Search Results (3,715)

Class imbalance severely limits Network Intrusion Detection Systems (NIDSs) for minority Web attack classes: CICIDS2017 contains only 21 SQL Injection instances among 2.27 million benign flows. This study enriches CICIDS2017 with authentic SQL Injection, Cross-Site Scripting (XSS), and Web Brute Force (WBF) traffic captured from a controlled DVWA/XAMPP environment, processed with CICFlowMeter to match the original feature space. An anti-data-leakage protocol (stratified partitioning, post-split normalization, five-fold cross-validation, and a SHA-1 cryptographic membership audit of an 8881 –flow test sub-sample) found no hash collisions between this sub-sample and the evaluation partitions. The framework added 32,670 authentic flows, increasing SQL Injection from 21 to 10,678, XSS from 652 to 13,212, and WBF from 1507 to 10,960. Among four evaluated ensemble models, LightGBM performed best, achieving 99.85% Accuracy, 99.85% F1-score, 99.29% Balanced Accuracy, and 97.87 ± 1.88% in five-fold cross-validation, improving detection rates by 44.9% (XSS), 23.0% (WBF), and 16.6% (SQL Injection) over the original dataset. A volume-matched ablation study showed comparable aggregate accuracy to synthetic balancing methods (SMOTE, SMOTE-Tomek), while geometric diversity analysis confirmed that authentic traffic occupies feature-space regions unreachable by interpolation, and chronological holdout evaluation confirmed generalization to unseen traffic (F1: 98.53–99.90%). Real-traffic enrichment thus offers a practical, more realistic complement to synthetic balancing for minority Web-attack detection. Full article

Agentic large language model (LLM) networks are increasingly used in safety-critical settings where autonomous agents invoke tools, exchange context, and coordinate decisions. Prompt-injection attacks remain a significant threat to these multi-agent pipelines because they can compromise data flows between agents, bypass instruction hierarchies, and corrupt output integrity. Although defenses against injected prompts and mechanisms for cryptographically verifying model-related computations have been studied independently, no common framework unifies these complementary security perspectives in a protocol suitable for real-time agentic deployments. From the perspective of symmetry, secure inter-agent communication requires the preservation of an invariant integrity relationship between a message at its source and the corresponding message accepted at its destination. A benign communication path therefore exhibits a form of integrity symmetry, whereas prompt injection or message manipulation creates an asymmetric state in which the received payload, its semantic effect, or the receiving model’s internal activation pattern deviates from the trusted reference state. In this paper, we propose SecurePrompt-IntegrityNet (SPI-Net), a prompt-injection-resilient data integrity verification protocol that combines cryptographic attestation with anomaly-aware activation monitoring. SPI-Net provides three closely related mechanisms: a Merkle-tree-based commitment system that verifies the provenance and integrity of data payloads exchanged between agents; a layer-wise Mahalanobis-scoring Activation Anomaly Detector (AAD) that identifies distributional shifts in the intermediate representations of LLMs; and a Trust Propagation Consensus (TPC) mechanism that combines cryptographic and behavioral evidence into per-payload integrity verdicts. In this formulation, the Cryptographic Attestation Module (CAM) tests whether message-level structural symmetry is preserved between the sender and receiver, whereas the AAD detects behavioral symmetry breaking in activation space. Experiments on three multi-agent benchmarks under five adaptive attack strategies show that SPI-Net achieves a 96.8% detection rate with a 1.7% false positive rate, reduces the attack success rate by 94.3% relative to undefended baselines, verifies data integrity with 99.2% accuracy, and introduces only 38 ms of median per-message latency. These results demonstrate that jointly preserving cryptographic integrity symmetry and identifying activation-level asymmetry provides substantially stronger prompt-injection resilience than either verification mechanism alone. Full article

