Proper Element Research Articles

Peculiarities of Electric and Dielectric Behavior of Ni- or Fe-Doped ZnO Thin Films Deposited by Atomic Layer Deposition.

The physical properties of ZnO can be tuned efficiently and controllably by doping with the proper element. Doping of ZnO thin films with 3D transition metals that have unpaired electron spins (e.g., Fe, Co, Ni, etc.) is of particular interest as it may enable magnetic phenomena in the layers. Atomic layer deposition (ALD) is the most advanced technique, which ensures high accuracy throughout the deposition process, producing uniform films with controllable composition and thickness, forming smooth and sharp interfaces. In this work, ALD was used to prepare Ni- or Fe-doped ZnO thin films. The dielectric and electrical properties of the films were studied by measuring the standard current-voltage (I-V), capacitance-voltage (C-V), and capacitance-frequency (C-f) characteristics at different temperatures. Spectral ellipsometry was used to assess the optical bandgap of the layers. We established that the dopant strongly affects the electric and dielectric behavior of the layers. The results provide evidence that different polarization mechanisms dominate the dielectric response of Ni- and Fe-doped films.

An interface formulation for the poisson equation in the presence of a semiconducting single-layer material

In this paper, we consider a semiconducting device with an active zone made of a single-layer material. The associated Poisson equation for the electrostatic potential (to be solved in order to perform self-consistent computations) is characterized by a surface particle density and an out-of-plane dielectric permittivity in the region surrounding the single-layer. To avoid mesh refinements in such a region, we propose an interface problem based on the natural domain decomposition suggested by the physical device. Two different interface continuity conditions are discussed. Then, we write the corresponding variational formulations adapting the so called three-fields formulation for domain decomposition and we approximate them using a proper finite element method. Finally, numerical experiments are performed to illustrate some specific features of this interface approach.

Study on Singularity Passing Method for Large Industrial Robot Based on Proper Element Improvement of Inverse Matrix

Singularity has become a limitation to the expected diversification of industrial robot applications in production. Here, we propose a novel solution for the inverse kinematics of a 6-DOF manipulator that suppresses rapid joint rotation when passing through a singularity. The proposed method is based on the optimization of the inverse Jacobi cofactor matrix utilized in the inverse kinematics calculation. By optimizing only the elements related to the four and six joints of the cofactor matrix in the inverse matrix, we were able to suppress the divergence of the joint velocities and achieve smooth robot motion when the robot entered a singular posture at the wrist. The developed system application range and tuning gain that minimize the position and orientation error were also determined. Hence, the position and orientation errors were improved by approximately 76%, and rapid rotation of the joints was almost completely suppressed. The method did not require consideration of tools attached to the hand tip, and the hand tip position, orientation, and velocity were all maintained.

Analysis of bucket foundation installation in clay considering soil large deformation

Bucket foundations are increasingly used to support offshore wind turbines. Its bearing performance has been extensively investigated, but its installation process has been addressed in a few investigations. This study investigates the penetration resistance during the installation of bucket foundations in clay through finite element models that consider large soil deformations. The proper finite element modeling scheme is assessed first, then a validated numerical model is employed to investigate the effects of length-diameter ratio and soil properties on the soil plug and penetration resistance. The results indicate that a minimum element dimension and penetration velocity should be set to 1/6th of skirt thickness and 0.3 m/s to ensure a good balance between computational accuracy and efficiency. An increase in the bucket length-to-diameter ratio increases the height of soil heave, while soil nonuniformity reduces it. In addition, the height of soil heave is slightly influenced by the friction coefficient and undrained shear strength of the soil. On the other hand, the penetration resistance is strongly affected by the soil undrained shear strength and bucket length-diameter ratio, but slightly affected by the friction coefficient.

Use of silicon rubber as a viscoelastic material in dampers

One of the most extensively utilized structural control devices is the viscoelastic damper (VD), and significant study has gone into enhancing their efficiency in structures. The mechanical response of a VD supplied with silicone rubber as viscoelastic material (SRD) under various loading conditions is investigated in this research. A conventional VD is the SRD, which is made up of dual layers of rubber mounted between three steel plates. A total of two specimens were produced. To evaluate the influence of strain amplitude and excitation frequency on the mechanical characteristics of SRD, each damper was exposed to harmonic loading with different values. Hysteretic loops for each loading case were extracted, and the variations of several mechanical parameters with the variated loading conditions were inspected. The results indicate that SRD has a high energy dissipation capacity, and has stable performance under different working conditions. Finally, a proper simplified element model was created using SAP2000 software to evaluate the dissipation characteristics and control impact of the SRD in structures, and then a time history analysis was executed on multi storey structure. Due to the obvious dampers’ extra stiffness and efficient damping property, the control impact of the SRD dampers on structural displacement is preferred and reflected on reducing the excessive displacement due to structure movement, according to data obtained.

