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The growing demands of sustainable, portable, and wearable electronics pose new demands on miniaturized energy storage devices that can be integrated on flexible substrates such as paper. Microsupercapacitors (MSCs), especially MXene‐based pseudocapacitive MSCs with fast charging/discharging rate, high power density, and long cycle life, are competitive candidates as power supply for emerging flexible and wearable on‐paper electronics. However, few studies have reported MXene‐based on‐paper MSCs to simultaneously attain ultrahigh‐rate (>1000 mV s−1) capability and large areal capacitance >10 mF cm−2. Herein, ultrafast metal‐free on‐paper MSCs are fabricated through leveraging the synergistic effect of conductive PEDOT:PSS and capacitive MXene (Ti2C) to achieve a remarkable areal capacitance of 30 mF cm−2 and long lifetime (>96% capacitance retention after 10 000 cycles) at an ultrahigh scan rate of 1000 mV s−1, outperforming most of the present on‐paper or MXene‐containing MSCs. Moreover, the printed on‐paper metal‐free MSC arrays attain extended working voltage window of up to 6 V and outstanding capacitive performance at an ultrahigh scan rate of 10 V s−1. The on‐paper PEDOT:PSS‐Ti2C composite MSCs offer new opportunities as eco‐friendly microscale power sources for emerging paper‐based portable and wearable electronics. [ABSTRACT FROM AUTHOR]

Self‐charging power systems (SCPSs) are envisioned as promising solutions for emerging electronics to mitigate the increasing global concern about battery waste. However, present SCPSs suffer from large form factors, unscalable fabrication, and material complexity. Herein, a type of highly stable, eco‐friendly conductive inks based on poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are developed for direct ink writing of multiple components in the SCPSs, including electrodes for miniaturized spacer‐free triboelectric nanogenerators (TENGs) and microsupercapacitors (MSCs), and interconnects. The principle of "one ink, multiple functions" enables to almost fully print the entire SCPSs on the same paper substrate in a monolithic manner without post‐integration. The monolithic fabrication significantly improves the upscaling capability for manufacturing and reduces the form factor of the entire SCPSs (a small footprint area of ≈2 cm × 3 cm and thickness of ≈1 mm). After pressing/releasing the TENGs for ≈79000 cycles, the 3‐cell series‐connected MSC array can be charged to 1.6 V while the 6‐cell array to 3.0 V. On‐paper SCPSs are promising to serve as lightweight, thin, sustainable, and low‐cost power supplies. [ABSTRACT FROM AUTHOR]

This study delves into the dynamic evolution of solids content in a pilot-scale through air drying tissue machine, aiming to enhance comprehension and refine optimization strategies for tissue manufacturing. It focuses on development of solids content throughout the process. Analyzing the interaction between process parameters and solids content provides deeper insights into water removal dynamics. The research employs solid contents monitoring techniques in pilot scale, offering a detailed view of solids content evolution from the wet web's inception to the final tissue product. It significantly highlights the impact of key parameters, particularly pulp refining, on solids content across all positions of the pilot machine. Additionally, the study emphasizes the influence of vacuum system configurations, identifying the relationship between energy expended in the vacuum system and evaporation energy. Furthermore, the results indicate that compression and air displacement dewatering in vacuum boxes are less speed-sensitive compared to heat-driven evaporation in the TAD- and Yankee cylinders. Solid contents at all positions in the tissue machine correlates between various dewatering elements. Optimizing site-specific dewatering and evaporation strategies can potentially save drying energy in the Yankee drying phase which hold promise for enhanced energy and resource utilization, aligning with demands for sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]

Overwintering insects are facing energetic challenges because of food shortage, low temperature, and desiccation stress. Paper wasps of the genus Polistes overwinter as mated adults (gynes) in hibernacula protecting them from predation, snow, and rain but barely from low environmental temperature. In different climates, they face differing overwintering temperature regimes, and therefore they may differ in their energy use. We investigated how much of energy resources built up until autumn is used during diapause dormancy in natural hibernacula by measuring lipid, glycogen, and free carbohydrate content in autumn and early spring in Polistes dominula from temperate European (Austrian) and warm Mediterranean (Italian) climate and Polistes gallicus from Mediterranean climate. Winter energy consumption amounted to ~ 339 and ~ 310 J per wasp in the Austrian and Italian Polistes dominula populations. The smaller Italian Polistes gallicus consumed ~ 247 J. This amounts to 2.62, 2.35, and 1.79 J per day. Of this, the energy demand was mainly fuelled by lipids (84%, 93%, and 90%, respectively), but glycogen stores contributed also considerably (16%, 6%, and 9%). Free carbohydrates decreased only by 0.7%, 1%, and 0.8%. While fat stores seem still sufficient in spring, the wasps depleted most of their carbohydrates. The energy reserves of 396, 400, and 147 J per wasp remaining in spring in the three populations seem sufficient to fuel rest or simple brood care activities for a whole summer but restrict foraging flights to a few hours (~ 3.5–6 h). Results suggest that energy supply might become challenging in expected future climate scenarios. [ABSTRACT FROM AUTHOR]

