Search Results (9,260)

To address the poor temperature resistance of conventional gel breakers, the uncontrollable gel-breaking time, and the risk of secondary reservoir damage during temporary plugging of fractured formations with polymer gels, a high-temperature-resistant double-shell encapsulated gel breaker, UF-EC/SA, was prepared using oil-phase phase separation combined with in situ polymerization. In this material, urea-formaldehyde resin (UF) served as the outer shell, ethyl cellulose (EC) as the inner shell, and sulfamic acid (SA) as the core. Unlike conventional single-shell persulfate or directly added acid breakers, this double shell design integrates a thermally resistant UF barrier, a diffusion-controlling EC layer, and an acid core to delay premature gel degradation while enabling subsequent cleanup. The physical structure and sustained-release behavior of the capsules were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), and conductivity measurements. The compatibility between the encapsulated breaker and the polymer gel, as well as the effects of salinity and breaker dosage on the rheological properties of the gel, were investigated. The regulatory effects of temperature and capsule dosage on gel-breaking performance were studied in detail. In addition, high-temperature/high-pressure displacement experiments were conducted to evaluate the temporary plugging performance of the gel containing the encapsulated breaker in fractured cores and packed-sand tubes. The results showed that the prepared capsules had good sphericity and a dense shell structure, with an encapsulation efficiency of 76.7%. The capsules exhibited temperature resistance up to 150 °C and favorable sustained-release characteristics. The UF-EC/SA breaker showed good compatibility with the polymer gel and did not inhibit gelation within the temperature range of 80–150 °C or at dosages of 0–16 wt.%. The gel maintained good mechanical strength even in highly mineralized brines. At 150 °C and a capsule dosage of 16 wt.%, the gel was completely broken within 2.5 d; the residue concentration was only 351 mg/L, and the residue size was mainly distributed within 100–500 um. The high-temperature/high-pressure displacement tests demonstrated that the gel containing 16 wt.% capsules achieved a maximum breakthrough pressure of 5.16 MPa in a 3 mm wedge-shaped fracture core, and the pressure remained stable for 5 d. After gel breaking, the residue could be readily flowed back, indicating excellent synergy between temporary plugging and subsequent gel breaking. Therefore, the UF-EC/SA encapsulated breaker provides a new technical option for efficient gel breaking in high-temperature fractured formations. Full article

Irradiation can impact the properties of semiconductor materials and the function of microelectronic devices. In the present review, we consider how irradiation interacts with semiconductor materials important, primarily silicon (Si), focusing on the defect processes. These, in turn, will have an impact on the physical properties of the material and can impact important properties for devices such as the electrical conductivity and mechanical integrity. We consider the ways that irradiation impacts the operation of microelectronic devices. We thereafter review the defect engineering strategies and other ways to mitigate against the impact of irradiation in devices. Finally, we consider the potentially important role of irradiation defects as qubits in the emerging quantum technologies. Full article

Natural gas hydrates are regarded as a vital strategic energy resource for the future owing to their high energy density and clean combustion characteristics. To facilitate research into the physical and mechanical properties of pressure-maintained hydrate samples, this paper presents an integrated multi-parameter online analysis system capable of rapidly measuring the P-wave velocity, electrical resistivity, thermal conductivity, and shear strength of core samples under pressure-maintaining conditions. The system comprises hardware acquisition boards based on ZYNQ and ARM platforms, specialized measurement probes, and comprehensive data acquisition and analysis software. To mitigate the susceptibility of P-wave signals to noise interference, an improved denoising algorithm combining Empirical Mode Decomposition (EMD) and wavelet thresholding is proposed. By employing autocorrelation function analysis, the algorithm identifies the transition boundary between noise-dominated and signal-dominated Intrinsic Mode Functions (IMFs), subsequently applying wavelet soft-thresholding to the noise-dominant components. Experimental results demonstrate that the proposed algorithm achieves a superior signal-to-noise ratio (SNR) compared to traditional EMD methods, particularly under low SNR conditions. System validation indicates measurement accuracies of 3.2% for P-wave velocity at 20 °C, 1.76% for electrical resistivity at 25 °C, and within 7% for both thermal conductivity and shear strength. Furthermore, sea trials conducted aboard the “HAIYANG SHIYOU 708” drilling vessel confirm that the system operates stably and effectively fulfills the requirements for deep-sea core parameter characterization. Full article

