Optimal Properties Research Articles

Silver Nanoparticles (AgNPs) Incorporation into Polymethyl Methacrylate (PMMA) for Dental Appliance Fabrication: A Systematic Review and Meta-Analysis of Mechanical Properties

Silver Nanoparticles (AgNPs) Incorporation into Polymethyl Methacrylate (PMMA) for Dental Appliance Fabrication: A Systematic Review and Meta-Analysis of Mechanical Properties

Development and Characterization of PVA Membranes Modified with In(BTC) Metal–Organic Framework for Sustainable Pervaporation Separation of Isopropanol/Water

Development and Characterization of PVA Membranes Modified with In(BTC) Metal–Organic Framework for Sustainable Pervaporation Separation of Isopropanol/Water

Process optimization and mechanical properties analysis of Inconel 718/stainless steel 316 L multi-material via direct energy deposition

Additive manufacturing (AM), also known as 3D printing, is a recent innovation in manufacturing, employing additive techniques rather than traditional subtractive methods. This study focuses on Directed Energy Deposition (DED), utilizing a blend of nickel-based superalloy IN 718 and stainless steel SS316 powders in varying ratios (25%+75%, 50%, and 75%+25%). The objective is to assess the impact of process parameters on quality and optimize them. Mechanical properties of the different powder mixtures are compared. In the study, Taguchi-grey relational analysis is employed for parameter optimization, with four key factors identified: laser power, overlap ratio, powder feed rate, and scanning speed, affecting cladding efficiency, deposition rate, and porosity. Verification experiments confirm optimization repeatability, and further fine-tuning is achieved through one-factor-at-a-time experiments. Optimized parameters yield varied tensile properties among different powder mixtures; for example, a 25% SS316L and 75% IN718 blend demonstrates the highest ultimate tensile strength (499.37 MPa), while a 50% SS316L and 50% IN718 blend exhibits the best elongation (13.53%). This study offers an effective approach for using DED technology to create mixed SS316 and IN718 powders, enabling tailored mechanical performance based on mixing ratios.

Evaluating novel piperazine derivatives as aluminum corrosion inhibitor: a computational study

Purpose The aim of this study is to evaluate the corrosion inhibitory properties of three piperazine derivatives – Ethyl 5-(piperazine-1-yl) benzofuran-2-carboxylate (EPBC), 5-[4–(1-tert-butoxyethenyl) piperazin-1-yl]-1-benzofuran-2-carboxamide (BBPC) and Tert-butyl-4–(2-(ethoxycarbonyl)benzofuran-5-yl)-piperazine-1-carboxylate (TBPC) – on Al surfaces in the presence of hydrochloric acid (HCl). The research uses density functional theory (DFT) and molecular dynamics simulations to explore the effectiveness of these derivatives as corrosion inhibitors and to understand their adsorption behavior at the molecular level. Design/methodology/approach This study uses a computational approach using DFT at various levels (B3LYP/6–31+G(d,p), B3LYP/6–311+G(d,p), WB97XD/DGDZVP) to calculate essential quantum chemical parameters such as energy gap (ΔE), ionization energy (I), absolute electronegativity (χ), electron affinity (E), dipole moment (µ), absolute softness (s), fraction of electron transferred (ΔN) and absolute hardness (η). The Fukui function and local softness indices are used to assess the sites for electrophilic and nucleophilic attacks on the inhibitors. Molecular dynamics simulations are performed to analyze the adsorption behavior of these derivatives on the Al (110) surface using the adsorption locator method. Theoretical methods like DFT provide quantum chemical parameters, explaining inhibitor reactivity, whereas molecular dynamics simulate adsorption behavior on Al (110), both supporting and correlating with experimental inhibition efficiency trends. Findings This study demonstrates that all three piperazine derivatives exhibit strong adsorption on the Al surface, with high adsorption energies, good solubility and low toxicity, making them effective corrosion inhibitors in acidic environments. Among the three, TBPC showed superior inhibitory performance, particularly in the presence of HCl, due to its optimal electronic properties and stable adsorption on the Al (1 1 0) surface. Originality/value This research contributes to the field by combining DFT calculations and molecular dynamic simulations to evaluate the corrosion inhibition potential of piperazine derivatives comprehensively. This work advances the understanding of the adsorption mechanisms of organic inhibitors on metal surfaces and offers a detailed quantum chemical and adsorption behavior analysis.

