As the commercially filter material used in a face mask, polypropylene (PP) non-woven fabric is considerably important for personal and medical protection, which plays an essential role in reducing ...exposure to infectious respiratory bacteria and airborne aerosol particles. Herein, a facial and rapid strategy for in situ synthesis of cuprous oxide nanoparticles (Cu2O NPs) on PP nonwovens with the durable antibacterial property was demonstrated using high-temperature polydimethylsiloxane based on the concept of material engineering. Owing to the instantaneously slight melting of the PP surface layer at high temperature, Cu2O NPs were rapidly in situ constructed and immobilized on the fiber surface to form an organic and inorganic hybrid layer. The as-prepared Cu2O-PP non-woven fabric exhibited excellent broad-spectrum antibacterial properties towards both the Gram-positive and Gram-negative bacteria, showing an inhibition zone of 39 mm and 18 mm for B. subtilis and P. aeruginosa, respectively. Furthermore, a durable antibacterial property was also achieved after 50 times of standard washing. Finally, the as-prepared Cu2O-PP non-woven fabric was used as an insert filter to fabricate a four-layer PP-based face mask, which may significantly improve the antibacterial performance of masks. The method provides a facile engineering strategy for medical protection with great application potential.
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•A novel strategy for rapid synthesis of Cu2O NPs on PP fabric was proposed.•Cu2O NPs were constructed on slight melting surface layer of PP fiber within 50s.•Cu2O-PP exhibited durable antibacterial properties in protection applications.
Ethanol (EtOH)-water (H
2
O) mixture, as an environmentally friendly organic solvent, has been widely used in green textile dyeing technologies to reduce water consumption. However, it is essential ...to develop a sustainable and energy-saving approach for the recovery of the EtOH-H
2
O mixture to mitigate the global energy crisis. Herein, inspired by the transpiration process of a tree, we designed a bilayer structured solar energy-driven recovery device composed of a solar absorption layer and a liquid transport layer using the lignocellulosic biomass
Juncus effusus
(JE) and carbon nanotubes (CNTs). Benefiting from the structural design and distinct properties of the 3D hierarchically porous JE fibres, the as-prepared device exhibited an excellent light absorbability (>95.90%) and photothermal conversion capability, and was further used to purify the dye-contaminated EtOH-H
2
O mixture by steam generation from solar energy. By using this stable recovery device, the evaporation rate towards the EtOH-H
2
O mixture was up to 2.43 kg m
−2
h
−1
under one-sun illumination, which is approximately 3.6 times that of natural evaporation. Furthermore, we fabricated a large-scale steam evaporator with a total area of 900 cm
2
for the recovery of the EtOH-H
2
O mixture, which was placed in an outdoor environment for one whole day (0:00-24:00) to evaluate the real-world evaporation and recovery performance. The EtOH content of the collected mixture remained almost invariable after evaporation, showing great potential in industrial production. The lignocellulosic JE-based evaporation device may be a promising solar energy-driven system for the highly efficient recovery of the EtOH-H
2
O mixture.
A highly efficient and stable solar energy-driven device was fabricated using lignocellulosic biomass
Juncus effusus
for the recovery of ethanol-water mixture.
The principle of the dynamic voltage restorer (DVR) to the voltage sag problem with phase angle jump is analyzed in this paper. Based on the fundamental component of steady-state equivalent circuit, ...the phase diagram with voltage fluctuations and phase angle jump is shown. According to instantaneous reactive power theory and the low-pass filter theory, the initial phase of the source fundamental phase voltage and phase angle jump are given. And with the optimum voltage injection angle based on minimum energy compensation, the target voltage function on which gives the appropriate compensation output voltage of DVR is determined. The simulation process and results are also offered. The harmonic current of nonlinear rectifier can generate the grid pollution and reduce the power factor when correcting. To solve this problem the paper proposes to adopt active power factor correction (APFC) circuit on the input side to reduce harmonic and improve the power factor. A prototype using digital signal processing (DSP) as the master control chip is designed and the software process is developed. Finally, the experimental results are provided to verify the rationality of the optimal voltage injection angle of series compensation based on the minimum energy control strategy.
