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Purpose: The purpose of this paper is to predict a suitable paper substrate which has high capillary pressure with the tendency of subsequent fluid wrenching in onward direction for the fabrication of microfluidics device application. Design/methodology/approach: The experiment has been done on the WhatmanTM grade 1, WhatmanTM chromatography and nitrocellulose paper samples which are made by GE Healthcare Life Sciences. The structural characterization of paper samples for surface properties has been done by scanning electron microscope and ImageJ software. Identification of functional groups on the surface of samples has been done by Fourier transform infrared analysis. A finite elemental analysis has also been performed by using the "Multiphase Flow in Porous Media" module of the COMSOL Multiphysics tool which combines Darcy's law and Phase Transport in Porous Media interface. Findings: Experimentally, it has been concluded that the paper substrate for flexible microfluidic device application must have large number of internal (intra- and interfiber) pores with fewer void spaces (external pores) that have high capillary pressure to propel the fluid in onward direction with narrow paper fiber channel. Originality/value: Surface structure has a dynamic impact in paper substrate utilization in multiple applications such as paper manufacturing, printing process and microfluidics applications. [ABSTRACT FROM AUTHOR]

Old corrugated container (OCC) pulp was fractionated and it was found that the longer fiber fraction represented 76.54% and the short fiber fraction – 21.3% of the OCC pulp. The fiber length was 1.22 mm for the long fiber fraction and 0.6 mm for the short fiber, which was longer and shorter, respectively, than the fiber length of the whole OCC pulp (0.95 mm). In addition to fibers in pulp, the cellulosic microparticles that pass through a mesh screen or a perforated plate with a hole diameter of 76 μm, called fines, also have an impact on the properties of the final paper product. The fines content in both longer and shorter fiber fractions was lower than in the whole OCC pulp, consequently, drainage resistance (°SR) in the longer fiber fraction decreased to 14 from 21 in the whole OCC pulp. The air permeability and papermaking properties of the longer fiber were higher than those corresponding to the whole OCC and shorter fiber pulp. Therefore, the longer fraction of pulps can be used to manufacture test liner products and the shorter fiber fraction – for fluting paper. [ABSTRACT FROM AUTHOR]

A high-Ca fly ash generated from a paper mill using a fluidized bed boiler was used as the potential medium to sequester CO2 via the direct carbonation process. In this study, the fly ash samples were exposed to accelerated carbonation to produce hardened pastes. The influence of the porosity controlled by the amount of foam in the matrix for maximizing CO2 sequestration was determined. The effect of porosity on carbonation was evident. The samples prepared with 40 % foam and a water-to-fly ash ratio of 0.79 recorded porosities of 56.1 % (carbonated) and 66.8 % (naturally carbonated (NC)) with the lowest mechanical strength of 2.1 and 1.1 MPa, respectively. These naturally carbonated (NC) samples have been cured naturally without using high CO2 pressure. Meanwhile, the samples prepared with 10 % foam and a water-to-fly ash ratio of 0.5 recorded porosities of 41.1 % (carbonated) and 52.9 % (NC) with the highest strength at 10.2 and 4.6 MPa, respectively. The highest carbonation efficiency determined by thermogravimetric analysis was obtained from the carbonated samples with 40 % foam. Scanning electron microscopy–energy-dispersive spectroscopy depicted the areas with high Al/Si content but low Ca–O content (dark areas) and carbonated areas with high Ca–O content (bright areas). Mercury intrusion porosimetry was used to determine the pore size distribution, whereby the samples were dominated by large capillary pores, resulting in their high porosity in this study.

This study presents an integrated approach to understanding fluid dynamics in Microfluidic Paper-Based Analytical Devices (µPADs), combining empirical investigations with advanced numerical modeling. Paper-based devices are recognized for their low cost, portability, and simplicity and are increasingly applied in health, environmental monitoring, and food quality analysis. However, challenges such as lack of flow control and the need for advanced detection methods have limited their widespread adoption. To address these challenges, our study introduces a novel numerical model that incorporates factors such as pore size, fiber orientation, and porosity, thus providing a comprehensive understanding of fluid dynamics across various saturation levels of paper. Empirical results focused on observing the wetted length in saturated paper substrates. The numerical model, integrating the Highly Simplified Marker and Cell (HSMAC) method and the High Order accuracy scheme Reducing Numerical Error Terms (HORNET) scheme, successfully predicts fluid flow in scenarios challenging for empirical observation, especially at high saturation levels. The model effectively mimicked the Lucas–Washburn relation for dry paper and demonstrated the increasing time requirement for fluid movement with rising saturation levels. It also accurately predicted faster fluid flow in Whatman Grade 4 filter paper compared with Grade 41 due to its larger pore size and forecasted an increased flow rate in the machine direction fiber orientation of Whatman Grade 4. These findings have significant implications for the design and application of µPADs, emphasizing the need for precise control of fluid flow and the consideration of substrate microstructural properties. The study’s combination of empirical data and advanced numerical modeling marks a considerable advancement in paper-based microfluidics, offering robust frameworks for future development and optimization of paper-based assays.