Effect of Mn/P atomic ratio on the microstructure and properties of Cu-Mn-P alloy

In this study, Cu-Mn-P alloys with Mn/P atomic ratios ranging from 1 to 3 were designed based on computational phase diagrams. The microstructures of these alloys were systematically investigated using a combination of TEM, EPMA, EBSD, and XRD. The results indicate that the alloy with a Mn/P atomic ratio of 2 exhibits optimal comprehensive properties. A simple thermomechanical treatment involving solution treatment followed by 70 % cold rolling and aging at 400°C for 6 hours resulted in a hardness of 186.8 HV, a tensile strength of 577 MPa, a yield strength of 548 MPa, and an electrical conductivity of 63.5 % IACS. Alloys with Mn/P ratios below 2 showed a reduced density of precipitates, leading to diminished precipitation hardening, while higher ratios resulted in increased manganese content in the solid solution, causing lattice distortions and reduced conductivity. TEM analysis confirmed that the precipitated phase was rod-shaped hexagonal Mn2P, which grew along the (100) plane of the matrix and maintained a coherent interface with the matrix. This research provides insights for the future development of high-performance quaternary Cu-Mn-X-P alloys.

Improving Antimicrobial Properties of Biopolymer-Based Films in Food Packaging: Key Factors and Their Impact

Biodegradable films derived from polysaccharides are increasingly considered eco-friendly alternatives to synthetic packaging in the food industry. The study’s purpose was to improve the antimicrobial properties of biopolymer-based films made from starch, chitosan, alginate, and their blends (starch/chitosan and starch/alginate) and to evaluate the effects of modifiers, i.e., plant extracts, plasticizers, cross-linking agents, and nanofillers. Films were prepared via the Solution Casting Method and modified with various plasticizers, calcium chloride, oxidized sucrose, and nanofiber cellulose (NC). Chestnut, nettle, grape, and graviola extracts were tested for antimicrobial activity against Staphylococcus epidermidis, Escherichia coli, and Candida albicans. The film’s mechanical and hydrophilic properties were studied as well. The chestnut extract showed the strongest antimicrobial properties, leading to its incorporation in all the films. The chitosan films displayed better antibacterial activity against Gram-positive than Gram-negative bacteria but were ineffective against C. albicans. NC significantly improved the mechanical and antimicrobial properties of the chitosan films. The alginate films, modified with various plasticizers cross-linked with calcium chloride, demonstrated the highest antimicrobial efficacy against E. coli. The starch films, cross-linked with oxidized sucrose, exhibited slightly lower antimicrobial resistance due to a more compact structure. Films such as ALG6 and ALG5, including plasticizers EPGOS and PGOS, respectively, indicated optimal hydrophilicity and mechanical properties and achieved the best antimicrobial performance against all the investigated microorganisms. All these findings highlight the potential of these biodegradable films for food packaging, offering enhanced antimicrobial activity that prolongs shelf life and reduces spoilage, making them promising candidates for sustainable food preservation.

Uncovering the Potential of Two-Dimensional SrRuO3 as anode material in Li, Na, Mg, Ca, K, and Zn ion Batteries: First-Principles investigations of structural, electronic and electrochemical properties

