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The thermal properties of individual subwavelength objects, which defy Planck’s law, are attracting significant fundamental and applied interest in different research areas. Special attention has been devoted to anisotropic structures made of polar dielectrics featuring thicknesses smaller than both the thermal wavelength and the skin depth. Recently, a novel experimental technique has enabled the measurement of the thermal emissivity of anisotropic SiO2 nanoribbons (with thicknesses on the order of 100 nm), demonstrating that their emission properties can be largely tuned by adjusting their dimensions. However, despite the great interest aroused by these results, their rigorous theoretical analysis has remained elusive due to the computational challenges arising from the vast difference in the length scales involved in the problem. In this work, we present a systematic theoretical analysis of the thermal emission properties of these dielectric nanoribbons based on simulations within the framework of fluctuational electrodynamics carried out with the boundary element method implemented in the SCUFF-EM code. In agreement with the experiments, we show that the emissivity of these subwavelength structures can be largely tuned and enhanced over the thin-film limit. We elucidate that the peculiar emissivity of these nanoribbons is due to the very anisotropic thermal emission that originates from the phonon polaritons of this material and the properties of the waveguide modes sustained by these dielectric structures. Our work illustrates the rich thermal properties of subwavelength objects, as well as the need for rigorous theoretical methods that are able to unveil the complex thermal emission phenomena emerging in this class of systems, J.J.G.E. was supported by the Spanish Ministry of Science and Innovation through an FPU grant (FPU19/05281). J.B.A. acknowledges financial support from the Ministerio de Ciencia, Innovacioń y Universidades (RTI2018-098452-B-I00). J.C.C. acknowledges funding from the Spanish Ministry of Science and Innovation (PID2020-114880GB-I00)

We investigate a degenerating elliptic problem in a multi-structure $\Omega_\varepsilon$ of $ \mathbb{R}^3$, in the framework of the thermal stationary conduction with highly contrasting diffusivity. Precisely, $\Omega_\varepsilon$ consists of a fixed basis $\Omega^-$ surmounted by a thin cylinder $\Omega_\varepsilon^+$ with height $1$ and cross-section with a small diameter of order $\varepsilon$. Moreover, $\Omega^+_\varepsilon$ contains a cylindrical core, always with height $1$ and cross-section with diameter of order $\varepsilon$, with conductivity of order $1$, surrounded by a ring with conductivity of order $\varepsilon^2$. Also $\Omega^-$ has conductivity of order $\varepsilon^2$. By assuming that the temperature is zero on the top and on the bottom of the boundary of $\Omega_\varepsilon$, while the flux is zero on the remaining part of the boundary, under a suitable choice of the source term we prove that the limit problem, as $\varepsilon$ vanishes, boils down to two uncoupled problems: one in $\Omega^-$ and one in $\Omega^+_1$, and the problem in $\Omega^+_1$ is nonlocal. Moreover, a corrector result is obtained.

This paper investigates the application of Physics-Informed Neural Networks (PINNs) in modelling constitutive laws for transverse electromagnetic polarized waves in all three space dimensions governed by Maxwell Faraday equation and Ampere's circuital law. The constitutive relationships for electrical permittivity and conductivity are modelled for the 1D case. In 2D, constitutive laws for electric displacement and polarization fields are modelled for anisotropic materials without using the data for either of the two fields. Constitutive laws for bi-anisotropic media are modelled in 3D, where the electromagnetic fields are coupled. It is observed that using PDEs as a guiding constraint regularizes the learning procedure efficiently for training the neural network when no direct measurements of the functions of interest are available. Furthermore, the presented method outperforms the state-of-the-art Gaussian process regression and data-driven deep neural network in the presence of sparse indirect noisy measurement data. For all the numerical experiments, the presented method solves the forward problem simultaneously modelling the constitutive law.

Myocardial infarction is a leading cause of death worldwide and has severe consequences including irreversible damage to the myocardium, which can lead to heart failure. Cardiac tissue engineering aims to re-engineer the infarcted myocardium using tissues made from human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to regenerate heart muscle and restore contractile function via an implantable epicardial patch. The current limitations of this technology include both biomanufacturing challenges in maintaining tissue integrity during implantation and biological challenges in inducing cell alignment, maturation, and coordinated electromechanical function, which, when overcome, may be able to prevent adverse cardiac remodeling through mechanical support in the injured heart to facilitate regeneration. Polymer scaffolds serve to mechanically reinforce both engineered and host tissues. Here, we introduce a novel biodegradable, customizable scaffold composed of wet-spun polycaprolactone (PCL) microfibers to strengthen engineered tissues and provide an anisotropic mechanical environment to promote engineered tissue formation. We developed a wet-spinning process to produce consistent fibers which are then collected on an automated mandrel that precisely controls the angle of intersection of fibers and their spacing to generate mechanically anisotropic scaffolds. Through optimization of the wet-spinning process, we tuned the fiber diameter to 339 ± 31 µm and 105 ± 9 µm and achieved a high degree of fidelity in the fiber structure within the scaffold (fiber angle within 1.8° of prediction). Through degradation and mechanical testing, we demonstrate the ability to maintain scaffold mechanical integrity as well as tune the mechanical environment of the scaffold through structure (Young’s modulus of 120.8 ± 1.90 MPa for 0° scaffolds, 60.34 ± 11.41 MPa for 30° scaffolds, 73.59 ± 3.167 MPa for 60° scaffolds, and 49.31 ± 6.90 MPa for 90° scaffolds), while observing decreased hysteresis in angled vs. parallel scaffolds. Further, we embedded the fibrous PCL scaffolds in a collagen hydrogel mixed with hiPSC-CMs to form engineered cardiac tissue with high cell survival, tissue compaction, and active contractility of the hiPSC-CMs. Through this work, we develop and optimize a versatile biomanufacturing process to generate customizable PCL fibrous scaffolds which can be readily utilized to guide engineered tissue formation and function.

Anisotropic CuCrO2 thin films were successfully prepared on glass substrate by the electrospinning method followed by annealing at 600 °C. The directionality of the nanowires increased with increases in rotation speed. In addition, the structural formation and optoelectronic behavior of the CuCrO2 thin films have been studied by X-ray powder diffraction studies, transmission electron microscopy, field emission scanning electron microscopy, and UV-vis spectroscopy. The X-ray diffraction studies revealed a delafossite properties of the CuCrO2. The electrical conductivity in the parallel and vertical directions of the films produced at 2000–3000 rpm differed by two to three orders of magnitude. The optical transmittance properties of the CuCrO2 thin films were improved by increasing the rotation speed.

