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A passive field conversion-amplification scheme, is proposed and demonstrated for the first time, by integrating a magnetic cantilever with a TMR (Tunnel magnetoresistance) for current monitoring. In the scheme, a magnetic structure with a strong field, is driven and vibrated by the interaction with a weak field. The passive movement of magnetic structure physically results in a movement of strong field. The weak field, is converted by the movement and further passively amplified into a strong one. The degree of amplification is determined by the structure geometry, the position of magnetic structure, as well as the weak field. A TMR cantilever current sensor, mainly composed of two units, is developed to demonstrate the proposed scheme. One is a cantilever with a permanent magnet fixed at its free end as a sensing unit and the other is the TMR as a detecting unit. Experimental measurements demonstrate that a higher detection sensitivity can be achieved, compared to that with only TMR detection. The gain of the sensitivity reaches more than an order of magnitude. If an energy harvesting unit is integrated into the current sensor, a self-powered sensing node can be accomplished for potential wireless sensor network (WSN) applications.

We study the impact of redundant via placement on Fraunhofer interference patterns in superconductor-insulator-superconductor Josephson junctions with thin counter electrodes. By varying the number and location of contact vias to the counter electrode in otherwise equivalent junctions and studying the magnetic field dependence of the critical current, we observe a variety of unconventional features in the interference patterns, including a lifting of critical current minima and differences in node positions and side lobe amplitudes. We attribute these features to local changes in the Josephson phase gradient arising from the non-uniform magnetic thickness resulting from the vias. Our findings highlight the significant role that contact vias on thin counter electrodes play in the response of Josephson junctions to applied magnetic fields.

Ferroelectric vertical gate-all-around field-effect-transistor (Fe-VGAAFET) suits a memory cell with a 5 nm technology node and beyond since it is less constrained by gate length, thereby providing sufficient space for the ferroelectric film compared with ferroelectric FinFET (Fe-FinFET) and ferroelectric lateral gate-all-around field-effect-transistors (Fe-LGAAFET). Also, Fe-VGAAFET achieves multilayer vertical stacking, which further increases the integrated density of devices. Here, we develop ferroelectric vertical sandwich gate-all-around field-effect-transistors (Fe-VSAFETs) with large memory windows (the maximum 2.3 V), high program/erase speeds (100 ns), and excellent retention properties using a self-aligned high-k metal gate process. Furthermore, vertical nanosheet devices with two channel thicknesses of approximately 16 and 42 nm and nanowire devices with a channel diameter of 30 nm were successfully fabricated, and excellent device characteristics were obtained.

The convergence and stability of the fully nonlinear simulation in a three-dimensional potential numerical wave tank is vulnerable along the time marching algorithm of the free surface, as integrating the boundary element's solution into the high-order time integration of the free surface can trigger the numerical instability in the material node approach. Although this matter was identified in some of the prior studies on three-dimensional wave tanks, the approximation of the velocity components plays a crucial role in the sustainability of a simulation. Therefore, a methodology for deriving the Cartesian components of the fluid particles’ velocity over the exact free surface is proposed in this paper. Various circumstances come across while determining the velocity components of fluid particles, which are the function of the location of the free surface nodal points. Since plenty of prior techniques have been based on the tangential derivatives of the free surface boundary value from the previous iteration, the disruption in the convergence of the model occurs most often. Hence, achieving a generic algorithm that merely depends on the boundary element solutions, is a highly important achievement for retaining the stability and simultaneously the convergence of the solution.

Elastic wave imaging with ocean-bottom four-component (4C) seismic data offers unique advantages in offshore oil and gas exploration, but for sparse ocean-bottom node/ocean-bottom seismometer (OBN/OBS) 4C seismic data, the problems of imaging acquisition footprints, poor phase continuity, and low signal-to-noise (S/N) persist. Pressure data acquired by towed streamer (TS) are dense and can be used in elastic imaging of sparse OBN/OBS data using acoustic–elastic coupled equations (AECEs). Based on the AECEs, we propose a novel method for elastic wave joint imaging of dense TS and sparse OBN/OBS seismic data, including joint elastic reverse-time migration (J-ERTM) and joint elastic least-squares reverse-time migration (J-ELSRTM), to solve the above problems in elastic imaging with sparse OBN/OBS data. J-ERTM of TS and OBN/OBS data can address the problem of imaging acquisition footprints, but with low S/N ratio. J-ELSRTM uses Hessian information and can theoretically suppress the negative influences caused by sparse acquisition, thereby obtaining better images than J-ERTM with higher S/N ratio. The results of synthetic and field data experiments show that our method is of prime importance for addressing the elastic wave imaging problems of sparse OBN/OBS data in deep-water oil and gas seismic exploration.

