Higher Release Research Articles

Chronic Peroxisome Proliferator-Activated Receptor α/γ and Cannabinoid Receptor 2 Agonist Treatments Attenuated Visceral Adipose Tissue (VAT)–Derived Extracellular Vesicle–Related VAT and Intestinal Abnormalities in Nonalcoholic Steatohepatitis Mice

This study explores the mechanisms and combined effects of chronic peroxisome proliferator-activated receptor (PPAR)α/γ and cannabinoid receptor 2 (CB2R) agonists on visceral adipose tissue (VAT)-derived extracellular vesicle (EVs) release and associated systemic/VAT inflammation, decreased VAT capillary density/fibrosis, and intestinal inflammation/hyperpermeability in nonalcoholic steatohepatitis (NASH) mice. NASH mice receiving 1 month of PPARα/γ agonist aleglitazar (10 mg/kg/day), CB2R agonist JWH015 (3 mg/kg/day) alone or combined. High EV release from VAT of NASH mice was associated with severe systemic/VAT/intestinal inflammation, reduced capillary network of VAT, and intestinal hyperpermeability. Combined JWH015 with aleglitazar treatment significantly suppressed HFD-induced obesity/adiposity, inhibited VAT expansion, reduced VAT inflammation/fibrosis, normalized VAT capillary network, and attenuated intestinal mucosal injury, inflammation, and hyperpermeability in NASH+aleg+JWH015 mice. The inhibition of AT-derived EV release and hypoxia inducible factor (HIF)1α levels in AT-derived EV, normalization of CB2R, PPARα, PPARγ, PPARγ1, PPARγ2, tight junction proteins, VEGF/CD31 expression, and downregulations of HIF1α, MCP-1 and TGFβ1 were observed in the VAT and intestine of the NASH+aleg+jwh015 group. In vitro experiments revealed that PPARα/γ and CB2R activation attenuated NASH AT-derived EV (EVnash)-induced pathogenic changes in the J774/SVEC4-10/Caco2 /3T3-L1 cell system. This study suggested that VAT-derived EVs contribute to the pathogenesis of NAFLD and that combined PPARα/γ and CB2R agonist treatment reduces VAT-released EV release and HIF1/MCP-1 signals to ameliorate hepatic steatosis and VAT/intestine abnormalities of NASH mice.

Optimizing Concentrated Solar Power: High‐Temperature Molten Salt Thermal Energy Storage for Enhanced Efficiency

ABSTRACTMolten salts (MSs) thermal energy storage (TES) enables dispatchable solar energy in concentrated solar power (CSP) solar tower plants. CSP plants with TES can store excess thermal energy during periods of high solar radiation and release it when sunlight is unavailable, such as during cloudy periods or at night. This capability allows these plants to provide reliable, dispatchable power, ensuring a continuous electricity supply to the grid. This paper examines the challenges and opportunities of utilizing higher‐temperature molten salt formulations to enhance power cycle efficiency. Drawing on existing literature, performance analysis of existing power plants, and novel simulation results, we project the expected technological improvements by the end of this decade. By using 15 h of TES and a higher temperature MS formulation, with heat transfer fluid hot temperatures of 700°C, and a power cycle 350 bar 700°C of efficiency 48%, the annual electricity production from a 115 MW power plant in Daggett, California is 688 GWh, the total installed cost is $684 m while the 25‐year LCOE is 6.37 c/kWh.

Microscope-enabled disc dissolution system: Concordance between drug and polymer dissolution from an amorphous solid dispersion disc and visual disc degradation

A microscopic erosion time test was recently described to anticipate amorphous solid dispersion (ASD) drug load dispersibility limit, using 0.5 ml media volume. Studies here build upon this microscope-enabled method but focus on drug and polymer dissolution from an ASD disc, along with imaging. The objective was 1) to design and build a microscope-enabled disc dissolution system (MeDDiS) with a 900 mL dissolution volume and 2) assess the ability of MeDDiS imaging of dissolving discs to provide concordance with measured drug and polymer dissolution profiles. MeDDiS employed a digital microscope to image ASD discs and a one-liter vessel for dissolution. ASD discs containing ritonavir (5–50 % drug load) and PVPVA were fabricated and subjected to in vitro dissolution using MeDDiS, where disc diameter was quantified with time. Ritonavir and PVPVA release were also measured. Results indicate concordance between imaging and dissolution. Both found 25 % drug load to provide high drug and polymer release, but 30 % yielded low release. Quantitatively, MeDDiS images predicted drug and polymer release profile, both above and below the drug load cliff. Overall, studies here describe a MeDDiS which has promised to anticipate drug and polymer dissolution, via imaging of dissolving discs, above and below the ASD drug load cliff.

