Energy Conversion Rate Research Articles

AI-Driven Decision Support System for Green and Sustainable Urban Planning in Smart Cities

Abstract This study focuses on innovative practices in sustainable urban planning, demonstrating significant advancements in key areas such as solar panel efficiency, rainwater harvesting capacity, community garden space, and bike-sharing station accessibility through in-depth experimentation and analysis. The research results show that the energy conversion rate of solar panels reached 25%, surpassing the market standard of 24%, which is crucial for enhancing self-sufficiency in energy in urban areas. The rainwater harvesting system performed well, achieving a capacity of 600 liters per square meter, slightly below the market rate of 650 liters, but still demonstrating significant potential in dense urban environments. Additionally, our project provided 3 square meters of community garden space per resident, exceeding the market average, effectively promoting urban greening and improving residents’ quality of life. In terms of transportation, our experimental model featured 1.5 bike-sharing stations per 1000 residents, better than the market data of 1.2 stations, contributing to the development of sustainable urban transportation. These outcomes not only showcase the potential of sustainable urban planning but also provide practical references and guidance for future urban development.

Intense Magnetic Reconnection Process Embedded in Three‐Dimensional Turbulent Current Sheet

AbstractRecent magnetospheric observations and three‐dimensional (3D) kinetic simulations have shown that plasma wave activities are significantly enhanced around the reconnection x‐line, implying that the reconnection process is fully 3D. However, how the turbulence affects the local reconnection process has been poorly understood so far. We find by means of large‐scale particle‐in‐cell simulation in 3D system that the local reconnection rate can be significantly enhanced, reaching 0.4, which is much larger than theoretical predictions for two‐dimensional (2D) reconnection. The large reconnection rate is associated with large energy conversion rate and strong electron acceleration. The enhancement of the reconnection rate is caused by local increases of electron momentum transport and pressure gradient force induced by turbulence, which can not occur in 2D system. The result is expected to give better interpretations to in‐situ satellite observations where magnetic reconnection proceeds in 3D system.

Performance of a Raft-Type Wave Energy Converter with Diverse Mooring Configurations

The development and utilization of wave energy, heralded as a potential leading source of clean energy worldwide, have garnered considerable attention from the global research community. Among the diverse array of wave energy converters (WECs), the raft-type WEC stands out for its potential to efficiently harness and utilize wave energy, offering high energy conversion rates and a broad frequency response range. This paper delves into the evaluation of a raft-type WEC’s performance in various mooring configurations under different wave conditions. Our analysis primarily focuses on the dynamics of the two-body WEC using a weakly nonlinear three-dimensional potential flow solver. The considered device comprises two interconnected floating barges, incorporating a power take-off system at the hinged connection point. This investigation involves the use of equivalent linear damping to model the power take-off (PTO) system. To validate the numerical simulations, we conduct physical model experiments with WECs. Additionally, the coupling of the raft-type WEC’s dynamics and its mooring dynamics was examined, highlighting the performance differences between various mooring systems through a comparative analysis.

Concave microlens arrays with tunable curvature for enhanced photodegradation of organic pollutants in water: A non‐contact approach

AbstractSolar‐driven photodegradation for water treatment faces challenges such as low energy conversion rates, high maintenance costs, and over‐sensitivity to the environment. In this study, we develop reusable concave microlens arrays (MLAs) for more efficient solar photodegradation by optimizing light distribution. Concave MLAs with the base radius of μm are fabricated by imprinting convex MLAs to polydimethylsiloxane elastomers. Concave MLAs possess a non‐contact reactor configuration, preventing MLAs from detaching or being contaminated. By precisely controlling the solvent exchange, concave MLAs are fabricated with well‐defined curvature and adjustable volume on femtoliter scale. The focusing effects of MLAs are examined, and good agreement is presented between experiments and simulations. The photodegradation efficiency of organic pollutants in water is significantly enhanced by 5.1‐fold, attributed to higher intensity at focal points of concave MLAs. Furthermore, enhanced photodegradation by concave MLAs is demonstrated under low light irradiation, applicable to real river water and highly turbid water.image

