Permeable Layer Research Articles

Electromechanical Properties of 3D-Printed Stretchable Carbon Fiber Composites.

The addition of fillers has been implemented in fused filament fabrication (FFF), and robust carbon fillers have been found to improve the mechanical, electrical, and thermal properties of 3D-printed matrices. However, in stretchable matrices, the use of fillers imposes significant challenges related to quality and durability. In this work, we show that long carbon staple fibers in the form of permeable carbon fiber cloth (CFC) can be placed into a stretchable thermoplastic polyurethane (TPU) matrix to improve the system. Four CFC sample series (nominally 53–159-µm-thick CFC layers) were prepared with a permeable and compliant thin CFC layer and a highly conductive and stiff thick CFC layer. The sample series was tested with single pull-up tests and cyclic tensile tests with 10,000 cycles and was further studied with digital image correlation (DIC) analyses. The results showed that embedded CFC layers in a TPU matrix can be used for stretchable 3D-printed electronics structures. Samples with a thin 53 µm CFC layer retained electrical properties at 50% cyclic tensile deformations, whereas the samples with a thick >150-µm CFC layer exhibited the lowest resistance (5 Ω/10 mm). Between those structures, the 106-µm-thick CFC layer exhibited balanced electromechanical properties, with resistance changes of 0.5% in the cyclic tests after the orientation of the samples. Furthermore, the suitability of the structure as a sensor was estimated.

Numerical simulations of the synthetic processes and consequences of secondary hydrates during depressurization of a horizontal well in the hydrates production

The depressurization method was implemented through a horizontal well in the production test at Shenhu, the South China Sea in 2020. The numerical model of a layered hydrate reservoir was established based on the in-field data of this test. The gas production rates measured was validated by comparing with the numerical results. The synthesis time, scopes, gas sources and maximum saturations of secondary hydrates were originally clarified by analyzing the data from different monitoring sections, which followed by the sensitivity analyses against the initial permeability of each hydrate-bearing layer. The effect of secondary hydrates on the short-term and long-term productions was quantified. The hydrates were resynthesized extensively above the interface between the natural gas hydrate layer and the mixing layer, which reduced the in-situ permeability and then the well gas production seriously. The areas affected by depressurization were constrained within the mixing layer. The gas sources were supplemented by the primary free gas and the gas decomposed by the hydrates in the upper mixing layer. The vertical extensions of the secondary hydrates were limited to about 5 m due to the lower permeability, while the horizontal distributions were approximately 78 m away from the horizontal well after 3 years. Given that the secondary hydrates were eliminated artificially, the cumulative gas volume produced in the horizontal well was increased by 24% after 3 years. The sensitivity analysis showed that the variations of permeability in the mixing layer had more obvious effects on secondary hydrates. Therefore, the hydraulic fracturing could be used to prevent the resynthesis of hydrates.

Optimizing the Porohyperelastic Response of a Layered Compliance Matched Vascular Graft to Promote Luminal Self-Cleaning.

Thrombosis and intimal hyperplasia have remained the major failure mechanisms of small-diameter vascular grafts used in bypass procedures. While most efforts to reduce thrombogenicity have used a biochemical surface modification approach, the use of local mechanical phenomena to aid in this goal has received somewhat less attention. In this work, the mechanical, fluid transport, and geometrical properties of a layered and porous vascular graft are optimized within a porohyperelastic finite element framework to maximize self-cleaning via luminal reversal fluid velocity (into the lumen). This is expected to repel platelets as well as inhibit the formation of and/or destabilize adsorbed protein layers thereby reducing thrombogenic potential. A particle swarm optimization algorithm was utilized to maximize luminal reversal fluid velocity while also compliance matching our graft to a target artery (rat aorta). The maximum achievable luminal reversal fluid velocity was approximately 246 μm/s without simultaneously optimizing for host compliance. Simultaneous optimization of reversal flow and compliance resulted in a luminal reversal fluid velocity of 59 μm/s. Results indicate that a thick highly permeable compressible inner layer and a thin low permeability incompressible outer layer promote intraluminal reversal fluid velocity. Future research is needed to determine the feasibility of fabricating such a layered and optimized graft and verify its ability to improve hemocompatibility.

