Tensile behaviour of pitting corroded steel bars:Laboratory investigation and probabilistic-based analysis

Localised corrosion in steel bars has been a long-standing issue in the durability of reinforced concrete structures, but a comprehensive scheme for the analysis of pitting corroded steel bars, especially with respect to the deformation capacity, is not currently available. In this study, the morphological characteristics of 27 pitting steel bars were captured using a 3D scanner. The measured data were used to establish the probability distribution model of the cross-sectional areas of the corroded bars. Uniaxial tensile tests were conducted, and the evolving deformation field of the corroded bars was recorded through Digital Image Correlation (DIC). Based on the 3D reconstructed model and DIC results, an analytical method for evaluating the mechanical properties of pitting steel bars was developed and validated. The results show that the two-component Gaussian mixture distribution model outperforms conventional unimodal distribution models. Comparison of the analytical results with experimental data demonstrates that the proposed procedure is capable of predicting not only the ultimate strength but also the gauge length-dependent ultimate strain of corroded bars. Additionally, there exists a strengthening effect in the ultimate stress at the critical sections and this effect should not be ignored for accurate predictions.</p

Progress in deep shale gas engineering technology in Weirong gas field in southern Sichuan

Weirong gas field is the first deep shale gas field in China, with the characteristics of "deep burial depth, thin high-quality reservoirs, high ground stress, high horizontal stress difference, high plasticity and high formation pressure". The engineering technologies of drilling, completion, fracturing, and drainage face challenges such as long drilling cycles, small renovation volumes, low complexity, and complex wellbore flow laws. In response to complex geological challenges, we continuously enhance geological understanding, deeply integrate gas reservoir geology and engineering technology, and continue to research the drilling and production engineering technology with the goal of reducing costs and increasing efficiency and breaking through the benefits of deep shale gas. After three rounds of exploration and optimization of drilling technology, we strengthen and improve mechanical drilling speed, reduce downhole complexity, and shorten drilling cycles. The optimization of fracture configuration in fracturing technology has increased the breadth of complex fractures, and the integration of large displacement expansion and high sand carrying has achieved the increase and support of fracture control volume. The drainage process is based on gas-liquid two-phase flow research to identify wellbore flow patterns, forming a decision-making method for the entire lifecycle drainage process. Finally, an engineering technology sequence focusing on "fine trajectory control for optimal and fast drilling", "balanced expansion of fractures for strong support fracturing", and "full cycle effective drainage" was formed, continuously promoting the process of benefit deve-lopment. With the deep shale gas development engineering technology proposed herein, an accumulated new production capacity of 2.5 billion cubic meters in Weirong gas field has been completed, providing valuable experience for deep shale gas engineering technology at home and abroad, as well as a direction for further exploration and research in ultra-deep shale gas development

Methylparaben as a preservative in the development of a multi-dose HPV-2 vaccine

The human papillomavirus (HPV) vaccine is the simplest, most economical, convenient, and effective method of preventing cervical cancer. However, the current HPV vaccine is supplied as a single-dose vial with a relatively high cost per dose, which hinders its supply to low- and middle-income countries (LMICs), where the demand for HPV vaccine is highest. Therefore, it is necessary to develop a multi-dose HPV vaccine to promote large-scale affordable vaccination in LMICs. Moreover, the addition of preservatives is required to reduce the risk of microbial contamination in multi-dose vaccines within a single vial. In this study, we investigated the effects of six preservatives on HPV 16L1 and 18L1 virus-like particles in solution, as well as the aluminum adsorption status, under normal and high-temperature conditions. Multiple methods were employed, including dynamic light scattering, differential scanning calorimetry, an in vitro relative potency assay, and an in vivo potency assay in mice. Based on the above results, four types of selected preservatives were further studied, and an antimicrobial effectiveness test was performed on the HPV-2 vaccine, which was employed as a model HPV vaccine. Finally, three preservatives were selected based on their performance to evaluate the long-term stability of the HPV-2 vaccine. The results indicated that 0.12% methylparaben is the most suitable preservative for the multi-dose HPV-2 vaccine, guaranteeing the shelf life for at least three years and meeting “B” standards for antimicrobial effectiveness. The formula developed in this study can contribute toward combating cervical cancer in LMICs

