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The sol-gel approach prepared Sr-doped BiFeO3 samples using citric acid as fuel. The structure, lattice dynamics, magnetization, and dielectric properties have all been studied using various techniques, including the LCR meter for dielectric analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and vibrating sample magnetometer (VSM). X-ray diffraction (XRD) analysis of powdered Sr-doped BiFeO3 shows the formation of a pure BiFeO3 rhombohedral structure of the perovskite-type. The FESEM micrograph shows the morphology of the pallets of the samples unaffected by Sr doping at low concentrations. Vibrational modes surrounding the Fe–O–Fe stretching bonds are briefly described by FTIR spectra in transmittance mode. Moreover, it has been found that at room temperature, the dielectric constant and dielectric loss tangent of the samples, evaluated in the frequency range of 100–107 Hz, decrease significantly. The magnetic investigation results indicate that the saturation magnetization is slightly enhanced with an increased concentration of Sr2+. The pristine BiFeO3 had the lowest remanent magnetization value. The ions' saturation magnetization and remanence magnetization values reached 1.85 emu/g and 0.88 emu/g, respectively, at x = 0.25. [ABSTRACT FROM AUTHOR]

Here, the abilities of Fe-Si42, Fe-Al21N21, Cu-C60, Cu-B30P30, Fe-SiNT(9, 0), Fe-AlNNT(9, 0), Cu-CNT(6, 0) and Cu-BPNT(6, 0) as nano-catalysts of OER and ORR processes are investigated in alkaline environment. The calculated formation energy of Fe- and Cu-doped nanocages and Fe- and Cu-doped nanotubes (Fe-Si42, Fe-Al21N21, Fe and Cu doped nanotubes) are acceptable values and these structures are stable. The Fe-AlNNT(9, 0) and Cu-BPNT(6, 0) have higher capacity for adsorption of OER/ORR species than other studied catalysts. The *OH removal and *OOH formation on Fe-Si42, Fe-Al21N21, Fe and Cu doped nanotubes are potential-determining steps for OER/ORR processes in alkaline environment. The Fe-AlNNT(9, 0) and Cu-BPNT(6, 0) catalysts for OER/ORR processes have lower over-potential than other studied catalysts. The Fe-AlNNT(9, 0) and Cu-BPNT(6, 0) as effective catalysts are suggested to catalyze the OER/ORR processes in alkaline environment. [ABSTRACT FROM AUTHOR]

In daily routine movement, the ankle joint plays a crucial role in stability and mobility, especially when different types of terrain are involved. However, the simple task of standing can become a biomechanical difficulty when performed on a slope since demands that have to be accommodated are made on the complex structure of the ankle joint. The purpose of this study is to develop finite element (FE) models of the ankle joint with different inclined foot postures and to analyse the stress distributions on the ankle joint while standing on an inclined or declined surface. In this study, the FE model of the foot was developed, and von Mises stress distribution at the ankle joint was explored. The results show that the bone, cartilage, and ligament of the ankle experienced a different von Mises stress distribution pattern during flat standing in comparison with slope standing. In addition, this study found that the maximum von Mises stress distribution at the component of the ankle joint is higher during slope standing than flat standing. Taken together, these results suggest that slope standing, both inclined and declined, with more than 10° inclination, might contribute to a higher risk of injury as a higher maximum stress was observed. Therefore, to maintain proper body posture, it is suggested that weight be evenly distributed at both feet, since this can reduce stress at the ankle. [ABSTRACT FROM AUTHOR]

An effective approach to enhance the photocatalytic performance of CuO nanoparticles (NPs) is the use of hydrothermal synthesis. The CuO NPs were synthesized by hydrothermal technique in the presence of anionic surfactant. Structural, functional, morphological, chemical composition and optical properties of the synthesized NPs were characterized by using XRD, FTIR, SEM, UV-visible DRS and PL. The average crystallite size for pure, 0.05 M SHMP and 0.05 M SHMP assisted CuO samples are around 13 nm, 11 nm and 10 nm respectively. It was observed that the size of particle is affected by the nature of surfactant. Additionally, in all the samples, FTIR spectra show three identical Cu-O vibration modes that indicate the presence of crystalline CuO monoclinic structure. Thus, the spherical like CuO nanostructure can be used as an ideal material for photocatalytic performance. The synthesized NPs are then used to photo-catalytically degrade the methyl violet dye in aqueous media. Surfactant-assisted CuO NPs showed better photocatalytical activity than bare CuO NPs. [ABSTRACT FROM AUTHOR]

