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Flexural guided waves that preserve the circumferential focusing characteristics provide insights into the structural integrity and thus have great application potential. An improved transducer called cross-exciting circumferential phased array is proposed for generating pure flexural mode in pipes. It is divided into two cross-exciting sub-arrays, with opposing excitation angles with respect to the pipe axis, forming a standing wave in the circumference and thereby a clear circumferential focus. The excitation response of the proposed transducer is theoretically analyzed with the normal mode expansion method. Finite element simulations of flexural mode excitation with the proposed transducer and a conventional circumferential array are further compared. The simulation results agree well with the theoretical predictions. Pure flexural modes of circumferential order of one are successfully generated. The excited signals are comprehensively analyzed. Furthermore, purity improvements are investigated with respect to the excitation frequency, element number, element width, and axial length. The excitation frequency should be appropriately chosen to suppress the unwanted modes. The element number should be sufficiently large to prevent the excitation of high circumferential order modes. The element width has negligible effect on the target flexural mode purity, whereas the element axial length significantly should be carefully chosen. [ABSTRACT FROM AUTHOR]

The performance of machines has not been fully exploited when processing large-scale dynamic graph in heterogeneous GPU clusters. To improve the performance of graph computing, a distributed heterogeneous engine (DHE) has been designed. A new heterogeneous graph partitioning algorithm is implemented, which can achieve load balancing among internal nodes in GPU clusters. DHE introduces synergy model to quantify the co-computing performance of heterogeneous processors and designs computing pipelines to optimize the performance of accessing memory. The graph algorithms PageRank, CC, SSSP and K-core are selected for the experiment. Under the same conditions, DHE’s partitioning algorithm improves scalability and load balancing ability compared to other graph partitioning algorithms. The heterogeneous computing pipeline exhibits better memory access compared to the basic engine. The experiments show that the synergy of this system converges to 1 stably. Compared with the other three graph partitioning algorithms, the system reduced processing time by approximately 20–30% and the performance is improved by a factor of 1.2 times. [ABSTRACT FROM AUTHOR]

Pipeline networks have a wide range of applications, from the transportation of energy sources such as oil and natural gas to the conveyance and distribution of water resources. However, leaks and ruptures in pipelines can cause significant harm to the environment. Therefore, it is crucial to accurately detect pipeline faults in order to avoid economic losses and protect the environment. In this study, pipeline networks carrying water fluid are represented using graph structures. The graph convolutional network (GCN) algorithm is employed for the detection of leaks and blockages in pipeline networks. Experimental methods are employed to collect the necessary data (pressure data) for the GCN algorithm, creating two datasets by considering five different scenarios. The fault detection performance of the GCN algorithm is compared with other graph machine learning algorithms, namely, RGCN, HinSAGE, and GraphSAGE. The results of this study indicate that the performance of the GCN model surpasses that of the other algorithms. Reviewing the literature, accuracy rates for fault diagnosis in pipeline networks using machine learning algorithms range from 78.51% to 99%. In this study, it is found that the GCN, GraphSAGE, HinSAGE, and RGCN algorithms achieve fault detection accuracies of 91%, 90%, 87%, and 89%, respectively, in pipeline networks. Classical machine learning SVM model was used to compare the performance of graph-based algorithms. It is seen that the performances of the algorithms face the literature and the results are above the literature average. [ABSTRACT FROM AUTHOR]

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As processor microarchitecture is getting complicated, an accurate analytic model becomes crucial for exploring large processor design space within limited development time. An interval simulation is a widely used analytic model for processor designs in the early stage. However, it cannot accurately model modern microarchitecture, which has an unbalanced pipeline. In this work, we introduce IntervalSim++, an accurate analytic model for a modern microarchitecture design based on the interval simulation. We identify key components highly related to the unbalanced pipeline and propose new modeling techniques atop the interval simulation without incurring significant overheads. Our evaluations show IntervalSim++ accurately models a modern out-of-order processor with minimal overheads, showing 1% average CPI error and only 8.8% simulation time increase compared to the baseline interval simulation. [ABSTRACT FROM AUTHOR]

Based on a 0.5 MM TPY moving bed light hydrocarbon aromatization unit, this paper explores the basic points and precautions of the development and application of pipeline engineering for the reaction section from the aspects of reaction framework layout, main equipment layout, oil transfer pipe design, catalyst pipe design, etc. The application results show that the design of the reaction framework meets the requirements of process flow, safety production, pipeline layout, operation and maintenance, etc.; the selection of materials for the oil transfer pipe meets the requirements of high-temperature and hydrogen environments, and the stress analysis of the pipeline fully considers various working conditions such as normal operation of the pipeline system, start-up drying, and start-up system drying, and the pipeline layout meets the process requirements of the drop of temperature and pressure of the pipeline system within the specified value, the oil transfer pipe can operate safely and stably for a long time under harsh conditions; the catalyst pipeline design meets the requirements of low catalyst wear. The expected results have been achieved in the research and application of pipeline engineering for the reaction system. [ABSTRACT FROM AUTHOR]

