Permeability Of Material Research Articles

Use of municipal solid waste incineration (MSWI) bottom ash as a permeable subgrade material: An experimental and mechanism study

ABSTRACT As a traditional method of waste treatment, municipal solid waste incineration (MSWI) has become one of the main methods of urban waste treatment. However, as a byproduct of MSWI, a large amount of MSWI bottom ash is not reused in current practice. This study innovatively posits MSWI bottom ash as an eco-friendly adsorbent rather than a pollutant, exploring its potential application as a permeable subgrade material. The results reveal that MSWI bottom ash exhibits promising properties to serve as a permeable subgrade material to achieve the permeability and improve the sustainability for subgrade. Due to the arrangement of its particles, it shows excellent performance in shear strength and permeability, which are comparable to or surpass those of sandy soils. The average pore width of 14.200 nm allows heavy metal substances to be encapsulated within the matrix, significantly reducing their leachability, thereby aligning with environmental friendliness standards. Its adsorption capacity is about 6.60 mg/g, and the adsorption capacity per volume is 3.66 times and 2.04 times that of fly ash and clay, respectively. The mechanism analysis shows that the adsorption process is monolayer heterogeneous adsorption. This paper presents a novel perspective on reusing MSWI bottom ash and provides evidence supporting its effective utilization as a permeable subgrade material, offering substantial environmental benefits through enhanced adsorption ability. Implications: Municipal solid waste incineration (MSWI) is a common method for municipal solid waste treatment, while the MSWI bottom ash is often not reused. This paper explored the explores the feasibility of using MSWI bottom ash as a permeable road base material. The results show that the particle arrangement enables excellent shear strength and permeability, comparable to sandy soil. It meets safety requirements for the leaching of heavy metals and acts as an adsorbent for pollutants leaching from permeable pavements. Furthermore, the mechanisms underlying these behaviors of MSWI were confirmed by microstructural and mineralogical analyses. These indicate that MSWI bottom ash has great potential as a permeable road base material. This paper provides a clear understanding of the physical, mechanical and environmental properties of MSWI bottom ash, which can promote its reuse in practice.

Evaluation of Fused Deposition Modeling Materials for 3D-Printed Container of Dosimetric Polymer Gel.

Accurate dosimetric verification is becoming increasingly important in radiotherapy. Although polymer gel dosimetry may be useful for verifying complex 3D dose distributions, it has limitations for clinical application due to its strong reactivity with oxygen and other contaminants. Therefore, it is important that the material of the gel storage container blocks reaction with external contaminants. In this study, we tested the effect of air and the chemical permeability of various polymer-based 3D printing materials that can be used as gel containers. A methacrylic acid, gelatin, and tetrakis (hydroxymethyl) phosphonium chloride gel was used. Five types of printing materials that can be applied to the fused deposition modeling (FDM)-type 3D printer were compared: acrylonitrile butadiene styrene (ABS), co-polyester (CPE), polycarbonate (PC), polylactic acid (PLA), and polypropylene (PP) (reference: glass vial). The map of R2 (1/T2) relaxation rates for each material, obtained from magnetic resonance imaging scans, was analyzed. Additionally, response histograms and dose calibration curves from the R2 map were evaluated. The R2 distribution showed that CPE had sharper boundaries than the other materials, and the profile gradient of CPE was also closest to the reference vial. Histograms and dose calibration showed that CPE provided the most homogeneous and the highest relative response of 83.5%, with 8.6% root mean square error, compared with the reference vial. These results indicate that CPE is a reasonable material for the FDM-type 3D printing gel container.

