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Particle tracking (PT) is a popular technique in microscopy, microfluidics and colloidal transport studies, where image analysis is used to reconstruct trajectories from bright spots in a video. The performance of many PT algorithms has been rigorously tested for directed and Brownian motion in open media. However, PT is frequently used to track particles in porous media where complex geometries and viscous flows generate particles with high velocity variability over time. Here, we present an evaluation of four PT algorithms for a simulated dispersion of particles in porous media across a range of particle speeds and densities. Of special note, we introduce a new velocity-based PT linking algorithm (V-TrackMat) that achieves high accuracy relative to the other PT algorithms. Our findings underscore that traditional statistics, which revolve around detection and linking proficiency, fall short in providing a holistic comparison of PT codes because they tend to underpenalize aggressive linking techniques. We further elucidate that all codes analyzed show a decrease in performance due to high speeds, particle densities, and trajectory noise. However, linking algorithms designed to harness velocity data show superior performance, especially in the case of high-speed advective motion. Lastly, we emphasize how PT error can influence transport analysis.

This study reveals the dynamics of short optical pulses in nonlinear media. Then, for the survival of different types of solitary waves in the nonlinear medium, the constraint relations to the physical parameters and chirps associated with each of the solitary waves are explicitly shown. We authenticate numerically all those obtained from the analytical method and show the chirping effect is saturative in nature and can be managed by changing coefficients of inter-modal dispersion, stimulated Raman scattering (SRS), and self-steepening effect. We also verify the more operative condition of intermodal dispersion. [ABSTRACT FROM AUTHOR]

Graphene's unique characteristics have piqued a great deal of academic and industrial curiosity. Its potential as a composite material reinforcement is the subject of intensive study. When it comes to reinforcing fillers, graphene stands head and shoulders above the rest due to its remarkable thermal, electrical, and mechanical capabilities. Epoxy resin, is widely used in a variety of industrial processes, including the production of laminates, coatings, and composites due to its processing simplicity, its tenacious adhesion to substance types, and its resistance to chemical agents. The performance of the composite relies on how the graphene nanoparticles are dispersed and interact with the polymer. Graphene‐enhanced composites use a variety of methods, such as dispersing graphene in a polymer matrix, to incorporate the material into its structure. Composites find their most common use in competitive situations settings where elements like mass and mechanical characteristics are prioritized over economic consideration. The use of carbon fiber and other state‐of‐the‐art fibers in composite structures is becoming increasingly common. This study aims to conduct an experimental analysis of a graphene‐reinforced epoxy composite's flexural and tensile properties containing varying amounts graphene. In this study, a multi‐step procedure was designed to ensure uniform distribution graphene. The results of a study on tensile and flexural strength showed good enhancement at a weight percent of G0.6% compared to clean epoxy. Highlights: The novel method of manufacturing of graphene enhanced composite sheet.The lower weight fraction of graphene gives good results in terms of mechanical properties.Improvement in tensile strength by 53.35% and flexural test occurs of 8.04% in stress value at 0.6 wt% addition of GrapheneTensile Modulus and flexural modulus improvement of 76.26% and 16.87% respectively at 0.6% of wt. of grapheneFourier transform infrared spectroscopy showed promising results which shows existing of functionalized groups of amines.Scanning electron microscopy revealed graphene's interaction with the polymer matrix at the interface. [ABSTRACT FROM AUTHOR]

Nanomaterials have emerged as a revolutionary force in the realm of cement‐based materials (CBMs), opening new horizons for the construction industry. This comprehensive review delves into the synthesis, dispersion mechanisms, and profound impacts of nanomaterials on the properties of CBMs. This paper explores the synthesis and dispersion of nanomaterials, shedding light on the diverse techniques used to synthesize nanoscale particles for specific applications in CBMs. It emphasizes the significance of achieving consistent dispersion to fully harness the potential of these materials. In the following section, our focus shifts to the transformative impact of nanomaterials on various aspects of CBMs. Notably, nanomodified CBMs experience significant improvements in their hydration kinetics, mechanical characteristics, rheological properties, and thermal resistance, all of which are discussed in detail. Moreover, self‐healing cementitious composites employing nanomaterials offer innovative strategies for addressing remedies for structural deterioration with time. While the potential of nanomaterials is promising, it is crucial to exercise caution due to concerns about potential health risks. While nanomaterials have shown promise in enhancing the mechanical properties of cementitious materials, future research endeavors will focus on their potential to create multifunctional concrete with applications extending beyond simple load‐bearing capacity. This study concludes with a look into the future, imagining the inclusion of nanomaterials into civil infrastructure applications such as 3D printing, sustainable construction, and smart materials. [ABSTRACT FROM AUTHOR]

To improve the poor thermal conductivity of microencapsulated phase change materials (MPCMs), a strategy was designed with effective combinations between graphene nanosheets (GNs) and shells to prepare thermally conductive MPCMs–GNs by using cellulose nanofibers (CNFs) to assist GN dispersion. The experiments and theoretical calculations both illustrated that CNFs effectively prevented GNs from aggregating due to the strong Van der Walls interactions between CNFs and GNs. The morphologies and structures of MPCMs with and without GNs were characterized by SEM, FTIR and XRD. The thermal properties of MPCMs were evaluated by DSC, TG, and a thermal conductivity test. The MPCMs with 10 wt.% GNs exhibited a melting enthalpy as high as 187.2 J/g and a thermal conductivity as high as 1.214 (W/m⋅K). The results indicate that the prepared MPCMs possessed a good thermal stability. In addition, MPCMs–GNs exhibited outstanding mechanical properties using a nano-indentation test. With an excellent melting enthalpy and thermal conductivity, the prepared MPCMs–GNs/textile showed a potential ability to be used for comfort thermal regulation. [ABSTRACT FROM AUTHOR]

The dispersion of structural waves, where wave speed varies with frequency, introduces significant challenges in accurately localizing occupants in a building based on vibrations caused by their movements. This study presents a novel multi-sensor vibro-localization technique that accounts for dispersion effects, enhancing the accuracy and robustness of occupant localization. The proposed method utilizes a model-based approach to parameterize key propagation phenomena, including wave dispersion and attenuation, which are fitted to observed waveforms. The localization is achieved by maximizing the joint likelihood of the occupant's location based on sensor measurements. The effectiveness of the proposed technique is validated using two experimental datasets: one from a controlled environment involving an aluminum plate and the other from a building-scale experiment conducted at Goodwin Hall, Virginia Tech. Results for the proposed algorithm demonstrates a significant improvement in localization accuracy compared to benchmark algorithms. Specifically, in the aluminum plate experiments, the proposed technique reduced the average localization precision from 7.77 cm to 1.97 cm, representing a ∼74% improvement. Similarly, in the Goodwin Hall experiments, the average localization error decreased from 0.67 m to 0.3 m, with a ∼55% enhancement in accuracy. These findings indicate that the proposed approach outperforms existing methods in accurately determining occupant locations, even in the presence of dispersive wave propagation. [ABSTRACT FROM AUTHOR]

