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A dynamic fluid system using ozonated water flowing over the bovine peritoneal membrane was developed. Histological analyses were performed to verify the maximum time of ozone exposure to maintain ...

We consider the equations of a rotating incompressible non-Newtonian fluid flow of grade two in a three dimensional torus. We prove two different results of global existence of strong solutions. In the first case, we consider that the elasticity coefficient α is arbitrary and we suppose that the third components of the vertical average of the initial data and of the forcing term are small compared to the horizontal components. In the second case, we consider a forcing term and initial data of arbitrary size but we restrict the size of α. In both cases, we show that the limit system is composed of a linear system and a second grade fluid system with two variables and three components.

Green inhibitors are promising alternatives to toxic corrosion inhibitors. Recently, several researches are conducted to investigate the anti-corrosive property of henna extract in different media....

We introduce a method to train a bio-inspired neural network model, having the characteristics of spiking-timing-dependent interaction and learning, in a manner of supervised learning. We assume the spiking neural network model has the tendency to obey the charge conservation principle or the junction rule on a long (or the learning dynamics) time scale. The tendency makes the distribution of connectivities is determined depending on not only the incoming stimuli to input neurons but also the outgoing stimuli from output neurons as if a solution of the finite elementary method in a fluid system. We apply the learning method to several cases in simulations and find the adoption of the conservation principle exerts desired effects on the neural network learning. Finally, we discuss the significance and the drawbacks of the introduced method and compare it with the supervised learning method implemented by the artificial neural network model.

Background Parabolic trough solar collectors (PTSCs) are used to focus the solar rays on absorber tube. The main aim of this paper is to investigate the effects of applying novel corrugated absorber tube filled with hybrid nanofluid on energy efficiency of a novel double fluid PTSC to achieve the maximum energy efficiency value. Method The Eulerian-Eulerian two-phase model is employed for modelling the PTSC and evaluating its energy efficiency. Numerical study is carried out for different values of Reynolds number (Re), nanoparticles volume fraction (ϕ) and geometrical parameters of novel corrugated absorber tube. Findings It is found that usage of corrugated absorber tube has a significant effect on energy efficiency of single- or double fluid parabolic trough solar collectors. Besides it is understood that usage of double fluid system for collector with smooth channel can also increase the energy efficiency, but not more than using corrugated channel for single fluid collector. Moreover, usage of double fluid system at higher Re is also efficient. The results also show that the efficiency of the PTSC enhances with increasing the nanoparticles concentration. Finally, the optimum model of corrugated absorber tube is presented.

The Keller-Segel-Stokes type system with indirect signal production, as given by { n t + u ⋅ ∇ n = Δ n − ∇ ⋅ ( n S ( n ) ∇ v ) , x ∈ Ω , t > 0 , v t + u ⋅ ∇ v = Δ v − v + w , x ∈ Ω , t > 0 , w t + u ⋅ ∇ w = Δ w − w + n , x ∈ Ω , t > 0 , u t + ∇ P = Δ u + n ∇ ϕ , ∇ ⋅ u = 0 , x ∈ Ω , t > 0 , is considered in a bounded domain Ω ⊂ R N , N ∈ { 2 , 3 } , with smooth boundary, where ϕ ∈ C 2 ( Ω ‾ ) and S ∈ C 2 ( [ 0 , ∞ ) ) . Under the assumption that there exist C S > 0 and α ≥ 0 such that | S ( n ) | ≤ C S ( n + 1 ) − α for all n ≥ 0 , it is shown that for all suitably regular initial data an associated initial-boundary value problem possesses a globally defined bounded classical solution in the case N = 2 . In the case of N = 3 , the conclusion is also true provided α > 1 9 .

The chemotaxis-Stokes system{nt+u·∇n=Δn−∇·(n∇c),ct+u·∇c=Δc−nc,ut=Δu+∇P+n∇ϕ, ∇·u=0, (⋆)is considered in a bounded domain Ω⊂R3 with smooth boundary. The corresponding solution theory is quite wel...

We present regularized phase flield model for description of threephase «fluid–fluid–solid» system, where solid body obeys elastic rheology. It is assumed that one of the liquid phases chemically interacts with the solid one. As the corresponding equations of chemical kinetics, simple model equations describing a bimolecular reaction are considered. A feature of the model under consideration is its preliminary regularization according to quasi-hydrodynamic technique. A fully explicit finite difference approximation of this model is presented. Results of a simulation in two-dimensional setting are presented.

