Porosity Structure Research Articles

Liquid and gas permeabilities of nanostructured layers: Three-dimensional lattice Boltzmann simulation

Liquid water and gas permeabilities in nanostructured catalyst layers (CLs) (pore size ∼10–150 nm) and microporous layers (MPLs) (pore size ∼50 nm-5 μm) are crucial to reduce the mass transport loss in proton exchange membrane fuel cells (PEMFCs). Experimental measurement of their permeabilities poses great challenges due to their brittle and thin characteristics. Presently, considerable discrepancy exists in the reported permeability values for CLs and MPLs in the literature with variation spanning several orders of magnitude. This study digitally reconstructed various nanostructures of similar pore size as CLs and MPLs to calculate their permeabilities using the Lattice Boltzmann Method (LBM) based on no-slip (e.g. for liquid water flow in MPL and CL's secondary pores) or slip condition (e.g. for gas flow in MPL). Analysis was performed to evaluate the range of pore size in nanostructures for the two boundary conditions. A comprehensive investigation was conducted under various parameters such as the Reynolds number (Re), sphere diameter, porosity, and pore structure. The results revealed that permeability exhibits an increasing trend with the diameter and porosity. The predicted permeability of randomly arranged spheres agrees well with established correlations. The random sphere structure demonstrates higher permeability than their body-centered cubic (BCC) and face-centered cubic (FCC) counterparts. Under slip boundary condition, the permeability was enhanced, compared to the no-slip condition. This study's novelty lies in using distinct boundary conditions to assess the permeabilities of liquid and air, based on flow pattern analysis in the CL and MPL pore structures. A new empirical correlation describing the influence of the Knudsen number (Kn) on the slip permeability was developed, exhibiting consistency with simulation across the entire porosity spectrum.

Functionalizing heavy metal contained incinerated sewage sludge ash in recycled glass-based alkali-activated materials for sewer environment

This study evaluates the performance of alkali-activated cement (AAC) mortars in an artificial sewage environment. The mortars, initially prepared with waste glass powder (GP) and ground granulated blast furnace slag (GGBS) in a 50:50 mass ratio, were modified by replacing 10 wt% of GGBS with incinerated sewage sludge ash (ISSA) with the goal of offering a biocidal effect. Comparisons were made with calcium aluminate cement (CAC), metakaolin (MK), and MK combined with zinc ferrite nanoparticles, each at a similar GGBS replacement level. The results showed that only incorporating CAC improved the strength development, achieving compressive and flexural strengths of 62.7 MPa and 7.4 MPa, respectively, at 28 days, while introducing ISSA or MK reduced the compressive strength to 47 MPa and flexural strength to 4.5 MPa. Although heavy metal ions from ISSA or zinc ferrite nanoparticles minimized biofilm thickness, they could not compensate for the reduced strength and increased alkalis leaching. Among all the tested mixtures, the 50GP40GGBS10CAC mixture exhibited superior biogenic acid resistance, possibly due to its Al-rich C-N-A-S-H gel phases (Ca/Si = 0.4, Na/Al = 0.8, Si/Al = 3.4) and refined pore structure (porosity = 3.4 %), making it the most microbial acid-resistant option for sewer rehabilitation.

Enhancing the performance of ionic conductivity for solid-state electrolytes: an effective strategy of injecting lithium ions within anionic metal-organic frameworks.

Metal-organic frameworks (MOFs) are considered as potential solid-state electrolyte (SSE) materials due to their structural diversity and porosity. Adding lithium ions into the anionic frameworks of MOFs and then realizing single-ion transport is an efficient way to enhance the performance of ionic conductivity of SSE materials. Herein, an ionotropic MOF (Li+[Cu-BTC]-) with lithium ions in the pores of the lattice was synthesized through an ion exchange strategy, which exhibits outstanding lithium ionic conducting properties over a wide temperature range (ionic conductivity: 0.11-2.96 × 10-3 S cm-1 in the temperature range of -40 to 100 °C). The strategy of injecting Li+ within anionic metal-organic frameworks provides a new opportunity for exploring advanced SSEs.

