Material Orientation Research Articles

A Piezocatalysis Strategy to Enable Efficient Redox in Solid‐State Battery

Piezocatalysis is considered to be a favorable catalytic technology by utilizing external mechanical stimulation to promote the specific redox reactions. The application of piezocatalysis in batteries is promising but faces formidable challenges. Herein, the operation principles of piezocatalysis were successfully demonstrated by constructing a solid‐state Li−Se (S) battery model with interfacial stress accumulation. Lead zirconate titanate with an ultra‐high piezoelectric coefficient was applied as the piezoelectric catalyst. The uniformity of the dipole orientation in materials was essential for achieving piezocatalysis in batteries. The accumulated high‐stress converts to piezopotential for catalyzing most reaction processes in batteries, while the rapid stress change prevents the internal charge reorganization, ensuring continuous efficient catalysis. The internal stress change alters the internal polarisation strength, driving excess screening charge to participate in the electrochemical reaction. Under piezocatalysis, solid‐state Li−Se batteries exhibited a initial discharge capacity of 670.9 mAh g−1 (99.4% of the theoretical value) at 0.1C, and Li−S batteries showed a capacity of 1463 mAh g−1 at 0.2C, which was still maintained up to 1084 mAh g−1 at an elevated rate of 0.5C. This piezocatalysis strategy provides a strong theoretical basis and design specification for enhancing Li−Se (S) cell reaction kinetics.

A Piezocatalysis Strategy to Enable Efficient Redox in Solid-State Battery.

Piezocatalysis is considered to be a favorable catalytic technology by utilizing external mechanical stimulation to promote the specific redox reactions. The application of piezocatalysis in batteries is promising but faces formidable challenges. Herein, the operation principles of piezocatalysis were successfully demonstrated by constructing a solid-state Li-Se (S) battery model with interfacial stress accumulation. Lead zirconate titanate with an ultra-high piezoelectric coefficient was applied as the piezoelectric catalyst. The uniformity of the dipole orientation in materials was essential for achieving piezocatalysis in batteries. The accumulated high-stress converts to piezopotential for catalyzing most reaction processes in batteries, while the rapid stress change prevents the internal charge reorganization, ensuring continuous efficient catalysis. The internal stress change alters the internal polarisation strength, driving excess screening charge to participate in the electrochemical reaction. Under piezocatalysis, solid-state Li-Se batteries exhibited a initial discharge capacity of 670.9 mAh g-1 (99.4% of the theoretical value) at 0.1C, and Li-S batteries showed a capacity of 1463 mAh g-1 at 0.2C, which was still maintained up to 1084 mAh g-1 at an elevated rate of 0.5C. This piezocatalysis strategy provides a strong theoretical basis and design specification for enhancing Li-Se (S) cell reaction kinetics.

Radiation Limits the Yield Potential of Main Crops Under Selected Agrivoltaic Designs—A Case Study of a New Shading Simulation Method

Agrivoltaics (APVs) represent a growing technology in Europe that enables the co-location of energy and food production in the same field. Photosynthesis requires photosynthetic active radiation, which is reduced by the shadows cast on crops by APV panels. The design of the module rows, material, and field orientation significantly influences the radiation distribution on the ground. In this context, we introduce an innovative approach for the effective simulation of the shading effects of various APV designs. We performed an extensive sensitivity analysis of the photovoltaic (PV) geometry influence on the ground-incident radiation and crop growth of selected cultivars. Simulations (2013–2021) for three representative arable crops in eastern Austria (winter wheat, spring barley, and maize) and seven different APV designs that only limited to the shading effect showed that maize and spring barley experienced the greatest annual above-ground biomass and grain yield reduction (up to 25%), with significant differences between the APV design and the weather conditions. While spring barley had similar decreases within the years, maize was characterized by high variability. Winter wheat had only up to a 10% reduction due to shading and a reduced photosynthetic performance. Cold/humid/cloudy weather during the growing season had more negative yield effects under APVs than dry/hot periods, particularly for summer crops such as maize. The lowest grain yield decline was achieved for all three crops in the APV design in which the modules were oriented to the east at a height of 5 m and mounted on trackers with an inclination of +/−50°. This scenario also resulted in the highest land equivalent ratios (LERs), with values above 1.06. The correct use of a tracker on APV fields is crucial for optimizing agricultural yields and electricity production.