A numerical thermodynamic model is proposed for one of the most important geological fluid systems, the ternary H2O–CO2–NaCl system, at P-T conditions of the middle and lower crust and crust-mantle boundary (up to P = 20 kbar and up to T = 1400°C). The form of the model is analoguous to the model developed earlier for the system H2O–CO2–CaCl2. The model is based on an equation for the Gibbs excess free energy for the fluid H2O–CO2–NaCl, also including terms responsible for the interaction of the fluid with the solid phase of NaCl. The model allows predicting physical-chemical properties of fluids, which participate in the majority of deep petrogenic processes: the phase state of the system (homogeneous or multi-phase fluid, presence or absence of solid NaCl), chemical activities of the components, densities of the fluid phases, and concentrations of the components in the co-existing phases. The P-T dependencies of coefficients of the equation for the Gibbs excess free energy are expressed via molar volumes of water and CO2 at corresponding pressure and temperature. The numerical parameters of the model are obtained by fitting experimental data on the phase state of the fluid system in the range of pressures from 1 to 9 kbar and temperatures from 500 to 930°C. Our parametrization of the P-T dependencies provides applicability of the model for pressures and temperatures beyond the experimental region, namely up to P = 20 kbar and up to T = 1400°C. The validity of the model above these P-T parameters is limited due the properties of the thermodynamic description of the CO2 employed.

There are microfractures and fractures in the carbonate formation of M oilfield, which are easy to cause collapse and borehole instability. On the basis of the liquefiable cleanflo drilling fluid system for open hole completion of horizontal wells designed in the early stage, this paper has carried out the research work of matching acidizing completion fluid system. In this paper, the influence factors, cleaning ability, compatibility, acidizing situation and protection effect of acidizing completion fluid system are evaluated in laboratory. The way of density adjustment and specific dosage of NaCl and hcoona were established to inhibit the formation of salt crystallization. HTA solid acid and JCI are used to counteract each other to reduce the corrosion of casing steel. The core displacement results show that the permeability recovery value of carbonate core after completion fluid treatment can reach 97.54%, and that of sandstone core after treatment can reach 114.7%. Moreover, the completion fluid system also has a certain acidizing effect, which can not only clean and remove the plugging, but also serve as the early induction of acidizing and stimulation.

We consider the coupled chemotaxis–Navier–Stokes system with logistic source term [Formula: see text] in a bounded, smooth domain [Formula: see text], where [Formula: see text] and where [Formula: see text], [Formula: see text] and [Formula: see text] are given parameters. Although the degradation here is weaker than the usual quadratic case, it is proved that for any sufficiently regular initial data, the initial-value problem for this system under no-flux boundary conditions for [Formula: see text] and [Formula: see text] and homogeneous Dirichlet boundary condition for [Formula: see text] possesses at least one globally defined weak solution. And this weak solution becomes smooth after some waiting time provided [Formula: see text].

In this paper we deal with the initial-boundary value problem for a chemotaxis-fluid model involving a complicated nonlinear coupling term, precisely, the following self-consistent system with porous medium diffusion { n t + u ⋅ ∇ n = Δ n m − ∇ ⋅ ( n ∇ c ) + ∇ ⋅ ( n ∇ ϕ ) , x ∈ Ω , t > 0 , c t + u ⋅ ∇ c = Δ c − n c , x ∈ Ω , t > 0 , u t + ∇ P = Δ u − n ∇ ϕ + n ∇ c , x ∈ Ω , t > 0 , ∇ ⋅ u = 0 , x ∈ Ω , t > 0 , under no-flux boundary conditions in a bounded domain Ω ⊂ R 3 with smooth boundary. One of the novelties here is that both the effect of gravity (potential force) on cells and the effect of the chemotactic force on fluid is considered, which leads to the stronger coupling than the most-studied chemotaxis-fluid model for swimming bacteria proposed in [28] . We shall establish the existence of global weak solutions whenever m > 4 3 , thereby supplementing previously gained knowledge on its two-dimensional version.

