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• A novel pressure distribution testing method of piston/cylinder interface. • A piston pump test rig has been set up. • Experimental investigations are conducted and a hydrodynamic lubrication model is developed. • The experimental results closely match the numerical simulations. The piston/cylinder lubricating interface is one of the most critical components in piston pumps. The characteristics of the interface, such as pressure distribution, leakage flow and viscous friction, etc., have significant effect on the performance of the piston pump. Previous experiments obtained data distribution by installing pressure sensors on a fixed cylinder block. However, too many measurement points on the cylinder block may disrupt the lubricating film; insufficient measurement points will result in incomplete oil film pressure distribution. This paper presents a novel time domain location testing method which a measuring point is placed on each cylinder surface as a time-domain calibration reference, enabling the acquisition of the pressure distribution over one shaft revolution. Real-time pressure between the piston and cylinder is measured under various operating conditions. Further research results show that the pressure distribution obtained through this method exhibits a high degree of conformity with the simulation results. [ABSTRACT FROM AUTHOR]

The boundary conduction mode (BCM) totem-pole boost power factor correction (PFC) topology is becoming popular in high-efficiency and high power density applications because of its advantages of fewer devices and low conduction losses. The ideal design methodology for the BCM boost converter ignores the reverse recovery of mosfet s’ body diode and the resonance between the inductance and output junction capacitances of switches. However, as the switching frequency increases, these two factors affect the peak value of the inductance current and the switching frequency significantly, which are critical parameters for the boost PFC inductor design. In order to calculate the practical peak current and switching frequency range accurately, this letter proposes an analytical reverse recovery model of the body diode and presents accurate switching cycle operating modes. Either the predicted inductance peak current or the switching frequency range matches the measured result on a 600-W totem-pole boost PFC prototype. [ABSTRACT FROM AUTHOR]

To understand the changes in RSV hospitalization burden in children younger than two years following the onset of the COVID-19 pandemic, we reviewed hospital records of children with acute lower respiratory infection (ALRI) between January 2018 and June 2022 in Split-Dalmatia County, Croatia. We compared RSV activity, age-specific annualized hospitalization rate, and disease severity between pre-COVID-19 and COVID-19 periods. A total of 942 ALRI hospital admissions were included. RSV activity remained low for the typical RSV epidemic during 2020–2021 winter. An out-of-season RSV resurgence was observed in late spring and summer of 2021. Before the COVID-19 pandemic, the annualized hospitalization rate for RSV-associated ALRI was 13.84/1000 (95% CI: 12.11–15.76) and highest among infants under six months. After the resurgence of RSV in the second half of 2021, the annualized hospitalization rate for RSV-associated ALRI in children younger than two years returned to the pre-pandemic levels with similar age distribution but a statistically higher proportion of severe cases. RSV immunization programs targeting protection of infants under six months of age are expected to remain impactful, although the optimal timing of administration would depend on RSV seasonality that has not yet been established in the study setting since the onset of the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

The photovoltaic array can be used as a medium for carrier communication to realize monitoring of photovoltaic components. Photovoltaic array channel noise, especially the pulse-type noise therein, seriously interferes carrier communication, so it is necessary to grasp the characteristics of the photovoltaic array channel noise. Photovoltaic array channel noise modeling is a key process when conducting anti-noise immunity tests of monitoring equipment. Based on the time-domain waveform of photovoltaic series channel noise which is measured in a photovoltaic power station, this paper proposes a photovoltaic array noise modeling method of Wavelet Peak-Type Markov chain, and studies the influence on modeling accuracy when different mother wavelets are adopted for modeling. From the simulation results, root mean square errors of the predicted output for Haar, Biorthogonal and Daubechies wavelet-based function modeling case are 0.9614 V, 1.4915 V and 0.7928 V, respectively, validating that Daubechies wavelet-based function is the best wavelet-based function of modeling. In the case that the peak of original noise reaches 20 V, the predicted mean absolute error of this model is only 0.4926 V, which not only verifies the applicability of the Wavelet Peak-Type Markov chain model to the photovoltaic array channel noise, but also verifies the applicability to the pulse-type noise. [ABSTRACT FROM AUTHOR]

