Search Results (568)

Plasma-assisted nitrogen fixation is emerging as a promising alternative to the dominant industrial method of the Haber–Bosch (H–B) process, which is energy-intensive and environmentally detrimental. Nonthermal plasma technology represents a cutting-edge innovation with the potential to revolutionize nitrogen fertilizer (N-fertilizer) production, offering a more sustainable approach by operating under mild conditions, making it suitable for decentralized N-fertilizer production. Toward the goal, in this study, we demonstrate our development and test of a novel nonthermal plasma system for continuous on-site production of N-fertilizer. This technology results in a product of aqueous N-fertilizer on-site, from only air, water, and electricity without carbon emissions, directly applicable to plants, bypassing costly and hazardous multiple steps in the production and transportation of the industrial N-fertilizers. Full article

Dielectric barrier discharge (DBD) plasma provides a solvent-free and energy-efficient approach for the in situ polymerization of styrene on cotton textiles. Traditional methods for polystyrene (PS) coating often require elevated temperatures, chemical initiators, or organic solvents, conditions that are incompatible with porous, heat-sensitive substrates such as cotton. In this work, we demonstrate that DBD plasma can initiate and sustain styrene polymerization directly on cotton fibers under ambient conditions. FT-IR spectroscopy confirms the consumption of the vinyl C=C bond and the formation of atactic, amorphous polystyrene. Thermogravimetric analysis indicates that the cotton coated with DBD polymerized PS exhibits enhanced thermal stability compared to cotton coated with commercial PS. Additionally, UV aging tests confirm that the plasma-deposited coating maintains its hydrophobicity after exposure to light. Together, these findings highlight DBD plasma as a sustainable and effective approach for producing hydrophobic, thermally robust, and UV-stable textile coatings without the need for solvents, initiators, or harsh processing conditions. Full article

An increasing number of different types of dielectric liquids are appearing on the market. This is undoubtedly related to sustainable development goals. This paper presents comparative studies of the lightning impulse breakdown voltage (LIBV) of six dielectric liquids with different chemical compositions: naphthenic uninhibited mineral oil (UMO), naphthenic inhibited mineral oil (IMO), natural ester (NE), synthetic ester (SE), bio-based hydrocarbon (BIO), and an inhibited liquid produced using gas-to-liquids technology (GTL). Tests were conducted in a point-to-sphere electrode configuration with a 5 mm thick pressboard barrier placed between them. This configuration was designed to more closely replicate the actual configuration found in transformers, where the oil channels are separated by pressboard barriers. Tests were performed for two inter-electrode gap distances of 25 mm and 40 mm, and for both lightning impulse voltage polarities. The pressboard barrier was placed so that the distance between point electrode and the barrier was always the same (10 mm). Measurements were performed using the step method. Before measurements began, the pressboard barrier was impregnated with the dielectric liquid being tested. The obtained measurement results were compared with previous studies conducted by the authors, which used a similar electrode system but without the pressboard barrier. The results confirmed that inserting the pressboard barrier between the electrodes effectively inhibits development of discharges and significantly increases the electrical strength of the entire insulation system. Full article

Low-temperature plasma treatments were applied to barley seeds using a dielectric barrier-stabilized corona discharge operated in ambient air enriched with oxygen or nitrogen to quantify surface chemical modifications and seed wettability. X-ray photoelectron spectroscopy showed that oxygen-enriched plasma produced the strongest oxidation, increasing surface oxygen from 9 ± 5 at% (control) to 24 ± 5 at%, while reducing carbon from 88 ± 5 at% to 76 ± 5 at%. Nitrogen-enriched plasma induced more moderate changes (O: 13 ± 5 at%, C: 85 ± 5 at%) but resulted in clear nitrogen incorporation, with an enhanced N 1s amine/amide component at ~400.8 eV. The hydroxyl O 1s contribution increased from 70% (control) to 82% (oxygen) and 90% (nitrogen), indicating substantial surface hydroxylation. SEM-EDX showed only minor micrometer-scale composition changes and no detectable morphological damage. Raman and ATR-FTIR spectra confirmed that polysaccharide, protein, and lipid structures remained intact, with intensity variations reflecting increased hydrophilicity. Water imbibition kinetics fitted with the Peleg model demonstrated faster initial hydration after plasma exposure, with 1/k₁ increasing from 20.25 ± 1.90 h⁻¹ (control) to 36.70 ± 6.56 h⁻¹ (oxygen) and 38.87 ± 7.57 h⁻¹ (nitrogen), while 1/k₂ remained nearly unchanged. Full article