Supercritical CO₂ (SC-CO₂) acid fracturing injects an SC-CO₂-acid mixture into carbonate formations to create high-conductivity channels. It retards acid-rock reaction at high temperature, creating long acid-etched fractures and facilitating CO₂ transport and storage. Fracture conductivity is critical for fluid transport; however, the influence of shut-in time on this property remains poorly understood. In this study, we conducted SC-CO₂ acid-etching experiments and fracture conductivity tests on tight dolomite samples at shut-in times of 0, 30, 60, and 120 min. The interval-averaged acid–rock reaction rates during the 0–30, 30–60, and 60–120 min shut-in periods were 2.23, 3.08, and 2.77 times those during acid injection, respectively. Because temperature increased while residual acid concentration decreased during shut-in, the reaction-rate evolution reflects their combined effects. Fracture morphology exhibited a non-monotonic response to shut-in time. After 30 min, pronounced flow-aligned channels developed along the acid-flow direction, accompanied by a marked increase in surface roughness. At 60 min, channel prominence and roughness amplitude decreased despite continued surface recession, whereas the 120-min fracture exhibited the highest roughness and stronger directional differentiation, with the morphology tending toward flow-perpendicular channels. Fracture conductivity was strongly dependent on closure stress. At 2.5 MPa, conductivity followed the order 30 min > 120 min > 0 min > 60 min, consistent with the ranking of mean and median fracture apertures. In the 25–60 MPa range, the ranking changed to 30 min > 0 min > 120 min > 60 min, indicating the increasing importance of persistent and connected residual flow pathways. Although the 120-min fracture exhibited the highest roughness, its high-stress conductivity remained lower than that of the 30-min fracture, demonstrating that roughness alone is insufficient to determine fracture conductivity. Among the investigated conditions, the 30-min shut-in exhibited the most favorable overall conductivity performance in the 25–60 MPa closure-stress range. Full article

Mineral scale deposition is one of the most persistent flow assurance challenges in the oil and gas industry, causing formation damage, reduced injectivity and productivity, equipment fouling, pipeline blockage, and substantial economic losses. The increasing application of seawater injection, produced-water reinjection, and enhanced oil recovery (EOR) techniques has intensified scaling problems by promoting the mixing of incompatible waters and altering reservoir geochemistry. Consequently, the development of efficient scale management strategies has become essential for maintaining production performance and ensuring the long-term integrity of oilfield assets. This review comprehensively examines the mechanisms of scale formation, the physicochemical and operational factors governing mineral precipitation, and recent advances in scale inhibition technologies for production enhancement. The review discusses the characteristics and formation mechanisms of the major oilfield scales, including carbonate, sulfate, silica, iron-containing, and mixed mineral deposits, together with their effects on reservoir permeability and production facilities. Conventional phosphonate- and polymer-based inhibitors are critically evaluated alongside emerging environmentally friendly inhibitors, nanotechnology-assisted formulations, and controlled-release squeeze treatment systems. Furthermore, laboratory evaluation techniques, adsorption and coreflooding studies, thermodynamic and kinetic modeling, molecular simulations, and artificial intelligence-based predictive methods are reviewed to demonstrate their roles in improving inhibitor design, scale prediction, and treatment optimization. Recent developments in machine learning, digital twins, and intelligent optimization algorithms are also highlighted as enabling technologies for next-generation scale management. Finally, current research challenges and future perspectives are discussed, emphasizing sustainable inhibitor development, integrated experimental and computational approaches, and real-time predictive monitoring systems. By integrating advances in chemistry, materials science, computational modeling, and petroleum engineering, this review provides a comprehensive framework for understanding and implementing effective scale management strategies to enhance hydrocarbon production, reduce operational costs, and improve the sustainability of oilfield operations. Full article