Surgeons face a significant challenge due to the heat generated during drilling, as excessive temperatures at the bone–tool interface can lead to irreversible damage to the regenerative soft tissue and result in thermal osteonecrosis. While previous studies have explored the use of machine learning to predict the temperature rise during bone drilling, this in vitro study introduces a comprehensive approach by combining the Response Surface Methodology (RSM) with advanced machine learning techniques. The main objective lies in the comprehensive evaluation and comparison of support vector machine (SVM) and random forest (RF) models specifically for the optimization of the bone drilling parameters to prevent thermal bone necrosis. A total of 27 experiments were conducted using a multi-level factorial method, with analysis performed via the Minitab software version 19.1. Performance metrics such as the mean squared error (MSE), mean absolute percentage error (MAPE), and coefficient of determination (R2) were used to assess model accuracy. The RF model emerged as the most effective, with R2 values of 94.2% for testing and 97.3% for training data, significantly outperforming other models in predicting temperature fluctuations. This study demonstrates the superior predictive capabilities of the RF model and offers a robust framework for the optimization of surgical procedures to mitigate the risk of thermal damage. [ABSTRACT FROM AUTHOR]

The sol–gel auto-combustion process synthesized materials with Mg2+ and Ce3+-substituted CoFe2O4 nano ferrites. The research focuses on the nanoparticles, specifically Co1−xMgxFe2−yCeyO4 (where x = 0.0, 0.25, 0.5, and 0.75; y = 0.0, 0.03, 0.06, and 0.09) (CMC) ferrite nanomaterials characterizations utilizing techniques such as XRD, FESEM with EDS, FTIR, electrical analysis, and VSM. The X-ray powder diffraction (XRD) patterns indicate the formation of a spinel structure, with no distinct peaks for rare earth ions, likely due to their minimal doping. Increasing the ionic sizes of RE3+ ions decreases the lattice parameter of the resulting nanoferrites. Field emission scanning electron microscopy (FESEM) shows the samples are aggregated and nearly spherical. At the same time, energy-dispersive X-ray spectroscopy (EDS) confirms the presence of Co, Mg, Ce, Fe, and O. Fourier-transform infrared spectroscopy (FTIR) absorption bands predict the range of spinel ferrites, indicating that RE3+ ions replace Fe3+ ions in the B sites. DC electrical resistivity decreases with the concentration of substituted ions. Dielectric properties, including the dielectric constant, dielectric loss, and AC conductivity, were studied using LCR meters across various frequencies. AC conductivity increases with frequency while both the dielectric constant and loss decrease. These observations align with the Maxwell–Wagner polarization theory. The magnetic properties of CMC nanoparticles, such as squareness ratio (SQR = Mr/Ms), coercivity, saturation magnetization, remanence, and magnetic moment, were determined and analyzed using the vibrating sample magnetometer (VSM). [ABSTRACT FROM AUTHOR]

In the present investigation, aluminum metal matrix composites (AMMs) reinforced with aluminum nitride (AlN) nanoparticulates at different volumetric ratios of (0, 0.5, 1, 1.5, and 2 vol.%) were manufactured via a microwave-assisted powder metallurgy technique. The morphological, physical, mechanical, and electrochemical properties of the produced billets were examined to reflect the impact of the successive addition of AlN into the aluminum (Al) matrix. The morphological analysis revealed the high crystalline patterns of the formation of the Al-AlN composites. The microstructural analysis confirmed the presence of the elemental constituents of Al and AlN particles in the fabricated composites, showing an enhanced degree of agglomeration in conjunction with the additional amount of AlN. Positive behavior exhibited by the micro- and nanohardness was noticeable in the Al-AlN composites, especially at the ultimate concentration of AlN in the Al matrix of a 2 vol.%, where it reached 669.4 ± 28.1 MPa and 659.1 ± 11 MPa compared to the pure Al metal at 441.2 ± 20 MPa and 437.5 ± 11 MPa, respectively. A declining trend in the compressive strength was recorded in the reinforced Al samples. The corrosion resistance of the AlN-reinforced Al metal matrix was estimated at 3.5 wt.% NaCl using electrochemical impedance spectroscopy and potentiodynamic polarization. The results reveal that the inclusion of 2.0 vol.%AlN led to the lowest corrosion rate. [ABSTRACT FROM AUTHOR]

