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This study aims to explore the channel patterns and the characteristic parameters of the zigzag microchannel based on microfluidic paper-based analytical devices (μPADs), in which the mixing efficiency and speed can be greatly enhanced. Better mixing of the solutions was obtained by adding a simple directing electric field to the optimized structure of the zigzag microchannel on paper-based chips instead of the traditional complex devices. A higher mixing efficiency was reached when the direct-current (DC) power supply reached 20 V. Meanwhile, a piezoelectric transducer (PZT) driver was used in the mixing experiment with the paper-based zigzag microchannel. The results show that the mixing efficiency reached a maximum value when the input voltage and frequency were 30 V and 150 Hz, respectively. These paper-based devices meet the requirements of the biochemical analysis field because they are low cost, easy to operate, and have high efficiencies, giving them good prospects for future applications. [ABSTRACT FROM AUTHOR]

Renewable energy resources can potentially solve global warming issues that arise from the large amounts of CO2 emissions from currently used energy resources. Microbial fuel cells (MFC) can produce electrical energy from the environment, making them attractive for energy harvesting. The structures and mechanisms of MFC have been studied for a few decades, and the performance of MFC has constantly been improved using new materials in the devices or by interacting microbial species on the anode chamber of MFC. However, the ecological phenomena, especially inter‐species interactions, within the microbial community in MFC are still largely unknown. Analysis and control of the microbial community have high potential to improve the MFC performance. In this idea paper, I have provided ways to analyze the species interactions in the microbial communities of MFC: (a) empirical dynamic modeling for detecting species interactions in MFC, and (b) network analysis to explore the core microbe species in the MFC. The interaction analyses of the microbial communities in MFC devices can potentially contribute to improving the performance of MFC. [ABSTRACT FROM AUTHOR]

In this work, a handheld paper-based bipolar electrode-electrochemiluminescence (P-BPE-ECL) system has been proposed. In this system, a rechargeable battery is used for power supply, while a smartphone is applied for read-out of ECL signal. For the P-BPE-ECL, the carbon ink-based BPE and driving electrodes are screen-printed on the paper, and the wax-screen-printing is employed to fabricate microfluidic channels on electrode-patterned paper. Moreover, the luminol/H 2 O 2 -based ECL reaction is applied to demonstrate the quantitative ability of the P-BPE-ECL system. Under optimized conditions, H 2 O 2 can be determined over the range of 5–5000 μM, with a detection limit of 1.75 μM, and relative standard deviations (RSDs) of 7.59%, 3.82% and 4.93% for 10, 100 and 1000 μM H 2 O 2 (n = 5). Thus, this system has an acceptable sensitivity, dynamic range, stability and reproducibility. Finally, the applicability of the P-BPE-ECL system is demonstrated for detection of glucose in phosphate buffer solution (PBS) and artificial urine (AU) samples, with the detection limits of 0.017 mM and 0.030 mM, respectively. Moreover, the P-BPE-ECL system has the ability to perform high-throughput detection of glucose. Therefore, the developed system can provide a new platform for many applications such as point-of-care testing, health diagnosis and environmental monitoring. [ABSTRACT FROM AUTHOR]

For high-power quasi-continuous laser drivers, the switched pulse power supply (PPS) is a promising technique due to its higher efficiency when compared with linear drivers. However, there are some digital control challenges with high precision, fast response and zero overshoot during the flat-top current stage. To promote the use of a switched PPS, this paper proposes a digital control strategy based on predictive current control under a multiphase PPS converter circuit. The key of the proposed control strategy is that predictive inner current control is only used for the master phase circuit. Meanwhile, the current sharing control is used for balancing the phase currents, and the setting outer current controller is used for keeping the whole converter control system stable and robust. Furthermore, to obtain fast and precise current tracking, a predictive average current control independent from the load values is derived. Moreover, a reducing gain method is applied to guarantee the stability of the inner current control. When compared with the conventional multiphase control, the proposed strategy possesses a faster dynamic response and a higher accuracy. In addition, it is more flexible under digital control implementation. A 360 W dual-interleaved PPS prototype is utilized for verifying the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

The Buck converter is a commonly used voltage regulator (VR) structure that supplies power to the load devices and responds to load transients. In most of the applications, the VR is controlled by voltage or current mode control, and some nonlinear approaches are used to improve the transient response which brings more complexities to the closed loop design. To achieve a fast transient response without over-regulation under a load step transient, this paper proposes a digital single-cycle regulation (SCCR) controller, which comprised a fast path, a slow path, and a neutralization path. Unlike the conventional PID control, the neutralization path of the SCCR controller is used to offset the excessive energy change in the first cycle after a load step occurs, which makes the inductor current reach its new static condition in a shorter period of time. The mathematical model of the SCCR control is established in this paper and a scanning algorithm is proposed for the design of the compensator parameters. Experimental results are presented to verify the improvement of the transient response when compared to the conventional and nonlinear PID control, the recovery time is decreased by 64.3% and 43% for load step-up and step-down when compared with nonlinear PID control. [ABSTRACT FROM AUTHOR]

