Field Permeability Research Articles

Modeling of Electric MHD Flow of Nanoparticles in a CMC-Water Based Casson Hybrid Nanofluid over a Porous Medium

The principal focus of this exploration is to study the computationally simulate the combined convection of CMC-water-based Casson hybrid nanofluid through a stretching sheet with electric magnetic force in a porous medium. Copper (Cu) and Silver (Ag) nanoparticles are included to enhance the heat transfer performance of CMC-water. The physical problem is formulated with mathematical PDEs, and to solve this, initially we used similarity transformation technique to reduce the PDEs into ODEs, then Runge-Kutta Fehlberg method (RKFM) of order four with shooting technique is adopted for further reduction from the non-linear ODEs to first order DEs. The influence of key parameters such as the magnetic field parameter (M), porous medium parameters (K), electric field factor (E), radiation parameter (Nr), permeability parameter (λ), Casson parameter (β), and Eckert number (Ec) on relevant physical quantities is illustrated through tables and graphical visualizations. The impact of these parameters on velocity and temperature profiles, as well as on the skin friction coefficient and Nusselt number of the nanofluid, is observed. Our results indicate that an increase in the Casson parameter values leads to a decrease in the velocity of the host fluid in the case of opposite flow, and a similar behavior is observed with the nanoparticle porous medium parameter (K) in the case of assisting flow. Furthermore, the use of the Runge-Kutta Fehlberg Method (RKFM) is found to be more accurate and reliable in dealing with the problem studied in this work.

Evaluation of the effect of binder type and layer thickness on the performnce of open graded friction courses

To improve the long-term durability and functionality of open graded friction courses (OGFC), the Florida Department of Transportation (FDOT) investigated the use of a highly modified asphalt binder and increased thickness using Accelerated Pavement Testing (APT). A total of six test sections with combinations of two modified binder types (PG 76–22 and PG 82–22) and three lift thicknesses of 0.75 (19.05 mm), 1.25 (31.75 mm) and 2 (50.8) inches were constructed at FDOT’s APT facility. Accelerated loading was performed using a Heavy Vehicle Simulator (HVS) to evaluate the relative rutting performance of the test sections. Supplementary field and laboratory tests to evaluate tensile strength, Cantabro loss, field permeability, surface characteristics, and asphalt binder properties were also conducted. Test results indicated that the use of PG 82–22 polymer modified asphalt (PMA) binder may be beneficial to improve long-term durability of the OGFC. Thicker layers of OGFC were found to have considerably lower durability. It is recommended that the use of a highly modified PMA asphalt binder in OGFC layers be considered when raveling and other durability issues are of concern.

Influence of a Shaky Start upon Overdamped or Underdamped Field Permeability (Slug) Test Results

Influence of a Shaky Start upon Overdamped or Underdamped Field Permeability (Slug) Test Results

An experimental study on the influence of pressure on permeability and seismic velocity in the Montserrat geothermal field (West Indies)

Volcanic regions are prime areas for harnessing geothermal energy. However, the geological complexity of these regimes can hinder the efficient exploitation of this renewable resource. As useful as geophysical surveys are in understanding the subsurface, models can be unconstrained due to the lack of realisitic data. Here, we present the results of a new laboratory study measuring permeability and P-wave velocity on altered lavas, volcaniclastic sediments and limestones samples obtained from three cores retrieved from the MON-3 well, drilled in the Montserrat geothermal field. By measuring these parameters at increasing effective pressure varying from 10 to 70 MPa, we found permeability stress senstivity factors varying from 0.006 to 0.122 MPa−1 and increases in P- wave velocity between 2 and 20 %. The highest permeability stress senstivity factor and largest increase in P-wave velocity found in altered lavas were interpreted to be as a result of the easy closure and deformation of slit shaped microfractures and smectite clays characteristic of low bulk modulus. Conversely, lowest permeability stress senstivity factors and smallest increases in P-wave velocity found in volcaniclastic sediments, were coincident with intergranular pore geometries and higher bulk modulus minerals such as quartz and illite-smectite that may enhance the rigidity of the rock. Additionally, by measuring permeability and P-wave velocity on samples cored perpendicular (vertical) and parallel (horizontal) to the axis of the core, we found higher permeability senstivity factors (0.001–0.05 MPa−1 higher) and P-wave velocity increases (1–4 % higher) on horizontal samples, which is consistent with the preferential closure of horizontally oriented pore spaces. From this experimental study, we provide implications for enhancing geothermal energy recovery in Montserrat. Overall, our findings can be utilized to help improve on geophysical and numerical models of volcanic geothermal regimes.