The development of robust and efficient electrode materials is priority area in the battery research to realize large capacity, high stability, and hasty carrier mobility. In this study, first principles investigations are carried out to evaluate potential of SrRuO3 as anode material for use in rechargeable monovalent and multivalent ion batteries including Li ion batteries (LIBs), Na ion batteries (NIBs), Mg ion batteries (MIBs), Ca ion batteries (CIBs), potassium ion batteries (KIBs) and Zn ion batteries (ZIBs). The optimal anodic properties of the material are systematically examined, focusing on its structural properties, electronic characteristics, diffusion barriers, storage capabilities, and studies on adsorption sites. The layered structure of the material appeared to accommodate several atoms of different metal during charge / discharge cycles. The exothermic interactions of Li, Na, Mg, Ca, K, and Zn with the host SrRuO3 show their appropriateness for the intercalation process in the batteries. The storage capacity for the LIB, NIB, MIB, CIB, KIB, and ZIB is calculated as 1211 mAhg−1, 990 mAhg−1, 2201 mAhg−1, 1100 mAhg−1, 770 mAhg−1 and 1516 mAhg−1, respectively. The respective values of open circuit voltage are determined as 0.48 V, 0.94 V, 1.3 V, 1.15 V, 0.7 V and 1.17 V for LIB, NIB, KIB, MIB, CIB and ZIB. The minimal diffusion barrier calculated for active ion migration of Li (0.38 eV), Na (0.18 eV), K (0.35 eV), Mg (0.81 eV), Ca (0.86 eV) and Zn (0.92 eV) in the host material indicate excellent transport character for the batteries. The low values of volume expansion (%) of the host material calculated as 1.29 %, 30 %, 25 %, 5 %, 12 % and 7 % for LIB, MIB, KIB, NIB, CIB and ZIB respectively, point to good cyclic stability. Furthermore, non-equilibrium Greens function approach was employed to examine electron transport characteristics involved in solid electrolyte interphase (SEI) formation. The findings of the study predict the excellent anodic performance of SrRuO3 for multivalent ion batteries.

Optimizing the properties of nano WC-10Co-4Cr HVOF coatings by using RSM

One of the limitations of using tungsten carbide nanoparticles in the HVOF coating method is decarburization of these particles during the coating operation. These unwanted changes lead to severe drop in coating properties. Optimized effective HVOF parameters is one of the solutions to control this issue. In this article, HVOF effective parameters (oxygen flow rate, powder flow rate and spray distance) were optimized using RSM (response surface methodology) to control this phenomenon and achieve optimum hardness, deviation of hardness and bending strength. The results showed that oxygen flow rate has the greatest effect on hardness and hardness deviation, while spray distance has the most influence on bending strength. In order to obtain optimal properties, in oxygen flow rate: 858 lit/min, distance: 34 cm and powder flow rate: 82 gr/min, the highest hardness (>1270HV0.1) and strength (cracking bending angle <80 degrees) and the lowest hardness deviation (<17HV0.1) reached with more than 92% probability. The validity of the results was confirmed by using XRD analysis. The validation results confirmed the coating properties and RSM model.

Thermo-Mechanically Coupled Settlement and Temperature Response of a Composite Foundation in Complex Geological Conditions for Molten Salt Tank in Tower Solar Plants

The degradation of complex geological structures due to thermo-mechanical cycling results in a reduction in bearing capacity, which can readily induce engineering issues such as uneven settlement, cracking, and even the destabilization of the foundations of molten salt storage tanks. This study establishes a foundational model for a molten salt storage tank through the use of COMSOL Multiphysics and conducts a numerical simulation analysis to evaluate the settlement deformation and temperature distribution of the foundation under the influence of thermo-mechanical coupling. Concurrently, the research proposes two distinct design approaches for the tank’s foundational structure. A comparative analysis of the results indicates that the use of a pile raft foundation in conjunction with a traditional foundation mode results in a reduction of settlement at the center of the foundation’s top surface by 380.1 mm, while also decreasing the maximum effective stress in the steel ring wall by 240.7 MPa. The thermal effects impact a depth of 10 m in the foundation soil and an influence radius of 20 m. Additionally, the foundation soil exhibits optimal thermal insulation properties, resulting in minimal energy loss. These findings indicate that the pile raft foundation in conjunction with a traditional foundation mode displays remarkable adaptability to complex geological conditions, with both settlement and temperature distribution of the foundation maintained within acceptable limits.