Based on the principle and the mathematical model of Active Power Filter(APF), this paper proposes a improved method which is aiming to solve the selection for dc capacitor parameter. On the basis of ...the instantaneous reactive power theory the energy flow relationships of ac and dc sides in APF inverters for different compensation purposes are analyzed. The voltage fluctuation is caused by the inverter power losses and instantaneous active power ac component. Taking a three-phase non-controllable load as an example, the calculation method of capacitor parameter selection is given. The voltage fluctuation of dc capacitor is less than 0.55 per cent. Then it is turned out to be true by the outcome of emulation
In this paper, the main circuit structure with series dynamic voltage restorer (DVR) and shunt active power filter (APF) of unified power quality conditioner (UPQC) is taken as the research object. ...According to its fundament component of steady-state equivalent circuit the phasor representation in voltage changing is shown. The optimum angle voltage injection of DVR is proposed by the principle of main circuit minimum total capacity. The output compensation voltage of UPQC is given according to optimum angle voltage injection on minimum total capacity. The initial phase of fundament component of source phase voltage and phase angle jump are based on the instantaneous reactive power and soft phase locked loop (SPLL) theory. The harmonic current is compensated by using self-adaptive fuzzy control technology which can improve harmonic current detection method on the shunt inverter. The experiment results are provided in order to verify the rationality of this control strategy.
Objective To investigate the relationship between mean platelet volume （MPV） and β2-microglobulin and cardiac valve calcification （CVC） in maintenance hemodialysis patients， aiming to provide a basis ...for clinical prediction and diagnosis of CVC. Methods Seventy patients on regular hemodialysis were selected and divided into the non-CVC （n=36） and CVC groups （n=34） according to the presence or absence of CVC. Gender， age， dialysis age， blood phosphorus， blood calcium， parathyroid hormone， 25 hydroxy-vitamin D3， albumin， prealbumin， iron， unsaturated iron， transferrin， ferritin total iron binding capacity， alkaline phosphatase， lipids， β2-microglobulin， MPV and neutrophil-to-lymphocyte ratio （NLR） were statistically compared between two groups. The risk factors for the incidence of CVC were assessed by Logistic regression analysis. Results Compared with the non-CVC group， age， dialysis age， MPV， β2-microglobulin and NLR were significantly higher in the CVC group， and all differences were statistically significa
This study aims to investigate delays, delay increases, and delay recovery characteristics, by using statistical methods to clarify delay propagation patterns according to historical records of the ...Wuhan-Guangzhou high-speed railway (HSR) in China in 2014 and 2015. Specifically, we examined arrival and departure delay duration distributions and used heatmaps to demonstrate the spatiotemporal frequency distribution of delays, delay increases, and delay recovery, and the heatmaps clearly show hot spots (coordinates with high frequencies) in a timetable. Then, we separated delays as discrete intervals according to their severity, and analyzed the delay increasing frequency and the delay increasing severity within each interval, so as to clarify the relationships of delay increasing probability and delay increasing severity with delay extents. Next, we investigated the observed delay recoveries and prescheduled buffer times at (in) station (section), which demonstrate the recovery ability of each station and section. Finally, to understand the key influencing factor of delay propagation, we analyzed the relationship between capacity utilization and delays, delay increases, and delay recoveries, by examining their Pearson correlation coefficients. These indicate that delay frequencies and delay increasing frequencies with Pearson correlation coefficients as high as 0.9 are highly dependent on capacity utilization. The uncovered delay propagation patterns can enrich dispatchers' experience, and improve their decision-making ability during real-time dispatching in HSR.
Fatty acid biosynthesis （FAS） is a vital process in cells. Fatty acids are essential for cell assembly and cellular meabolism. Abnormal FAS directly correlates with cell growth delay and human ...diseases, such as metabolic syndromes and various cancers. The FAS system utilizes an acyl carrier protein （ACP） as a transporter to stabilize and shuttle the growing fatty acid chain throughout enzymatic modules for stepwise catalysis. Studying the interactions between enzymatic modules and ACP is, therefore, critical for understanding the biological function of the FAS system. However, the information remains unclear due to the high flexibility of ACP and its weak interaction with enzymatic modules. We present here a 2.55 A crystal structure of type II FAS dehydratase FabZ in complex with holo-ACP, which exhibits a highly symmetrical FabZ hexamer-ACP3 stoichiometry with each ACP binding to a FabZ dimer subunit. Further structural analysis, together with biophysical and computational results, reveals a novel dynamic seesaw-like ACP binding and catalysis mechanism for the dehydratase module in the FAS system, which is regulated by a critical gatekeeper residue （Tyr100 in FabZ） that manipulates the movements of the β-sheet layer. These findings improve the general understanding of the dehydration process in the FAS system and will potentially facilitate drug and therapeutic design for diseases associated with abnormalities in FAS.
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