Peripheral nerve regeneration with large defects needs innovative design of nerve guidance conduits (NGCs) which possess anisotropic guidance, electrical induction and right mechanical properties in one. Herein, we present, for the first time, facile fabrication and efficient neural differentiation guidance of anisotropic, conductive, self-snapping, hydrogel-based NGCs. The hydrogels were fabricated via crosslinking of graphitic carbon nitride (g-C 3N 4) upon exposure with blue light, incorporated with graphene oxide (GO). Incorporation of GO and in situ reduction greatly enhanced surface charges, while decayed light penetration endowed the hydrogel with an intriguing self-snapping feature by the virtue of a crosslinking gradient. The hydrogels were in the optimal mechanical stiffness range for peripheral nerve regeneration and supported normal viability and proliferation of neural cells. The PC12 ​cells differentiated on the electroactive g-C 3N 4 H/rGO3 (3 ​mg/mL GO loading) hydrogel presented 47% longer neurite length than that of the pristine g-C 3N 4 H hydrogel. Furthermore, the NGC with aligned microchannels was successfully fabricated using sacrificial melt electrowriting (MEW) moulding, the anisotropic microchannels of the 10 ​μm width showed optimal neurite guidance. Such anisotropic, electroactive, self-snapping NGCs may possess great potential for repairing peripheral nerve injuries.

Modern technology shows increased demands on the strength properties of machines, their parts, as well as various structures, reducing their weight, volume and size, which leads to the need to use anisotropic composite materials. Finding criteria to determine the ultimate strength characteristics of structural elements, engineering structures is one of the urgent problems of solid mechanics. Strength problems in structures are often reduced to finding out the nature of the local stress state at the vertices of the joints of the constituent parts. The solution of this urgent problem for composite anisotropic plates can be found in this article, where the author continues the research in this area, extending them to the bending of anisotropic composite plates. The aim of the work is to study the limit stress state of anisotropic composite plates in the framework of the classical theory of plate bending. The outer edges of the plate are considered to be free. Using the classical theory of anisotropic plate bending in the space of physical and geometric parameters, the hypersurface equations determining the low-stress zones for the edge of the contact surface of a composite cylindrical orthotropic plate are obtained. Modern technological processes of welding, surfacing, soldering and bonding allow to produce structural elements of monolithic interconnected dissimilar anisotropic materials. The combination of different materials with qualities corresponding to certain operating conditions opens up great opportunities to improve the technical and economic characteristics of machines, equipment and structures. It can contribute to a significant increase in their reliability, durability, reduce the cost of production and operation. On this basis, the solution proposed in this work can be useful to increase the strength of composite materials.

An anisotropic metasurface that performs a reflectarray and transmitarray on each side is proposed. The proposed configuration comprises $15\times15$ unit cells that consist of polarization converters and a polarization filter. Two topologies are developed for the unit cells to meet five design goals simultaneously, including reflection magnitude, transmission magnitude, reflection phase difference, transmission phase difference, and polarization conversion ratio. By arranging the two topologies of unit cells according to a required phase distribution, in-phase reflection and transmission are achieved on each side. A prototype is designed, fabricated, and analyzed at 28.0 GHz. The feed is implemented as a quasi-Yagi antenna with gain of 8.0 dBi. When linearly-polarized electromagnetic waves impinge on the top, the proposed metasurface functions as a reflectarray and offers gain of 17.9 dBi. When the feed antenna illuminates the bottom, the proposed metasurface performs a transmitarray and depicts gain of 19.1 dBi. Moreover, when the both sides are arranged with feeds, a unidirectional pattern with power gain of 20.3 dBi is obtained. Such a “twin-feed mode” demonstrates a highly-directed main beam with orthogonal polarization components, which is useful in dual-polarized communications. Thus, the proposed metasurface provides antenna applications with low-cost, low-complexity, and multifunctional wavefront manipulation.

The plate problem has been investigated for centuries while exact solutions for anisotropic plates are still hard to obtain. In this paper, we aim to get exact solutions for rectangular anisotropic plates with four clamped edges through the state space method. A state space equation for the anisotropic elasticity is derived from the linear elasticity theory for the first time. The Fourier series in exponential form are adopted in the current work. This can transform the transfer matrix with differential operators in state space into a constant matrix. After superposition and differential treatments, the equations for the boundary conditions of four clamped edges are then combined with the state space equation for the anisotropic elasticity, forming a new compound state space which represents the 3D anisotropic plate problem to be solved. By use of the state space method, a solvable linear equation system under the compound state space is formed. Example solution cases for both orthotropic and monoclinic plates with different thicknesses are provided. For comparison purpose, numerical results from the finite element method are also given to indicate the reliability and accuracy of the current state space method.

Anisotropic mesh adaptation is important for accurately predicting engineering quantities of interest with high-order finite element discretizations. Spacetime approaches, whereby time is treated as an additional spatial dimension and the mesh is fully coupled in space and time, have also shown to be effective in reducing the number of degrees of freedom needed to achieve a certain level of accuracy. Previous efforts have successfully demonstrated four- dimensional mesh adaptation capabilities so as to support adaptive simulations in 3d + t. However, these algorithms have been restricted to sequential implementations. Parallel mesh adaptation strategies have become increasingly important in 3d numerical simulations. Therefore, the goal of this work is to extend those strategies to perform parallel four-dimensional anisotropic mesh adaptation. We employ a functionality-first approach to parallelize an existing sequential mesh adaptation tool. This approach iteratively adapts the mesh while keeping partition interfaces fixed, and then migrates partition interfaces into the interior so they can be adapted during a subsequent pass within an adaptation iteration. We demonstrate that the algorithm scales well as the number of processors increases while maintaining good metric conformity for three- and four-dimensional problems.