Blending Modification Technology of Insulation Materials for Deep Sea Optoelectronic Composite Cables

The insulation layer of deep-sea optoelectronic composite cables in direct contact with high-pressure and highly corrosive seawater is required for excellent water resistance, environmental stress cracking resistance (ESCR), and the ability to withstand high DC voltage. Although high-density polyethylene (HDPE) displays remarkable water resistance, it lacks sufficient resistance to environmental stress cracking (ESCR). This article is based on a blend modification approach to mixing HDPE with different vinyl copolymer materials (cPE-A and cPE-B). The processing performance and mechanical properties of the materials are evaluated through rheological and mechanical testing. The materials’ durability in working environments is assessed through ESCR tests and water resistance experiments. Ultimately, the direct current electrical performance of the materials is evaluated through tests measuring space charge distribution, direct current resistivity, and direct current breakdown strength. The results indicate that, in the polyethylene blend system, the rheological properties and ESCR characteristics of HDPE/cPE-A composite materials did not show significant improvement. Further incorporation of high melt index linear low-density polyethylene (LLDPE) material not only meets the requirements of extrusion processing but also exhibits a notable enhancement in ESCR performance. Meanwhile, copolymerized polyethylene cPE-B, with a more complex structure, proves effective in toughening HDPE materials. The material’s hardness significantly decreases, and when incorporating cPE-B at a level exceeding 20 phr, the composite materials achieve excellent ESCR performance. In a simulated seawater environment at 50 MPa, the water permeability of all co-modified composite materials remained below 0.16% after 120 h. The spatial charge distribution and direct current resistivity characteristics of the HDPE, cPE-A, and LLDPE composite systems surpassed those of the HDPE/cPE-B materials. However, the HDPE/cPE-B composite system exhibited superior dielectric strength. The application of composite materials in deep-sea electro–optical composite cables is highly promising.

Williamson Nanofluid Over A Cone and Wedge: Numerical Modelling of Hydromagnetic Brownian Motion Using the Extended Darcy Model

The originality of this experiment lies in examining how the Lorentz force and Fr affect the Williamson fluid as it moves over the cone and wedge, two very different geometries. Along with the modifiable parameters of non-isothermal settings, the effects of Soret and Dufour are also taken into account. The non-linear equations of conservation are converted into the ordinary differential equations by utilizing appropriate similarity transformations. Finally, solutions to the system of ODEs are obtained by employing a finite difference scheme known as bvp4c in MATLAB. The relative tolerance of the scheme is set to 10−6 and a grid size of 10−3. The stability and convergence of the scheme have been verified by the grid point stability test. The behaviour of momentum of molecules and their thermal and mass diffusion of the fluid, and also the velocity–gradient, temperature-gradient, and species-gradient are portrayed explicitly and deliberated in detail for the influence of numerous fluid parameters. It is found that the heat-transmission on the surface of the cone is advanced than the wedge, and the rate of transmission of heat is supreme for Newtonian fluid in comparison to Williamson fluid. In contrast to the cone, the wedge has a greater impact of Fr on velocity, temperature, and concentration. Additionally, it is discovered that the enlarged values of the Williamson parameter decrease fluid velocity while increasing temperature and concentration dispersion. By adjusting the surface suction, magnetic field strength, and permeability of the porous material, fluid velocity can also be reduced to a minimum. Fr, M, Nt, and K all increase fluid temperature, while the suction parameter decreases fluid temperature. Non-Newtonian fluid has applications in the field of lubrication in numerous devices such as micro heat exchangers, micro cooling systems, micromixers, and so on. This study has a substantial influence on numerous engineering applications that analyse energy transfer in thermal equipment, designing heat exchanger devices and engines of gas turbines.

Influence of thickness on porous lining when the inclined channel walls are bounded by a deformable porous layer

This paper deals with the viscous fluid flow in an inclined channel bounded by a deformable porous layer. The coupled phenomenon of fluid movement and solid deformation in the porous layer was considered. The governing equations were obtained for the fluid velocity, solid displacement and temperature distribution in the deformable porous medium. Analytical solutions were obtained for solid displacement, fluid velocity, velocity in the free flow region and temperature distributions. The results were analysed for different physical parameters using graphs. The results revealed that the effect of the thickness of the porous layer was significant on solid displacement and fluid velocity. The solid displacement decreased by increasing the volume fraction of the fluid and the thickness of the porous layer. Since the drag coefficient was the ratio of fluid viscosity to the permeability of the porous material, it follows that the enhancement in drag reduces the permeability of the bounding porous layer. The flow in the blood vessels (capillaries) is surrounded by a tissue layer which is modelled as a deformable porous medium.

