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Recently, we demonstrated that the local heating of degassed water can generate water vapor microbubbles and induce a rapid flow around the bubble. Although flow generation involves the self-excited oscillation of bubbles at a local heating point, the conditions under which the bubbles oscillate are not fully understood. In this study, the dependence of microbubble size and oscillation frequency on the concentration of non-condensable gases in water was investigated. A continuous-wave laser beam was focused on a β -FeSi 2 thin film, and water was locally heated using the photothermal conversion properties of the film. The results showed that the lower the concentration of non-condensable gases dissolved in water, the smaller the bubble size and the higher the oscillation frequency. Furthermore, it was found that the bubbles oscillate when the amount of non-condensable gas absorbed by the bubbles, i.e., the bubble size, falls below a specific level. This study can provide a new understanding of the bubble oscillation mechanism and lead to the development of fluid control technology using bubbles. [ABSTRACT FROM AUTHOR]

An experimental validation of a steady-state model for water-to-water heat pumps is conducted on a 10 kW test bench. The objective of the model is to predict the capacity and the required compressor power, based on the inlet conditions of the secondary fluids in the evaporator and condenser. Detailed manufacturer performance maps based on the AHRI 540-2020 standard are utilized to model the fixed-speed scroll compressor. A new semi-empirical model for the thermostatic expansion valve incorporates condensing temperature effects on superheating prediction. Sub-models for individual components, including detailed representations of the evaporator and condenser, are integrated into a global model, resulting in a set nonlinear equation solved using an equation solver with appropriate guess values. The validation of the model is conducted in an experimental test facility equipped with two precisely controlled secondary fluid loops. The heat pump is instrumented to measure condensation and evaporation pressures, the compressor discharge temperature, compressor power, superheating, and sub-cooling. The results are divided into three sub-sections: the first validates the complete heat pump model by comparing its power consumption and COPs in heating and cooling; the second compares the predicted and measured operational conditions; finally, it is shown how the model can be used to predict the non-operational conditions of the heat pump for specific scenarios. [ABSTRACT FROM AUTHOR]

The ever‐increasing consumption of fossil energy highlights the urgent need to develop technologies to ensure the efficient drilling and exploration of oil and gas resources mainly distributed in deep layers. The complex geological conditions in deep formations with the feature of high temperature, high pressure, and high salinity result in high requirements for the performance of drilling fluids. Various additives are demonstrated to decide the physicochemical properties and functional characteristics of water‐based drilling fluids. As one of the most widely used additives in water‐based drilling fluids, various polymeric filtrate reducers play an important role in minimizing fluid loss, maintaining wellbore stability, ensuring drilling safety and efficiency as well as avoiding formation damage. Herein the design, preparation, and applications of polymer‐based filtrate reducers for fluid loss control in drilling operation are comprehensively summarized. The spotlight is centered on the design strategies and structure–property–performance relationships of polymeric filtrate reducers to minimize fluid loss under high temperature, high pressure, and high salinity conditions. Future perspectives for achieving excellent comprehensive performance are also discussed to motivate new strategies and technologies to design and develop high‐performance drilling fluids with optimal rheological and filtration properties. [ABSTRACT FROM AUTHOR]

Cellular processes are subject to inherent variability, but the extent to which cells can regulate this variability has received little investigation. Here, we explore the characteristics of the rate of cellular protein synthesis in single cells of the eukaryote fission yeast. Strikingly, this rate is highly variable despite protein synthesis being dependent on hundreds of reactions which might be expected to average out at the overall cellular level. The rate is variable over short time scales, and exhibits homoeostatic behaviour at the population level. Cells can regulate the level of variability through processes involving the TOR pathway, suggesting there is an optimal level of variability conferring a selective advantage. While this could be an example of bet-hedging, but we propose an alternative explanation: regulated 'loose' control of complex processes of overall cellular metabolism such as protein synthesis, may lead to this variability. This could ensure cells are fluid in control and agile in response to changing conditions, and may constitute a novel organisational principle of complex metabolic cellular systems. Synopsis: How tightly global cellular metabolic processes are regulated remains unclear. Here, single-cell measurements of amino acid acid flux into nascent proteins reveal high variability of cellular protein synthesis in growing eukaryotic fission yeast, suggesting that a genetically-regulated 'loose' control ensures optimal manoeuvrability. Global protein synthesis rates in exponentially-growing unperturbed fission yeast populations exhibit high cell-to-cell variability. Global protein synthesis is dynamic over short time scales, and exhibits homeostatic behaviour at the population level. Genetic modulation of the TOR pathway and cell-cycle controllers modulates protein translation variability. Amino-acid acid flux into nascent proteins is highly variable and TOR-dependent in growing eukaryotic fission yeast. [ABSTRACT FROM AUTHOR]

The aqueous fluid (water) is accumulated near the interfaces between fractures (hydraulic and natural) and the matrix during hydraulic fracturing. The accumulated water can be partially removed either through the immediate well flow back or through shutting in well before the flow back. Which method is more effective for oil recovery? The answers are mixed in the literature from field reports and experimental or simulation studies. This article proposes a hypothesis that the flow back of fracturing fluid is controlled mainly by two mechanisms: viscous displacement and capillary imbibition. The shut-in can outperform the immediate flow, or vice versa, depending on reservoir and operation conditions. When the viscous displacement dominates, the immediate flow back is more effective. When the capillary imbibition dominates, the shut-in is more effective. The hypothesis is verified by the results of many simulation models which are built by modifying some parameters of the same base model. Those parameters include pressure drawdown, capillary pressure, matrix permeability, wettability, initial water saturation, and formation compressibility. It is implied from this study that the immediate flow back is preferred to the shut-in method if the capillary pressure is small; otherwise, the shut-in is preferred. [ABSTRACT FROM AUTHOR]

Microfluidic lab-on-a-chip technologies enable the analysis and manipulation of small fluid volumes and particles at small scales and the control of fluid flow and transport processes at the microscale, leading to the development of new methods to address a broad range of scientific and medical challenges. Microfluidic and lab-on-a-chip technologies have made a noteworthy impact in basic, preclinical, and clinical research, especially in hematology and vascular biology due to the inherent ability of microfluidics to mimic physiologic flow conditions in blood vessels and capillaries. With the potential to significantly impact translational research and clinical diagnostics, technical issues and incentive mismatches have stymied microfluidics from fulfilling this promise. We describe how accessibility, usability, and manufacturability of microfluidic technologies should be improved and how a shift in mindset and incentives within the field is also needed to address these issues. In this report, we discuss the state of the microfluidic field regarding current limitations and propose future directions and new approaches for the field to advance microfluidic technologies closer to translation and clinical use. While our report focuses on using blood as the prototypical biofluid sample, the proposed ideas and research directions can be extrapolated to other areas of hematology, oncology, biology, and medicine. [ABSTRACT FROM AUTHOR]

The current problem is significant because it concerns the modeling of electroosmosis regulated peristaltic flow of hybrid Newtonian liquid as seen within a symmetric tube. This model provides an exciting mathematical formulation with unexpected features, especially when impacted by electroosmotic forces, which aids in understanding how these complex fluids behave under different conditions. It is essential for maintaining product integrity, which can help us avoid problems in the future. The manuscript focuses on the perception of copper and SIO2 hybrid nanoparticles using blood as a means of transport fluid. The theoretical formulation is based on nanoparticles having blades, platelets, and cylindrical forms. At the microscale, physiological transport phenomena generated by pressure to form a pressure gradient, velocity, and thermal slip may be used to articulately construct a theoretical treatment for rheumatoid arthritis and biomimetic thermal pumping systems. The boundary conditions for computation are generated using the proper transformations, and Euler's technique is used to produce an accurate solution of the resulting system of nonlinear ODEs raised by governing PDEs. "Mathematica" computer software applications are associated to the various physical aspects that impact flow and pumping. A comprehensive parametric study found that employing blood-infused nanoparticle blades to treat autoimmune disorders produced positive results. Trapping, a basic peristaltic pumping phenomenon, is also depicted and quickly discussed. This research could have uses in microfluidic devices, medication delivery systems, and other industries where precise fluid flow control is required. Researchers may be able to improve the efficiency and accuracy of such systems by regulating fluid flow using an electric field. [ABSTRACT FROM AUTHOR]