Chert outcrops differentiation by means of low-field NMR relaxometry

Siliceous rocks served as raw materials in the production of stone tools from the Middle Paleolithic onwards. Due to migration, the provenance of archaeological artefacts can differ from their natural outcrop location. The aim of this work was the application of 1D and 2D low-field nuclear magnetic resonance (LF-NMR) relaxometry to distinguish cherts by their original source. Herein, bedded cherts and accompanying nodular cherts coming from three different outcrops of Kraków-Częstochowa Upland were investigated. 1D and 2D (T1-T2) experiments of water-saturated and dry rock sample states delivered T1, T2 times and T1/T2 ratios of distinct hydrogen populations – parameters sensitive to pore size, surface properties, and hydrogen bonding length. In-depth analysis of NMR data showed substantial differences in the porosity, pore surface and pore structure properties of investigated chert samples tested in the three different saturation levels (100% water-saturated, dried and differential). Finally, principal component analysis (PCA) was performed to reduce the number of correlations obtained and highlight the most important NMR properties specific to the particular outcrop localization."Please check captured corresponding author email if correct.""The email is correct"

Synthesis Techniques and Biomedical Applications of Cyclodextrin Metal-Organic Frameworks.

Cyclodextrin Metal-Organic Frameworks (CD MOFs) represent an innovative class of materials with remarkable properties and a broad range of applications. This review provides a comprehensive overview of the synthesis techniques, structural characterization, and diverse applications of CD-MOFs. By combining cyclodextrins (CDs) with metal-organic frameworks (MOFs), CD-MOFs are developed with enhanced functionality. The synthesis methods, including various metal sources, coordination modes, and post-synthesis modifications, are discussed alongside advanced structural characterization techniques like X-ray crystallography and spectroscopic methods. The unique characteristics of CD-MOFs, such as high specific surface area, tunable porosity, and customizable chemical structure, make them exceptional candidates for applications in gas adsorption, drug delivery, catalysis, sensing, and environmental remediation. Notably, CD-MOFs show significant promise as nanocarriers in drug delivery systems, offering improved therapeutic outcomes due to their efficient encapsulation and controlled release capabilities. The review highlights recent advancements and underscores the potential impact of CD-MOFs in driving future innovations across various scientific fields.

Dual metal centers within a water-stable Co/Ni bimetallic metal-triazolate framework contribute to durable photocatalysis for water treatment.

Bimetallic metal-organic frameworks (MOFs) have been studied extensively in various fields, including photocatalytic and electrocatalytic applications. The enhanced catalytic activity is typically attributed to the synergistic effect of the two metals, often without further explanation. Here, we demonstrate a CoNi-bimetallic triazolate MOF with fixed metal occupancy within the MOF's secondary building unit. Due to the difference in electronegativity and so on, the charge redistribution between the two metal centers could be responsible for the enhanced photocatalytic activity. In addition, the metal(II)-triazolate MOFs we synthesized exhibit unique metal-N coordination and a strong bond between the metal center and triazole ring. Therefore, their crystal structure and high porosity are highly retained even after exposure to humid environments for several months or stirring in water for several days. Overall, the CoNi-bimetallic triazolate MOF combines the excellent water stability and high surface area of its two monometallic counterparts. It can be further tailored to yield the highest colloidal stability during photocatalytic water treatment. As a result, the dual metal centers within the bimetallic MOF, combined with boosted colloidal stability, demonstrate the highest reactive oxygen species generation and promising antibacterial performance compared to their Ni- or Co-based counterparts. These findings shed light on the future design of robust MOF-based photocatalysts, particularly bimetallic ones.

Direct-through channels of ZIF-8 composite membranes via in-situ PolyBMA sealing: Radical-induced phase transformation and dye removal efficiency

