Coupled Device Research Articles

Engineering grain orientation and local heterogeneous enable further breakthroughs in piezoelectricity for NaNbO3-based piezoelectric oxides

Eco-friendly NaNbO3 (NN)-based relaxor ferroelectric ceramics with high dielectric constants cannot meet the high piezoelectric activity quality factors (FOMs: d33 × g33) requirements of electromechanically coupled devices. To solve this issue, we successfully improved the piezoelectricity of NN-based relaxor piezoceramics while reducing the dielectric constant based on microstructural tuning by virtue of the chemical design and texturing engineering. Mainly affected by the highly <001>c orientation and relaxor MPB, the obtained novel 88.5NaNbO3–10Ba(Ti0.7Sn0.3)O3–1.5NaSbO3 texture ceramics enjoys an ultrahigh piezoelectric coefficient (d33 = 423 pC/N), reaching a record high in NaNbO3-based lead-free ceramics. Meanwhile, a large FOMs value (d33 × g33 = 13.3·10−12 m2/N) is successfully realized due to the suppression of the dielectric constant. More importantly, the stable phase/domain evolution also encourages excellent temperature stability for piezoelectricity and FOMs. Especially for the piezoelectricity, when the annealing temperature is < 140 °C, the d33 of the 1.5T ceramics can be stabilized ∼ 400 pC/N. Such excellent electrical temperature stability shows more competition in the reported NN-based piezoceramics. This work not only provides a design paradigm for high-performance piezoelectric materials, but also facilitates their development in electromechanical coupling devices.

Study on Two-Dimensional Exit Pupil Expansion for Diffractive Waveguide Based on Holographic Volume Grating

Diffraction gratings are becoming a preferred option for waveguide head-mounted in–out coupling devices due to their flexible optical properties and small size and light weight. At present, diffraction waveguide coupling devices for AR head-mounted displays (HMD) have difficulties such as a long development cycle and complicated processing. In this paper, we first establish a set of two-dimensional (2D) grating ray tracing models, based on which we determine the initial architecture of the dual-region two-dimensional exit pupil expansion (2D-EPE) AR-HMD holographic waveguide diffraction system. Second, we propose a honeycomb coupled grating array and optimize the optical energy utilization and brightness uniformity of the holographic waveguide and use a custom dynamic linked library (DLL) function to implement the ray tracing of the 2D grating and add a probabilistic splitting function to the DLL, which reduces the single simulation time from 11.853 min to 1.77 min. We also propose a holographic lithography device composed of holographic optical elements (HOEs) and a method for preparing HOEs. Finally, in order to obtain the diffraction efficiency preoptimized by the above DLL for the uniformity of the exit pupil brightness and light energy utilization, we inverse design with the preparation process parameters as the optimization variables and develop the adaptable electromagnetic calculation program Holo-RCWA. Using Holo-RCWA with nondominated sorting genetic algorithm II (NSGA-II), we inverse design to obtain the process parameters satisfying the diffraction efficiency distribution, and the optimization time of the whole system is reduced from 2–3 days to 10 h. This work is of great significance for AR/VR applications.

Numerical and Experimental Reconstruction of Temperature Distribution and Soot Concentration Field for Thin-Slice Flames Using a Charge Coupled Device Camera

This work proposed a novel model to simultaneously reconstruct temperature distribution and soot volume fraction field for two-dimensional thin-slice flames using the knowledge of monochromatic radiation intensities at two wavelengths using a CCD camera. The deduction process and numerical analysis of the model were described. Effects of wavelength combinations and measurement errors on reconstruction accuracy were considered in detail. Numerical results have proven the model’s accuracy and showed that the temperature and soot volume fraction fields can be reconstructed well even with noisy input data from flame radiation. In addition, a series of experiments were conducted on a mesoscale combustor to obtain the real thin-slice flames for further experimental reconstruction via the model. The experimental results indicated that the proposed model can successfully reconstruct the flame temperature distribution and soot volume fraction field and the main features of thin-slice flames also can be reasonably reproduced.