Chemical and structural degradation of room temperature vulcanizing (RTV) silicone at high temperatures

Room temperature vulcanizing (RTV) silicone is an insulating adhesive used on thermal protection systems of space capsules. RTV materials experience significant heating during entry into an atmosphere. To understand the response of RTV materials in entry environments, RTV 511 and RTV 560 are heated in a mass spectrometer, a thermogravimetric analyzer, and a high-temperature flow tube furnace to understand the underlying chemical and structural degradation processes occurring during the decomposition of the two RTV materials. In addition, infrared spectroscopy is used to identify the functional groups and the polymer backbone configuration. X-ray computed tomography is used to create three-dimensional volumes of the decomposed samples to examine the structure of the degraded RTV materials. The three-dimensional volumes are also used to evaluate the permeability of degraded RTV materials. It is observed that both RTV materials decompose in three stages. Analysis of the three-dimensional volumes generated through X-ray computed tomography indicates that the decomposition begins with the formation of small cavities in both RTV variants. However, as the materials are subjected to higher temperatures, RTV 511 evolves into an outer solid layer with cavities inside, while the solid material in RTV 560 is distributed more homogeneously throughout the material, resulting in a structure with better mechanical integrity. Although most regions of both RTV variants are impermeable, certain regions of RTV 511 have a permeability that is two orders of magnitude higher than the permeability of the base heat shield material. The overall analysis indicates that the response of RTV materials to heat must be considered in the design and analysis of thermal protection systems.

Structural, morphological, dielectric, and spectral properties of Sr-Mg-Ho X-type magnetic nano materials suitable for microwave absorption application

Holmium (Ho3+) substituted Sr2Mg2Fe28O46 X-type hexa-ferrites were synthesized using the sol-gel auto-combustion route. The single phase of Sr2Mg2Fe28-xHoxO46 where 0.00 ≤ x ≤ 0.20, Δx = 0.05, X-type hexa-ferrites was confirmed using XRD peaks. The crystalline size was studied from XRD data and found to be in the 11 nm–24 nm range. The micro strain increased with the substitution of Ho3+. FTIR exposed the specific stretching vibration and absorption peaks in the 400 cm−1 - 600 cm−1 range. The force constant (ko) decreased from 1.74 N/cm to 1.65 N/cm with the increasing concentration of Ho3+. The grain size range is 371–493 nm, measured by SEM analysis, and plate-like structure plays a crucial role in enhancing the permeability of magnetic material. Transmission electron microscopy (TEM) analysis showed the hexagonal structure of X-type ferrites (x = 0.20). The results of the X-ray photoelectron spectroscopy (XPS) experiment confirmed the presence of all metal ions in the given composition with their required valences. The dielectric constant, dielectric loss, and tangent loss are found to increase with the substitution of the Ho3+ ion. In addition, the higher values of dielectric parameters and dielectric loss suggest that the material may suitable for high-frequency applications and best for microwave absorbers. Our aim is to discuss the characteristics and applications of microwave absorption materials, understand their behavior, and contribute to the development of upcoming novel devices. The resonance peak's appearance shows that these materials are best for multilayer chip inductors and EMI attenuation.

