Search Results (30)

The presence of a gas film at the solid–liquid interface can effectively reduce fluid flow resistance. This study utilizes numerical simulations to explore how groove microstructures on the lower wall of microchannels affect the evolution of trapped bubbles into gas films, as well as the resultant fluid flow behaviors inside microchannels. The influences of groove number, groove shape and double-layer microstructures on gas film formation and fluid boundary slip length are analyzed in detail. The results show that increasing the groove number can significantly improve the continuity and stability of the gas film. Groove shape also has a prominent effect on the evolution of bubbles and gas films. With the longest spreading length of gas film, rectangular grooves present a slip length about 23.9% higher than that of triangular grooves. Simultaneously, it was discovered that bilayer microstructures, especially in cases with smaller periods, can notably enhance the spreading speed, length and thickness of gas film. This improvement, in turn, further increases the slip length and boosts the drag reduction effect. This work highlights that rational optimization of wall microstructures in superhydrophobic microchannels facilitates the generation of stable, continuous gas films, yields a prominent enhancement in slip length, and consequently achieves efficient drag reduction in microfluidic systems. The present findings offer valuable fundamental understanding and technical guidance for the structural design of advanced microfluidic devices. Full article

The field of developing effective catalysts for heterogeneous catalysis has recently focused on controlling the structures of catalysts themselves to optimise the density and energy of crystal lattice defects. This can significantly influence catalytic activity in terms of both reaction rates and reaction mechanisms, and thus the selective production of desired substances as well. In many cases, these crystal lattice defects manifest themselves as so-called electron traps (ETs) and thus significantly influence charge transfer between the catalyst and reactants. ETs provide the missing electronic link between atomic-scale defects and macroscopic performance in heterogeneous catalysis. Therefore, the importance of ETs for catalysis is particularly evident in areas where charge transfer plays a fundamental role in the reaction mechanism, such as photocatalysis and electrocatalysis. In the field of thermally initiated reactions, the importance of ETs in heterogeneous catalysis has not yet been fully appreciated. However, several studies have already addressed the importance of ETs for this type of reaction. This review consolidates and extends the concept of ETs to purely thermal-initiated reactions, with a focus on CO₂ hydrogenation using typical transition metal catalysts. Firstly, in this review, ETs are defined as band gap states associated with internal and external defects, and their depth, density, spatial location, and dynamics are then coupled with key steps in thermocatalytic cycles, including charge storage/release, reactant activation, intermediate stabilisation, and redox turnover. Secondly, electron trap detection is reviewed based on advanced spectroscopic techniques, including reversed double-beam photoacoustic spectroscopy (RDB-PAS), thermally stimulated current (TSC), deep-level transient spectroscopy (DLTS), thermoluminescence (TL), electron paramagnetic resonance (EPR), and photoluminescence (PL), highlighting how each method describes trap energetics and populations under realistic operating conditions. Finally, case studies on the application of metal oxides and supported metals are discussed, as these are typical catalysts for the reaction mentioned above. This review highlights how oxygen vacancies (OVs), polarons, and metal–support interfacial sites act as robust electron reservoirs, lowering the barriers for CO₂ activation and hydrogenation. By reframing thermocatalysts through the lens of ET chemistry, this review identifies ETs as actionable targets for the rational design of next-generation materials for CO₂ hydrogenation and related high-temperature transformations. Full article

In this paper, the propagation of surface gravity waves over multiple bottom-standing porous semicircular humps is examined in the absence and presence of double floating $\mathit{C}$-type detached asymmetric breakwaters. Both wave scattering and trapping phenomena are investigated within the framework of small-amplitude linear water wave theory, with the governing problem numerically solved using the multi-domain Boundary Element Method (BEM) in finite-depth water. A detailed parametric analysis is conducted to evaluate the effects of key physical parameters, including hump radius, porosity, spacing between adjacent humps, and the separation between the two $\mathit{C}$-type detached breakwaters. The study presents results for reflection and transmission coefficients, free-surface elevations, and the horizontal and vertical forces acting on the first perforated semicircular hump, as well as on the shore-fixed wall. The findings highlight the significant role of porous humps in altering Bragg scattering characteristics. For larger wavenumbers, wave reflection increases notably in the presence of a vertical shore-fixed wall, while it tends to vanish in its absence. Reflection is also observed to decrease with an increase in semicircle radius. Furthermore, as the wavenumber approaches zero, the vertical force on multiple permeable semicircles converges to zero, whereas for impermeable semicircles, it approaches unity. In addition, the horizontal force acting on the shore-fixed wall diminishes rapidly with increasing porosity of the semicircular humps. Full article

