Displacive Phase Research Articles

Constitutive modeling of the slip-twinning transition in martensitic transformations

Martensite is the result of a diffusionless displacive phase transition. In Fe-based alloys it transforms the FCC to the BCC, BCT, or HCP structures and occurs at high strain rates. It has two typical morphologies, known as lath and plate. A quantitative constitutive description of the slip-twinning transition in the martensitic transformation is presented. It is based on the temperature and strain-rate sensitivities of slip, which are much higher than those for twinning. Thus, twinning becomes a favored deformation mechanism at low temperatures and high strain rates. The Hall-Petch coefficient, for the inclusion of grain size effects, is two times larger for twinning than slip. Constitutive relationships for slip and twinning are presented and applied to the martensitic transformation in steels; the lath-to-plate morphology change observed with increasing carbon content is successfully predicted as a function of grain size by calculations incorporating the two modes of deformation. A simple calculation of the strain rates during martensitic transformation is also provided. This methodology is applied to the Fe–C system and can be extended to the Fe–Ni–C system and to thermoelastic martensites, where twinning is favored over slip to enhance reversibility.

Zipper-Like Dynamic Switching ofCoordinationBonds GivesaPolar Bimetallic Halidetoward Self-Driven X-ray Detection.

Polar molecular crystals hold a promise for controlling bulk physical properties originated intheir unique switchable polarity viastructural transformation.However, the mechanisms for switching polarization are mainly limited to displacive and disorder-order phase transitions, which rarelyinvolve thereconstruction of chemical bonds. Here, we have switchedand tuned electric polarizationina bimetallic halide, (Neopentylammonium)4AgBiBr8(1), as verified by light-excited pyroelectric effect. Most notably, its Ag-Br coordination bonds show a zipper-like dynamic switching behavior from the 'locked'to 'unlocked'state, namely, reconstruction of chemical bonds.Coupling with the dynamic ordering of organic cations,this bond-switching transitionmakes a contribution to switchable polarization of 1. As expected, its polaritycreates pyroelectric effectfor self-driven X-ray detectionwithhighsensitivity (3.8×103μC Gy-1cm-2) and low limitof detection(4.8 nGy s-1). This work onthe bond-switching mechanism provides an avenue to designpolar molecularcandidatefor smart optoelectronic devices.

A Dynamical Approach to the α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}–β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} Displacive Transition of Quartz

The problem of displacive phase transitions (by which crystals pass on heating from a less symmetric to a more symmetric form) is investigated through numerical integration of the Newton equations of motion for a realistic model, in the paradigmatic case of quartz. Usually such transitions are discussed in terms of the positions of the atoms, while the role of normal modes is emphasized here. The key preliminary property established, in agreement with the indications given by Landau in his thermodynamic-like approach, is that four well definite modes are sufficient to describe the transition, the remaining modes just acting as a noise. The main result is then that such four modes constitute a closed Hamiltonian subsystem presenting an effective potential parametrically dependent on specific energy. The effective potential is actually computed, through (appropriately defined) time-averages of the accelerations of the relevant modes, and is found to describe, as energy is varied, a pitchfork bifurcation, once more confirming in dynamical terms the Landau result. The effective potential also allows one to advance a possible explanation of the “soft mode” phenomenon, namely the occuring, in the Raman spectrum, of a peak whose frequency depends on temperature and vanishes at the transition.

Understanding temporary residential mobility during urban renewal: Insights from a structured community survey and machine learning analysis

Existing studies on urban renewal have primarily focused on the final effects of urban redevelopment, while often overlooked the social costs incurred during the temporary displacement phase. This gap is significant, as many residents must vacate their homes for an average of 3–5 years during Shantytown redevelopment, which brings about challenges of renting houses and the associated negative impacts on their well-being before returning to their resettled homes. Therefore, this study focuses on examining the temporary residence arising during Shantytown redevelopment while awaiting resettlement. We selected Heze city as our case study area, which has been through China's most intensive redevelopment between 2016 and 2018 that affected about 1.2 million population. A structured community survey was conducted, and 1035 valid samples were collected. We then applied spatiotemporal analysis and the Random Forest model to examine stability, direction, and distance of temporary residence mobility, along with its influencing factors. Findings reveal that 92.4% of households move just once or twice during the temporary phase, indicating the preference for stable residence. Regarding moving direction, households seek life service centers rather than city centers, and prefer familiar community environments. Furthermore, 74.8% of households resettled within 2.5 km of their original residence, indicating a preference for nearby temporary housing. The built environment emerged as the most critical factor influencing the mobility, followed by family socioeconomic status, while housing costs, surprisingly, having the minimal impact. This study highlights the importance of considering the interim social costs in urban renewal projects and provides valuable insights for housing market regulation and urban planning to mitigate these effects.

