Capillary Radius Research Articles

Textile fabric's in-plane water permeability determination during wicking

Based on a mathematical formulation of the water flow for different wicking configurations (ascendant-horizontal and descendant), a combined ascendant, horizontal and descendant wicking experimental test was designed to provide detailed measurements of the pertinent wicking performance properties: capillary pressure and in-plane direction permeability. This method was proposed due to capillary flows found in standard vertical wicking tests as well as erroneous assumptions made in other wicking tests. The effective capillary radius was assumed to remain constant as the height of the liquid increases. This assumption would suggest that saturation, capillary pressure, and permeability are also constants. However, experiments show that these properties are only constants in the case of the descendant wicking when liquid front height is varied. The capillary pressure and permeability calculations were made using Darcy’s law and the Lucas-Washburn equation as a function of the saturation level. In the combined wicking test, conducting a horizontal wicking test allows us to calculate the effective capillary radius of a fabric as the saturation rate was found to be constant, which in turn can be used to solve for capillary pressure. That capillary pressure can then be used in a descendant wicking test, where the liquid front flow and the saturation rate remain constant, and Darcy’s law to solve for permeability. A series of experiments was conducted on cotton jersey knitting. The results showed that the ability to wick the water depends on pore size and porosity scales: macro and micropores. The in-plane water permeability was found to be directly related to the saturation rate.

Study on the Law and Influencing Factors of Spontaneous Imbibition in Chang 7 Reservoir of Ordos Basin

Abstract This paper examines the imbibition and oil displacement process of fracturing fluid in a laboratory setting, focusing on the Chang 7 tight oil reservoir block in Ordos Basin. The study investigates the capability of different imbibition fluid systems to alter wettability and reduce interfacial tension. Additionally, it explores the imbibition and oil displacement abilities of cores with varying levels of wettability and permeability focusing on the imbibition equilibrium time, imbibition recovery rate, and the imbibition recovery multiplier. The reasons for these results were also examined. A multivariate nonlinear regression model is established to analyze the relationship between imbibition recovery, capillary radius, wettability angle, and interfacial tension. Additionally, neural network analysis is employed to determine the significance of these influencing factors. The findings from this research provide theoretical guidance for enhancing understanding of imbibition mechanisms and improving recovery rates in tight oil reservoirs.

Design of high-temperature sodium heat pipe with composite wick based on non-dominated sorting genetic algorithm (NSGA)

As small modular reactors continue to advance, heat pipe reactors (HPRs) are being developed by multiple organizations. Designing heat pipes with optimal heat transfer capability is crucial for the effective performance of HPRs. Based on NSGA-III genetic algorithm, this paper presented the design method of a high-temperature heat pipe featuring a composite wick. The study examined the influence of heat pipe structure parameters on performance parameters and heat transfer limits. Based on the analysis, we built multi-objective modeling of heat pipe and obtained the optimal structural parameters by NSGA-III. Verification confirmed that the heat pipe met the Mach number and effective capillary radius requirements. This study provided valuable insights for improving heat pipe manufacturing techniques and reactor miniaturization.

An analytical solution model of oil–water dynamic imbibition considering dynamic contact angle effect and osmotic pressure at micro-nano scale

Spontaneous imbibition is one of the important mechanisms to enhance oil recovery during hydraulic fracturing process of shale reservoirs. The dynamic contact angle effect in imbibition kinetics of liquid–liquid system is complicated due to the large number of micro-nano pores in shale reservoir. Moreover, the content of clay minerals is high, the chemical osmosis effect is significant, and the impact of osmotic pressure on imbibition is not clear. In order to clarify the dynamic contact angle effect in imbibition kinetics and correctly understand the role of osmotic pressure in imbibition process. In this paper, based on the molecular kinetic theory (MKT), the dynamic contact angle effect is successfully coupled with imbibition kinetic equation, and a capillary pressure equation is developed. On the basis, considering the effects of osmotic pressure, external displacement pressure and boundary layer effect on imbibition, An analytical solution model of oil–water dynamic imbibition model is developed. The results shows that under the respective effects of capillary pressure and osmotic pressure, the imbibition velocity initially stabilizes before increasing over time; under the action of displacement pressure, the imbibition velocity increases with time. Imbibition velocity is directly proportional to interfacial tension and capillary radius, but inversely proportional to contact angle and oil viscosity. With the salt concentration difference increasing from 80 mol/m3 to 4710 mol/m3, the imbibition velocity increased by about 54 times. Compared with the membrane efficiency of 30 % and 5 %, the imbibition velocity is increased by 4.95 times. In this work, the dynamic contact angle effect in the imbibition kinetics of liquid–liquid system was accurately characterized, clarified the action mechanism of osmotic pressure, and provided theoretical support for enhancing oil recovery of shale reservoirs.