The Chang 8 reservoir in the Baima Middle Block of the Ordos Basin is an ultra-low-permeability reservoir that has faced formation-pressure depletion, a rising water cut, and poor remaining-oil recovery during long-term water-injection development. CO₂ flooding in CCUS can simultaneously enhance oil recovery and achieve carbon sequestration; however, comprehensive and integrated research on the CO₂–crude oil phase behavior, miscibility characteristics, and nonlinear flow in porous media for this block is still lacking. To address this gap, this study used crude oil and natural cores from the block and natural cores to conduct a series of experiments at 70 °C, including PVT high-pressure physical-property tests, CO₂ constant-mass-expansion tests, slim-tube minimum-miscibility-pressure (MMP) tests, pendant-drop oil–gas interfacial-tension measurements, and CO₂-flooding threshold-pressure-gradient measurements in cores of different permeability. The results showed that as the CO₂ mole fraction increased from 0% to 61.78%, the bubble-point pressure of the crude oil rose from 17.424 to 22.575 MPa, the viscosity decreased from 9.026 to 4.906 mPa·s, and the volumetric expansion coefficient increased from 1.0000 to 1.1454. As the water cut increased from 0% to 80%, the apparent MMP of CO₂ increased from 15.83 to 17.69 MPa. The oil–gas interfacial tension gradually decreased with increasing system pressure, and droplet instability and atomization occurred under near-miscible high-pressure conditions. The CO₂-flooding threshold pressure gradient decreased with core permeability following a power-law relationship, and a knee-like trend appeared near 0.5 mD within the limited permeability dataset of this study; this trend cannot be generalized without further experimental evidence. This study comprehensively reveals the coupled mechanisms of phase behavior, miscibility, and nonlinear flow during CO₂ flooding in the target block, providing experimental and theoretical support for optimizing the injection pressure and reservoir-stimulation schemes of CCUS-EOR in ultra-low-permeability reservoirs. Full article

How suspended grains traverse energy-dissipating micro-passages determines whether sediment-laden water can be used without rapid emitter deterioration. A novel cylindrical asteroid-shaped drip emitter was investigated through laboratory anti-clogging tests and two-way coupled computational fluid dynamics–discrete element method (CFD–DEM) simulations. The laboratory tests comprised 20 intermittent irrigation cycles at five pressures ranging from 60 to 140 kPa, with relative discharge used to characterize hydraulic performance. The simulations tracked particle motion, wall collisions, and mass transmission over a 0.20 s observation window to examine the effects of operating pressure, injected particle mass, and flow-path radius. Numerical cases isolated hydraulic forcing and, at 100 kPa, changes in solids dose and cavity radius. Measured discharge retention occupied a narrow 96.45–97.83% interval, whereas the fraction of particulate mass leaving the domain spanned 81.3–92.7%. Despite representing different responses, both indices followed pressure in a closely associated manner (Pearson r = 0.975, p = 0.0046). Stronger forcing extended the high-speed portion of individual trajectories and brought the final wall contacts forward in time, although contact totals did not follow a monotonic sequence. Changing the dose between 1.0 and 2.0 × 10⁻⁶ kg altered the selected upper-speed statistics by only +1.8% and −2.1% but reshaped the contact histories. Expanding the radius from 0.65 to 0.85 mm produced much larger reductions of 28.1% and 91.3%; the latter record then showed sustained near-stagnation with relatively few impacts. Thus, low collision frequency cannot independently demonstrate effective sediment passage. Combining effluent mass balance with trajectory and contact information provides a mechanistic basis for diagnosing retention in irrigation microchannels. Full article

The spunbond process is one of the main technologies for producing polypropylene (PP)-based nonwoven fabrics, widely used in industrial applications and in the automotive sector. In this work, an injection-molding-grade polypropylene was modified through the addition of 0.5 wt% Nexamite R202, a concentration representative of the levels typically employed in commercial controlled-rheology grades for spunbond applications. The effects of controlled degradation on the material’s properties were then evaluated, together with its potential suitability to produce nonwoven fabrics intended for car cover coatings. Characterization included mechanical tests (tensile and impact), thermal analysis (DSC, VICAT) and rheological measurements. The results show that peroxide addition increases melt flow rate (MFR) from 12.5 to 33.3 g/10 min (+167%), reduces capillary viscosity, lowers the maximum tensile stress from 25.5 to 22.7 MPa, keeps the strain at break statistically comparable (18.9% to 18.6%) and reduces the impact energy from 139.6 to 102.2 kJ/m². In the regrading stage, formulation SB#4, containing a regrading additive, antioxidants, and a virgin fraction, showed the best compromise between processability and toughness, although without fully restoring the properties of the virgin material. These results indicate that a combined regrading strategy represents an effective route for valorizing reprocessed PP within a circular economy framework. Full article

