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Unbonded flexible risers are widely applied to transport oil and gas resources from seabed to platform, and composite cylindrical layers are sometimes contained due to design requirements. Based on an 8-layer unbonded flexible riser model, the bending properties of the unbonded flexible risers with composite cylindrical layers are studied. A theoretical method of combining axisymmetric and bending loads acting on unbonded flexible risers is proposed, and a numerical method with detailed geometric characteristics taken into account is established for verification. The influence of two typical composite materials as well as the fibre volume fraction on the bending properties of the unbonded flexible risers is analyzed. The theoretical and the numerical results are in good agreement, which shows that the bending properties of the unbonded flexible risers are greatly affected by the axial Young’s modulus of the composite cylindrical layers, and composite material with larger axial Young’s modulus would greatly enhance the bending stiffness of the unbonded flexible risers, expecially in the full-slipping stage. In addition, the axial tensile stiffness and bending stiffness of full-slipping stage are proportional to the fibre volume fraction of the composite cylindrical layers.

Stiffened panel is a typical strength member in ships. Considering the change of material properties under the action of fire and high temperature, according to the thermal elastic-plastic finite element theory, based on the nominal temperature-time curve, the protective effect of the passive fire protection layer on the high temperature response characteristics and the residual strength of the stiffened panel and the influence of coating positions on the failure mode of the stiffened panel are studied, which provides reference for structural performance evaluation and structural fire protection design. Numerical analyses indicate that passive fire protection layer can effectively slow down the increase of stress and deformation induced by temperature rise. Overall coating does not change the failure mode of the overall buckling of the structure accompanied by the tripping of the stiffener, but significantly delays the failure time and has an obvious effect on maintaining residual ultimate strength. Partial coating will change the failure characteristics of the structure. Overall failure occurs when only the plate is coated, and beam-column failure occurs when only the stiffener is coated, accompanied by local buckling of the web. Overall coating shows the best protective performance on the residual strength of the stiffened panel, followed by plate coating. Stiffener coating, however, has a weak protective effect. The protection performance mainly depends on the heating and failure mode of the structure.

The blast wall is an important protection facility for offshore platforms, whose anti-explosion performance needs to be focused on. Based on the nonlinear finite element method, the structural dynamic response of the blast wall under the explosion at normal temperature was studied. The applicability of the quasi-static and dynamic algorithms was compared with the experimental data, and the structural impact deformation forms at room temperature were analyzed. Considering the effects of high temperature on materials and structures, the structural dynamic response characteristics of the blast wall were analyzed. The study shows that the high temperature has a significant aggravating effect on structural response. That is, given the load level, the maximum displacement can reach 5 times of that at normal temperature. Under the impact of normal temperature load, the structural strain is elastic with no permanent deformation or with small deformation, but it may aggravate to huge permanent deformation at a high temperature. The effect of high temperature will change the response pattern of the structure. This research can provide reference for the design of blast wall.

The measurement of pig weight holds significant importance for producers as it plays a crucial role in managing pig growth, health, and marketing, thereby facilitating informed decisions regarding scientific feeding practices. On one hand, the conventional manual weighing approach is characterized by inefficiency and time consumption. On the other hand, it has the potential to induce heightened stress levels in pigs. This research introduces a hybrid 3D point cloud denoising approach for precise pig weight estimation. By integrating statistical filtering and DBSCAN clustering techniques, we mitigate weight estimation bias and overcome limitations in feature extraction. The convex hull technique refines the dataset to the pig's back, while voxel down-sampling enhances real-time efficiency. Our model integrates pig back parameters with a convolutional neural network (CNN) for accurate weight estimation. Experimental analysis indicates that the mean absolute error (MAE), mean absolute percent error (MAPE), and root mean square error (RMSE) of the weight estimation model proposed in this research are 12.45 kg, 5.36%, and 12.91 kg, respectively. In contrast to the currently available weight estimation methods based on 2D and 3D techniques, the suggested approach offers the advantages of simplified equipment configuration and reduced data processing complexity. These benefits are achieved without compromising the accuracy of weight estimation. Consequently, the proposed method presents an effective monitoring solution for precise pig feeding management, leading to reduced human resource losses and improved welfare in pig breeding. [ABSTRACT FROM AUTHOR]

Background: Accumulating evidence suggests inhibiting neuroinflammation as a potential target in therapeutic or preventive strategies for Alzheimer's disease (AD). MAPK-activated protein kinase II (MK2), downstream kinase of p38 mitogen activated protein kinase (MAPK) p38 MAPK, was unveiled as a promising option for the treatment of AD. Increasing evidence points at MK2 as involved in neuroinflammatory responses. MMI-0100, a cell-penetrating peptide inhibitor of MK2, exhibits anti-inflammatory effects and is in current clinical trials for the treatment of pulmonary fibrosis. Therefore, it is important to understand the actions of MMI-0100 in neuroinflammation. Methods: The mouse memory function was evaluated using novel object recognition (NOR) and object location recognition (OLR) tasks. Brain hippocampus tissue samples were analyzed by quantitative PCR, Western blotting, and immunostaining. Near-infrared fluorescent and confocal microscopy experiments were used to detect the brain uptake and distribution after intranasal MMI-0100 application. Results: Central MMI-0100 was able to ameliorate the memory deficit induced by Aβ 1-42 or LPS in novel object and location memory tasks. MMI-0100 suppressed LPS-induced activation of astrocytes and microglia, and dramatically decreased a series of pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β, COX-2, and iNOS via inhibiting phosphorylation of MK2, but not ERK, JNK, and p38 in vivo and in vitro . Importantly, one of the reasons for the failure of macromolecular protein or peptide drugs in the treatment of AD is that they cannot cross the blood-brain barrier. Our data showed that intranasal administration of MMI-0100 significantly ameliorates the memory deficit induced by Aβ 1-42 or LPS. Near-infrared fluorescent and confocal microscopy experiment results showed that a strong fluorescent signal, coming from mouse brains, was observed at 2 h after nasal applications of Cy7.5-MMI-0100. However, brains from control mice treated with saline or Cy7.5 alone displayed no significant signal. Conclusions: MMI-0100 attenuates Aβ 1-42 - and LPS-induced neuroinflammation and memory impairments via the MK2 signaling pathway. Meanwhile, these data suggest that the MMI-0100/MK2 system may provide a new potential target for treatment of AD., (Copyright © 2019 Jiang, Wang, Liang, Nie, Chang, Xue, Li and Min.)