A novel collaborative control algorithm for maximum power point tracking of wind energy hydraulic conversion system

AbstractWind has been admitted as one of the most promising renewable energy resources in multinational regionalization policies. However, the energy conversion and utilization are challenging due to the technique reliability and cost issues. Hydraulic wind turbine (HWT) may solve the above problems. HWT is taken as a research object, and the maximum power point tracking (MPPT) control strategy is proposed collaborating with active disturbance rejection control (ADRC) and linear quadratic regulator (LQR) control methods, to solve multiplicative nonlinearity problems in the plant models and the influence of external disturbance on control performance in the MPPT control process. A nonlinear simulation model is built to explain the main findings from the experiments and obtain a better understanding of the effect of time‐varying system parameters and random fluctuation in wind speed. The collaborative control algorithm is experimentally verified on a 24‐kW HWT semi‐physical test platform that results in a promising energy conversion rate, plus the hydraulic parameters can satisfy the demand, accordingly. Ultimately, the potential challenges of implementing this technique in a smart wind energy conversion system are discussed to give a further design guidance, either theoretically or practically.

Macro- and micromechanical properties of flawed sandstone and their degradation mechanisms under hydrodynamic scouring

To reveal the degradation mechanisms of the mechanical properties of a rock mass in a reservoir bank slope under hydrodynamic scouring, a hydrodynamic scour test device was developed in this study. Sandstone specimens containing prefabricated flaws were used as the research objects. Three conditions, namely, natural conditions, hydrostatic immersion, and hydrodynamic scouring, were considered. By considering the results of laboratory testing, digital image correlation (DIC), scanning electron microscopy (SEM), and thermodynamic analysis and fractal theory, the effects of different flow states on the mechanical properties of the flawed rock mass were systematically investigated in terms of the macromechanical parameters, strain field, strain energy, and microstructure. A crack initiation stress identification method based on the differentiation rate of the effective variance of strain fields was proposed. The energy conversion in the rock loading process was quantitatively characterized using three strain energy characteristic indicators. The internal microstructure of the rock was quantitatively characterized using a combination of SEM image characteristics and the fractal dimension. It was found that the uniaxial compressive strength, elastic modulus, crack initiation stress, energy storage limit, elastic strain energy conversion rate, and dissipated strain energy conversion rate of the hydrodynamically scoured specimen were the smallest, while the fractal dimension was the largest. There was a strong correlation among the mechanical parameters, energy characteristic indicators, and fractal dimensions of differently treated sandstone specimens because the macromechanical response and energy conversion characteristics of a rock mass are closely correlated with changes in its internal structure.

Loss of Farnesoid X receptor (FXR) accelerates dysregulated glucose and renal injury in db/db mice.

End-stage renal disease is primarily caused by diabetic kidney disease (DKD). The Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily, has anti-inflammatory, lipid-lowering and hypoglycemic properties. It also inhibits renal fibrosis. Although its physiological role is not fully understood, it also plays a role in the control of diabetic nephropathy (DN). In the present study, we examined male FXR & leptin receptor double knockout mice, in which weight, blood glucose, body fat, and other indicators were monitored. After 6 months of rearing, blood and urine samples were collected and biochemical parameters were measured. Fibrosis was assessed by Masson's stain, while the assessment of the resuscitation case's condition was performed using succinate dehydrogenase (SDHA) stain immunohistochemistry, which measures aerobic respiration. Expression of molecules such as connective tissue growth factor (CTGF), SMAD family members 3 (Smad3) and 7 (Smad7), and small heterodimer partner were detected by RT-PCR and Western blotting as part of the application. FXR knockout decreased body weight and body fat in db/db mice, but increased blood glucose, urine output, and renal fibrosis. Primary mesangial cells (P-MCs) from FXR+/+ mice stimulated with transforming growth factor β1 (TGFβ1) showed significantly higher levels of related fibrosis factors, TGFβ1 and Smad3 mRNA and protein, and significantly reduced levels of Smad7. These effects were reversed by the action of FXR agonist chenodeoxycholic acid (CDCA). P-MCs from FXR-/- mice stimulated with TGFβ1 resulted in an increase in the expression and protein levels of collagen I and TGFβ1, and the addition of CDCA had no significant effect on TGFβ1 stimulation. However, compared with FXR+/+db/db mice, the rate of oxygen consumption, the rate of carbon dioxide production, and the rate of energy conversion were increased in FXR-/-db/db mice, whereas the SDHA succinate dehydrogenase, a marker enzyme for aerobic respiration, was significantly decreased. These results provide evidence that FXR plays a critical role in the regulation of mesangial cells in DN. The likely mechanism is that aberrant FXR expression activates TGFβ1, which induces extracellular matrix accumulation through the classical Smad signaling pathway, leading to mitochondrial dysfunction.