Digital image correlation and infrared thermography data for seven unique geometries of 304L stainless steel

Material Testing 2.0 (MT2.0) is a paradigm that advocates for the use of rich, full-field data, such as from digital image correlation and infrared thermography, for material identification. By employing heterogeneous, multi-axial data in conjunction with sophisticated inverse calibration techniques such as finite element model updating and the virtual fields method, MT2.0 aims to reduce the number of specimens needed for material identification and to increase confidence in the calibration results. To support continued development, improvement, and validation of such inverse methods—specifically for rate-dependent, temperature-dependent, and anisotropic metal plasticity models—we provide here a thorough experimental data set for 304L stainless steel sheet metal. The data set includes full-field displacement, strain, and temperature data for seven unique specimen geometries tested at different strain rates and in different material orientations. Commensurate extensometer strain data from tensile dog bones is provided as well for comparison. We believe this complete data set will be a valuable contribution to the experimental and computational mechanics communities, supporting continued advances in material identification methods.

Ultrasonic characterization of defects in polycrystalline materials based on TFM image reconstruction using denoising diffusion probabilistic models

This paper presents a refined ultrasonic total focusing method (TFM) for accurately characterizing key defect parameters including size, orientation, and location in complex materials. The proposed approach aims to accurately reconstruct the defect shape in images compromised by grain interference. First, a TFM image database was generated with varying defect parameters and grain noise levels by adopting a custom forward modeling process based on superposition of defect and grain scattering data. Second, a new architecture called TFM-DDPM was then proposed which incorporates TFM and the conditional denoising diffusion probabilistic model (DDPM). Third, pixel-level uncertainty can be quantified through repeated sampling of noise which follows a standard normal distribution. An acceptance criterion for the reconstruction was further established by analyzing the quantified uncertainty. In simulation, the median Dice coefficient between the de-noised TFMs of 30° cracks and their corresponding ground truth images increased from 0.5585 to 0.9137 using the proposed approach, and the median IoU metric rose from 0.3875 to 0.8408. By applying the 6-dB drop approach to the reconstructed images, the root mean squared errors (RMSEs) of size, angle and location were decreased by 93.59%, 86.90% and 86.25%, respectively. It is also demonstrated that our method can reject 69.19% of incorrect characterization results caused by high levels of noise and/or images with steeply inclined (e.g., 45°) cracks, while accepting 97.29% accurate results. Experimental results obtained on nickel-based alloy K403 specimens also exhibited significant improvements. For 2–3 mm cracks, the average sizing error reduced from 0.46 mm to 0.13 mm, and the error in crack angle decreased from 28.63° to 1.50°. Comparable performance enhancements were observed for 4–5 mm cracks using the proposed approach.

Strategic priorities for digitalization of the mining sector of Kazakhstan

Global uncertainty has transformed the economy of Kazakhstan, which is striving to become a center of innovative development in Central Asia. According to the authors, one of the reasons for the raw material orientation of the country's economy, along with the predominance of energy-intensive types of production, is the technological backwardness of the mining sector. The article shows that the strategic goal of the Kazakhstan mining complex to integrate into the world economy involves a focus on innovative development. PEST analysis of the most important micro- and macroeconomic factors made it possible to assess the current situation of enterprises. It was revealed that one of the significant reasons for the innovative lag in the mining sector of Kazakhstan is the lack of a strategic vision of digital transformation and change management mechanisms among enterprises. The authors conclude that the continuous complication of mining and geological conditions and the growing demands of stakeholders require enterprises to build internal production processes, promote R&D, improve the organization of analytical work based on an engineering and economic approach to the selection of tools for the digital basis of production, and active interaction with external partners and startups. It is substantiated that for further progress an integrated approach to the creation of intra-production digital competencies is necessary; enterprises should focus on organizational and technological transformation, including changes in the organizational structure and transformation of the business model. The results of the study are of interest to industrial enterprises when they develop proactive innovative strategies focused on reorganizing operational activities and increasing investment to promote business.

Ejection and deposition of mica suspension droplets under electric field

Inkjet printing of ceramic materials is a shaping process of interest for building micrometer-sized components. It consists of depositing droplets of colloidal inks according to a printing pattern designed to obtain a given final part. Improving the printed part properties, e.g., thermal or electrical, requires to tailor the printed material's local structure and orientation. Electric field is an efficient external stimulus to control particle orientation. A major challenge is to efficiently couple the effects of electric field and those of capillary, viscous, and evaporation phenomena occurring during inkjet printing. In this paper, the effect of an external electric field on the structuration of inkjet deposits is investigated. Suspensions of mica platelets dispersed in binary mixtures of chloroform and silicone oil are ejected on demand on a glass plate. An electric potential difference is applied by means of a set of electrodes below the glass substrate, separated by a small gap in order to maximize the electric field on the surface of the plate. A cartography of splat morphology and structuration for different inks as a function of applied field is performed. Promising experimental conditions display particle arrangement and limited splat deformation, whereas others lead to fingering. This paves the way to a novel additive shaping process by adding another smaller scale of structuration to inkjet printed parts.