Macrophage extracellular traps (METs), which are extracellular immune structures released by macrophages, consist primarily of double-stranded DNA, histones, elastase, matrix metalloproteinase, myeloperoxidase, and other components. Recent studies have found that various pathogens (such as bacteria, fungi, and parasites) and environmental pollutants could induce the formation of METs through different mechanisms to help the host resist infection. However, accumulating evidence suggests that METs play a double-edged role in immune response, enhancing host defense while potentially contributing to tissue damage under certain pathological conditions. This review summarizes the mechanisms underlying the formation of METs, including different pathways triggered by various pathogens and environmental pollutants. We also discussed the role of METs in respiratory diseases, autoimmune diseases, metabolic diseases, tumors, and transplantation and injury, as well as recent advances in MET-targeted drugs, aiming to provide new insights for improving treatment strategies of relevant diseases. Full article

Refugee tents are essential temporary shelters in disaster-prone regions like Aceh, Indonesia, which experiences a warm and humid tropical climate. Ensuring thermal comfort in these shelters is crucial for the well-being and recovery of displaced individuals. This study evaluates the thermal comfort of refugee tents deployed in Aceh through a combination of field measurements and computational simulations using Ansys Fluent 19.2 (CFD software). Field measurements captured real-time environmental data, including temperature, humidity, and airflow inside and around the tents. Thermal comfort was assessed using the Indonesian National Standard (SNI 03-6572-2001) through Effective Temperature (ET), and the ASHRAE 55 through Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD). This study also analyzed the thermal performance of alternative tent configurations designed to improve thermal comfort in tropical climates. Two new tent designs were proposed: one with rooftop openings to release trapped hot air and another with both upper ventilation and a double-layer outer skin with a 10 cm air gap. The results show that the tent with upper ventilation reduces the air temperature by approximately 0.5 K and increases air speed by around 0.18 m/s. The design combining upper ventilation and a double skin achieves a greater temperature reduction of 2.9 K compared to the outside environment, with a faster airflow than ventilation alone. These findings highlight the importance of advanced ventilation strategies and thermal insulation in improving indoor environments, offering valuable insights for future refugee tent designs aimed at enhancing thermal comfort. Full article

The Middle Permian Maokou Formation carbonate rocks in the southern Sichuan Basin are import targets for hydrocarbon exploration, with numerous gas fields discovered in structural traps. However, as exploration extends into slope and syncline zones, the limestone reservoirs become denser, and fluid distribution becomes increasingly complex, limiting efficient exploration and development. Identifying the key factors controlling natural gas accumulation is therefore critical. This study is the first to apply deep learning techniques to fault detection in the southern Sichuan Basin, identifying previously undetected WE-trending subtle strike-slip faults (vertical displacement < 20 m). By integrating well logging, seismic, and production data, we highlight the primary factors influencing natural gas accumulation in the Maokou Formation. The results demonstrate that 80% of production comes from less than 30% of the well, and that high-yield wells are strongly associated with faults, particularly in slope and syncline zones where such wells are located within 200 m of fault zones. The faults can increase the drilling leakage of the Maokou wells by (7–10) times, raise the reservoir thickness to 30 m, and more than double the production. Furthermore, 73% of high-yield wells are concentrated in areas of fault intersection with high vertical continuity. Based on these insights, we propose four hydrocarbon enrichment models for anticline and syncline zones. Key factors controlling gas accumulation and high production include fault intersections, high vertical fault continuity, and local structural highs. This research demonstrates the effectiveness of deep learning for fault detection in complex geological settings and enhances our understanding of fault systems and carbonate gas reservoir exploration. Full article

