4 research outputs found
Adjacent Slice Feature Guided 2.5D Network for Pulmonary Nodule Segmentation
More and more attention has been paid to the segmentation of pulmonary
nodules. Among the current methods based on deep learning, 3D segmentation
methods directly input 3D images, which takes up a lot of memory and brings
huge computation. However, most of the 2D segmentation methods with less
parameters and calculation have the problem of lacking spatial relations
between slices, resulting in poor segmentation performance. In order to solve
these problems, we propose an adjacent slice feature guided 2.5D network. In
this paper, we design an adjacent slice feature fusion model to introduce
information from adjacent slices. To further improve the model performance, we
construct a multi-scale fusion module to capture more context information, in
addition, we design an edge-constrained loss function to optimize the
segmentation results in the edge region. Fully experiments show that our method
performs better than other existing methods in pulmonary nodule segmentation
task
Steel Slag Decorated with Calcium Oxide and Cerium Oxide as a Solid Base for Effective Transesterification of Palm Oil
For further resource utilization of solid waste steel slag and the reduction in biodiesel production costs, this study used steel slag as a carrier to synthesize a CaO-CeO2/slag solid base catalyst for the effective transesterification of palm oil into fatty acid methyl esters (FAMEs). The synthesis involved a two-step impregnation of steel slag with nitrate of calcium and cerium and thermal activation at 800 °C for 180 min. Then, the catalysts’ textural, chemical, and CO2 temperature-programmed desorption properties were characterized. The catalytic activity depended highly on the ratio of Ca-Ce to steel slag mass; the CaO-CeO2/slag-0.8 catalyst showed outstanding performance. Characterization showed that the surface area and total basicity of the Ca-Ce/slag-0.8 catalyst were 3.66 m2/g and 1.289 mmol/g, respectively. The reactivity results showed that FAMEs obtained using 7 wt.% catalyst, 9:1 of methanol-to-palm-oil molar ratio, 180 min reaction duration, and 70 °C reaction temperature was optimum (i.e., 95.3% yield). In addition, the CaO-CeO2/slag-0.8 catalyst could be reused for at least three cycles, retaining 91.2% of FAMEs yield after n-hexane washing. Hence, the catalyst exhibits an excellent potential for cost-effective and environmentally friendly biodiesel production
Eccentric Compressive Behavior of Round-Ended Rectangular Concrete-Filled Steel Tubes with Different Central Angles
The application of round-ended rectangular concrete-filled steel tubes (RRCFSTs) in high-rise buildings or bridge structures is increasing, improving structural performance and meeting aesthetic requirements. Researching this novel steel–concrete composite helps to fully utilize the properties of the materials. In this study, 15 specimens were tested for analysis of the behaviors of RRCFSTs with different central angles under eccentric compression. Influences of central angles of round ends (θ), aspect ratios of rectangular parts (κ), steel strength and the eccentric ratio on failure modes, material utilization, confinement effect and eccentric bearing capacity are studied. Besides, the mechanism of confinement effects of steel tubes with different θ values was evaluated with the finite element method (FEM). The results show that local buckling usually occurs at the compression zone. When θ gradually changes from 0° to 180°, the local buckling position of straight steel plate changes from mid-length to both ends of the columns. Additionally, the interfacial stress between steel tube and concrete at round ends rises, but that at the corner, it decreases continuously, which results in an improved overall confinement effect and increased material utilization. In contrast, a larger κ leads to lower material efficiency because of the reduced overall confinement effect. The increases in both θ and κ enlarge the cross-sectional area and the eccentric ultimate bearing capacity, whereas θ has a better influence on the ductility than κ. A feasible simplified calculating approach for the eccentric ultimate bearing capacity of RRCFSTs is presented and validated