A two-stage mechanistic reduced-order model of pharmaceutical tablet dissolution: Population balance modeling and tablet wetting functions

We propose a two-stage reduced-order model (ROM) of pharmaceutical tablet dissolution that is comprised of (i) a mechanistic dissolution function of the active pharmaceutical ingredient (API) and (ii) a tablet wetting function. The former is derived from a population balance model, using a high-resolution finite volume algorithm for a given API crystal size distribution and dissolution rate coefficient. The latter is obtained from the mechanistic understanding of water penetration inside a porous tablet, and it estimates the rate at which the API is exposed to the buffer solution for a given formulation and the dimensions of the tablet, contact angle, and surface tension between the solid and liquid phases, liquid viscosity, and mean effective capillary radius of the pore solid structure. In turn, the two-stage model is mechanistic in nature and one-way coupled by means of convolution in time to capture the start time of the API dissolution process as water uptake, swelling, and disintegration take place. The two-stage model correlates dissolution profiles with critical process parameters (CPPs), critical material attributes (CMAs), and other crucial critical quality attributes (CQAs). We demonstrate the model’s versatility and effectiveness in predicting the dissolution profiles of diverse pharmaceutical formulations. Specifically, we formulate and fabricate acetaminophen and lomustine solid tablets using different API content and size distributions, characterize their dissolution behavior, and estimate capillary radius as a function of tablet porosity. The estimations generated by the proposed models consistently match the experimental data across all cases investigated in this study.

A multiscale model to predict the equation of state of a saturated cement paste

An advanced multiscale analytical approach for predicting the Equation of State (EOS) of fully saturated cement pastes is presented. This approach models the matrix as an elastic–plastic material with linear hardening that includes capillary pores filled with water. The model takes into account both the stochastic variation of pore sizes and their spatial distribution. The microscale level is represented by a spherical medium having the mechanical properties of the cement paste matrix. A single spherical pore that is filled with compressible water is located at the center of the micro-domain. The behavior of the compressible water is modeled by the nonlinear Tait equation of state. The EOS at the macro level is obtained by averaging the micro level domain strains over the pore sizes and pore wall thicknesses. It is shown that the solution depends only on the ratio between the minimum pore wall thickness and the lower limit of capillary pore radius and is independent of each of these parameters separately. The EOS obtained by the proposed model shows good agreement with experimental data for cement paste with water/cement ratio w/c = 0.50. The performed parametric study shows that the bulk modulus and yield stress of undisturbed cement gel matrix significantly affect the EOS, while the variation of Poison ratio, plastic hardening parameter and minimum limit pore size and wall thickness (within physically accepted range) slightly affect the cement paste bulk behavior.