Synergistic Enhancement of Carboplatin Efficacy through pH-Sensitive Nanoparticles Formulated Using Naturally Derived Boswellia Extract for Colorectal Cancer Therapy.

Carboplatin (Cp) is a potent chemotherapeutic agent, but its effectiveness is constrained by its associated side effects. Frankincense, an oleo-gum resin from the Boswellia sacra tree, has demonstrated cytotoxic activity against cancer cells. This study explored the synergistic potential of nanoparticles formulated from Boswellia sacra methanolic extract (BME), to enhance the therapeutic efficacy of Cp at reduced doses. Nanoparticles were prepared via the nanoprecipitation method, loaded with Cp, and coated with positively charged chitosan (CS) for enhanced cell interaction, yielding Cp@CS/BME NPs with an average size of 160.2 ± 4.6 nm and a zeta potential of 12.7 ± 1.5 mV. In vitro release studies revealed a pH-sensitive release profile, with higher release rates at pH 5.4 than at pH 7.4, highlighting the potential for targeted drug delivery in acidic tumor environments. In vitro studies on HT-29 and Caco-2 colorectal cancer cell lines demonstrated the nanoformulation's ability to significantly increase Cp uptake and cytotoxic activity. Apoptosis assays further confirmed increased induction of cell death with Cp@CS/BME NPs. Cell-cycle analysis revealed that treatment with Cp@CS/BME NPs led to a significant increase in the sub-G1 phase, indicative of enhanced apoptosis, and a marked decrease in the G1-phase population coupled with an increased G2/M-phase arrest in both cell lines. Further gene expression analysis demonstrated a substantial downregulation of the anti-apoptotic gene Bcl-2 and an upregulation of the pro-apoptotic genes Bax, PUMA, and BID following treatment with Cp@CS/BME NPs. Thus, this study presents a promising and innovative strategy for enhancing the therapeutic efficacy of chemotherapeutic agents using naturally derived ingredients while limiting the side effects.

Analysis of Occupational Safety Risk Management in Crane Based Well Services Activities in Budi Field Oil Field

Crane Based Well Services (CBWS) is a new technology in oil well maintenance in the oil and gas world. Tately N.V. is one of the marginal oil and gas companies, has implemented several CBWS campaigns in their oil wells. This study examines how the analysis and management of occupational safety risks arising from these activities. In CBWS activities, there are several potential hazards in the stages of its activities, including the danger of gas coming out of the well, the danger of wild sprays, the danger of lifting tools failure, the danger of working at heights, the danger of high pressure release, the danger of pinch points, the danger of irregular material swings and the danger of crane legs collapsing. Activities with these potential hazards have a high to moderate risk of causing work accidents. To reduce the risk of accidents from CBWS activities, Tately N.V. has taken mitigation measures for each potential hazard identified. The results of the study showed that the mitigation measures were quite successful with a decrease in the risk assessment to light, so that activities can be carried out with the mitigation that has been carried out. This study shows that much simpler and more economical CBWS activities can be carried out safely and with zero accidents by implementing the recommended mitigation or prevention measures to reduce existing K3 risks.

Poly(malic acid) Nanoconjugates of Pyrazinoic Acid for Lung Delivery in the Treatment of Tuberculosis.