Acoustic manipulation is a non-contact process that applies acoustic waves to immobilize particles into a specific region for a variety of potential applications. This provides an alternative way to address air ventilation requirements where building systems are becoming smarter and more efficient. Development of such a process within confined spaces can incorporate microscopic interactions to filter aerosol-based particulate matter (PM). In real-engineering conditions, it is hard to filter sub-micron particles (0.25–1.0 μm) than super-micron particles (> 2.5 μm) by using low-grade filters. The objectives of this work are twofold. First, we propose a new acoustic-driven pre-filtering device (i.e., a U-shaped resonant acoustic chamber) that can improve the working efficiency of low-grade filters for capturing such particles. Second, the device can optimize spatial homogeneity to enhance the removal efficiency of airborne particles under lower sound intensity requirements. The U-shaped acoustic-driven device in the form of a resonant chamber allows PM to reside at the pressure node of a standing wave. Experimental studies are conducted to verify the present design. The results show that an overall filtration efficiency of up to 89% for 1.0-μm airborne particles can be achieved when the acoustic-driven device is coupled together with a low-grade MERV-6 coarse filter. As a standalone device, the acoustic effect works well for the sub-micron particles with a filtration efficiency of up to 61% under a lower sound pressure level (116 dB) than as previously reported in the literature. In the analysis, we also discuss the performance dependence on frequency, sound pressure level and flow rate in terms of particle size distribution. The relevance of this research is a major step towards engineering an acoustic-based pre-filtering technique for developing future innovative ventilation solutions.

This work reports on low temperature epitaxial growth solutions for the processing of advanced CMOS devices beyond the 3 nm technological node. The complex stacking of highly compositionally contrasted strained group IV materials is first demonstrated at 500°C. It enables the formation of active nanosheet channels with bottom isolation, necessary for ultimate transistor scaling. Using high order Si and Ge precursors also offers great opportunities for the epitaxy of advanced source/drain materials. It allows achieving hole active concentrations as high as 1.3x1021 cm-3 in in-situ B-doped Si0.5Ge0.5, providing Ti / SiGe:B contacts with low specific resistivity. Grown at temperatures as low as 400°C, the epilayers deposit in a conformal manner, thereby wrapping high aspect ratio 3-dimensional structures and maximizing the contact areas, being an additional option to further decrease device access resistances. As an alternative to B-doping only, we also demonstrate uniformly Ga-doped materials with concentrations ~ 1x1020 cm-3. B and Ga are finally combined to co-dope SiGe and further reduce the Ti / p-SiGe contact resistivity.

Two types of aluminum alloy mega-latticed structures were generated through ANSYS to investigate the suitable material and form for super-long span spatial structures. The joint stiffness of the structures was first discussed, and a proper simulation method for the joints was proposed. Subsequently, the analysis of these two structures with spans from 800 m to 1200 m was conducted by emphasizing the peculiar differences with steel ones, based on the mechanical performance and economic indices. Also, the reasons for these differences were analyzed in detail. It was found that both structures had good mechanical performance, but the aluminum alloy structures had much better economic indices for spans greater than 1000 m. The material consumptions of the aluminum alloy structures were 1/3–1/7 of those of the steel structures at spans from 800 m to 1200 m. The aluminum alloy structures are more sensitive to wind but less sensitive to node imperfections than the steel structures. To further explore the applicability of aluminum alloy structures, the static and stability performance of structures with spans of 1600 m and 2000 m were analyzed. This showed that these super-long span structures could have excellent mechanical performance. Finally, four key structural parameters, namely support conditions, sections of the 3D trussed beams, sections of the chord members, and rise-span ratios, were examined. The influences of these parameters were thereby identified, and some reasonable values of these parameters were obtained. This work may provide a reference for the design and application of aluminum alloy mega-latticed structures.

This research presents a new approach formula that predicts the flexural behavior of steel cold-formed I-beam with strengthened hollow tubular flanges. Rectangularity aspect ratio and strength of the strengthening material effect on the flexural behavior of steel cold-formed I-beam with strengthened hollow tubular flanges were studied and analyzed. A wide range of investigations was carried to figure out the effect of the hollow flanges rectangularity aspect ratio and its strengthening material. Eighty-eight numerical models were created and analyzed using the finite element technique. Three-dimensional nonlinear finite element models were prepared using eight nodes solid element with three degrees of freedom per node. Material nonlinearity and geometric effects have been considered in the model analysis. A good agreement between the experimental work done by the authors [1] and FE-model results was achieved and presented. The ultimate load values of the strengthened models were presented and compared with non-strengthened models. The increase of rectangularity aspect ratio and strength of the strengthening material lead to an increase in the section capacity of the studied models. Finally, new equations for the values of the section capacity of the strengthened sections were deduced, taking into account the factors described in this study.

Radial gate, mainly composed of gate leaf, arm and hinge, is a widely used gate types in hydraulic structures. This study proposed an improved model structure of radial gate, On the basis of the traditional radial gate, a pressure rod is added to connect the support arm and the bifurcation point of the lower flange of the longitudinal beam. The improved model structure of radial gate is designed, simulated and analyzed by using the general finite element software ANSYS. The results illustrate that the stress value and displacement value of each component of radial rigid gate with compression bar arrangement are greatly reduced compared with traditional gate, among which the arm stress reduction and the longitudinal radial displacement reduction are up to 28.14%, and 27.35%, respectively. In addition, the overall ultimate bearing capacity increased by 26.80% with only a few increase of steel consumption; When the gate is closed without water, the natural frequency and amplitude response frequency of the improved gate are higher than that of the traditional gate, furthermore the response amplitude of each key node is reduced. Hence, this new design provides a high potential for the overall stability and the anti-vibration performance of traditional radial gate.

The present study devised a method of representing and analyzing the mechanical behavior of fabrics in the clothing care system and examined the mechanical movement under various conditions using simulations and an image analysis program called TEMA Motion-Outline tracker. Through this, we proposed an algorithm to improve dust removal by finding conditions that could optimize the mechanical behavior of fabrics. The complex movement algorithm with various RPM configurations could change the number and location of nodes and antinodes. The algorithm effectively removed the dust at all locations, and the improved performance was also seen for real clothes.

