g. zhang

Butterfly valves are critical control equipment widely used in transmission systems across various fields, including energy, water conservancy, materials and chemical industries, metallurgy, and aerospace engineering. Cavitation, induced when the local pressure is decreased to saturated vaporization pressure, is a common phenomenon in butterfly valves and causes severe damage to valve components. Numerical studies were conducted to explore the progression of dynamic cavitation in a butterfly valve under different actual conditions by using Large Eddy Simulation (LES) coupled with Schnerr-Sauer cavitation model.  The detailed evolution process of generation, development, and collapse was discussed by analyzing the corresponding vapor volume fraction. With the increase of valve opening, there is a corresponding increase in cavitation volume, leading to the rise of disturbance coefficient in full flow field as well as the decrease of shedding frequency of cavitation. The decline of shedding frequency of cavitation exhibits a sudden and pronounced drop at valve opening degree of 60%, which can be attributed to a shift in cavitation shedding behavior from unilateral to bilateral shedding. Periodic changes in cavitation evolution and the presence of attached cavitation on the upper surface of valve plate are obtained and discussed in detail. A comparative analysis of vortex distribution and structure within the flow field reveals insights into the spatial and temporal correlation between cavitation and vortices. The present study of the cavitation mechanism and the in-depth exploration of the evolution law of cavitation provide a clearer understanding of cavitation phenomenon, offering a reference for the structural optimization of butterfly valve in cavitation inhibition.

transcatheter arterial chemoembolization (TACE) is the standard treatment for advanced and unresectable hepatocellular carcinoma (HCC) patients. Lenvatinib (LVTN) is one of the novel oral antiangiogenic drugs demonstrating promising application prospects, which has been widely concerned and studied. This work was to systematically analyze efficacy and safety of TCAE combined with LVTN plus radiotherapy (RT) on HCC through the meta-analysis.

a comprehensive search was conducted on PubMed, Web of Science, Embase, and The Cochrane Library databases from January 2000 to the present to identify studies examining the effectiveness and safety of combining TCAE with LVTN and RT for the treatment of HCC. Relevant literature was screened, and essential information along with evaluation indicators were extracted for analysis. RevMan5.3 was employed for quality assessment and meta-analysis of the included studies, and forest maps (FMs) were drawn.

five studies were included. Meta-analysis showed that TCAE combined with LVTN plus RT enhanced the total objective response rate (ORR) of HCC (OR = 3.16, 95%CI = 1.37-7.32, P < 0.05). TCAE combined with LVTN plus RT enhanced the total survival (OS) rate of HCC patients (OR = 2.01, 95%CI=1.30-3.12, P < 0.05). TCAE combined with LVTN plus RT could reduce the diarrhea rate greatly (OR = 2.84, 95%CI = 1.16-6.96, P< 0.05). However, no observable difference was found in the incidence of hypertension caused by TCAE combined with LVTN plus RT (OR = 2.39, 95%CI = 0.62-9.23, P > 0.05).

LVTN combined with TACE had superior efficacy on HCC compared with non-LVTN combined with TCAE, but the related side effects (SEs) may affect the scope of application and the quality of life of patients.

A numerical investigation of the particle deposition characteristics inside film holes and on the blade was conducted using an improved particle deposition model and dynamic grid updating. The computation model was numerically simulated using Reynolds-Averaged Navier-Stokes (RANS) equations with second-order spatial accuracy and the SST k-ω turbulence model, combined User Defined Function (UDF) in FLUENT 2021R1. The influence of the deposition morphology on film effectiveness was analyzed. The results revealed that a conical deposition in the exit region inside the film holes enhanced the separation of the coolant ejected from the film holes at a low coolant mass flux ratio (MFR). Increasing the MFR inhibited deposition, and the enhanced particle detachment significantly reduced particle deposition inside the film holes. Deposition downstream of the film holes significantly affected the cooling performance. Strip deposition on both sides of the region covered by the coolant limited the spanwise diffusion of the coolant. Compared to the non-deposition case, The surface-averaged film effectiveness was lower after deposition at MFRs of 0.1%-0.5% and slightly higher at MFRs of 0.6%. The most significant reduction in the surface-averaged film effectiveness after deposition was 34.9% at an MFR of 0.3%.

Water lubricated bearings can be used to reduce contamination due to lubricant leakage in heavy machinery such as power positioning systems of offshore platforms and ship propulsion systems. The lubrication model of a textured two-dimensional parallel friction pair and a textured water-lubricated journal bearing are developed to investigate the lubrication performance. The governing equation is solved, and the fluid cavitation is analyzed using the Zwart-Gerber-Belamri (ZGB) model. A multi-objective optimization method combining the response surface and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is used to optimize the textured journal bearings. The results indicate that a small texture width will inhibit the occurrence of liquid film cavitation. With the rise in the texture width, the cavitation effect gradually rises and stabilizes. As the texture depth deepens, the micro dynamic pressure effect is enhanced and liquid film pressure rises. Through the tests, it is found that the optimized texture parameters can be implemented to effectively diminish the friction and wear volume, also the optimized textured bearing hydrodynamic pressure effect is enhanced at the same speed.