Particle gradation and water content are important factors affecting shear strength of soil. However, due to chemical cementation and molecular attraction, loess particles commonly stick together forming conglomerations. Till date, the superposition effect of water content and conglomeration gradation on loess shear strength has rarely been studied and undeniably requires further systematic explorations and development. In this study, loess samples were prepared with three conglomeration gradations and five water contents, and the direct shear tests were systematically performed. The shear strength of sample 1 (continuous conglomeration gradation) was found to be the best, followed by sample 2 (large size conglomerations), and sample 3 (small size conglomerations). The difference of samples' shear strength decreased with increasing water content, and almost closed to zero when water content was 20%. The cohesion of samples first increased and then decreased with increasing water content, the maximum cohesion occurred at 10% water content. The internal friction angles decreased with increasing water content, and reached similar minimum values when the water content was 15%. The increased percentage values of cohesion and internal friction angle caused by conglomeration gradation are in the range of 33.2%–42.1% and 9.8%–32.5%, respectively. Finally, the empirical formulas for water content-cohesion and water content-internal friction angle of different conglomeration gradations samples were established, and the calculated values are in good agreement with test data. The effect of loess conglomeration gradation on shear strength decreased with increasing water content. When the water content was less than 15%, using a good conglomeration graduation could effectively improve loss shear strength. [ABSTRACT FROM AUTHOR]

Ascorbic acid (AA) is an indispensable nutrient required to sustain optimal poultry health and performance, which is commonly excluded from the diet of broilers. To investigate the synthesis and distribution of AA during broiler growth and clarify its possible turnover, 144 1 d old healthy Arbor Acres broilers with a body weight of approximately 41 g were randomly assigned to eight groups of 18 broilers each. The kidney, liver, ileum, and spleen of one bird from each group were collected every week until 42 d to detect the synthesis capacity, tissue distribution, and transporter gene expression of AA. The results showed that kidney L-gulonolactone oxidase (GLO) activity responded quadratically (p < 0.001), with maximum activity observed at 7 to 21 d old. Hepatic total AA and dehydroascrobate (DHA) concentration increased linearly (p < 0.001) with age, as did splenic total AA (p < 0.001). In the ileum, mRNA expression of sodium vitamin C transporter 1/2 (SVCT1/2) decreased with the growing age of the broilers (p < 0.05). The expression of SVCT1 in the kidney was not influenced by the growing age of the broilers. The progressive buildup of AA in the liver and spleen of broilers as they age implies an amplified demand for this nutrient. The waning synthesis capacity over time, however, raises concerns regarding the possible inadequacy of AA in the latter growth phase of broilers. The addition of AA to the broilers' diet might have the potential to optimize their performance. However, the effectiveness of such dietary supplementation requires further investigation. [ABSTRACT FROM AUTHOR]

Multi‐mode green internet of things (IoT) network that integrates multiple communication media can well meet data transmission and processing demands of low‐carbon smart building. However, network resource management optimisation including joint optimisation of gateway and channel selection still faces technical challenges such as differentiated quality of service (QoS) demand guarantee, coupling between optimisation problems with different timescales, and adversary caused by multi‐device competition. To address these challenges, an adversarial learning‐based multi‐timescale network resource management algorithm for multi‐mode green IoT is proposed. Specifically, the minimisation problem of weighted difference between energy consumption and throughput under the long‐term queuing delay constraints is formulated to achieve differentiated QoS guarantee. Large‐timescale gateway selection is decoupled from small‐timescale channel selection by establishing matching preferences based on empirical performance, and optimised by using bilateral matching with quota. Finally, an exponential‐weight algorithm for exploration and exploitation (EXP3)‐based small‐timescale channel selection algorithm is proposed to achieve adversary awareness. Simulation results demonstrate that compared with asynchronous greedy matching algorithm and auction‐based many‐to‐many matching algorithm, the proposed algorithm performs superior in terms of energy consumption and throughput. [ABSTRACT FROM AUTHOR]