Analytical solution for MHD nanofluid flow over a porous wedge with melting heat transfer

This study employs the Hybrid Analytical-Numerical (HAN) method to investigate steady two-dimensional magnetohydrodynamic (MHD) nanofluid flow over a permeable wedge. Analyzing hyperbolic tangent nanofluid flow, the governing time-independent partial differential equations (PDEs) for continuity, momentum, energy, and concentration transform into a set of nonlinear third-order coupled ordinary differential equations (ODEs) through similarity transformations. These ODEs encompass critical parameters such as Lewis and Prandtl numbers, Brownian diffusion, Weissenberg number, thermophoresis, Dufour and Soret numbers, magnetic field strength, thermal radiation, power law index, and medium permeability. The study explores how variations in these parameters impact the velocity field, skin friction coefficient, Nusselt, and Sherwood numbers. Noteworthy findings include the sensitivity of fluid velocity to parameters like Weissenberg number, power law index, wedge angle, magnetic field strength, permeability, and melting heat transfer. The skin friction coefficient experiences a significant increase with specific parameter changes, while Nusselt and Sherwood numbers remain relatively constant. The local Reynolds number significantly affects Nusselt and Sherwood numbers, with a less pronounced impact on the skin friction coefficient. The study's uniqueness lies in employing the analytical HAN method and extracting recent insights from the results.

Performance Characteristics and Optimization of a Single-Stage Direct Air Capture Membrane System in Terms of Process Energy Intensity

The increase in emissions and concentration of carbon dioxide in the atmosphere necessitates the implementation of direct carbon dioxide capture technologies. The article presents the characteristics of a single-stage membrane unit for the direct capture of carbon dioxide from the air. A membrane with a selectivity of αCO2/N2=70 and permeability PCO2=108m3(STP)(m2·h·bar) is chosen as the reference variant. It is demonstrated that increasing the pressure difference in the system by reducing the pressure of the permeate stream results in an improvement of all analyzed parameters. Manipulating both the membrane surface and its CO2 permeability yields similar results. With an increase in permeability or membrane surface area, the proportion of CO2 in the retentate and permeate decreases, while the degree of carbon dioxide recovery increases. However, the energy intensity of the process is a complex issue due to the presence of a local minimum in the obtained characteristics. Therefore, a relationship between the constants of energy intensity values for the separation process on the surface area field and CO2 membrane permeability is presented. The minimum energy intensity of the process obtained is 22.5 kWh/kgCO2. The CO2 content in the retentate for all analyses did not exceed 280 ppm.

Bridging Field and Laboratory Permeabilities of Pervious Pavement Mixtures Using XRCT-Based Numerical Modeling

Bridging Field and Laboratory Permeabilities of Pervious Pavement Mixtures Using XRCT-Based Numerical Modeling

A case of Legionella pneumonia after robot‐assisted radical prostatectomy

IntroductionPostoperative Legionella pneumonia is very rare.Case presentationA 71‐year‐old male patient with prostate cancer (cT2bN0M0) underwent a robotic‐assisted radical prostatectomy. On the 5th postoperative day, the patient developed chills and a fever of 39.2°C. Chest radiography revealed decreased permeability in the right middle lung field, leading to the diagnosis of postoperative pneumonia. Antimicrobial therapy was initiated immediately. Blood tests on postoperative day 10 revealed mild liver function abnormalities, electrolyte abnormalities, and a markedly elevated inflammatory response. Legionella pneumonia was suspected based on blood sample results and systemic symptoms, such as diarrhea and nausea. Furthermore, Legionella antigens were detected in the patient's urine, prompting further administration of levofloxacin. The patient's subsequent clinical course was favorable.ConclusionWhen bacterial pneumonia fails to respond to antimicrobial therapy and systemic symptoms develop, atypical pneumonia, caused by pathogens such as Legionella pneumophila, should be considered even in cases of postoperative pneumonia.