Energy audit based identification of energy efficiency improvement opportunities for existing houses

Energy efficiency in the building has two dimensions; efficient use of energy resources and energy conservation. Energy-efficient houses play a critical role in energy conservation and achieving sustainable built environment goals. The energy efficiency of a house depends on its building envelope (design, orientation, and energy properties of construction material) and operational characteristics appliance efficiency, energy consumption patterns). Rather than merely ensuring new houses are energy-efficient, it is vital to energy retrofit existing houses. Energy audits can assist in evaluating the energy efficiency of existing houses and identify improvement measures. The main objectives of this study were to identify efficiency improvement opportunities through an energy audit of houses and apartments in Karachi. A detailed energy audit checklist was prepared using literature, standards, expert review, and code requirements. Data was collected through physical and owner-assisted virtual audits of 58 houses in six districts of Karachi. Architectural plans, information about doors, windows, air ducts, thermal images, historical data, and material properties were collected. Audit tools included; an anemometer and thermal imagining camera during physical audits. Android applications were used during owner-assisted audits. Data were analyzed for developing descriptive graphs, U and R-values, Pareto charts, and district-wise mapping of energy properties of the material. As a result, energy improvement opportunities were proposed. These are focused on building envelope aspects, including; window orientation, minimizing air infiltration, and using heatresistant paint. Improvement measures were confirmed through thermal imaging of selected buildings.

Multi-resonance terahertz (THz) generation from magnetized cylindrical and spherical nanoclusters of AlAs and InP nanoparticles

We report a theoretical model for THz generation from the interaction of Gaussian laser beams with semiconductor nanoparticles suspended in argon gas in the presence of a DC magnetic field. Our investigations include two different shapes of nanoparticles [spherical (SNPs) and cylindrical (CNPs)]. The laser fields ionize nanoparticles converting them into plasma, which takes the form of spherical and cylindrical periodic nanoclusters with the electron density profile n=n0+nqeiqz, where q is the wave number of the density ripple and nq is the amplitude of density modulation. In our investigations, nanoparticles of AlAs and InP semiconductors are considered. Resonance condition is obtained when the laser beat frequency matches with the surface plasmon frequency of nanoparticles. We obtain resonances at two different frequencies when we apply a DC magnetic field. The resonance frequencies of THz fields shift with the nanoparticles' shape and orientation. THz field amplitude varies with material properties, spacing, size, and orientation of the nanoparticles. The applied magnetic field enhances the THz field and also helps in controlling the field profile. A THz field ∼0.1GV/cm with ∼2% efficiency is obtained for an optimized set of parameters for CNPs.

Scanning Probe Nano‐Infrared Imaging and Spectroscopy of Biochemical and Natural Materials

The mid‐infrared with a characteristic wavelength of 3–20 μm is important for a wealth of technologies. In particular, mid‐infrared spectroscopy can reveal material composition and structure information by fingerprinting chemical bonds’ infrared resonances. Despite these merits, state‐of‐the‐art mid‐infrared techniques are spatially limited above tens of micrometers due to the fundamental diffraction law. Herein, recent progress in the scanning probe nanoscale infrared characterization of biochemical materials and natural specimens beyond this spatial limitation is reviewed. By leveraging the strong tip–sample local interactions, scanning probe nano‐infrared methods probe nanoscale optical and mechanical responses to disclose material composition, heterogeneity, orientation, fine structure, and phase transitions at unprecedented length scales. These advances, therefore, revolutionize the understanding of a broad range of biochemical and natural materials and offer new material manipulation and engineering opportunities close to the ultimate length scales of fundamental physical, chemical, and biological processes.

Thermal conductivity of 3D-printed block-copolymer-inspired structures

This study primarily focuses on examining the impact that geometric structure has on thermal conductivity of multi-phase constructs in different 3D-printed poly(lactic acid), PLA, samples. The investigated structures are inspired by morphologies formed by diblock copolymers: lamellae, hexagonally packed cylinders, and gyroid. This research also investigates how volume percentage and material combination influence the thermal conductivity of these structures. The samples can be tailored to simulate various thermal management structures observed in practical applications, such as thermal interface materials in electronic devices. Thermal conductivity ratio is controlled using air, the least conductive material at 0.026 W/(m K), PLA at 0.136 W/(m K), and thermal paste at 5.11 W/(m K). Different models were tested against thermal conductivity measurements in order to capture the effect of material type (PLA-Air versus PLA-Thermal Paste), volume percentage, structure, and orientation. Simple, effective medium models were good predictions of thermal conductivity in lamellar structures, but it was necessary to develop models for conduction through cylindrical and gyroid structures. Finally, all results were normalized to find a universal model that is independent of structure and material. This approach provides a simple method to predict how to reduce or enhance transport properties and heat management capabilities of 3D printed objects.

