Search Results (143)

The electrocatalytic CO₂ reduction reaction (CO₂RR) offers an energy-saving and environmentally friendly approach to producing hydrocarbon fuels. The use of a gas diffusion electrode (GDE) flow cell has generally improved the rate of CO₂RR, while the gas diffusion layer (GDL) remains a significant challenge. In this study, we successfully engineered a novel metal–organic framework (MOF) heterojunction through the controlled coating of zeolitic imidazolate framework (ZIF-L) on ultrathin nickel—metal–organic framework (Ni-MOF) nanosheets. This innovative architecture simultaneously integrates GDL functionality and exposes abundant solid–liquid–gas triple-phase boundaries. The resulting Ni-MOF@ZIF-L heterostructure demonstrates exceptional performance, achieving a formate Faradaic efficiency of 92.4% while suppressing the hydrogen evolution reaction (HER) to 6.7%. Through computational modeling of the optimized heterojunction configuration, we further elucidated its competitive adsorption behavior and electronic modulation effects. The experimental and theoretical results demonstrate an improvement in electrochemical CO₂ reduction activity with suppressed hydrogen evolution for the heterojunction because of its hydrophobic interface, good electron transfer capability, and high CO₂ adsorption at the catalyst interface. This work provides a new insight into the rational design of porous crystalline materials in electrocatalytic CO₂RR. Full article

Researchers increasingly agree that livestock farming is the leading cause of air pollution with ammonia (NH₃) gas. The existing research suggests that 30–80% of nitrogen is lost from slurry and liquid manure in the gaseous form of ammonia. Most studies have focused on environmental factors influencing ammonia volatilization and manure composition but not on controlling the moisture level on the surface of the excreta. Applying the principles of convective mass exchange, this study was undertaken to compare different types of organic covers that mitigate NH₃ emissions and offer recommendations on how to properly apply organic covers on the surface of manure. Data was obtained from research in laboratory conditions comparing well-known coatings (chopped straw) with less commonly used organic materials (peat) or waste generated in other industries (sawdust, hemp chaff). This research demonstrated that applying bio-coatings can reduce ammonia (NH₃) emissions at coating thicknesses of ≥5 cm for sawdust, ≥3 cm for peat, ≥10 cm for hemp chaff, and 8–12 cm for straw. These reductions are linked to the ability of the coatings to lower manure surface moisture evaporation, a key driver of ammonia volatilization, highlighting the role of surface moisture control in emission mitigation. Full article

As an emerging energy-saving approach, bio-inspired drag reduction technology has become a key research direction for reducing energy consumption and greenhouse gas emissions. This study introduces the latest research progress on bio-inspired microstructured surfaces in the field of underwater drag reduction, focusing on analyzing the drag reduction mechanism, preparation process, and application effect of the three major technological paths; namely, bio-inspired non-smooth surfaces, bio-inspired superhydrophobic surfaces, and bio-inspired modified coatings. Bio-inspired non-smooth surfaces can significantly reduce the wall shear stress by regulating the flow characteristics of the turbulent boundary layer through microstructure design. Bio-inspired superhydrophobic surfaces form stable gas–liquid interfaces through the construction of micro-nanostructures and reduce frictional resistance by utilizing the slip boundary effect. Bio-inspired modified coatings, on the other hand, realize the synergistic function of drag reduction and antifouling through targeted chemical modification of materials and design of micro-nanostructures. Although these technologies have made significant progress in drag reduction performance, their engineering applications still face bottlenecks such as manufacturing process complexity, gas layer stability, and durability. Future research should focus on the analysis of drag reduction mechanisms and optimization of material properties under multi-physical field coupling conditions, the development of efficient and low-cost manufacturing processes, and the enhancement of surface stability and adaptability through dynamic self-healing coatings and smart response materials. It is hoped that the latest research status of bio-inspired drag reduction technology reviewed in this study provides a theoretical basis and technical reference for the sustainable development and energy-saving design of ships and underwater vehicles. Full article