Preparation and Electromagnetic-Wave-Absorption Properties of Cement-Based Materials with Graphite Tailings and Steel Fiber

The development of functional building materials that can absorb electromagnetic radiation is important for preventing and controlling electromagnetic pollution in urban areas. In this study, cement-based electromagnetic wave (EMW)-absorbing materials were created using graphite tailings (GTs) as a conductive admixture and steel fiber (SF) as an EMW absorber, which resulted in materials with a wide effective bandwidth and high reflection loss (RL). In particular, a GT–cement matrix with excellent mechanical and electrical properties was obtained. This study explored the influence mechanism of the SF content on the mechanical, electrical, and EMW-absorption properties of cement-based materials under the synergistic effect of GTs and SF. Findings demonstrate that the combination of GTs and SF notably improved the electrical and EMW-absorption characteristics of the cement-based materials. Optimal EMW-absorption properties were observed for a combination of 30% GTs and 6% SF. A developed cement-based EMW-absorbing material with a thickness of 20 mm displayed a minimum RL of −25.78 dB in the frequency range of 0.1–5 GHz, with an effective bandwidth of 0.953 GHz. Thus, the cement-based composite materials developed in this study have excellent EMW-absorption performance, which provides an effective strategy for preventing and controlling electromagnetic pollution in urban spaces.

Effect of bionic shield texture on friction behavior of silicon carbide under water lubrication condition

Abstract Reasonable texture parameters can effectively generate local dynamic pressure effects and promote the formation of lubrication film. The synergistic friction reduction mechanism of the shield-shaped texture on the Silicon Carbide (SiC) surface under water-based lubrication conditions between the flow pressure effect and the ‘rolling ball’ effect is investigated by combining simulation analysis and friction experiments. The effects of shield textured surface on the friction and wear characteristics of SiC surface and the characteristics of interfacial polarization electric field under different rotational speeds and different load conditions were analyzed. The results display that synergistic texture lubrication has a beneficial effect on improving tribological properties. The surface with 6% texture area occupancy showed the best tribological characteristics. The surface with a textured area occupancy of 6% displays the optimal tribological properties. Moreover, the friction reduction mechanisms under different working conditions are discussed, with the textured uniformly arranged surfaces being more suitable for high-speed and heavy load (140 N, 2000 rpm) conditions and the textured non-uniformly arranged surfaces being more suitable for low-speed and light load (40 N, 400 rpm) conditions.

In Situ Crosslinked Biodegradable Hydrogels Based on Poly(Ethylene Glycol) and Poly(ε-Lysine) for Medical Application.

Hydrogels have emerged as promising biomaterials due to their excellent performance; however, their biocompatibility, biodegradability, and absorbability still require improvement to support a broader range of medical applications. This paper presents a new biofunctionalized hydrogel based on in situ crosslinking between maleimide-terminated four-arm-poly(ethylene glycol) (4-arm-PEG-Mal) and poly(ε-lysine) (ε-PL). The PEG/ε-PL hydrogels, named LG-n, were rapidly formed via amine/maleimide reaction by mixing 4-arm-PEG-Mal and ε-PL under physiological conditions. The corresponding dry gels (DLG-n) were obtained through a freeze-drying technique. 1H NMR, FT-IR, and SEM were utilized to confirm the structures of 4-arm-PEG-Mal and LG-n (or DLG-n), and the effects of solid content on the physicochemical properties of the hydrogels were investigated. Although high solid content could increase the swelling ratio, all LG-n samples exhibited a low equilibrium swelling ratio of less than 30%. LG-7, which contained moderate solid content, exhibited optimal compression properties characterized by a compressive fracture strength of 45.2 kPa and a deformation of 69.5%. Compression cycle tests revealed that LG-n demonstrated good anti-fatigue performance. In vitro degradation studies confirmed the biodegradability of LG-n, with the degradation rate primarily governing the drug (ceftibuten) release efficiency, leading to a sustained release duration of four weeks. Cytotoxicity tests, cell survival morphology observation, live/dead assays, and hemolysis tests indicated that LG-n exhibited excellent cytocompatibility and low hemolysis rates (<5%). Furthermore, the broad-spectrum antibacterial activity of LG-n was verified by an inhibition zone method. In conclusion, the developed LG-n hydrogels hold promising applications in the medical field, particularly as drug sustained-release carriers and wound dressings.

Effect of Deformed Prior Austenite Characteristics on Reverse Phase Transformation and Deformation Behavior of High-Strength Medium-Mn Steel.