Mechanical metamaterials can exhibit extraordinary mechanical properties due to a specific architecture rather than the base material. When the structural dimensions reach the sub-micrometer range, such micro- and nanolattices may also benefit from size-affected mechanical properties. However, well-defined geometric adjustments on this length scale are limited by the resolution limits of the underlying manufacturing technology. Here, we used a 3D direct laser writing (3D-DLW) process with integrated laser power variation to fabricate polymeric microlattices, which were then pyrolized to obtain glassy carbon structures. The laser power was varied by a quadratic function along the beams from one node to another over the length of a unit cell, thus enabling geometric adjustments in the range of a few nanometers. Rounded and notch-like joints were realized by increased and reduced laser power at the nodes, respectively. Furthermore, the beam cross section was varied along the beam length, thereby creating convex or concave beam shapes. A laser power variation opens up new design possibilities for micro- and nanolattices in the sub-micrometer range by overcoming process related limitations.

An improved finite element modeling method is developed for isotropic curvilinearly stiffened plates under a thermal environment. The existing modeling method for curvilinearly stiffened plates avoids the difficulty of node overlap, which is suitable for plates with different thicknesses. By introducing the influence of temperature on material parameters and thermal stress on additional stiffness, the existing method is improved and extended to the study of thermodynamics. The proposed method is verified by modal test at normal temperature and commercial finite element software at the thermal environment. The variation of dynamic characteristics with temperature under different boundary conditions was studied. Results show that when the boundary conditions are asymmetric, the influence of temperature on the thermal mode shape is more significant than the case of symmetrical.

This article builds the mathematical model of randomized 3D particles using a Python program to study the densification behavior of heterogeneous powder particles of non-equal diameter under pressure. The Python interface reserved by the finite element software Marc was applied to compile relevant command files and link them to carry out the numerical simulation of powder particle densification. The principles of particle distribution, deformation, and nodal flow were obtained by analyzing the powder particle compaction outcomes. The impact of particle parameters, compaction temperature, and coefficient of friction on the relative density of compacts was investigated. The results of the simulation show that the powder particles in the mould cavity are spiraling. Cu particles form concave arcs and cylindrical arcs at contact points, and the node trajectories rotate from top to bottom and from the center to the periphery. The overall deformation of Cr powder particles is not obvious. In the pressing process, the larger the powder particles, the greater the degree of deformity. As the temperature in the cavity increases, the relative density decreases. The higher the cavity friction, the higher the relative density, but once it reaches a certain value, the relative density reduces. The relative density of compacts can be greatly enhanced by selecting soft powder particles with a larger size, a higher temperature cavity, and a certain value of friction force. The experimental results verify the accuracy of the simulation, which is an important benchmark for numerical simulation of randomized particle densification. The findings provide a theoretical basis for further improvement in the density and properties of heterogeneous metal doping.

We predict that conduction electrons in a semiconductor film containing a centered square array of metal nanowires normal to its plane are bound in quantum states around the central wires, if a positive bias voltage is applied between the wires at the square vertices and these latter. We obtain and discuss the eigenenergies and eigenfunctions of two models with different dimensions. The results show that the eigenstates can be grouped into different shells. The energy differences between the shells is typically a few tens of meV, which corresponds to frequencies of emitted or absorbed photons in a range of 3 THz to 20 THz approximately. These energy differences strongly depend on the bias voltage. We calculate the linear response of individual electrons on the ground level of our models to large-wavelength electromagnetic waves whose electric field is in the plane of the semiconductor film. The computed oscillator strengths are dominated by the transitions to the states in each shell whose wave function has a single radial node line normal to the wave electric field. We include the effect of the image charge induced on the central metal wires and show that it modifies the oscillator strengths so that their sum deviates from the value given by the Thomas-Reiche-Kuhn rule. We report the linear response, or polarizability, versus photon energy, of the studied models and their absorption spectra. These latter show well-defined peaks as expected from the study of the oscillator strengths. We show that the position of these absorption peaks is strongly dependent on the bias voltage so that the frequency of photon absorption or emission in the systems described here is easily tunable. This makes them good candidates for the development of novel infrared devices., Comment: 15 pages, 15 figures, 23 references

Si(111) wafers patterned with an array of vertical 100 µm-wide Al-doped (1 × 1019 cm−3) p-channels extending through the whole wafer were studied by X-ray Laue diffraction techniques. The X-ray techniques included projection topography, and measurement of rocking curves and cross sections in the vicinity of the 02\overline 2 reciprocal space node in the double- and triple-crystal geometry, respectively. The channels are uniform along the depth of the wafer, and their structural perfection is comparable to that of the silicon matrix between the channels. Simulation of the rocking curves was performed using the methods of the dynamical theory of X-ray diffraction. The rocking-curve calculations both taking into account and neglecting the effect of the instrumental function were carried out using the Takagi–Taupin equations. The calculated angular dependences of intensities of both diffracted and transmitted X-rays correspond well to the experimentally obtained rocking curves and demonstrate their high sensitivity to the structural distortions in the channel. An unambiguous reconstruction of strain and structural distortions in the Si(Al) channel using the Laue diffraction data requires further development of the theoretical model.

A new version of the reflecting interferometer for $$S$$ -polarized light consisting of a thin metal film placed in front of a multilayer dielectric interferometer is considered. The appearance of narrow extremes in the spectral or angular dependence of the reflection coefficient depends on the location of the metal film in the node or antinode of the standing wave reflected from the interferometer (maxima or minima).

