Coupled Device Research Articles

Homogeneous dielectric barrier discharge in CO2

This study investigates dielectric barrier discharges generated in CO2 at atmospheric pressure. According to the literature, under these conditions, discharges usually work in the filamentary regime. On the contrary, the experimental results reported in the present study demonstrate for the very first time that it is also possible to obtain a diffuse CO2 discharge under these conditions. The diffuse regime appears to be related to a memory effect mechanism occurring at the dielectric surface. Both the filamentary and diffuse regimes were compared in this work based on electrical measurements coupled with intensified charged coupled device (iCCD) imaging and optical emission spectroscopy. The clear difference between both regimes is discussed.

Offset compensation cable external diameter measurement system

In the process of industrial production cables and pipes, the precise measurement of the produced product line diameter parameters is very important. In the present paper, we propose an offset compensation diameter measurement system based on analytical geometry and spatial coordinate transformation. The right-angle coordinate system is established in the corresponding planes of the two sets of charge coupling devices and the corresponding laser light source, and the center coordinates of the measured cable are obtained by the analytical geometric method, and the spatial coordinate transformation is used to connect the two coordinate systems to build the offset compensation measurement system. In the actual test (taking θ=45° as an example), considering the overall measurement results of the cylinder standard bar, the overall absolute error is between ± 4 μm without offset, and the relative error is 0~0.05%; and the relative average error (deviation angle is more than 0° and less than 35°) can be maintained at less than 0.7%. The above results demonstrate the feasibility of accurate measurement of this offset-compensated measurement system.

Исследование возникновения и развития трещин при упрочнении деталей подвижного состава индукционно-металлургическим способом

Purpose: To conduct study to obtain data on the appearance and propagation of cracks in the layer that’s welded by induction-metallurgical method, cracks’ impact on exploitation safety of a part and its service age. Methods: Using metallographic studies, the analysis of samples of automatic coupler device with layer, welded by inductive-metallurgical way, was carried out. Results: According to the study results, it was confirmed that cracks do not propagate from welded layer into main metal of a part. Practical significance: The conducted study of crack presence and propagation estimation made it possible to prove further safe exploitation of a part without its performance loss or its structure or technical characteristics deterioration.

Information System of the Robotic Towing Airfield System

Relevance. The development of aviation technology is associated with the development of new means that directly ensure the movement of aircraft (AF) at the airfield. To carry out ground maneuvers with aircraft, towing airfield systems (UAS) are used, which can significantly reduce noise and air pollution near the airport, as well as reduce the inefficient resource consumption of aircraft engines and provide significant savings in aviation fuel. UAS is also used when the aircraft loses the ability to move and is located on or near the working area of the airfield, which creates a serious problem leading to the closure of the airport for flights, while airlines incur significant losses.Purpose of research. Improving the efficiency of the towing airfield system through the development of an information system. Objectives. Development of the structure of a robotic towing airfield system, drawing up a structural diagram of the ACS layout of the towing platform, design of block diagrams of the logical controller of the ACS platform.Methods. The level of horizontal deviation of the platform from the contrast line was chosen as the setting influence determining the position of the platform in space, which is measured by analyzing images coming from the technical vision system installed on the tow truck. Results. In the course of the study, the structure of a robotic towing airfield system was developed. Based on this structure, a block diagram of the ACS layout of the towing platform was designed and a block diagram of the logical controller of the ACS platform was developed.Conclusions. 1. The structure of a robotic towing airfield system has been developed, including a mobile tow truck, a coupling device, an aircraft, and an on-board control system. 2. An algorithm for controlling the positioning of a robotic towing airfield system based on the logical processing of signals of an optocoupler matrix has been developed. 3. Algorithms have been developed for controlling the movement of the RBAS along a given contrast line under the action of external disturbing influences of a deterministic and random type, allowing for high-precision movement of the RMB.

Review on Key Technologies and Development of Magnetic Coupling Resonant-Dynamic Wireless Power Transfer for Unmanned Ground Vehicles

With the fast development of magnetic coupling resonant-dynamic wireless power transfer (MCR-DWPT), it is more likely that high-efficiency wireless charging between unmanned ground vehicles (UGVs) will be practically realized, especially in desolate places that are far away from a city center or charging depot and always experiencing large load fluctuations, varying operating conditions, and complex working targets. Based on this, the wireless charging of UGVs demands higher reliability and efficiency. This paper reviews the MCR-DWPT system of UGVs, and the basic structure and key technologies are introduced. Then, the key technologies, which include the coupling device design, compensation topology design, and system control strategy, are discussed in detail. After that, by considering the current research, the main challenges of the MCR-DWPT of UGVs are investigated and its developing prospects are explored.

