Despite previous efforts to map the proportioning of a concrete to its strength, a robust knowledge-based model enabling accurate strength predictions is still lacking. As an alternative to physical or chemical-based models, data-driven machine learning methods offer a promising pathway to address this problem. Although machine learning can infer the complex, non-linear, non-additive relationship between

We propose a short length plasmonic integrated optic sensor with ultrahigh sensitivity and resolution for aqueous environment. The sensor section is a simple multilayer structure consisting of a dielectric planar waveguide separated from a thin metal film by a low index buffer layer. The sensor is based on the hybrid coupling between the guided mode and the short range plasmonic mode supported by the

A few layers graphene-based phototransistor was fabricated and investigated. Graphene layers were mechanically exfoliated and transferred into a p-doped Si/SiO2 substrate to fabricate a graphene field effect transistor. Gold electrodes were deposited to create a drain and source to the graphene and a back contact gate to the p-doped silicon. The device performance was examined by measuring the current-voltage

In this paper, the deterioration of structural parameters namely equivalent stiffness, mass and damping due to corrosion in prestressed concrete (PC) structures using a smart probe-based piezo sensor (SPPS) via electro-mechanical impedance (EMI) technique is presented. The effectiveness of the SPPS was first demonstrated qualitatively by a change in the raw conductance signatures during the corrosion

We experimentally study Stochastic Resonance in an artificial neuron and demonstrate that pink noise amplifies the input signal considerably—up to twenty times more—compared to white noise. The experimental results are consistent with biological observations and theoretical calculations. Possible applications include the design of electro-optical devices.

The sensor devices are becoming an essential aspect of electronics, while an accurate, economical, and printable device is constantly in high demand. Particularly, it is indispensable to develop the printed flexible sensor electronics with a fast response time, high sensitivity, and selectivity, as well as hybrid scalable manufacturing at a low cost. Here we demonstrate a printable and flexible oxygen

The aim of this paper is to propose the methods to select reasonable normalization method in TOPSIS and decide best optimal material combined with individual results from TOPSIS with some popular normalization methods. In this paper, to evaluate performance of normalization method, entropy-based and variation coefficient-based performance scores are introduced. To decide final result of materials selection

A tapered nanobeam is modelled by Euler–Bernoulli beam theory and nonlocal theory of elasticity. A solution technique based on homotopy perturbation method is proposed to analyse the dynamic behavior of the tapered nanobeam. Beam becomes tapered along the width exponentially. The effects of flexible and rigid supports on the vibration of tapered nanobeam are analysed. Influences of tapered ratio and

Objective:The positioning of the external camera in current designs of retinal prostheses may affect the egocentric spatial frame of reference and lead to pointing and localisation errors. The present simulated prosthetic vision (SPV) study investigated the immediate effects of four camera positions: (i) centre-mounted (CM), (ii) head-mounted (HM), (iii) left-mounted (LM), (iv) right-mounted (RM) on

In our fast-changing world, human-machine interfaces (HMIs) are of ever-increasing importance. Among the most ubiquitous examples are touchscreens that most people are familiar with from their smartphones. The quality of such an HMI can be improved by adding haptic feedback—an imitation of using mechanical buttons—to the touchscreen. Thin-film actuators on the basis of electro-mechanically active polymers

In this work, a model of cellular structures in thermal fields has been established based on methods of material mechanics, structural mechanics and thermodynamics. Cellular structures have different deformation behaviors in thermal environment with different coefficients of thermal expansion (CTE), the desirable equivalent coefficient of thermal expansion (ECTE) of cellular structures can be achieved

Magnetohydrodynamic study of eddy formation and heat transfer in a bottom heated two-dimensional lid-driven cavity with the insulated sidewall is reported in this paper. We consider the classic problem of a two-dimensional lid driven cavity in the presence of an applied external magnetic field. In the standard nonlinear Navier–Stokes equation and the energy equation, appropriate terms are added to