Simulation study of abdominal hemorrhage based on magnetic induction tomography.

Abdominal hemorrhage is an important clinical disease that can be life-threatening in severe cases. Therefore, timely detection and treatment of abdominal hemorrhage is crucial for the health and safety of patients. Magnetic induction tomography is a non-invasive, nonradioactive, and non-contact electromagnetic imaging technology with potential application value for disease screening and continuous monitoring. In this paper, a simulation model of electrical impedance distribution close to the real human abdominal tissue was constructed, and based on this model, the magnetic induction tomography simulation method of internal bleeding was studied by the finite element numerical method, and the comparison was verified by phantom experiments. The eddy current density distribution inside the abdominal tissue and the magnetic induction phase data at the tissue boundary are solved, and sensitivity analysis of phase differences caused by changes in the radius and position of bleeding volume was conducted, and three sensitivity indicators were proposed. Both the simulation and phantom experiment show that when there are six types of tissues with different conductivity in the abdomen, the radius of bleeding increases from 10 to 30mm, and the radius phase difference sensitivity index Ar increases approximately linearly monotonically. Its radius transformation sensitivity Kr is 3.0961 × 10-5°/cm. When the position of the bleeding volume changes, the sensitivity index Ax of the x-axis displacement phase difference shows a quasilinear monotonic decrease, and the x-axis displacement sensitivity Kx is -6.3744 × 10-6°/cm. The y-axis displacement phase difference sensitivity Ay index shows a quasilinear relationship and monotonically increases, with a y-axis displacement sensitivity Ky of 5.2870 × 10-4°/cm. The results indicate that the phase difference sensitivity before and after the occurrence of bleeding can be used as a quantitative monitoring indicator to monitor the occurrence and trend of intra-abdominal hemorrhage, laying the foundation for the preliminary screening and continuous monitoring of abdominal hemorrhage diseases using magnetic induction imaging.

Effect of CO2 Pressure on Microemulsion Phase Behavior and Displacement Efficiency in Sandstones

Effect of CO₂ Pressure on Microemulsion Phase Behavior and Displacement Efficiency in Sandstones

Occurrence phase of peak responses to symmetric pulse loads

This study fills a challenging gap in the field of structural dynamics. A potential rule is theoretically proved: The peak displacements of undamped single-degree-of-freedom (SDOF) systems subjected to nonnegative but symmetric pulse loads necessarily occur within the pulse loading duration if the frequency ratio β<1, and after the pulse loading duration if the frequency ratio β>1. As a special case, the first peak displacements accurately take place at the end of the pulse loading when β=1. Also, the occurrence time of the first peak displacements has a theoretic value of tϕ=tp/2+T/4 in the case of β>1. Although this potential rule can be easily verified in certain cases, it has not been theoretically and systematically proved so far. A rigorous and complete proof is presented and featured by the proposed analysis based on Duhamel's integral. The analyzation circumvents the difficulties in analytically solving dynamic responses to different pulse loads in different shapes, but still reaches theoretical conclusions and yields a general law of structural dynamics. The proved law can be used to predict the occurrence phase of the first peak displacements when undamped SDOF systems subjected to nonnegative but symmetric pulse loads.

