Efficient Utilization Research Articles

Experimental study on the co-firing and NOx emission characteristics of bituminous coal and its medium temperature pyrolysis char

To address the issues of ignition difficulty, incomplete burnout, and high NOx emissions during coal char combustion in industrial applications, a series of co-firing experiments involving bituminous coal and its medium-temperature pyrolysis char were conducted using a micro fluidized bed analysis system. The experiments explored co-firing behaviors and NOx emission characteristics for five different fuel blending ratios in an environment with 21% oxygen concentration, across temperatures between 923 K and 1223 K. The study delved into the synergistic effects of coal and char co-firing, as well as the influence of combustion temperature and fuel blend ratio on the co-firing efficiency and NOx emissions. The results show a synergistic effect in the co-firing of bituminous coal and char, influenced by reaction temperature and coal-to-char blend ratio, which evolves as combustion progresses. In the 923 to 1073 K range, initial coal addition to the blend enhances reactivity. However, as the reaction advances or coal content exceeds 75%, this synergy shifts to an inhibitory effect. At temperatures above 1023 K, increased proportions of coal in the blend are associated with improved burnout rates, especially when the coal content is at or above 50%. Moreover, at a combustion temperature of 1123K, there is a marked decrease in nitrogen oxide emissions, with coal blend ratio of 25% and 50% showing particular efficacy in reducing these emissions. These results provide valuable insights for the efficient and clean utilization of coal char in industrial combustion processes.

Sulfur nanosheets deposited on reduced graphene oxide enable excellent cycling life for lithium-sulfur battery

A lithium-sulfur (Li–S) battery cathode composed of sulfur nanosheets and reduced graphene oxide (rGO) was successfully synthesized. During cycles, the sulfur nanosheets form a protective sulfur layer that acts as a barrier against the shuttle effect, attributed to physical confinement and spontaneous chemical reactions. Simultaneously, the pores within the nanosheets create pathways for lithium ions, ensuring efficient sulfur utilization even at high sulfur content levels of up to 89 %. This design enables the cathode to achieve a high discharge capacity of 1596.9 mAh g−1 at 0.1C and 1433.5 mAh g−1 at 0.5C during the first cycle. Furthermore, the capacity of a Li–S battery has been shown to maintain over 1200 h at 0.5C and 450 h at 1 C simply by adjusting the morphology of the sulfur source. This significant discovery not only offers a new research direction for Li–S batteries, but also has the potential to advance the application of Li–S batteries in various fields.

Predicting the impact of climate change on crop water footprint using CMIP6 in the Shule River Basin, China

Quantitatively predicting the impacts of climate change on water demands of various crops is essential for developing measures to ensure food security, sustainable agriculture, and water resources management, especially in arid regions. This study explored the water footprints (WFs) of nine major crops in the middle and downstream areas of Shule River Basin, Northwest China, from 1989 to 2020 using the WF theory and CROPWAT model and predicted the future WFs of these crops under four emission and socio-economic pathway (SSPs-RCPs) scenarios, which provides scientific support for actively responding to the negative impacts of climate change in arid regions. Results indicated: (1) an increasing trend of the overall crop WF, with blue WF accounting for 80.31–99.33% of the total WF in the last 30 years. Owing to differences of planting structure, water-conservation technologies, and other factors, the multi-year average WF per unit area of crops was 0.75 × 104 m3 hm−2 in downstream area, which was higher than that in midstream area (0.57 × 104 m3 hm−2) in the last 30 years; therefore agricultural water use efficiency in the downstream area was lower than that in the midstream area, implying that the midstream area has more efficient agricultural water utilization. (2) an initial increase and then decrease of crop WFs in the study area under SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios by the end of the century, reaching their peak in 2030s which was higher than that from 1989 to 2020; with the maximum growth rates in the midstream area ranging from −0.85% in SSP5-8.5 to 5.33% in SSP2-4.5 and 29.74% in SSP5-8.5 to 34.71% in SSP2-4.5 in the downstream area. The local agricultural water demand would continue to increase and water scarcity issues would be more severe in the next 10–20 years, affecting downstream areas more. Under the SSP3-7.0 scenario, crop WF values of the midstream and downstream regions will be 2.63 × 108 m3 and 4.22 × 108 m3 in 2030, respectively, which is significantly higher than those of other scenarios and show a long-term growth trend. The growth rate of the midstream and downstream regions will reach 44.71% and 81.12%, respectively, by the end of this century, so the local agricultural water use would be facing more strain if this scenario materializes in the future. Therefore, the Shule River Basin should encourage development of water-saving irrigation technologies, adjust the planting ratio of high water consuming crops, and identify other measures to improve water resource utilization efficiency to cope with future water resource pressures.