Phase envelopes are routinely employed by reservoir engineers for fluid characterisation. These envelopes are controlled by reservoir fluid composition, pressure and temperature. As a result of increasing source-rock maturation, fluids with decreasing molecular weights and densities and increasing gas-to-oil ratios (and hence different phase envelopes) are generated, which are thus linked to fluid history. In addition to their importance for exploration, charge models can play a key role in constraining reservoir models and optimising field development, particularly when pressure–volume-temperature (PVT) data are properly integrated with fluid geochemistry. Two contrasting scenarios of fluid phase evolution from two different fields are presented, and their relations to charge analysis and reservoir models are discussed. The first example discusses the identification, based on hydrocarbon geochemistry complemented by overlapping modeled phase envelopes, of compartmentalised filling cycles in what was initially considered a single oil-rimmed gas accumulation. The second example presents an opposite scenario where two wet gas accumulations 20-km apart laterally and 400-feet average depth difference appear to represent a single more-expansive accumulation spread over areas of variable PVT conditions and reservoir qualities. The wet gas across both accumulations is characterised by a continuous phase evolution pattern that shrinks systematically (cricondentherm shifts to lower temperature and cricondenbar to lower pressure), suggestive of phase fractionation of a charge of single maturity. The proposed gas distribution model represents a discovery of a hybrid conventional and unconventional (tight sand) system, with potential for basin-centered gas. These findings provided better understanding of observed and projected fluids, impacting the development and completion plans by locating new gas producers. A recent well drilled midway between the two accumulations indeed tested wet gas, confirming fluid connectivity. Future work will attempt to link the gas distribution model with seismic attributes. [ABSTRACT FROM AUTHOR]

The current revolution in the field of machine learning is leading to many interesting developments in a wide range of areas, including fluid mechanics. Fluid mechanics, and more concretely turbulence, is an ubiquitous problem in science and engineering. Being able to understand and predict the evolution of turbulent flows can have a critical impact on our possibilities to tackle a wide range of sustainability problems (including the current climate emergency) and industrial applications. Here, we review recent and emerging possibilities in the context of predictions, simulations, and control of fluid flows, focusing on wall-bounded turbulence. When it comes to flow control, we refer to the active manipulation of the fluid flow to improve the efficiency of processes such as reduced drag in vehicles, increased mixing in industrial processes, enhanced heat transfer in heat exchangers, and pollution reduction in urban environments. A number of important areas are benefiting from ML, and it is important to identify the synergies with the existing pillars of scientific discovery, i.e., theory, experiments, and simulations. Finally, I would like to encourage a balanced approach as a community in order to harness all the positive potential of these novel methods. [ABSTRACT FROM AUTHOR]

The gasoline fractionation scheme used in catalytic cracking has a significant impact on the blended gasoline's octane number. This study proposes an improved three-cut fractionation scheme for the fluid catalytic cracking gasoline fractionator and optimizes the process with respect to evaluation metrics such as total annual cost (TAC), light gasoline recovery, and CO 2 emissions (E CO2). To achieve energy efficiency and reduce emissions in the process, the dividing wall column is employed for process intensification. In comparison to the cascaded binary columns process, the middle cracked naphtha recovery of the FCC-DWC-M has increased by 1.96%, the TAC has decreased by 22.15%, and the E CO2 has decreased by 26.18%. Finally, the study investigates the dynamic characteristics of the FCC-DWC-M process, establishes a control scheme, and examines its performance while experiencing disturbances in feed flow rates of ±10% and ±20%. The findings indicate exceptional control performance of the FCC-DWC-M process. [Display omitted] • Propose two methods for fluid catalytic cracking gasoline fractionation. • The dividing wall column process is both cost-effective and eco-friendly. • The enhanced configuration's control scheme demonstrates strong robustness. [ABSTRACT FROM AUTHOR]

Oil and gas extraction is difficult without understanding the subsurface formation up to the desired depth. Wellbore instability, such as lost circulation and pipe sticking, is an issue when drilling a well for a high-temperature, high-pressure reservoir. To maintain the stability of the borehole, optimum drilling mud should be simulated by preventing formation fracture or formation break-out. The main goal of this work is to propose a model with a 3D extended Mohr–Coulomb criterion that helps to achieve maximum wellbore stability using drilling fluid weight as a controlling parameter. This criterion includes the effect of the intermediate principal stress as a linear relation of principal stresses. this study also validated the extended Mohr–Coulomb criterion for in situ failure. To implement a new criterion on the wellbore for stability, a numerical mechanical earth model (NMEM) is developed as an empirical correlation of the wire-line well-log data. The mud weight is calculated using mechanical parameters derived from NMEM and lithology. The pore pressure, fracture pressure, and stress profile were also predicted by this NMEM, which gives insights into the subsurface formation's faulting regime. To achieve maximum wellbore stability, optimum mud weight is recommended based on the stress profile and faulting regime. One onshore and one offshore well is taken as a case study from the online dataset via the Dutch Oil and Gas Portal (NLOG) to simulate the NMEM. Mud weight using Mohr–Coulomb and Mogi–Coulomb criteria was also used to compare mud weight predicted by the proposed new 3D linear failure criterion. The treading line for the mud weight by the new 3D linear criterion is more accurate as a new criterion considering the effect of σ 2 . The new criterion has been proved to be more specific, easy to compute, and a unique solution for estimating parameters using NMEM. This NMEM, which includes a new linear 3D criterion, can also solve sand production issues, hydrofracturing, and CO2 sequestration. Highlights: A study about safe mud weight prediction using the new Extended Mohr–Coulomb criterion to prevent break-out and drilling-induced fracture with all six combinations of stress regimes. A numerical mechanical earth model is developed to stimulate appropriated reservoir conditions from actual well-log data. The prediction of mud weight to maintain wellbore stability is further compared with the Mohr–Coulomb and Mogi–Coulomb criteria results. A new 3D criterion with a numerical earth model has the potential to solve sand production issues and is also helpful for modeling hydrofracturing and CO2 sequestration. [ABSTRACT FROM AUTHOR]

High-temperature heat pumps are a key technology for enabling the complete integration of renewables into the power grid. Although these systems may come with several variants, Brayton heat pumps are gaining more and more interest because of the higher heat sink temperatures and the potential to leverage already existing components in the industry. Because these systems utilize renewable electricity to supply high-temperature heat, they are particularly suited for industry or energy storage applications, thus prompting the development of various demonstration plants to evaluate their performance and flexibility. Adapting to varying load conditions and swiftly responding to load adjustments represent crucial aspects for advancing such systems. In this context, this study delves into assessing the transient capabilities of Brayton heat pumps during thermal load management. A transient model of an emerging prototype is presented, comprising thermal and volume dynamics of the components. Furthermore, two reference scenarios are examined to assess the transient performance of the system, namely a thermal load alteration due to an abrupt change in the desired heat sink temperature and, secondly, to a sudden variation in the sink mass flow rate. Finally, two control methodologies—motor/compressor speed variation and fluid inventory control—are analyzed in the latter scenario, and a comparative analysis of their effectiveness is discussed. Results indicate that varying the compressor speed allows for a response time in the 8–20 min range for heat sink temperature regulation (first scenario). However, the regulation time is conditioned by the maximum thermal stress sustained by the heat exchangers. In the latter scenario, regulating the compressor speed shows a faster response time than the inventory control (2–5 min vs. 15 min). However, the inventory approach provides higher COPs in part-load conditions and better stability during the transient phase. [ABSTRACT FROM AUTHOR]

Controlling surface wettability and directing the flow of working fluids have crucial implications in various natural and engineering contexts. Understanding the fundamental principles of wettability and directional wetting is essential for effectively leveraging these phenomena to enhance the performance of engineering systems, such as microfluidics or heat exchangers. This comprehensive review summarizes of previous research, emphasizing recent advances by categorizing the structures and working principles associated with directional wetting surfaces. The efforts of researchers who have employed diverse strategies to manipulate the wetting behavior of liquids through both passive and active control mechanisms are highlighted. Passive directional transport surfaces require no additional energy while enabling large‐scale and continuous fluid control. Conversely, active directional wetting surfaces offer enhanced flexibility and precise control of liquid movement. Furthermore, insights into recent studies that focused on practical applications are provided and the current challenges that need to be addressed are discussed. This study serves as a guide for future research directions on the development of directional wetting surfaces and offers valuable recommendations for practical implementation. [ABSTRACT FROM AUTHOR]

