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Reduced graphene oxide (rGO) films suffer from low capacitance for inner unreduced oxygen functional groups, restacking of sheets and high contact resistance. Herein, carbon spheres derived from renewable xylan were added to graphene oxide with large sheet area to fabricate film by gelation and filtration, followed by in situ reduction for high-performance flexible supercapacitor. rGO film with transverse size about 13 μm showed a good specific capacitance of 967 mF/cm2 at a scanning rate of 5 mV/s and increased to 1786 mF/cm2 by in situ reducing its inner part, which generally remained oxidized due to outer hindering from hydrophobic graphene. Then, by hydrothermal carbonization of xylan and activation with KOH, activated carbon sphere (aXCS) was prepared, which had a diameter of 150–200 nm and a specific capacitance of 270 F/g. The aXCS acted as spacer and connector to avoid restacking of graphene sheets and decrease interlayer contact resistance, resulting 94% increase in capacitance performance from rGO film to aXCS/rGO film. Therefore, combined in situ reduction and enhancement through compositing aXCS, the final film (aXCS/rGO-AA) showed a boosted specific capacitance of 755 mF/cm2 at 1 mA/cm2 in double electrode system, power density of 22.5–2250 mW/cm2, and energy density of 11.88–25.2 mWh/cm2. Meanwhile, aXCS/rGO-AA had outstanding cycling stability that its specific capacitance maintained 108.7% after 10,000 cycles of charge–discharge, showing promising potential in wearable and portable electronics. [ABSTRACT FROM AUTHOR]

Currently, pulsed adders are used as pulsed voltage sources maturely. However, their use as pulsed current sources is significantly limited due to circuit impedance and the characteristics of power devices. This paper presents a simple yet effective design for a pulsed current source, incorporating a solid-state Marx pulsed adder as the primary power source and an inductor for energy storage. In the pulsed current source, a Marx pulsed adder produces high voltage to charge the inductor. Then, the stored inductance energy is converted to generate current pulses on the load; the amplitude of the pulsed current is unaffected by the load impedance within a certain range. The pulsed current source can be designed as a standard module, and several modules can form a cascade system for producing current pulses with higher voltage. Finally, a pulsed current source was developed, which can produce adjustable current pulses with high voltage. The design principles, control methods and the effects of the distribution parameters are described. The feasibility of the cascade pulsed power system was validated in experiments. Nine modules were connected to generate pulses of current 10 A on a 15 kΩ resistor. [ABSTRACT FROM AUTHOR]

In the past few decades, Pulsed Power (PP) has been one of the fastest growing technologies, with more and more systems frequently emerging in domains such as civil, medical and military. These systems are based on high-voltage pulses, up to several hundreds of kilovolts, with temporal parameters ranging from microsecond levels to sub-nanosecond levels. One of the biggest challenges in this technology is the accurate and precise measurement of the generated PP. The PP measurement systems must possess high-voltage and wideband properties simultaneously, which is often conflicting. The central elements of a PP measurement system are a voltage divider and a termination load. The work presented in this article is dedicated to the second element of the PP measurement system. This paper describes the development of a 50 Ω coaxial termination load and its connectors for a high power ultrawideband (UWB) pulse measurement systems. The principle roles of these devices are to serve as a dummy matched load for the former and to facilitate the connections between different components of the pulse measurement system for the latter. These devices are designed to withstand pulse voltage amplitudes at least up to 500 kV with temporal parameters, such as rise time and pulse duration, varying from nanosecond to sub-nanosecond ranges. The main challenge in the development of a high-voltage UWB termination load is the tradeoff between the high-voltage and wideband characteristics, both of them requiring opposite dimensional aspects for the load device. This challenge is overcame by the special exponential geometry of the load device. The design employs a 30 cm long low-inductance tubular ceramic 50 Ω resistor, enclosed in a critically dimensioned shielding conductor of an exponential inner profile. This shrinking coaxial structure makes it possible to maintain a good level of matching all along the 50 Ω load. The results obtained through 3D electromagnetic modeling and vector network analyzer measurements show good agreement and confirm the reflection coefficient below −27 dB up to at least 2.5 GHz for the load device. Moreover, calculations demonstrate that the load device is very well adapted for nanosecond and sub-nanosecond pulses with voltage peaks as high as 500 kV. These results demonstrate the high-voltage and UWB properties of the developed load device and prove the utilization of this device in the measurement systems for the accurate and precise measurements of the PP. [ABSTRACT FROM AUTHOR]