Metal-organic frameworks (MOFs)-based hybrid composite membranes are promising candidates for achieving highly efficient water purification. In this study, a facile, novel pressure-induced filtration method involving in-situ polymerization of butyl methacrylate (BMA) was proposed for sealing ZIF-8 nanoparticles on top of polyethersulfone (PES) ultrafiltration membrane support. The developed (ZIF-8+polyBMA)/PES composite membranes with thin toplayers of <1 μm present attractive water permeance (up to 31 LMH/bar) and good rejection of Congo red (99.2 %) and Methylene blue (99.1 %). The ZIF-8 particles served as direct-through channels with superior separation performance due to their high porosity and tunable pore structure, while the interstices were successfully sealed with polyBMA by in-situ polymerization, as demonstrated by SEM and dye removal experiments. It was found that the morphology of ZIF-8 transformed from a rhombic dodecahedron to two-dimensional hexagonal nanosheets during the fabrication process. We hypothesize that this surprising phenomenon is caused by the reaction of the initiators (Na2S2O5 and K2S2O8) that generate the hydroxyl and sulfate radicals attacking and transforming the Zn-MIM bond network of ZIF-8. However, insights into the structural changes need to be further investigated to understand the mechanism involved.

Optimization of Hydrogen Utilization and Process Efficiency in the Direct Reduction of Iron Oxide Pellets: A Comprehensive Analysis of Processing Parameters and Pellet Composition

The article deals with the H2 consumption for different processing conditions and the composition of the processed pellets during the direct reduction process. The experiments are carried out at 600–1300 °C, with gas pressures of 1–5 bar, gas flow rates of 1–5 L min−1, and basicity indices of 0 to 2.15. Pellets with different compositions of TiO2, Al2O3, CaO, and SiO2 are analyzed. The gas flow rate is crucial, with 0–10 L min−1 leading to an H2 consumption of 0–5.1 kg H2/kg pellet. The gas pressure (0–10 bar) increases the H2 consumption from 0 to 5.1 kg H2/kg pellet. Higher temperatures (600–1300 °C) reduce H2 consumption from 5.1 to 0 kg H2/kg pellet, most efficiently at 950–1050 °C, where it decreases from 0.22 to 0.10 kg H2/kg pellet. An increase in TiO2 content from 0% to 0.92% lowers H2 consumption from 0.22 to 0.10 kg H2/kg pellet, while a higher Fe content (61–67.5%) also reduces it. An increase in SiO2 content from 0% to 3% increases H2 consumption from 0 to 5.1 kg H2/kg pellet. Porosity structure influences H2 consumption, with the average pore size decreasing from 2.83 to 0.436 mm with increasing TiO2 content, suggesting that micropores increase H2 consumption and macropores decrease it.

Synchronous hot-pressed metakaolin-fly ash based geopolymer: Compressive strength and hydration products

The dense structure of geopolymers typically requires long curing times, resulting in excessively lengthy production cycles for related products. To address this issue, synchronous hot-pressed curing technology is employed to accelerate the preparation of geopolymers. A comparative experiment was contrived to analyze the impacts of high-temperature curing and synchronous hot-pressed curing of metakaolin-fly ash geopolymer, examining how the silicon-aluminum ratio, alkali equivalent, and curing time influence the compressive strength and hydration products of synchronous hot-pressed cured metakaolin-fly ash geopolymer (SHPMFG) through orthogonal experiments. The outcome indicate that the compressive strength of SHPMFG test specimens can reach 80 % of their final strength within 20 min, with a more complete hydration reaction observed in SHPMFG, resulting in a denser microstructure. The alkali equivalent emerged as the dominant factor affecting SHPMFG strength, with a sample exhibiting a denser matrix structure and lower porosity achieving a maximum compressive strength of 95.33 MPa at 28 days when the alkali equivalent was 8 wt%, the silica-to-alumina ratio was 2.0, and the curing time was 30 min.

Effect of Electromagnetic Stirring on Solidification Structure and Central Porosity of Large‐Sized Round Bloom in Continuous Casting

The effect of strand (S‐) and final (F‐) electromagnetic stirring (EMS) on solidification structure characteristic of a φ690 mm continuously cast round bloom has been investigated industrially and theoretically. The newly designed S1‐EMS equipped just below the foot zone takes great effect on both equiaxed ratio and distribution alignment, as well as central porosity. Larger current S1‐EMS leads to higher equiaxed ratio, more symmetrical equiaxed zone, and smaller diameter of central porosity, and the effect is much more obvious than conventional S2‐EMS and F‐EMS. It is also noticed that there should be a saturation effect of S1‐EMS on the promotion of equiaxed dendrite nucleation. The S2‐EMS is beneficial for the expanding of equiaxed zone and improving of central porosity. When S1‐EMS is weak, strong S2‐EMS results in more asymmetrical equiaxed zone. However, when S‐EMS is strong, strong S2‐EMS results in more symmetrical distribution of equiaxed zone. The F‐EMS takes a little impact on the expanding of equiaxed zone in the large‐sized round bloom, and almost no effect on the alignment. The central porosity, however, is improved by F‐EMS with the help of decrease in temperature gradient and compensation of solidification contraction.