The use of Acoustic Emission (AE) to detect impacts is of interest within industries where vital components are prone to impact damage, in particular where Carbon Fibre Reinforced Polymers (CFRP) are used, as damage can often go un-noticed within them. For AE monitoring of impacts piezoelectric sensors are used to detect the ultrasonic wave produced by an impact. Classification is also possible of

Very high currents can be induced in pairs of current-carrying superconducting rings when they are coaxially brought closer. If the currents are uniformly distributed through the cross-section of the rings their magnitude can be derived from the mutual inductance of interacting rings. However, if the currents are not uniformly distributed that calculation procedure should be no longer applicable. The

A comprehensive review paper concerning the geometry, topology, implementation methodology, feeding mechanisms and application domain of wideband and ultrawideband (UWB) antennas for high power applications is presented. Single element antennas, reflector based antennas and array type antennas developed across the globe are taken into account. The antennas considered here are grouped based on their

An improved parasitic resistance extraction from small-signal equivalent-circuit and effect of C ds in GaN HEMTs is presented. Parasitic capacitances are evaluated at ‘cold pinch off’ condition. More accurate extraction method of parasitic resistance is presented at low gate bias voltages compared to earlier published work. The impact of drain to source capacitance (C ds ) at low gate bias voltage

The existence of periodic impacts in collected vibration signal is the representative symptom of rolling bearing localized defect. Due to the complicacy of the working condition, the fault-related impacts are usually submerged in other ingredients. This article proposes an adaptive Resonance-based Sparse Signal Decomposition (RSSD) for extracting the fault features of rolling bearings. Adaptive RSSD

Next Generation Microshutter Array (NGMSA) is an electrostatically operated micro electro-mechanical system (MEMS) device for programmable spatial light filtering application. Original microshutter array (MSA), which is magnetically operated, was developed for the James Webb Space Telescope (JWST) NIRSpec multi-object spectrometer, and NGMSA inherited its design from the original MSA. Even though there

Audible sound generation due to snap-through buckling during bending deformation was studied using an injection-molded product with a hinge. The sound was clearly generated in a rigid plastic product with a specific shape of the hinge that was markedly deformed. The large elastic energy stored in the hinge by the bending deformation, which was suddenly released during buckling deformation, was responsible

A versatile Arduino based source measure unit (ASMU) is fabricated for measuring both the DC and low-frequency AC electrical characteristics of multi-terminal semiconductor devices. The ASMU system is capable of bidirectional voltage sourcing and current measurement in all four quadrants. The system is programmed with the LabVIEW environment for real-time data acquisition. The voltage bias and current

We report the enhanced performance of near-ultraviolet (NUV) InGaN/GaN multiple quantum-well (MQW) light-emitting diodes (LEDs) with a staircase hole injector (SHI). Simulation results indicate that the internal electrostatic field in the QW of the LED-SHI is decreased owing to the reduced sheet charge density at the interface between QW and quantum barrier (QB) caused by the smaller In content difference

Many research works focused on using vegetable oils alone as cutting fluid and some with nanoparticles for better lubrication. But very few literature pieces are available for the use of environment-friendly nanoparticles and vegetable oils in machining. Also, the nanoparticles generally used for the research is expensive. With this paper’s help, some alternatives to conventional machining fluids are

The reliability of turbine blades is largely maintained by damage tolerance approach based on monitoring and pre-set periodic inspections. This can result in unnecessary downtimes, premature part retirement and unforeseeable failures. Therefore, there is growing interest in systems that can reliably detect damages in real‐time. However, many current sensors are based on blade tip clearance and time

In this research work, aluminum alloy (Al-20Fe-5Cr) matrix-based aluminum oxide (Al2O3) reinforced composites were developed through the powder metallurgy (P/M) process. Effect of compaction pressure (200, 250 & 300 MPa) and wt.% of Al2O3 (0, 10, 20 & 30 wt.) on tensile strength and percentage elongation has been analyzed through statistical and artificial neural network techniques (ANN). The mixture