This study evaluated the acaricidal effects of biosurfactants produced by Serratia ureilytica against the two-spotted spider mite Tetranychus urticae and their compatibility with the predatory mite Ambliseus swirski. The biosurfactants were obtained via liquid cultures of the bacterial strains. In the laboratory, T. urticae was exposed via acaricide-immersed leaves and A. swirskii via acaricide-coated glass vials. In the greenhouse, mite-infested plants were sprayed with the biosurfactants. In the laboratory, biosurfactants produced by S. ureilytica NOD-3 and UTS exhibited strong acaricidal activity, causing 95% mortality in adults and reducing egg viability by more than 60%. In the greenhouse trial, all biosurfactants significantly suppressed T. urticae populations at all evaluated periods (7, 14, and 21 days post-application). Gas chromatography–mass spectrometry (GC-MS) analysis of the biosurfactants identified several fatty acids, including hexadecanoic acid, pentanoic acid, octadecanoic acid, decanoic acid, and tetradecanoic acid, as well as the amino acids L-proline, L-lysine, L-valine, and glutamic acid. These fatty acids and amino acids are known structural components of lipopeptides. Furthermore, the bioinformatic analysis of the genomes of the three S. ureilytica strains revealed nonribosomal peptide synthetase (NRPS) gene clusters homologous to those involved in the biosynthesis of lipopeptides. These findings demonstrate that S. ureilytica biosurfactants are promising eco-friendly acaricides, reducing T. urticae populations by >95% while partially sparing A. swirskii. Full article

This study explores how production technology influences spray-applied rigid polyurethane (PUR) foam insulation’s cryogenic performance. In cryogenic applications such as liquid gas storage, insulation must minimise heat transfer and resist moisture ingress under severe thermal gradients. Experimental aluminium vessels were insulated with PUR foam of varying thicknesses and surface conditions—rough, machined smooth, and with a urea-based protective coating—and then tested using dynamic boil-off of liquid nitrogen (LN₂). Foam properties, including adhesion, mechanical strength, thermal expansion, thermal conductivity, and closed-cell content, were evaluated. The results revealed that thicker insulation reduced both effective thermal conductivity and moisture uptake. Although the urea-coated vessel showed minimal water absorption, the coating increased overall thermal conductivity due to its heat conduction and condensation behaviour. Moisture was primarily absorbed near the foam surface, and no cumulative effects were observed during repeated tests. The effective thermal conductivity was determined by interpolating boil-off data, confirming that insulation performance strongly depends on thickness, surface condition, and environmental humidity. These findings provide valuable guidance for the design and application of PUR foam insulation in cryogenic environments. Full article

PVD hard coatings improve the wear and frictional properties in metal cutting and, therefore, extend the lives of cutting tools. Cutting fluids, including the novel use of liquid carbon dioxide (LCO₂), are crucial for reducing tool wear and enhancing machining efficiency. This experimental research is focused on ball-on-disc wear tests of TiAlN hard coatings in environmental, N₂ and CO₂ atmospheres. In the latter case, the experiments were also performed by adding LCO₂ directly into the contact zone. In order to achieve the same temperatures as real cutting conditions, tests were performed at 250 °C, 500 °C and 700 °C, in addition to room temperature. Results show that the TiAlN coating had the highest wear rate in room-temperature tests, regardless of the atmosphere. The wear significantly dropped with the test temperature. It was the lower in the CO₂ atmosphere at all temperatures than in all gas-only atmospheres. When LCO₂ was introduced to the contact, the wear was at its highest at 500 °C, which is the opposite of all other gas-only atmospheres, where it was at its lowest. In all tribological LCO₂ tests, we noticed increased friction coefficient fluctuations. In all gas-only atmospheres, adhered material was observed on the wear tracks, but in LCO₂, wear debris was not detected either on the disk or on the ball. Full article

International projects study the safety aspects of the storage and long-distance transportation of liquid hydrogen at large scales. Catalytic recombiners, which are today key elements of hydrogen risk mitigation in nuclear power plants, could become an efficient safety device to prevent flammable gas mixtures after liquid hydrogen leakages in closed rooms. This study tackles fundamental questions about the operational behavior of typical recombiner catalysts related to the conditions of the start-up and the termination of the catalytic reaction. For this purpose, small-scale catalyst sheets with coatings containing either platinum or palladium as active materials were exposed to gas mixtures of air and hydrogen of up to 4 vol.% at temperatures between −50 °C and 20 °C. Both platinum and palladium showed variation to performance and had stochastic results. Overall, the initialized platinum catalyst was better than the palladium. The experimental results show that the transfer of the recombiner technology from its current application is not easily possible. Full article

