The process monitoring method for industrial production can technically achieve early warning of abnormal situations and help operators make timely and reliable response decisions. Because practical industrial processes have multimodal operating conditions, the data distributions of process variables are different. The different data distributions may cause the fault detection model to be invalid. In addition, the fault diagnosis model cannot find the correct root cause variable of system failure by only identifying abnormal variables. There are correlations between the trend states of the process variables. If we do not consider these correlations, this may result in an incorrect fault root cause. Therefore, multimodal industrial process monitoring is a tough issue. In this paper, we propose a three-step framework for multimodal industrial process monitoring. The framework aims for multimodal industrial processes to detect the faulty status timely and then find the correct root variab... [more]

The thermal recovery method of steam flooding is one of the most common development methods for heavy oil reservoirs. However, after multiple rounds of steam injection development, the composition of crude oil and reservoir rock properties have changed greatly, which is unfavorable for the subsequent enhanced oil recovery. It is necessary to study the distribution of the remaining oil after the thermal recovery of heavy oil reservoirs, and clarify the change characteristics of the components of the crude oil under different steam injection conditions. At the same time, the change of porosity and the permeability of the rocks after steam flooding, and its influence on oil recovery, are investigated. In this paper, the composition changes of heavy oil before and after steam flooding are studied through experiments and numerical simulation methods. A numerical model is established to study the retention characteristics of heavy components in heavy oil reservoirs by the CMG software. The e... [more]

To study the mechanical behavior and energy evolution law of gas-filled deep coal, conventional triaxial compression experiments under different confining pressure and gas pressure conditions and cyclic loading and unloading experiments under different gas pressures were carried out. The failure characteristics and mechanical parameters evolution of two loading modes were analyzed. In addition, the energy density and ratio evolution law under cyclic loading was revealed, and based on these findings, an attempt was made to depict the relation of cumulative dissipated energy density and volumetric strain by fitting the experimental data. The results indicated that failure of coal is expressed as a single shear surface under conventional compression, while under cyclic loading mode, coal behaves with multi-fracture crushing failure. Mechanical parameters showed a trend of decay with increasing gas pressure, and that cyclic loading and unloading increases the bearing capacity of coal by 8−... [more]

Object recognition and tracking is a challenge for underwater vehicles. Traditional algorithm requires a clear feature definition, which suffers from uncertainty as the variation of occlusion, illumination, season and viewpoints. A deep learning approach requires a large amount of training data, which suffers from the computation. The proposed method is to avoid the above drawbacks. The Siamese Region Proposal Network tracking algorithm using two weights sharing is applied to track the target in motion. The key point to overcome is the one-shot detection task when the object is unidentified. Various complex and uncertain environment scenarios are applied to evaluate the proposed system via the deep learning model’s predictions metrics (accuracy, precision, recall, P-R curve, F1 score). The tracking rate based on Siamese Region Proposal Network Algorithm is up to 180 FPS.

With the aim of determining the influence of the fluid−structure coupling dynamic effect of the oil and gas transmission medium and pipeline on the seismic response, an oil pipeline supported by a cable-stayed spanning structure was taken as the study object. Kinetic equations taking into account the action of oil and gas medium were studied, and a finite element model structure considering the additional-mass method and the fluid−structure coupling effect were established separately. In addition, the mechanism of the oil−gas−pipeline coupling action on the seismic response of pipeline structure was analyzed, and the results were obtained. The results show that the pipeline has a minimal seismic response at the abutment location, the seismic response gradually increases along the abutment to the main tower, and the seismic response reach is maximized at about one-fifth of the bridge platform. The seismic response of the oil and gas pipeline model structure using the additional-mass met... [more]

When designing crash absorber particles for application as a filling material in the double-hull of ships, the main goal is to achieve an optimal mechanical performance, in combination with a low-density particle structure, while fulfilling several additional requirements regarding, for example, non-toxic and hydrophobic behavior. In this study, a fluidized bed was used to coat Poraver® glass particles with Candelilla wax and silicone to attain these specifications. A uniform coating was achieved with wax, but the process turned out to be far more challenging when using silicone. To evaluate the suitability of coated particles as a granular filling material, and to compare their performances with that of untreated Poraver® particles, several mechanical tests, as well as structural investigations, were conducted. While no notable improvement in mechanical behavior was observed on the single-particle level, bulk tests showed promising results regarding compressibility and abrasion resist... [more]