This paper exploits smart inverters of distributed energy resources (DERs) for the mitigation of fault-induced delayed voltage recovery (FIDVR). According to the IEEE Standard 1547-2018, smart inverters with voltage ride-through and var injection capabilities are promising technologies for mitigating FIDVR. This paper quantitatively investigates the effectiveness of smart inverters for FIDVR from a system-wide perspective. It shows that the penetration of smart inverters and induction motors are important factors affecting mitigation success. In addition, the over-voltages at the end of FIDVR due to load disconnections can be prevented with coordinated control of DERs and automated switching capacitors. The control scheme of smart inverters used for FIDVR is extended from the distributed volt/var droop control to include low- and high-voltage ride-through capabilities. The IEEE 13-bus feeder, the 8500-node test feeder, and the IEEE 390-node low-voltage network test system are used to illustrate the impact of DER penetration. For example, one can determine the residential air conditioner penetration level (for a given system at certain DER penetration level) that makes a system susceptible to FIDVR. The effects of solar intermittency are also studied. [ABSTRACT FROM AUTHOR]

As the world No.1 emitter of carbon dioxide (CO2), China has made up its mind to act on climate change. After trials in six pilot regions- Shenzhen, Shanghai, Beijing, Guangdong, Tianjin, Hubei, and Chongqing- a nationwide ETS has been established and implemented in line with the Thirteenth Five-Year Plan period (2016–2020). This paper simulates the effect of a national ETS in China using GTAP 9.1 database and a revised GTAP-E model. The simulation results show that the ETS is very effective in emissions reduction but will cause a mild economic contraction. At the sectoral level, the energy and resource sectors and energy intensive sectors are to be hit hard while most other sectors are affected negatively but insignificantly. [ABSTRACT FROM AUTHOR]

A low power consumption is an essential issue for all of the electrical products, especially for the wearable electrical products, and the liquid crystal displays. This manuscript proposed a single polarized light emitting diode (LED) chip which is used for a direct back light unit for LCD. A wire grid polarizer and a meta‐ surface textures are set on the top and bottom of the LED chip in order to obtain a high polarization and transparency. After optimization the potential parameters, the transmittance of TM and the polarization are 93.71% and 99.3% respectively. It can replace the normal LED of direct back light unit in order to obtain a high efficiency of 20% improvement, by comparing liquid crystal display using the APF polarizer. It can be used for reducing power consumption and supply dependence, as well as the cost of displays. [ABSTRACT FROM AUTHOR]

With the continuous development of new energy power generation and smart grid, Power Electronic Transformer (PET) has a good prospect for development because of its remarkable advantages. Based on the topology of AC/DC/AC, the modulation strategy with dual-PWM (Pulse Width Modulation) is adopted to control the operation of power electronic transformers in this paper. The PET structure consists of three units: importation portion, isolation portion and output portion. Model building and analyzing both at the input and output terminals are achieved step by step. And the simulation of the whole PET system with dual-PWM is accomplished with MATLAB/ Simulink. The simulation results show the control system stability and output voltage regulation precision are improved with feed-forward voltage decoupling vector control system. The correctness and effectiveness of the control strategy are demonstrated through the simulation. PETs play an important role in enhancing power supply reliability for Power Grid and promoting the new energy power generation development. [ABSTRACT FROM AUTHOR]

This paper proposes a carbon nanotube FET (CNFET)-based ultra-low-power dual- V DD ternary half adder (HA) circuit. The proposed design utilizes both the available ternary power supply voltages ( V DD & V DD / 2 ) and prevents direct path between the power supplies and ground, thus significantly reducing the power dissipation as compared to the conventional designs. The performance of the proposed CNFET dual- V DD HA has been compared with the same circuit implemented with 45 nm MOSFETs and also with other CNFET-based state-of-the-art HA designs proposed in the literature. The proposed HA consumes merely 86 nW of power which is significantly lesser (66–90% lower) than the power required by other ternary HA designs, and also exhibits 69–91% lower delays. The overall PDP of the proposed HA circuit is merely 4–11% of the PDP of corresponding CMOS ternary HA and other benchmarked CNFET HA designs. [ABSTRACT FROM AUTHOR]

Based on recent developments, hydrogen-based combustion systems have received wide attention, mainly due to increasing awareness of enduring environmental pollutants and restricted access to fossil fuel usage. In the relevant literature, there are evidences of the possibilities on the partial or total replacement of hydrocarbon fuels with hydrogen in power plants and vehicle engines. However, some challenging issues particularly on hydrogen storage are remained to be resolved. This paper reviews and comments on addressing the effectiveness of hydrogen-enrichment on the engines and burners׳ performance includes the chemical kinetic analysis, the flame propagation structures and the effects of inhibitors on global burning velocity of hydrogen–hydrocarbon mixtures in different combustion bombs, chambers and vessels. It is recommended that future researches should aim towards the different application of hydrogen–hydrocarbon i.e. transportation and clean energy carrier. [ABSTRACT FROM AUTHOR]