Study on the design and laboratory investigation of permeable semi-rigid base material with large air voids

PurposeTo explore the economical and reasonable semi-rigid permeable base layer ratio, solve the problems caused by rainwater washing over the pavement base layer on the slope, improve its drainage function, improve the water stability and service life of the roadbed pavement and promote the application of semi-rigid permeable base layer materials in the construction of asphalt pavement in cold regions.Design/methodology/approachIn this study, three semi-rigid base course materials were designed, the mechanical strength and drainage properties were tested and the effect and correlation of air voids on their performance indexes were analyzed.FindingsIt was found that increasing the cement content increased the strength but reduced the air voids and water permeability coefficient. The permeability performance of the sandless material was superior to the dense; the performance of the two sandless materials was basically the same when the cement content was 7%. Overall, the skeleton void (sand-containing) type gradation between the sandless and dense types is more suitable as permeable semi-rigid base material; its gradation is relatively continuous, with cement content? 4.5%, strength? 1.5 MPa, water permeability coefficient? 0.8 cm/s and voids of 18–20%.Originality/valueThe study of permeable semi-rigid base material with large air voids could help to solve the problems of water damage and freeze-thaw damage of the base layer of asphalt pavements in cold regions and ensure the comfort and durability of asphalt pavements while having good economic and social benefits.

Hydraulic Characterization of Permeable Materials Used for Filling Mole Drain Channels in Structurally Unstable Soils

Highlights Permeable materials can be used to fill mole drains and provide support to the cavity walls in structurally unstable soils. Permeable materials extend the lifespan and improve the hydraulic performance of mole drainage systems. Darcy’s law for nonlinear porous flow explained the hydraulic performance of the permeable materials used in this study. A numerical method was established to assess the suitability of permeable materials of unknown hydraulic performance. Design guidelines were developed to assist in the planning of filled mole drainage systems installed in structurally unstable soils. Abstract. Mole drainage in soils with low permeability is a cost-effective technique for managing soil drainage. Following installation, the satisfactory performance of the system will depend on having sufficient soil fissure development extending from the soil surface to the roof of the mole channel and mole channel stability to avoid its collapse. Permeable materials such as river-run gravel and crushed stone can be used to fill mole channels to prevent channel collapse in halomorphic and high-silt content (e.g., 50%–70%) soils and extend the lifespan of the system. The objectives of this work were to: (i) characterize a range of permeable materials that can be used to fill mole drains and provide support to the cavity walls in structurally unstable soils; (ii) verify the applicability of Darcy’s law to explain the hydraulic performance of such materials, and (iii) develop a set of design and planning guidelines aimed at improving the performance of mole drainage systems that are filled with permeable materials. Five permeable materials were characterized, namely: three types of river-run gravels, crushed baked mud bricks, and crushed stone. The materials were characterized for their mechanical and hydraulic properties, and the applicability of Darcy’s law was experimentally determined. Small- and medium-sized gravels are easy to handle and apply during field installation due to their shape and flowability properties and the reduced risk of clogging when placed in the mole channel. However, the hydraulic performance of these materials would not allow for system designs longer than about 100 m, which therefore would limit their utilization in practice. Large-sized gravel offered an intermediate solution with overall satisfactory hydraulic performance. Crushed brick and crushed stone offered good alternatives to gravel, allowing for longer (e.g., >120 m) system designs for all combinations of drain spacing and drain gradient. However, their angularity, poor uniformity, and size range distribution can compromise the efficiency of handling and delivery in current mole plough systems. For all materials, the hydraulic conductivity (Kh) decreased with an increase in the hydraulic gradient. For a given hydraulic gradient, Kh was dependent on aggregate size, such that a larger D50 value led to increased Kh. The nonlinear performance of Darcy’s law was verified for all materials, and potential equations were fitted to represent such relationships, all showing acceptable fits to the nonlinear models (P<0.001). A linear relationship (P<0.05) between the parameter m of the potential model and total porosity was established. The set of equations developed by this study will enable estimating Kh based on the aggregate size distribution or as a function of the total porosity of the material. Crushed brick and crushed stone could provide a cost-effective solution for the installation of filled mole drain systems in structurally unstable soils. Keywords: Darcy’s law, Extreme rainfall, Halomorphic soils, Hydraulic conductivity, Reynolds number, Silty soils.

