Permeability Parameters Research Articles

Effect of Batch Dissimilarity on Permeability of Stacked Ceramic Foam Filters and Incompressible Fluid Flow: Experimental and Numerical Investigation

Ceramic foam filters (CFFs) are used to remove inclusions and/or solid particles from molten metal. In general, the molten metal poured on the top of a CFF should reach a certain height to form the pressure (metal head) required to prime the filter. For estimating the required metal head and obtaining the permeability coefficients of the CFFs, permeability experiments are essential. Recently, electromagnetic priming and filtration of molten aluminum with low and high grades of CFF, i.e., 30, 50 and 80 pore per inch (PPI) CFFs, have been introduced. Since then, there has been interest in exploring the possibility of obtaining further inclusion entrapment and aluminum refinement by using electromagnetic force to prime and filter with stacked CFFs. The successful execution of such trials requires a profound understanding concerning the permeability parameters of the stacked filters. Such data were deemed not to exist prior to this study. As a result, this study presents experimental findings of permeability measurements for stacks of three 30, three 50 and three 80 PPI commercial alumina CFFs from different industrial batches and compares the findings to numerically modelled data as well as previous research works. Both experimental and numerical findings showed a good agreement with previous results. The deviation between the experimentally and numerically obtained data lies in the range of 0.4 to 6.3%.

Magnetohydrodynamic Effects on Third-Grade Fluid Flow and Heat Transfer with Darcy–Forchheimer Law over an Inclined Exponentially Stretching Sheet Embedded in a Porous Medium

The major aim of the current investigations is to study the magnetohydrodynamic effects on heat and mass transfer phenomena in third-grade fluid past an inclined exponentially stretching sheet fixed in a porous medium with Darcy–Forchheimer law influence. The constitutive equations compatible for heat and mass transportation in third-grade fluid in terms of partial differential equations are modeled. These partial differential equations are then converted to ordinary differential equations by using suitable similarity variables formulation. The transformed flow model is solved by using MATLAB built-in numerical solver bvp4c. Effects of pertinent parameters on physical properties that are velocity field, temperature field and mass concentration along with skin friction coefficient, Nusselt number and Sherwood number are demonstrated in graphs and tables. The impact of dimensionless numbers on the physical properties is analyzed and discussed with a physical view point at angle α=π/6 (inclined sheet). It is seen that as the third-grade fluid parameter (0.1≤β≤11) is increased, the velocity profile increases, but the temperature field and mass concentration are decreased. It is observed that as the permeability parameter (1≤K*≤11) is raised, the velocity distribution decreases and mass concentration increases. It is concluded from the results that owing to an increase in the local inertial coefficient (0.1≤Fr≤5), the velocity profile reduces but an increment in mass concentration is noted. It is concluded that by increasing values of magnetic field parameter (0.1≤M≤10) the velocity field is delineated and temperature field is elevated exactly according to the physics of magnetic field parameters. The present results are compared with already published results and it is observed that there is good agreement between them. This good agreement ensures the validation of accuracy of the results.

Parigi Carbonate Reservoir for Underground Gas Storage in West Java, Indonesia

DOI:10.17014/ijog.9.2.219-228This paper focuses on the characteristics and distribution of shallow reservoir carbonate in an underground gas storage. This study was done on Parigi carbonate as a significant reservoir carbonate in West Java Basin. The carbonate is abundant, and it occurs at shallow depths 800 to 1000 m below sea level. This formation broadly spreads out in onshore and offshore West Java areas as platform and build-up carbonates. The development of buildup carbonates is mostly in a low relief offshore. They well-developed onshore where the build-up exhibits coral reef frameworks, high relief, reaching over 450 m in thickness. The carbonate outcrop in Palimanan, western Cirebon which has been studied is grouped into four types of lithofacies. The preservation condition of this carbonate reservoir is important, for the storage capacity can inject a big gas volume. The porosity and permeability parameters are the most influential factor in reservoir evaluation. The parameters for gas storage in this field are within the range of the existing field parameters in Europe and America.