A combined flow control method, integrating nanosecond pulsed surface dielectric barrier discharge (NS-SDBD) with pulsed jets, is proposed to address the challenge of low mixing efficiency in supersonic combustion. Numerical validation and mechanism analysis were conducted by solving the three-dimensional unsteady Reynolds-averaged Navier–Stokes (RANS) equations, coupled with the shear stress transport (SST) k–ω turbulence model. The simulations were carried out under a Mach 2.8 inflow condition with a 50 kHz pulsed frequency for H₂ jets. The results demonstrate that, compared to the steady jet case, the combined control scheme increases the combustion product mass flow rate by 27.1% and enhances combustion efficiency by 26.8%. The average temperature in the wake region increases by 65 K, while the total pressure recovery coefficient shows only a marginal change. The pressure disturbance center evolves along the outer edge of the counter-rotating vortex pair (CVP) and is eventually absorbed by the vortex core. This process generates favorable velocity and vorticity perturbations, which enhance O₂ entrainment into the CVP and increase the average wake temperature. Meanwhile, the strengthened reflected shock induces favorable velocity perturbations in the upper shear layer of the wake and further elevates the local temperature. Full article

Chickpea seed quality is highly susceptible to mechanical damage during handling and to rapid deterioration under postharvest storage. Atmospheric pressure Non-Thermal Plasma (NTP) has shown positive effects on seed quality in several species, but its long-term impact on chickpea remains poorly understood. This study evaluated the effect of NTP on the physiological germination process and postharvest deterioration of Cicer arietinum L. (Fabaceae) ’Felipe UNC-INTA’ seeds. Seeds were treated for three minutes with dielectric barrier discharge using O₂ and N₂ as carrier gases. Results showed that NTP optimized the triphasic germination response in embryo, especially in phases II and III, where radicle protrusion occurred earlier in treated (27 and 30 h) than in control (33 h) seeds, accompanied with a partition ratio < 1, indicating the roots’ preferential assimilate allocation. Fungal incidence decreased notably, e.g., Aspergillus decreased from 31% (control) to 11% (N₂) and 10% (O₂). O₂-treated seeds exhibited higher germination (94%) than the control (90%) and an 11% reduction in individual electrical conductivity, indicating enhanced membrane integrity. After six months of storage, both treatments delayed aging, maintaining higher vigor than untreated seeds. Overall, NTP emerges as a promising postharvest technology to enhance and preserve seed vigor and viability in C. arietinum. Full article

The current study presents a holistic technology evaluation and integration methodology for enhancing the aerodynamic efficiency and performance of a tactical, fixed-wing Blended-Wing-Body (BWB) Unmanned Aerial Vehicle (UAV) through the synergetic integration of several aerodynamic and performance-enhancing technologies. Based upon several individual technology investigations conducted in the framework of the EURRICA (Enhanced Unmanned aeRial vehicle platfoRm using integrated Innovative layout Configurations And propulsion technologies) research project for BWB UAVs, a structured Technology Identification, Evaluation, and Selection (TIES) is conducted. That is, a synergetic examination is made involving technologies from three domains: configuration layout, flow control techniques, and hybrid-electric propulsion systems. Six technology alternatives, slats, wing fences, Dielectric Barrier Discharge (DBD) plasma actuators, morphing elevons, hybrid propulsion system and a hybrid solar propulsion system, are assessed using a deterministic Multi-Attribute Decision Making (MADM) framework based on Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Evaluation metrics include stall velocity (V_s), takeoff distance (s_g), gross takeoff weight (GTOW), maximum allowable GTOW, and fuel consumption reduction. Results demonstrate that certain configurations yield significant improvements in low-speed performance and endurance, while the corresponding technology assumptions and constraints are, respectively, discussed. Notably, the configuration combining slats, morphing control surfaces, fences, and hybrid propulsion achieves the highest ranking under a performance-future synergy scenario, leading to over 25% fuel savings and more than 100 kg allowable GTOW increase. These findings provide quantitative evidence for the potential of several technologies in future UAV developments, even when a novel configuration, such as BWB, is used. Full article