When laying pipelines using concrete supports and frames in the overhead laying scheme, the pipes may experience deformation and tension due to the height at which they are installed, typically between 1.0-1.5m from the ground surface. The installation of overhead pipeline on hard or collapsible foundations causes bending due to the combined weight of the pipes and the transported product. This text discusses the use of three moment equations to solve this problem. [ABSTRACT FROM AUTHOR]

In the article, the solution of the issues of transportation of the produced product in the oil and gas extraction department occupies one of the main places. Pipelines belong to technological systems that represent fire-explosion dangerous objects with a complex structure capable of hydrate formation, erosion, ignition, explosion and environmental pollution. By reducing technological risks that may occur in underwater pipelines, it is possible to ensure technological and environmental safety at sea and protect marine bioresources. Risk analysis using statistical data can reveal the negative consequences of natural hazards and other external influences on the pipeline system. [ABSTRACT FROM AUTHOR]

The issues of reliability and efficiency of operation of field and main oil and gas pipelines and control of energy characteristics during their operation are of no small importance. The efficiency of pipelines depends on the technical condition of facilities and equipment and the rationality of their use. The practice of operating pipelines shows that emergency and abnormal cases occur in them. Significant irregular pressure and flow pulsations are observed in pipelines. Waves of high and low shock pressure often occur and propagate along the pipeline. Along with density, additional pressure in the system from hydrodynamic impacts also arises from the elasticity of the pumped liquid and the pipeline itself. This pressure is determined by the elastic compression of the transported system and the elastic expansion of the pipeline as the pressure in it increases. The pipeline through which the multiphase flow is pumped, and its structures and other components must withstand dynamic loads. The work analyzes various modes of water impact. The volume of oil caused by its compression during hydraulic impact was calculated. The results of calculating the increase of an oil pipeline volume due to a dynamic impact are presented. [ABSTRACT FROM AUTHOR]

Landslides, as a common geological hazard, pose a significant threat to critical infrastructure such as pipelines. With numerous large-scale engineering projects in China crossing active fault zones, the impact of geological hazards on the safe operation of pipelines is becoming increasingly prominent. To accurately assess the impact of landslides on pipelines, this study employs the open-source DualSPHysics code and constructs a three-dimensional numerical model of landslide impact on pipelines based on the Smoothed Particle Hydrodynamics (SPH) method. The study conducts a quantitative analysis of key factors such as sliding displacement and landslide scale, thoroughly exploring the mechanisms by which landslides affect pipelines. The results indicate that as the landslide displacement increases, the rate at which the pipeline's stress increases accelerates, and the rate of stress decrease after reaching the peak also accelerates. Additionally, when the width of the landslide mass increases, its volume correspondingly increases, leading to a significant enhancement in the impact force experienced by the pipeline. Furthermore, the study analyzes the impact of different initial distances between SPH particles on the pipeline to optimize the accuracy and computational efficiency of the simulations. This research not only provides new perspectives and approaches for assessing pipeline safety but also holds significant implications for enhancing pipeline disaster resistance and guiding design and safety assessments in geological engineering and infrastructure projects. [ABSTRACT FROM AUTHOR]

Perception-based autonomous system design methods are widely adopted in various domains like transportation, industrial robotics, etc. However, attaining safe and predictable execution in such systems depends on the platform-level integration of perception and control tasks. This letter presents a novel methodology to co-optimize these tasks, assuming a CPU-GPU-based real-time platform, a common choice of compute resource in this domain. Unlike the traditional methods that separately address AI-based sensing and control concerns, we consider that the overall performance of the system depends on the inferencing accuracy of the perception tasks and the performance of the control tasks iteratively executing in a feedback loop. We propose a design-space exploration methodology that considers the above concern and validates the same on an autonomous driving use case using a novel simulation setup. [ABSTRACT FROM AUTHOR]

It has been established that in the vicinity of V-shaped elements with a sharp apex, the stress field has a singularity of type σ → ∞, which requires the use of the concept of "stress intensity factor" in strength calculations. This need arose due to different dimensions of the SIF and fracture toughness. Special criteria for the destruction of structures with V-shaped stress concentrators have been developed, which include, as special cases, the criteria of classical mechanics and the criteria of fracture mechanics. An experimental test of the proposed criteria and calculation methods was carried out. The information obtained is useful for analyzing welded joints on main pipelines and other equipment. [ABSTRACT FROM AUTHOR]

