Electrical Input Research Articles

Characterization of Argon/Hydrogen Inductively Coupled Plasma for Carbon Removal over Multilayer Thin Films

Inductively coupled plasma with an argon/hydrogen (Ar/H2) mixture is a potential solution to many surface treatment problems, especially when encountering carbon contamination in optical X-ray and extreme ultraviolet instruments. Removing carbon contamination on multilayer thin films with Ar/H2 plasma extends the lifetime of the above devices. To further investigate the reaction between plasma and carbon, both optical emission spectroscopy and finite element method with multiphysics fields were employed. The results demonstrated that the intensities of the Balmer lines were in good agreement with the densities of the radical hydrogen atoms from the simulation model, showing a dependence on the mixing ratio. At an electrical input power of 165 W and a total pressure of 5 Pa, an optimum mixing ratio of about 35 ± 5 % hydrogen produced the highest density of hydrogen radicals, coinciding with the highest carbon removal rate. This shows that the carbon removal with Ar/H2 plasma was mainly controlled by the density of hydrogen radicals, and the mixing ratio showed a significant impact on the removal rates.

Operability evaluation of electrical wires and cables subjected to simultaneous fire and current loadings

Introduction. Intumescent coatings are used as a means of protection from heat flows, and their mission is to preserve the operability of wires and cables under fire conditions coupled with simultaneous current loading. However, the effect of insulation destruction on the operability of cables has not been studied for the case of a real fire regime.Goals and objectives. The purpose of the article is to evaluate the experimental operability of electrical wires and cables subjected to simultaneous effects of fire and current loadings.To achieve this purpose, an experimental testing unit was applied to conduct the experimental testing of wires and cables manufactured by various producers. At the same time, the temperature effect of the heated environment on electrical parameters of wires and cables, such as resistivity, inductance and capacitance, was evaluated.Theoretical background. In real fire conditions, dependence of indoor temperature, affecting the heating of cable insulation, differs essentially from the same dependencies in cases of various standard fire conditions. Therefore, the insulation destruction process may occur before the coating intumescence starts.Results and discussion. An experimental testing unit has been developed. This unit allows for the gradual cable heating with a pre-set temperature measurement interval and cable electrical characteristics. Dependencies of resistivity, inductance and capacitance of standard electrical cables on the temperature of the air surrounding the cable are obtained. It’s been discovered that the gradual heating of an electrical conductor or cable eventually leads to a short circuit between its conductive cores and further electric current transmission in electrical wires and cables. It is shown that phases and amplitudes of an input electrical signal can drastically change before the short circuit.Сonclusions. The simultaneous effect of fire and current loadings on standard electrical wires and cables causes a short circuit in the temperature range, in which no intumescence of flame retardant coatings is initiated on the insulation surface. Therefore, these coatings can ineffectively maintain the operability of electrical wires and cables.

Fast luffing control of flexible boom of mobile elevated work platform with uncertain control input gain

In this paper, the dynamic model between input electric signal of hydraulic valve and boom luffing angle is established, and luffing control of flexible boom of mobile elevated work platform (MEWP) is studied. The control input gain for the luffing motion of the MEWP is extremely difficult to solve and varies with boom length, work platform load, and luffing angle. For the variable control input gain, all low-order state quantities, rigid-flexible coupling quantity, and control input are included as the “total disturbance” to be observed. Based on the third-order linear tracking differentiator and the first-order ordinary differential linear equation, an active disturbance rejection controller without control input gain is proposed. With the bandwidth-based parameter settings, the controller only needs to adjust two parameters. As a comparison, this paper analyzes in detail the proposed controllers, the fixed input gain active disturbance rejection controller and the PID controller in terms of tracking error, overshoot, setting time, tracking stability, and robustness.

