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Distributed energy resources (DERs) provide flexible load restoration strategies, which can effectively enhance the resilience of active distribution systems (ADSs). Whereas, the widespread DERs in ADSs complicate the supply-demand relationship and make the system resilience difficult to access. Therefore, this paper proposes a simulation-based resilience assessment algorithm of ADSs considering the microgrid formation based on grid-edge DERs. Microgrid formation is used to depict the resilience gain of grid-edge DERs on ADSs. Specifically, a resilience assessment framework for ADSs is firstly proposed, where the uncertainty of component state and supply-demand is modelled based on probability statistics. Then the mixed integer linear programming is used to search for optimal load restoration strategies with microgrid formation. On this basis, a set of resilience indices are defined to quantitatively analyse the resilience of ADSs, and a resilience assessment algorithm with uncertainty scenario generation is proposed to obtain these indices. Furthermore, extensive numerical results based on a modified IEEE 123-bus feeder validate the effectiveness of our proposed method.

A hetero-phase junction was constructed with metallic 1T and semiconductive 2H MoS2, which exhibited outstanding photo-Fenton catalytic performance to effectively degrade organic pollutants in the aquatic environment.

Fully understanding the environmental implications of engineered nanomaterials is crucial for their safe and sustainable use. Cyanobacteria, as the pioneers of the planet earth, play important roles in global carbon and nitrogen cycling. Here, we evaluated the biological effects of molybdenum disulfide (MoS2) nanosheets on a N2-fixation cyanobacteria (Nostoc sphaeroides) by monitoring growth and metabolome changes. MoS2 nanosheets did not exert overt toxicity to Nostoc at the tested doses (0.1 and 1 mg/L). On the contrary, the intrinsic enzyme-like activities and semiconducting properties of MoS2 nanosheets promoted the metabolic processes of Nostoc, including enhancing CO2-fixation-related Calvin cycle metabolic pathway. Meanwhile, MoS2 boosted the production of a range of biochemicals, including sugars, fatty acids, amino acids, and other valuable end products. The altered carbon metabolism subsequently drove proportional changes in nitrogen metabolism in Nostoc. These intracellular metabolic changes could potentially alter global C and N cycles. The findings of this study shed light on the nature and underlying mechanisms of bio-nanoparticle interactions, and offer the prospect of utilization bio-nanomaterials for efficient CO2 sequestration and sustainable biochemical production.

To better understand the mechanisms of hydrogen peroxide (H2O2)’s decomposition and reactive oxygen species (ROS)’s formation on the catalyst’s surface is always a critical issue for the environmental application of Fenton/Fenton-like reaction. We here report a new approach to activate H2O2 in a co-catalytic Fenton system with oxygen incorporated MoS2, namely MoS2−xOx nanosheets. The MoS2−xOx nanosheets assisted co-catalytic Fenton system exhibited superior degradation activity of emerging antibiotic contaminants (e.g., sulfamethoxazole). Combining density functional theory (DFT) calculation and experimental investigation, we demonstrated that oxygen incorporation could improve the intrinsic conductivity of MoS2−xOx nanosheets and accelerate surface/interfacial charge transfer, which further leads to the efficacious activation of H2O2. Moreover, by tuning the oxygen proportion in MoS2−xOx nanosheets, we are able to modulate the generation of ROS and further direct the oriented-conversion of H2O2 to surface-bounded superoxide radical (·O2 surface−). It sheds light on the generation and transformation of ROS in the engineered system (e.g., Fenton, Fenton-like reaction) for efficient degradation of persistent pollutants.

Bay is a unique part of the ecosystem, acting as the intersection for marine and terrestrial systems and hosting diverse biological organisms. The ubiquitous application of plastics has resulted in a massive amount of plastic waste released and accumulated in the bay ecosystem, posing significant ecological effects. Thus, thoroughly understanding plastic pollution's occurrence, speciation, and ecological effect in the bay ecosystems is of vital importance. We conducted a comprehensive review on the sources and distribution of plastics in the bay ecosystem, and the associate ecological effects, from individual toxicity to trophic transfer in ecosystems. Among bay areas around the world, the concentrations of microplastics vary from 0.01 to 3.62 × 10

The advancement of analytical methods for nanoparticle measurements is critical both for the growing industrial exploitation of engineered nanoparticles and for developing robust strategies to understand and control the concentration of nanomaterials in humans and the environment. For high value nanoparticles, the measurement of nanoparticle number concentration in a liquid directly impacts the ability to assess the scale and reproducibility of the production process, it allows optimisation of efficiency and supports regulatory compliance. This measurement is also useful to monitor and control the intentional or accidental release of engineered nanoparticles into the environment at the production plant, as well as by end-users., peer-reviewed