CMK: Enhancing Resource Usage Monitoring across Diverse Bioinformatics Workflow Management Systems

The increasing use of multiple Workflow Management Systems (WMS) employing various workflow languages and shared workflow repositories enhances the open-source bioinformatics ecosystem. Efficient resource utilization in these systems is crucial for keeping costs low and improving processing times, especially for large-scale bioinformatics workflows running in cloud environments. Recognizing this, our study introduces a novel reference architecture, Cloud Monitoring Kit (CMK), for a multi-platform monitoring system. Our solution is designed to generate uniform, aggregated metrics from containerized workflow tasks scheduled by different WMS. Central to the proposed solution is the use of task labeling methods, which enable convenient grouping and aggregating of metrics independent of the WMS employed. This approach builds upon existing technology, providing additional benefits of modularity and capacity to seamlessly integrate with other data processing or collection systems. We have developed and released an open-source implementation of our system, which we evaluated on Amazon Web Services (AWS) using a transcriptomics data analysis workflow executed on two scientific WMS. The findings of this study indicate that CMK provides valuable insights into resource utilization. In doing so, it paves the way for more efficient management of resources in containerized scientific workflows running in public cloud environments, and it provides a foundation for optimizing task configurations, reducing costs, and enhancing scheduling decisions. Overall, our solution addresses the immediate needs of bioinformatics workflows and offers a scalable and adaptable framework for future advancements in cloud-based scientific computing.

Thermal and electrical performance evaluation of single and double pass photovoltaic-thermal solar collector with cross-flow baffles and varying transparency: A computational analysis

The present work deals with the development of a semi-transparent photovoltaic thermal (PV-T) solar collector (STPVT) through computational fluid dynamics (CFD) modelling using COMSOL Multiphysics. The study was carried out in three stages; firstly, the CFD model was developed for STPVT and validated with experimental data. Secondly, three different configurations of semi-transparent PV-T collector were investigated, i.e., single pass with PV module on top (SPC), double pass with PV module on top followed by glass cover and absorber plate (DPT), and double pass with PV module in between the glass cover and absorber plate (DPS). The absorber plate was incorporated with cross-flow baffles for improved thermal performance due to increased surface area and turbulence. The study found a thermal efficiency of 76.94% for DPS configuration and a total heat utilisation of 289.63 W at 50% transparency level, i.e., 2-4 times higher than other configurations. Furthermore, the DPS model was investigated for thermal and electrical performance with different PV module transparency levels (52,42,27,13%). The DPS with 18 solar cells having 13% transparency exhibited peak power density (8%) at 717 W/m2 and 101.89°C panel temperature, achieving superior thermal efficiency (84%) and total heat utilization (315.09 W), surpassing configurations with higher transparency.

Carbon sources influence on heterotrophic ammonia assimilation: Performance and mechanism