Environmental and spatial factors can affect the distribution of aquatic insect metacommunities. In tropical springs, few studies have been conducted on the subject, especially regarding the influence of spatial variables. Our main objective was to assess the influence of environmental and spatial factors on the composition of Chironomidae assemblages in 48 pristine springs in different watersheds in Minas Gerais state, Brazil. This is the first study of the composition of Chironomids assemblages in springs in the Neotropical region. A single time in the dry season, three samples of the substrate at each spring were collected with a hand net. To assess the importance of environmental and/or spatial predictors of the composition of the Chironomidae metacommunities Partial redundancy analysis was performed. The results show that environmental variables explained little of the composition of Chironomids assemblages in Atlantic Forest springs. The local environmental factors selected by the model were dissolved oxygen, conductivity and plant cover, and the spatial factors selected were PCNM 1 and PCNM 6. Most of the variation in the Chironomidae assemblage remained unexplained by the partial redundancy models. Our results suggest the influence of temporal and spatial variables on the structure of metacommunities of Chironomidae in tropical springs. [ABSTRACT FROM AUTHOR]

Cationic reverse flotation of kaolinite from bauxite is an alternative to adequate high silica bauxites to the specifications of the Bayer process. However, the presence of clay minerals influences the slurries rheology decreasing the flotation performance. The objective of this work was to investigate the use of ultrasonic pre-treatment on kaolinite flotation and contrast it with the traditionally used chemical dispersant. Two bauxite samples were characterized in terms of chemical and mineralogical composition, as well as particle size distribution. Flotation was accomplished after conditioning with sodium polyacrylate and/or pre-treatment in ultrasound. Determinations of viscosity, sedimentation yield, and screening followed by the analysis of available alumina and reactive silica were also conducted. By increasing the concentration of solids to more than 20 wt.%, the slurry behavior changed from a Newtonian to a non-Newtonian behavior, the viscosity increased, and the flotation performance decreased. The use of chemical dispersant and ultrasonic pre-treatment increased the flotation performance. The ultrasound had a more marked effect in slurries with higher concentrations of solids. This result is related to the synergic effect of particle dispersion and reduction of the slime coating promoted by kaolinite onto gibbsite particles. [ABSTRACT FROM AUTHOR]

The Airy phase is the frequency at which group velocity of a surface acoustic wave (SAW) attains a stationary value. In turn, a stationary value of the group velocity causes SAW to propagate with a lesser attenuation than at other frequencies. At present, no conditions for the appearance of stationary values of the group velocity are known for dispersive modes of Lamb waves propagating in stratified plates. Herein, the closed form solutions are derived for double zero group velocity (ZGV) belonging to the same Lamb mode. It is also found that the double ZGV leads to the appearance of the Airy phase located between the twofold ZGV. The analysis relies on the Cauchy formalism and the exponent fundamental matrix method. [ABSTRACT FROM AUTHOR]

The paper aims at studying dispersion of elastic waves in a sandwich plate with the parameters, characteristic of aerogel core and hard skin layers, typical for aerospace applications including optimal design of fuselage structural components. The proposed approach relies on multiparametric analysis, taking into account the effect of strong transverse inhomogeneity. It is demonstrated that both an additional low-frequency propagating wave and a slowly decaying evanescent one appear due to a high contrast in geometric and mechanical parameters of the layers. The key findings include the derivation of two-mode asymptotic expansions of the full dispersion relation at the low-frequency limit, as well as elucidation of the non-trivial link between long-wave evanescent and propagating modes. A sophisticated composite nature of the obtained expansions involving various shortened forms is investigated. The range of validity for each of these forms over frequency and wave-number domains is evaluated. Comparison of asymptotic results with the numerical solution of the full dispersion relation is presented. [ABSTRACT FROM AUTHOR]

Aim: The species that compose local communities possess unique sets of functional and ecological traits that can be used as indicators of biotic and abiotic variation across space and time. Body size is a particularly relevant trait because species with different body sizes typically have different life history strategies and occupy distinct niches. Here we used the body sizes of non‐volant (i.e., non‐flying) terrestrial mammals to quantify and compare the body size disparity of mammal communities across the globe. Location: Global. Time Period: Present. Major Taxa Studied: Non‐volant terrestrial mammals. Methods: We used IUCN range maps of 3982 terrestrial mammals to identify 1876 communities. We then combined diet data with data on climate, elevation and anthropogenic pressures to evaluate these variables' relative importance on the observed body size dispersion of these communities and its deviation from a null model. Results: Dispersion for these communities is significantly greater than expected in 54% of communities and significantly less than expected in 30% of communities. The number of very large species, continent, range sizes, diet disparity and annual temperature collectively explain > 50% of the variation in observed dispersion, whereas continent, the number of very large species, and precipitation collectively explain > 30% of the deviation from the null model. Main Conclusions: Climate and elevation have minimal predictive power, suggesting that biotic factors may be more important for explaining community body size distributions. However, continent is consistently a strong predictor of dispersion, likely due to it capturing the combined effects of climate, size‐selective human‐induced extinctions and more. Overall, our results are consistent with several plausible explanations, including, but not limited to, competitive exclusion, unequal distribution of resources, within‐community environmental heterogeneity, habitat filtering and ecosystem engineering. Further work focusing on other confounding variables, at finer spatial scales and/or within more causal frameworks is required to better understand the driver(s) of these patterns. [ABSTRACT FROM AUTHOR]

In this study, the models for the DNA origami lattice will be investigated. Our aim is to theoretically explore the ways of constructing DNA origami. To achieve this goal the DNA origami structure, consisting of nanowires embedded in a host material, will be treated from the perspective of nanowire metamaterial. Surface plasmon polaritons propagating at the interface of air and DNA metamaterial are analyzed. The dispersion relation is attained using the transfer matrix technique and employing continuity conditions of electric fields and their derivatives at the boundary separating two regions. We have concluded that with numerous nanowires into the metamaterial unit, cell frequencies of surface plasmon polaritons are altered to higher frequencies. In this study, we have studied the effect of modifications of the metamaterial, allowing for the shift of the dispersion maps toward higher frequencies. It is possible to obtain the propagation of spoof plasmons mimicking the behavior of surface waves at lower frequencies. All the properties and parameters of the inorganic metamaterials are applicable to study the phenomenon of the organic substances. [ABSTRACT FROM AUTHOR]