Three-dimensional (3D) printing has great potential for creating tissues and organs to meet shortfalls in transplant supply, and biomaterial inks are key components of many such approaches. There is a need for biomaterial inks that facilitate integration, infiltration, and vascularization of targeted 3D-printed structures. This study is therefore focused on creating new biomaterial inks from self-assembled capillary alginate gel (Capgel), which possesses a unique microstructure of uniform tubular channels with tunable diameters and densities. First, extrusions of Capgel through needles (0.1–0.8 mm inner diameter) were investigated. It was found that Capgel ink extrudes as slurries of fractured and entangled particles, each retaining capillary microstructures, and that extruded line widths W and particle sizes A were both functions of needle inner diameter D, specifically power-law relationships of W~D0.42 and A~D1.52, respectively. Next, various structures were successfully 3D-printed with Capgel ink, thus demonstrating that this biomaterial ink is stackable and self-supporting. To increase ink self-adherence, Capgel was coated with poly-L-lysine (PLL) to create a cationic “skin” prior to extrusion. It was hypothesized that, during extrusion of Capgel-PLL, the sheared particles fracture and thereby expose cryptic sites of negatively-charged biomaterial capable of forming new polyelectrolyte bonds with areas of the positively-charged PLL skin on neighboring entangled particles. This novel approach resulted in continuous, self-adherent extrusions that remained intact in solution. Human lung fibroblasts (HLFs) were then cultured on this ink to investigate biocompatibility. HLFs readily colonized Capgel-PLL ink and were strongly oriented by the capillary microstructures. This is the first description of successful 3D-printing with Capgel biomaterial ink as well as the first demonstration of the concept and formulation of a self-adherent Capgel-PLL biomaterial ink.

The human brain, primarily composed of white blood cells, is centered on the neurological system. Incorrectly positioned cells in the immune system, blood vessels, endocrine, glial, axon, and other cancer-causing tissues, can assemble to create a brain tumor. It is currently impossible to find cancer physically and make a diagnosis. The tumor can be found and recognized using the MRI-programmed division method. It takes a powerful segmentation technique to produce accurate output. This study examines a brain MRI scan and uses a technique to obtain a more precise image of the tumor-affected area. The critical aspects of the proposed method are the utilization of noisy MRI brain images, anisotropic noise removal filtering, segmentation with an SVM classifier, and isolation of the adjacent region from the normal morphological processes. Accurate brain MRI imaging is the primary goal of this strategy. The divided section of the cancer is placed on the actual image of a particular culture, but that is by no means the last step. The tumor is located by categorizing the pixel brightness in the filtered image. According to test findings, the SVM could partition data with 98% accuracy.

The increasing application of aluminum alloy, in combination with the growth in the complexity of components, provides new challenges for the numerical modeling of sheet materials. The material elastic–plasticity constitutive model is the most important factor affecting the accuracy of finite element simulation. The mixed hardening constitutive model can more accurately represent the real hardening characteristics of the material plastic deformation process, and the accuracy of the material property-related parameters in the constitutive model directly affects the accuracy of finite element simulation. Based on the Hill48 anisotropic yield criterion, combined with the Voce isotropic hardening model and the Armstrong–Frederic nonlinear kinematic hardening model, a mixed hardening constitutive model that considers material anisotropy and the Bauschinger effect was established. Analysis of the tension–compression experiment on the sheet using finite element method. Using the finite element model, the optimum geometry of the tension–compression experiment sample was determined. The cyclic deformation stress–strain curve of the 2A11 aluminum alloy sheet was obtained by a cyclic tensile–compression test, and the material characteristic parameters in the mixed hardening model were accurately determined. The reliability and accuracy of the established constitutive model of anisotropic mixed hardening materials were verified by the finite element simulation and by testing the cyclic tensile–compression problem, the springback problem, and the sheet in bending, unloading, and reverse bending problems. The tensile–compression experiment is an effective method to directly and accurately obtain the characteristic parameters of constitutive model materials.

Here we studied Bianchi type-I cosmological models with massive strings in general relativity in five dimensional space time. Out of the two different cases obtained here, one case leads to a five dimensional Bianchi type-I string cosmological model in general relativity while the other yields the vacuum Universe in general relativity in five dimensional space time. The physical and geometrical properties of the model Universe are studied and compared with the present day’s observational findings. It is observed that our model is anisotropic, expanding, shearing, and decelerates at an early stage and then accelerates at a later time. The model expands along x, y, and z axes and the extra dimension contracts and becomes unobservable at t → ∞. We also observed that the sum of the energy density (ρ) and the string tension density (λ) vanishes (ρ + λ = 0).

There are three subfamilies of patatin-related phospholipase A (pPLA) group of genes: pPLAI, pPLAII, and pPLAIII. Among the four members of pPLAIIIs (α, β, γ, δ), the overexpression of three isoforms (α, β, and δ) displayed distinct morphological growth patterns, in which the anisotropic cell expansion was disrupted. Here, the least studied pPLAIIIγ was characterized, and it was found that the overexpression of pPLAIIIγ in Arabidopsis resulted in longitudinally reduced cell expansion patterns, which are consistent with the general phenotype induced by pPLAIIIs overexpression. The microtubule-associated protein MAP18 was found to be enriched in a pPLAIIIδ overexpressing line in a previous study. This indicates that factors, such as microtubules and ethylene biosynthesis, are involved in determining the radial cell expansion patterns. Microtubules have long been recognized to possess functional key roles in the processes of plant cells, including cell division, growth, and development, whereas ethylene treatment was reported to induce the reorientation of microtubules. Thus, the possible links between the altered anisotropic cell expansion and microtubules were studied. Our analysis revealed changes in the transcriptional levels of microtubule-associated genes, as well as phospholipase D (PLD) genes, upon the overexpression of pPLAIIIγ. Overall, our results suggest that the longitudinally reduced cell expansion observed in pPLAIIIγ overexpression is driven by microtubules via transcriptional modulation of the PLD and MAP genes. The altered transcripts of the genes involved in ethylene-biosynthesis in pPLAIIIγOE further support the conclusion that the typical phenotype is derived from the link with microtubules.

Introduction. Modern processes of welding, surfacing, soldering and bonding provide producing structural elements of monolithic interconnected dissimilar anisotropic materials. The combination of different materials with qualities corresponding to certain operating conditions offer comprehensive facilities to improve the technical and economic characteristics of machines, equipment and structures. It can contribute to a significant increase in their reliability, durability, and to reduction of the production and operation costs. Materials and Methods. The work objective is to study the boundary state of stress of anisotropic composite plates in the framework of the classical theory of plate bending. The outer edges of the plate are considered free. Using the classical theory of bending of an anisotropic plate in the space of physical and geometric parameters, hypersurface equations are obtained that define low-stressed zones for the contact surface edge of a cylindrical orthotropic composite plate.Research Results. Finding the criteria for engineering structures to determine the limiting strength characteristics of structural elements is one of the urgent tasks of the deformable solid mechanics. Strength problems in structures are often reduced to elucidating the nature of the local stress state at the tops of the joints of the constituent parts. This paper is devoted to solving this problem for composite anisotropic plates in the area of their bending.Discussion and Conclusions. The solution proposed in this paper may be useful for increasing the strength of composite products.