Imidazole-based ionic liquids hold immense potential in the field of mineral flotation due to their tunable properties. In this study, three imidazole-based ionic liquids with varying carbon chain lengths (OMB, DMB, and HMB) were selected as collectors for quartz flotation to systematically investigate the microscopic mechanisms by which carbon chain length influences the agglomeration and flotation behavior of quartz. Flotation tests and online particle-bubble monitoring (PBM) results indicate that the elongation of the collector’s carbon chain significantly enhances its collecting ability and reduces the required reagent dosage. To achieve the complete recovery of quartz in a neutral system, a dosage of 35 mg/L is required for OMB, whereas HMB requires only 8 mg/L. As the carbon chain lengthens, the optimal pH range for highly efficient flotation shifts from alkaline to neutral-acidic. Interfacial measurements and mechanistic analyses (Zeta potential and FTIR spectroscopy) confirm that the imidazole ring of the collector physically adsorbs onto the quartz surface through the synergistic action of electrostatic forces and hydrogen bonding, thereby inducing the hydrophobic agglomeration of particles. Notably, in a strongly alkaline system (pH = 11), the long-chain HMB promotes the formation of oversized quartz agglomerates. This leads to a depletion of free reagents in the liquid phase and destabilizes the bubble liquid film, ultimately triggering a sharp decline in recovery. Density functional theory (DFT) calculations further corroborate the structure–activity relationship at the molecular level: the extension of the carbon chain increases the highest occupied molecular orbital (HOMO) energy and electron-donating ability. The adsorption energy of HMB on the quartz (001) surface reached −350.2 kJ/mol, exhibiting the strongest solid–liquid interfacial affinity. This study elucidates the competitive mechanism of carbon chain length in regulating electrostatic adsorption, hydrophobic agglomeration, and froth stability, providing a solid theoretical foundation for the molecular design of novel green flotation reagents for quartz. Full article

Silicone rubber foam is widely used in multi-field engineering protection due to its excellent cushioning and thermal insulation properties. However, its performance degradation caused by long-term service aging seriously affects equipment reliability. Establishing a constitutive model that can accurately characterize the mechanical response during aging is crucial for studying performance degradation and finite element simulation. Traditional multi-parameter aging constitutive models suffer from problems such as easy convergence to local optimal solutions and poor physical interpretability of parameters. To address these issues, this study systematically characterizes the evolution laws of the stress–strain response, compression set, and stress relaxation of silicone rubber foam over an aging period of 0–768 h through accelerated thermal aging and uniaxial compression tests and proposes a second-order Ogden aging constitutive model with a single time-varying parameter. This model fixes α₁, α₂, and μ₂ as constants and only sets μ₁ as the time-varying parameter, reducing the number of parameters to be fitted from four to one. The coefficient of determination (R²) of the full-cycle stress–strain curve fitting is ≥0.9966. Meanwhile, a quantitative physical correlation between μ₁ and macroscopic aging performance indicators is established, enabling the direct prediction of the mechanical response of aged materials using measurable macroscopic indicators. This work provides an efficient and reliable modeling method for the aging performance evaluation and structural simulation of silicone rubber foam. Full article