Modelling the Impregnation of a Pressure-Tight Casting

AbstractPressure tightness is important for many die-cast aluminium castings, but the interconnected porosity formed in the aluminium alloy high-pressure die castings (HPDC) can form a network connecting several surfaces of the casting, especially as a result of machining after casting. The resulting potential leakage path can be imagined as a series of discontinuities varying in size over wide limits, where voids of different volumes are connected by channels of smaller cross section. Although vacuum impregnation is often used to ensure pressure-tightness is a robust technology, cavity systems through the casting can still cause leakage after impregnation. This study addresses the issues of the impregnation of discontinuities with a complex geometry. The elementary part of a complex cavity geometry consists of a cavity and a capillary channel. We estimated the limited permeability of the capillary section using a mathematical model based on the Hagen–Poiseuille equation. The calculation results prove that the degree of filling of the cavity with a capillary section is basically a function of the geometrical characteristics of the cavity, primarily the radius of the capillary. If the cavity system also contains a section with a diameter of less than 28 μm, impregnation does not necessarily ensure the gas tightness of the casting. Depending on the radius of the capillary, the impregnation of a cavity of a given volume and connected to the surface through a capillary section of a given length can produce three different results. Above a certain capillary radius, filling is complete, below a certain capillary radius only the capillary itself will contain resin, and between the two limit values, the partial impregnation of the cavity is expected but the capillary section is not filled.

Gradient-Pattern Micro-Grooved Wicks Fabricated by the Ultraviolet Nanosecond Laser Method and Their Enhanced Capillary Performance.

Capillary-gradient wicks can achieve fast or directional liquid transport, but they face fabrication challenges by traditional methods in terms of precise patterns. Laser processing is a potential solution due to its high pattern accuracy, but there are a few studies on laser-processed capillary-gradient wicks. In this paper, capillary step-gradient micro-grooved wicks (CSMWs) were fabricated by an ultraviolet nanosecond pulsed laser, and their capillary performance was studied experimentally. The CSMWs could be divided into three regions with a decreasing capillary radius. The equilibrium rising height of the CSMWs was enhanced by 124% compared to the non-gradient parallel wick. Different from the classical Lucas-Washburn model describing a uniform non-gradient wick, secondary capillary acceleration was observed in the negative gradient direction of the CSMWs. With the increase in laser power and the decrease in scanning speed, the capillary performance was promoted, and the optimal laser processing parameters were 4 W-10 mm/s. The laser-enhanced capillary performance was attributed to the improved hydrophilicity and reduced capillary radius, which resulted from the increased surface roughness, protrusion morphology, and deep-narrow V-shaped grooves induced by the high energy density of the laser. Our study demonstrates that ultraviolet pulsed laser processing is a highly efficient and low-cost method for fabricating high-performance capillary gradient wicks.

Особенности изменения гидродинамического сопротивления в сосудах микроциркуляторного русла легких при COVID-19 по результатам морфометрического исследования

Introduction. The nature of damage to the body in COVID-19 is of major interest; however, the cardiac mechanisms of death have not been fully studied. The causes of deaths from CVDs require a search for heart failure mechanisms, one of which is an increased burden on the right ventricle due to changes in the affected pulmonary blood vessels. The aim was to assess changes in hydrodynamic resistance in the pulmonary microvasculature in accordance with the variant of the prevailing pathological process in them and the COVID-19 phase. Materials and methods. We performed clinical and morphological analyses of 20 lethal cases with the primary diagnosis of coronavirus infection caused by SARS-CoV-2. We used morphometry to measure the internal diameter of arterioles and venules, the specific capillary area (SCA), and the total radius of the capillary bed. The vascular radius formed the basis for calculating the hydrodynamic resistance in the sections of the microvasculature of the pulmonary circulation. Results. The exudation phase is accompanied by an increased lumen of arterioles and venules against the background of a decreased specific density of the capillary bed. In the early proliferation phase, the capillary bed reduces significantly, and dilatation is replaced by spastic manifestations in arterioles and, to a lesser extent, in venules. The late proliferative phase has similar reduction levels in the total capillary radius and the degree of vasoconstriction of arterioles especially in the zone of increased airiness and grown connective tissue. Conclusion. The reduced capillary bed is of primary importance in increasing the calculated hydrodynamic resistance in the lung tissue during COVID-19. The growth in the average calculated hydrodynamic resistance in the lung tissue occurs to a greater extent during the proliferative phases (early and late) of COVID-19 infection. Keywords: COVID-19, SARS-CoV-2, lungs, vessels

Numerical Simulation and Analysis of the Acoustic Properties of Bimodal and Modulated Macroporous Structures