Dose and volume metrics to organs at risk are used for evaluation and optimization in radiotherapy planning. However, the numerous choices of metrics can be confusing. In a series of patients treated with hypofractionation and an integrated boost for breast cancer, we aim to determine if a parsimonious selection of representative metrics can be identified. The dosimetries of 42 patients receiving 42 Gy to the breast, with or without nodal irradiation, and 51 Gy integrated boost to tumor bed in 15 fractions were reviewed. For each organ—heart, lungs, and contralateral breast—cumulative dose-volume histograms were used to extract values for 3 basic metric classes: 1. The dose D.yy (Gy) received by yy% of the organ volume. 2. The percentage of organ volume Vrel.xx (%) receiving the dose of xx Gy. 3. The absolute organ volume Vabs.xx (mL) receiving the dose of xx Gy. Two additional classes were considered: • The mean dose (Gy) received by the organ. • The dose standard deviation (Gy) received by the organ. Pearson correlation coefficient R was calculated between pairs of values within each basic class and with the 2 additional classes for each organ. The interquartile ranges of correlations for D.yy, Vrel.xx, and Vabs.xx were as follows: • Heart: 0.90-0.99, 0.50-0.92, and 0.58-0.93. • Ipsilateral lung: 0.81-0.98, 0.35-0.95, and 0.46-0.96. • Contralateral lung: 0.83-0.98, 0.71-1.00, and 0.65-1.00. • Contralateral breast: 0.74-0.97, 0.30-0.92, and 0.45-0.95. The mean dose correlated with all basic classes for the heart and lungs, and with dose D.yy and volumes at Vrel.10-Vabs.10 for the contralateral breast. The standard deviation correlated with Vrel.xx and Vabs.xx for the heart and lungs (R ≥ 0.70). Among the D.yy, D.50 (median dose) correlated with the mean and standard deviation for all organs (R = 0.65-0.96). The mean, standard deviation, and median doses were the preeminent correlators. These statistics appear to be parsimonious representatives of doses to organs. Further studies with other radiotherapy series will be necessary to validate these observations. [ABSTRACT FROM AUTHOR]

Due to the large specific surface area and strong van der Waals force, bulk aggregation of nano- TiO2 immediately occurs when it is mixed with fresh cement mixture, limiting its reinforcing efficiency to cement-based materials. This study proposes a novel strategy to improve the mechanical and photocatalytic properties of cement mortar using nano- TiO2 hydrosol instead of conventional nano- TiO2 powder. Compared with pure mortar, the 28-day compressive and flexural strength of mortar with 0.6% by weight nano- TiO2 hydrosol were enhanced by 51% and 15%, respectively, the water absorption and chloride ion diffusion coefficient were decreased by 21% and 31%, respectively. The observed improvements were attributed to the denser microstructure and enhanced micromechanical properties in the bulk matrix and around interfacial transition zone (ITZ), resulting from the better dispersion of nano- TiO2 hydrosol in alkaline environment. In addition, compared with the mortar with nano- TiO2 powder, the degradation efficiency of Rhodamine B and NO by the mortar with nano- TiO2 hydrosol (0.6% by weight) was enhanced by 18.3% and 17.1% at 28 days, respectively. The enhancement resulted from the higher intrinsic photocatalytic activity and larger exposed surface area of nano- TiO2 hydrosol due to better dispersion. The research outcomes demonstrate the potential of using nano- TiO2 hydrosol in cement mortar to significantly increase the mechanical strength, durability, and photocatalytic activity, which can lead to the development of cement-based constructions with the integrated design of functionality and structure. [ABSTRACT FROM AUTHOR]

The dispersion of titanium dioxide (TiO2) determines the performance of TiO2-based formulations in cosmetic and coating applications. In particular, the chemical and structural characteristics of the surfactants used to prepare TiO2 dispersions are significant. However, the influence of surfactants on TiO2 dispersion quality has not been systematically investigated. In this study, we observed the effects of the ionic character of commercial surfactants on the dispersion stability and UV-blocking efficacy of TiO2. Among the experimental surfactant groups, anionic sodium dodecyl sulfate was efficient in stabilizing TiO2 as a water-in-oil formulation and enhancing its UV-blocking efficacy. Furthermore, an anionic fatty acid as a surfactant with a longer alkyl chain length was sufficient to stabilize the TiO2 formulation, which also displayed the highest UV-blocking efficacy, comparable to the values of commercial TiO2-based cosmetic products. [ABSTRACT FROM AUTHOR]

The study evaluated the influence of aquatic environmental features, morphological and functional traits of water bodies and directional spatial processes on the macrophyte community of floodplain ecosystems formed as a result of water flow regulation by the construction of dams. The fluvial processes were found to be still the main factor in the formation of geomorphological and ecological characteristics of floodplain ecosystems, and also determine the spatial patterns of variability of aquatic macrophyte communities. The influence of water properties on macrophytes is significantly spatially structured, as it is modified by the morphological and functional characteristics of the water bodies. The exchange of water in the floodplain system is influenced by the functional types of water bodies, which explains their significant correlation with spatial variables. The development of macrophyte communities on a broad scale is driven by the characteristics of the aquatic environment, the morphology of the water bodies and the functional types of the water bodies. On a fine scale, the patterns are described by a pure spatial component. The impact of fine scale patterns on the variability of macrophyte communities increases with increasing community disturbance, both natural and anthropogenic. [ABSTRACT FROM AUTHOR]

Physical doping is a general and effective strategy to fabricate host‐guest room temperature phosphorescence (RTP) polymer materials. However, some aggregates of phosphors will appear due to their limited solubility and phase separation in polymer matrix, resulting in unstable and/or poor RTP property. In this work, a new strategy, the utilization of cyclodextrins with fit cavity size, is proposed to improve the dispersion of phosphors and enhance RTP performance both in covalent and ionic bond system. The resultant high Förster resonance energy transfer (FRET) efficiency (ΦFRET) and outstanding RTP performance confirmed that the added cyclodextrins can effectively disperse fluorescence dye (guest) in covalently modified sodium alginate (SA‐R) matrix. Thanks to the introduced “ FRET ruler”, the distance between energy donor and acceptor can be measured, accompanying with the afterglow color of SA‐R films changing from green to red. For SA‐NpC@RhB, the introduction of β‐CD can enhance the ΦFRET up to 57.4%, with corresponding photoluminescence quantum yield (ΦPL) as high as 21.15%. The ΦFRET for SA‐NpC/γ‐CD@SR101 is ≈8.5 times enhanced, with the corresponding ΦPL rising from 0.87% to 19.13%. Besides, this strategy is also successfully applied into ionic bond system (SA/R), and the ΦPL for SA/BDA/γ‐CD@RhB can reach 24.05%. Furthermore, these materials with good RTP performance are applied in multiple information encryption, optical information storage, and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

