flow behaviour of AA2060 Al alloy under warm/hot deformation conditions is complicated because of its dependency on strain rates (ε˙), strain (ε), and deformation modes. Thus, it is crucial to reveal and predict the flow behaviours of this alloy at a wide range of temperatures (T) and ε˙ using different constitutive models. Firstly, the isothermal tensile tests were carried out via a Gleeble-3800 thermomechanical simulator at a T range of 100, 200, 300, 400, and 500 °C and ε˙ range of 0.01, 0.1, 1, and 10 s−1 to reveal the warm/hot flow behaviours of AA2060 alloy sheet. Consequently, three phenomenological-based constitutive models (L-MJC, S1-MJC, S2-MJC) and a modified Zerilli–Armstrong (MZA) model representing physically based constitutive models were developed to precisely predict the flow behaviour of AA2060 alloy sheet under a wide range of T and ε˙. The predictability of the developed constitutive models was assessed and compared using various statistical parameters, including the correlation coefficient (R), average absolute relative error (AARE), and root mean square error (RMSE). By comparing the results determined from these models and those obtained from experimentations, and confirmed by R, AARE, and RMSE values, it is concluded that the predicted stresses determined from the S2-MJC model align closely with the experimental stresses, demonstrating a remarkable fit compared to the S1-MJC, L-MJC, and MZA models. This is because of the linking impact between softening, the strain rate, and strain hardening in the S2-MJC model. It is widely known that the dislocation process is affected by softening and strain rates. This is attributed to the interactions that occurred between ε and ε˙ from one side and between ε, ε˙, and T from the other side using an extensive set of constants correlating the constitutive components of dynamic recovery and softening mechanisms.

This study aims to investigate the feasibility of hydroforming (HF) technology coupled with response surface optimization for producing high-quality five-branched AISI 304 stainless steel tubes with different diameters, addressing the shortcomings of traditional manufacturing processes. Conventional techniques often result in issues with multiple consumables, low precision, and subpar performance. The research focuses on finding optimal forming parameters for a more effective process. Initial attempts at a five-branched tube proved unfeasible. Instead, a multi-step forming approach was adopted, starting with the formation of the upper branch tube followed by the two reducing lower branch tubes, a strategy termed “first three, then five”. This method, enhanced by a subsequent solid solution treatment, yielded promising results: the combined height of the upper and lower branches was 141.1 mm, with a maximum thinning rate of 26.67%, reduced to 25.33% after trimming. These outcomes met the product usage requirements. Additionally, the study involved designing and developing dies for manufacturing five-branched tubes with different diameters using servo HF equipment. The effectiveness of the multi-step forming process and parameter combinations was confirmed through experimental validation, aligning closely with the FE simulation results. The maximum thinning rate observed in the experiments was 27.60%, indicating that FE simulation and response surface methodology can effectively guide the production of high-quality parts with superior performance.

Forming tubes with various bending radii without changing the bending dies is much easier for the 3D free bending forming (FBF) process. In the 3D-FBF process, different bending radii were realized by adapting the eccentricities of the bending dies. The accuracy of the U-R curve is crucial for the precision forming of complex bending components. In this study, the U-R relation curve of the Al alloy tube with a specific friction coefficient, fixed geometry size, clearance between tubes, and bending die was fitted first based on the forming results of AA6061-T6 tubes under different eccentricities. Second, the U-R relationship curve based on the experiment is used to propose the U-R relationship’s mathematical formula based on many hypotheses. Finally, the modified U-R mathematical formula was applied in the finite element (FE) simulation and the actual FBF experiments for the AA6061-T6 Al alloy complex shape space bending members. The U-R relationship curve’s reliability was verified by comparing the simulation and experimental results. The results obtained from the modified U-R relationship align well with the FE modeling results and can be directly applied to the bending process for the intended components.

This study aimed to propose a new approach for predicting the warm deformation behaviour of AA2060-T8 sheets by coupling computational homogenization (CH) with crystal plasticity (CP) modeling. Firstly, to reveal the warm deformation behaviour of the AA2060-T8 sheet, isothermal warm tensile testing was accomplished using a Gleeble-3800 thermomechanical simulator at the temperatures and strain rates that varied from 373 to 573 K and 0.001 to 0.1 s−1. Then, a novel crystal plasticity model was proposed for describing the grains’ behaviour and reflecting the crystals’ actual deformation mechanism under warm forming conditions. Afterward, to clarify the in-grain deformation and link the mechanical behaviour of AA2060-T8 with its microstructural state, RVE elements were created to represent the microstructure of AA2060-T8, where several finite elements discretized every grain. A remarkable accordance was observed between the predicted results and their experimental counterparts for all testing conditions. This signifies that coupling CH with CP modelling can successfully determine the warm deformation behaviour of AA2060-T8 (polycrystalline metals) under different working conditions.