In recent decades, cellular metallic materials have increasingly been used for control of reverberation and cutback. These materials offer a unique combination of expanded pores, high specific surfaces, improved structural performance, low weight, corrosion resistance at high temperatures, and a fixed/rigid pore network (i.e., at the boundaries, porosity does not change). This study examines the ability of sphere-packing models combined with numerical modelling and simulations to predict the acoustic properties of bimodal and modulated bottleneck-shaped macroporous structures that can realistically be achieved through liquid melts infiltration casting technique. The simulations show that porosity, openings, pore sizes and permeability of the material have significant effects on acoustics, and the predictions are consistent with experimental data substantiated in the literature. The modelling suggests that the creation of bimodal structures increases the capacity of the interstitial pores and pore contacts. The result is improved sound absorption properties and spectra, characterised by a pore volume fraction of 0.73 and a mean pore size to mean pore opening ratio of 4.8 for the 50% volume bimodal structure created at a 10 µm capillary radius. The importance of how pore structure-related parameters and existing fluid flow regimes can modulate the sound absorption performance of macroporous structures was revealed by numerical simulations of the sound absorption spectra for dual-porosity and dilated macroporous structures working from high-resolution tomography datasets. Sound absorption properties were optimised for structures having pore volume fractions between 0.68 and 0.76, maintaining the mean pore size to mean pore opening ratios between 4.0 and 6.0. Using this approach, enhanced and self-supporting macroporous structures may be designed and fabricated for efficient sound absorption in specific applications.

Characterization of high-performance nanostructured wick for heat pipes

To investigate the best performance wick forms to support the design and fabrication of high-performance heat pipes. This paper investigates the comprehensive performance of wicks by nanosurface technology and experimental methods to predict heat pipe performance rapidly. In this paper, two kinds of nanostructured wick were prepared by the oxidation-reduction method. They are stainless steel fiber mat-type nanostructured and nickel foam-type nanostructured wicks. The effect of surface nanostructure on the wick performance was investigated by comparing the surface characteristics, capillary properties, permeability, and evaporation properties. In this study, the competitive relationship between the characteristic parameters of the wick is measured by the capillary performance factor M: K/reff, which is used as a measure of the comprehensive performance of the wick, and its maximum value is pursued industrially. The result shows that the nanostructured wick presented excellent super hydrophilic properties. A liquid-lift visualization experimental method for measuring the capillary performance factor M was proposed, and it was verified to be correct by the separation effect of the capillary pumping experiment under a vacuum environment. With the increasing oxidized degree, the densification of nanoparticles on the wick surface increased the capillary performance factor M from 8.68 μm to 13.81 μm, with a maximum enhancement of 59.1%. The effective capillary radius decreased from 47.0 μm to 40.1 μm, with a maximum reduction of 14.9%. The permeability increased from 433 μm2 to 583 μm2, with a maximum enhancement of 34.7%. The increase in porosity made the effective capillary radius dominate the competition for permeability, and the capillary performance factor decreased by 17.1%. The thermal resistance of the wick decreased with the enhancement of the capillary performance factor, which fell from 20.3 cm2·K/W to 12.6 cm2·K/W. The current study provides a reference for the future design and preparation of high-performance heat pipe wicks.

Damping of an Oscillatory System with Incomplete Sealing of the Air Cavity by a Magnetic Fluid