In this paper, the two-dimensional incompressible chemotaxis fluid with logical source is studied as following: nt+u⋅∇n=Δn−∇⋅(n∇c)+n−n2,ct+u⋅∇c=Δc−nc,ut+u⋅∇u+∇P=Δu−n∇φ,∇⋅u=0. By taking advantage of...

We numerically investigate the linear instability problem of Poiseuille flow in a channel partially filled with a porous medium on the bottom side. We are primarily interested in the influence of the interface momentum distribution including stress continuity and jump interface conditions. A spectral collocation method is applied in solving the fully coupled instability problem arising from the adjacent porous and free channel flows. The results show that the “interface stress coefficient” in a negative range has a larger effect on the trajectory of the eigenvalues than that in the positive range, especially the most unstable mode. Moreover, with a low permeability in the porous region, the interface momentum distribution has less effect on the stability of core flow. And when the “interface stress coefficient” is equal to its minimum negative value, the flow passing through the channel is at its most stable state. If the “interface stress coefficient” varies in a positive range, the degree of fluid stability is predicted to slightly diminish due to stress continuity condition at the interface.

In the present study, centrifugal pump noise is examined with increasing the redial gapbetween the impeller and pump casing. Increasing the radial gap will be obtained byimpeller trimming. Impeller trimming is the process of decreasing the diameter of animpeller by machining to decrease the energy added to the fluid system. The impellertrimming leads to a reduction both of pump flow rate and head. A closed loop withcirculation pump is designed and fabricated to study the effect of impeller trimming oncentrifugal pump performance and pump noise. Pump performance is obtained for thethree impellers at constant drive speeds. Also, sound pressure level and frequencyspectrum of noise is measured at different circumferential positions around impeller forthree impeller diameters in the same casing. Results of pump performance at constantspeed are found to be in good agreement with affinity laws. Finally, the sound pressurelevel is found to increase with impeller trimming at some locations around the impellerand decreases at others due local changes in flow behavior. فى ھذه الدراسة؛ سيتم البحث فى ز يادة المسافة القطرية بين دفاع المضخة الطاردة المرکزية وغلافھا و تأثير ذلکعلى کفاءة المضخة وکذلک الضوضاء الصادرة منھا. تتم عملية القطع فى حافة دفاع المضخة الطاردة المرکزيةعن طريق اجراء عملية خراطة عليھ بغرضتقليل الطاقة التى يعطيھا للسائل وعندھا فيقل کلا من کمية السائلالخارج من المضخة وضغطھ. تأتى ھذه الطريقة والتى الغرضمنھا تقل يل کمية السائل الخارج من المضخة کبديلعن غلق بلف الطرد تجنبا لما قد يحدث من فقد فى الطاقة. لھذا تعتبر ھذه العملية أکثر توفيرا و کفاءة مقارنة بشراءمضخة جديدة تعطى کمية السائل المطلوبة. وذلک مع الآخذ في الاعتبار تأثير تقليل قطر الدفاع على الضوضاءالمتولدة من المضخة لما فيھ من تأثير على بعضالمستخدمين مثل المستشفيات والبنوک الخ.وضع تصميم لدائرة مياه مغلقة بھا مضخة طاردة مرکزية وتم تصنيعھا لدراسة تأثير القطع فى حافة دفاع المضخةالطاردة المرکزية على أداء المضخة والضوضاء الصادرة منھا. وتم رسم کلا من منحنى الأداء والقدرة للمضخة عند الثلاثة أقطار المشار إليھا عند ثبوت سرعة الدوران وتم التأکد من صحة النتائج وفقا لل (قوانين التقارب).وکذا تم قياس مستوى ضغط الصوت والتحليل الطيفى عند أکثر من موضع لدفاع المضخة وذلک لثلاثة أقطارمختلفة للدفاع عند نفس غطاء المضخة.وجدت النتائج الخاصة بمنحنى الأداء والقدرة موافقة للنتائج النظرية المستنتجة من ال (قوانين التقارب). وقد وجدتزيادة في مستوى ضغط الصوت مع تقليل کمية السائل التى تخرج من المضخة. وکذلک وجدت زيادة فى مستوىضغط الصوت مع تقليل قطر الدفاع عند بعض المواضع ووجد نقصان فى مستوى ضغط الصوت عند مواضعأخرى. يختلف مستوى ضغط الصوت بين موضع لأخر على دفاع المضخة لنفس کمية السائل وقطر الدفاع.