In this article, we delve into the influence of fiber orientation (structural anisotropy) on paper imbibition, with a particular focus on in-plane imbibition. Utilizing the XLPA experimental method, we analyze several papers with different anisotropies, employing a constant volume of ethanol as the imbibing fluid. Our findings contribute novel insights into the anisotropic behavior of imbibition, a topic not extensively covered in the literature. We analyze how the orientation of fibers significantly influences lateral imbibition, providing a deeper understanding of the microfluidic properties of paper. The anisotropies found for imbibition fit perfectly with the existing data found in the literature, indicating the influence of fiber orientation. Furthermore, the kinetics are shown to be linked directly with the porosity. [ABSTRACT FROM AUTHOR]

This study presents an integrated approach to understanding fluid dynamics in Microfluidic Paper-Based Analytical Devices (µPADs), combining empirical investigations with advanced numerical modeling. Paper-based devices are recognized for their low cost, portability, and simplicity and are increasingly applied in health, environmental monitoring, and food quality analysis. However, challenges such as lack of flow control and the need for advanced detection methods have limited their widespread adoption. To address these challenges, our study introduces a novel numerical model that incorporates factors such as pore size, fiber orientation, and porosity, thus providing a comprehensive understanding of fluid dynamics across various saturation levels of paper. Empirical results focused on observing the wetted length in saturated paper substrates. The numerical model, integrating the Highly Simplified Marker and Cell (HSMAC) method and the High Order accuracy scheme Reducing Numerical Error Terms (HORNET) scheme, successfully predicts fluid flow in scenarios challenging for empirical observation, especially at high saturation levels. The model effectively mimicked the Lucas–Washburn relation for dry paper and demonstrated the increasing time requirement for fluid movement with rising saturation levels. It also accurately predicted faster fluid flow in Whatman Grade 4 filter paper compared with Grade 41 due to its larger pore size and forecasted an increased flow rate in the machine direction fiber orientation of Whatman Grade 4. These findings have significant implications for the design and application of µPADs, emphasizing the need for precise control of fluid flow and the consideration of substrate microstructural properties. The study's combination of empirical data and advanced numerical modeling marks a considerable advancement in paper-based microfluidics, offering robust frameworks for future development and optimization of paper-based assays. [ABSTRACT FROM AUTHOR]

The co-pyrolysis of paper mill sludge (PS) and biomass has attracted significant attention due to its potential for simultaneous resource utilization and waste disposal. In this work, the co-pyrolysis of PS with corn stover (CS) was carried out in a fixed bed reactor to investigate the effect of temperature and PS to CS ratio on the product characteristics. A comparison between the experimental and calculated values of product yield and composition was performed to obtain a deeper understanding of the synergistic interactions. The results exhibited a positive synergistic effect on bio-oil production at lower CS proportions with higher temperatures. Higher temperatures and lower CS proportions were favorable for the formation of aromatics (up to 45.03%) in co-pyrolysis, while the synergistic interactions promoted the production of phenols and exhibited an inhibitory effect on aromatics production. The interactions also inhibited H 2 but promoted CO production due to the enhanced decarbonylation of co-pyrolysis intermediates in the presence of PS internal minerals. Additionally, the characterization of biochars indicated an increasing degree of aromaticity with higher temperatures and CS proportions. The synergistic interactions at higher temperatures facilitated the development of pore structures in the biochar, especially micropores. This study provides valuable insights into the relationship between parameters, products, and synergies in the co-pyrolysis of PS and biomass wastes. [Display omitted] • A comprehensive study on the co-pyrolysis of paper sludge and corn stover was conducted. • Lower corn stover ratios with higher temperatures jointly promoted bio-oil yield. • The formation of phenols and CO was synergistically enhanced during co-pyrolysis. • Higher temperatures facilitated the development of micropores in the biochars. [ABSTRACT FROM AUTHOR]

Waste paper and tyre are typical solid wastes with distinct composition. Their pyrolysis could generate varied volatiles that may interact with each other or with resulting char. In this study, the co-pyrolysis of waste paper and tyre was investigated at 400 and 600 ºC, with the focus on understanding the interaction of the volatiles on evolution of the products. The results show that the interaction of the volatiles at 400 ºC forms more gaseous products like CO and CO 2 , while the interactions of the heavier organics at 600 ºC forms more oil (49.3% vs 42.6%). The interaction of the volatiles also affects the generation of sulfur-containing organics and diminishes the paper-derived aldehydes and ketones or the heavy organics with the π-conjugated structures in the oil. In addition, the volatile-char interactions exist and form the char of higher carbon content through promoting carbonization and deoxygenation reactions, generating char of higher thermal stability and higher hydrophilicity via tailoring functional group, pore structures and morphologies of the char. [Display omitted] • Interaction of volatiles in co-pyrolysis of waste paper and tyre exists. • Co-pyrolysis promotes formation of gases at 400 ℃ while oil at 600 ℃ via condensation. • Paper-derived intermediates capture CH x * /H* radicals, minimizing CH 4 /H 2 formation. • Volatiles interactions interfere formation of S-containing organics and aldehydes/ketones. • Co-pyrolysis affects composition, stability, functionality and morphologies of char. [ABSTRACT FROM AUTHOR]