Intestinal Barrier Permeability in Overweight Individuals with or Without Metabolic Syndrome

Abstract Objectives To evaluate the intestinal barrier permeability relating with metabolic and anthropometric parameters in overweight individuals with or without Metabolic Syndrome (MS). Methods This was an observational, case control study, with data collection from September 2019 to June 2021 at the Federal University of Rio Grande do Norte. Urine, blood samples and anthropometric measurements were collected. MS was defined according the National Cholesterol Education Program (NCEP: ATP III) criteria. Intestinal barrier permeability was measured by High Performance Liquid Chromatography (HPLC) assay using lactulose/mannitol as sugar probe in urinary collection. Correlations between intestinal permeability, metabolic and anthropometric parameters were assessed using Spearman's (r2) correlations. Results Overall, 42 individuals participated in the study, 28.6% were normal weight, 35.7% were overweight without MS and 35.7% were overweight with MS. The mean age was 59.5 (47.75–67.25) years and the female gender (64.3%) was the most prevalent. Fasting glucose, insulin, triglycerides and HOMA index were significantly higher in the overweight with MS group. Lactulose and mannitol excretion and the L/M ratio were higher in the overweight with MS group but not statistically significant. L/M ratio and C-reactive protein (PCR) were positively correlated in overweight without MS individuals (r2 = + 0.626, p < 0.05). Mannitol excretion and HOMA index were also positively correlated in overweight with MS group (r2 = + 0.520, p < 0.05). There was no correlation between intestinal permeability variables and anthropometric parameters (Body Mass Index, waist and hip circumference, weight). Conclusions Intestinal barrier permeability parameters were not associated with overweight nor MS. Nevertheless, increased intestinal permeability was associated to elevated inflammatory status in overweight without MS individuals and to insulin resistance in overweight with MS individuals. Data reinforces the association between intestinal permeability and nutritional and metabolic status. Funding Sources CNPq (406,353/2018-2).

Aqua Cobalt Ferrite/Mn–Zn Ferrite Hybrid Nanofluid Flow Over a Nonlinearly Stretching Permeable Sheet in a Porous Medium

In the present article, the problem of ferro hybrid nanofluid flow over a nonlinearly stretching permeable sheet in a porous medium has been studied. The main motivation of this research is to present a comprehensive analysis of the hydrodynamics and thermal boundary layers as well as the skin friction and heat transfer as two important quantities of engineering interest for the relevant ferro hybrid nanofluid flow. The ferro hybrid nanofluid is a nanofluid that can be composed of several nanoparticles and has a magnetic property; it means that has its own behavior in the magnetic field. Two different types of ferroparticles, namely, Mn–Zn ferrite (Mn–ZnFe2O4) and cobalt ferrite (CoFe2O4) are considered with water as a base fluid. The similarity solution is used to decrease the governing set of partial differential equations (PDEs) to the nonlinear ordinary differential equations (ODEs) system, which is solved numerically by the bvp4c function of MATLAB. The effects of pertinent parameters, namely, magnetic parameter, nonlinear velocity parameter, permeability parameter, and volume fraction of the second nanoparticle on velocity and temperature profiles, skin friction coefficient, and local Nusselt number are computed and shown through graphs. The prominent novelty of this research is related to the use of ferro hybrid nanofluid as a working fluid, where many studies have been carried out in the field of the determination of heat transfer and skin friction in nanofluids/ferro nanofluids on different geometries. To the best of our knowledge, no one has ever attempted to study the present boundary layer problem with applying ferro hybrid nanofluid. The results of this paper indicate that Nusselt number and skin friction coefficient decrease with increasing magnetic field.

Downregulation of miR-1270 mediates endothelial progenitor cell function in preeclampsia: Role for ATM in the Src/VE-cadherin axis.

