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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.

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.

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.

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.

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 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.

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.

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.

Extreme ultraviolet lithography (EUVL) is a main lithographic technology for cutting-edge node. Also, ArF lithography will continue to be used in conjunction with EUVL for advanced node production. Critical ArF imaging layers require photomasks with tight resolution and "rigid CD and Positional accuracy". Those specifications are tightening due to the narrow process window. The etching process for phase-shifter has to precisely controlled to achieve the targets. . Various pattern density in PSM (Phase-Shifter Mask) shows phase angle variation due to the digging of the Quartz substrate(QZ). In the high transmittance PSM, the error has larger impact on the lithography due to strong phase shift effects. To prevent phase shift error from the target phase angle, QZ etching stop film is considered. It is possible to obtain a high etching selectivity compared with QZ and to apply an aggressive dry etching condition. In order to control in-plane phase angle distribution due to QZ etching during PSM etching, we proposed a novel high transmission etching stop film for ArF lasers.

Dynamic color modulation in the composite structure of a graphene microelectromechanical system (MEMS)-photonic crystal microcavity is investigated in this work. The designed photonic crystal microcavity has three resonant standing wave modes corresponding to the three primary colors of red (R), green (G) and blue (B), forming strong localization of light in three modes at different positions of the microcavity. Once graphene is added, it can govern the transmittance of three modes. When graphene is located in the antinode of the standing wave, it has strong light absorption and therefore the structure’s transmittance is lower, and when graphene is located in the node of the standing wave, it has weak light absorption and therefore the structure’s transmittance is higher. Therefore, the graphene absorption of different colors of light can be regulated dynamically by applying voltages to tune the equilibrium position of the graphene MEMS in the microcavity, consequently realizing the output of vivid monochromatic light or multiple mixed colors of light within a single pixel, thus greatly improving the resolution. Our work provides a route to dynamic color modulation with graphene and provides guidance for the design and manufacture of high resolution, fast modulation and wide color gamut interferometric modulator displays.

The remote control and monitoring of a tunable optical correlator based on nonlinear wave-mixing is demonstrated. The correlator is remotely controlled via the bidirectional transmission of multiple waves over an optical link. The effects of the temperature-drift and link backscattering are mitigated at the transmitter.

In this paper, the static bending behavior of the functionally graded sandwich beams is investigated using a novel mixed beam element based on the first-order shear deformation theory. The proposed beam element consists of two nodes and three degrees of freedom per node as the traditional Timoshenko beam element. By introducing a special process, selective or reduced integration are not required to calculate the element stiffness matrix and nodal force vector. The efficiency and accuracy of the proposed element are verified via some comparison studies. Then the proposed element is applied to study the bending behavior of the functionally graded sandwich beams with various boundary conditions. The influences of some parameters such as the power-law index, the slender ratio and the boundary conditions are studied carefully. The comparison studies and numerical results present that the new beam element is compatible with the static bending analysis of the functionally graded sandwich beams with a very coarse mesh. Besides, the numerical results show that the stress concentration may occur on the separated surface of the core layer and two face sheets, which should be noticed in practical applications of the FG sandwich beams.

Optical biosensor is the most promising device with high sensitivity for the detection and analysis of biochemical composition. Due to the compact size, these designs have a vast application in biomedical and healthcare. In this paper, a nanocavity based 2-D photonic crystal sensor for sensing of several biochemical are proposed. In these structures, nanocavity is explored in the waveguide as a sensing node. This explored sensing node can detect the change in refractive index. The proposed nanocavity structure is designed for analyst refractive index in an optical wavelength of 1.43–1.65μm. For detecting the different analysts, the sensing node refractive index is changed. Simulation has been done for biotin-streptavidin, ethanol, hemoglobin, and water. For the different refractive index analysts, it has been observed that change in refractive index has shifted the resonating wavelength to higher wavelength. All the simulation has been done using Finite Difference Time Domain (FDTD) Method.

Polarized Stress Imaging is an excellent method for monitoring bulk stress distribution in silicon wafers. In this study, the correlation of bulk Si stress and lithography defects are shown using Semilab’s Polarized Stress Imager (PSI) system. 300 mm diameter samples with 7 nm advanced node FinFET devices were investigated with PSI optical imaging metrology tool and AMAT’s UVision wafer inspection tool. Two sets of samples were analyzed after shallow trench isolation etch and after gate etch. Results show that stress imaging can detect process deviations that lead to high defectivity and may have uses in failure analysis to pinpoint root causes of failures.