Thermal buckling of steel tube using finite element method

The present research work focuses on obtaining the critical buckling temperature (ΔTcri) of an offshore pipeline model from one-dimensional and three-dimensional finite element analysis. In this work, the pipeline model considered for analysis has a prismatic and hollow cross-section. The dimensions used for the pipeline model are: Length (L) = 360 mm, Outer Diameter (D) = 12 mm, and Thickness of the pipeline model (t) = 1 mm. The one-dimensional (1D) finite element analysis is conducted with proper element selection as BEAM188 element, and the three-dimensional (3D) finite element analysis is carried out using the SOLID186 element. The mesh element length or size for 1D analysis is 20 mm, while it is 1 mm for 3D analysis, as determined by a detailed convergence study on both 1D and 3D finite element models. The pinned–pinned boundary conditions used for 1D finite element analysis are (at × = 0 mm, u = 0 &v = 0; at × = 360 mm, u = 0 &v = 0). Similarly, the following boundary conditions are used for 3D finite element analysis: at z = 0 mm, u (x, y, 0) = 0, v (x, y, 0) = 0, and w (x, y, 0) = 0, and at z = 360 mm, u (x, y, 360) = 0, v (x, y, 360) = 0, and w (x, y, 360) = 0. The displacements along the ×,y, and z directions are represented in the 3D analysis as u, v, and w. The critical buckling temperature values (ΔTcri) obtained in the 1D and 3D thermal buckling analysis are (ΔTcri)1D = 72.06 °C and (ΔTcri)3D = 72.27 °C.

Isomorphism and non-isomorphism for interval groups of type Dn

We consider presentations that were derived in [3] for the interval groups associated with proper quasi-Coxeter elements of the Coxeter group W(Dn). We use combinatorial methods to derive alternative presentations for the groups, and use these new presentations to show that the interval group associated with a proper quasi-Coxeter element of W(Dn) cannot be isomorphic to the Artin group of type Dn. While the specific problems we solve arise from the study of interval groups, their solution provides an illustration of how techniques indicated by computational observation can be used to derive properties of all groups within an infinite family.

High isolation circularly polarized in-band full-duplex anisotropic dielectric resonator antenna

A novel high-isolation, monostatic, circularly polarized (CP) simultaneous transmit and receive (STAR) anisotropic dielectric resonator antenna (DRA) is presented. The Proposed antenna is composed of two identical but orthogonally positioned annular sectoral anisotropic dielectric resonators. Each circularly polarized (CP) resonator consists of alternating stacked dielectric layers of relative permittivities of 2 and 15 and is excited by a coaxial probe from the two opposite ends to have left and right-hand CP. Proper element spacing and a square absorber are placed between the resonators to maximize Tx/Rx isolation. Such a structure provides an in-band full-duplex (IBFD) CP-DRA system. Measurement results exhibit high Tx/Rx isolation better than 50 dB over the desired operating bandwidth (5.87–5.97 GHz) with a peak gain of 5.49 and 5.08 dBic for Ports 1 and 2, respectively.

Structural, BET and EPR properties of mixed zinc-manganese spinel ferrites nanoparticles for energy storage applications

X-ray diffraction data (XRD) validated the characteristic crystalline spinel cubic structure and a Field-emission scanning electron microscope/energy dispersive spectroscopy (FE-SEM/EDS) validated the proper stoichiometric element ratio of the prepared materials. By using X-ray photoelectron spectroscopy (XPS), the oxidation state of the elements in the prepared materials was verified. An electron paramagnetic resonance (EPR) spectrometer confirmed that Lande factor (g) values decreased as Zn2+ concentration in MnFe2O4 increased. The electrochemical (EC) characteristics of the materials were verified during production using a three electrode instrument. The EC performances confirm the EC behavior of the electrode materials. We investigated the EC properties of the electrodes using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) methods. The Mn0.85Zn0.15Fe2O4 (code as: MZF1) electrode material has a specific capacitance (Cs) of 62.96 F/g compared to Mn0.75Zn0.25Fe2O4 (code as: MZF2) and Mn0.65Zn0.35Fe2O4 (code as: MZF3) electrode at a current density (CD) of 0.5 A/g. According to recent research, electrode materials should be made with the necessary form and size for great act supercapacitor (SC) applications.