The wide application of manufactured nanomaterials (MNMs) has resulted in the inevitable release of MNMs into the aquatic environment along their life cycle. As the primary producer in aquatic ecosystems, algae play a critical role in maintaining the balance of ecosystems’ energy flow, material circulation and information transmission. Thus, thoroughly understanding the biological effects of MNMs on algae as well as the underlying mechanisms is of vital importance. We conducted a comprehensive review on both positive and negative effects of MNMs on algae and thoroughly discussed the underlying mechanisms. In general, exposure to MNMs may adversely affect algae’s gene expression, metabolites, photosynthesis, nitrogen fixation and growth rate. The major mechanisms of MNMs-induced inhibition are attributed to oxidative stress, mechanical damages, released metal ions and light-shielding effects. Meanwhile, the rational application of MNMs-algae interactions would promote valuable bioactive substances production as well as control biological and chemical pollutants. Our review could provide a better understanding of the biological effects of MNMs on algae and narrow the knowledge gaps on the underlying mechanisms. It would shed light on the investigation of environmental implications and applications of MNMs-algae interactions and meet the increasing demand for sustainable nanotechnology development.

Quantitatively monitoring the presence of engineered, natural, or incidental nanoparticles (NPs) is essential to understand their potential environmental and ecotoxicological implications. In parti...

The increasing use of nanoscale TiO2 particles (nTiO2) and their subsequent leakage into aquatic environments poses a threat to the ecosystem. One major concern is that nTiO2 may alter the environm...

Reliability evaluation of power distribution systems is a well-studied and understood problem, but topology analysis efficiency and failure feature description are still limiting the practical application of reliability evaluation in distribution systems. One approach the authors proposed in this study is to incorporate the machine-learning technique into the simulation-based reliability evaluation method, and assess the system reliability in an empirical fashion. In this study, a framework for performing the machine-learning-based reliability evaluation, and corresponding modelling processes are first established. Then, by inducing a supervised learning algorithm named perceptron, a state-space classification-based (SSC) method for system state assessment, the core procedure of reliability evaluation, is proposed. On this basis, a reliability evaluation algorithm combining the SSC-based system state assessment and sequential Monte Carlo simulation is proposed, where the workload of topology analysis required in conventional reliability evaluation methods can be released. Furthermore, extensive case studies are conducted on the Roy Billinton Test System (RBTS) bus 2 system and an actual distribution system to verify the proposed models and algorithms. Results show that the proposed framework supports a more efficient reliability evaluation pattern while ensuring the evaluation accuracy.

Nanomaterials with enzyme-like activities (nanozyme) have shown potential to augment the inherent functions of plants, e.g. photosynthesis and stress resistance. Mechanistically understanding the interaction between plants and nanozymes is important. In this study, Mn3O4 NPs (1 and 5 mg per plant) with excellent antioxidant enzyme mimicking activities were synthesized and were foliarly applied to 3 week-old cucumber plants for 7 days. The response of plants to Mn3O4 NPs was determined at physiological and metabolic levels. Results showed that Mn3O4 NPs at 1 mg per plant significantly increased leaf photosynthetic pigment content, net photosynthesis, and biomass. Gas chromatography-mass spectrometry based metabolomics revealed that Mn3O4 NPs at 1 mg per plant altered the metabolomes in the cucumber leaves. A notable change was that both precursors (phenylalanine and tyrosine) and down-stream products (resveratrol, chlorogenic acid, dihydroxycinnamic acid, benzenetriol, hydroxybenzoic acid, trihydroxybenzene, quinic acid, and catechin) in shikimate and phenylpropanoid pathways were up-regulated in response to the Mn3O4 NPs, indicating the boosting of endogenous antioxidants. Mn3O4 NPs were then applied to 3 week-old cucumber plants subjected to salinity stress to test their performance to stress tolerance. Mn3O4 NPs at 1 mg per plant levels were found to successfully alleviate oxidative stress in cucumber plants allowing them to maintain their biomass. These results indicate that Mn3O4 NPs can boost endogenous antioxidant defenses in the plant, which may enable Mn3O4 NPs to be a promising nano-regulator helping to counter the undesirable effects of oxidative stress.

More and more attention has been redirected to per- and polyfluorinated alkyl substances (PFASs), particularly perfluorooctanoic acid (PFOA), owing to their ecotoxicity and environmental risks. As one of the major emerging and persistent contaminants in the environment, the current treatment processes could not remove PFOA efficiently. The recent advances in heterogeneous photocatalysis have demonstrated high efficiencies in degrading persistent contaminants, which provides an alternative approach for PFOA removal. Notably, Ga2O3-based photocatalysts exhibited great potential for PFOA remediation due to their high oxidizing capability and energy sustainability. Thus, Ga2O3 hierarchical nanosheets modified by a series of transition metals were rationally developed, and applied as heterogeneous photocatalysts for fast and efficient PFOA degradation. Noteworthily, the indium modified Ga2O3 hierarchical nanosheets achieved prominent PFOA decomposition activity, which can completely degrade 20 mg L−1 PFOA within 1 hour. The In–Ga2O3 hierarchical composites have dramatically enhanced the degradation kinetics for PFOA, which was 7.8 times higher than that of pristine Ga2O3. With in-depth mechanism investigation, we have demonstrated that In modification can not only enhance light harvesting and suppress photogenerated carrier recombination, but also favor the improvement of the adsorption ability for PFOA through the coexistence of monodentate and bidentate/bridging coordination modes. The transition metals–modification strategy paves the way for fabricating high-performance nanoscale photocatalysts for the removal of PFASs in water.