Preeclampsia, a pregnancy-related hypertensive disorder, is associated with endothelial dysfunction and increased cardiovascular risk of the offspring in adulthood. In preeclampsia, endothelial colony-forming cells (ECFC) are reduced in number and function. Recently, we have shown that miR-1270, which is involved in cancer in vitro proliferation, migration, and tumor progression, is downregulated in fetal ECFC from preeclamptic pregnancies. We now hypothesize that miR-1270 dysregulation contributes to vascular endothelial dysfunction occurring after preeclampsia via ATM (ataxia telangiectasia mutated) overexpression, the key kinase of DNA damage repair. Here, we show that miR-1270silencing in normal ECFC and downregulation in preeclamptic ECFC are accompanied by an increase in the expression levels of ATM. Furthermore, ATM activation correlates with upregulated tyrosine kinase Src leading to phosphorylation and internalization of VE-cadherin (vascular endothelial-cadherin) which subsequently compromises endothelial barrier permeability and morphodynamic cell parameters. Treatment with specific ATM inhibitors reveals a novel role of ATM upstream of tyrosine kinase Src activation. Subsequently, Src phosphorylation and internalization of VE-cadherin compromise endothelial barrier permeability. Our findings suggest that downregulation of miR-1270 contributes to impaired ECFC function via the associated ATM overexpression, which further identifies ATM as a novel and critical factor for ECFC defects in preeclampsia. Our study provides new insights into the understanding of ECFC impairment associated with cardiovascular risk in preeclamptic offspring and identifies potential novel therapeutic targets.

Influence of Slip Parameter, Viscous Dissipation and Joule Heating Effect on Boundary Layer Flow and Heat Transfer Over a Power-Law Stretching Wedge-Shaped Surface with the Correlation Coefficient and Multiple Regressions

The influence of slip parameter, viscous dissipation, and Joule heating parameter on MHD boundary layer nanofluid flow over a permeable wedge-shaped surface was analysed. The PDEs and the associated boundary conditions were transformed to a set of non-similar ODEs and the obtained system of equations was solved numerically with the help of the spectral quasi-linearization method (SQLM) by applying suitable software. This method helps to identify the accuracy and convergence of the present problem. The current numerical results were compared with previously published work and are found to be similar. The fluid velocity, fluid temperature, and nanoparticle concentration within the boundary layer region for various values of the parameters such as the slip effect, magnetic strength, Prandtl number, Lewis number, stretching ratio, viscous dissipation, suction, Brownian motion, Joule heating, heat generation, and thermophoresis are studied. It is observed that the Brownian motion, Joule heating, viscous dissipation, and thermophoresis lead to decreases in the heat and mass transfer rate. The skin friction coefficient enhances with slip, magnetic, permeability, and suction parameters, but reduces with the Brownian motion, wedge angle, and stretching ratio parameters whereas there is no effect of mixed convection, thermophoresis, heat generation parameters, the Prandtl and Eckert number.

Heat and mass transfer on unsteady MHD flow of Casson fluid over an infinite perpendicular absorbent plate with slip effects

AbstractWe study the radiative magnetohydrodynamic flow of an incompressible viscous electrically performing non‐Newtonian Casson fluid past an exponentially accelerated perpendicular surface under the influence of slip velocity in the revolving frame. A steady homogeneous magnetic strength is applied under the assumption of a less magnetic Reynolds number. The ramped temperature and time‐altering concentration near the plate are taken into consideration. Primary order consistent chemically reacting and thermal absorptions are also considered. Laplace transformation technique is engaged in the nondimensional leading equations for the closed‐form solutions. Supporting these results, the phases for nondimensional shear stresses, rate of heat as well as mass transport are also found. The graphical profiles are represented to examine the impacts of physical parameters on the important physical flow features. The computational quantities of the shears stress, rates of heat as well as mass transportation near the surface are tabulated with a variety of implanted parameters. It is observed that the resultant velocity is growing by an increase in heat and solutal buoyancy forces, while revolution, as well as slip parameters, has reverse outcomes on this. The resulting velocity is falling by an increase in the Hartmann number while the permeability parameters have overturned the impacts on this. Species concentration of Casson fluid is reduced by an increase in Schmidt quantity as well as a chemically reacting parameter.