To achieve integrated resource utilization of graphite tailings to improve their water-holding capacity, river silt and cow dung powder were added to graphite tailings as organic matter improvers. Improver ratios were designed using 4 g cow dung powder and 20, 30, and 50 g river silt. Soil–water characterization tests were performed using a combined tensiometer and filter paper method based on optimum density measurements. Analysis of the influence of river silt dosing on the soil–water characteristic curves of improved graphite tailing specimens was performed with data fitting using the Van Genuchten model. Here, we investigated the effect of river silt dosing on the internal pore structure and water-holding capacity of modified graphite tailing samples and verified the applicability of the model to graphite tailings. Our results demonstrate that the organic matter improver incorporated into graphite tailings can improve the internal structural compactness of graphite tailings, improving the water holding capacity. With an increase in river silt dosage, the saturated water content is larger, and the residual water content increases and then decreases. When river silt dosage is 30 g, the residual water content is the highest at a value of 3.32%. The van Genuchten model was highly accurate for assessing the graphite tailings. With an increase in river silt doping, the internal pore space first decreased and then increased, and the internal structure gradually became compact and loosened. The internal structure was in the optimal state in the experimental study when the dosage of cow dung powder was 4 g and the dosage of river silt was 30 g. The water holding capacity was optimal at this time. The results of this study provide a theoretical foundation for graphite-tailing-based mine reclamation and play a guiding role in exploring the value of the hydraulic characteristic index parameters when applying graphite tailings engineering. [ABSTRACT FROM AUTHOR]

Potassium–oxygen batteries (KOBs) are a promising energy storage technology with high theoretical energy density, low overpotential and a long cycle life. The cathode microstructure plays a significant role in the electrochemical performance of KOB. In this article, hierarchical porosity was introduced to commercially available carbon paper cathodes by thermal pretreatment in air at different pretreatment times. This pretreatment modifies the properties, such as surface area, defects, oxygen functional groups, etc. The discharge performance was determined at three different current densities, i.e., 0.1 mA/cm2, 0.5 mA/cm2, and 1.0 mA/cm2. It has been found that an increase in specific surface area with the introduction of micropores and mesopores is beneficial for the improvement in the discharge capacity by enabling homogeneous discharge product, KO2 distribution and high degrees of pore filling over the volume of the cathode. A reduction in the discharge overpotentials was observed, which is attributed to the introduction of oxygenic functional groups and defects. Samples treated for the longest pretreatment time of 24 h showed the highest discharge capacity of 5 mAh/cm2 and lowest discharge overpotential of 0.03 V. [ABSTRACT FROM AUTHOR]

This study evaluates the potential use of discarded plasterboard paper as fibers from buildings to reinforce concrete. Various concentrations of wastepaper fibers (0.5%, 1%, 1.5%, 2%, and 2.5% by weight of the binder) were investigated in this research. To mitigate the water absorption effect of the paper fibers, metakaolin was employed as a partial cement replacement. The results demonstrate that the inclusion of the wastepaper fiber enhances the mechanical and durability performance of the concrete. The optimal fiber proportion was identified as 1%, leading to a 29% increase in the compressive strength, a 38% increase in the splitting tensile strength, a 12% decrease in the water absorption, and a 23% decrease in the drying shrinkage with respect to the concrete containing 20% metakaolin. However, exceeding this optimal fiber content results in decreased mechanical and durability properties due to the fiber agglomeration and non-uniform fiber distribution within the concrete matrix. Based on the microstructural analysis, the improved performance of the concrete is ascribed to decreased porosity, more refined pore structure, and reduced propagation of microcracks within the concrete matrix in the presence of wastepaper fiber. According to the results, concrete containing 20% metakaolin and 1% wastepaper fiber exhibits durability and mechanical properties comparable to those of the traditional concrete. This finding highlights the significant promise of reducing dependency on conventional cement and incorporating suitable recycled materials, such as discarded plasterboard, and secondary by-products like metakaolin. Such a strategy encourages the preservation of resources, reduction in carbon dioxide emissions, and a decrease in the ecological footprint resulting from concrete production. [ABSTRACT FROM AUTHOR]