Large piezoelectricity with enhanced thermal stability in BiScO3-BiInO3-PbTiO3 ternary perovskite ceramics

Simultaneously achieving large piezoelectricity and excellent thermal stability in a piezoceramic is highly desired for constructing advanced high-temperature electromechanical coupling devices. Here, a large high-temperature piezoelectric coefficient (d33 = 523 pC/N at 200 °C) with a small fluctuation rate (η ≤ ±10 %) over an ultra-broaden temperature range of 48–342 °C was achieved in novel zBiScO3-xBiInO3-yPbTiO3 (zBS-xBI-yPT) ternary perovskite piezoceramics with a high Curie temperature of 440 °C. The morphotropic phase boundary (MPB) of multiphase coexistence can be driven and optimized in this system, which is mainly responsible for the enhanced piezoelectricity, and the optimal MPB composition is located at x/y/z = 0.010/0.625/0.365. The excellent temperature stability of the optimal MPB sample should be attributed to the increase in the number of thermally stable irreversible non-180° domains. zBS-xBI-yPT perovskite ceramics with excellent comprehensive high-temperature piezoelectric properties exceed many reported lead-based counterparts, and are more suitable for electromechanical coupling applications at harsh elevated temperatures.

Maintenance policy of degradation components based on the two-phase Wiener process

This paper proposes a condition-based maintenance policy for the two-phase Wiener degradation process components. The main contribution of this article is to provide the time distribution of degradation failures for the two-phase Wiener process degradation component, as well as the modeling and solving methods for two-phase maintenance. The two-phase maintenance policy includes two-phase inspection and preventive replacement maintenance operations. The established optimization maintenance policy model aims to minimize long-term operation costs. The specific cost calculation equation and the solution method of the maintenance model are given. The feasibility of the maintenance policy model is verified using the two-phase degradation data of the Liquid Coupling Devices. The Particle swarm optimization algorithm can stably solve the described problem, and the results show that the two-phase maintenance policy can be more economical and improve components availability. After that, we also analyzed the impact of the cost parameters on the maintenance policy through sensitivity analysis.

A Safe and Innovative Method to Apply Venous Coupler in Oncologic Head and Neck Reconstruction.

Venous anastomosis with a coupler device is an effective alternative to the hand-sewn anastomosis technique. Twist in the veins following a coupler anastomosis is a troublesome complication that needs a revision of venous anastomosis. The author proposes a simple technique to reduce the incidence of this complication. This technique is particularly useful in head and neck reconstruction and for beginners in the initial part of the learning curve.

ОБЕСПЕЧЕНИЕ НАДЕЖНОСТИ СРАБАТЫВАНИЯ АВТОСЦЕПНЫХ УСТРОЙСТВ ПРИ НАЛИЧИИ ГЕОМЕТРИЧЕСКИХ НЕРОВНОСТЕЙ ПУТИ

The growing need to ensure the safe operation of rolling stock makes it necessary to study the criteria that lead to failures and breakdowns both during operation and downtime.&#x0D; Ensuring trouble-free coupling of carriages is one of the top priority tasks on the railway. This concerns both the coupling of new carriages and the prevention of self-discoupling of rolling stock carriages. Due to the track imperfection, namely, the presence of curved sections both horizontally and vertically, it is likely that the axes of the auto-coupling devices will diverge. Despite the developed standards for the maintenance of railway tracks, the departure of the carriage overall dimensions is not always correctly assessed, which leads to irreparable consequences. The paper proposes a method to improve the reliability of the operation of automatic coupling devices by introducing guiding centering systems.

Evaluation of Anastomosis Efficiency in Arteriovenous Shunts Created by Using Hand-Sewn Microsurgery and Microvascular Anastomotic Coupler Device.

Microsurgery has made great contributions to the advancement of surgery. In parallel with the developments in microsurgery, various techniques have been developed to perfect the technique. Microvascular anastomotic coupler device (MACD) is one of these techniques. The aim of the study was to evaluate the effectiveness of anastomoses created by using hand-sewn microsurgery (HSM) and MACD. Twenty male Sprague-Dawley rats weighing 250 to 300g were divided into 2 groups randomly. Arteriovenous shunt was performed between carotid artery and internal jugular vein with the principles of HSM in the first group (n=10) and by using the 1-mm anastomotic microvascular device in the second group (n=10). Groups were evaluated for anastomose time, success of anastomosis, thrombosis formation, color Doppler ultrasonography, and histopathological features. Anastomotic time was faster with the coupler device compared with HSM technique. Flow rates were found significantly higher in the MACD group. Endothelialization and wall integrity rates were better in MACD group. Microvascular anastomotic coupler device is faster than HSM. High quality and durability of vascularization, insignificant foreign body reactions are histopathological advantages of MACD.

