Dispersion Of Particles Research Articles

Multiscale finite element modeling to achieve the mechanical properties of FSPed and SiC-reinforced austenitic 316L stainless steel produced by selective laser melting

In this study, austenitic 316L stainless steel produced by Selective Laser Melting (SLM) was reinforced with SiC nanoparticles using Friction Stir Processing (FSP). The microstructure and mechanical properties of the resulting nanocomposite were experimentally investigated, and multiscale finite element modeling was performed using the Mori-Tanaka homogenization method to predict its macroscopic mechanical properties based on microstructural interactions. SLM-fabricated samples were reinforced via FSP with 10 vol% SiC and subjected to tensile tests. Results showed a 17% increase in tensile strength for the solely FSP-processed sample compared to the as-built SLM sample (from 570 MPa to 670 MPa), with a slight improvement in ductility (from 27% to 29%). The addition of SiC nanoparticles further increased tensile strength to 743 MPa, while ductility decreased to 23%. This represented a 30% and 11% strength increase compared to the as-built SLM sample and the solely FSP-processed sample, respectively. The strength improvement was attributed to the dispersion of particles along grain boundaries and within grains, as well as to recrystallization and grain refinement induced by FSP. The stress-strain curves from finite element modeling aligned closely with experimental results. Predicted tensile strength and ductility were 668 MPa and 30% for the solely FSP-processed sample, and 740 MPa and 25% for the nanocomposite.

Impact of DC Electric Field Direction on Sedimentation Behavior of Colloidal Particles in Water

Colloidal particles in water exhibit increased sedimentation velocity under a horizontal DC electric field of several V/mm compared to no field. Hollow particles with a lower density than water show an increased ascent velocity with the horizontal electric field. These phenomena suggest that colloidal particles form flocs due to the electric field, known as the Electrically Induced Rapid Separation (ERS) effect. This study investigates, for the first time, the impact of the DC electric field direction on the ERS effect. The electric field was defined as horizontal when the inclination angle θ = 0° and vertical at θ = 90°, covering all inclination angles. Results showed that the ERS effect increased for θ < ~20–30° in both upward and downward directions. However, beyond this range, the ERS effect decreased or disappeared. At larger θ values, convection was observed, significantly improving colloidal particle dispersion stability. Additionally, negatively charged particles were observed to be “repelled” near the negative electrode. This study offers new insights into controlling particle dispersion stability using electric fields and suggests potential applications in colloid and material science.

Impact of Micro and Nano Zinc Oxide Particles on Lentil Seed’s Internal Activity Using Biospeckle Optical Coherence Tomography (bOCT)

The increasing use of nanoparticles (NPs) in various industries has intensified research into plant–NP interactions. NP properties significantly impact their cellular uptake and plant effects, highlighting the need for advanced monitoring techniques to understand their influence on plant growth and seed germination. This study uses biospeckle optical coherence tomography (bOCT) to investigate the size-dependent effects of zinc oxide (ZnO) NPs and microparticles (MPs) on lentil seed internal activity, visualizing dynamic changes under ZnO particle stress. ZnO was selected for its agricultural relevance as a micronutrient. Lentil seeds were submerged in ZnO particle dispersions (<50 nm, <100 nm, 5 μm, 45 μm) at concentrations of 0 (control), 25, 50, 100, and 200 mg/L. OCT structural images were obtained at 12.5 frames per second using a swept-source OCT (central wavelength 1.3 μm, bandwidth 125 nm, sweep frequency 20 kHz). OCT scans were performed before immersion (0 h) and 5, 10, and 20 h after lentil seed exposure to particle dispersion. The biospeckle image, representing dynamic speckle patterns characteristic of biological tissues, was calculated as the ratio of standard deviation to mean of 100 OCT structural images over 8 s. Biospeckle contrast was compared 0, 5, 10, and 20 h post-exposure. ZnO NPs <50 nm and 100 nm negatively impacted lentil seed biospeckle contrast at all concentrations. In contrast, 45 µm ZnO MPs significantly increased it even at 100 mg/L, while 5 μm MPs decreased biospeckle contrast at higher concentrations. bOCT results were compared with conventional morphological (germination percentage, growth, biomass) and biochemical (superoxide dismutase, catalase, and hydrogen peroxide) measurements. Conventional methods require one week, whereas bOCT detects significant changes in only five hours. The results from bOCT were consistent with conventional measurements. Unlike standard OCT, which monitors only structural images, bOCT is capable of monitoring internal structural changes, allowing rapid, non-invasive assessment of nanomaterial effects on plants.