Electrochemical Control of Cell Metabolism Improves Ethanol Production of Zymomonas mobilis in an Electro-Fermentation System

This study investigated ethanol fermentation by Zymomonas mobilis in an electro-fermentation system (EFS) for efficient alcohol production, which increased the ethanol titer by 12.8% compared to fermentation without electricity input. The underlying mechanism was revealed by exploring the correlation among intracellular redox parameters such as NAD(P)H/NAD(P)+ ratio, total antioxidant capacity, and cell membrane permeability. Transcriptome analysis further investigated that genes related to glucose uptake, ethanol, and succinic acid synthesis were upregulated in the cathode chamber, which promoted ethanol production. Two strategies to enhance EFS were proposed. First, the supplementation of electron shuttles (methylene blue, HNQ) can facilitate electron transport between electrodes and cells. Second, the manipulation of essential electricity-sensing genes (ZMO1211, ZMO1753) amplified the metabolic change. This study showed the possible use of electro-regulation for the efficient production of alcohol in Z. mobilis, which also provided insights into other microbial electrochemical processes in the future.

Intrinsically Synchronized Flexible Visuo‐Haptic Device Operated by Single External Electric Field

AbstractProviding multisensory expression in a synchronized form helps human perception in human‐machine interfaces. Synchronized visuo‐haptic integration has been relatively less explored because the two expressions operate by different principles. This study demonstrates a flexible visuo‐haptic device that generates haptic sensation by electrovibration (EV) in conjunction with the synchronized optical expression by alternating‐current electroluminescence (ACEL). This study suggests material design and electric field modulation that are effective for both EV and electroluminescence (EL). Owing to the structural simplicity of the opto‐electrovibration (O‐EV) device, the EV and EL are intrinsically coupled under single electric field input. A curved O‐EV device simultaneously provides localized frictional tactile expression and localized luminescence on the touch screen. This study opens a simple material approach for multisensory expression that can be useful in soft haptic devices.

Performance study of thermoelectric dehumidification system integrated with heat pipe heatsink

The thermoelectric (TE) cooler is a key component in a TE dehumidifier system. This study represents an experimental investigation on the performance of the TE dehumidifier system integrated with heat pipe heatsink. The system is composed of TE modules, fin heatsink, and heat pipe heatsinks. A rectangular fin heatsink is attached to the cold side of TE modules, while the heat pipe heatsink are mounted to the hot side. Air circulates from the test chamber through the cold-side heatsink to remove moisture, and heat pipe heatsink are used to dissipate heat from the hot side of the TE modules. The effect of relevant parameters such as electrical current input to the TE modules and cold air flow rate on the system's performance is studied. It is found that the cold air flow rate and the electrical current input to the TE modules have the highest impact on the system's performance. Improvements to the coefficient of performance (COP) and cooling capacity of the system can be achieved by using heat pipe heatsinks. Experimental results show that the optimum occurs at 3 A of electrical current input to the TE modules and 1.34 g/s of cold air flow rate with corresponding cooling capacity of 93.1 W, yielding an effectiveness of 2.638E-07 L/J and a coefficient of performance (COP) of 1.1.

Permeate Flux Control of a Conductive Membrane through a PEDOT Redox Switch

A filtration membrane was modified with a conducting polymer coating for the permeate flux control through an electric input. The filtration membrane was first soaked in ferric chloride to load the oxidants on the membrane surface, followed by vapor-phase polymerization of 3,4-ethylenedioxythiophene (EDOT). Optimizations were carried out to balance the filtration performance and the electrical performance of the conductive membrane. Infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the formation of PEDOT coatings on the membrane surfaces. Spectroelectrochemistry was carried out to confirm the reversible redox reactivity of the PEDOT coating when charged and discharged at +1 and −1 V. The permeate flux of the conductive membrane showed a switchable behavior during the PEDOT charging/discharging cycles. The swelling behavior of PEDOT coatings on the membrane in the charging/discharging cycle was confirmed by electrochemical atomic force microscopy with the ingress/egress of dopant ions being responsible for the membrane’s switchable flux properties. The reversible redox switching behavior of the conductive polymer coating on the filtration membrane provides a potential application for permeate flux control through an electric input.