Study on the feasibility of the heat treatment after shale gas reservoir hydration fracturing

Hydraulic fracturing is typically required before shale gas production. Residual fracturing fluid in the reservoir leads to a hydration reaction and weakens the fracturing effect. To address these problems, an additional process during the reservoir heat treatment at the time point after hydraulic fracturing and before formal extraction is proposed, namely, heat treatment after shale gas reservoir hydraulic fracturing, and analysis of the Sichuan Longmaxi Shale is used as an example. The feasibility of the method has been demonstrated by observing the changes in porosity, permeability, tensile strength and other parameters of hydrated shale after heating and exploring the influencing factors and change laws associated with each parameter. Experiments can be conducted to verify that after heating the hydrated shale, the heating temperature, heating rate and holding time are positively correlated with shale porosity, permeability and tensile strength. After shale hydration, the elastic modulus, yield limit and compressive strength decrease; after hydrated shale heat treatment, the compressive strength decreases slightly, while the elastic modulus and yield limit increase, but they are lower than those of the original shale. The changes in the parameters have a positive effect on shale gas production, and this method is theoretically feasible.

Implications of Indirect Biomarkers of Intestinal Permeability in the Stools of Newborns and Infants with Perinatal Risk Factors for Intestinal Colonization Disorders and Infant Feeding Patterns.

Background: The intestinal microbiota of pregnant women and factors disturbing the microbial balance of their gastrointestinal tract during the perinatal period may be the cause of dysbiosis and thus intestinal permeability syndrome in their children. The purpose of this study was to analyze the implications of intestinal permeability parameters in the stools of newborns and infants with perinatal risk factors for intestinal colonization disorders (the route of delivery, antibiotic therapy in the neonatal period and the abandonment of breastfeeding). Methods: The study included 100 mother–child pairs. All children were born from uncomplicated and term pregnancies (between 37 and 42 weeks of gestation). In order to determine the parameters of dysbiosis and intestinal permeability, we determined the concentrations of zonulin and occludin in stool samples taken from all children at 0 (i.e., at birth), 3, 6 and 12 months of age. Elevated levels of lipopolysaccharide (LPS) are associated with metabolic diseases and its presence may be indicative of TJ injury and the onset of leaky gut syndrome. To indirectly determine the presence of endotoxemia, the concentrations of lipopolysaccharide were also measured in stool samples taken from all children at 0, 3, 6 and 12 months of age. We analyzed the relationship between the markers studied and perinatal risk factors for impaired intestinal colonization, including the mode of delivery, the method of feeding, and a family history of allergy. Results: During the first 3 months of infant life, higher concentrations of fecal occludin and zonulin were most often accompanied by higher values of fecal LPS. Similarly, higher concentrations of zonulin were accompanied by higher values of occludin. There were no significant differences in the stool concentrations of the studied markers during the first year of life between children born by caesarean section and those born naturally. In addition, the method of feeding had no significant effect on the changes in the concentrations of the determined fractions. Antibiotic therapy was associated only with an increase in the fecal occludin concentration after birth, without any effect on zonulin, occludin or LPS levels. The use of probiotic therapy in infants resulted in a decrease in only LPS concentrations at 3 months of age, with no effect on zonulin or occludin concentrations at 0, 6 and 12 months. Conclusions: Perinatal factors related to intestinal permeability are important during the first 3 months of infant life. However, we found that the mode of delivery had no influence on the parameters of infant intestinal leakage during the first year of life. In addition, the mode of infant feeding—breast or exclusively formula—did not significantly affect the changes in the concentrations of LPS, zonulin or occludin in the stools of children. A short-term increase in occludin concentrations after delivery in the stools of children from mothers undergoing antibiotic therapy indicates a negative but reversible influence of intrapartum antibiotics on the intestinal integrity of children in the perinatal period. Probiotic therapy seems to have a positive effect on reducing endotoxemia in children during the first 3 months of life. The presence of LPS at 3 months did not affect intestinal tightness at any of the later measured periods of the infants’ lives.