We consider generalized models on coral broadcast spawning phenomena involving diffusion, advection, chemotaxis, and reactions when egg and sperm densities are different. We prove the global-in-time existence of the regular solutions of the models as well as their temporal decays in two and three dimensions. We also show that the total masses of egg and sperm density have positive lower bounds as time tends to infinity in three dimensions., 27 pages

In this paper, we investigate the chemotaxis-fluid system with singular sensitivity and logistic source in bounded convex domain with smooth boundary. We present the global existence of very weak solutions under appropriate regularity assumptions on the initial data. Then, we show that system possesses a global bounded classical solution. Finally, we present a unique globally bounded classical solution for a fluid-free system. In addition, the asymptotic behavior of the solutions is studied, and our results generalize and improve some well-known results in the literature, and partially results are new.

This paper is devoted to investigating the existence and uniqueness of mild solution to the 3D incompressible micropolar fluid system in the Fourier-Herz framework. By taking advantage of microlocal analysis and the mutual effect in the same frequency range of convection term, we give a special initial data (u0, ω0) whose norm of $$F\dot B_{1, q}^{- 1}\left({q > 2} \right)$$ is arbitrarily small, however, the couple (u0, ω0) produces a solution which is arbitrarily large in $$F\dot B_{1, q}^{- 1}$$ after an arbitrarily short time. This implies the system is ill-posed in the sense of “norm inflation” as q > 2.

A nonlocal form of a two-layer fluid system is proposed by a simple symmetry reduction, then by applying multiple scale method to it a general nonlocal two place variable coefficient modified KdV (VCmKdV) equation with shifted space and delayed time reversal is derived. Various exact solutions of the VCmKdV equation, including elliptic periodic waves, solitary waves and interaction solutions between solitons and periodic waves are obtained and analyzed graphically. As an illustration, an approximate solution of the original nonlocal two-layer fluid system is also given.

In this paper, we consider an initial-boundary value problem for the 2D incompressible magneto-micropolar fluid equations with zero magnetic diffusion and zero spin viscosity in the horizontally infinite flat layer with Navier-type boundary conditions. We establish the global well-posedness of strong solutions around the equilibrium $(0,e_1,0)$.

A numerical thermodynamic model is proposed for one of the most important geological fluid system – triple system H 2 O-CO 2 -CaCl 2 at P-T conditions of the middle and lower crust, as well as for the crust-mantle boundary. The model is based on the equation for concentration dependence of the excess Gibbs free energy, proposed earlier, and for the first time obtained P-T dependencies of the coefficients of the equation of state (EOS) expressed via molar volumes of the components. The EOS allows predictions of the properties of the fluid, participating in the majority of the processes of depth petrogenesis: its phase state (homogeneous or multi-phase), densities of the fluid phases, concentrations of the components in the co-existing phases, and chemical activities of the components. The model precisely reproduces all available experimental data on the phase state of the ternary fluid system H 2 O-CO 2 -CaCl 2 in the ranges of temperature 773.15–1073.15 K and pressures 0.1-0.9 GPa and allows, as well, correct application of the EOS beyond the experimentally studied domain of temperatures and pressures – namely up to P = 2 GPa and up to T = 1673.15 K. The possibility of the correct extrapolation of our EOS is ensured by using the parametrization of P-T dependencies via the molar volume of water. The latter remains in the experimental domain of values or very near to its boundaries, when increasing temperatures and pressures.

In this paper, we discuss the interfacial internal waves with a rigid boundary in a three-layer fluid system, where the density of the upper layer fluid is smaller than that of the lower layer. With the Lagrangian matching conditions at the interfaces, the first-order solutions, the second-order solutions and the third-order asymptotic solutions for the interfacial internal waves are obtained in the Lagrangian description using the perturbation method, and the mass transport velocity, the wave frequency, the mean level and the particle trajectory are also given. The results show that the discontinuities across the interfaces appear for the mass transport velocity, wave frequency and mean level, but we find that these discontinuities may disappear if the water depth ratio and the density ratio of the three layer fluids satisfy certain conditions.