Different carbon contents of organic carbon sources can be used as the reaction substrates of heterotrophic ammonia assimilation (HAA), which effectively dominates the recovery of available nutrients in wastewater. However, the influences of organic carbon sources on nutrient metabolism, degradation kinetics, and functional microbes of HAA were largely unknown. Here, HAA bioreactors fed with acetate, glucose, sucrose, starch, methanol, and sludge alkaline fermentation liquid (SAFL) were constructed to compare the nitrogen recovery performance, kinetic analysis, sludge characteristics, and microbial community structure. Higher COD and NH4+-N removal efficiencies were found in bioreactors supplied with acetate, glucose, and SAFL. Kinetic analysis showed that the acetate-fed bioreactor had more efficient organic utilization for assimilation. Corynebacterium, Pseudohoeflea, and Methylophaga emerged as the primary assimilation bacteria for typical carbon sources of organic acids, sugars, and alcohols, whereas Halomonas, Corynebacterium, and Marinobacter dominated in SAFL. Acetate- and SAFL-supported sludge particles displayed enhanced internal and external oxygen mass transfer, along with heightened sedimentation performance and deconsolidation ability. High-quality assimilative gene expression, assimilative enzyme activity, and assimilated organic nitrogen product synthesis with direct effects were observed in a reactor supplied with acetate and SAFL. The cost-effectiveness of SAFL preparation positions it as a promising candidate for practical engineering applications. This research underscored the pivotal role of different carbon contents in the nutrient recovery process of the HAA reaction, providing essential insights for optimizing wastewater treatment strategies and enhancing environmental sustainability.

Low-toxicity natural pyrite on electro-Fenton catalytic reaction in a wide pH range

The resource utilization of natural pyrite not only reduces secondary pollution but also brings certain environmental benefits. However, the green and efficient use of pyrite presents certain challenges. In this study, a novel electro-Fenton (EF) system was constructed utilizing copper modified graphite felt (GF/Cu) as cathode and natural pyrite (com-FeS2) as catalyst. The results demonstrated that the system exhibited a remarkable stability over an extensive pH range (3.0–10.0) and remained effective even under adverse environmental conditions, such as high salinity or elevated antibiotic concentration. After optimizing the reaction conditions, 0.2 mM sulfamerazine (SMZ) was almost completely degraded within 1.5 h. The results highlighted the catalytic role of Fe(II) on the com-FeS2 surface. Combined with quenching experiments and quantitative analysis of reactive oxygen species (ROS), the removal of SMZ was primarily attributed to the generation of •OH, ordered by 1O2 > •O2− > •OHads, a possible degradation pathway was proposed by HR-LC-MS. The biological toxicity after the reaction was detected, and the introduction of polyvinylpyrrolidone (PVP) was beneficial to reduce the biological toxicity of iron dissolution. This work provides new insights into the green and efficient resource utilization of natural pyrite and significantly expands the pH applicability range of the Fenton process, demonstrating the large-scale industrial application potential of pyrite.

Two-stage hydrothermal liquefaction of Spirulina: Experimental observations, energy analysis and techno-economic assessment

The intensification of environmental pollution and significant consumption of fossil fuels has led to widespread attention on developing renewable resources. As a carbon-containing renewable energy source, Spirulina is characterized by its fast growth cycle and wide distribution. Currently, one of the research hotspots is the conversion of Spirulina into bio-oil through hydrothermal liquefaction. However, studies on the two-stage hydrothermal liquefaction of Spirulina predominantly concentrate on the product yield or composition. There is relatively little research on thermodynamic (energy) analysis and techno-economic assessment during the reaction process. The main bio-oil components from two-stage hydrothermal liquefaction of Spirulina are ketones and acids with 44.9% and 34.1%, respectively. Compared to no-catalysis, two-stage hydrothermal liquefaction of Spirulina over HZSM-5, alkili-modified HZSM-5, and Ni@alkali-modified HZSM-5 increase the relative content of hydrocarbons to 6.6%, 32.9% and 48.1%, respectively. Energy analysis and techno-economic assessment are conducted with Aspen Plus simulation, revealing a exergy efficiency of 56.4% for the catalytic two-stage hydrothermal liquefaction of Spirulina compared with 43.6% over no-catalyst. The primary losses occur in the first stage of the reaction process (248.6kW) and the cooling process (10.7kW) for catalytic two-stage hydrothermal liquefaction of Spirulina. The hourly price of producing 1kg bio-oil with a catalyst is $3.67, while without a catalyst, it is $4.54kg-1; obtaining a unit of chemical exergy costs $0.14×10-3 kJ-1 through catalysis. Moreover, the fluctuations in the prices of sulfuric acid and catalysts are most sensitive to the cost price of bio-oil with or without catalysts in the two-stage hydrothermal liquefaction process, with the values being 10.06% and 8.10%. This study has important significance for efficient transformation and energy utilization of Spirulina.

