In this work, the polyacrylonitrile monolayer/composite nanofibrous membranes were successfully fabricated at different processing parameters. As expected, compared with monolayer membranes, the ...composite membrane revealed high breaking strength, high breaking elongation, high porosity, and good filtration performance. The composite method used in this article also provides new ideas for designing filter materials.
There have been some advances in multivariate control charts in recent years. This paper presents a new simultaneous scheme for monitoring both the mean and variability of a multivariate normal ...process in a single chart, which is developed by improving and modifying another recently proposed scheme. We not only propose a new control scheme but also make it adaptive by varying all control chart parameters. Our scheme, for the first time, considers the process variability in two forms: "covariance matrix" and "multivariate coefficient of variation (MCV)". This scheme, again for the first time, considers simultaneous monitoring of the MCV with another process parameter (in our case, the mean vector). In addition, we develop a Markov chain model to compute the average run length and average time to signal values. We conduct extensive numerical analyses to measure the performance of the proposed scheme in two scenarios of process variability. At last, we present a numerical example by using a real dataset from a healthcare process to illustrate how the scheme can be implemented in practice.
•Mechanism analysis of municipal solid waste incineration (MSWI) has been narrated.•Numerical simulation method of the MSWI process is compared and discussed.•Coupling several software can produce ...customized simulation models based on actual process data.•Digital twin model construction for environmental protection requires artificial intelligence.
Determining the status of the municipal solid waste incineration (MSWI) process due to the composition variations of MSW, operational differences of the MSWI plants, and maintenance uncertainties of the incineration devices is difficult. Moreover, the optimal control algorithms developed off-line lack the support of the incineration mechanism. These conditions complicate the cost-effective operation of the MSWI plants. The development of customized numerical simulation models can simulate the incineration effects and obtain the extreme value of key process parameters to support its operational optimal control. This article aims to review the mechanical characteristics and numerical simulation methods of the MSWI process based on mechanical grates, thus providing support for the construction of a customized numerical simulation model and the realization of a digital twin system for the actual MSWI process. First, the mechanical characteristic of the MSWI process is comprehensively analyzed. Then, the numerical simulation method based on commercial and self-developed software is summarized and compared. Furthermore, the difficulties in creating customized numerical simulations and constructing digital twin models are discussed. Finally, the conclusion and research directions are established on the basis of the concluding ideas and specific commentaries. Results show that coupling several types of software can facilitate the creation of customized simulations based on actual process data. The development of an intelligent digital twin encounters several difficulties that must be highlighted because the combination of the numerical simulation model of the entire process can analyze the mechanism and the realization of matching the model with actual process data. The current study revealed that the digital twin model based on mechanical characteristics and numerical simulations by using actual process data and artificial intelligence technology could play a significant role in the safety and operation optimization of the MSWI process.
Inkjet printing is recognised as an efficient method for direct deposition of functional materials on flexible substrates in predesigned patterns owing to simple processing, low cost and higher ...adaptability for large scale fabrication of electronic devices, sensors, light emitting diodes,
etc.
Inks used in inkjet printing mostly consist of organic polymers, metal nanoparticles and carbon materials such as graphene and carbon nanotubes. For effectiveness of the printing process, the fluid dynamic parameters such as viscosity and surface tension, as well as dimensionless quantities such as the Weber number, Reynolds number, and Ohnesorge number, must be within a suitable limit. More frequently, this process suffers due to the formation of a coffee ring during the post printing process, which affects the morphology as well as electrical conductivity of the printed pattern. In this review, we have summarized the various aspects of inks such as fluid dynamical parameters of inks, mechanism of the coffee ring formation, different types of ink preparation strategies and their applications in sensors, thin film transistors, and energy storage devices.
The recent progress, challenges and promising future of design and synthesis of inks and device fabrication by inkjet printing are reviewed and discussed.