In this paper, we have investigated the homogeneous and anisotropic Bianchi type–I cosmological model with a time-varying Newtonian and cosmological constant. We have analytically solved Einstein’s field equations (EFEs) in the presence of a stiff-perfect fluid. We show that the analytical solution for the average scale factor for the generalized Friedman equation involves the hyper-geometric function. We have studied the physical and kinematical quantities of the model, and it is found that the universe becomes isotropic at late times.

This paper presents the modeling and design of a frequency agile antenna using an anistropic artificial dielectric layer (AADL) for multi-band phased array radar applications. The proposed AADL material is placed underneath the patch radiator and is designed using periodically arranged metallic cylinders in which varying height, diameter, and the distance used between them allows the control of the effective permittivity of the patch antenna. Closed form design expressions are formulated to synthesize the dielectric properties of the AADL as a function of the cylindrical unit cell dimensions. Design trade-offs based on the proposed formulation and numerical simulations show the overall performance of the AADL on microstrip patch (MS) antennas. To validate the proposed concept, five individual AADL MS patch antennas in C-band were designed, fabricated, and tested. Simulated and measured results ( ${s}$ -parameters and radiation patterns) are in good agreement with the results obtained from the theoretical model. The proposed AADL concept has the potential to be used in the development of future reconfigurable tunable multiband antennas that use liquid metal to dynamically change the heights of the cylinders.

The present work introduces the optimization-based approach for the design of metadevices to manipulate the heat flux in transient regime. It consists of solving a continuous, nonlinear, constrained, large-scale optimization problem where the objective function (to be minimized) is the error in accomplishing a given heat flux manipulation task along a transient heat conduction process. The response of the metadevice is modeled by using the finite element method, and its design is characterized by a set of parameters defining the material at all the finite elements in the device. These parameters are the design variables of the optimization problem, being chosen from an admissible design set in order to guarantee the feasibility of the optimal solution. As an example, this optimization-based approach is applied to the design of a heat flux shielding metadevice. Compared to a metadevice designed under the classical thermodynamics transformation approach and intuition, the current device performs the shielding task with considerably higher success. In order to highlight the versatility of the proposed optimization-based design method, this approach is also applied to the design of metadevices to satisfy multiple different simultaneous tasks, particularly shielding and cloaking. Fil: Álvarez Hostos, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentina Fil: Fachinotti, Victor Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentina Fil: Peralta, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentina Fil: Tourn, Benjamin Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentina

Among the numerical approaches to fracture mechanics analysis of cracked anisotropic solids, the boundary element method is notable for high accuracy and performance due to its semi-analytical nature and the use of only boundary mesh. Various boundary element techniques were proposed for 3D fracture mechanics analysis. However, the main problem of these approaches is the treatment of singular and hypersingular integrals, which can demand analytic evaluation of coefficient at kernel singularity at singular point in local curvilinear coordinates, which produce cumbersome equations in the case of non-planar geometries. Therefore, the paper presents novel formulation of the boundary element method for 3D fracture mechanics analysis of anisotropic solids with non-planar cracks. Pan’s single domain boundary element formulation is extended with several novelties, which allow accurate analysis of non-planar geometries. These are modified Kutt’s numerical quadratures with Chebyshev nodes for accurate evaluation of singular and hypersingular integrals; polynomial mappings for smoothing the integrand at the crack front line; and special shape functions, which account for a square-root stress singularity at crack front and allow accurate determination of stress intensity factors. The kernels of boundary integral equations are evaluated using the exponentially convergent quadrature, which allows derivation of fast boundary element technique. The procedure for accurate numerical determination of stress intensity factors at arbitrary point of the crack front is also developed. Numerical examples are presented, which show high accuracy of the proposed boundary element method. It is shown that non-planar cracks exhibit shearing mode opening along with normal one due to its geometry and direction of the applied loading. Present approach can be combined with Sih’s strain energy density criterion to study 3D cracks propagation in anisotropic elastic solids under fatigue loading, which is the direction of future research.

Accurate predictions of the failure behaviors of quasi-brittle materials are of practical significance to underground engineering. In this work, a novel anisotropic damage model is proposed based on continuous damage mechanics. The anisotropic damage model includes a two-parameter parabolic-type failure criterion, a stiffness degradation model that considers anisotropic damage, and damage evolution equations for tension and shear, respectively. The advantage of this model is that the degradation of elastic stiffness only occurs in the direction parallel to the failure surface for shear damage, avoiding the interpenetration of crack surfaces. In addition, the shear damage evolution equation is established based on the equivalent shear strain on the failure face. A cyclic iterative method based on the proposed anisotropic damage model was developed to numerically simulate the fracture process of quasi-brittle materials. The developed model and method are important because the ready-made finite element software is difficult to simulate the anisotropic damage of quasi-brittle materials. The proposed anisotropic damage model was tested against a conventional damage model and validated against two benchmark experiments: uniaxial and biaxial compression tests and Brazilian splitting tests. The results demonstrate that the proposed anisotropic damage model simulates the mesoscale damage mode, macroscale fracture modes, and strength characteristics more effectively and accurately than conventional damage models.

Electrical exploration has become an important means of shale gas reservoir exploration and evaluation, and is expected to play a key role in the later stages of reservoir fracturing and development. At present, the research on the electrical response characteristics of shale gas reservoirs and their relationship with reservoir parameters is extensive and in-depth, but there is little research on their complex resistivity anisotropy characteristics and influencing factors, which restricts petrophysical modeling and reservoir parameter prediction, and reduces the reliability of shale gas exploration and reservoir evaluation by electromagnetic methods. In this paper, shale samples from the Longmaxi Formation and the Wufeng Formation of shale gas wells in southern Sichuan were collected, the complex resistivity of 34 shales in bedding direction and vertical bedding direction were measured, and the induced polarization (IP) parameters of shales were extracted by inversion. The electrical anisotropy response characteristics under different temperature and pressure conditions were analyzed, and the influencing factors and laws of complex resistivity anisotropy of shales were revealed. Combined with the test results of shale porosity and permeability, the evaluation model of resistivity, polarizability and porosity and permeability parameters was established. The research results have formed a set of testing methods and analysis techniques for electrical anisotropy of shale reservoirs, which are mainly based on complex resistivity parameter testing. It is helpful to understand the electrical anisotropy characteristics of shale gas reservoirs in southern Sichuan; this will provide the theoretical and physical basis for shale gas reservoir evaluation and fracturing monitoring by electrical exploration.