Power capacitors are highly reliable due to their completely enclosed configuration. They are relatively trouble-free over the long term. However, their dielectric strength can be reduced due to some stresses, including overvoltage application or thermal degradation of the insulation material during long periods of operation; these events can result in dielectric breakdown of capacitors in extreme cases. Since almost all power capacitors with oil-impregnated paper have been operated for more than twenty years, some kind of failure should be expected. To prevent these incipient accidents, it is important to examine the insulation deterioration mechanism and evaluate the degree of deterioration before capacitor breakdown. To establish a diagnostic method of deterioration of the capacitors with oil-impregnated paper, we have conducted thermally and electrically accelerated deterioration tests and investigated the changes of their characteristics. Based on the experimental results we obtained, it can be concluded that the behavior of the oil-dissolved gases can be used as a useful index to diagnose the insulator deterioration of these capacitors. [ABSTRACT FROM AUTHOR]

In order to address the planning problem of integrated energy system (IES) under the goal of "dual-carbon", this paper proposes a multi-objective planning method for IES with carbon trading mechanism based on CVaR (Conditional Value at Risk). Firstly, this paper establishes the IES energy supply equipment model and the improved stepped carbon trading model. Moreover, this paper proposes the IES multi-objective two-layer planning model based on the consideration of carbon trading cost. The upper layer of the planning model takes the optimization of economy and environmental as the goal to realize the rational planning of the integrated energy system. The lower layer model takes the minimum operating cost as the goal to optimize the system operating conditions and verify the rationality of the planning results. Then, the uncertainty model based on mean-CVaR is established for the uncertainty of carbon trading price and new energy output in the planning process. Finally, this paper sets up cases and solves the model using non-dominated sorting genetic algorithm-II (NSGA-II) and solver, which shows that the proposed method can realize the IES low-carbon planning while guaranteeing the economy. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-efficiency (2 orders of magnitude), reproducible (RSD 2.5%), fast (within 2 min) parallel electric stacking PAD was created; • The wet real-time photographic colorimetry results of the parallel PAD system are insensitive to the changes of light conditions; • On-line colorimetric detection of pigments in drinks and off-line MS/MS detection of serum amino acids are used to demonstrate their applicability. A microfluidic paper-based analytical device (PAD) with both pre-concentration and parallel operation functions is of great promise for sensitive and high throughput detection. In this paper, a fast and multiplexed PAD was designed based on wax-screen-printing with glass fiber paper substrate and validated by image-based colorimetry. Driven by the same DC power supply, parallel electrokinetic stacking with the PAD of 8 channels can be completed within 2 min, and each channel can be loaded with different samples. Enrichment factor of 2 orders of magnitude was demonstrated with RSD below 2.5% between the chips and the channels of a chip. Reproducible and multiplexed stacking operations of this PAD provide a solid foundation for online calibration and sample detection on the same chip at the same time. Applications of this PAD was demonstrated by online colorimetric detection of food pigments from beverages and offline MS/MS detection of amino acids from a serum sample. Besides high-throughput and sensitive point-of-care test detection, this PAD method could also find applications for efficient pre-separation and pre-concentration of complex samples. [ABSTRACT FROM AUTHOR]

Summary: The aim of the paper is to provide seamless transition between the grid connected to an islanded mode and vice versa by switching the control of the load connected VSC (LCVSC) ensuring uninterruptable power supply. In the grid connected mode, a TOQSG (third‐order quadrature signal Generator) based method is applied for power quality improvement at the grid. During synchronization, the LCVSC adapts the phase and frequency of the grid voltage for seamless transition. The paper presents a smart microgrid, which manages the mode of operations and generation of reference signals for the smooth operation. The proposed approach is validated through test results. The grid current and CCP voltage distortion are as per the IEEE‐519 and the IEEE‐1547 standards. [ABSTRACT FROM AUTHOR]

The shift towards green aviation necessitates the adoption of all‐electric aircraft, marking an essential trend in the aviation industry. Distributed propulsion systems enhance aircraft flexibility and reliability, synchronously reducing performance demands and costs of single propulsion units compared to centralized propulsion system. The high reliability and lightweight characteristics of brushless DC motors have made them increasingly popular in distributed propulsion systems. Despite its advantage which helps to build efficient aircraft aerodynamic layout, there are more cables in the distributed propulsion system, which accounts for most of the weight of the aircraft. To address this, all‐electric aircraft utilizes high‐voltage power supply to reduce the current, so it uses SiC MOSFETs as power devices to improve its efficiency and heat dissipation. The speed controller in all‐electric aircraft determines the efficiency and reliability of the propulsion unit. However, the traditional high‐voltage speed controller poses challenges for aircraft maintenance because of high cost. Therefore, this paper emphasizes the significance of designing a low‐cost, high‐performance speed controller for all‐electric aircraft. Challenges such as circuit interference, battery voltage fluctuation, and sampling noise affecting the high‐voltage controller during operation are solved, respectively. First, to address the likelihood of mutual interference in the bridge arm, a self‐bootstrapping voltage reduction drive mode is designed to turn off SiC MOSFET and enhance circuit anti‐interference. Second, to solve the challenge of wide battery voltage fluctuation range and inconsistent controller output, an adaptive pulse width modulation (PWM) regulation mode for battery voltage is proposed, ensuring stable controller output. Finally, to counteract the impact of the comparator threshold on zero‐crossing sampling, an electrical angle delay method based on delay compensation is designed to improve the efficiency of the brushless DC motor during operation. Experimental results show that the three solutions proposed in this paper are helpful to improve the anti‐interference, stability, and efficiency of the controller in the high‐voltage distributed electric propulsion system and contribute to reduce the cost and weight in the propulsion unit. [ABSTRACT FROM AUTHOR]

