In this work, we investigate the phonons modes behaviors of scandium-doped aluminum nitride (Sc-AlN) using first-principles density functional theory (DFT). We analyze the phononic dispersion, phonon density of states, group velocity, and Raman spectra of ScAlN for various scandium concentrations and compare them with undoped AlN. Our results show that Sc doping is significantly affect the phononic properties of AlN, including the formation of defect states within the phononic band gap and changes in the group velocities of phonon modes. Our analysis reveals that the introduction of Sc dopants causes a notable narrowing of the phononic band gap in AlN. Additionally, we observe a zero group velocity in the band gap, indicating the suppression of phononic transmission through the material. Moreover, Sc doping also affects the Raman spectrum of AlN, by inducing new vibrational modes. The known E2(high) peak in the Raman spectrum of AlN shifts to lower frequencies upon Sc doping, and new peaks appear due to the interactions of scandium and the AlN lattice. Our findings highlight the importance of understanding the effects of dopants on the phononic properties of AlScN and have implications for the design and optimization of AlScN-based devices for acoustic wave applications

5A02 Al alloys with gradient structures were designed by controlling the number of torsional revolutions of 1, 2, 4, and 8. The results showed that the yield strength increased and the uniform elongation decreased with the increasing torsional revolution. Preferable comprehensive properties with yield strength of 196.7±3.7 MPa and uniform elongation of 1.9±0.2% were obtained at the torsional revolution of 4. It is revealed that the increment in yield strength contributed by HDI stress, grain refinement and the introduction of dislocations, in which dislocation strengthening played the major role. The ductility came from HDI hardening and the strain hardening ability of the center region with low dislocation density. The finding provided a promising and cost-effective method to enhance mechanical properties of Al alloys by tailoring gradient structures.

In this research, the complex refractive index of polyaniline (PANI)/hexamethylene diisocyanate-modified graphene oxide (HDI-GO) nanocomposites has been obtained. The PANI/HDI-GO nanocomposites were prepared via in situ polymerization of aniline monomer in the presence of HDI-GO nanofillers, and their crystalline structure and surface morphology were investigated via X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements. Then, the experimental reflectance and transmittance for pure PANI and PANI/HDI-GO nanocomposite films with HDI-GO contents of 0.5, 1 and 2 wt% deposited on glass substrates were measured using UV-Vis spectrophotometry within the spectral region 300-900 nm. Then, the refractive index and extinction coefficient have been obtained using a novel method developed by the authors. The model is based on the generalized Scattering Matrix Method, which is used to obtain the theoretical values for the thin film/substrate reflectance and transmittance. Root mean square errors obtained are systematically lower than 0.21%, which corroborates the excellent accuracy of the model. The proposed method does not require sophisticated equipment, just a spectrophotometer, to obtain the complex refractive index of a thin film from transmittance and reflectance measurements.

Bi2212 high-temperature superconducting thin films (HTSFs) have emerged as the most promising material for terahertz (THz) devices due to their intrinsic Josephson effect. Enhancing the surface smoothness of these films is crucial for their practical application. In this study, metal nitrates were utilized as the raw material to prepare Bi2212 HTSFs on SrTiO3 (100) substrates using the Pechini sol-gel method. The chelating agent ethylenediamine tetraacetic acid (EDTA) and the surfactant polyvinyl alcohol (PVA) were employed to improve the dissolution characteristics of Bi2212 solution. The influence of various parameters such as sintering temperatures, surfactant concentrations, and metal ion ratios was systematically investigated to assess the phase purity, crystallinity, surface morphology, and electrical properties of the Bi2212 superconducting thin films. The results demonstrated that a higher concentration of PVA led to reduced solubility of the Bi2212 solution. Notably, when the PVA concentration was set at 1%, the fabricated Bi2212 thin film exhibited exceptional epitaxial properties, enhanced Bi2212 phase purity, reduced surface roughness, and higher Tc. These outcomes provide valuable insights for the development of Bi2212 HTSFs in superconducting devices, as they serve as a reference point for achieving optimal film characteristics.