Reinforcement Learning-Based Satellite Formation Attitude Control Under Multi-Constraint

As the complexity of space missions increases, the constraints on satellite attitude control become more stringent, particularly for satellites working in orbit formation. This paper introduces a novel method, based on the categorization and modeling of different constraints, for attitude control of satellite formations under multiple constraints. The method employs the Phased Priority Reinforcement Learning (PPRL) approach, which utilizes Deep Deterministic Policy Gradient (DDPG) technology. Considering the complexity of constraints and the challenge posed by the high control dimensionality due to multi-satellite coordination, the method addresses these challenges through a two-step training strategy. The first step addresses the multi-constraint issue for individual satellites and increases the priority of single-satellite training experience data in the experience replay buffer of the second step to enhance data utilization efficiency. To address the issue of reward sparsity in complex high-dimensional constraint models, a detailed reward mechanism is proposed, incorporating both local and global constraints into the reward function, thereby achieving both efficient and effective attitude control. This approach not only meets dynamic, state, and performance constraints but also demonstrates adaptability and robustness through numerical simulations. Compared to traditional methods, this approach achieves significant improvements in control performance and constraint satisfaction, offering a novel solution pathway for high-dimensional control problems in multi-constraint satellite formations.

Cubature Kalman fusion filtering under stochastic communication protocol: Tackling dynamical bias, scheduling probability and channel noise

The paper addresses the problem of cubature Kalman fusion filtering (CKFF) for nonlinear systems subject to dynamical bias and stochastic communication protocol (SCP). To account for the engineering practice of networked environment, the channels from sensors to filters, affected by Gaussian channel noise, are considered in the system model incorporating dynamical bias. With the purpose of reducing communication load and enhancing resource utilization efficiency, the SCP is adopted for information transmissions, where the scheduling probability is allowed to deviate within bounds from its designated value owing to possible implementation errors. The objective of this paper is to design a CKFF algorithm in spite of the presence of dynamical bias, channel noise and SCP with uncertain scheduling probability. Specifically, the local filter is constructed such that an upper bound on the filtering error covariance (FEC) is calculated through the resolution of matrix difference equations, and the filter gain is subsequently designed to minimize this upper bound. Then, the local filters are fused by utilizing the inverse covariance intersection fusion rule. Moreover, the boundedness of the FEC’s upper bound is also investigated using the matrix theory. The feasibility and effectiveness of the proposed CKFF approach are demonstrated through a simulation experiment.

Enhancing CO2 reduction with formamide-Ni@TiO2 catalyst

Formamide condensation with Ni can generate the NC structure, widely recognized as an efficient catalyst for electrocatalytic CO2 reduction reaction (CO2RR). To improve the utilization efficiency of Ni atoms, we introduced metal oxides as substrates to modulate the growth of a formamide-Ni (FA-Ni) condensate. FA-Ni@TiO2 demonstrated 2.8 times higher partial CO current density and Ni turnover frequency than FA-Ni, which were also higher than those of other FA-Ni@metal oxides, including ZrO2, Al2O3, Fe2O3, and ZnO. The improved performance of CO2RR can be attributed to the Ni content exposed on FA-Ni@TiO2 being twice that of the raw FA-Ni condensate. The Fourier transform infrared results suggested that formamide was adsorbed on TiO2 via the -CHO group, exposing -NH2 for potential interaction with Ni. As a result, Ni atoms were predispersed on the TiO2 surface. By contrast, the dispersion of Ni atoms was not enhanced by other metal oxides, such as Al2O3, Fe2O3, and ZnO, owing to the robust acidity of their surface sites. These metal oxides adsorbed formamide via -NH2, leading to the absence of extra -NH2 available for binding to Ni atoms. This study provides new insights into the development of appropriate substrates for single-atom catalysts.