Modeling of three-link road trains

It is proposed to use graphs for developing the mathematical model of multi-link road trains with coupling devices of different designs. The calculation scheme is formed on the basis of the structure graph of the multi-link road train construction scheme. Next, the structure graph of the mathematical model generalized coordinates levels is written. This allows to develop the mathematical model of appropriate complexity depending on the research objectives. The developed mathematical motion model of a multi-link road train with an elastic-damping joints of their main elements was represented by a system of nonlinear inhomogeneous ordinary differential equations of the second order. The acceleration process for three-link road train with pneumatic coupling devices between train links was modeled.

Self-Assembling Systems for Optical Out-of-Plane Coupling Devices.

Micromirrors are used in integrated photonics to couple extraplanar light into the planar structure of a device by redirecting light via specular reflection. Compared with grating or prism-based couplers, micromirrors allow for coupling of light over a broader range of wavelengths, provided that the micromirror is fabricated with a specific 3D shape to ensure proper reflection angles. In principle, self-assembly methods could enable reliable, parallelizable fabrication of such devices with a high degree of precision by designing self-assembling components that produce the desired microscale geometry as their thermodynamic products. In this work, we use DNA-functionalized nanoparticles to assemble faceted crystallites with predetermined crystal shapes, and demonstrate with microscale retroreflectance measurements that these self-assembled nanoparticle arrays do indeed behave like optically flat mirrors. Furthermore, we show that the tilt angle of the micromirrors can be intentionally controlled by altering the crystallographic symmetry and preferred crystal orientations as a function of the self-assembly process, thereby altering the resulting specular angle in a programmable manner. Measurements of optical coupling from normal incidence into the substrate plane via an optical fiber confirm that the faceted structures can function as optical out-of-plane coupling devices, and coating these structures with reflective materials allows for high efficiency of light reflection in addition to the angular control. Together, these experiments demonstrate how self-assembled nanoparticle materials can be used to generate optically relevant architectures, enabling a significant step in the development of self-assembly as a materials fabrication tool for integrated optical devices.

Integrated Photonic Device for Wavelength-Stable Laser Oscillation and Simultaneous Input Coupling

A guided-mode-resonance device for both narrow-band retroreflection and waveguide input coupling was designed and fabricated for operation wavelength of 1550 nm. It consists of a focusing grating coupler (FGC) integrated in a waveguide cavity resonator constructed by a pair of distributed Bragg reflectors (DBRs) on a reflection substrate. The size of the FGC was 31 × 20 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The device was used as a laser mirror of an external cavity laser. The oscillation wavelength was fixed to the retroreflection wavelength, and the laser power was coupled to a waveguide. The coupled power depends on the length of one DBR. The optimal length for the maximum coupling was also discussed theoretically and experimentally.

Consideration on the Expression of Amplification Function of PTT with Positive Feedback Circuit Based on Approximated Characteristic Equations of LED and PD

In 1989, B.J. Van Zeghbroeck et al., who was working for IBM Research Center at that time, announced the notion of PTT (Photon Transport Transistor) as an optical coupling device of light emitting diode (LED) and light receiving diode (Photo Diode, PD), where the carrier of the base layer is light (Photon) only. Later, it was theoretically shown that PTT has an amplification function in a positive feedback circuit and works as an extremely low-noise transistor element. In this paper, based on the characteristics of the electronic circuit including the LED and PD, we discuss the expression of the amplification function of the PTT positive feedback circuit. First, we theoretically formulate the fundamental equations for the circuit based on Kirchhoff’s Law and V-I characteristics of LED and PD. Second, we perform the actual circuit operation experiments of PTT positive feedback circuit. Lastly, we analyze the expression of amplification function and its operational behavior based on the measured values in the experiments, using approximated characteristic equations of LED and PD.

Sm-Doped PIN-PMN-PT Transparent Ceramics with High Curie Temperature, Good Piezoelectricity, and Excellent Electro-Optical Properties.