Three-phase balance relay using numerical techniques experimentally verified on synchronous machines

In this paper, a multifunction three-phase balance relay based on normalized correlation coefficients is proposed to detect and estimate imbalances and perturbations in synchronous machine output signals. Furthermore, fresh definitions of imbalance and disturbance indicators derived using the correlation estimators are introduced, taking into account the changes in the waveform phase displacement, frequency, amplitude, and shape of the machine three-phase waves. Experimental tests are performed on a motor–generator set connected to a three-phase load, which is used to identify and evaluate the imbalance and disturbance conditions of the voltage and current measurements. Extensive tests for different fault types have been presented. The practical results show that the proposed protection can respond quickly to faults, and assess online the level of the imbalance/disturbance with high accuracy. Its running time is within one cycle. In addition, the proposed algorithm’s reliability and accuracy are its most significant attributes, whose percentages exceed 96.6%. The present algorithm considers the impact of both negative and zero sequence components when measuring di-symmetry factors, while some conventional approaches merely rely on the negative sequence component computed for the machine voltages and currents.

Phase behavior of the carbon dioxide/toluene/poly(ethylene glycol) ternary system

The phase behavior of a carbon dioxide (CO2)/toluene (Tol)/poly(ethylene glycol) (PEG) ternary system was investigated in this study to consider the effect of the polymer species on the phase diagram. Measurements were performed using a synthetic method combined with laser displacement and turbidity measurements. Bubble points (vapor–liquid phase separation) were determined from changes in the piston displacement and cloud points (liquid–liquid (LL) phase separation) were determined from changes in the turbidity. The phase boundaries of the CO2 mass fractions ranging from 0.113 to 0.496 were measured by varying the Tol/PEG mass ratio. The homogeneous phase area decreased when the mass ratio of PEG to Tol increased and/or the temperature decreased. These changes in the LL phase-separation behavior were explained by referring to the free volume fraction and solubility parameter estimated using the Sanchez–Lacombe equation of state. The free volume integral fraction could explain the phase diagram, but not the solubility parameter; the effect of polymer species on the Px phase diagram of the ternary system was explained by considering specific interactions between dissimilar components. These results could promote a comprehensive understanding of the phase diagram of CO2/organic solvent/polymer systems and aid the prediction of phase behavior.

A phase field framework for corrosion fatigue of carbon steel

Corrosion fatigue damage occurs when metallic materials are subjected to cyclic loading in a corrosive medium. In this study, a phase field framework is proposed to predict the corrosion fatigue of carbon steels. The coupling effect of fatigue and corrosion is explicitly implemented in the proposed phase field framework by coupling the displacement field, electrochemical field and phase field. A degradation function of the interface free energy density with the consideration of elastic and plastic strain energies is introduced to account for the fatigue damage accumulated during the corrosion fatigue process. The applicability of this framework is validated by accurately capturing the pure fatigue and corrosion fatigue behaviors of compact tension specimens, particularly the acceleration effect of corrosion on the fatigue crack growth. The propagation morphology and rate of the corrosion fatigue crack in single pit and multiple pit models are studied. The distribution of stress state and strain energy density induces the directionality of crack propagation. The influence of loading frequency on the corrosion fatigue process is discussed in detail. Due to the corrosion-fatigue coupling effect, the corrosion rate increases with increasing of the loading frequency, resulting in an accelerated corrosion fatigue process. Moreover, the significance of the plasticity in the prediction of corrosion fatigue is emphasized.

Potential and Limitations of the New European Ground Motion Service in Landslides at a Local Scale

Mass movements represent one of the most significant geohazards worldwide. The aim of this research is to highlight the potential and limitations of the European Ground Motion Service (EGMS) in detecting and monitoring mass movements at a local scale, especially in cases where data from in situ instrumental devices are unavailable. The study area corresponds to the La Miera landslide, located in Asturias (NW Spain). The multidisciplinary methodology applied involved the following steps: (1) downloading, acquiring, and analyzing Sentinel-1 A-DInSAR datasets (2015–2021) through the EGMS; (2) conducting a detailed geomorphological map and identifying evidence of movement; (3) classifying building damage by means of a damage inventory; (4) compiling and analyzing daily rainfall records with respect to deformation time series. Sentinel-1 A-DInSAR results revealed maximum LOS and East–West velocities of −11.6 and −7.9 mm/yr related to the landslide activity. Geomorphological mapping allowed for the updating of the landslide boundaries and its characterization as an active, complex movement. Registered building damage, which ranged from moderate to serious, was correlated with LOS and East–West velocities. The displacement recorded by the EGMS closely corresponds with rainfall periods, while periods of reduced rainfall coincide with the stabilization and recovery phases of displacement. This emphasizes a noteworthy quantitative correlation between rainfall events and EGMS data, evident both spatially and temporally. This work highlights that areas in which the EGMS data indicate deformation but lack in situ instrumental records, geomorphological techniques, and building damage surveys can provide spatial validation of the EGMS displacement, while rainfall records can provide temporal validation.