Cyclic liquefaction resistance of sand under a constant inflow rate

Cyclic resistance curves, derived through undrained element tests, are central to the study of liquefaction. Their use implies that water drainage is negligible during an earthquake. Nevertheless, a growing body of evidence suggests that this hypothesis is not realistic. In proximity to the interface of a liquefiable layer with an overlying lower permeability layer, upwards water flow can lead to localised, co-seismic pore volume increase. The aim of this paper is to quantify the effects of pore volume increase on cyclic resistance curves. Cyclic triaxial experiments are presented, performed under undrained conditions and under conditions of volumetric expansion. A constant inflow rate is chosen for the sake of simplicity. Results show that even small inflow rates have a detrimental effect on cyclic resistance. A simplified methodology is developed, which can estimate cyclic resistance under constant water inflow rates, by assuming a superposition of isotropic unloading and undrained cyclic shearing. The results presented add to increasing evidence on how current liquefaction susceptibility assessments might not be conservative for layered deposits. In addition, they highlight significant aspects of soil response under partially drained conditions.

Comparison of the deuterium permeability of copper, CuCrZr, and Cu layers

In order to estimate the fuel loss in ITER and further future fusion devices, the deuterium permeation through different wall and structural materials are studied. In order to determine the effective permeability, gas-driven deuterium permeation measurements are performed on Cu and ITER grade CuCrZr. The obtained permeabilites for Cu and ITER grade CuCrZr are very similar and in agreement to literature values for Cu. For a better estimation for fusion reactor components, combined material samples are studied. Cu layers were applied on steel substrates by magnetron sputter deposition. With these studies, the influence of interfaces and microstructure on the hydrogen permeation is investigated. Our study reveals that in the case of Cu layered steel substrates the influence of the interface on the permeation flux is minor compared to the influence of the microstructure on the permeability. The Cu layer permeability is around one order of magnitude smaller than the Cu bulk permeability in the temperature range between 300 ∘ C and 550 ∘ C . • Study of the deuterium permeation through first wall materials of fusion devices • Cu, CuCrZr-IG, and Cu layers on ITER steel are prepared, characterized and analyzed • The influence of an interface on the permeation flux was studied • The permeability of Cu layers is one order of magnitude lower than of bulk Cu • The reduction of the permeability is mainly due to the microstructure of the layer

Research on rational development mode of gas cap marginal water reservoir

In this paper, based on the 3D physical simulation experiment of gas cap marginal water reservoirs, a reasonable development method for gas cap marginal water reservoirs is studied. The results show that the ultimate recovery rate of exhausted development is 32.24%, and that of flooding water flooding development is 51.17%, which is 18.93% higher than that of exhausted development. In different permeability layers, there is an amount of residual oil, which is distributed in the oil ring and gas cap. At the same time, the injection time and productivity of flooding water flooding were compared and analyzed by numerical simulation. The one-year recovery rate of exhausted development is the highest, and when the injection ratio is 1.2, the recovery rate is the highest. The research in this paper is of great significance to the formulation of production parameters and the implementation of later reformation measures for the depleted gas cap marginal water reservoirs.

Assessment of the impact of diluted and pretreated olive mill wastewater on the treatment efficiency by infiltration-percolation using natural bio-adsorbents.