Micro Fuel cells or microfluidic fuel cells (μMFCs) are one of the most promising power supplies for portable electronics. However, the necessary electrode spacing is required to prevent fuel-crossover and maintain the stable operation, introducing the unavoidable ohmic resistance and retarding the miniaturization. Herein, we propose a novel μMFC device combining the cellulose paper as separator, with selective catalysts at the cathode side to eliminate the unwanted side reactions and increase the system compactness. One single reactant solution containing fuel and electrolyte is applied to keep the device stable operation. The power-generation properties are evaluated in typical alkaline conditions. A great construction simplification makes the device a substantial high-power density of 2.14 W cm−3 and maximum current density of 15.82 A cm−3. The μMFC stacks are arranged in series and parallel manners, which delivers a maximum power output of 23.6 mW and current of 194.6 mA. It is expected that innovative and customizable performance from commercial paper and low-cost carbonaceous catalysts can provide a forum for future advancement in chip-based electrochemical energy generation and storage devices. • Filter paper served as a membrane for μMFC is proposed. • The electrode-pair distance is greatly minimized (∼140 μm). • The optimized μMFC delivers an ultrahigh power density of 2.14 W cm−3. • The μMFC stacks power output of 23.6 mW and current output of 194.6 mA are achievable. [ABSTRACT FROM AUTHOR]

Sustaining life on the Earth with its ever-growing population is forcing changes in people’s way of life, industrial and agricultural production, exploitation of energy resources, and approaches to ecology. We face continual growth in the world’s population, and the demand for materials is growing even more rapidly. Every manufacturing and consumer sector is looking for ways to save energy and materials, attempting to minimize their negative impacts on the environment. In the pulp and paper industry, one of the segments in which progress can be made and help protect the planet is to reduce the brightness of paper. Such a reduction would lead to a lowering in the energy and material costs associated with paper production. [ABSTRACT FROM AUTHOR]

The conversion of ubiquitous hygrothermal resources into renewable energy offers significant potential for cable‐free, self‐powered systems that can operate worldwide without regard to climatic or geographic limitations. Here, an all‐printed flexible hygro‐thermoelectric paper generator is demonstrated that uses bifunctional mobile ions and electrons to make the moist‐diffusion effect, the Soret effect, and the Seebeck effect work synergistically. In the ordinary hygrothermal settings, it generates an unconventional hygro‐thermoelectric output pattern and shows almost a dozen‐fold increase in positive hygro‐thermopower of 26.70 mV K−1 and also another negative hygro‐thermopower of −15.71 mV K−1 compared to pure thermopower. A single paper generator can produce a giant 680 mV displaying typical cyclic sinusoidal waveform characters with volt‐sized amplitudes. The ion‐electron conductive ink is easily printable and consists primarily of a Bi2Te3/PEDOT:PSS thermoelectric matrix modulated with a hygroscopic glycerol that releases ion charges for moist‐diffusion effect and Soret effect, as well as electron charges for Seebeck effect. The emerged hygro‐thermoelectric harvesting strategy from surrounding hygrothermal resources offers a revolutionary approach to the next generation of hybrid energy with cost‐efficiency, flexibility, and sustainability, and also enables large‐scale roll‐to‐roll production. [ABSTRACT FROM AUTHOR]

The large-scale implementation of renewable energy systems necessitates the development of energy storage solutions to effectively manage imbalances between energy supply and demand. Herein, we investigate such a scalable material solution for energy storage in supercapacitors constructed from readily available material precursors that can be locally sourced from virtually anywhere on the planet, namely cement, water, and carbon black. We characterize our carbon-cement electrodes by combining correlative EDS-Raman spectroscopy with capacitance measurements derived from cyclic voltammetry and galvanostatic charge-discharge experiments using integer and fractional derivatives to correct for rate and current intensity effects. Texture analysis reveals that the hydration reactions of cement in the presence of carbon generate a fractal-like electron-conducting carbon network that permeates the load-bearing cement-based matrix. The energy storage capacity of this space-filling carbon black network of the high specific surface area accessible to charge storage is shown to be an intensive quantity, whereas the high-rate capability of the carbon-cement electrodes exhibits self-similarity due to the hydration porosity available for charge transport. This intensive and self-similar nature of energy storage and rate capability represents an opportunity for mass scaling from electrode to structural scales. The availability, versatility, and scalability of these carbon-cement supercapacitors opens a horizon for the design of multifunctional structures that leverage high energy storage capacity, highrate charge/discharge capabilities, and structural strength for sustainable residential and industrial applications ranging from energy autarkic shelters and self-charging roads for electric vehicles, to intermittent energy storage for wind turbines and tidal power stations. [ABSTRACT FROM AUTHOR]