Recent advances of silver nanoparticle-based polymer nanocomposites for biomedical applications.

Silver nanoparticle-polymer nanocomposites (AgNP-PNCs) represent a transformative advancement in biomedical material science, integrating the potent antimicrobial properties of AgNPs with the structural versatility of polymer matrices. This synergy enables enhanced infection control, mechanical stability, and controlled drug delivery, making these nanocomposites highly suitable for applications such as wound healing, medical coatings, tissue engineering, and biosensors. Recent progress in synthesis and functionalization has led to greater control over particle morphology, dispersion, and stability, optimizing AgNP-PNCs for clinical and translational applications. However, challenges related to cytotoxicity, long-term stability, immune response, and scalability persist, necessitating systematic improvements in surface functionalization, hybridization strategies, and biocompatibility assessments. This review critically evaluates the latest advancements in AgNP-PNC development, focusing on their functionalization techniques, regulatory considerations, and emerging strategies to overcome biomedical challenges. Additionally, it discusses preclinical and translational aspects, including commercialization barriers and regulatory frameworks such as FDA and EMA guidelines, ensuring a comprehensive outlook on their clinical feasibility. By bridging the gap between innovation and practical application, this review investigates the transformative potential of AgNP-PNCs in advancing next-generation biomedical materials.

The substantiation of the technology of the cream with lespedeza extracts

Aim. To study the dependence of the properties of a cream with lespedeza extracts on the technological parametersof its manufacture and to develop the technology of the cream.Materials and methods. The study object was an emulsion-based cream with bicolor lespedeza extracts. The experimental samples of the cream were emulsified using an MI-2 mixer at the speed range from 1000 to 3000 rpm inincrements of 500 rpm for 5-20 min in increments of 5 min for each sample. The quality of the manufactured sampleswas assessed by appearance, thermal stability, colloidal stability, and the degree of dispersion of particles of the dispersed phase and viscosity indicators.Results. According to the results of the experimental studies, the parameters of the technological process havebeen substantiated, the manufacturing technology has been developed, and control points in the production of anemulsion cream with lespedeza extracts for the treatment of infectious and inflammatory skin diseases have beendetermined. The development of the cream technology was based on the results of the previous experimental studiesof the cream composition containing a liquid alcohol lespedeza extract and an oil lespedeza extract. Standard equipment used in the production of soft drugs was applied to produce the emulsion-based cream. The cream technologyconsists of the stage of auxiliary work, several stages of the technological process (preparation of the aqueous phase,preparation of the oil phase, preparation of the cream, preparation and homogenization of the cream), the stage ofpackaging in containers, packaging in packs and group packaging for shipment to the finished product warehouse. To scalethe laboratory technology of the emulsion cream “Lespedin” into industrial production, critical production points andconditions of the technological process have been determined, which will allow obtaining products that will meet therequirements of the current regulatory documentation.Conclusions. The parameters of the technological process for the production of an emulsion cream with extractsof bicolor lespedeza have been experimentally substantiated. The technological process for manufacturing the emulsion cream with the conditional name “Lespedin” has been developed. The critical technological parameters for obtaining a soft dosage form have been determined.

Ultrasonic Dispersion for Iron Recovery from Slime Tailings: Microprocesses Unveiled through Molecular Dynamics Simulations.

Chemical dispersion has been commonly used to mitigate the negative effects of ultrafine particles in iron ore concentration processes. However, mechanical solutions such as ultrasound are proving to be more effective and without harmful side effects. This study compared the performance of different dispersants and ultrasound as pretreatments for reverse cationic flotation of goethite-rich slime tailings through sedimentation, dispersion, and flotation tests, along with particle size analysis. Additionally, large-scale molecular dynamics simulations were used for the first time to investigate the effects of ultrasonic shockwaves on mineral particle interactions. The results showed that ultrasonication is a superior pretreatment, enhancing particle dispersion and separation performance, cleaning mineral surfaces, and improving flotation results. Ultrasound achieved an increase in metallurgical recovery of around 9% while using only a dispersant reagent did not reach 5%. Simulations demonstrated the known effects of ultrasound, such as extreme temperature, bubble cavitation, and particle detachment, revealing the crucial microscopic mechanisms involved in particle separation by sonic waves. This study bridges experimental data with computational simulations, offering a comprehensive understanding of ultrasonication's effects on particle separation, paving the way for more efficient and sustainable processing technologies.