In this study, microstructure evolution during prior austenite decomposition and reverse phase transformation processes was revealed in a high-strength medium-Mn steel. Furthermore, the relationship between deformed prior austenite characteristics and deformation behavior was studied. The results indicated that the recovery and recrystallization of the deformed prior austenite were significantly inhibited during hot rolling in the non-recrystallized zone, the grain size was obviously refined along the normal direction (ND), and that the strain hardening of prior austenite via hot deformation could increase the resistance of shear transformation, resulting in the preservation of high-density lattice defects in the quenched martensite matrix. Before the nucleation of intercritical austenite, the dislocation and grain boundary can provide fast diffusion paths for C and Mn, and the enrichment of C and Mn before intercritical austenite formation can reduce the critical temperature of ferrite/austenite transformation. The nucleated sites and driving force for intercritical austenite were strongly increased by rolling in the non-recrystallization region. The resistance of crack propagation was found to be enhanced by the sustained transformation-induced plasticity (TRIP) effect (via retained austenite with different stability) and for the laminated microstructure, the optimum properties were obtained as being a combination of yield strength of 748 MPa, tensile strength of 952 MPa, and total elongation of 26.2%.

Experimental study on optical properties of various paraffin-based PCM glazing unit and radiative transfer model optimization

Integrating phase change material (PCM) into glazing units can lead to the ability of dynamic response to solar radiation and enhance thermal mass. In order to clarify the optical performance of phase change material glazing unit (PCMGU) during the dynamic response stage, this study analyzes the variations of transmittance and reflectance of PCMGUs filled with different paraffins during phase change process, by using a spectrophotometer and a temperature measurement device. Additionally, the impact of the paraffin cooling rate on this process was also examined. The experimental results indicate that: (1) During the solid-liquid phase change process, the curve of PCMGU transmittance and reflectance versus paraffin temperature exhibits a significant linear characteristic, with 75–93 % of transmittance and reflectance changes appearing during this stage; (2) Adjusting the paraffin cooling rate does not alter this linear characteristic; (3) Approximately 19 % and 36 % of PCMGU transmittance and reflectance changes occur during the solid-solid phase change process, respectively. Finally, based on the experimental patterns, the radiative transfer model for PCMGU was optimized, reducing its calculation error to a range of 0.17–0.92 times that of previous models (in terms of root mean square error).

Effect of industrial multi-walled carbon nanotubes on the mechanical properties and microstructure of ultra-high performance concrete

To enhance the safety and functionality requirements of engineering structures, carbon nanotubes are used to improve the performance of concrete. However, their high cost limits their large-scale application. In this study, industrial multi-walled carbon nanotubes (IMWCNT) were employed to ultra-high performance concrete (UHPC) to achieve a balance between nanomodification and economy. The effects of different IMWCNT contents on the flowability, mechanical properties, and water resistance of UHPC were investigated. Moreover, the hydration products, microstructure, and fiber–matrix interface characteristics of UHPC specimens were analyzed using thermogravimetric analysis and scanning electron microscopy. The incorporation of appropriate amounts of IMWCNTs could effectively improve the mechanical properties and crack resistance of UHPC and partly prevent the infiltration of water into the matrix. Adding 0.1 wt% IMWCNTs resulted in optimal mechanical properties, and the flexural/compressive strengths of fiberless UHPC mortar and fibrous UHPC (2 vol% steel fibers) were increased by 6.7/5.2 % and 8.5/11.3 %, respectively. Microstructural analysis of the samples showed that uniformly dispersed IMWCNTs can enhance cement hydration and bridge the cracks at the microscale and nanoscale. In addition, incorporating an appropriate amount of IMWCNTs in UHPC reduced the porosity of its fiber–matrix interface and optimized steel fiber distribution in the matrix. Cost-benefit analyses results showed that although the addition of IMWCNTs increases the manufacturing cost of fibrous UHPC, their addition in moderate amounts (0.1 wt%) does not adversely affect the economic index due to the improvement in mechanical properties.

