Liquid Layer Research Articles

Marangoni-driven spreading of a droplet on a miscible thin liquid layer

HypothesisThe coalescence of droplets with liquid–gas interfaces of different surface tensions is common in nature and industrial applications, where the Marangoni-driven film spreading is an essential process. Unlike immiscible fluids governed by triple contact line dynamics, the mixing between two miscible fluids strongly couples with the film spreading process, which are expected to manifest distinct power-law relations for the temporal increase in the film radius. ExperimentsWe experimentally investigate the Marangoni-driven film spreading phenomenon for a droplet with lower surface tension dropping onto a miscible, thin liquid layer. The temporal growth of the film radius was detected by using a novel deep convolutional neural network, the U2-net method. Scaling analysis was performed to interpret the spreading dynamics of the film. FindingsWe find that the film radius exhibits a three-stage power-law relation over time, with the exponent varying from 1/2 to 1/8, and back to 1/2. The diffusion-affected Marangoni stresses in these three stages were derived, and two estimations of viscous stress were considered. Through estimating and balancing the viscous stress with the Marangoni stress, the three-stage power-law relation was derived and validated.

Inducing low-temperature melting of TiNiCuNb eutectic alloy for manufacturing strong C/C-SiC composite joints

This work designed a novel TiNiCuNb eutectic alloy for manufacturing C/C-SiC composite joints. By introducing Ti into the semi-solid TiNiCuNb alloy, low-temperature melting of this eutectic alloy was induced. Ti/TiNiCuNb/Ti composite interlayers were utilized to join C/C-SiC composite lower than the melting temperature of TiNiCuNb alloy. Effects of joining temperature on the microstructure evolution and mechanical property of joints were investigated. The melting range of this TiNiCuNb alloy was 944 °C to 1064 °C. During the initial melting of the TiNiCuNb alloy, a thin liquid layer formed on the alloy's surface, which provided a path for the rapid diffusion of elements. Without pressure, Ti could be easily introduced into the TiNiCuNb alloy, which induced the complete melting of this alloy at 950 °C. Based on this, we successfully brazed C/C-SiC composite using Ti/TiNiCuNb/Ti interlayers. It not only hindered the formation of brittle compounds in the joints, but also weakened the overreaction between filler and C/C-SiC composite. Due to the high solubility of Si in liquid filler, the joint microstructure was controlled by the interaction between filler and SiC at different temperatures. At 1010 °C for 10 min, the maximum shear strength of 28.5 MPa was obtained. This work contributed to preparing and repairing the C/C-SiC composite.

Investigating Mass Transfer and Reaction Engineering Characteristics in a Membrane Biofilm Using Cupriavidus necator H16.

Membrane biofilm reactors are a growing trend in wastewater treatment whereby gas-transfer membranes provide efficient bubbleless aeration. Recently, there has been a growing interest in using these bioreactors for industrial biotechnology using microorganisms that can metabolise gaseous substrates. Since gas fermentation is limited by the low solubilities of gaseous substrates in liquid media, it is critical to characterise mass transfer rates of gaseous substrates to enable the design of membrane biofilm reactors. The objective of this study is to measure and analyse mass transfer rates and reaction engineering characteristics for a single tube membrane biofilm reactor using Cupriavidus necator H16. At elevated Reynolds numbers, the dominant resistance for gas diffusion shifts from the liquid boundary layer to the membrane. The biofilm growth rate was observed to decrease after 260 μm at 96 h. After 144 h, some sloughing of the biofilm occurred. Oxygen uptake rate and substrate utilisation rate for the biofilm developed showed that the biofilm changes from a single-substrate limited regime to a dual-substrate-limited regime after 72 h which alters the localisation of the microbial activity within the biofilm. This study shows that this platform technology has potential applications for industrial biotechnology.