In this work, large-eddy simulations of hydrogen dispersion from turbulent subsonic hydrogen-gas emissions in a 5.8 × 0.9 × 0.8 m 3 open-ended channel are described. Such numerical modeling of hydrogen-related processes can provide new insights into the safety aspects of hydrogen, an increasingly more common energy carrier, particularly related to explosion hazards. Ten simulations, with jet mass flow rates ranging from 0.08 g/s to 1.27 g/s, have been simulated using the open-source OpenFOAM® 10 suite. The predicted concentrations in the channel are compared to corresponding experimental data, generally showing good agreement. Two distinct dispersion regimes are observed from the numerical data; a strongly stratified "filling box" regime is found for hydrogen mass flows ≲ 0. 15 g/s, whereas a more homogenized "fading box" regime emerges for higher mass flows. Based on the local Froude number in the channel, a novel model for the momentum length scale of the hydrogen jet is proposed, applicable to downward, strongly buoyant (i.e., non-Boussinesq) jets. It is demonstrated that the ratio of this length scale to the vertical length scale of the geometry can be used to predict the dispersion regime, which may benefit simplified predictive models for hydrogen concentrations and, consequently, ignition risks. • Experimental and numerical study of hydrogen dispersion in an open-ended channel. • Subsonic, turbulent jets with mass flows from 0.09 to 1.27 g/s. • Predicted concentrations compared to experimental measurements at 29 locations. • Two dispersion regimes, "filling box" and "fading up box", identified. • A new jet momentum-length model for strongly buoyant, downward jets is proposed. [ABSTRACT FROM AUTHOR]

In this study, nano‐magnesium oxide (MgO) was modified with surfactants sodium polyacrylate, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) based on the agglomeration problem of nano‐MgO in cement. The surfactant PEG with the best modification effect was selected to modify nano‐MgO and synergize with the dispersing effect and early‐strengthening effect of triethanolamine (TEA) to prepare a new type of composite cementitious sealing material with high early compressive strength and good fluidity. The optimal ratio of the mass fraction of the composite early‐strengthening agent was determined by the response surface method: 0.02% PEG + 2% nano‐MgO + 0.04% TEA. The effects of the composite early‐strengthening agent on the cementitious sealing material were investigated by the compressive strength, fluidity, setting time, X‐ray diffraction experiments (XRD), thermogravimetric (TG‐DSC), scanning electron microscopy (SEM), etc. The effect of the composite early‐strengthening agent on the cementitious sealing material was also investigated by the response surface method. The compressive strength of the composite cement specimens at 1d, 3d, and 7d was increased by 92.59%, 35.50%, and 47.73% respectively compared to the blank group. In comparison to the control group, the flowability increased by 31.96%, and the initial and final setting time was shortened to 377 min and 394 min, respectively. [ABSTRACT FROM AUTHOR]

In this study, the dispersion and explosion of liquid hydrogen (LH 2) in leakage accidents are investigated using the Flame Accelerator Simulator (FLACS) code. The study focus was a liquid hydrogen research facility in Gimhae, South Korea. Simulations were conducted under various conditions by varying the mass flow rates (0.61 and 0.3 kg/s), directions (lateral in areas with minimal structures, lateral towards a tube trailer truck, and downward), and durations (90 and 180 s) of leakage. The results indicated that higher leakage mass flow rates produce a larger flammable cloud volume (FCV), resulting in higher maximum overpressures than that caused by lower flow rates. Downward leakage generally resulted in a larger FCV and higher overpressure than lateral leakage. The explosion characteristics were also influenced by geometry of LH 2 facility, including the presence of structures in the leakage path. Contrastingly, leakage duration had a minimal effect on the maximum overpressure because an increased duration causes a greater dilution of hydrogen, only slightly expanding the FCV. According to the overpressure–impulse diagram, higher leakage flow rates cause severe health risks, approaching thresholds for lung rupture and 100% fatality. Contrary to the minor damages caused by lower leakage flow rates. High flow rates, particularly with downward leaks, can cause significant structural damage in brick buildings, potentially leading to partial demolition. • Higher leakage mass flow rates result in larger flammable cloud volumes and increased maximum overpressures. • Downward hydrogen leaks lead to larger flammable clouds and higher overpressures than lateral leaks. • Facility geometry and structures significantly affect explosion overpressure magnitude and distribution. • Leakage duration has a minimal effect on maximum overpressure due to hydrogen dilution during leakage. [ABSTRACT FROM AUTHOR]

Understanding hydrogen dispersion in a semi-confined space is crucial for the safe operation of hydrogen-related systems, such as hydrogen fuel cell vehicles. Analyzing hydrogen release and its subsequent dispersion can be effectively conducted using computational models, which necessitate experimental measurements for validation. For safety reasons, accidental scenarios are frequently replicated using helium as a hydrogen simulant in experiments, despite some concerns about the comparability of helium and hydrogen dispersions. Hence, this study conducts a comprehensive parametric numerical analysis of the similarities between hydrogen and helium dispersion when released in a semi-confined space. The model is based on the Macquarie Dispersion Chamber and the simulation results are first validated against the measurements. The study focuses on the impact of the leakage rate and ventilation velocity. Three release models were analysed: equal concentration (Method A), equal volumetric flow rate (Method B), and equal buoyancy (Method C). This study extends previous research on Method B, used for gas release in open spaces, to environments where flow-wall interactions become important. It also compares Methods A and C for a few scenarios, examining variations in concentration distribution, purge time, and activation time under different conditions. In the absence of ventilation, Method B effectively compares hydrogen and helium flow rates by accounting for volumetric flow rates, regardless of buoyancy effects. However, under increased ventilation velocities, Method A and Method C exhibit superior agreement across sensors, highlighting the necessity of choosing detection methods according to prevailing environmental conditions. [Display omitted] • A CFD model for gas release in semi-confined space equipped with ventilation is established. • Three release models are studied to investigate similarity between hydrogen and helium gas dispersion. • Purge time and activation time are analysed with the aim of safe hydrogen infrastructure development. • Influence on gas dispersion by various ventilation velocity and flow rate at leakage are analysed. [ABSTRACT FROM AUTHOR]

The diffraction efficiency of blaze gratings is optimized only at a specific frequency due to a fixed blaze angle, resulting in reduced and variable diffraction efficiencies over the working frequency band. Additionally, blazed gratings demonstrate polarization dependence due to their groove structures and the interaction of light with their surfaces. Consequently, designing gratings with constant diffraction efficiencies across a wide frequency bandwidth while maintaining polarization independence remains a challenge. Here, a design paradigm of dispersion engineerable meta‐grating inspired by orthogonal harmonic oscillations (OHO) is presented. Utilizing the OHO model, the phase dispersion of a metasurface can be precisely controlled, which applies to any unit cell featuring two orthogonal electromagnetic resonances. As a proof of concept, a polarization‐insensitive meta‐grating is showcased, where the blazed angle adapts with the incident frequency, ensuring broadband performance. In the experiment, the adaptively‐blazed grating measured an optimized and constant diffraction efficiency of ≈80% over the working wavelength range, i.e., 8.7–12.2 µm. The difference in diffraction efficiency between the two perpendicular linear polarization states remains within 4.6%. The proposed paradigm paves the way for meta‐device design based on precise dispersion engineering, which has potential applications in spectrometers, broadband beam forming and steering, hyperspectral imaging, etc. [ABSTRACT FROM AUTHOR]

