The current study examines thin film flow and heat transfer phenomena with some additional effects such as magnetohydrodynamic, viscous dissipation, and slip condition over unsteady radially stretching surfaces for various shapes of copper ( Cu ) \left({\rm{Cu}}) nanoparticles dispersed in ethylene glycol ( EG ) \left({\rm{EG}}) . The effective thermal conductivity of a nanofluid made of Cu nanometer-sized particles distributed in EG {\rm{EG}} is significantly higher than that of pure EG. Partial differential equations are transformed into ordinary differential equations using the proper transformations. An effective convergent technique (i.e., BVP4C) is used to compute the solutions of nonlinear systems. MATLAB software is used to perform the calculations. The effect of numerous emerging physical characteristics on temperature and velocity, such as unsteadiness parameter ( S ) \hspace{ 1em}\left(S) , slip parameter ( K ) \left(K) , Hartmann number ( M ) \left(M) , solid volume fraction ( ϕ ) (\phi ) , and Eckert number ( EC ) \left({\rm{EC}}) is investigated and illustrated graphically. The physical quantities, such as the skin friction coefficient and the Nusselt number, are calculated, described, and displayed in tabular form. It is observed that blade-shaped Cu nanoparticles had the lowest surface drag, highest heat transfer rate, and minimum film thickness compared to the brick and cylinder-shaped nanoparticles. According to our detailed investigation blade-shaped Cu {\rm{Cu}} nanoparticle is the most suited solution for manufacturing unsteady radially stretching modules.

Due to their advantages such as high tensile strength, low cost of production, easy manufacturing methods, and ease of use, cementitious materials are extensively utilized in the construction industry. The applications of nanomaterials in cementitious materials have been found to enhance their properties. It allows molecular changes to improve the material behaviour and the performance of civil infrastructure structures, including buildings and highways. Owing to the high ductility of polyvinyl alcohol-engineered cementitious composites (ECCs), it was suggested to be used in steel-reinforced structural elements to enhance the strength and ductility of the components. The presence of hybrid fibres provided increased shattering resistance with decreased scabbing, spalling, destruction, and damage zone and better absorption of energy through distributed microcracking. The presence of nanomaterials in ECCs modifies its atomic macroscopic scales, enhancing its mechanical and microstructural properties. The versatile properties of nanomaterials offer immense potential to cementitious composite for structural applications.

Elastic modulus plays a key role in the application of porous metallic materials. However, to the best of our knowledge, few attempts have been made to model the simultaneous dependence of elastic modulus on temperature and porosity for metallic materials. The present article contributes to a rational temperature-porosity-dependent elastic modulus model for metallic materials with all parameters having definite physical significance. The model can well predict the elastic moduli of porous metallic materials, from extremely low temperature to ultrahigh temperature, and from dense material to about 0.9 porosity, with reference to an easy-to-access elastic modulus. In a special case, when intrinsic elastic modulus [M] = 2 and critical porosity P C = 1, a phenomenological parameter-free predictive model can be obtained. The model can be applied when the matrix Poisson ratio is 0.1 < v < 0.4 for Young’s modulus and 0.17 < v < 0.27 for shear modulus, which covers most metallic porous materials.

Fly ash (FA) and slag could improve the performance of glazed hollow bead (GHB) thermal insulation mortar, but little research touched on how the FA and slag affect its performance and optimize its component contents. In this study, an experimental and statistical investigation is conducted to analyze the influences of FA and slag variables on the performance of GHB mortar based on the response surface methodology (RSM). The predicted model was proved statistically significant in terms of the fluidity, compressive strength, flexural strength, and thermal conductivity. Then, the validated model was used to identify the critical parameters and discuss their mechanisms of action. It can be found that (i) FA plays a significant role in fluidity and compressive and flexural strength owing to its morphological and physical filler effects; (ii) slag has an obvious influence on compressive strength and thermal conductivity due to its microaggregate effect. Finally, optimization design was conducted using the desirability approach of RSM to give the optimal component of 20.73% FA and 21.49% slag. The predicted combination was validated by confirmatory tests within an error of 1.52%. This study provides a feasible and effective solution for optimizing GHB thermal insulation mortar to achieve higher performance.