The development of advanced composite materials has taken center stage because of its advantages over traditional materials. Recently, carbon-based advanced additives have shown promising results in the development of advanced polymer composites. The inter- and intra-laminar fracture toughness in modes I and II, along with the thermal and electrical conductivities, were investigated. The HMWCNTs/epoxy composite was prepared using a multi-dispersion method, followed by uniform coating at the mid-layers of the CF/E prepregs interface using the spray coating technique. Analysis methods, such as double cantilever beam (DCB) and end notched flexure (ENF) tests, were carried out to study the mode I and II fracture toughness. The surface morphology of the composite was analyzed using field emission scanning electron microscopy (FESEM). The DCB test showed that the fracture toughness of the 0.2 wt.% and 0.4 wt.% HMWCNT composite laminates was improved by 39.15% and 115.05%, respectively, compared with the control sample. Furthermore, the ENF test showed that the mode II interlaminar fracture toughness for the composite laminate increased by 50.88% and 190%, respectively. The FESEM morphology results confirmed the HMWCNTs bridging at the fracture zones of the CF/E composite and the improved interlaminar fracture toughness. The thermogravimetric analysis (TGA) results demonstrated a strong intermolecular bonding between the epoxy and HMWCNTs, resulting in an improved thermal stability. Moreover, the differential scanning calorimetry (DSC) results confirmed that the addition of HMWCNT shifted the Tg to a higher temperature. An electrical conductivity study demonstrated that a higher CNT concentration in the composite laminate resulted in a higher conductivity improvement. This study confirmed that the demonstrated dispersion technique could create composite laminates with a strong interfacial bond interaction between the epoxy and HMWCNT, and thus improve their properties.

Abstract A bionanocomposite based on biosynthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and reinforced with silver@zinc oxide (Ag–ZnO) was synthesized in variable loadings of Ag–ZnO using the in-situ casting dissolution technique. The degradable biopolymer PHBV had been biosynthesized from date waste as a renewable carbon source. The fabricated products were investigated as promising antibacterial materials. The Ag–ZnO nanoparticles were also synthesized using the green method in the presence of Gum Arabic. The Ag–ZnO nanoparticles were loaded within the PHBV biopolymer backbone at concentration of 1%, 3%, 5% and 10%, PHBV/Ag–ZnO(1,3,5,10%). The chemical structure, morphology, physical and thermal properties of the PHBV/Ag–ZnO bionanocomposites were assessed via common characterization tools of FTIR, TGA, XRD, SEM and EDX. One step of the degradation process was observed in the range of 200–220 °C for all the obtained materials. The onset degradation temperature of the bionanocomposites have been noticeably increased with increasing the nanofiller loading percentage. In addition, fabricated products were investigated for their interesting antibacterial performance. A detailed biological screening for the obtained products was confirmed against some selected Gram-positive and Gram-negative strains S. aureus and E. coli, respectively. Overall, the bionanocomposite PHBV/Ag–ZnO(10%) was the most potent against both types of the selected bacteria. The order of bacterial growth inhibition on the surface of the fabricated bionanocomposites was detected as follows: PHBV/Ag–ZnO(10%) > PHBV/Ag–ZnO(5%) > PHBV/Ag–ZnO(3%) > PHBV/Ag–ZnO(1%).

This paper presents a detailed methodological framework for collecting microscopic driver and vehicle behaviour data over a long road segment with an application to the entire stretch of a freeway ramp segment using single and multiple unmanned aerial vehicles (UAVs). The methodology allows users to collect reliable and complete trajectories of traffic movements in areas with challenging physical characteristics (long road segment, horizontal curvature, changing elevation, and presence of shadow), challenging traffic characteristics (high traffic volume, high speeds, and high-speed changes), and restrictive regulations (UAVs prohibited from hovering over the freeway or the right-of-way). Different UAV setups are recommended and can be used depending on the site conditions. Specific commercial software and procedures used to complete the data collection are explained. The methodology was applied at two ramps and verified with speed data acquired from differential GPS receivers using three different error metrics. The results showed good performance of the proposed methodology, including when aerial videos were taken from oblique angles. Key words: traffic data collection, microscopic driver behavior data, freeway ramp terminal, multiple unmanned aerial vehicles, traffic analysis. Cet article presente un cadre methodologique detaille pour la collecte de donnees microscopiques sur le comportement des conducteurs et des vehicules sur un long segment de route avec une application sur l'ensemble du troncon d'une bretelle d'autoroute en utilisant des vehicules aeriens sans pilote (UAV) simples et multiples. La methodologie permet aux utilisateurs de recueillir des trajectoires fiables et completes des mouvements de la circulation dans des zones presentant des caracteristiques physiques difficiles (long segment de route, courbure horizontale, elevation changeante et presence d'ombre), des caracteristiques de la circulation difficiles (debit de circulation eleve, vitesses elevees et changements de vitesse) et une reglementation restrictive (les UAV ne peuvent survoler l'autoroute ou le droit de passage). Differentes configurations d'UAV ont ete recommandees et peuvent etre utilisees en fonction de l'etat du site. Les procedures et les logiciels commerciaux specifiques utilises pour completer la collecte de donnees sont expliques. La methodologie a ete appliquee a deux bretelles et verifiee a l'aide de donnees de vitesse obtenues a partir de recepteurs GPS differentiels a l'aide de trois mesures d'erreur differentes. Les resultats ont montre un bon rendement de la methodologie proposee, y compris lorsque des videos aeriennes doivent etre prises a partir d'angles obliques. [Traduit par la Redaction] Mots-cles : collecte de donnees sur la circulation, donnees microscopiques sur le comportement des conducteurs, bretelle de sortie d'autoroute, vehicules aeriens sans pilote multiples, analyse de la circulation., 1. Introduction Little information is available in the literature about the speeds and behaviour of freeway drivers as they travel along an interchange's ramp and speed change lane (SCL). Most [...]