MoO3 thin film was fabricated on an indium tin oxide substrate using the physical vapor deposition technique. X‐ray diffraction and scanning electron microscopy study to investigate surface morphology, grain size, and surface structure, which are critical for absorbing solar spectra in water splitting for hydrogen energy generation. Ultraviolet–visible spectroscopy was used to confirm the absorption of solar spectra and the percentage of transmittance. Fourier‐transform infrared analysis provided the functional groups present in the deposited thin film. The Tauc plot was used to determine the thin‐film band gap, which allowed for the analysis of charge carrier transitions from the conduction band to the valence band. Electrochemical impedance spectroscopy investigations confirmed the charge transfer processes to the counter electrode and electrolyte interfaces. The observed low curve for MoO3 indicated low resistance and allowed efficient charge transfer. Linear sweep voltammetry analysis was used to measure photocurrent and solar light to hydrogen emission when the thin film was exposed to solar spectra. The thin film's observed hydrogen emission rate was 3731.74 mol g−1 h−1, and the STH% of MoO3 was found to be 0.345% at 0.8 V. These findings highlight the promising potential of MoO3 as a material for hydrogen energy generation using solar light. [ABSTRACT FROM AUTHOR]

The quest for lightweight, high-performance structural materials for demanding applications such as in the fields of automotive, aerospace, and other high-tech and military industries pushes the boundaries of material science. The present work aims to draw attention to a novel, sustainable manufacturing approach for the development of next-generation 7xxx series aluminum alloys that have higher strength by rejuvenating a sustainable compositional and thermomechanical processing strategy. Our innovative strategy integrates two key synergies: trace hafnium (Hf) addition for microstructural refinement, unique thermomechanical treatment involving cryorolling, and a short annealing method. Experimental results revealed that our base alloy exhibited a 33 µm grain size and impressive initial mechanical properties (334 MPa UTS, 150 HV). Adding 0.6 wt.% Hf and employing 50% cryorolling with short annealing led to a remarkable 10 µm grain size reduction and significant mechanical property leaps. The resulting alloy boasts a 452 MPa UTS and 174 HV, showcasing the synergistic advantageous effect of Hf and cryorolling plus annealing treatment. The developed alloys were compositional- and work hardening-dependent, leading to a rich mix of strengthening mechanisms. Optical and scanning electron microscopy reveal several intermetallic phases within the fcc matrix, wherein the Al3Hf phase plays a key role in strengthening by impeding dislocation movement. In addition to experimental results, a 12-full-factorial design experiment via ANOVA analysis was also utilized to validate the significant influence of Hf and cryorolling on properties with (p-values < 0.05). Among the different parameters, cryorolling plus annealing appeared as the most noteworthy factor, followed by the composition. Using the regression model, the ultimate tensile strength and hardness were predicted to be 626 MPa UTS and 192 HV for an alloy with 0.6 wt.% Hf and 85% cryorolling, which opens a new avenue for ultra-high-strength Al7xxx alloys. [ABSTRACT FROM AUTHOR]

In the process of solar photovoltaic, ferroelectric semiconductors such as BiFeO3 are found to be new class of materials as an alternative to traditional semiconductors for more energy generations. The efficient chare transformation as well as the enhanced optical absorbance are the key factors for better performance of these ferroelectric semiconductors, which can be facilitated by depositing plasmonic Au nanoparticles on the surface of BiFeO3. As a result, the photoelectrochemical (PEC) and photovoltaic (PV) performance of BFO could be enhanced. We developed the BiFeO3 nanostructures via a facile approach and then we have deposited Au nanoparticles on the surfaces of the BiFeO3 nanoparticles. Electron microscopic images revealed the aggregation of 20–40 nm sized BiFeO3 nanoparticles and the spherical shaped Au nanoparticles of ~ 30 nm. In addition to a noticeable enhancement in the optical spectrum, the plasmonic effect could be seen in the absorbance spectra after the decoration of Au nanoparticles. In order to assess the enhanced photovoltaic and photoelectrochemical performance of the Au-decorated BFO nanostructures, a comparative examination of pristine BFO was performed. Studies on the time-dependent photocurrent density also confirmed the stability of treated photoelectrode materials using Au nanoparticles. This really raised the charge transfer efficiency by delivering better conductivity, which was investigated using Nyquist plot. The incident photon-to-current conversion efficiency [IPCE(%)] also confirmed the enhancement of photovoltaic by Au nanoparticles. The DSSC efficiency of produced Au-decorated BiFeO3 nanostructures is ~ 20% higher than the pristine BiFeO3-based cells. [ABSTRACT FROM AUTHOR]

