Search Results (3,445)

Although amine-based post-combustion carbon capture is among the most established routes for CO₂ capture, it suffers from the high energy demand associated with amine regeneration. Recent research proposals suggest that microwave or frequency-tuned infrared heating may lead to more efficient amine regeneration processes. However, such approaches inherently introduce oscillating electromagnetic fields whose non-thermal effects on reaction pathways and energetics remain poorly understood. In this series paper, we employ high-accuracy quantum computational chemistry calculations to quantify the non-thermal effects of external electric fields on CO₂ absorption and desorption in monoethanolamine (MEA) and triethanolamine (TEA) under both aqueous and non-aqueous conditions. In this first part, we focus on static electric fields in order to establish a mechanistic reference framework helpful for interpreting non-thermal effects arising from frequency-tuned infrared laser excitation, which are addressed in Part II of this series. Our results show that static electric fields stabilize CO₂–amine reaction products, lowering absorption barriers, while consistently increasing both activation energies and reaction enthalpies associated with the amine regeneration process. This effect is particularly pronounced for MEA, where carbamate species become progressively more resistant to conversion to zwitterion as the field strength increases. These findings demonstrate that non-thermal static electric field effects counter the fundamental requirement for low-energy amine regeneration. By defining this intrinsic mechanistic limitation, the present study provides a useful baseline for assessing infrared laser-assisted carbon capture and underscores the importance of carefully selecting excitation frequencies to avoid adverse non-thermal stabilization effects. Full article

The redox mechanisms of RAW 264.7 macrophages exposed to 2.45 GHz RF-EMF at subthermal specific absorption rates and to lipopolysaccharide (LPS) and/or the SARS-CoV-2 spike protein (CSP) were investigated. To this end, cellular responses (lysosomal and mitochondrial activity, nitric oxide (NO) production, and cell survival/death) were measured after 6, 24, and 48 h. Selective loss of viability in cells exposed to RF and LPS was observed at 6 h, consistent with early defects in membrane permeability. Lysosomal activity was significantly enhanced in cells treated with RF + LPS. Mitochondrial activity decreased in cells exposed to RF + LPS at 6 h and increased in cells treated with RF + CPS/LPS. Cell viability decreased greatly in cells treated with LPS and CSP + LPS after 24, particularly after 48 h. Nitrite levels peaked in non-irradiated cells treated with RF + LPS and in CSP + LPS at 24 h and decreased in irradiated cells after 48 h. Irradiation affected selection of the death mode: apoptosis decreased or remained unchanged in cells subjected to any of the treatments, while necrosis increased in cells treated with CPS, LPS, or both for 48 h. The combination of RF-EMF and infectious agents reprogrammed the interaction between mitochondria/lysosomes/nitric oxide (NO)/cell death in macrophages in a time- and stimulus-dependent manner. Full article

Research on low-concentration CO₂ capture technology is of great significance for China to achieve “carbon peak and carbon neutrality”. However, there are currently two challenges in low-concentration CO₂ capture technology: high energy consumption and significant methane loss. Therefore, in this study, a numerical simulation method is used to establish the reaction model of the piperazine-activated N-methyl diethanolamine (abbreviated as MDEA-PZ) system with CO₂ using Aspen HYSYS industrial software, taking shale gas from a production area as the raw material gas. Single-factor sensitivity analysis is conducted to study the impact of N-methyl diethanolamine (abbreviated as MDEA) mass fraction, piperazine (abbreviated as PZ) mass fraction, CO₂ absorption temperature, and amine liquid regeneration temperature on the process. The results show that when the N-methyl diethanolamine mass fraction is between 37% and 42% and the piperazine mass fraction is between 2.5% and 5%, the regeneration energy consumption is lower and methane loss is smaller. For the raw material gas in this study, the recommended optimal amine liquid mass ratio is 40% of N-methyl diethanolamine + 3% of piperazine. Under this condition, the preferred absorption temperature is 46 °C, the amine liquid circulation rate is 45 m³/h, and the regeneration temperature is 118 °C, resulting in a significant reduction in the total energy consumption by 8.9% compared with the initial value. Full article