The wide application of liquid hydrogen as a key energy carrier is severely limited by the reliability of high-pressure and low-temperature pumps. The traditional research on liquid hydrogen pumps relies on empirical analysis of isolated components, but fails to reveal the fundamental failure mechanism of these pumps. This review argues for a paradigm shift in the understanding and design of liquid hydrogen pumps. We systematically decomposed the failure of the liquid hydrogen pump into a thermodynamic-driven, cross-scale cascading process rather than the failure of isolated components. At the molecular level, the extreme thermal physical properties of liquid hydrogen (ultra-low latent heat and surface tension) can lead to widespread nucleation under slight thermal disturbances. At the mesoscopic scale, the initial perturbation is significantly amplified through the nonlinear dynamics of bubble clusters. This amplification is characterized by intense collapse and strong energy concentration due to the low density and low viscosity of liquid hydrogen. At the component level, this enhanced destructive energy will cause faults similar to phase transitions; namely, the liquid lubrication in the bearings will disappear, the seals will shift from viscous blockage to gas diffusion, and at the same time, the damage caused by low-temperature hydrogen cavitation and corrosion to the materials will also occur simultaneously. At the system level, the strong dynamic coupling among the subsystems has led to a nonlinear performance collapse. This cross-scale failure chain reveals the flaws in the classical cavitation theory, which is based on the assumptions of isothermal and inertia dominance. We have expounded the thermodynamic-dominated cavitation state in liquid hydrogen. This state is quantified by the Σ parameter and governs the multimodal behavior of low-temperature cavitation phenomena. To address this complexity, we have proposed a comprehensive framework that integrates multi-scale collaborative simulation and digital twin, combining molecular dynamics, CFD, system dynamics, and targeted experiments. This review proposes a candidate physical framework for addressing the reliability challenges of liquid hydrogen pumps. It also provides a clear roadmap for the next generation of inherently robust cryogenic fluid machinery, and offers a reference for the design of energy systems under other extreme conditions. Full article

This article presents a technology for the physical recycling of printed circuit boards (PCBs) that is consistent with the principles of circular economy and sustainable production. A life cycle assessment (LCA) was performed for PCB recycling using shredding, grinding, and physical and physicochemical processes such as electrostatic separation, gravity separation, and flotation for the separation of metals and plastics. Based on this assessment and the selectivity criterion, electrostatic separation was found to be the best separation method, followed by shredding and cryogenic grinding. For this option, the yield of metals and plastics was 25.1% and 72.5% of feed, respectively, while the yield of the middling’s product (mixture of metals and plastics) was only 2.4%. Furthermore, the financial benefits of recycling, including economics of the business case and the environmental benefits are presented. The possibility of using non-metallic fraction (plastic) generated during recycling as an additive in the production of composite materials was also assessed. The results suggest that low filler contents (2.5–5%) provide a compromise between maintaining mechanical performance and improving hardness and tribological properties. Physical recycling technology is a pretreatment method for WPCB, complementing conventional chemical recycling methods. The global warming potential for the entire physical and chemical process is then lowered by about 70%, due to the smaller mass of input material going to the downstream metallurgical processes. Full article

Today, the development of ion exchange membranes has increased considerably in various applications, such as water treatment, energy conversion and storage, as well as environmental applications. In this study, several ion exchange membranes based on cellulose acetate propionate (CAP) and ionic liquids (ILs) were fabricated using the phase inversion method, aiming to develop more sustainable membrane materials for environmental and energy applications. Three different ILs with a similar cation and different anions (1-(4-sulfobutyl)-3-methylimidazolium trifluoromethanesulfonate [SMIM][TFS], 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate [SMIM][HS], and 1-(4-sulfobutyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [SMIM][TFSI]) were used in three concentrations (i.e., 9, 17, and 23 wt.%). The main objective of this work is to evaluate the influence of the anion structure on the membrane’s physical, morphological, hydrophilic, thermal, mechanical, and electrochemical properties. Water contact angle measurements demonstrated the weaker hydrophilicity of composite membranes containing [SMIM][TFS] (81–106°) and [SMIM][TFSI] (87–94°) in comparison with pure CAP (~79°) and CAP/[SMIM][HS] (79–83°) membranes. The CAP/[SMIM][HS] membrane showed higher elongation at break (~36%) compared with the pure CAP membrane (~24%), confirming the plasticization behavior of [SMIM][HS]. The CAP/[SMIM][TFS] membrane containing 23 wt.% of IL showed promising membrane potential, permselectivity, transport number and ion flux ratio values of 53.2 mV, 74.7%, 0.85, and 5.5, respectively, indicating its potential as a candidate for further evaluation in electrochemical membrane processes such as electrodialysis and fuel cells. Full article

