Interparticle Space Research Articles

Towards Ultrahigh Performance Concrete Produced with Aluminum Oxide Nanofibers and Reduced Quantities of Silica Fume.

Ultrahigh performance concrete (UHPC), which is characterized by dense microstructure and strain hardening behavior, provides exceptional durability and a new level of structural response to modern structures. However, the design of the UHPC matrix often requires the use of high quantities of supplementary cementitious materials, such as silica fume, which can significantly increase the cost and elevate the production expenses associated with silica fume handling. This paper demonstrates that a fiber-reinforced composite with properties similar to conventional UHPC can be realized with very low quantities of silica fume, such as 1% by mass of cementitious materials. The proposed UHPC is based on reference Type I cement or Type V Portland cement with very low C3A (<1%) that also complies with Class H oil well cement specification, silica fume, small quantities of Al2O3 nanofibers, and high-density polyethylene or polyvinyl alcohol macro fibers. Previous research has demonstrated that nanofibers act as a seeding agent to promote the formation of compact and nanoreinforced calcium silicate hydrate (C-S-H) clusters within the interparticle and nanofiber spaces, providing a nanoreinforcing effect. This approach produces a denser and stronger matrix. This research expands upon this principle by adding synthetic fibers to ultrahigh strength cement-based composites to form a material with properties approaching that of UHPC. It is indicated that the developed material provides improved strain hardening and compressive strength at the level of 160 MPa.

Graphene quantum dots (GQDs)-assembled membranes with intrinsic functionalized nanochannels for high-performance nanofiltration

Recent innovations highlight the great potential of zero-dimensional materials of graphene quantum dots (GQDs) as attractive candidates for fabricating advanced nanofiltration membranes. In this study, a novel class of thin-film composite (TFC) nanofiltration membranes derived from assembled GQDs with amino/sulfonic modification (GQDs_N/S) as building blocks directly, is developed to achieve highly selective water transport for high-performance nanofiltration via interfacial polymerization. Based on the transport behavior, the intrinsically hydrophilic sulfonic groups are introduced to endow the membrane with stronger internal polarity and more accessible sites for easier water molecules infiltration, while engineering the nanochannels by covalently immobilizing GQDs between the terminal amino groups and trimesoyl chloride. Furthermore, an enhanced interparticle space with enlarged free volumes between GQDs is obtained for rapidly transporting water molecules inside the membrane, owing to the intercalation of sulfonic groups acting as spacers to break up the tightly stacking structure of GQDs. The resultant GQDs_N/S TFC membrane exhibits superior separation properties with high water permeance of 9.82 L m-2h−1 bar−1 and 97.4% rejection against Na2SO4, giving rise to more than 2-fold higher water permeability without obviously sacrificing the membrane selectivity, and revealing an outperformed separation property when compared to state-of-the-art nanofiltration membranes. Simultaneously, the sulfonic and amino sites firmly anchored on GQDs with custom-tailored functionality further enables the GQDs_N/S TFC membrane to perform an outstanding antifouling property and durability over the long-term operation condition. The proposed approach opens new pathways to fabricate highly permeable-selective nanofiltration membranes.

Combustion behaviour of composite sandwich propellants containing RDX

Addition of nitramine particles (RDX) to composite solid propellants are promoted in advanced propulsion systems for better performances, high energy, high specific impulse, and environmentally benign combustion products. This study is performed for understanding the combustion mechanism of RDX based matrices and sandwich propellants. Four types of fine AP/Al/binder matrix mixtures are considered, two samples contain 5% and 20% RDX while another two mixtures are without RDX, for comparison. Burning rate experiments are carried out on sandwich propellants and matrices in the pressure range of 2–10 MPa. The condensed phase behaviour of RDX decomposition and RDX melt flow, their influence on the matrix flame and interaction with leading edge flames (LEFs) located over lamina interfaces of sandwich propellants are assessed from quenched surface profiles and SEM micrographs. The effect of middle lamina thickness and pressure on burning rates of sandwich propellants are investigated. It is noticed that different levels of addition of RDX to matrix induces either an increase or decrease in burning rates depending upon the composition and fine AP/binder ratio. The binder melt flow effect is reduced in RDX containing matrix lamina due to presence of near-surface premixed flame. The effect of middle lamina thickness on burning rates of RDX containing sandwich propellants is significant. The overall burning rates of RDX sandwich propellants are relatively high when compared to their corresponding non-RDX counterparts. This is due to the existence of RDX assisted matrix flame that re-establishes the interaction between the LEFs anchored over lamina interfaces. Such matrix flames that are located over the regions of matrix in inter-particle spaces of the propellant microstructure would have a positive effect on the LEFs and outer diffusion flames over coarse AP particles.