Transparent piezoelectric materials are capable of coupling several physical effects such as optics, acoustics, electricity, and mechanical deformation together, which expands applications for mechanical-electro-optical multifunctional devices. However, piezoelectricity, transparency, and Curie temperature restrict each other, so it is difficult to achieve high piezoelectricity with both good transparency and a high Curie point. In this paper, Sm-doped 24Pb(In1/2Nb1/2)O3-42Pb(Mg1/3Nb2/3)O3-34PbTiO3 (PIN-PMN-PT) transparent ceramic with a high piezoelectric coefficient of 905 pC/N, excellent electro-optical coefficient of 814 pm/V, and high Curie-point of 179 °C is fabricated. Sm doping effect on the phase structures, piezoelectricity, ferroelectricity, optical transparency, electro-optical properties, and thermal stability is systematically investigated. Compared with PMN-PT transparent ceramics, PIN-PMN-PT transparent ceramics exhibit better temperature stability. Electro-optical modulation and energy conversion are achieved using PIN-PMN-PT transparent piezoelectric ceramic, which indicates that it has great potential to develop mechanical-electrical-optical multifunctional coupling devices for optical communication, energy harvesting, photoacoustic imaging, and so on.

Tailoring photoluminescence of WS2-microcavity coupling devices in broad visible range

Abstract Most of the previous TMDC-photon coupling devices were mainly based on A exciton due to its high oscillator strength and large exciton binding energy. Less effort has been focused on the modulation of the emission of B exciton and Rydberg states in TMDCs, especially in monolayer WS2. Here, we demonstrate that the photoluminescence (PL) emission of WS2-microcavity coupling devices can be tailored in a broad visible wavelength range (490 nm–720 nm). In contrast to the intrinsic PL emission of monolayer WS2, 25-fold enhanced B exciton emission and significant PL emission from the 2s Rydberg state can be observed. From the transient absorption (TA) measurements, the strongly coupled hybrid states based on B exciton can be remarkably fingerprinted. Furthermore, the strongly enhanced PL emission from the coupled B exciton has been demonstrated due to the strongly increased lower polariton (LP) state population and the internal conversion pathway being blocked in the strong coupling regime. Besides, the remarkable PL emission from the 2s Rydberg state is also revealed and confirmed by the additional ground state bleaching signal in TA spectra. These physical mechanisms about tailoring the PL emission in low dimensional TMDCs can provide significant references for constructing highly efficient optoelectronic devices.

Low-loss and broadband cascaded SiN RGB coupler with dual-mode interference.

We design and demonstrate a cascaded SiN-based RGB coupler with dual-mode interference (DMI) for a micro laser scanning image projector. The DMI configuration in SiN-based waveguides mitigates the adverse effects of self-image point deviation caused by wavelength dispersion, achieving decreased device length and high transmission efficiency. The underlying mechanisms are discussed based on coupled-mode theory and 3D finite difference time domain simulation. A small footprint of 3µm×70µm is achieved for the RGB coupler device without input/output circuits, and the insertion losses are less than 0.56dB at RGB wavelengths. There are two orders of magnitude reduction in device length as compared with the conventional S i O 2-based RGB coupler, which greatly promotes the miniaturization of the couplers and displays integration advantages with a laser diode and waveguide photodetector. In addition, the 3dB bandwidth is over 50nm for the coupler, and it demonstrates good fabrication tolerance. This design can further be integrated into visible light communication systems and applied to visible light integrated photonics.

Economic operation strategy of integrated hydrogen energy system considering the uncertainty of PV power output

To address the negative influence caused by power randomness of distributed PV output on energy system’s economic operation, in this work, an economic operation strategy considering the uncertainty features of PV output has been designed and applied on an integrated hydrogen energy system. First, the thermal system operation model and the thermoelectric output control model are precisely built for the integrated hydrogen energy system and the hydrogen-based fuel cell, respectively. Then, referring to the PV output prediction data, the uncertainty of light intensity variation is analyzed to correct the PV output prediction curve. Finally, a cost–benefit model for the optimal economic operation of the integrated hydrogen energy system including PV, hydrogen fuel cell and cogeneration unit is designed with an objective function of achieving an optimal economic operation of the multi-energy coupling devices. The simulation tests validate that considering the influence of PV output uncertainty on hydrogen fuel cell output can make the system operation more reasonable, which ensures the economic and reliable operation of hydrogen energy systems.