To improve the efficiency of loading operation by researching the optimization of the pre-marshalling operation scheme in the export container block between the time when the ship stowage chart was published and the beginning time of loading, a two-stage mixed integer programming model was established. The first stage established an optimization model of the container reshuffling location, based on the objective function of the least time-consuming operation of a single-bay-yard crane, and designed an improved artificial bee colony algorithm to solve it. Based on the first stage, an optimization model of yard crane configuration and scheduling was built to minimize the maximum completion time of the yard crane in the export block, and an improved genetic algorithm was designed to solve the built model. Through comparative analysis, the performance of our algorithm was better than CPLEX and traditional heuristic algorithms. It could still solve the 30 bays quickly, and the solving quali... [more]

Hydraulic fracturing is an important measurement for the stimulation of oil and gas wells and is widely used in the development of low-permeability and ultra-low-permeability reservoirs. However, fractures can pass through barriers with poor properties during fracturing, resulting in fractures that do not reach the pre-designed length. In a worse situation, it is possible to communicate with the water layer and cause sudden water flooding, resulting in the failure of the fracturing construction. In order to improve the efficiency of fracturing construction, an effective way to control the height of fractures is by laying diverting agents to form artificial barriers. In this study, we established a three-dimensional numerical calculation model of fracture propagation, considering artificial barriers in the finite element analysis framework; the fracture propagation is governed by a cohesive zone model. The influence of artificial barriers with different Young’s modulus and different per... [more]

The demand for products based on natural ingredients is increasing among cosmetic and textile consumers. Cork extracts contain components of interest with special properties, including antioxidant, anti-inflammatory, and antibacterial activities, that might improve the effectiveness of cosmetic formulations currently on the market and may impart new characteristics to textiles. The main goal of this work was to investigate the effect of the incorporation of three cork extracts into two commercial cosmetic formulations (formulation A and B) and evaluate their role as textile dyeing agents. The extracts (E1, E2, and E3) were obtained from cork powder using natural deep eutectic solvents (NADES) (E1-NADES 1: lactic acid:glycerol, E2-NADES 2: lactic acid:glycine, and E3-NADES 3: lactic acid:sodium citrate) and applied in combination with the solvent. The impact of the extracts on the cosmetic formulations’ properties was evaluated in terms of pH, viscosity, antioxidant activity, transderma... [more]

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To improve the hydraulic performance of a new type of dishwasher pump and solve the multi-parameter optimization problem, a genetic algorithm was introduced to optimize the special design of the twin-volute structure. Six curvature radii of the twin-volute structure were defined as the optimization parameters, and 100 groups of design samples were generated based on the Latin hypercube sampling (LHS) method. The pump head and the efficiency were taken as the optimization objectives, i.e., to improve the efficiency as much as possible while ensuring that the head would not be lower than 2 m. The important parameters were identified via sensitivity analysis, and the optimization problem was solved in detail by using the multi-objective genetic algorithm (MOGA). The results showed that the external profile of the first to the fourth section of the twin-volute structure had the most significant effect on the pump head and efficiency. The response surface method (RSM) was used to select the... [more]

The stress wave generated by impact or dynamic load will produce significant reflection and transmission at the rock coal or rock interface during the propagation process. This will produce dynamic effects such as dynamic tensile, stress superposition and mutation. These dynamic effects will lead to obvious vibration at the interfaces, which is a key factor leading to dynamic damage and the failure of coal and rock mass. In the process of underground engineering excavation, the dynamic damage of a series of layered rock masses is one of the important factors causing geological disasters. Based on the two−dimensional similar material simulation experiment, the coal and rock mass combined of five layers of fine sandstone, medium sandstone, coal, coarse sandstone and mudstone was taken as the research object, and single and multi-point excitation (synchronous/step-by-step) were used to test the time−history vibration curves of rock−coal and rock−rock interfaces under impact load. It was c... [more]

As a particular kind of detection technology under weak magnetization, metal magnetic memory testing is very likely to be affected by external factors in the detecting process, which may lead to incorrect results. In order to minimize the negative influence of interrupting signals and improve the detection accuracy, this paper adopted the enhanced metal magnetic memory testing method to preliminarily increase the signal-to-noise ratio (SNR) of the detection signal and then compares the denoising effects of wavelet threshold denoising method, empirical mode decomposition (EMD) denoising method, EMD-wavelet threshold denoising method, ensemble EMD (EEMD), complementary EEMD (CEEMD), variational mode decomposition (VMD), local mean decomposition (LMD) and empirical wavelet transform (EWT) on the detection signal and the gradient signal respectively. The results show that the enhanced metal magnetic memory testing method can significantly increase the SNR of the obtained signal and cannot... [more]