Understanding how immune cells such as monocytes or macrophages within our blood and tissue engulf and destroy foreign organisms is important for developing new therapies. The process undertaken by these cells, called phagocytosis, has yet to be observed in real-time at the single cell level. Microfluidic-based imaging platforms offer a wide range of tools for precise fluid control and biomolecule manipulation that makes regulating long term experiments and data collection possible. With the compatibility between acoustofluidics and light-sheet fluorescent microscopy (LSFM) previously demonstrated, here an acousto-optfluidic device with on-chip fluid flow direction control was developed. The standing surface acoustic waves (SSAWs) were used to trap, load and safeguard individual cells within a highly controllable fluid loop, created via the triggering of on-chip PDMS valves, to demonstrate multiple rounds of live single cell imaging. The valves allowed for the direction of the fluid flow to be changed (between forward and reverse operation) without altering the inlet flow rate, an important factor for performing reproducible and comparable imaging of samples over time. With this high-resolution imaging system, volumetric reconstructions of phagocytosed bacteria within macrophages could be resolved over a total of 9 rounds of imaging: totalling 19 reconstructed images of the cell membrane with visible intracellular bacteria. [ABSTRACT FROM AUTHOR]

A valve is a kind of mechanical device used to control the flow of fluid in pipelines or systems, which has a wide range of uses in various industrial, commercial, and household applications. When the fluid passes through the valve, cavitation often occurs in the valve, resulting in the valve not working properly and even damaging the valve and related systems. In this paper, experimental visualization was used to investigate cavitation evolution through a butterfly valve with different plate shapes under different pressure conditions. The results show that with the increase in the curvature of both sides of the butterfly plate and the increase in the total pressure condition, the cavitation type inside the butterfly valve will change from non-attached cavitation to attached cavitation. In addition, the maximum length and thickness of the attached cavitation bubbles gradually increase as well. However, when the shape of both ends of the butterfly plate is triangular, the adhesion ability to cavitation bubbles is greatly reduced. As the curvature increases, the frequency of the shedding of cavitation bubble gradually decreases, the volume of cavitation bubble increases, and the shedding of the cavitation bubble caused by the shock wave is more obvious. When the shape of both sides of the butterfly plate is triangular, the position where the bubble collapses is closer to the front end of the butterfly plate, and the shock wave generated by the bubble collapse will lead to the collapse of the attached cavitation bubble. [ABSTRACT FROM AUTHOR]

In fluid mechanics, modal decomposition, deeply intertwined with the concept of symmetry, is an essential data analysis method. It facilitates the segmentation of parameters such as flow, velocity, and pressure fields into distinct modes, each exhibiting symmetrical or asymmetrical characteristics in terms of amplitudes, frequencies, and phases. This technique, emphasizing the role of symmetry, is pivotal in both theoretical research and practical engineering applications. This paper delves into two dominant modal decomposition methods, infused with symmetry considerations: Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD). POD excels in dissecting flow fields with clear periodic structures, often showcasing symmetrical patterns. It utilizes basis functions and time coefficients to delineate spatial modes and their evolution, highlighting symmetrical or asymmetrical transitions. In contrast, DMD effectively analyzes more complex, often asymmetrical structures like turbulent flows. By performing iterative analyses on the flow field, DMD discerns symmetrical or asymmetrical statistical structures, assembling modal functions and coefficients for decomposition. This method is adapted to extracting symmetrical patterns in vibration frequencies, growth rates, and intermodal coupling. The integration of modal decomposition with symmetry concepts in fluid mechanics enables the effective extraction of fluid flow features, such as symmetrically or asymmetrically arranged vortex configurations and trace evolutions. It enhances the post-processing analysis of numerical simulations and machine learning approaches in flow field simulations. In engineering, understanding the symmetrical aspects of complex flow dynamics is crucial. The dynamics assist in flow control, noise suppression, and optimization measures, thus improving the symmetry in system efficiency and energy consumption. Overall, modal decomposition methods, especially POD and DMD, provide significant insights into the symmetrical and asymmetrical analysis of fluid flow. These techniques underpin the study of fluid mechanics, offering crucial tools for fluid flow control, optimization, and the investigation of nonlinear phenomena and propagation modes in fluid dynamics, all through the lens of symmetry. [ABSTRACT FROM AUTHOR]

Carlin-type gold deposits are among the most important gold-bearing hydrothermal ore systems and are mainly located in Nevada, USA, and southwestern China. However, the source and evolution of the ore-forming fluids for these deposits remain controversial, especially those found within China. In this study, lithium and oxygen isotopic analyses of quartz-hosted fluid inclusions are used to elucidate the source and evolution of the giant Shuiyindong Carlin-type gold deposit. Fluid inclusions trapped in quartz of three distinct genetic stages have low salinity (0.8–6.3wt% NaCl equiv.) and moderate temperature (154–343 °C), but display variable Li and O isotope signatures. The Li and O isotopes of stage I fluids (δ7Li values from + 5.1 to + 9.1‰; δ18O values from + 6.3 to + 10.0‰) indicate predominantly a magmatic source for the initial ore-forming fluids. The large variations of Li and O isotopes of stage II fluids (δ7Li values from + 9.3 to + 16.0‰; δ18O values from + 0.1 to + 7.7‰) suggest that the fluids are controlled by mixing of magmatic fluids and meteoric water, which in turn triggered the precipitation of gold-bearing sulfides. The isotopic compositions of stage III fluids (δ7Li values from + 15.5 to + 22.8‰; δ18O values from − 5.4 to − 2.8‰) confirm that the final fluids are dominated by meteoric water. Furthermore, this work demonstrates that the combined Li–O isotopic analysis of fluid inclusions is a powerful tracer to decode the source and evolution of ore-forming fluids in hydrothermal mineralizing systems. [ABSTRACT FROM AUTHOR]

Fluid flow control problems play a crucial role in various industrial applications. The optimal control of the Navier-Stokes equations poses a significant challenge. By employing Oseen's approximation to linearize the problem, we encounter a series of large sparse structured linear systems. These coefficient matrices exhibit a two-by-two block structure with square blocks. Leveraging this block structure, we exploit matrix splitting preconditioners. Theoretical analysis indicates that the real parts of all eigenvalues of preconditioned matrix are equal to 1/2. A large number of eigenvalues are clustered in (1 ± i) / 2. The imaginary part of the eigenvalues is bounded explicitly. The eigenvalue distribution predicts the fast convergence of Krylov subspace methods. To avoid solving the saddle point subsystems in the preconditioning procedure, we propose a practical variant of the preconditioner. The theoretical analysis demonstrates that if the approximation is sufficiently close to Schur complement, the eigenvalues of the modified preconditioned matrix will lie within a circle centered at the original eigenvalues with a radius less than 1. This implies that the modified preconditioner exhibits excellent performance in terms of preconditioning. The numerical experiments demonstrate that the generalized minimal residual method, when combined with the proposed preconditioners, proves to be an efficient and effective solution for Oseen's control optimization with a variable viscosity coefficient. The number of iterations required by the preconditioned methods remains unaffected by the mesh size used in finite element discretization and only marginally depends on the regularization parameter. • Computing time is linear dependent of the degrees of freedom. • The convergence rate is independent of the discretization mesh size, regularization parameter, and Reynolds number. • Eigenvalues of the preconditioned matrix are clustered on a line segment. • The preconditioning improves the condition number of the original linear system. [ABSTRACT FROM AUTHOR]

The tight shale matrix has the structural characteristics of low porosity and low permeability. It is easy to cause water sensitivity damage, water lock damage and solid phase damage during fracturing, which greatly affects the gas reservoir transportation process of core. At the same time, fracturing fluid will invade the reservoir matrix, causing permeability damage and reducing gas production efficiency. This study analyzes the process and mechanism of fracturing fluid damage to shale matrix in the process of fracturing fluid retention, and proposes fracturing fluid damage control methods. Taking a tight sandstone reservoir in the ZJ block in South Sichuan as the research object, the mineral type, viscosity content and various physical parameters of shale gas reservoir are analyzed, and the quantitative index of fracturing fluid damage index is calculated. Using HPG as the precursor fluid, KW-1 and KDF as the drainage aids to prepare the fracturing fluid for experiment, the viscosity of the gel breaker reached 1.3 mPa·s, the interfacial tension between the gel breaker and kerosene reached 1.05 mN/m, and the surface tension was 22.8 mN/m. The fracturing fluid has good flowback performance. By collecting 4 core samples from ZJ block, the gas permeability of core samples is selected as three permeability sections 0.05·10–3 μm2, 0.15·10–3 μm2 and 0.25·10–3 μm2. And the correlation experiments of water sensitive damage, water lock damage and solid damage are carried out. The results show that when the permeability of the fracturing fluid decreases from 0.25·10–3 μm2 to 0.05·10–3 μm2, the damage value of the permeability section of the JS experimental group also increases from 8.25% to 18.35%, the movable water retention also increases from 0.032 PV to 0.046 PV, and the bound water increase increases from 0.032 PV to 0.086 PV. Therefore, the smaller the osmotic pressure is, the greater the retained amount of movable water and the increased amount of bound water are, and the greater the damage value of fracturing fluid is. In addition, when the mass fraction of XJHX in this experiment reaches 0.8%, its anti-swelling rate can reach 85%, which has excellent anti-swelling performance and can effectively reduce the permeability damage caused by fracturing fluid to shale formation. [ABSTRACT FROM AUTHOR]