Impact of solid–liquid interfacial layer in the nanofluid flow between stretching stationary disk and a rotating cone

The present study explores the flow of nanofluid between a cone and a disk with the thermophoresis and Brownian motion impact. The flow is due to an expanding disk and a rotating cone. In the current study, radiative heat flux is considered. Using proper similarity transformations, the governing differential equations of momentum, temperature and concentration are transformed into a set of nonlinear ordinary differential equations (ODEs). The Runge-Kutta Fehlberg fourth fifth-order (RKF-45) technique and the shooting strategy are employed to solve the reduced ODEs. The impact of various parameters is illustrated through graphs and used to comprehend flow profile behaviour easily. The obtained results demonstrate that the velocity profiles enhance as improve in values of the Reynolds number. The rise in radiation, thermophoresis and Brownian motion parameters increases the thermal profile due to the potency of Brownian movement which results in a compelling nanoparticle interaction and boosts the fluid's thermal efficiency. Increasing values of the thermophoresis parameter reduces the heat transmission rate at the disk. As the Brownian motion parameter elevates, the concentration profile reduces, but the concentration profile increases as the thermophoresis parameter is raised.

Metallurgical interactions in solid/liquid diffusion couples of AA4343/AA3xxx/AA4343 layered aluminum sheet

The effect of pre-stretching on solid-liquid interaction, microstructure and brazing performance of AA4343/AA3xxx/AA4343 layered aluminum sheet during brazing at the atomic level (solid solution), nanoscale (dislocation) and micron level (grain boundary) are studied by glow discharge optical emission spectrometry (GDOES), scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The microstructure after brazing largely depends on the forming condition. The driving force of liquid film migration (LFM) is the reduction of stored deformation energy. The interaction between the liquid clad and solid core layers changes the elemental distribution and microstructure, which in turn affects the brazing performance of the sheet. The results reveal the mechanism of solid-liquid interaction of layered aluminum sheet during brazing and clarify the driving force of LFM of layered aluminum sheet during brazing. Consequently, these results provide important insights for the design and theoretical research of functional layered aluminum sheet.

Isolation, Characterisation and Corrosion Inhibition Evaluation of 1, 3, 5-Trimethoxymethylbenzenefrom Seeds Extract of Cola nitida on Mild Steel Surface in Hyhrochloric Acid Solution

Corrosion inhibition of Mild steel in 1 M hydrochloric acid solution by 1, 3, 5-trimethoxymethylbenzene (TMMB) isolated from seeds extract of Cola nitida was studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopic methods. TMMB was isolated from seeds of C. nitida by 72 hours maceration of the chopped seeds with dichloromethane. Filtered and concentrated extract was subjected to a combination of vacuum liquid, column and thin layer chromatographic techniques. The isolated compound was characterized using Fourier Transform Infra-Red (FT-IR) spectrophotometer, proton nuclear magnetic resonance (+H-NMR), C13 – NMR and DEPT-135 NMR spectrophotmeters. The results showed that the inhibition efficiency recorded by the weight loss method increased with the increase in TMMB concentration, but decreased with increasing temperature. The inhibition efficiencies recorded by the potentiodynamic polarization and electrochemical impedance spectroscopic methods also increased with increase in the concentration of TMMB. The calculated thermodynamic parameters showed that the corrosion inhibition process was endothermic and spontaneous in nature. Potentiodynamic polarization measurements confirmed that TMMB worked as a mixed – type inhibitor considering the value of Ecorrbeing less than 85 mV. Impedance measurement revealed that the charge transfer resistance offered by TMMB to the migration of aggressive ions on the surface of mild steel in acidic solution was enough to impede corrosion. The best line of fit to the adsorption of TMMB onto mild steel surface was found in Temkin isotherm. Formation of protective dense film on the steel surface in the presence of TMMB compared to the blank was revealed by scanning electron microscopy. The molecular structure of TMMB was optimized using Gausian 09 with density functional theory [DFT/B3LYP/6-31G (d,p)]. Physical adsorption has been proposed for the adsorption of TMMB onto mild steel surface.