CHARACTERIZATION OF POLYETHYLENE TEREPHTHALATE CORE-PINEAPPLE FIBRE SANDWICH COMPOSITE TOUGHENED USING SURFACE-TREATED NEEM FRUIT HUSK BIOSILICA

This study investigates the mechanical, fatigue, water absorption, and flammability properties of polyethylene terephthalate (PET) core-pineapple fiber sandwich composites reinforced with silane-treated neem fruit husk (NFH) biosilica additives. The novel approach includes modifying the fiber’s surface and incorporating biosilica to enhance environmental resistance. The composites were prepared using a hand layup method, followed by silane treatment of the biosilica, pineapple fiber, PET core and vinyl ester resin. Subsequently, to evaluate environmental impacts on composite’s performance, sandwich composites were subjected to temperature aging at 40∘C and 60∘C in a hot oven for 30 days and warm water aging at the same temperatures in tap water with pH 7.4. According to the results, adding 1%, 3%, and 5 vol.% silane-treated biosilica significantly improved the mechanical properties. The composite with 3% biosilica (L2) showed a tensile strength of 120.8[Formula: see text]MPa, flexural strength of 194.4[Formula: see text]MPa, compression strength of 182.4[Formula: see text]MPa, rail shear strength of 20.21[Formula: see text]MPa, ILSS of 23.14[Formula: see text]MPa, hardness of 85 Shore-D, and Izod impact strength of 6.56 J. Even under temperature and water aging conditions, the composites showed only minimal reductions in properties, highlighting the efficacy of the silane treatment. The temperature-aged L2 composite had a tensile strength of 104[Formula: see text]MPa, flexural strength of 172.8 MPa, compression strength of 164[Formula: see text]MPa, and ILSS of 22.5[Formula: see text]MPa, while the water-aged L2 composite exhibited a tensile strength of 96[Formula: see text]MPa, flexural strength of 152.8[Formula: see text]MPa, compression strength of 146.4[Formula: see text]MPa, and ILSS of 21.4[Formula: see text]MPa. Scanning electron microscope (SEM) analysis confirmed uniform dispersion of biosilica particles, critical for improved performance, though higher concentrations led to agglomeration and stress points. The composites also demonstrated excellent flame retardancy, maintaining a UL-94 V-0 rating with decreased flame propagation speeds, specifically 9.05[Formula: see text]mm/min for L2. These findings underscore the potential of silane-treated biosilica as a reinforcing additive to enhance the durability and performance of composites in adverse conditions.

Systematic study on mix design optimization and on fresh properties of grouts containing crystalline admixtures

Crystalline admixtures (CA) are often proposed as admixtures for improving self-healing ability of cement-based materials. While significant progress has been made in smart concretes and mortars, the application of self-healing technology in grouts remains underexplored. The design of a grout is complex because any change in its composition will have a significant effect on its properties, especially in the fresh state. This work analyses the effect of the incorporation of the CA on the production of a self-repairing grout. The study focuses on the effects of CA on the fresh and hardened properties of grouts. A comprehensive analysis of grout design highlights the influence of critical parameters such as water/binder (w/b) and sand/binder (s/b) ratios, supplementary materials (fly ash and limestone), and superplasticizer (SP) dosages. Formulating a grout with CA requires greater efforts to achieve an optimal balance between the fresh and hardened properties. CA affected particle dispersion, stability and consistency of grouts. Designing grouts (with and without CA) with similar fluidity required higher SP dosages, which improved the viscosity and delayed the setting time. CA accelerates the hydration of C3S and C3A hydrates formation and shortens the induction period, but when combined with SP, its contribution is reduced. Compressive strength of grout with CA were higher than reference at all tested ages.