The cost of the coolant and its disposal cost are significant issues in metal machining processes. In biocompatible magnesium alloy-based medical implants and instrument manufacturing, the cost hikes are owing to the use of unconventional machining processes and computerised numerical control machines. This research aims to improve machinability performance and optimize process parameters for biocompatible magnesium implant manufacturing for biomedical applications using eco-friendly nanofluid of MoS2 nanoparticles suspended in waste coconut oil. The nanofluid was prepared from the multiple times used waste coconut oil (waste) and was mixed with MoS2 nanoparticles. The orthogonal array L16, Taguchi analysis, and analysis of variance were employed in experimental design and statistical optimization. The machinability performance was determined by measuring and comparing the responses like cutting force, feed force, surface roughness, cutting zone temperature, and tool wear. They were compared with machining using a nanofluid and conventional commercial coolant. The results reveal that the proposed method of machining improved machinability performance appreciably; therefore, the observations of the proposed method were used and the process parameters were optimized. Mathematical models were developed for the prediction of process parameters. The proposed method exhibited the average reduction of the cutting force by 68.23167 N, feed force requirements by 34.180 N, the cutting zone temperature by 60.435°C, the surface roughness by 0.118908 µm, and the tool wear by 039938 mg·h−1.

Acoustic black holes have good application prospects in the field of vibration and noise reduction. Based on engineering practice, this study proposes a systematic process method for the application of acoustic black hole structure in raft structure, which provides new ideas and references for improving the vibration isolation performance of floating raft system and reducing the level of ship vibration and noise. The influence law of each parameter on structural vibration and the recommended value range of each parameter are given, which provides support for the systematic method and process of the application of acoustic black holes in the raft structure. Then, the acoustic black hole process is applied to a floating raft system. According to the characteristics of the raft structure, an application scheme of the acoustic black hole in the raft structure is formed, and the vibration level drop of the floating raft vibration isolation system before and after the acoustic black hole is embedded, calculated, and analyzed. The changes further improve the vibration reduction and isolation performance of the raft system and effectively reduced the mechanical noise level of the ship’s cabin.

This research focuses on the addition of low-cost rare earth metals (REMs) to improve the comprehensive properties of hyper duplex stainless steels (DSSs). The effects of REM on the microstructure, mechanical properties, and pitting corrosion of hyper DSSs were analyzed by optical/scanning electron microscope metallographic examination, X-ray diffraction analysis, tensile test, impact test, and potentiodynamic polarization test. With the addition of REM, micro/nanoscale REM inclusions were formed, and the microstructure of the alloy was refined. With the increasing content of REM, the average diameter and area of inclusions in the alloy decreased at first and then increased. While the mechanical properties showed a trend of first increasing and then decreasing. An appropriate amount of stable REM inclusions could reduce the susceptibility of pitting corrosion and improve the pitting corrosion resistance of the alloy. The hyper DSSs with REM content in the range of 0.018–0.031 wt% have excellent mechanical properties and pitting resistance.

Fused deposition modelling is known for its ability to customise materials at peak performance for instant use but lacks in terms of interfacial adhesion of layup sequences. Hence, the mechanism of acquiring excellent interfacial adhesion, mainly via dried-up printed sample, has been discovered, resulting in the proper bonding formation upon layers. Result reveals that the flexural strength increased by 23% under 70°C drying conditions (5 h) and the impact strength increased by 240% compared to pure polyamide. This mechanism resists the deformation growth between the layers and enhances the mechanical strength at the highest level.

Glass fiber-reinforced polymer (GFRP) composite materials are widely used in many manufacturing industries due to their low density and high strength properties, and consequently, the need for precision machining of such composites has significantly increased. Since composite materials have an anisotropic and heterogeneous structure, the machinability of composite materials is quite different from conventional materials. In the machining of GFRP composite pipes, tool wear, cracks or delamination, a rough surface, etc., many unwanted problems may occur. Therefore, GFRP composite pipes are difficult to process. To prevent such problems, it is very crucial to select suitable process parameters, thereby achieving the maximum performance for the desired dimensional integrity. In this study, through turning of GFRP composites with different orientation angles (30°, 60°, and 90°), the effects of cutting speed (50, 100, and 150 m·min−1), feed rate (0.1, 0.2, and 03 mm·rev−1), and depth of cut (1, 2, and 3 mm) on cutting force and surface roughness were determined. Then, with the use of these machining parameters, a model of the system for determining cutting force and surface roughness was established with artificial neural networks (ANNs). The ANN was trained using Levenberg–Marquardt backpropagation algorithm. It has been observed that the results obtained with the ANN model are very close to the data found in experimental studies. In both experimental and model-based analysis, minimum cutting force (44 N) and surface roughness (2.22 µm) were achieved at low fiber orientation angle (30°), low feed rate (0.1 mm·rev−1), and depth of cut (1 mm) at high cutting speeds (150 m·min−1).