• ZIF-67 particles can be evenly distributed and tightly attached to the cellulose paper substrate. • Mild synthesis conditions combined with papermaking processes are suitable for mass production. • The composite filter has a hierarchical porous structure with a large specific surface area. • The optimum sample exhibited removal efficiencies of 98.52% for PM 2.5 and 99.00% for PM 10. • Composite papers possessed excellent mechanical properties and reusability. The combination of functional zeolitic imidazolate frameworks (ZIFs) with suitable substrates is promising for the preparation of advanced filtering materials. In this study, the bleached kraft softwood pulp (NBKP) was composited with ZIF-67 particles via an in situ growth method to fabricate functional paper. Enabled by the traditional papermaking process, ZIF-67 crystals were uniformly and tightly anchored on cellulosic fibers in a facile and economic way. The introduction of ZIF-67 boosted the mechanical performances of the composite paper owing to the presence of electrostatic interactions and hydrogen bonds. Meanwhile, the resultant paper presents hierarchical porous structure with a large specific surface area of 327.07 m2·g−1. The filters with hierarchical pore structure will provide a complex tortuous channel for passing particulates, which can increase the frequency of effective collision between filters and particulates. Air filtering tests demonstrated that the ZIF-67 entrapped paper has superior particle removal efficiency with a low pressure drop and a large dust holding capacity. The optimal ZP-3 sample displayed removal efficiencies of 98.52 % for PM 2.5 and 99.00 % for PM 10. Meanwhile, filtration quality factors were calculated to be 0.15 (PM 2.5) and 0.17 (PM 10), respectively. The filter also has good antibacterial activity. In addition, ZP-x composite paper is easy to regenerate and possesses good reusability. The high-efficient ZP-x filter will have potential applications in fields of air purification. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Moisture sorption and diffusion processes of plant fiber materials have a significant impact on their properties and product quality in healthcare, food production, cigarette processing, textile field, and papermaking industry. The infiltration process affects the rate of water sorption and processing of flavoring liquids, and exploring its mechanisms can optimize the production process. Here, multi-scale imaging approach was employed to identify the heterogeneous structure of plant leaves and the impact of multilevel fiber structure and pore channels on water adsorption. The dissipative changes and mechanisms of water adsorption, osmotic diffusion, and hygroscopic swelling in plant leaves were illustrated. Furthermore, the effects of temperature and water activity on water diffusion under different environmental conditions are determined through a comparison of adsorption equilibrium and diffusion electrochemical impedance analysis (EIS), with a focus on the water-blocking effect of the waxy layer interface. This work investigated the correlation between the impedance change in water transport and the natural layered water-blocking polymer film structure and multi-level pore structure. This study sheds new light on biological multi-scale fiber materials and these findings are important reference value for manufacturing processes to improve the moisturizing properties of functional plant fibers in the field of food preservation. [ABSTRACT FROM AUTHOR]

The present study investigated the fresh, hardened, and physicochemical properties of CO 2 -cured belite-rich cement (BRC) paste incorporating hygiene tissue paper (HTP) as an additive. HTP was added at 0.5% and 1.0% by wt. of BRC paste. The BRC paste was prepared at a water-to-cement ratio of 0.4 and cured under water and carbonation. The results demonstrated that upon carbonation, the incorporation of HTP at 1.0% increases the CO 2 uptake and compressive strength of specimens by 18.60% and 22.29%, respectively. A pore structure analysis shows a decrease in the threshold pore size diameter with an increase in the HTP content for CO 2 -cured samples. An SEM analysis revealed precipitation and impregnation of calcites in and around the HTP microfiber particles. The incorporation of HTP under water curing on the other hand did not significantly influence the strength or the physicochemical properties. It was observed that HTP contributes to improving the properties of CO 2 -cured BRC paste in two ways; the porous structure of HTP provides pathways for the deep permeation of CO 2 into the matrix, and the surface of HTP offers an additional area for calcite precipitation. [ABSTRACT FROM AUTHOR]

The recent paper "Low-field 1 H NMR study on geopolymers: The effect of paramagnetic Fe(III)" is discussed. After examining the NMR test method and results, it is deduced that, the relaxation signals of the geopolymers with various Fe(III) contents were inconsistently obtained and interpreted without attention to total intensity. The calibration of surface relaxivity was also questionable. These inappropriate interpretations not only make the experimental results about the effect of Fe(III) loading on spin relaxation unreliable, but also make the discussion about its effect on pore structure of the geopolymers too ambitious, which is further incompatible with current understandings of geopolymerization. [ABSTRACT FROM AUTHOR]

Gas reactant transport plays a crucial role in various gas‐consumption reaction‐based electrochemical devices, but the pivotal performance limitation still centers on gas diffusion electrodes (GDEs). To this end, natural cross‐cut wood to prepare GDEs for aluminum–air batteries is introduced by utilizing the ordered structure with microchannels. With cobalt–nitrogen co‐doped carbon nanotubes as the oxygen reduction reaction catalysts grown inside the channels of carbonized wood slice and wettability gradient modification, cherry‐based GDE achieves higher power density (267 vs. 236 mW cm−2) than the commercial carbon fiber paper‐based electrode. By bridging the identified characteristics of pore structure via deep‐learning image recognition technology with the permeability of other three typical kinds of (ash, pine, and oak) wood‐based GDEs, it is revealed that the ratio of effective porosity to the average pore size is key to the performance. This work demonstrates the feasibility of bio‐derived wood‐based materials for fabricating high‐performance GDEs and provides insights into pore structure for the rational design of structured electrodes. [ABSTRACT FROM AUTHOR]