CO2-free hydrogen production via microwave-driven methane pyrolysis

Hydrogen will play an integral role in achieving net-zero emissions by 2050. Many studies have been focusing on green hydrogen, but this method is highly electricity intensive. Alternatively, methane pyrolysis can produce hydrogen without direct CO2 emissions and with modest electricity inputs, serving as a bridge from fossil fuels to renewable energies. Microwaves are an efficient method of adding the required energy for this endothermic reaction. This study introduces a new method of CO2-free hydrogen production via non-plasma methane pyrolysis using microwaves and carbon products of this process. Carbon particles in the fluidized bed absorb microwave energy and create a hot medium (>1200 °C) in contact with flowing methane. As a result, methane decomposes into hydrogen and solid carbon achieving over 90% hydrogen selectivity with ∼500 cumulative hours of experiments This modular pyrolysis system can be built anywhere with access to natural gas and electricity, enabling distributed hydrogen production.

Light‐Triggered and Polarity‐Switchable Homojunctions for Optoelectronic Logic Devices

AbstractSemiconductor homojunctions based on 2D materials are promising candidates for optoelectronic logic devices due to their excellent electrostatic tunability and photoelectric characteristic. However, to reach programmable logic functions, the 2D homojunctions usually suffer from compulsory combinations of electrical and optical inputs. Here, a light‐triggered and polarity‐switchable homojunction made from the vertically stacked MoTe2/CuInP2S6/Au layers in a dual‐floating gate transistor configuration, is demonstrated. Utilizing the band alignment between MoTe2 and CuInP2S6, the photocarriers in MoTe2 can be excited to Au layer across the insulating CuInP2S6 efficiently, serving as floating gate to modulate the polarity of the MoTe2 homojunctions which produce photocurrents simultaneously in photovoltaic mode. A logic gate XOR is achieved in one single device without the need for any applied voltage. Moreover, the devices exhibit both anomalous photoresponse and optical memory behaviors in photoconductive mode. The results provide a potential route for the development of optoelectronic logic devices with fully light‐actuated sensing capability.

Increased light scattering in electrically stimulated beef longissimus muscle fibres contributes to the observed meat colour at grading

Context Electrical stimulation is often used by meat processors to promote fast muscle pH decline and optimise meat quality. Meat colour can be made more acceptable by this process, but how this relates to the microstructure and light-scattering properties of muscle is still unknown. Aims To investigate the effect of electrical stimulation of beef carcasses on the meat colour at grading and the role of the muscle fibre microstructure and light scattering in determining colour differences. Methods Electrical stimulation inputs (electrical stimulation inputs (ES), n = 8; no electrical stimulation inputs (NS), n = 8) were applied to beef carcasses from female cattle of approximately 18–24 months of age. ES comprised electrical immobilisation, bleed rail electric simulation and hide puller rigidity probe, which have all been shown to increase pH fall post-mortem in beef carcasses. pH fall was monitored, the longissimus thoracis was graded at 20–22 h postmortem and measurements were made of colour, muscle-fibre structure and light scattering. Key results The decline of pH was increased in ES relative to NS, as indicated by lower pH at 2 h postmortem (5.83 vs 6.86 respectively, s.e. = 0.068; P < 0.05) as well as changes in both chromatic colour a* b* and achromatic (no colour) lightness in the muscle. Chromatic changes were evident as higher grader colour scores, increased redness (a*) and yellowness (b*) with higher levels of oxymyoglobin and lower levels of deoxymyoglobin. Achromatic changes were evident as increased lightness (L*) and surface reflectance (%R) at the meat surface, and increased global brightness within the muscle fibres. Conclusions Increased lightness and brightness in electrically stimulated muscles were likely to be due to formation of contraction nodes and distortion of muscle fibres, which changed the microstructure of muscle in ways that increased its light-scattering properties. Implications Consideration of the role of light scattering in determining beef colour at grading will advance understanding of how to improve this important quality trait.