Flow and spontaneous imbibition phenomena in porous media are important for various industrial applications, including printing and medical lateral flow assays. Their quantitative characterization is important to better understand and select the appropriate raw materials. However, standard methods often require time-consuming tests, and/or expensive equipment. Different time scales must be considered, limiting the range of possible characterization tools. A novel experimental approach based on image analysis for characterizing spontaneous imbibition processes is presented. Hence, ultra-fast diffusion may be quantitatively characterized. Models are issued from the literature to consider physical phenomena at small (milliseconds) and medium range (seconds) of time scales. The obtained experimental data fit with theoretical results, providing valuable insights into the understanding of fluid flow behavior at different time scales. Furthermore, the identification of some physical properties for either the fluid, or the substrate, based on the theoretical models are possible, as the contact angle, which remains to be otherwise challenging. This study contributes to bridging the gap between spontaneous imbibition and capillary phenomena at different time scales, their modeling, and a characterization of material and/or fluid properties paving the way for enhanced understanding and control of fluid behavior in porous media. Different papers are considered to illustrate the method. [ABSTRACT FROM AUTHOR]

Pyrite, the most common sulfide mineral, is a ubiquitous component of many hydrothermal gold deposits. Geochemical patterns within the refractory pyrite structure represent a valuable repository of information that can help constrain the sources of ore-forming materials, and the evolution of ore-forming processes over time. However, there are still a lot of debates on the mechanisms of physico-chemical processes in ore-forming fluid controlling trace element and sulfur isotope distributions in pyrite during growth. In our manuscript, we use cutting-edge complementary microanalytical methods to understand the origin and evolution of zoned gold-bearing pyrite in samples from the largest gold deposit in the Ailaoshan gold belt, SW China, Zhenyuan (exceeding 100t Au, average grade: 5.3 g/t). Pyrite, arsenopyrite, chalcopyrite, and stibnite are the most abundant sulfide minerals in most orebodies. Of these, pyrite is dominant and is also the most important host for gold. Two types of pyrite can be clearly distinguished: framboidal pyrite and hydrothermal pyrite. Gold is most commonly hosted by hydrothermal pyrite. Framboidal pyrite, mainly hosted by carbonaceous slate, hosts negligible Au, and features low δ34S values ranging from − 35.0 (± 0.9) to − 25.6 (± 1.0)‰. Hydrothermal pyrite is characterized by complex intra-grain zoned textures with alternating As-rich and As-poor bands readily recognizable on backscattered electron images. Scanning electron microscopy and trace-element analyses show that both visible and invisible gold occur only in the As-rich bands. Compared to the As-poor bands (72.1% of Au concentration data < 1.96 ppm, n = 43), the As-rich bands are characterized by far higher concentrations of Au (up to 1420 ppm), Cu, Ag, Sb, and Tl, but lower concentrations of Co and Ni. In-situ sulfur isotope analysis indicates that the δ34S values of As-rich zones range from − 7.3 (± 0.6) to 2.9 (± 0.6)‰ and are similar to those of As-poor zones (from − 6.9 (± 0.7) to 2.8 (± 0.6)‰), but distinct from the framboidal pyrite. Combined with published fluid inclusion data and a probable age for the magmatic event associated with mineralization, these data suggest that magmatic–hydrothermal fluids contributed most ore-forming materials and that periodic boiling led to formation of the rhythmic As-rich and As-poor bands in pyrite. Our data for pyrite constrain the evolution of ore-forming processes and provide new insights into the formation of zoned pyrite, with the conclusions having broad implications for analogous hydrothermal gold deposits worldwide. [ABSTRACT FROM AUTHOR]

[Display omitted] Microfluidics has recently been proposed as a viable method for producing bulk nanobubbles for use in various applications. The portability, compact size, and capacity to precisely control fluids on a small scale are a few of the benefits of microfluidics that may be exploited to create customized bulk nanobubbles. However, despite the potential of microfluidic nanobubble generation, low throughput and limited nanobubble concentration remain challenging for microfluidics. Here, we integrate a microporous silicon membrane into a polydimethylsiloxane microfluidic chip to generate bulk nanobubbles in the 100–140 nm diameter range with a concentration of up to 108 mL−1. We investigate the nanobubble size and morphology using several characterisation techniques, including transmission electron microscopy, resonance mass measurement, dynamic light scattering, and the Tyndall effect. This new nanobubble generation technique can increase nanobubble concentration by ∼ 23 times compared to earlier microfluidic nanobubble generation platforms, which should increase the feasibility of translation to medical applications. [ABSTRACT FROM AUTHOR]

The communication between different cell populations is an important aspect of many natural phenomena that can be studied with microfluidics. Using microfluidic valves, these complex interactions can be studied with a higher level of control by placing a valve between physically separated populations. However, most current valve designs do not display the properties necessary for this type of system, such as providing variable flow rate when embedded inside a microfluidic device. While some valves have been shown to have such tunable behavior, they have not been used for dynamic, real-time outputs. We present an electric solenoid valve that can be fabricated completely outside of a cleanroom and placed into any microfluidic device to offer control of dynamic fluid flow rates and profiles. After characterizing the behavior of this valve under controlled test conditions, we developed a regression model to determine the required input electrical signal to provide the solenoid the ability to create a desired flow profile. With this model, we demonstrated that the valve could be controlled to replicate a desired, time-varying pattern for the interface position of a co-laminar fluid stream. Our approach can be performed by other investigators with their microfluidic devices to produce predictable, dynamic fluidic behavior. In addition to modulating fluid flows, this work will be impactful for controlling cellular communication between distinct populations or even chemical reactions occurring in microfluidic channels. [ABSTRACT FROM AUTHOR]

Pneumatic drive bellows pumps (PDBPs) are a crucial fluid control component in the semiconductor industry. However, when dealing with specific chemical mechanical polishing (CMP) slurries, agglomeration of particles can occur, leading to scratches, particle residues, pits, and other defects on the wafer surface. The leading cause of agglomeration has been proposed to be cavitation and excessive shear in PDBPs. A high-fidelity multiphase computational fluid dynamics (CFD) model, which fully resolves the response of check valves under hydrodynamic and other external loads, was established to evaluate cavitation behaviour and shear distribution in PDBPs. Moreover, a test rig was built to visualize cavitating flow patterns in PDBPs and verify the accuracy of the CFD model. Among different cavitation regions captured by high-speed visualization, the region near the inner leading edge of the end-ring of the inlet valve is dominant, with high intensity, long duration, and complex morphology evolution. Detailed initiation and development process of cavities in the dominant region are analysed numerically. The shear rate in different domains of PDBPs is estimated, and the inlet valve domain stands out from the other. The strongest shear rate is observed near the leading edge of the end-ring. Furthermore, an analysis of the relationship between cavitation and shear indicates that the high-intensity vortices generated owing to strong shear account for the inception of cavitation. This study contributes to understanding inner flow details in PDBPs and provides a guideline for further optimization of similar pumps. [ABSTRACT FROM AUTHOR]

Controls on fluid transfer into massive hydraulic fractures are investigated due to reactivation of, and proppant penetration into, oblique fractures transecting the main fracture face during long-term reservoir depletion through tightly constrained laboratory experiments. Permeability evolution of fracture-contained proppant permeability/conductivity is highly sensitive to both normal stress and proppant loading concentration and less sensitive to shear displacement rate. By experimentally examining the shale and steel fractures—as an analog to end-member manifestations of weak/deformable and strong/rigid fracture surfaces—and calibrating using granular mechanics models (DEM), we conclude that the evolution of friction–permeability relationship of a propped shale fracture is largely controlled by the rock friction/rigidity. To be specific, propped strong/rigid fractures show a continuous permeability decay at near-constant rate throughout a shear deformation. Conversely, permeability of weak/deformable fractures declines rapidly during pre-steady-state friction and then declines more slowly after transitioning to steady-state friction. It is posited that weak fracture walls accommodate shear deformation via the combined effects of distributed deformation across the interior of the proppant pack and from sliding at the fracture–proppant interface. However, strong rocks accommodate shear deformation primarily through distributed deformation within the proppant pack. Highlights: The permeability of shear-reactivated and propped fractures evolves synchronously with the evolution of friction. Both factors depend on normal stress and proppant loading concentration but are less sensitive to shear displacement rate. The degree of permeability reduction decreases with increasing effective normal stress and for samples with thicker proppant packs. Coefficients of friction during steady-sliding decrease as normal stress increases. Rock friction/rigidity controls the degree of fracture surfaces damage (as striations or indentations) in shale and consequently impacts the evolution of permeability. Specifically, Strong and rigid fractures show a steady permeability decline during shear deformation, while weak and deformable fractures exhibit a rapid reduction in unsteady-state friction, followed by a slower decline in steady-state friction. Weak and deformable fractures accommodate shear deformation via the combined effects of distributed proppant pack deformation and interface sliding, while strong and rigid rocks primarily reply on distributed proppant pack deformation. [ABSTRACT FROM AUTHOR]