The persistence of organochlorine pesticides, such as Aldrin and Dieldrin, in water bodies worldwide necessitates the development of efficient Advanced Oxidation Processes (AOPs) for water treatment or remediation. However, comparative studies evaluating the performance of distinct plasma discharge geometries against acoustic cavitation for the mineralization of these specific chlorinated cyclodienes remain scarce. This study investigates the comparative efficacy of four non-thermal technologies, ultrasound, dielectric barrier discharge (DBD) plasma, glow discharge plasma, and corona discharge plasma, for the simultaneous degradation of Aldrin and Dieldrin in a model contaminated aqueous solution (5 μg/L). All experiments followed a 3²-factorial design, and the residual concentrations of these pesticides were quantified by GC-MS after Solid-Phase Microextraction (SPME). All four methods achieved high degradation efficiencies, ranging from 92.5% to 100% for Aldrin and 92.6% to 99.2% for Dieldrin. Corona discharge plasma achieved the highest performance, resulting in 100% removal of Aldrin. However, ultrasound proved to be the most advantageous, achieving a 98% removal efficiency for both pesticides under its mildest conditions (3125 W/L ultrasonic power density for 3 min). The study confirmed that while Aldrin is highly susceptible to these technologies, Dieldrin remains the limiting factor for regulatory compliance. Chemical analysis did not conclusively identify any organic degradation by-products, suggesting that these AOPs may promote complete mineralization of the pollutants. Full article

Non-thermal plasma (NTP) is a fast, reagent-free technology for dye removal, yet its performance is highly dependent on the operating conditions and on plasma–catalyst interactions. In this work, a coaxial falling-film dielectric barrier discharge (DBD) reactor was optimized for the degradation and decolorization of organic dyes, with ceria (CeO₂) employed as a catalyst. For the first time, CeO₂ prepared via a supercritical antisolvent (SAS) micronization route was tested in plasma-assisted dye decolorization and directly compared with its non-micronized counterpart. Optimization of plasma parameters revealed that oxygen feeding, an input voltage of 12 kV, a gas flow of 0.2 NL·min⁻¹, and an initial dye concentration of 20 mg·L⁻¹ resulted in the fastest decolorization kinetics. While the anionic dye Acid Yellow 36 exhibited electrostatic repulsion and negligible plasma–ceria synergy, the cationic dyes Crystal Violet and Methylene Blue showed strong adsorption on the negatively charged CeO₂ surface and pronounced plasma–catalyst synergy, with SAS-derived CeO₂ consistently outperforming the non-micronized powder. The SAS catalyst, characterized by a narrow particle size distribution (DLS) and spherical morphology (SEM), ensured improved dispersion and interaction with plasma-generated species, leading to significantly shorter decolorization radiation times compared to the literature benchmarks. Importantly, this enhancement translated into higher energy efficiency, with complete dye removal achieved at a lower specific energy input than both plasma-only operation and non-micronized CeO₂. Scavenger tests confirmed •OH radicals as the dominant oxidants, while O₃, O₂•⁻, and e⁻_a played secondary roles. Tests on binary dye mixtures (CV + MB) revealed synergistic decolorization under plasma-only conditions, and the CeO₂-SAS catalyst maintained high overall efficiency despite competitive adsorption effects. These findings demonstrate that SAS micronization of CeO₂ is an effective material-engineering strategy to unlock plasma–catalyst synergy and achieve rapid, energy-efficient dye abatement for practical wastewater treatment. Full article