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.

This article introduces a chip-scale ultralow-power atomic clock (ULPAC) in the microwave frequency region. A new suspended quantum package architecture along with a fully integrated frequency probing and locking loop implemented in CMOS technology results in a compact package and ultralow-power consumption. In addition, dedicated low-noise magnetic field and temperature control loops are incorporated for isolating and mitigating the internal and external factors affecting the frequency stability. The output frequency of a crystal oscillator is continuously compensated and stabilized by locking to the peak of a coherent population trapping signal, thereby inheriting the superior frequency stability of the atomic resonance. The proposed ULPAC system achieves a frequency stability of $2.2 \times 10^{-12}$ at an averaging time of 105 s, while consuming 59.9 mW. The frequency probing and locking circuits implemented in a standard 65-nm CMOS process node occupy an area of 2.55 mm2. The prototype of this atomic clock occupies a volume of 15 cm3.

The future photonic age largely depends on our ability to manipulate optical waves in confined systems. Particularly, understanding the behavior of a plasmonic charge density wave (p-CDW) in optical resonators is vital for engineering 2D plasmonic devices. In this study, the standing p-CDW on the surface of a gold triangle resonator is examined through diffraction limited all-optical far field power loss microscopy. The scattering light map captured by this microscopy, named plasmonic Chladni figure, is directly proportional to the entire in-plane photonic local density of state. The theoretical model of the plasmonic Chladni figure proposed in this study is related to the 2D standing p-CDW node pattern, which is similar to the mechanical Chladni, but follows a special node selection rule. Investigating the plasmonic Chladni phenomenon provides an in-depth understanding of fundamental plasmonic physics and plasmonic chemistry and presents various possibilities for plasmonic application, such as 2D dimensi...

The mistuning modeling methods and mistuning effects on the vibration characteristics of uncoated blisks have been extensively investigated over the past years. Most of these studies mainly focus on single-factor mistuning. In this work, we study the effect of coating thickness random mistuning on the forced response, which contains mass, stiffness and damping mistuning simultaneously and has not yet been investigated in previous studies. Furthermore, to satisfy the requirement of variable coating thicknesses, a new finite element model (FEM) is presented to resolve the new stiffness and mass matrices when the coating thickness changes. This FEM only needs the element node coordinates of one sector for the uncoated blisk and is verified by ANSYS software. For the mistuned blisk, the Craig-Bampton (C-B) method and the subset of nominal system modes (SNM) are employed to statistical analysis. The results indicate that the maximum amplification factor of forced response grows monotonously with the increased mistuning value of coating thickness.

Purpose The capability of microparticle/objects patterning in the three-dimensional (3D) printing structure could improve its performance and functionalities. This paper aims to propose and evaluate a novel acoustic manipulation approach. Design/methodology/approach A novel method to accumulate the microparticles in the cylindrical tube during the 3D printing process is proposed by acoustically exciting the structural vibration of the cylindrical tube at a specific frequency, and subsequently, focusing the 50-μm polystyrene microparticles at the produced pressure node toward the center of the tube by the acoustic radiation force. To realize this solution, a piezoceramic plate was glued to the outside wall of a cylindrical glass tube with a tapered nozzle. The accumulation of microparticles in the tube and printing structure was monitored microscopically and the accumulation time and width were quantitatively evaluated. Furthermore, the application of such technology was also evaluated in the L929 and PC-12 cells suspended in the sodium alginate and gelatin methacryloyl. Findings The measured location of pressure and the excitation frequency of the cylindrical glass tube (172 kHz) agreed quite well with our numerical simulation (168 kHz). Acoustic excitation could effectively and consistently accumulate the microparticles. It is found that the accumulation time and width of microparticles in the tube increase with the concentration of sodium alginate and microparticles in the ink. As a result, the microparticles are concentrated mostly in the central part of the printing structure. In comparison to the conventional printing strategy, acoustic excitation could significantly reduce the width of accumulated microparticles in the printing structure (p Originality/value This paper proves that the proposed acoustic approach is able to increase the accuracy of printing capability at a low cost, easy configuration and low power output.

