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Subsea pipelines operate in harsh marine environments, and corrosion is the major cause threatening their operational safety. In this paper, the failure pressure of pipelines with multiple corrosion defects under combined loadings is investigated. A finite-element model of a pipeline with multiple corrosion defects is developed, and this model is verified with experiments. The effect of defect depth, axial, and circumferential spacings between corrosion defects on the pipeline's residual strength is estimated. Furthermore, the failure pressure of a pipeline with multiple corrosion defects under combined loadings, such as internal pressure, axial pressure, and bending moment, is examined. This study aims to support the integrity management of subsea pipelines with multiple corrosion defects. [ABSTRACT FROM AUTHOR]

Underground hydrogen storage represents an innovative approach to energy storage. To ensure the secure operation of subterranean hydrogen storage strings, a computational fluid dynamics (CFD) methodology was employed to devise an erosion assessment model tailored for high-velocity conditions. The research delved into the erosion and abrasion dynamics of these storage strings when subjected to high-speed gas flows. This study further examined the impacts of gas velocity, particle size, pipe material, and pipe wall corrosion imperfections on flow patterns and erosion wear rates across the column. The outcomes revealed several noteworthy trends. As fluid velocity increased, the flow field's maximum pressure augmented, while it decreased alongside enlarging pipe diameter and particle size. P110 pipe material exhibited higher maximum pressure in comparison to N80. The effect of centrifugal force induced pressure to surge from the inner to the outer portion of the column. In the curved pipe section's outer wall, the frequent occurrence of high-angle collisions engendered elevated rates of erosion wear over time. Particularly noteworthy was the observation of the highest erosion rate in curved pipes showcasing three corrosion defects, attributed to the backflow effects of erosion pits. [ABSTRACT FROM AUTHOR]

Summary: The uncertainty of wind farm power and load both have a certain impact on the economic dispatch of the power system. First, this study deals with the fuzzy processing of power prediction error and load forecasting error of wind farms based on fuzzy random theory. On this basis, a multi‐objective fuzzy stochastic dispatch model of a power system with flexible load is established under the carbon trading mechanism. And, the nonlinear cost of flexible load response and the cost of carbon emission compensation is introduced to the multi‐objective function of the model. In addition, the fuzzy chance constraint of the spinning reserve is added to the constraint conditions. By introducing the variable, the fuzzy random dispatch model is transformed into a clear equivalent model. Finally, the discrete bacterial colony chemotaxis algorithm is used to process the model, and the optimal solution to the multi‐objective function is obtained by a compromise strategy based on a small degree of satisfaction. In the simulation, a classic IEEE10 system and a wind farm are taken as examples. The results show that compared with the other three traditional dispatch models, the total power generation cost is reduced by US$13 670, US$5610 and US$86 010, respectively using the model proposed in this article. [ABSTRACT FROM AUTHOR]

Hydrogen generation is with highly operational risk, and the catastrophic consequence may be caused as hydrogen is easily inflammable and explosive. It is of great importance to perform an effective risk assessment to ensure the operational safety of hydrogen generation unit. This paper presents a novel framework comprising of fuzzy DEMATEL implemented with TOPSIS to assess the comprehensive risk of hydrogen generation unit. This methodology is capable of capturing the interdependencies among different hazards, and prioritize the hazards in the decision-making process. An index-based risk assessment system is built by identifying hazards related to hydrogen generation. Subsequently, fuzzy DEMATEL is used to extract the interrelationships among risk indices and determine their weights, and TOPSIS model is utilized to prioritize hazards and calculate their risk values. Eventually, the risk of hydrogen generation unit is assessed by integrating the initial risk values with the weights of evaluation indices. The safety strategies based on assessment outcomes are developed to reduce the risk of hydrogen generation. A case study is used to test the practicability of the methodology, and it is observed that it can be a useful tool to risk assessment and management of hydrogen generation unit. • A novel methodology is proposed to assess the risk of hydrogen generation unit. • Fuzzy DEMATEL is employed to capture the interdependences among hazards. • TOPSIS is used to prioritize hazards and determine their risk values. [ABSTRACT FROM AUTHOR]

This paper performs a simulation and assessment of dispersion of natural gas containing hydrogen released from transmission pipeline using a Computational Fluid Dynamics (CFD) approach. A 3D CFD model is established to evaluate the dispersion behavior of hydrogen-enriched natural gas in the hydrogen-natural gas mixing station. The simulations include a matrix of scenarios for hydrogen doping ratios, gas release rates, wind speeds and wind directions. The development process of flammable gas cloud is predicted, and the dangerous area generated in the hydrogen-natural gas mixing station is assessed. Additionally, the effects of some critical factors on flammable gas dispersion behavior are analyzed. The simulations produce some useful outcomes including the parameters of flammable gas cloud and the dangerous area in the station, which are useful for conducting a prior risk assessment and contingency planning. • A 3D numerical model for dispersion of natural gas containing hydrogen is developed. • Effect of source and surrounding parameters on dispersion of gas mixtures is studied. • Distribution of flammable gas cloud in hydrogen-natural gas mixing station is presented. • Dangerous area generated on hydrogen-natural gas mixing station is assessed. [ABSTRACT FROM AUTHOR]

The most damaging disease affecting citrus globally is Huanglongbing (HLB), primarily attributed to the infection by ' Candidatus Liberibacter asiaticus' ( Ca Las). Based on comparative transcriptome data, two cellulose synthase (CESA) genes responsive to Ca Las infection induction were screened, and one gene cloned with higher differential expression level was selected and named CsCESA1 . we verified the interaction between CsCESA1 and citrus exopolysaccharide 2 (CsEPS2) proteins. Subcellular localization in tobacco indicated that both CsCESA1 and CsEPS2 proteins are primarily located in the nucleus and cytoplasm. RT-qPCR analysis indicated that the expression levels of CsCESA1 and CsEPS2 were associated with variety tolerance, tissue site, and symptom development. Furthermore, we generated CsCESA1 and CsEPS2 silencing plants and obtained CsCESA1 and CsEPS2 silencing and overexpressing hairy roots. The analysis of hormone content and gene expression also showed that CsCESA1 and CsEPS2 are involved in transcriptional regulation of genes involved in systemic acquired resistance (SAR) response. In conclusion, our results suggested that CsCESA1 and CsEPS2 could serve as potential resistance genes for HLB disease, offering insights into the plant's defense mechanisms against HLB.