An increased demand for natural products nowadays most specifically probiotics (PROs) is evident since it comes in conjunction with beneficial health effects for consumers. In this regard, it is well known that encapsulation could positively affect the PROs’ viability throughout food manufacturing and long-term storage. This paper aims to analyze and review various double/multilayer strategies for encapsulation of PROs. Double-layer encapsulation of PROs by electrohydrodynamic atomization or electrospraying technology has been reported along with layer-by-layer assembly and water-in-oil-in-water (W₁/O/W₂) double emulsions to produce multilayer PROs-loaded carriers. Finally, their applications in food products are presented. The resistance and viability of loaded PROs to mechanical damage, during gastrointestinal transit and shelf life of these trapping systems, are also described. The PROs encapsulation in double- and multiple-layer coatings combined with other technologies can be examined to increase the opportunities for new functional products with amended functionalities opening a novel horizon in food technology. Full article

Inorganic scintillation crystals have been widely used in applications of high-energy physics, nuclear medical imaging, industrial nondestructive inspection, etc. In this work, a single crystal Ba₃Y(PO₄)₃ (BYP) with 1.0 at% Ce³⁺-doping concentration was first grown by the Czochralski method, and the electronic structure was calculated using first principles based on density functional theory. In addition, a series of Ce³⁺-doped BYP phosphors were synthesized, and the fluorescence emission under UV excitation was measured through low-temperature spectroscopy, containing double-peaked emission from 5d–4f transition and self-trapped exciton recombination. A comparison of the UV and X-ray-excited fluorescence spectra reveals the existence of oxygen vacancies as well as F+ centers in the crystal. The air annealing of the crystal effectively reduces the thermoluminescence defects but reduces the emission intensity under UV or X-ray excitation. The BYP:Ce crystal shows a fast decay lifetime of 15.5 ns, and the fast component is as short as 8 ns. The results show that the Ce³⁺-doped BYP crystal has potential as a kind of scintillator with fast decay properties. Full article

The transition zone (TZ) of hydrocarbon reservoirs is an integral part of the hydrocarbon pool which contains a substantial fraction of the deposit, particularly in carbonate petroleum systems. Consequently, knowledge of its thickness and petrophysical properties, viz. its pore size distribution and wettability characteristic, is critical to optimizing hydrocarbon production in this zone. Using classical formation evaluation techniques, the thickness of the transition zone has been estimated, using well logging methods including resistivity and Nuclear Magnetic Resonance, among others. While hydrocarbon fluids’ accumulation in petroleum reservoirs occurs due to the migration and displacement of originally water-filled potential structural and stratigraphic traps, the development of their TZ integrates petrophysical processes that combine spontaneous capillary imbibition and wettability phenomena. In the literature, wettability phenomena have been shown to also be governed by electrostatic phenomena. Therefore, given that reservoir rocks are aggregates of minerals with ionizable surface groups that facilitate the development of an electric double layer, a definite theoretical relationship between the TZ and electrostatic theory must be feasible. Accordingly, a theoretical approach to estimating the TZ thickness, using the electrostatic theory and based on the electric double layer theory, is attractive, but this is lacking in the literature. Herein, we fill the knowledge gap by using the interfacial electrostatic theory based on the fundamental tenets of the solution to the Poisson–Boltzmann mean field theory. Accordingly, we have used an existing model of capillary rise based on free energy concepts to derive a capillary rise equation that can be used to theoretically predict observations based on the TZ thickness of different reservoir rocks, using well-established formation evaluation methods. The novelty of our work stems from the ability of the model to theoretically and accurately predict the TZ thickness of the different lithostratigraphic units of hydrocarbon reservoirs, because of the experimental accessibility of its model parameters. Full article