Postural stability may be affected during slope walking, as there are different body kinetics and kinematic responses compared with level walking. Understanding body adaptations toward different inclinations is essential to prevent the risk of injury from falls or slips. This study was conducted to determine the correlations between stability parameters and loading response in terms of joint reaction force at the lower-extremity joints during inclined and declined walking. Twenty male subjects walked in the level, incline, and decline directions on a custom-built platform at three different slope angles (i.e., 5°, 7.5°, and 10°). To determine the ground reaction force (GRF), joint reaction force (JRF), center of pressure (COP), and center of mass (COM), a motion capture system was used to read the data of the ten reflective markers and transfer them to visual three-dimensional (3D) software. Pearson's correlation test was performed with statistical significance set at p < 0.05 to evaluate the correlation of the required coefficient of friction (RCOF), postural stability index (PSI), and COP-COM distance with the JRF. This study has identified that the JRF changes in opposition to the changes in the RCOF during the initial strike during incline and decline walking, as JRF increases, the RCOF decreases with different strengths of correlation. There is also a strong positive correlation between the PSI and JRF in the proximal–distal direction, where the JRFs change in accordance with the change in the PSI, and the JRF increases with the increment of PSI. In addition, the JRF of the lower extremity also changed in a manner similar to the COP-COM distance in the medial–lateral direction. Overall, each stability parameter was correlated with the JRF of the lower-extremity joints in different directions and strengths. This study demonstrated that slope walking is particularly affected by surface inclination in terms of stability and loading. Therefore, this research can serve as a basis for future studies on slopes, as there is no specific basis for a maximum degree of inclination that is safe and suitable for all applications. [ABSTRACT FROM AUTHOR]

Spinal deformity refers to a range of disorders that are defined by anomalous curvature of the spine and may be classified as scoliosis, hypo/hyperlordosis, or hypo/hyperkyphosis. Among these, scoliosis stands out as the most common type of spinal deformity in human beings, and it can be distinguished by abnormal lateral spine curvature accompanied by axial rotation. Accurate identification of spinal deformity is crucial for a person's diagnosis, and numerous assessment methods have been developed by researchers. Therefore, the present study aims to systematically review the recent works on spinal deformity assessment for scoliosis diagnosis utilizing image processing techniques. To gather relevant studies, a search strategy was conducted on three electronic databases (Scopus, ScienceDirect, and PubMed) between 2012 and 2022 using specific keywords and focusing on scoliosis cases. A total of 17 papers fully satisfied the established criteria and were extensively evaluated. Despite variations in methodological designs across the studies, all reviewed articles obtained quality ratings higher than satisfactory. Various diagnostic approaches have been employed, including artificial intelligence mechanisms, image processing, and scoliosis diagnosis systems. These approaches have the potential to save time and, more significantly, can reduce the incidence of human error. While all assessment methods have potential in scoliosis diagnosis, they possess several limitations that can be ameliorated in forthcoming studies. Therefore, the findings of this study may serve as guidelines for the development of a more accurate spinal deformity assessment method that can aid medical personnel in the real diagnosis of scoliosis. [ABSTRACT FROM AUTHOR]

Ti–Nb–Fe–Sn alloys with relatively low Nb content, located near the phase boundary of (β + ω)/β, are designed on the basis of electron‐to‐atom (e/a) ratio, d‐electron alloy design concept, and Mo equivalent (Moeq) aiming at low Young's modulus comparable to human bone. The effect of Sn content and Nb content on the microstructure and the mechanical properties is investigated in Ti–5Nb–3Fe–(0–6)Sn (at%) and Ti–(3–9)Nb–3Fe–4Sn (at%) alloys. The composition dependence of Young's modulus and tensile strength of Ti–Nb–Fe–Sn alloys is analyzed in terms of the phase stability, ω phase, and recrystallization texture. Both Nb and Sn are effective in suppressing the athermal ω phase and stabilizing the β phase. The recrystallization texture is strongly influenced by the content of Sn and Nb. A strong {110}β<001>β Goss texture is formed in the Ti–5Nb–3Fe–(2–4)Sn and Ti–(3–5)Nb–3Fe–4Sn alloys. The Ti–5Nb–3Fe–4Sn alloy exhibits an exceptionally low Young's modulus of 30 GPa due to the combined effects of low stability of the β phase, a small amount of ω phase, and a strong Goss texture. [ABSTRACT FROM AUTHOR]

An understanding of the biomechanical characteristics and configuration of flexible and locked plating in order to provide balance stability and flexibility of implant fixation will help to construct and promote fast bone healing. The relationship between applied loading and implantation configuration for best bone healing is still under debate. This study aims to investigate the relationship between implant strength, working length, and interfragmentary strain (εIFM) on implant stability for femoral midshaft transverse fractures. The transverse fracture was fixed with a fragment locking compression plate (LCP) system. Finite element analysis was performed and subsequently characterised based on compression loading (600 N up to 900 N) and screw designs (conventional and locking) with different penetration depths (unicortical and bicortical). Strain theory was used to evaluate the stability of the model. The correlation of screw configuration with screw type shows a unicortical depth for both types (p < 0.01) for 700 N and 800 N loads and (p < 0.05) for configurations 134 and 124. Interfragmentary strain affected only the 600 N load (p < 0.01) for the bicortical conventional type (group BC), and the screw configurations that were influenced were 1234 and 123 (p < 0.05). The low steepness of the slope indicates the least εIFM for the corresponding biomechanical characteristic in good-quality stability. A strain value of ≤2% promotes callus formation and is classified as absolute stability, which is the minimum required value for the induction of callus and the maximum value that allows bony bridging. The outcomes have provided the correlation of screw configuration in femoral midshaft transverse fracture implantation which is important to promote essential primary stability. [ABSTRACT FROM AUTHOR]