The effects of nanosecond pulse laser-generated processing Ti-6Al-4V alloy with different conditions were investigated by numerical simulations and experiments. A dynamic model of Ti-6Al-4V during laser shock processing (LSP) was established based on LS-DYNA. The attenuation characteristics and variation rules of stress waves were described. Further, the formation behaviors of residual stress fields with different power densities were discussed, and the interaction between residual stresses and plastic strains was revealed under different pulse widths. Results showed that the simulation values were consistent with the experimental results. In particular, the maximum radial velocity of node reached 8.6 m/s when the node had the strongest sparse wave, and the stress wave attenuated faster in the process of stress wave propagating from the depth of 0.1 to 0.3 mm. The maximum residual compressive stress was not at the geometric center of laser spot, but at a distance about 0.57 mm from the center of laser spot under different power densities.

Based on Lagrange interpolation polynomials, the penny-shaped cracks placed on but not limited to flat surface are simulated with a single high order smooth boundary element in the present work. By taking advantage of geometrical features of circular shape such as the symmetry and periodicity, the smoothness within the element is realized by repeated use of real nodes for interpolation in both the radial and circumferential directions of the element using high order shape functions, so that the end node/line effects existing in conventional low order elements have been removed. In the application of the boundary element method (BEM) for crack problems, the hyper-singular integrals are treated with the aid of the technique of shape function manipulations. The near hyper-singular integrals are treated with the tangential distance transformations together with the subdivision techniques. The crack-related parameters including the crack opening displacements (COD), the stresses ahead of crack tip, the stress intensity factors (SIF) and the T-stresses are computed under various loads and compared with the analytical solutions in the numerical examples, showing the accuracy, efficiency and effectiveness of the proposed high order smooth crack element.

We present a new numerical algorithm for the simulation of dispersive media. This model named ADE-TLM is based on the transmission line modeling method with the symmetrical condensed node (SCN-TLM) and novel voltage sources and exploits the polarization current density J along with the voltage electric as well as the average approximation. We extend the proposed algorithm to media with dispersions described by multiple second-order Lorentz poles; the obtained results of the reflection and transmission coefficients are compared with analytical solutions.

Gaseous hydrogen/liquid oxygen turbulent shear coaxial flames were subjected experimentally to both pressure antinode (PAN) and pressure node (PN) transverse acoustic forcing as a function of the g...

The objective of this research is to analyze the multistoried RC building on a sloping ground with different angles. In this research of multistoried RC G+10 building with different sloping angles (25˚, 26˚, 27˚, 28˚, 29˚, 30˚). We have determine the results on this G+10 structure without slope and angles having plane ground. For this analysis two types of condition taken for the study along sloping ground i.e. set back and step back. The results compare from this analysis are storey drift, node displacement, base shear.

In this paper, a turbine runner blade under hydraulic excitation was taken as the object of study and the mathematical hydrodynamic pressure model of a turbine runner blade under the rotor-stator interaction was established using quasi-three-dimensional finite element model. The regularity of the distribution of the hydrodynamic pressure was then investigated. First, the quasi-three-dimensional finite element model of a runner blade was established using the quasi-three-dimensional theory. Next, according to the pressure distribution from the numerical simulation, the mathematical mean pressure model of a node was established using the relative pressure difference method; the pressure fluctuation was then established taking the rotor-stator interaction into consideration. Then, based on the mean pressure and the pressure fluctuation of a node, the mathematical hydrodynamic pressure model for any position of a runner blade was obtained. Finally, the feasibility of the mathematical model was verified by an example analysis, and the internal relationship between the hydrodynamic pressure and its hydraulic parameters and the structural parameters of the blade was revealed, which provides a theoretical basis for further study of the dynamic characteristics of turbine runner blades under the rotor-stator interaction.

Let $\mathfrak g$ be an affine Lie algebra with index set $I = \{0, 1, 2, \cdots , n\}$. It is conjectured in \cite{KNO} that for each Dynkin node $k \in I \setminus \{0\}$ the affine Lie algebra $\mathfrak g$ has a positive geometric crystal whose ultra-discretization is isomorphic to the limit of a coherent family of perfect crystals for the Langland dual ${\mathfrak g} ^L$. In this paper we show that at the spin node $k=6$, the family of perfect crystals given in \cite{KMN2} form a coherent family and show that its limit $B^{6,\infty}$ is isomorphic to the ultra-discretization of the positive geometric crystal we constructed in \cite{MP} for the affine Lie algebra $D_6^{(1)}$ which proves the conjecture in this case.

In the present investigation, the influence of centrally placed circular cutouts, ply-orientation and boundary conditions on the vibration characteristics of laminated trapezoidal composite panels has been studied by using finite element technique. Towards this investigation, an eight node iso-parametric plate element has been used to discrete the laminated composite panel with seven degrees of freedom at each node. In the present mathematical formulation, the effect of shear deformation has been incorporated by using higher order shear deformation theory. Therefore, the present model is holds good for both thin and thick panels without applying any shear correction factors. The accuracy of the present model is confirmed by comparing present results with approachable literature. The parametric studies are carried out to examine the effect of various parameters such as different edge conditions, trapezoidal shape ratio, cutout ratio and aspect ratio of the trapezoidal laminated panel. It is observed from this study that the variation in natural frequency of the panel under different ply- orientations and boundary condition is predominant as compared to that of thick plate configuration.