Framework structure design based on porous permeable concrete material in expressway tunnel drainage system

As an important construction material for drainage system construction, permeable concrete has the characteristics of porous and breathable, but the existing mix preparation technology makes it difficult to prepare high-strength porous permeable concrete material. The study introduces a permeable concrete skeleton structure that considers compressive strength and permeability coefficient. Moreover, the proportion design method is adjusted based on the spherical characteristics of the aggregates, which are analyzed using Image Pro-Plus image processing technology. The parameters of the permeable concrete skeleton structure, such as the number of contact points, width of the contact zone, and thickness of the inter-aggregate slurry, are quantified. Additionally, the proportion design method is refined by incorporating the target mechanical properties and water permeability performance of the permeable concrete, aiming to enhance its mechanical properties and water permeability. To enhance the mechanical properties and water permeability of pervious concrete, modifications are made to the proportion design method based on target mechanical properties and water permeability. This includes balancing the mechanical properties and water permeability through the design of the concrete's skeleton structure, the composition of the cement slurry, and the adjustment of additive mixing amounts. The use of a single-graded pyrophyllite aggregate enables the preparation of high-strength and high-permeability concrete. The experiment showed that the minimum deviation of compressive strength of group A was 15.29%, the average was 18.17%, and the minimum deviation of compressive strength of group B was 42.59%, the average was 45.27%. The minimum deviation of the water permeability coefficient in group A was 10.60%, with an average of 16.50%, and the minimum deviation of the water permeability coefficient in group B was 11.35%, with an average of 19.18%. In addition, the correction coefficient relationship between aggregate sphericity and the number of contact points, contact zone width and paste thickness between aggregates was established. Through the correction of the coefficient, the high strength, and high permeability concrete with permeability coefficient, compressive strength, and effective porosity of 1.15, 23.6mpa, and 18.5% can be obtained. The mix proportion design of permeable concrete using a skeleton structure in this study has economic and social benefits for construction engineering, "sponge city" construction, and urban sustainable development. In terms of economic benefits, permeable concrete, as an ecological and environmentally friendly concrete, has low production costs and good bearing capacity and permeability, reducing construction costs. In terms of social benefits, the application of permeable concrete can make urban floors more breathable and permeable, alleviate the pressure on urban drainage systems, and improve the ecological balance and environmental quality of the city. The application of permeable concrete can reduce reliance on traditional drainage materials and reduce negative impacts on the environment. Materials can also be recycled and reused, which helps to enhance the sustainable development capacity of cities.

Impact of alteration corridors on karst reservoir organisation and evolution of groundwater flow path: An example from the southern border of the Larzac Causse, southern France

All the features of karstic reservoirs result from the chemical and/or mechanical erosion of an initial rock volume, which modifies the initial petrophysical properties (i.e., porosity and permeability). The spatial distribution and organisation of the karst system in a carbonate massif are often overlooked in studies on karst hydrological functioning. However, these parameters are key to understand and accurately model dynamic flow. This contribution aims at characterising the nature and impact of alteration corridors on the organisation and evolution of the karstic reservoir and its present-day functioning. We focus on characterising the specific impact of the late onset of pocket valley regressive erosion on the organisation of the present-day drainage system. We used a 3D approach to correlate field observations on the surface and in caves, with remote sensing. The expression of alteration corridors is analysed in a 40 km2 area on the southern border of the Larzac Causse. This Jurassic carbonate massif is affected over its entire thickness by a network of vertically elongated alteration corridors containing dissolution-collapse breccia, mainly oriented in a N-S direction. Ghost-rock karstification played a significant part in the karstic reservoir structure and evolution. Alteration corridors result from the in-situ dissolution of the bedrock along an initial jointing pattern. The dissolution-collapse breccia corridors correspond to ghost-rock corridors selectively emptied of their alterite, under the effect of a hydraulic gradient. The vertically elongated structure of alteration corridors that cross-cut the Jurassic sequence enables fluid circulation from an upper to a lower aquifer, which were initially separated by a Toarcian marly seal unit. The subsequent initiation of pocket valleys led to the rapid evacuation of the residual alterite contained in ghost-rock corridors, under the influence of gravity. These alteration corridors determine the position of present-day pocket valley springs and enhance the regressive erosion dynamics, that progressively capture a north-east flowing watershed (Vis River). Finally, residual alterites are evacuated below the overflow spring altitude during high-flow events by flooding/dewatering of galleries. Such mechanisms of alterite evacuation provide insight into i) the part of the karstic reservoir that is connected to the spring, and ii) the dynamics of the associated flows. This study suggests that corridor networks constitute a substantial volume of porous and permeable materials that plays a major role in the present-day groundwater flow path. Such features should be considered valuable drilling targets for water exploration when located below the piezometric level.