Purpose. Investigate the damping of an oscillatory system with incomplete sealing of the air cavity with a magnetic fluid.Methods. The study was carried out on an experimental setup developed on the basis of known methods and equipment for magnetic measurements and manufactured independently. A ring neodymium magnet (NdFeB alloy) 60x24x10 mm in size was used as a magnetic field source. The magnetic field strength at the center of the magnet, measured with a TPU-01 milliteslamer, is 220 kA/m. An inductor, a GVT-427B amplifier, and a GwInstek GDS-72072 digital oscilloscope were used to display oscillograms. Samples of magnetic fluid based on Fe3O4 magnetite stabilized with oleic acid were studied. Kerosene was used as the carrier liquid.Results. The results of an experimental study of the elasticity and damping of an oscillatory system with incomplete sealing of the air cavity by a magnetic fluid bridge are presented. The level of sealing of the air cavity varies due to the process of pumping gas through capillaries of various radii. To explain the regularities obtained, a model theory is proposed in the approximation of a viscous gas flow according to the Poiseuille law, and the conclusions of the wellknown theory of sound propagation in molecular acoustics and the theory of sound ducts are also drawn. The relaxation mechanism imposes a restriction on the type of vibrational gas flow through the capillaries, which takes into account the "throughput" capacity of the capillaries. The proposed model explains the presence of a maximum in the dependence of the attenuation coefficient on the capillary radius and its decrease with an increase in the volume (height) of the gas cavity.Conclusion. The proposed relaxation theory of vibrational gas flow through capillaries predicts anomalously large damping coefficients and almost complete damping of an oscillatory system with a magnetic fluid inertial element. The use of the data obtained is advisable in the design of new shock absorbers, since a magnetic fluid damper with capillaries is capable of damping low-frequency oscillations.

ON THE AUTOGENOUS SHRINKAGE OF CEMENT PASTES

Introduction: This study focuses on autogenous shrinkage in cement pastes and presents a novel calculation method considering variations in internal relative humidity (IRH). IRH significantly influences autogenous shrinkage, and its evolution is modeled based on decline curves. The proposed method accurately evaluates autogenous shrinkage and aligns well with experimental data. Additionally, we calculate capillary depression and meniscus radius using the Laplace–Kelvin equation. Methods: To address early autogenous shrinkage in construction materials, we developed our calculation method, emphasizing IRH variation. We analyzed decline curves to model IRH and validated our model using literature-based experimental data. Results: Our validated model for predicting IRH and autogenous shrinkage in Portland cement pastes, based on cement paste hydration degree, water-to-cement ratio (w/c), and the critical degree of hydration (αcr), closely aligns with experimental data and existing models.

Design and fabrication of fibrous media to facilitate autogenous smart self-healing properties in cracked-cementitious structures using polyethylene glycol (PEG) and silicon dioxide nanoparticles

A novel approach is introduced for smart of cracked cementitious structures using a fibrous media occupied by polyethylene glycol (PEG) and silicon dioxide (SiO2) nanoparticles. A series of fibrous media were designed and fabricated using different fiber types (polyethylene terephthalate (PET), hollow polyethylene terephthalate (HPET) and polypropylene (PP)), areal densities, thicknesses and porosities. The fibrous media was filled by PEG/SiO2 nanoparticles to perform further hydration and then healing the crack by capillary rise of water into the cracked paths. An analytical model was proposed to predict the minimum critical crack radius in cementitious structure to initiate smart release of nano-particles through fibrous media. The developed model calculates minimum crack radius based on properties of polymeric components and associate media’s porosity with capillary rise of nano-particles in accordance with Washburn’s equation. An artificial neural network (ANN) based on multilayer perceptron (MLP) was used to determine the most important parameter influencing self-healing efficiency. The self-healing efficiency of samples were also evaluated via ultrasonic test, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS) and X-Ray diffraction (XRD) analyses. CaCO3 formation and C-S-H growth deducted from FESEM image analysis and EDS/XRD results. The PET media showed more healing efficiency because of less crack radius. The areal density parameter was found to be the most effective parameter in reducing the capillary radius. The new proposed method is simple and applicable to promote hydration and crack filling of cement products such as canvas concrete.

Enhancement in the Capillary Performance of Aluminum Groove through Laser Textured Deposition

Groove is widely used in the wicks of heat pipes. In this paper, a laser texture deposition (LTD) process was proposed to texture deposit SiO2 in rectangular aluminum groove. Both the SEM and XPS analysis revealed that a fluffy SiO2 layer was deposited on the surface of alumina fluff, which increased the fluff density. Statistically, the density of fluff on the surface of LTD was 1.12 times higher than that on the laser texture (LT) surface, leading to an increase in porosity and decrease in effective capillary radius. This significantly improved the capillary performance of the LTD groove. The results showed that, compared to the Raw and LTD grooves, the increase in height of the LTD groove was enhanced by 2.42 and 1.07 times, respectively, in 5 s, while the capillary performance factor (M) was increased by 2.83 and 1.04 times, respectively, in 1 s. This study introduces a novel process for enhancing the capillary performance of aluminum groove.

