Input Power Research Articles

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.

Spherical Fe3O4 morphology modulation for enhancing infrared emissivity and radiant heat dissipation

Radiant heat dissipation has emerged as a critical technique for effective thermal management, offering energy efficiency, cost-effectiveness, and adaptability to various shapes while promoting environmental sustainability. However, the intricate relationship between material structures and emissivity remains inadequately understood. This study primarily utilizes a straightforward and economical solvothermal method to regulate the synthesis of Fe3O4 ferrite, exploring its structural relationship with infrared radiation performance. By adjusting the solvent ratio of ethylene glycol and diethylene glycol in the solvothermal system, we successfully synthesized uniformly dispersed Fe3O4 nanospheres ranging from 10 to 800 nm. Notably, our research revealed a positive correlation between infrared emissivity and the particle size. Submicron hollow spheres with a size of 800 nm exhibit an exceptionally high emissivity of 0.992 within the 8∼13 μm wavelength range. Morphological and size variations induced alterations in lattice strain, oxygen vacancies, and phonon lifetimes, which consequently influencing the lattice vibration absorption and infrared emissivity. Moreover, the device surface with a composite coating formed by combining 15wt% Fe3O4 particles with organic matter, achieves a temperature difference of 17.6 °C under a 4 W input power condition compared to blank device. This finding contributes to further revealing the process of material radiative heat dissipation, driving the application of high-emissivity materials for heat dissipation in high-power electronic devices.

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.

Enhancing Linearity of Light Response in Avalanche Photodiodes by Suppressing Electrode Size Effect

The nonlinear characteristics of avalanche photodiodes (APDs) inhibit their performance in high-speed communication systems, thereby limiting their widespread application as optical detectors. Existing theoretical models have not fully elucidated complex phenomena encountered in actual device structures. In this study, actual APD structures exhibiting lower linearity than their ideal counterparts were revealed. Simulation analysis and physical inference based on GaN APDs reveal that electrode size is a noteworthy factor influencing response linearity. This discovery expands the nonlinear theory of APDs, suggesting that APD linearity can be enhanced by suppressing the electrode size effect. A physical model was developed to explain this phenomenon, which is attributed to charge accumulation at the edge of the contact layer. Therefore, we proposed an improved APD design that incorporates an additional gap layer and a buffer layer to stabilize the internal gain under high-current-density conditions, thereby enhancing linearity. Our improved APD design increases the linear threshold for optical input power by 4.46 times. This study not only refines the theoretical model for APD linearity but also opens new pathways for improving the linearity of high-speed optoelectronic detectors.

Experimental and Numerical Investigation of Single-Phase Liquid Cooling for Heterogeneous Integration Multichip Module

Abstract The variety of new electronic packaging technologies has grown significantly over the last 20 years as a result of market demands for higher device performance at lower costs and in less space. Those demands have pushed for heterogeneous packaging, where computer chips with different stack heights are closely packed, creating nonuniform heat flux and temperature and additional challenges for thermal management. Without implementing an appropriate thermal management strategy for heterogeneous packages, large temperature gradients can be observed within the package, which would increase the thermal stresses on the chip and raise reliability issues. To mimic this real-life scenario of such packaging, an experimental setup was designed and built. The design of the new experimental setup consists of four identical 1.2 cm × 1.2 cm ceramic heaters, each of which is connected to a separate power supply and can reach a heat flux of 140 W/cm2. Accordingly, this mock package is capable of delivering different power levels to mimic different multicore microprocessor conditions. To give the heater the ability to move precisely in the x-, y-, and z-directions, each heater is mounted to an XYZ linear stage. Deionized water (DI) was used as the working fluid, and a pin-fin heat sink was used to run the initial steady-state tests on the experimental rig. The tests showed how different flow rates at a constant fluid temperature and input power affect the temperatures of the heaters and the thermohydraulic performance of the heat sink. In addition, a three-dimensional numerical model has been developed and validated with experimental data in terms of heat sink pressure drop and the temperatures of the heaters.