This paper presents a method to improve source/drain extension (SDE) ion implantation (I/I) process for sub-20 nm node FinFETs with no extra step in transistor process. Traditionally, SDE I/I process needs a large implant tilt angle and a high dose to obtain a heavy and conformal doping. However, this process leads to implantation shadow effects and Si-fin amorphization. These drawbacks can be removed in our new approach when SDE I/I is modified and moved after S/D epitaxy process (SDE I/I-last). Because of the facet planes of the SiGe layer, the ions are allowed to be implanted with small tilt. This is helpful to avoid shadow effects of implantation and to keep the low defect density in the S/D. As a result, the external resistance (REXTRNL) is not high and the strain relaxation is minor in S/D epitaxy layer. Finally, p-type FinFETs with 25 nm gate length with SDE I/I-last are fabricated. These new FinFETs demonstrate ~ 50% on-state current (ION) improvement compared to those transistors fabricated by traditional method.

As feature sizes shrink with each integration node, wire and interconnect resistivity in the back end of the line increasingly becomes a challenge due to size dependent effects. Microstructural control of metal thin films is critical for accessing the lowest resistivities alongside materials choice. In this paper, we describe depositing a metal material onto a substrate via ion beam deposition with assist in a process chamber at a temperature of at least 250°C to produce ultra-low resistivity metal films. Ion beam deposited thin tungsten films were grown with large and highly oriented α(110) grains having a resistivity less than 9 μΩ-cm and thickness less than 300 A, with no discernable β-phase, presaging benefits for memory and logic applications using tungsten for wiring.

We design a dual-band absorber based on metal multiplexed gratings at mid-infrared (mid-IR) frequencies. The metal multiplexed gratings are realized with two constitutive gratings and separated from a metallic ground plate by a thick dielectric spacer in order to construct the metal–insulator–metal architecture. Simulations indicate that two different absorption frequencies from the excitation of surface plasmon–polariton modes can be achieved under normal incidence, due to the different field distributions of each resonance node numbers in supercell. The doublet resonance positions can be independently and arbitrarily adjusted by varying the constitutive grating periods. We also confirmed that the absorption performance of the resonance peak is related to the non-uniform distribution level of the corresponding constitutive grating ridge. The designed absorber can be easily fabricated with planar processing technology and used in many applications where multispectral control of mid-IR signals is required.

Coupled optical resonators show a rich dynamical behaviour that can be exploited in different applications, e.g. chaos based communication and sensing, information processing and mimicking of neural networks [1] . Random lasers (RLs) are light sources in which optical feedback is provided by scattering elements, resulting in multi-mode emission with narrow resonances randomly distributed in frequency [2] . Our group has previously demonstrated that RLs can be implemented by placing the active medium between two scattering surfaces [3] . Here, we apply this fabrication approach to the realization of in-plane networks in which the nodes are made of disordered scattering media, acting as coupling elements between different resonators [4] . The active medium employed is a dye doped polymer film and the single RL consists of a stripe shaped pumped area, placed between two scattering elements. Each scattering element, obtained by pulsed laser ablation of the polymer film, consists of random surface defects at the polymer/air interface able to provide feedback for lasing. We first consider a network formed by two RLs which share one scattering node. In Fig. 1(a) , RL1 (RL2) consists of the pumped stripe labelled 1 (2) and the two scattering nodes A and B (B and C). Independent spectral signatures are detected at node B, when one laser at a time is turned on, see Fig. 1(b) . In Fig. 1(c) , we compare the compound cavity emission, when both lasers are turned on (RL1&RL2), with the sum of the emissions of each laser turned on, one at a time (RL1+RL2). A rearrangement of lasing peaks is observed with respect to the sum of spectral profiles that would result only from the scattering of each independent laser from node B.

The body of the new-type dry gas holder is a large stiffened cylindrical shell. Limited by the test site and economic conditions, the buckling characteristics of such holders are generally studied through scale model experiments. Taking the longitudinal-ring rectangular stiffened cylindrical shell as the research object, the generalized similitude condition and scaling principle formula of the structure are derived innovatively based on Donnell’s assumption and the energy method. By means of displacement loading and node coordinates updating, dimple imperfections are introduced into the ideal structure of the stiffened cylindrical shell, and then, the complete similitude and partial similitude analysis of axial compression nonlinear buckling for imperfect structures are carried out. The analysis results show that the complete similitude analysis of stiffened cylindrical shell axial-compression nonlinear buckling can be realized accurately; the partial similitude model for stiffened cylindrical shell axial-compression nonlinear buckling can better predict the buckling characteristics of its prototype structures, and the closer the Poisson’s ratio between the model and the prototype materials is, the more accurate the prediction results are. Meanwhile, the generalized similitude condition and scaling principle formula derived based on the energy method can provide useful reference for the model design and experimental verification of the axial compression buckling of the stiffened cylindrical shell with local geometric imperfections.