Direct field-to-pattern monolithic design of holographic metasurface via residual encoder-decoder convolutional neural network

Complex-amplitude holographic metasurfaces (CAHMs) with the flexibility in modulating phase and amplitude profiles have been used to manipulate the propagation of wavefront with an unprecedented level, leading to higher image-reconstruction quality compared with their natural counterparts. However, prevailing design methods of CAHMs are based on Huygens-Fresnel theory, meta-atom optimization, numerical simulation and experimental verification, which results in a consumption of computing resources. Here, we applied residual encoder-decoder convolutional neural network to directly map the electric field distributions and input images for monolithic metasurface design. A pretrained network is firstly trained by the electric field distributions calculated by diffraction theory, which is subsequently migrated as transfer learning framework to map the simulated electric field distributions and input images. The training results show that the normalized mean pixel error is about 3% on dataset. As verification, the metasurface prototypes are fabricated, simulated and measured. The reconstructed electric field of reverse-engineered metasurface exhibits high similarity to the target electric field, which demonstrates the effectiveness of our design. Encouragingly, this work provides a monolithic field-to-pattern design method for CAHMs, which paves a new route for the direct reconstruction of metasurfaces.

Enhanced IDA-PBC Applied to a Three-Phase PWM Rectifier for Stable Interfacing Between AC and DC Microgrids Embedded in More Electrical Aircraft

To cope with future goal of efficiency, next generation of more electrical aircraft is likely to embed reconfigurable microgrid for the primary electrical distribution. The stability analysis of such time-varying structure is challenging. Conventional linear and nonlinear approaches failed to produce proper answers from a practical point of view. Under conditions, passivity property of each equipment is sufficient to ensure stability of the overall microgrid. But with improper passivity-based control (PBC) design, the passivity property may not be propagated. The main contribution of this article is to propose a modified IDA-PBC procedure that will ensure the passivity properties of the system regarding its electrical inputs and outputs involved in the interconnection. Thus, for electrical microgrids resulting from the interconnection of controllable equipment, input/output filters, and electrical lines, if all the equipment embed the proposed control, the whole microgrid have passive properties and the global stability of the system is ensured. Moreover, this article will also present how to achieve the proposed control with high transient and robust performances thanks to nonlinear parameters’ estimator preserving the passivity proper. Experimental validation of the proposed control in representative electrical conditions is provided.

Minimizing emissions from grid-based hydrogen production in the United States

Low-carbon hydrogen could be an important component of a net-zero carbon economy, helping to mitigate emissions in a number of hard-to-abate sectors. The United States recently introduced an escalating production tax credit (PTC) to incentivize production of hydrogen meeting increasingly stringent embodied emissions thresholds. Hydrogen produced via electrolysis can qualify for the full subsidy under current federal accounting standards if the input electricity is generated by carbon-free resources, but may fail to do so if emitting resources are present in the generation mix. While use of behind-the-meter carbon-free electricity inputs can guarantee compliance with this standard, the PTC could also be structured to allow producers using grid-supplied electricity to qualify subject to certain clean energy procurement requirements. Herein we use electricity system capacity expansion modeling to quantitatively assess the impact of grid-connected electrolysis on the evolution of the power sector in the western United States through 2030 under multiple possible implementations of the clean hydrogen PTC. We find that subsidized grid-connected hydrogen production has the potential to induce additional emissions at effective rates worse than those of conventional, fossil-based hydrogen production pathways. Emissions can be minimized by requiring grid-based hydrogen producers to match 100% of their electricity consumption on an hourly basis with physically deliverable, ‘additional’ clean generation, which ensures effective emissions rates equivalent to electrolysis exclusively supplied by behind-the-meter carbon-free generation. While these requirements cannot eliminate indirect emissions caused by competition for limited clean resources, which we find to be a persistent result of large hydrogen production subsidies, they consistently outperform alternative approaches relying on relaxed time matching or marginal emissions accounting. Added hydrogen production costs from enforcing an hourly matching requirement rather than no requirements are less than $1 kg−1, and can be near zero if clean, firm electricity resources are available for procurement.