With distributed energy sources connected to the distribution grid on a large scale for distributed photovoltaic power randomness, this paper proposes a flexible interconnection system optimization operation strategy. First, the virtual synchronous control technology is improved to improve the DC bus voltage stability; second, it analyzes the system operation mode to judge the output logic of PV and storage units, takes DC bus power balance as the underlying logic, and puts forward the power coordination optimization strategy and fault power supply restoration strategy with full consideration of factors such as the load balance degree of the distribution station area, the economic operation of the main transformer, and the amount of power lost in the faulty station area. It also establishes a multi-objective optimization model to obtain the power commands of each port and achieves the power flexibility mutualization of the flexible interconnected system through the accurate regulation of the soft normally open point (SNOP). Finally, a simulation model of the flexible interconnection system is built using MATLAB/Simulink to verify the effectiveness of the proposed optimization strategy. [ABSTRACT FROM AUTHOR]

Accurate short-term load forecasting (STLF) plays an essential role in sustainable energy development. Specifically, energy companies can efficiently plan and manage their generation capacity, lessening resource wastage and promoting the overall efficiency of power resource utilization. However, existing models cannot accurately capture the nonlinear features of electricity data, leading to a decline in the forecasting performance. To relieve this issue, this paper designs an innovative load forecasting method, named Prophet–CEEMDAN–ARBiLSTM, which consists of Prophet, Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN), and the residual Bidirectional Long Short-Term Memory (BiLSTM) network. Specifically, this paper firstly employs the Prophet method to learn cyclic and trend features from input data, aiming to discern the influence of these features on the short-term electricity load. Then, the paper adopts CEEMDAN to decompose the residual series and yield components with distinct modalities. In the end, this paper designs the advanced residual BiLSTM (ARBiLSTM) block as the input of the above extracted features to obtain the forecasting results. By conducting multiple experiments on the New England public dataset, it demonstrates that the Prophet–CEEMDAN–ARBiLSTM method can achieve better performance compared with the existing Prophet-based ones. [ABSTRACT FROM AUTHOR]

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In the context of global climate change, energy conservation and greenhouse effect gases (GHG) reduction are major challenges to mankind. The forestry-pulp and paper industry is a typical high energy consumption and high emission industry. We conducted in-depth research on the energy flows and carbon footprint of the forestry-pulp paper industry. The results show that: (1) The main sources of energy supply include external fossil fuel coal and internal biomass fuel black liquor, which supply 30,057,300 GJ and 14,854,000 GJ respectively; in addition, the energy produced by diesel in material transportation reaches 11,624,256 GJ. (2) The main energy consumption processes include auxiliary engineering projects, material transportation, papermaking, alkali recovery, pulping and other production workshops. The percentages of energy consumption account for 26%, 18%, 15%, 10% and 6%, respectively. (3) The main sources of carbon include coal and forest biomass, reaching 770,000 tons and 1.39 million tons, respectively. (4) Carbon emissions mainly occur in fuel combustion in combined heating and power (CHP) and diesel combustion in material transportation, reaching 6.78 million tons and 790,000 tons of carbon, respectively. (5) Based on steam and electricity consumption, the indirect carbon emissions of various thermal and electric energy production units were calculated, and the key energy consumption process units and hotspot carbon flow paths were further found. This research established a theoretical and methodological basis for energy conservation and emission reduction. [ABSTRACT FROM AUTHOR]

In order to give full play to the energy supply potential of distributed energy resources, this paper studies the scheduling optimization of CHP-VPP. First, the CHP unit and various distributed energy sources are aggregated into VPP. Carbon recycling and utilizing are realized through carbon capture and power-to-gas devices. At the same time, carbon storage and hydrogen storage devices are added to decouple carbon capture and P2G procedures. Then, the risk of VPP real-time scheduling is quantified through uncertainty scenario generation and CVaR. Finally, with the goals of operating cost, carbon emission, and operation risk, a multi-objective stochastic scheduling optimization model of VPP is constructed, and the subjective and objective ensemble weighting method is used to solve the problem. The example results show that the proposed method can boost the wastage of wind and photovoltaic power, and also lower the carbon emissions of VPPs. [ABSTRACT FROM AUTHOR]