Selecting techniques is a crucial aspect of disease detection analysis, particularly in the convergence of computer vision and agricultural technology. Maintaining crop disease detection in a timely and accurate manner is essential to maintaining global food security. Deep learning is a viable answer to meet this need. To proceed with this study, we have developed and evaluated a disease detection model using a novel ensemble technique. We propose to introduce DenseNetMini, a smaller version of DenseNet. We propose combining DenseNetMini with a learning resizer in ensemble approach to enhance training accuracy and expedite learning. Another unique proposition involves utilizing Gradient Product (GP) as an optimization technique, effectively reducing the training time and improving the model performance. Examining images at different magnifications reveals noteworthy diagnostic agreement and accuracy improvements. Test accuracy rates of 99.65 %, 98.96 %, and 98.11 % are seen in the Plantvillage, Tomato leaf, and Appleleaf9 datasets, respectively. One of the research's main achievements is the significant decrease in processing time, which suggests that using the GP could improve disease detection in agriculture's accessibility and efficiency. Beyond quantitative successes, the study highlights Explainable Artificial Intelligence (XAI) methods, which are essential to improving the disease detection model's interpretability and transparency. XAI enhances the interpretability of the model by visually identifying critical areas on plant leaves for disease identification, which promotes confidence and understanding of the model's functionality. [ABSTRACT FROM AUTHOR]

This article addresses the study of the internal hydraulic infrastructure of the Royal Monastery of San Lorenzo del Escorial. The vast network of pipes that supplied water to the numerous fountains, tanks, and other devices in the building. The methodology was based on two fundamental pillars: an analysis of the historical sources related to water and a cataloguing of the preserved architectonical remains of the infrastructure. A new sketch of the water supply network of the building has been drawn using ArcGIS Pro software. In doing so, this article provides a more accurate and detailed knowledge of the building's plumbing system. [ABSTRACT FROM AUTHOR]

The barrier performance of epoxy-based powder coatings for pipelines was evaluated through salt transport measurements through free-standing coating films and via cyclic testing of coated steel panels. The permeability of salt through the free-standing coating films was measured using reverse osmosis techniques under hydraulic pressures relevant to industrial use. These tests showed that fusion bonded epoxy (FBE) and high-performance powder coating (HPPC) have low salt permeability. Accelerated exposure tests were then conducted on the coated steel panels, subjecting them to humidified environments, ultraviolet (UV) light, and salt/fog conditions, all in accordance with ASTM D5894. Some of the exposure conditions (e.g., intensity of UV light and humidity) were modified to examine the impact of each parameter on the relative performance of these coating systems. The reversibility of the coating properties was characterized by a thermal cycling protocol and adhesion performance analysis. Alternative exposure to dry- and wet-cycles (at 60 °C and 50 °C, respectively), salt/fog conditions and UV light results in irreversible damage to the coatings as early as two weeks. However, coated panels exposed to a lower UV intensity (one tenth of the value defined by the standard) showed minimal degradation of FBE, meaning that the most critical parameter was the UV radiation exposure. For one 336-h ageing sequence under UV exposure, the HPPC exhibited superior performance compared to FBE. More importantly, our extended exposure sequences showed that while the FBE coating structure undergoes a slow ablation process, indicating significant surface damage, it still retains its effectiveness as a barrier. However, the osmotic pressures around coated pipes and the pre-existing, unavoidable porosity throughout the coating thickness can facilitate local through-thickness pinholes, which could potentially serve as areas susceptible to cathodic disbondment. [ABSTRACT FROM AUTHOR]

To promote the fair opening of pipeline facilities and improve the utilization efficiency of infrastructure, Chinese government has implemented the pipe network reform by learning from the successful experience of Europe and America. Under the market-oriented mode, the pipe carrier will rationally allocate the transport capacity to third-party customers according to their nominations and formulate a schedule in line with the operational process. Aiming at the new scheduling mode, this study develops a method for detailed scheduling of multiproduct pipelines under the market-oriented mode. The method consists of the sequence-decision model and the scheduling model, covering several operational aspects of real-world pipeline systems, such as multi-source injection, the constraints for contamination volume and the constraints for restart frequency of stations. Data from practical pipelines is adopted as the case study to validate the method. Results show that the proposed framework can improve the satisfaction of shippers to the greatest extent. The delivery satisfaction of each shipper at designated stations all reaches 100 %. The method guarantees the delivery quality of products, decreases the number of operation interruptions. The number of times that operation interruptions occur at stations does not exceed 2 times. To a certain extent, the operating cost of the pipe company will be reduced. [ABSTRACT FROM AUTHOR]