Magnetorheological elastomers (MREs) are well-known for their ability to self-adjust their mechanical properties in response to magnetic field influence. This ability, however, diminishes under high-strain conditions, a phenomenon known as the stress-softening effect. Similar phenomena have been observed in other filled elastomers; hence, the current study demonstrates the role of fillers in reducing the effect and thus maintaining performance. Anisotropic, silicone-based MREs with various carbonyl iron particle (CIP) concentrations were prepared and subjected to uniaxial tensile load to evaluate high-strain conditions with and without magnetic influence. The current study demonstrated that non-linear stress–strain behavior was observed in all types of samples, which supported the experimental findings. CIP concentration has a significant impact on the stress–strain behavior of MREs, with about 350% increased elastic modulus with increasing CIP content. Microstructural observations using field emission scanning electron microscopy (FESEM) yielded novel micro-mechanisms of the high-strain failure process of MREs. The magnetic force applied during tension loading was important in the behavior and characteristics of the MRE failure mechanism, and the discovery of microcracks and microplasticity, which was never reported in the MRE quasi-static tensile, received special attention in this study. The relationships between these microstructural phenomena, magnetic influence, and MRE mechanical properties were defined and discussed thoroughly. Overall, the process of microcracks and microplasticity in the MRE under tensile mode was primarily formed in the matrix, and the formation varies with CIP concentrations.

Most metals exhibit a critical minimum in ductility for plane strain tension. The fracture strain for this particular state of loading is an important reference point for the calibration of ductile fracture models. Here, an axisymmetric V-bending technique is proposed to identify the strain to fracture for plane strain tension for the weakest in-plane direction of sheet metal. After clamping the center and outer boundary of a disc specimen onto an axisymmetric fixture, the specimen is drawn over a tubular knife until fracture initiates on the specimen surface. Throughout the experiment, the specimen surface is monitored with a digital camera for timely crack detection and strain measurement by planar Digital Image Correlation (DIC). It is shown through numerical simulations that the experimental setup is remarkably robust with the results exhibiting a low sensitivity to geometric imperfections. Experiments are performed on aluminum AA2024 and two dual phase steels (DP780 and DP 980) to demonstrate the validity of the proposed technique through comparison with conventional V-bending and dihedral mini-Nakazima experiments., International Journal of Solids and Structures, 252, ISSN:0020-7683, ISSN:1879-2146

In this review article, tissue engineering and regenerative medicine are briefly explained and the importance of scaffolds is highlighted. Furthermore, the requirements of scaffolds and how they can be fulfilled by using specific biomaterials and fabrication methods are presented. Detailed insight is given into the two biopolymers chitosan and collagen. The fabrication methods are divided into two categories: isotropic and anisotropic scaffold fabrication methods. Processable biomaterials and achievable pore sizes are assigned to each method. In addition, fiber spinning methods and textile fabrication methods used to produce anisotropic scaffolds are described in detail and the advantages of anisotropic scaffolds for tissue engineering and regenerative medicine are highlighted.

Changes of failure mechanism with increasing confinement, from extensional to shear-dominated failure, are widely observed in the rupture of intact specimens at the laboratory scale and in rock masses. In an analysis published in 2018, both unconfined and triaxial compressive tests were conducted to investigate the strength characteristics of 84 specimens of a Utah coal, including the spalling limits, the ratio of apparent unconfined compressive strength to unconfined compressive strength (UCS), the damage characteristics, and the post-yield dilatancy. These mechanical characteristics were found to be strongly anisotropic as a function of the orientation of the cleats relative to the loading direction, defined as the included angle. A total of four different included angles were used in the work performed in 2018. The authors found that the degree of anisotropic strength differed according to the included angle. However, the transition from extensional to shear failure at the given confinements was not clearly identified. In this study, a total of 20 specimens were additionally prepared from the same coal sample used in the previous study and then tested under both unconfined and triaxial compressive conditions. Because the authors already knew the most contrasting cases of the included angles from the previous work using the four included angles, they chose only two of the included angles (0° and 30°) for this study. For the triaxial compressive tests, a greater confining stress than the mean UCS was applied to the specimens in an attempt to identify the brittle-ductile transition of the coal. The new results have been compiled with the previous results in order to re-evaluate the confinement-dependency of the coal behavior. Additionally, the different confining stresses are used as analogs for different width-to-height (W/H) conditions of pillar strength. Although theW/Hratios of the specimens were not directly considered during testing, the equivalentW/Hratios of a pillar as a function of the confining stresses were estimated using an existing empirical solution. According to this relationship, theW/Hat which in situ pillar behavior would be expected to transition from brittle to ductile is identified.

We propose a black phosphorus-silicon carbide (BP-SiC) metasurface with in-plane structural symmetry that can act as both a nearly perfect anisotropic absorber and tunable polarized source of mid-infrared (MIR) radiation. The metasurface is a periodic array of square SiC patches integrated with a BP flake at the top and separated from a bottom reflector by a BaF2 spacer. We first use analytical calculations and numerical simulations to study the hybridization of the anisotropic plasmons of BP with isotropic phonons of SiC. We also analyze the in-plane characteristics of the resulting hybrid modes of the BP/SiC heterostructure and the BP-SiC metasurface. It is then demonstrated that the proposed metasurface can serve as a nearly perfect anisotropic absorber of MIR radiation with highly selective and omnidirectional features. It is also shown that the metasurface can be used as a polarized MIR source with tunable temperature, which is determined by the thermal equilibrium between the matter and radiation. The suggested design holds promise for artificial coatings that can tune the blackbody thermal signatures, MIR sensing, and highly directional in-plane transportation of the MIR energy.

Heat transfer within carbon fiber in the geopolymer composite is predicted from parallel in phase to a perpendicular direction within the fabrics. Temperature distribution is higher along the fiber axis with a perpendicular position. The use of curvilinear coordinates along the fiber axis are useful in estimating thermal conductivity within the geopolymer composite theoretically. Experimental findings are also carried out in carbon fiber reinforced geopolymer composite. It has been observed that thermal conductivity has remained constant throughout the composite as a function of temperature. A correlation has been established that shows the heat transfer in the composite falls within the standard range of the specification of insulating materials. This study offers insights and a possible strategy for the development of an anisotropic low-thermal-conductivity geopolymer composite for potential applications in insulating material systems.