Static Characteristics and Energy Consumption of the Pressure-Compensated Pump

The motivation of this research was to assess the possibility of speed control for the selected pressure-compensated pump. Measured static characteristics of an axial piston pump with pressure compensation are presented in the paper. Based on these characteristics, the pump efficiencies are determined. The characteristics and efficiencies are determined for the different pump outlet pressures, pump speeds, relative displacements and for the different pressures set at the pressure compensator. In addition, the different methods of pump control were compared. These are displacement control, speed control and both controls. The efficiency of each control method was compared based on the determined mechanical input power at the pump drive shaft. By comparing these control methods, it was found that the combination of both control methods can achieve up to 93% savings of mechanical power in the controlled state (stand-by state). Also, the adverse effects resulting from each control method that reduces pump efficiency were defined.

Experimental exploration of nano-phase change material composites for thermal management in Lithium-ion batteries

The present study reports an experimental investigation carried out for the thermal management of cylindrical lithium-ion battery simulator using aluminium oxide (nano particle)-eicosane (phase change material) composites. The experiment involves varying the power input from 4 to 10 W in 2 W increments and adjusting the weight percentage of nanoparticles (wt %) from 0.5 to 0.9 in 0.2 wt % intervals. The examination of battery temperature evolutions in response to heating power, a comprehensive heat transfer analysis incorporating Nusselt number, determination of maximum temperature difference, thermal resistance analysis, and exploration of temperature variations in the absence of Phase Change Material (PCM) are considered. The results show that increase in weight percentage of alumina nanoparticles in phase change material cannot always improve the thermal performance. The results of the present study give a guideline for designing battery thermal management system. The power levels used in the experiment vary from 4 W to 10 W in steps of 2 W. For a power level of 4 W, the heat flux is 1.088 kW/m2, and for a power level of 10 W, the heat flux is 2.72 kW/m2.

Enhancement of Biogas (Methane) Production from Cow Dung Using a Microbial Electrochemical Cell and Molecular Characterization of Isolated Methanogenic Bacteria

Biogas has long been used as a household cooking fuel in many tropical counties, and it has the potential to be a significant energy source beyond household cooking fuel. In this study, we describe the use of low electrical energy input in an anaerobic digestion process using a microbial electrochemical cell (MEC) to promote methane content in biogas at 18, 28, and 37 °C. Although the maximum amount of biogas production was at 37 °C (25 cm3), biogas could be effectively produced at lower temperatures, i.e., 18 (13 cm3) and 28 °C (19 cm3), with an external 2 V power input. The biogas production of 13 cm3 obtained at 18 °C was ~65-fold higher than the biogas produced without an external power supply (0.2 cm3). This was further enhanced by 23% using carbon-nanotubes-treated (CNT) graphite electrodes. This suggests that the MEC can be operated at as low as 18 °C and still produce significant amounts of biogas. The share of CH4 in biogas produced in the controls was 30%, whereas the biogas produced in an MEC had 80% CH4. The MEC effectively reduced COD to 42%, whereas it consumed 98% of reducing sugars. Accordingly, it is a suitable method for waste/manure treatment. Molecular characterization using 16s rRNA sequencing confirmed the presence of methanogenic bacteria, viz., Serratia liquefaciens and Zoballella taiwanensis, in the inoculum used for the fermentation. Consistent with recent studies, we believe that electromethanogenesis will play a significant role in the production of value-added products and improve the management of waste by converting it to energy.

