483 research outputs found

    Numerical calculation and experimental research of pressure fluctuation in the pump under different operating conditions

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    Pressure fluctuation, which impacts on operating security, is the common phenomenon in the pump. In order to study pressure fluctuation phenomenon in the pump, TJ04-ZL-02 axial flow pump model is investigated under different operating conditions by experiment and unsteady calculation based on k-ω turbulence model. Numerical results show that the basic frequency amplitude of monitoring points in four sections under small operating condition are larger than that under design operating condition and large operating condition. And there are more random frequency components in each monitoring point, which are low frequency components. Experimental results show that compared with different operating conditions the basic frequency amplitude under design operation condition is not smallest. Under small operating condition the basic frequency amplitude is larger than that under large operating condition. Therefore, running under small operating condition will be easy to cause resonance. Based on this study, it’s recommended that avoiding small operating condition should contribute to improving operational stability

    Distribution of unsteady pressure in volute type axial flow pump

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    In order to study the distribution of unsteady pressure in volute type axial flow pump, the k-ε turbulence model was applied, and ANSYS CFX was provided for numerical simulation calculation. Experiments of external characteristics and pressure fluctuation have been done to verify the results of numerical simulation. The results show that under the design operating condition, the main fluctuation frequencies in the volute, at the inlet and outlet of the impeller are the blade passing frequency. The amplitudes of fluctuation at the inlet of the impeller decrease gradually from the rim to the hub, while those at the export decrease firstly and then increase, the amplitudes at the tongue are much higher than that at other sections of the volute. Under the off-design operating conditions, the main fluctuation frequency at the inlet and outlet of the impeller is still the blade passing frequency, while that at the tongue is between the twice shaft frequency and the blade passing frequency, fluctuation amplitudes are both larger than those under the design operating condition. Under the design operating condition, the radial force on the impeller is the minimum, however, the axial force increases with the increase of flow rate. The distributions of unsteady pressure in volute type axial flow pump are different with general centrifugal or axial flow pump

    Growth of Human Colorectal Cancer SW1116 Cells Is Inhibited by Cytokine-Induced Killer Cells

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    Previous reports have suggested that treatment with cytokine-induced killer (CIK) cells may benefit patients with various types of tumor. The aim of this study was to evaluate the antitumor effects of CIK cells against the colorectal cancer line SW1116 in vitro and in vivo. CIK cells were generated routinely from peripheral blood mononuclear cells of healthy human donors, and the number of CD3+CD56+ cells was expanded more than 1300-fold after 14-day culture. At an effector : target cell ratio of 50 : 1, the percentage lysis of SW1116 cells reached 68% in the presence of CIK cells, Experimental mice injected with SW1116 cells subcutaneously were divided randomly into four groups: untreated, 5-fluorouracil (5-FU)-treated, CIK-consecutive treated (injected once/day) and CIK-interval treated (injected once every 5 days). CIK cells were injected abdominally five times in total. Compared with the untreated group, xenograft growth was inhibited greatly by CIK treatment, to nearly the same extent as with 5-FU treatment. We demonstrated that the necrotic area in the tumor xenograft was markedly larger in the CIK-treated groups than in the other groups. These findings suggest that CIK-based immunotherapy may represent an effective choice for patients with colorectal cancer

    Advancements in 3D Lane Detection Using LiDAR Point Clouds: From Data Collection to Model Development

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    Advanced Driver-Assistance Systems (ADAS) have successfully integrated learning-based techniques into vehicle perception and decision-making. However, their application in 3D lane detection for effective driving environment perception is hindered by the lack of comprehensive LiDAR datasets. The sparse nature of LiDAR point cloud data prevents an efficient manual annotation process. To solve this problem, we present LiSV-3DLane, a large-scale 3D lane dataset that comprises 20k frames of surround-view LiDAR point clouds with enriched semantic annotation. Unlike existing datasets confined to a frontal perspective, LiSV-3DLane provides a full 360-degree spatial panorama around the ego vehicle, capturing complex lane patterns in both urban and highway environments. We leverage the geometric traits of lane lines and the intrinsic spatial attributes of LiDAR data to design a simple yet effective automatic annotation pipeline for generating finer lane labels. To propel future research, we propose a novel LiDAR-based 3D lane detection model, LiLaDet, incorporating the spatial geometry learning of the LiDAR point cloud into Bird's Eye View (BEV) based lane identification. Experimental results indicate that LiLaDet outperforms existing camera- and LiDAR-based approaches in the 3D lane detection task on the K-Lane dataset and our LiSV-3DLane.Comment: 7 pages, 6 figure
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