An Antibacterial, Antioxidant Adherent Sponge Constructed for Control of Arterial Bleeding Via Gallic Acid-Mediated Robust Assembly of Fibrous Clay in Collagen.

Acute hemorrhage death on battlefields, during clinical surgeries, and in major accidents is a widespread worldwide problem. Clay-based hemostatic materials have received considerable attention for their low cost and reliable clotting activity, especially in cases of severe bleeding, such as QuikClot, which is a kaolin-based hemostatic gauze that is preferred for battlefield resuscitation. However, the easy detachment of clay particles and the associated risk of thrombosis have seriously hindered the development of clay-based hemostatic materials. Here, inexpensive palygorskite (Pal) nanoclay was integrated into the collagen (COL) matrix by loading Ca2+ in the clay and further using gallic acid (GA) to mediate the robust assembly of clay on the COL matrix. This targeted interfacial design is a simple and gentle method that effectively improves the dispersion of the Pal particles and reduces the risk of shedding. Unlike QuikClot where the aqueous solution was significantly turbid after 2 min of ultrasonic washing, the aqueous solution of the composite sponge (Ca-Pal-GA-COL) remained clear and was accompanied by 82.71% of the mass residue after 10 min of ultrasonic washing. The composite sponge also exhibited excellent antibacterial (87.93% inhibition rate of Escherichia coli), antioxidant, and tissue adhesion properties. Importantly, the Ca-Pal-GA-COL sponge exhibited less blood loss (632 mg) and a shorter hemostasis time (151 s) in a rat femoral artery hemorrhage model than the medical gauze (3850 mg and 299 s), pure COL sponge (1627 mg and 201 s), and Pal-COL sponge (1494 mg and 193 s) in a co-mingled mode, which are comparable to those of QuikClot (559 mg and 142 s). Furthermore, certain tissue adhesion properties render the Ca-Pal-GA-COL sponge more suitable than QuikClot for severe femoral artery active bleeding scenarios. Cellular experiments confirmed that the composite dressing has a certain biosafety.

Enhanced Hydrophobicity, Thermal Stability, and X-Ray Shielding Efficiency of BaSO4/P(VDF-HFP) Nanocomposites for Advanced Lead-Free Radiation Protection

In this research, polymer composite sheets were developed by blending poly (vinylidene fluoride-co-hexafluoropropylene) or P(VDF-HFP) with varying concentrations of barium sulfate (BaSO4) for X-ray shielding applications. The photon counting technique was used to evaluate the composite shielding characteristics through the linear attenuation coefficient. Surface properties, including surface morphology, hydrophobicity, and surface energy, were analyzed using an atomic force microscope (AFM) and a water contact angle machine. Scanning electron microscopy (SEM) was employed to investigate the microstructural distribution and dispersion of BaSO4 particles within the polymer matrix, providing insights into the composite’s uniformity and structural integrity. Additionally, the bulk properties of the composite polymer sheets, such as crystal structures, tensile strength, and thermal stability, were examined. The results demonstrate that increasing the concentration of BaSO4 in BaSO4/P(VDF-HFP) composite sheets significantly improves their X-ray attenuation capabilities. Moreover, higher BaSO4 concentrations enhance the material’s hydrophobicity, flexibility, and thermal stability, highlighting the potential of these composites for advanced radiation shielding applications.

Synergistic effect of RuNi alloy supported by carbon nanohorns for boosted hydrogen evolution from ammonia borane hydrolysis.

Synergistic effect of RuNi alloy supported by carbon nanohorns for boosted hydrogen evolution from ammonia borane hydrolysis.

Suppression of Liver Fibrogenesis with Photothermal Sorafenib Nanovesicles via Selectively Inhibiting Glycolysis and Amplification of Active HSCs.