Recently, as the use of wearable devices and the demand for eco-friendly energy have increased, many studies have been conducted on triboelectric nanogenerators (TENGs), which can economically harvest energy. Paper is considered a promising substrate and frame material that can be used to manufacture self-powered TENGs, owing to its flexibility, low cost, and accessibility. Herein, we present a sandwich-structured foldable paper-based TENG (FP-TENG) that comprises flexible materials and uses paper as a substrate. The FP-TENG can generate up to 572 mW/m2 of power via contact–separation of the triboelectric electrified body at the top and bottom. With more folds of the FP-TENG, the triboelectric cross-sectional area increases, and, thus, the electrical output increases. In addition, the proposed TENG exhibits excellent durability without signal degradation under 5000 cycles of repeated pushing motions. To demonstrate its practicality, the FP-TENG was manufactured in the form of a wristwatch Velcro and connected to an electronic watch panel to supply power. Various deformations are possible with origami, and they can drive wristwatches through external forces. Therefore, the FP-TENG is expected to be utilized as a sustainable and promising eco-friendly energy source for small electronic devices. [ABSTRACT FROM AUTHOR]

The direct integration of paper-based microfluidic fuel cells (μFC's) toward creating autonomous lateral flow assays has attracted attention. Here, we show that an air-breathing paper-based μFC could be used as a power supply in pregnancy tests by oxidizing the human urine used for the diagnosis. We present an air-breathing paper-based μFC connected to a pregnancy test, and for the first time, as far as we know, it is powered by human urine without needing any external electrolyte. It uses TiO 2 -Ni as anode and Pt/C as cathode; the performance shows a maximum value of voltage and current and power densities of ∼0.96 V, 1.00 mA cm − 2 , and 0.23 mW cm − 2 , respectively. Furthermore, we present a simple design of a paper-based μFC's stack powered with urine that shows a maximum voltage and maximum current and power densities of ∼1.89 V, 2.77 mA cm − 2 and 1.38 mW cm − 2 , respectively, which powers the display of a pregnancy test allowing to see the analysis results. [ABSTRACT FROM AUTHOR]

This work describes a direct optical readout of an ion-selective potentiometric sensing array without an external power supply. Electronic paper (e-paper) was chosen as the signal transducer owing to its fast response on the order of seconds and its wide dynamic range of about 1.5 V. The capacitive character of the display allows one to observe the optical response at zero current, which is a desired condition for the potentiometric measurement. An applied potential of 1 V gives a transient charge flow of about 11 μC for the e-paper to exhibit a maximal intensity change. The cathodes of three different pixels of the e-paper were connected to three different ISEs responsive to Na+, K+, and Ca2+, while their common anode was connected to the shared reference electrode (RE). In this manner, each pixel is mapped to the behavior of one sensor, making it possible to detect multiple ions with an e-pixel array. The sensor configuration gave quantitative information on Na+, K+, and Ca2+ from 10−5 M to 10−1 M by analyzing the RGB information of the pixels. The e-paper exhibited a stable response within half a minute, much faster than previously established electrochromic material transducers such as Prussian Blue (PB). With this approach we successfully carried out multi-ion concentration sensing without external power, which is potentially attractive for applications in environmental monitoring, clinical assays and wearable sensing devices. [Display omitted] • A self-powered multi-channel potentiometric sensor array for simultaneous monitoring of potassium, calcium, and sodium. • The rapid optical response of this sensor is adequate for real time monitoring. • Excellent correlation between this approach and direct potentiometry. [ABSTRACT FROM AUTHOR]

Plant operators and policy makers frequently use energy benchmarking to assess the potential for reducing energy consumption from industrial plants. As benchmarking studies require considerable resources and the cooperation of plant operators it is tempting to try to merge or compare data from different studies. This paper reviews published benchmarks and energy-saving estimates from the paper and pulp industries to explore how comparable data from independent studies are. A literature review was conducted which identified that benchmarks were either produced through a top-down process using annual production and fuel consumption data or through a bottom-up process from process-level data. It was concluded that top-down benchmarks are useful in measuring national trends but are of little value to individual plants. For common process such as Kraft pulp production it is possible to compare values from different studies but only if sufficient information is given in the original studies to confirm that their scope is identical. However, it is unlikely that improvement rates in energy use can be inferred from the difference between studies that use different sources, as the degree of disagreement between contemporary studies is of the same order as the identified potential energy savings. Benchmarking studies were found to provide good summaries of potential technological improvements although there is some inconsistency in estimations of potential impacts. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) capable of efficiently harvesting various mechanical energies from the environment are an effective way to solve the energy supply problem of wearable electronic devices. A series of flexible and lightweight TENGs with different surface morphologies of "dots"–"lines"–"honeycombs" hierarchical micro-structures are developed using low-cost and easily accessible background paper as a substrate. Polydimethylsiloxane films with dots–lines–honeycombs hierarchical micro-structures are prepared by the spin coating to obtain larger contact areas and, thus, enhance the triboelectric effect. Under the same test conditions, the honeycombs TENG (H-TENG) with complex surface morphology has the largest output performance with an open-circuit voltage of 55 V and a short-circuit current of 2.7 μA, which is 2.1 and 2.5 times that of the flat TENG, respectively. By combining with nylon gloves, the H-TENG can harvest the mechanical energy during hand movement and realize sensing of hand movement patterns through the difference of electrical signals. In addition, this device can power the liquid crystal display screen through a rectifier circuit and capacitor. This simple and efficient TENG device shows great potential in the wearable field. [ABSTRACT FROM AUTHOR]