The twin zero group velocity (ZGV) points are observed, which belong to the fundamental symmetric branch (S0) of Lamb waves propagating in a composite traction-free layered plate containing odd number of layers with alternating physical properties. It is shown that in a vicinity of these ZGV points an ambiguity of dispersion spectrum takes place, resulting in the appearance of several waves, which (i) belong to the same fundamental mode; (ii) satisfy the same boundary conditions; and, (iii) propagate at the same frequency, however (iv) with different phase velocities. The analysis is based on a combination of Cauchy formalism and the exponential fundamental matrix method. [ABSTRACT FROM AUTHOR]

The dispersion of nano‐SiO2 (NS) in cement plays a critical role in enhancing the properties of cementitious materials. In this study, the combination of ultrasonic dispersion and polycarboxylic acid water reducing agent (PCE) was used to significantly improve the dispersion of NS. The effects of ultrasonic dispersion time, NS content, and PCE content on dispersion quality were investigated, alongside their impact on mechanical properties, electrical resistivity, and frost resistance. The results demonstrated that this synergistic method optimized the dispersion of NS, leading to superior mechanical properties and frost resistance. With an ultrasonic dispersion time of 40 min, NS content of 1.0 wt.%, and PCE content of 0.75 wt.%, the cement paste achieved its optimal performance. Compared to non‐dispersed samples, compressive strength increased by 33.7%. After 75 freeze–thaw cycles, the mass loss was 2%, the relative dynamic elastic modulus was 99.15%, and the strength loss was 13.74%. [ABSTRACT FROM AUTHOR]

Fiber optic research continues to develop due to the need for fast information technology. The input signal in an optical fiber is in the form of a soliton wave that propagates in the fiber with a balanced index of refraction, dispersion, and diffraction. Fiber optics may lose some of the signal over time if they solely use a nonlinear refractive index. This study aims to examine into the dynamics and decoherence of multi-peak solitons caused by electromagnetic signal attenuation and potential trap in the propagation via optical fibers. The methods used start with the stationary solution of the nonlinear Schrödinger Cubic Quintic equation, the Newton-Raphson method, and the fourth-order Runge-Kutta. In stationary solutions, the p (state energy) and ρ (Lèvy index) values affect the number, pulse width, and height of soliton peaks. Increased p and ρ values lead to increased instability, causing the data transmitted into the optical fiber to collapse and become unreadable by the receiver. In the excited state (p > 0), the decoherence phenomenon occurs and causes wave instability and destruction. In term of energy intensity, a stable form of transmission in the ground state has a pattern of continuously weakening, decreasing, and smoothing, while in the excited state there is a spike in the intensity of the electromagnetic wave. Based on this study, multi-peak solitons can only be applied for propagation distances, which tend to be short due to their dynamics and decoherence. [ABSTRACT FROM AUTHOR]

Multistatic imaging systems are commonly used in radar systems and microwave imaging. In these systems, many antennas are arranged three-dimensionally and connected to RF switches. The length of each transmitter (Tx) and receiver (Rx) channel differs slightly, causing artifacts in high-resolution image reconstruction. This study presents a novel method for the phase calibration of multistatic systems. This method does not require system reconstruction and can automatically perform phase calibration in a short time. This method is expected to facilitate an accurate phase measurement in multistatic systems. The approach involves phase calibration by analyzing the reflection coefficients of antenna elements in the time domain. Imaging experiments were performed on a multistatic imaging system using this calibration method, and the position and shape of a metal rod with a diameter one-fourth of a wavelength were reconstructed by simple back-projection with an accuracy beyond the diffraction limit. [ABSTRACT FROM AUTHOR]

Oil spills pose significant threats to marine and freshwater environments, impacting ecosystems and drinking water sources. The present review incorporated an up‐to‐date statistical analysis of the oil spills globally including the types and sources of oil spills and the main habitats affected by the past incidents. It presented immediate and long‐term effects on aquatic organisms and habitats highlighting the necessity for action to protect the aquatic environment. The paper also elucidated a range of effective remediation and cleanup methods, presenting a comprehensive toolkit to mitigate ecological damage. Noticeably, the review identified crucial knowledge gaps in the literature: (i) the absence of marine plastic pollution in studies on oil spill impacts and (ii) the absence of a modeling framework that considers the presence of microplastics in the spillage region and their impacts on the overall weathering rate. From synthesizing essential knowledge on oil spill dynamics and identifying the knowledge gap in the literature, this review aims to enhance understanding and guide future research. [ABSTRACT FROM AUTHOR]

Research into particulate polymer composites is of significant interest due to their potential for enhancing material properties, such as strength, thermal stability, and conductivity while maintaining low weight and cost. Among the various techniques for preparing particle-based composites, ultrasonic wave stimulation is one of the principal laboratory-scale methods for enhancing the dispersion of the discontinuous phase. Nevertheless, there is a scarcity of empirical evidence to substantiate the impact of stimulating materials with natural sound frequencies within the acoustic spectrum, ranging from 20 Hz to 20 kHz, during their formation process. The present work investigates the effect of acoustic stimuli with frequencies of 56, 111, and 180 Hz on the properties of an acrylic-based polymer and its discontinuous carbon-based composites. The results indicated that the stimulus frequency affects the cure time of the studied systems, with a notable reduction of 31% and 21% in the cure times of the neat polymer and carbon-nanofiber-based composites, respectively, after applying a frequency of 180 Hz. Additionally, the higher stimulation frequencies reduced porosity in the samples, increased the degree of dispersion of the discontinuous phase, and altered the composite materials' thermal, optical, and electrical behavior. [ABSTRACT FROM AUTHOR]