Critical buckling loads of composite laminates are usually calculated by using analytical solutions based on the assumptions of uniform in-plane loads, despite of the fact that real structures are often subjected to various nonuniform loads. The present work is focused on the buckling behavior of composite trapezoidal laminates panel with cutouts, subjected to various nonuniform in-plane loads. The effect of variation is size of trapezoidal plate on the buckling behavior has been studied using finite element method. The governing differential eigenvalue equations have been solved using subspace algorithm. The analytical solution for such problems is very difficult. Hence in this work, a finite element software FORTRAN is used to study the buckling behavior of thin and thick laminated panels with cutouts subjected to various kinds of non-uniform edge loads. The panel is modeled by using eight node elements with five degrees of freedom at each node. The accuracy of the model is confirmed by comparing present results with available literature. The effect of various parameters such as cutout size, boundary conditions and ply-orientations of panel are included in this work. It is observed from this study that the non-uniform edge loads and cutout size has remarkable effect on the buckling behavior of said panels.

This brief presents a new resonator for class-C oscillators which not only decreases the phase noise, but solves their inevitable start-up problem. The aforementioned resonator has two separate nodes that increasing inductance energy factor (IEF) in output node provides lower phase noise. By connecting a class-B active pair to the other node of the resonator, with larger equivalent impedance, start-up problem has been solved. By reaching the steady state, the auxiliary class-B active pair transistors will be switched off in order to achieve lower phase noise besides power consumption goals. The proposed oscillator, implemented in 130 nm standard CMOS technology, oscillates at the frequency of 3.4 GHz and its phase noise is about −136.8 dBc/Hz at 3 MHz offset. The power consumption and FoM are 9.5 mW and 188.1 dBc/Hz, respectively.

The effect of the radiation force on a spherical drop of an ideal liquid in the vicinity of the free boundary of the liquid when an acoustic wave is normally incident on the liquid surface is studied. As a result, the liquid sphere is located in the field of standing acoustic wave of pressure with the node at the free liquid surface. The measure of interaction is the radiation force: the time-average integral over the pressure in the external fluid caused by the acoustic wave over the surface of the sphere. The approach assuming the use of the velocity field potential obtained by solving the linear diffraction problem when determining the pressure in the liquid is used. It is established that there are frequencies of the incident wave at which the radiation force does not act on the spherical drops, which, therefore, will be stationary.

In this article, a numerical model based on the Morison equation and lump-mass method is developed to simulate the failure of an aquaculture net cage system, by changing an upstream anchor from a fixed node to a free node. Current-only and wave-current conditions are employed to investigate the mooring line tension and volume reduction coefficient of a net cage after a failure. The results show that both mooring line tension and volume reduction coefficient increase after a failure. The failure causes the cage system to drift downstream and move aside. Remaining mooring lines twist to rotate and deform the net cage. The maximum mooring line tension for the current-only cases increases with the current speed. However, the tension ratio only increases up to some certain value, i.e., 1.91 instead of 2. Beyond this, the cage system is completely collapsed resulting in a smaller minimum volume reduction coefficient compared to its counterpart under the normal state. When examined under wave-current conditions, the cage system exhibits oscillatory motion, and a large excitation of the mooring line tension is induced. The corresponding minimum volume reduction coefficient is larger than under the normal state, due to the twisting deformation of the net cage. Different instances of failure time are also examined. It is found that the results at later times (steady-state region), including the mooring line tension, the volume reduction coefficient, and the body motion of the floating collar, are not affected by the failure time. Different wave heights, wave periods, and current speeds are also simulated. The results show that the tension ratio increases with the wave height and the current speed but it decreases with the wave period.

In this paper, a localized meshless collocation method, the generalized finite difference method (GFDM), is first applied to calculate the bandgaps of anti-plane transverse elastic waves in 2D solid phononic crystals with square and triangular lattice. The corresponding theoretical consistency analysis of the GFDM is given. The universal algorithm for the uniform/scattered node generation in the GFDM is presented. In comparison with the traditional plane wave expansion (PWE) method and Pressure Acoustics Module in COMSOL software, the proposed GFDM can provide the similar accurate results with less computational times for calculating the band structures of the simple/complicated shape scatterers in the square/triangular lattice. Three influence factors (Filling fractions (Ff), rotation angles (Ra) and arm widths (Aw) in the unit-cell) of the bandgap properties in 2D phononic crystals are numerically discussed.

This paper discusses a possibility of detecting structural damage caused by an earthquake, by measuring the time history of the strain of beams and columns before and/or after the earthquake. An index called “local stiffness” is defined as the ratio of section force amplitude to representative displacement amplitude, and this ratio can be physically interpreted as stiffness. By calculating section force amplitude at a section or node from the measured strain amplitude under a microtremor or small aftershocks and comparing it with the results of a static pushover analysis, it becomes possible to detect any structural damage, such as fractures. This methodology was applied and the microstrain data of a steel moment frame were measured in a large-scale shaking table test; beam-end fractures were observed after some excitation tests. After the beam-end fracture formed, the measured local stiffness dropped significantly below the analysis value, indicating the possibility of employing this value to detect fractures using the analysis value as a threshold value.