Acid-etched fracture conductivity testing (AFCT) is a key technique for evaluating the effectiveness of acid fracturing, but the existing test apparatus still presents many problems. One of these problems is the sudden expansion at the connection part, which leads to flow instabilities. To address the limitations of the current experimental apparatus, a new structure for the conductive chamber was developed. By using computational fluid dynamics methods, a numerical model of the fluid domain, was established. A numerical parameter sensitivity analysis was subsequently conducted, with the diverging angle ranging from 12° to 22°, the buffering section length ranging from 10 to 35 mm, and the inner diameter of the injecting pipe ranging from 2 to 7 mm. Considering factors such as the fluid flow characteristics, material costs, and processing costs, the recommended structural parameters for the conductive chamber were determined as follows: a diverging angle of 16°, a buffering section length of 30 mm, and an injecting pipe inner diameter of 5 mm. A simple preliminary experimental comparison between the existing and new structures was conducted; the experimental results primarily show a more uniform etching pattern when using the new structure under simulated conditions. This study provides a scientific basis for upgrading and improving AFCT apparatus. The new geometry may reduce hydraulic interference and potentially improve test reliability. Full article

Modern distribution networks increasingly face reverse power flow, heavy loading or overloading, and voltage violations as distributed generation and flexible demand introduce large spatiotemporal variations in active-power injections and withdrawals. This paper proposes a planning-operation consistent DC-AC time-series optimal power flow (OPF) method for flexible-resource planning and operation optimization to mitigate these problems. The DC module optimizes investment decisions with embedded DG curtailment and flexible-load regulation to improve the operational relevance. The AC module further considers resource reactive-power flexibility and optimizes their operation under voltage constraints. The consistent design of the two modules in objective structure, operating constraints, and flexible-resource representation allows the planning results to be parsed as the initial schedule for AC operation refinement, improving operation-optimization efficiency. Furthermore, the model introduces discrete type-and-number BESS planning, endogenous initial state of charge (SOC) optimization, and a unified flexible-load model to improve operability and economic relevance. The method is implemented in a CloudPSS-based DSLab environment and tested on a real distribution feeder and the IEEE 123-node benchmark. The real-feeder case demonstrates coordinated mitigation of reverse-power export, branch overloads, and voltage violations. In the IEEE 123-node benchmark, the 8760 h AC operation case converges in 376.31 s, confirming tractability for long-horizon time-series optimization. Full article

Accurate water level observations are essential for flood forecasting, hydrological analysis, and water resource management; however, sensor malfunctions and telemetry errors frequently introduce anomalous observations that compromise data quality. This study proposes a reconstruction-oriented Bidirectional Long Short-Term Memory (BiLSTM) Autoencoder for river water level anomaly correction and compares its performance with conventional first-, second-, and third-order polynomial and exponential regression models. The proposed framework incorporates a simplified encoder–decoder architecture, a dynamic block masking strategy to emulate contiguous sensor failures in highly autocorrelated water level series, and a threshold-based peak-oriented training scheme to improve reconstruction during high-flow events. Model hyperparameters were optimized using Gaussian process-based Bayesian optimization. The methodology was evaluated using hourly observed water level data from the Han River, Republic of Korea. Results showed that the proposed BiLSTM Autoencoder achieved reconstruction accuracy comparable to conventional regression models during calibration while exhibiting superior generalization to unseen validation datasets and better preserving the temporal continuity and dynamic characteristics of downstream hydrographs. Furthermore, a model calibrated using a relatively short but hydrologically representative period successfully reconstructed a substantially longer unseen record. Synthetic outlier injection experiments further demonstrated that reconstruction accuracy gradually deteriorated with increasing training data contamination, emphasizing the importance of high-quality training data for reliable sequence reconstruction. The proposed framework demonstrates potential as an effective sequence-reconstruction approach for offline river water level quality control. Full article