Properties of the ionization region in a magnetron plasma at gas-aggregation-source-relevant pressure regime explored using a global model

A global (volume averaged) model is developed for the ionization region (IR) of a gas aggregation source (GAS) plasma. The case of using argon gas and a copper target is considered. The model describes the densities of thermal and hot electrons, argon and copper ions, copper atoms and argon atoms in different excited states, the temperature of thermal electrons, the kinetic energies of the ions with which they bombard the target, the sheath width near the target cathode and the energy fluxes by different plasma species to a planar probe in the IR. Also, the fraction of input power is estimated which is dissipated to energize the thermal electrons in the IR. The gas discharge properties are analyzed for different pressures and discharge currents under conditions corresponding to the experimental conditions (Gauter et al 2018 J. Appl. Phys. 124 073301). The calculated pressure- and current-dependences for the GAS properties are used to explain the measured dependences for the deposition rate and the energy flux. It is found that the deposition rate increases with increasing discharge current because of the growth of currents of copper atoms and ions. With increasing pressure, the rate decreases due to drop of the densities of copper atoms and ions because of decreasing the kinetic energies of the ions with which they bombard the target. The model indicates that in the gas-aggregation-source relevant pressure regime, the energy flux by ions dominates over the energy fluxes of other plasma species.

Editorial: Driving innovation: harnessing the power of patient input in research

Editorial: Driving innovation: harnessing the power of patient input in research

Absolute measurement of vacuum ultraviolet fluxes from inductively coupled plasmas via metal surface photoemission currents

Quantifying vacuum-ultraviolet (VUV) fluxes typically requires vacuum-compatible spectrometers and is often associated with significant cost and effort. A simple technique for the absolute measurement of local VUV fluxes from plasmas using the photoemission from a set of coated metal plates, is described. The radiant power from a 13.56 MHz hydrogen plasma operating at 40–87 mTorr and with an radio frequency (RF) input power from 100 to 120 W was investigated by irradiating a set of 2 cm diameter Au, Ag and Cu plates. The variation in photoemission currents was compared with the photoelectric yield curves to estimate the absolute flux incident on the surfaces in the 113–190 nm range. The measured fluxes were found to have an uncertainty of 5%–30% when compared with the VUV spectrometer measurements. The VUV output power was found to have a maximum at a pressure of 70–80 mTorr and to increase with RF power. In all cases, the VUV output power was measured to be approximately 12%–16% of the RF input power to the matching network, in good agreement with spectroscopy results.

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

Abstract ELM frequency (fELM ) 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 power ratio between neutral beam injection (NBI) and ECH (PNBI/PECH ) is kept at ~1. Performance of the pedestal in the ECH heated cases is compared with a pure NBI reference discharge while keeping the total input power constant. All these discharges are performed at balanced input torque condition. Further, in the pure NBI discharge strong decoupling of the peeling-ballooning (PB) thresholds is observed. The PB decoupling is preserved when ECH is deposited at ρ = 0.8 and PNBI/PECH ~1, while the thresholds manifest a closed stability boundary when ECH is deposited at ρ = 0.4. 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 (DBS) and magnetic diagnostics for the ECH at 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 fELM . 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 ρ = 0.8 case is more susceptible to ITG/TEM turbulence.

A CMOS Rectifier with a Wide Dynamic Range Using Switchable Self-Bias Polarity for a Radio Frequency Harvester

This paper presents a switchable self-bias polarity on the CMOS complementary cross-coupled rectifier to improve the rectifier’s power conversion efficiency (PCE) profile across a wide input power (PIN) dynamic range. This technique achieves this by adaptively switching the polarity of the bias on the n-MOS to overdrive it during low PIN to improve the sensitivity and underdrive it during high PIN to suppress the shoot-through loss and the unnecessary discharge of the coupling capacitor. The popular self-biased p-MOS is also implemented further to reduce the reverse conduction loss during high PIN. The proposed rectifier is fabricated in a 40 nm CMOS process and operates at 900 MHz with a load of 50 kΩ. The proposed rectifier achieved a peak PCE of 72.1% and maintained a 0.8xPCEPEAK across a PIN dynamic range of 11.5 dB.