Enhancing ionic conductivity in polymer melts results in smaller diameter electrospun fibers

Chemically compatible additives were utilized to increase the ionic conductivity of polyethylene melts. When subjected to unconfined electrospinning, a predictable and significant decrease in the resultant fiber diameter with enhanced melt conductivity was observed. This generalized approach was confirmed for viscous melts, varying in conductivity over five orders of magnitude and viscosity 5×, from multiple commercial polyethylene formulations with various additives. These experimental results are connected to theory for the relevant length scales of capillary length, jet spacing, and jet radius. In particular, jet radius scales as conductivity to the −1/4 power. Fitting experimental fiber radius vs ionic conductivity data results in a similar power law exponent (−0.29). This trend, occurring at orders of magnitude higher viscosity and six orders of magnitude lower conductivity, is similar to results from needle-based, solution phase electrospinning, suggesting the generality of the effect. The connection between larger length scales, such as the distance between jets and the thickness of the film at the plate edge, and fluid properties (surface tension, viscosity, and conductivity) is also discussed.

Capillary effect of layers of rubber-fabric composite

Rubber-fabric composites are a representative of a class of anisotropic reinforced composite laminates designed for operation in contact with a liquid medium. Each layer of the composite performs a specific function in the operation of printing machines. The rubber layer is located on the surface of the material and is impervious to hydrophilic liquids, but can swell to a limited extent in organic solvents. Layers of fabrics provide structural integrity and tension of the layered composite material and are protected from the penetration of the liquid medium by layers of rubber in a plane perpendicular to the arrangement of the layers. In a plane parallel to the arrangement of layers, the fabric is permeable to aqueous solutions and organic solvents. Permeability is based on the capillary effect of absorption. To eliminate the anisotropy of the permeability of reinforced composite layered materials, it is proposed to apply additional layers on the end surface that block the access of liquid to the capillary space through the pores, gaps between the threads and fibers of the fabric layers. An additional layer is applied by brushing or dipping into solutions of suspensions and emulsions of film-forming polymers: polyvinyl alcohol, polytetrafluoroethylene and acrylic polyester. The article describes an experimental technique for estimating porosity and calculating the average radius of capillaries using a physical model of the porous structure of the composite. The capillary pressure leading to absorption is described by Laplace's law. The laboratory stand is a modernized Klemm-Winkler device. The penetration of liquids into the porous structure of a composite rubber-fabric material through the end surface was measured. The sizes of pores in the structure of the composite, their number, volume, and the rate of filling of pores with water through the end surface in samples of anisotropic reinforced composite layered materials used in printing were calculated. A decrease in water permeability through protective layers on the end surface is shown depending on the chemical and phase composition of film-forming polymers. Diagrams of permeability, absorption kinetics and tables of porosity parameters of the rubber-fabric composite are compared. The proportions of capillaries of different diameters and their distribution over the cross-sectional area were determined.

Development of a quantitative systems pharmacology (QSP) model to support dose optimization of DS-1103a (anti SIRPa antibody) in combination with trastuzumab deruxtecan in patients with cancer.