Preparation and properties of PCL coaxial electrospinning films with shell loaded with CEO and core coated LEO nanoemulsions

During storage and transportation, the reduction of microbial contamination and management of the exudation of fluids from the fish can effectively mitigate spoilage and degradation of fish fillets. In this work, the coaxial electrospinning films loaded with natural plant preservatives, namely laurel essential oil (LEO) and clove essential oil (CEO), were prepared by the coaxial electrospinning method synergistic with nanoemulsion techniques, and the hydrophilic preservation pads were prepared. The morphology of the film fiber is clear, without beads or damage, with fiber diameters falling within the 230–260 nm range. It has a distinct core–shell structure, exceptional thermal stability, and strong antibacterial and antioxidant properties. The core–shell structure of the fiber subtly regulates the release of preservatives and significantly improves the utilization efficiency. At the same time, the synergistic use of two essential oils can reduce the amount while amplifying their effectiveness. The pads significantly slowed down the increase of key indicators of spoilage, such as total viable count (TVC), pH, thiobarbituric acid reactive substances (TBA), and total volatile base nitrogen (TVB-N), during the storage of the fish fillets. Furthermore, the pads effectively slowed down the decline in water-holding capacity, the deterioration of textural qualities, and the negative changes in the microstructure of the fish muscle. Ultimately, the pads notably delayed the spoilage of fish fillets, extending their shelf life from 5 d to 9 d. The efficient utilization of biological preservatives in this film can provide technical support for the development of food preservation materials.

Analysis of dynamic evolution characteristics and driving factors of regional synergistic effect of reducing carbon and saving water: the case of Yangtze River Delta Urban Agglomerations, China.

Carbon emissions and water consumption are both important factors affecting sustainable development. Therefore, it is necessary to put them in the same research framework and investigate the synergy. In this study, the dynamic evolution characteristics of the synergistic effect of reducing carbon and saving water (RCSW) were analyzed. Then, taking the Yangtze River Delta Urban Agglomerations (YRDUA) as the research object, the influencing factors and specific paths of the synergistic effect were clarified. The results showed that the low-carbon emission efficiency (LCEE) had a stable synergy with the intensive utilization efficiency of water resources (IUEWR) in the YRDUA. Government financial expenditure, actual use of foreign capital, and population density were the most significant driving forces for the synergistic effect of RCSW, with q values of 0.561, 0.363, and 0.240, respectively. In addition, most of the interactions of the driving factors were nonlinear enhancement and double-factor enhancement.

The phosphate-solubilising fungi in sustainable agriculture: unleashing the potential of fungal biofertilisers for plant growth.

Phosphate-solubilising fungi (PSF) are beneficial microorganisms that play a pivotal role in plant growth by increasing the availability of phosphorus (P) in soil. Although phosphorus is an essential nutrient for plants, it often becomes inaccessible as it binds into insoluble forms. PSF effectively facilitate the release of this bound phosphorus through diverse mechanisms. Numerous fungal species demonstrate the ability to solubilise various types of phosphate compounds. Among the commonly researched PSF are Penicillium, Aspergillus, Rhizopus, Fusarium, Trichoderma, and Sclerotium. Moreover, yeasts such as Saccharomyces cerevisiae can potentially be leveraged as PSF. PSF secrete organic acids that chelate phosphate ions, thereby increasing their solubility in the soil. Moreover, PSF contribute to the decomposition of organic phosphorus compounds in soil by employing enzymes such as phosphatases, phytases, and phosphonatases. Furthermore, PSF can interact with other soil microorganisms, including nitrogen-fixing bacteria and arbuscular mycorrhizal fungi (AM-fungi), fostering synergistic effects that further enhance plant growth and nutrient absorption. The utilisation of PSF as biofertilisers offers numerous advantages over chemical fertilisers, including environmental friendliness, cost-effectiveness, and enhanced fertiliser utilisation efficiency. Furthermore, PSF can prove beneficial in challenging environments characterised by high phosphate sorption. Hence, this review serves as an updated study aimed at broadening the understanding of PSF and its potential applications in P solubilisation. This review also focuses on the diversity of PSF, the mechanisms underlying solubilisation, ecological roles of PSF in soil microbiome, and the benefits of sustainable agriculture. By delving into the ecological roles of PSF and their potential as biofertilisers, this study contributes to a deeper understanding of sustainable agriculture practices and addresses challenges in phosphate-scarce environments.