An Analysis of Allocative Efficiency of Wheat Growers in Northern Pakistan

For the last couple of years several agricultural and trade experts have been advocating if Pakistan has to compete in the international market for export of agricultural products then it needs to decrease the cost of production. In the light of Agreement on Agriculture of WTO, member countries are required to provide increased market access, decrease domestic support and tariff. These agreements are likely to increase the cost of production of various agricultural products for farmers producing these products, and make international competition tougher for export of agricultural commodities. There are three possible ways to decrease the cost of production—by decreasing cost of inputs, by developing cost effective high yielding technologies or by improving management practices. There is little hope for decrease in the cost of inputs. Over the recent years prices of the petroleum products, were revised upward several times and this trend is likely to continue in future. Similarly, there was increase in the prices of gas, electricity and other agricultural inputs. Historically, in Pakistan, increase in prices of agricultural inputs has been much higher than the increase in prices of agricultural outputs [Pakistan (1988)]. Under these circumstances there is little hope of decease in prices of agricultural inputs. As far as development of new agricultural technologies, particularly high yielding varieties, is concerned it is a long-term process. It takes several years to develop a new variety and in its formal approval for distribution to farmers. Nevertheless, there is room for decreasing cost of producing through improvement in the management practices. When economists talk about improvement in the management practices they talk in terms of ‘technical efficiency’ and ‘allocative efficiency’. Technical efficiency has been defined as firm’s ability to produce maximum output given a set of inputs and technology.

Influence and Mechanism Study of Ultrasonic Electric Power Input on Heavy Oil Viscosity

The reserves of heavy oil are enormous. However, its high viscosity and other characteristics make heavy oil extraction and transportation extremely difficult. Power ultrasonic (US) reforming technology on heavy oil has the advantages of environmental protection and fast results, so it is important to understand the mechanism of ultrasonic reforming. We examine the influence law of the electric power input of the US transducer on the viscosity of heavy oil. Fourier Transform Infrared Spectrometer (FTIR) and Gas Chromatography (GC) are applied to explain the changes in different functional groups, heavy components, and carbon chains before and after US irradiation. The cavitation noise method is also used to study the influences of variance in the intensity of cavitation on the viscosity of heavy oil. The results indicate that the viscosity of heavy oil first decreases, and next increases with an increase in electric power. The functional groups and chromatographic distillation also change in different forms, and with an increase in electric power, the cavitation effect is gradually enhanced. These findings suggest that it is not that the stronger the cavitation, the greater the influence on the viscosity of heavy oil.

On the Application of Support Vector Method for Predicting the Current Response of MR Dampers Control Circuit

Magnetorheological (MR) dampers are controlled energy-dissipating devices utilizing smart fluids. They operate in a fast and valveless manner by taking advantage of the rheological properties of MR fluids. The magnitude of the response of MR fluids, when subjected to magnetic fields, is of sufficient magnitude to employ them in various applications, namely, vibration damping, energy absorption, exoskeletons, etc. At the same time, predicting their response to arbitrary mechanical and electrical inputs is still a research challenge. Due to the non-linearities involved in material properties or the design of the solenoid used for activating the fluid modeling the relationships between the control circuit and the material’s response is complex. Modeling studies can be classified into two categories. The parametric approach requires the knowledge of the internal material’s properties and takes advantage of physics formulas to infer the I/O relationships present in the damper. For comparison, the non-parametric approach harnesses various data mapping techniques to describe the device’s behavior. While the latter is more suited for design studies, the former seems ideal for control algorithm prototyping and the like. In this study, based on the so-called Support Vector Method (SVM), the authors develop a non-parametric model of the control circuit of an exemplary rotary MR damper. To the best of the author’s knowledge, it is the first attempt at an SVM application for MR dampers’ control circuit modeling. Using the acquired experimental data, the I/O relationships are inferred using the SVM algorithm, and its performance is verified across a wide range of excitation frequencies. The obtained results are satisfactory, and the current response of the MR damper is well-predicted. The model performance shows the potential for incorporating it into model-based prototyping and designing of MR control systems.