e14509 Background: DS-1103a, an anti-human signal regulatory protein α (SIRPα) monoclonal antibody (mAb), is designed to block the SIRPα-CD47 axis “Don’t Eat Me” signal and trigger phagocytosis of tumor cells when combined with an Fc-active antitumor mAb. DS-1103a is being developed as a combination therapy with trastuzumab deruxtecan (T-DXd; DS-8201a) as the antibody-dependent cellular phagocytosis (ADCP) enabling antibody. We developed a QSP model to support the first in human (FIH) intravenous dosing (IV) based on predicted intratumoral receptor occupancy (RO) within immunological synapses (the intercellular contact zone between macrophages and cancer cells) and corresponding ADCP activity. Methods: The QSP model mechanistically integrated DS-1103a plasma pharmacokinetics (PK), tumor distribution and binding of receptors to both antibodies and their ligands to simulate RO in the tumor microenvironment (TME). A proximal pharmacodynamics pathway model was first developed to estimate the intratumoral RO required to induce desired levels of ADCP for DS-1103a+T-DXd combination therapy. A human model was then developed to integrate DS-1103a PK with derived intratumormal RO in patients considering key human pathophysiological parameters, including SIRPα expression, tumor lesion permeability, SIRPα+ cell fractions in TME, tumor capillary radius, SIRPα internalization, CD47 expression and tumor lesion size. Virtual patient simulations were conducted in various cancer types to facilitate FIH dose selection. Results: The proximal pharmacodynamics pathway model quantitatively recapitulated the dose dependent in vitro ADCP activities for DS-1103a+T-DXd combination therapy. The intratumoral RO (within synapses) required to induce desired levels of ADCP activity were also derived. The human model predicted similar dose dependent intratumoral RO in various cancer types. Virtual patient simulations indicated that a flat dose of 100 mg Q3W IV DS-1103a could achieve steady-state intratumoral RO sufficient to reach half of the maximal ADCP activity and would be a suitable FIH starting dose. The predicted steady-state intratumoral RO after a flat dose of ≥1000 mg Q3W IV DS-1103a is well above the predicted intratumoral RO threshold to achieve maximum ADCP activity. Conclusions: The QSP model mechanistically characterized DS-1103a mechanism of action and linked PK to intratumoral RO and corresponding ADCP activity in both in vitro and in vivo setting. The model was used to derive the FIH starting dose and potentially clinically effective doses for DS-1103a in combination with T-DXd. This QSP model will be integrated into a large-scale disease platform to support dose expansion and further dose optimization as new clinical data emerge.

Optimal displacement of immiscible two-phase fluids in a pore doublet

Multiphase fluid flow in a pore doublet is a fundamental problem and is important for understanding the transport mechanisms of multiphase flows in porous media. During the displacement of immiscible two-phase fluids in a pore doublet, the transport process is influenced not only by the capillary and viscous forces, but also the channel geometry. In this paper, a mathematical model is presented of the two-phase fluid displacement in a pore doublet considering the effects of capillary force, viscous force, and the geometric structure. This leads to a new and more general analytical solution for the pore doublet system, and it is found that the displacement process is dominated by the capillary number, viscosity, and radius ratios. Also, the optimal displacement is defined, which refers to the wetting fluids in the two daughter channels breaking through the branches simultaneously (i.e., both having the same breakthrough time). Also, the critical capillary number corresponding to the optimal displacement is obtained, which is related to the radius ratio of the two daughter channels and the viscosity ratio of the two immiscible fluids. Finally, analytical results are presented for the displacement in the pore doublet, which can be used to explain and understand the preferential flows in porous media, such as for improving oil recovery from porous media; these are usually observed in oil recovery, groundwater pollution, and the geological sequestration of carbon dioxide.

Dynamics of liquid flow through fabric porous media: Experimental, analytical, and numerical investigation

Over the past few decades, there has been a significant increase in the use of paper-based microfluidic devices in various fields, including environmental monitoring, food safety analysis, and medical diagnostics. As a result, flow through paper-based substrates has gained much attention in the research community. Liquid flows through a paper substrate due to the inherent capillary suction pressure. In order to predict the flow through a paper substrate, we used macro- and microscopic methodologies to construct an analytical and numerical model. We have considered the effect of different factors, e.g., roughness, swelling, dynamic contact angle, and evaporation simultaneously to predict liquid wicking. A modified capillary radius technique is used to incorporate the effects of roughness and swelling into the numerical model, while a sink factor in Darcy's equation is used to model the evaporation. Experiments are performed to validate the developed models, and it is found that both models are in good agreement with the experiments, with a maximum error of 5%. The proposed analytical and numerical models can be used to forecast the capillary rise in a paper-based substrate, which has implications for paper-based microfluidic devices.