This article provides a fundamental study into the trade-offs between the location of piezoceramic elements, resonant frequency, and achievable ultrasonic vibration amplitude at the working end of the bolted Langevin-style transducers (BLTs) for ultrasonically assisted machining (UAM) applications. Analytical models and finite-element (FE) models are established for theoretical study, which are then validated by experiments on four real electromechanical transducers. The results suggest that resonant frequency and oscillation amplitude of the BLTs depend essentially on the dimensions of the system and the location of the piezoceramic elements. The highest resonant frequency and the maximal vibration are achieved when the piezoceramic elements are at the longitudinal displacement node, where the highest effective electromechanical coupling coefficient value is exhibited. However, the minimal resonant frequency and the lowest vibration, which is almost equal to zero, are observed when the piezoceramic elements are located at the displacement antinode. In addition, the longitudinal displacement node locations are dependent on the resonant frequency of the devices rather than the locations of the piezoceramic elements.

The open multi-processing parallelism was implemented into a serial code to compute a high-order boundary integral equation based on the second Green's identity. on symmetric multiprocessing computer platforms. The parallel code is augmented to a three-dimensional potential numerical wave tank for fully nonlinear wave-body interaction problems in the time domain. The non-uniform rational B-Spline surface was manipulated to define the geometry of the computational boundaries and the distribution of boundary values either as a high-order iso-geometric formulation. The material node approach and fourth-order Runge-Kutta time integration method were compounded for time marching the fully nonlinear free surface boundary. The propagation of a fifth-order Stokes wave was simulated to examine the scalability of the parallel constructs implementation. Afterwards, the second-order Stokes wave interaction with a cylindrical pile was modeled as a practical case study to show the benefits of the parallel code. The results were compared with former experiments and numerical studies.

Nonradiative relaxation, a ubiquitous phenomenon in natural and artificial molecules and materials, has been extensively studied in contemporary chemistry. In this report, we show the nonradiative ...

Purpose. To evaluate the fire resistance of spun reinforced concrete columns of annular section under joint temperature and power load through full-scale experimental studies. Methods. Conducting full-scale fire tests of columns as a part of a fragment of a framed building. Visual observation of the behavior of the columns during the fire test. Temperature measurement of fire gaseous medium, reinforcement, concrete on the inner surface of columns, including in the place of the connection node with monolithic overlap. The measurement of the temperature and excess pressure of the gaseous medium in the hollow of the columns. Findings. Experimental dependences of changes in temperature of reinforcement and concrete on the inner surface of columns, including at the site of the node connection with monolithic overlap were obtained. The behavior of temperature and excess pressure change in the hollow of the columns is obtained. It was revealed that walls of spun reinforced concrete columns with free air hollow have higher rate of heating than the walls with monolithic concrete cotter in the hollow. The significant effect of increasing pressure of the gaseous medium in the hollow of the columns on their bearing capacity is not fixed. Explosive destruction of concrete of the columns during the fire tests is not fixed. The destruction of one of the columns during the fire tests occurred in the middle part of the height after the formation of main cracks, directed at an angle of 75–80° to the longitudinal axis of the construction, and increasing of bending deformation. The factual fire resistance limit of the experimental spun reinforced concrete columns of annular section with an eccentric applied load of 18.25 t was R60. Application field of research. The results of the study can be used to determine the thermophysical characteristics of spun concrete and to develop calculation model of fire resistance of spun reinforced concrete columns of annular section.

Laws of traveling wave data related to fault location for medium voltage distribution network are discussed and summarized. Given the tree structure of a distribution network, an image of nodes voltage is created combining the use of real-time traveling wave meters at all nodes of the tree. The novelty of this paper is that travelling wavefront are analyzed based on the dynamic changes of these images. Based on principle of the traditional fault location with traveling wave-based method for transmission networks, traveling wave data of fault location for medium voltage distribution networks are plotted in order to estimate propagation velocity and distance between the fault position and the reference node. The results indicate that taking advantage of the laws of data related to first wave front can improve the reliability of the fault location for medium voltage networks.

This paper presents an experimental study into dynamics of chamber pressure and heat release rate during self-excited spinning and standing azimuthal mode in NTO/MMH (nitrogen tetroxide/monomethylhydrazine) impinging combustion chambers. Nine cases including two combustion chamber configurations were conducted. The operating conditions of all unstable cases were located in the instability region according to Hewitt empirical correlation. The results show that chamber pressure oscillations keep pace with the corresponding OH* chemiluminescence intensity over the whole combustion region in the spinning and standing modes. It is indicated that the Rayleigh index is positive over the whole combustion area in all the unstable cases. A significant supersonic flame front structure of the first-order spinning mode was found in a cylindrical chamber, which means that a detonation wave could exist in the cylindrical chamber without a center body. The pressure and heat release rate oscillations at the pressure node are nonnegligible although their amplitudes are lower than those at the pressure antinode in the first-order standing mode with an annular chamber. Besides, the dominant frequency of pressure and heat release rate oscillations at the pressure node is twice as high as that at the pressure antinode.

The topological nodal-line semimetal (TNS) is a unique class of materials with a one dimensional line node accompanied by a nearly dispersionless two-dimensional surface state. However, a direct observation of the so called drumhead surface state within current nodal-line materials is still elusive. Here, using high-resolution angle-resolved photoemission spectroscopy (ARPES) along with first-principles calculations, we report the observation of a topological nodal-loop (TNL) in SrAs3, whereas CaAs3 exhibits a topologically trivial state. Our data reveal that surface projections of the bulk nodal-points are connected by clear drumhead surface states in SrAs3. Furthermore, our magneto-transport and magnetization data clearly suggest the presence (absence) of surface states in SrAs3 (CaAs3). Notably, the observed topological states in SrAs3 are well separated from other bands in the vicinity of the Fermi level. RAs3 where R = Ca, Sr, thus, offers a unique opportunity to realize an archetype nodal-loop semimetal and establish a platform for obtaining a deeper understanding of the quantum phase transitions.