TEMPO-Oxidized Cellulose with High Degree of Oxidation

In this paper, water-soluble 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose with a high degree of oxidation was prepared by a two-step process using bamboo dissolving pulp. The first step was to destroy the cellulose crystal I by NaOH/urea solution to obtain cellulose powder with decreased crystallinity. The second step was to oxidize the cellulose powder by TEMPO oxidation. The TEMPO-oxidized cellulose was analyzed by Fourier transform infrared spectroscopy (FTIR), conductimetry, X-ray diffraction (XRD), fiber analyzer, and transmission electron microscopy (TEM). FTIR showed that the hydroxymethyl groups in cellulose chains were converted into carboxyl groups. The degree of oxidation measured by conductimetry titration was as high as 91.0%. The TEMPO-oxidized cellulose was soluble in water for valuable polyelectrolytes and intermediates

DS-Depth: Dynamic and Static Depth Estimation via a Fusion Cost Volume

Self-supervised monocular depth estimation methods typically rely on the reprojection error to capture geometric relationships between successive frames in static environments. However, this assumption does not hold in dynamic objects in scenarios, leading to errors during the view synthesis stage, such as feature mismatch and occlusion, which can significantly reduce the accuracy of the generated depth maps. To address this problem, we propose a novel dynamic cost volume that exploits residual optical flow to describe moving objects, improving incorrectly occluded regions in static cost volumes used in previous work. Nevertheless, the dynamic cost volume inevitably generates extra occlusions and noise, thus we alleviate this by designing a fusion module that makes static and dynamic cost volumes compensate for each other. In other words, occlusion from the static volume is refined by the dynamic volume, and incorrect information from the dynamic volume is eliminated by the static volume. Furthermore, we propose a pyramid distillation loss to reduce photometric error inaccuracy at low resolutions and an adaptive photometric error loss to alleviate the flow direction of the large gradient in the occlusion regions. We conducted extensive experiments on the KITTI and Cityscapes datasets, and the results demonstrate that our model outperforms previously published baselines for self-supervised monocular depth estimation

Investigating the mechanism of Sinisan formula in depression treatment: a comprehensive analysis using GEO datasets, network pharmacology, and molecular docking

The herbal formula Sinisan (SNS) is a commonly used treatment for depression; however, its mechanism of action remains unclear. This article uses a combination of the GEO database, network pharmacology and molecular docking technologies to investigate the mechanism of action of SNS. The aim is to provide new insights and methods for future depression treatments. The study aims to extract effective compounds and targets for the treatment of depression from the T CMSP database. Relevant targets were searched using the GEO, Disgenet, Drugbank, PharmGKB and T T D databases, followed by screening of core targets. In addition, GO and KEGG pathway enrichment analyses were performed to explore potential pathways for the treatment of depression. Molecular docking was used to evaluate the potential targets and compounds and to identify the optimal core protein-compound complex. Molecular dynamics was used to further investigate the dynamic variability and stability of the complex. The study identified 118 active SNS components and 208 corresponding targets. Topological analysis of P P I networks identified 11 core targets. GO and KEGG pathway enrichment analyses revealed that the mechanism of action for depression involves genes associated with inflammation, apoptosis, oxidative stress, and the MAP K3 and P I3K-Akt signalling pathways. Molecular docking and dynamics simulations showed a strong binding affinity between these compounds and the screened targets, indicating promising biological activity. The present study investigated the active components, targets and pathways of SNS in the treatment of depression. Through a preliminary investigation, key signalling pathways and compounds were identified. These findings provide new directions and ideas for future research on the therapeutic mechanism of SNS and its clinical application in the treatment of depression. Communicated by Ramaswamy H. Sarma</p