Biodegradable bioplastics have emerged as a promising sustainable alternative to minimize the environmental impact of traditional plastics. Nevertheless, many of them degrade slowly under natural or industrial conditions, raising concerns about their practical biodegradability. This fact is related to the high-order structure of the polymer backbones, i.e., high molar mass and high crystallinity. Research efforts are being devoted to the development of technologies capable of reducing the length of polymer segments by accelerated chain scission, which could help improve biodegradation rates upon disposal of bioplastic products. The objective of this review is to examine the current state of the art of abiotic degradation techniques, physically driven by temperature, mechanical stress, UV/gamma/microwave irradiation, or plasma or dielectric barrier discharge, and chemically induced by ozone, water, or acidic/basic solutions, with the aim of enhancing the subsequent biodegradation of bioplastics in controlled valorization scenarios such as composting and anaerobic digestors. Particular attention is given to pretreatment degradation technologies that modify surface properties to enhance microbial adhesion and enzymatic activity. Technologies such as ozonation and plasma-driven treatments increase surface hydrophilicity and introduce functional groups with oxygen bonds, facilitating subsequent microbial colonization and biodegradation. Irradiation-based techniques directly alter the chemical bonds at the polymer surface, promoting the formation of free radicals, chain scission, and crosslinking, thereby modifying the polymer structure. Pretreatments involving immersion in aqueous solutions may induce solution sorption and diffusion, together with hydrolytic chain breakage in bulk, with a relevant contribution to the ulterior biodegradation performance. By promoting abiotic degradation and increasing the accessibility of biopolymers to microbial systems, these pretreatment strategies can offer effective tools to enhance biodegradation and, therefore, the end-of-life management of bioplastics, supporting the transition toward sustainable cradle-to-cradle pathways within a biocircular economy. Full article

Background: The conversion of carbon dioxide (CO₂) into valuable products like carbon monoxide (CO) is an important process facing limitations due to poor energy efficiency. Dielectric barrier discharge (DBD) plasma reactors offer a potential solution through synergistic plasma catalysis, making the selection of an optimal solid packing material a critical design challenge. Methods: This study investigated the impact of four different packing materials—Al₂O₃, ZrO₂, glass beads, and kaolin pellets—on the CO₂ conversion process in a DBD reactor. The materials’ physical and chemical properties (porosity and composition) were analyzed. Experiments were conducted to examine the influence of gas flow rates and bead size on CO₂ and CO concentrations. The study utilized optical emission spectroscopy (OES) and kinetic mathematical modeling to characterize the discharge and the reaction. Results: Higher gas flow rates led to a decrease in CO₂ conversion due to reduced specific energy input. The addition of solid packing significantly improved system efficiency by promoting filamentary and surface discharges, with smaller beads yielding higher conversion rates. Notably, kaolin demonstrated unique performance characteristics, suggested by its increased plasma brightness, likely due to flow-induced turbulence promoting the reaction. Conclusions: Proper material selection and packing design are crucial for efficient CO₂ splitting, concurrently boosting energy efficiency and maintaining high conversion. While Al₂O₃ (corundum) shows high intrinsic activity, kaolin emerges as a highly competitive and advantageous material when associated costs are considered paramount for large-scale applications. Full article

Water convolvulus (Ipomoea aquatica Forssk.) is a fast-growing leafy vegetable valued for its nutritional and antioxidant properties; however, suboptimal seed physiology can hinder its germination and early growth. Non-thermal plasma (NTP) treatment is an eco-friendly seed-priming method that enhances seed performance and crop quality without the use of chemical inputs. This study evaluated the effects of NTP exposure (0, 5, 10, and 20 min) using a dielectric barrier discharge (DBD) plasma with an air gas flow rate of 1.5 lpm on the germination, seedling growth, pigment and protein content, nitrogen assimilation, and antioxidant capacity of water convolvulus. Plasma treatment of seeds increased germination in a time-dependent manner. The surface hydrophilicity improved with increasing treatment time. Seedlings grown from seeds treated for 10 min exhibited longer shoots (+10.1%) and roots (+17.8%). The shoot nitrate content increased by 66.3%. At 10 min, the total phenolics and flavonoids increased by 26.5% and 37.2%, respectively, with an accompanying increase in antioxidant activity, as measured by DPPH, ABTS, and FRAP assays. These findings demonstrate that a 10 min NTP treatment of seeds improves germination, growth, nutrient assimilation, phytochemical accumulation, and antioxidant activity in water convolvulus seedlings, highlighting its potential as a sustainable and chemical-free seed-priming technology with considerable potential to enhance the productivity and nutritional quality of plant microgreens in modern agriculture. Full article