In this work, a composite photocatalyst consisted of the porous graphitic carbon nitride (pg‐C3N4) nanosheets decorated with in‐situ grown gold (Au) nanoparticles were prepared. By characterizing and analyzing chemical compositions and structures, and optical and electrical properties of this Au/pg‐C3N4 composite, the excellent photocatalytic performance mainly comes from the following aspects: firstly, pg‐C3N4 synthesized from melamine by high‐temperature calcination with the assistance of ascorbic acid has larger specific surface area and narrower band gap width than common g‐C3N4; secondly, localized surface plasmon resonance (LSPR) effect of Au nanoparticles can enhance light absorption of pg‐C3N4 via near‐field enhancement‐induced excitation; thirdly, the heterojunction formed between Au nanoparticles and pg‐C3N4 nanosheets can promote electron transfer. Consequently, Au/pg‐C3N4 presented the obvious improvement of photocatalytic activity on the degradation of rhodamine B and amaranth under simulated solar irradiation that the kinetic rate constant of degradation reaction can be increased by 3.9 and 5.7 times compared with g‐C3N4, respectively. [ABSTRACT FROM AUTHOR]

A COVID-19 outbreak emerged in Wuhan, China at the end of 2019 and developed into a global pandemic during March 2020. The effects of temperature on the dynamics of the COVID-19 epidemic in China are unknown. Data on COVID-19 daily confirmed cases and daily mean temperatures were collected from 31 provincial-level regions in mainland China between Jan. 20 and Feb. 29, 2020. Locally weighted regression and smoothing scatterplot (LOESS), distributed lag nonlinear models (DLNMs), and random-effects meta-analysis were used to examine the relationship between daily confirmed cases rate of COVID-19 and temperature conditions. The daily number of new cases peaked on Feb. 12, and then decreased. The daily confirmed cases rate of COVID-19 had a biphasic relationship with temperature (with a peak at 10 °C), and the daily incidence of COVID-19 decreased at values below and above these values. The overall epidemic intensity of COVID-19 reduced slightly following days with higher temperatures with a relative risk (RR) was 0.96 (95% CI: 0.93, 0.99). A random-effect meta-analysis including 28 provinces in mainland China, we confirmed the statistically significant association between temperature and RR during the study period (Coefficient = −0.0100, 95% CI: −0.0125, −0.0074). The DLNMs in Hubei Province (outside of Wuhan) and Wuhan showed similar patterns of temperature. Additionally, a modified susceptible-exposed-infectious-recovered (M-SEIR) model, with adjustment for climatic factors, was used to provide a complete characterization of the impact of climate on the dynamics of the COVID-19 epidemic. Unlabelled Image • Temperature is an environmental driver of the COVID-19 outbreak in China. • The incidence of COVID-19 decreases with the increase of temperature. • A modified susceptible-exposed-infectious-recovered model was developed. [ABSTRACT FROM AUTHOR]

Functional material — G-TiO 2 /VTMS/Cot which has the superhydrophobicity and effective degradation for water-soluble pollutants was prepared by simple impregnation and spraying combination. • Functional cotton fabrics were prepared by the immersion and spraying combination. • Hydrophobic materials with photocatalytic activity were prepared by spraying titanium dioxide. • Functional cotton fabrics have effective photocatalytic degradation of wastewater. • Functional cotton fabrics have excellent self-cleaning, oil-water separation and stability. Constructing functional filtration-membrane materials for effective oil-water separation and water further purification are of great significance not only to the environment but also to human health. In this work, we present a facile approach to fabricate TiO 2 -composited cotton fabrics with silanized surfaces by the immersion and spraying combination. The functionalized fabrics not merely exhibited the desirable superhydrophobic and oleophilic property towards the application of oil-water separation, but also synchronously performed the considerable photocatalytic activity for the degradation of water-soluble pollutants during the oil and water separating process. Moreover, the fabrics have the good self-cleaning ability. Importantly, the excellent performance of oil-water separation and photocatalytic degradation has been maintained through more than ten-cycles test, verifying the fabrics with the sustainability and stability. The chemical constituents, structures, morphologies, wettability and photocatalytic activity of the fabrics have been characterized by series of infrared spectrum, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, water contact angle and ultraviolet-visible absorption spectrum measurements. Our primary results provide the facile and promising strategy to fabricate superhydrophobic TiO 2 -composited cotton fabrics combined oil-water separation and photocatalytic degradation functions, which show great potential in the oil-contained wastewater treatment and environmental restoration. [ABSTRACT FROM AUTHOR]