Magnetohydrodynamic unsteady natural convective flow in a porous medium over a moving infinite cylinder

AbstractThe effect of the magnetic field on the unsteady natural convective one‐dimensional laminar flow of an incompressible viscous and slightly electrically conducting fluid over a vertical cylinder is investigated analytically. The cylinder is assumed to be embedded in a porous medium, and it moves with a uniform velocity along the vertically upward direction. The boundary layer flow equations are converted to a non‐dimensional form using appropriate non‐dimensional parameters, and the closed‐form solutions are obtained using the Laplace transform method. Fluid velocity depends on radial distance, time, magnetic parameter, Grashof number, permeability parameter, and Prandtl number. Graphical and tabulated results of the fluid velocity profile and shear stress based on the analytical solutions are presented and discussed. The analytical solution reveals that the unsteady fluid velocity tends to a steady state at a large time. The present study demonstrates that increased porosity leads to enhancement in the fluid velocity, whereas the transverse magnetic field resists the fluid velocity. Furthermore, the absolute value of shear stress decreases with a decrease in porosity of the medium or an increase in magnetic field effect.

Magneto-convective flow through a porous enclosure with Hall current and thermal radiation effects: numerical study

This paper reports the numerical study of magnetohydrodynamic radiative-convective flow in a square cavity containing a porous medium with Hall currents. This study is relent to hydromagnetic fuel cell design and thermofluidic dynamics of complex magnetic liquid fabrication in enclosures. The governing equations of this fluid system are solved by a finite-difference vorticity stream function approach executed in MATLAB software. A detailed parametric investigation of the impact of Rayleigh number (thermal buoyancy parameter), Hartman number (magnetic body force parameter), Darcy number (permeability parameter), Hall parameter and radiation parameter on the streamline, temperature contours, local Nusselt number along the hot wall and mid-section velocity profiles is computed. Validation with previous special cases in the literature is included. Hall current and radiative effects are found to significantly modify thermofluidic characteristics. From the numerical results, it is found that the magnetic field suppresses the natural convection only for small buoyancy ratios. But, for larger buoyancy ratio, the magnetic field is effective in suppressing the thermal convective flow.

Extremely angle-stable transparent window for TE-polarized waves empowered by anisotropic metasurfaces.

Impedance mismatch generally exists upon interfaces between different media. This is especially true for TE-polarized waves with large incident angles since there is no Brewster effect. As a result, high-efficiency transmission can only be guaranteed within limited incident angle range. It is desirable that transparent windows possess robust angle-stability. In this work, we propose a strategy of realizing transparent windows with extreme angle-stability using anisotropic metasurfaces. Different from traditional isotropic materials, anisotropic metasurfaces require specific three-dimensional permittivity and permeability parameters. Theoretical formulas are derived to realize a highly efficient transmission response without angular dispersion. To validate our design concept, a two-layer cascaded electromagnetic anti-reflector is designed, and it exhibits a characteristic impedance matching for nearly all incidence angles under TE-polarization illumination. As a proof-of-concept, a prototype of extremely angle-stable transparent window is fabricated and measured. Compared with the pure dielectric plate, the reflection coefficients are on average reduced by 40% at 13.5 GHz for TE-polarized waves from 0° to 80°. Therefore, we think, anisotropic cascaded electromagnetic transparent windows are capable of tailoring the electromagnetic parameter tensors as desired, and provide more adjustable degrees of freedom for manipulating electromagnetic wavefronts, which might open up a promising way for electromagnetic antireflection and find applications in radomes, IR windows and others.

Kitchen Diet vs. Industrial Diets-Impact on Intestinal Barrier Parameters among Stroke Patients.