Tailoring the Microstructure and Porosity of Porous Piezoelectric Ceramics for Ultrasonic Transducer Application.

Porous piezoelectric ceramics and composites are advantageous for ultrasonic transducers due to their capability to decouple longitudinal and transverse modes, their improved voltage sensitivity, and their enhanced acoustic matching. However, the design and fabrication of porous piezoelectric ultrasonic transducers with excellent electromechanical properties are still challenging. In this work, porous lead zirconate titanate (PZT) ceramics with an aligned pore structure were prepared using the freeze-cast technique, and the effect of porous structure and porosity on the electromechanical parameters was investigated. The introduction of an aligned pore structure is beneficial to enhance the electromechanical properties and reduce the acoustic impedance. A high d33 (∼530 pC/N), a higher kt (∼0.676), and a lower acoustic impedance (∼10.4 MRalys) were achieved in the porous PZT ceramic with the porosity of 44 vol %. The effect of porosity and pore structure on the decoupling degree of vibration modes and ferroelectric polarization was considered to correct the homogeneous medium model, which can quantify the relationship between the kt and porosity of the porous structure. A demonstration of a piezoelectric ultrasonic transducer based on freeze-cast porous PZT ceramics was presented, which exhibits a -6 dB bandwidth of 52% and a theoretical axial resolution of 520 μm. This work therefore provides a potential alternative of piezoelectric ultrasonic transducers for nondestructive testing and imaging applications.

7793 Bone Mineral Density, Turnover And Bone Microarchitecture Alterations With Dapagliflozin In Post-menopausal Women With Type 2 Diabetes Mellitus: An Open-Label, Parallel-Arm, Randomized, Controlled Study

Abstract Disclosure: S.K. Bhadada: None. L. Das: None. M. Baruah: None. V. Singla: None. V. Dhiman: None. S. Ram: None. S. Sharma: None. N. Sachdeva: None. P. Dutta: None. Introduction: Evidence is limited and there is no consensus about the effects of SGLT2i on bone metabolism. The objective of the current study was to assess changes in bone mineral density (BMD), turnover markers (BTMs), and microarchitecture with the use of dapagliflozin in type 2 diabetes mellitus (T2DM). Methods: Post-menopausal women (&amp;lt;65 years) with T2DM (both menopause and T2DM duration &amp;gt; 5 years and HbA1c 7-11%) were randomly allocated (1:1) to receive either add-on dapagliflozin with standard-of-care or standard-of-care alone for T2DM management. Those with osteoporosis, on anti—osteoporotic medication, chronic glucocorticoids (&amp;gt;3 months), thiazolidinediones, phenytoin, tamoxifen, estrogen, eGFR&amp;lt;30ml/min/1.73m2, contraindication/past usage of SGLT2i, or with known endocrinopathy were excluded. Patients were made Vitamin D sufficient [25(OH)D &amp;gt; 30ng/ml] with oral cholecalciferol (60K daily for 1 week), if deficient. BMD (DXA, Hologic), BTMs (P1NP, CTX) and microarchitecture were assessed at baseline, 6 and 12 months. Results: A total of 131 patients were screened, of which 101 were randomized (50 dapagliflozin, 51 non-dapagliflozin). The mean age (± SD) in the dapagliflozin group was 58.1 ± 5.8 years, diabetes duration was 9.4 ± 5.2 years and HbA1c was 8.5 ± 1.7%. Baseline clinico-biochemical, areal BMD, volumetric BMD, trabecular structural (number, thickness, separation) and cortical structural (thickness and porosity) parameters were comparable between both groups. Only cortical pore diameter (Ct.Po.Dm) (±SD) at radius (0.199 ± 0.04 vs 0.180 ± 0.03, p =0.01) and tibia (0.256 ± 0.04 vs 0.226 ± 0.03, p =0.001) were higher in the dapagliflozin than the non-dapagliflozin group. At 6 months, BMD at lumbar spine (LS), hip, femoral neck (FN), and distal radius and BTMs were comparable between the dapagliflozin (n=38) and the non-dapagliflozin (n=39) groups. However, there was significantly higher trabecular thickness (Tb.Th) (0.230 ± 0.02 vs 0.218 ± 0.01, p=0.003), cortical thickness (Co.Th) (1.104 ± 0.2 vs 0.998 ± 0.2, p=0.04), intra-cortical porosity (Ct.Po) (0.008 ± 0.005 vs 0.005 ± 0.003, p= 0.020) and Ct.Po.Dm (0.192 ± 0.03 vs 0.169 ± 0.02, p=0.003), all at radius in the dapagliflozin group. At 12 months follow-up, BMD (g/cm2) at all 4 sites were again comparable between the dapagliflozin (n=36) and non-dapagliflozin (n=36) groups. Serum CTX (pg/ml) (388.8 ± 191.5 vs 327.4 ± 140.8, p = 0.06), and P1NP (ng/ml) (38.8 ± 16.3 vs 32.5 ± 16.3, p = 0.12) were non-significantly higher with dapagliflozin use. Among microarchitecture parameters, only Ct.Po.Dm at the radius (0.189 ± 0.03 vs 0.169 ± 0.03, p= 0.025) and tibia (0.251 ± 0.05 vs 0.228 ± 0.03, p= 0.030) remained significantly higher in the dapagliflozin group. Conclusion: Dapagliflozin has no long-term detrimental effects on BMD, BTMs or bone microarchitecture after 1 year of treatment in postmenopausal women with T2DM. Presentation: 6/1/2024