Study of permeability and permittivity of [formula omitted]-Fe[formula omitted]O[formula omitted] using computer simulation method

This study proposes a computational method to directly obtain the frequency-dependent permeability and permittivity of materials from computer simulation data. The method combines first-principles calculations, Green’s function formalism, and magnetic moment dynamics simulations. Using α-Fe2O3 as an example, we demonstrate the validation process of the computational approach. By calculating the time correlation functions of electric and magnetic dipole moments and applying linear response theory, we successfully obtained the frequency-dependent permeability and permittivity of α-Fe2O3 at 300 K. The calculated results agree well with experimental values, proving the efficacy of the proposed computational method. This study provides a reliable computational pathway to predict electromagnetic parameters of materials using computer simulations.

A Green Infrastructure SDGS Num 11: Approach Planning Design Model Reliability of Permeability and Concrete Quality Rural Roads P3MD Program in Wonogiri

Design planning permeability and quality of rural concrete road construction work in the Program Pembangunan dan Pemberdayaan Masyarakat Desa (P3MD) of the Ministry of Villages, Development of Disadvantaged Regions and Transmigration in Wonogiri, which is environmentally friendly in accordance with the sustainable development goals of SDGs Number.11 Villages "Sustainable Cities and Community", is the urgency of global action to reduce the impact of climate change and overcome challenges in developing a village road infrastructure model that is sustainable and leads to Green Infrastructure. Testing the permeability of village road construction materials using a rational classification method based on the Unified Soil Classification System, ASTM and International Nomenclature Darcy’s Law by calculating the input discharge of rainwater seeping into the soil through the pores of road construction using a rational method, testing the compressive strength of concrete roads using Rebound Hammer / Concrete Hammer Test method, SNI Standard 03-4430-1997. The results of the input volume of rainwater seeping into the ground through the pores (run off) of rural roads construction in Wonogiri one year is 724,866 m3. The average compressive strength of concrete roads from the hammer test results for concrete road test is 290 kg/cm2> K-225 kg/cm2, than the desired construction, namely; standard deviation; (S=1.75), coefficient of variation (Kv= 7.35%), indicating that the data taken has a sufficient level of accuracy, while the uniform data is quite representative of the road section studied.

Hydro-mechanical analysis of water-induced pothole patch failure in asphalt pavement

Pothole repair is one of most common roadway maintenance to improve driving comfort and reduce safety risk. This study aimed to conduct hydro-mechanical analysis of water-induced pothole patch failure in asphalt pavement. Three-dimensional finite element models are used to analyze the coupled hydraulic and mechanical responses of surface patching under moving traffic loading considering different wheel path locations and asphalt patch sizes. The model results under dry and saturated conditions were validated against field measurements and simulation results from the literature, respectively. Laboratory tests were conducted to measure dynamic modulus and permeability of asphalt patch material. Analysis results show that regardless of patch size and wheel path, the maximum pore water pressure occurs either at the patch body or the interface between the patch and surrounding pavement when traffic loading approaches the pothole. The hydraulic scouring effect was observed with positive and negative pore pressure under moving loads. The maximum interface shear stress at the interface between the patch and surrounding pavement under traffic loading was found close to the bonding strength, especially for big-shallow patch. The comparison of asphalt patch responses at dry and saturated conditions indicates that water intrusion mainly accelerates edge disintegration of pothole patch.