The current study was carried out to treat the olive mill wastewater (OMW) via infiltration percolation process, using low-cost natural adsorbents that could improve the ability of the system to enhance the disposal rate of elimination of pollutant from the OMW. The experimental pilot was composed of three PVC(polyvinyl chloride)columns with 10cm in diameter and 110-cm height equipped with lateral air entries. Each column was filled with four layers of 10cm of a mixture of sand (70%), charcoal (20%) and sawdust (10%) respectively. These layers were alternated by four permeable layers of 10cm of Pouzzolane. To assess the effect of the pretreatment on the efficiency of the system, three types of OMW were used: raw OMW, diluted OMW with domestic wastewater at 1/1(v/v) ratio and OMW pretreated with lime. For the column feed with raw OMW, an average removal of total COD (41%), dissolved COD (54%), NH4-N (40.25%), NO3- (15.76%), total phosphorus (55.63%) and orthophosphate (50.84%) was recorded. The results showed that the column feed with diluted OMW with domestic wastewater was the most efficient one with a removal rate that reached 93.2% of total COD, 86.2% of dissolved COD, 92% of polyphenol, 92% of orthophosphate (OP), 97.2% of total phosphorus (TP) and 81% of NH4-N. The pretreatment of OMW with lime gave the lowest removal rate for all the parameters: total COD (34%), dissolved COD (50%), NH4-N (30%), NO3- (- 21%), total phosphorus (15.19%) and orthophosphate (9.04%). This study demonstrated that the dilution is a way to optimize the efficiency of the system of infiltration-percolation in treating the OMW.

Magnetoimpedance modulation in a planar magnetoelectric ferromagnet – piezoelectric heterostructure

The effect of a giant change in the impedance of ferromagnetic materials under the action of an external magnetic field is widely used to elaborate highly sensitive magnetic field sensors. The purpose of this work was to demonstrate the possibilities of controlling the magnitude of the magnetoimpedance in a ferromagnet-piezoelectric structure using an electric field. Method. In the measurements, we used a planar heterostructure containing a strip of amorphous ferromagnet Metglas, 25 µm thick and 25 mm long, mechanically connected to a bimorph, 0.5 mm thick and 30 mm long, made of piezoceramic lead zirconate titanate. An alternating current with a frequency of 30 kHz...10 MHz was passed through the strip, the structure was placed in a longitudinal permanent magnetic field of 0...500 Oe, an alternating electric field up to 400 V/cm with a frequency of 60 Hz...50 kHz was applied to the piezobimorph, and the change in the impedance of the strip was recorded. Results. In the absence of electric field, a narrowing of the magnetoimpedance magnetic fields region with a decrease in the current frequency and saturation of the magnetoimpedance in magnetic fields above 334 Oe were observed. The maximum value of the magnetoimpedance reached 18% at a current frequency of 1 MHz. The application of electric field to the piezobimorph led to the appearance of side components in the frequency spectrum of the voltage on the ferromagnetic layer, which indicates the amplitude-phase modulation of the magnetoimpedance. The amplitude modulation coefficient reached a maximum value of 6 · 10−3 for the electric field frequency of 11.2 kHz and decreased monotonically with an increase in the magnetic field. The modulation of the magnetoimpedance occurs due to the converse magnetoelectric effect in the heterostructure, which leads to the modulation of the magnetization of the ferromagnetic layer, and the subsequent change in the relative magnetic permeability and thickness of the skin layer in the ferromagnet. The results obtained can be used to create magnetic fields sensors controlled by an electric field.

Fracture characterization based on improved seismic amplitude variation with azimuth inversion in tight gas sandstones, Ordos Basin, China