As a mainstream power storage and supply device, batteries are continuously upgraded. The microfluidic fuel cell has great development potential, and the paper-based microfluidic fuel cell is the latest achievement of its lightweight, which can be applied in the field of medical and biological detection. In this work, the cell models with various folding forms and unconventional absorption pads are creatively constructed, then the influence mechanism on cell performance is revealed by numerical simulation. Both transient and steady-state simulation methods are employed to monitor the whole process of paper-based microfluidic fuel cell. Conclusions show that the cell performance decreases with the increase of folding angle, the peak power density is as low as 1.71 mW/cm2, and the corresponding fuel utilization is only 2.73%. The changes in the absorbent pad shapes have little improvement on cell performance, thus the most direct way is increasing the absorbent pad volume. Moreover, materials with better water absorption capacity can increase the maximum current density to 28.70 mA/cm2, and the appropriate increase of operating temperature can also increase the peak power density to 2.36 mW/cm2, but the effect on the cell is significantly weakened if the temperature exceeds a certain limit. [ABSTRACT FROM AUTHOR]

In this framework, experimental tests on different battery technologies, BMS and cooling systems are extremely important to extend the battery life and BEV performance (Sehil et al. [[13]]). Electrical machines and magnetic components, high-voltage voltage power converters, and battery storage systems are some basic bricks to build an effective and efficient energy conversion environment. Electrical Machines and Power Converters The electrical power conversion from renewable energy sources plays a crucial role in the development of a sustainable society. Finally, the fil rouge of every contribution in this section is oriented to investigate the power converters, electrical machines, magnetic components, and battery storage systems in actual energy conversion applications for renewable energy sources integration by a modelling approach. [Extracted from the article]

Rationale: Plasma‐based ionization sources play a vital role in rapidly analyzing diverse compounds without extensive sample pretreatment. In contrast to other sources, DC voltage‐based ionizations are more advantageous due to their high analytical sensitivity and good tandem with commercially available mass spectrometers without extra power supplies. However, their performance is at the risk of high current DC voltage and helium flow rate, which poses significant challenges to practical operation and increased expense. Methods: In this work, we propose a novel focusing plasma desorption ionization (FPDI) in which a visible plasma beam is favorably generated between a conducting wire in a polymeric tube and a counter electrode composed of metal mesh and filter paper drilled with holes. A systematic investigation has been conducted on the influences of the geometry of drilled holes in filter paper, applied DC voltage, helium flow rate, and filter paper size. The optimized system is used to analyze various pesticides in fluid foodstuffs. Results: Compared to metal mesh and conducting paper as the counter electrode for FPDI‐MS, combining metal mesh and filter paper drilled holes improved the analysis sensitivity by a factor of more than five. By applying the developed protocol for determining pesticides in complex matrixes such as orange juice and milk, a limit of detection as low as 1.3–3.0 ng mL−1 could be achieved. Conclusions: A novel FPDI‐MS technique has been developed by combining metal mesh and filter paper drilled with holes as the counter electrode and sample carrier. The corresponding improvement in analysis sensitivity facilitates the future expansion of FPDI‐MS applications into different pesticides and other compounds in complex matrixes. [ABSTRACT FROM AUTHOR]

Traction transformers are one of the most important equipment in the traction power supply system. Thermal aging of transformer insulation system determines its reliable life. To achieve an estimation of the insulation life of traction power transformers operated under real load condition, the effects of traction loads on the thermal aging of oil-paper insulation in traction transformers were investigated. First, the design principles for the accelerated thermal aging experiment were studied and proposed by considering magnitude (i.e., load rate) and frequency (i.e. spare time and lasting time) of the traction load. Then, an experimental system was established in the laboratory to conduct extensive accelerated thermal aging experiments, in which the traction loads were mimicked by using positive temperature coefficient (PTC) heating plates and a programmable logic controller (PLC). Finally, the experimental results were analyzed and discussed to reveal the effects of traction load on the thermal aging of oil-paper insulation in traction transformers. [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]

Self-powered electronic equipment has rapidly developed in the fields of sensing, motion monitoring, and energy collection, posing a greater challenge to triboelectric materials. Triboelectric materials need to enhance their electrical conductivity and mechanical strength to address the increasing demand for stability and to mitigate unpredictable physical damage. In this study, polyaniline-modified cellulose was prepared by means of in situ polymerization and compounded with polydimethylsiloxane, resulting in a triboelectric material with enhanced strength and conductivity. The material was fabricated into a tubular triboelectric nanogenerator (TENG) (G-TENG), and an electrocatalytic pretreatment of mixed office waste paper (MOW) pulp was performed using papermaking white water as the flowing liquid to improve the deinking performance. The electrical output performance of G-TENG is highest at a flow rate of 400 mL/min, producing a voltage of 22.76 V and a current of 1.024 μA. Moreover, the deinking effect of MOW was enhanced after the electrical pretreatment. This study explores the potential application of G-TENG as a self-powered sensor power supply and emphasizes its prospect as an energy collection device. [ABSTRACT FROM AUTHOR]