High flow rate electrospray cooling performance of water–ethanol mixtures

Electrospray (ES) is an effective approach for cooling high-power density devices, owing to its desirable features such as uniform droplet diameter, suppression of droplet rebound, and low power consumption. Despite its excellent thermal properties, water has not been extensively employed as a working fluid in ES setups due to difficulties in establishing a stable ES mode. In this study, ES cooling performance of high flow rate water–ethanol mixtures is investigated. The stable region of the cone-jet mode is identified by capturing the meniscus profile and detecting the corona discharge. The study investigates the effect of ES variables, including flow rate (20 mlhr −100 mlhr), applied voltage (5.30 KV − 12.15 KV), and working fluid including pure ethanol (xH2O= 0 %), mixture I (xH2O= 35 %), and mixture II (xH2O= 70 %), on the cooling performance within the stability region. The results show that raising the flow rate from 20 mlhr to 100 mlhr augments the onset voltage of the cone-jet mode in each fluid. In the case of pure ethanol and mixture I, the end voltage corresponding to the multi-jet mode increases with the rise in flow rate. However, As a result of the heightened surface tension, no multi-jet mode is observed for mixture II, and only the occurrence of corona discharge defines the end voltage. In the single-phase regime, the cooling behavior only depends on the flow rate, owing to the thick liquid layer formed on the heated surface. However, it has been revealed that when the mixture water volume fraction increases up to 70 %, the critical heat flux rise is approximately82 % (Q = 20 mlhr), 148 % (Q = 60 mlhr), and 167 % (Q = 100 mlhr), at the onset voltage and 98 % (Q = 20 mlhr), 131 % (Q = 60 mlhr), and 147 % (Q = 100 mlhr), at the end voltage due to the improved thermal properties of the fluid. Next, the effect of each ES variable on cooling performance is investigated separately. Based on the results, an increase in the flow rate from 40 mlhr to 80 mlhr leads to an approximately 70 % rise in the critical heat flux for both mixture I and mixture II. Additionally, increasing the mixture water volume fraction from 35 % to 70 % results in an approximately 29 % rise in the critical heat flux, attributed to the larger latent heat of mixture II. In the transition regime, mixture II demonstrates superior performance compared to mixture I by suppressing the rebounding effect and enhancing the cooling performance. This improvement is due to the rise in the image force caused by the increase in water volume fraction. However, this enhancement is more significant at the lower flow rate due to the shorter impact time.

Serpentine liquid electrode based Dual-mode skin Sensors: Monitoring biomechanical movements by resistive or triboelectric mode

Flexible and stretchable electrodes are crucial components for wearable electronic devices. Herein, a serpentine liquid electrode based dual-mode skin sensors (SLEDSS) that leverages a highly deformable and serpentine liquid electrode is developed. The functional carboxylated multi-walled carbon nanotubes / Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (MWCNT-COOH / PEDOT: PSS) network structure endows the SLEDSS with a stable linear change in resistance. Additionally, a solid–liquid double electric layer generated between the solid surface and liquid electrode facilitates a higher triboelectric output performance. As a result, the SLEDSS features dual-modal sensing capabilities, including both resistive and triboelectric modes. The flowability of the liquid electrode enables it to fully adapt to different types of deformation, thereby allowing SLEDSS to effectively collect energy in different forms of movement, such as tapping, stretching, bending, twisting, and unpredictable transformations based on practical applications. SLEDSS can maintain its performance even at up to 550.32% strain, displaying a monotonically increasing relationship between the stretchable length and open-circuit voltage. Finally, the SLEDSS is applied as a wearable power source and self-powered sensor for monitoring biomechanical movements, the excellent stretchable performance and ultra-high sensitivity to mechanical stimulation provided by the SLEDSS offer new prospects for self-powered sensors.