This study investigates the development of sustainable ceramic materials using industrial and agricultural waste from the Kyzylorda region of Kazakhstan. The research focuses on the combined use of local clay, ash from the Kyzylorda thermal power plant (TPP), and rice husk ash (RHA). Experimental investigations included the evaluation of chemical composition, linear and volumetric shrinkage, water absorption, bulk density, and compressive strength of ceramic samples fired at 950–1050 °C. Microstructural (SEM) and phase composition (XRD) analyses were performed to explain the observed behavior. The results showed that the optimal composition was 70% clay, 20% TPP ash, and 10% RHA, which demonstrated the highest compressive strength (15.45 MPa), reduced water absorption, and improved densification. The enhanced performance is attributed to partial vitrification and viscous-phase-assisted densification and the formation of crystalline phases such as mullite, cristobalite, and anorthite. The study confirms that the combined use of TPP ash and RHA enables effective recycling of local waste materials and improves the physical and mechanical properties of ceramic products. Full article

Conductive intracardiac communication (CIC) is one of the most innovative and promising communication technologies in multi-point cardiac pacing schemes that utilize the heart as the transmission channel in recent years. Current research predominantly focuses on static channel characteristics. Although some studies have explored dynamic responses, they are largely confined to basic amplitude–frequency and amplitude–time behaviors, lacking in-depth analysis of underlying dynamic mechanisms such as path loss, shadowing, multipath, and Doppler effects. Designing CIC systems solely on the basis of static properties can result in inaccurate channel estimation, distorted channel state information (CSI), and elevated bit error rate (BER). To solve the problems of dynamic channel measurement and modeling, this paper for the first time proposes a dynamic channel modeling method for CIC based on sinusoidal response and impulse response. Firstly, we develop a physical simulation and miniaturized measurement setup to measure the dynamic cardiac channel, and analyze the amplitude–frequency characteristics and amplitude–time characteristics. The influence of factors such as instrument differences, heart rate, flow rate, and motion artifacts is also discussed. Secondly, we systematically analyze the path loss, shadowing effect, multipath effect, and Doppler effect of the CIC channel. Combined with the dynamic channel characteristics and parameters, we propose a composite fading dynamic channel model and analyze the BER performance of baseband signal transmission and On–Off Keying (OOK) modulation systems. We conclude that (1) the CIC channel exhibits capacitive characteristics. Fixed electrodes can effectively suppress motion artifacts. (2) The dynamic channel gain of CIC varies periodically with the heartbeat, and the fluctuation range of the signal is less than 1–2 dB. (3) The dynamic CIC channel presents extremely weak shadow fading, no significant multipath, and no measurable Doppler characteristics, belonging to an extremely slow-fading channel. This work provides effective dynamic channel measurement approaches and a parameter basis for the transceiver design of CIC and a reliable model for the simulation of CIC systems. Full article