Hydroflux Synthesis and Structural Phase Transition of Rare-Earth Borate Hydroxides Na2[RE(BO3)(OH)2] (RE = Y, Gd-Er).

Reacting RE2O3 and H3BO3 in an ultra-alkaline NaOH hydroflux at about 250 °C yielded pure, crystalline samples of Na2[RE(BO3)(OH)2] (RE = Y, Gd-Er). The compounds dehydrate to Na3RE(BO3)2 upon heating in air to about 500 °C. Na2[RE(BO3)(OH)2] (RE = Tb-Er) are photoluminescent under UV radiation. Their UV-Vis spectra show the typical absorptions associated with 4f-4f transitions and absorption edges in the UV (band gaps ≥ 5.7 eV). The RE3+ cation is coordinated by seven oxygen atoms, which define a distorted pentagonal bipyramid. The bipyramids share trans-edges of their base forming infinite chains. Triangular (BO3)3- groups connect the chains into layers. The crystal structure of Na2[Ho(BO3)(OH)2] was investigated at various temperatures in the range 100 K ≤ T ≤ 320 K. Above 310(2) K, the compound crystallizes in the orthorhombic space group Cmcm (β-phase), below, it undergoes a displacive phase transition of second order resulting in a monoclinic structure in space group C2/c (α-phase). The critical exponents derived from different structural parameters indicate a cooperative distortion of the borate layers, but a rather uncorrelated adaptation of the sodium cations to their local environment. The other compounds of the series also adopt the structure of the α-phase at 296 K.

Effects of Silicon and Aluminum Alloying on Phase Transformation and Microstructure Evolution in Fe–0.2C–2.5Mn Steel: Insights from Continuous–Cooling–Transformation and Time–Temperature–Transformation Diagrams

The impact of silicon and aluminum on phase transformation behavior, particularly bainite, and microstructure evolution in Fe–0.2C–2.5Mn steel are presented. Continuous–cooling–transformation (CCT) and time–temperature–transformation (TTT) diagrams are determined experimentally. An aluminum extended empirical formula is introduced to estimate the martensite start temperature (Ms) with a thorough assessment of existing formulae. Results show that aluminum significantly increases Ms and has a stronger influence on promoting ferritic microstructures than silicon. During continuous cooling, alongside bainite, formation of Widmanstätten structures is induced in aluminum‐alloyed steel at higher cooling rates due to increased prior austenite grain size. Silicon decelerates bainite transformation kinetics by enhancing austenite's chemical stability through carbon enrichment via preventing carbide precipitation and by strengthening austenite against displacive phase transformation via solid solution hardening. Although aluminum has similar effects, incubation time is shortened during isothermal treatment because of the increased driving force, which overcompensates for the retardation effects. A finer carbide‐free bainitic microstructure is achieved in aluminum‐alloyed steel with more pronounced film‐like retained austenite (RA) formation and superior carbon enrichment, improving RA stability and suppressing martensite–austenite island formation. Finally, with the proposed formula, an accurate approximation to experimental Ms is accomplished.

Extended quantum process tomography of logical operations on an encoded bosonic qubit

We demonstrate the use of coherent-state quantum process tomography (csQPT) for a bosonic-mode superconducting circuit. We have enhanced our methodology over previous implementations of csQPT by leveraging Kraus operators and constrained gradient descent to learn the underlying process. We show the results of our method by characterizing a logical quantum gate implemented using displacement and selective number-dependent arbitrary phase operations on an encoded qubit. Our use of csQPT allows for the reconstruction of Kraus operators for the larger Hilbert space rather than being limited to the logical subspace. This approach enables us to more accurately identify and quantify the various error mechanisms that can lead to gate infidelity, including those occurring outside of the computational subspace. We showcase the potential of our approach by demonstrating the ability to quantify leakage outside of the computational subspace, a key factor for developing more robust and reliable quantum gates in high-dimensional systems. Published by the American Physical Society 2024