The demand for sustainable packaging has increased the interest in biopolymer coatings as alternatives to plastic-based barriers on paper and board. Alginate and chitosan offer promising barrier properties by improving gas barrier and grease resistance. However, their high viscosity at low solid contents presents challenges for uniform coatings, especially in possible future large-scale applications but also in existing research. This study evaluates spray coating, a non-conventional application method in the paper industry, to apply biopolymer coatings, an approach underexplored in previous studies. The effects of substrate surface energy and biopolymer surface tension on air permeability, grease resistance, and water vapor transmission were evaluated. Contact angle measurements showed that surface energy strongly influences the wetting behavior of these biopolymers, with hydrophilic substrates and lower-surface-energy liquids promoting better droplet spreading. This improved wetting resulted in better barrier performance at low application weights, further enhanced by surfactant addition. At higher application weights, surface energy had less impact on barrier properties. SEM imaging revealed drying defects at increased coat weights, affecting film integrity. These findings demonstrate the potential of spray coating as a scalable method for biopolymer application while highlighting the need for optimized drying conditions to enhance film uniformity and barrier performance. Full article

Plant extracts, such as olive extract (OE), have been used in human and pet foods for their biological benefits; however, no available data have demonstrated OE’s effect on palatability in dogs. The current study aimed to evaluate acceptance of dry and canned dog foods with differing inclusions of OE as a flavor component. Flavor compounds in OE were analyzed by gas chromatography–mass spectrometry and high-pressure liquid chromatography, detecting 137 volatile compounds, including acetic acid and hydroxytyrosol. Dog kibbles were coated with liquid commercial palatants containing OE that resulted in application rates of 0 (control), 120, 200, and 500 ppm of OE in the diets. OE was also added at 0 (control), 120, 200, and 500 ppm into a wet food formulation with a commercial palatant before retort processing. Two separate panels of adult beagles were used for monadic testing to determine acceptance rates for kibble (5/treatment; 20 total) and canned foods (4/treatment; 16 total) in a 4 × 4 Latin square design. None of the tested inclusions impacted food acceptance in this preliminary study (p > 0.05). As a flavor ingredient, OE can be added into dry or wet dog food up to 500 ppm without deterring effects on palatability. Full article

Olive extract (OE) has been used in human foods for its nutraceutical effects, making it a product of interest for pet food. However, OE’s effect on palatability has not been examined. The study objective was to evaluate the palatability of dry cat foods with OE applied at differing inclusions within liquid or dry palatants. Twenty-seven volatile compounds were identified by gas chromatography–mass spectrometry for a potentially earthy or fruit-like flavor profile. Liquid palatants were formulated to supply 0 (control), 15, 30, 50, 75, and 150 ppm OE, and dry palatants were formulated to provide 0, 100, 200, 400, and 600 ppm OE when coated onto kibble. Palatability was evaluated using two-day, two-bowl testing of OE-containing versus control rations in adult cats (n = 20) with two-tailed t-tests to determine if OE affected intake ratio (IR). The observed IR of rations with OE were 0.45 to 0.56. The only preference was the 200 ppm treatment (IR = 0.56; p = 0.01) while the other OE rations were not different from the control (p ≥ 0.05). These findings indicate that palatant formulations can supply kibble diets with up to 150 ppm OE for liquid and 600 ppm for dry applications without negatively impacting cat food palatability. Full article

Liquid vermicompost (LVC) is one of the organic ingredients for improving plant growth. This study aims to investigate the impact of the application of LVC coating formulations in distinct ratios on seeding emergence, seedling growth parameters, and nitrogen content as well as the systemic uptake characteristics in seedlings. Coating formulations contained gum arabic (GA) mixed with 5–15% of LVC and were applied to pumpkin seeds and compared to non-coated seeds. All samples were stored under cold and ambient conditions for 3 months to evaluate the performance of the coating. Results showed no statistical distinctions in the percentage of seedling emergence. Nevertheless, the 5LVC-GA in the organic formulation significantly increased shoot length, seedling growth rate (SGR), seedling vigor index (SVI), and nitrogen content (%) in the coated seedlings. Additionally, the evaluation of seedling uptake was achieved using rhodamine B as a fluorescent tracer which was diluted in the organic formulation. This explored the transportation of the treatment within a seedling. Therefore, the application of an optimum concentration of 5LVC-GA treatment can improve seedling growth and nitrogen accumulation. This could be confirmed with fluorescence imaging of translocation to seedling organs. However, seed storability declines over three months, emphasizing the need for better coatings and packaging solutions. Full article