Dielectric capacitors have been widely studied in advanced electronics systems due to their rapid discharge rate and high-power density. Among them, relaxor ferroelectrics characterized by nanodomains possess broad application prospects as dielectricmaterialswith high energy density and high efficiency. In this paper, the dielectric characteristics, energy storage performance, and charge--discharge behavior of rare-earth Yb-doped Sr0.7Bi0.2TiO3 ceramics are systematically investigated. The Yb-doped SBT ceramics reduced the grain size, improved the insulation and thermal conductivity, and significantly improved the dielectric breakdown strength. Finally, a high recoverable energy density of 2.32 J/cm³ and an excellent energy storage efficiency of 92.2% were obtained at 300 kV/cm. In addition, pulsed charge--discharge tests show that Sr0.7Bi0.15Yb0.05TiO3 possesses a rapid discharge rate and high-power density with superior thermal stability. Based on these outstanding characteristics, Sr0.7Bi0.15Yb0.05TiO3 exhibits promising applications in pulsed power systems. [ABSTRACT FROM AUTHOR]

Face masks can reduce the spread of several viruses as well as coronavirus and help people to save many lives. Many people are not serious about wearing face masks. This work results in a system that can detect the face mask of a person with CNN. The system can identify anyone without a face mask. An IoT-based module is integrated with the system to monitor people's temperature, blood pulse, and oxygen levels. Which can collect all the sensor data and send the data to a cloud database. From the cloud server, the mask condition and health condition can be monitored. The collected data can also be used for future analysis. The proposed low-cost system worked properly with a success rate. [ABSTRACT FROM AUTHOR]

• Oxygen vacancies were introduced into the ceramics by changing the valence of Sb element during high temperature sintering. At the same time, the concentration of oxygen vacancies in ceramics was regulated by controlling the doping amount of Sb element. • Through a variety of characterization methods and simulation calculations, the generation mechanism of high E b in ceramics and the influence of oxygen vacancies on the energy storage characteristics of ceramics are described in detail. • Through managing the content of oxygen vacancies, the 0.83NN–0.17SNS ceramics achieved a high energy storage density (W rec) of 6.27 J/cm3 and an energy storage efficiency (η) of 82.79 % at 705 kV/cm. Ceramic materials possessing high polarization and substantial breakdown electric fields represent a principal strategy for enhancing the performance of pulse power systems. To augment the energy storage capabilities of ceramic materials, numerous studies have suggested a variety of specific control methods. However, reports on the vacancy defects arising during the regulatory process and the relationship between these vacancy defects and energy storage performance are scarce. This paper introduces an optimal quantity of oxygen vacancy defects into the prepared NN–based ceramics for characterization and analysis, aiming to elucidate the impact of oxygen vacancy defects and their concentration on the structure and energy storage properties of ceramics. Through managing the content of oxygen vacancies, the 0.83NN–0.17SNS ceramic achieved a high energy storage density (W rec) of 6.27 J/cm3 and an energy storage efficiency (η) of 82.79 % at 705 kV/cm. This work presents a novel approach to regulating the energy storage performance, offering a new method for optimizing the performance of lead-free energy storage materials. [ABSTRACT FROM AUTHOR]

Many charged particles in space, including α -particles, neutrons, heavy ions, electrons, and photons, wreak havoc on the stability and reliability of memory circuits. In addition, these high-energy particles produce an ion track within the memory chip, which disrupts the storage bit. Standard 6T SRAM cannot withstand this upset condition. This paper presents a novel RRS-14T radiation-resistant SRAM memory cell with redundant nodes and a polar design to address the soft error issue. The performance of the proposed RRS-14T memory cell is compared to the performance of existing radiation-resistant memory cells, such as RHS-14T, RHMC-12T, NRHC-14T, QCCS-12T, HRRT-13T, and RHBD-13T. The RRS-14T cell protects against single and multiple-node disruptions. The read stability of the proposed RRS-14T memory cell is 2.83x/ 1.5x/ 2.10x/ 1.34x/ 3.38x/ 1.68x greater than the existing RHS-14T/ RHMC-12T/ NRHC-14T/ QCCS-12T/ HRRT-13T/ RHBD-13T memory cells. Moreover, 1.08x/ 1.27x/ 1.06x/ 1.05x/ 1.16x/ 1.07x larger write trip voltage than RHS-14T/ RHMC-12T/ NRHC-14T/ QCCS-12T/ HRRT-13T/ RHBD-13T memory cells. In addition, the write access time, hold power, and critical charge are enhanced when the supply voltage is at 1 V. • Designing reliable and stable memory devices outside space is difficult. • Self-state restoration method ensures reliability in space memory applications. • A double exponential current pulse accesses the RHBD memory's soft error upset rate. • Under worst-case PVT analysis, the proposed memory cell's performance remains stable. • The proposed memory cell exhibits less trade-off between stability and reliability. [ABSTRACT FROM AUTHOR]