Background and aims: Strokes are the second highest cause of death in the world and the most common cause of permanent disability in adults. Intestinal barrier permeability thus contributes to diminished homeostasis within the body, which further affects the healing process and convalescence. Each stroke patient should be administered with ingredients that support the intestinal barrier (e.g., protein and fiber). The aim of this study was to compare the effect of various types of diet (enteral with or without fiber vs. a mixed kitchen diet) on the metabolic activity of intestinal microbiota, namely short chain fatty acids, and gut barrier integrity parameters (zonulin and calprotectin. Methods: Patients (n = 59), after suffering an ischemic stroke, were randomly allocated to three groups receiving: the kitchen diet (n = 32; 1.2 g fiber in 100 mL); Nutrison Energy® (n = 14; 0.02 g fiber in 100 mL); and Nutrison Diason Energy HP® (n = 13; 1.8 g fiber in 100 mL). The patients underwent anthropometric measurements and blood samples (for prealbumin measurements), and stool samples (for zonulin and calprotectin determinations) were taken twice, on admission and a week later. Results: Industrial diets enriched with fiber maintained nutritional status and had a beneficial effect on intestinal barrier permeability parameters. Patients fed with kitchen diets demonstrated a decreased number of lymphocytes, hemoglobin, erythrocytes, and increased serum concentration of C-reactive protein, but improved gut barrier markers. Proton pump inhibitors were shown to increase the inflammatory process in gut. Conclusions: Stroke patients should be administered with industrial diets enriched with fiber to improve gut barrier integrity and nutritional parameters.

Experimental study of the formation of a mud cake and its characteristics on the example of the Jurassic oil reservoir

Using the geophysical and hydrodynamic compatibility model allows to reduce ambiguity of the solution of the inverse problem and to increase the reliability of productive layer parameters definition. It includes the parameters of permeability and porosity of the filter cake, which significantly affect the result of filtration modeling, but are not determined during the drilling. To investigate the process of formation of a mud cake, to study its properties and to determine the main parameters, the authors of the article carried out a series of experiments on a setup assembled at IPGG SBRAS, on core samples of low-permeability sandstone extracted from the YUS collector. The results of experiment with core samples from the Tevlinsko-Russinskoe and Russinskoe oil fields.

A stability result for the identification of a permeability parameter on Navier–Stokes equations

In this work, we present a stability result for the inverse problem of recovering a smooth scalar permeability parameter given by the Brinkman’s law applied to the steady Navier–Stokes equations from local observations of the fluid velocity on a fixed domain. In comparison with (Choulli et al 2013 Appl. Anal. 92 2127–43), we prove a logarithmic estimate under weaker assumptions, since our proof is based in a strategy that does not require pressure observations. This kind or result are useful for inverse problems in soft tissue elastography (see Honarvar et al 2012 Phys. Med. Biol. 57 5909–27). Finally, we present some numerical tests that validate our theoretical results.

Effects of Dietary Indole-3-carboxaldehyde Supplementation on Growth Performance, Intestinal Epithelial Function, and Intestinal Microbial Composition in Weaned Piglets.

As a microbial tryptophan metabolite, indole-3-carboxaldehyde (ICA) has been suggested to confer benefits to host, such as regulation of intestinal barrier function. This study aimed to elucidate the role of ICA in modulating intestinal homeostasis via using a weaned pig model. Twenty-four weaned piglets were randomly allocated into three groups: the control group (a basal diet), ICA100 group (the basal diet supplemented with 100 mg/kg ICA), and ICA200 group (the basal diet supplemented with 200 mg/kg ICA). The experiment lasted 14 d, and pigs from the control and ICA100 groups were slaughtered. The results showed no significant differences in the average daily gain (ADG) and average daily feed intake (ADFI) among the three groups (P > 0.05). However, the ICA100 group had a lower feed to gain ratio (F:G) (P < 0.05). Dietary ICA supplementation did not alter the villus height, crypt depth, and villus height/crypt depth ratio in the small intestine, and did not change the intestinal permeability and antioxidant parameters (P > 0.05). Intriguingly, ICA treatment significantly increased the jejunal, ileal and colonic indexes in piglets (P < 0.05). Besides, the expression of proliferating cell nuclear antigen (PCNA) in the intestine was up-regulated by ICA treatment. Moreover, in vitro experiments demonstrated that 15 μM ICA significantly accelerated the proliferation activity of IPEC-J2 cells, and increased the expression of the ICA receptor aryl hydrocarbon receptor (AHR) and the proliferation markers PCNA and Cyclin D1 (P < 0.05). In addition, dietary ICA supplementation modulated the intestinal flora, increasing the richness estimators and diversity index, decreasing the abundances of phylum Fibrobacterota and genera Alloprevotella, Prevotella, and Parabacteroides, and enriching the abundance of genera Butyrivibrio. These data reveal a beneficial role for the microbial metabolite ICA on intestinal epithelial proliferation, rather than intestinal barrier function, in weaned piglets.