Design and use of multi-linear drainage geocomposites for gas collection layers

Pore pressures generated by gas underneath a geomembrane can affect its integrity and the entire lining system. It can create whales/hippos in a surface impoundment, significantly reduce normal stress on the lower interface and create a veneer instability on final landfill cover. The membrane is lifted by the pressure of the gas trapped beneath it. The solution to avoid such occurrences is to install a permeable material that collects and transmits the gas outside the lining system. It can be vented to the atmosphere in the case of impoundments or collected in a gas collection network for valorization in case of landfills, for example. A sand layer is certainly possible, but drainage geocomposites offer an efficient and economical alternative. Depending on the application, the drainage geocomposite is designed to act as a passive system (no mechanical vacuum applied) or active. This paper presents the use of multi-linear drainage geocomposite for gas collection and its hydraulic behavior to collect and evacuate the gas. A case study is also given with the use of geocomposite as venting layer under a lined pond.

An experimental investigation into the characteristics and performance of reactive powder concrete to choose the ideal mix

reactive Powder Concrete (RPC) originated in the early 1990s as a cutting-edge concrete material renowned for its outstanding strength, durability, and ductility. Its remarkable durability attributes stem from a low water-cement ratio, high density, and elevated strength. With high ductility, RPC exhibits significant deformation capabilities before reaching failure. Additionally, its low porosity contributes to reduced material permeability, enhancing resistance against chemical attack and water infiltration. The primary goal of this experimental investigation is to choose an ideal mix for reactive powder concrete after implementing several experimental mixes based on mixing ratios implemented during previous studies to choose the optimal mix. Subsequently, the chosen mixture underwent testing at 7 days to assess its behavior and mechanical properties, utilizing six standard cylindrical specimens (10*20) cm and six cubes (15*15) cm. The results demonstrated a substantial increase in the ultimate compressive strength of the (RPC) specimen by 72% compared to the Normal Concrete (NC) specimen. Moreover, the tensile strength of the RPC exhibited a 35.4% increase compared to the (NC) specimen. The stress-strain analysis indicated a remarkable 118% increase in the (RPC) specimen's maximum stress compared to the (NC) counterpart. In contrast, the strain values for ordinary concrete rose by 22.5% at the point of maximum stress compared to the RPC specimen. Specifically, the tensile stress of the (RPC) specimen increased by 10% compared to the (NC), accompanied by a 29% uptick in tensile strain for the RPC specimen at the point of maximum stress. Furthermore, the (RPC) specimen demonstrated a 38.2% increase in the Modulus of Elasticity and a 35.7% increase in Poisson's ratio compared to the (NC) specimen.

Standalone cell culture microfluidic device-based microphysiological system for automated cell observation and application in nephrotoxicity tests.

Microphysiological systems (MPS) offer an alternative method for culturing cells on microfluidic platforms to model organ functions in pharmaceutical and medical sciences. Although MPS hardware has been proposed to maintain physiological organ function through perfusion culture, no existing MPS can automatically assess cell morphology and conditions online to observe cellular dynamics in detail. Thus, with this study, we aimed to establish a practical strategy for automating cell observation and improving cell evaluation functions with low temporal resolution and throughput in MPS experiments. We developed a versatile standalone cell culture microfluidic device (SCCMD) that integrates microfluidic chips and their peripherals. This device is compliant with the ANSI/SLAS standards and has been seamlessly integrated into an existing automatic cell imaging system. This integration enables automatic cell observation with high temporal resolution in MPS experiments. Perfusion culture of human kidney proximal tubule epithelial cells using the SCCMD improves cell function. By combining the proximal tubule MPS with an existing cell imaging system, nephrotoxicity studies were successfully performed to automate morphological and material permeability evaluation. We believe that the concept of building the ANSI/SLAS-compliant-sized MPS device proposed herein and integrating it into an existing automatic cell imaging system for the online measurement of detailed cell dynamics information and improvement of throughput by automating observation operations is a novel potential research direction for MPS research.