Hydrogen embrittlement (HE) is a broadly recognized phenomenon in metallic materials. If not well understood and managed, HE may lead to catastrophic environmental failures in vessels containing hydrogen, such as pipelines and storage tanks. HE can affect the mechanical properties of materials such as ductility, toughness, and strength, mainly through the interaction between metal defects and hydrogen. Various phenomena such as hydrogen adsorption, hydrogen diffusion, and hydrogen interactions with intrinsic trapping sites like dislocations, voids, grain boundaries, and oxide/matrix interfaces are involved in this process. It is important to understand HE mechanisms to develop effective hydrogen resistant strategies. Tensile, double cantilever beam, bent beam, and fatigue tests are among the most common techniques employed to study HE. This article reviews hydrogen diffusion behavior, mechanisms, and characterization techniques. Full article

The ability of particles to “tunnel” through potential energy barriers is a purely quantum phenomenon. A classical particle in a symmetric double-well potential, with energy below the potential barrier, will be trapped on one side of the potential well. A quantum particle, however, can sit on both sides, in either a symmetric state or an antisymmetric state. An analogous phenomenon occurs in conservative classical systems with two degrees of freedom and no potential barriers. If only the energy is conserved, the phase space will be a mixture of regular “islands” embedded in a sea of chaos. Classically, a particle sitting in one regular island cannot reach another symmetrically located regular island when the islands are separated by chaos. However, a quantum particle can sit on both regular islands, in symmetric and antisymmetric states, due to chaos-assisted tunneling. Here, we give an overview of the theory and recent experimental observations of this phenomenon. Full article

In the present study, we propose a new transparent thin-film ITO surface radio-frequency (RF) trap. Charged hybrid microstructures were localized in the developed ITO trap. We show, analytically and experimentally, that the position of the localization zones in the trapped hybrid structure are stable. The transfer of charged particles between localization zones was studied under the action of gravity-compensating laser radiation. We highlight the advantages of transparent thin-film ITO traps to investigate and manipulate charged particles. Full article

Deep laser cooling of atoms, ions, and molecules facilitates the study of fundamental physics as well as applied research. In this work, we report on the narrow-line laser cooling of thulium atoms at the wavelength of $506.2\mathrm{nm}$ with the natural linewidth of $7.8\mathrm{kHz}$, which widens the limits of atomic cloud parameters control. Temperatures of about $400\mathrm{nK}$, phase-space density of up to $3.5\times {10}^{-4}$ and $2\times {10}^6$ number of trapped atoms were achieved. We have also demonstrated formation of double cloud structure in an optical lattice by adjusting parameters of the $506.2\mathrm{nm}$ magneto-optical trap. These results can be used to improve experiments with BEC, atomic interferometers, and optical clocks. Full article

The addition of synthetic eugenol and benzyl acetate to the known floral chemical and moth attractant phenylacetaldehyde synergized the attraction of Amata phegea (Lepidoptera: Amatidae). Traps baited with the ternary blend caught ca. four times more A. phegea moths than traps baited with phenylacetaldehyde alone. Both female and male moths were attracted; in a preliminary test, the female numbers caught were almost double compared to the males. Most A. phegea were caught when the blend was formulated in a dispenser with medium release rates. Traps baited with the ternary lure in polyethylene bag dispensers detected a single well-pronounced peak in seasonal trapping, suggesting that this multicomponent bisexual lure could be efficient enough to be applied to the detection and monitoring of female and male A. phegea. Full article

Various solitary wave excitations are found for a Bose-Einstein condensate in presence of two hybrid potentials in the form of triple mixtures of optical lattices. One of these potentials comprises of a combination of two important lattice profiles, such as frustrated optical lattice and double-well super-lattice, within one. Another represents a composite lattice combination, resulting in a wider and deeper frustrated optical lattice. The dynamical equation for such a system is solved by the exact analytical method to obtain a bright solitary wave, periodic wave and cnoidal wave excitations. We also report Anderson localization, bifurcation of condensate at the center and a competition between two different types of localizations upon trap engineering. Dynamical and structural stability analyses are also carried out, which reveal the obtained solutions as extremely stable for structural noise incorporation and sufficiently stable for dynamical stability. These triple mixtures of optical lattices impart better tunability on the condensate profile, which has made this system a true quantum simulator. Full article