Grain-scale pore geometry primarily controls the fluid distribution in rocks, affecting material transport and geophysical response. The dihedral angle (θ) in the olivine-fluid system is a key parameter determining pore fluid geometry in mantle wedges. In the system, curved and faceted olivine-fluid interfaces define θ, resulting in faceted-faceted (FF), faceted-curved (FC), and curved-curved (CC) angles. The efect of faceting on θ under various pressure and temperature (P-T) conditions and fluid compositions, however, has not been constrained, and mineralogical understanding remains unresolved. This study evaluated facet-bearing θ and their proportions in olivine-multicomponent aqueous fluid systems. Our results show that 1/3 of olivine-fluid θ are facet-bearing angles, regardless of the P-T conditions and fluid composition. Faceting produces larger dihedral angles than CC angles. The grain boundary plane (GBP) distribution reveals that the GBPs of faceted interfaces at triple junctions have low Miller index faces ({100}, {010}, and {101}). The misorientation angle/axis distributions of adjacent grain pairs are in accord with a theoretical distribution of random olivine aggregate. Moreover, the calculation of the FF angles for adjacent grain pairs with low Miller index GBPs reproduces measured angle values based on the olivine crystal habit. Therefore, our study suggests that the FF angle is strongly afected by olivine crystallography. The presence of faceting increases θ and a critical fluid fraction (φc) for percolation, lowering permeability. In the mantle wedge, where olivine crystallographic preferred orientation (CPO) is expected owing to corner flow, increasing the FF angle proportion with associated changes in fluid pore morphology will lead to permeability anisotropy, and controlling the direction of the fluid flow, and it will result in geophysical anomalies such as seismic wave attenuation and high electrical conductivity. [ABSTRACT FROM AUTHOR]

Deposition of terrestrial carbonate (i.e. travertine) and silica sinter in geothermal areas is always closely linked to the presence of relevant crustal structures which enhance the permeability in the upper crust favouring the upflow of fluids to the surface. Most travertine deposits are originated by geothermal fluids stored within carbonate reservoirs in continental crust, and their morphology and areal distribution provide useful information on geometry, kinematics, and age of faults which control the fluid flow. In this paper, we focus on the tectonic control on a travertine depositional system, associated with silica sinter, developing in oceanic crust, in the Lýsuskarð volcano-geothermal area on the Snæfellsnes Peninsula, West Iceland. The presence of HCO3 and Ca in the geothermal fluids is related to chemical-physical processes linked to fluid–rock interaction that occurs in the geothermal reservoir made up of tholeiitic basalt, by fluids enriched in CO2 of deep origin (i.e. magmatic). Travertine deposits consist of mounds and slopes, which are still in formation and overlie the silica sinter deposits. Both sinter and travertine deposits derive from thermal springs aligned according to two trends: NNE-SSW and WNW-ESE. This evidence suggests the occurrence of buried, permeable, and thus active faults, which control the circulation of fluids containing HCO3 and Ca. Faults are near parallel to those which define the rift systems and transform zones in Iceland, and probably comprise the still active sector of the abandoned transform zone that, starting with the Snæfellsnes Peninsula, interrupts eastward the northern continuation of the western and eastern rift-zones in the south-central Iceland. In this setting, we refer, for the first time, travertine and silica sinter deposition to an oceanic active crustal structure. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD) is the most common type of dementia, affecting individuals over 65. AD is also a multifactorial disease, with disease mechanisms incompletely characterized, and disease-modifying therapies are marginally effective. Biomarker signatures may shed light on the diagnosis, disease mechanisms, and the development of therapeutic targets. tRNA-derived RNA fragments (tRFs), a family of recently discovered small non-coding RNAs, have been found to be significantly enhanced in human AD hippocampus tissues. However, whether tRFs change in body fluids is unknown. Objective: To investigate whether tRFs in body fluids are impacted by AD. Methods: We first used T4 polynucleotide kinase-RNA-seq, a modified next-generation sequencing technique, to identify detectable tRFs in human cerebrospinal fluid and serum samples. The detectable tRFs were then compared in these fluids from control, AD, and mild cognitive impairment patients using tRF qRT-PCR. The stability of tRFs in serum was also investigated by checking the change in tRFs in response to protein digestion or exosome lysis. Results: Among various tRFs, tRF5-ProAGG seemed to be impacted by AD in both cerebrospinal fluid and serum. AD-impacted serum tRF5-ProAGG showed a correlation with the AD stage. Putative targets of tRF5-ProAGG in the hippocampus were also predicted by a computational algorithm, with some targets being validated experimentally and one of them being in a negative correlation with tRF5-ProAGG even using a small size of samples. Conclusions: tRF5-ProAGG showed the potential as an AD biomarker and may play a role in disease progression. [ABSTRACT FROM AUTHOR]

The analysis of Boundary Layer Flows (BLFs) is of huge significance due to its large-scale applications most likely in aerodynamics, manufacturing of vehicles front faces and many other advanced research areas. Therefore, this study is organized by exercising significant important engineering parameters like surface convection, radiative flux, MHD and thermal and mass diffusion. The developed model embedded the concrete effects of velocity slip, diffusion convection, thermal radiations, magnetic field, chemical reaction and thermo-mass gradients. Later, the numerical treatment is made via RK scheme and the model efficaciously is tackled with desired accuracy. Then the results are decorated over the region (wedge and sheet) and deeply examined. It is observed that slippery surface of wedge and sheet (S 1 = 0. 1 , 0. 3 , 0. 5 , 0. 7 , 0. 9) enlarges the fluid movement rapidly. The directed magnetic field (M = 0. 0 , 0. 1 , 0. 2 , 0. 3 , 0. 4) controlled the fluid motion which can be beneficial from industrial view point. Further, temperature and concentration distributions upsurge by strengthening convective heat ( B i = 0. 1 , 0. 2 , 0. 3 , 0. 4 , 0. 5) and diffusion convection processes. Moreover, skin friction and Nusselt number improved against the parameters under consideration. [ABSTRACT FROM AUTHOR]

A lactic acid (LA) monitoring system aimed at sweat monitoring was fabricated and tested. The sweat LA monitoring system uses a continuous flow of phosphate buffer saline, instead of chambers or cells, for collecting and storing sweat fluid excreted at the skin surface. To facilitate the use of the sweat LA monitoring system by subjects when exercising, the fluid control system, including the sweat sampling device, was designed to be unaffected by body movements or muscle deformation. An advantage of our system is that the skin surface condition is constantly refreshed by continuous flow. A real sample test was carried out during stationary bike exercise, which showed that LA secretion increased by approximately 10 μg/cm2/min compared to the baseline levels before exercise. The LA levels recovered to baseline levels after exercise due to the effect of continuous flow. This indicates that the wristwatch sweat LA monitor has the potential to enable a detailed understanding of the LA distribution at the skin surface. [ABSTRACT FROM AUTHOR]

Turbulent fountains are widespread natural phenomena with numerous industrial applications. Extensive research has focused on the temporal evolution and maximum height of these fountains, as well as their dependence on Reynolds and Froude numbers. However, the lower boundary of the spreading flow attained by the mixture of the ejected fluid and the surrounding ambient fluid has received little attention. Here, we focus on the dependence of the lower boundary height on the characteristics of the fountain and demonstrate how to control it. Large Eddy simulations were carried out based on a Navier–Stokes solver which implements fully implicit 3D incompressible finite volume method with second-order accuracy in space and time using curvilinear coordinates, and validated with laboratory experiments. Our results present important implications for technological applications of turbulent fountains, particularly in protecting crops from frost. We discuss the potential of our results to improve the efficiency of such applications. [ABSTRACT FROM AUTHOR]