Thermocapillary convection in shallow liquid layers for moderate Prandtl number liquids using different cylinder configurations

In this paper, the influence of thermocapillary convection in a shallow annular pool using different cylinder configurations is numerically investigated. An axisymmetric, two-dimensional, cylindrical geometry with two concentric cylinders kept at two different temperatures constitutes the model. The main cylinder has a radius of 40 mm and the secondary cylinder has a radius of 20 mm. The effects of Prandtl numbers (Pr = 6.7, 16.1, and 25.2) and layer depths (d = 3.0 mm and 11.0 mm) on the streamlines, isotherms, velocity, and temperature profiles at various locations of the flow are investigated. Depending on the position of the secondary cylinder, three different configurations: 1) an internal cylinder 2) an external cylinder, and a 3) central cylinder is analysed. The flow is characterized by a rapid inward flow along the hot outer wall towards the colder inner wall. In deeper pool at lower Prandtl numbers, flow patterns are characterized by a single rolling cell structure. Conversely, secondary cell formations appear in shallow pool regardless of the Prandtl number. Based on the comparative analysis of various cylinder configurations, it is clear that the external cylinder generates greater velocities and temperatures along its surface. The maximum disparity in surface velocity between an external cylinder and other configurations is 7%, 12%, and 13% for Prandtl numbers of 6.7, 16.1, and 25.2 respectively. Therefore, positioning the cylinder externally promotes swifter convection and more effective mixing of the fluid.

Curvature-enhanced membrane asymmetry slows down protein diffusion

Diffusion of transmembrane proteins plays a vital role in various cellular processes, such as endocytosis, raft formation and signal transduction. Current understanding of protein diffusion dynamics in lipid membranes is mostly based on hydrodynamic analyses, in which lipid membrane is simply treated as a thin layer of viscous liquid, same for highly curved ones. Therefore, how the mechanical state of highly curved membranes may affect the transmembrane protein diffusion remains unclear. In this study, we employed molecular dynamics (MD) simulations to analyse membrane curvature effect on the diffusion of cylindrically shaped Aquaporin-0 (AQP0) protein. Slowing down of protein diffusion with the increase in membrane curvature was observed. The possible contributions from membrane tension and asymmetric pressure profile were systematically investigated by simulating the protein diffusion dynamics in planar membranes with various tension levels or with various lipid number ratios between the two leaflets, respectively. We found no significant effect of membrane tension on AQP0 diffusion. Instead, the asymmetric pressure profile present in highly curved bilayer membranes was identified as a key factor that contributes to the slowing down of transmembrane protein diffusion. Our work thus contributes to a more complete picture of transmembrane protein diffusion on highly curved biological membranes.

Cross-linking gradient model in disperse systems

The article presents the research results of the disperse systems cross-linking process containing solid and liquid phase bases on the continuum mechanics apparatus use within the incompressible fluid model framework. The system formation schemes of interfacial layers in fine clearances between solid particles with wall-adjacent zones formation, in which conditions of liquid and solid phase interphase contact are provided, and the cores with constant interphase pressure are considered. The authors have obtained expressions for the values of wedging pressure depending on the thickness of the interfacial layers overlapping area, which determine the interfacial contacts strengthening degree. The dependences given in the paper are a theoretical basis for a new approach to modelling surface phenomena from the position of continuum mechanics equilibrium. The facilitating mechanism of the wedging pressure long-range action outside the interfacial layers system area is given. The authors present the modelling results of a single liquid-solid interphase layer bounded, on the one side, by a solid surface and, on the other side, by a volume liquid phase and the results of modelling the effects of structuring disperse systems based on the liquid interphase layer study formed in the clearance between solid surfaces. Under certain conditions in such systems the effect of structuring, leading to a sharp increase in the strength properties of disperse-filled composite materials, which is the basis of modern nanotechnology concepts, is manifested. The dualism of the liquid phase, consisting in the ability to exhibit the properties of both liquid and solid body, is shown. It is proved that the main disperse systems structure formation factor is the formation of interphase stresses powerful gradients at the thickness of interphase layers.