In this study, the vibration characteristics of fixed ends beam are analysed after attached with dynamic vibration absorbers at vibrational node and antinode by simulation using ANSYS APDL. This study aim to obtain the best location and optimum number of DVAs placed on the fixed ends beam in order to reduce vibration of beam. The dynamic vibration absorber were attached to the fixed ends beam vibrational node and antinode for a total of three modes of vibration. The 0.84 m long beam is modelled by ANSYS and divided into 21 elements where each element is 0.04 m. A harmonic force, Fo of 28.84 N is exerted at node 3 of beam element. Modal analysis and harmonic analysis are carried out in this study to obtain the natural frequency and frequency response of the beam respectively. The vibration characteristics of fixed ends beam without DVA and beam attached with DVAs were compared. The simulation results show reduction of vibration amplitude of the beam especially when the DVA were attached at the vibrational antinode. The DVA amplitude increase when amplitude of beam decreases. From this study, it is proved that DVAs absorb vibration of the beam structure. The best position to attach DVAs is the vibrational antinode based on the modes of vibration. The increment of DVAs number will not affect the percentage reduction of vibration amplitude as long as the DVAs are placed at optimum location.

Values of static and kinetic friction coefficient in micro slide bearings, consisting of journals and bushings (with the diameter of 3.5 mm) made of pairs of 5 polymer materials (16 chosen combinations of PA11, ABS, PC, PS and PETP), were determined. A method of measuring static and kinetic friction coefficient, at various values of: load, rotational speed, and standstill time, as well as the structure of a dedicated test rig, were discussed. Chosen mechanical properties of polymers measured using indentation method, and conclusions from the conducted experiments, are shown. The presented results provide key information for a proper choice of polymer materials, which are to work as a friction node. The biggest observed difference in the moment of friction among the tested slide bearings reached almost 40% (with respect to the highest value).

Temperature dependence under various HCD conditions was analyzed in 14 nm node FinFETs. Unlike oxide traps, interface traps show different temperature dependence depending on HCD voltage conditions. Therefore, the interface traps were separated into three components and the temperature dependence was analyzed for each component. Multiple particle process (MP) and Field enhanced thermal degradation process (FP) have a constant temperature dependence regardless of voltage conditions. On the other hand, the temperature dependence of Single particle process (SP) varies depending on the voltage condition because SP is affected by scattering. However, the components of the interface traps in at nominal operating voltage changes since self-heating effect is different comparing the accelerated voltage. Therefore, we predicted the ratio of each component under nominal operating condition.

Design considerations of vertically stacked horizontal nanosheet (NSH) gate-all-around pMOSFETs are examined at the sub-5-nm technology node using in-house-developed non-equilibrium Green’s function (NEGF) quantum ballistic transport simulator. In the individual Si and Ge NSHs, ON-state current and subthreshold swing are evaluated and analyzed for different crystal orientations and various sheet widths. Performance benchmarking of the stacked FET arrays at the iso-footprint is accomplished to explore the roles of sheet configurations further with stack number and sheet spacing changed. It is found that the benefit of the larger effective channel width provided by the wider NSH is always compromised by degraded gate control, especially in the Ge channel. [111] and [100] are shown to be the best transport orientations for individual Si and Ge NSHs, respectively. However, [100] channel vertically confined along [011] shows greater potential for the applications of wider Si and Ge NSHs in the stacked FET array. The process-induced NSH width variation is studied statistically, and it is shown to cause significant performance fluctuations in the stacked array consisting of wide Si or narrow Ge NSHs.

The acoustic radiation force, originating from ultrasonic standing waves and utilized in numerous cell oriented acoustofluidic applications, is dependent on the acoustic contrast factor which describes the relationship between the acousto-mechanical properties of a particle and its surrounding medium. The acousto-mechanical properties of a cell population are known to be heterogeneously distributed but are often assumed to be constant over time. In this paper, we use microchannel acoustophoresis to show that the cell state within a cell population, in our case living and dead cells, influences the mechanical phenotype. By investigating the trapping location of viable and dead K562, MCF-7 and A498 cells as a function of the suspension medium density, we observed that beyond a specific medium density the viable cells were driven to the pressure anti-node while the dead cells were retained in the pressure node. Using this information, we were able to calculate the effective acoustic impedance of viable K562 and MCF-7 cells. The spatial separation between viable and dead cells along the channel width demonstrates a novel acoustophoresis approach for binary separation of viable and dead cells in a cell-size independent and robust manner.

In this paper, we further extend the local radial basis function collocation method (LRBFCM) for efficient computation of band structures of phononic crystals from 2D to 3D. The proposed LRBFCM uses one fictitious node to tackle instability problems caused by calculation of derivatives of the wave pressure. A few examples of sound pressure wave propagation are modelled to validate the developed method. Comparisons with finite element modeling demonstrate the high stability and efficiency of the new method in computation of band structures of 3D phononic crystals.