Tuberculosis (TB) remains a major global infection, and TB treatments could be improved by site-specific targeting with delivery systems that allow tissue and cell uptake. To increase the drug concentration at the target sites following lung delivery, polymeric nanoconjugates based on biodegradable poly(malic acid) were designed. Pyrazinoic acid (POA), the active moiety of pyrazinamide─a first-line antituberculosis drug─was covalently bound to poly(malic acid) using a hydrophobic linker at mole ratios of 25%, 50%, and 75%. Three linkers, hexanediol, octanediol, and decanediol, were considered. Independently of the linker or ratio, all the conjugates were able to self-assemble, forming nanoconjugates (NCs) in water with 130-190 nm in diameter. Pyrazinoic acid could be released in a controlled manner without any burst release effect. Its kinetics can be adjusted by modifying the grafting ratio and linker length. No cytotoxicity was observed on RAW 264.7 macrophages up to ∼14 μg/mL of POA. In addition, the nanoconjugates were efficiently taken up by these cells over 5 h. Thanks to their high loading capacity and modulable release profiles, these nanoconjugates hold great promise for more effective treatment of tuberculosis.

Innovative temperature-responsive membrane with an elastic interface for biofouling mitigation in industrial circulating cooling water treatment

To address the issues of scaling caused by heat and water evaporation in regard to circulating cooling water (CCW), TFC membrane filtration systems have been increasingly considered for terminal treatment processes because of their excellent separation performance. However, membrane biofouling phenomenon significantly hinders the widespread utilization of TFC membranes. In this study, to harness the thermal phenomenon of CCW and establish a stable and durable multifunctional antibiofouling layer, temperature-responsive Pnipam and the spectral antibacterial agent Ag were organically incorporated into commercially available TFC membranes. Biological experimental findings demonstrated that above the lower critical solution temperature (LCST), the contraction of Pnipam molecular chains facilitated the inactivation of bacteria by the antibacterial agent, resulting in an impressive sterilization efficiency of up to 99 %. XDLVO analysis revealed that below the LCST, the establishment of a hydration layer on the functional interface resulted in the creation of elevated energy barriers, effectively impeding bacterial adhesion to the membrane surface. Consequently, a high bacterial release rate of 98.4 % was achieved on the low-temperature surface. The alterations in the functional membrane surface conformation induced by temperature variations further amplified the separation between the pollutants and the membrane, creating an enhanced "elastic interface." This efficient and straightforward cleaning procedure mitigated the formation of irreversible fouling without compromising the integrity of the membrane surface. This study presents a deliberately engineered thermoresponsive antibiofouling membrane interface to address the issue of membrane fouling in membrane-based CCW treatment systems while shedding new light on the mechanisms of "inactivation" and "defense."

Microstructure and energy release properties of W-Zr-Al energetic structural material fabricated by explosive consolidation

Multi-element intermetallic energetic structural materials (ESMs) as a new typical ESMs characterized by their high heat release properties and strength, which could be applied as reactive fragment, reactive shell and reactive shaped charge. Al-based ESMs had been extensively studied due to their excellent mechanical properties and high energy release characteristics. But, the low density of Al-based ESMs hindered its application. However, the need for higher density and energy release persists. In this work, the nearly fully dense W-Zr-Al ESMs with a molar ratio of 1.9:1:1 was fabricated successfully by explosive consolidation. The density reached 10.12 g/cm3 (97.5 % of the theoretical maximum density). Microstructure of the specimen was characterized by X-ray diffractometer (XRD), optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectrometry (EDS) and transmission electron microscope (TEM). The heat treatment was used to further improve the performance of the specimen and the mechanical properties of quasi-static compression was investigated before and after heat treatment. The reaction activity and process of W-Zr-Al ESMs was discussed by differential scanning calorimetry (DSC). Besides, the impact-induced energy release tests were carried out to evaluate the reactive characteristics of the W-Zr-Al ESMs. The results indicated that high-density, good-strength and high energy release unreacted W-Zr-Al energetic materials were fabricated successfully by explosive consolidation.

Nanocarrier-Based Delivery Approaches of Mangiferin: An Updated Review on Leveraging Biopharmaceutical Characteristics of the Bioactive.

