Search

At present, the visible light (Vis) catalytic oxidation, as a wastewater treatment approach without secondary pollution, has captured the interest of many researchers. However, the efficiency of visible photocatalysis still needs to be continuously improved. In this study, a piezoelectric photocatalyst Bi2WO6 (BWO) responding to both Vis and ultrasound (US) was prepared, characterized, and employed to treat Rhodamine B (RhB) in water. The removal efficiencies of RhB under different systems (Vis/BWO, US/BWO, (Vis + US)/BWO) were investigated and the reuse capacity of BWO were examined. Moreover, the piezoelectric photocatalytic mechanism of (Vis + US)/BWO system on RhB removal was analyzed. The results exhibited that the prepared Bi2WO6 possessed excellent photoresponsive and piezoresponsive properties, and the removal and mineralization of RhB could reach 100% and 77.2% within 60 min, respectively. Under the combined effect of photocatalysis and piezoelectricity, the superoxide radicals, hydroxyl radicals, and photogenerated holes produced, which were responsible for the degradation of RhB in (Vis + US)/BWO system. [ABSTRACT FROM AUTHOR]

Aims/Background Chronic renal failure (CRF) is the eventual outcome shared by various progressive renal diseases, posing a serious threat to the physical health of patients. CRF patients are required to undergo hemodialysis (HD), which imposes heavy psychological and mental burdens for most individuals. This study explores the effects of Internet Plus-based continuous nursing on the compliance of CRF patients with HD. Methods This study retrospectively analyzed the clinical data of 160 CRF patients undergoing HD in the Yantai Yuhuangding Hospital from March 2021 to April 2023, after excluding eight cases from an originally selected cohort of 168 cases. These patients were divided into two groups: 79 cases who received the routine nursing from March 2021 to March 2022 were categorized as the routine group, whereas 81 cases who were given Internet Plus-based continuous nursing from April 2022 to April 2023 were assigned into the observation group. The treatment adherence, self-management behaviors, quality of life and incidence of HD complications were compared in both groups. Results Both groups demonstrated no significant difference in the baseline information (p > 0.05). The scores of adherence in terms of HD attendance, medications, fluid restrictions and diet recommendations in the observation group were significantly higher than those in the routine group (p < 0.001). No significant difference in the Hemodialysis Self-Management Instrument (HDSMI) scores on the day of discharge between the two groups was found (p > 0.05). After 6 months of follow-up, the observation group showed significantly higher scores of partnership, problem solving, self-management execution and emotional processing than the routine group (p < 0.001). Both groups had no significant difference in the scores of Kidney Disease-Targeted Areas (KDTA) and 36-Item Short Form (SF-36) on the day of discharge (p > 0.05). After 6 months of follow-up, the scores of KDTA and SF-36 in the observation group were significantly higher than those in the routine group (p < 0.001). The incidence of HD complications in the observation group (7.41%) was significantly lower than that in the routine group (21.52%) (p < 0.05). Conclusion Internet Plus-based continuous nursing can effectively improve treatment adherence, self-management behaviors as well as quality of life in patients, and reduce the incidence of HD complications. [ABSTRACT FROM AUTHOR]

AbstractTesting for the autoregressive conditional heteroscedasticity (ARCH) effect is an important problem in economic and financial time series. In this article, we consider the ARCH effect test for high-dimensional time series. Our test statistic is built based on the maximum element of Spearman’s rank correlation at different lags. The bootstrap methods are used to approximate the null distribution of the proposed test statistics. We also consider the goodness-of-fit test for ARCH models by applying the test to the residuals of fitted models. Simulation results show that the proposed test statistics enjoy good properties of size in finite samples. Compared to the existing methods, the new test possesses much better power. Moreover, the test is not sensitive to the underlying distribution of the time series. The proposed method is illustrated via two real data. [ABSTRACT FROM AUTHOR]

Ammonia–methane (NH3–CH4) mixtures have potentials to serve as low-carbon fuels for gas turbines. Recent studies demonstrated that secondary air injection was an effective strategy to reduce NOx emissions from the combustion of NH3–CH4–air mixtures. However, the effects of secondary air injection on the performance of thermoacoustic instability of NH3–CH4–air flames remain unknown. To this end, this study experimentally investigated the thermoacoustic instability performance of a premixed, swirl-stabilized NH3–CH4–FF air combustor without and with secondary air injection. Without secondary air injection, thermoacoustic instabilities were widely detected at NH3 ratios below 50% (by volume). It was discovered that such instabilities were significantly suppressed by secondary air injection over a wider range of operating conditions. In conjunction with the analysis of the flame and flow dynamics, it was revealed that the secondary air injection suppressed the large amplitude axial oscillations of the flame and the flow field. Combined with the experimental results, it was inferred that the introduction of secondary air changed the velocity and pressure distribution downstream of the primary combustion zone, which in turn affected the formation and evolution of the vortex structures, thereby mitigating thermoacoustic coupling. Finally, emission measurements were discussed and the results indicated that the secondary air injection strategy reduced unburnt NH3 and CO emissions to a certain extent as well as decreased NOx emissions at specific equivalence ratios. [ABSTRACT FROM AUTHOR]