The continuous growth of energy requirements, together with diminishing production, necessitates tireless efforts to develop new technology frontiers in oilfield operations. The hydrocarbon reservoirs residing below the shale and near to the depletion stage are not recoverable using conventional methods. Therefore, innovation is necessary to drill non-traditional hydrocarbon reservoirs present in the basin scale with a difficult approach. An understanding of drilling fluid rheology helps to design a fluid system with better features that can overcome issues faced during unconventional drilling processes. The attention of the scientific community has been diverted towards the water base drilling fluid system that has a low environmental footprint. When the water base drilling fluid physically and chemically interact with clay, this may cause swelling, bit balling, or blockage of the wellbore. The aim of this paper is to provide a comprehensive review of inhibitors, aiming to understand the clay swelling mechanisms and the development of water-based mud additives for hydration restriction. The suitable shale inhibitors must not only efficiently diminish the clay hydration swelling but also fulfill the progressively rigorous environmental regulations, even though staying cost-efficient. The green shale inhibitors reported in the literature include amines, acrylamide, alcohols, biomolecules and silica-based additives for water-based mud. Further critical analysis is provided with a comprehensive understanding of the inhibition mechanisms for shale and the development of effective water-based shale inhibitors. The gaps in the current literature are identified to help readers to identify prospects for improvements in the drilling fluids that can help to explore possible future directions.

In this paper, we are concerned with optimal temporal decay rates of solutions for the initial value problem of three-dimensional incompressible micropolar fluid system. By carefully examine the algebraic structure of micropolar fluid system, we show that some weighted negative Fourier–Besov norms of solutions are preserved along time evolution, which yields the optimal temporal decay rates of solutions in the framework of homogeneous Fourier–Besov spaces by solving an ordinary differential inequality through the interpolation techniques.

The kinetics of flow of a viscous incompressible fluid between two closely lying parabola-shaped inserts (plates) rotating with the same angular velocity around a common axis is studied. The flow, in the inter-plate gap of the separator drum, of a weakly concentrated liquid + solid type of two-phase fluid is modeled. Based on the postulates of the theory of fluid flows in “sliding” mode, the internal problem of hydrodynamics along the flow in the chosen working space of the centrifugal equipment is proposed to be solved in linear formulation. For an isolated small spherical particle moving in the flow, the critical diameter of the particle (settling in the working space of the separator), which determines the separation efficiency, is calculated by solving the external problem of hydrodynamics.

In this paper, we consider a model arising from biology, consisting of fractional chemotaxis equations coupled to viscous incompressible fluid equations throughout transport and external force in R 3 . We establish the existence and uniqueness of global solution with small initial data by combining the local existence and a priori estimates as well as continuation argument. Moreover, the decay rates of the solutions and their higher-order spatial derivatives are established towards the equilibrium by introducing the negative Sobolev space H − s ( 0 ⩽ s 3 2 ).

We study the Cauchy problem of the incompressible micropolar fluid system in R 3 . In a recent work of the first author and Jihong Zhao (Zhu and Zhao, 2018), it is proved that the Cauchy problem of the incompressible micropolar fluid system is locally well-posed in the Fourier–Besov spaces F B p , r 2 − 3 p for 1 p ≤ ∞ and 1 ≤ r ∞ , and globally well-posed in these spaces with small initial data. In this work we consider the critical case p = 1 . We show that this problem is locally well-posed in F B 1 , r − 1 for 1 ≤ r ≤ 2 , and is globally well-posed in these spaces with small initial data. Furthermore, we prove that such problem is ill-posed in F B 1 , r − 1 for 2 r ≤ ∞ , which implies that the function space F B 1 , 2 − 1 is sharp for well-posedness. In addition, using a similar argument we also prove that this problem is ill-posed in the Besov space B ∞ , r − 1 with 2 r ≤ ∞ .

In this article, we study the electromagnetic fluid system in three-dimensional whole space ℝ3. Under assumption of small initial data, we establish the unique global solution by energy method. Moreover, we obtain the time decay rates of the higher-order spatial derivatives of the solution by combining the Lp − Lq estimates for the linearized equations and an elaborate energy method when the L1-norm of the perturbation is bounded.

Although well-researched as a prototype Hamiltonian for strongly interacting quantum systems, the Bose–Hubbard model has not so far been explored as a fluid system with waterlike anomalies. In this work we show that this model supports, in the limit of a strongly localizing confining potential, density anomalies which can be traced back to ground state (zero-temperature) phase transitions between different Mott insulators.