Atmospheric pressure pulsed modulated arc discharge plasma

Direct-current (DC) arc plasma has great application values in the field of the chemical industry, but it has the problem of low energy efficiency. Facing the requirement for improving the energy efficiency of the arc, this paper proposes a unique method of pulsed modulated arc (PMA). This method uses high-frequency pulses and reduces the arc current to improve the control of electron temperature. The electrical characteristics, optical characteristics and products are tested. The test results show that during the PMA process, all of the experimental results which include voltage, current and light will significantly increase. These results are analyzed from the perspective of functionality, repeatability and energy conversion. The analysis results show that although the PMA method does not show good parameter consistency, it has potential application prospects because it increases the energy conversion rate by 4.5% and 8% from the perspective of light and products, respectively.

New energy grid connection power control method based on predictive tuning performance and embedded system

Nowadays, due to the cleanliness and high efficiency of grid-connected new energy, it has become more and more popular in the market. However, there are still some problems in grid-connected power control and cannot be well supervised. Therefore, this paper studies a new energy grid-connected power control method based on predictive regulation performance and embedded systems, aiming to control new energy grid-connected power through predictive regulation performance and embedded systems. In this paper, the predictive regulation performance and energy conversion rate of the embedded system new energy grid connection are tested. In the experiment, the energy conversion rate was between 60% and 70%, while the traditional new energy grid connection rate was between 40% and 60%. The maximum power generation efficiency of new energy grid-connected with predictive regulation performance and embedded systems was 83%, while the maximum power generation efficiency of traditional new energy grid-connected was 68%. It can be seen from these experimental results that predictive regulation performance and embedded systems have good effects on new energy grid-connected power control.

Synthesis of La–Mg–Ni@Ag composite catalyst and its catalytic performance for borohydride

Direct borohydride fuel cells (DBFC) have a promising future as a new type of fuel cell with a high energy conversion rate and a green profile, the performance of which is mainly determined by the anode catalyst. Precious metals as anode catalysts have better catalytic ability but are expensive, limiting their application. Hydrogen storage alloys as anode catalysts can inhibit hydrolysis and enhance the conversion efficiency, but have poor catalytic ability. On this basis, Ag modified La–Mg–Ni hydrogen storage alloy catalyst (La–Mg–Ni@Ag) was synthesized by photo-deposition method in this study. The microstructures and surface morphologies of Ag, La–Mg–Ni alloy and La–Mg–Ni@Ag composite alloy were investigated in detail by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their catalytic and electrochemical properties towards BH4− were evaluated by cyclic voltammetry (CV) and chronoamperometry (CA). The results show that the La–Mg–Ni@Ag composite catalyst is composed of Ag and La–Mg–Ni alloy phase structure, and La–Mg–Ni alloy particles are closely covered by tiny particles of Ag. In addition, the La–Mg–Ni@Ag composite catalyst has better catalytic activity and stability than those of La–Mg–Ni hydrogen storage alloy catalyst, with an increase in peak oxidation current density of about 50% and an increase in the number of transferred electrons of about 3.