The Fast Discharge Units (FDUs) of the Superconducting (SC) Toroidal Field (TF) coils in the European demonstration fusion power plant DEMO warrant the machine integrity over its full lifetime against severe failure events, such as SC coil quenches or any other plant events requiring the safe TF magnet system discharge. A low (75 kA) and a high current (105 kA) configuration are under study for the TF coils for DEMO. The FDUs must be extremely reliable for the purpose of commutating in short time (∼1 s) the currents and to discharge the TF magnets safely into resistors outside of the tokamak building. Malfunctions of the FDUs must be avoided. The FDUs are considered as Safety Important Class (SIC) components that need to discharge high amounts of energy of about 161 GJ (@75 kA) resp. 118 GJ (@105 kA) stored in the DEMO TF coils. The TF FDUs Circuit Breakers (CBs) shall be installed in the lower level of the tokamak to minimize the length of the connecting busbars. The FDUs integration is challenging because of the high neutron and gamma radiation and stray magnetic fields of the tokamak. Since in DEMO the neutron fluence over lifetime is much higher than in ITER, the problems of using FDUs with electronic subsystems was expected to be more severe, so that their integration has been considered from the beginning of the DEMO project. Sufficient shielding or possible re-positioning of the whole FDUs or sensitive FDU components compared to ITER are being investigated, to reduce the neutron fluxes and neutron and gamma ray fluences. Alternative concepts, e.g., fully mechanical CBs are studied in the EUROfusion Work Package Plant Electrical System (WPPES) in parallel. This paper presents the CAD integration work on the DEMO TF FDUs supported by neutronics assessments. It is assumed the same FDU technology as in ITER. The magnet feeder´s integration is commenced at the same time. [ABSTRACT FROM AUTHOR]

• STEAM will experimentally characterize the EU-DEMO Steam Generator mock-up. • DEMO pulsed operation arises challenges requiring thermal hydraulic characterization. • A complete RELAP5/Mod3.3 model of the experimental facility was developed. • STEAM low power pre-test analyses were performed by using the developed model. • RELAP5 analysis provided feedbacks on the facility design and operative procedures. While nuclear fusion reactors hold promise, their realization faces significant complexities, not only in the construction but also in managing the auxiliary systems required for safely operating plasmas. Pulsed plasma regime, integral to reactor normal operations, determines atypical operative conditions that can cause high thermal stresses on the components and generate instabilities. R&D activities are therefore required to characterize the components behavior in the extremely severe conditions of pressure and temperatures associated with fusion, especially during sudden power transitions. ENEA, as part of the EUROfusion consortium, is planning the construction of STEAM, an experimental facility aimed at qualifying the DEMO Steam Generator during pulse-dwell-pulse transitions within the W-HYDRA platform. Dedicated experimental campaigns will reproduce the low-power phase associated with the only material activation (dwell), the full-power phase (pulse) and the corresponding power transitions. This paper focuses on the low-power phase, presenting the performed RELAP5/Mod3.3 simulations, investigating the thermal-hydraulic performances of the system at 1 %, 5 % and 10 % of the nominal power, hence in conditions considerably different from fission standard practices. The simulation results are essential for defining regulation strategies for the SG test section and ensuring the correct operation of the entire system. [ABSTRACT FROM AUTHOR]

Surveillance data published since 2010, although limited, showed that there is no evidence of zoonotic parasite infection in market quality Atlantic salmon, marine rainbow trout, gilthead seabream, turbot, meagre, Atlantic halibut, common carp and European catfish. No studies were found for greater amberjack, brown trout, African catfish, European eel and pikeperch. Anisakis pegreffii, A. simplex (s. s.) and Cryptocotyle lingua were found in European seabass, Atlantic bluefin tuna and/or cod, and Pseudamphistomum truncatum and Paracoenogonimus ovatus in tench, produced in open offshore cages or flow‐through ponds or tanks. It is almost certain that fish produced in closed recirculating aquaculture systems (RAS) or flow‐through facilities with filtered water intake and exclusively fed heat‐treated feed are free of zoonotic parasites. Since the last EFSA opinion, the UV‐press and artificial digestion methods have been developed into ISO standards to detect parasites in fish, while new UV‐scanning, optical, molecular and OMICs technologies and methodologies have been developed for the detection, visualisation, isolation and/or identification of zoonotic parasites in fish. Freezing and heating continue to be the most efficient methods to kill parasites in fishery products. High‐pressure processing may be suitable for some specific products. Pulsed electric field is a promising technology although further development is needed. Ultrasound treatments were not effective. Traditional dry salting of anchovies successfully inactivated Anisakis. Studies on other traditional processes – air‐drying and double salting (brine salting plus dry salting) – suggest that anisakids are successfully inactivated, but more data covering these and other parasites in more fish species and products is required to determine if these processes are always effective. Marinade combinations with anchovies have not effectively inactivated anisakids. Natural products, essential oils and plant extracts, may kill parasites but safety and organoleptic data are lacking. Advanced processing techniques for intelligent gutting and trimming are being developed to remove parasites from fish. [ABSTRACT FROM AUTHOR]

Neurotransmitter receptors are essential components of synapses for communication between neurons in the brain. Because the spatiotemporal expression profiles and dynamics of neurotransmitter receptors involved in many functions are delicately governed in the brain, in vivo research tools with high spatiotemporal resolution for receptors in intact brains are highly desirable. Covalent labeling by chemical reaction (chemical labeling) of proteins without genetic manipulation is now a powerful method for analyzing receptors in vitro. However, selective target receptor labeling in the brain has not yet been achieved. This study shows that ligand-directed alkoxyacylimidazole (LDAI) chemistry can be used to selectively tether synthetic probes to target endogenous receptors in living mouse brains. The reactive LDAI reagents with negative charges were found to diffuse well over the whole brain and could selectively label target endogenous receptors, including AMPAR, NMDAR, mGlu1, and GABAAR. This simple and robust labeling protocol was then used for various applications: three-dimensional spatial mapping of endogenous receptors in the brains of healthy and disease-model mice; multi-color receptor imaging; and pulse-chase analysis of the receptor dynamics in postnatal mouse brains. Here, results demonstrated that bioorthogonal receptor modification in living animal brains may provide innovative molecular tools that contribute to the in-depth understanding of complicated brain functions. [ABSTRACT FROM AUTHOR]

Gas discharge and breakdown phenomena have become increasingly important for the development of an ever-growing number of applications. The need for compact and miniaturized systems within power, pulsed power, semiconductor, and power electronic industries has led to the imposing of significant operating electric field stresses on components, even within applications with low operating voltages. Consequently, the interest in gas discharge processes in sub-millimeter and microscale gaps has grown, as the understanding of their initiation and propagation is critical to the further optimization of these technologies. In this work, a computational study of primary ionization fronts has been conducted, which systematically investigated the role of voltage rate-of-rise in point-plane and point-point electrode geometries with an inter-electrode gap maintained at 250 μ m and a needle radius of 80 μ m. Using the hydrodynamic approach with the local mean energy approximation, along with simplified plasma chemistry, simulations have been performed under positive and negative ramp voltages, rising at 50, 25, 16.67, 12.5, and 10 kV/ns in synthetic air and in pure CO 2 . Results on the developed electric field, electron densities, and propagation velocities are presented and discussed. Effects on the cathode sheath thickness scaling with voltage rate-of-rise have been additionally analyzed, the mechanisms behind these effects and their potential impacts are discussed. The work conducted in this study contributes towards an increased understanding of the gas discharge process, under fast-transients and nonuniform electric fields, with relevance to microelectromechanical, power, and pulsed power system design. [ABSTRACT FROM AUTHOR]

High-harmonic generation from a gas target exhibits sharp spectral features and rapid phase variation near the Cooper minimum. By applying spectral filtering, shaped isolated attosecond pulses can be generated where the pulse is split into two in the time domain. Using such shaped extreme-ultraviolet (XUV) pulses, we theoretically study attosecond transient absorption (ATA) spectra of helium 2s2p autoionizing state which is resonantly coupled to the 2s² dark state by a time-delayed infrared laser. Our simulations show that the asymmetric 2s2p Fano line shape can be readily tuned into symmetric Lorentzian within the time delay of a few tens of attoseconds. Such efficient control is due to the destructive interference in the generation of the 2s2p state when it is excited by a strongly shaped XUV pulse. This is to be compared to prior experiments where tuning the line shape of a Fano resonance would take tens of femtoseconds. We also show that the predicted ATA spectral line shape can be observed experimentally after propagation in a gas medium. Our results suggest that strongly shaped attosecond XUV pulses offer the opportunity for controlling and probing fine features of narrow resonances on the few-ten attoseconds timescale. [ABSTRACT FROM AUTHOR]