Explore the vast range of titles available.

In the realm of sensorless control for a permanent magnet synchronous motor (PMSM), the flux observer algorithm is widely recognized. However, the estimation accuracy of rotor position is adversely impacted by the interference from DC bias and high-order harmonics. To address these issues, an advanced flux observation method, second-order generalized integrator flux observer extend (SOGIFO-X), is introduced in this paper. The study begins with a theoretical analysis to establish the relationship between flux observation error and rotor position error. The SOGIFO-X method, developed in this study, is compared with traditional methods such as the Low Pass Filter (LPF) and second-order generalized integrator flux observer (SOGIFO), employing mathematical rigor and Bode plot analysis. The emphasis is on the methodology and the general performance improvements SOGIFO-X offers over conventional methods. Simulations and experiments were conducted to assess the impact of SOGIFO-X on the steady-state and dynamic performances of sensorless control. Findings indicate that SOGIFO-X demonstrates significant enhancements in terms of reducing the reduced flux observation error, contributing to the advancement of position estimation accuracy and sensorless motor control technology.

Assessing bladder function is pivotal in urological health, with bladder volume a critical indicator. Traditional devices, hindered by high costs and cumbersome sizes, are being increasingly supplemented by portable alternatives; however, these alternatives often fall short in measurement accuracy. Addressing this gap, this study introduces a novel A-mode ultrasound-based bladder volume estimation algorithm optimized for portable devices, combining efficient, precise volume estimation with enhanced usability. Through the innovative application of a wavelet energy ratio adaptive denoising method, the algorithm significantly improves the signal-to-noise ratio, preserving critical signal details amidst device and environmental noise. Ultrasonic echoes were employed to acquire positional information on the anterior and posterior walls of the bladder at several points, with an ellipsoid fitted to these points using the least squares method for bladder volume estimation. Ultimately, a simulation experiment was conducted on an underwater porcine bladder. The experimental results indicate that the bladder volume estimation error of the algorithm is approximately 8.3%. This study offers a viable solution to enhance the accuracy and usability of portable devices for urological health monitoring, demonstrating significant potential for clinical application.

In deep drilling operations, the interaction mechanism between the Polycrystalline Diamond Compact (PDC) cutter and the granite directly affects the granite breaking efficiency and the service life of the cutter. To reveal the correlation between the infrared radiation characteristics and the granite mechanics failure behavior during the single-tooth cutting process, the study utilized a modified shaper testing machine and a high-precision infrared thermal imager (with a measurement accuracy of ± 0.01 °C and a spatial resolution of 0.6mrad) to monitor the dynamic contact process between PDC cutter and granite under the condition of 15° ~ 30° rake angles. The results show that the infrared temperature undergoes a significant increase at the moment of contact, and as the rake angle increases from 15° to 30°, the peak initial contact temperature rises from 26.30 °C to 91.46 °C, indicating that an escalation of the rake angle intensifies the degree of granite fragmentation but leads to an upward shift in the temperature fluctuation range at the contact interface, posing a potential threat to the durability of the PDC cutter. Infrared imaging analysis reveals that the granite fragmentation pattern exhibits the characteristics of diffusing from the local contact center to the circumferential direction, following a three-stage evolution law of energy accumulation, mixed failure, and unloading. By comparing the simultaneously collected cutting force data, it is found that the fluctuation of infrared radiation temperature is strongly correlated with the rock compaction-fracture cycle process, and the peak-valley changes in temperature highly coincide with the reciprocating characteristics of the cutting force waveband, verifying the feasibility of infrared thermal signals as real-time indicators of rock failure status. With the raise of the rake angle, the infrared characteristic temperature tends to decrease (mean is 39.54 at 30°, a decrease of 32% compared to 15°), while the variance significantly increases (variance is 21.34 at 30°, an increase of 48%), reflecting intensified energy dissipation but improved fragmentation stability during the granite breaking process. Comprehensive analysis of the Specific Energy of Rock Fragmentation (SERF) and cutting force reveals that when the rake angle exceeds 25°, the intensity of infrared radiation response, and cutting force increase simultaneously. Based on the principle of collaborative optimization of efficiency and service life, it is recommended to control the rake angle within the range of 15° ~ 25° to balance the granite breaking efficiency and cutter wear characteristics. This paper reveals the damage evolution law of granite to some extent.

This paper focuses on the use of advanced optimization design strategies to improve the performance and service life of engine pistons, with emphasis on enhancing their stiffness, strength, and dynamic characteristics. As a core component of the engine, the structural design and optimization of the piston are of great significance to its efficiency and reliability. First, a three-dimensional (3D) model of the piston was constructed and imported into ANSYS Workbench for finite element modeling and high-quality meshing. Based on the empirical formula, the actual working environment temperature and heat transfer coefficient of the piston were accurately determined and used as boundary conditions for thermomechanical coupling analysis to accurately simulate the thermal and deformation state under complex working conditions. Dynamic characteristic analysis was used to obtain the displacement–frequency curve, providing key data support for predicting resonance behavior, evaluating structural strength, and optimizing the design. In the optimization stage, five geometric dimensions are selected as design variables. The deformation, mass, temperature, and the first to third natural frequencies are considered as optimization goals. The response surface model is constructed by means of the design of the experiments method, and the fitted model is evaluated in detail. The results show that the models are all significant. The adequacy of the model fitting is verified by the “Residuals vs. Run” plot, and potential data problems are identified. The “Predicted vs. Actual” plot is used to evaluate the fitting accuracy and prediction ability of the model for the experimental data, avoiding over-fitting or under-fitting problems, and guiding the optimization direction. Subsequently, the sensitivity analysis was carried out to reveal the variables that have a significant impact on the objective function, and in-depth analysis was conducted in combination with the response surface. The multi-objective genetic algorithm (MOGA), screening, and response surface methodology (RSM) were, respectively, used to comprehensively optimize the objective function. Through experiments and analysis, the optimal solution of the MOGA algorithm was selected for implementation. After optimization, the piston mass and deformation remained relatively stable, and the working temperature dropped from 312.75 °C to 308.07 °C, which is conducive to extending the component life and improving the thermal efficiency. The first to third natural frequencies increased from 1651.60 Hz to 1671.80 Hz, 1656.70 Hz to 1665.70 Hz, and 1752.90 Hz to 1776.50 Hz, respectively, significantly enhancing the dynamic stability and vibration resistance. This study integrates sensitivity analysis, response surface models, and genetic algorithms to solve multi-objective optimization problems, successfully improving piston performance.