As a key target for hydrocarbon exploration in clastic rocks in the Tarim Basin, reservoir characteristics of the Cretaceous Bashijiqike Formation in the Kuqa Depression vary significantly in different areas, especially ultra-deep reservoirs. Understanding the development mechanism and controlling factors of effective reservoirs is critical for ultra-deep hydrocarbon exploration. This study focuses on typical gas reservoirs in the Bozi (BZ) and Keshen (KS) areas. Core observation, polarizing microscope, cathodoluminescence microscope, scanning electron microscope, X-ray diffraction analysis, porosity and permeability test, and imaging logging interpretation have been used to systematically investigate reservoir petrology, diagenesis, physical property, and fracture characteristics. The results indicate that the BZ8 and BZ9 reservoirs experienced weak paleostress and tectonic deformation, resulting in relatively weak tectonic compaction, abundant primary intergranular pores, and sparse fractures. Reservoir cements are dominated by dolomite, indicating diagenesis was mainly affected by lagoonal fluids. In contrast, the KS31 reservoir is characterized by strong paleostress and deformation, leading to intense compaction and negligible primary pores but well-developed fractures. The reservoir is dominated by calcite, quartz and albite cements, suggesting a dominant influence of meteoric water. Furthermore, reservoirs are significantly affected by structural positions within an individual anticline. Compared with the anticlinal limbs, the anticline core undergoes overall upward arching and folding. The outer strata above the neutral surface develop intense horizontal tensile stress perpendicular to the fold hinge. This promotes fracture development and primary pore preservation, thus facilitating the seepage of diagenetic fluids and enhancing local dissolution. Full article

The contamination of aquatic environments, including treated and drinking water, by microplastics poses a significant threat to ecosystems and human health. Current detection methods often rely on slow laboratory-based tests and offline analysis, which do not support real-time monitoring. This paper presents a novel focusing and concentrating device designed to enhance the real-time detection of microplastics in flowing water. The device utilizes an electrokinetic manipulation mechanism to focus microplastics toward the center of the water flow inside a pipe or fluid channel. A set of 3D rectangular electrodes, with dimensions of 5 mm × 2.5 mm × 1 mm, are arranged circumferentially and longitudinally along the inner perimeter of the fluid channel to generate an intense, non-uniform electric field. Simulation results indicate that microplastics near the channel wall experience a repulsive force on the order of ${10}^{-16}$ to ${10}^{-10}$ N toward the channel center. The applied signal amplitude and the physical properties of the microplastics strongly influence this repulsive force. The trajectories and output concentration of microplastics are investigated under varied conditions. A Voltage of approximately 25 V and a flow rate of 0.05 m/s are found to be ideal for concentrating microplastics into a narrow particle stream, enabling more efficient downstream detection and analysis. Pre-concentrating microplastics in fluid channels prior to sensing is expected to increase sensor sensitivity and improve selectivity. Full article

Acidic mine water generated during underground CO₂ sequestration and sulfide oxidation can alter the pore-fracture structure of coal, and threaten the stability of abandoned mine spaces. However, the mechanism through which acidic environments influence the deterioration of coal remains insufficiently understood. In this study, uniaxial compression experiments were conducted on coal samples treated with solutions with different pH values, and acoustic emission (AE) monitoring technology was used to characterize fracture activity and damage evolution during loading. A quantitative model linking acidity to the mechanical behavior of coal was established by integrating fractal theory with damage mechanics. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were further employed to reveal the microstructural and mineralogical mechanisms of coal deterioration. The results show that acidic environments significantly degrade the mechanical properties of coal samples. With decreasing pH, peak stress and elastic modulus of the selected representative sample progressively decrease, and the failure mode becomes increasingly fragmented and dispersed. At pH = 1, the degradation of peak stress and elastic modulus reaches 73.01% and 49.38%, respectively. Increasing acidity also enhances AE activity during loading and increases the correlation dimension, indicating greater crack complexity and instability. On this basis, the proposed quantitative model accurately describes the transformation process of coal samples from microscopic damage to macroscopic mechanical degradation induced by acidity. SEM and XRD results further show that stronger acidity promotes pore enlargement, crack interconnection, mineral dissolution, secondary mineral formation, and weakening of cementation, revealing the physical essence of the multi-scale damage and degradation of coal samples. The findings can provide a theoretical basis for assessing coal stability in acidic environments and ensuring the safe storage of CO₂ in abandoned mines. Full article