Experimental study on dynamic characteristics of organic Rankine cycle coupled vapor compression refrigeration system with a zeotropic mixture

The organic Rankine cycle coupled vapor compression refrigeration system is an attractive refrigeration technology that converts low-grade thermal energy into cooling capacity to improve waste heat utilization efficiency. Due to the inevitable change in ambient temperature and cooling demand, the dynamic characteristics of the combined system are worth studying. In this paper, a small experimental apparatus with a common condenser is designed and developed. The dynamic characteristic experiments under different disturbances are carried out to understand the response characteristics of operating parameters and the variation of system performance. The results show that the maximum response time of the system under different disturbances ranges from 493 s to 694 s. The impact of throttle opening on the response characteristics of refrigeration subsystem parameters is significantly higher than that of the organic Rankine cycle. The mass flow rate of organic Rankine cycle has the fastest response to pump frequency, while the compressor inlet temperature changes rapidly with the cooling water temperature. Under a step cooling water temperature, it is important to control the compressor inlet temperature to avoid liquid droplets in its inlet. In addition, the mass flow rate of organic Rankine cycle should be controlled reasonably to achieve the maximum coefficient of system performance. The cooling capacity of the system is mainly affected by the cooling water temperature and the throttle valve opening. During the experiment, the maximum cooling capacity and performance coefficient of the system are 3.75 kW and 0.275, respectively. This work can provide guidance for the design of the control strategy of the combined system.

Ammonia-regulated dynamic evolution of Ti precursor incorporating into dealuminized beta for efficient 1-Hexene epoxidation

Demetalation-metalation method has gained prominence for its higher metal loading, efficiency and shortened synthetic period, particularly in the incorporation of metal atoms with large radii into zeolite framework in recent years. An ammonia-regulated approach has been developed for selectively evolved deep-substituted Ti precursors in dealuminized beta zeolites, which enables a controlled promotion of metalation of Ti atoms. Additionally, this ammonia-regulated approach could also enhance 1-hexene kinetic adsorption by constructing mesopores, which is demonstrated by the lower reaction order of 1-hexene. The synthesized ammonia-regulated N-Ti-beta exhibits rich framework Ti species and a high specific surface area, leading to significantly improved 1-hexene epoxidation performance (conversion of 61%, selectivity of 98%, and a high H2O2 utilization efficiency of 93%). This study not only provides a new strategy to dynamically regulate evolution of Ti precursors by ammonia but also holds promise for advancing related industrial processes in demetalation-metalation methods.

Eco-friendly solid waste-based cementitious material containing a large amount of phosphogypsum: performance optimization, micro-mechanisms, and environmental properties

Reusing phosphogypsum (PG) waste to manufacture eco-cementitious materials is sustainable. However, PG faces the challenge of high stacking volume and low utilization rate, and the low-content PG in eco-cementitious materials currently limits its large-scale potential application. This study provides a solution to use high-content PG to fabricate eco-friendly solid waste-based cementitious material (PBC), associated with ground granulated blast furnace slag (GGBS), fly ash (FA), and hydrated lime. Respond surface methodology (RSM) was undertaken to optimize and discuss the influence of independent design factors of GGBS, FA, and hydrated lime content on the unconfined compressive strength (UCS). Besides, the micro-mechanisms and environmental properties of PBC were also investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and the leachate test. The results indicated that the optimal raw material contents were (by mass): 50.57% PG, 28% GGBS, 20% FA, and 1.43% hydrated lime. The UCS of the optimal PBC mixture is 23.57 MPa at 28 days, which was confirmed via experimental verification (24.65 MPa). Hence, the RSM is an effective method for optimizing PBC's UCS. The micro-mechanisms analysis shows that the ettringite is the primary hydration product within the reaction system of PBC, which is attributed to the substantial amount of PG. The leachate test results indicate that the fluoride ion concentration of the leaching solution of PBC remains below the PG, and the pH value falls within the range of 6–9. The leaching test results meet the Chinese environmental standard of GB 8978-1996. The cost and CO2 emission of the optimal PBC mixture could achieve a reduction of 71.25% and 99.98%, respectively, compared to Ordinary Portland cement (OPC). The findings of this study could serve as a theoretical foundation for the practical implementation of large-scale and efficient utilization of PG waste. The developed eco-friendly PBC has excellent potential to partially substitute conventional OPC binders and reduce engineering project costs.