The analysis of transient phenomena in electromagnetic pulse welding is of great interest for unraveling the underlying principles. This research systematically investigates the mechanism of the discharge phenomenon by integrating finite element modeling with surface morphology analysis. The results revealed that the discharge area is discretely distributed on the surface, primarily concentrated around the welding area where the severe collision occurs. In contrast, when the collision is eliminated, the discharge is confined only to the edge. Given a fixed input energy, the discharge ablation on the surface is more pronounced for materials with a low work function. The research further establishes that both electron emission and the intense electric field contribute to the discharge behavior. This discharge behavior subsequently leads to high temperatures in the discharge area, facilitating element diffusion and shock wave generation. However, intermetallic compounds are not observed due to the brief duration of the discharge. This study illuminates the adverse effects of the collision and provides profound insights into the dynamic behaviors during welding. The findings offer valuable theoretical guidelines for the development and optimization of welding processes.

In this study, the adsorption of three industrial gases (CO2, NO2 and SO2) on ZrSe2 monolayers with modified transition metal (TM=Y, Zr, Nb, Mo, Rh, Ru, Pd, Ag) are calculated using first-principles methods for possible applications of different TM-ZrSe2 as industrial gas sensors and adsorbents. Studying the density of states (DOS), adsorption energy (Eads), charge transfer (Q), charge difference density (CDD), work function (W) and recovery time of three kinds of gas molecules adsorbed on TM-ZrSe2 monolayers and their sensing performance are evaluated. The findings reveal that CO2 gas molecules are more likely to be adsorbed on Zr-ZrSe2 monolayer, NO2 is apt to be adsorbed on Y-ZrSe2 monolayer, and SO2 gas molecules have stronger adsorption behavior on Zr-ZrSe2 monolayer. The analysis of CDD and DOS shows that the Eads of gas molecules are related to charge transfer and orbital hybridization. Additionally, the degree of electron migration is shown by the transformation of the work function's magnitude. In summary, the effectiveness of TM-ZrSe2 as sensing materials in various gas sensors is assessed, and the desorption times are compared. We anticipate that this work will offer fresh perspectives and a theoretical basis for the possible application of the TM-ZrSe2 monolayer layer to the sensing and processing of three gases.

A study was carried out to determine the phase-dependent electromagnetic wave (EMW) absorption performance of MoS2 particles via systematically diversified hydrothermal synthesis conditions such as time, temperature, precursor molarity, and oxalic acid concentration. The formation of mixed-phase structure was verified depending on the presence of the characteristic diffraction peaks belong to 1 T (trigonal, P3̅m1 space group) and 2H (hexagonal, P63/mmc space group) phases in the X-ray diffraction (XRD) patterns. Phase-pure 2H-MoS2 was obtained at 200°C after 12 h of reaction and using 5 mmol oxalic acid. Microscopic examinations indicate that MoS2 particles formed by assembling several nanosheets to create a flower-like morphology. The size, shape, and the distance between the nanosheets were observed to change with increasing temperature, time, and acid concentration. The band gap was found to be modified depending on the phase distribution and decreased from 1.54 eV (2H) to a minimum of 0.64 eV (1 T/2H) with the formation of the 1 T (metallic) phase. Finally, the minimum reflection loss was measured as -67.73 dB (99.9999% of absorption at 9.05 GHz) with an effective absorption bandwidth (EAB) of 3.52 GHz for the sample composed of 1 T/2H mixed-phased structure.