Based on signal decomposition, a tractor engine state recognition method is proposed to explore the degree of information recognition of vibration signals at measurement points at different distances from the engine and the degree of correlation in different directions. The accuracy of engine operating state information recognition was obtained by analyzing the vibration signals of the tractor at different measurement points. The main contents are as follows: Based on variational mode decomposition (VMD), the modal component, which includes the state information, was obtained by measuring the vibration signal of the tractor at each measurement point under different driving conditions, and the exogenous excitation of the tractor under different road conditions was simulated by changing the tire pressure. Then, the state characteristics of the modal component were quantified based on permutation entropy (PE), and the correlation coefficient was used as the evaluation index to select the... [more]

Green synthesized silver nanoparticles (AgNPs) have been used against antibiotic-resistant bacteria and chemo-resistant cancer cells. We synthesized AgNPs from Acacia nilotica pods, evaluating their antibacterial activity against eight bacterial strains and anticancer efficiency against two colon cancer cell lines, SW620 and SW480. Expression levels of eight genes (β-catenin, APC, TP53, Beclin1, DKK3, Axin, Cyclin D1, and C-myc) were checked by a reverse transcription-polymerase chain reaction in cancer cells before and after treatment with A. nilotica extract and A. nilotica-AgNPs. Prepared nanoparticles were characterized through ultraviolet-visible (UV-vis), Zetasizer, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FTIR) was used to identify the functional group in extracts. At first, AgNPs were confirmed by a sharp peak of surface plasmon resonance at 375 nm. The Z-average size was 105.4 nm with a polydispers... [more]

The present work is in the framework of water resource control and optimization. Specifically, an advanced process control system was designed and implemented in a hydroelectric power plant for water management. Two reservoirs (connected through a regulation gate) and a set of turbines for energy production constitute the main elements of the process. In-depth data analysis was carried out to determine the control variables and the major issues related to the previous conduction of the plant. A tailored modelization process was conducted, and satisfactory fitting performances were obtained with linear models. In particular, first-principles equations were combined with data-based techniques. The achievement of a reliable model of the plant and the availability of reliable forecasts of the measured disturbance variables—e.g., the hydroelectric power production plan—motivated the choice of a control approach based on model predictive control techniques. A tailored methodology was propose... [more]

SSCN is a new type of self-sensitive photocatalyst. It consists of oxygenated carbon nitride-containing microspheres inside and polymerized triazine dye (TBO) formed on its surface by in situ polymerization. The presence of TBO endows SSCN with a wide range of optical responses. However, the TBO would self-degrade under light, making SSCN extremely unstable in photocatalytic reactions and limiting the practical application of SSCN. The introduction of phosphorus into the structure of SSCN significantly improved the electron−hole separation efficiency and reduced the self-degradation of surface TBO. Phosphorus-doped self-sensitive carbon nitride microspheres (P-SSCN) are easily synthesized by a one-pot solvothermal method—the phosphorus source was added to the precursor solution of SSCN. This resulting material was used for the photodegradation of tetracycline hydrochloride (TC-HCl) for the first time, giving improved visible light sensitivity and high stability in the photocatalytic pr... [more]

With the increasing population worldwide, the consumption of fossil energy is grows to be enormous [...]

TG-FTIR and PY-GC/MS were used to analyze the pyrolysis behaviors of pine wood, urea-formaldehyde resin (UF resin) and their blended pellets. The pyrolysis process was divided into three stages: water evaporation, devolatilization and pyrolysis residue decomposition. During the pyrolysis process of the blended pellets, with the increase of the addition ratio of UF resin, the peak value of the weight loss decreased in the decomposition stage of the pyrolysis residue, while the temperature shifted to the low-temperature region. This was mainly due to the structural stability of pyrolytic carbon produced by UF resin, which hindered the thermal decomposition of lignin-produced residues in pine. FTIR showed that CO2 was the main product of pyrolysis. For UF resin, nitrogen compounds accounted for a large proportion. With the addition of UF resin, the nitrogen in the blended pellets increased significantly. Since the synergistic effect promoted the further decomposition of the organic oxygen... [more]