The powder metallurgy method was used to manufacture three Ti-based alloys: Ti-15%Zr-2%Ta-4%Sn (Ti-Zr-Ta-4Sn), Ti-15%Zr-2%Ta-6%Sn (Ti-Zr-Ta-6Sn), and Ti-15%Zr-2%Ta-8%Sn (Ti-Zr-Ta-8Sn). Electrochemical measurements and surface analyses were used to determine the effect of Sn concentration on the corrosion of these alloys after exposure to a simulated body fluid (SBF) solution for 1 h and 72 h. It was found that the passivation of the alloy surface significantly increased when the Sn content increased from 4% to 6% and then to 8%, which led to a significant reduction in corrosion. The impedance spectra derived from the Nyquist graphs also explained how the addition of Sn significantly improved the alloys' polarization resistances. According to the change in the chronoamperometric current at an applied anodic potential over time, the increase in Sn content within the alloy significantly reduced the currents over time, indicating that the uniform and pitting corrosion were greatly decreased. The formation of an oxide layer (TiO2), which was demonstrated by the surface morphology of the alloys after exposure to SBF solution for 72 h and corrosion at 400 mV (Ag/AgCl) for 60 min, was supported by the profile analysis obtained by an X-ray spectroscopy analyzer. It was clear from all of the findings that the tested alloys have a remarkable improvement in resistance to corrosivity when the Sn content was increased to 8%. [ABSTRACT FROM AUTHOR]

Studies on paediatric spines commonly use human adult or immature porcine spines as specimens, because it is difficult to obtain actual paediatric specimens. There are quite obvious differences, such as geometry, size, bone morphology, and orientation of facet joint for these specimens, compared to paediatric spine. Hence, development of synthetic models that can behave similarly to actual paediatric spines, particularly in term of range of motion (ROM), could provide a significant contribution for paediatric spine research. This study aims to develop a synthetic paediatric spine using finite element modelling and evaluate the reliability of the model by comparing it with the experimental data under certain load conditions. The ROM of the paediatric spine was measured using a validated FE model at ±0.5 Nm moment in order to determine the moment required by the synthetic spine to achieve the same ROM. The results showed that the synthetic spine required two moments, ±2 Nm for lateral-bending and axial rotation, and ±3 Nm for flexion-extension, to obtain the paediatric ROM. The synthetic spine was shown to be stiffer in flexion-extension but more flexible in lateral bending than the paediatric FE model, possibly as a result of the intervertebral disc's simplified shape and the disc's weak bonding with the vertebrae. Nevertheless, the synthetic paediatric spine has promising potential in the future as an alternative paediatric spine model for biomechanical investigation of paediatric cases. [ABSTRACT FROM AUTHOR]