Successive Energy Conversion at a Stepwise Dipolarization Front

Dipolarization fronts (DFs), ion-scale magnetic structures characterized by sharp enhancement of northward magnetic field developed within plasma jets, have been suggested to play a crucial role in the energy transfer chain in the terrestrial magnetotail. Here we present the first observation of successive energy conversion driven by multiple current layers at a stepwise DF, using high-cadence measurements from NASA’s Magnetospheric Multiscale mission. The multiple current layers are adjacent and cause gradual variations of particles and electromagnetic fields, leading to an intense, successive increase of energy conversion rates at the DF in the satellite frame, with electromagnetic field energy being transformed into particle energy. The energy conversion is contributed by both ion and electron currents. The motional electric field drives the energy conversion, while the wave electric field fed by lower hybrid drift instability modulates the energy partition. These results provide new insights into understanding energy transfer in the terrestrial magnetotail.

High-Efficient Anti-Icing/Deicing Method Based on Graphene Foams.

Anti-icing/deicing has always been a focal issue in modern industries. A novel anti-icing/deicing material based on graphene foams (GF) is prepared in this paper, which integrates multiple functions, including electrothermal conversion, photothermal conversion, and superhydrophobicity. The GF sheet is used as a bottom layer bonded on the protected substrate, which is covered by a polymeric composite coating filled with TiN and SiO2 nanoparticles. Electric heating and light heating experiments are performed to study the anti-icing/deicing performances of such a GF-based material. It is found that, under the unique action of electric fields, a voltage of only 1 V is needed to increase the surface temperature from minus tens of degrees to the one above zero within 400 s, which is much lower than their previous counterparts of more than 10 V to achieve the same unfreezing effect. A slight increase of the applied voltage to 1.5 V can even result in a remarkable increase of the surface temperature from room temperature to more than 150 °C within 200 s, in contrast to existing electric heating techniques to attain peak temperatures of about 100 °C at the expense of tens of volts. Such performances enable the GF-based material to achieve an outstanding electrothermal energy conversion rate of more than 90%. Furthermore, with the help of sunlight illumination in addition to the electric power, not only can the critical voltage to prevent icing be reduced but also a much more rapid and adequate removal of ice or frost from the surface can be realized compared with the deicing/defrosting performance under either electric or light field alone. All of these results demonstrate the obvious advantages of the present method in superior energy utilization efficiency and universal applicability to dark and sunlight environments, which should be particularly useful for at-all-cost protection of key components in industrial equipment from icing.

Multiphysics Modeling for Solid Oxide Electrolyzer Cell with Heterogenous Synthetic Microstructure

Solid oxide fuel cell (SOFC) and electrolyzer cell (SOEC) are the main focus for researchers in recent times to diminish greenhouse gas emissions and meet cleaner energy demand, as these devices have highest energy conversion rates and efficiencies [1]. The major hinderance in commercializing SOEC is due to its faster cell degradation under higher current density, compared against its SOFC counterpart. The delamination of oxygen electrode (OE) from the electrolyte (EL) is one of the major causes for the cell degradation [2].We employed a multi-physics numerical model to understand the electrochemical performance of a SOEC half-cell more precisely at a microscale. In this study, widely used mixed ionic and electronic conductor (MIEC) La1-xSrxCo1-yFeyO3-d (LSCF) and Gadolinium-doped Ceria (GDC) composite is used as the oxygen electrode and, pure ionic conductor 8 mol% Y2O3 doped ZrO2 (YSZ) is used as the electrolyte. A GDC buffer layer is tucked in between to prevent undesirable side reactions between OE and EL during long term polarization operation. Until now, a homogenous OE structure has commonly been used with effective physicochemical properties to predict the performance of SOFC/SOEC [3,4]. Only a few researchers have worked on heterogenous microstructure model [5] and simulated the electrochemical performance of the cell.Synthetic microstructure of LSCF-GDC porous electrode as shown in Figure 1 are constructed with an opensource software Dream 3D with particle size ranging from 0.45um - 1.5um. We developed in-house Matlab code for labelling domains, interfaces (2PB and 3PB) and digitally removing the unconnected phases to reduce numerical instabilities while solving the mathematical model in COMSOL Multiphysics 6.0. Mesh in these domains is constructed using Iso2Mesh toolbox [6] and translated as mphtxt file which is later imported into COMSOL. This practice reduces the computational time and memory.We employed Nernst-Planck theory for solving the transport of species like vacancy, hole and electron within LSCF inside OE. Multi-step charge transfer at two phase boundary (2PB) and triple phase boundary (3PB) interfaces for oxygen evolution reaction are formulated by Butler-Volmer expressions [4]. A physics-based impedance model under DC bias is developed to separate the electrochemical contributions from 2PB and 3PB transport pathways. The voltage-current curve during long-term polarization test is coupled with the model for validation and approximation of process parameters. Furthermore, we will simulate the crack propagation at OE-buffer layer interface in various directions and orientations to understand the failure mechanism on the synthetically constructed microstructure.