Simulation of Electrochemical Double Layer Formation with Complex Geometries

A novel method is introduced to simulate the formation of electrochemical double layers on complex electrode particle geometries. Electrochemical double layers play the most crucial role in electrical energy storage of supercapacitors and in capacitive deionization (desalination) devices. The double-layer region usually spans 20 to 50 nanometers, whereas other significant length scales, e.g., particle size or inter-particle space in electrodes, are in tens to hundreds of microns. Thus, a direct numerical simulation in the continuum scale must resolve the ionic concentration and potential gradients in spatial scales across 3 ∼ 4 orders of magnitude difference and is highly challenging. In this paper, we use the smoothed boundary method that defines complex microstructures with a continuous domain-parameter function to reformulate the Nernst-Planck-Poisson equations and solve the reformulated governing equations on adaptively refined meshes. The method allows for accurate simulations of arbitrarily complex geometries with resolutions spanning from nanometers in the double layer to micron/millimeters in the particle/electrode scales. The results show that ions first rapidly adsorb onto or are repelled from the particle surfaces, followed by long-distance diffusion to alleviate the concentration gradient until the system reaches the steady state. The concentration and potential evolutions highly depend on the particle geometries.

Evaluation of Bentonite Mixed Indigenous Clays for Development of Clay Liners

This study presents experimental investigation of indigenous clays mixed with Bentonite to assess their suitability in potential use as clay liners. Soil samples with 0, 4, 8, and 12% Bentonite content from three different sites in Peshawar region were tested for various geotechnical properties. Grain size distribution, specific gravity, Atterberg limits and free swell were found through laboratory tests using appropriate ASTM procedures. Maximum dry density and optimum moisture content were calculated using Atterberg limits in available relationships. Finally, one dimensional consolidation tests were conducted to find relevant parameters for calculating hydraulic conductivity. A decrease in specific gravity, increase in free swell, and in optimum moisture content, decline in maximum dry density and hydraulic conductivity was observed with increase in Bentonite content across all three soil samples. During free swell, the soil clusters become larger leading to formation of floccules resulting in the narrowing of inter-particle space and thus blocking of permeable paths. It is concluded that 8% Bentonite content by weight yields a suitable mixture for a clay liner that has hydraulic conductivity in the range of recommended limits.

Permeability's response to dolomitization, clues from Permian–Triassic reservoirs of the central Persian Gulf

Understanding the pattern of spatial permeability distribution in carbonate reservoirs strongly depends on its relationships to geological factors. Despite this importance, the relationship between dolomitization and permeability changes is poorly understood. This study represents the effects of dolomitization on permeability variations in carbonate Permian–Triassic strata of the central Persian Gulf. Porosity and permeability measured on 1389 plug samples using Boyle and Darcy lows, respectively. Petrographical studies under a polarizing microscope showed that various types of facies are recognizable including boundstone, mudstone, wackestone, packstone and grainstone. Dolomitization and dissolution are the main diagenetic processes. Permeability increases along with dolomite content in the samples with higher than 1 mD permeability. Dolomitization of the allochems increased the interparticle spaces and so improved the pore connectivity. High permeability is also due to the intercrystalline pores between dolomite crystals and vuggy porosities which have been created as the result of high degree of dolomitization. Classifying the dolomitic rocks based on dolomite crystal shapes indicates that nonplanar dolomites are more frequent in the samples with less than 0.001 mD permeability while samples with more than 1 mD permeability have more euhedral dolomites. The subhedral dolomites are more frequent in the sample with 0.1–1 mD permeabilities. Nonplanar dolomites are more abundant in K1 and K3 units which are non-reservoir parts. Also, pore spaces in coarse crystal dolomites are connected to each other more effectively, which mainly occurs in K2 and K4 reservoir units. Pore typing in the studied carbonates demonstrates that moderate amounts of dolomites (about 50%) connect the other pore types while they produce a contiguous pore network in higher quantities. In the samples with more than about 60% dolomites, the intercrystalline pores are combined together and touching vugs are created, which strongly increase the permeability of the samples.