Chloride corrosion is an important reason for the degradation of bearing capacity of reinforced concrete structures. When chloride ions transport from external environment into concrete, a part of ions will be bound by the cement matrix through the behaviors of chemical binding and physical adsorption. In this paper, the cement paste samples (R0, R5 and R15) with different degrees of calcium leaching are prepared to investigate the chloride binding capacity, by performing the experiment of chloride isothermal adsorption and desorption. In the experiment, the R0, R5 and R15 are immersed into NaCl-CH composite solutions with different chloride concentrations (Cf-Cl). The change of total binding chloride ion (TBCI), physically adsorbed chloride ion (PACI) and chemically bound chloride ion (CBCI) concentrations in the samples with Cf-Cl is obtained. Then, the linear and nonlinear adsorption laws are adopt to fit the experimental data of chloride concentrations, and the most appropriate adsorption laws are determined separately for the behaviors of TBCI, PACI and CBCI. Finally, the equations for chloride binding capacity of R0, R5 and R15 are obtained, which can be used to analyze the capacity of TBCI, PACI and CBCI of cement-based materials subjected to calcium leaching.

Lithium-sulphur batteries (LSBs) are a promising candidate for the next generation of high energy density, safe, green and affordable batteries but their practical utilization is hindered by several roadblocks including low cycle life, fast capacity fade, low sulfur utilization due to insulating nature of sulfur and “polysulfide shuttle”. This work employs multiple strategies to circumvent the aforementioned issues like utilizing (i) a reduced graphene oxide (rGO) conducting carbon framework for improving conductivity and mechanical stability of cathode, (ii) polyaniline conducting polymer with polar groups to restrain soluble lithium polysulfides (LiPS) to the electrolyte (iii) separator modification with graphene oxide to act as a second barrier layer to suppress LiPS migration and support the cathode current collector to enhance sulfur utilization. The combination of these strategies led to a LSB cell that exhibited high initial capacity, low capacity fade and improved lithium ion diffusion as well as lowered cell impedance. The synthesized cathode composite of PANI-rGO-sulfur (PGS) was characterized by several techniques like power x-ray diffraction, scanning electron microscopy, thermogravimetry etc. Electrochemical characterization of cells was performed by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic cycling. The coin cell delivered a superior initial capacity of 807 mAhg-1 at 100 mAg-1 current density. Upon cycling at a high current density of 1Ag-1 it delivered a capacity of 478 mAhg-1 with excellent stability for 500 cycles and lower capacity fade of 0.02% per cycle.

Aluminum-based composites (AMMCs) have become a popular topic in industrial progress. The aluminum (Al) structure is such that, while it is very light, it also has significant strength. This capability has increased the use of Al in various industries, especially the aerospace and marine industries, even more. Other properties of Al include the favorable plasticity of these structures. It is worth mentioning that many methods can be used to produce Al metal matrix composite (AMMC). One of these methods is Accumulated Press Bonding (APB). APB is one of the most powerful processes as a solid welding method for making MMCs. This method can be called a complex technology that has many advantages. One of this method’s main advantages is that it has a high potential to refine the nanostructures that make up a composite, making it possible to design, produce and refine composites consisting of several layers. In addition to advantages, this process also has disadvantages. Actually, in this process, the bond strength (BS) is weak. This study uses Sn particles to improve the BS of Al laminates as filler metal. So, AA1060 bars with different Wt. % of Sn particles (interlayer filler material) were manufactured at various pressing temperatures(Temp’s) and APB steps. The peeling test was used to evaluate the bonding strength. It was found that the pressing Temp increased APB number of steps and Sn Wt. %, popular bonds with upper strength were shaped. Also, to illustrate the peeling surface of AA1060/Sn samples, scanning electron microscope (SEM) was used.