Steel tubular structures in pipelines, or those connections such as concentric reductions, reduced tees, and elbows, all differ in their response to loading, they are sometimes solicited to complex and combined loads, which accumulate with the internal pressure to their solicitation cause in certain situation their damage, the objective in this analysis is to numerically predict the mechanical behavior until damage of a complete tubular structure, which contains the connecting elements of an elbow and a reduced tee attached to each other by straight tubular parts, this structure, by its standardized dimensions presents a real design of a main pipeline spigot for a possible supply line, this tubular structure is analyzed in this work under these real pressure conditions, and combined loads probably coming from the weight of a valve, or a pipe flanged to this spigot element or other, in X60 steel This structure is solicited under different combined modes of loading. The elastic-plastic behavior is under Voce's model and Von Mises' equivalent stress flow theory, the damage of the structure by crack initiation and propagation is ensured by using the XFEM technique, the response up to damage of the structure is evaluated under the effect of the parameters of the combined loading mode, we present by angular bendingrotation moment curves that these parameters clearly condition the response and the level of damage. [ABSTRACT FROM AUTHOR]

One of the negative effects of linear infrastructures is the formation of barriers to the movements for arboreal wildlife resulting in the reduction in connectivity between populations and thus increasing the risk of extinction. One of the most widely used ways to mitigate these barrier effects is canopy bridges. There is a lack of knowledge about how behavioral differences between species may affect the efficacy of canopy bridges. The purpose of this study was to evaluate the hypothesis that Leontopithecus rosalia (an endangered endemic species) and Callithrix spp. hybrids (introduced invasive species) perceive canopy bridges as sites with risk of predation. We compared the behavior of these species during attempts to cross four canopy bridges installed over oil and gas pipeline right-of-way strips, and another 4 bridges installed inside the forest near the pipeline bridges. The behavior was recorded from 30-second videos obtained from two camera traps installed at each end of the bridges. Of the 1917 crossing events identified, 356 events were randomly chosen for behavioral data collection. Of these, 173 were social group crossing events and 183 individual crossing events. There were few crossings (7.9%) with the two species present. The differences between the species were more quantitative than qualitative and may be related to interspecific differences in vulnerability to predation and anti-predatory tactics. Both species exhibited significantly more behaviors related to perception of risk of predation (vigilance, hesitation, rapid passage) in the pipeline bridges than in the forest bridges. One vigilance measure showed higher occurrence during the first months after installation of the cameras, especially for Callithrix spp., but in general there was little waning of the risk-assessment response. Alarm calls, scent marking and social and feeding behaviors were rare or absent. Low-cost simple canopy bridges may be an effective strategy to overcome the barrier effect of right-of-way strips over gas and oil pipelines. However, the results on perceived risk of predation raise the hypothesis that there may be a cost-benefit ratio between distance to be traveled and risk perception that would lead to a reduction in effectiveness of bridges in greater distance. We discuss the implications for conservation of an endangered species and management of an invasive species. [ABSTRACT FROM AUTHOR]

This article helps understand why locations close to strategic infrastructure to transport illegal drugs (seaports, airports, highways, and US ports of entry along the Mexico-US border) or to increase income (pipelines) experience different levels of violence due to DTOs operations. Our theory breaks down the impact of the geographical distance to these facilities on violence into two effects. The first effect is produced by the level of (violent) competition among DTOs, measured by the number of DTOs employing violence. We report that greater proximity to the U.S. ports of entry along the Mexico-US border, ports, and airports furthers the number of competitors, and such increase boosts violence. The second effect shapes the intensity of competition among DTOs. Reductions in the costs of excluding competing DTOs from using the facility could trigger greater confrontation among DTOs. We confirm the importance of this second effect in relation to ports and the U.S. ports of entry along the Mexico-US border. [ABSTRACT FROM AUTHOR]

This paper presents the effectiveness of a hybrid YUKI-RANDOM-FOREST, Particle Swarm Optimization-YUKI (PSO-YUKI), and balancing composite motion optimization algorithm (BCMO) based on artificial neural networks (ANN) for the best prediction of patch design considering the maximum principal stress. The study compares the maximum principal stress in a damaged pipe under different composite patch designs. Robust models have been developed and utilized in various applications. The research investigates the influence of cracks on the mechanical characteristics of API X70 steel in a test pipe under critical pressure. The numerical model employs the extended finite element method (XFEM) to simulate notches. Extending the optimization technique, the study examines the effect of crack presence in a pipeline section under internal pressure without and with composite repairs on the maximum principal stress. The sensitivity of stress is analyzed with respect to the design parameters of the composite patch. Finally, YUKI-RANDOM-FOREST, NN-PSO-YUKI, and NN-BCMO, with different parameters and hidden layer sizes are employed to predict the maximum principal stress under different composite patch designs, and yielding minimal error. Once the database was built, our model was prepared to predict various situations at the composite patch level. Compared to other methods, the obtained results with hybrid YUKI-RANDOM-FOREST are effective. The investigation technique is relevant to real-world engineering applications, structural safety control, and design processes. [ABSTRACT FROM AUTHOR]