Minimization of Anthropogenic Impact on the Environment of Waste of Mining Complex by Recycling Them in the Soil Concrete Modified with Natural Zeolites

The article considers the possibility of reduction of anthropogenic impact on ecosystems of various levels of waste of mining complex by their largetonnage direct using in the construction industry. The methods of utilization of waste crushed production modified with natural zeolites and stabilizing additive in the composition of soil concrete are studied. The chemical and phase compositions of the inital mineral raw materials and soil concrete based on them are studied by a complex of modern methods. Optimal mass fractions of clinoptilolite rock (5–15 wt. %) and a polymeric stabilizing additive (1 wt. %) allowing to obtain composites with a maximum strength grade of 100 (М 100) are established. The increase of strength characteristics of soil concrete modified with zeolite-containing rock is associated with an increase of their density by the presence of crystalline calcium and magnesium silicates in the structure as well as the filling of the interparticle space with mineral and polymer additives.

Direct Numerical Simulation of Electric Double Layer Formation

We will present an innovative method to simulate the formation of electric double layers on complex electrode geometries. Electric double layers are omnipresent and affect the ionic diffusion in many natural systems. It plays the most crucial role in the energy storage of supercapacitors and electric-field desalination. Upon imposing an electrostatic potential, the cations and anions near the electrode surface separate to form a localized polarization counterbalancing the potential. The charge-separated region usually spans 20 to 50 nanometers, whereas other significant length scales, e.g., particle size or inter-particle space in electrodes, are in tens to hundreds of microns. A direct numerical simulation in the continuum scale requires to resolve the ionic concentration and potential gradients across 3~4 orders of magnitude in spatial scales and is incredibly challenging. Therefore, continuum-scale numerical studies are limited to one-dimensional or simple symmetric geometries, or in nanoscales where double-layer thickness and particle size are comparable. In this work, we use the smoothed boundary method that defines complex microstructures with a phase-field-order-parameter-like continuous function to reformulate the Nernst-Planck-Poisson equations and solve the equations on adaptively refined meshes. Thus, the method allows for accurately simulating the charge separation and potential distribution in arbitrarily complex geometries with resolutions spanning from nanometers in the double layer to micron/millimeters in the particle/electrode scales. Simulations of the dynamics during double layer formation and the resultant capacitance on complex electrode microstructures will be presented. The coupling of charge separation and fluid mechanics in simulating the electric-field desalination process through porous electrodes will also be discussed.

Injectable dual-scale mesoporous silica cancer vaccine enabling efficient delivery of antigen/adjuvant-loaded nanoparticles to dendritic cells recruited in local macroporous scaffold

Despite the potential of nanoparticle-based vaccines, their therapeutic efficacy for cancer immunotherapy is limited. To elicit robust antigen-specific adaptive immune responses, antigen-loaded nanoparticles are employed for transport into host dendritic cells (DCs); however, only a minority of the nanoparticles can be engulfed by host DCs. Herein, an injectable dual-scale mesoporous silica vaccine consisting of mesoporous silica microrods (MSRs) coupled with mesoporous silica nanoparticles (MSNs) is introduced. The MSRs form a three-dimensional macroporous scaffold after injection, and the subsequent release of DC-recruiting chemokine loaded in the mesopores of MSRs leads to the recruitment of numerous DCs into the scaffold. Subsequently, MSNs co-loaded with an antigen and Toll-like receptor 9 agonist, which exist in interparticle space of the MSR scaffold, are internalized by the recruited DCs, leading to the generation of antigen-presenting activated DCs. Strikingly, the MSR-MSN dual-scale vaccine generates a significantly larger number of antigen-specific T cells and inhibits melanoma growth to a greater extent compared with a single MSR or MSN vaccine. Moreover, the dual-scale vaccine is synergized with an immune checkpoint inhibitor to inhibit tumor growth in tumor-bearing mice. The findings suggest that the MSR is a novel platform for delivering nanoparticle vaccines for the enhancement of cancer immunotherapy.