This review analyzes papers presented at the "Second International Kosygin Readings: Energy- and Resource-Efficient Environmentally Safe Technologies and Equipment," an International Scientific and Technical Symposium Celebrating the 100th Anniversary of the Kosygin State University of Russia, which was held as part of the International Kosygin Forum. These papers consider the fundamental principles of methods for intensifying basic processes in various industrial technologies, the scientific fundamentals of the development of energy- and resource-efficient chemical and other processes, innovative developments in this field, issues of the environmental safety of technological processes and equipment, effective systems for increasing technosphere safety, the theory and calculation of heat and mass transfer processes in technosphere protection systems, the issues of digitization as an intellectual and technological factor for increasing the energy and resource efficiency of chemical-manufacturing processes and plants, and the results of studies aimed at developing the theoretical fundamentals of energy- and resource-efficient industrial machinery and equipment. [ABSTRACT FROM AUTHOR]

Paper-based microfluidics (lab on paper) emerges as an innovative platform for building small-scale devices for sensing, diagnosis, and energy storage/conversions due to the power-free fluidic transport capability of paper via capillary action. Herein, we report for the first time that paper-based microfluidic concept can be employed to fabricate high-performing aluminum–air batteries, which entails the use of a thin sheet of fibrous capillary paper sandwiched between an aluminum foil anode and a catalyst coated graphite foil cathode without using any costly air electrode or external pump device for fluid transport. The unique microfluidic configuration can help overcome the major drawbacks of conventional aluminum–air batteries including battery self-discharge, product-induced electrode passivation, and expensive and complex air electrodes which have long been considered as grand obstacles to aluminum–air batteries penetrating the market. The paper-based microfluidic aluminum–air batteries are not only miniaturized in size, easy to fabricate and cost-effective, but they are also capable of high electrochemical performance. With a specific capacity of 2750 A h kg−1 (@20 mA cm−2) and an energy density of 2900 W h kg−1, they are 8.3 and 12.6 times higher than those of the non-fluidic counterpart and significantly outperform many other miniaturized energy sources, respectively. The superior performance of microfluidic aluminum–air batteries originates from the remarkable efficiency of paper capillarity in transporting electrolyte along with O2 to electrodes. [ABSTRACT FROM AUTHOR]

Rapid, low-cost, and sensitive nucleic acid detection and quantification assays enabled by microfluidic paper-based analytical devices (μPADs) hold great promise for point-of-care disease diagnostics and field-based molecular tests. Through the capillary action in μPAD, flexible manipulation of nucleic acid samples can be achieved without the need for external pumps or power supplies, making it possible to fabricate highly integrated sample-to-answer devices that streamline the nucleic acid extraction, separation, concentration, amplification, and detection. To detect minute amounts of genetic materials from clinical and biological samples, it is also critical to develop sensitive signal readouts that generate physically detectable signals for in-device nucleic acid detection and/or quantification. In this review, we will focus on μPAD approaches for the facile manipulation of nucleic acids and emerging signal transduction strategies allowing sensitive and specific nucleic acid detection in μPAD. [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]

This paper examines the problem of synthesizing a two-loop control system for a three-phase voltage source inverter designed for an autonomous power supply system. This type of DC/AC converters is an essential part of power supply systems with renewable energy sources as primary sources, and, accordingly, must corresponds to the requirements for the electric power quality. These requirements are met through circuit design solutions, as well as through the construction of high-precision automatic control systems. The system integrates: a hydrogen electrolyzer, a hydrogen storage system, and a hydrogen fuel cell. The paper proposes a method for calculating the parameters of PI controllers with resonant components, based on the time-scale separation method and allowing independent adjustment of the controller components. The introduction of a resonant component ensures high tracking accuracy for a desired main voltage harmonic and selective suppression of external harmonic influences. The proposed approach allows to synthesize an automatic control system that significantly improves the quality of the voltage inverter output parameters. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid technique for enhancing power quality (PQ) in distributed generation (DG) systems by deploying a unified power quality conditioner (UPQC). Here, the proposed hybrid method is the joint execution of white shark optimizer (WSO) and recalling-enhanced recurrent neural network (RERNN), called the WSO-RERNN technique. The primary objective of this novel approach is to effectively mitigate voltage sag and reduce voltage harmonics under varying load conditions. It is important to investigate the voltage sag, swell and harmonic distortion of the system to obtain an enhanced PQ of the energy supply. Therefore, this paper shows the brief impact of PQ in DG utilizing the proposed unified PQ conditioner controller. The WSO-RERNN control technique enhances the performance of the UPQC controller by providing the optimal control signal. By then, the efficiency of the proposed approach is done in MATLAB, and the performance is compared with those of existing optimization techniques, including Ant Lion Optimizer (ALO), Grey wolf optimization (GWO) and Salp swarm algorithm (SSA) methods. [ABSTRACT FROM AUTHOR]