This paper investigates a quantitative comparison of the Love wave propagation due to traction-free and rigid boundary surfaces on the piezoelectric-dispersive layer over a non-dispersive initially stressed half-space. The model is considered (a) transversely isotropic piezoelectric material in the upper layer, (b) exponentially increasing dispersive (non-homogeneous) layer in the intermediate, and (c) initially stressed non-dispersive (homogeneous) medium in the lower half-space. Electrical potential fields in the piezoelectric layer are defined in terms of electrical potential function with open and short circuit piezoelectricity using the quasi-static Maxwell's equation. We have derived analytical dispersion relations for two cases of boundary conditions: (i) free surface with zero tractions and (ii) rigid boundary, in both the open and short circuit cases. The validities of the dispersion relations are shown by deriving some particular cases and compared with the classical dispersion relation of the Love wave. A novel numerical representation of changes in displacement amplitude with depth and comparative effect of various piezoelectric materials such as PZT-4, PZT-5A, PZT-7A, and BaTiO3 are shown using MATLAB software. The rigid boundary surface case is more effective than traction-free boundary surfaces in terms of electromechanical coupling factor. It is also identified that there are significant effects on the dispersion of the Love-type waves due to different boundary conditions on the upper surface of the model. These comparative studies highlight the present work and may be helpful in the fields of solid mechanics and material fabrication processes. [ABSTRACT FROM AUTHOR]

Basalt fibers were widely used as reinforcing matrix materials because of their thermal and chemical stability and environmental friendliness. The properties of composite materials were affected by the interaction between the basalt fibers and matrix materials. Surface modification of basalt fibers and the dispersion property have become key points of research in recent years. This study focuses on the impact of a dispersant on surface modification. Basalt fibers were dispersed by polyethylene glycol (PEG) before modification with 3-aminopropyltriethoxysilane (KH550), which significantly increased the surface roughness, thus increasing the surface area and facilitating mechanical bonding. The morphology, structure, and composition were characterized via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy analysis (XPS), respectively. The distribution characteristics of fiber were evaluated by the response surface method. When the mass fraction of PEG was 0.5 wt.%, the modification time was 2.5 hours, and the modification temperature was 60°C, the fiber dispersion degree in KH550 solution reached 83%. The grafting degree test indicates that the weight of the grafting increased to 6.67 times that of the undispersed basalt fibers. This enhancement allowed for greater grafting of the KH550, thereby optimizing the effect of modified fibers. [ABSTRACT FROM AUTHOR]

Fullerene has been acknowledged as a significant nanocarbon nanofiller enhancing the imperative polymer characteristics. Since, thermoplastic polymers constitute a large group of polymeric materials, fullerene has been used as reinforcement in these matrices mostly via non-covalent means. This state-of-the-art review article summarizes thermoplastic polymer nanocomposites reinforced with fullerene nano-additives without involving any covalent interactions. Accordingly, thermoplastic polymer/fullerene nanocomposites of interest have non-covalent or physical interactions in the matrix-nanofiller such as van der Waals forces, electrostatic interactions, hydrogen bonding, and aromatic stacking interactions. Number of thermoplastic polymers including polyamide, polyurethanes, and block copolymers have been non-covalently or physically reinforced with the fullerene molecules. Ensuing high performance thermoplastic polymer/fullerene nanocomposites exhibited improved microstructure, electrical, mechanical, thermal, and other physical properties. Enhancements in the thermal, mechanical, and electrical properties of the thermoplastic/fullerene nanomaterials were found dependent upon the nanofiller contents, orientations, interfacial effects, and processing. Consequently, the polyamide/fullerene systems were found efficient to enhance the glass transition up to 260°C, in addition to optimum mechanical properties. Polyurethane/fullerene systems performed better for improved tensile strength and young's modulus features up to 90 MPa and 48 GPa, respectively. System based on poly (methyl methacrylate) and fullerene has resulted in high thermal degradation temperature in the range of 501-633°C with fine electrical conductivity of 1.3 Scm−1. Using combination of fullerene and graphene nanofiller (due to synergistic effects) has been found to improve the electrical conductivity considerably in the range of 1.8–2.5 Scm−1 for a polystyrene and block copolymer system. However, attaining fine fullerene nanoparticle dispersion of non-covalently reinforced matrices have been found important affecting the final nanocomposite properties. Consequently, processability and essential characteristics of non-covalently fullerene filled nanocomposites can be influenced due to nanoparticle aggregation. Hence, the physical property enhancement potential of physical linking between the non-covalently linked thermoplastics-fullerene has been portrayed in this article. Research on non-covalently interacted thermoplastic polymer/fullerene nanocomposites revealed technical potential ranging from energy/electronic devices to engineering and biomedical sectors. This review article can be a useful guide for the field researchers towards the development of advanced systems using non-covalently linked polymer/fullerene nanomaterials for future technical applications. [ABSTRACT FROM AUTHOR]

This review paper summarizes properties, uses, working principle and applications of the Photonic Crystal Fiber and its comparison with conventional fiber. In simple terms, conventional optical fiber is a wired transmission medium that offers an optical channel that is more reliable as well as flexible than the atmosphere. The most crucial aspects of any communication systems are its bandwidth and signal-to-noise ratio, which determine the channel's capacity. At 1550 nm, the optical fiber link currently has a loss of 0.2 dB/km. A single fiber-optic communication link has a bandwidth of about 50 THz. Thus, the foundation of modern communication systems is made up of fiber optic communication systems. Optical fiber is used in a wide range of sensor applications in addition to communication. However, optical fiber is not able to offer design flexibility. Thus, Photonic Crystal Fiber--a desirable substitute fiber--came into existence. With only little changes to its geometrical dimensions, photonic crystal fiber offers exceptional design freedom and opens opportunities in various sensing applications. This article covers comparative analysis of different sensing parameters like birefringence, confinement loss for liquids mediums like water, ethanol, benzyne, glucose solution, human mucosa etc. The geometrical structural dependence of sensitivity of PCF based sensors have been reviewed. Further, for different gases their absorption wavelengths, relative sensitivity, confinement loss at different operating frequencies sensitivity and effective mode area have been reviewed. Performance parameters of PCF-based temperature sensors for different PCF designs have also been analysed. It is suggested that by adjusting the geometrical structure of air holes the performance of PCF based sensors can be optimized. [ABSTRACT FROM AUTHOR]

Understanding the dispersion of floating objects and ocean properties at the ocean surface is crucial for various applications, including oil spill management, debris tracking and search and rescue operations. While mesoscale turbulence has been recognized as a primary driver of dispersion, the role of submesoscale processes is poorly understood. This study investigates the largely unexplored mechanism of dispersion by refracted wave fields. In situ observations demonstrate significantly faster and distinct dispersion patterns for objects influenced by wind, waves and currents compared to those solely driven by ocean currents. Numerical simulations of wave fields refracted by ocean eddies corroborate these findings, revealing diffusivities that exceed those of turbulent diffusion at scales up to 10 km during energetic sea states. Our results highlight the importance of ocean waves in dispersing surface material, suggesting that refracted wave fields may play a significant role in submesoscale spreading. As atmospheric forcing at the ocean surface will only strengthen due to anthropogenic contributions, additional research into wave refraction is necessary. This requires concurrent high-resolution measurements of wind, waves and currents to inform the revisions of large-scale coupled models to better include the submesoscale physics. [ABSTRACT FROM AUTHOR]