The incompatible interface between carbon nitride (CN) nanosheets and polymer resin is a huge challenge to develop high-performance polymer/CN nanocomposites. Recently, the complicated surface functionalization methods reported severely hinder the commercial production and practical application of polymer/CN nanocomposites. Herein, conducted by the first-principles calculations, a simple surface engineering is put forward to change the surface characteristic of CN nanosheets by rapidly introducing oxygen atoms with a chemical oxidation method. Presented by the first-principles calculations, it is found that the introduction of oxygen atoms can enhance the adsorption energy between oxygen-doping carbon nitride nanosheets (OCN) and waterborne polyurethane (WPU) resin. As a result, a stronger interfacial interaction and better dispersion state are presented in WPU/OCN nanocomposites, thus laying the foundation for the properties enhancement. Further, effective suppression effects for thermal pyrolysis and fire hazards of WPU resin are demonstrated by OCN nanosheets. As presented by cone calorimeter results, the peak values of heat release rate and total heat release in WPU/OCN-2 are decreased to 806 kW/m2 and 43.3 MJ/m2, significantly less than those of pure WPU (1028 kW/m2 and 55.9 MJ/m2). Meanwhile, more char residue, lower signal intensity of pyrolysis gas, and a prolonged time for signal peak also confirm that the addition of 2.0 wt% OCN nanosheets can hinder the thermal degradation behavior of WPU resin. In addition, the introduction of oxygen atoms promotes the formation of hydrogen bond interactions between OCN nanosheets and WPU matrix, thus enhancing interfacial compatibility and overcoming the re-stack problem. As a result, break strength and elongation at break of WPU/OCN-2 are up to 621% and 24.4 MPa, respectively. The combination of first-principles calculations and surface engineering opens a new approach for designing and developing high-performance polymer nanocomposites.

Surface defects and the ability to tune the physicochemical properties of zirconium oxide nanoparticles (ZrO2 NPs) have made them a hot topic in biological research. We investigated the anticancer properties of Acacia nilotica (L.) fruit extract–green produced ZrO2/RGO nanocomposites (NCs). Fruit extract's polyphenolic and flavonoid compounds served as reducing and capping agents for the creation of ZrO2 adorned RGO sheets. Our goal was to maximize the anticancer potential of ZrO2/RGO NCs while simultaneously reducing their toxicity to normal tissues and reducing their impact on the environment. The XPS, XRD, TEM, SEM, EDS, and PL were used to characterize the pure ZrO2 NPs and ZrO2/RGO NCs that were green produced. XRD analysis revealed that ZrO2 crystallized in two different phases, monoclinic and tetragonal. TEM and SEM images demonstrated that ZrO2 particles were uniformly attached on RGO sheets. XPS and EDX analysis of the produced NCs verified the presence of ZrO2 and RGO. ZrO2 NPs had their particle size and PL intensity decreased after RGO addition. Anticancer data shown that ZrO2/RGO NCs was two-times more effective than pure ZrO2 NPs in inhibiting the growth of different human cancer cells (A549, HepG2, and MCF7). Mechanistic evidence revealed that intracellular reactive oxygen species production and glutathione reduction constituted oxidative stress that caused the anticancer response of ZrO2/RGO NCs. Apoptosis is also suggested by the decrease of mitochondrial membrane potential in cancer cells after they have been exposed to as produced NCs. In addition, when compared to pure ZrO2 NPs, ZrO2/RGO NCs showed greater cytocompatibility in normal cell lines (IMR90 and MCF10A). This innovative method highlights the significance of plant-based synthesis of nanocomposites for biomedical research as being both environmentally benign and low-cost.

Ni-rich layered lithiated transition metal oxide LiNi0.6Co0.2Mn0.2O2 (NCM622) is a promising candidate for Li-ion batteries. However, the high nickel content in NCM622 leads to significant capacity degradation during battery cycling. In this study, we investigated the effectiveness of niobium (Nb) doping in enhancing the performance of NCM622. Our findings demonstrate that Nb-doping reduces cation mixing and preserves the solid solution state of NCM622, as confirmed by calculated formation energy. Furthermore, the introduction of Nb imparts remarkable electrochemical properties to the material. Even under high-temperature and high-voltage conditions, the Nb-doped sample exhibits significantly improved cycling performance compared to the undoped sample, starting from the fifth cycle onwards. Through a combination of atomic-level mechanisms and experimental techniques, this research establishes that Nb-doping can enhance the structural stability and electrochemical properties of NCM622, providing a viable pathway for the industrial advancement of Ni-rich materials.