Hydrogen is emerging as a critical player in transitioning to sustainable and renewable energy systems, serving roles in energy storage, grid balancing, and decarbonization. This paper explores various aspects of hydrogen, including its production through renewable-electricity-driven electrolysis, advanced storage techniques, and incorporation into current energy systems. It highlights primary electrolysis methods like PEM and alkaline, noting their improved efficiency and cost-effectiveness. Various hydrogen storage methods, such as physical, chemical, and advanced porous materials, are examined for their benefits and limitations. The review further explores hydrogen's integration into grid storage systems and microgrids to enhance energy reliability. It discusses hydrogen's application in fuel cells for electricity generation, focusing on technological advancements that improve efficiency and reduce costs. Additionally, the paper underscores hydrogen's crucial role in reducing CO 2 emissions in industrial processes like steel production and its use in residential and commercial energy supply through combined heat and power systems. Economic aspects and supportive policies from regions are analyzed, highlighting the global efforts and policies supporting the potential hydrogen in renewable energy systems. This analysis emphasizes hydrogen's comprehensive role in enhancing renewable energy systems and achieving global sustainability objectives, providing a thorough review of recent progress and challenges. • Identifies PEM and alkaline as efficient electrolysis methods. • Analyzes varied H 2 storage options for mobility and stationarity. • Highlights advancements in H 2 fuel cells for vehicles. • Discusses global policies supporting H 2 integration. • Reviews economic impacts of scaling H 2 infrastructure. [ABSTRACT FROM AUTHOR]

The clean transformation of building energy consumption is a critical pathway for achieving deep decarbonization. In light of the diversity of building energy needs, this paper proposes an integrated zero-carbon energy supply building architecture that involves the coupling of electrical, hydrogen, heat, and cooling energy sources. To address challenges in real-time supply-demand balancing and reliability of supply under extreme or boundary conditions due to complex energy couplings, the paper introduces an energy management framework with two control layers comprising mixed-integer linear programming (MILP) and model predictive control (MPC). This framework conducts hierarchical optimization to synergize economic and technical objectives. At the economic optimization layer, optimal economic parameters are formulated based on MILP; while at the MPC optimization layer, these parameters serve as reference states. By incorporating state relaxation method, the framework accommodates the uncertainties associated with system operation. Simulation analyses of typical weeks during summer and winter seasons demonstrate that the energy optimization management approach proposed in this paper can achieve highly reliable and economically stable operation of the building energy supply system. • A zero-carbon energy supply building energy structure is constructed. • Dynamic evolution model of electricity-hydrogen-heat-cooling multi-energy coupling system is established. • A double-layer energy management method including economic optimization and MPC optimization is proposed. [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]

Unmanned aerial vehicles (UAVs) have become an integral part of modern life, serving both civilian and military applications across various sectors. However, existing power supply systems, such as batteries, often fail to provide stable, long-duration flights, limiting their applications. Previous studies have primarily focused on battery-based power, which offers limited flight endurance due to lower energy densities and higher system mass. Proton exchange membrane (PEM) fuel cells present a promising alternative, providing high power and efficiency without noise, vibrations, or greenhouse gas emissions. Due to hydrogen's high specific energy, which is substantially higher than that of combustion engines and battery-based alternatives, UAV operational time can be significantly extended. This paper investigates the potential of PEM fuel cells as an alternative power source for electric propulsion in UAVs. This study introduces an adaptive, fully functioning PEM fuel cell model, developed using a reduced-order modeling approach and optimized for UAV applications. This research demonstrates that PEM fuel cells can effectively double the flight endurance of UAVs compared to traditional battery systems, achieving energy densities of around 1700 Wh/kg versus 150–250 Wh/kg for batteries. Despite a slight increase in system mass, fuel cells enable significantly longer UAV operations. The scope of this study encompasses the comparison of battery-based and fuel cell-based propulsion systems in terms of power, mass, and flight endurance. This paper identifies the limitations and optimal applications for fuel cells, providing strong evidence for their use in UAVs where extended flight time and efficiency are critical. [ABSTRACT FROM AUTHOR]

In today's world, the concept of security is incomplete without the concept of energy security. Unless a country has access to uninterrupted flow of energy resources, its massive stockpile of weapons and ammunition is unlikely to keep it safe. Therefore, contemporary security studies include concerns about energy security as one of the key components of non-traditional security issues. Ensuring free access to energy for all – is a top priority in the BIMSTEC region. Trans-border cooperation can help diversify energy sources, reduce average supply costs, and meet peak demands as the gap between supply and demand grows in BIMSTEC countries. The paper examines the current energy scenario in BIMSTEC, evaluates the scope of cross-border energy trade in the region. Energy security and maritime security are intertwined with each other in today's world. The paper also addresses the broader geopolitical, geostrategic, and geoeconomic aspects of the Bay of Bengal, illustrating how maritime security is integral to ensuring energy security in the region. [ABSTRACT FROM AUTHOR]

To address the global warming issue, China is prioritizing the development of clean energy sources such as wind and solar power under its "dual carbon target". However, the expansion of these resources is constrained by their intermittency and the spatial and temporal distribution of wind and solar energy. This paper systematically reviews the evolution of wind and solar energy reserves, their development potential, and their current status in China from a geographical perspective. In conjunction with existing research, this paper anticipates future exploration in the realm of wind–solar complementary development or multi-energy complementary development, viewed through the lens of resource quantity. The anticipated findings are intended to furnish a theoretical foundation for further studies on the development and utilization of wind and solar energy resources within China. [ABSTRACT FROM AUTHOR]