In Situ Probing the Short-Lived Intermediates in Visible-Light Heterogeneous Photocatalysis by Mass Spectrometry.

Visible-light-mediated heterogeneous photocatalysis has recently emerged as an environmentally friendly and energy-sustainable alternative for organic transformations. Despite the advancements in developing wide varieties of photocatalysts during the past decades, the accurate probing and identification of the photogenerated species, especially the short-lived radical intermediates, are still challenging. In this work, we reported a hybrid ion emitter that integrated with a pico-liter heterogeneous photocatalytic reactor, which was fabricated by depositing the photocatalyst (e.g., TiO2) into the front tip of a quartz micropipette. Benefited from the dual-function feature of the hybrid micropipette (i.e., a clog-free tip-confined pico-liter reactor for heterogeneous photocatalysis and an ion emitter for nanoelectrospray ionization), sensitized photoredox reactions at the catalyst-solution interface can be triggered upon visible-light irradiation using a cheap LED laser (453 nm), and the newly produced transient radical intermediates can be rapidly transformed into gaseous ions for mass spectrometric identification. Using this novel low-delay coupling device, photogenerated intermediates, including the cationic radicals produced during the photooxidation of anilines and the anionic radicals produced during the photoreduction of quinones, were successfully captured by mass spectrometry. We believe that our hybrid photochemical microreactor/ion emitter has provided a new and powerful tool for exploring the complicated heterogeneous photochemical processes, especially their ultrafast initial transformations.

Wireless Charging System with Three Arc-Transmitting Coils for Autonomous Underwater Vehicle

To enhance the misalignment tolerance of the coupling device of the autonomous underwater vehicle wireless charging system, this paper proposes a magnetic coupling device with strong misalignment tolerance. Through the Ansys Maxwell finite element analysis software, it is concluded that, under the dislocation state of the proposed magnetic coupling device, the magnetic field is mainly distributed near the shell wall of the autonomous underwater vehicle. The coupling coefficient change range under the rolling dislocation state is 0.35~0.83, the axial dislocation coupling coefficient fluctuation range is 0.79~0.83, and the radial dislocation coupling coefficient variation range is 0.48~0.83. We design and calculate the compensation network in a wireless charging system and obtain the calculation method of the compensation network. A prototype of that wireless charging system containing arc-emitting coils applied to the AUV has been made, which transfers 48 W power with an efficiency of 87.3%.

Prototype of a Coupling Device to Investigate Focused Ultrasound-Induced Inertial Cavitation for Drug Delivery Applications

Abstract Focused ultrasound (FUS) can be used as a drug delivery application for localized chemotherapy to treat cancer. The effect of ultrasound-induced inertial cavitation is promising to trigger drug release from nanocarriers. To investigate this effect, usually, a passive cavitation detection setup is employed. However, applying such a setup is challenging for in vivo experiments, as the test object may need to be fixed inside the water tank. Thus, we present a prototype of a coupling device that could significantly simplify experiments. Since this setup favors undesired sound wave interference and their resulting exceedance of the Mechanical Index, we additionally investigated different signal lengths. The occurrence of standing waves at a signal length of 44 cycles can both be derived from a changing cavitation activity and our calculations. The appearing interference also results in a mean increase of the cavitation activity by ≈ 5.1 %, verified by our experiments as well.

Using and Testing Camera Sensors with Different Devices at Cosmic Ray Detection

Cosmic Ray (CR) is high-energy charged particles that reach the earth from space. CR detection methods and studies have been progressing rapidly since the beginning of the 20th century. One of these methods is the use of digital cameras with Charge Coupled Device (CCD) and Complementary Metal Oxide Semiconductor (CMOS) sensors. Mobile phone cameras or webcams offer an easily using and economical measurement system for CR measurement. The sensors are exposed to CR during a long exposure. CRs leave traces in the background. Cosmic particle tracks are then separated from the background noise and can be classified. Making the traces of the particles visible is important for understanding the subject. In this context, traces of particles such as electrons, muons, and alphas can be seen with the cloud chamber experiments. Help of sensor technology and cameras have developed in recent years, CR traces can be easily detected so that it can be seen. There are many software and international projects that detect CR using CMOS sensors in cell phone cameras. In this study, related projects, programs and studies were researched; CR traces that we captured with the help of Cosmic-Ray Extremely Distributed Observatory (CREDO) and Cosmic Ray Finder (CRF) software with web cam and a mobile phone cam CMOS sensor are presented. Links have been made about astrophysical events coinciding with previously detected particle images.