Comparison of pore evolution for a Mesoproterozoic marine shale and a Triassic terrestrial mudstone during artificial maturation experiments

Semi-closed pyrolysis experiments were performed on a Mesoproterozoic Hongshuizhuang marine shale sample and a Triassic Chang 7 terrestrial mudstone sample, in order to understand the mechanisms of pore evolution in shales with similar organic geochemical characteristics in different depositional environments. The pore characteristics of the solid samples from the thermal maturation experiments were investigated by low-pressure gas (N2 and CO2) sorption isotherms tests and Field Emission - Scattering Electron Microscopy (FE-SEM) imaging. Results indicate the marine shale samples develop more micropores than that of the terrestrial mudstone samples during the artificial maturation. Secondary organic pores are observed in the unheated samples (~0.76% EqRo) for the marine shale, which is earlier than that of in the terrestrial mudstone (observed in the sample at 250 °C, ~0.8% Ro). Significant development of organic pores at 350 °C for both the two shales. And the transformation of smaller pores into larger pores takes place at 450 °C for the marine shale, as well as for the terrestrial mudstone. In highly overmatured shales, the overpressure formed by organic matter cracking to gas can make surrounding interparticle space to vanish. The high content of rigid minerals in the marine shale is more conducive to the preservation of organic pores than the terrestrial mudstone with rich in ductile clay minerals. Therefore, pore increases continuously for the marine shale but decreases for the terrestrial mudstone after 500 °C. Micropores would be generated if a high lithostatic pressure exists under experimental conditions, which may be largely responsible for the disagreement of pore evolution of similar shales in other publications. Finally, a conceptual model of pore evolution for type-II marine and terrestrial shales is proposed. The study reveals that the pore evolution of shales with different sedimentary environments is divergent, and this need to be separately considered in the future work.

Targeting changes in soil porosity through modification of compost size and application rate

The global demand to increase food production from underperforming, water and nutrient limited soils is increasing, which has resulted in an increased dependency on water for irrigation. As fresh water is a finite resource, the increase in irrigation use has resulted in competition between water used for municipal purposes and that used for food and fibre production for an increasing global population. An opportunity exists to improve the efficiency of both urban and agricultural systems by taking green waste compost generated in urban centres and incorporating it into agricultural soils with poor water retention, thereby increasing the ability of these soils to efficiently retain irrigation water for plant use and also to capture a greater volume of water from rainfall. Addition of amendments to soil changes the pore space. The magnitude and cause for this change depends on amendment type, application rate, soil type and climatic conditions. The aim of this research was to determine if the incorporation of municipal compost (MC) can increase the quantity (total volume) and concentration (total volume per unit volume) of soil pores that hold readily available water (defined as macro-mesopores of 30–3 μm diameter) and plant available water (defined as mesopores of 30–0.3 μm diameter). We hypothesised that increases in total porosity would be positively correlated with MC application rate and increases in water holding porosity (macro-mesoporosity and mesoporosity) would be positively correlated with decreasing MC particle size due to the creation of inter-particle pore spaces &amp;lt; 30 μm in diameter. The MC was screened to three different maximum particle sizes – MC4 (&amp;lt;4 mm), MC2 (&amp;lt;2 mm) and MC0.25 (&amp;lt;0.25 mm) – and incorporated into repacked soil cores at five different rates: 0, 5, 25, 50 and 80% wt/wt. Incorporation of MC0.25 increased the concentration and quantity of macro-mesopores and mesopores at significantly lower application rates than MC4 and MC2. The finding that modification of MC particle size can produce targeted changes in inter-particle porosity suggests that this practice has potential to remediate hydraulic limitations of soils.

Multiscale petrographic heterogeneity and their implications for the nanoporous system of the Wufeng-Longmaxi shales in Jiaoshiba area, Southeast China: Response to depositional-diagenetic process