ОЦЕНКА ПОВРЕЖДАЕМОСТИ АВТОСЦЕПНОГО УСТРОЙСТВА ГРУЗОВЫХ ВАГОНОВ В ЭКСПЛУАТАЦИИ

The paper objective is to estimate the damage to the automatic coupling device of freight cars in operation. A statistical analysis of auto-coupling breaks on roads and a statistical estimation of nondestructive testing of auto-coupling device parts are carried out. During the analysis, it is found that 68% of breaks occur due to the presence of cracks in the body of the automatic coupler, 60% of breaks of the automatic couplers occur in areas where the track has a slope, including the mountain pass areas and 77% of breaks occur in the train traction mode. The scientific novelty is in obtaining a logarithmically normal law of the crack length distribution in the coupling body and traction clamp during the operation of the car in the overhaul period. The most likely crack formation in the body of the automatic coupling during the operation of the car between scheduled repairs is 41 mm long, in the traction clamp it is 63 mm. The practical significance of the work is in the fact that the obtained results can be used in making recommendations and organization of technical measures to reduce the cases of auto-coupling breaks and increase the quality of repair and maintenance of the auto-coupling device.

Physics-guided co-designing flexible thermoelectrics with techno-economic sustainability for low-grade heat harvesting.

Flexible thermoelectric harvesting of omnipresent spatial thermodynamic energy, though promising in low-grade waste heat recovery (<100°C), is still far from industrialization because of its unequivocal cost-ineffectiveness caused by low thermoelectric efficiency and power-cost coupled device topology. Here, we demonstrate unconventional upcycling of low-grade heat via physics-guided rationalized flexible thermoelectrics, without increasing total heat input or tailoring material properties, into electricity with a power-cost ratio (W/US$) enhancement of 25.3% compared to conventional counterparts. The reduced material usage (44%) contributes to device power-cost "decoupling," leading to geometry-dependent optimal electrical matching for output maximization. This offers an energy consumption reduction (19.3%), electricity savings (0.24 kWh W-1), and CO2 emission reduction (0.17kg W-1) for large-scale industrial production, fundamentally reshaping the R&D route of flexible thermoelectrics for techno-economic sustainable heat harvesting. Our findings highlight a facile yet cost-effective strategy not only for low-grade heat harvesting but also for electronic co-design in heat management/recovery frontiers.

Fixation of CO2 from ethanol fermentation for succinic acid production in a dual-chamber bioreactor system

Harnessing the ability of microorganisms to fix, convert and utilize CO2 for chemical production has important implications for global carbon reduction. In this study, carbonic anhydrase (CA) and/or phosphoenolpyruvate carboxykinase (PEPCK) were overexpressed in Corynebacterium acetoacidophilum. A process was established to capture CO2 and convert it into succinic acid (SA) from the off-gas produced by Saccharomyces cerevisiae fermenting ethanol (EtOH), using the engineered strain of C. acetoacidophilum. By constructing a coupling device and optimizing the ratio of working medium volumes in the two-chamber bioreactor, the maximum yields of EtOH and SA from glucose were 0.51 g/g and 0.70 g/g, respectively. A scale-up trial was performed in a 3-L fermenter and calculation of the environmental factors demonstrated that the linked-fermentation strategy was more environmentally-friendly than conventional SA fermentation, indicating potential for industrial application.

ВЛИЯНИЕ РЕЖИМОВ ДВИЖЕНИЯ ЛЕСОВОЗНОГО АВТОПОЕЗДА ПРИ ВЫВОЗКЕ ЛЕСОМАТЕРИАЛОВ НА ЭФФЕКТИВНОСТЬ РЕКУПЕРАЦИИ ЭНЕРГИИ В ПНЕВМОГИДРАВЛИЧЕСКОМ СЕДЕЛЬНО-СЦЕПНОМ УСТРОЙСТВЕ

The necessity of increasing the efficiency of logging road trains by reducing the transport costs spent on hauling timber in existing road and climatic conditions is substantiated. A review of scientific research by foreign scientists is presented, which made it possible to identify the most significant factors influencing transportation costs. A promising design of a recuperative pneumohydraulic fifth wheel coupling device has been proposed, which makes it possible to reduce transportation costs by reducing the amount of fuel used by a road train, to increase the reliability of a logging road train by reducing the dynamic loads that occur between its links when driving over uneven surfaces of a logging road. The mathematical model of the movement of a timber tractor with a semi-trailer equipped with the proposed coupling device, under conditions of frequent accelerations and decelerations, over the unevenness of the logging road has been improved, which makes it possible to perform a preliminary assessment of the energy recovery by the proposed device in various modes of transient processes, as well as to investigate the influence of the main parameters of the recuperative pneumohydraulic fifth wheel coupling device for performance indicators. Two computer programs have been developed to study the performance indicators of a recuperative pneumohydraulic fifth wheel coupling under various transient modes of movement of a logging road train with given parameters of roughness of a logging road. It has been established that the use of the proposed coupling device in a logging road train makes it possible, when driving with randomly repeated decelerations and accelerations, to regenerate power up to 6.5 kW, and also to achieve a value of longitudinal acceleration of the semi-trailer relative to the tractor of 0.72 m/s2. Computer modeling made it possible to establish the value of the optimal diameter of the hydraulic cylinder, which provides the highest value of recuperated power at the lowest value of the acceleration of the semi-trailer relative to the tractor.