A concise review of technologies for converting forest biomass to bioenergy

The use of biomass is vital in reducing the negative effects of rising fossil fuel consumption. Given its quantity and diversity, forest biomass has garnered a lot of interest among the many kinds of biomass. This study evaluates the various strategies for transforming woody waste into usable biofuels. Carbon dioxide emissions from traditional energy generation systems could be mitigated through the direct utilization of forest biomass. Low energy conversion rates, as well as soot emissions and residues, are some of the problems that come up when directly using forest biomass. The sustainability of direct energy generation from forest biomass is also seriously threatened by the lack of constant access to biomass. Co-combustion with coal and pelletizing biomass is two solutions proposed for this issue. Co-combustion of forest biomass with coal has the potential to lower the process's emissions of carbon monoxide, nitrogen oxides, and sulfides. This article reviews and discusses the biochemical and thermochemical mechanisms that can transform forest biomass into a variety of liquid and gaseous biofuels. Future research using cutting-edge sustainability assessment tools like life cycle assessment, exergy, etc. should investigate the sustainability of forest biomass conversion processes to bioenergy further.

Ultra-broadband low-frequency high-efficiency acoustic energy harvesting with metamaterial-enhanced loudspeakers

Acoustic energy harvesters (AEHs) open up opportunities to recycle noise waste and generate electricity. They provide potential power solutions to a wide range of sensors. However, the practicality of AEHs has long been limited by their narrow bandwidths and low efficiencies. In this study, we present an ultra-broadband AEH and a highly efficient AEH that transforms sound energy into usable electrical power. Our broadband device comprises an electrodynamic loudspeaker driver and an optimized acoustic metamaterial matching layer and is capable of converting 7.6% to 15.1% of total incident sound energy from 50 to 228 Hz. Moreover, we demonstrate that by replacing the loudspeaker surround with a lower-loss material such as PDMS, the energy conversion rate can be significantly increased to 67%. The proposed broadband AEH has a fractional bandwidth eight times the state-of-the-art, while the proposed highly efficient AEH has a peak efficiency three times the state-of-the-art. The outstanding performance makes our designs cost-effective and scalable solutions for noise reduction and power generation.

Greenhouse Warming Reduces Global Energy Conversion Into Oceanic Lee Waves

AbstractOceanic lee waves play an important role in dissipating wind‐driven ocean circulations and powering turbulent diapycnal mixing. Here we investigate impacts of the greenhouse warming on global energy conversion into lee waves using a linear theory of lee wave generation and output from a high‐resolution (0.1° for the ocean) coupled global climate model. The global energy conversion rate into lee waves under the historical (1930s) climate condition is estimated to be 193.0 ± 3.0 GW. Under the high carbon emission scenario, this conversion rate is projected to decrease by about 20% by the end of 21st century, due to weakened bottom large‐scale mean flows, mesoscale eddies and stratification. The decrease of the conversion rate is widespread and particularly pronounced in the Gulf Stream and Drake Passage.