Analysis of Discharge Failure Mechanism of IGBT Power Modules

IGBT power modules are usually used as circuit-breaking components in power systems, and are widely used in solid-state DC circuit breakers, hybrid DC circuit breakers, all-electric aircraft, high-speed railways, new energy vehicles, and power transmission systems. In these systems, IGBT power modules are usually faced with extremely harsh working conditions and there is a failure risk. Insulation degradation should be a cause for concern as a potential path of power module failure. In this paper, the discharge phenomena of the IGBT power module were observed based on Intensified Charge Coupled Devices (ICCD), and the triple junctions composed of copper–ceramic–silicone gel inside IGBT were found as the discharge points. Furthermore, the directed bonded copper (DBC) ceramic filled with silicone gel was used as a test sample to study the discharge failure process, including the partial discharge (PD), surface charges, and electric trees. The mechanism of discharge failure is discussed and analyzed. The insulation degradation process is accompanied by phenomena such as severe partial discharge and rapid electric tree growth. This research provides support for the analysis idea and guidance of the research method for the cause of power module failure.

Studying the Factors Affecting De-Emulsification of Crude Oil

The paper deals with highly stable emulsions. It is concentrated on de-emulsification of crude oil. In the petroleum industry, de-emulsification is an important and urgent task that is typically required for the treatment of crude oil. This work, suggests method using coupling device integrated centrifuge with chemical to strengthen the de-emulsification efficiency. A number of de-emulsification runs were conducted to determine how centrifuge and chemical components affected the effectiveness of de-emulsifying crude oil and the separation of water, Different types of de-emulsifiers the (ethylene glycol, choline chloride and ethyl cellulose), were used with different concentration of de-emulsifiers, de-emulsification time in centrifuge and centrifugal speed. Also studied at the same time. Studies on the de-emulsification of crude oil were conducted at room temperature. As the concentration of de-emulsifiers was increased, crude oil's de-emulsification efficiency rose , centrifuge time and centrifugal speed ,with de-emulsifier type effect on de- emulsification ,which reached maximum (85.9%,84.4% and 74.07%) at rate 4% of ethylene glycol, choline chloride and ethyl cellulose respectively ,at 60 min and 4000 rpm . This method provides higher water separation from crude oil emulsion and quicker method.

Microvascular anastomotic coupler for venous end-to-side anastomoses in head and neck reconstructive surgery.

The use of coupler devices has become mainstream in microsurgical end-to-end venous anastomoses (EEA) for free flaps in head and neck reconstruction. Reports about end-to-side venous anastomoses (ESA) using a coupler are scarce, though. The surgical technique of end-to-side anastomosis using a coupler device is described. End-to-side anastomoses and end-to-end anastomoses with a vascular coupler are compared with respect to postoperative vascular complications. 124 patients were included, 76 with EEA, 48 with ESA. Postoperative venous complications occurred in 5.3% and 2.1%, respectively. ESA is a valuable alternative to EEA when using a coupler device providing more flexibility to the surgeon.

Developing and Optimizing the S-Band Accelerating Structure and Coupling Device for the Radiation Therapy Facility

Developing and Optimizing the S-Band Accelerating Structure and Coupling Device for the Radiation Therapy Facility

Capacitive Deep Trench Isolation-Based CCD-on-CMOS Image Sensor Sensitivity to Total Ionizing Dose

This work presents a new type of Charge Coupled Device (CCD) manufactured using a CMOS process and featuring Capacitive Deep Trench Isolation (CDTI). The device is used in a Multi-Pinned Phase mode (MPP) enabling almost constant oxide interface passivation. Flatband shift, Dark current and Charge Transfer Inefficiency (CTI) induced by Total Ionizing Dose (TID) are investigated. Despite the increase of interface states, results show that dark current can be efficiently mitigated by use of short charge transfer duration, avoiding full interface depletion and free charge generation. It is further shown that trapping by interface states is only lightly affecting CTI as the Buried Channel keeps electrons far from interfaces. Finally, a clear correlation on flatband shift with Full Well Charge (FWC) reduction is established.