Abstract The organic matter-rich shales in Wufeng-Longmaxi Formation, Jiaoshiba area, Southeast China, are showing a notable petrographic heterogeneity characteristic within the isochronous stratigraphic framework, which lead to vast differences in the mineral composition and organic matter abundance in the adjacent sections of the shale reservoir. The studied shale has been divided into three systems tracts: a transgressive systems tract (TST), an early highstand systems tract (EHST), and a late highstand systems tract (LHST). Multiple-scale petrographic observation and detailed mineralogical and geochemical analyses were combined to investigate the manifestation, origin, and the ways by which the shale heterogeneity is affected. The results indicate that polytropic depositional environments lead to different components in sediment. Subsequently, these differences among shale sections become more apparent through different diagenetic pathways. During the deposition of the section TST, the Hirnantian glaciation and regional volcanism played a crucial role, contributing to the abundant accumulation of fine-grained intrabasinal silica and organic matter. In diagenesis stage, authigenic quartz aggregates derived from siliceous organisms are formed. They filled in primary interparticle pores, forming a rigid particle-bracing structure that provide effective resistivity against the compaction and spaces for organic matter migration and occlusion. Finally, the migrated organic matter left plenty of newly created pore spaces that constituted a great portion of the total porosity of shale reservoir. The depositional process of section EHST is strongly influenced by contour current, which brings about more extrabasinal influx and impoverishes organic matter. In diagenesis stage, the rigid particle-bracing structure could only be preserved in limited areas, since insufficient siliceous supply could not produce enough authigenic quartz. Primary interparticle pores are significantly reduced owing to compaction, leaving less space for later organic matter migration and occlusion. As a result, the total porosity of shale reservoir declines in this section. In a rapid tectonic-uplifting background, the deposition of section LHST is associated with a rapid increase in terrigenous clay minerals, which further dilutes organic matter. Ductile clay experienced strong compaction and then occupies most of the primary interparticle space. Rigid particles are wrapped by a large number of clays, which has destroyed the particle-bracing structure. As a result, the nanoporous system in the shale could not be well preserved.

Saturn's C ring and Cassini division: Particle sizes from Cassini UVIS, VIMS, and RSS occultations

Abstract Saturn's C ring and Cassini Division share many morphological traits: both contain numerous opaque, sharp–edged ringlets and gaps, broader low optical depth “background” regions, larger-optical depth regions that rise abruptly from the background (known as the C ring's plateaus and the Cassini Division's triple band feature), and linear ramps in optical depth up to the abrupt inner edges of the B ring and A ring, respectively. Throughout the majority of both regions, the surface mass density of the rings is small enough that the Toomre critical wavelength (most unstable wavelength for gravitational collapse) is comparable in size to, or smaller than, the largest individual ring particles. Thus, self-gravity wakes do not form in these regions, unlike the A and B rings where the critical wavelength is tens of meters and the self-gravity wakes introduce strong dependence of the observed optical depth on viewing geometry. In the absence of self-gravity wakes, we model the ring particle size distribution with a simple power-law, where the number of particles per unit area of the rings in the size range [a, a + da] is given by n(a)da = Ca-qda between amin and amax. We fit normal optical depths derived from the power-law size distribution parameters and the thin-layers ring model of Zebker et al. (1985) to the wavelength-dependent optical depth profiles obtained by 3 Cassini Instruments: UVIS at λ = 0.15 μm, VIMS at λ = 2.9 μm, and RSS Ka-band (λ = 9.4 mm), X-band at (λ = 3.4 cm), and S-band (λ = 13.0 cm). We find that the C ring is best characterized by five or more thin layers of particles with a mean power-law index of q ~ 3.16 in the C ring background and q ~ 3.05 in the C ring plateaus, in the rings. We find a minimum particle radius of amin ~ 4.1 mm in the background C ring and plateaus and amin ~ 6 mm in the plateaus. The cross-section-weighted effective particle radius determined using the excess variance of UVIS signal beyond Poisson counting statistics by Colwell et al. (2018) constrains the size of the largest particles in the rings. We find the largest particles contributing to the power-law size distribution, and thus to the optical depth, are amax ~ 10–15 m in the background C ring and amax ~ 5–6 m in the C ring plateaus. This substantial difference in the sizes of the largest ring particles together with the overall shallower power law index in the plateaus explains their optical depth difference relative to the background C ring. Additionally, Baillie et al. (2013) used UVIS stellar occultations to find a distribution of small-scale, low optical depth gaps in the plateaus. These regions, with radial widths of We constrain the particle densities by dividing the surface mass densities determined from the dispersion of spiral density waves by the total particle volume integrated over a square meter of the ring slab. We derive low bulk particle densities of ρ ~ 0.1–0.3 g/cm3 except in the central background C ring where we find ρ ~ 0.9 g/cm3. These low derived densities may be due to inter-particle spaces within 1–20 m particle aggregates that contribute to the measured optical depth and thus to the upper end of the size distribution. Our results are consistent with Zhang et al. (2017) who reported particles with porosities >75% made of water ice with up to 11% silicate contaminate in the central background C ring.