The Design of a Glycerol Concentration Sensor Based on an LRSPP Hybrid Photonic Biosensor.

A refractive index sensor based on an on-chip silicon nitride (Si3N4) ridge waveguide long-range surface plasmon polariton (LRSPP) is theoretically designed. The waveguide sensor consists of a gold film to enable the plasmonic resonance on top of a Cytop polymer layer. A proper finite element method was used to design and optimize the geometric parameters at the optical wavelength of 633 nm. In addition, the spectral performance was evaluated using the transfer matrix method from 580 to 680 nm. The redshifted interference spectrum results from an increasing analyte refractive index. The sensitivities of 6313 dB/cm/RIU and 251.82 nm/RIU can be obtained with a 400 nm wide and 25 nm thick Au layer. The proposed sensor has the potential for point-of-care applications considering its compactness and simplicity of construction.

Dynamic Simulation Analysis of the Working Process of the Picking Mechanism of a Sugarcane Leaf Cutting and Returning Machine

Leaf–device interaction can effectively be modeled with a finite element model when proper finite element model parameters are applied. In order to investigate the contact mechanism of picking up sugarcane leaf during the operation of a sugarcane leaf cutting and returning machine, a geometric solid model of sugarcane leaf picking was established. A finite element numerical model to analyze the large deformation problem of flexible bodies was developed in LS-DYNA to simulate the picking process of the returning machine. A dynamic simulation of the sugarcane leaf-picking process was carried out to obtain the change of stress field and the motion posture of the sugarcane leaf and the elastic teeth. The picking process of the picking mechanism, the change in posture of the sugarcane leaves, the change in stress on the sugarcane leaf, the change in the bending angle of the sugarcane leaf and the change in stress on the elastic teeth were analyzed in detail. The results showed that the picking process can be divided into four stages: picking, lifting, pushing and retrieving. The posture changes of sugarcane leaf are “C”, logarithmic curve, wavy shape and “V”, in turn. During the picking process, the sugarcane blade showed some breakage, the sugarcane vein remained intact, and the elastic teeth did not fail. During the whole picking cycle, the maximum Von Mises stress of the blade, vein and elastic teeth were 22.8 MPa, 17.5 MPa and 900 MPa, respectively. An evaluation criterion of bending angle was creatively put forward to measure the bending deformation of leaves. The trend in the sugarcane leaf bending angle shows that it is largely variable, gradually decreasing, fluctuating and increasing with interval fluctuations. The working process of the picking mechanism was observed through a quick camera experiment. Comparing the experiment with the simulation, the changing trend of the simulation data and experimental data was generally similar. The experimental and simulation values of the average sugarcane leaf bending angle were 27° and 19°, respectively. The relative error of the average bending angle was 29.6%. It was concluded that the developed finite element model is substantial and could be applied to optimize and improve the picking mechanism. In addition, some references were provided for the contact mechanism between the picking mechanism and the sugarcane leaf.

Analytical Studies of the Application Aspects of Fuzzy Intuitionistic and Fuzzy Type 2 Set

The main aim of this paper is to introduce the definition of intuitionistic fuzzy set and operations on it that will prove fruitful to conclude to a solution on problems of real life and how fuzzy logic and Graphics Processing unit can be used together to solve different domain problems for faster responses. Various comprehensive survey of Type-2 fuzzy set and the intuitionistic fuzzy set theories have been described here. IFS is nothing but a simple extension of the fuzzy set defined in the domain of discourse. Graphics Processing Unit (GPU) has been used to enhance the speed of execution. The intuitionistic fuzzy set is utilized as a proper element for representing the degree of hesitation concerning both the non-membership and membership degrees of an element of a set. Recent trends show how GPU is used for various computational applications that are run parallel to reduce overall execution time. Both the fuzzy domains seek application in tackling of the situation of vagueness with their respective characteristic feature sets to the fields concerned to different engineering domains of interdisciplines. This paper highlights the overview of the two eminent fuzzy categories like Fuzzy type 2 and intuitionistic fuzzy theory along with their application on greater scale.

In-Plane BO3 Configuration in P2 Layered Oxide Enables Outstanding Long Cycle Performance for Sodium Ion Batteries.