In the middle and late stages of offshore carbon-rich gas reservoir development, insufficient reservoir energy poses significant challenges and difficulty in improving gas recovery. Injecting CO2 back into the reservoir is a promising development approach that can address both carbon emissions and enhanced gas recovery (EGR). During the CO2 injection process, the CO2–CH4 dispersion significantly impacts the recovery of CH4. To understand the mass transfer and dispersion laws of CO2 and high-carbon natural gas under current in situ reservoir conditions, this study conducted 1-m-long core experiments to investigate the effects of different gas compositions and permeabilities on gas recovery and diffusion laws in offshore reservoirs, taking into account the evolution of permeability in the porous medium. The experimental results indicate that the higher carbon concentration helps reduce mixing with formation gas, which consists of 70% methane, 25% nitrogen, and 5% carbon dioxide, resulting in a smaller diffusion coefficient. Under the conditions of an injection rate of 0.4 mL/min, a temperature of 81 °C, and a pressure of 7 MPa, the diffusion coefficient decreases by 27.5% as the carbon dioxide concentration increases from 70% to 90%, resulting in a 1.5% increase in recovery efficiency. As the permeability decreases, the viscous resistance of the fluid increases, leading to longer breakthrough times, and the reservoir fluid becomes more akin to piston displacement, reducing the degree of dispersion. The findings of this study provide guidance for optimizing gas injection strategies by reducing CO2 dispersion and further enhancing natural gas recovery. [ABSTRACT FROM AUTHOR]

We investigated the Diels‐Alder reaction of 6,13‐bis(triisopropylsilylethynyl)pentacene (1) with small dienophiles such as (bridged) dihydronaphthalenes/cyclohexenes that yielded adducts at the central ring, the other dienophiles predominantly or exclusively attacked the unsubstituted off‐center ring. The difference in regioselectivity was investigated by DFT calculations. Apart from dispersion interactions, it is due to the steric demand of the dienophiles, which need to fit in between the silylethynyl substituents to react at the central ring. Epoxynaphthalene adducts of 1 as well as its anthracene and tetracene congeners were deoxygenated, easily furnishing triarenobarrelenes with TIPS‐ethynyl substituents at the bridgeheads, attractive building blocks for porous solids and higher acene‐based trimers. [ABSTRACT FROM AUTHOR]

AbstractThe experimental study assessed the impact of choline chloride cation-based ionic liquid (IL), on the dispersion stability and wear characteristics of copper (II) oxide (CuO) nanoparticles (NPs) in synthetic base oil (PAO 10). CuO NPs, averaging 50 nm in size, underwent surface modification using varying concentrations of the IL (0.25%, 0.5%, 0.75%, and 1% by weight). The formulations were subjected to sliding wear tests to evaluate their wear behavior. Analysis of the worn surfaces utilized scanning electron microscopy, energy-dispersive x-ray spectroscopy, and atomic force microscopy. The results indicated that the combination of 0.75% IL and 1% CuO NPs provided optimal dispersion and exhibited effective surface mending, enhancing wear protection by 21.1% than that of PAO 10. The formulation containing 1% IL and 1% CuO NPs demonstrated the highest load carrying capacity among all tested compositions. In terms of wear behavior, the nanolubricant formulations with 0.75% and 1% IL outperformed the lubricant formulation containing 1 wt% of the commercial antiwear additive Zinc dialkyldithiophosphates (ZDDP). [ABSTRACT FROM AUTHOR]

Mechanistic investigations at the density functional theory level of organic and organometallic reactions in solution are now broadly accessible and routinely implemented to complement experimental investigations. The selection of an appropriate functional among the plethora of developed ones is the first challenge on the way to reliable energy barrier calculations. To provide guidelines for the choice of an initial and reliable computational level, the performances of commonly used non‐empirical (PBE, PBE0, PBE0‐DH) and empirical density functionals (BLYP, B3LYP, B2PLYP) were evaluated relative to experimental activation enthalpies. Most reactivity databases to assess density functional performances are primarily based on high level calculations, here a set of experimental activation enthalpies of organic and organometallic reactions performed in solution were selected from the literature. As a general trend, the non‐empirical functionals outperform the empirical ones. The most accurate energy barriers are obtained with hybrid PBE0 and double‐hybrid PBE0‐DH density functionals, both providing similar performance. Regardless of the functional under consideration, the addition of the GD3‐BJ empirical dispersion correction does not enhance the accuracy of computed energy barriers. [ABSTRACT FROM AUTHOR]

AbstractAn investigation on the propagation of bending waves along the edge of a piezoelectric thin plate resting on an elastic foundation (cf. Pasternak foundation) and under the action of a point-load is carried out in this paper. The displacement field of the plate is based on the classical plate theory. The Kelvin-Voigt type viscoelastic model is used to examine the viscous effect on the characteristics of the bending wave. The Moore-Gibson-Thompson (MGT) thermoelastic equation is solved for an external time variant harmonic heat source at the upper surface of the plate. The piezoelectric potential is obtained for an electrode-covered upper surface and an electrically shorted lower surface. The displacements of the propagating bending wave along the edge are examined under a time-harmonic point-load acting near the vicinity of the free edge of the plate. The well-known Green function technique and Fourier transform method are implemented to generate an analytical solution for the non-homogeneous boundary value problem. The examination of the derived explicit form of the dispersion relationship and the displacements of the bending edge wave under external loading are discussed and presented both analytically and graphically, and the results are summarized. [ABSTRACT FROM AUTHOR]

Two‐photon polymerization 3D‐printing is a well‐known technique for fabricating passive micro/nanoscale structures, such as microlenses and inversely designed polarization splitters. The integration of light emitting nanoparticle (NP) dopants, such as quantum dots (QDs) and rare‐earth doped nanoparticles (RENPs), into a polymer resist would enable 3D printing of active polymer micro‐photonic devices, including sensors, lasers, and solid‐state displays. Many NPs contain oleic acid ligands to prevent degradation, but oleate‐capped NPs (oc‐NPs) tend to agglomerate in nonpolar media despite the hydrophobicity of the ligand. This results in an uneven nanoparticle distribution and increased optical extinction. In this work, a general approach is proposed for dispersing oc‐NPs in commercial 3D printable polymers. Controlled growth of small carbon chains around the oc‐NPs is achieved by functionalizing them with methyl‐methacrylate monomers. The proposed approach is validated on RENPs (≈65 nm) and CdSe/ZnS quantum dots (≈12 nm) using commercial polymer resists (IP‐Dip and IP‐Visio). Dispersions of functionalized NPs (f‐NPs) have improved the NP density by an order of magnitude and are shown to be stable for several weeks with minimal impact on printing quality. The approach is generalizable to other oc‐NPs, enabling synthesis of functional resins for high‐quality polymer‐based optical and electronic devices. [ABSTRACT FROM AUTHOR]