Upcycling of molybdenum tailings, coal gangue and slag into sustainable repaired composites by geopolymerization technology: Workability, embodied carbon and mechanical-microstructural development

The major disadvantage of reinforced concrete structure was multi cracks under loading, seriously affecting its normal performance, but using traditional repaired materials to strengthen reinforced concrete structures can bring some side-effects, such as higher carbon oxide and cost. Herein, this study successfully designed an eco-friendly geopolymer repaired composites developed by molybdenum tailings, ground granulated blast-furnace slag and coal gangue. Firstly, the fresh and harden properties of geopolymer repaired composites was systematically studied including water bleeding rate, fluidity, setting time, unconfined compressive strength and bonding strength. The micro performance of geopolymer repaired composites was analyzed via scanning electron microscopy, thermogravimetry-derivative thermogravimetry, X-ray diffraction and fourier transform infrared spectroscopy to give some new viewpoints for revealing the coupled geopolymerization mechanism of molybdenum tailings/coal gangue/ground granulated blast-furnace slag in geopolymer repaired composites. Meanwhile, the gray level of concrete contact surface is calculated. The results show that the properties of geopolymer repaired composites with 5% NaOH designed by 1:3 binder/sand, 0.5 w/c and 1:3 molybdenum tailings/ground granulated blast-furnace slag were optimal properties with 1.73% water bleeding rate, 192 mm fluidity, 58 min and 178 min the initial and final setting time, respectively, 21.443 MPa 28-d unconfined compressive strength and 2.642 MPa bonding strength. Excessive NaOH amount would inhibit the unconfined compressive strength and bonding strength of geopolymer repaired composites, while the increase of ground granulated blast-furnace slag would improve unconfined compressive strength and bonding strength. The primary hydration products of geopolymer repaired composites were C–S–H and C-A-S-H gels. Molybdenum tailings, coal gangue, and ground granulated blast-furnace slag showed an important synergistic effect, improving its geopolymerization reaction and strength. Besides, bonding strength of geopolymer repaired composites was highly correlated with unconfined compressive strength and fractal dimension of surface roughness. The relation coefficients are 0.92005 and 0.94006, respectively. With the higher the unconfined compressive strength of geopolymer repaired composites and the larger fractal dimension of the concrete contact surface, the bonding strength of geopolymer repaired composites is higher and the bond between geopolymer repaired composites and concrete is denser. The increase in the amount of NaOH and the increase in ground granulated blast-furnace slag have an increasing and decreasing trend on the carbon emissions of geopolymer repaired composites, respectively. The most obvious increasing and decreasing trends are that the carbon emissions of GRC increase from 66.41 kg CO2-e/m3 to 96.28 kg CO2-e/m3 and decrease from 79.81 kg CO2-e/m3 to 76.37 kg CO2-e/m3. The increase in the amount of NaOH is the main reason for the increase in the carbon emissions of geopolymer repaired composites, while the increase in ground granulated blast-furnace slag helps to reduce the carbon emissions of geopolymer repaired composites. The carbon emission of geopolymer repaired composites was reduced by 75.08%–83.4% compared with traditional mortar. The 28-day per unit unconfined compressive strength carbon emission of the geopolymer repaired composites with the optimal mix is 46.63% lower than that of the traditional mortar. Overall, this study can provide new viewpoints and novel channels for converting solid waste, including molybdenum tailings and coal gangue, into green recycled construction materials, provide highly promising insight for designing green construction products and new ideas in the development of low-carbon remediation materials for environmental sustainability, contribute an important force to environmental protection, and promote the growth of economic benefits in the process.

Elevating alloy performance: the role of bioactive glass in Mg-9Al-Zn matrix composites through friction stir back extrusion

ABSTRACT This study investigates the impact of friction stir back extrusion (FSBE) parameters on the microstructure and mechanical properties of magnesium matrix composites reinforced with bioactive glass particles. Higher rotational speeds (1600 rpm) generate more heat and stirring, promoting finer grains and better particle dispersion, while lower speeds lead to larger grains. Conversely, slower extrusion speeds allow more time for heat dissipation and better mixing, contributing to smaller grains and a more uniform particle distribution. Key findings show that increasing the bioactive glass content enhances both hardness and ultimate tensile strength (UTS), with optimal mechanical properties achieved at 1600 rpm rotational speed, 48.97 mm/min extrusion speed, and 5 vol.% bioactive glass. The introduction of bioactive glass particles restricts grain growth and improves load transfer, thereby reinforcing the composite. Additionally, the study identifies a gradient microstructure in the composite wire, with smaller grains near the surface due to higher plastic strain and temperature, in contrast to the core, which exhibits larger grains.