P2-phase layered cathode materials with distinguished electrochemical performance for sodium-ion batteries have attracted extensive attention, but they face critical challenges of transition metal layer sliding and unfavorable formation of hydration phase upon cycling, thus showing inferior long cycle life. Herein, a new approach is reported to modulate the local structure of P2 material by constructing a state-of-the-art in-plane BO3 triangle configuration ((Na0.67 Ni0.3 Co0.1 Mn0.6 O1.94 (BO3 )0.02 ). Both are unveiled experimentally and theoretically that such a structure can serve as a robust pillar to hold up the entire structure, by inhibiting the H2 O insertion upon Na (de)intercalation and preventing the structure from deformation, which significantly boost the long cycle capability of P2-materials. Meanwhile, more Na ions in the architecture are enabled to site on the edge sharing octahedrons (Nae ), thus benefiting the Na+ transportation. Consequently, the as produced material demonstrates an ultralow volume variation (1.8%), and an outstanding capacity retention of 80.1% after 1000 cycles at 2 C. This work sheds light on efficient architecture modulation of layered oxides through proper nonmetallic element doping.

Asteroid spin-states of a 4 Gyr collisional family

Context. Families of asteroids generated by the collisional fragmentation of a common parent body have been identified using clustering methods of asteroids in their proper orbital element space. However, there is growing evidence that some of the real families are larger than the corresponding cluster of objects in orbital elements, and there are families that escaped identification by clustering methods. An alternative method has been developed in order to identify collisional families from the correlation between the asteroid fragment sizes and their proper semi-major axis distance from the family centre (V-shape). This method has been shown to be effective in the cases of the very diffuse families that formed billions of years ago. Aims. Here we use multiple techniques for observing asteroids to provide corroborating evidence that one of the groups of asteroids identified as a family from the correlation between size and proper semi-major axis of asteroids are real fragments of a common parent body, and thus form a collisional family. Methods. We obtained photometric observations of asteroids in order to construct their rotational light curves; we combine them with the literature light curves and sparse-in-time photometry; we input these data in the light curve inversion methods, which allow us to determine a convex approximation to the 3D shape of the asteroids and their orientation in space, from which we extract the latitude (or obliquity) of the spin pole in order to assess whether an object is prograde or retrograde. We included in the analysis spin pole solutions already published in the literature aiming to increase the statistical significance of our results. The ultimate goal is to assess whether we find an excess of retrograde asteroids on the inward side of the V-shape of a 4 Gyr asteroid family identified via the V-shape method. This excess of retrograde rotators is predicted by the theory of asteroid family evolution. Results. We obtained the latitude of the spin poles for 55 asteroids claimed to belong to a 4 Gyr collisional family of the inner main belt that consists of low-albedo asteroids. After re-evaluating the albedo and spectroscopic information, we found that nine of these asteroids are interlopers in the 4 Gyr family. Of the 46 remaining asteroids, 31 are found to be retrograde and 15 prograde. We also found that these retrograde rotators have a very low probability (1.29%) of being due to random sampling from an underlying uniform distribution of spin poles. Conclusions. Our results constitute corroborating evidence that the asteroids identified as members of a 4 Gyr collisional family have a common origin, thus strengthening their family membership.

Ultralow Scattering Design of Wideband Conformal Arrays Based on Optimally Loaded Resistors

A novel approach based on the use of a resistor-loaded meta-surface (RL-MS) with optimized resistor values is proposed for scattering control in wideband conformal phased arrays. Specifically, the resistance of the loaded resistor in each RL-MS element is varied. As a result, the proposed RL-MS structure not only absorbs incident EM waves but also scatters the remainders away from threatening directions. To accelerate the design process, the scattering matrix approach is used to calculate the scattering patterns efficiently. Proper resistor element distribution can be achieved by optimizing the scattering characteristics. The RL-MS structure is used as the cover layer of a wideband conformal array. By loading the optimized resistors, scattering in the proposed array is reduced to a relatively low level with little degradation of radiation performances. The final designed array achieves 3:1 impedance bandwidth with scanning up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pm 60^{\circ }/\pm 45^{\circ }$ </tex-math></inline-formula> in the E-/H-plane. Remarkably, a monostatic scattering reduction of approximately 30 dB is observed throughout the X-band in the simulated results of the optimized array. To demonstrate the effectiveness of this design, prototype arrays are fabricated and measured. The measured results are in reasonable agreement with the simulated results.