Since the electronic power conditioner (EPC) is a crucial part of a space traveling-wave tube amplifier (STWTA), its reliability issue must be considered. The most effective way to prevent insulation breakdown is potting. Silicone elastomers are commonly used as an encapsulant for the EPC because of their good physical and electrical properties. The properties of the encapsulant and the interfaces change under the influence of γ-radiation, which may result in the failure of the potted modules. In this work, a comprehensive evaluation methodology is proposed for silicone-based potted modules, where besides physical and electrical properties, the effect of γ-radiation on the encapsulated interface is also considered. The results show that with the increase of the irradiation dose, the crosslinking density, hardness, elastic modulus, volume resistivity, dielectric constant, and storage modulus are increased by 301.6%, 76.3%, 289.7%, 396.1%, 5.0%, and 589.8%, respectively. In contrast, the... [more]

This study aims to provide a comprehensive overview of risk management research developments in the energy sector by using bibliometric analysis techniques. We apply the SciMAT bibliometric analysis software to understand how the intellectual base of this topic has evolved over time and what the major themes are that have contributed to this evolution. We analyse 679 publications referenced in the Web of Science Core Collection and Scopus to map the content of publications on risk management research in the energy sector over a period of 30 years (1993−2022), following the methodical rigour of PRISMA (Preferred Reporting Items for Systematic and Meta-Analyses). Our results identify and support the evolution of risk management research in the energy industry, its interactions, its stability, and changes in its research network. Our work contributes to the current debate on identifying trends and enhancing understanding of the evolution in the energy sector from the perspective of risk m... [more]

Since the 1950s, major breakthroughs have been made in the field of carbonate oil and gas exploration, and large reservoirs have been found in carbonate strata in many countries; however, the validity of highly evolved carbonate source rocks has been controversial. Because of the loss of organic carbon during acid-solution processing in conventional total organic carbon (TOC) determination, we decided to use a new method of reducing acid-solution losses in order to more effectively quantify acid-soluble organic matter in carbonate rock samples. Different levels of acid-soluble organic matter were present in different types of samples, and there was no positive correlation between the content of acid-soluble organic matter and conventionally measured TOC values. However, the thermal evolutionary maturity of samples with high acid-soluble organic matter content is relatively low, and the high hydrocarbon generation conversion rate of acid-soluble organic matter and conventional TOC in ca... [more]

Various experiments, including routine petrophysical measurements, thin section and scanning electronic microscope (SEM), high-pressure mercury intrusion (HPMI), and nuclear magnetic resonance (NMR), were performed to characterize the microscopic pore structure of tight sandstone in the Huagang Formation (E3h), Xihu Sag, East China Sea Basin, China. Specifically, NMR was used to investigate the dynamic variation of fractal dimensions during centrifugation, and the comparison of HPMI and NMR were used to clarify the difference of fractal dimensions. The results showed that there were four types of pores observed in thin section and SEM images: primary intergranular pores, intergranular dissolution pores, intragranular dissolution pores, and micropores within clay aggregates. The geometric shape and pore size of different pore types showed huge differences, indicating the formation of complex and diverse pore structures in the E3h formation. The flow capability of the reservoir was domin... [more]

Electrical resistance is among the characteristics that fastening systems must meet to ensure the proper functioning of signaling systems in railway infrastructure. The EN 13146-5:2012 standard specifies a laboratory testing method for determining the electrical resistance under wet conditions between running rails provided by a fastening system on steel or concrete sleepers. In urban railway tracks, the electrical resistance of fastening systems affects the stray current; however, there is no standardized electrical resistance measuring method. There is also no definition for the minimum value that the electrical resistance of fastening systems must satisfy to prevent stray currents. For this reason, this paper analysis the possibility of using the standard EN 13146-5:2012 for the measurement and analysis of the electrical resistance of fastening systems in urban railway tracks. In this study, the electrical resistance of different fastening systems used in urban railway tracks was me... [more]

With the increasing demand of the power industry for load forecasting, improving the accuracy of power load forecasting has become increasingly important. In this paper, we propose an ultra short-term power load forecasting method based on similar day clustering and EEMD (Ensemble Empirical Mode Decomposition). In detail, the K-means clustering algorithm was utilized to divide the historical data into different clusters. Through EEMD, the load data of each cluster were decomposed into several sub-sequences with different time scales. The LSTNet (Long- and Short-term Time-series Network) was adopted as the load forecasting model for these sub-sequences. The forecast results for different sub-sequences were combined as the expected result. The proposed method predicts the load in the next 4 h with an interval of 15 min. The experimental results show that the proposed method obtains higher prediction accuracy than other comparable forecasting models.