Optical properties of Au–Ag nanosphere dimer: Influence of interparticle spacing

In this paper, the extinction and near-field properties of Au–Au, Ag–Ag nanosphere homo-dimer and Au–Ag nanosphere hetero-dimer were studied by using the discrete dipole approximation method. The relation between extinction and interparticle spacing was investigated under y- polarization (perpendicular to dimer axis) and z-polarization (parallel to dimer axis) incidence. The results show that the both extinction peak position and enhancement factor of electric field are sensitive to interparticle spacing when the dimer is illuminated by z-polarization incidence. For Au–Ag hetero-dimer, double same-intensity extinction peaks in visible band were found by regulating interparticle space under z-polarization incidence, and the experience forum was obtained for realizing the double same-intensity peaks.

The Origins of Enhanced and Retarded Crystallization in Nanocomposite Polymers.

Controlling the crystallinity of hybrid polymeric systems has an important impact on their properties and is essential for developing novel functional materials. The crystallization of nanocomposite polymers with gold nanoparticles is shown to be determined by free space between nanoparticles. Results of large-scale molecular dynamics simulations reveal while crystallinity is affected by the nanoparticle size and its volume fraction, their combined effects can only be measured by interparticle free space and characteristic size of the crystals. When interparticle free space becomes smaller than the characteristic extended length of the polymer molecule, nanoparticles impede the crystallization because of the confinement effects. Based on the findings from this work, equations for critical particle size or volume fraction that lead to this confinement-induced retardation of crystallization are proposed. The findings based on these equations are demonstrated to agree with the results reported in experiments for nanocomposite systems. The results of simulations also explain the origin of a two-tier crystallization regime observed in some of the hybrid polymeric systems with planar surfaces where the crystallization is initially enhanced and then retarded by the presence of nanoparticles.

Zingiber officinale Extract (ZOE) Incorporated with Layered Double Hydroxide Hybrid through Reconstruction to Preserve Antioxidant Activity of ZOE against Ultrasound and Microwave Irradiation.

We prepared Zingiber officinale extract (ZOE) incorporated in a layered double hydroxide (LDH) hybrid through a reconstruction method in order to preserve the antioxidant activity of ZOE from ultrasound and microwave irradiation. X-ray patterns, infrared spectroscopy, and scanning electron microscopy suggested that ZOE moieties were encapsulated in the interparticle space of reconstructed LDH, thus preserving its intact structure. Dynamic light scattering and zeta-potential measurement also supported the hypothesis that ZOE moieties were located in the interparticle pore of LDH rather than at the surface of LDH particles. Thermogravimetry analysis revealed that thermal stability of encapsulated ZOE could be enhanced by LDH encapsulation. Radical scavenging assay showed that antioxidant activity of ZOE–LDH hybrid was increased after ultrasound and microwave irradiation, while ZOE itself dramatically lost its antioxidant activity upon ultrasound and microwave treatment.

Characterization of Aged Li-Ion Battery Electrodes for Direct Recycling Process Design

Developing a recycling protocol for lithium-ion batteries (LIBs) at their end of life is crucial to both supply chain stability and waste mitigation. Novel nondestructive recycling methods are under investigation, but lack the process engineering specifications required for full-scale operation. Specifically, the ability of end-of-life LIB components (i.e., recycling feedstock) to withstand the mechanical stresses inherent in industrial reprocessing techniques has not been established. To this end, we have mechanically characterized the electrodes of both fresh cells and “cycled-aged” (C-A) cells (cells that have been cycled and subsequently calendar-aged, and thus reflect a representative recycling input). We report the components’ performance under uniaxial tensile stress and compressive loads, and determine the effects of tensile strain rate and electrode coating on mechanical response. Further, we explore how these measured mechanical properties affect design parameters for a roll-to-roll (R2R) direct recycling process. Cycle-aging is found to significantly reduce the tensile strength of coated electrodes across all strain rates, and electrodes are found to have significantly lower elastic moduli than their respective current collectors. Positive strain rate dependence is observed for bare current collectors but not for coated electrodes, implying that the coating of active material permanently alters the current collector matrix. Compressive failure is not observed for any of the samples; however, C-A cathodes reach elastic deformation at a lower strain than do fresh cathodes. In the context of direct recycling, these findings suggest that roll tension may need to be reduced by 13-65% for C-A components relative to fresh components to avoid irreversible damage. Additionally, C-A cathodes are expected to permanently deform at a lower calendering force than fresh cathodes. Finally, we have investigated each component’s contribution to overall cell capacity loss, and have probed the degradation mechanisms of cathodes to inform recycling method development. Electrochemical analysis suggests that phase shift (layered to spinel phase) and buildup of electrolyte residues at both the primary particle and in the inter-particle pore space may significantly contribute to cathode degradation. Washing C-A cathodes with aprotic solvents is found to improve half-cell cycling performance, likely due to the removal of electrolyte residues, but does not reverse structural degradation. These electrochemical results suggest the importance of a washing step prior to chemical relithiation in direct recycling methods. Thus the present work, which combines mechanical and electrochemical analyses of cycle-aged LIB components, informs the process design of industrial-scale nondestructive LIB recycling.