Fractures are essential for gas accumulation in tight sandstones, as they enhance reservoir permeability and provide migration paths for fluid transport. The presence of fractures facilitates the formation of fracture networks during hydraulic fracturing and, therefore, is important for effective development of tight gas sandstones. Accordingly, predicting fracture distribution could provide insight into the reservoir quality of tight gas sandstones. Seismic amplitude variation with azimuth can evaluate the properties of vertical fractures embedded in tight sandstone. This study proposes an improved inversion scheme based on azimuthal amplitude differences to compute anisotropic parameters for fracture characterization by incorporating rock physics relationships. Our proposed method improves the robustness of the anisotropic parameter estimates by removing the effect of the isotropic background using azimuthal amplitude difference data obtained after evaluating fracture strikes. Theoretical modeling and real data analysis illustrated the enhanced sensitivity of the azimuthal amplitude differences to the anisotropy related to fractures. Real data applications indicated that the predicted fracture strikes coincide with the results estimated by tectonic stress field analysis. The computed fracture density correlates with logging permeability, implying considerable influence from fractures on permeability improvement in tight sandstones. Further analysis indicated that the gas production capacity of tight sandstones is affected simultaneously by fractures and gas enrichment. Accordingly, an integrated indicator is proposed to evaluate reservoir quality, that simultaneously considers the degree of fracture development quantified by the fracture density, and gas enrichment represented by rock compressibility. The proposed indicator is correlated positively with comprehensive reservoir properties defined by the cumulative sand layer thickness, porosity, gas saturation, and permeability, providing a reliable and practical pointer to identify favorable areas in tight gas sandstones.

Investigating porosity structure effects on hydrothermal mineralization patterns within permeable horizontal layers of fluid-saturated rocks: Semi-analytical approach through generic models

The porosity structures of a permeable rock can have remarkable effects on pore-fluid flow within the rock. According to the modern mineralization theory, the mineralization pattern in a hydrothermal ore-forming system is strongly dependent on the pore-fluid flow velocity, so that different porosity structures of a permeable rock can affect significantly hydrothermal mineralization patterns within the permeable layers consisting of fluid-saturated porous rocks. This paper presents a semi-analytical approach, in which pore-fluid velocity is directly used as fundamental primary variables in the governing equations of the problem and the property matrices of finite elements are analytically evaluated in a purely mathematical manner, to ensure the high accuracy of the obtained pore-fluid velocity, which is involved in controlling mineralization patterns in hydrothermal ore-forming systems. After the proposed semi-analytical approach is verified through comparing the numerical solution with the analytical solution for a benchmark problem, it has been used to investigate how different porosity structures can affect the hydrothermal mineralization patterns within permeable horizontal layers consisting of fluid-saturated porous rocks through using a generic model, which can be viewed as the representation of a generalized and simplified geological model. Main outcomes of this study have demonstrated that: (1) the proposed semi-analytical approach can produce highly-accurate numerical solutions for solving coupled pore-fluid flow and heat transfer problems in fluid-saturated porous rocks with different porosity structures; (2) the different porosity structure within a permeable horizontal layer consisting of fluid-saturated porous rocks can have a significant effect on the hydrothermal mineralization pattern of the permeable horizontal layer; (3) layered pore-fluid vertical velocity focusing may take place within a permeable horizontal layer involving a heterogeneous porosity structure.

STUDI POTENSI AIR TANAH MENGGUNAKAN METODE GEOLISTRIK KONFIGURASI SCHLUMBERGER DAN WENNER DI KAMPUNG NAMBON KABUPATEN JAYAPURA

Kampung Nambon is a village in Jayapura regency which has no access to clean water. Groundwater is an alternative water source for villages which are prone to surface water sources. Groundwater aquifers are porous and permeable subsurface layers which can hold and transmit groundwater. Geoelectric method is a common geophysical method for groundwater exploration due to direct relationship between resistivity and water content. The objective of this study is to characterize subsurface structure of Kampung Nambon and to estimate the depth of potential groundwater aquifer using Vertical Electrical Sounding (VES) of Schlumberger array and Electrical Resistivity Tomography (ERT) of Wenner array. An ERT line of 100 metres whose midpoint is the sounding point of VES with maximum electrode spacing (AB/2) of 250 metres were performed. The results show that subsurface at Kampung Nambon is heterogeneous with significant lateral variation where karst formation was estimated at depth range of 5 – 15 meters. This karst formation might contain groundwater flow as indicated by relatively low resistivity values compared to high resistivity background of Limestone from Jayapura formation (Qpj).

