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Bearing health is key for maintaining good performance and safety in rotating machinery. As the diagnosis of mechanical faults develops toward intelligence and automation, accurate and systematic fault diagnosis algorithms are imperative. Focusing on the diagnosis of rolling bearing failures, this study utilizes a sliding time window to extract essential data segments. A series of signal processing techniques, including filtering, amplitude–frequency analysis, Hilbert envelope analysis, and energy analysis, is applied to establish a comprehensive dataset. For extraction of the hidden properties of the data, the recurrence quantity spectrum is defined for the input of the neural network. The goal is to obtain a cleaner dataset with enhanced features. A convolution neural network is constructed. Different activation functions in the activation layer are compared for better fault diagnosis algorithms. The established feature matrices are specifically defined to accurately identify the subtlest defects of bearings, thereby facilitating early detection. The proposed procedure distinguishes various fault modes. As for the multidimensional complexities of fault signals, this study carries out a comprehensive comparison of energies, recurrence quantification, and amplitude–frequency characteristics of bearing fault detection to assess the accuracy, computational efficiency, and robustness of bearing fault diagnosis. The proposed method and bearing fault detection procedures have potential in practical applications. [ABSTRACT FROM AUTHOR]

In this paper, hydroxyapatite (HAP) was synthesized by clean and simple multi-scan cycle voltammetry. The crystal structure and functional group of intermediate products calcium hydrogen phosphate dihydrate (DCPD) and hydroxyapatite(HAP) were characterized by X-ray diffraction and infrared spectroscopy. Scanning electron microscope showed that the surface of HAP was a rod-like structure with good dispersion. Taking fluorine ions in water as adsorption objects, the effects of the parameters such as pH, possible coexistence anions and temperature on the adsorption capacity of synthesized HAP were studied. The results showed that in the range of pH of 3-6, the adsorption capacity of HAP to fluorine ions gradually increased with the increase of pH and reached the maximum when the pH was 6; in the range of pH of 6-10, and the adsorption of HAP to fluorine ions gradually decreased with the increase of pH. Anions that may coexist in water, such as Cl-, NO3-, SO2-4, CO2-4, did not interfere with HAP adsorption of fluorine ions. In the range of temperature of 15-55 °C, the adsorption capacity of HAP increased with the temperature increase, and reached the maxum of 8.36 mg/g at 55 °C, which was higher than the similar materials reported . After 4 times of adsorptiondesorption experiments, the removal effect of HAP on fluoride ions in simulated wastewater was still in line with the national standard. In addition, the adsorption of fluorine ions by HAP was a spontaneous process of entropy increase and heat absorption, which conformed to the adsorption isothermal models of Langmuir-Freundlich and Dubinin-Radushkevich, and followed the kinetic reaction mechanism of intra particle diffusion. [ABSTRACT FROM AUTHOR]

Objective of this study is to assess the clinical performance of a urine-based high-risk human papillomavirus (hrHPV) test for the detection of cervical intraepithelial neoplasia grade 2 or higher (CIN2+).Methods: Between September and December 2021, women aged 20 to 65 years referred to colposcopy clinic were prospectively recruited at three clinical centers in China. Paired urine and cervical specimens from all enrolled women were obtained for hrHPV DNA fluorescence quantitative PCR test. The results of liquid-based cytology (LBC), colposcopy and diagnostic biopsies were collected. We evaluated the sensitivity and specificity for CIN and assessed the agreement/kappa value.Results: A total of 732 women (median age, 40 years) with valid results were included in the study, and 130 (17.8%) women were histologically confirmed as CIN2+. The sensitivity of urine and cervical test for CIN2+ and CIN3+ were 87.69% and 85.45%, respectively. The specificity of urine test performed better than cervical test in women with Conclusion: The data suggested that the urine-based hrHPV test may be an alternative approach for cervical cancer screening. [ABSTRACT FROM AUTHOR]

Precise prediction of PV power in the short term is crucial for maintaining power system stability and balance. However, the performance of conventional time series prediction models on short-term long series prediction is scarcely sufficient because of the stochastic and turbulent character of PV power data. This work suggests a PV short-term power forecast model based on weather type, AHA-VMD-MPE decomposition reconstruction, and improved Informer combination to tackle this issue. Firstly, a SUM-ApEn-K-mean++ multidimensional clustering method to group the dataset by weather conditions. Then an AHA-VMD-MPE decomposition model is proposed to decompose the historical power data Finally the Informer model is improved and the improved model is utilized to predict the PV power under various weather conditions. The model exhibits great accuracy and stability in short-term PV power prediction, as demonstrated by the experimental results, which were validated using measured data from many PV power plants. • A weather typing method based on SUM-ApEn-K-means++ has been proposed. • A sequence decomposition method based on AHA-VMD-MPE has been proposed. • The improved Informer model has been applied to short-term PV forecasting. • Validation has been performed on multiple time scales. [ABSTRACT FROM AUTHOR]

A thermohydrodynamic model was used to study the influence of partial composite coatings on the behavior of plain journal bearings, considering solid elastic deformations and wall slip occurring at the oil film–polytetrafluoroethylene coating interface, and heat conduction between film, coating, interlayer and basement. The purpose is to design partial polytetrafluoroethylene coating to obtain improved bearing behavior based on analyzing the maximum temperature and minimum film thickness in different coating positions (or slip zones). The influences of coating thickness and coating materials (polytetrafluoroethylene, graphite and diamond-like carbon coatings) at different coating positions are also presented. Results show that polytetrafluoroethylene coatings that are completely located in the film convergent region have a small influence on thermal behavior in both nonslip and slip cases. Without slip, a full polytetrafluoroethylene coating can increase the maximum temperature; however, wall slip occurring on a full polytetrafluoroethylene coating surface is helpful in decreasing the maximum temperature when accompanied by a lower minimum film thickness. A thicker polytetrafluoroethylene coating causes bearing seizures more readily. Unlike polytetrafluoroethylene, graphite and diamond-like carbon coatings improve the thermal behavior. [ABSTRACT FROM AUTHOR]