This paper presents an integrated coil design method for inductive power-transfer (IPT) systems. Because a medium-voltage direct current (MVDC) distribution network transmits power at relatively high voltages (typically in the tens of kV), accurate fault diagnosis using high-performance sensors is crucial to improve the safety of MVDC distribution networks. With the increasing power consumption of high-performance sensors, conventional power supplies using optical converters with 5 W-class output characteristics face limitations in achieving the rated output power. Therefore, this paper proposes a safe and reliable power supply method using the principle of IPT to securely maintain the insulation distance between the distribution network and the current sensor-supply line. A 100 W prototype IPT system is investigated, and its feasibility is validated by comparing its performance with conventional optical converters. [ABSTRACT FROM AUTHOR]

In order to extend the service life of a highway power supply system and the level of new energy consumption, a power dispatching strategy considering the health status of multi-energy conversion equipment is proposed in this paper. Firstly, the energy and load forms of the highway power supply system are introduced, and the structure of the multi-energy conversion equipment, the topological structures of the DC–DC and DC–AC modules, and the operating characteristics are analyzed. Secondly, the module temperatures and output voltages are used as main parameters to establish the health indexes of DC–DC and DC–AC modules, and then the health index of the multi-energy conversion equipment is further calculated. Thirdly, the new energy consumption index is defined, and a multi-objective optimization model for power dispatching of highway power supply systems is established with the goal of improving the health index of multi-energy conversion equipment and the new energy consumption index. The case study shows that the power dispatching strategy in this paper can better control the temperature of each module, improve the health status of multi-energy conversion equipment, and have a high level of new energy consumption. [ABSTRACT FROM AUTHOR]

After the integration of large-scale Distributed Generation (DG) into the distribution network, the randomness and volatility of its output result in a reduction of spatiotemporal alignment between power generation and demand in the distribution network, exacerbating the phenomenon of wind and solar power wastage. As a novel power system model, the fundamental concept of Regional Autonomous Power Grids (RAPGs) is to achieve localized management and energy autonomy, thereby facilitating the effective consumption of DGs. Therefore, this paper proposes a distributed resource planning strategy that enhances the autonomy capabilities of regional power grids by considering multiple evaluation indexes for autonomy. First, a regional Energy Storage (ES) configuration strategy is proposed. This strategy can select a suitable reference value for the upper limit of ES configuration based on the regional load and DG output to maximize the elimination of source load deviations in the region as the upper limit constraint of ES capacity. Then, a control strategy for regional ES is proposed, the charging and discharging reference line of ES is set, and multiple autonomy and economic indexes are used as objective functions to select different proportions of ES to control the distributed resources of the regional power grid and establish evaluation indexes of the internal regional generation and load power ratio, the proportion of power supply matching hours, new energy consumption rate and tie line power imbalance outside the region to evaluate changes in the regional autonomy capabilities. The final simulation results show that in the real regional grid example, the planning method in the planning year in the region of the overall power supply matching hour ratio and new energy consumption rate increased by 3.9% and 4.8% on average, and the power imbalance of the tie line decreased by 7.8% on average. The proposed planning approach enables the maximization of regional autonomy while effectively smoothing the fluctuation of power exchange between the regional grid and the higher-level grid. This presents a rational and effective planning solution for the regional grid, facilitating the coordinated development between the region and the distribution network. Graphic Abstract [ABSTRACT FROM AUTHOR]

The purpose is to use power line communication technology to re-optimize the power acquisition terminals of electromechanical equipment and improve the efficiency of information acquisition and management of the system grid. This paper analyzes the power and signal composite modulation mode of power line data communication in distributed power grids. Combined with the topology of the communication network in the power transmission process, the management mode of integration of power lines and wireless communication equipment is redesigned. Firstly, the characteristics of power line communication and wireless channel are analyzed. Aiming at the problem that most communication network operators use the fixed relay for communication, the main network communication mode is selected for optimization. Then, the information fusion method is adopted to integrate the network structure of the enterprise, network, and physical layer. The management of wireless communication equipment is carried out by reasonably allocating power resources. Additionally, the structure of the power acquisition terminal model is designed based on strict standards and practice. Finally, the communication fusion method is used for experimental simulation. The results show that when the input current is 1A, the experimental, theoretical value of the system is 3A, and the actual instrument output is close to 5A. When the input current is 6A, the instrument output of the system is 7.5A. Therefore, loading a reasonable load impedance value in the system can optimize the current output value of the model. The paper has important reference value for optimizing electromechanical equipment and power acquisition terminal. [ABSTRACT FROM AUTHOR]