Theoretical and experimental study of plasmon oscillation dispersion in Si and Ge crystals

Plasma fluctuation dispersion has been theoretically and experimentally studied in monocrystal samples of Si (111) and Ge (111). It has been shown that the dispersion depends on crystallographic orientations of materials under study. In this work, the dispersion effects in the CLEE spectra, which manifest themselves in bulk samples of Si and Ge, have been studied. The loss energy electron was studied by the CLEE method upon their reflection from Si(111) and Ge(111) at different angles of incidence of the electron beam on the surface. Calculation of the total electron energy loss with formula (5) shows that the form of the CLEE spectrum of primary electrons depends on the nature and magnitude of the electron density in a given direction and is in satisfactory agreement with the experimental data. Thus, the theoretical and experimental results show that in the case of single-crystalline Si and Ge, with increasing k, the values of the bulk plasma oscillation increase by 2–3 eV.

Looping: Load-oriented optimized paths in non-planar geometry

Effective material utilization in the additive manufacturing of lightweight components is of increasing importance. The Looping (Load-oriented optimized paths in non-planar geometry) method presented in this work enables the translation of desired material orientations into suitable manufacturing instructions. The desired material orientations are derived from the principal stress directions that would manifest for an isotropic material. By employing non-planar slicing, these orientations can be followed by the deposited material beads. The novel path planning algorithm combines load-orientation and path continuity. While this can be beneficial for load-oriented printing in general, it is an especially significant step for load-oriented printing of continuous fiber reinforced polymers. The ability to follow desired material orientations with continuous paths shows particularly high potential for highly anisotropic fiber reinforced polymers. The algorithms are implemented and demonstrated in a complete process chain. However, challenges remain in the optimization of the orientation and manufacturing system for fiber reinforced polymers, which are not the focus of this work. For this reason, the process chain is realized for a neat polymer. In this context, the developed method is computationally evaluated with respect to layer height, unfilled areas, manufacturing time, geometric accuracy, and physical fabrication. The continuous and load-oriented path planning algorithm is tested against a continuous contour parallel approach and planar slicing through tensile testing. The investigations show an applicability of the process chain to successfully produce complex parts with the desired load-oriented paths. The proposed algorithm shows an increase in mechanical performance compared to the contour parallel approach highlighting its potential for non-planar printing. However, it is also found that limitations of the non-planar manufacturing process still limit its potential to surpass optimally oriented planar printing for the investigated geometry.

Thermomechanical characterisation and plane stress linear viscoelastic modelling of ethylene-tetra-fluoroethylene foils

Ethylene-tetra-fluoroethylene (ETFE) is a polymer employed in tension membrane structures with mechanical properties that strongly depend on time and temperature effects. A comprehensive understanding of the mutual influence of these variables and a unified viscoelastic constitutive model design can enable wider exploitation of ETFE in sustainable lightweight construction. This study presents a thermomechanical characterisation of ETFE foils through quasi-static tensile experiments spanning two orders of magnitude of strain rates, creep, relaxation, shear and dynamic cyclic tests in a wide range of temperatures suitable for building applications, from −20∘ C\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$-20^{\\circ }\ ext{ C}$\\end{document} to 60∘ C\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$60^{\\circ }\ ext{ C}$\\end{document}. The experimental results in different material orientations are used to identify the limits of the linear viscoelastic domain, define the direction-dependent creep compliance master curves and calibrate the parameters of a plane stress orthotropic linear viscoelastic model, employing the Boltzmann superposition and the time-temperature superposition principles. The model has been numerically implemented using a recursive integration algorithm and its code is provided open source. A validation on independently acquired data shows the accuracy of the constitutive model in predicting ETFE behaviour within the linear viscoelastic regime usually adopted during structural design, with excellent extrapolation capabilities outside the range of the calibration data.