The vast expanses of remote onshore areas in oil-producing countries are home to a network of flow and collection pipelines that are susceptible to leaks. Most of these areas lack the infrastructure to enable the use of remote monitoring systems equipped with sensors and real-time data analysis to provide early detection of anomalies. This paper proposes a proof of concept for a monitoring system based on the Internet of Things (IoT) for real-time detection of pipeline leaks in onshore oil production fields. The proposed system, based on a thermal imaging leak detection method, informs the operator of the system's operating status via a web page. The leak detection system communicates via a Zigbee network between the IoT devices and a 4G mobile network. The results of the tests carried out show that a visual and automatic IoT-based leak detection system is possible and plausible. The proposed leak detection system enables supervisors at remote stations and field workers to monitor the operating status of pipelines via computers, tablets, or smartphones, regardless of where they are. [ABSTRACT FROM AUTHOR]

The proper selection of a relevant mixer generally requires an effective assessment of several models against the application requirements. This is a complex task, as traditional evaluation methods generally focus only on a single aspect of performance, such as pressure loss, mixing characteristics, or heat transfer. This study assesses a urea-based selective catalytic reduction (SCR) system installed on a ship, where the installation space is limited and the distance between the urea aqueous solution injection position and the reactor is low; therefore, the static mixer installed in this pipeline has special performance requirements. In particular, four evaluation indices are used in this study: The B value, C value, pressure loss correction factor (Z′), and the ratio of the required distance to the equivalent diameter of the pipe (LV/D) when the velocity field after the mixer attains uniformity. Six types of static mixers were simulated with varying concentrations, flow speeds, and positions. A fuzzy comprehensive evaluation method was introduced to evaluate and compare the related advantages and disadvantages. The results showed that 1) mixing performance was related to the shape of the mixer and had no direct relationship with flow velocity. 2) For the same mixer position, the lower the urea concentration, the greater the difficulty of evenly mixing the solution. 3) At a constant urea concentration, the mixing performance improved when the mixer was closer to the injection inlet. 4) The installation of a GK mixer in the SCR system of a 9L20C diesel engine was best. [ABSTRACT FROM AUTHOR]

Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments. In recent years, such methods have been widely used in metal mines where pipeline transportation typically plays a decisive role in the safety and stability of the entire filling system. Because the filling slurry contains a large percentage of solid coarse particles, the involved pipeline is typically eroded and often damaged during such a process. A possible solution is the so-called nesting repair technology. In the present study, nesting a 127 mm outer diameter pipeline in 151 mm inner diameter borehole is considered to meet the repair objective. First, by using the rheological theory, the pipeline transmission resistance and self-flow conveying range are calculated under different working conditions. It is shown that the pipeline transmission resistance is larger when the inner diameter of casing is 80 mm, and the limit flow rate of vertical pipeline self-flow is 120 m3/h; moreover, when the pipeline diameter is 100 mm and the flow rate is 140 m3/h, the self-flow conveying can be satisfied in most of the underground −455 m stage. Accordingly, a plan is presented for the nesting repair strategy, based on the installation of a drill bit under the casing and lowering the casing into the borehole as if it were a drill pipe. Finally, the outcomes of such a strategy are verified. The filling flow rate range using the new pipelines is found to be in the range from 188.60 to 224.39 m3/h, and its average filling flow rate reaches 209.83 m3/h when conveying 2319.6 m long-distance quarry. [ABSTRACT FROM AUTHOR]