On the Peculiarities of Wire-Feed Electron Beam Additive Manufacturing (WEBAM) of Nickel Alloy–Copper Bimetal Nozzle Samples

In order to gain insight into the unique characteristics of manufacturing large-scale products with intricate geometries, experimental nozzle-shaped samples were created using wire-feed electron beam additive technology. Bimetal samples were fabricated from nickel-based alloy and copper. Two distinct approaches were employed, utilizing varying substrate thicknesses and differing fabrication parameters. The two approaches were the subject of analysis and comparison through the examination of the surface morphology of the samples using optical microscopy, scanning electron microscopy, and X-ray diffraction analysis. It has been demonstrated that the variation in heat flux distributions resulting from varying the substrate thicknesses gives rise to the development of disparate angles of grain boundary orientation relative to the substrate. Furthermore, it is demonstrated that suboptimal choice of the fabrication parameters results in large disparities in the crystallization times, both at the level of sample as a whole and within the same material volume. For example, for the sample manufacturing by Mode I, the macrostructure of the layers is distinguished by the presence of non-uniformity in their geometric dimensions and the presence of unmelted wire fragments. In order to characterize the experimental nozzle-shaped samples, microhardness was measured, uniaxial tensile tests were performed, and thermal diffusivity was determined. The microhardness profiles and the mechanical properties exhibit a higher degree of strength than those observed in pure copper samples and a lower degree of strength than those observed in Inconel 625 samples obtained through the same methodology. The thermal diffusivity values of the samples are sufficiently close to one another and align with the properties of the corresponding materials in their state after casting or rolling. The data discussed above indicate that Mode II yields the optimal mechanical properties of the sample due to the high cooling rate, which influences the structural and phase state of the resulting products. It was thus concluded that the experimental samples grown by Mode II on a thinner substrate exhibited the best formability.

Utilizing Binary Phase Segregation and Extrusion to Enhance the Electronic Properties of Graphene Nanocomposites.

Our goal in this study is to incorporate graphene nanoplatelets (GNPs) in a polymer blend of poly(lactic acid) (PLA) and isotactic polypropylene (iPP) to facilitate the dispersion of GNPs and use the morphology of phase segregation to create a pathway for concentrating GNPs to achieve percolation with lower GNP concentration. Investigating the interfacial properties between PLA/GNPs and iPP/GNPs, we noticed that iPP has a lower contact angle on GNPs compared to PLA on GNPs. This showed a great potential that the GNP are easily confined in iPP rather than in PLA domains or at the PLA/PP interfaces. Utilizing this property, as the PLA content increases, the iPP content decreases, resulting in a reduction of the available space for GNPs. This decrease in space leads to a higher chance for GNPs to accumulate together. Furthermore, through careful control of the concentration in the immiscible blend of PLA/PP, it is possible to achieve a bicontinuous structure. This structure facilitates the creation of a pathway for the fillers, allowing for the use of minimal GNPs while achieving optimal electrical conductivity properties. The PLA/PP/GNPs can be oriented by the shear forces coming from the nozzle that produce a higher performance.

Advancing nonlinear problem solutions: Newton-like iterative techniques for varied convergence orders using homotopy perturbation

Abstract Iterative methods are crucial in numerical analysis for approximating solutions to nonlinear problems encountered in various fields, such as biomathematics, thermodynamics, chemical engineering, and fluid mechanics. This paper introduces innovative iterative methods of convergence orders three and six to eight, developed using the homotopy perturbation technique (HPT). We address the limitations of traditional derivative-based methods by incorporating divided differences, resulting in derivative-free schemes with optimal convergence properties. We present four newly designed algorithms (HPM1, HPM2, HPM3, and HPM4) and provide a comprehensive convergence analysis. Numerical simulations and basins of attraction demonstrate the superior performance of the proposed methods compared to existing methods of the same order. The proposed methods exhibit faster convergence and larger basins of attraction, making them highly effective for solving nonlinear equations. Our new numerical methods rely on approximations and iterative processes, with each small step bringing us closer to the exact solution. Exploring these numerical methods encourages us to apply mathematics to solve challenging problems in physics, engineering, finance, and more.