Energy Degradation Research Articles

Near-Infrared Unimolecular Chemiluminescence Probes for Deep-Tissue Imaging.

Chemiluminescence (CL) imaging has emerged as a promising optical imaging technique due to minimal background autofluorescence and being excitation-free. However, the emission of most chemiluminescent probes was concentrated in the visible light region, which limited the tissue penetration. Although some NIR chemiluminescence probes have been reported based on the chemiluminescence resonance energy transfer (CRET) strategy, the energy loss was inevitable. Thus, it is crucial to develop near-infrared (NIR) unimolecular probes with direct chemiluminescence. Herein, we propose a strategy of increasing conjugation for designing and synthesizing novel NIR chemiluminescence unimolecular probes that consist of luminol, electron acceptor, π-bridge, and electron donor. Luminol was conjugated to the unimolecular backbone to produce direct NIR chemiluminescence. Notably, the direct CL mechanism of probes was investigated. Compared with CRET-based chemiluminescence, this direct CL was more advantageous to immediately convert the chemical energy into chemiluminescence, avoiding energy degradation. Furthermore, the corresponding nanoparticles with great biosafety were prepared by self-assembly with amphiphilic DSPE-PEG. Especially, TTBL@PEG-NPs with NIR-I emission were successfully used in the sensitive in vivo chemiluminescence imaging of various inflammation models, such as peritonitis, ear swelling, and colitis. This study paves the way for the design of NIR unimolecular chemiluminescence probes and deep-tissue imaging.

Research on dynamic vibration absorption technology for power equipment based on energy degradation

Research on dynamic vibration absorption technology for power equipment based on energy degradation

Sodium disilicate pretreatment enhancing methane production from anaerobic digestion of waste activated sludge

Improving the efficiency of digestion is a major focus of waste activated sludge (WAS) anaerobic digestion (AD) research. This study investigates the viability and mechanism of sodium disilicate (SD) in enhancing the digestive efficacy of WAS. Batch AD experiments for the sludges pretreated by varied amounts of SD were carried out, and the results revealed that a dosage of 90 mmol/L resulted in the highest methane yield (247.9 mL/g·VS), marking a 90.0 % increase compared to the raw sludge. Mechanistic investigations highlighted that SD pretreatment facilitated EPS degradation, cell lysis, and modulation of interfacial interaction energy, ultimately enhancing sludge disintegration and methane generation. Microbial community analysis unveiled an enrichment of crucial functional microorganisms associated with hydrolysis, acidification, and methanation. The heightened presence of acetotrophic and hydrogenotrophic methanogens significantly boosted methane production. Furthermore, metagenomic analysis corroborated that the SD pretreatment stimulated amino acid metabolism, energy metabolism (specifically ABC transporter proteins), and carbohydrate metabolism, thereby enhancing methanogenic activity through increased microbial metabolic activities and upregulated key enzyme expression. This research underscores the potential of SD-assisted pretreatment strategies in augmenting WAS digestion, introducing supplementary pretreatment avenues for optimizing anaerobic biotechnology.

A phase-field fracture model in thermo-poro-elastic media with micromechanical strain energy degradation

This work extends the hydro-mechanical phase-field fracture model to non-isothermal conditions with micromechanics based poroelasticity, which degrades Biot’s coefficient not only with the phase-field variable (damage) but also with the energy decomposition scheme. Furthermore, we propose a new approach to update porosity solely determined by the strain change rather than damage evolution as in the existing models. As such, these poroelastic behaviors of Biot’s coefficient and the porosity dictate Biot’s modulus and the thermal expansion coefficient. For numerical implementation, we employ an isotropic diffusion method to stabilize the advection-dominated heat flux and adapt the fixed stress split method to account for the thermal stress. We verify our model against a series of analytical solutions such as Terzaghi’s consolidation, thermal consolidation, and the plane strain hydraulic fracture propagation, known as the KGD fracture. Finally, numerical experiments demonstrate the effectiveness of the stabilization method and intricate thermo-hydro-mechanical interactions during hydraulic fracturing with and without a pre-existing weak interface.

Numerical modeling of shrinkage induced cracking in cementitious materials with three-dimensional simulation and phase-field method

This study investigates the damage and cracking of concrete induced by drying shrinkage. While previous studies have primarily focused on two-dimensional configurations, this research employs three-dimensional phase-field simulations of concrete samples undergoing the drying process. The distribution of inclusions is derived from tomographic images of real samples. The analysis includes the evolution of the damage field and the propagation of cracked zones. The study introduces the formulation and implementation of the numerical method and applies it to elucidate the cracking process resulting from drying shrinkage in concrete composites with various types of inclusions. Numerous numerical simulations were conducted to accurately depict the cracking process induced by drying shrinkage in the samples, evaluating the effects of different inclusions with varying stiffness on the concrete’s cracking phenomenon and comparing the impact of various energy degradation methods on crack simulation. Moreover, the study analyzes the influence of the spatial distribution of the inclusions in the three-dimensional simulation and compares the numerical results with experimental observations.