Modeling and semi-analytical solution for immiscible and miscible fingers formation during enhanced oil recovery

ABSTRACT The fingering phenomenon arises during the secondary and tertiary oil recovery processes when injected fluid (water, gases, nano/biomaterials, or polymer particles) shoots through a porous medium at a relative speed. Oil recovery is influenced by various factors including the fluid type, capillary pressure, permeability, and porous material structure. All these elements play crucial roles in determining the success and efficiency of the oil recovery process. Many scientists have debated the fingering phenomenon from different perspectives. Here, we developed mathematical models with and without considering mass flow rates of oil and water for an inclined oil layer flowing through a homogenous porous medium to generate immiscible fingers. Furthermore, a mathematical model of miscible viscous finger formation with carbonated water injection (flooding) during the enhanced oil recovery process (EOR) has been analyzed in this paper. To solve each of these mathematical models, we used the recently developed approach known as the Method of Directly Defining the inverse Mapping (MDDiM). We found approximate solutions to the nonlinear partial differential equations (PDEs), which describe each modeling of the fingering phenomenon in a homogeneous porous medium by incorporating gravitational effects for several types of flooding and discussed the effects of the saturation rate.

Design of equilibrium modified atmosphere packaging for postharvest cabbages preservation based on introducing available active sites into film materials as gas transport channels

This work aims to explore an available avenue to design an equilibrium modified atmosphere packaging (EMAP) by the modification of gas permeability of material. In this work, the introduction of available active sites endowed materials with adjustable gas permeability properties. With varying concentrations of the resulting materials with various gas permeability, the CO2 and O2 gas permeability of the blending films were modified at the range of 3.92 ∼ 17.84 barrier and 0.65 ∼ 3.46 barrier, respectively. On this basis, the films were used as EMAP to preserve postharvest cabbages. The results indicated that each EMAP achieved an equilibrium atmosphere containing 6.8 % ∼ 3.8 % CO2 and 2.1 % ∼ 5.2 % O2 within 15 h and maintained it continuously. In these atmosphere, the respiratory rate of the preserved cabbages was significantly inhibited, thereby delaying the deterioration of their storage quality. As the results, sensory scores of the preserved samples were maximally maintained. Declines of color indexes and texture indexes were obviously inhibited. Chemical variations in chlorophyll content, total phenolics content, total flavonoids content, ascorbic acid and nitrite content were significantly suppressed. The overall findings revealed that this method is suitable and promising to develop EMAP for the postharvest vegetables.

STUDY OF THE AIR PERMEABILITY INDICATOR OF A PACKAGE OF MATERIALS OF THERMAL CLOTHING FOR CHILDREN WITH A DIAGNOSIS OF CP

This article reports the results of breathability tests on upper materials, nonwoven insulation materials, lining materials, and material packs. The importance of air permeability values for packages of materials of thermal protective clothing for children diagnosed with cerebral palsy (CP) is substantiated. Objects and methods for studying the air permeability of materials are defined and described. The method according to State Standard ISO 9237–2013 was used to assess the properties of air permeability of materials. A method for calculating the predicted values of the air permeability of packages of materials is also given. The article analyses the results of air permeability of packages of materials obtained both theoretically and experimentally. The article compares the values of the air permeability of the packages of materials with the previous study of the packages of materials on the total thermal resistance. Conclusions are drawn about the requirements for air permeability of packages of materials for thermal protective clothing for children with cerebral palsy.