Denoising of pipeline leak signals is of great significance to improve the accuracy of pipeline leak detection. Variational mode decomposition (VMD) has the function of signal denoising. However, the inaccurate setting of VMD parameters will affect the result of signal decomposition. This paper proposes a method for optimizing VMD parameters using particle swarm optimization (PSO-VMD). The ratio of

A polymerase chain reaction (PCR) is a method typically active in genetic research, especially to amplify or copy genes. Herein, the application of microfluidic devices for nucleic acid amplification has recently been extensively and vigorously studied and implemented. However, the existing classical instruments are hefty, excessive thermal loss, more power consumption, laborious, and require more

High beam quality, highly efficient radially polarized vector vortex beam has been generated in a Yb:YAG microchip laser pumped with an annular beam formed with a hollow focus lens. The output power of 2.15 W has been achieved at the absorbed pump power of 3.53 W. The optical-to-optical efficiency is 60.9%. The radially polarized vector vortex lasers working at 1030 nm, 1050 nm, 1030/1050 nm dual-wavelength

Graphene, as two-dimensional material with many properties of the gate-voltage tunable Fermi-level and zero band gap, can be utilized for optical modulators by the integration with other material. In this work, an electro-optic modulator based on the fiber-surface waveguide and graphene capacitance has been proposed with the device length of 50 μm, featuring excellent controllable polarization modulation

Advances in the field of auxetics have realized fabricated auxetic materials such as foams, fabrics, and fibers as well as a better theoretical understanding of the auxetic response. Because of their unique properties and applications, commodity auxetic materials are particularly desirable. Needle-punched nonwovens, several kinds of paper, and many knitted and woven fabrics have the potential to be

This paper presents a structural health monitoring (SHM) methodology for detecting damage in a composite bonded repair. The application of guided wave based techniques in a step-sanded bonded repair under operational and environmental load is thoroughly investigated. A two step damage detection and localization algorithm is presented, were in the first level the path damage indices (PDIs) for each

Droplet-Based energy harvesting is one of the most recent techniques used to convert environmental mechanical energies into electrical energy. Despite unique properties like compatibility with MEMS fabrication and efficient performance in reduced spaces, their operation is limited by the negative effects of electrowetting. In presence of an external electric filed, the wetting state of a droplet can

We investigate theoretically the dependence of the extinction ratio, metal layer thickness and buffer thickness of a short length plasmonic polarizer on the buffer layer index. The polarizer section consists of a thin metal layer above the single mode dielectric waveguide separated by a low index dielectric buffer layer. Strong coupling between the surface plasmon polariton (SPP) mode and the guided

In many engineering applications, such as thermal coating and structural insulation, 2D modelling is deemed sufficient to identify design parameters. For the effective thermal conductivity evaluation of heterogeneous composites, a 2D computational homogenization procedure is developed in this study. The inclusions are distributed randomly within the plane. The boundary conditions tested for homogenization

The present work aims to develop an automated solution for analysis of dimple tensile fracture surfaces. An image processing based technique has been proposed to extract the voids from the fractographic images of dimple fracture surfaces and also to analyse the void features. A two-stage process has been developed to extract the closed contour of the voids. At the first stage a global thresholding

The use of dielectric elastomers as integrated actuators and strain sensors offers a simple approach for closed-loop control in a wide range of applications. While a number of approaches for self-sensing have been proposed, the adaptive online algorithm offers an appealing combination of high accuracy and low computational cost. In this work, the recursive least squares algorithm will be applied to

In this study, the effect of different parameters of pulsed Nd:YAG laser welding, including pulse energy, pulse frequency, pulse duration, and welding speed on the melting rate of IN738 Nickel-based superalloy, was investigated. The results of this study were obtained based on the modification of a formula for calculating the melting rate of welding by pulse method (pulse overlap). According to this