In recent years, bioactive constituents from plants have been investigated as an alternative to synthetic approaches of therapeutics. Mangiferin (MGF) is a xanthone glycoside extracted from Mangifera indica and has shown numerous medicinal properties, such as antimicrobial, anti-diarrhoeal, antiviral, anti-inflammatory, antihypertensive, anti-tumours, and anti-diabetic effects. However, there are numerous challenges to its effective therapeutic usage, including its low water solubility, limited absorption, and poor bioavailability. Nano formulation approaches in recent years exhibited potential for the delivery of phytoconstituents with key benefits of high entrapment, sustained release, enhanced solubility, stability, improved pharmacokinetics, and site-specific drug delivery. Numerous techniques have been employed for the fabrication of MGF-loaded Nano formulations, and each technique has its advantages and limitations. The nanocarriers that have been employed to fabricate MGF nanoformulations for various therapeutic purposes include; polymeric nanoparticles, nanostructure, lipid carriers, polymeric micelles, Nano emulsions, microemulsion & self-microemulsifying drug delivery system, solid lipid nanoparticles, gold nanoparticles, carbon nanotubes, transfersomes, nanoliposomes, ethosomes & transethosomes, and glycethosomes. Different biopharmaceutical characteristics (size, shape, entrapment efficiency, zeta potential, in vitro drug release, ex vivo drug permeation,, and in vivo studies) of the mentioned MGF-loaded nanocarriers have been methodically discussed. Patent reports are also included to further strengthen the potential of MGF in the management of diseases.

Effect of H[formula omitted] addition on NH[formula omitted] flame structure and dynamics in a mixing layer

Hydrogen addition has been widely used to improve the combustion performance of low-reactivity fuels such as NH3. In this study, a series of two-dimensional NH3/H2 flames in mixing layers were investigated numerically. The aim is to assess and interpret the effects of H2 addition on the structure and dynamics of ammonia flames. Detailed chemistry and transport models were considered in the simulations. It was shown that for pure hydrogen or ammonia flames, a classical tribrachial structure was observed. The non-premixed branch in the tribrachial flame of NH3 combustion features high heat release rate (HRR), while the two premixed branches are weak. The mixture fraction corresponding to the maximum HRR of NH3 combustion is significantly lower than the stoichiometric mixture fraction. When blending ammonia with hydrogen, a tetrabrachial flame structure consisting of two premixed branches and two non-premixed branches was observed, where one non-premixed branch corresponds to the reaction of NH3, while the other is formed due to the reaction of H2. It was suggested that the formation of the tetrabrachial flame is related to the preferential diffusion of hydrogen. After decreasing artificially the diffusivity of hydrogen to suppress the preferential diffusion effect, the flame exhibits only three branches with the merging of the two non-premixed branches. By analyzing the flame dynamics at the leading edge, it was found that the flame speed (Sd∗) is negatively correlated with the flame stretch (κ) and scalar dissipation rate (χ), with Sd∗ decreasing almost linearly with κ or χ, consistent with previous studies of methane and hydrogen flames. As the H2 concentration is increased, the values of Sd∗ increase due to the enhanced reactivity.

HMNPs@PDA-GQDs-FA as carries of gambogic acid for inhibiting VX2 tumor cells

Ellipsoidal hollow magnetic nanoparticles (HMNPs) were first synthesized through a hydrothermal method and coated with SiO2 via the Stöber method, followed by template hydrothermal synthesis using C18TMS/TEOS volume ratio for silica-shell formation. Then, the core–shell structure was grafted with graphene quantum dots (GQDs), dopamine hydrochloride (PDA), and folic acid (FA) by amide reaction to obtain HMNPs@PDA-GQDs-FA. Transmission electron microscopy, X-ray photoelectron spectroscopy, fluorescence spectroscopy, and N2 adsorption/desorption analysis confirmed the successful construction of the HMNPs@PDA-GQDs-FA nanoscale carrier–cargo composite. The carrier HMNPs@PDA-GQDs-FA had improved loading (51.63 %) and higher release (47.18 %) of gambogic acid (GA) at an acidic pH (5.7) than the release (32.23 %) at an acidic pH (7.4), showing the pH response of PDA to the surrounding environment of tumor cells. Cytotoxicity test results showed that the cell survival rate was above 95 %, indicating that the carrier–cargo had low cytotoxicity. Cell lethality was greatly improved after loading GA, and the advantages of using FA-grafted HMNPs as a targeting ligand for tumor imaging were demonstrated by SPECT imaging analysis. These results showed that HMNPs@PDA-GQDs-FA had good biocompatibility and could be used for the treatment of VX2 tumors after loading GA.