Marine heatwaves and invasive tunicate fouling increasingly co-occur in mussel aquaculture, yet their combined effects on rope-level performance and plankton dynamics remain unclear. A 9-day field-based mesocosm experiment in Georgetown Harbour (Prince Edward Island, Canada) examined the independent and interactive effects of heatwaves (~4.5 °C above ambient) and tunicates on 50 cm sections of Mytilus edulis culture rope. Oxygen consumption rate (OCR), clearance rate (CR), capture efficiency (CE), absorption efficiency (AE), scope for growth (SFG), and condition index (CI) were quantified to assess rope-level performance, and net primary productivity (NPP) was examined to evaluate ecosystem-level effects. OCR increased with rope biomass and exhibited a biomass-temperature interaction, with a stronger increase observed under heatwave conditions. CR also increased with biomass and decreased with temperature. These shifts in metabolism and feeding resulted in near-zero SFG and reduced CI under heatwave conditions, independent of biomass. Both grazer biomass and temperature significantly influenced NPP under high-light conditions, with increasing biomass reducing NPP. Tunicate presence enhanced the retention of smaller particles, highlighting species-specific differences in particle retention within the mussel rope community. The findings suggest that warming can reduce the performance of mussel rope communities, while fouling-associated shifts in community composition may amplify grazing pressure and alter particle removal dynamics, with potential consequences for ecosystem functioning. Full article

Pulmonary arterial hypertension (PAH) is a severe and progressive cardiopulmonary disorder with limited treatment options. Camellia petelotii (Merr.) Sealy (CP) contains multiple flavonoids and other phytochemicals, but its active compounds and molecular mechanisms in PAH remain unclear. Active compounds of CP were screened by comprehensive literature mining and absorption, distribution, metabolism, and excretion (ADME) evaluation. PAH-related hub targets were identified from transcriptomic data using weighted gene co-expression network analysis (WGCNA), machine learning, and external validation. Functional enrichment, immune infiltration, and single-cell RNA-sequencing analyses were performed to characterize their biological roles and cellular localization. Molecular docking and molecular dynamics simulations assessed compound–target interactions. The effects of CP were further evaluated in hypoxia-induced rat pulmonary artery smooth muscle cells (RPASMCs). Five core bioactive compounds were identified, among which luteolin and quercetin were prioritized for further analysis. HSP90AA1 and ROCK2 were screened as hub targets. Bioinformatic analyses suggested that these targets were mainly associated with the “Lipid and atherosclerosis” pathway, metabolic reprogramming, and modulation of the immune microenvironment. Single-cell analysis showed broad expression of HSP90AA1 and enrichment of ROCK2 in fibroblasts and endothelial cells. Molecular docking and molecular dynamics simulations supported stable binding of luteolin to HSP90AA1. In vitro, CP extract inhibited hypoxia-induced hyperproliferation of RPASMCs and reduced HSP90AA1 protein expression. HSP90AA1 may represent a candidate molecular mediator of CP in PAH, and CP inhibited hypoxia-induced RPASMC proliferation in association with downregulation of HSP90AA1. Full article

The incorporation of phase change materials in concrete is a practical strategy that holds great promise for enhancing the energy efficiency of buildings and reducing CO₂ emissions. However, the direct contact between phase change materials and cement interferes with the cement hydration reaction, leading to a significant reduction in the mechanical strength of cementitious composites. To encapsulate polyethylene glycol and prevent leakage, this study developed a shape-stabilized phase change aggregate via the cold-bonding method and the vacuum impregnation method. The nanoscale pore structure of the aggregate was regulated by adjusting the biochar content to enhance the phase-change material loading capacity. The phase change aggregate was characterized by indicators including crushing strength and water absorption. Meanwhile, its microstructure, the correlations between nano-sized hydration products, chemical compatibility, and phase change properties were analyzed. The fabricated phase change aggregate has a crushing strength of over 5 MPa, latent heat of 42.84 J/g, and phase change temperature of 29.17 °C while also exhibiting good mechanical properties and thermal energy storage performance. The compressive strength of phase change concrete can meet the strength requirements for structural building material. Moreover, phase change aggregate contributed to reduced CO₂ emissions during service, with favorable economic and low-carbon benefits over its service life, demonstrating good performance in both economic efficiency and CO₂ emission reduction. Full article