Optimization of the numerical treatment of the Darcy–Forchheimer flow of Ree–Eyring fluid with chemical reaction by using artificial neural networks

AbstractIn this study, Darcy Forchheimer flow paradigm, which is a useful paradigm in fields such as petroleum engineering where high flow velocity effects are common, has been analyzed with artificial intelligence approach. In this context, first of all, Darcy–Forchheimer flow of Ree–Eyring fluid along a permeable stretching surface with convective boundary conditions has been examined and heat and mass transfer mechanisms have been investigated by including the effect of chemical process, heat generation/absorption, and activation energy. Cattaneo–Christov heat flux model has been used to analyze heat transfer properties. Within the scope of optimizing Darcy–Forchheimer flow of Ree–Eyring fluid; three different artificial neural network models have been developed to predict Nusselt number, Sherwood number, and skin friction coefficient values. The developed artificial neural network model has been able to predict Nusselt number, Sherwood number, and skin friction coefficient values with high accuracy. The findings obtained as a result of the study showed that artificial neural networks are an ideal tool that can be used to model Darcy–Forchheimer Ree–Eyring fluid flow towards a permeable stretch layer with activation energy and a convective boundary condition.

Numerical modeling of species transport and functional characteristics of a proton exchange membrane fuel cell using an agglomerate model with a multi-phase model

In this study, the species transport and functional characteristics of a Proton Exchange Membrane Fuel Cell (PEMFC) using the agglomerate model are carried out. The modeling is two-dimensional and a two-phase flow is provided to separate liquid water and gas inside the fuel cell. The water transfer modeling is carried out using three mechanisms of vapor, liquid water, and dissolved water through the membrane. The entropy generations due to viscous loss, heat transfer, Ohmic losses, mass transfer, and latent heat are obtained. The effects of agglomerate radius, active layer thickness, permeability, and porosity on the current density, species transport, power density, liquid water, temperature distribution, and entropy generation are investigated. The results show that permeability has a significant effect on water management formed in the cathode gas diffusion layer. Also, the total entropy generation is more evident at the low voltages. The findings show that using a smaller agglomerate radius and larger active layer thickness has a better effect on the current density and thus results in higher power density. At 0.7 V, as the agglomerate radius doubles, the current decreases by 41 %. At 0.6 V, however, a 34 % increase in power density is seen in the minimum agglomerate radius.

Evaluation of the In Vitro Wound-Healing Potential of Ayahuasca.

Ayahuasca is an Amazonian drink, which contains β-carboline alkaloids and N,N-dimethyltryptamine. The aim of this study was to evaluate the healing potential of decoctions of a commercial mixture, four individual plants and four mixtures of two plants used in the ayahuasca preparation. Thus, the cytotoxic potential of the samples was evaluated and a wound-healing assay was performed with a NHDF cell line. Subsequently, a parallel artificial membrane permeability assay was also performed, to verify if any psychoactive compound could be absorbed by skin fibroblasts. The integrity and permeability of the cell layer were also evaluated, using the transepithelial electrical resistance assay and Lucifer yellow permeability assay, respectively. The compounds absorbed by the cell layer were quantified by high-performance liquid chromatography coupled to a diode array detector. The results showed that only one sample showed cytotoxicity and all the others promoted the migration of skin fibroblasts. Additionally, it was also verified that β-carbolynic alkaloids and N,N-dimethyltriptamine were not absorbed by the cell layer, and in general, did not interfere with its permeability and integrity. To the best of our knowledge, this is the first study where ayahuasca’s wound-healing potential was evaluated.