Tetragonal zirconia (t-ZrO2) with exceptional properties is crucial in catalytic applications. Defects effectively enhance its electronic properties and plasticity, making t-ZrO2 a valuable material for high-efficiency industrial catalysts, and flexible electronic devices. In this study, we utilize first-principles calculations to compare the impact of vacancy defects and nitrogen doping on the structural and electronic properties of wide bandgap semiconductor t-ZrO2. Additionally, we analyze the tuned plasticity of t-ZrO2 by varying N-dopant and vacancy concentrations using molecular dynamics simulations and cyclic-nanoindentation tests. The estimation of energy release associated with plastic deformation is conducted using the Griffith energy balance model. Our study reveals significantly distinct electronic properties and plastic deformation maps in oxygen-deficient and N-doped t-ZrO2 compared to the perfect counterpart, where the defect nature dictates the band gap energy and plastic zone size. t-ZrO2-x exhibits a greater bandgap narrowing than t-ZrO2-xNx, resulting from increased atomic displacement, decreased free energy for plastic deformation, and enhanced plastic dissipated energy. Furthermore, we demonstrate that electronic properties and the plasticity of t-ZrO2-xNx, including bandgap energy and energy release rate during cyclic-nanoindentation, are unable to compete with those of the small-bandgap counterpart t-ZrO2-x. Herein, t-ZrO2-x, x=0.2 exhibits the highest plasticity and the smallest bandgap of 1.28 eV, contrasting with the 5.6 eV bandgap of perfect t-ZrO2. Thereby, t-ZrO2-x displays pronounced band gap tightening and enriched flexibility, providing it a favorable semiconductor for photoelectrochemical energy conversion (PEC) applications.

To date, debinding and sintering of parts fabricated through material extrusion (MEX) has been done in a time-consuming disconnected approach, with geometries initially shaped, then debinded and lastly sintered. Little progress has been made to process MEX bodies within the same device, eliminating part transportation to sophisticate and expensive equipment. This study shows that debinding and sintering in-situ, within the same volume, can be achieved efficiently by selectively applying local energy on the as-built green parts. A hybrid device is disclosed, combining traditional MEX with local debinding and sintering. The hybrid machine is integrated with a low intensity infrared diode laser and an induction heater, whereby the combination of concentrated energies during the manufacturing process can lead to near-net shaped geometries. The results establish that the main binder matrix of a Highly Filled (HF) stainless steel 316 L filament can be removed effectively across the entire 3D volume during the shaping stage. It is further reported that local sintering of debinded geometries results in high densities with short soaking times, being a promising improvement compared to conventional methods. Local thermal debinding and sintering allows to simplify the processing of MEX parts, avoiding the use of toxic agents and expensive post-processing equipment.

W-Zn-Co-Y2O3 tungsten heavy alloys were produced using a two-step mechanical milling method. In the first step, Zn-Co raw materials were milled for 24 hours. Then, in the second stage, the Zn-Co compounds obtained were mechanically milled with tungsten (W) and yttrium(III) oxide (Y2O3). This study compared the new W-Zn-Co-Y2O3 alloy, obtained through two-stage mechanical alloying, with the same alloy produced using classical mechanical milling. The aim was to investigate and compare their structural, morphological, and mechanical properties. Yttrium oxide was used to promote the formation of in-situ oxide dispersoids during mechanical alloying. Oxide dispersion-strengthened tungsten heavy alloys are known for their exceptional mechanical properties, making them suitable for various high-temperature applications. The structures were analyzed using XRD, crystallite size, TEM, SEM, and EDX techniques. The microstrain of the final alloys was calculated as 15.79 ×10-3 and 13.12 ×10-3 for the classically obtained alloy and secondary milled alloys after 24 hours of milling, respectively. Additionally, the reinforcing effects of the produced alloy on single-lap joints of aluminum composites were investigated. The results demonstrated that the tungsten alloy produced using the secondary ball method exhibited better mechanical performance.