Thin-film cobalt oxides have attracted increasing attention due to their visible-light activity and potential environmental applications. In this work, Co₃O₄ coatings were prepared on glass substrates through a sol–gel dip-coating process followed by thermal treatment at 450, 500, and 550 °C. Structural characterization was carried out using X-ray diffraction (XRD) and Raman spectroscopy. Diffraction patterns, together with the Raman spectra, indicate the formation of the cubic spinel phase of Co₃O₄, while sharper diffraction peaks appeared at higher annealing temperatures, indicating improved crystallinity of the films. Surface morphology was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM observations revealed continuous polycrystalline coatings, whereas AFM measurements showed clear variations in surface topography and roughness produced by thermal treatment. Wettability measurements obtained from contact angle (CA) analysis indicate modifications in the surface properties of the films as the annealing temperature changes. Optical characterization performed by ultraviolet–visible spectroscopy (UV–Vis) showed strong absorption in the visible region with an indirect band gap close to 1.58 eV. Photocatalytic activity was evaluated through the degradation of methylene blue under visible-light irradiation. Degradation efficiencies of approximately 93.9%, 97.4% and 98.7% were obtained after 5 h for films annealed at 450, 500, and 550 °C, respectively. Full article

Integrating direct air carbon capture (DAC) into buildings offers a promising pathway for reducing atmospheric CO₂, yet the role of architectural design in enhancing passive carbon-capture performance remains underexplored. This study presents a computational framework developed to optimize architectural design and enclosure geometry for enhanced passive airflow, using mass-flow rate as a proxy for the comparative assessment of carbon absorption potential. Implemented within Rhino3D and Grasshopper using Ladybug and Eddy3D, the workflow integrates weather data and CFD simulation to compute segmented mass-flow rates through stacked capture trays. The framework simplifies traditionally complex CFD processes by introducing a custom segmented mass-flow calculation approach that enables comparative performance assessment during early-stage design. Results confirm the validity of the proposed workflow, revealing that façade rotation can modify total mass flow by up to 96.5%; seasonal wind variability can cause airflow to range from approximately 8.5 kg/s in January to 169.5 kg/s in May in Seattle. Spatial configuration can alter airflow by up to an order of magnitude and introduce substantial spatial heterogeneity within capture zones. This research establishes a performance-driven design framework that enables architectural geometry to actively enhance passive carbon-capture integration, positioning building design as a measurable contributor to climate mitigation strategies. Ultimately, this work bridges architectural design and carbon-capture engineering, supporting interdisciplinary approaches to scalable, climate-responsive building systems. Full article

We report on X-ray-induced Sm³⁺ → Sm²⁺ reduction in SrF₂:Sm³⁺ nanocrystals of ~40 nm size synthesized via a co-precipitation method. Non-irradiated samples show characteristic Sm³⁺ f-f ⁴G_5/2 → ⁶H_5/2, ⁶H_7/2, ⁶H_9/2, and ⁶H_11/2 emissions, while X-irradiation induces intense low-temperature Sm^{2+ 5}D₀ → ⁷F₁ emission and other Sm²⁺ lines. The evolution of Sm³⁺ and Sm²⁺ photoluminescence intensities with X-ray dose (0–300 Gy) follows first-order kinetics, consistent with a trapping–detrapping mechanism. Compared to CaF₂:Sm³⁺, SrF₂:Sm³⁺ exhibits faster Sm³⁺ reduction due to the higher X-ray absorption cross section of strontium compared to calcium for Cu-Kα (8 keV) radiation, highlighting its potential as a nanoscale X-ray storage phosphor. Full article