To enhance the power supply reliability of the microgrid cluster consisting of AC/DC hybrid microgrids, this paper proposes an innovative structure that enables backup power to be accessed quickly in the event of power source failure. The structure leverages the quick response characteristics of thyristor switches, effectively reducing the power outage time. The corresponding control strategy is introduced in detail in this paper. Furthermore, taking practical considerations into account, two types of AC/DC hybrid microgrid structures are designed for grid-connected and islanded states. These microgrids exhibit strong distributed energy consumption capabilities, simple control strategies, and high power quality. Additionally, the aforementioned structures are constructed within the MATLAB/Simulink R2023a simulation software. Their feasibility is verified, and comparisons with the existing studies are conducted using specific examples. Finally, the cost and efficiency of the application of this study are discussed. Both the above results and analysis indicate that the structures proposed in this paper can reduce costs, improve efficiency, and enhance power supply stability. [ABSTRACT FROM AUTHOR]

Abstract: Coalbed methane (CBM) or coal seam gas (CSG) as it is known in Australia is becoming an increasingly important source of energy around the world. Many countries such as United States, Canada, Australia and China are investing in the CSG industry. A rise in the cost of conventional natural gas and many other energy resources, along with a decline in these conventional resources and issues such as climate change have encouraged a global interest in alternative sources of energy like CSG. The estimated quantity of CSG worldwide is around 1.4×1014 m3, it is clear that coal seam gas is a significant source of energy. The first section of this paper will discuss the production size of CSG worldwide and the future of the industry. The usage of the coal bed seam for the sequestration of CO2 is also an added benefit. The reduction of CO2 released to the environment may help in the future mitigation of global warming. In addition, the re-injecting of the co-produced CO2 enhances the commercial recovery and production of CSG wells. In the second section, the impact of the CSG industry's by-products on the environment, the freshwater ecosystem and human health are analysed. The second section includes issues associated with the large volume of co-produced water with undesirable composition in the CSG industry. The management of this enormous amount of water requires cost effective technologies and methods. Many methods for dealing with water problems are discussed and analysed in this paper. [Copyright &y& Elsevier]

A demonstration is described of electrophoretic separation of carmine and sunset yellow with a paper-based device. The channel in the paper device was fabricated by hand with a wax pen. Electrophoretic separation of carmine and sunset yellow was achieved within a few minutes by applying potential on the channel using a simple and inexpensive power supply. This demonstration could not only motivate the students' passion in learning analytical chemistry but also introduce two important analytical techniques (microfluidic paperbased analytical devices and electrophoresis) to the classroom. With further modification and improvement, this demonstration may be suitable for students to perform as a laboratory experiment in the teaching lab. [ABSTRACT FROM AUTHOR]

Dielectric testing techniques, in both time and frequency domains, are currently widely used by power utilities for assessment of the condition of transformer oil-paper insulation systems. However, it has been reported that results of these tests are highly influenced by the operating temperature during measurements. The distribution, migration and equilibrium of moisture between oil and paper in a complicated insulation system is highly temperature dependent. It requires adequate experience and proper understanding to interpret the dielectric response results in the presence of temperature variations and thermal instability. Proper analysis of the dielectric test result is only possible with an understanding of the physical behavior of the insulation system in response to temperature. A circuit model, which describes the dielectric behavior of the transformers main insulation system, has been investigated in this paper. The values of the parameters of the model have been identified from the dielectric tests. A correlation has been observed between the operating temperature and the equivalent model parameters that can be used as additional information for better interpretation of the dielectric test results. This paper thus reports a detailed study on the effects of temperature on dielectric measurements of a transformer under controlled laboratory conditions. Some results of practical on-site testing are also presented to demonstrate the possibility of errors that may be introduced in dielectric test results analysis unless temperature effects are taken into consideration. [ABSTRACT FROM AUTHOR]

Abstract: The waste hierarchy is being widely discussed these days, not only by cost-benefit analysts, but a growing number of life cycle assessments (LCA) have also begun to question it. In this article, we investigate the handling of waste paper in Denmark and compare the present situation with scenarios of more waste being recycled, incinerated or consigned to landfill. The investigations are made in accordance with ISO 14040-43 and based on the newly launched methodology of consequential LCA and following the recent guidelines of the European Centre on Waste and Material Flows. The LCA concerns the Danish consumption of paper in 1999, totalling 1.2million tons. The results of the investigation indicate that the waste hierarchy is reliable; from an environmental point of view recycling of paper is better than incineration and landfilling. For incineration, the reason for the advantage of landfilling mainly comes from the substitution of fossil fuels, when incinerators provide heat and electricity. For recycling, the advantage is related to the saved wood resources, which can be used for generating energy from wood, i.e., from renewable fuel which does not contribute to global warming. [Copyright &y& Elsevier]

The article presents the author's opinion on five selected technical reports which were discussed at the Photovoltaic Technical Conference held in Provence, France in 2011. These papers reportedly tackles low cost photovoltaic solutions to address the grid parity objectives crucial for competitive electricity produced by renewable energy sources. She comments that the solutions presented are key factors in the success of future photovoltaic technologies for consumer production of electricity.