The Effect of the Turbulence Coefficient on the Formation of a Turbulent Process: 2. Existing Scenarios for the Occurrence and Development of Turbulence

Some characteristic features of three scenarios for the occurrence and development of turbulenceare presented: the Landau-Hopf scenario, the scenario of transition to turbulence on a strange attractor, andthe scenario followed by the solutions of the multimoment hydrodynamics equations. The analysis of the presentedcharacteristic features allows us to conclude that these scenarios can be used to interpret turbulence.It is shown that only one of the scenarios satisfactorily interprets the experimental data: the scenario followedby the solutions of the multimoment hydrodynamics equations supplemented with stochastic components.The Landau-Hopf scenario leads to a system that has lost stability in the wrong direction. The scenario of thetransition to turbulence on a strange attractor correctly reproduces only the initial stage of the evolution ofthe liquid layer in the Bénard experiment, namely, heat transfer in the resting layer and convective shafts.Analysis of the behavior of solutions of the Lorentz model leaves no hope for the ability of this scenario tointerpret turbulence

Surface and internal gravity waves on a viscous liquid layer: Initial-value problems

Surface and internal gravity waves on a viscous liquid layer: Initial-value problems

A novel and intelligent chemometric-electrochemical-enzymatic biosensing procedure and mimicking a clinical condition environment to trick the red blood cells for counting them under physiological conditions: A new connection among chemometry, electrochemistry and hematology

Here, a novel electrochemical biosensing procedure has been developed for determination of the number of red blood cells (RBCs) under physiochemical conditions based on chemometric modeling of hydrodynamic differential pulse voltammetric (HDPV), and amperometric data as responses of a modified edge plane pyrolytic graphite electrode (EPPGE). In order to obtain a good sensitivity from the EPPGE, its surface was modified with a thin layer of multiwalled carbon nanotubes-ionic liquid (MWCNTs-IL). Catalase (CAT) was immobilized onto the surface of MWCNTs-IL/EPPGE with help of nafion. The response of the biosensor was based on electrochemical reduction of oxygen of the blood samples which was enhanced by a trick based on addition of hydrogen peroxide (H2O2) to blood samples which can be reduced by the CAT to produce extra oxygen. Prior to experiments, the solution in electrochemical cell was bubbled with pure N2 to purge the oxygen in the solution, but in order to increase the selectivity of the biosensor towards detection of the oxygen obtained from the red blood cells, voltammetric responses of the biosensor were modeled by multivariate chemometric calibration methods with the help of radial basis function-partial least squares (RBF-PLS), least squares-support vector machines (LS-SVM), recursive weighted partial least squares (rPLS), ant colony optimization-mathematical pre-processing selection by genetic algorithm-sample selection through a distance-based procedure-partial least squares-1 (ACO-GA-SS-PLS1), and radial basis function-artificial neural networks (RBF-ANN) to select the best method for determination of the number of the RBCs. The results confirmed the amperometric methods modeled by RBF-ANN showed the best performance for supporting the biosensor in determination of the number of the RBCs with a performance which had an excellent compatibility with the results of a hemocytometer. The results of this study as the newest application of chemometric-electrochemical methods can make a strong connection among electrochemists, chemometricians and hematologists to expand their collaborations on determination of blood factors.

Distinct Temperature Trends in the Uptake of Gaseous n-Butylamine on Two Solid Diacids.

Uptake coefficients of n-butylamine (BA) on solid succinic (SA) and glutaric acids (GA) from 298 to 177 K were measured using a newly combined Knudsen cell temperature-programmed desorption apparatus. The uptake coefficients on SA increase monotonically from (1.9 ± 0.5) × 10-4 at 298 K to 0.14 ± 0.05 at 177 K (errors represent 2σ statistical errors, overall errors are estimated to be ±60%). This is consistent with a surface reaction mechanism to form solid aminium carboxylate. In contrast, the uptake coefficients on GA increase from 0.11 ± 0.04 at 298 K to 0.25 ± 0.04 at 248 K but then decrease to 0.030 ± 0.010 at 177 K. This unusual trend in temperature dependence of the uptake coefficient is due to formation of an ionic liquid (IL) layer upon the surface reaction of BA with GA, leading to a competition between the rate of desorption of BA and the rates of diffusion and reaction within the IL. Overall, the kinetic multi-layer model of aerosol surface and bulk chemistry (KM-SUB) satisfactorily reproduces these unique trends. This work provides mechanistic insight and predictive capability for the temperature-dependence of reactive uptake processes involving multiple phase changes upon surface reaction.