Titanium alloys are very hard to machine materials, which can be machined effectively by using advanced manufacturing processes. Electro discharge machining (EDM) process is one of the most efficient methods of machining electrically conductive materials. EDM is focused more on the precision and accuracy of the machined parts. This particular work focuses on the machinability study of titanium diamond

A constraining factor in the development of flapping wing micro air vehicles (MAVs) is the power density and efficiency of actuators. Piezoelectric and rotary electromagnetic actuators have been shown to have functional power densities but can require mechanically complex transmissions to create flapping motion. Electromagnetic Linear actuators (ELAs) have unique characteristics, allowing them to be

Acoustic power transfer and communication through metal layers is of great interest in many applications where the integrity of metal boxes, tanks, pipes or walls must be preserved by avoiding through-hole electrical connections. While acoustic power transfer has been widely studied last decades, the optimization of such systems has not been assessed comprehensively regarding the choice of transducers’

In a cryomodule, bellows are commonly used to connect two adjacent superconducting cavities. It provides cavities a mechanical flexibility facilitating for thermal contraction or expansion during temperature transitions. While heat from superconducting cavities are removed from helium flowing through their jackets, non-superconducting bellows are cooled down through a relatively slow process of conduction

Eye bolts are part of a system used to anchor electrical insulators in substations and on transmission lines, connected by concrete structures. Structural failures in these devices may lead to service interruption, financial losses and risks for the general population. In this article, we propose a signal adapter capable of applying and receiving high frequency signals to a portable vector network

Dimensional stability in a space telescope is one of the important factors for performing high-resolution observations. The supporting structures between the primary and the secondary mirrors in a space telescope are required to maintain the mirror positions with the proper focus for minimizing the optical alignment error. In orbit, the harsh environment subjects a space telescope to temperature variations

We report the simulation outcomes of a highly efficient CuI/n-Si heterojunction solar cell (HJSC) by SCAPS-1D simulator using the parameters obtained from spin-coated CuI thin film characterizations. The influence of thickness and doping concentration of Si substrate as well as CuI hole transport layer (HTL) on the photovoltaic (PV) parameters and built-in potential has been explored. The optimum values

A study of the impact of dimension and temperature on a state of the art 4H-SiC power vertical DMOSFET has been carried out using drift-diffusion calculations in conjunction with electrical characterizations to extract physical parameters and doping profiles in a 6 μm channel length device. The model presented in this paper includes the effect of trapping in the channel/oxide interface. Using these

In this article detailed electro-analytical comparison of the commercial mono-crystalline silicon and passivated emitter and rear contact (PERC) solar cells has been presented that can help in device optimization during manufacturing process. This study indicates fundamental differences between these two technologies in terms of the series resistance, shunt resistance and junction quality including

Fiber Bragg gratings (FBGs) have numerous advantages over traditional foil strain gages, most notably in that they can be embedded in host materials and used to evaluate local deformation. Among the wide variety of grating architectures that have been studied, FBGs inscribed in polarization-maintaining (PM) or other birefringent fibers provide a unique, quantifiable response to strain transverse to

Limitations in further miniaturization of lenses and arrays to achieve varifocal capabilities in compact 2D/3D switchable imaging devices have spurred investigations into the use of alternative materials. To this end, we fabricated a new deformable microlens array (MLA) utilizing polyvinyl chloride (PVC) gel, containing 67–90 wt.% of dibutyl adipate (DBA), sandwiched between an anode with apertures

New types of antennas such as Substrate Integrated Waveguide (SIW) antennas are being used for high frequency applications. In this paper, the development of an array of novel slotted SIW epsilon near zero (ENZ) antenna is presented. Due to the limited fabrication facilities, the study is conducted in the 5 GHz band. The effective permittivity falls to zero at the cut off frequency of the waveguide