Environmental issues such as the depletion of nonrenewable energy resources and pollution are very topical and would need more scientific attention in order to be addressed in a way beneficial to life. The extent of solid waste production is a global concern and development of its bioenergy potential can simultaneously address issues such as pollution control and renewable energy development. Various wastepaper materials, a major component of solid waste, have been treated with cellulase from Trichoderma viride to bioconvert its cellulose component into fermentable sugars that could be utilized as feedstock for bioproduct development. These paper materials exhibited different susceptibilities toward the cellulase and showed different sugarreleasing patterns when increasing amounts of each paper were treated with the enzyme. Bioconversion of paper with different enzyme concentrations and during various time intervals also resulted in nonsimilar sugar-releasing patterns. With all the paper materials, a general decline in efficiency was observed with increasing amounts of sugar produced during the different bioconversion variables investigated. [ABSTRACT FROM AUTHOR]

In the process of promoting energy green transformation, the optimization of regional integrated energy system faces many challenges such as cooperative management, energy saving and emission reduction, as well as uncertainty of new energy output. Therefore, this paper proposes a multi-agent game operation method of regional integrated energy system based on carbon emission flow. First, this paper establishes a carbon emission flow calculation model for each subject, and proposes a comprehensive tariff model based on the carbon emission flow, which discounts the carbon emissions from the power supply side to the power consumption side. Secondly, considering the interests of each subject, this paper establishes the decision- making model of each subject. And the new energy uncertainty, the cost of energy preference of prosumers, and the thermal inertia of buildings are considered in the decision model. Finally, the model is solved using differential evolution algorithm and solver. The case study verifies that the comprehensive electricity pricing model based on carbon emission flow developed in this paper can play a role in balancing economy and low carbon. [ABSTRACT FROM AUTHOR]

Purpose: The reason for writing the paper is growing complexity of management of the electric grid. Our collective electric system faces accelerating, multi-dimensional needs that must be addressed to deliver to our communities. Design/methodology/approach: The supply, transmission, distribution, and consumption of electricity are closely coupled, and must be actively coordinated. This requires the coordinated sensing, measurement, and control of devices and systems spread across the grid. This paper assesses the suitability of blockchain for this purpose, as a platform for transactive energy. Findings: Blockchain technology can facilitate secure and transparent record-keeping and transactions and thus may have many potential applications in the energy sector. Practical implications: Blockchain technology is still evolving and faces some challenges, such as scalability, interoperability, regulation, and adoption. However, blockchain has the potential to revolutionize the energy sector by transforming the way energy is produced, distributed, consumed, and traded. Social implications: High electricity demand, aging power grids, and climate disasters are straining our current energy system. As a result, more people are looking to optimize energy usage—and transactive energy may offer an answer. A Blockchain-enabled transacted energy framework can help everyone from consumers to corporations benefit from improved energy efficiency and profit in the process. Originality/value: Distributed energy resources, such as energy efficiency, smart demand response, smart electric vehicle charging, building-level energy storage and distributed solar photovoltaics, become more critical every year. Review of recent papers on these issues may be a valuable source of knowledge for interested parties. [ABSTRACT FROM AUTHOR]

With the introduction of automated driving, new requirements for the design and control of a vehicle powernet and powertrain arise, since the increasing level of driving automation shifts the responsibility for passengers’ safety from a driver towards automation system. Therefore, the functionality of the subsystems required for the automated transition to a standstill in case of a failure must be guaranteed. The work presented in this paper proposes a novel and generic system architecture for the energy management of a fail-operational powernet and powertrain in fault-free and failure case operation. The underlying control strategy is based on a concept enabling safety based range extension with the main goal to complete a driving mission at the safest possible location for the passengers. The proposed Energy Management System (EMS) approximates a driving trajectory to the destination based on route preview, which is then used for the dynamic optimization of the torque split in a powertrain with multiple motors. In this way, the total energy required for propulsion, which is also used as an input for the energy distribution, can be accurately predicted. The optimal distribution of the energy for the supply of safety-critical subsystems and powernet auxiliaries is then estimated by solving a mixed-integer optimization problem. If the desired driving mission cannot be completed, a three-level-degradation concept adapting the driving mission is applied. The individual modules of the EMS are presented in this paper and a system architecture enabling model predictive and adaptive energy distribution in a vehicle powertrain and powernet with automated fault reactions is proposed and exemplified with simulation results. [ABSTRACT FROM AUTHOR]

The application of renewable energies such as wind and solar has become an inevitable choice for many countries in order to achieve sustainable and healthy economic development [[1]]. The paper "Steady-State Analysis and Output Voltage Minimization Based Control Strategy for Electric Springs in the Smart Grid with Multiple Renewable Energy Sources" by Y. Zou et al. presented a general steady-state analysis and minimal compensating voltage control scheme for the second generation of electric springs in the power system with substantial penetration of intermittent renewable energy sources. The paper "Parallel LSTM-Based Regional Integrated Energy System Multienergy Source-Load Information Interactive Energy Prediction" by B. Wang et al. proposed an energy prediction strategy for multienergy information interaction in regional integrated energy systems from the perspective of horizontal interaction and vertical interaction. [Extracted from the article]