Fluid manipulation and control is crucial for space exploration. Motivated by the "Thermocapillary-based control of a free surface in microgravity" (ThermoSlosh) experiment (Salgado Sánchez et al. in Acta Astronautica 205:57–67, 2023), we conduct here a detailed numerical analysis of interfacial dynamics in a two-dimensional cylindrical cell, half-filled with different silicone oils or a fluorinert, and subjected to thermal forcing and vibrations. The effect on the free surface dynamics of the applied temperature difference, vibrational amplitude, fluid viscosity, and contact angle is analyzed; both static and dynamic contact angle models are considered. Results strongly suggest that thermocapillary flows can be used to control the interface orientation within the cell, while supplemental vibrations can be added to increase the system responsiveness. This control can be further improved by using classical proportional-integral-derivative feedback to adjust the cell boundary temperatures in real-time. The proportional and derivative gains of the controller can be selected to optimize the stabilization time and/or energy cost, while the integral contribution is effective in reducing the steady-state error. Overall, the present analysis highlights the potential of using the thermocapillary effect for fluid management in reduced gravity, and evaluates different types of experimental tests that can be executed in the frame of the ThermoSlosh microgravity project. [ABSTRACT FROM AUTHOR]

This article concerns the identification of a transfer function which contains principal design and dynamic parameters of a hydraulic viscous disc clutch operated and controlled by an electrorheological (ER) fluid as a working fluid. A mathematical model of clutch dynamics is created as part of the clutch identification. It is considered that the changes in torque over time are described by transfer function represented by the first-order system with time delay. A prototypic clutch and a test bench are constructed, and tests are performed. A high voltage step input is used to trigger the torque changes. Constant parameters of the first-order system with time delay are identified on the basis of bench tests. According to the values of these parameters, a proportional-integral (PI) controller is selected for the closed-loop control system. It is found that operation of such a control system utilizing the identified design parameters is acceptable with high accuracy under external disturbances. [ABSTRACT FROM AUTHOR]

Faults play a pivotal role in controlling fluid migration and retention within sedimentary basins, particularly in the context of fault-bound hydrocarbon reservoirs. Assessing the stability and sealing capabilities of faults enhances our comprehension of these systems and aids in the identification of pathways for fluid migration. In this study, we focus on a series of fault-bound hydrocarbon accumulations located in the southern Wenchang A subbasin within the Pearl River Mouth Basin. We emphasize the significant influence of faults in governing the processes of hydrocarbon migration and accumulation. By leveraging 3D seismic data and well information, we have assessed the sealing potential of ten faults that either currently retain hydrocarbon columns or have the potential to do so. Our analysis reveals that even faults with a relatively low Shale Gouge Ratio (as low as 15%) can effectively support substantial column heights. Taking into account factors, such as the source rock maturity, fault activity, geometry, sealing potential, and the distribution of hydrocarbon accumulations, we have formulated a conceptual model for hydrocarbon migration and accumulation within the study area. This model underscores potential fluid traps within the rift basin, shedding light on the complex dynamics of hydrocarbon movement in this region. [ABSTRACT FROM AUTHOR]

Pipe structures are commonly encountered in the geophysical context, and in particular in sedimentary basins, where they are associated with fluid migration structures. We investigate pipe formation through laboratory experiments by injecting water locally at a constant flow rate at the base of water-saturated sands in a Hele–Shaw cell (30 cm high, 35 cm wide, gap 2.3 mm). The originality of this work is to quantify the effect of a discontinuity. More precisely, bilayered structures are considered, where a layer of fine grains overlaps a layer of coarser grains. Different invasion structures are reported, with fluidization of the bilayered sediment over its whole height or over the finer grains only. The height and area of the region affected by the fluidization display a non-monotonous evolution, which can be interpreted in terms of fluid focusing vs. scattering. Theoretical considerations can predict the critical coarse grains height for the invasion pattern transition, as well as the maximum topography at the sediment free surface in the regime in which only the overlapping finer grains fluidize. These results have crucial geophysical implications, as they demonstrate that invasion patterns and pipe formation dynamics may control the fluid expulsion extent and localization at the seafloor. [ABSTRACT FROM AUTHOR]

Hydrogel microparticles, generally accepted as significant green materials, have been widely used in chemical, biological, and biomedical fields owing to their excellent biocompatibility, biodegradability, and noncytotoxicity. Among these, non-spherical hydrogel microparticles with diverse shape anisotropy have great potential in applications such as drug delivery, cellular interaction, micromotors, etc. Benefiting from their shapes, their functionalities in such fields cannot be satisfied by the typical spherical types. Recently, microfluidics with precise control and domination of fluids at microflow sizes has emerged as a powerful method for synthesizing shape-controllable hydrogel microparticles with good monodispersity and unique morphology. In this review, we tried to provide an overview of the production of non-spherical microparticles composed of green hydrogel materials, emphasizing the microfluidic approaches. Furthermore, a brief introduction to their current applications is also presented. [ABSTRACT FROM AUTHOR]

The fluidic pintle nozzle, a new method to control the thrust of a solid rocket motor, has been proposed in recent years by combining the pintle with the aerodynamic throat (fluidic throat). The study of static characteristics has proved that it has a remarkable effect on thrust control. To study the transient characteristics of the fluidic pintle nozzle, 2D transient simulations of a fluidic pintle nozzle propulsion system were conducted, employing dynamic meshing techniques. The Reynolds-averaged Navier–Stokes equations were meticulously solved, implementing a k–ω SST turbulence model. The thrust control principle of the fluid pintle nozzle was studied, and the wave structure was summarized. The transient characteristics of the secondary flow opening, secondary flow closing, pintle moving forward (pressure rise), and pintle moving backward (pressure drop) were obtained, and the effects of the injection angle and injection port position were studied. The response process after injection can be roughly divided into three stages: pressure propagation, pressure oscillation, and equilibrium stability, with time distributions of 0.4%, 5.39%, and 94.21%, respectively. In the process of the pintle moving forward, the rate of combustion chamber pressure increases and thrust decreases gradually because of the arc wall of the nozzle throat upstream, and the process of throats moving backward is just the opposite. Compared with the condition with a maximum throat opening and no secondary flow, the thrust of the condition with a minimum throat opening and a 0.3-flow-ratio secondary flow is increased by 80.95%. Under conditions of constrained flow ratio, the injection angle of the secondary flow ostensibly exerts negligible influence on the dynamic modulation of thrust. Nevertheless, it remains evident that a reduction in throat opening accentuates the impact of reverse injection. Furthermore, the proximity of the injection port to the head of the pintle is directly proportional to the efficacy of thrust control. [ABSTRACT FROM AUTHOR]

In many geological systems, the porosity of rock or soil may evolve during mineral precipitation, a process that controls fluid transport properties. Here, we investigate the use of 4D neutron imaging to image flow and transport in Bentheim sandstone core samples before and after in‐situ calcium carbonate precipitation. First, we demonstrate the applicability of neutron imaging to quantify the solute dispersion along the interface between heavy water and a cadmium aqueous solution. Then, we monitor the flow of heavy water within two Bentheim sandstone core samples before and after a step of in‐situ mineral precipitation. The precipitation of calcium carbonate is induced by reactive mixing of two solutions containing CaCl2 and Na2CO3, either by injecting these two fluids one after each other (sequential experiment) or by injecting them in parallel (co‐flow experiment). We use the contrast in neutron attenuation from time‐resolved tomograms to derive three‐dimensional fluid velocity field by using an inversion technique based on the advection‐dispersion equation. Results show mineral precipitation induces a wider distribution of local flow velocities and leads to alterations in the main flow pathways. The flow distribution appears to be independent of the initial distribution in the sequential experiment, while in the co‐flow experiment, we observed that higher initial local fluid velocities tended to increase slightly following precipitation. The outcome of this study contributes to progressing the knowledge in the domain of reactive solute and contaminant transport in the subsurface using the promising technique of neutron imaging. Plain Language Summary: Flow and mixing processes in porous media control many natural and industrial systems, such as microbial clogging, oil extraction, and effluent disposal. In many systems, the porosity may evolve during mineral precipitation, such as in rocks, and control fluid transport properties. Here, we use time‐lapsed three‐dimensional neutron imaging to explore fluid transport into Berea sandstone core samples during in‐situ carbonate precipitation. Neutron imaging can track fluid flow inside the rock, whereas X‐ray imaging illuminates the regions where mineral precipitation occurs. We control the precipitation of calcium carbonate in the rock through reactive mixing between solutions containing CaCl2 and Na2CO3. By solving the adverse advection‐diffusion equation using the contrast in neutron attenuation from time‐lapse images, we derive the 3D velocity field of the injected fluids. Results show that under the effect of mineral precipitation, a wide range of local flow velocities develop in the sample, and we quantify the distribution of flow velocities in the sample. The finding of this experimental study is useful in progressing the knowledge in the domain of reactive solute and contaminant transport in the subsurface. Key Points: 4D neutron imaging is used to image flow and transport in porous rock and investigate the effect of carbonate precipitationThe velocity field of injected fluid is estimated by solving the advection‐dispersion equation using the contrast in neutron attenuationCarbonate precipitation widens the distribution of fluid velocities due to local pore‐clogging [ABSTRACT FROM AUTHOR]