Selective catalytic reduction (SCR) systems in coal-fired power plants must maintain low NOx emissions during increasingly frequent load changes. Variations in flue gas temperature and flow complicate ammonia-injection control and can cause NOx overshoot or excessive NH₃ slip. This study evaluates an implicit generalized predictive self-tuning controller using a coupled dynamic model of a 660 MW ultra-supercritical coal-fired power plant and its SCR system. The controller combines recursive least-squares identification with generalized predictive control (GPC) and is compared with proportional–integral–derivative (PID) control between 50% and 75% turbine heat acceptance (THA), at load-cycling rates of 0.5–2.0% $P_{\mathrm{e}0}$ min⁻¹. GPC improves NOx set-point tracking and reduces NH₃ slip over the conditions examined. During loading-down, the maximum outlet NOx concentrations are 48.43 mg m⁻³ with GPC and 65.78 mg m⁻³ with PID. During loading-up at 1.0% and 2.0% $P_{\mathrm{e}0}$ min⁻¹, GPC reduces the cumulative NH₃-slip index by 46.52% and 75.56%, respectively. The identified model coefficients vary more strongly at higher ramp rates, while the loading-down response also depends on the transient SCR inlet temperature. These results indicate that online model adaptation can improve ammonia-injection control during load-cycling. Full article

Hydraulic fracture propagation directly affects stimulation efficiency in low-permeability unconventional reservoirs and is influenced by in situ stress, fluid injection, and bedding structure. In this study, a coupled hydro-mechanical phase-field model was developed by combining solid mechanics, porous media flow, and phase-field fracture theory. Bedding planes were represented as lower-dimensional interfaces. The model was used to investigate the fracture initiation and propagation under different stress ratios, fluid injection rates, and bedding angles. The results show that under anisotropic stress conditions, fractures propagate mainly in the direction of the maximum principal stress. Under equal stress conditions, no consistent preferred direction is observed during the fracture initiation or subsequent propagation. Increasing the fluid injection rate results in a higher initiation pressure and an earlier initiation time while producing little change in the final fracture geometry. For bedded rock, three typical fracture propagation patterns are identified: bedding-dominated, stress-dominated, and mixed-control propagation. Under equal biaxial stress conditions, bedding-dominated propagation occurs regardless of bedding angle. These results indicate that the final fracture morphology is governed mainly by the relative influence of the stress field and bedding interfaces, whereas the fluid injection rate primarily affects the fracture initiation pressure and initiation time. Full article