MOF-based photothermal Janus membrane with robust anti-fouling performance for enhanced membrane distillation

As a promising desalination technology, photothermal membrane distillation (PMD) is confronted with challenges such as low freshwater yield and membrane fouling. Herein, we have introduced a copper-based metal-organic framework (Cu-CAT) into a hydrophilic/superhydrophobic polyvinylidene fluoride (PVDF) Janus tree-like nanofiber membrane (TLNMs) to construct photothermal Janus TLNMs (P-Janus TLNMs) for enhanced PMD. Given the exceptional photothermal properties of the hydrophilic Cu-CAT layer, coupled with the fine pore structure and elevated porosity characteristics of the superhydrophobic PVDF TLNMs, P-Janus TLNMs have demonstrated outstanding performance when integrated into a PMD system. Upon exposure to solar illumination of 1 kW·m−2, the P-Janus TLNMs achieved a remarkable surface temperature of 88 °C, yielding a permeation flux of 1.46 L m−2 h−1, a salt rejection rate exceeding 99.99 %, and an energy utilization rate of 81 %. Furthermore, after 20 days of continuous operation with simulated seawater containing oil and surfactant, the P-Janus TLNMs presented a salt rejection of 99.9 % and a stable permeation flux of 1.71 L m−2 h−1 at the feed/permeate temperatures of 24/20 °C. This work introduces a novel membrane with immense potential for boosting permeation flux and enhancing anti-fouling properties in PMD, thereby advancing the frontier of sustainable seawater desalination.

Wet-chemical preparation and physicochemical characterization of nanostructured Zn-Bi2O3/CeO2 composite: A visible-light-driven catalyst for the annihilation of pharmaceutical pollutant