Permeability, compressive strength and Proctor parameters of silts stabilised by Portland cement and ground granulated blast furnace slag (GGBFS)

Permeability, compressive strength and Proctor parameters of silts stabilised by Portland cement and ground granulated blast furnace slag (GGBFS)

Daily blood pressure profile and blood–brain barrier permeability in patients with cerebral small vessel disease

Cerebral small vessel disease (CSVD) plays an important role in cognitive impairment, stroke, disability, and death. Hypertension is the main risk factor for CSVD. The use of antihypertensive therapy has not resulted in the expected decrease in CSVD complications, which may be related to the underestimation of significance of daily blood pressure profile for blood–brain barrier (BBB) permeability. 53 patients with CSVD of varying severity (mean age 60.08 ± 6.8 years, 69.8% women, subjects with treated long-standing hypertension vs. normotensive subjects − 84.8% vs. 15.2%) and 17 healthy volunteers underwent ambulatory blood pressure monitoring (ABPM) and MRI, including T1-weighted dynamic contrast-enhanced magnetic resonance imaging for assessing BBB permeability. Most of ABPM parameters in CSVD patients did not differ from controls, but were associated with the severity of white matter hyperintensity (WMH) and the total CSVD score. BBB permeability in normal-appearing white matter (NAWM) and grey matter (GM) was significantly higher in CSVD patients, and the severity of BBB permeability remained similar in patients with different stages of WMH. Among BBB permeability parameters, the area under the curve, corresponding to an increase in the contrast transit time in NAWM, had the greatest number of correlations with deviations of ABPM parameters. BBB permeability in CSVD is a universal mechanism of NAWM and GM damage associated with a slight increase in ABPM parameters. It is obvious that the treatment of hypertension in patients with not severe WMH should be more aggressive and carried out under the control of ABPM.

Reservoir Characterization and Productivity Forecast Based on Knowledge Interaction Neural Network

The reservoir characterization aims to provide the analysis and quantification of the injection-production relationship, which is the fundamental work for production management. The connectivity between injectors and producers is dominated by geological properties, especially permeability. However, the permeability parameters are very heterogenous in oil reservoirs, and expensive to collect by well logging. The commercial simulators enable to get accurate simulation but require sufficient geological properties and consume excessive computation resources. In contrast, the data-driven models (physical models and machine learning models) are developed on the observed dynamic data, such as the rate and pressure data of the injectors and producers, constructing the connectivity relationship and forecasting the productivity by a series of nonlinear mappings or the control of specific physical principles. While, due to the “black box” feature of machine learning approaches, and the constraints and assumptions of physical models, the data-driven methods often face the challenges of poor interpretability and generalizability and the limited application scopes. To solve these issues, integrating the physical principle of the waterflooding process (material balance equation) with an artificial neural network (ANN), a knowledge interaction neural network (KINN) is proposed. KINN consists of three transparent modules with explicit physical significance, and different modules are joined together via the material balance equation and work cooperatively to approximate the waterflooding process. In addition, a gate function is proposed to distinguish the dominant flowing channels from weak connecting ones by their sparsity, and thus the inter-well connectivity can be indicated directly by the model parameters. Combining the strong nonlinear mapping ability with the guidance of physical knowledge, the interpretability of KINN is fully enhanced, and the prediction accuracy on the well productivity is improved. The effectiveness of KINN is proved by comparing its performance with the canonical ANN, on the inter-well connectivity analysis and productivity forecast tasks of three synthetic reservoir experiments. Meanwhile, the robustness of KINN is revealed by the sensitivity analysis on measurement noises and wells shut-in cases.