Approximately 130,000 metal fuel pins were irradiated in the Experimental Breeder Reactor II (EBR-II) during its 30 years of operation to develop and characterize existing and prospective fuels. For many of the metal fuel irradiation experiments, neutron radiography imaging was performed to characterize fuel behavior, such as fuel axial expansion. While several fuel expansion results obtained from neutron radiography imaging have been published, the analysis of neutron radiography for the purpose of describing statistical properties of porous matter formed on top of the fuel pins, also referred to as fluff in previous publications, is significantly less represented in the literature with just a single paper so far. This study aims to validate and augment results reported in previous publications using automated image processing. The paper describes the statistical properties of the porous matter in terms of nine parameters derived from radiography images and correlates those parameters with such fuel properties as composition, expansion, temperature, and burnup. The reported results are based on 1097 fuel pins of eight different fuel compositions. For three major fuel types, U-10Zr, U-8Pu-10Zr, and U-19Pu-10Zr, a clear negative correlation is found between the Pu content and five parameters describing the amount of porous matter generated. The parameters describing granularity properties, however, showed either negative correlation or nonlinear dependency from fuel composition. The parameters describing the amount showed a positive correlation with fuel axial expansion, while granularity parameters showed a negative correlation with axial expansion. The dependency on cladding temperature was found to be weak. A positive correlation is demonstrated for volume parameters and fuel burnup. In general, reported results confirm and validate findings published in previous studies using a much larger number of pins and automated processing techniques, which easily lend themselves to reproducibility, thus avoiding subjective bias. [ABSTRACT FROM AUTHOR]

In the process of long-term water flooding in the Gaoqian Southern Area with an average porosity of 30% and an average permeability of 1333.5 × 10 − 3 μm2, the fluid-solid interaction among oil, water, and rock has a great influence on the pore structure. It has resulted in changes in reservoir parameters with the extension of time. This paper used electron microscopy scanning, mercury injection, X-ray diffraction, physical properties, and oil-water relative permeability curves to study the variation of clay mineral content, pore throat structure, porosity, permeability, and relative permeability curves of high-permeability sandstone after high-pressure water flooding. The results showed that clay minerals such as montmorillonite and kaolinite were dissolved, hydrated, and migrated after long-term water flooding, which resulted in the decrease of clay mineral content in fine sandstone and medium sandstone, the increase of pore throat radius, and the decrease of displacement pressure, median pressure, and separation coefficient. The saturation of the isotonic point of the oil-water relative permeability curve was obviously shifted to the right, the hydrophilicity was significantly enhanced, and the porosity and permeability were effectively improved, but there was a blockage of the throat less than 2 μm in the fine sandstone. In addition, this paper established the equations of water injection, permeability, irreducible water saturation, residual oil saturation, and oil-water relative permeability curve coefficient and establishes the initial permeability model with the well data before water flooding. The logging interpretation results of development wells in the process of water flooding as verification data were used, and the relative error of permeability far lower than the general requirement of permeability error within an order of magnitude was less than 30%, which verified the rationality of the method. [ABSTRACT FROM AUTHOR]

In this paper, in order to satisfied the design and manufacturing requirements of functional materials, an investigation is carried out to study the free vibration and thermal buckling characteristics of porous P- and S-type functionally graded materials (FGM) circular plates in non-uniform thermal fields in the context of first-order shear deformation theory. FGM is formed by gradient changes in metals and ceramics, the thermomechanical properties were characterized by a gradient along the thickness direction of the circular plate by a power-law function containing porosity correction. The differential equations of motion control are derived using the Hamiltonian variational principle, and the dimensionless equations of motion and boundary conditions are solved analytically by the DTM transformation procedure. The problem has been degraded and compared with the results of the existing literature to confirm its validity. In conclusion, the influence of each parameter on the dimensionless natural frequency of the porous FGM circular plate and the influence of relevant parameters on the critical temperature rise are calculated and evaluated. The porosity weakens the overall stiffness and equivalent mass of the structure, and the foundation enhances the stiffness. The DTM calculation iteration speed is fast, and the results are highly consistent. The results can be used to provide model guidance and data support for future studies of porous FGM circular plates as well as follow-up studies. [ABSTRACT FROM AUTHOR]