Hydrogen production at intermediate temperatures with proton conducting ceramic cells: Electrocatalytic activity, durability and energy efficiency

Proton conducting ceramic cells (PCCs) are an attractive emerging technology operating in the intermediate temperature range of 500 to 700 °C. In this work, we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis (PCCEL). We demonstrate a high-performance steam electrolysis owing to a composite positrode based on BaGd0.8La0.2Co2O6−δ (BGLC1082) and BaZr0.5Ce0.4Y0.1O3−δ (BZCY541). The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as –0.8Acm−2 close to the thermoneutral cell voltage at 600 °C. The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg−1 that is comparable to state-of-the-art low temperature electrolysis technologies, while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells (SOCs). Compared to SOCs, the results verified the higher performances of PCCs at the relevant operating temperatures, due to the lower activation energy for proton transfer comparing with oxygen ion conduction. However, because of the p-type electronic conduction in protonic ceramics, the energy conversion rate of PCCs is relatively lower in steam electrolysis. The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions, making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen. To increase the faradaic efficiency by optimizing the materials, the cell design, or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits.

Thermodynamic prediction of ferroelectric mechanical to electrical energy harvesting capabilities utilizing phase dependent electromechanical coupling factors

Prediction of the mechanical to electrical energy harvesting capabilities in [011]C cut PIN-PMN-PT is presented as a function of thermodynamic analysis of hysteresis in the stress induced ferroelectric phase transformation, and phase dependency of the electromechanical coupling factors. Energy conversion rates vary from 0.528 for low transformation hysteresis to 0.432 for high transformation hysteresis. While these predicted values are lower than the experimentally determined value from literature (“approximately 60%”), differences are explained through limitations of the mechanical loading mechanism. This brings the predicted values into agreement with literature. Ferroelectric rhombohedral phase behavior is found to dominate energy harvesting capabilities.

The high performance lithium metal composite anode by excessive alloying process

With the rapid development of technology and the severe environmental crisis, improving the utilization and conversion rate of sustainable energy has become an important way to alleviate ecological and sustainable development. Therefore, the development of a new generation of anode materials with high specific capacity, long cycle life has become the primary task. Elements that can react with lithium and form alloy can be used as electrode materials, but these materials have limited capacity and poor electrochemical property. Lithium metal, as the ideal anode in lithium batteries, are restrained because of the dendrites formation. Herein, we introduced lithium metal composite anode by excessive alloying process, and to some extent, lithium dendrite formation and electrochemical issues are solved. The results show that lithium metal can be deposited evenly on the silver and silicon electrode surface, and both silver and silicon can enhance the coulombic efficiency and improve the electrochemical stability. In particular, silver-lithium composite electrodes can maintain 70 cycles with coulombic efficiency over 60 % which is twice as much as bare Cu electrodes. By this way, we make a new lithium metal composite anode structure and provide excessive alloying process to extend the application of commercial anode.

Optimal integration of electrolysis, gasification and reforming for stable hydrogen production

Engineering industries such as petroleum and petrochemicals have strict requirements for the stability of hydrogen supply to ensure the safety and reliability of system operations. However, relying on a single hydrogen production technology is insufficient to meet the requirements of both stable and green hydrogen. This study proposes an integrated hydrogen production system combining water electrolysis, biomass gasification, and natural gas reforming to achieve stable and green hydrogen. To capitalise on the advantages of the individual technologies, the integration among the different hydrogen production methods considers not only energy but also materials. As a by-product of water electrolysis, oxygen can create a pure oxygen atmosphere for biomass gasification and natural gas reforming, thereby considerably improving the energy conversion rate. The heated gases from the biomass gasification transport thermal energy to the natural gas reforming. Stable and maximised hydrogen production can be achieved through optimal coordination of the three hydrogen production technologies and storage devices. Optimisation models are built for each component, and case studies show that the proposed integrated system exhibits energy efficiency of 64.19 %, which is 9.87 % higher than the 54.32 % efficiency of single-energy hydrogen production, and achieves an 67 % carbon emission reduction compared with the existing industrial technology. The integrated system proposed in this study provides a solution for stable hydrogen production under the broad requirement of carbon neutrality, and it will provide valuable guidance for future integrated hydrogen production system development and offer information that is of interest to operators and investors.