Importance of the Relationship Between VMA and Permeability on the Durability Properties by using Crumb Rubber with Different Percentage Portions

For the past ten years, engineers have been deeply researching the permeability of asphalt concrete. High-air voids have generally been the main indicator of permeable hot asphalt concrete in the work that has been done. The prediction of the field permeability values is inconsistent with that indicated in the current published literature. Furthermore, the precise correlations between the various components influencing the field permeability are unclear and complex. One of our objectives of this research work is to present the investigations performed using the model-ling of Hot Mix Asphalt's (HMA's) field permeability using crumb rubber (CR). The primary benefit of using crumb rubber in asphalt mixture is to produce pavement that could be friendly and environmentally acceptable from a duration usable point of view. Other benefits of this procedure are to decrease the friction phenomena on pavement surfaces and improve the mechanical and long-term qualities of the asphalt mixture. This study's findings are presented to explore the benefits of employing crumb rubber to minimize excessive water infiltration and optimize field permeability. This paper offers a significant and straightforward method for comprehending the variables influencing permeability. Asphalt was modified using a fine crumb rubber shred (2.36 - 0.85 mm) that was produced by grinding used truck tires at room temperature. Using the dry process method, the fine crumb rubber with varying contents (2.5%, 4.5%, and 6.5%) was added to the mixture. Hot Mix Asphalt's (HMA) field permeability must be regulated to avoid excessive water infiltration, which can cause an early failure of asphalt pavements.

Preparation and magnetic properties of high DC-bias performance Fe-Si-Nb-B-Cu/carbonyl iron chip inductors

In this study, a gradient temperature rise technique was employed to prepare ultra-fine nanocrystalline alloy magnetic powder with excellent high-frequency and low-loss characteristics. It was found that increasing the holding time effectively refines the grain structure in the perpendicular direction of the Fe-Si-Nb-B-Cu alloy's (220) crystal plane. This refinement contributes to a reduction in eddy current losses within the soft magnetic composite material. The addition of carbonyl iron to the nanocrystalline magnetic powder resulted in further enhancements in the density, strength, and magnetic properties of soft magnetic composites under high-frequency magnetic fields. Consequently, soft magnetic composites exhibiting superior DC bias performance were successfully obtained, with a power loss of 2629.50 kW/m3 at a magnetic induction of 20 mT and a frequency of 3 MHz, and more than 70 % percent permeability in a DC biased magnetic field of 7.96 kA/m. The relationship between relative permeability and quasi-static hysteresis loops was established. Additionally, the dynamic hysteresis loops of the soft magnetic composites revealed a relaxation phenomenon, which elucidated the mechanism behind the variations in power loss with changes in magnetic induction strength and frequency. Finally, through simulations, it was determined that the number of turns and the winding method significantly influenced the internal magnetic field and inductance of the chip inductor. Utilizing this information, a chip inductor with ultra-small inductance, compact size, and excellent DC bias characteristics for 10 A circuits was successfully fabricated.

Effect of the Rotation and Inclined Magnetic Field on Peristaltic Slip Flow of a Bingham Fluid in Asymmetric Channel and Porous medium

This essay aims to describe the peristaltic behavior of Bingham's fluid in an asymmetric channel and porous material. The liquid is thought to flow in a porous media and be susceptible to a powerfully inclined magnetic field. The long wavelength dependency and low Reynolds number result in a major simplification of the nonlinear equations. The pressure gradient, pressure rise per wavelength, axial velocity, spin velocity, volume flow rate, and tilted magnetic number are all given specific attention. The findings reveal that rotation, density, permeability, coupling diversity, and non-dimensional wave amplitude all play significant roles in the phenomenon. With rising slip coefficient values and falling magnetic field strengths, permeability, and yield stress coefficients the trapped bolus grows in size

Thermal pattern of nano-encapsulated PCM in a lid-driven cavity with presence of a heated body, magnetic field and limited permeability