We study robust regularity estimates for a class of nonlinear integro-differential operators with anisotropic and singular kernels. In this paper, we prove a Sobolev-type inequality, a weak Harnack inequality, and a local H\"older estimate., Comment: 28 pages, 2 figures, slight modifications and corrections

We introduce Fundamental solutions of Barenblatt type for the equation $$\displaystyle \begin{aligned} u_t=\sum _{i=1}^N \bigg ( |u_{x_i}|{ }^{p_i-2}u_{x_i} \bigg )_{x_i}, \quad \quad p_i >2 \quad \forall i=1,..,N , \quad \quad \text{on} \quad \Sigma _T=\mathbb {R}^N \times [0,T], \end{aligned} $$ (1)

An easy-to-use representation of vapor chambers is developed in terms of effective anisotropic properties. This approach enables accurate simulation of the vapor chamber represented as a solid conduction block by assigning appropriate values to its effective density, specific heat, in-plane thermal conductivity, and through-plane thermal conductance. These effective properties are formulated such that the vapor chamber operation in terms of steady-state and transient thermal responses matches a full, physical simulation of phase change and energy transport in the vapor core; they are intrinsic properties that can be applied independently of the boundary conditions and heat input.

The anisotropy and inhomogeneity exhibited by austenitic steel in welds poses a challenge to nondestructive testing employing ultrasonic waves, which is predominantly utilized for the inspection of welds in power plants. In this study, we assess the reliability of phased array ultrasonic testing (PAUT) by analyzing the flaw detection sensitivity of ultrasonic beams in anisotropic welds, based on the inspection conditions. First, we simulated the sectorial scan technique, frequently employed for the inspection of actual welds, while taking into account the ultrasonic wave mode, frequency, and shape and position of a flaw. Subsequently, we analyzed the flaw sensitivity by comparing A-scan signals and S-scan results. The sensitivity analysis results confirmed the detection of all flaws by considering at least two inspection methods based on the shape and position of the flaw. Furthermore, we verified our model by performing an experiment under the same conditions as the simulation and found that the results were in agreement. Hence, we find that the simulation modeling technique proposed in this study can be utilized to develop suitable inspection conditions, according to the flaw characteristics or inspection environment.

Adaptability of properties of magnetic materials such as magnetorheological (MR) fluids, MR elastomers (MRE), and other magneto-active (MA) materials drives scientific activities worldwide, trying to broaden the fields of application of such materials. In our work, we focused on the utilization and implementation of existing material models to realize a praxis-oriented coupled anisotropic material model for the commercial finite element (FE) software ABAQUS taking into account magneto-mechanical interactions. By introducing this material model, a first step is done to predict and optimize the behavior of MA materials. Data Set License: CC-BY

Producción Científica, Self-assembling bioinks offer the possibility to biofabricate with molecular precision, hierarchical control, and biofunctionality. For this to become a reality with widespread impact, it is essential to engineer these ink systems ensuring reproducibility and providing suitable standardization. We have reported a self-assembling bioink based on disorder-to-order transitions of an elastin-like recombinamer (ELR) to co-assemble with graphene oxide (GO). Here, we establish reproducible processes, optimize printing parameters for its use as a bioink, describe new advantages that the self-assembling bioink can provide, and demonstrate how to fabricate novel structures with physiological relevance. We fabricate capillary-like structures with resolutions down to ∼10 µm in diameter and ∼2 µm thick tube walls and use both experimental and finite element analysis to characterize the printing conditions, underlying interfacial diffusion-reaction mechanism of assembly, printing fidelity, and material porosity and permeability. We demonstrate the capacity to modulate the pore size and tune the permeability of the resulting structures with and without human umbilical vascular endothelial cells. Finally, the potential of the ELR-GO bioink to enable supramolecular fabrication of biomimetic structures was demonstrated by printing tubes exhibiting walls with progressively different structure and permeability., The work was supported by the ERC Starting Grant (STROFUNSCAFF), the Medical Research Council (UK Regenerative Medicine Platform Acellular/Smart Materials 3D Architecture, MR/R015651/1), and the AO Foundation AOCMF-17-19M.

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A metal-insulator-metal plasmonic structure that contains a circular cavity with anisotropic material (AM) is designed and numerically simulated. Attributed to filling the cavity with AM, the standing wave patterns in the cavity rotate clockwise as the wavelength increases, resulting in a new valley on the transmission spectrum, which will not appear in the isotropic-material case. In order to understand the underlying physical mechanism of the phenomena, the influences of the parameters of AM, such as optical axis angle and refractive indexes, on transmission spectrum were investigated. All results can be explained well by the index ellipsoid method and the coupled mode theory. This work shows the unique role of AM in the plasmonics nanostructure and these phenomena may have potential applications in the nanoscale integrated photonic circuits.

In this paper, the generalized recursive formulations of the finite difference time domain (FDTD) for updating the electric and magnetic fields in the multi-layer anisotropic media are derived with a uniaxial perfectly matched layer. The stability condition of the proposed method is clearly analyzed and verified. Then this method is used to calculate the three-dimensional complex scattering fields in planar multilayered anisotropic microstructures with optical axis perpendicular to the layered interface and the scattering fields of arbitrary shape scatters in the anisotropic layered structures. The electric field induced by the sine dipole source is calculated in the spatial domain and the corresponding spectral domain results are achieved through Fourier transform. The scattering field of composite materials with submillimeter thicknesses used in the industrial engineering is calculated using a terahertz wave with operation frequency of 0.3 THz. Robustness of the derived formulations for the complex uniaxial anisotropic media is verified by comparing with the COMSOL software, which is based on FEM analysis. The comparison of memory and CPU time shows the efficiency of the proposed FDTD method. Finally, the scattering fields of different scatters buried in multilayer anisotropic media are studied. So it is expected to become an effective simulation tool for dealing with complex electromagnetic environment in the future, such as abnormal detection of aircraft coating materials and detection of hidden target and so on.

This paper studies the free vibration of polymer nanocomposite reinforced by graphene sheet. In this work, the new size dependent formulation is presented for nanocomposites based on couple stress theory. For this purpose, the first shear deformation theory is applied. The effect of scale parameter is investigated based on anisotropic couple stress theory. Vibration equations of the composite lamina are extracted using Hamilton’s principle. Numerical results are provided for Poly methyl methacrylate/graphene composite.Mechanical properties of the composite are obtained from molecular dynamics simulation. Based on eigenvalue procedure, an analytical solution is obtained for the natural frequency of composite lamina. In the results section, the effect of dimensional and physical parameters are investigated on lamina natural frequency. It is observed that graphene defects caused to diminish the lamina frequency. Furthermore, it is revealed that the increase in graphene volume fraction leads to natural frequency be greater.