This paper focuses on the performance of a braced deep excavation in soft soil based on field monitoring and numerical modeling. Laboratory tests were conducted to determine the soil parameters used in the modified Cam-Clay (MCC) model. Intelligent field monitoring means were adopted and a three-dimensional model was established. Spatial and temporal effects induced by the excavation are investigated for the deep-large foundation pit in soft soil. Deformation characteristics of the enclosure structure and the surrounding environment throughout the excavation process are presented. The behaviors of diaphragm walls, columns, the maximum wall deflection rate, ground surface settlement, and utility pipelines were focused on and investigated during the whole excavation process. Besides, the axial forces of the internal supports are analyzed. Based on the measured and simulated data, the following main conclusions were obtained: the numerical simulation results are in good agreement with the measured values, which proves the accuracy of the model parameters; the wall and the ground surface showed the maximum displacement increment at stage 9, which was a coupled product of the "creep effect" of the soft soil in Nanjing, China and the "depth effect" of the excavation; as the excavation progressed, the ground settlement changed from a "rising" to a "spoon-shaped" trend, dvm was measured between dvm = 0.0686%H and dvm = 0.1488%H; the rebound deformation curve of the pit bottom was corrugated, and the depth of disturbance of the pit bottom after the completion of soil unloading was 2-3 times the excavation depth; the closer the pipeline is to the corner of the pit, the less the excavation process will affect the settlement of the pipeline and the less the obvious pit corner effect will occur; the support strength of the buttress and the longest corner brace should be strengthened during the actual construction process to ensure the stability of the foundation deformation. [ABSTRACT FROM AUTHOR]

Purpose: Cleaning pigs made of highly elastic materials are used to remove contaminants from industrial gas pipelines. To ensure the movement of the pig in normal operation and narrow sections of the pipeline, it is necessary to generate the required gas pressure in the pig space. The study aims to establish the analytical conditions for the movement of a deformable pig in a cylindrical channel without stopping. Design/methodology/approach: A one-dimensional quasi-static model has been developed to analyse the frictional interaction of a moving deformable rod with a cylindrical pipe wall under conditions of uniform radial tightness. The normal contact is assumed to be dense, with no interfacial gas flow along the pig. Findings: Based on the solution of the formulated contact problem, the influence of frontal resistance, tension, friction, modulus of elasticity of the material and geometric dimensions of the rod on its stress state and on the value of pressure behind the pig required for the pig to pass through the pipeline without stopping is investigated. It is shown that an increase in the value of each factor leads to an increase in the driving gas pressure in the space behind the pig. Research limitations/implications: In the future, developing the proposed approach for the analytical modelling of pig motion in a pipe with variable narrowing is advisable. Practical implications: Recommendations for the design of deformable pigs for efficient gas pipeline cleaning are given. Originality/value: In analytical form, the dependences of the driving pressure on the key geometric and mechanical parameters of the process were found. [ABSTRACT FROM AUTHOR]

Stress corrosion cracking, similar to intergranular corrosion in austenitic steel welds, primarily affects grain boundaries in the heat-affected zone when exposed to a corrosive environment, leading to sensitization – a reduction in structural integrity, which causes cracking and grain loss. The object of research were samples cut out of «coils» of pipelines of the 3rd power unit of the Chernobyl NPP in the areas of damaged welded joints. Based on radiographic and ultrasonic inspection of pipeline welds, as well as determination in the examined samples of the content of alloying elements, mechanical properties, metallographic, fractographic and micro-X-ray spectral studies, including investigation of fracture surfaces of samples that were cyclically loaded, taking into account fatigue grooves, and with regard to solution of the problem of corrosion cracking of austenitic steels in boiling water reactors, a set of measures was developed: long-term measures – replacement of steels with others not prone to corrosion cracking; short-term measures – application of external weld coating, repair of defective areas, relieving residual stresses; temporary measures – justification of the admissibility of the defective weld for operation. [ABSTRACT FROM AUTHOR]

Subsea pipelines subjected to impacts are prone to generating significant deformations and residual stresses, which could reduce their structural integrity and increase the risk of failure. This paper introduces analytical and numerical frameworks aimed at predicting residual stress behavior induced by subsea pipeline impacts. An empirical formula to regulate residual stress levels in extensively deformed submarine pipelines is derived through a parameter-fitting method. This formula enables the swift and accurate computation of the residual stress magnitudes in such pipelines. Abaqus is employed to simulate the residual stresses in large-deformation submarine pipelines. The results of the finite element analysis are validated through experimental work. A comprehensive database is constructed via the finite element method to fit an empirical formula for residual stresses in large-deformation submarine pipelines. The empirical formula places particular emphasis on the influence of the diameter-to-thickness ratio and dent depth on the residual stresses. It is crucial for pipeline design and maintenance. [ABSTRACT FROM AUTHOR]

Aspect Sentiment Triplet Extraction (ASTE) is an essential task in fine-grained opinion mining and sentiment analysis that involves extracting triplets consisting of aspect terms, opinion terms, and their associated sentiment polarities from texts. While prevailing approaches primarily adopt pipeline frameworks or unified tagging schemes for this task, these methods tend to either overlook syntactic structural information and inherent semantic features, or lack explicit mechanisms for integration of syntax and semantics among the triplets’ elements. To overcome these shortcomings, we propose an Enhanced Multi-Encoder Network for ASTE with Syntax and Semantics (SynSem-ASTE). Our model innovatively incorporates syntactic information and semantic features derived from syntactic structures and attention weights, which is achieved through the design of a syntax encoder and a semantics encoder. Furthermore, we adopt a grid tagging scheme and an effective inference strategy to extract triplets simultaneously. Extensive evaluations on four benchmark datasets reveal that SynSem-ASTE not only achieves superior performance in terms of the primary metric F1-score, but also exhibits enhanced robustness against variations in model architecture. [ABSTRACT FROM AUTHOR]