Theoretical and Experimental Research on Thermal Dynamic Characteristics of Single-Screw Compressor with a New Composite SLIDE Valve

Based on the single-screw compressor (SSC) structure, a new type of composite slide valve (CSV) has been proposed and designed, featuring internal volume ratios of 2.8, 3.9, and 5.6 and operating under a partial load of 35%. The theoretical model describing the dynamic features and thermodynamic performance of the SSC with CSV has also been built. The pressure ratio of the experimental system can be adjusted from 3.3 to 7.8, and the experimental results demonstrate the CSV’s effective performance. The deviations between the calculated and measured results for volume ratio and input power are 3.33–9.08% and 0.32–8.03%, and the deviations for heating capacity and adiabatic efficiency range from 0.92–8.73% to 2.09–9.67%, respectively. The introduction of the CSV offers a novel approach to enhancing SSC efficiency. Both the theoretical and experimental findings lay a foundation for future optimization and design improvements in variable load and internal volumetric ratio single-screw compressors.

Degradation mechanism and decomposition of sulfamethoxazole aqueous solution with persulfate activated by dielectric barrier discharge

ABSTRACT The present study focused on the degradation of sulfamethoxazole (SMX) aqueous solution and the toxicity of processing aqueous by the dielectric barrier discharge (DBD) activated persulfate (PS). The effects of input voltage, input frequency, duty cycle, and PS dosage ratio on the SMX degradation efficiency were measured. Based on the results of the Response Surface Methodology (RSM), SMX degradation efficiency reached 83.21% which is 10.54% higher than that without PS, and the kinetic constant was 0.067 min−1 in 30 min when the input voltage at 204 V (input power at 110.6 W), the input frequency at 186 Hz, the duty cycle at 63%, and the PS dosage ratio at 5.1:1. The addition of PS can produce more active particles reached 1.756 mg/L (O3), 0.118 mg/L (H2O2), 0.154 mmol/L (·OH) in 30 min. Furthermore, the DBD plasma system effectively activated an optimal amount of PS, leading to improved removal efficiency of COD, and TOC to 30.21% and 47.21%, respectively. Subsequently, eight primary by-products were pinpointed, alongside the observation of three distinct pathways of transformation. Predictions from the ECOSAR software indicated that most of the degradation intermediates were less toxic than SMX. The biological toxicity experiments elucidated that the treatment with the DBD/PS system effectively reduced the mortality of zebrafish larvae caused by SMX from 100% to 20.13% and improved the hatching rate from 55.69% to 80.86%. In particular, it is important to note that the degradation intermediates exhibit teratogenic effects on zebrafish larvae.

Design of high‐efficiency rectenna for microwave power wireless transmission systems

AbstractRadio power transmission is studied herein. A rectenna with high‐efficiency microwave power transmission is proposed. Improvement on the traditional Yagi antenna structure is implemented by using a rectenna. In this design, the antenna is fed by a coplanar waveguide, and the impedance bandwidth is widened by adding a set of radiation dipoles. A set of parasitic directors is used to enhance the directionality of the antenna. A rectifier circuit based on a power‐recovery network is designed using an open branch‐line network with harmonic rejection characteristics as a low‐pass filter. The rectifier network topology is adopted with a diode in parallel connection to increase the output voltage of the circuit. The reflected power generated by the impedance mismatch can be recycled by the power‐recovery network. Thus, the rectifying efficiency can be improved. Finally, experimental data show that the radiofrequency–direct current power conversion efficiency of the rectenna can be as high as 77.5% at the operating frequency 2.45 GHz and the input power 12 dBm. The proposed rectenna can be potentially used for the power supply of various wireless sensor nodes with high efficiency.