In this study, cobalt oxide (Co₃O₄) ceramics were synthesized using the sol–gel method and calcined at 300 °C and 600 °C to investigate the influence of thermal treatment on their structural, thermal and optical properties. X-ray diffraction (XRD) analysis confirmed the successful formation of a pure cubic spinel Co₃O₄ phase with nanocrystalline features, belonging to the Fd3m space group. As the calcined temperature increased, the samples exhibited enhanced crystallinity, with the average crystallite size ranging from 15 to 26 nm, sharper and more intense diffraction peaks, indicating grain growth and improved structural ordering. Thermogravimetric analysis (TGA) indicated the elimination of surfaceadsorbed species and residual organics during the initial stages, succeeded by the stabilization of a pure cubic spinel Co₃O₄ phase, which exhibits remarkable thermal stability without any additional phase transitions. UV–Vis diffuse reflectance spectroscopy (DRS) analysis showed that the Co₃O₄ nanostructures displayed significant absorption in the visible region, consistent with their intrinsic narrow band gap characteristics. Unlike earlier sol–gel synthesized Co₃O₄ ceramics, the present work highlights enhanced crystallinity and structural development with increasing calcination temperature. Full article

Primary coenzyme Q10 (CoQ10) deficiency results from mutations in genes involved in the CoQ10 biosynthetic pathway. In humans, at least 10 genes (PDSS1, PDSS2 to COQ10) are required for the biosynthesis of functional CoQ10, a mutation in any one of which can result in a deficit in CoQ10 status and present as primary CoQ10 deficiency. Furthermore, the genes NDUFA9 and HPDL, whilst not part of the PDSS1, PDSS2 to COQ10 gene sequence, have also been shown to have a crucial role in CoQ10 biosynthesis. A major problem in treating primary CoQ10 deficiencies is the poor bioavailability of supplemental CoQ10, both in terms of lack of absorption from the digestive tract and inability to cross the human blood–brain barrier. Bypass strategies aim to circumvent this problem by using more bioavailable precursor analogues that can enter the cell and be incorporated into the CoQ10 synthesis pathway downstream of the affected enzyme, examples being 4-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid or vanillic acid, which, in contrast to CoQ10, are small, water-soluble molecules. In this article, we have, therefore, reviewed potential bypass mechanisms for primary CoQ10 deficiencies, PDSS1, PDSS2 to COQ10, together with NDUFA9 and HPDL, using such precursors. Most of the published data relating to the bypass therapy of primary CoQ10 deficiency is derived from cell lines or animal models, and few human studies have so far been undertaken. In addition, further research is required to investigate the potential mechanisms by which bypass compounds such as 4-HB may access the human blood–brain barrier (BBB), for example, using in vitro co-culture BBB model systems incorporating CoQ10-deficient neurons. Overall, the objective of this article is, therefore, to systematically review the available data for each of the primary CoQ10 deficiencies, PDSS1, PDSS2 to COQ10 together with NDUFA9 and HPDL, in particular to identify the clinical potential of such studies. Full article

Micro-scale counter-rotating wind turbines (CRWTs) offer enhanced potential for wake energy recovery. This study proposes an integrated cascade–coupling design framework for high-solidity CRWTs, in which rear rotor geometry and rotor coupling are co-designed based on stereoscopic particle image velocimetry measurements of the front rotor wake. Experiments are conducted at a tip-speed ratio of $\lambda =1.0$, solidity $\sigma =1.25$, spacing ratios of $d=0.6R_T$, $1.0R_T$, and $3.0R_T$, and a tip radius of $R_T=70$ mm. At the physical limit spacing of $d=0.6R_T$, the integrated design increases the system power coefficient by 24.1% while limiting front rotor power reduction to 17.2%, compared to a 10.3% system gain and 34.5% front rotor suppression for the baseline mirrored configuration. Wake measurements confirm near-complete absorption of rotational kinetic energy from the front rotor wake without exacerbating upstream interference. These results demonstrate that cascade-based energy extraction and coupling-based interference mitigation can operate synergistically, enabling compact, high-performance micro-scale CRWTs suitable for space-constrained and urban energy applications. Full article