Today, the growth of the cosmetic industry and dramatic technological advances have led to the creation of functional cosmetical products that enhance beauty and health. Such products can be defined as topical cosmetic drugs to improve health and beauty functions or benefits. Implementing nanotechnology and advanced engineering in these products has enabled innovative product formulations and solutions. The search included organic molecules used as cosmeceuticals and nanoparticles (NPs) used in that field. As a result, this document analyses the use of organic and inorganic particles, metals, metal-oxides, and carbon-based particles. Additionally, this document includes lipid and nanoparticles solid lipid systems. In conclusion, using NPs as vehicles of active substances is a potential tool for transporting active ingredients. Finally, this review includes the nanoparticles used in cosmeceuticals while presenting the progress made and highlighting the hidden challenges associated with nanocosmeceuticals.

The large-scale application of phenolic aerogel is limited by its complex and lengthy production process as well as its expensive cost. Herein a simultaneous drying-curing method for phenolic aerogels was designed based on the sol–gel process, and a series of phenolic aerogels with different hexamethylenetetramine (HMTA) contents were prepared. The material parameters such as microstructure, pore structure, mechanical properties, shrinkage, and density of the aerogel were characterized. The results show that compared with the conventional full-sealing method, the simultaneous drying-curing method shortens the preparation time of aerogels by nearly half and improves the safety of the preparation process. The prepared phenolic aerogels still maintain the nanoporous microscopic morphology. When the HMTA content is 1/6 of the phenolic mass, the linear shrinkage rates of the aerogels prepared by this method and the conventional full-sealing method are 9.8 and 9.4%, respectively. The densities are 0.25 and 0.22 g·cm−3, and the BET specific surface areas are 54.42 and 54.31 m2·g−1, and the compressive yield strengths are 1.76 and 1.16 MPa. At the same time, the thermal conductivity of the phenolic aerogels prepared by the simultaneous drying-curing method is less than 0.06 W·(m·K)–1 at room temperature. These results indicate that the properties of the aerogels prepared by the simultaneous drying-curing method are close to those prepared by the conventional method, which proves that this method has guiding significance for the large-scale, low-cost, and rapid production of nanoporous phenolic aerogels.

To achieve better mechanical properties and higher scour resistance of yellow mud in Qiang Village, this study investigated how to improve yellow mud by single factors of straw, starch, cement, and epoxy resin. First, the effect of each material on the shear strength of yellow mud was analyzed through the direct shear test, and the effect of the respective material on the scour resistance of yellow mud was examined using a self-made spray device. Subsequently, combined with the results of the two experiments, the improvement effect of the material was comprehensively studied, and the optimal dosage of the respective material was determined. Lastly, an electron microscope was used to observe the microscopic morphology of the samples, and the improvement mechanism of each material was discussed from qualitative and quantitative perspectives. As revealed by the results, straw, starch, cement, and epoxy resin improved the shear strength and scour resistance of yellow mud. Peaks of straw, starch, and epoxy resin were found in their corresponding properties-dosage curves, corresponding to the optimal dosage in the experimental range. The corresponding performance curve of cement showed a unidirectional change, which was found with a significant improvement effect.

In the course of the construction of deep foundation pits during the winter in seasonally frozen areas, the pit wall soil is often unstable due to frost heave and thawing settlement, which leads to hidden safety hazards in engineering construction. Based on the analysis of the deformation data of a pile-anchor supporting a deep foundation pit in Harbin obtained from monitoring during the winter, the influence of freezing and thawing cycles was investigated. The results show that the horizontal displacement in the middle of the shallow layer of the foundation pit is significantly larger than that on both sides during the freeze–thaw cycles, and the spatial effect becomes noticeable. The stress concentration at the external corner of the foundation pit, coupled with the effects of atmospheric precipitation and freeze–thaw cycles, led to the maximum growth rate of horizontal displacement up to 1.40 mm·day−1. The external corner effect is evident from 1 m in the shallow layer of the pit to the depth H/2 of the foundation pit. The support scheme is generally feasible, and we can appropriately enhance the support of the shallow layer of the foundation pit during the freeze–thaw cycles. For similar projects experiencing freeze–thaw cycles, the safety reserve can be appropriately enhanced when carrying out support design.