CircadiPy: An open-source toolkit for analyzing chronobiology time series

BackgroundChronobiology is the scientific field focused on studying periodicity in biological processes. In mammals, most physiological variables exhibit circadian rhythmicity, such as metabolism, body temperature, locomotor activity, and sleep. The biological rhythmicity can be statistically evaluated by examining the time series and extracting parameters that correlate to the period of oscillation, its amplitude, phase displacement, and overall variability. New methodWe have developed a library called CircadiPy, which encapsulates methods for chronobiological analysis and data inspection, serving as an open-access toolkit for the analysis and interpretation of chronobiological data. The package was designed to be flexible, comprehensive and scalable in order to assist research dealing with processes affected or influenced by rhythmicity. ResultsThe results demonstrate the toolkit's capability to guide users in analyzing chronobiological data collected from various recording sources, while also providing precise parameters related to the circadian rhythmicity. Comparison with existing methodsThe analysis methodology from this proposed library offers an opportunity to inspect and obtain chronobiological parameters in a straightforward and cost-free manner, in contrast to commercial tools. ConclusionsMoreover, being an open-source tool, it empowers the community with the opportunity to contribute with new functions, analysis methods, and graphical visualizations given the simplified computational method of time series data analysis using an easy and comprehensive pipeline within a single Python object.

Study on fracture of hyperelastic Kirchhoff-Love plates and shells by phase field method

Thin walled structures such as plates and shells are widely used in many engineering fields. To Predict its fracture behavior is of great significance for integrity design and strength evaluation of engineering structures. Numerical simulation of the fracture behavior of hyperelastic plates and shells is a challenge due to complex kinematic description, hyperelastic constitutive relationship, geometric nonlinearity and the degradation on elastic parameter caused by fracture damage. Combining Kirchhoff Love (K-L) shell theory with the fracture phase field method, and numerically discretizing the first and second order partial derivatives of displacement field and phase field by using T-splines and meeting the requirements of K-L plate and shell theory for the C1 continuity of the shape function, a model for the isogeometric analysis numerical formulation of the phase field fracture in hyperelastic K-L plates and shells is established. The fracture failure behavior of hyperelastic K-L plates and shells under the uniform load and displacement load is simulated, and the effect of the Gaussian curvature on the fracture behavior of hyperelastic K-L shells is studied. The simulation results show that the present numerical scheme can effectively capture the complex crack propagation path of plates and shells under the uniform load, and the displacement field can effectively reflect the crack distribution of materials. The thin shell with negative Gaussian curvature shows the excellent fracture performance under the internal pressure, and can withstand the greater internal pressure.

Experimental demonstration of quantum encryption in phase space with displacement operator in coherent optical communications

We provide experimental validation of quantum encryption in phase space using displacement operators in coherent states (DOCS) in a conventional coherent optical communication system. The proposed encryption technique is based on displacing the information symbols in the phase space using random phases and amplitudes to achieve encryption randomly and provide security at the physical layer. We also introduce a dual polarization encryption approach where we use two different and random DOCS to encrypt the X and Y polarizations separately. The experimental results show that only authorized users can decrypt the signal correctly, and any mismatch in the displacement operator coefficients, amplitudes, or phases will lead to a bit error ratio (BER) of approximately 50%. We also compare the performance of the system with and without encryption over 80 km of standard-single mode fiber (SSMF) transmission to assess the added penalty of such encryption. The achieved net bit rates are 224, 448, and 560 Gb/s for QPSK, 16QAM, and 32QAM modulation formats, respectively. The experimental results showcase the efficacy of the DOCS encryption technique in resisting various decryption attempts, demonstrating its effectiveness in ensuring the security and confidentiality of transmitted data in a real-world transmission scenario.