A modified co-precipitation technique assisted with cetyltrimethylammonium bromide (CTAB) surfactant was used to synthesize a nanostructured and zinc-doped mixed metal oxide (Zn-Bi2O3/CeO2) composite. Using X-ray diffraction (XRD), the synthesized nanocomposite was studied in terms of its crystal structure, grain size, percentage crystallinity, and percentage porosity. Energy dispersive X-ray elemental analysis (EDX) was used to ascertain the chemical composition, SEM to confirm the creation of nanostructure material, and Fourier transform infrared spectroscopy (FTIR) to extract the existing functional groups. Investigation of light harvesting properties (UV/Vis) and thermogravimetric analysis (TGA) reveals that the doped composite exhibits a band gap driven by visible light and remarkable thermal stability at high temperatures. The pH value at which a material's net charge is zero, known as pHpzc, is 7.93 for the doped mixed metal oxide composite. The Zn-Bi2O3/CeO2 nanocomposite effectively eliminates 98.4 percent of the quinolone antibiotic (levofloxacin) via a mechanism that integrates sorption and photocatalytic degradation induced by visible light. To determine the optimal circumstances for the efficient operation of a photocatalyst, we experimented with different time intervals, beginning drug concentrations, catalyst dosages, operating temperatures, and pH levels. Reusability tests and post-activity FTIR analysis were used to investigate the long-term usability and structural stability of the newly developed doped composite photocatalyst. The scavenging tests revealed a potential photocatalytic mechanism to explain the annihilation of the levofloxacin drug on the synthesized catalyst. The physicochemical and photocatalytic evaluations recommend that the assembled integrated material has excellent potential for mineralizing medicinal products in pharmaceutical wastes.

Electrically-modified bacterial cellulose tailored with plant based green materials for infected wound healing applications

Effective treatment of infected wounds remains a challenge due to the rise of antibiotic-resistant microorganisms. The development of advanced materials with strong antimicrobial properties is necessary to address this issue. In this study, a unique composite of electrically modified bacterial cellulose (EBC) with allantoin (ABC) and zein was developed by dipping diffusion method. Morphological structural analysis revealed a uniform distribution of zein and aligned fibers, confirming the synthesis of the ABC-Zein composite. The formation of ABC-Zein was further confirmed by attenuated total reflection-Fourier transform infrared (ATR-FTIR), which displayed additional peaks corresponding to EBC, indicating the incorporation of zein into ABC. X-ray diffraction (XRD) analysis of ABC-Zein demonstrated a similar crystalline structure with EBC. The ABC-Zein showed mechanical integrity (tensile strength: 1.15 ± 0.21 MPa), thermal stability (degradation temperature: 290 °C), porous structure (porosity: 40.23 0.21 %), and hydrophilic (water contact angle: 53.3 ± 5.3°) properties. Furthermore, the antimicrobial agent terpinen-4-ol (T4O), derived from tea tree oil, was incorporated into the ABC-Zein composite. Biological studies confirmed the antimicrobial efficacy (Staphylococcus aureus inhibition: 88.5 ± 7.19 %) and biocompatible (cell viability: 84.95 ± 5.6 %, hemolysis: 4.479 ± 0.39 %) nature of the T4O-ABC-Zein composite. The combined effects of the aligned fiber structure, zein protein, and antimicrobial T4O significantly enhanced infected wound healing by day 7, promoting inflammatory response, granular tissue formation, cell proliferation, and angiogenesis. By day 14, T4O-ABC-Zein facilitated complete wound healing, with reepithelization, collagen I deposition, and downregulation of CD 31, Ki67, and α-SMA. Overall, the innovative T4O-ABC-Zein composite, with an aligned fiber structure, improved biocompatibility, and antimicrobial properties, holds significant potential for the treatment of infected wounds.

3D-printed gradient conductivity and porosity structure for enhanced absorption-dominant electromagnetic interference shielding

The application of 3D printing for the development of electromagnetic interference (EMI) shielding materials is currently constrained by a limited range of material options and design schemes. In this work, we developed conductivity-modulated polylactic acid (PLA)-MXene composite filaments for fused deposition modeling (FDM) 3D printing, demonstrating excellent printability and durability. Utilizing these filaments, we propose a design scheme focused on absorption-dominant EMI shielding materials. Our design features non-conductive PLA with larger pores at the incident surface, transitioning to layers with increasing conductivity and decreasing pore sizes. This gradient structure minimizes reflection by providing impedance matching and enhances absorption by extending the propagation path of EM waves through multiple reflections and scattering within the pores. Additionally, interfacial polarization effects between air, PLA, and MXene nanoflakes strengthen the absorption mechanisms. Both simulation and experimental results confirm that the combined gradient conductivity and pore size structures significantly improve EMI shielding effectiveness (EMI SE) and absorptivity, achieving an EMI SE of 65 dB and an absorptivity of 0.76 in the X-band. Our findings underscore its potential to create adaptable, high-performance EMI shields suitable for complex geometries and reducing secondary interference.