The quantity of silane chemically bonded to the organoclay's surface significantly influences its dispersion within the polymer matrix, as well as the interfacial interaction. This research presents a groundbreaking method for enhancing the surface properties of montmorillonite (Mt) through the use of γ‐(methacryloxy) propyl trimethoxy silane (KH570) coupled with acid treatment, leading to increased grafting efficiency. Confirmed by FT‐IR, TGA, and XRD, the process effectively bonds organo‐silanes to Mt and achieves a high grafting level of 1.59 mequiv/g. Utilizing a latex compounding method, Mt/rubber nanocomposites are synthesized with thoroughly modified clay for peak performance. Dispersion and interfacial properties are evaluated through XRD, TEM, AFM, and DMTA. The findings reveal that the well‐modified Mt is an exceptional filler, ensuring a high level of dispersion and robust interaction with the rubber matrix. This synergy translates to a marked improvement in the mechanical properties of the composite, with notable enhancements observed in both tensile strength and elongation at break of 9.7 MPa and 1141%, respectively. This innovative approach to the graft modification of clays presents a potent method, offering the potential for the industrial‐scale manufacture of high‐performance clay‐based composites. Highlights: A processing method for preparing high grafting clay with a silane coupling agent.Functionalized clay presents better nano‐dispersion in the polymeric matrix.Strong covalent interfacial interaction is constructed between clay and rubber.Tensile Strength and elongation at break of the composites are obliviously improved. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSThe advancement of carbon nanotube (CNT) polymer composites has significantly revolutionized material science by offering exceptional mechanical, electrical, and thermal properties. However, the practical application of these composites is often hindered by the poor dispersion and compatibility of CNTs within polymer matrices. This paper explores advanced functionalization techniques to address these challenges, aiming to achieve superior dispersion and compatibility. Through a comprehensive review of chemical, physical, and hybrid functionalization methods, this study evaluates their effectiveness in enhancing CNT-polymer composite properties. Additionally, key characterization techniques, including spectroscopic and microscopy methods, are utilized to assess the quality of dispersion, interfacial bonding, and the presence of functional groups. Detailed case studies showcase the successful application of these advanced functionalization techniques, with significant improvements in mechanical properties such as tensile strength, modulus, and fracture toughness, resulting in composites with enhanced performance. This research advances the understanding of functionalization strategies and provides a robust framework for future studies and industrial applications, paving the way for the commercialization of high-performance CNT-polymer composites.Tailored functionalization optimizes electrical and mechanical performance.Hybrid functionalization enhances CNT dispersion in polymer matrices.Covalent and noncovalent methods combine for superior composite properties.Improved interfacial bonding boosts tensile strength and thermal stability.Enhanced CNTpolymer compatibility leads to advanced industrial applications.Tailored functionalization optimizes electrical and mechanical performance.Hybrid functionalization enhances CNT dispersion in polymer matrices.Covalent and noncovalent methods combine for superior composite properties.Improved interfacial bonding boosts tensile strength and thermal stability.Enhanced CNTpolymer compatibility leads to advanced industrial applications. [ABSTRACT FROM AUTHOR]

Introduction/purpose: Fractured formations recently gained significant interest as a landscape for securing both energy and groundwater demands, However, the dual role of fracture in transporting fluids and contaminants underscores the need for further investigations to mitigate the impact on human health. This study aims to numerically investigate the combined effect of particle density and flow velocity on their transport and deposition in different fracture orientations. Methods: A 2D particle tracing simulation was implemented accounting for drag and gravity forces on a smooth fracture. The derived particle numbers under the studied scenario e.g., fracture orientation, particle density, and flow velocity, were fitted to a 1D advection-dispersion equation with a deposition term. Results: The model elucidated that both particle densities yielded an increase in the normalized concentration in non-horizontal scenarios as the fracture orientation angle increased. The overall increment led to an observed decrease in the deposition coefficients and was associated with an increase in the dispersion coefficients. Hence the effect was more pronounced for denser particles where gravitational settling dominated, particularly in horizontal fractures. Less dense particles (1.05 g/cm³) were more strongly influenced by hydrodynamic forces, exhibiting lower overall deposition and dispersion across all fracture orientations. Additionally, increased flow velocity enhanced mechanical mixing and amplified dispersion and deposition coefficients. Conclusion: The findings demonstrated a clear dependency on the combined effect of fracture orientation, particle density, and flow velocity. These valuable insights into particle transport mechanisms in fractured media have applications in subsurface flow, contaminant migration, and reservoir engineering. [ABSTRACT FROM AUTHOR]

In this work, we propose a novel dual guided PCF design capable of supporting the transmission of 68 OAM modes. The innovative design features a specialized structure with multiple layers composed of pure silica and SF57 material arranged alternately. To enhance physical strength and minimize loss, the fiber is enclosed by a perfectly matched layer (PML). Air holes are strategically added and optimized in the third and fifth layers. Through numerical analysis, we observed that the proposed design yields excellent results across all evaluated parameters. The maximum confinement loss recorded is 10–12 dB/m. The effective refractive index values range from 1.444 to 1.8, with effective refractive index difference values in the order of 10–2. Furthermore, the modal purity and power fraction values exceed 99% for all modes. Dispersion values are maintained below 9.87 ps/THz/cm, and crosstalk values are less than − 12 dB. These results demonstrate the potential of our dual guided PCF design in meeting the increasing demands for high-speed and reliable communicating systems. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions is one of the largest energy and environmental challenges currently faced globally. To achieve carbon neutrality, the development of new technologies and simultaneous improvement of conventional technologies are required. Catalysis, which determines the success or failure and efficiency of the process, is at the center of addressing these problems. Innovative advancements in catalysis have been accomplished through the extensive research on catalytic materials. Oxygen storage materials with oxygen storage capacity (OSC) have been widely applied in supports and active cocatalysts for energy and environmental catalytic applications. This review provides knowledge on the extended applications (reforming, water-gas shift reaction, and partial oxidation of methane (POM) for high-value-added chemicals, including hydrogen production, deoxygenation of fatty acids for second-generation biofuel production, selective catalytic reduction of NOx with NH3, hydrocarbon (HCs) oxidation for emission control, CO oxidation for vehicle exhaust control and purification of gaseous product fuel, and soot oxidation for the removal of motor-type pollutants) of these materials, which are mainly used as three-way catalysts (TWC) in automotive catalysis, to the carbon-neutral field. In particular, this study focuses on the physico-chemical properties that are closely synergistic with OSC, such as reducibility, dispersion, surface acid/base properties, and physical properties, such as surface structure or morphology. [ABSTRACT FROM AUTHOR]