Femtosecond-laser-inscribed cladding waveguides in KTiOPO4 crystal for second-harmonic generation and Y-branch splitters

In this study, the fabrication of straight- and Y-branch-cladding waveguides in KTiOPO4 crystals using femtosecond laser-direct writing is described. The second-harmonic generation (SHG) of green light through the cladding waveguides was realized using a pulsed-wave pump at 1,064 nm. The guiding properties of straight-cladding waveguides fabricated by varying the laser-writing conditions were investigated. The minimum insertion loss was approximately 2.0 dB at 1,064 nm. Confocal micro-Raman spectroscopy was used to investigate the lattice micro-modifications. The maximum SHG conversion efficiency of the straight-cladding waveguide reached 31.4% with a maximum output power of 79.29 mW from an input power of 252.6 mW. The performances of the Y-branch splitters with splitting angles ranging from 0.5° to 2.6° were characterized at 1,064 nm, showing excellent properties, including symmetrical output ends and approximately equal splitting ratios. An SHG conversion efficiency of 13.4% and maximum output power of 33.63 mW were achieved in the Y-branch splitter with a splitting angle of 1.0°. These findings support potential applications in constructing compact-frequency converters by using femtosecond laser-written KTiOPO4 depressed-cladding waveguides.

Assessment of using different ozone-friendly R22 alternative refrigerants in residential air conditioners in a high-ambient temperature country

The performance of a vapor compression refrigeration system (VCRS)-based residential air conditioner operating in a high-ambient temperature (HAT) country was investigated using six zero-ODP (ozone depletion potential) refrigerants as replacements to R22. The non-flammable alternative refrigerants considered in the present research were R134a, R404A, R407C, R410A, R448A, and R507A. Using the basic conservation laws, the VCRS was modeled during steady-state operation and solved using engineering equation solver (EES) software. Coefficient of performance (COP), pressures and temperatures at compressor suction and discharge, Global Warming Potential (GWP), critical pressure and temperature, compressor pressure ratio, volumetric cooling capacity (VCC) specific cooling capacity (SCC), and refrigeration effect were utilized as assessment criteria for the alternative refrigerants considered. From these refrigerants, the highest values of suction pressure, discharge temperature, and condenser pressure were attained by R410A. In addition, the discharge temperatures for all refrigerants, except R134a, were all higher than their corresponding critical values, causing a quicker drop in the VCRS’s performance. As an alternative refrigerant, R407C showed the highest SCC of 141.0 kJ/kg followed directly by 139.2 and 138.0 kJ/kg for R410A and R448A, respectively. A reverse trend was found for VCC with respective values of 4722 and 3775 kJ/m3 for R410A and R448A. Lower volume flow rates and smaller-sized compressors are expected for higher VCC refrigerants. The same trend was found for the compressor’s specific work input and condenser’s specific heat transfer with values of (51.14, 46.82, and 45.38 kJ/kg) and (190.3, 187.8, and 183.4 kJ/kg) for R410A, R407C, and R448A, respectively. For applications in HAT countries, larger condenser’s specific heat transfer makes the refrigerant more applicable. Conversely, with respect to COP, refrigerant R134a with a value of 3.075 was the superior alternative followed by R448A and R407C with respective COPs of 3.042 and 3.011. Based on the overall assessment in terms of environmental obligation, COP, compressor input power, refrigerant flow rate required, and all the evaluations made in this research, refrigerant R448A was recommended as the most appropriate substitute to R22 which can effectively be used in residential air conditioners in a HAT country.

Thermal defocus-free Hartmann Wavefront Sensors for monitoring aberrations in Advanced Virgo

Earth-based gravitational waves interferometric detectors are shot-noise limited in the high-frequency region of their sensitivity band. While enhancing the laser input power is the natural solution to improve on the shot noise limit, higher power also increases the optical aberration budget due to the laser absorption in the highly reflective coatings of mirrors, resulting in a drop of the sensitivity of the detector. Advanced Virgo exploits Hartmann Wavefront Sensors (HWSs) to locally measure the absorption-induced optical aberrations by monitoring the optical path length change in the core optics. Despite the very high sensitivity of Hartmann sensors, temperature fluctuations can cause a spurious curvature term to appear in the reconstructed wavefront due to the thermal expansion of the Hartmann plate, that could affect the accuracy of the aberration monitoring. We present the implementation and validation of a control loop to stabilize the Advanced Virgo HWS temperature at the order of ΔT⩽0.01 K, keeping the spurious curvature within the detector’s requirements on wavefront sensing accuracy.