Study on the key parameters of ice particle air jet ejector structure

Existing ice particle jet surface treatment technology is prone to ice particle adhesion during application, significantly affecting surface treatment efficiency. Based on the basic structure of the jet pump, the ice particle air jet surface treatment technology is proposed for the instant preparation and utilization of ice particles, solving the problem of ice particle adhesion and clogging. To achieve efficient utilization of ice particles and high-speed jetting, an integrated jet structure for ice particle ejection and acceleration was developed. The influence of the working nozzle position (Ld), expansion ratio (n), and acceleration nozzle diameter ratio (Dn) length-to-diameter ratio (Ln) on the ice particle ejection and acceleration was systematically studied. The structural parameters of the ejector were determined using the impact kinetic energy of ice particles as the comprehensive evaluation index, and the surface treatment test was conducted to verify the results. The study shows that under 2 MPa air pressure, the ejector nozzle parameters of n = 1.5, Dn = 4.0, Ld = 4, and Ln = 0 mm can effectively eject and accelerate the ice particles. The aluminum alloy plate depainting test obtained a larger paint removal radius and resulted in a smoother aluminum alloy plate surface, reducing the surface roughness from 3.194 ± 0.489 μm to 1.156 ± 0.136 μm. The immediate preparation and utilization of ice particles solved the problems of adhesion and storage in the engineering application of ice particle air jet technology, providing a feasible technical method in the field of material surface treatment.

Droplet-enabled controllable manipulation of tribo-charges from liquid-solid interface

Efficient utilization of electrostatic charges is paramount for numerous applications, from printing to kinetic energy harvesting. However, existing technologies predominantly focus on the static qualities of these charges, neglecting their dynamic capabilities as carriers for energy conversion. Herein, we report a paradigm-shifting strategy that orchestrates the swift transit of surface charges, generated through contact electrification, via a freely moving droplet. This technique ingeniously creates a besptengngoke charged surface which, in tandem with a droplet acting as a transfer medium to the ground, facilitates targeted charge displacement and amplifies electrical energy collection. The spontaneously generated electric field between the charged surface and needle tip, along with the enhanced water ionization under the electric field, proves pivotal in facilitating controlled charge transfer. By coupling the effects of charge self-transfer, contact electrification, and electrostatic induction, a dual-electrode droplet-driven triboelectric nanogenerator (DD–TENG) is designed to harvest the water-related energy, exhibiting a two-order-of-magnitude improvement in electrical output compared to traditional single-electrode systems. Our strategy establishes a fundamental groundwork for efficient water drop energy acquisition, offering deep insights and substantial utility for future interdisciplinary research and applications in energy science.

Thermodynamic and parametric analyses of a zero-carbon emission SOFC-based CCHP system using LNG cold energy

A novel zero-carbon emission combined cooling, heating and power (CCHP) system is currently proposed. The thermal energy of the solid oxide fuel cell (SOFC) exhaust is recovered in a transcritical CO2 (T- CO2) power cycle. Relying on the efficient utilization of liquefied natural gas (LNG) cold energy, CO2 capture has been achieved at low energy consumption. The thermodynamic performance is evaluated by using energy and exergy analysis methods for this hybrid process. The electrical, exergy, and CCHP efficiencies are obtained as 60.37 %, 62.83 %, and 79.09 %, respectively. The CO2 condenser, with the largest exergy destruction ratio (18.60 %) and a low exergy efficiency (37.16 %), is regarded as the weakest point in terms of thermodynamic perfectibility. In addition, the influences of the current density, stack temperature and pressure, and fuel utilization rate have also been studied from different aspects of system performance. The current density, stack temperature, stack pressure, and fuel utilization rate are recommended as 0.3 A/cm2∼0.4 A/cm2, 900 °C, 5 bar, and 85 %, respectively. This research provides practical reference and pragmatic guidance for the integration, analysis, and optimization of SOFC-based CCHP systems.