Simultaneously integrating electromagnetic absorption and wavefront-shaping into a single metasurface with flat and low profile is crucial for many practical applications both in science and engineering community. Here, by introducing lossy components to properly design the impedance of metasurface, we propose an anisotropic metasurface capable of broadband absorption and high-efficient wavefront manipulation, which is sensitive to the excitation of different polarizations. As a practical example, we present a flat metasurface reflector to achieve high-directional radiation with reduced backward scatterings. When a standard waveguide antenna is used to illuminate the metasurface, the reflected wavefront is shaped to directive beam across X-band in microwave regime, with the gain reaches about 25 dBi around 10 GHz. Under the illumination of an orthogonally polarized wave, the incident power is dissipated by the chip resistors to achieve broadband and high-efficient microwave absorption. Experiments are carried out to validate the design principle, and good agreements are observed between the measured and simulated results.

This PhD thesis describes the design, the study and the synthesis of NIR-harvesting hybrid nanomaterials, consisting of an inorganic (noble metal) and an organic component. Indeed, this strategy can be applied to enhance the emission of proper NIR dyes by exploitation the plasmon-enhanced fluorescence (PEF). This phenomenon rises from the coupling of the organic dyes with plasmonic nanostructures, such as nanoparticles (NPs), and nanorods (NRs). In the first part of the thesis, a host-guest approach was studied and exploited in order to have a control on the aggregation of nanostructures and, in principle, to modify their properties. In particular, the attention was focused on the synthesis of calix[n]arene derivatives used either as multivalent hosts for the decoration of noble metal NPs and NRs or as aggregators for properly functionalized NPs. In the second part of the thesis, the work was focused on the design and the synthesis of the organic part of the hybrid nanomaterial. Firstly, cyanine-type dyes characterized by a D-A-D structure (D = donor, A = acceptor) were prepared. The central acceptor core is represented by the croconic acid and for this reason these dyes are called croconates or croconaines. In order to have a better interaction and a major control on the effective coupling between the dye and the surface, the introduction of linker units, basically on the donor, was design. The linkers are characterized by the presence of a functional group in order to have a covalent grafting of the dyes on the metal (e.g. thiol, amine, carboxylic acid). Another type of NIR-compound is represented by acene class. On this topic, a research period of three months was spent in the laboratories of CEMES-CNRs of Toulouse (France) with the aim to obtain suitable precursors for the construction of long acenes and [16]starphene(5.5.5). Questa tesi di dottorato descrive la progettazione, lo studio e la sintesi di nanomateriali ibridi caratterizzati da un assorbimento e da un’emissione nella regione NIR (NIR-harvesting) e costituiti da una componente inorganica (di metalli nobili) e una componente di natura organica. Questa strategia può essere applicata per aumentare la fluorescenza di appropriati cromofori NIR-harvesting sfruttando l’effetto denominato plasmon-enhanced fluorescence (PEF). Questo fenomeno nasce dall'accoppiamento dei cromofori organici con nanostrutture plasmoniche, come nanoparticelle (NP) e nanorod (NR). Nella prima parte della tesi, un approccio di tipo host-guest è stato studiato e sfruttato al fine di avere un controllo sull'aggregazione delle nanostrutture e, in linea di principio, modificarne le proprietà. In particolare, l'attenzione si è concentrata sulla sintesi di derivati calix[n]arenici usati come host multivalenti per la funzionalizzazione di NP e NR di metalli nobili o come aggreganti per NP adeguatamente funzionalizzate. Nella seconda parte della tesi, il lavoro si è concentrato sulla progettazione e sulla sintesi dell’unità organica del nanomateriale ibrido. In primo luogo, sono stati sintetizzati cromofori caratterizzati da una struttura D-A-D (D = donatore, A = accettore), in cui il nucleo accettore centrale è rappresentato dall'acido croconico e per questo motivo chiamati croconati o croconaine. Al fine di avere una migliore interazione e un maggiore controllo sull'effettivo accoppiamento tra il cromoforo e la superficie metallica, è stata progettata l'introduzione di catene alchiliche funzionalizzate, denominate linker, e caratterizzate dalla presenza di un gruppo funzionale terminale al fine di avere un’interazione covalente dei cromofori sulla superficie (come gruppi tiolici, amminici o carbossilici). Un’altra classe di composti NIR-harvesting è rappresentata dagli aceni. Su questo argomento, presso i laboratori del CEMES-CNRs di Tolosa (Francia), sono stati studiati e sintetizzati precursori adeguati per la costruzione di aceni e [16]starphene(5.5.5).

With the development and wide applicability of rubber materials, it is imperative to determine their performance under various conditions. In this study, the effect of cyclic shear fatigue on natural-rubber-based anisotropic magnetorheological elastomer (MRE) with carbonyl iron particles (CIPs) was investigated under a magnetic field. An anisotropic MRE sample was prepared by moulding under a magnetic field. Cyclic shear fatigue tests were performed using a modified electromechanical fatigue system with an electromagnet. The storage modulus (G′) and loss factor in the absence or presence of a magnetic field were measured using a modified dynamic mechanical analysis system. Under a magnetic field, fatigue exhibited considerable effects to the MRE, such as migration and loss of magnetised CIPs and suppressed increase in stiffness by reducing the energy loss in the strain cycle. Therefore, the G′ of the MRE after fatigue under a magnetic field was lower than that after fatigue in the zero field. The performance of the MRE, such as absolute and relative magnetorheological effects, decreased after subjecting to cyclic shear fatigue. In addition, all measured results exhibited strain-dependent behaviour owing to the Payne effect.

An anisotropic multi phase-field model is developed in this paper to investigate the interaction between the crack propagation and interfacial damage in a fiber-reinforced composite. The proposed modeling approach can capture the fracture patterns of composite microstructures through the introduction of the crack phase field and the interface phase field. By considering the free energy related to the interface and crack phase fields, the interfacial debonding, matrix cracking and the interaction of two fracture patterns can thus be simulated. The anisotropic phase-field approach is further adopted to describe the interface interaction associated with a crack. The phase-field equations are solved using the isogeometric-meshfree collocation approach to achieve high computational efficiency. An adaptive h-refinement scheme is incorporated into the phase-field formulations using phase-field variables and their gradients as the error indicators. The proposed method is shown to be effective and robust in both case studies of 2D and 3D fiber-reinforced composite microstructures. Moreover, fracture behaviors including the crack initiation, propagation, coalescence, interfacial debonding, and matrix cracking in composite microstructures are found to be precisely modeled by the proposed approach. Nanyang Technological University National Research Foundation (NRF) The authors acknowledge the financial support from the SMRT-NTU Smart Urban Rail Corporate Laboratory with funding support from the National Research Foundation, SMRT and Nanyang Technological University (Grant No. M4061892).