As the major driving factor of hepatic fibrosis, the activated hepatic stellate cells (aHSCs) rely on active glycolysis to support their aberrant proliferation and secretion of the extracellular matrix. Sorafenib (Sor) can combat liver fibrosis by suppressing HIF-1α and glycolysis, but its poor solubility, rapid metabolism, and low bioavailability restrict such a clinical application. Here, Sor was loaded onto polydopamine nanoparticles and then encapsulated by a retinoid-decorated red blood cell membrane, yielding HSC-targeted Sor nanovesicles (PDA/Sor@RMV-VA) with a high Sor-loading capacity and photothermally controlled drug release for antifibrotic treatment. These Sor RMVs not only exhibited a good particle size, dispersity and biocompatibility, prolonged circulation time, enhanced aHSC targetability, and hepatic accumulation both in vitro and in vivo, but also displayed a mild photothermal activity proper for promoting sorafenib release and accumulation in CCl4-induced fibrotic mouse livers without incurring phototoxicity. Compared with nontargeting Sor formulations, PDA/Sor@RMV-VA more effectively downregulated HIF-1α and glycolytic enzyme in both cultured aHSCs and fibrotic mice and reversed myofibroblast phenotype and amplification of aHSCs and thus more significantly improved liver damage, inflammation, and fibrosis, all of which could be even further advanced with NIR irradiation. These results fully demonstrate the antifibrotic power and therapeutic potential of PDA/Sor@RMV-VA as an antifibrotic nanomedicine, which would support a new clinical treatment for hepatic fibrosis.

DEVELOPMENT AND EVALUATION OF ACECLOFENAC-LOADED NANOSPONGE HYDROGEL FOR ENHANCED TOPICAL ANTI-INFLAMMATORY DELIVERY

Objective: Aceclofenac (ACE) is a derivative of phenylacetic acid and a non-steroidal anti-inflammatory drug (NSAID) known for its anti-inflammatory, analgesic, and antipyretic properties. This study aims to enhance ACE's solubility and therapeutic efficacy by developing NanoSponges (NS) loaded into a hydrogel for topical drug delivery, addressing the limitations of current ACE formulations, such as rapid metabolism and short half-life. Methods: NS were synthesized using the emulsion solvent diffusion technique with varying concentrations of Ethyl Cellulose (EC) and Poly Vinyl Alcohol (PVA). Ten NS formulations were evaluated for particle size (PS), Particle Dispersion Index (PDI), Production Yield percentage (PY%), and Entrapment Efficiency percentage (EE%). Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analyses confirmed the compatibility between ACE and the excipients. The surface morphology of the NS was examined using Field Emission Scanning Electron Microscopy (FESEM). The optimal Formulation (F2) was integrated into seven hydrogel formulations based on Hydroxy Propyl Methyl Cellulose (HPMC). Results: The F2 had a PY% of 77.92±2.2%, an EE% of 90.05±1.1%, a PS of 127.3±3.2 nm, and a PDI of 0.1±0.02. The optimal hydrogel formulation (G1) showed a pH of 6.2±0.15, a Drug Content (DC%) of 95.19±0.23%, a spreadability of 9.5±0.2 cm, and a permeation rate of 55.94±1.4% over 8 h. Additionally, G1 demonstrated in vivo anti-inflammatory activity of 65.38±1.1% over 24 h and a cumulative drug release of 84.5±3.8% over the same period. Conclusion: The NS-loaded hydrogel presents a promising strategy for enhancing ACE's therapeutic potential by providing extended drug release and improved stability, effectively addressing the limitations of existing formulations.

Virus Particle Dispersion and Infection Risk Assessment in Aircraft Cabins: A CFD Approach

The work employed computational fluid dynamics to model virus-carrying particle transport mechanisms in a low-cost carrier passenger cabin. The study investigated the effect of virus source location and particle size on particle dynamics and infection risk. The infection risk assessment was conducted based on particle deposition onto surfaces such as passenger bodies and seats. The study found that the direction and velocity magnitude of the airflow in the cabin were almost symmetric about the aisle, with some asymmetry in the velocity magnitude observed due to the coughing passenger's location. Most particles in the cabin were found to be either deposited onto surfaces or removed through the ventilation system within 10 minutes. The study also found that the particle deposition and removal dynamics were strongly affected by the particle source location and the particle size due to the proximity to different surfaces depending on the source location and the propagation distance of the particles, which depends on the gravitational effect based on the size of the particles. The propagation of the particles was found to be mostly contained within the row of the source and two rows in front of the source throughout the 10 minutes. The infection risk assessment indicated a higher risk for passengers seated in the column directly in front of the virus source and for passengers seated on the same side of the aisle as the virus source.

Advanced Characterization of Lignin Nanoparticles by Asymmetric Flow-Field Flow Fractionation.