Piceatannol is a natural plant-derived compound with protective effects against cardiovascular diseases. However, its effect on cerebral ischaemia–reperfusion injury (CIRI) induced by oxidative stress remains unclear. This study aimed to investigate piceatannol’s antioxidation in CIRI. An in vitro oxygen–glucose deprivation followed by reoxygenation model was used and cell viability was measured. A middle cerebral artery occlusion followed by reperfusion model was used in vivo. Neurological function, encephalisation quotient, oedema, and volume of the cerebral infarction were then evaluated. The effects of piceatannol on histopathological findings, as well as the ultrastructure of the cortex, were analysed. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and lactate dehydrogenase (LDH) and the malondialdehyde (MDA) content was measured both in vitro and in vivo. Finally, the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 (NQO1) in cerebral tissue was detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Our results demonstrated that cell viability in the piceatannol groups was increased. The SOD, GSH-Px activities were increased as LDH activity and MDA content decreased in the piceatannol groups both in vitro and in vivo, reflecting a decrease in oxidative stress. The neurological severity score and infarction volume in the piceatannol groups at doses of 10 and 20 mg/kg were lower than those of the model group. Furthermore, the damage seen on histopathological examination was partially attenuated by piceatannol. RT-qPCR and western blot analysis indicated that the expression of Nrf2, HO-1, and NQO1 were significantly increased by piceatannol. The results of the study demonstrate that piceatannol exerts a protective effect against CIRI.

Background The progression and recurrence are the fatal prognostic factors in glioma patients. However, the therapeutic role and potential mechanism of TRAF7 in glioma patients remain largely unknown. Methods TRAF7 RNA-seq was analysed with the TCGA and CGGA databases between glioma tissues and normal brain tissues. The expression of TRAF7, cellular senescence and cell cycle arrest pathways in glioma tissues and cell lines was detected by real-time quantitative PCR (RT-qPCR), western blotting and immunohistochemistry. The interaction between TRAF7 and KLF4 was determined by Co-immunoprecipitation (Co-IP) assays. The functions of TRAF7 combined with lomustine in glioma were assessed by both in vitro , in vivo and patient-derived primary and recurrent glioma stem cell (GSC) assays. Results High TRAF7 expression is closely associated with a higher recurrence rate and poorer overall survival (OS). In vitro , TRAF7 knockdown significantly inhibits glioma cell proliferation, invasion, and migration. RNA-seq analysis revealed that TRAF7 inhibition activates pathways related to cellular senescence and cell cycle arrest. In both in vitro and patient-derived GSC assays, the combination of sh-TRAF7 and lomustine enhanced therapeutic efficacy by inducing senescence and G0/G1 cell cycle arrest, surpassing the effects of lomustine or TRAF7 inhibition alone. Mechanistically, TRAF7 interacts with KLF4, and a rescue assay demonstrated that KLF4 overexpression could reverse the effects of TRAF7 depletion on proliferation and cellular senescence. In vivo , TRAF7 knockdown combined with lomustine treatment effectively suppressed glioma growth. Conclusion TRAF7 could be used as a predictive biomarker and the potential therapeutic target among National Comprehensive Cancer Network (NCCN) treatment guidelines in the progression and recurrence of glioma. Lomustine, regulating cellular senescence and cell cycle could be the priority choice in glioma patients with high-level TRAF7 expression. Key points • High TRAF7 expression is linked to glioma progression and recurrence. • TRAF7 knockdown inhibits glioma cell proliferation, invasion, and migration via cellular senescence and cell cycle arrest. • Lomustine may be prioritized for glioma patients with high-level TRAF7 expression.

Prefabricated buildings are at a stage of rapid development in China. However, there is an absence of detailed scientific research or case studies of this field. This paper is concerned with the in-plant transportation's carbon emissions of prefabricated building components at the production stage. The discussion is largely guided by the qualitative analysis and the basic information of the plant, measuring equipment and points, data accounting and analysis combined with actual measurement data. The qualitative analysis consists of three interrelated parts: stage division, determination of carbon emission calculation boundary, calculation and release method. Through the discussion and the analysis, this paper concludes the influencing factors affecting the carbon emissions of in-plant transportation.

The steel structure building system is a system suitable for resource recovery. This paper studies the carbon emission calculation model and economic analysis method for the recovery process of steel structure prefabricated building components. And a steel structure sales office is selected for verification calculation. The results show that the use of recycled components within a reasonable transport distance can not only reduce carbon emissions, but also reduce economic costs compared to the full use of new components.

This paper constructs a carbon emission calculation model for the production, recovery and transportation of steel structure prefabricated building components. Taking a steel structure sales office in Beijing as the research object, the carbon emissions of the dismantled components under non-recycling and different recycling conditions (transport distance and recycling ratio) were calculated. From the perspective of reducing CO2 emissions, the feasibility of recycling steel components in sales offices is analyzed.