A new nonlocal macro-micro-scale consistent damage model for layered rock mass

Layered rock mass exhibits transverse isotropic characteristics in deformation and strength, and the strength anisotropy is difficult to achieve in traditional local action modes. Therefore, in the framework of nonlocal macro–micro-scale consistent damage (NMMD) theory, this paper constructed a micro damage criterion suitable for layered rock, where both the critical elongation and the brittleness index of material bond are defined as an elliptic function of the bond angle. Next, based on the geometric damage reflecting continuity loss of material point, which is obtained by the weighted average of bond damages around the point, an energy degradation model of a transversely isotropic stiffness matrix is established to achieve localized damage propagation of macroscopic cracks in the layered rock mass. The reliability and advantage of the NMMD model for transversely isotropic material are verified by comparison with the experimental and phase field results through a three-point bending shale beam with different bedding orientations. Finally, the splitting mechanism and bearing capacity of the Brazilian disk with different bedding directions and different inclinations of notch are explored through the established NMMD finite element model. The model is easily implemented, enabling automatic tracing of cracks and accurate prediction of load–displacement curves.

Phase field modeling of ductile fracture with isotropic hardening and radius return method

Phase field model has been investigated for brittle fracture in many static and dynamic scenarios, but its applications to ductile fracture is not as common as brittle fracture, especially implementing in software LS-DYNA with explicit scheme. In this study, an efficient LS-DYNA implementation of the phase field modeling of ductile fracture is presented and both with and without the split of elastic strain energy have been considered for the damage evolution. In more detail, plasticity formulation of ductile material with isotropic hardening is briefly presented first and then the governing equations of the classical phase field model are derived, which gives the displacement-phase coupled problem. For with the split of elastic strain energy, the shear component of elastic strain energy is considered for the damage evolution. The influence of degradation function on stress–strain curve is also investigated by using three kinds of function (polynomial function, algebraic fraction function and sigmoid function), which leads to linear and nonlinear finite element method (FEM) formulation of the phase field model and Newton–Raphson method is used to solve the nonlinear FEM formulation of the phase field model. A tensile bar test shows the influence of critical energy release rate and degradation function on stress–strain curve. Mode Ⅰ failure of three-point bending test, Mode Ⅱ failure of single-edge notched plate and mixed-mode failure of asymmetrical double-notched plate verify the proposed model in this study. From these simulations, with the split of elastic strain energy shows improvements on plastic deformation than without the split of elastic strain energy.

Investigating the Energy Potential and Degradation Kinetics of Nine Organic Substrates: Promulgating Sustainability in Developing Economies

To standardize, systematize, and improve the efficiency of the evaluation of biodegradable materials for large-scale biogas projects to support clean and sustainable energy development in emerging economies from a sub-Saharan African perspective, this paper analyzes and fits the potential for methane production (biochemical methane potential, BMP) and degradation kinetics of materials based on the gas production and degradation dynamics obtained from methane potential experiments. The first-order, modified first-order, and Gompertz models are used for analysis and fitting. The Gompertz model shows higher accuracy in fitting the methane production potential curve of screened materials, and the fitted methane potential values are close to the experimental values. When using BMP1% (cumulative gas production reaching 1% of cumulative gas production per day) as a quantitative indicator for the methane production potential of materials, the cumulative methane production reaches over 85% of the cumulative methane production at the end of the experiment. The BMP test time is shortened by 26.98% to 72.06%. Among the screened materials, the methane production potential (calculated using BMP1%) of dry rice straw, maize leaves, fresh rice, soybean straw, maize stalks, chicken manure hydrolysate, chicken feathers, kitchen/food waste, and chicken offal are 234.14, 241.01, 253.34, 331.40, 305.80, 508.41, 510.10, 630.7, and 621.32 mL/g, respectively. The kinetic parameters show that among the nine materials, cellulose materials (except for maize stalks and soybean straw), chicken manure, and kitchen waste are easily degradable materials. In contrast, chicken feathers and offal are slowly degradable materials. The study posits that comparing standardized methane production potential and methane production kinetic parameters among materials improves the efficiency of screening materials and is critical for biogas projects.