The design of the implant and osseointegration play an important role in the long-term stability of implants. This study aims to investigate the impact of porous implants on full and partial osseointegration in varying bone qualities. Finite element models of porous implants were modeled and assembled with normal and weak bones considering full and partial osseointegration. These assemblies were simulated under an occlusal load of 200 N when the outer surfaces of bones were fixed in all directions. The results showed that in the case of full osseointegration, the stresses in surrounding bones were increased with decreasing implant stiffness, while decreased in partial osseointegration. Moreover, the maximum octahedral shear strain in the weak bone exceeded 3000 µε in all the cases but decreased (from 7256 to 3632 µε) with decreasing implant stiffness. According to the mechanostat hypothesis, using porous implants in normal bone may enhance bone density in full osseointegration, while susceptivity of bone damage may reduce in weak bones using porous implants. Thus, careful selection of implant material and design based on the patient's specific bone quality is crucial for successful outcomes. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the influence of magnesium (Mg) on the mechanical properties and corrosion behavior of wrought Al–4Cu–xMg–0.6Ag alloys. The results from Optical Microscope, SEM, XRD analysis, and Thermo-Calc simulation were used to identify the microstructure formed after the aging process. Testing for hardness and tensile strength was conducted, in addition to corrosion testing. It was found that Mg significantly impacts the hardness of the alloys, with a high Mg content (low Cu/Mg ratio) increasing the hardness but reducing the tensile strength and ductility. This study attributed this to the formation of the S phase, which is dependent on both the quantity in the bulk and the size of the phase. The grain size was found to be finer with a higher Mg content, since the particle size inhibits grain growth during the artificial aging process. Counterintuitively, the corrosion activity was reduced in the high-Mg-content alloy due to its large particle size and the reduced galvanic cell effect. This study highlighted the importance of considering the effects of Mg on the mechanical properties and corrosion behavior of Al–Cu–Mg–Ag alloys. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation (SDIE) is considered a sustainable and environmentally friendly technology for using solar energy to produce fresh water, which is a crucial resource for the existence of human life. Porous membranes are widely used in SDIE owing to their porous structure, which is highly suitable for this kind of photothermal material and allows an efficient supply of water and escape of vapor during the evaporation process. Electrospinning is perhaps the most versatile technique to produce highly porous structures of nanofiber membranes with a large surface-to-volume ratio, high porosity, low density, and many advantages. Nevertheless, acquiring a stronger background on the initial research questions in this enticing field of research needs further investigation. Typically, for the enhancement of process control, the impact of flow rate on the morphology of the prepared membrane is quite important. This research article has two-fold objectives: firstly, it discusses the fundamental description of the photothermal conversion mechanism of polymer-based photothermal materials for water treatment. A systematic investigation supported by previous studies revealing the working mechanism and the design of solar-driven interfacial evaporation has been provided. On the other hand, our interim experimental results elaborate on the influence of process conditions such as electrospinning parameters on the structural morphology and diameter of fabricated electrospun nanofibers produced by using the coaxial electrospinning setup in our lab. The scanning electron microscope (SEM) was used to examine the morphology of the electrospun nanofibers. Our introductory results provide a useful insight into tuning the necessary process parameters to fabricate electrospun polyacrylonitrile (PAN) nanofiber membranes by electrospinning technique. From our preliminary results after the three processing experiments, it is revealed that a polymer concentration of 10% wt., an applied voltage of 20 kV, a tip-to-collector distance of 18 cm, and a flow rate of 0.8 mL/h produce the optimum nanofiber membranes with a uniform structure and a diameter in the range 304–394 nm. The variation in the diameter of nanofibers in the three processing conditions is endowed by the regulation of the initiating droplet extruded from the tip of the metallic needle (syringe jet) to the collector using the electrospinning setup. [ABSTRACT FROM AUTHOR]

Ti-15%Zr alloy and Ti-15%Zr-2%Ta alloy were fabricated to be used in biomedical applications. The corrosion of these two alloys after being immersed in simulated body fluid for 1 h and 72 h was investigated. Different electrochemical methods, including polarization, impedance, and chronoamperometric current with time at 400 mV were employed. Also, the surface morphology and the compositions of its formed film were reported by the use of scanning electron microscope and energy dispersive X-ray. Based on the collected results, the presence of 2%Ta in the Ti-Zr alloy passivated its corrosion by minimizing its corrosion rate. The polarization curves revealed that adding Ta within the alloy increases the corrosion resistance as was confirmed by the impedance spectroscopy and current time data. The change of current versus time proved that the addition of Ta reduces the absolute current even at high anodic potential, 400 mV. The results of both electrochemical and spectroscopic methods indicated that pitting corrosion does not occur for both Ti-Zr and Ti-Zr-Ta alloys, even after their immersion in SBF solutions for 72 h. [ABSTRACT FROM AUTHOR]

Very often, pure Ti and (α + β) Ti-6Al-4V alloys have been used commercially for implant applications, but ensuring their chemical, mechanical, and biological biocompatibility is always a serious concern for sustaining the long-term efficacy of implants. Therefore, there has always been a great quest to explore new biomedical alloying systems that can offer substantial beneficial effects in tailoring a balance between the mechanical properties and biocompatibility of implantable medical devices. With a view to the mechanical performance, this study focused on designing a Ti-15Zr-2Ta-xSn (where x = 4, 6, 8) alloying system with high strength and low Young's modulus prepared by a powder metallurgy method. The experimental results showed that mechanical alloying, followed by spark plasma sintering, produced a fully consolidated (α + β) Ti-Zr-Ta-Sn-based alloy with a fine grain size and a relative density greater than 99%. Nevertheless, the shape, size, and distribution of α-phase precipitations were found to be sensitive to Sn contents. The addition of Sn also increased the α/β transus temperature of the alloy. For example, as the Sn content was increased from 4 wt.% to 8 wt.%, the β grains transformed into diverse morphological characteristics, namely, a thin-grain-boundary α phase (αGB), lamellar α colonies, and acicular αs precipitates and very low residual porosity during subsequent cooling after the spark plasma sintering procedure, which is consistent with the relative density results. Among the prepared alloys, Ti-15Zr-2Ta-8Sn exhibited the highest hardness (s340 HV), compressive yield strength (~1056 MPa), and maximum compressive strength (~1470). The formation of intriguing precipitate–matrix interfaces (α/β) acting as dislocation barriers is proposed to be the main reason for the high strength of the Ti-15Zr-2Ta-8Sn alloy. Finally, based on mechanical and structural properties, it is envisaged that our developed alloys will be promising for indwelling implant applications. [ABSTRACT FROM AUTHOR]