TRIM46 aggravated high glucose-induced hyper permeability and inflammatory response in human retinal capillary endothelial cells by promoting IκBα ubiquitination

BackgroundDiabetic retinopathy (DR) as a severe diabetic complication contributes to blindness. The increased permeability of retinal capillary endothelial cells (RCECs) as well as the production of inflammatory markers are closely related to DR occurrence. We recently revealed that TRIM46 promotes high glucose (HG)-caused ferroptosis in human RCECs (HRCECs). The current study aims to explore the molecular mechanism of how TRIM46 plays its role in DR progression.MethodsWestern blot was utilized to determine protein expression. The cell counting kit-8 assay was used to observe cell viability. The permeability of the cell layer was determined by measuring the transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran leak. Enzyme-linked immunosorbent assay was used to quantify the protein level of pro-inflammatory cytokines and co-immunoprecipitation was employed to verify the relationship between TRIM46 and IκBα.ResultsHG dramatically upregulated TRIM46 protein expression in a dose-dependent way. Silencing TRIM46 effectively reversed HG-induced cell growth inhibition, cell cycle arrest, hyper permeability and pro-inflammatory cytokines secretion in HRCECs, while overexpression of TRIM46 exhibited an opposite effect. Furthermore, TRIM46 was able to interact with IκBα and promote the ubiquitination and degradation of IκBα. IκBα overexpression recovered the effects of TRIM46 overexpression in HRCECs. Furthermore, inhibiting the activation of NF-κB partially recovered HG-induced HRCEC injury, whereas TRIM46 overexpression reversed these effects.ConclusionThis study demonstrates that TRIM46 interacts with IκBα to activate the NF-κB signaling pathway, thereby enhancing cell proliferation inhibition, hyper permeability and the inflammatory response of HRCECs in a HG state.

Investigating poromechanical causes for hydraulic fracture complexity using a 3D coupled hydro-mechanical model

Hydraulic fracturing is widely used to increase permeability of tight deep geological formations for improving oil and gas production and enhance geothermal energy extraction. Prior studies often predicted simple planar or near planar hydraulic fractures even though these simple fractures do not adequately explain the measured data. Instead, it is likely that complex fracture networks are created. The phenomenon of hydraulic fracture branching that gives rise to complex fracture networks is poorly understood. In this study, we develop a numerical modeling tool, based on sequential coupling of solid solver HOSS and fluid solver PFLOTRAN, to investigate the mechanisms for hydraulic fracture branching. The spherocylindrical microplane constitutive model is implemented to model fracture growth in anisotropic rocks. We verify our coupled model using the KGD analytical solution. Using a set of simulations, we demonstrate that a hydraulic fracture can branch into lateral directions for certain in situ stress conditions if there are pre-existing permeable weak layers whose initial Biot effective stress coefficient is greater than that of the matrix. In addition, we investigate the effect of three-dimensional pre-existing geological discontinuities on the creation of complex fracture systems. Our results demonstrate that branched hydraulic fractures can be predicted if we account for (1) damage-dependent Biot effective stress coefficients and (2) pre-existing geologic discontinuities. This represents a 3D poromechanics mechanism for the creation of branched fracture networks where multiple fractures can propagate simultaneously in a dense parallel swarm.

Thermosolutal natural convection cooling process of a thermal source inside a partially porous cavity

This work deals with the numerical study of the thermosolutal natural convection from a heat source immerged in a porous layer, which is placed vertically inside a square cavity. All walls of the cavity are thermally insulated, except the right wall, which is maintained at cold temperature. For the mass boundary conditions, the vertical walls are subjected to a gradient of concentration, whereas the horizontal walls and the part of the left wall that contacts with the heat source are impermeable. The finite volume method and the SIMPLER algorithm are employed to solve the mathematical equations. The effects of several geometrical and physical parameters are analyzed, such as vertical heat source positions (0 ≤ Yp ≤ 0.8), the porous layer thickness (0 ≤ Xp ≤ 1), the thermal conductivity ratio (1 ≤ Kr ≤ 100), Darcy number (10−6 ≤ Da ≤ 10−2), Rayleigh number (104 ≤ Ra ≤ 106), Lewis number (0.1 ≤ Le ≤ 10), and the buoyancy ratio (-5 ≤ N ≤ 5). The results indicate that the best cooling of the heat source is observed when the Yp is located between 0.38 and 0.55. Moreover, the case of coupling heat and mass transfer (N ≠ 0) offers low maximum heat source temperature compared to that of the classical natural convection (N = 0), especially with an increase in the Ra number and N and/or a decrease in the Le number. In addition, an increase in the thermal conductivity ratio and the permeability of the porous layer (Da) enhances the cooling process of the thermal source.