THE STRUCTURE OF THE ANTERIOR CORNEA EPITHELIUM OF THE SUS SCROFA DOMESTICUS AT THE CRYOPHIXATION

The classic histological picture of the anterior corneal epithelium, known from the results of standard histological techniques and light microscopy of preparations of chemically fixed material, describes the presence of three cell layers: basal - germinative, middle and superficial. On preparations of cryofixed material, another homogeneous layer is identified above the cells of the third layer, which is usually identified as the precorneal tear film, that is, a layer of liquid. Analysis and comparison of known data allows us to identify a scientific problem, which is as follows. The structure of the homogeneous layer has not been previously studied, its structure is unknown, therefore, the identification of the homogeneous layer with the precorneal tear film is not justified. We assume that the histological picture of the anterior epithelium on preparations of chemically fixed material is incomplete, and the homogeneous layer is a structural component of the anterior epithelium. Purpose of the study: the structure of the anterior epithelium and homogeneous layer on preparations of cryofixed material. The material for the study was preparations of the eyes of the domestic pig Sus scrofa domesticus, the research method was light microscopy. As a result of the study, it was established for the first time that the homogeneous layer is a structural component of the anterior corneal epithelium. Between the homogeneous layer and the layer of flat cells of the anterior epithelium, another layer is determined in the form of a microscopically detectable thin strip. Taking into account the established fact, it should be concluded that the anterior epithelium of the cornea consists of five layers. The cells in the layers are in a compacted state, the degree of which increases from the basement membrane to the frontal surface of the epithelium, reaching a maximum at the level of the homogeneous layer. The cells of the surface layer are anucleate, filled with an oxyphilic mass, presumably keratin, which indicates the process of keratinization of epithelial cells. The results of the study confirmed the assumption that the histological picture on preparations of chemically fixed material is incomplete. The identification of a homogeneous layer with the precorneal tear film is unfounded.

Breakup of planar liquid sheets injected at high speed in a quiescent gas environment

Using a combination of mean flow spatial linear stability and two-dimensional volume-of-fluid (VoF) simulations, the physics governing the instability of high-speed liquid sheets being injected into a quiescent gas environment is studied. It is found that the gas shear layer thickness $\delta _G$ plays an influential role, where for values $\delta _G/H\lesssim 1/8$ , the growth of sinuous and varicose modes is nearly indistinguishable. Here, $H$ is the liquid sheet thickness. With larger values of $\delta _G/H$ , a second peak develops in the lower wavenumber region of the dispersion relation, and becomes increasingly dominant. This second peak corresponds to a large-scale sinuous mode, and its critical wavelength $\lambda _{crit,sinuous}$ is found to scale as $\lambda _{crit,sinuous}/H = 14.26 (\delta _G/H)^{0.766}$ . This scaling behaviour collapses onto a single curve for various combinations of the liquid-based Reynolds ( $Re_L$ ) and Weber ( $We_L$ ) numbers, provided that $\delta _G/H > O({10^{-1}})$ . For the varicose modes, the shape of the dispersion relation does not change with variations in $\delta _G/H$ , and the liquid shear layer thickness has an almost negligible influence on the growth of instabilities. Two-dimensional VoF simulations are employed to examine the validity of the linear stability assumptions. These simulations also show that the dominant sinuous mode remains active as the process transitions into the nonlinear regime, and that this mode is ultimately responsible for fragmenting the sheet. Based on an energy budget analysis, the most influential contributors to the growth of the sinuous mode are the gas Reynolds shear stress and the lateral working of pressure on the gas side.