Anisotropic elasticity and inelasticity is of relevance in many practical applications. The Eulerian formulation for anisotropic elastic and inelastic response based on microstructural vectors is used here to model an injection-moulded low-density polyethylene. In contrast with Lagrangian models of inelasticity, the Eulerian formulation is insensitive to arbitrariness of the reference and intermediate configurations as well as to measures of total and inelastic deformations. A specific strain-space-type anisotropic yield function is proposed that depends on anisotropic measures of elastic deformation and anisotropic hardening variables. Use is also made of a rate-independent model with a smooth elastic-inelastic transition. The material parameters were calibrated to reproduce uniaxial test data for loading in three directions in the moulding plane. In addition, a strongly objective numerical implementation is presented and used to simulate stretching of a plate with a circular hole. In contrast with metals, this polyethylene experiences elastic deformations of about 10%. Although the inelastic spin rate could not be determined by the available test data, simulations of loadings in different material directions yield observable influences of inelastic spin rate.

The main aim of this paper was to develop an advanced processing method for analyzing of anisotropic thermoelastic metal and alloy discs with holes. In the boundary element method (BEM), the heat impact is expressed as an additional volume integral in the corresponding boundary integral equation. Any attempt to integrate it directly will necessitate domain discretization, which will eliminate the BEM’s most distinguishing feature of boundary discretization. This additional volume integral can be transformed into the boundary by using branch-cut redefinitions to avoid the use of additional line integrals. The numerical results obtained are presented graphically to show the effects of the transient and steady-state heat conduction on the quasi-static thermal stresses of isotropic, orthotropic, and anisotropic metal and alloy discs with holes. The validity of the proposed technique is examined for one-dimensional sensitivity, and excellent agreement with finite element method and experimental results is obtained.

A technique to significantly shift down the resonant frequency of the higher order modes of a uniaxial anisotropic rectangular dielectric resonator nanoantenna (DRNA) without any considerable change in the resonant frequency of the fundamental mode is presented. The method aims to adjust the ratio of the resonant frequency of the higher order modes without changing the physical dimensions of DRA. This method can be used to adjust the frequency distance between the high-order and fundamental modes of the antenna. The performances of the method are numerically validated for different contrast values between the dielectric tensor entries.

Its multiplicative nature complicates speckle noise reduction in images because of the effort required for separation of noisy pixels from other pixels. In this study, a novel adaptive anisotropic diffusion filter algorithm based on Haar wavelet transform has been proposed. Initially, Haar transform of image to be filtered was taken and then median absolute deviation of wavelet coefficients was used to tune the conductance parameter, K of diffusion filter with different diffusion functions. The suggested strategy has been tested with different images and different noise variances. Moreover, experimental results have been compared with conventional diffusion filters, and also Lee filter and Wiener filter which are frequently used for despeckling.

This paper deals linear and weak nonlinear stability analysis of double-diffusive convection in an anisotropic porous layer with internal heat source saturated by viscoelastic fluid. For linear stability analysis we use normal mode technique and obtained the expression for oscillatory thermal Rayleigh number which is used to plot neutral stability curve for oscillatory case. For nonlinear analysis truncated representation of Fourier series upto two terms is used. The system of time dependent nonlinear equation is solved numerically and plot the curve for heat transfer and mass transfer with respect to time for different parameters. Effect of thermal anisotropy parameter, mechanical anisotropy parameter, relaxation parameter, retardation parameter, internal heat source parameter, solute Rayleigh number, diffusivity ratio, Darcy-Prandtl number on the onset of convection, heat and mass transfers have been discussed. We also draw the stream lines, isotherms, isohalines at different times.

We report on thermal stability and phase transition behaviors of triangular Au nanoprisms through in situ heating transmission electron microscopy. With rising temperature, Au nanoprisms exhibit fluctuating surface reconstructions at the corner regions. When a quasi-melting state is reached at the temperature below bulk melting points, the evaporation is initiated commonly at a corner with low curvature and containing sharp intersection points. The subsequent annealing process leads to the gradual evaporation, which, in the absence of thick carbon coverages, is accompanied by marked shape reconstructions. The thermal stability and evaporation behaviors are not evidently regulated by nanoprism aggregations.

A new freestanding sensor-based 3ω technique is presented here, which remarkably expands the application of traditional 3ω technology to anisotropic materials. The freestanding flexible sensor was fabricated using the mature flexible printed circuit production technique, which is non-destructive to the samples and applicable to porous surfaces. The thermal conductivities of potassium dihydrogen phosphate (KDP) crystal along the (100), (010) and (001) crystallographic planes were measured based on this new sensor at room temperature. We found that the freestanding flexible sensor has considerable application value for thermal properties’ characterization for crystals with anisotropic thermophysical properties and other structures for which the traditional 3ω technique is not applicable.

In this study, magnetorheological elastomer (MRE) was fabricated using an electromagnetic device with a new configuration mold at the orientation of 0°, 45° and 90°. This new curing concept enhanced the alignment of carbonyl iron particles (CIPs) within the silicone matrix in the presence of silicone oil (SO) during solidifying, by eliminating air gaps to prevent magnetic flux losses. Using a mold made of steel, which is a magnetic material, the mold functions as a guide for concentrated magnetic flux of 0.315 T to pass through the MRE sample. Scanning electron microscopy (SEM) was used to observe the surface morphology of the fabricated MRE samples particularly the alignment of the CIPs. The field-dependent dynamic properties of the MREs were measured using a rheometer. The analysis implied that the effectiveness of the MRE operating under shear deformation with this curing concept provided the highest magneto-induced modulus of 1.01 MPa when a 45° orientation mold is used, with relative magnetorheological (MR) effect value up to 918%, followed by 0° mold orientation with 0.79 MPa magneto-induced modulus and 646% relative MR effect. The high modulus properties offered by this MRE are believed to be potentially useful in industrial applications where a high range of stiffness is required particularly in the shear direction.