Rate‐dependent mechanical properties and acoustic emission characteristic of recycled aggregate concrete under four‐point bending

AbstractThe application of recycled aggregate is crucial for waste concrete recycling, while the loading rate significantly influences the fracture behavior of recycled aggregate concrete. Herein, we investigate the effect of loading rate on the flexural and fracture behaviors of recycled aggregate concrete, along with associated acoustic emission characteristics. Results show that the flexural strength and energy absorption capacity maximum increase by 15.18% and 38.39%, respectively, as the loading rate rises. As the loading rate increases from 0.05 to 1 mm/min, peak frequency is primarily clustered in 0 ~ 75 kHz and 75 ~ 225 kHz and tends to be dense, while the b value decreases by 19.28%, 23.30%, and 30.17%, respectively. Additionally, the proportion of shear failure also decreases, which relates to the high energy release rate. Further, the multifractal spectrum α − f(α) resembles a quadratic distribution, with both multifractal intensity ∆f and spectrum width ∆α showing a downward trend as the loading rate rises.

Enhanced release of volatile halocarbons of microalgae in response to antibiotic-induced stress: Based on laboratory and ship-field experiments

This study investigated the impacts of sulfamethazine (SMZ) and oxytetracycline (OTC) antibiotics on the marine microalgae Nitzschia closterium and its release of volatile halocarbons (VHCs), which contribute to ozone depletion and climate change. High concentrations of SMZ and OTC suppressed cell density, reduced chlorophyll a content, and hindered Fv/Fm elevation in N. closterium, indicating its growth was inhibited. The exposure of N. closterium to antibiotics led to increased reactive oxygen species (ROS), reduced soluble protein content, and heightened catalase (CAT) activity, indicative of increased oxidative stress. This stress increased the release of three VHCs (CHBrCl2, CHBr2Cl, and CHBr3). Ship-borne experiments showed that high phytoplankton biomass was linked to high VHC release. Notably, the production and release of VHCs were significantly higher in the high-concentration antibiotic group (100 μg/L) than the low-concentration group (0.1 μg/L). These findings suggested that antibiotics induce excess ROS in algal cells, stimulating VHC production and release.

Optimization of potassium (K) recovery via electrochemical precipitation of K-struvite upon magnesium addition in urine

Potassium (K)-struvite precipitation is a promising approach to K recovery but faces the critical challenge of co-precipitation of sodium (Na)-struvite mainly due to the addition of sodium hydroxide (NaOH) for pH adjustment. To avoid using NaOH, this study investigated the electrochemical addition of magnesium (Mg) and hydroxide ions for K-struvite recovery. Results showed that a high release rate of Mg and hydroxide ions in the electrolysis led to a Mg:Phosphorus (P) ratio higher than 1:1 and pH higher than 11.3, which however resulted in a decrease in the K recovery efficiency. Subsequent optimization experiments conducted in synthetic urine, diluted fivefold, maintained a process pH of 10.811.0, with a current density of 5 mA/cm2 and an electrode spacing of 20 mm. Under these conditions, K recovery efficiency reached 38 %, while P recovery efficiency reached 93 % after 30 minutes of electrolysis. Compared to chemical precipitation methods, electrochemical recovery exhibited a 41 % increase in K recovery efficiency and a 153 % increase in K-struvite:Na-struvite molar ratio in the precipitates. Furthermore, a predictive model was developed to estimate optimal K recovery time and energy consumption, showcasing the effectiveness of electrochemical Mg addition in urine for high-efficiency K recovery.