As a common industrial valve solution in slurry pipeline systems, Y-type slurry valves must be designed with properly shaped valve seat sealing rings to alleviate particle erosion and keep the valve operating in optimal condition. In this study, we investigate four different valve seat shapes with varying inner angles to understand the effect of the seat structure on particle erosion in Y-type slurry valves. We conducted computation fluid dynamics discrete element method simulations to analyze the impact of different valve seat shapes on the characteristics of particle–liquid two-phase flows and erosion. We also performed a detailed analysis of velocity and pressure distributions for liquid phase and particle velocity distributions as well as surface erosion on key valve components. We observed the primary erosion areas to be the back surface of the valve body, the inner surface of the valve seat, and the front surface of the valve disc, and as a result, we investigated the erosion distribution in these areas with different valve seat structures. Our simulation results indicate that the variation in particle diameter and the inner angle of the valve seat sealing ring have significant impacts on erosion in the studied areas.

This article studies the aerodynamic performance of a novel bypass shock-induced thrust vector nozzle. An arc-shaped bypass is innovatively designed to optimize nozzle performance and equips a variable shrinkage part. The nozzle performance is investigated numerically under diverse shrinkage area ratios. Computational results indicate that both geometry and friction choking have important effects on the nozzle performance. Normally, in the case of without any bypass shrinkage, the flow choking occurs at the bypass outlet. Very small bypass shrinkage is unable to change the flow choking location. The bypass geometry choking comes up at its throat as the shrinkage area ratio of the bypass reaches 0.06. According to computational results, the vectoring angle diminishes with the increasing shrinkage area ratio of the bypass, thrust force ratio, thrust efficiency, specific impulse ratio, and coefficient of discharge increase. As the NPR enlarges, the deflection angle and thrust efficiency decrease, and the thrust force ratio increases.

The aim of this study was to evaluate the influence of lesion size on the performance of real-time two-dimensional shear wave elastography (2D-SWE) in the diagnosis of breast lesions.

A total of 118 consecutive female patients with 129 breast lesions (50 malignant and 79 benign) who underwent surgical excision and/or core biopsy were studied. The lesions were categorized into three subgroups according to their size: (1) group 1: < 1.0 cm3; (2) group 2: 1.0–4.0 cm3; (3) group 3: > 4.0 cm3. The maximum elasticity (Emax), mean elasticity (Emean), and their standard deviation (SD) in the three subgroups were compared and analyzed in terms of the cutoff values acquired by pathological results.

The lesion size significantly differed between benign and malignant masses (P < 0.05). Malignant lesions exhibited significantly elevated values of Emax, Emean, and SD, compared with benign lesions in the three subgroups. The optimal threshold was higher for larger malignant and benign lesions (P < 0.05). In malignant lesions, the SWE parameters in group 1 were significantly different from those in groups 2 and 3. The area under the receiver operating characteristics curve (AUROC) of SD was higher than that of Emax and Emean in all three subgroups.

The values of 2D-SWE parameters  increase with the increase in size of a breast mass, and the adjustment of the threshold based on lesion size yields a more accurate diagnosis. Among the SWE parameters, SD has the best diagnostic performance.

To explore the application of contrast-enhanced ultrasound and color Doppler ultrasonography in the treatment of primary hepatocellular carcinoma (PHC) after Transhepatic Artery Chemoembolization (TACE).

49 patients with primary hepatocellular carcinoma were treated with TACE for 3-5 times. Before and after treatment, digital subtraction angiography, contrast-enhanced ultrasound and color Doppler ultrasound were performed. The lesions before and after contrast-enhanced ultrasonography and color Doppler ultrasonography were compared. The residual or recurrence and swelling of lesions before and after contrast-enhanced ultrasonography and color Doppler ultrasonography were analyzed. Detection of the capsule of the lesion.

The detection accuracy of contrast-enhanced ultrasound (95.77%) was significantly higher than that of color Doppler ultrasound (84.51%) (P<0.05). The detection rate of tumor envelope by contrast-enhanced ultrasound (22.54%) was significantly higher than that by color Doppler ultrasound (9.86%) (P < 0.05). The accuracy of detecting residual or recurrent lesions by contrast-enhanced ultrasound (91.67%) was significantly higher than that by color Doppler ultrasound (58.33%) (P<0.05).

The rate of bone metabolism of perimenopausal women in Xuzhou is not optimistic. We need to pay close attention to the risk of bone metabolism disorder of perimenopausal women with older age, diabetes mellitus and osteoporosis, so as to provide useful help for improving the quality of life of perimenopausal women in Xuzhou.