The main contribution of this study is the development of an efficient element in modeling thin to thick functionally graded (FG) square plates. To accomplish this goal, a 3D plate bending element is developed by taking advantages of the mixed interpolation of tensorial components approach (MITC). The recommended element has four nodes with six degrees of freedom at each node. Both higher-order shear deformation and the thickness stretching are considered. A fully 3D constitutive relation is adopted. Utilizing an assumed strain field for transverse normal strain causes the element to perform well, even when the thickness becomes thin. Based on the rule of mixture and Mori–Tanaka scheme, a Voigt model is also employed in this study to represent through the thickness distribution of FG material property. Static, free and force vibration analyses of the square FG plates, with different boundary conditions, are investigated in this paper. Several benchmark problems are studied to demonstrate the ability of the element in the static and dynamic analysis of thin/thick plates. Moreover, the effects of different power index and boundary conditions on the response of plate are also investigated.

This paper deals with the theory of primary aberrations for perturbed double-plane symmetric optical systems consisting of a combination of tilted and decentered surfaces and a circular pupil. First, the analytical expressions describing the full field behavior of Zernike polynomials are derived from the fourth-order wavefront aberration function for this class of optical systems. Then, such expressions are combined to retrieve the full field dependence of primary coma, primary astigmatism, and field curvature. They are described by an elliptical conic-shaped surface with a variable apex location over the field of view, by a binodal surface with two nodes over the field of view, and by a general elliptical surface with one node. The proposed analytical expressions provide a better understanding of the primary aberration behavior for these systems and can be of great use in their optical design and aberration correction. An optical system constituted by a pair of tilted and decentered biconic lenses is studied to validate the proposed expressions. (C) 2020 Optical Society of America

Improved signal to interference ratio (SIR) is demonstrated for 8-channel multiplexing OAM communication with loop antenna arrays in a 5 GHz band. Current distributions are scrutinized, and the unique scattering of the OAM waves by the feeding coaxial cables is shown to undermine the orthogonality for the OAM waves. Induced interference waves are shown to be reduced by implementing resistors at the antinodes of the current on the antennas of the orthogonal port azimuth. The signal wave is not affected, because the position of the resistor becomes the node for the signal wave. With the configuration, 8-element arrays are designed and fabricated, and the measured SIR for the communication distance of 3 cm is better than 9.7 dB at 5.21 GHz. The measured SIR is improved by 6.2 dB by implementing the resistors.

In this work, quantum ballistic transport study of a Si double-gate pMOSFET has been carried out in an ultra-thin structure. The simulation is performed by using non-equilibrium Green’s function (NEGF) solver that incorporates six band k • p model. Based on this framework, we analyze the device characteristics for a channel length of 5 nm considering different transport directions, confinement directions and channel thickness. In the on and off state of the device several physical parameters are necessary for performance analysis including threshold voltage, subthreshold slope, on/off current ratio. Our results confirm that for 5nm gate length, best electrical performance is obtained at (001)/[100] crystal orientation. It is observed that better ON current, subthreshold swing and lower value of tunneling ratio can be achieved by optimizing the channel thicknesses and selecting the proper crystallographic orientation for the device. The I ON /I OFF ratio is also calculated for both high performance and low operating power applications. We find that large channel thickness leads to worse sub-threshold slope due to the stronger source-to-drain tunneling caused by electrostatics degradation. The potential barrier and spectral current density are also presented in order to find the source-to-drain tunneling and ratio for different crystal orientations and body thickness.

We present the experimental results regarding an excitable, two – section quantum dot laser exhibiting resonate and fire dynamics. Moreover, we explore the beneficial role of quantum dot assisted multi – waveband emission in enhancing the firing rate and the temporal resolution of photonic neuromorphic processors.

This paper presents the linear and nonlinear analyses of functionally graded carbon nanotube- reinforced composite (FG-CNTRC) plates using a four-node quadrilateral element based on the C0-type of Shi’s third-order shear deformation theory (C0-STSDT). Shi’s theory is taking the advantages and desirable properties of the third-order shear deformation theory. Besides, material properties of FG-CNTRC plates are changed from the bottom to top surface and based on the rule of mixture. Numerical results and comparison with other reference solutions suggest that the advantages of present element are accuracy and efficiency in analysis of FG-CNTRC plates. Some nonlinear numerical results of FG-CNTRC plates are also given in this paper and this contributes to providing additional data for future research work.