For the sustainability of the construction industry, geopolymers (GPMs) play an important role compared with Portland cement due to their improved mechanical properties, enhanced durability, and outstanding performance in alkali and acidic conditions. Most of the previous review investigations explored the general behavior of GPM developed with kaolin, silica fume (SF), rice husk ash, ground granulated blast furnace slag, fly ash, etc., but a comprehensive review study on the industrial by-products, including granite waste powder (GWP) and bauxite residue (BR), is required to investigate their suitability in the construction industry. The current investigation aims to present a detailed review of the fresh, mechanical, durability, and microstructural behavior of the GPM paste produced using BR and GWP from the literature. The effect of different ingredients and testing conditions are evaluated for the fresh, mechanical, durability, thermal, and microstructural performance of the GPM paste. The results indicate that the pure BR having a lower ratio of SiO2/Al2O3 reacts poorly; therefore, it should be blended with other aluminosilicates comprising a higher ratio of SiO2/Al2O3 for better geopolymerization. Pre-activation of BR including 3 h calcination at 800°C, 1 h thermal pretreatment of alkali with solid activators at 800°C, mechanical co-grinding, and pulverization presented improved strength and microstructural properties of GPM. When mixing GWP in large quantities, heat curing is preferred for 8 h at 60–80°C for better behavior of GPM. Incorporating the nanomaterials into GWP-based GPM showed a significant impact on initial compressive and tensile strengths. Further studies on the synergistic use of GWP with aluminosilicate products and BR with silica-rich pozzolanic ingredients for GPM are required. Improved physiochemical features of BR-GPM and GWP-GPM are the potential research areas that can be addressed by incorporating raw materials for enhancing the internal matrix, such as nanoparticles, bio-additives, micro-fibers, etc., that have been observed to be effective for the GPM pastes.

The current study has portrayed the synthetic mixtures of Themeda quadrivalvis using gas chromatography–mass spectrometry (GCMS), the combination of green silver nanoparticles (AgNPs) formed with macrolide antimicrobials. The counter microbial effects were investigated with various concentrates of plant compounds, AgNPs, and macrolide-formed AgNPs against respiratory microorganisms. GCMS examination has shown the presence of various substances that intensifies the chloroform concentrate of T. quadrivalvis. A total of 51 mixtures were distinguished, and furthermore, the most severe zone of restraint was found in chloroform removal and against Klebsiella sp. (18 ± 4.7 mm). It has been demonstrated that the green mixture of AgNPs containing macrolide anti-toxins, such as azithromycin, erythromycin, and clarithromycin, demonstrates extensive antibacterial activities against a wide range of microorganisms. In contrast, the green union of AgNPs also demonstrates their efficacy against a wide range of respiratory microbes. The particles containing numerous relatively small fragments that were observed in the scanning electron microscopy analysis were found to be 20 nm in size. Previous studies have focused on phytochemicals and green amalgamations of AgNPs, but not much detail has been provided on T. quadrivalvis. It has been reported that the two concentrates (a plant concentrate in combination with consolidated green nanoparticle macrolide anti-toxins). The present study aims to treat respiratory microorganisms with a green methodology approach using nanotechnology; this analysis primarily focuses on offering creative approaches to make drugs against respiratory microbes.

This work summarizes the different natural lighting systems applied for pollutant treatment systems using photocatalysis. The principles and fundamentals of the technologies used are revisited and examples of technologies most used for treatment either at the laboratory or at the pilot plant level are disclosed. This unveils a general panorama of treatment technologies via photocatalysis, using natural sunlight as an illumination source. Aside from these concentrated solar power systems that are inviable for photocatalytic aqueous treatments, reported scientific works are shown about heliostats, parabolic troughs, Fresnel lenses, and direct illuminated systems. As a valuable result of this review, the power used in photocatalytic systems requires higher attention not only in these systems but in laboratories and prototypes. Photocatalysts and their countless configuration variants are limited due to the potential barriers in particle borders, interfaces, and surfaces to cause redox reactions in water and pollutant target molecules. These factors reduce photocatalyst efficiencies for converting light energy to useful electron pair charge carriers for water treatments. The use of solar concentration systems applied to photocatalytic treatment systems can generate enough charge carriers, improving the efficiency of the systems, and making it feasible to scale up various configurations of this treatment pathway. Subsequently, the photocatalyst material and light are both important.