The analysis of the nanofluid flow across a spinning disc has great significance due to its wide range of applications, i.e. cancer treatments, nanoscience, chemotherapy, drug delivery, biosensors, food sciences, electronics and biomedicines. Based on the above applications, the nanofluid flow over a spinning disc is modeled. The magneto-hydrodynamic (MHD) nanofluid flow has been studied under the consequences of viscous dissipation, non-uniform heat source, and thermal radiation. The nanofluid is prepared by the dispersion of aluminum oxide (Al2O3) nanoparticles (nps) in the water. The effects of Al2O3 nps radius and inter-particle spacing (IPs) on the 2D flow of nanoliquid are also studied. The modeled equations are reset into non-dimensional form of ODEs using the similarity conversions. The numerical approach parametric continuation method “PCM” is used to tackle the reduced form of ODEs. The energy and velocities distributions are analyzed versus the discrete flow constraints and figured out for the large and IPs (h = 10 and h = 1/) and for large and small radii (Rp=5/2 and Rp=3/2) of Al2O3 nps. It has been noticed that the fluid velocity is amplified due to the rising effect of the suction factor for both large and small radii of Al2O3 nps. Moreover, it is observed that the energy conduction rate is higher when the nanoparticle volume fraction and Eckert number is rises for both cases (linear and nonlinear) of radiation.

The eigenstrain model is widely used to predict residual stress and deformation resulting from laser shock peening (LSP). However, most existing eigenstrain models rely on the input of layered average eigenstrain (LAE), which has not been fully verified, particularly considering the non-uniform eigenstrain distribution in the workpiece. To address this issue, a modified eigenstrain model is proposed that uses periodic array eigenstrain (PAE) as input to verify the accuracy of the LAE method. First, a dynamic LSP model is developed to obtain the initial eigenstrain, which is then used in both the LAE and PAE models. The effects of overlapping rate and laser energy of LSP are analyzed by comparing the results of residual stress and displacement predictions. The results show that although the LAE model accurately predicts the displacement induced by LSP, it has errors in predicting residual stress. Although the LAE model has errors in predicting residual stress, its results can still be used to predict the stress intensity factor (SIF) of laser shock peening with some fluctuations. Therefore, we conclude that the LAE method is applicable under high overlapping conditions in LSP, while the proposed PAE-based eigenstrain model provides a more accurate approach for predicting residual stress and deformation during LSP. This has practical implications for the design and optimization of LSP processes.

The quantum spin hall (QSH) insulator in a hexagonal lattice motivates the future searching for novel two-dimensional (2D) materials due to the potential applications caused by the dissipationless helical edges located in the band gap on spintronic devices, in which the symmetry of crystals has a significant effect on topological properties. Here, we investigate the topological property of the Sb2S3 monolayer by means of the group theory and symmetries based on first principle calculations. Our results demonstrate that the Sb2S3 monolayer is a Z2 insulator with a huge bulk band gap of 252 meV in the presence of SOC effect. The characterization of topological non-trivial band gap is the irreducible representation of the conduction band and valence band undergoes a reversal when crossing the path along the band gap under the operation of crystal point groups, resulting in the band inversion. This result is convinced by the evolution of the wave-functions. Our finding deepens the insight into the quantum hall effects and provides some theoretical ideas for a deeper knowledge on topological non-trivial band.

Chitin nanofibers (ChNFs) are emerging as a very attractive material due to their biocompatibility, renewability, and excellent mechanical properties. ChNFs have broad applications in various fields. In this paper, ChNFs were prepared from commercially available chitin power through a dual modification of esterification with maleic anhydride followed partial deacetylation and subsequent ultrasonic treatment. Meanwhile, potential application of the ChNFs in antireflective coatings was explored. It was found that, as the deacetylation reaction time increased, the ChNFs became finer and more uniform. The ChNFs were positively charged under acidic conditions and negatively charged under basic conditions. At pH of 3.5, the ChNFs were dispersed well in water and the ChNF suspension showed excellent stability. The ChNF coatings fabricated by casting the ChNF suspensions with pH of 3.5 on glass substrate possessed antireflective capacity and yielded a 3% transmission gain in the wavelength range of 390-800 nm compared to the uncoated glass.