Characterization of lead–zinc mill tailings, fly ash and their mixtures for paste backfilling in underground metalliferous mines

Surface disposal of mill tailings and fly ash is a major concern for many countries, as it pollutes the environment including air, water, and soil. Paste backfilling is an emerging mine backfilling technique, wherein the industrial wastes such as mill tailings, fly ash and blast furnace slag are backfilled inside the stopes. This study examines the physico-chemical characteristics of lead–zinc mill tailings, fly ash and their mixtures for their possible utilization in paste backfilling in underground metalliferous mines. Three different mill tailing–fly ash mixtures, viz., 95:5, 92:8 and 90:10 (wt%), have been considered. The chemical, morphological and mineralogical compositions are analyzed by XRF, SEM and XRD. The morphological analysis revealed that the mill tailings are irregular in shape and fly ash particles are almost spherical in nature. The filling of inter-particle spaces of irregular mill tailings with spherical fly ash and finer mill tailings (− 20 µm) particles will enhance the rheology of mill tailing–fly ash mix paste backfill. Chemically, the lead–zinc mill tailings is enriched in SiO2, CaO, Fe2O3, and Al2O3, whereas fly ash is mainly composed of SiO2 and Al2O3 with small amounts of Fe2O3, CaO, K2O, TiO2, MgO, SO3, Na2O, and P2O5. The XRD analysis revealed that the lead–zinc mill tailings mainly contain quartz, pyrite, dolomite, hematite and calcite, while fly ash contains quartz, mullite, kaolinite and hematite. This study proved that lead–zinc mill tailings and fly ash together can be suitably used for paste backfilling in underground metalliferous mines.

A hidden single-stage martensitic transformation from B2 parent phase to B19′ martensite phase in an aged Ni51Ti49 alloy

The aged Ni-rich NiTi shape memory alloys (SMAs) exhibit the multi-stage martensitic transformation (MMT), which has important influences on functional properties and practical applications of the NiTi SMAs. A hidden single-stage martensitic transformation from B2 parent phase to B19′ martensite phase is found in an aged Ni51Ti49 alloy, which happens concurrently with a commonly observed two-stage martensitic transformation B2–R–B19′ (R: martensite phase) and actually composes one stage of a multi-stage martensitic transformation (MMT) together with the two-stage one. B2–B19′ martensitic transformation occurs in the NiTi matrix containing Ni4Ti3 precipitates with relatively large inter-particle space, while B2–R–B19′ transformation takes place in the NiTi matrix with Ni4Ti3 precipitates having relatively small inter-particle space.

The influence of batter formulation and predrying time on interparticle space fractions of a coated meat analog.

The purpose of the study was to understand the mechanism of microstructural changes in vegetable-based meat analogs coated with different batter formulations. A meat analog (substrate) was developed by using vegetable proteins, coated with batters formulated from different combinations of wheat and rice flours, predried at various durations, and subsequently fried. The effect of batter formulation, predrying time, and frying time on spaces occupied by air (porosity, SOA), moisture (SOM), and fat (SOF) in the core region (the meat analog) was studied. The SOA, SOM, and SOF ranged between 8.28-32.72%, 16.73-58.31%, and 16.73-58.31%, respectively. All three fractions of pores in the meat analog were significantly influenced by predrying and frying times; however, batter formulation did not show any significant influence. Batter formulation did not show any significant influence on moisture and fat content within the meat analog. Fat content was not influenced by frying time; and only 90 min predrying made a difference.