This paper presents an implicit conjugate heat transfer (CHT) model designed for 1D systems of both solids and fluids. It demonstrates that this approach can be extended to include 2D and 3D elements being co-solved in a 2D or 3D thermal product. The approach is applied to a simple analytical problem and then to a Secondary Air Cavity within a Gas Turbine to illustrate the potential of this technique to be applied to more complex thermo-fluid simulations. Such simulations are important in trade off studies to balance minimizing engine bleed whilst ensuring sufficient cooling. The benefits of this CHT model are presented by comparison with the traditional approach of explicit co-simulation in which the temperature from the fluid domain is applied as a boundary condition to the thermal simulation and heat flux from the thermal simulation is applied as a boundary condition to the fluid domain (or vice versa). The ability to replace 1D elements with 2D or 3D elements allows model continuity from conceptual to detailed design and the reverse process potentially offers a route for model reduction later in lifecycle to support operation and maintenance through the use of an executable digital twin.

The use of micronized weighting agents, in multiple operations, have become more commonplace over the years, with current applications now going far beyond their targeted original purpose of reducing pressure losses in extended reach wells. This specific case reports the development of a fit for purpose system engineered to tackle multiple challenges such as: limitation in using heavy density brines composed of bromides in an offshore environment; hydrate suppression under Drill Stem Test (DST) conditions; weighting agent sagging control; plugging of downhole tools due to heavy solids loading; proper pressure transmission for downhole tools activation; and formation damage prevention. The operation involved the following steps: 1 - development of a Water-based Micronized Weighting Agent Fluid System (WBMWAFS), laboratory testing, simulation evaluation and testing validation for all target properties; 2 - development of an appropriate DST approach with the usage of a designed set of explosives to minimize formation damage and the interaction of the DST fluid with such cargos; and 3 - the evaluation of the overall system performance in order to validate the integrated approach used to design such solution. The DST results indicated that the WBMWAFS is capable of delivering all the technical requirements for a trouble-free operation, with no significant register of weighting agent sag, hydrates or with any variation in fluid properties, whilst enabling a DST operation that demonstrated a negative skin damage during the clean-up period and no damage associated with the WBMWAFS. The WBMWAFS performance opens the possibility of the application of this type of fluid as a replacement for high-density clear brines in many challenging environments.

The physical configuration of the problem is a porous-fluid layer which is horizontally unbounded, in the presence of uniform heat source/sink in the layers enclosed by adiabatic and isothermal boundaries. The problem of double diffusive Bènard-Marangoni convection in the presence of vertical magnetic field is investigated on this porous-fluid system for non-Darcian case and is subjected to uniform and nonuniform temperature gradients. The eigenvalue, thermal Marangoni number is obtained in the closed form for lower rigid and upper free with surface tension velocity boundary conditions. The influence of various parameters on the Marangoni number against thermal ratio is discussed. It is observed that the heat absorption in the fluid layer and the applied magnetic field play an important role in controlling Benard-Marangoni convection. The parameters which direct this convection are determined and the effect of porous parameter is relatively interesting.

A oilfield is a super-deep water carbonate oil field in Brazil with thick reservoir of dissolved pore and strong heterogeneity and there are multiple oil water contacts drilled by exploration wells. The reservoir model and connectivity is of vital importance for the development plan. In view of the complex reservoir and fluids distribution characteristics in this area, the method of combining dynamic and static information for connectivity analysis is proposed, and the method of combining fluids property analysis, pressure data analysis and production dynamic characteristics research is applied in this paper. The results show that the non-reservoir zones at the bottom of the reservoir in the front area of A oilfield act as barriers to separate the water layers and some lower oil layers in the north and South regions, forming a special fluid system with connected oil and separated water.

Over time, Spain developed into a strong imperialist state. This chapter explores its use of interventionist censuses to govern Puerto Ricans through regularized enumeration. Everyday understandings of race likely influenced early imperialist censuses; census records used multiple and varied terms related to race. Racial markers also varied (except blanco [White] and negro [Black], which were universally used). The information gathered varied regionally: some areas reported categories only for some groups but not others. Starting in 1860, the state employed more systematic, uniform, and rigid binary and tripartite racial categories. Such a system was not in the interests of most Puerto Ricans. Thus, while binary/tripartite distinctions were widely used, the more fluid system of multiple and varied racial markers still figured prominently in daily life. Thus, the census did not transform everyday categorizations.