Mechanistic study of plastic layer permeability during coking of Australian metallurgical coals

The plastic layer permeability of five Australian coals was analyzed using two permeability measurement apparatuses operating under isothermal and thermal gradient induced coking conditions. In addition, the microstructure transitions across the plastic layers of the coals were analyzed using Synchrotron micro-CT. The permeability results and pore structure parameters derived from those analyses were correlated to better understand the mechanisms of plastic layer permeability. The high-rank coking coal with low fluidity showed a low plastic layer permeability over a wide temperature range and the generation of high internal gas pressure (IGP). Among all samples tested, the high-rank coal formed an intermediate plastic layer with the lowest number of isolated pores and the smallest size of open pores. This suggests that the lower deformability of the pore structures brought about by the low fluidity prevented additional pore growth and thus hindered pore interconnectivity. Additionally, it is possible that the low permeability in the resolidfied layer lends to pore expansion due to the difficulty of volatile release, evidenced by the larger volume of open pores within a larger size range of 50–100 µm. It appears that the intermediate plastic layer with less interconnectivity solidified into the expanded open pore structures in the resolidified layer through the driver of high IGP, thus contributing to the low permeability. In addition, the formation of the low permeable barrier seemed to redirect the volatiles evolved from the plastic layer toward the loose coal side, which dramatically reduced the temperature range of the plastic layer during its progression from the wall to the center. These results suggest that the plastic layer permeability is influenced by several factors which affect mass transfer in the plastic layer. As such, various approaches were used in this study to observe phenomena of plastic layer permeability.

A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites

AbstractA new method to determine fluid flux at high pressures and temperatures has been developed and used to study serpentinites at subduction zone conditions. Drill cores of a natural antigorite‐serpentinite with a strong foliation were used in multi‐anvil experiments in the range of 2–5 GPa and 450–800°C. Fluids released upon dehydration are fixed by the formation of brucite in an adjacent fluid sink. The amount and distribution of brucite serves as a proxy for fluid flow. In our specific setup the sample reacted with the surrounding fluid sink to form an additional layer of olivine, which has the potential to limit fluid flux within our experiments. For conditions prior to serpentine dehydration we used Al(OH)3 as fluid source. Fluid in this experiment did not migrate through the serpentinite, indicating that serpentine has a low diffusivity. The experiments also show that small deviatoric stresses have an influence on the fluid flux and can cause an anisotropic fluid flux. Comparison between the time scales of the determined fluid flux with fluid production rates indicates fluid pressure buildup during dehydration reactions. Adjacent less permeable layers can inhibit fluid flux and cause fluid pressure buildup even at conditions when an interconnected pore space formed.

Super-resolution imaging of Maxwell’s fish-eye lens based on surface polaritons

Super-resolution imaging plays a crucial role in the fields of nanolithography, high volume transmission and sensing. Relentless efforts have been made to realize super-resolution imaging in the past decades. In this work, inspired by the mechanism of surface plasmon polaritons (SPPs), we find that Maxwell’s fish-eye lens (MFEL) coated with cylindrical layer of negative permeability can achieve super-resolution imaging. The amplification of evanescent waves in the negative permeability layer facilitates the transmittance of high spatial frequency information from object point to imaging point in the form of magnetic surface polaritons (MSPs). Both analytical calculations and numerical simulations are employed to prove the super-resolution imaging performance of MSPs-assisted MFEL. Our results may pave a new way for super-resolution imaging in metallic systems.