PH-responsive mupirocin-loaded hybrid nanoparticles in hydrogel and film forming spray against resistant bacterial wound infections

The aim of this work was to fabricate smart Mupirocin loaded Lipid Polymeric Hybrid Nanoparticles (MUP-LPHNs) based hydrogel and Film forming spray (FFS) for targeted release of MUP in response to wound pH. The MUP-LPHNs were optimized through design expert v.12. The optimized MUP-LPHNs had a particle size of 270.7 ± 3.20 nm with zeta potential of 17.05 ± 1.20 mV and entrapment efficiency of 88.0 ± 0.35 %. MUP-LPHNs showed no major chemical interaction, spherical morphology and amorphous nature as confirmed by FTIR, SEM and XRD, respectively. MUP-LPHNs were loaded to MUP-LPHNs based hydrogel (MUP-LPHNs-HG) and MUP-LPHNs based film forming spray (MUP-LPHNs-FFS) with successful characterization. In vitro release data confirmed sustained and pH dependent release from both MUP-LPHNs-HG and MUP-LPHNs-FFS as higher release was observed at pH 7.4. MUP-LPHNs-HG and MUP-LPHNs-FFS showed high efficiency and long-term inhibition of Staphylococcus aureus (SA), Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) with 4–6 fold increase in the antibacterial activity compared to MUP solution. MUP-LPHNs-HG and MUP-LPHNs-FFS exhibited both in vitro and in vivo wound pH contingent, sustained drug release. Moreover, the prepared nanocarriers systems flaunted significant therapeutic efficacy against MRSA infected wound model by significant reduction in bacterial load and wound area, increased hydroxy proline level and antioxidant enzymes and reduced proinflammatory cytokines. Similarly, immunohistochemistry, histopathological and trichrome assessment showed significant reduction in level of inflammatory markers, accelerated and enhanced re-epithelization, improved connective tissue remodeling and effectively promote collagen deposition with effective wound regeneration, respectively. It can be concluded that LPHNs could be a potential carrier system for enhancing the therapeutic efficacy of MUP against resistant bacterial wound infections.

Biennial variability of boreal spring surface air temperature over India

In this study, we report significant biennial variability or oscillation (BO) in the boreal spring (March–May) Surface Air Temperature (SAT) over India and unravelled the causative mechanisms. The positive phase of the BO exhibit significant seasonal warming over India, whereas seasonal cooling is observed during the negative phase of BO. Heat wave days are more during the positive phase of BO compared to negative or neutral phase. The positive (negative) phase of BO is generally coherent with the central (eastern) Pacific warming (cooling) years. The anomalous low-level divergence associated with low-level anticyclonic circulation induces less cloudiness and intense surface solar radiation ovr India during the positive phase, favouring surface warming. The evolution of some positive and/or negative phases of BO without any large scale forcing from the equatorial Pacific suggested the possibility of alternate pathways. The strong anomalous upper-level (at 200 hPa) anticyclonic circulation provoked by mid-latitude Rossby waves is found contributing to the positive phase, thereby highlighting the role of dominant mid-latitude pathways in the biennial SAT variability in addition to El Niño forcing. The sinking motion associated with persistent high, and the associated adiabatic compression also supported surface heating during the positive phase of BO. On the other hand, the mid-latitude Rossby wave induced upper-level cyclonic circulation is found contributing to the negative phase. The sinking motion associated with persistent high, and the associated adiabatic compression also supported surface heating during the positive phase of BO. In contrast, negative soil temperature anomalies and high latent heat flux release to the atmosphere supported surface cooling during the negative phase.

Tea saponin-Zein binary complex as a quercetin delivery vehicle: preparation, characterization, and functional evaluation

In this study, in order to solve the application problems of poor water solubility and low bioavailability of quercetin, we prepared a nano-delivery system with core-shell structure by anti-solvent method, including a hydrophilic shell composed of tea saponin and a hydrophobic core composed of Zein, which was used to improve the delivery efficiency and biological activity of quercetin. Through the optimal experiments, the loading rate and encapsulation rate of nanoparticles reached 89.41 % and 7.94 % respectively. And the water solubility of quercetin is improved by 30.16 times. At the same time, the quercetin acted with Zein through non-covalent interaction and destroyed its spatial network through structural characterization, while tea saponin covered the surface of Zein through electrostatic interaction, making it change into amorphous state. In addition, the addition of tea saponin makes the nanoparticles remain stable under the changes of external environment. During simulating gastrointestinal digestion procedure, ZQTNPs has higher release rate and bioavailability than free quercetin. Importantly, ZQTNPs can overcome the limitations of a single substance through synergy. These results will promote the innovative development of quercetin precision nutrition delivery system.