Zanazour Oilfield has the typical characteristics of large perforation interval span, large number of perforation intervals, large differences in physical properties between different layers, and uneven fluid production profile. In order to achieve uniform acidification requirements, improve fluid production profile, and increase the use of low permeability layers, a multifunctional diverting acid fluid system suitable for the characteristics of the Zanazour oilfield was developed. The system has the characteristics of temporary blocking and diverting, selective acidification, and energy-assisted flowing back and so on. Based on the reservoir and fluid characteristics, lithology and physical properties of the oilfield, three acid liquid systems with good compatibility and temporary plugging, diverting, deep acidification, and energy-enhancing flowing back were developed, and their properties were tested with laboratory tests. At the same time, in order to give full play to the advantages of different functional acid liquid systems and achieve the purpose of synergistic enhancement, selective foamed acid systems and technologies, as well as emulsified self-diverting acid systems and technology have been formed. The pilot implementation of the field experiments, through high construction success rate and significant better production increasing effect than that of conventional liquids, indicated that the multifunctional diverting acid system and synergistic acidification technology have better adaptability in the oil field.

We consider an attraction-repulsion chemotaxis model in the whole space $${\mathbb {R}}^3$$ with logistic source coupled with the incompressible Navier–Stokes equations. By means of a contraction argument, we obtain the existence and uniqueness of global mild solutions in a framework of Besov type, namely Besov spaces based on Morrey spaces. In comparison with previous results for the system dealt with, that framework provides new solutions and allows us to consider larger initial data and force classes for global existence and uniqueness. To carry out our results, we prove some essential lemmas and estimates related to the heat semigroup and continuity properties for the Bony decomposition in our setting.

Summary Introduction Inadvertent perioperative hypothermia (a drop in core temperature to below 36 °C) occurs because of interference with normal temperature regulation by anaesthetic drugs, skin exposure for prolonged periods and the introduction of large volumes of intravenous and irrigation fluids. If the temperature of these fluids is below core body temperature, they can cause significant heat loss. Warming irrigation fluids might prevent some of this heat loss and subsequent hypothermia and that is the role of warming irrigation fluid systems. Material And Methods The video describes prone ultra mini PCNL with suction-evacuation access sheath under warming irrigation fluid system in a 15 month-old boy with a 2 cm-600HU staghorn calculi and one stone of 7 mm-500HU in proximal ureter. Results The surgery was performed without intraoperative complications and perioperative hypothermia was prevented. The patient started the surgery at 35.4 °C and the final temperature was 36.3 °C in 90 minutes of procedure, in addition to being free of stones. Conclusions The warming irrigation fluid system can be helpful in preventing inadvertent perioperative hypothermia in children, improving the safety of ultra mini PCNL with suction-evacuation access sheath and shows promising results with high stone-free rates and low complications.

This paper presents a novel approach that couples system modelling of both the thermo-fluid system and the thermal solid system by modelling conjugate heat transfer within a single 1D system analysis solver and applies it to the Secondary Air System of a Gas Turbine. The Secondary Air System design has to balance minimizing engine bleed whilst ensuring sufficient cooling. To achieve this, designers model both the secondary air flow and the temperature distribution in solid components. System CFD tools like Simcenter Flomaster may be used to solve flow, pressure and temperature distributions and a 3D thermal solver used to perform the thermal analysis of the blade and disc solids. The thermal interaction between the secondary flow system and the solid components is a key part of the model and is known as conjugate heat transfer analysis (CHT). This approach is problematic early in the design cycle when detailed or stable geometry information may not be available for the 3D thermal tool. An approach that couples the modelling of both the thermo-fluid system and the thermal solid system within a single 1D/system analysis tool offers the advantage of faster modelling and consistent model accuracy of both fluid and solid components, especially in the early concept design stage. This 1D-CHT approach has been implemented within Simcenter Flomaster and validated using an idealized analytical solution. It is shown that the model can be applied to the analysis of gas turbine secondary air systems including cavity flows and thermal analysis of the rotor and stator discs that form the thermal boundary of these cavities using Simcenter Flomaster alone.