A comparative study of bifacial versus monofacial PV systems at the UK’s largest solar plant

Abstract This paper presents an extensive analysis of the UK’s largest bifacial photovoltaic (PV) power plant, located in North Yorkshire. Commissioned in January 2020, this trailblazing facility, with a total installed capacity of 34.7 MW, is a benchmark for the evaluation of bifacial solar technology within the region. This pioneering study provides a thorough comparative assessment of bifacial and monofacial PV systems through a methodical investigation of their energy production, degradation rates, and spectral responses over a 4-year operational period. Our findings reveal that bifacial PV modules, distributed across four segments of the power plant, demonstrate a remarkable average power gain ranging between 15.12% and 17.31% compared with monofacial modules. Despite experiencing marginally higher annual degradation rates—1.17% for bifacial compared with 0.91% for monofacial systems—bifacial modules show superior resilience and energy yield, particularly during winter months when albedo effects are pronounced due to snow coverage. The study also highlights the strategic importance of spectral response analysis in optimizing PV performance. Bifacial modules have shown greater efficiency in capturing infrared radiation—a property that could be exploited to enhance overall energy yield under specific environmental conditions. The empirical data indicate a consistent performance of bifacial modules with an average normalized energy output clustering around the expected efficiency level. Therefore, the results of this study are pivotal for understanding the practical implications of deploying bifacial PV technology on a large scale. They provide valuable data for stakeholders in the solar energy sector, guiding future installations and innovations in solar panel technology.

A thermodynamically consistent creep constitutive model considering damage mechanisms

This paper derives a physically-based creep-damage and life prediction model through the basic laws of thermodynamics. The model divides creep damage into two parts: one corresponding to high temperature and low stress, related to cavity nucleation and cavity growth, and the other corresponding to high stress, related to dislocation movement. The creep strain rate consists of two components: diffusion creep, which is assumed to occur in all stress ranges, and dislocation-related creep, which activates when the external stress exceeds a certain threshold. The proposed model characterizes damage by the degradation of creep free energy. It accurately describes creep behavior over a wide stress range, including the transition phenomena observed in creep strain rate curves and creep life curves. This provides a constitutive reference for simulating long-term creep damage and life based on short-term creep data.

The role of financial inclusion, technology innovation, energy and environmental degradation in determining sustainable growth in Asia

AbstractSustainable growth is a top priority for all economies as they work towards creating a prosperous and resilient future for current and future generations. This study empirically explores the important role of financial inclusion (FI), energy consumption, technological (TECH) innovation and environmental degradation in the economic growth of 13 selected developing Asian countries from 2000 to 2021. The feasible generalized least squares method is used for empirical examinations due to the nature of the data. The study focuses on three dimensions of FI: penetration, usage and availability of financial institutions. The results show that FI, energy consumption and TECH innovation encourage economic growth, whereas ecological footprint discourages economic growth in selected Asian countries. The empirical findings highlight the importance of promoting sustainable growth in Asia through enhanced FI, TECH innovation, sustainable energy practices and environmental conservation. Governments in these countries should prioritize strengthening the financial sector, investing in research and development and implementing effective policies to ensure a clean and green environment. This will lead to inclusive and environmentally responsible development that benefits both current and future generations in the region.

A One‐Dimensional Model of Atmospheric Sputtering at Io Driven by S++ and O+

AbstractIo, the closest of Jupiter's four Galilean moons, suffers from intense ion bombardment from Jupiter's magnetosphere. The constant atmospheric erosion by energetic ion precipitation, referred to atmospheric sputtering, serves as an important mechanism of Io's atmospheric escape. This study is devoted to a state‐of‐the‐art study of atmospheric sputtering at Io, with the aid of constantly accumulated understandings of Io's space environment and atmospheric photochemistry, as well as the updated laboratory measurements. A Monte Carlo model is constructed to track the energy degradation of incident S++ and O+ and atmospheric recoils from which the sputtering yields of different atmospheric species are determined. Our calculations suggest a total escape rate of 3 × 1029 atom s−1 on Io, and SO2 is the dominant sputtered species. Further investigations reveal that S++ is the most efficient species for atmospheric sputtering on Io, and sputtering yields increase substantially with increasing incident ion mass, energy, and incidence angle. The model sensitivity to different influence factors is also discussed, including scattering angle distribution, atmospheric column density, proton precipitation, inelastic process, and surface sputtering, of which the former two dominate.