Seed processing effects induced by two types of cold plasma, CP (low-pressure plasma, LCP; dielectric barrier discharge plasma, DBD), and vacuum (V) treatments were compared by estimating changes in the emergence and growth of lavender seedlings, the density of leaf trichomes, and the biochemical composition of leaf extracts, including the content of photosynthetic pigments, TPC, antioxidant activity, and the amounts of two hydroxycinnamic acids associated with antioxidant activity—chlorogenic and rosmarinic acid. DBD treatment for 3 min stimulated the emergence and growth of seedlings but induced negative or neutral effects on biochemical parameters. All treatments, except DBD3, increased the density of glandular trichomes in leaves. Short-term treatments with LCP (0.5 min), DBD (2 min), and V (2 min) increased the total phenolic compound (TPC) content by 15–25%, and the first two treatments enhanced antioxidant activity (21–32%). HPLC analysis revealed that V (2 min) treatment was the most effective, increasing the content of chlorogenic (49%) and rosmarinic (14%) acid. LCP (1 min) and DBD (2 min) treatments increased chlorogenic acid content by 9% and 26%, respectively. The obtained results support the potential of pre-sowing seed treatments with CP and vacuum to produce raw lavender material enriched by biologically active compounds for pharmaceutical and nutraceutical applications. Full article

Respiratory syncytial virus (RSV) is a major cause of severe respiratory infections, particularly in infants and young children. Although disinfection methods using alcohol and detergents are effective, their application in pediatric environments poses safety concerns. Ozone (O₃) has been employed for water treatment, food preservation, and air purification, but its efficacy against RSV has not been well studied. Here, we investigated the inactivation of RSV using a dielectric barrier discharge (DBD)-based ozone generator (SFG1210). The RSV A2 strain was spotted on glass coverslips and exposed to low-concentration ozone (0.5 ppm) for 1 h under controlled temperature (24.6~27.2 °C) and relative humidity (71.9~75.1%) conditions. Subsequent infectivity assays combined with immunochromatography showed that ozone exposure significantly reduced RSV infectivity. Specifically, viral titration assay of median tissue culture infectious dose (TCID₅₀) showed that RSV titers were reduced by more than 6 logs. In addition, biochemical analyses showed significant reductions in intact RSV genomic RNA and F protein levels after ozone treatment, suggesting that ozone inactivates RSV by damaging both the viral genome and surface proteins. These findings demonstrate the potential applicability of the SFG1210 ozone generator as an effective tool for surface disinfection of RSV, providing a safe, non-contact, and practical approach for infection control in healthcare and childcare settings. Full article

This study investigates the ozone generation characteristics of a nanosecond bipolar pulse-excited single-water electrode (dielectric barrier discharge) DBD reactor, with a particular focus on the effects of pulse width (T_p) on discharge behavior, plasma parameters, and ozone generation efficiency. The results indicate that the bipolar pulse voltage displays a symmetric alternating waveform, and the reactor demonstrates excellent thermal stability. Rotation temperature (T_rot) remains stable between 307 and 310 K (close to room temperature, which effectively suppresses O₃ thermal decomposition), while vibrational temperature (T_vib) stabilizes at 3120 ± 50 K (sufficient to ensure the electron energy required for O₂ dissociation). Electron excitation temperature (T_exc) increases with both the specific input energy (SIE) and T_p. At SIE = 200 J/L, extending T_p from 200 ns to 1000 ns results in an increase in T_exc from 2633 K to 2724 K. The ozone generation efficiency exhibits a “rise-then-decline” trend with increasing T_p. The optimal T_p is 500–600 ns, at which the maximum efficiency reaches 102 g/kWh (corresponding to SIE = 35.95 J/L), which is slightly higher than the peak efficiency of the unipolar pulse-driven water electrode reactor (99.64 ± 0.87 g/kWh, corresponding to SIE = 33.60 ± 1.53 J/L). This work innovatively applies nanosecond bipolar pulse excitation to a single-water electrode DBD reactor for ozone generation, an understudied configuration that integrates the discharge stability advantage of bipolar pulses and the superior cooling advantages of water electrodes. This study offers significant insights into the pulse power excitation of ozone generation. Full article