In southern Brazil, a large proportion of farmers maintain their fields under fallow conditions during the transition period between summer and winter crops. During this interval, mechanical practices such as chiseling or the introduction of cover crop species may contribute to improving soil management and conservation in no-tillage systems. Therefore, this study aimed to investigate the effects of mechanical soil chiseling and production system intensification on soil physical–hydric properties and soybean performance. The experiment was conducted in São José do Ouro, Rio Grande do Sul, Brazil, from September 2023 to April 2025. The experimental design consisted of three factors: soil management (spring 2023 chiseling, autumn 2024 chiseling, and a no-till control), post-maize cover (millet and fallow conditions), and winter cover crops (black oat, white oat, vetch, and radish) grown either as monocultures or in mixtures. A randomized block design with split plots and three replicates was used. The evaluated variables included dry biomass of winter cover crops, soil bulk density, total porosity, microporosity, macroporosity, soil water content at field capacity, soil penetration resistance, plant gas exchange, leaf area index, thousand-grain weight, and soybean grain yield. The results indicated that soil chiseling altered soil physical properties by reducing soil bulk density, penetration resistance, microporosity, and field capacity, while increasing total porosity and macroporosity. Soil chiseling promoted short-term increases in thousand-grain weight and soybean grain yield, with no persistent effects after 20 months. Production system intensification, through the use of cover crops and millet, did not affect grain yield but increased stomatal conductance and soybean leaf area index. Therefore, occasional tillage in high-clay subtropical Oxisols should be strategically applied and associated with long-term conservation agriculture practices to sustain improvements in soil physical quality. Full article

In oil-rich countries, petroleum contamination of soils frequently occurs during refining, transportation, and exploitation. Such contamination significantly alters soil behavior and properties from a geotechnical perspective. Given that some fine-grained soils exhibit insufficient bearing capacity or excessive settlement, soil improvement is often necessary. The selective use of nanoparticles offers a promising novel approach in this regard. This study investigates the effects of diesel contamination and nanosilica modification on the physical and mechanical properties of clayey sand and aims to interpret the variations in the mechanical properties and the permeability of the treated soil based on microstructural observations. Diesel (0–10% in 2% increments) and nanosilica (0%, 1%, 2%) were added to the soil, preparing a total of 18 mixtures for testing. The microstructural changes directly alter the physical parameters such as specific gravity, optimum moisture content (OMC), and maximum dry unit weight, consequently affecting the permeability and the mechanical behavior. The microstructural analysis via scanning electron microscopy revealed diesel-induced clay flocculation and increasing macroporosity, while the nanosilica at 1% improved the soil fabric through pore filling and interparticle bonding, whereas 2% nanosilica led to partial dispersion and agglomeration. The findings demonstrate that soil behavior is controlled by the interplay between diesel (lubrication, pore blocking, hydrophobicity) and nanosilica (surface activation, micro-bonding, agglomeration). Increasing the diesel content consistently reduces the specific gravity across all the mixtures, due to the replacement of heavier mineral particles by lighter hydrocarbon, diesel adsorption onto the soil grains, the formation of low-density organic films, and increased micro-voids. Diesel addition reduces the OMC but increases the maximum dry unit weight due to its lubrication effect. Mechanically, the unconfined compressive strength (UCS) peaked at approximately 4% diesel contamination, with the addition of 1% nanosilica yielding the highest strength overall. Conversely, the California Bearing Ratio (CBR) increased continuously with diesel due to improved packing and frictional resistance and was further improved by nanosilica. The results show that permeability decreases with increasing diesel content due to hydrophobic diesel molecules coating soil particles, filling micro-voids, and blocking pore channels, while the consolidation parameters exhibit non-monotonic trends, peaking at moderate contamination levels. An optimal nanosilica content effectively mitigated some of the adverse effects of diesel and enhanced the mechanical performance, providing valuable insights for managing hydrocarbon-contaminated soils. Full article