Shear devices coupling exoskeleton and existing RC buildings for seismic improvement

Usually, the works for seismic improvement do not allow the use of the building. The interruption of use in many cases is not allowed especially for buildings with strategic or public service functions. In recent years, an alternative approach to intervention has spread that allows operating exclusively outside the structure through the use of a technology called a structural exoskeleton. The exoskeleton in many cases consists of a bi-dimensional or three-dimensional truss steel structure. The goal of this technology is to transfer most part the seismic action to the external structure. This allows for avoiding reinforcements to the existing structure. for the building-exoskeleton system to be effective against seismic action, the exoskeleton must be sufficiently stiff and the coupling device between the two structures must not produce internal constraints and generate unwanted stresses for the existing structural elements. A critical aspect of the application of this technology is the transfer of the floor seismic forces from the existing structure to the exoskeleton. The present work illustrates the study of an innovative building-exoskeleton coupling device to transfer the seismic shear forces of the floor from the existing structure to the exoskeleton without generating in-plane and out-of-plane bending interactions. The study of the coupling device was carried out as part of the seismic improvement project of a real case study. The seismic improvement project involves the construction of external shear walls consisting of steel trusses. The results of nonlinear numerical analyses on the global models of the building-exoskeleton systems as well as the results of local numerical analyses of the coupling device are illustrated.

Rational Design of Wheel Systems of Multi-Axle Heavy Trucks Taking into Account the Stressed State of Pavement

There are special agricultural tractors abroad converted from serial all-wheel drive. They are much more powerful and carrying capacity than serial ones. For example, the permissible total mass of a road train with a Czech tractor Agrotruck based on the Tatra Phoenix 6 × 6 model is 75 tons. In Germany, in turn, there is an Agro Mover tractor created by Paul Nutzfahrzeuge based on the Mercedes Arocs 4 × 4 model. Both cars, both Czech and German, have “robot” gearboxes and tires measuring from 445/65 R22.5 to 600/60 R22.5 (that is, about half a meter wide), while Arocs, which has two coupling devices, can carry not only semi-trailers, but also trailers. One of the main factors hindering the development of domestic multi-axle multi-wheeled vehicles of extra-large payload capacity is the strength of those pavements on which they are intended to operate.

Blockchain inspired secure and reliable data exchange architecture for cyber-physical healthcare system 4.0

A cyber-physical system is considered to be a collection of strongly coupled communication systems and devices that poses numerous security trials in various industrial applications including healthcare. The security and privacy of patient data is still a big concern because healthcare data is sensitive and valuable, and it is most targeted over the internet. Moreover, from the industrial perspective, the cyber-physical system plays a crucial role in the exchange of data remotely using sensor nodes in distributed environments. In the healthcare industry, Blockchain technology offers a promising solution to resolve most securities-related issues due to its decentralized, immutability, and transparency properties. In this paper, a blockchain-inspired secure and reliable data exchange architecture is proposed in the cyber-physical healthcare industry 4.0. The proposed system uses the BigchainDB, Tendermint, Inter-Planetary-File-System (IPFS), MongoDB, and AES encryption algorithms to improve Healthcare 4.0. Furthermore, blockchain-enabled secure healthcare architecture for accessing and managing the records between Doctors and Patients is introduced. The development of a blockchain-based Electronic Healthcare Record (EHR) exchange system is purely patient-centric, which means the entire control of data is in the owner's hand which is backed by blockchain for security and privacy. Our experimental results reveal that the proposed architecture is robust to handle more security attacks and can recover the data if 2/3 of nodes are failed. The proposed model is patient-centric, and control of data is in the patient's hand to enhance security and privacy, even system administrators can't access data without user permission.