Energy characteristics of the vapor-gas shell formation stage during electrolyte-plasma treatment

The article presents the results on energy characteristics and the thermophysical state in the vapor-gas shell formation stage during electrolyte-plasma treatment. The vapor-gas shell formation stage is characterized by intense heating of the anode layer, a transition to undeveloped bubble boiling with high heat release capacity, boiling crisis emergence, and by a transition to the film mode with low heat release capacity. At the same time, a traditional electrochemical process occurs on the anode, which is accompanied by dissolving the surface layer. Dependences characterizing the influence of electrolyte-plasma treatment parameters on the specific power and specific energy of the vapor-gas shell formation stage are established. The obtained results allow optimizing the parameters of new effective processes of electrolyte-plasma treatment in controlled pulse modes, at which both electrochemical (vapor-gas shell formation) and electrolyte-plasma stages are realized within one pulse of millisecond duration.

Ebullition drives high methane emissions from a eutrophic coastal basin

The production of methane in coastal sediments and its release to the water column is intensified by anthropogenic eutrophication and bottom water hypoxia, and it is still uncertain whether methane emissions to the atmosphere will be enhanced. Here, we assess seasonal variations in methane dynamics in a eutrophic, seasonally euxinic coastal basin (Scharendijke, Lake Grevelingen). In-situ benthic chamber incubations reveal high rates of methane release from the sediment to the water column (74–163 mmol m−2 d−1) during monthly measurements between March and October 2021. Comparison of these in-situ total benthic methane fluxes and calculated diffusive fluxes point towards a major role for ebullition. In spring and fall, when the water column was oxic, microbial removal of dissolved methane occurred aerobically in the bottom water. In summer, in contrast, dissolved methane accumulated to concentrations of up to 67 μmol L−1 below the oxycline. Shifts in δ13C–CH4 and δD-CH4 towards higher values and the abundant presence of methane oxidizing bacteria point towards removal of methane around the oxycline, likely through both aerobic and anaerobic pathways, with the latter possibly linked to iron oxide reduction. Shifts in δ13C–CH4 and δD-CH4 to lower values above the oxycline indicate that bubble dissolution contributed to dissolved methane. Methane emissions to the atmosphere were observed in all seasons with the highest, in-situ measured diffusive fluxes (1.2 mmol m−2 d−1) upon the onset of water column mixing at the end of summer. Methane release events during the measurement of in-situ water-air fluxes and model calculations point towards a flux of methane to the atmosphere in the form of bubbles, which bypass the microbial methane filter. The model calculations suggest a potential year-round ebullitive methane flux between 30 and 120 mmol m−2 d−1. We conclude that methane emissions from eutrophic coastal systems may be much higher than previously thought because of ebullition.

Comparative study on the influence of chemical reaction mechanisms on turbulent jet flame

Abstract This paper focus on the influence of chemical reaction mechanisms on the simulation of turbulent jet flame of 11 different chemical reaction mechanisms. These mechanisms are mainly selected from GRI series and their reduced mechanisms, and their reaction kinetics were analyzed. This paper uses LES-TPDF method to simulate Sandia Flame D turbulent jet flame and then analyze the difference of time-averaged temperature, heat release rate and species concentration results in different mechanisms. The results show that the kinetic performance of different chemical mechanisms is very different. The ignition delay time of JL4, SMOOKE and z42 mechanisms are either overestimated or underestimated due to the omission of multi-carbon species and other important species. The differences of the LES results in different mechanisms increase along the axis. The differences near the fuel inlet are mainly due to the difference of kinetic performance, while the difference away from the fuel inlet is more due to the different species and elementary reactions involved in different chemical reaction mechanisms. For all chemical mechanisms, there is a tendency that the more species used in the chemical reaction, the more concentrated the region of high heat release rate, the shorter the flame length, and the higher the maximum temperature throughout the field.