There are many flexible vertical members in offshore platforms like mooring lines and risers. These are exposed to wave, vessel motion and drilling loads during operation. For the smooth operation of these structures, the lateral excursion of these members should be minimal. This paper explains about the vibration analysis of a flexible vertical member subjected to base excitation. Initially, the flexible member was analysed as a SDOF non-linear spring-mass system. A qualitative understanding of the system was determined by solving the system using continuation method. Further, a numerical and experimental analysis was carried out on this member. Numerically, the member was analysed as an Euler–Bernoulli beam in MATLAB using the finite element method with three degrees of freedom at each node. The buckling load was determined using the Eigen value analysis. The minimum length required for buckling under gravity load was determined. The system was subjected to base excitation and the variation in the maximum response with respect to base excitation frequency was noted in the axial and lateral direction. The maximum response was obtained near the resonant frequency. Experimentally, the flexible member with a force transducer at its base was connected to the modal exciter through a stinger. The material of the member chosen was acrylic polymer as it buckles easily and can be used for testing. Forced excitation was provided using the modal exciter. On varying the frequency, the response of the member was observed. The length of the member was also a parameter that was varied such that the excursion was within controllable limits. Also, the area of the cross section in the upper half of the section was increased as an additional parameter for controlling the excursion. It was observed that the excursion was reduced as obtained from the theoretical analysis.

The traditional Modified Later Silicon-Controlled Rectifier (MLSCR) devices for one- or dual-direction are realized based on 110nm technology node. Through TLP test, it is found that with the same 45-μ $m$ width of the single device, by increasing the size of N-type floating region between PW and NW, the increase of the holding voltage $(V_{\mathrm{h}})$ for dual-directional DDMLSCR device is more obvious compared with the one-direction MLSCR device. In addition, the attenuation ratio of failure current $(I_{\mathrm{t}2)}$ is much smaller than that of the one-directional device. Both of these are beneficial for high voltage ESD applications.

In this paper, for the first time, a rigorous analysis of determining minimum number of biomolecules and maximum length of the nanogap cavity, used to entrap biomolecules for the detection purpose, has been done. A pTFET-based biosensor (pTB-sensor) device is being proposed, and the corresponding detection sensitivity in terms of threshold voltage (Vth)—sensitivity, threshold voltage (Vth)—shift, subthreshold swing (SS) sensitivity, subthreshold swing (SS) shift, ON current/OFF current (ION/IOFF)—shift, leakage power (Pleak)—sensitivity is determined. It is found that the minimum number of biomolecules or minimum detection limit is 2 for Myoglobin and Apomyoglobin, while the same is 3 for Protein-G, Ferricytochrome-C, and Ferrocytochrome-C, respectively. The maximum biomolecules required for successful detection are found to be 5 for Myoglobin and Apomyoglobin, while the same is 7 for Protein-G, Ferricytochrome-C, and Ferrocytochrome-C, respectively, with 78%, 67%, 41%, 55%, and 50% Vth—sensitivity and 83%, 74%, 53%, 63%, and 58% SS sensitivity for Apomyoglobin, Myoglobin, Protein-G, Ferrocytochrome-C, and Ferricytochrome-C, respectively. This leads to the minimum cavity length of 8 nm and maximum or optimum cavity length to be 20 nm, respectively, for the detection of all the five biomolecules successfully allowing space for scaling down of the channel length to sub-100 nm technology node.

The possibility to form bipolar pulses with a duration of 1 and 2 ns and an amplitude of up to 80 kV at a load of 12.5 Ohm using a single spark gap is shown. Simulation has shown, that the parasitic capacitance of the voltage supply to the forming lines can distort the second half-wave of the bipolar pulse. The influence of the parasitic capacitance was eliminated by placing the supply node in close proximity to the spark gap.

This work analyzes the impact of temperature on the Analog figures of Merit of vertically stacked nanosheet nMOSFETs. The excellent electrostatic control between gate and channel results in a strong reduction of the short channel effect, as expected. The analog parameters like the intrinsic voltage gain, transistor efficiency and Early voltage are analyzed as a function of temperature. A high intrinsic voltage gain and a weak temperature dependence are observed, mainly at strong inversion region. The transistor efficiency and subthreshold swing maintain their value close to the theoretical limit.