As an important gelling material, cementitious materials are widely used in civil engineering construction. Currently, research on these materials is conducted using experimental and numerical image processing methods, which enable the observation and analysis of structural changes and mechanical properties. These methods are instrumental in designing cementitious materials with specific performance criteria, despite their resource-intensive nature. The material genome approach represents a novel trend in material research and development. The establishment of a material gene database facilitates the rapid and precise determination of relationships between characteristic genes and performance, enabling the bidirectional design of cementitious materials' composition and properties. This paper reviews the characteristic genes of cementitious materials from nano-, micro-, and macro-scale perspectives. It summarizes the characteristic genes, analyzes expression parameters at various scales, and concludes regarding their relationship to mechanical properties. On the nanoscale, calcium hydrated silicate (C-S-H) is identified as the most important characteristic gene, with the calcium–silicon ratio being the key parameter describing its structure. On the microscale, the pore structure and bubble system are key characteristics, with parameters such as porosity, pore size distribution, pore shape, air content, and the bubble spacing coefficient directly affecting properties like frost resistance, permeability, and compressive strength. On the macroscale, the aggregate emerges as the most important component of cementitious materials. Its shape, angularity, surface texture (grain), crushing index, and water absorption are the main characteristics influencing properties such as chloride ion penetration resistance, viscosity, fluidity, and strength. By analyzing and mapping the relationship between these genes and properties across different scales, this paper offers new insights and establishes a reference framework for the targeted design of cementitious material properties. [ABSTRACT FROM AUTHOR]

A previous study (Paper I) investigated the polarization properties of a variety of simple convex grain shapes, some of which were found to be consistent with the observed polarization properties of interstellar dust from far-ultraviolet to far-infrared. Here, we study the optical properties of 45 nonconvex shapes, all aggregates of N equal-sized spheres. We consider N = 2, N = 3, and N = 256 random aggregates obtained from three different aggregation schemes. We also consider "trimmed" N = 256 aggregates obtained by systematically trimming initially random aggregates to increase either flattening or elongation. The "macroporosities" of the studied aggregates range from P macro = 0.18 (for the N = 2 bisphere) to P macro ≈ 0.85 (for the N = 256 "BA" aggregates). The only aggregates consistent with observations of starlight polarization and polarized thermal emission are shapes that have been trimmed to increase their asymmetry. If interstellar grains are high-porosity aggregates, there must be processes causing extreme elongation or flattening; if not, interstellar grains must be dominated by fairly compact structures, with at most moderate porosities. The ratio of polarization in the 10 μ m silicate feature to starlight polarization in the optical is shown to be insensitive to porosity and shape. X-ray scattering may be the best tool to determine the porosity of interstellar grains. We propose that modest porosities of interstellar grains could be the result of "photolytic densification." High polarization fractions observed in some Class 0 cores require processes to reduce porosities and/or increase asymmetries of aggregates in dense regions. [ABSTRACT FROM AUTHOR]

In this study, the pore structure and oil-water phase seepage characteristics of sandstone reservoirs of the Yanchang Formation in the Ordos Basin were deeply analyzed. Through scanning electron microscopy observation, oil-water phase percolation experiments and nuclear magnetic resonance (NMR) experiments on 30 core samples, the pore structure was categorized into uniform macroporous, striated, microfractured and dense types. The experimental results show that the uniform macroporous type pore structure shows the strongest seepage capacity, and its ratio of liquid-measured to gas-measured permeability is 0.724 on average, while the dense type pore structure has the weakest seepage capacity, and the ratio is 0.091 on average; NMR T2 spectral analysis reveals that the cores with different types of pore structure show significant characteristic differences in the water-driven oil drive process, especially in the substitution of oil in the macroporous and micrometer pore In particular, the oil substitution in large pores and micron pores is remarkable, that is, the oil-water seepage process and the response of seepage and suction of cores with different types of pore structure are obviously different, which is a better way to study the characteristics of oil-water seepage and distribution of oil and water; the uniform macroporous type and the striptype pore structure are more effective in oil-water two-phase seepage, and the microfracture type and the dense type are relatively poor. This paper provides a basis for the exploitation of tight reservoirs in the study area, which is of great theoretical and practical significance for optimizing the oilfield development strategy and improving the efficiency of oil and gas exploitation. [ABSTRACT FROM AUTHOR]

The widely used discrete-element particle flow software PFC's (PFC 7.0 and previous versions) algorithm for calculating porosity is not sufficiently accurate. Because of this, when the particles are densely packed, the solution to the equation produces an algorithm exception for odd calculations of porosity, which results in the inability to calculate the results. This paper, based on a Darcy seepage model of fluid flow through a granular bed, analyzed the shortcomings of the two porosity calculation methods of PFC and the function analysis method. Combining this analysis with the theory of computer graphics, a new and efficient porosity calculation algorithm was proposed. The result showed that the new proposed porosity calculation algorithm calculated a more accurate and reasonable porosity field and made the iterative solution of the CFD equation more stable. This method makes porosity-related models of PFC more accurate. The algorithm can be not only used to calculate porosity, but also applied to other fields. [ABSTRACT FROM AUTHOR]

The article deals with the use of computed tomography, an advanced method for evaluating the quality of aluminium castings. Casting quality is a key factor in ensuring safety and reliability in industrial applications. Computed tomography is a comprehensive method allowing a three-dimensional, high-resolution view of the internal structure of materials. The main focus of this paper is the study of BRACKET REAR aluminium castings, manufactured in two-piece moulds using a high-pressure die-casting technology. In this paper, four castings have been analysed which are produced in one cycle. The focus is on the problem of porosity and open stagnation in the castings. A numerical simulation has also been used to illustrate the occurrence of porosity, which can be used to determine both the occurrence of porosity and the occurrence of unfilled volume. The experimental part of the paper describes the methods used to evaluate the BRACKET REAR castings. The numerical simulation was performed in ProCAST 18.0 to determine the occurrence of porosity in the castings under study. The evaluation of computed tomography was performed in myVGL 3.0 2023 software to analyse the internal defects in the castings. The evaluation focused on assessing internal defects and their subsequent effect on the functionality of the final casting. [ABSTRACT FROM AUTHOR]