Research on mechanical damage-energy evolution characteristics of coal based on digital image measurement technology

This study investigates the mechanical damage-energy evolution characteristics of coal using digital image measurement technology. Traditional measurement methods, such as strain gauges and extensometers, often suffer from limitations and inaccuracies in measuring coal deformation and damage. In contrast, digital image measurement technology offers a non-contact and non-interfering approach, providing high precision and real-time monitoring of coal deformation and strain changes. The study utilizes a tri-axial fluid–solid coupling device and non-contact digital image processing technology to measure the deformation of coal samples under different confining pressures. By analyzing the total input energy, dissipative energy, and releasable strain energy of coal, the research sheds light on the energy distribution and transformation during coal failure. The advantages of digital image measurement technology over traditional methods are highlighted, including its high precision, real-time monitoring capabilities, non-disturbing measurement approach, and cost-effectiveness. These advantages enhance the accuracy and efficiency of testing and monitoring coal samples, leading to improved coal mining practices and energy production processes. Overall, this study contributes to a better understanding of the mechanical damage-energy evolution characteristics of coal. The insights gained from digital image measurement technology provide valuable information for the prediction and prevention of geological disasters, the analysis of stability in coal mining operations, and the development of improved safety protocols. Further research is encouraged to explore additional factors and mechanisms that may influence coal damage and energy evolution, ensuring a comprehensive understanding of coal behavior.

Improving the stability and handling of tractors when towing trailers and coupled units

BACKGROUND: Currently, almost all agricultural work is performed using tractors. As the transport speed of a tractor train increases, the amplitude of lateral and horizontal oscillations of its coupled units emerges and increases. At certain velocities, these oscillations become so large that they can lead to a rollover, in addition, shock loads occur in coupling devices, which make it difficult to handle a tractor train. The traditional method to prevent this is the velocity limit, which does not guarantee a positive result.&#x0D; AIMS: Development of methods to improve stability, handling and safety of wheeled tractor trains by reducing the galloping and yawing of a truck tractor when towing heavy loads.&#x0D; METHODS: The following options of the design of the system for countering the occurrence of self-oscillations in the design of a wheeled tractor train ensuring a reduction in the level of self-oscillations, increasing the stability, handling and safety of the tractor train have been proposed: the coupling device equipped with hydraulic damping devices operating at longitudinal and lateral folding; the control system for the individual traction electric drive of a truck tractor preventing the loss of wheel grip with the ground surface; the combined use of the control system for the individual traction electric drive of a truck tractor and the coupling device equipped with hydraulic damping devices; the combined use of the coupling device equipped with hydraulic damping devices and a steering correction system.&#x0D; RESULTS: With use of simulation modeling methods, it has been established that the coupling device equipped with hydraulic damping devices adjustable by the folding angle of the tractor train and by the yaw angle oscillations of a truck tractor body should be recognized as the most acceptable and effective system for reducing self-oscillations of a wheeled tractor train at the current state of the art.&#x0D; CONCLUSIONS: The practical value of the study lies in the possibility of using the proposed methods to eliminate the risk of self-oscillating processes in the design of promising types of agricultural machinery.

Three-Dimensional Shape and Deformation Measurements Based on Fringe Projection Profilometry and Fluorescent Digital Image Correlation via a 3 Charge Coupled Device Camera.

We propose a novel hybrid FPP-DIC technique to measure an object's shape and deformation in 3D simultaneously by using a single 3CCD color camera, which captures the blue fringe patterns and red fluorescent speckles within the same image. Firstly, red fluorescent speckles were painted on the surface of the specimen. Subsequently, 12 computer-generated blue fringe patterns with a black background were projected onto the surface of the specimen using a DLP projector. Finally, both the reference and deformed images with three different frequencies and four shifted phases were captured using a 3CCD camera. This technique employed a three-chip configuration in which red-green-blue chips were discretely integrated in the 3CCD color camera sensor, rendering independent capture of RGB information possible. Measurement of out-of-plane displacement was carried out through the implementation of Fringe Projection Profilometry (FPP), whereas the in-plane displacement was evaluated using a 2D Digital Image Correlation (DIC) method by leveraging a telecentric-lens-based optical system. In comparison to the traditional FPP-DIC hybrid methodology, the present approach showed a lower incidence of crosstalk between the fringe patterns and speckle patterns while also offering a corrective for the coupling of the in-plane displacement and out-of-plane displacement. Experimental results for the in-plane cantilever beam and out-of-plane disk comparisons with the traditional 3D-DIC method indicated that the maximum discrepancy obtained between FPP-DIC and 3D-DIC was 0.7 μm and 0.034 mm with different magnifications, respectively, validating the effectiveness and precision of the novel proposed FPP-DIC method.