This study attempts to improve the thermal characteristics of nano-encapsulated phase change materials (NEPCMs) for heating and cooling applications. The PCM particles are added to water to improve the thermal performance by the latent heat of phase change. NEPCM is confined in a porous prism lid-driven cavity with a lower zigzag wall. The cavity contains an elliptic heated cylinder and is subjected to magnetic field. The study is modeled using the Galerkin finite element method to solve the governing equations. The influential parameters are highlighted, including the impacts of medium permeability (Darcy number (Da) = 10−2 – 10−5), the strength of the magnetic field (Hartmann number (Ha) = 0–100), the orientation of an elliptic heated body (θ = 0° – 135°), and the speed of the lid (Reynolds number (Re) = 1–500). For all studied cases, it was observed that the thermal performance is improved by increasing the Re and Da and decreasing Ha. Increasing Re from 0 to 500 and Da from 10−5 to 10−2 enhances Nu by 335% and 94.7%, respectively. While raising Ha from 0 to 100 and the inclination angle to 90° decreases Nu by 5.3% and 6.7%, respectively.

Dielectric constant and magnetic permeability in the Newtonian gravitational field derived by the elastic energy

The pressure distribution in the Earth’s interior is expressed using the Adams‐ Williamson equation. The elastic energy is stored inside the Earth by the pressure. The Newtonian gravitation is derived by this energy. The Newtonian gravitation refracts light at the surface of the Sun. When light is an electromagnetic wave, this refraction is expressed by the dielectric constant and magnetic permeability in the Newtonian gravitational field. The propagation of electromagnetic waves in a black hole is discussed using the dielectric constant and magnetic permeability.

Electromagnetic shielding properties of LPBF produced Fe2.9wt.%Si alloy

Ferromagnetic materials are used in various applications such as rotating electrical machines, wind turbines, electromagnetic shielding, transformers, and electromagnets. Compared to hard magnetic materials, their hysteresis cycles are featured by low values of coercive magnetic field and high permeability. The application of additive manufacturing to ferromagnetic materials is gaining more and more attraction. Indeed, thanks to a wider geometrical freedom, new topological optimized shapes for stator/rotor shapes can be addressed to enhance electric machines performances. However, the properties of the laser powder bed fusion (LPBF) processed alloy compared to conventionally produced counterpart must be still addressed. Accordingly, this paper presents for the first time the use of the LPBF for the manufacturing of Fe2.9wt.%Si electromagnetic shields. The process parameter selection material microstructure and the magnetic shielding factor are characterized.

New Model for Absolute Permeability Prediction in Coal Samples: Application of Modified Purcell Model to Mercury Injection Pressure and Nuclear Magnetic Resonance Data.

The permeability of rocks is a critical parameter in many subsurface geological applications, and pore properties measured on rock samples (including rock fragments) can be used to estimate rock permeability. A major use of MIP and NMR data is to assess the pore properties of a rock in order to estimate the permeability based on empirical equations. Although sandstones have been extensively studied, permeability in coals has received less attention. Consequently, in order to obtain reliable predictions for coal permeability, a comprehensive study of different permeability models was performed on coal samples having a range of permeabilities from 0.003 to 1.26 mD. The model results showed that the seepage pores in coals account for the bulk of the permeability, while the contribution of adsorption pores to permeability is negligible. The models that only consider a single pore size point on the mercury curve, such as the Pittman and Swanson model, or those that use the entire pore size distribution, like the Purcell and SDR model, are inadequate for predicting permeability in coals. This study modifies the Purcell model to determine permeability from the seepage pores of coal, resulting in the enhancement of the predictive capability, with an increased R2 and reduction in the average absolute error by approximately 50% compared to the Purcell model. To apply the modified Purcell model to NMR data, a new model was developed that provides a high degree of predictive capability (∼0.1 mD). This new model can be used for cuttings, which could lead to a new method for field permeability estimation.

Effect of Various Aspects of Joints on Permeability of Jointed Glacial Till, Northeastern Ohio

ABSTRACT Glacial till bluffs along Lake Erie's shoreline, northeastern Ohio, contain three sets of joints that influence the hydraulic behavior of till mass like joints in rock influence the hydraulic behavior of rock mass. According to the Unified Soil Classification System, the till classifies as low plasticity silt to low plasticity clay, with a clay content of 36–41 percent. Mineralogically, it consists of quartz, illite, and kaolinite. The joints in till are either open or filled with sand, silt, or both from the overlying lacustrine material or with disintegrated till from the joint walls. We used double-ring infiltration and dye tests to estimate field permeability. Laboratory permeability tests were performed on dry and saturated samples of till material, with manually created joints that were either kept open or filled with sand or disintegrated till material to simulate field conditions. Field and laboratory test results showed that permeability of jointed till depended upon whether the joints were open or filled, the nature of the joint-filling material, and the water content of the till (dry versus saturated) and that permeability generally decreased with increasing test time. Dry samples exhibited a substantially larger decrease in permeability than saturated samples, with the largest decrease occurring during the first 24 hours. Open joints in dry samples collapsed during the test procedure, and the permeability of these samples was generally similar to the permeability of the collapsed till material. Permeability tests on saturated samples with open joints were inconclusive. We present a comparison of field and laboratory test results.