Copyright of DEPARCH Journal of Design Planning & Aesthetics Research is the property of DEPARCH Journal of Design Planning & Aesthetics Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tight reservoirs are the focus of unconventional oil and gas resource development, but most tight reservoirs exhibit complex pore structures, strong non-homogeneity, and limited water drive development. Fracturing fluid imbibition is a critically important way to improve the recovery of tight reservoirs. In this paper, an NMR experimental device was used to conduct imbibition experiments in tight reservoirs, and the relationship between temperature, pressure, matrix permeability, and imbibition recovery was investigated. Based on the fracturing fluid imbibition recovery curve, the imbibition process is divided into the fast imbibition stage, slow imbibition stage, and imbibition equilibrium. In addition, based on the pore structure division, the recovery changes of each pore under different experimental conditions were quantitatively analyzed. The results indicate that the highest imbibition recovery is achieved at an experimental pressure of 5 MPa within the range of 0 MPa to 15 MPa. Increasing the experimental pressure can increase the imbibition rate but will not increase imbibition recovery. Within the investigated range in this paper, fracturing fluid imbibition increases with rising temperature and matrix permeability. Moreover, the recovery of each pore gradually increases with the experimental pressure ranging from 0 MPa to 5 MPa. The recovery of each pore is positively correlated with matrix permeability and temperature. During the experiment, micropores contributed the most to the recovery, while macropores contributed the least. The study in this paper guides the efficient development of tight reservoirs. [ABSTRACT FROM AUTHOR]

A cold recycling asphalt mixture has significant economic and environmental benefits compared to other pavement material recycling technologies. The cold recycling mixture contains reclaimed asphalt pavement (RAP), new aggregate particles (NAPs), asphalt emulsion, cement, and fillers. The internal material composition is complex, and the interface form is changeable. Both have a significant impact on the mechanical properties. Therefore, this paper aims to study the influence of material composition and related content on the strength performance of a cold recycling mixture from the two aspects of macroscopic mechanical tests and microscopic characteristics analyses. In this paper, the strength evolution law of a cold recycling mixture under changed amounts of cement, emulsified asphalt, and RAP content is carried out. The test result shows that low cement content has little effect on the strength of a cold recycling mixture and is not the main factor affecting its strength composition. The asphalt mainly plays the role of a binder. Compared with the NAPs, the aged asphalt mortar and emulsified asphalt mortar have better interfacial bonding effects. The NAP surface needs more asphalt to form structural asphalt. From the microscopic characteristics of the interfacial transition zone, the cement hydration products and asphalt mortar are intertwined to form a network structure, and the pore structure is filled with asphalt. Compared with the aggregate-asphalt interface, the cement hydration product has poor adhesion with the aggregate. Some micro-cracks are visible in the interface transition zone, which is mainly used as an interface modifier and interface improver to enhance the interface bonding effect. [ABSTRACT FROM AUTHOR]

Under the policy background and advocacy of carbon capture, utilization, and storage (CCUS), CO2-EOR has become a promising direction in the shale oil reservoir industry. The multi-scale pore structure distribution and fracture structure lead to complex multiphase flow, comprehensively considering multiple mechanisms is crucial for development and CO2 storage in fractured shale reservoirs. In this paper, a multi-mechanism coupled model is developed by MATLAB. Compared to the traditional Eclipse 300 and MATLAB Reservoir Simulation Toolbox (MRST), this model considers the impact of pore structure on fluid phase behavior by the modified PengeRobinson equation of state (PR-EOS), and the effect simultaneously radiate to MaxwelleStefan (MeS) diffusion, stress sensitivity, the nano-confinement (NC) effect. Moreover, a modified embedded discrete fracture model (EDFM) is used to model the complex fractures, which optimizes connection types and half-transmissibility calculation approaches between non-neighboring connections (NNCs). The full implicit equation adopts the finite volume method (FVM) and NewtoneRaphson iteration for discretization and solution. The model verification with the Eclipse 300 and MRST is satisfactory. The results show that the interaction between the mechanisms significantly affects the production performance and storage characteristics. The effect of molecular diffusion may be overestimated in oil-dominated (liquid-dominated) shale reservoirs. The well spacing and injection gas rate are the most crucial factors affecting the production by sensitivity analysis. Moreover, the potential gas invasion risk is mentioned. This model provides a reliable theoretical basis for CO2-EOR and sequestration in shale oil reservoirs. [ABSTRACT FROM AUTHOR]