This systematic review examines the prevalence, underlying mechanisms, cohort characteristics, evaluation criteria, and cohort types in white matter hyperintensity (WMH) pipeline and implementation literature spanning the last two decades. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we categorized WMH segmentation tools based on their methodologies from January 1, 2000, to November 18, 2022. Inclusion criteria involved articles using openly available techniques with detailed descriptions, focusing on WMH as a primary outcome. Our analysis identified 1007 visual rating scales, 118 pipeline development articles, and 509 implementation articles. These studies predominantly explored aging, dementia, psychiatric disorders, and small vessel disease, with aging and dementia being the most prevalent cohorts. Deep learning emerged as the most frequently developed segmentation technique, indicative of a heightened scrutiny in new technique development over the past two decades. We illustrate observed patterns and discrepancies between published and implemented WMH techniques. Despite increasingly sophisticated quantitative segmentation options, visual rating scales persist, with the SPM technique being the most utilized among quantitative methods and potentially serving as a reference standard for newer techniques. Our findings highlight the need for future standards in WMH segmentation, and we provide recommendations based on these observations. [ABSTRACT FROM AUTHOR]

A physical description is given of the formation of corrosion product deposits on the surfaces of pipelines of heat supply systems, and an investigation has been made into the effects of various factors on this process. An analysis has been made of the existing models of formation of corrosion deposites. A mathematical model has been developed for the formation of corrosion product deposites in the liquid's motion through pipelines of heat supply systems in the region of linear velocity of the growth of deposits at a constant temperature of the heat transfer agent. The model is based on equations of conservation of the mass of dissolved depolarizer and solid particles suspended in the solution. The parametric calculations performed on the basis of the developed mathematical model have shown a possibility for the existence of a maximum in the thickness of the corrosion product deposit layer through the pipe length. [ABSTRACT FROM AUTHOR]

Offshore structures are deployed extensively to harvest marine resources. Due to the harsh marine environments and heavy-duty working conditions, the risks associated with failure due to scour are high, and the need for accurate prediction of these risks is increasing. Often, pipelines and cables are critical elements of subsea energy transportation and telecommunication, and they are highly susceptible to scour-induced failure. The scour around spheres is relevant to the offshore industry as a simplified three-dimensional representation of subsea structures. This paper presents a numerical study, using FLOW-3D HYDRO, of the scour around on-bottom cylinders and spheres. Whereas most published research investigated scour around stationary solid objects, this paper presents numerical results of a more challenging case of scour around sagging cylinders and spheres. The model was validated against published experimental and numerical results. The scour depth was found to increase with the decrease of the sagging velocity of the solid object. For sagging horizontal cylinders, the scour depth reaches a plateau of 1.1 times the cylinder diameter when the dimensionless sagging velocity is smaller than 0.094. For sagging spheres, the maximum scour depth reaches 0.37 times the sphere diameter when the dimensionless sagging velocity is reduced to 0.0103. The findings provide guidelines for future research on more complicated interactions between flow, solid objects, and the seabed, accounting for the deformation of infrastructure over time. Practical Applications: This paper concerns the flow, sediment transport, and scour around horizontal cylinders and spheres undergoing slow downward motion, which resembles the sagging of on-bottom infrastructure under the influence of gravity and bed erosion. Offshore structures are deployed extensively to harvest marine resources. Pipelines and cables are critical subsea infrastructures that are susceptible to scour-induced failure. Spherical objects are commonplace in the offshore industry, so a sphere can be deemed as an idealized three-dimensional body. This paper provides detailed FLOW-3D simulations and developed empirical relationships between the dimensionless scour depth and dimensionless sagging speed. Most previous research considered only the scour around fixed objects, so this paper provides a novel addition to the existing knowledge on the scour phenomenon. The computational methods established in this study are useful for simulating more-complicated scenarios. The findings provide guidelines for more-realistic predictions of scour and for the design of scour mitigation measures. [ABSTRACT FROM AUTHOR]

This paper presents a pressure management technique for the reduction of leaks considering as a case study a branched water distribution system. The proposed technique is based on the detection and location of the leak using a genetic algorithm (GA) and pressure control using a Linear Quadratic Regulator (LQR). The validation of the proposed method uses measured pressure and flow data from a laboratory-scale water distribution system and its dynamic model. [ABSTRACT FROM AUTHOR]