T-stress extraction in arbitrarily cracked orthotropic composites with the numerical manifold method and Stroh formalism

The escalating utilization of composites over the past decades has necessitated the fracture investigation of orthotropic materials. The T-stress, namely, the first non-singular term of the normal stress parallel to the crack in William’s expansion, is of great significance for fracture analysis. In this work, the numerical manifold method (NMM) is advanced to assess the T-stress of arbitrary-shaped cracks (including non-intersecting cracks and multi-branched cracks) in two-dimensional orthotropic composites. Attributing to the bi-cover systems, the NMM can conveniently discretize the physical domain and naturally accommodate the discontinuity across crack surface. Meanwhile, the singularity at crack tip can be well captured by the wise choice of local approximation function. Through the application of interaction integral technology in the NMM postprocessing, the T-stress is extracted with the Stroh-form auxiliary fields. The accuracy of the proposed method is verified by comparing with reference solutions and then applied to arbitrarily branched and intersecting cracks. The results indicate that the present approach has convincing accuracy and also considerable convenience in T-stress evaluation. Additionally, the impacts of material orientations, crack geometries and loading conditions on the T-stress are also investigated.

Fabric soft pneumatic actuators with programmable turing pattern textures

This paper presents a novel computational design and fabrication method for fabric-based soft pneumatic actuators (FSPAs) that use Turing patterns, inspired by Alan Turing’s morphogenesis theory. These inflatable structures can adapt their shapes with simple pressure changes and are applicable in areas like soft robotics, airbags, and temporary shelters. Traditionally, the design of such structures relies on isotropic materials and the designer’s expertise, often requiring a trial-and-error approach. The present study introduces a method to automate this process using advanced numerical optimization to design and manufacture fabric-based inflatable structures with programmable shape-morphing capabilities. Initially, an optimized distribution of the material orientation field on the surface membrane is achieved through gradient-based orientation optimization. This involves a comprehensive physical deployment simulation using the nonlinear shell finite element method, which is integrated into the inner loop of the optimization algorithm. This continuous adjustment of material orientations enhances the design objectives. These material orientation fields are transformed into discretized texture patterns that replicate the same anisotropic deformations. Anisotropic reaction-diffusion equations, using diffusion coefficients determined by local orientations from the optimization step, are then utilized to create space-filling Turing pattern textures. Furthermore, the fabrication methods of these optimized Turing pattern textures are explored using fabrics through heat bonding and embroidery. The performance of the fabricated FSPAs is evaluated through three different deformation shapes: C-shaped bending, S-shaped bending, and twisting.

Characterization of the lattice preferred orientation of hcp iron transformed from the single-crystal bcc phase in situ at high pressures up to 80 GPa

Studying the anisotropic physical properties of hexagonal closed-packed (hcp) iron is essential for understanding the properties of the Earth’s inner core related to the preferred orientation of the inner core materials suggested by seismic observations. Investigating the anisotropic physical properties of hcp iron requires (1) the synthesis of hcp iron samples that exhibit several distinctive types of strong lattice preferred orientation (LPO) and (2) the quantitative LPO analysis of the samples. Here, we report the distinctive LPO of hcp iron produced from single-crystal body-centered cubic (bcc) iron compressed along three different crystallographic orientations ([100], [110], and [111]) in a diamond anvil cell based on synchrotron multiangle X-ray diffraction measurements up to 80 GPa and 300 K. The orientation relationships between hcp iron and bcc iron are consistent with the Burgers orientation relationship with variant selection. We show that the present method is a way to synthesize hcp iron with strong and characteristic LPO, which is beneficial for experimentally evaluating the anisotropic physical properties of hcp iron.

Fracture modeling of curved composite shell structures using augmented finite element method

This paper presents an augmented finite element method for the fracture modeling of curved composite shell structures considering geometric nonlinear effects. We first derive the composite shell AFEM (CS-AFEM) formulation using a dynamic implicit algorithm, which enhances the numerical convergence when dealing with unstable crack propagations. Besides, the cohesive zone model featuring with shell kinematics is incorporated into the CS-AFEM to describe the quasi-brittle fracture behaviors of composite laminates. Furthermore, a coordinate transformation scheme is proposed to describe both the local material orientation and the crack evolving path in the curved shell structures. Finally, several benchmark examples are numerically investigated, and the capability of the proposed method in modeling the arbitrary evolving cracks in curved composite shell structures has been thoroughly demonstrated.

Probing Local Strain and Orientation in Layered Materials using 4D-STEM Moiré Analysis

Probing Local Strain and Orientation in Layered Materials using 4D-STEM Moiré Analysis

Aftermath of Ag embedding on structural, optical, and supercapacitor electrode attributes of USP-grown CuO thin films

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs).