Input Power Research Articles

Off-target gradient driven flows in 3D simulations of ADITYA-Upgrade tokamak scrape-off layer plasma transport

Abstract Coupled plasma-neutral transport simulations are performed of ADITYA-Upgrade tokamak scrape-off layer (SOL)
plasma where flows in the core and SOL were measured to reverse sign with density variation. The simulations per-
formed using EMC3-Eirene plasma-neutral code combination incorporate the toroidally continuous high-field-side
belt-limiter placed in a moderate-circular tokamak equilibrium. Development of mutually counter-propagating toroidal
plasma flows in top and bottom regions of both SOL and core is recovered for relatively high upstream density cases
with high input power (300 kW and 3 m 2 s −1 ). The origin of the flows is traced to the poloidal density variation introduced
by high recycling on the inboard localized belt limiter. The results are compared with the similar observations, for
example, in Doppler shifted passive charge exchange line emission on the ADITYA-Upgrade (ADITYA-U) tokamak ,
highlighting the role played by residual stress in the total Reynold stress. The external stimuli, like a localized gas
puff, are discussed as potential drivers of flow, by means of residual stress, based on the existing resonant model of the
tokamak plasma rotation.

Advancing sustainable cooling: Performance analysis of a solar-driven thermoelectric refrigeration system for eco-friendly solutions

The solar-powered thermoelectric refrigerator (SPTR) is an innovative approach that uses solar energy to cool spaces. Its effectiveness relies on solar insolation rates and an intelligent dual-axis solar tracking system (STS) that maximizes solar energy capture. Performance analysis of SPTR with the fixed panel solar system (WST) and dual-axis STS by keeping the SPTR at a standard ambient temperature of 25 °C was carried out under local climate conditions. The experimental test setup includes a thermoelectric refrigerator (TER), thermoelectric module (TEM), solar panels, and STS. The experimental findings showed that the coefficient of performance (COP) of SPTR depends on the solar irradiance, the system's input power, the surface temperature of the solar panels, and the cooling rate. The maximum and minimum values of COPs were 1.19 and 0.27 for directly coupled SPTR with a WST and 2.07 and 0.39 for STS, respectively. Compared with the stand-still solar system, a COP enhancement of 44–75 % is achieved. The results also show that the cooling load is a function of the refrigerated space, and the products are to be cooled, which is affected by the thermoelectric properties of the TEM. The cooling rate is recorded at its maximum when the system is operated using an STS on a clear sunny day with a maximum solar insolation rate. The SPTR has proven to be environmentally friendly, the best alternative to conventional cooling systems, and sustainable due to the independence of traditional energy resources.

Modeling optimization design and amplification characteristics of O-band irregular Bragg bismuth-doped fiber amplifier

In recent years, O-band bismuth-doped fiber amplifier (BDFA) have been rapidly developed due to the fluorescence properties of bismuth-doped glass in the near-infrared (NIR) band, while there are still few studies on bismuth-doped fibers (BDF) with large mode fields as of now. In addition, although the use of a double-pass structure on the amplifier can lead to gain improvement, this also deteriorates the noise figure (NF). Therefore, the study of bismuth-doped fibers with large mode-field areas is a promising path to develop high-performance BDFA. In this work, taking a commercial bismuth-doped fiber as an instance, we first measured the refractive index distribution of the BDF in the O-band using a self-developed fiber refractive index tester, and thereby obtained its actual mode-field area. Then, based on this we further propose an irregular Bragg bismuth-doped fiber with the refractive index growing layer by layer. The results suggests that the effective mode-field area of this fiber reaches 401 um2 at 1320 nm, which is nearly 5.8 times that of a common single-mode BDF. Finally, we performed numerical simulations of the amplification performance based on this fiber. Under the condition of total pumping power of 8 W, the signal with −20 dBm input power obtains a gain of more than 54 dB and an NF of less than 5 dB at 1320 nm wavelength. This work demonstrates the great potential of this Bragg bismuth-doped fiber as an O-band high-gain amplifier and high-power laser.

High efficiency dual‐band rectifiers with wide input power range for wireless power transfer

High efficiency dual‐band rectifiers with wide input power range for wireless power transfer

Decoupling of peeling and ballooning thresholds for pedestal stability and reduction in ELM frequency via enhanced turbulence with edge electron cyclotron heating in DIII-D

The edge localized mode (ELM) frequency (f ELM) decreased by 63% when electron cyclotron heating (ECH) deposition location is shifted from ρ = 0.4 to ρ = 0.8 in DIII-D discharges where the power ratio between neutral beam injection (NBI) and ECH (P NBI/P ECH) is kept at ∼1. The performance of the pedestal in the ECH heated case is compared with a pure NBI reference discharge while keeping the total input power constant. All these discharges are performed at balanced input torque conditions. Furthermore, in the pure NBI discharge a strong decoupling of the peeling–ballooning (PB) thresholds is observed. The PB decoupling is preserved when the ECH is deposited at ρ = 0.8 and P NBI/P ECH ∼ 1, while the thresholds manifest a closed stability boundary when the ECH is deposited at ρ = 0.4. The inter-ELM pedestal recovery time is considerably larger for the ECH at ρ = 0.8 case. Increased pedestal turbulence is observed in beam emission spectroscopy (BES), Doppler backscattering and magnetic diagnostics for the ECH at the ρ = 0.8 case. Strong growth of a TEM-like mode is observed in BES and the mode growth is correlated with the decrease in f ELM. In view of these observations, the increased pedestal turbulence seems to be the plausible reason behind the delayed pedestal recovery following an ELM event in the ECH at ρ = 0.8 case, and the preservation of PB decoupling through temperature pedestal profile widening. TRANSP interpretative simulations show that the ECH at the ρ = 0.8 case is more susceptible to ITG/TEM turbulence.

Degradation of methyl orange using hydrodynamic cavitation coupled with plasma oxidation and ultraviolet C

Combining multiple advanced oxidation processes (AOPs) is essential for the efficient treatment of dye wastewater. In this study, the degradation efficiencies of various oxidation methods, including hydrodynamic cavitation (HC), dielectric barrier discharge (DBD) plasma oxidation, ultraviolet C (UVC), and their combination HC + DBD + UVC, were investigated for Methyl Orange (MO). The photolysis of ozone (O3) and the degradation mechanism associated with HC + DBD + UVC were analyzed to elucidate the pathway of MO degradation. The results demonstrated that the combination of HC + DBD + UVC exhibited a significantly enhanced degradation efficiency compared to other process combinations, achieving a removal efficiency exceeding 91% within a 5-min timeframe. Optimal parameters for achieving a 99.5% degradation rate of 10 mg/L MO were determined as follows: pH 4, inlet pressure of 1.5 MPa, utilization of eight UV lamps with a power input of 46.11 W. During the degradation process, hydroxyl radicals (·OH) and ozone (O3) played crucial roles, while the incorporation of UV lamps effectively mitigated ozone (O3) emissions and enhanced the oxidation of ozone (O3). In conjunction with the analysis of degradation products using liquid chromatography-mass spectrometry, it is highly probable that the MO degradation pathway involves reductive cleavage of the azo bond through ·OH attack. Compared to other experimental methods in literature, HC + DBD + UVC exhibits significant advantages such as enhanced efficiency and absence of additives. This innovative approach offers a rapid and practical on-site solution for efficient MO dye wastewater treatment.

3-level inverter based compensator for power quality enhancement using proposed Trianguzoidal PWM technique

In today’s scenario, the integration of a grid-connected load system with a hybrid energy system (HES) is encouraged to improve the reliability of the system. With the stunning rise in nonlinear loads in HES over the last two decades, the power quality (PQ) of the system has emerged as a paramount concern in contemporary times. The power quality problems include the injection of harmonics in the source current, low input power factor, poor voltage regulation, the burden of reactive power, etc. So, to mitigate these power quality problems in a single-phase distribution system, a 3-level Cascade H-bridge (CHB) inverter-based shunt active power filter (SAPF) is employed alongside a proposed Trianguzoidal pulse width modulation (TRZ PWM) strategy. The single-phase distribution system with SAPF is simulated in fixed and dynamic load conditions to check the system’s efficacy. The proposed PWM techniques for SAPF are compared with conventional PWM techniques, i.e., level shift, phase shift, and hybrid PWM techniques. Results indicate satisfactory performance of the proposed PWM techniques, exhibiting low harmonic distortion in source current, well within IEEE 519 limits, and high active filtering efficiency (AFE) compared to conventional PWM methods. Furthermore, this paper provides detailed comparisons of conventional and proposed PWM techniques in the context of active & reactive power supplied or delivered by load, source, and compensator, input power factor, harmonics in source or grid current, AFE, and individual harmonic components concerning fundamental component of source current.

Pt─O Bond Accelerated Cu0/Cu+ Activity for Boosting Low-Energy Bipolar Hydrogen Production.

To address the imperative challenge of producing hydrogen in a low-energy consumption electrocatalytic system, this study emphasizes the utilization of thermodynamically favorable biomass oxidation for achieving energy-efficient hydrogen generation. This research integrates ultralow PtO2-loaded flower-like nanosheets (denoted as PtO2@Cu2O/Cu FNs) with Cu0/Cu+ pairs and Pt─O bonds, thereby yielding substantial enhancement in both hydrogen evolution reaction (HER, -0.042 VRHE at 10mAcm-2) and furfural oxidation reaction (FFOR, 0.09 VRHE at 10mAcm-2). As validated by DFT calculations, the dual built-in electric field (BIEF) is elucidated as the driving force behind the enhanced activities, in which Pt─O bonds expedite the HER, while Cu+/Cu0 promotes low-potential FFOR. By coupling the FFOR and HER together, the resulting bipolar-hydrogen production system requires a low power input (0.5072kWhperm3) for producing H2. The system can generate bipolar hydrogen and high value-added furoic acid, significantly enhancing hydrogen production efficiency and concurrently mitigating energy consumption.

The influence of individual physical capabilities for cycling adoption: Understanding its influence and mode-shift potentials

We show the importance of individual physical capabilities for cycling in Switzerland, as well as introducing a routing-tool that integrates these capabilities into the estimation of cycling demand potentials. A binary logit model to predict daily cycling was estimated, using data from the Swiss Health Survey. It is found that the frequency of physical exercise explains most of the variability of the choice to cycle or not. Since previous work in the literature has shown a clear link between exercise frequency and physical strength, one valid, although so far not directly observable hypothesis is that more physical power leads to faster speeds and higher competitiveness of cycling against other modes. The higher power output of E-Bikes and S-Pedelecs further increase cycling potentials in this context. We therefore use data from the Swiss Health Survey to impute cycling potentials for individuals who participated in the Swiss Mobility Microcensus and evaluate mode-shifts potentials to bikes based on travel times of public transport and car trips. Because our router makes use of an elevation-aware physical model, which takes into account bike and cyclist characteristics, such as input power and weight, we also model pedelecs and speed-pedelecs and show how such bike types increase the mode-shift potentials towards bicycles.

Resistive Heating Catalytic Micro-Reactor for Process Intensified Fuel Reforming to Hydrogen

Abstract Process intensification of fuel reforming using micro-reactors has become crucial for feed flexibility in H2 production for fuel cells. In the literature on microreactors, energy supply for these endothermic reactions has faced limitations, relying on external heating, or autothermal operation. This paper explores a novel approach using a thin-film catalytic heater to develop micro-reactors. The study focuses on dry methane reforming in a simplified micro-reactor where thermal energy is supplied through electric resistive heating of a thin carbon sheet with a catalyst applied to its surface. The thin catalytic heated layer inside the reactor minimizes energy losses and the reactor footprint. Power input was varied from 90-225 W to understand its impact on the reactor temperature, CH4 conversion, H2 and CO yields. Fast thermal response times were achieved using the carbon paper as thin film for heating. Ni/MgO impregnated onto carbon paper was utilized as the catalytic heating element which resulted in CH4 conversions greater than 60% at temperature above750 K. Influence of operating conditions such as the input molar ratio of CO2/CH4, and gas hourly space velocity (GHSV) were also investigated to understand the scope of the catalyst in this setup. High GHSVs (592,885 and 948,617 mL/(hr.gcatalyst)) were tested to understand the throughput achievable using this setup. This approach demonstrates improved scope and feasibility for further intensification compared to conventionally heated microreactors. The research paves the way for efficient and compact micro-reactors for fuel reforming processes.

Control strategy for trading off solar power and control input while rendezvous and docking

This paper presents a novel strategy for decoupling the attitude and orbit equations of a CubeSat for rendezvous and docking with an uncontrollable cooperative target. For computing a safe trajectory, the proposed control algorithm takes into account the solar energy received by the CubeSat. The CubeSat is equipped with a thruster for orbit maneuvers, magnetic coils for attitude control, and four fixed single-sided rectangular solar panels. The coupled dynamics arising from the dynamical model of the spacecraft is solved using a novel weighted vector-based approach. This paper presents a linearized nonlinear optimal control problem arising in small spacecrafts while trying to maximize solar energy input in the rendezvous and docking process. An intermediate orbit is defined and used to divide the problem into two different optimal control problems: rendezvous optimization and docking optimization problems. A geometrical approach based on the shape of the chaser and the target is contemplated for collision avoidance while docking. The proposed controller design is modified whenever the sunlight is obstructed by the Earth, and the maneuvering controls are redesigned accordingly for optimal rendezvous and docking. Numerical simulations have been carried out to show the efficacy of the proposed concept for steering the trade-off between solar energy and control input during the rendezvous and docking of CubeSat with a tumbling target.

Power-modulated reconfigurable nonlinear plasmonic devices without DC power supply and feed circuit

High-power electromagnetic (EM) waves can directly modulate the parameters of nonlinear varactor diodes through the rectification and Kerr effects without relying on external sources. Based on this principle, we propose a power-modulated reconfigurable nonlinear device based on spoof surface plasmon polariton (SSPP) waveguide loaded by varactor diodes, without applying DC power supply or feed circuit. Increasing the input power level reduces the effective capacitance of the varactor diode, leading to a blueshift in the cutoff frequency of the SSPP waveguide. This feature can be employed to realize the switching on/off of the input signal depending on the signal power. On the other hand, the transmission state of a low-power signal can be controlled by inputting another independent high-power EM wave simultaneously. Increasing the power of the control wave will enable the low-power signal within a wider bandwidth switched from off to on states. Experimental results are presented to show the excellent performance of the power-modulated reconfigurable SSPP device. This method can reduce the system complexity and provide inspiration for reconfigurable all-passive multifunctional devices and systems.

Dual-Module Ultrawide Dynamic-Range High-Power Rectifier for WPT Systems

Rectifier plays a pivotal role in wireless power transfer systems. While numerous studies have concentrated on enhancing efficiency and bandwidth at specific high-power levels, practical scenarios often involve unpredictable power inputs. Consequently, a distinct need arises for a rectifier that demonstrates superior efficiency across a broad range of input power levels. This paper introduces a high-power RF-to-DC rectifier designed for WPT applications, featuring an ultrawide dynamic range of input power. The rectification process leverages a GaN (gallium nitride) high electron mobility transistor (HEMT) to efficiently handle high power levels up to 12.6 W. The matching circuit was designed to ensure that the rectifier will operate in class-F mode. A Schottky diode is incorporated into the design for relatively lower-power rectification. Seamless switching between the rectification modes of the two circuits is accomplished through the integration of a circulator. The proposed rectifier exhibits a 27.5 dB dynamic range, achieving an efficiency exceeding 55% at 2.4 GHz. Substantial improvement in power handling and dynamic range over traditional rectifiers is demonstrated.

Low-Polarization, Broad-Spectrum Semiconductor Optical Amplifiers.

Polarization-insensitive semiconductor optical amplifiers (SOAs) in all-optical networks can improve the signal-light quality and transmission rate. Herein, to reduce the gain sensitivity to polarization, a multi-quantum-well SOA in the 1550 nm band is designed, simulated, and developed. The active region mainly comprises the quaternary compound InGaAlAs, as differences in the potential barriers and wells of the components cause lattice mismatch. Consequently, a strained quantum well is generated, providing the SOA with gain insensitivity to the polarization state of light. In simulations, the SOA with ridge widths of 4 µm, 5 µm, and 6 µm is investigated. A 3 dB gain bandwidth of >140 nm is achieved with a 4 µm ridge width, whereas a 6 µm ridge width provides more output power and gain. The saturated output power is 150 mW (21.76 dB gain) at an input power of 0 dBm but increases to 233 mW (13.67 dB gain) at an input power of 10 dBm. The polarization sensitivity is <3 dBm at -20 dBm. This design, which achieves low polarization sensitivity, a wide gain bandwidth, and high gain, will be applicable in a wide range of fields following further optimization.

Increase the operational reliability of the electric drive of the weaving machine

The main purpose of this research work is to analyze malfunctions, power consumption, engine overheating and vibrations based on the loadings of electrical circuits through artificial neural networks. The reliability of artificial intelligence systems was proven on the basis of a model-based system depending on the task, and the obtained values were experimentally compared in the electrical operation of existing equipment in general industrial enterprises. An imitation model of the real object was developed. A concept of increasing productivity was set up to identify malfunctions, in contrast to the existing annular method. The article developed an algorithm for increasing the operational reliability of the electrical operation of the weaving machine on the basis of integrated indicators of excitation to determine the probability of failure of electrical operation. The article proposes the possibility of directly processing the diagnostic energy parameters through artificial neural networks. An experimental combination of signals resulted in a model based on input power and torque, and was based on an asynchronous motorized electrical circuit. It has been proven that intellectual reliability can be increased by 3-5% compared to operational reliability in traditional methods.

Computer simulation of open-circuit fault-tolerant boost rectifier based on SPMC

This paper presents a computer simulation of an open-circuit fault-tolerant boost rectifier based on a single-phase matrix converter using MATLAB/ Simulink. The proposed converter employs a fault identification technique to identify the faulty switch by generating a binary code extracted from the output voltage, magnitude of inductor current, and cycle of the input power supply. Upon identifying the faulty switch, the current is redirected to any available path through operational switches by controlling the switching devices. The aim is to ensure uninterrupted power supply from the source to the load. The paper includes a detailed analysis of the fault identification technique and the options for rerouting the current path. The outcomes of this paper are simulated using MATLAB/Simulink.

X‐band high isolation single pole double throw switch based on resonant concept

AbstractUtilizing the 0.25 μm GaN HEMT process, a high‐isolation single pole double throw (SPDT) RF switch has been meticulously designed for the X‐band. The circuit topology employs a series‐shunt configuration to prevent signal leakage, thereby enhancing chip isolation. By incorporating series transistors and shunt inductors, LC resonance is achieved, significantly boosting isolation performance. To optimize port matching and ensure both heightened isolation and minimized insertion loss, inductors are strategically integrated into each port. The inclusion of these lumped inductors contributes significantly to reducing the chip's footprint. Die measurement results demonstrate that across the 8–12 GHz frequency spectrum, insertion loss remains below 1.1 dB, with isolation exceeding 36 dB. Remarkably, at 10.5 GHz, isolation peaks at an impressive 52 dB. Moreover, return loss surpasses 12 dB, and the 0.1 dB compression point input power stands at 43.5 dBm, all achieved within a compact chip area of only 1 mm2.

Mechanical behavior and underlying mechanism of nickel-based superalloy during coupling electrical pulse and ultrasonic treatment

Coupling electric pulse and ultrasonic treatment (CEPUT) is a multi-energy field-assisted forming technology that can improve the forming efficiency of materials. The current research focused on the surface modification of materials by CEPUT, lacking the explanation of its coupling mechanism. In this study, Inconel 718 was adopted as the research object to observe the mechanical behavior and microstructure after CEPUT uniaxial tension experiment. The deformation tendency of grain under coupling multi-energy field was described by analyzing the texture evolution and dislocation morphology. The coupled mechanism of ultrasonic vibration and pulsed current was revealed in CEPUT. The experimental results revealed that there was a nonlinear relationship between the increase of flow stress softening efficiency and the increase of ultrasonic energy density and current density. This phenomenon was the macroscopic manifestation of interference between initial ultrasonic vibration and vibration after energy attenuation, which was related to dislocation slip and recrystallization under coupled multi-field. In addition, more efficient path of dislocation slip was demonstrated through the CEPUT. Among them, ultrasonic vibration caused local resistance to rise at the dislocation source and dislocation pile-up, which strengthened the local Joule heating effect; while the pulse current reduced the activation energy required for dislocation slip near the waning point. This effectively reduced the resistance of dislocation motion near the pinning point, promoting the chance of dislocation crossing and annihilation. Meanwhile, the high temperature caused by pulsed current and local high strain caused by ultrasonic vibration were more favorable to dynamic recrystallization, and the change of grain orientation was more active. The texture strength and grain orientation of the matrix can be effectively controlled by adjusting the input power of ultrasonic vibration and pulsed current.

Enhancing Microwave Freeze Drying: Exploring Maximum Drying Temperature and Power Input for Improved Energy Efficiency and Uniformity

Enhancing Microwave Freeze Drying: Exploring Maximum Drying Temperature and Power Input for Improved Energy Efficiency and Uniformity

Feasibility of solar-powered air-conditioning system using natural refrigerants

This research focuses on low carbon dioxide alternatives to air-conditioning systems that use sustainable and low-power drives. This detailed research takes into account a 1 t capacity air-conditioning system using several refrigerants based on vapor compression. Natural refrigerants should be used instead of all-synthetic ones due to their environmentally favorable properties. Using the CoolPack software platform, a comparative analysis was conducted, and it was found out that the natural refrigerants R290 and R600a exhibited promising results in terms of heat removal from the evaporator (Q e (kW)), heat removal from the condenser (Q c (kW)), work done by the compressor (W (kW)) and coefficient of performance when fixed temperatures of 10°C for the evaporator and 50°C for the condenser were maintained. For the refrigerant R600a, superheating at the compressor (inlet) suction by 5°C was necessary to maintain the running cycle within a practical working zone. Given that a 1 t vapor compression cycle air-conditioning system based on R290 has a compressor work consumption of 640 W, the motor power input for a single-phase induction motor will be roughly 1000 W. In contrast, direct-current (DC) motors require about 30% less power (770 W) and can be readily driven by solar photovoltaic systems (DC). Thus, by presenting solar thermal (required for R600a) and solar photovoltaic power (DC) applications for the natural refrigerants R290 and R600a, the present work will contribute to a sustainable environment and demonstrate the capabilities of dependable operation with optimal power usage.