Investigation of cockleshell waste as a natural biocarrier and its performance efficiency for blackwater treatment in a free-floating plant-constructed wetland

ABSTRACT This study investigated the potential of using waste cockleshell (CS) as a natural biocarrier for blackwater treatment. The CS were analysed for surface porosity, area, volume, elements, and crystal structure. Then, the pilot-scale study confirmed biofilm growth on the CS surface after 29 days, using a crystal violet assay and scanning electron microscopy (SEM) analysis. The free-floating plant-constructed wetland (FFP-CW) was optimally designed with a redox gradient: an aerobic-aquatic zone for nitrification and an anoxic gravel-filled zone for denitrification. The effect of integrating CS biocarriers and active aeration in FFP-CW (aquatic zone) treatment efficiency was investigated. The FFP-CW treatment efficiency for nitrate, chemical oxygen demand (COD), and total ammonia nitrogen (TAN) increased by 9.62%, 6.8%, and 4.83%, respectively, after integrating CS biocarriers of 0.55% filling ratio. Furthermore, the optimal dosage of 192.51 mol of oxygen in FFP-CW increased in TAN and COD removal by 31.11% and 16.54%, respectively. The X-ray diffractometry of CS unravelled aragonite and calcite crystalline forms at 2θ range from 10 to 70°C. The stability of CS biocarriers during 427 days of treatment was monitored using SEM-energy-dispersive X-ray spectroscopy to assess the physical and chemical changes. Thus, CS holds the potential to be a sustainable biocarrier.

A qualitative analysis on the double porous thermoelastic bodies with microtemperature

This study examines a mixed initial-boundary value problem in thermoelastic materials with a double porosity structure, taking into account the effects of microtemperature. The existence of a solution is established by converting the problem into a Cauchy-type problem. Given the complexity of the equations, unknowns, and conditions, we apply contraction semigroup theory within a specific Hilbert space. We prove the existence of a solution using the Lax-Milgram theorem. Additionally, the uniqueness of the solution is demonstrated based on the Lumer-Phillips corollary, which corresponds to the Hille-Yosida theorem. In the final section, we show the continuous dependence of the solution on the mixed initial-boundary value problem for double porous thermoelasticity with microtemperature.

Investigating Discrepancies in Adsorption Enthalpy Predictions: An Analysis of CO2 Adsorption on HKUSTs

The pressing need to mitigate the presence of harmful gases in the atmosphere motivates scientific and engineering endeavors to devise effective adsorption solutions. Achieving practical and specific adsorption is essential for improving capture processes, with CO2 being a prominent target due to its significant environmental repercussions. Metal-organic frameworks (MOFs), distinguished by their high porosity and adaptable structure, have emerged as promising candidates for CO2 adsorption. Especially noteworthy are functionalized MOFs, which augment adsorption capacity, selectivity, and heat of adsorption. This research investigates CO2 adsorption on HKUST-1 modified with three amines of varying strengths, evaluating adsorption capacity and thermal impacts using direct adsorption calorimetry and Van't Hoff thermodynamic models.

Construction of Yolk@shell Nanocomposite Particles with Controlled Multisized Pore Structures by Monomicelle Confined Assembly.

Hollow nanoparticles with tunable structures and spatial and chemical specificity are considered as promising carriers. However, it remains a formidable challenge to endow hollow nanomaterials with precisely controlled multisized macro/mesoporous structures up to now. This paper demonstrates a "polydopamine (PDA) expansion-shrinkage" strategy combined with a monomicelle interfacial confined assembly method to achieve the highly controllable preparation of a series of yolk@shell PDA@SiO2 composite nanoparticles with structural asymmetry and a tunable multisized pore in the shell. The strategy allows systematic manipulation of the average pore size of large slit pores in the range of 15.4-86.5 nm by adjusting the reaction temperature. Benefiting from advantages such as an asymmetric structure and multilevel porosity, they exhibit excellent performance in the applications of on-demand loading of dual-sized cargoes, dual-propelled nanomotors, and particle size-selected encapsulation and separation. These findings provide inspiration for the construction of asymmetric yolk@shell structures with tunable multisized pores for a wide range of biological and chemical applications.