The advanced high-strength steels (AHSSs) with high Si and Mn contents are extensively applied in the automobile manufacturing industry. To improve the corrosion resistance, Zn coatings are generally applied to the steel substrate. However, heat input and tensile stress occur during the resistance spot welding (RSW) process; thus, Zn-induced liquid metal embrittlement (LME) can be produced due to the existence of liquid Zn. Unfortunately, the LME occurrence can trigger the premature failure of welded joints, seriously affecting the service life of vehicle components. In this study, the LME behaviors in high Si and Mn RSW joints with electrogalvanized (EG) and galvannealed (GA) Zn coatings were comparatively investigated. Based on the Auto/Steel Partnership (A/SP) criterion, 16 groups of different welding currents were designed. In particular, four typical groups of RSW joints were selected to reveal the characteristics of the LME behaviors. Moreover, these four typical groups of EG and GA high Si and Mn RSW joints were, respectively, etched to measure their nugget sizes. The results indicated that with the increase in the welding current, more severe LME cracks tended form. As determined during the comprehensive evaluation of the 16 groups of EG and GA welded joints, higher LME susceptibility occurred in the EG high Si and Mn steels. It was concluded that the formation of Fe-Zn intermetallic compounds (IMCs) and internal oxide layers during the annealing process could account for the lower LME susceptibility in the GA welded joints. Full article

In this study, tin oxide (SnO₂)/polyaniline (PANI) composite nanowires (NWs) with varying amounts of PANI were synthesized for carbon dioxide (CO₂) gas sensing at room temperature (RT, 25 °C). SnO₂ NWs were fabricated via the vapor–liquid–solid (VLS) method, followed by coating with PANI. CO₂ sensing investigations revealed that the sensor with 186 μL PANI exhibited the highest response to CO₂ at RT. Additionally, the optimized sensor demonstrated excellent selectivity for CO₂, long-term stability, and reliable performance across different humidity levels. The enhanced sensing performance of the optimized sensor was attributed to the formation of SnO₂-PANI heterojunctions and the optimal PANI concentration. This study underscores the potential of SnO₂-PANI composites for CO₂ detection at RT. Full article

This study offers a comprehensive summary of the current states as well as potential future directions of transparent conducting oxides (TCOs), particularly tin-doped indium oxide (ITO), the most readily accessible TCO on the market. Solar cells, flat panel displays (FPDs), liquid crystal displays (LCDs), antireflection (AR) coatings for airbus windows, photovoltaic and optoelectronic devices, transparent p–n junction diodes, etc. are a few of the best uses for this material. Other conductive metals that show a lot of promise as substitutes for traditional conductive materials include copper, zinc oxide, aluminum, silver, gold, and tin. These metals are also utilized in AR coatings. The optimal deposition techniques for creating ITO films under the current conditions have been determined to be DC (direct current) and RF (radio frequency) MS (magnetron sputtering) deposition, both with and without the introduction of Ar gas. When producing most types of AR coatings, it is necessary to obtain thicknesses of at least 100 nm and minimum resistivities on the order of 10⁻⁴ Ω cm. For AR coatings, issues related to less-conductive materials than ITO have been considered. Full article

Cannabis sativa L. cv. ‘Cheungsam’ is an industrial hemp plant of Republic of Korea origin, primarily cultivated for fiber and seed production. In vitro seed germination and tissue culture are valuable tools for developing various biotechnological techniques. In the present study, we aimed to develop a tissue culture process for hemp plants using Cheungsam as a model plant and examine the secondary metabolites produced from its callus. We also developed a method to prepare pathogen-free seedlings from field-derived seeds using hydrogen peroxide (H₂O₂) solution as a liquid germination medium. Treating seedlings with removed seed coat in 3% H₂O₂ significantly reduced the contamination rate. Callus formation and de novo organogenesis of shoots and roots from callus were successfully achieved using cotyledon and leaf tissues prepared from the pathogen-free seedlings. The most effective in vitro regeneration results were obtained using the Murashige and Skoog (MS) medium supplemented with certain targeted growth regulators. An optimal combination of 0.5 mg/L thidiazuron (TDZ) and 1.0 mg/L 1-naphthalene acetic acid proved highly effective for callus induction. The addition of 0.5 mg/L TDZ in the MS medium significantly stimulated shoot proliferation, while robust root development was best supported by MS medium supplemented with 2.5 mg/L indole-3-butyric acid for both cotyledon and leaf explants. Finally, gas chromatography–mass spectrometry (GC–MS) analysis of ethanol extract from Cheungsam leaf callus revealed the presence of different secondary metabolites, including 9-octadecenamide, methyl salicylate, dodecane, tetradecane, and phenol, 2,4-bis-(1,1-dimethylethyl). This study provides a comprehensive de novo regeneration protocol for Cheungsam plants and insight into the secondary metabolite profiles of its callus. Full article