The action of heated RC joints strengthened with a novel strategy combined CFRP and SSEMSM under a quasi-static cyclic load

The current work presents the application of a novel strategy for strengthening heated beam column (B-C) joints under a quasi-static cyclic load. This technique involves utilizing a layer of carbon fiber-reinforced polymers (CFRP) sheets with a layer of stainless-steel expanded metal sheet mesh (SSEMSM). These two layers are installed on the steel reinforcement cage inside the joint before concrete casting. Then the reinforced concrete B-C joints, after being cast and cured, were subjected to heat (i.e., 400 °C and 600 °C). The joints were divided into three groups: three joints were kept as is (i.e., reference joints; no strengthening was applied), whereas three joints were strengthened with the previously mentioned strategy. With a view to investigating the seismic behavior of RC joints, a quasi-static cyclic load was applied to the joints to simulate a seismic load. Results showed that the average maximum load capacity for upgraded joints (strengthened) increased by 30%, 19%, and 1% at ambient (i.e., 23 °C), 400 °C, and 600 °C temperatures, respectively, with respect to the reference joint (JCTA). More importantly, the experimental results reveal a significant increase in the cyclic response of strengthened joints (i.e., higher load capacity, greater displacement, higher dissipated energy, higher ductility, and slower degradation in the secant stiffness).

Study of the irradiation hardening of a Fe9Cr ferritic model alloy by nanoindentations

This paper presents a series of Berkovich indentation results obtained on unirradiated and 7.2 MeV proton irradiated specimens of a Fe9Cr model alloy with an equiaxed ferritic microstructure. Using a energy degrader wheel made of 24 aluminum foils of different thickness, a flat damage profile of about 50 μm resulted from the irradiation, allowing to perform indentations within a volume material that is homogeneously irradiated. The indentation size effect on measured hardness was analyzed with a model based on the disloction-slip distance theory built on the concept of combined spatial frequency of all obstacles to dislocation motion. The effects on hardness of the tip-specimen contact size (or penetration depth), dislocation density and mean distance between irradiation defects were quantified and discussed. The irradiation hardening was characterized by the increase of hardness determined at large penetration depths.

Vacancy Engineering in 2D Transition Metal Chalcogenide Photocatalyst: Structure Modulation, Function and Synergy Application.

Transition metal chalcogenides (TMCs) are widely used in photocatalytic fields such as hydrogen evolution, nitrogen fixation, and pollutant degradation due to their suitable bandgaps, tunable electronic and optical properties, and strong reducing ability. The unique 2D malleability structure provides a pre-designed platform for customizable structures. The introduction of vacancy engineering makes up for the shortcomings of photocorrosion and limited light response and provides the greatest support for TMCs in terms of kinetics and thermodynamics in photocatalysis. This work reviews the effect of vacancy engineering on photocatalytic performance based on 2D semiconductor TMCs. The characteristics of vacancy introduction strategies are summarized, and the development of photocatalysis of vacancy engineering TMCs materials in energy conversion, degradation, and biological applications is reviewed. The contribution of vacancies in the optical range and charge transfer kinetics is also discussed from the perspective of structure manipulation. Vacancy engineering not only controls and optimizes the structure of the TMCs, but also improves the optical properties, charge transfer, and surface properties. The synergies between TMCs vacancy engineering and atomic doping, other vacancies, and heterojunction composite techniques are discussed in detail, followed by a summary of current trends and potential for expansion.

Experimental Investigations of Quasi-Coherent Micro-Instabilities in J-TEXT Ohmic Plasmas

Quasi-coherent micro-instabilities is one of the key topics of magnetic confinement fusion. This work focuses on the quasi-coherent spectra of ion temperature gradient (ITG) and trapped-electron-mode instabilities using newly developed far-forward collective scattering measurements within ohmic plasmas in the J-TEXT tokamak. The ITG mode is characterized by frequencies ranging from 30 to 100 kHz and wavenumbers (kθρ s) less than 0.3. Beyond a critical plasma density threshold, the ITG mode undergoes a bifurcation, which is marked by a reduction in frequency and an enhancement in amplitude. Concurrently, enhancements in ion energy loss and degradation in confinement are observed. This ground-breaking discovery represents the first instance of direct experimental evidence that establishes a clear link between ITG instability and ion thermal transport.

Towards optimal 3D battery electrode architecture: Integrating structural engineering with AI-driven optimization

The rapid evolution of energy storage devices, driven by increasing demands for prolonged battery life in electronics as well as sustainable energy solutions has elevated lithium-ion batteries (LIBs) to prominence in modern energy systems. With electric vehicle sales and LIB demand surging, the need for high-performing batteries is at an all-time high. However, critical issues with LIBs have become apparent, particularly in energy degradation due to poor mass transport, emphasising the need for advancements in electrode design. This review explores the influence of electrode structural factors on mass transport properties, with a specific focus on the latest developments in three-dimensional (3D) battery electrodes featuring diverse pore arrangements—ranging from random to ordered pores or porosity gradients. The review delves into recent breakthroughs achieved through structural diversification by applying an inverse design to Proximity-field nanoPatterning (PnP), laying the groundwork for collaborative efforts aimed at advancing energy storage technologies. Various fabrication methods for 3D electrodes are discussed, highlighting the promising role of integrating the PnP technique with computational algorithms to enhance the precision and design capabilities of 3D nanostructures.