Islanded photovoltaic microgrids with limited inertial support can undergo steep frequency excursions after sudden generation loss or abrupt load changes. This paper develops and evaluates a synthetic inertia strategy supported by a supercapacitor energy storage unit for fast frequency containment in this type of system. The proposed approach commands rapid active-power injection or absorption from the measured rate of change of frequency, thereby emulating the immediate inertial contribution usually associated with rotating machines while preserving a simple and physically interpretable control structure. The supercapacitor is represented through a resistance–capacitance model that includes equivalent series resistance and is interfaced through a bidirectional buck–boost power converter subject to practical current, voltage, and power limits. Rather than claiming a fundamentally new storage-support concept, the contribution of this paper lies in providing a transparent and constraint-consistent benchmark that integrates measured operating profiles, explicit supercapacitor limits, hybrid frequency–RoCoF support, and stress-aware comparative assessment under a common set of plant assumptions. The methodology is assessed in time-domain simulations under representative benchmark disturbances, including an approximately ten percent photovoltaic generation loss, a ten percent load increase, and a combined event. Performance is evaluated through the peak rate of change of frequency, frequency nadir, integral error indices, time outside the admissible band, and supercapacitor stress indicators such as current peaks, voltage depletion, and energy throughput. An additional non-ideal assessment is also included to examine the behavior of the RoCoF-based support law under bounded frequency-measurement perturbations and delayed control action. A complementary variability-driven case based on a highly fluctuating measured irradiance window is also used to examine the behavior of the adaptive energy-management mechanism under repeated photovoltaic-power variations. A local small-signal analysis is also included to show that the selected gain region is dynamically plausible in the unsaturated regime. The results show that the proposed adaptive hybrid strategy improves the overall frequency response while maintaining admissible supercapacitor operation, thus providing a stronger methodological basis for rapid frequency support in islanded photovoltaic microgrids. Full article

This study investigates the effect of metakaolin (MK) as a partial replacement of cement (CEM I) in high-workability mortars, with emphasis on fresh-state behaviour, mechanical properties, microstructural development, and carbon footprint implications. Mortars were produced with MK replacement levels ranging from 0 to 50% by mass of binder, under a constant water-to-binder ratio and fixed superplasticiser amount. Fresh-state results showed that increasing MK content reduced flowability due to its high fineness; however, high workability was maintained for replacement levels up to 20%. At 28 days, MK replacement up to 10% retains approximately 90–95% of the control compressive and flexural strength, whereas higher replacement levels lead to gradual strength reductions (to ~55–60% at 50% MK), despite comparable early-age strength gains across all mixes. Durability-related indicators demonstrated reduced water absorption and capillary uptake at moderate MK contents (approximately 20–30%), indicating refined pore structure and reduced pore connectivity. Microstructural analyses using SEM, TGA, and XRD confirmed effective portlandite consumption and the formation of dense C–A–S–H-type hydration products at moderate MK replacement levels, whereas excessive MK contents resulted in unreacted MK. A comparative carbon footprint assessment showed that MK incorporation leads to proportional reductions in embodied CO₂ emissions, with replacement levels of 10–20% providing the most favourable balance between mechanical performance, durability, and environmental benefit. Therefore, the results demonstrate that MK can be used as a supplementary cementitious material for producing low-carbon, high-workability mortars. Full article

Titanium and its alloys are widely used in orthopedic and dental implantology for their corrosion resistance and biocompatibility supporting osseointegration; however, their usage is accompanied by release of wear debris that may induce inflammatory responses. The necessity of formation of multifunctional coatings that accelerate osseointegration and provide long-term mechanical stability of titanium implants remains highly relevant. We propose a new simple and scalable coating method based on the laser shock processing technique, with TiO₂ and SrCO₃ powder mix used as an absorption layer. Our results show that this treatment created an approximately 158.3 ± 35.8 μm thick coating consisting of a mixed SrTiO₃-TiO₂ phase. The hardness of this coating evaluated by Vickers microhardness measurements showed a hardness increase of 3.3 times compared to the initial titanium substrate. Piezoelectric force microscopy (PFM) analysis revealed the presence of a reverse piezoelectric effect in the obtained structure confirming the highly likely successful synthesis of coating impregnated with SrTiO₃. This piezoelectric coating can be readily deposited onto titanium substrates using the proposed method, enabling exploration of potential biomedical applications in future research. Full article