The unique properties of lignin nanoparticles (LNPs)-uniform shape, surface charge and nanoscale-carry great potential for the desired material utilization of technical lignins. Especially, the particle size distribution and dispersity of LNPs are the key for their successful valorization. However, characterization of LNPs usually requires a rather elaborate combination of light scattering and microscopy techniques which moreover provide only average values, are often limited in sampling size and require tedious sample preparation. Here we introduce a method based on asymmetric flow field-flow fractionation (AF4) coupled with multi angle laser light scattering (MALLS), dynamic light scattering (DLS) and refractive index (RI) detection for the analysis of size and shape of LNPs. Exploiting the separation power of AF4 in combination with MALLS, DLS, and RI allowed us to obtain enhanced particle size distributions of LNP that are comparable to batch DLS and AFM measurements. Moreover, we discuss the influence of the particle size on the MALLS and DLS signals and determination of the shape factor ρ of LNPs.

Optimizing FSP Parameters for AA5083/SiC Composites: A Comparative Analysis of Taguchi and Regression

The fabrication of AA5083/SiC composites by the friction stir processing (FSP) method is the main objective of this study. The study looks at how the mechanical properties of the composites are affected by three important process parameters: traversal speed, rotational speed, and tilt angle. The Taguchi L9 design matrix was used to effectively investigate parameter effects, decreasing experimental trials and cutting expenses. Tensile testing measured tensile strength, whereas microhardness tests evaluated hardness. The findings showed that a maximum tensile strength of 243 MPa and a maximum microhardness of 94.80 HV were attained. The findings also showed that the optimal ultimate tensile strength (UTS) and percentage elongation (PE) were achieved at a tilt angle of 2°, a traverse speed of 30 mm per minute, and a rotating speed of 900 rev/min. On the other hand, a slightly greater traverse speed of 45 mm per minute was required to reach maximal microhardness (MH) with the same rotational speed and tilt angle. Analysis of variance (ANOVA) showed that rotational speed has a substantial impact on all mechanical properties, highlighting how important it is for particle dispersion and grain refining. This work is unique in that it systematically optimizes FSP parameters by using regression analysis and the Taguchi technique in addition to ANOVA. This allows for a better understanding of how these factors affect the mechanical properties of SiC-reinforced composites. The findings contribute to advancing the cost-effective fabrication of high-performance metal matrix composites for industrial applications requiring enhanced strength and durability.

Development of Mg-Zn-Mn Surface Composites Reinforced with ZnO Through Friction Stir Processing and Investigation of Corrosion and Wear Behavior

Magnesium (Mg) composites exhibit exceptional properties, making them ideal for diverse applications in the medical, aerospace, and energy industries. The extensive use of Mg-based composites has driven ongoing efforts to enhance their properties and performance. Therefore, the present work focused on the fabrication of Mg-Zn-Mn surface composites reinforced with Zinc oxide (ZnO) through friction stir processing (FSP). The effect of the addition of ZnO on microstructure, mechanical properties, corrosion, and wear behavior was investigated. The development of the microstructure is analyzed using a scanning electron microscope (SEM) and X-ray diffraction analysis. Surface topography and roughness are analyzed using atomic force microscopy (AFM) and revealed a Ra value of 68.4 nm. The mechanical properties of the friction stir processed samples are investigated using Vickers microhardness equipment. The FSP/ZnO-Mg-Zn-Mn surface nanocomposites demonstrated a microhardness of 152.7 Hv, which is 2.4 times greater than that of the H-Mg-Zn-Mn base materials. The enhancement in the corrosion resistance of the FSP/ZnO-Mg-Zn-Mn surface nanocomposites is primarily due to the combined effect of the refined grains and the uniform dispersion of ZnO particles. Furthermore, this surface composite had the best wear resistance as a result of significant grain refinement and higher hardness.