A Review of Heat Dissipation and Absorption Technologies for Enhancing Performance in Photovoltaic–Thermal Systems

With the growing demand for photovoltaic (PV) systems as a source of energy generation that produces no greenhouse gas emissions, effective strategies are needed to address the inherent inefficiencies of PV systems. These systems typically absorb only approximately 15% of solar energy and experience performance degradation due to temperature increases during operation. To address these issues, PV–thermal (PVT) technology, which combines PV with a thermal absorber to dissipate excess heat and convert it into additional thermal energy, is being rapidly developed. This review presents an overview of various PVT technologies designed to prevent overheating in operational systems and to enhance heat transfer from the solar cells to the absorber. The methods explored include innovative absorber designs that focus on increasing the heat transfer contact surface, using mini/microchannels for improved heat transfer contiguity, and substituting traditional metal materials with polymers to reduce construction costs while utilizing polymer flexibility. The review also discusses incorporating phase change materials for latent heat absorption and using nanofluids as coolant mediums, which offer higher thermal conductivity than pure water. This review highlights significant observations and challenges associated with absorber design, mini/microchannels, polymer materials, phase change materials, and nanofluids in terms of PV waste heat dissipation. It includes a summary of relevant numerical and experimental studies to facilitate comparisons of each development approach.

Unwinding the correlation between atmospheric pressure plasma jet operating parameters and variation in antibiotic wastewater characteristics

The influence of plasma operating parameters such as gas medium, electrode distance, applied voltage, gas flow rate, and their interdependency on reactive species generation was investigated. Full factorial design-based response surface methodology (RSM) was used to establish the correlation between the operating parameters. The optimization studies were carried out by taking energy yield and degradation efficiency as response parameters. The operating voltage of 9 kV, the airflow rate of 2 LPM, and the electrode distance of 5 mm are optimum for the system studied. The higher voltage of 9 kV and a flow rate of 2 LPM give maximum yield due to the increased rate of gas atoms undergoing ionization. However, at the low voltage (5 kV), the increase in air flow rate from 0.5 to 2 LPM, the energy yield decreases from 67.5 to 54.2 mg/kWh. These observations are further supported by measuring OH (A-X) intensity in an air medium using optical emission spectroscopy. The studies also reveal that the degradation efficiency is adversely affected by scavenges, with a maximum from isopropyl alcohol, followed by tert-butyl alcohol and methanol. TOC and LC-MS analyses established complete mineralization and its degradation pathway. Phytotoxicity studies suggest that treated effluent, rich in nitrates, is suitable for irrigation, promoting seed germination. In short, the studies provide a strategy to optimize the generation of reactive chemical species in a reactor and how such optimization would help attain optimum energy yield, especially when there is a fluctuation in target pollutant concentration.

Generalization of crack growth mechanisms under isothermal and thermomechanical fatigue by COD and ERR parameters

An experimental-computational study of the crack opening displacement (COD) was performed to evaluate the ability of this parameter through the hysteresis loop area and energy release rate (ERR) to characterise fatigue crack growth under isothermal and thermomechanical conditions. To this end, a range of experimental crack growth tests were carried out including isothermal fatigue (IF), creep-fatigue interaction (CFI), in-phase (IP), and out-of-phase (OOP) thermomechanical fatigue (TMF). The crack growth experimental results in terms of COD and ERR were interpreted based on multi-physics finite element analyses of the stress–strain and displacement fields performed by incorporating Maxwell 3D, Fluent, and the transient structural modules of ANSYS. As a result of measurements and computations, the COD on the outer surface of the SENT specimen at the location of the original notch was found to be directly related to the crack tip opening displacement (CTOD). To gain insight into the fatigue crack growth mechanism operating under isothermal and TMF conditions, the fracture surfaces of all the tested specimens were examined using a scanning electron microscope to compare the morphology and changes in the dominant failure mechanisms. It was found that propagating cracks under isothermal and thermomechanical conditions interact with the microstructure of the material, and supporting fractography evidenced subtle differences in fracture mechanisms in terms of COD and ERR parameters. The relationship between the experimentally determined energy release rate and degradation function in the fatigue phase-field fracture methodology is discussed.