Dynamical Sensitivity of Three-Layer Micro Electromechanical Systems to the Optical Properties of the Intervening Liquid Layer

Here, we investigate the actuation dynamics of a micro device with different intervening liquids between the actuating components under the influence of Casimir and dissipative hydrodynamic forces. This is enabled via phase space portraits, which demonstrate that by increasing the dielectric response of the intervening layer the autonomous device may not come into stiction due to the decreasing in magnitude Casmir force. Unlike the micro devices that are placed in vacuum with an intervening liquid, the phase portraits show only a spiral trajectory which eventually stops at a rest position due to the strong energy dissipation by the position dependent hydrodynamic drag forces, even when considering sufficiently strong restoring forces. Moreover, it is feasible to expand the area of motion using intervening liquids with lower dynamic viscosity or increasing the slip length of the intervening fluid. Finally, under the influence of an external driven force, which is the realistic case for possible applications, the system can reach stable oscillation at larger separations with an amplitude higher for the liquid that led to lower Casimir and hydrodynamic forces. Hence, the results presented in this study are essential for studying the dynamical behavior of MEMS and their design in liquid environments.

Extended platelet-rich fibrin.

Platelet-rich fibrin (PRF) has been characterized as a regenerative biomaterial that is fully resorbed within a typical 2-3 week period. Very recently, however, a novel heating process was shown to extend the working properties of PRP/PRF from a standard 2-3 week period toward a duration of 4-6 months. Numerous clinicians have now utilized this extended-PRF (e-PRF) membrane as a substitute for collagen barrier membranes in various clinical applications, such as guided tissue/bone regeneration. This review article summarizes the scientific work to date on this novel technology, including its current and future applications in periodontology, implant dentistry, orthopedics and facial aesthetics. A systematic review was conducted investigating key terms including "Bio-Heat," "albumin gel," "albumin-PRF," "Alb-PRF," "extended-PRF," "e-PRF," "activated plasma albumin gel," and "APAG" by searching databases such as MEDLINE, EMBASE and PubMed. Findings from preclinical studies demonstrate that following a simple 10-min heating process, the transformation of the liquid plasma albumin layer into a gel-like injectable albumin gel extends the resorption properties to at least 4 months according to ISO standard 10 993 (subcutaneous animal model). Several clinical studies have now demonstrated the use of e-PRF membranes as a replacement for collagen membranes in GTR/GBR procedures, closing lateral windows in sinus grafting procedures, for extraction site management, and as a stable biological membrane during recession coverage procedures. Furthermore, Alb-PRF may also be injected as a regenerative biological filler that lasts extended periods with advantages in joint injections, osteoarthritis and in the field of facial aesthetics. This article highlights the marked improvement in the stability and degradation properties of the novel Alb-PRF/e-PRF technology with its widespread future potential use as a potential replacement for collagen membranes with indications including extraction site management, GBR procedures, lateral sinus window closure, recession coverage among others, and further highlights its use as a biological regenerative filler for joint injections and facial aesthetics. It is hoped that this review will pioneer future opportunities and research development in the field, leading to further progression toward more natural and less costly biomaterials for use in medicine and dentistry.

Probing the instability of surface structure on solid Hydrates: A microscopic perspective through experiment and simulation

The surface structural characteristics of clathrate hydrates play a significant role in mass transfer, interfacial properties, and mechanical stability during the hydrate growth process. However, the microstructure of hydrate surfaces remains unclear and controversial. In this study, a modified Atomic Force Microscopy (AFM) system was employed to confirm the presence of a quasi–liquid layer (QLL) on the solid tetrahydrofuran (THF) hydrate surface. Subsequently, sensitivity analyses were conducted on factors affecting the instability (fluidity) of QLL, including relative position, inclination angle, environmental temperature, and surface morphology. The results indicate that higher temperatures enhance the instability of the QLL surface, and altering the slope of the hydrate surface leads to an increase in the average thickness of the QLL due to the driving forces of gravity and surface tension, resulting in increased fluidity. Additionally, the surface morphological structure formed by Oswald ripening in polycrystalline THF hydrates affects the thickness of QLL. Furthermore, molecular dynamics simulations reveal that water molecules on the hydrate surface exhibit a multilayered structure, with the QLL region near the gas phase showing greater instability, while the region closer to the hydrate exhibits solid–phase characteristics, consistent with experimental findings.