The increasing use of renewable energy sources introduces significant fluctuations in power generation, demanding enhanced regulatory capabilities to maintain the balance between power supply and demand. To promote multi-energy coupling and the local consumption of renewable energy, integrated energy systems have become a focal point of multidisciplinary research. This study models adjustable sources, networks, and loads within electric–thermal integrated energy systems as energy storage entities, forming virtual energy storage systems to participate in the optimization and scheduling of integrated energy systems. This paper investigates the modeling and control strategies of virtual energy storage systems within electric–thermal integrated energy systems. Initially, it introduces the definition, logical architecture, and technical connotations of virtual energy storage. Next, it models temperature-controlled loads as virtual energy storage systems and compares them with traditional energy storage systems, analyzing their characteristic differences and summarizing virtual energy storage system modeling methods and characteristic indicators. This paper then focuses on the specific applications of virtual energy storage systems in four typical scenarios. Finally, it explores the future development directions of virtual energy storage. [ABSTRACT FROM AUTHOR]

Microgrids have increased in popularity thanks to both the integration of renewable energy resources and their energy distribution capability for remote locations. Moreover, the microgrids, mainly using multiple generators connected in parallel, acquire additional advantages by using both Hot-Swap and Current-Sharing techniques. This paper presents the development of a Hardware in the Loop platform to test Current-Sharing algorithms. It is reinforced that the use of a real-time simulation based on Hardware in the Loop is a viable and cost-effective alternative in the validation of controllers. The platform was developed in a graphical programming environment (LabVIEW 2015) and implemented with NI MyRIO 1900 (National Instruments Corp., Austin, TX, USA) development boards for easier reproducibility. The entire code project is openly available and provided in this paper. A system of photovoltaic energy generators was used to evaluate the performance of the HIL platform. As a result, the platform was able to reproduce a similar behavior to the photovoltaic generator, presenting average mean errors of 0.4 V and 0.2 A in its voltage and current, respectively. Additionally, the platform showed its capability to test Current-Sharing algorithms in the occurrence of Hot-Swap events. This work contributes with a validation tool for energy management systems applied to microgrids. [ABSTRACT FROM AUTHOR]

In this paper, an array piezoelectric energy harvester (APEH) is designed for energy collection from water hydraulic system. The APEH is arranged in a spatial axial array, exhibiting excellent insulation and waterproof properties. The effects of connection modes and pressure pulsation parameters on the output performance of APEH are investigated through theoretical analysis, simulation and experiment. The results show that the output electric energy of each piezoelectric disk is consistent, and it is generated by the deformation caused by pressure pulsation. The connection modes show significant differences at different resistances. Series and parallel connections have the same maximum output power. The parallel connection has a smaller optimal resistance and has advantages in practical engineering applications. Both the pressure amplitude and the pulsation frequency affect the output voltage and power and increasing the pulsation frequency leads to the decrease of optimal resistance. By employing parallel connection, APEH can achieve higher output at lower load resistances. When the resistance is 12 kΩ, the average power and power density are reach as 997.63 μ W and 2.54 μ W mm−3, respectively. In summary, the APEH proposed in this paper offering a viable solution for energy recovery in water hydraulic systems and the sustainable power supply of the sensors, along with providing relevant theoretical references and practical schemes. [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]

Summary: The integration of distributed energy resources (DERs) into DC microgrids has become commonplace in many applications, including electric vehicle (EV) systems that use batteries, fuel cells, and supercapacitors as energy storage systems. To make a sustainable charging system for electric vehicles, DERs can be used in conjunction with the grid. In many cases, charging systems based on isolated DC‐DC converters, such as the dual active bridge (DAB) converter, with various controls, are typically used. However, integrating multiple DERs at the common input DC link can result in a loss of isolation in the DAB converter and also leads to problems with circulating current. To maintain isolation, multiple DAB converters can be used, but this increases the system's size. Alternatively, the multiport isolated DC‐DC converter can address such issues but introduces complexities such as cross‐coupling between power flow. This paper proposes a hardware decoupling control methodology for a triple active bridge (TAB) based isolated DC‐DC converter, with power routing features for simultaneously charging two EV's battery stack. Through hardware decoupling control, appropriate passive components are designed and selected to connect with the individual H‐bridges of the TAB for power decoupling. The paper discusses the cross‐coupling issue in the TAB and describes a methodology derived from mathematical expressions for achieving power decoupling. For validation of the control, a 5 kW system is modeled in MATLAB Simulink, and the results demonstrate how the proposed approach overcomes cross‐coupling issues. Further, a 500 W hardware prototype has been developed to validate the proposed approach. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to carry out parameter design and dynamic stability verification experiment of controllable damping ferrofluid bearing. A new type of ferrofluid bearings is designed, and its internal magnetic fields are simulated by the finite element analysis software ANSYS. In this paper, the coefficient of magnetic leakage is taken as the optimization object, and the optimal parameters of ferrofluid bearings are updated. At the same time, the working principle of the ferrofluid bearings test platform is introduced, which includes a servomotor with a controller, an eddy displace sensor, an amplifier and a power supply. Finally, the dynamic stability of ferrofluid bearing is verified by experiments. The experimental results show that when the applied current is less than or equal to 0.08 A, the amplitude of the rotor supported by the ferrofluid bearing decreases with the applied current increment. Besides, the dynamic stability of the rotor is also related to the rotational speed. When the applied current is 0.08 A, the amplitude of the rotor supported by the ferrofluid bearing firstly increases and then decreases with the rotational speed increment. It is proved that the ferrofluid bearings have a strong function of the dynamic stability, which can suppress the vibration of the rotor, and have high accuracy of both position and rotation. [ABSTRACT FROM AUTHOR]