In the process of hydraulic fracturing, fracturing fluid invades the formation and reacts with shale. Water-sensitive clay minerals swell when exposed to water. This results in a change in the mechanical properties of shale. However, the influences of a long-term water–shale reaction on mechanical properties are still unclear, and an optimization strategy of the shut-in time is required. In this paper, an optimization strategy for the shut-in time based on a shale long-term hydration experiment is proposed. In this paper, the water–shale reaction is simulated by laboratory experiments under normal temperature and pressure. The experiments are performed based on specimens from a shale outcrop. Clay and mineral composition, Young's modulus, surface hardness, and tensile strength parameters are measured at 30-day intervals for 90 days. A CT scan was performed for 180 days. The experimental results show that the mass fraction of clay increased by 14.719%. In addition, significant argillaceous shedding occurs during the water–shale reaction period of 3–4 months. By testing the tensile strength, uniaxial compression decreases by 90.481% in three months. The Young's modulus of mineral points decreases to 40% after reaction for three months. The shale has softened. The softening process is nonlinear and there are inflection points. The diffusion behavior of clay minerals and the expansion behavior of new fractures are observed by CT during 3–4 months of water–shale reaction. The results show that the shale softening and pore fracture structure changes are non-linear and heterogeneous, resulting in critical water–shale reaction time. According to the experimental results, the critical water–shale reaction time can be summarized. In this time, the fracture volume increases significantly, which is conducive to increasing oil and gas production. However, the fracture volume is not significantly increased by prolonging the shut-in time. The experimental results can guide the design of hydraulic fracturing shut-in time of shale reservoirs. [ABSTRACT FROM AUTHOR]

In this paper, an enhanced VARTM process is proposed and its pressure effect on resin infusion behavior and composite material performance is studied to reveal the control mechanism of the fiber volume fraction and void content. The molding is vacuumized during the resin injection stage while it is pressurized during the mold filling and curing stages via a VARTM pressure control system designed in this paper. Theoretical calculations and simulation methods are used to reveal the resin's in-plane, transverse, and three-dimensional flow patterns in multi-layer media. For typical thin-walled components, the infiltration behavior of resin in isotropic porous media is studied, elucidating the control mechanisms of fiber volume fraction and void content. The experiments demonstrate that the enhanced VARTM process significantly improves mold filling efficiency and composite's performance. Compared to the regular VARTM process, the panel thickness is reduced by 4% from 1.7 mm, the average tensile strength is increased by 7.3% to 760 MPa, the average flexural strength remains at approximately 720 MPa, porosity is decreased from 1.5% to below 1%, and the fiber volume fraction is increased from 55% to 62%. [ABSTRACT FROM AUTHOR]

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This review offers a comprehensive analysis of thermal barrier coatings (TBCs) applied to metallic materials. By reviewing the recent literature, this paper reports on a collection of technical information, involving the structure and role of TBCs, various materials and coating processes, as well as the mechanisms involved in the durability and failure of TBCs. Although TBCs have been successfully utilized in advanced applications for nearly five decades, they continue to be a subject of keen interest and ongoing study in the world of materials science, with overviews of the field's evolution remaining ever relevant. Thus, this paper outlines the current requirements of the main application areas of TBCs (aerospace, power generation and the automotive and naval industries) and the properties and resistance to thermal, mechanical and chemical stress of the different types of materials used, such as zirconates, niobates, tantalates or mullite. Additionally, recent approaches in the literature, such as high-entropy coatings and multilayer coatings, are presented and discussed. By analyzing the failure processes of TBCs, issues related to delamination, spallation, erosion and oxidation are revealed. Integrating TBCs with the latest generations of superalloys, as well as examining heat transfer mechanisms, could represent key areas for in-depth study. [ABSTRACT FROM AUTHOR]

Zeolites are a class of catalysts with specific pore structures as well as different pore sizes, which are now widely used in various shape-selective catalytic reactions. In this paper, a uniform micro/mesoporous core–shell composite HZSM-@MCM-41 comprising zeolite was successfully prepared by coating mesoporous MCM-41 shells on nanosized ZSM-5 cores using a two-step hydrothermal method. Nanoscale ZSM-5 cores with different acidity were successfully prepared by changing the Si/Al of the initial solution of pristine ZSM-5, and three different thicknesses of MCM-41 shell layers were easily encapsulated on the surface of ZSM-5 with different acidity by varying the amount of silicon source added in the secondary hydrothermal crystallization process. The synthesized series of micro-mesoporous core–shell catalysts were also applied to the catalytic fast pyrolysis in lignin. In the catalytic fast pyrolysis of lignin, the mesoporous structure promoted the transition of biomass pyrolysis intermediate to liquid products, and the acidity of the HZSM-5 core facilitated their catalytic transformation to aromatic hydrocarbons. Among all the tested catalysts, the HZ@M-80-ll catalyst with an internal Si/Al = 80 and MCM-41 shell thickness of ∼25 nm exhibited the highest production of light aromatics and phenols. [ABSTRACT FROM AUTHOR]