High-resolution wide-swath SAR imaging with multifrequency pulse diversity mode in azimuth multichannel system

ABSTRACT High-resolution wide-swath (HRWS) imaging has emerged as a focal point in synthetic aperture radar (SAR) research. However, conventional SAR systems face challenges in achieving both high azimuth resolution and wide swath simultaneously due to the minimum antenna area constraint. In this paper, we propose a HRWS imaging method based on multifrequency pulse diversity (MFPD) and azimuth multichannel (AMC) technique, capable of resolving range and Doppler ambiguities concurrently. In MFPD mode, range ambiguous echoes can be separated by matched filters in the range frequency domain, as multifrequency pulses are transmitted by a single channel in the transmitter. To further enhance the ambiguity resolution ability of the system and address azimuth incoherence, a novel scheme applying the MFPD to AMC system is proposed, categorized into two distinct scenarios. 1) Uniform Sampling: This scenario satisfies the displaced phase centre antenna condition. Under this condition, high range resolution imaging can be achieved through spectrum splicing in range frequency domain, simultaneously resolving Doppler ambiguity. 2) Non-uniform Sampling: In this scenario, the ambiguous echoes are processed by spatial digital beamforming and spectrum splicing in two-dimensional frequency domain. Finally, the HRWS imaging can be obtained by performing the traditional SAR algorithm. Furthermore, the proposed method can synthesize a wideband signal from multifrequency signals, thereby enhancing the feasibility of super-high-resolution imaging. Simulation results demonstrate the effectiveness of the proposed method.

Influence of Local Aperture Heterogeneity on Invading Fluid Connectivity During Rough Fracture Drainage

Determining the (in)efficiency of wetting phase displacement by an invading non-wetting phase (drainage) in a single fracture is key to modelling upscaled properties such as relative permeability and capillary pressure. These constitutive relationships are fundamental to quantifying the contribution, or lack thereof, of conductive fracture systems to long-term leakage rates. Single-fracture-scale modelling and experimental studies have investigated this process, however, a lack of visualization of drainage in a truly representative sample at sufficient spatial and temporal resolution limits their predictive insights. Here, we used fast synchrotron X-ray tomography to image drainage in a natural geological fracture by capturing consecutive 2.75 μm voxel images with a 1 s scan time. Drainage was conducted under capillary-dominated conditions, where percolation-type patterns are expected. We observe this continuously connected invasion (capillary fingering) only to be valid in local regions with relative roughness, λb ≤ 0.56. Fractal dimension analysis of these invasion patterns strongly aligns with capillary fingering patterns previously reported in low λb fractures and porous media. Connected invasion is prevented from being the dominant invasion mechanism globally due to high aperture heterogeneity, where we observe disconnected invasion (snap-off, fragmented clusters) to be pervasive in local regions where λb ≥ 0.67. Our results indicate that relative roughness has significant control on flow as it influences fluid conductivity and thus provides an important metric to predict invasion dynamics during slow drainage.

Microscopic Particle Image Velocimetry Analysis of Multiphase Flow in a Porous Media Micromodel.

Pore-scale oil displacement behavior was investigated in a porous media micromodel using microscopic particle image velocimetry (μPIV). Porous media micromodels consisting of an ordered square array of cylindrical pillars with 50 and 70% porosities were fabricated with photolithography. The oil displacement was performed with the injection of water at flow rates of 37.5, 75, and 150 μL/h. These flow rates correspond to Reynolds number of 1.1 × 10-2, 2.2 × 10-2, and 4.4 × 10-2, respectively in the 50% porous channel, and 1.84 × 10-3, 3.69 × 10-3, and 7.38 × 10-3, respectively in the 70% porous channel. The capillary numbers for these flow rates are 2.18 × 10-5, 4.36 × 10-5, and 8.72 × 10-5, respectively in the 50% porous channel, and 1.56 × 10-5, 3.12 × 10-5, and 6.23 × 10-5, respectively in the 70% porous channel. The micromodel is initially saturated with oil, with the invading water phase following the path of least resistance as it displaces the oil. The μPIV data were used to construct probability density functions (PDFs) which show an initial, nonzero, peak in transverse velocity as the water enters the micromodel. The PDFs broaden with time, indicating that the water is spreading, before retracting to a peak velocity of 0 mm/s, indicating that the water displacement has achieved equilibrium. We developed a model based on conservation of mass to describe the efficiency of the displacement process. All flow conditions demonstrate peak displacement efficiency when the amount of oil phase displacement is ∼9 pore volumes in 50% porous channel and ∼4 pore volumes in 70% porous channel.