Dehydration reactions within subducted oceanic crust are important for fluid‐mediated element transfer within the subducting plate and potentially to the mantle wedge. The effects of metamorphic reactions and fluid flow on element recycling that occur during retrogression and exhumation of subducted continental crust from mantle depths are poorly understood. We study two metabasite pods with fresh eclogite cores and retrogressed amphibolite‐facies rims and surrounding host gneiss within the Western Gneiss Region (WGR), Norway, to better understand element mobility and mass transfer during exhumation of subducted continental crust. Bulk‐rock data were collected from samples taken across the pod and into the host gneiss. Phengite breakdown in eclogite and epidote recrystallization in veins and/or gneiss within pod cores contributed large ion lithophile elements and REE to retrogressed eclogite closest to the pod cores. In gneiss hosting the pods, phengite and epidote breakdown provided fluid that mediated elemental transfer and redistribution to the pod rim or tail. Compared to the studied pod in the southern WGR, the pod in the northern WGR underwent higher P‐T conditions, partial melting and higher strain rates. This resulted in the infiltration of external fluid farther into the pod interior from the rim and facilitated larger mass gain in trace elements in the amphibolite tail of the pod relative to fresh eclogite in the core. The results show clear evidence for retrogression dehydration reactions driving significant fluid‐mediated element redistribution as observed on the outcrop scale during exhumation following ultrahigh‐pressure metamorphism, which directly impacts element signatures within the exhuming crust. Plain Language Summary: A lot is not known about how fluids and metamorphic reactions recycle elements in continental crust as it is brought to the surface after being subducted to ∼100 km. We study two eclogite pods that are surrounded by gneiss in the Western Gneiss Region, Norway to study how different pressure‐temperatures (P‐T), deformation, and fluids control element movement in deep crust as it is exhumed. The pod cores have eclogite that record the rock conditions at ∼100 km, but the exteriors were altered during exhumation. We sampled transects from the pod cores to ∼20 m into the surrounding gneiss. Bulk‐rock and mineral trace‐element data show two situations of mineral breakdown that generated trace‐element‐rich fluid that reacted with and enriched metabasite in Rb, Sr, Ba, and light rare earth elements: (a) veins or gneiss in pod cores enriched adjacent eclogite, and (b) surrounding gneiss enriched the pod exteriors. As shown by the pod that experienced higher P‐T conditions and deformation than the second pod, larger amounts of elements were transferred into the pod rim, and fluid penetrated the pod, enriching eclogite near the pod rim. Clearly, exhumation conditions and mineral break‐down reactions are important for elemental recycling in crust during exhumation. Key Points: In the Western Gneiss Region, Norway, fluids redistribute elements during retrogression after ultrahigh‐pressure metamorphismRecrystallization of epidote‐group minerals and phengite in metabasite pod interiors facilitate elemental transfer within the podsHost gneiss‐derived fluids infiltrate amphibolite‐facies retrogressed pod rims, driving significant element redistribution and mass transfer [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "Morning sympathetic activity after evening binge alcohol consumption" published in the American Journal of Physiology: Heart & Circulatory Physiology. The corrigendum acknowledges an error in the calculations assessing hemodynamic reactivity to Valsalva's maneuver (VM) in the original article. The authors state that this error did not impact their primary outcome variable of MSNA (muscle sympathetic nerve activity) and did not affect the conclusions of the study. The corrigendum provides the corrected texts for the abstract, methods, results, discussion, and figure legends sections of the original article. [Extracted from the article]

This paper presents a mechanical analysis of the foundation of a temporary offshore platform using a temporary embedded eight-leg support structure. The model is simulated using the finite element simulation software MIDAS-3D, with the modified RANS equation and Forchheimer saturated resistance model used to control the fluid. The stress analysis principle of the structure is simplified by the pile group theory. The stability of the eight-legged supporting structure is investigated under different embedding depths, pile diameters, wave periods, and amplitudes of the main piles. The results show that the eight-legged supporting structure can intercept and divert water flow, eliminating the impact of the water flow on the main piles during large waves. Additionally, as the diameter of the structure increases under the same wave conditions, the influence of the base volume and surface curvature gradually increases, deteriorating the stress environment of the main pile and decreasing the supporting effect of the eight-legged support structure. Numerical calculations of the seabed rock foundation of the eight-leg supporting structure show that the shallow pile foundation undergoes significant deformation, while the eight-leg supporting structure is still supported by the dead weight of the main pile. [ABSTRACT FROM AUTHOR]

This work is concerned with nonlinear feedback control design for the problem of fluid mixing via advection. The overall dynamics is governed by the transport and Stokes equations in an open bounded and connected domain Ω ⊂ R d , with d = 2 or d = 3. The feedback laws are constructed based on the ideas of instantaneous control as well as a direct approximation of the optimality system derived from an optimal open-loop control problem. It can be shown that under appropriate numerical discretization schemes, two approaches generate the same sub-optimal feedback law. On the other hand, different discretization schemes may result in feedback laws of different regularity, which determine different mixing results. The Sobolev norm of the dual space (H 1 (Ω)) ′ of H 1 (Ω) is used as the mix-norm to quantify mixing based on the known property of weak convergence. The major challenge is encountered in the analysis of the asymptotic behavior of the closed-loop systems due to the absence of diffusion in the transport equation together with its nonlinear coupling with the flow equations. To address these issues, we first establish the decay properties of the velocity, which in turn help obtain the estimates on scalar mixing and its long-time behavior. Finally, mixed continuous Galerkin (CG) and discontinuous Galerkin (DG) methods are employed to discretize the closed-loop system. Numerical experiments are conducted to demonstrate our ideas and compare the effectiveness of different feedback laws. [ABSTRACT FROM AUTHOR]

The experiment was conducted to investigate the effect of fermented wheat bran polysaccharides (FWBPs) on rumen fermentation parameters of lamb in vitro. The experiments utilized an in vitro batch culture method. The rumen fluid was collected from four lambs (Dorper x Small-tailed Han Sheep) with the same body condition were selected as rumen fluid donors. A single-factor experimental design was employed, and the study was divided into one control group and four test groups, each group with three replicates. The fermentation substrate of the control group was basal diet, and group I, group II, group III and group IV were supplemented with 0.5‰, 1.0‰, 2.0‰ and 4.0‰ FWBPs in the basal diet, respectively. The pH value, NH3-N concentration, BCP content and gas production were measured at 3, 6, 9, 12 and 24 h after culture. The results showed that the pH value of rumen fluid of lambs in experimental group II and group IV was significantly lower than that in control group and experimental group I at 3 h of fermentation (P<0.05). The pH value of rumen fluid of lambs in experimental group II, group III and group IV was significantly lower than that in control group and experimental group I at 6, 9, 12 and 24 h of fermentation (P<0.05). After 3 h of fermentation, the pH value of NH3-N concentration in rumen fluid of lambs in experimental group II and group IV was significantly lower than that in experimental group I (P<0.05). After 12 h of fermentation, the concentration of NH3-N in rumen fluid of lambs in experimental group II was significantly lower than that in experimental group I and group IV (P<0.05). The content of BCP in rumen fluid of lambs in control group, experimental group I and group IV was significantly lower than that in experimental group I and group II at 3 and 6 h of fermentation (P<0.05). The content of BCP in experimental group II was significantly lower than that in control group and experimental group I at 24 h of fermentation (P<0.05). At 9 and 12 h of fermentation, the gas production of rumen fluid of lambs in experimental group II and group III was significantly higher than that in other groups (P<0.05). At 24 h of fermentation, the gas production of rumen fluid of lambs in experimental group III was significantly higher than that in other groups (P<0.05). Combined MFAEI, FWBPs supplementation level was 2.0‰, which had a better promotion effect on rumen fermentation in vitro. The experiment indicates that under in vitro culture condition, the addition of FWBPs can effectively regulate the rumen fermentation of lamb, and the suitable additive is 2.0‰. [ABSTRACT FROM AUTHOR]