The recent advancement in graphene-reinforced aluminium matrix composites improves wear behaviour in the production of lightweight and high-performance nanocomposites. Considerable works have been devoted to using graphene nanoparticles as solid self-lubricants to increase wear resistance, minimise friction coefficients, improve service efficiency, and extend the lifespan of related sliding components. In general, wear behaviour often depends on the homogeneous distribution of graphene in the aluminium matrix. The non-uniform distribution of reinforcement due to the tendency of graphene to agglomerate in aluminium matrix and its poor wettability becomes a challenge in developing optimum functional of composites. The wettability of graphene can be enhanced by proper processing methods and sufficient addition of magnesium that can improve the wear and frictional properties of the produced composites. Hence, this review article provides recent findings and the influence of graphene as reinforcement materials in composites, including the effects on wear behaviour and friction properties. This article also discusses new advancements in the effect of graphene in self-lubricating aluminium matrix composites and the impact of reinforcement on the wear mechanisms of the composites. The future direction of the wear properties of MMCs is also covered at the end of the review.

The development of hybrid composite materials using honeycomb structure, typically a lightweight material, is commonly used in aircraft structures. However, the use of honeycomb with natural or synthetic composite remains unexplored in the literature. Therefore, this study aims to partially replace synthetic fiber, woven glass with a natural fiber of woven kenaf and honeycomb core. An experimental analysis investigated the mechanical strength of three different compositions using glass, kenaf, and honeycomb materials for structural application purposes. The properties of the sample were evaluated through the tensile, flexural, and impact strength, and the morphological damage was observed using scanning electron microscopy. The results showed that the composition of GKGKG laminate composite is the highest in tensile strength (147.64 MPa) and modulus (3.9 GPa), while the GKHKG composite was good in flexural strength (219.03 MPa) and modulus (11.47 GPa). In terms of impact properties, there was a slight difference in energy level (20–30 J) by GKGKG and GKHKG, showing the optimal hybrid configuration of composite for the newly developed material. In conclusion, the application of the new hybrid of GKHKG composite is promising in semi-structural and structural light-weight applications.

To study the effects of macro- and micro-fiber on the concrete beams, bending resistance tests were conducted on the polypropylene fiber-reinforced concrete beams. Stepwise loaded tests were carried out to obtain the load–deflection curves for different test pieces, cracking load values of the first inclined crack, recording and depicting crack development, changes in mid-span deflection of the test pieces, load–strain relationships of concrete, etc. The crack patterns and failure modes were observed. The research findings have shown that the ultimate load of the concrete beams doped with multi-size polypropylene fiber is 58.31 and 34.08% higher than that of ordinary concrete beams and concrete beams with single macro-fiber, respectively. Notably, the ultimate anti-bending bearing capacity of the beams significantly improves following the addition of macro-fiber. Polypropylene fiber can offset the defects caused by macro-fiber, remarkably suppress the development of cracks, and control the deformation of beams due to the effects of micro-fiber of different dimensions.

In this study, composite nanofiber films for the wound dressing application were prepared with silk fibroin (SF) and polycaprolactone (PCL) by electrospinning techniques, and the SF/PCL composite nanofiber films were characterized by the combined techniques of scanning electron microscopy (SEM), the equilibrium water content, Fourier transform infrared spectrometer test, X-ray diffraction (XRD) and cell viability test. The results indicated several parameters, including the rotating roller speed, solution concentration, and SF/PCL ratio, affected SF/PCL composite nanofibers’ diameter size, distribution, and wettability. The SF/PCL composite nanofiber manifested a smaller fiber diameter and more uniform nanofibers than pure PCL nanofibers. The contact angle changed from 121 ± 2° of the neat pure PCL to full wetting of 40% SF/PCL composite nanofiber films at 2,000 rpm, indicating good hydrophilicity. Meanwhile, cells exhibit adhesion and proliferation on the composite nanofiber films. These results testified that SF/PCL composite nanofiber films may provide good wettability for cell adhesion and proliferation. It was suggested that optimized SF/PCL composite nanofiber films could be used as a potential biological dressing for skin wound healing.