Batch scheduling is a crucial part of pipeline enterprise operation management, especially in the context of market-oriented operation. It involves 3 main tasks: quickly preparing batch plans, accurately tracking interface movement, and operation condition in real time. Normally, the completion of multi-product pipeline batch scheduling depends on simulation models or optimization models and corresponding conventional solving algorithm. However, this approach becomes inefficient when applied to large-scale systems. The rapid development of machine learning has brought new ideas to batch scheduling research. This paper first reviews the current state of batch scheduling technology, and suggests that applying machine learning to it is a promising development direction. Then, we summarize the progress of machine learning applications in batch planning, interface movement tracking, and operational condition monitoring, and point out their limitations. Finally, considering the separation of refined oil production, transportation, and sales processes, 5 recommendations are put forward: oil supply and demand prediction and pipeline capacity prediction, batch planning, batch interface movement tracking, mixed oil development monitoring, and pipeline operation condition identification. [ABSTRACT FROM AUTHOR]

It is of paramount importance to ensure the safe operation of energy pipelines for pipeline owners and operators. Therefore, effective condition assessment of pipelines is imperative. For this purpose, there are a great number of models developed using various techniques. How to select a modeling approach and associated techniques to get the most of the effectiveness of the model under a condition with limited monitoring data and experience remains a big concern to pipeline operators. This paper provides a comprehensive review of the developed approaches and techniques for energy pipeline degradation condition assessment. The primary motivation behind this review is the pivotal role of condition assessment in energy pipeline integrity management and the proliferation of models and techniques, including statistical modeling, stochastic processes, machine learning, and deep learning, used for assessing pipeline degradation. This work aims to identify and assess the challenges and gaps inherent in the utilization of these condition modeling approaches. By systematically analyzing the current state of research and practice, this review not only highlights the strengths and limitations of various modeling approaches but also offers insights into future opportunities for enhancing the research and management practice in the field of pipeline integrity management. Our analysis offers valuable insights for researchers, practitioners, and policymakers in the domain of pipeline integrity management. It facilitates a better understanding of the complexities and intricacies of condition assessment, ultimately contributing to the development of more robust and effective strategies for safeguarding the integrity of energy pipelines. [ABSTRACT FROM AUTHOR]

A theory model with two kinds of material, which are used to describe the axis stress strain relationship of the pipe segment and girth weld joints, is proposed for the pipeline axial deformation analysis, and a pipeline deformation diagram is composed for the axis deformation combination within the pipeline design limit. According to the pipeline deformation diagram, it is found that the strength of the pipe segment at the design limit σAb plays a key role in the strength matching discussion. The pipeline axis deformation could be classified as three categories based on the yield strength σYw, ultimate tensile strength σcritw of the weld joints and the pipe design strength σAb, which are σYw>σAb, σcritw≥ σAb≥σYw and σAb>σcritw . For σYw>σAb, the axis plastic deformation will distribute along the pipe segment and this is the ideal states for the pipeline. For σAb>σcritw, the girth weld may fail as stress rupture with tensile strain as low as 0.003. For σcritw≥ σAb≥ σYw, the weld joint may endure the plastic deformation, and the material properties of the weld joint may change, such as the toughness may decrease. Charpy-V impact test have shown that the toughness decreases 35 % for 2 % deformation for the weld joints welded by FCAW-S. In this scenario, the girth weld may break up as brittle fracture due to the toughness decrease. This model could be used to explain the girth weld failures, optimize the strength matching and control the risk, especially for the buried high strength pipeline of the high stress locations. [ABSTRACT FROM AUTHOR]

Students enter the science, technology, engineering, and mathematics (STEM) pipeline in primary school, but leak out of it over time for various reasons. To prevent leaks, it is important to understand the variables that affect attitudes towards STEM learning from an early age. This study sought to examine the predictors of young students' STEM learning attitudes. In the study, 493 primary school students (Mage = 9.62, SD =.72) from a Turkish sample were reached through a survey. We recruited our participants using the convenience sampling technique. Data were collected with the STEM learning attitude scale, the Multidimensional 21st Century Skills Scale, and the Computational Thinking (CT) test. Descriptive and correlational analyses were performed on the data. Then the relationship between variables was tested with a structural equation modeling. The results of the analyses showed that STEM learning attitudes and CT skills of primary school students demonstrated good fit indexes. Also results showed that twenty-first century skills mediated the relationship between STEM learning attitudes and CT skills. The results of the analysis are discussed, and recommendations are presented in terms of strengthening young students' place in the STEM pipeline. [ABSTRACT FROM AUTHOR]