Multi-input power supply systems are mostly used in the field of combined power supply of multiple new energy sources. Multi-input inverters play an important role in these systems; however, they often face the issue of common-mode currents. This paper proposes an improved modulation mod for a non-isolated series simultaneous power supply type dual-input inverter with low common-mode current for new energy generation applications. In this paper, a circuit simulation is designed and a dual-input inverter circuit model is fabricated for experiments, after which it is verified that the improved modulation method can suppress the common-mode current to below 30 mA, providing an effective modulation scheme for mitigating common-mode currents in the joint power supply of multiple new energy sources. [ABSTRACT FROM AUTHOR]

The paper proposes a new stochastic multiobjective technoeconomic model for integrating photovoltaic (PV) and wind energy resources in electricity price (EP)‐driven distribution systems. The primary goal of this paper is to determine the optimal location and capacity for renewable energy‐based distributed generation, specifically PV and wind resources, while considering weather and system uncertainties. These uncertainties include stochastic variations in PV illumination intensity, wind speed, EP, and load fluctuations. To address these uncertainties, the paper employs scenario modeling techniques named as Latin hypercube sampling with Cholesky decomposition. This technique generates multiple correlated scenarios that represent uncertain variables. Subsequently, a scenario reduction technique is applied to identify the scenario with the highest probability. Later, a mathematical model is developed to minimize an objective function that encompasses various factors like system losses, node voltage deviations, the cost of purchasing power from the grid; and simultaneously maximize the total annual energy savings. The objective is to find optimal solutions that strike a balance between different objectives. To obtain an efficient optimum solution, this paper employs an effective meta‐heuristic technique named as JAYA algorithm. The results obtained by the JAYA algorithm are juxtaposed with those obtained using particle swarm optimization and genetic algorithm techniques. The proposed method is evaluated using Institute of Electrical and Electronics Engineers (IEEE) 33‐node and IEEE 69‐node test feeders to validate its feasibility and effectiveness. However, the effectiveness of the proposed method is not limited to any size of test systems. [ABSTRACT FROM AUTHOR]

The P&P (pulp and paper) industry in Taiwan is highly energy intensive and there is much product diversification. Taiwan has extremely limited coal and petroleum resources and imports 98% of its energy supply. Increased energy utilization efficiency to reduce energy consumption is necessary for industry in order to implement energy audit recommendations. This work summarizes the energy-saving potential of 118 firms from 2009 to 2013 as determined by on-site energy audits, as well as the energy savings implemented in 2011 by 72 firms in Taiwan's P&P industry, according to data from the on-line Energy Declaration System. It is found that the total of the energy-saving potential and the implemented energy savings are 168.3 and 762.1 TJ, respectively. The results of this study can serve as a reference for current P&P operations and as a base case for stimulating changes in energy utilization. [ABSTRACT FROM AUTHOR]

Use of recycled fiber material for the production of paper and paperboard has a significant share in solving problems related to environmental protection and conservation of energy resources. One of the most important processes for the paper recycling with printing press is a deinking. Perspective method for deinking of waste paper by the method of flotation is the enzyme treatment at neutral pH. The aim of this work is to study the deinking of recycled paper with offset printing press through flotation and use of enzymes. [ABSTRACT FROM AUTHOR]

Aiming to overcome the obstacles of power supply requirement and chip usefulness in practice, a low-cost and convenient portable electrochemical sensing device is introduced for the first time, featuring bipolar electrode system, LED read-out, laminated paper-based devices, and low-voltage button cells. The electric circuits of this practical device are constructed on laminating films with copper and conductive carbon tapes, and the reservoirs facilitating chemical reactions are made with chromatography paper. The device is sensitive to electrochemical responses, validated by the demonstrative hydrogen peroxide and enzyme-assisted glucose detection. The business-card-size chip achieves sensitive analyte detection by naked eyes as well as further image processing in both laboratory samples and human serum samples testing, featuring detection limit as low as 1.79 μM and a dynamic range from 10 μM to 10 mM. This new practical design of point-of-care sensing chip entails the properties of facile fabrication, simple usage, high robustness, low power consumption, and accurate sensing showing the attainability of fabricating a useful and portable analytical device. [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]