In the field of flow control research, oblique jets are known to offer several advantages over vertical jets. To gain a comprehensive insight into the flow field characteristics of a plasma synthetic jet actuator with an oblique-slot exit, the related experiments are conducted. The experiment employed high-speed schlieren imaging techniques and electrical parameter measurements to acquire the flow field characteristics and discharge properties of the oblique-slot actuator, followed by a comparative analysis with a vertical circular orifice actuator. The oblique-slot plasma synthetic jet exhibits a wall-attaching effect and asymmetric flow characteristics, which differ from those of the vertical circular orifice actuator. The actuator generates a wall jet with an initial velocity of 389.5 ± 15.08 m/s, effectively propelling the fluid within the boundary layer. The Mach number of the precursor shock wave in the direction of the jet reaches 1.59, but decreases to just 1.02 in the opposite direction. Over a period in the range of 10–70 μs, the Froude number of the plasma jet decreases from 1841 to 238. The dominant role of the inertial force gradually weakens, while the influence of buoyancy increases, causing the jet boundary to move upward. The oblique-slot jet configuration represents a typical planar jet, exhibiting superior flow control uniformity compared with the vertical circular orifice jet. The results indicate that the high-speed oblique-slot plasma synthetic jet actuator designed in this study possesses distinct advantages over vertical circular orifice actuators for high-speed fluid flow control. [ABSTRACT FROM AUTHOR]

Shear rupture and fault slip in crystalline rocks like granite produce large dilation, impacting the spatiotemporal evolution of fluid pressure in the crust during the seismic cycle. To explore how fluid pressure variations are coupled to rock deformation and fault slip, we conducted laboratory experiments under upper crustal conditions while monitoring acoustic emissions and in situ fluid pressure. Our results show two separate faulting stages: initial rupture propagation, associated with large dilatancy and stabilized by local fluid pressure drops, followed by sliding on the newly formed fault, promoted by local fluid pressure recharge from the fault walls. This latter stage had not been previously recognised and can be understood as fluid‐induced afterslip, co‐located with the main rupture patch. Upscaling our laboratory results to the natural scale, we expect that spontaneous fault zone recharge could be responsible for early afterslip in locally dilating regions of major crustal faults, independently from large‐scale fluid flow patterns. Plain Language Summary: Faults in rock form during what is known as rupture; rupture is followed by sliding along the newly formed fault. If this occurs quickly, we speak of an earthquake. When creating the fault during rupture, small cracks are formed in the intact rock that grow and link up. This creates local void spaces in the nascent fault zone. Pore fluids, which typically reside at pressure everywhere within the Earth's crust, will expand in this newfound space so that the pore pressure drops in the rupture zone. Such a drop may slow down the rupture and fault slip—an earthquake may be postponed. Here, we measure this so‐called dilatancy effect in unprecedented detail: We observe how the rupture is controlled by the dilatancy effect, and we discover that after rupture fluids from further away flow into the void spaces in the newly formed fault, thereby increasing pressure again and driving fault slip. This pore fluid control on fault behavior is a fundamental mechanism that can explain why faults continue slipping just after an earthquake. Key Points: We observe two stages during faulting in the presence of fluids: Dilatancy‐dominated shear rupture and slip accommodated by fluid rechargeFault formation by shear rupture evolves non‐linearly with stress drop and may be stabilized by dilatancy‐induced local pore pressure dropsSlip accommodated by local fluid recharge might be responsible for early afterslip following coseismic slip observed in nature [ABSTRACT FROM AUTHOR]

Purpose: Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design file is sliced to generate G-codes before printing. This paper aims to study the effect of key input parameters for slicer software on the final properties of printed products. Design/methodology/approach: The one factor at a time (OFAT) methodology is used to investigate the impact of selected parameters on the final properties of printed specimens, and the causes for the variations in outcomes of each variable are discussed. Findings: Finer aggregates can generate a more compact layer, resulting in a denser product with higher strength. Fluid pressure is directly determined by voxel rate (rV); however, high pressures enable better fluid penetration control for fortified products; for extreme rVs, residual voids in the interfaces between successive layers and single-line primitives impair mechanical strength. It was understood that printhead movement along the orientation of the parts in the powder bed improved the mechanical properties. Originality/value: The design of experiment (DOE) method assesses the influence of process parameters on various input printing variables at the same time. As the resources are limited, a fractional factorial plan is carried out on a subset of a full factorial design; hence, providing physical interpretation behind changes in each factor is difficult. OFAT aids in analyzing the effect of a change in one factor on output while all other parameters are kept constant. The results assist engineers in properly considering the influence of variable variations for future DOE designs. [ABSTRACT FROM AUTHOR]

We present the development and application of a multilayer microfluidic lung chip designed to accurately replicate the human respiratory bronchi, providing an innovative platform for controlled particle deposition in the lung. By employing a quantitative control method of fluid velocity through the deformation of an elastic PDMS membrane, this platform mimics the passive breathing process in humans and allows for precise simulation of the respiration cycle. We utilized time-lapse photography of fluorescent particles in a water/glycerol solution to qualitatively observe fluid morphology in the channel, while a chip-aerosol exposure device combined with microscopy imaging was employed to visualise aerosol deposition. Both experimental and numerical simulation results showed that particle concentration decreased towards the distal generations of the lung, and that changes in breathing pattern significantly affected particle deposition trends. Furthermore, we found that increasing the residence time of particles in the channel facilitated deeper particle deposition, achievable by adjusting parameters such as breath-hold time, exhalation time, respiration cycle length, and tidal volume. The proposed microfluidic lung chip device has significant potential for future research in respiratory health and inhaled drug delivery, providing an efficient, cost-effective, and ethical alternative to traditional in vivo studies. [ABSTRACT FROM AUTHOR]

Quantifying the dynamical features of discrete tasks is essential to understanding athletic performance for many sports that are not repetitive or cyclical. We compared three dynamical features of the (i) bow hand, (ii) drawing hand, and (iii) center of mass during a single bow-draw movement between professional and neophyte archers: dispersion (convex hull volume of their phase portraits), persistence (tendency to continue a trend as per Hurst exponents), and regularity (sample entropy). Although differences in the two groups are expected due to their differences in skill, our results demonstrate we can quantify these differences. The center of mass of professional athletes exhibits tighter movements compared to neophyte archers (6.3 < 11.2 convex hull volume), which are nevertheless less persistent (0.82 < 0.86 Hurst exponent) and less regular (0.035 > 0.025 sample entropy). In particular, the movements of the bow hand and center of mass differed more between groups in Hurst exponent analysis, and the drawing hand and center of mass were more different in sample entropy analysis. This suggests tighter neuromuscular control over the more fluid dynamics of the movement that exhibits more active corrections that are more individualized. Our work, therefore, provides proof of principle of how well-established dynamical analysis techniques can be used to quantify the nature and features of neuromuscular expertise for discrete movements in elite athletes. [ABSTRACT FROM AUTHOR]

The development of a refined conceptual model for the generation of volcanic-related uranium deposits includes studies in the character of magmatic, hydrothermal-metasomatic, and filtration-transport processes, as well as of the physicochemical conditions favoring the transport and deposition of uranium. We consider these issues using the examples of the Streltsovka caldera and the eponymous ore field in eastern Transbaikalia, the Xiangshan volcanic structure in South China, and the McDermitt caldera in the western United States (Oregon and Nevada). According to the IAEA classification (Geological Classification ..., 2018), these ore fields and deposits are of the volcanic-related type, while the Streltsovka and the Xiangshan ore field show a combination of the volcanic-related type in the volcanic-sedimentary cover and the granite-related type at the basement. Most industrially viable uranium deposits of the volcanic-related type were formed in the regions listed above during Mesozoic and Cenozoic times (although we know of older, Paleozoic objects of the type). Although the time spans in which ore-bearing volcanic-related edifices were formed are different, many features in the occurrence of magmatic, hydrothermal, and filtration transport processes in these edifices are rather similar. It is commonly supposed that these features are due to a common effect of intraplate tectonic regimes or to the evolution of outer parts in the ocean-continent zones where magmatic activity produced volcanism of the bimodal series in the dominant basites–acid volcanics–basites sequence, while the migration of uranium-transporting fluids was controlled by a joint action of seismogeodynamic and thermal convective processes. [ABSTRACT FROM AUTHOR]