Enhanced Drug Uptake on Application of Electroporation in a Single-Cell Model.

Electroporation method is a useful tool for delivering drugs into various diseased tissues in the human body. As a result of an applied electric field, drug particles enter the intracellular compartment through the temporarily permeabilized cell membrane. Consequently, electroporation method allows better penetration of the drug into the diseased tissue and improves treatment clinically. In this study, a more generalized model of drug transport in a single cell is proposed. The model is able to capture non-homogeneous drug transport in the cell due to non-uniform cell membrane permeabilization. Several numerical experiments are conducted to understand the effects of electric field and drug permeability on drug uptake into the cell. Through investigation, the appropriate electric field and drug permeability are identified, which lead to sufficient drug uptake into the cell. This model can be used by experimentalists to get information prior to conduct any experiment, and it may help reduce the number of actual experiments that might be conducted otherwise.

Magnetic properties of (Ni0.81Fe0.19/SiO2)n multilayers for high frequency on-wafer inductor applications

We investigated the magnetic properties of multilayer stacks of Ni81Fe19 thin films separated with SiO2 intended for use in inductors operating at sub-GHz frequencies. We measured saturation magnetization, anisotropy field, coercivity, and complex permeability of sputtered multilayer structures consisting of thin film stacks of 5, 10, 15, 20, and 25 layers, ranging from 160 to 1455 nm in total magnetic material thickness. Our analysis indicates that multilayer stacks composed of repeated layers thinner than 115 nm generally maintained the desired magnetic properties found in individual thin films, such as high permeability, low anisotropy, and low coercive field. Moreover, the multilayer stacks did not exhibit unwanted characteristics such as stripe domain formation and decreased value of real permeability, which commonly occurred in single thicker films. These properties make them suitable for on-wafer inductor applications.

Electrical, thermal and electro-magnetic analyses of a 100 kHz interleaved power electronic transformer

In this paper, the finite element electrical, thermal and electro-magnetic analysis of an interleaved power electronic transformer structure operable at 100 kHz is presented. The analysed power electronic transformer structure is modelled with an EE-shaped core and interleaved primary and secondary windings. Electromagnetic analysis was done on the structure to study its properties like magnetic flux density, magnetic field, current density and relative permeability. Electrical and thermal analysis was done on the transformer to study its operating efficiencies and losses in isolation, buck and boost working modes. The analyses were done for different frequencies to ascertain that 100 kHz is the better choice of frequency for the designed power electronic transformer. The results are compared to a non-interleaved power electronic transformer structure to study the improvement obtained in the interleaved model. It was seen that transformer efficiencies of about 99 % could be obtained on using interleaved winding technique rather than non-interleaved method. Finite element modelling software-Altair FLUX was used to simulate the transformer and analytic equations were used to verify the obtained results.

Stress Measurement of Ferromagnetic Materials Using Hybrid Magnetic Sensing

Stress measurement and evaluation of ferromagnetic components using electromagnetic nondestructive testing (ENDT) are affected by the microstructure properties of the material, such as inhomogeneity and anisotropy. This leads to magnetic induction sensitivity in the variety of both the stress and microstructure. To address this challenge, a hybrid magnetic sensing structure for measuring eddy current, alternating electromagnetic (EM) field, Barkhausen noise, and incremental permeability signals is designed and instrumented. Additionally, a stress detection verification test for oriented silicon steel samples is carried out, and a comparison with commercial instrument in terms of sensitivity and repeatability is performed. The results show that the proposed sensor has advantages in detection repeatability, good sensitivity as well as high signal-to-noise (SNR) for MBN features, which brings potential in stress characterization and assessment.