The evolution of hydrothermal fluids during metasomatic and/or hydrothermal processes is responsible for the formation of ore deposits and associated alteration. In systems with well-developed breccia and fractures, mineral reactions are largely driven by decompression boiling, fluid cooling or external fluid mixing, but in less permeable rocks, elements exchanges occur at fluid-mineral interfaces, resulting in a self-evolved fluid-mineral reaction system. However, the dynamic fluid evolution leading to large-scale (km) alteration remains poorly understood. We observed experimentally that the sequential sodic and potassic alterations associated with mineralization in large ore deposits, in particular Iron Oxide Copper Gold (IOCG) deposits, can occur via a single self-evolved, originally Na-only, hydrothermal fluid, driven by a positive feedback between equilibrium and kinetic factors. Albite formed first upon reaction of sanidine ((K,Na)AlSi3O8) with a NaCl fluid at 600˚C, 2 kbar. However, with increasing reaction time, some of the initially formed albite was in-turn replaced by K-feldspar (KAlSi3O8). Fluorine accelerated the process, resulting in nearly complete back-replacement of albite within 1 day. These experiments demonstrate that potassic alteration can be induced by Na-rich fluids, and pervasive sequential sodic and potassic alterations do not necessarily reflect near-equilibrium, externally-driven changes in fluid alkali contents.

A stationary nonwetting droplet in a constricted tube can attain resonance in response to external seismic stimulation. Key parameters controlling droplet resonance are analyzed through a proposed theoretical model. The nonlinear effect of a fluid system on the resonance is also addressed.

Large-amplitude internal solitary waves in a two-layer fluid system with a free surface are investigated in this paper. Laboratory experiments on strongly nonlinear internal solitary waves with a free surface for a deep configuration are conducted. After comparing the experimental data with the results of the Miyata–Choi–Camassa model that includes the free-surface effects (MCC-FS), we find that the MCC-FS model does not calculate accurately the internal solitary waves with a free surface. Thus, we develop a strongly nonlinear model for a deep configuration, namely the two-layer high-level Green–Naghdi (HLGN-FS) model that includes the free-surface effects. Numerical results of the HLGN-FS model, including the wave profile, velocity field and wave speed, are presented for three cases. The first case is a shallow configuration with . It is shown that the MCC-FS model can provide accurate results for the shallow configurations. Meanwhile, the HLGN-FS model is shown to be accurate for describing the internal solitary waves for both shallow and deep configurations.

We consider the large time behavior of weak solutions to the 3D magneto-micropolar fluid system. We establish the rate of decay $$\bigl \Vert \;\!({{\varvec{u}}},{{\varvec{w}}}, {{\varvec{b}}})(\cdot ,t)\,\!\bigr \Vert _{{{\varvec{L}}}^{2}({\mathbb {R}}^3)} \,\le \,C \;\!(t + 1)^{-\;\!\frac{3}{4}}$$ for all $$t \ge 0$$ through Fourier splitting method. Furthermore, we use a direct method to show how to take advantage of the particular form of the equation to the microrotational velocity and get the so far faster decay rate $$ \bigl \Vert \;\!{{\varvec{w}}}(\cdot ,t)\,\!\bigr \Vert _{{{\varvec{L}}}^{2}({\mathbb {R}}^3)} \,\le \, C \;\!(t + 1)^{-\;\!\frac{5}{4}} $$ for all $$t \ge 0$$.

Overheating is still a major problem in the use of conventional heating for milk and various dairy products, because it leads to the lowering of quality and sensory and nutritional values. Microwave (MW) heating has been credited with providing superior-quality dairy-based products with extended shelf-life, representing a good alternative to conventional heat treatment. The main drawback of MW heating refers to nonuniform temperature distribution, resulting in hot and cold spots mainly in solid and semisolid products; however, MW heating has been shown to be suitable for liquid foods, especially in a continuous fluid system. This review aims to describe the main factors and parameters necessary for the application of MW heating technology for dairy processing, considering the theoretical fundamentals and its effects on quality and safety aspects of milk and dairy products. MW heating has demonstrated great ability for the destruction of pathogenic/spoilage microorganisms and their spores, and also inactivation of enzymes, thereby preserving fresh characteristics of dairy products.