Background: Aortic dissection (AD) is a life-threatening vascular disease with high mortality, yet its molecular pathogenesis remains incompletely understood. This study investigated the role of regulated in development and DNA damage responses 1 (REDD1) in vascular smooth muscle cells (VSMCs) apoptosis and the underlying mechanisms. Methods: Single-cell RNA sequencing data from GSE222318 were analyzed to investigate the expression levels of REDD1 in VSMCs and its role in inducing apoptosis and autophagy. The target gene was silenced in C57BL/6J mice via tail-vein injection of Adeno-associated virus.β-aminopropionitrile (BAPN) was used for AD induction. Western blotting was used to assess REDD1, LC3B, p62, BAX, BCL-2 in aortic tissues. Aortic histopathological alterations were examined by hematoxylin and eosin (H&E), Elastica van Gieson (EVG), and Masson’s trichrome staining. Immunofluorescence was performed to examine REDD1 expression and its localization in α-SMA-positive vascular smooth muscle cells. REDD1, LC3B, p62, BAX, BCL-2, mTOR, and p-mTOR were also examined by Western blotting in cultured cells. Mitochondrial membrane potential was evaluated by JC-1 staining, and apoptosis was assessed by flow cytometry. Results: REDD1 expression levels were significantly increased in human AD tissues and localized predominantly to medial VSMCs. REDD1 levels were positively correlated with BAX and LC3B and negatively correlated with BCL-2 and p62. Knockdown of REDD1 in AD mice was associated with increased levels of BAX and p62 and decreased levels of BCL-2 and LC3B in aortic tissues, accompanied by more severe pathological manifestations. REDD1 silencing in VSMCs increased BAX, p62 and p-mTOR while reducing BCL-2 and LC3B, accompanied by increased apoptosis and loss of mitochondrial membrane potential, whereas rapamycin reduced apoptosis and alleviated mitochondrial injury. Conclusions: REDD1 appears to play a protective, compensatory role in AD. Increased REDD1 expression may help preserve mitochondrial membrane potential and attenuate VSMC apoptosis under pathological stress, accompanied by changes in static autophagy-related markers that suggest a possible association with increased autophagic activity. Loss of REDD1 activity promotes mitochondrial injury and VSMC apoptosis, thereby aggravating AD. Targeting REDD1 may therefore represent a potential therapeutic strategy for AD. Full article

The structural, processing, and mechanical response of a multiphase poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/poly(butylene adipate-co-terephthalate) (PBAT)/thermoplastic starch (TPS) matrix to two distinct glass fillers was investigated. Glass fibers and hollow glass spheres were incorporated by melt compounding and injection molding, while the unfilled blend served as the reference. Differential scanning calorimetry, X-ray diffraction, melt-flow-rate measurements, helium pycnometry, scanning electron microscopy with deep-learning-based segmentation, tensile, and Charpy impact tests were applied. At higher filler contents, the composite-level XRD-based crystallinity index decreased to approximately 47%, whereas the Scherrer-derived PHBV (110) coherent-domain size remained within approximately 21–24 nm. Preferred orientation, assessed independently from the PHBV reflection-intensity ratio, varied with filler type and content. Glass fibers progressively reduced melt flow and were associated with an increase in tensile modulus from 2.06 to 3.45 GPa and maximum tensile stress from 23.46 to 27.32 MPa at the highest investigated fiber content. Hollow glass spheres produced a non-monotonic melt-flow response, while the reduction in tensile performance at higher contents coincided with decreasing interparticle spacing and increasing specific external polymer–glass interfacial area. Within the analyzed SEM fields, no pronounced filler-rich clustering was evident. Notched specimens remained brittle, whereas unnotched specimens retained impact strength above 10 kJ × m⁻². Overall, the two filler geometries exhibited distinct relationships among apparent melt flowability, crystalline organization, quantitative microstructural descriptors, and mechanical response. Full article

Carbon capture and storage (CCS) is a critical technology for mitigating climate change by reducing atmospheric carbon dioxide concentrations. Effective monitoring of CCS sites is essential to ensure that injected CO₂ remains securely trapped and does not leak into the shallow subsurface or atmosphere. Large-scale CCS in the Gulf of Mexico could be facilitated by extensive existing infrastructure and suitable geologic containment; however, legacy wells and structurally complex geology remain critical challenges for ensuring storage integrity. Traditional monitoring methods, while effective, often lack the temporal resolution and cost-effectiveness needed for comprehensive leak detection, particularly in shallow seafloor environments. This study explores the potential of distributed acoustic sensing (DAS) as a novel monitoring solution for near-surface CO₂ leakage at geologic carbon storage (GCS) sites. We conducted a laboratory-scale controlled nitrogen gas bubble injection experiment to compare DAS responses at varying cable burial depths and evaluated these signals using simultaneous hydrophone measurements. Results indicate that while DAS effectively detects acoustic signals from bubbles in both sediment and water columns, its response amplitude diminishes with increased burial depth. These findings suggest that DAS could serve as a promising technology for long-term monitoring of marine GCS sites, providing insights into near-surface gas flow and leak detection. Full article