This study aimed to investigate the influence of the CaO/SiO 2 molar ratio on the physical, chemical and mechanical properties of alkali-activated fly ash with quicklime and assess the technical viability of the mortar with the highest compressive strength. Eight mortars were prepared, with a fixed sand to combined activator/precursor ratio of 3:1, varying the CaO/SiO 2 ratio from 0.25 to 2.00 every

During the last decade, piezoelectric micromachined ultrasonic transducer (pMUT) have raised a great interest for various applications. In particular, AlN material has been used to build bimorph structures made of two AlN layers sandwiched between metallic electrodes. This kind of pMUT offer good performances for both sensing and actuating because of the multi-electrodes scheme of the design. Yet,

A visible light photodetector made of CsPbBr 3 thin film prepared by solution process method was fabricated using a chromium interdigital structure. The device consists of two interdigitated electrodes deposited on glass substrate with 10 μ m channel width filled with CsPbBr 3 . The material was characterized by using absorbance, μ -photoluminescence ( μ -PL), and X-ray spectroscopies. The PL peak

In this paper, shape memory polymers (SMPs) are fabricated by blending Polyurethane (PU) and Polycaprolactone (PCL). A novel method is used to make tubular stents using this blend. The solution coating method is applied to fabricate the SMP stent samples with a non-groove structure. Some metallic commercial stents made of the platinum-chromium alloy are used to compare SMP stents’ the mechanical properties

The present work deals with comparative study on cutting performance of plain carbide and coated carbide inserts in turning of EN9 steel. The design of experiments (DOE) was done using response surface methodology (RSM) technique. The cutting parameters were spindle speed, feed and depth of cut (DOC). The combined interactions of cutting parameters on surface roughness, flank wear and crater wear were

As an important raw material for refining copper by electrolysis, copper anode plates are mainly manufactured by disc casting machine. However, those copper anode plates frequently have such defects as uneven thickness, broken lugs, porosity inside plates, and low production efficiency and low yield rate, failing to meet the demands of electrolysis for the quality and quantity of anode plates. To develop

This study proposes an alternative mass ratio definition for vortex-induced vibration (VIV) systems. The proposed definition, henceforth known as 'total mass ratio', differs from the conventionally used mass ratio definition (i.e. the ratio of the mass of the oscillating body to the mass of the displaced fluid) in that the added mass of the fluid is taken into account. Two-dimensional numerical simulations

We present the simulation and experimental demonstration of a coupled-cavity 1D photonic-crystal/photonic-wire (PhC/PhW) structure that produces multiple resonance wavelengths. The combination of several cavities results in the assembly of a spectral response that exhibits multiple resonance wavelengths and potentially leads to the wavelength control required for wavelength division multiplexing (WDM)

This paper reports on the experimental investigation of bending and tensile strength of the friction stir processed TIG-welded AA5083-H111 joint. The friction stir processed joint was studied comparatively with the TIG-welded joint (unprocessed joint). The TIG-welded joint was processed using a single-pass friction stir processing technique. The microstructural analysis revealed that the unprocessed

In order to solve the problems of complicated fault diagnosis and poor fault diagnosis of vertical mill operation, this paper proposes a diagnostic method based on fisher and information entropy difference classification. By extracting the fault feature of the anomaly attribute–the maximum value of the attribute, and the possible faults can be determined according to the fault characteristics. Then

The use of optical fiber sensors has been considered to realize smart structures, which can sense and respond to environments. To develop this concept in aviation, this paper reports on a smart wing framework that senses and responds to the environment to alleviate the wing structural loads. The wing is equipped with optical fiber sensors that measure the strain distributions on the wing surface. Considering

In large buildings, linking heating, cooling or ventilation systems between themselves and to physical spaces is a very time-consuming task that requires highly skilled engineering knowledge, as all these systems are interconnected and they have a certain influence to each other (ventilation systems are often connected to heating and cooling), which often makes task of locating the sources of error