Tidal effects on transport and dispersion of particles, cod eggs and larvae in the Lofoten and Vesterålen region, Norway

Lofoten and Vesterålen region in Northern Norway contains the main spawning areas for the Northeast Arctic (NEA) cod. A large embayment, partially sheltered from the continental slope and open ocean by the Lofoten-Vesterålen archipelago, called Vestfjorden contains approximately 60 % of the NEA cod spawning in this region. The dynamical ocean processes that control transport paths and transport times of cod eggs and larvae out of this embayment are of major importance, not only for the fish stock, but in general for the marine ecosystem in the region. This study investigates the net impact of nonlinear tidal dynamics on transport and dispersion of particles, resembling cod eggs and larvae, out of Vestfjorden. The coastal ocean circulation in and around Vestfjorden is simulated with a variable mesh model, both with and without tides. The two different flow fields are used to advect passive particles seeded near Henningsværstraumen, a key spawning location within the embayment. A comparison of the two transport calculations reveals that nonlinear tidal dynamics clearly impact the particle drift in the region. When including tides in the model simulation, transport through the various straits that cut through the Lofoten-Vesterålen archipelago becomes more important, causing the total particle drift out of Vestfjorden to increase by about 10%. One strait in particular, Moskstraumen, contributes with a significant transport (∼ 30%) in the model simulation with tides included, but other straits contribute as well. For comparison, in the simulation where tides are excluded, almost 90% of the particles are transported out of the embayment around the southern tip of the archipelago and only 6% through Moskstraumen. A key implication of the tidal transport through the straits is that the journey for a large fraction of the cod eggs/larvae from Vestfjorden to the shelf is considerably shortened.

Low-temperature steam reforming of toluene as a biomass tar model compound over biochar-supported catalysts

The removal of tar produced during biomass gasification is a significant challenge. Tar reforming is a highly effective way of eliminating tar. However, typical tar-reforming catalysts are prone to coke deposition and the sintering of active metal, especially at elevated temperatures. Consequently, it is crucial to develop highly active and stable catalysts under low reforming temperature. First, Ni, Co, and Fe-loaded wood chips biochar supported catalysts were synthesized via the wetness impregnation method. Toluene was chosen as a tar model compound. Overall, Ni/Biochar exhibited superior catalytic performance in toluene reforming compared to Co/Biochar and Fe/Biochar catalysts at a temperature below 500 °C. After active metal screening, 10 wt.% La and Ce-promoted biochar-supported Ni catalysts were also synthesized for tuning the metal–support interaction, basicity, and oxygen vacancy of the catalysts to enhance the low-temperature tar reforming performance. 10 wt.% La-doped 15 wt.% Ni/Biochar showed the best toluene reforming performance among the prepared catalysts, with a H2 yield of 87% and toluene conversion of 93% at reaction temperature of 400 °C. Moreover, this catalyst maintained uniform dispersion of Ni and La2O3 particles and did not show growth in Ni crystallite size and significant coke accumulation during 15 h continuous reforming reaction. The high catalytic activity and better stability of NiLa/Biochar were attributed to a small Ni particle size (9.05 nm), uniform dispersion of metal, strong metal-support interaction, high basicity (2.95 mmol g–1), and abundance of oxygen vacancies (84.1%), which promoted the activation, adsorption, and dissociation of H2O molecules as well as the removal of deposited coke.Graphical

Turbulent dispersion of particulates in the Ahmed body wake and effects of moving ground

This study investigates the influence of wind tunnel ground conditions on smoke particle dispersion and concentration fields in the near wake of a simplified vehicle model (Ahmed body). The effects of wind tunnel ground conditions are investigated with the implementation of a rolling road and boundary layer suction system inside the wind tunnel. In experiments, smoke particles were released from a source and illuminated with a laser sheet. The concentration of smoke particles was measured using a Mie-scattering-based concentration measurement technique. Concentration fields and particle dispersion were measured at six downstream positions in the near wake of Ahmed body at Rel=1.21×105 (based on model length). The concentration fields obtained were used to calculate dispersion parameters, such as the smoke spread in vertical (Sy) and lateral (Sz) directions. The findings indicate that the concentration fields and dispersion parameters in the near wake are highly dependent on the wind tunnel ground conditions. Particularly enhancing vertical spread under stationary ground conditions while showing minimal effect on lateral spread. It was observed that the maximum increase in the vertical spread is ≈29% for the stationary case. Notably, the lateral spread (Sz) is consistently greater than the vertical spread (Sy), regardless of downstream location or ground condition. The results underscore the critical influence of the correct choice of wind tunnel ground conditions in dispersion studies.