A novel synthetic jet based heat sink with PCM filled cylindrical fins for efficient electronic cooling

The current electronic industries strive to build an effective cooling solution for modern compact electronic gadgets. The current experimental study, thus, focused on assessing the performance of a heat sink that combines the benefit of active and passive cooling utilizing the synthetic jet and Phase change material (PCM), respectively. The PCM offers a high latent heat value, whereas the synthetic jet induces vortices-based turbulent flow. The cooling characteristics of the heat sink filled with PCM and without PCM are evaluated when subjected to three different operating conditions, which are (i) natural convection, (ii) forced convection using DC fan, and (iii) forced convection using a synthetic jet. The PCM selected for the current study are Eicosane and 1-hexadecanol. It is observed that the inclusion of PCM into the heat sink improved its performance. The multiple-orifice synthetic jet outperformed the single-orifice synthetic jet. The steady-state base temperature attained by multiple orifice synthetic jet is 5 °C lower than that of the synthetic jet with a single orifice. The heat sink cooling performance is best when it is operated at its optimum height measured from the heat sink tip. Heat sink filled with Eicosane subjected to synthetic jet with multiple orifice showed best results, the thermal resistance, heat transfer coefficient and COP is found to be 0.91 K/W, 420.4 W/m2, and 2.1, respectively. The synthetic jet with multiple orifices performed better than the DC (Direct Current) fan operated at the same electrical power input of 0.5 W.

Unidirectional mode selection in bistable quantum cascade ring lasers.

Ideal ring resonators are characterized by travelling-wave counter-propagating modes, but in practice travelling waves can only be realized under unidirectional operation, which has proved elusive. Here, we have designed and fabricated a monolithic quantum cascade ring laser coupled to an active waveguide that allows for robust, deterministic and controllable unidirectional operation. Spontaneous emission injection through the active waveguide enables dynamical switching between the clockwise and counterclockwise states of the ring laser with as little as 1.6% modulation of the electrical input. We show that this behavior stems from a perturbation in the bistable dynamics of the ring laser. In addition to switching and bistability, our novel coupler design for quantum cascade ring lasers offers an efficient mechanism for outcoupling and light detection.

Effects of low-grade gas composition on the energy/exergy performance of a polygeneration system (CH 2 HP) based on biomass gasification and ICE

Bio-hydrogen from sustainable biomass (i.e. agro-industrial residues) gasification can play a relevant role in the hydrogen economy, providing constant hydrogen from renewable sources. Nowadays, most hydrogen production systems integrate one or more water-gas shift (WGS) units to maximize the hydrogen yield that, however, needs additional syngas treatments, investment and operational costs. Besides, different electricity inputs are needed along the process to power the compression of raw syngas, shifted syngas, and pure hydrogen to the desired pressure. This common process integration with WGS generates a kind of off-gas from the hydrogen separation unit whose composition may or may not be suitable for power production, depending on the operating conditions of the gasification unit. In this regard, this work proposes a different approach in which no WGS reactors are involved and the off-gas is used to generate heat and power to provide the energy input needed by the system. In particular, the authors tested the bio-syngas and the corresponding off-gas in a 4-cylinders, spark ignition natural gas internal combustion engine operated in cogeneration mode with the aim to analyse the effect of removing the hydrogen from the original bio-syngas on mechanical/electric and thermal power, on fuel efficiency and CO2 specific emission.

Measurement and characterization of microwave interaction between integrated distributed feedback laser diode and electro-absorption modulator

Integrated electro-absorption-modulated distributed feedback laser diodes (EMLs) are attracting much interest in optical communications for the advantages of a compact structure, low power consumption, and high-speed modulation. In integrated EML, the microwave interaction between the distributed feedback laser diode (DFB-LD) and the electro-absorption modulator (EAM) has a nonnegligible influence on the modulation performance, especially at the high-frequency region. In this paper, integrated EML was investigated as a three-port network with two electrical inputs and a single optical output, where the scattering matrix of the integrated device was theoretically deduced and experimentally measured. Based on the theoretical model and the measured data, the microwave equivalent circuit model of the integrated device was established, from which the microwave interaction between DFB-LD and EAM was successfully extracted. The results reveal that the microwave interaction within integrated EML contains both the electrical isolation and optical coupling. The electrical isolation is bidirectional while the optical coupling is directional, which aggravates the microwave interaction in the direction from DFB-LD to EAM.