The electroslag remelting (ESR) process is widely used to produce high-quality ingots and billets for high-alloyed steels and alloys. Both the single-phase and three-phase alternating current diagram with bifilar and monofilar connection are in use for heavy ingot manufacturing. The numerical simulation of the three-phase bifilar circuit for the 120 t three-phase bifilar six-electrode ESR furnace at different variants of electric connection was presented and discussed. At the bifilar diagram of power supply, the geometrical location of electrodes in a mould holds critical importance for performances: the close location of bifilar pair electrodes provides the highest heat productivity, but the equidistant location of electrodes gives a much more uniform heat distribution. The monofilar mulit-electrode diagram of three-phase connection without phase shift shows the most uniform distribution of potential and heat generation as well as a favorable magnetic field that makes this kind the most promising for providing a high quality of heavy ingots. [ABSTRACT FROM AUTHOR]

Comments on the paper "Embodied and Operational Energy Consumption in the City," by P. Troy, D. Holloway, S. Pullen and R. Bunker, in the March 2003 issue of "Urban Policy and Research,' which explored the use of existing data to estimate at the small-area scale of the aggregate transport, building and infrastructure energy consumption attributable to urban development. Assertion that the methodology can be described as life cycle energy/emissions analysis; Limitations of area-based data; Underestimation of transport energy variability.

Due to the significant gap between demand and supply of electricity, power utility companies employ rolling blackouts, in which the power supply to different regions is cut-off periodically for a specified duration. However, this causes increased user inconvenience as consumers are left without power; also, a large undesirable blackout may occur if the circuit breakers are not opened in time. To solve this problem, this paper has developed a more pragmatic approach in which a power threshold limit is imposed on households during times of deficit power supply. This paper presents five algorithms designed to allocate load thresholds to households in a fair manner. Some of these algorithms perform the worst (high violations) in some time slots and best (minimal violations) in other slots, but none guarantees minimal mean violation across all the time slots. In this regard, this paper has also developed a novel optimal algorithm that ensures a minimal violation percentage of the allotted thresholds across all time slots in all the households of a neighbourhood. It also employs multiple heuristics for threshold allocation, thereby preventing household starvation. The algorithms are evaluated on a real-world dataset. Its mean violation across all the houses goes as low as nearly 45% and is minimum across all the time slots. It performs all the algorithms used for power limit distribution. This result demonstrates the effectiveness of the developed technique in the implementation of the brownout scheme in practise. [ABSTRACT FROM AUTHOR]

The load-adaptive behavior of the muscles in the human musculoskeletal system offers great potential for minimizing resource and energy requirements in many technical systems, especially in drive technology and robotics. However, the lack of knowledge about suitable technical linear actuators that can reproduce the load-adaptive behavior of biological muscles in technology is a major reason for the lack of successful implementation of this biological principle. In this paper, therefore, the different types of linear actuators are investigated. The focus is particularly on artificial muscles and rope pulls. The study is based on literature, on the one hand, and on two physical demonstrators in the form of articulated robots, on the other hand. The studies show that ropes are currently the best way to imitate the load-adaptive behavior of the biological model in technology. This is especially illustrated in the context of this paper by the discussion of different advantages and disadvantages of the technical linear actuators, where ropes, among other things, have a good mechanical and control behavior, which is very advantageous for use in an adaptive system. Finally, the next steps for future research are outlined to conclude how ropes can be used as linear actuators to transfer load-adaptive lightweight design into technical applications. [ABSTRACT FROM AUTHOR]

Electric railways use a single-phase system, with the line comprising a trolley wire (TF) that supplies power to the load with a neutral wire and an autotransformer (AF) feeder to absorb the return current of the rail. Testing the performance of the protective relay that detects the fault of the traction power-supply system (TPSS) and operates the circuit breaker is very important. Until now, the performance test of protective relays for the TPSS has been conducted via a simple-steady test or using an expensive real-time simulator. However, under a fast-moving environment in which the load consumes a large amount of power, the protective relay must always detect faults and operate properly. This paper proposes a digital simulator that enables the dynamic testing of protective relays without using any steady test and expensive real-time simulators. This simulator includes both external waveform import and internal waveform generation functions. Users can test the operation of the protective relay by entering the waveform generated externally or internally into the protective relay. Additionally, it has the ability to monitor the operating protection elements and pickup time when the protective relay detects a fault and orders the circuit breaker trip. [ABSTRACT FROM AUTHOR]

The power transformer is one of the most important equipment in the electrical power system due to its cost and potential failure????s consequences. To ensure a continuous energy supply, it is needed to assess abnormal condition such as thermal and electrical behavior. From this viewpoint, dissolved gas analysis (DGA) is very useful in detecting internal defects in oil-filled electrical equipment. A system has been developed that allows to simulate partial discharge and overheating in transformer????s insulation. By using this system, we have studied on DGA under low temperature overheating in mineral oil and vegetable oil. [ABSTRACT FROM AUTHOR]