The primary objective of this research was to open a promising avenue for designing new low-cost precipitation-hardened Al base alloys in semblance with the desired mechanical properties that can be exploited in the fabrication of lightweight exoskeleton frames, prosthetics, and wheelchair components. In multicomponent Al-Cu-based systems (2xxx), the substitution of elements such as copper (Cu), magnesium (Mg), and akin Cu/Mg ratio are mainly manipulated to improve the mechanical strength of these alloys. Nonetheless, these kinds of alloying optimizations are not well suited from the cost and sustainability points of view. The starting point of the present work is to screen out the optimum value of the Ag/Sn ratio, which can be a potential substitute for the conventional Cu/Mg alloy ratio in Al-Cu-Mg-based ternary alloys without sacrificing its key features of mechanical properties. Based on our microstructural and mechanical results, it was found that the chemical composition and microstructure were the most important variables influencing the mechanical properties. The increase in the mechanical strength of our alloys was mainly attributed to the precipitation hardening phenomenon. Typically, at peak-aged conditions, the correlation between the mechanical and subsequent microstructural analysis revealed that the synergistic increase in Ag and Sn content in the Al-Cu-Mg-based alloy led to an improvement in the mechanical strength and its trade-offs by changing the shape and distribution of the micron-scaled second phase in the matrix. From optical microscopy and subsequent scanning electron microscopy analyses, this continuous precipitated phase in the matrix is identified as the Mg2Sn phase, which is mainly elicited from the solid-state reaction during artificial aging treatment. Indeed, the presence of suitable microstructure at the peak aged condition that has uniformly dispersed, micron-scale Mg2Sn phase proved to be very useful in blocking the dislocation glide and increasing the mechanical strength of the alloys during tensile testing. This combination of precipitation-hardening phases has not been previously observed in alloys with higher or lower Cu/Mg ratios. Among the studied alloys, the alloy having Ag/Sn ratio of 23 (and chemical composition of Al-4 Cu-0.5 Mg-0.7 Ag-0.03 Sn (wt.%)-T6 (denoted as Al-loy-4) exhibited an average ultimate tensile strength of 450 MPa which is almost four times larger than the pure aluminum having an ultimate tensile strength of 90 MPa currently used in healthcare and medical industries. [ABSTRACT FROM AUTHOR]

Herein, the dual substitution of Li/Cr in CoFe2O4 ferrite nanoparticles synthesized through the sol‐gel auto combustion method is reported. X‐ray diffraction confirms mixed cubic spinel structure, while as dense morphology with well‐defined grain boundaries with the minimum grain size of 20 nm is obtained using FE‐TEM analysis. The thermal stability of the sample improves with an increase in dopant concentration. XPS study shows that Fe and Co exhibit +2 and +3 oxidation states with lower concentrations of oxygen vacancies. Raman spectroscopy confirms the substitution of Li/Cr ions at octahedral and tetrahedral sites, and the direct bandgap increases monotonously with doping. Saturation magnetization increases for x = 0.01, but it decreases for higher dopant concentration due to the spin canting effect, and the coercivity decreases for all the doping concentrations. The photodegradation studies show the enhanced activity against crystal violet (CV) dye when exposed to sunlight for 60 min but easily recoverable using a magnet. The increased activity by the doped nanoparticles is because of the decreased coercivity, particle size, and magnetic anisotropy. A 90.4% photocatalytic degradation is obtained for the composition, x = 0.03, which suggests that it can be an effective candidate for wastewater treatment. [ABSTRACT FROM AUTHOR]