The global occurrence of per- and polyfluoroalkyl substances (PFAS) in aquatic systems has raised concerns about their adverse effects on ecosystems and human health. Adsorption is a promising technique for the remediation of PFAS, yet effective adsorbents with rapid uptake kinetics and high adsorption capacity are still in high demand, and molecular-level understanding of the interfacial adsorption mechanisms is lacking. In this study, we developed a superior layered rare-earth hydroxide (LRH) adsorbent, ultrathin Y

Fully understanding the environmental implications of engineered nanomaterials is crucial for their safe and sustainable use. Cyanobacteria, as the pioneers of the planet earth, play important roles in global carbon and nitrogen cycling. Here, we evaluated the biological effects of molybdenum disulfide (MoS

Molybdenum disulfide (MoS

Perfluorooctanoic acid (PFOA) has raised significant health concerns due to its high ecotoxicological risks and difficulties in removal by conventional water treatment process. Previous studies have demonstrated that photocatalytic techniques exhibit great potential in PFOA removal. However, the underlying mechanism of the degradation process has not been fully understood, particularly the contribution of the facet effects of catalysts. In this study, a combination of experiments and first-principles calculations were conducted to shed light on the facet-dependence of the interfacial interactions and oxidation during the PFOA degradation process. We proved that the interfacial interaction was essential in initiating the hole-dominated degradation process, and the {110}R3c facet of hexagonal In2O3 features the strongest interaction with PFOA. The overall defluorination rate was mainly controlled by the hole-dominated oxidation processes under UV irradiation, which were further attributed to the electronic structures and reaction site distributions of different In2O3 surfaces. This study provides molecular-level insights on the facet-dependent PFOA catalytic degradation process, which can guide the rational design of photocatalysts to achieve superior decontamination efficiency.

Power systems are vulnerable to natural disasters and a proper load restoration strategy after blackouts is significant for the resilience enhancement. Current studies of load restoration including transient constraints have not considered the dynamic boundaries of microgrids and the software interaction between steady-state optimization and transient simulation has not yet been fully expounded on. To solve these problems, this paper proposes a load restoration scheme utilizing dynamic microgrids formation with transient constraints guaranteed. Specifically, an online closed-loop of steady-state optimization and transient simulation is established. For practical applications, the interaction between PSCAD and MATLAB is also presented in detail. The case study based on the IEEE 37-node test feeder shows the importance of integrating transient simulation verification and feedback in the load restoration strategies. In addition, the proposed scheme can provide guidance for further hardware-in-the-loop test and industrial controller design.

Copper (Cu) is the most extensively used bactericide worldwide in many agricultural production systems. However, intensive application of Cu bactericide have increased the selection pressure toward Cu-tolerant pathogens, including Xanthomonas perforans, the causal agent of tomato bacterial spot. However, alternatives for Cu bactericides are limited and have many drawbacks including plant damage and inconsistent effectiveness under field conditions. Also, potential ecological risk on nontarget organisms exposed to field runoff containing Cu is high. However, due to lack of alternatives for Cu, it is still widely used in tomato and other crops around the world in both conventional and organic production systems. In this study, a Cu-tolerant X. perforans strain GEV485, which can tolerate eight tested commercial Cu bactericides, was used in all the field trials to evaluate the efficacy of MgO nanomaterial. Four field experiments were conducted to evaluate the impact of intensive application of MgO nanomaterial on tomato bacterial spot disease severity, and one field experiment was conducted to study the impact of soil accumulation of total and bioavailable Cu, Mg, Mn, and Zn. In the first two field experiments, twice-weekly applications of 200 μg/mL MgO significantly reduced disease severity by 29-38% less in comparison to a conventional Cu bactericide Kocide 3000 and 19-30% less in comparison to the water control applied at the same frequency (p = 0.05). The disease severity on MgO twice-weekly was 12-32% less than Kocide 3000 + Mancozeb treatment. Single weekly applications of MgO had 13-19% higher disease severity than twice weekly application of MgO. In the second set of two field trials, twice-weekly applications of MgO at 1000 μg/mL significantly reduced disease severity by 32-40% in comparison to water control applied at the same frequency (p = 0.05). There was no negative yield impact in any of the trials. The third field experiment demonstrated that application of MgO did not result in significant accumulation of total and bioavailable Mg, Mn, Cu, or Zn in the root-associated soil and in soil farther away from the production bed compared to the water control. However, Cu bactericide contributed to significantly higher Mn, Cu, and Zn accumulation in the soil compared to water control (p = 0.05). This study demonstrates that MgO nanomaterial could be an alternative for Cu bactericide and have potential in reducing risks associated with development of tolerant strains and for reducing Cu load in the environment.

C60 could enhance the accumulation of pollutants in organisms, but their effects on higher trophic levels remain unknown. In the present study, the transfer of C60 from Daphnia magna to zebrafish (...