A portable optical measurement is configured by using a near-infrared laser diode of the 808 nm in a wavelength spectrum as a light source and operated at a power of 500 mW. The work within this study tests a sample of fresh tomato injected by black ink. The results are obtained by performing a shifted laser source in counter-clockwise direction respect to the measurement node on 36 degrees in each. Subsequently, the results are compared between fresh tomato and tomato injected by black ink to mimic rotten in the tomato. The results in graphical form represent the differences in power density between fresh tomato (without implanted ink) and ink inserted tomato. The design of this apparatus has advantages, such as low cost with a simple procedure and hence has a potential used in agriculture for examining the defect without destructing the surface structure of the agricultural products.

Creative digital artwork is usually the outcome of a long period of intellectual creation and labor of an artist. Similarly, computer-created digital artwork is an outcome of a large amount of machine time and computational resources. However, such intellectual properties can be easily copied by illegal users. Copyright protection of digital art is increasingly more important than before. Recently, using a computational approach to generate string art tends to be popular and attractive. To protect the illegal usage of the digital form of string art, we propose a data hiding algorithm specifically designed for string art. A digital string art image consists of a sequence of string lines, each specified by two nails fixed at the two ends of that line. The encrypted secret data (the watermark) is embedded into the list of line segments by odd&ndash, even modulation, where a bit &lsquo, 1&rsquo, is embedded by forcing the next node to be an odd node, and a bit &lsquo, 0&rsquo, is embedded by forcing the next node to be an even node. To minimize the impact of data embedding on the quality of the original string art image, a local optimization algorithm is developed to select the nodes that produce minimal distortion. To quantify the embedding distortion, we introduce a smoothing filter model for the human vision system (HVS) specifically tailored to string art image. Experimental results show that using the proposed algorithm, the distortion between the original string art image and the watermarked string art image is unnoticeable. The modified string art image is statistically indistinguishable from the original string art, and hence is secure under steganalysis. To our best knowledge, this is the first work towards data hiding and copyright protection of digital string art.

Theoretical solutions for buckling problems of laminated panels under uniform in-plane edge loads have been obtained without considering damage/cutouts. Nevertheless, in practice, the structures are provided with cutouts of various sizes subjected to non-uniform edge loads. Analytical solutions for such problems are difficult to achieve. Hence in this work, a finite element software (ABAQUS) is used to analyze the buckling behavior of thin and thick laminated panels with and without cutouts subjected to distributed edge loads with different variations. The panel is modeled by using eight nodded elements (S8R5) with five degrees of freedom at each node. The efficiency of the model is confirmed by correlating present results with accessible literature. The effect of various parameters such as cutout size and its position, boundary conditions, ply orientations, and thickness of panel are included in this work. It is observed from this study that the non-uniform edge loads and cutout sizes have a remarkable outcome on buckling behavior of panels.

Publisher's version (útgefin grein), The article investigates response mitigation of a reinforced concrete (RC) chimney subjected to pulse-like near-fault ground motions using tuned mass damper (TMD) schemes. The total height of the chimney is 265 m with a mass of 11,109 ton. Three TMD schemes are used: single tuned mass damper (STMD), multiple TMDs having equal stiffness (w-MTMDs) and multiple TMDs having equal masses (e-MTMDs). The STMD is tuned to the fundamental frequency of the chimney while both w-MTMDs and e-MTMDs have three TMDs for controlling each of the first and second modes (total of six TMDs) of vibration. Response of the uncontrolled and controlled structures is calculated for 69 recorded ground motions containing a dominant velocity pulse. Displacement and acceleration at top node of the RC chimney are the response of interest for performance assessment. It is found that e-MTMDs are more effective and robust than other schemes. It is also found that the pulse period of ground motion plays a very important role in how effective the control schemes are. There is a large variability in the reduction of response across these ground motions, and optimization methods independent of ground motion are not robust. There is a need for more advanced optimization methods incorporating information about local seismic sources., We acknowledge support from University of Iceland Research Fund.

In order to accurately simulate the movement of the cable and the sonar probe during the operation of the aviation winch, the force on the cable and the sonar probe are analyzed based on the knowledge of mechanics in this paper, and the differential equation of the cable and the mathematical model of the probe are established. The nonlinear differential equation of the cable is deduced and solved by quasi-Newton method, thus the shape of each node of the cable and the attitude of the probe are iterated. Through simulation and its results, the influence of drag speed on the angle of the sonar probe and the shape of cable is analyzed, and the accuracy of the algorithm in the paper is proved.