Covariant Space-Time Line Elements in the Friedmann–Lemaitre–Robertson–Walker Geometry

Most quantum gravity theories quantize space-time on the order of Planck length (ℓp ). Some of these theories, such as loop quantum gravity (LQG), predict that this discreetness could be manifested through Lorentz invariance violations (LIV) over travelling particles at astronomical length distances. However, reports on LIV are controversial, and space discreetness could still be compatible with Lorentz invariance. Here, it is tested whether space quantization on the order of Planck length could still be compatible with Lorentz invariance through the application of a covariant geometric uncertainty principle (GeUP) as a constraint over geodesics in FRW geometries. Space-time line elements compatible with the uncertainty principle are calculated for a homogeneous, isotropic expanding Universe represented by the Friedmann–Lemaitre–Robertson–Walker solution to General Relativity (FLRW or FRW metric). A generic expression for the quadratic proper space-time line element is derived, proportional to Planck length-squared, and dependent on two contributions. The first is associated to the energy–time uncertainty, and the second depends on the Hubble function. The results are in agreement with space-time quantization on the expected length orders, according to quantum gravity theories, and within experimental constraints on putative LIV.

Reduced proper orthogonal decomposition spectral element method for the solution of 2D multi-term time fractional mixed diffusion and diffusion-wave equations in linear and nonlinear modes

At the present work, we propose a fast and high order numerical method for the solution of 2D multi-term time fractional mixed diffusion and diffusion-wave equation on regular and irregular convex and non-convex domains. We use a finite difference scheme based on a Crank-Nicolson method to discretize this equation in time variable and prove that the presented semi-discrete scheme is unconditionally stable. Due to the features of geometric flexibility and high order accuracy of spectral element method (SEM), this method is used to discretize the equation in space components. Afterwards, an error estimate of fully discrete scheme is given. In order to save the elapsed CPU time of simulation, a reduced-order model based on the proper orthogonal decomposition (POD) method is employed. Also, we provide the error estimate between the reduced POD-SEM solutions and usual SEM solutions. Moreover, we use the non-uniform temporal discretization to overcome the initial singularity. To investigate the accuracy of method, the numerical simulations are provided on regular and irregular convex and non-convex domains. Also, to illustrate the efficiency of proposed method, we compare the numerical solutions with the results of other methods developed in literature on regular and irregular domains from both accuracy and CPU time point of views.

Virtual Inertia as an Energy Dissipation Element for Haptic Interfaces

Adding virtual damping to dissipate energy has been a major tool for designing stable haptic interfaces in most passivity-based approaches. However, virtual damping is known to dissipate a limited amount of energy. It even generates energy during high-velocity interaction because of the digitization effect, such as zero-order hold and quantization. Therefore, no proper energy dissipation element has been available to stabilize the interaction when the virtual damping is no longer functioning. This paper investigates the possibility of using virtual inertia as a complementary energy dissipation element of virtual damping for stable haptic interfaces. This paper analyzes the energy behavior of virtual inertia in the digital domain and finds that it can dissipate energy even in higher velocity interactions, unlike digital damping and digital springs. Furthermore, this paper proposes a unidirectional virtual inertia that can dissipate a considerable amount of energy compared with the conventional virtual inertia by storing energy and disappearing without returning it to the system. Simulation and experimental studies using a PHANToM haptic interface proved the performance of the proposed method.

Basil of Caesarea, Inseparable Operations, and the Divinity of the Holy Spirit

Abstract Basil of Caesarea is one of the most prominent pro-Nicene theologians and defenders of the Holy Spirit. One of the common features of pro-Nicene theology is the doctrine of inseparable operations—that all acts of the triune God in creation are undivided. But what role did the inseparability principle play in Basil’s trinitarian theology, especially regarding the Holy Spirit? Examining Basil’s historical context and his major works Against Eunomius and On the Holy Spirit, this article argues that the doctrine of inseparable operations is a critical and proper element in the bishop’s trinitarian theology and, therefore, is vital to his defending the Holy Spirit’s co-divinity alongside the Father and the Son. Basil’s coherence of the inseparability axiom with the other elements of pro-Nicene theology thus serves as a fitting case study of classical trinitarianism. His legacy has become our inheritance.

Basal-plane stacking fault energies of biodegradable Zn-based alloys: A first-principles study of alloying effects

Generalized stacking fault energies (GSFEs) associated with the basal planes of pure Zn and substitutional Zn47X (X = Li, Mg, Al, Ti, Mn, Fe, Cu or Ag) were investigated by first-principles calculations in combination with climbing-image nudged elastic band (CINEB) methods. The transition elements, including Ti, Mn and Fe, were found to have relatively strong ability to increase the stability of I2 stacking fault by forming strong interatomic bonding with surrounding Zn atoms. To develop biodegradable Zn-based alloys with superior mechanical properties, especially improved creep properties, Ti, Mn or Fe is recommended as a proper alloying element.