The creep behavior of single crystals of the nickel-based superalloy CMSX-4 was investigated at 1288 °C, which is the temperature of the hot isostatic pressing treatment applied to this superalloy in the industry. It was found that at this super-solvus temperature, where no γ′-strengthening occurs, the superalloy is very soft and rapidly deforms under stresses between 4 and 16 MPa. The creep resistance was found to be very anisotropic, e.g., the creep rate of [001] crystals was about 11 times higher than that of a [111] crystal. The specimens of different orientations also showed a very different necking behavior. The reduction of the cross-sectional area ψ of [001] crystals reached nearly 100 pct, while for a [111] crystal ψ = 62 pct. The EBSD analysis of deformed specimens showed that despite such a large local strain the [001] crystals did not recrystallize, while a less deformed [111] crystal totally recrystallized within the necking zone. The recrystallization degree was found to be correlated with deformation behavior as well as with dwell time at high temperature. From the analysis of the obtained results (creep anisotropy, stress dependence of the creep rate, traces of shear deformation, and TEM observations), it was concluded that the main strain contribution resulted from 〈011¯〉{111} octahedral slip. [ABSTRACT FROM AUTHOR]

A new superelastic Ti-23Hf-3Mo-4Sn biomedical alloy displaying a particularly large recovery strain was synthesized and characterized in this study. Its native passive film is very thick (18 nm) and contains very protective TiO2, Ti2O3, HfO2, MoO2, and SnO2 oxides (XPS analysis). This alloy revealed nobler electrochemical behavior, more favorable values of the corrosion parameters and open circuit potentials in simulated body fluid in comparison with commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy taken as reference biomaterials in this study. This is due to the favorable influence of the alloying elements Hf, Sn, Mo, which enhance the protective properties of the native passive film on alloy surface. Impedance spectra showed a passive film with two layers, an inner, capacitive, barrier, dense layer and an outer, less insulating, porous layer that confer both high corrosion resistance and bioactivity to the alloy. In vitro tests were carried out in order to evaluate the response of Human Umbilical Vein Endothelial Cells (HUVECs) to Ti-23Hf-3Mo-4Sn alloy in terms of cell viability, cell proliferation, phenotypic marker expression and nitric oxide release. The results indicate a similar level of cytocompatibility with HUVEC cells cultured on Ti-23Hf-3Mo-4Sn substrate and those cultured on the conventional CP-Ti and Ti-6Al-4V metallic materials. [ABSTRACT FROM AUTHOR]

Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by conventional casting techniques have been reported to date. However, no one has reported a comparison of mechanical and microstructural properties that simultaneously incorporates the effects of both alloy chemistry and mechanical testing environments for the as-cast Al-Cu-Mg-Ag alloy systems. This preliminary prospective paper presents the examined experimental results of two alloys (denoted Alloy 1 and Alloy 2), with constant Cu content of ~3 wt.%, Cu/Mg ratios of 12.60 and 6.30, and a constant Ag of 0.65 wt.%, and correlates the synergistic comparison of mechanical properties at room and elevated temperatures. According to experimental results, the effect of the precipitation state and the mechanical properties showed strong dependence on the composition and testing environments for peak-aged, heat-treated specimens. In the room-temperature mechanical testing scenario, the higher Cu/Mg ratio alloy with Mg content of 0.23 wt.% (Alloy 1) possessed higher ultimate tensile strength when compared to the low Cu/Mg ratio with Mg content of 0.47 wt.% (Alloy 2). From phase constitution analysis, it is inferred that the increase in strength for Alloy 1 under room-temperature tensile testing is mainly ascribable to the small grain size and fine and uniform distribution of θ precipitates, which provided a barrier to slip by deaccelerating the dislocation movement in the room-temperature environment. Meanwhile, Alloy 2 showed significantly less degradation of mechanical strength under high-temperature tensile testing. Indeed, in most cases, low Cu/Mg ratios had a strong influence on the copious precipitation of thermally stable omega phase, which is known to be a major strengthening phase at elevated temperatures in the Al-Cu-Mg-Ag alloying system. Consequently, it is rationally suggested that in the high-temperature testing scenario, the improvement in mechanical and/or thermal stability in the case of the Alloy 2 specimen was mainly due to its compositional design. [ABSTRACT FROM AUTHOR]

Owing to their superior biocompatibility, titanium and its alloys are often the first choice for implant materials in biomedical applications, especially for dental and bone repairs (orthodontics and prosthodontics). Titanium has low density and shows good mechanical and chemical properties. Although Ti-6Al-4V alloy exhibits excellent corrosion resistance properties, the metal ions released during corrosion are likely to induce aseptic loosening in long-term implantations. In the present study, Ti-6Al-4V alloy was subjected to two specific heat treatments, namely, air cooling and water quenching. The potentiodynamic polarization and electrochemical impedance spectroscopy measurements revealed remarkable improvement in the corrosion resistance properties of the heat-treated specimens. The presence of the β phase is a plausible reason for the improvement. Scanning electron microscopy, X-ray diffraction phase composition analysis, and microstructural characterization were performed to confirm the presence of the β phase. [ABSTRACT FROM AUTHOR]