Excess source and drain (S/D) recess depth ( $T_{SD}$ ) variations were analyzed comprehensively as one of the most critical factors to DC/AC performances of sub 5-nm node Si-Nanosheet (NS) FETs for system-on-chip (SoC) applications. Variations of off-, on-state currents ( $I_{off}$ , $I_{on}$ ) in three-stacked NS channels and parasitic bottom transistor ( $tr_{pbt}$ ), gate capacitance ( $C_{gg}$ ), intrinsic switching delay time ( $\tau _{d}$ ), and static power dissipation ( $P_{static}$ ) are investigated quantitatively according to the $T_{SD}$ variations. More S/D dopants diffuse into the $tr_{pbt}$ with the deeper $T_{SD}$ , so the $I_{off}$ and $I_{on}$ increase due to raised current flowing through the $tr_{pbt}$ . Especially, the $I_{off}$ of PFETs remarkably increases above the certain $T_{SD}$ ( $T_{SD,critical}$ ) compared to NFETs. Furthermore, the $I_{on}$ contribution of each channels having the $T_{SD,critical}$ is the largest at the top NS channel and the $tr_{pbt}$ has the ignorable $I_{on}$ contribution. Among the NS channels, the top (bottom) NS channel has the largest (smallest) $I_{on}$ contribution due to its larger (smaller) carrier density and velocity for both P-/NFETs. The $C_{gg}$ also increases with the deeper $T_{SD}$ by increasing parasitic capacitance, but fortunately, the $\tau _{d}$ decreases simultaneously due to the larger increasing rate of the $I_{on}$ than that of the $C_{gg}$ for all SoC applications. However, the $P_{static}$ enormously increases with the deeper $T_{SD}$ , and low power application is the most sensitive to the $T_{SD}$ variations among the SoC applications. Comprehensive analysis of the inevitable $tr_{pbt}$ effects on DC/AC performances is one of the most critical indicators whether Si-NSFETs could be adopted to the sub 5-nm node CMOS technology.

As an effective structure health monitoring technology, acoustic emission (AE) has been developed rapidly in various fields over recent years. AE source localization is the core element of AE technology. In this paper, a Node Block Location Method (NBLM) based on the collaborative model of node and block matrix was proposed to meet the high-precision requirement of source localization in the quasi-cylindrical structure with complex hole. NBLM can not only bypass the empty area, but also fit the actual propagation of elastic waves better in the complex boundaries. In order to evaluate the effectiveness of NBLM, lead-breaking tests were carried out on two cylindrical structure: one with square hole and the other with circular hole. The lead-breaking points were used as AE source in the test. The source coordinates were inverted by three separate location methods according to arrivals. Test results verify the superiority of NBLM and show that the location accuracy of the NBLM has been greatly improved compared to the existing methods.

We present Surface Evolver evaluations of the difference in energy between face-centred cubic (fcc) and hexagonal close-packed (hcp) foams in the usual idealized model, for liquid fractions ranging from the dry to the wet limit. The difference vanishes in both limits, and favours hcp for all intermediate liquid fractions, as has been proven. The maximum relative energy difference is very small, of the order of 10-5. The asymptotic dependence on liquid fraction is non-analytic in both limits: we present explicit expressions in both cases, derived from first principles. They have been obtained from identifying node interactions (dry limit) and contact interactions (wet limit) as the respective sources for energy differences between fcc and hcp. The wet limit is well described by Morse-Witten theory which has proven to be very powerful for the analytic computation of the surface energy of slightly deformed bubbles.

The adoption of 3D packaging technology necessitates the development of new approaches to failure electronic device analysis. To that end, our team is developing a tool called the quantum diamond microscope (QDM) that leverages an ensemble of nitrogen vacancy (NV) centers in diamond, achieving vector magnetic imaging with a wide field-of-view and high spatial resolution under ambient conditions. Here, we present the QDM measurement of 2D current distributions in an 8-nm flip chip IC and 3D current distributions in a multi-layer PCB. Magnetic field emanations from the C4 bumps in the flip chip dominate the QDM measurements, but these prove to be useful for image registration and can be subtracted to resolve adjacent current traces in the die at the micron scale. Vias in 3D ICs display only Bx and By magnetic fields due to their vertical orientation and are difficult to detect with magnetometers that only measure the Bz component (orthogonal to the IC surface). Using the multi-layer PCB, we show that the QDM’s ability to simultaneously measure Bx, By, and Bz is advantageous for resolving magnetic fields from vias as current passes between layers. We also show how spacing between conducting layers is determined by magnetic field images and how it agrees with the design specifications of the PCB. In our initial efforts to provide further z-depth information for current sources in complex 3D circuits, we show how magnetic field images of individual layers can be subtracted from the magnetic field image of the total structure. This allows for isolation of signal layers and can be used to map embedded current paths via solution of the 2D magnetic inverse. In addition, the paper also discusses the use of neural networks to identify 2D current distributions and its potential for analyzing 3D structures.

The optical wave wavefront measurement system can perform non-contact real-time quantitative monitoring of the gas flow rate according to the gas density changes in the wind tunnel test. Since the quality of the optical surface of the wind tunnel window directly affects the acquisition accuracy of wavefront information, it is necessary to evaluate the adaptability of the opto-mechanical structure to fluid load in the development stage. To solve this problem, this paper proposes a gas flow field change model based on Finite Element Analysis (FEA). By calculating the fluid-structure coupling response of the wind tunnel window, the displacement field of the wind tunnel window and the maximum displacement of the node are obtained. It is 0.00018mm, and the result shows that the window glass has good environmental adaptability at a flow rate of 885m/s.