Review articles on binding kinetics essentially focus on drugs that dissociate slowly from their target since this is required for the successful treatment of many pathophysiological conditions. ...Recently, the therapeutic benefit of a high kon (i.e. the second order association rate constant) has also been linked to fast association and to a fast clinical action. Other studies, however, called this assertion into question since additional factors, like the dosing paradigm and the binding mechanism, are important as well. The still ongoing reticence about integrating binding kinetics in lead optimization programs motivated us to critically review the link between the drug's kinetic rate constants and their in vitro and in vivo target occupancy profile, with special focus on kon. The presented simulations tally with a positive link between a drug's effective/observed association rate (which is quite easy to determine in vitro) and the swiftness of its clinical action. On the other hand, the simulations show that the kon-concept should not be confounded with the effective association process since increasing this parameter only enhances the drug's in vitro and in vivo association under certain conditions: the binding mechanism should be suitable, rebinding (and thus the factors within the target's micro-environment that favour this mechanism) should not be too prominent and the dosage should not be kept in par with the drug's affinity. Otherwise, increasing kon could be ineffective or even be counter-productive.
CO2 mineral sequestration is a promising strategy to combat global warming. Indirect CO2 mineral sequestration was proposed in our previous study by using blast furnace slag as feedstock. As the ...continuity of this research, the continuous experiment process was carried out in a self-designed rotary kiln, and the results were compared with those of the batch experiment. The results showed that several problematic situations, such as the formation of kiln rings, insufficient mass, and heat transfer, occurred in the continuous experiment. A “returning charge” operation by adding an inert component into the feedstock was suggested for the prevention of ring formation and achieved good results. The reaction conditions for the continuous experiment were harsher than those of the batch experiment due to the scale-up effects. Preliminary analysis of CO2 net-emission reduction was conducted based on the continuous experimental results. It was shown that the net reduction of CO2 emissions amounted to 36 kg for 1000 kg of blast furnace slag processed. The results demonstrated in this study can act as guidance for pilot- or industrial-scale applications of indirect CO2 mineral sequestration technologies, especially for process parameter optimization and equipment design.
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•A continuous experiment for CO2 mineralization was carried out.•A “returning charge” operation was suggested for the prevention of ring formation.•The net reduction of CO2 emissions amounted to 36 kg for disposal of 1000 kg slag.•The results can act as guidance for pilot- or industrial-scale applications of CO2 mineralization.
Heterogeneous Fenton oxidation based on interfacial reactions between solid iron catalysts (&z.tbd;Fe) and H
2
O
2
to produce hydroxyl radicals for organic wastewater treatment has attracted wide ...interest. Compared with homogeneous Fenton oxidation, it overcomes the pH limitation and sludge production problem, but also encounters several challenging issues, such as low-density &z.tbd;Fe(
ii
) sites and/or sluggish &z.tbd;Fe(
ii
) regeneration for H
2
O
2
activation, high H
2
O
2
consumption, and insufficient catalyst stability. Numerous studies have been devoted to optimizing catalyst's composition and structure and/or applying external physical energies to enhance electron transfer and accelerate the redox cycle of &z.tbd;Fe(
iii
)/Fe(
ii
) to boost H
2
O
2
activation. Among various strategies, the combination of photocatalysis and heterogeneous Fenton oxidation (heterogeneous catalytic photo-Fenton oxidation) is promising and has attracted wide attention with tremendous research progress being made. Based on a comprehensive literature survey, this review summarizes and analyses state-of-the-art research in this field. Firstly, a general background, especially the principles of heterogeneous photo-Fenton oxidation, is provided. Then, the recent developments in constructing supported iron catalysts for heterogeneous photo-Fenton oxidation are summarized, with a focus on iron catalysts supported on four popular semiconductors (TiO
2
, carbon nitride, bismuth-related crystals and metal-organic frameworks). The synthesis strategies of iron catalysts supported on these semiconductors are analysed with a focus on iron species in different states, from lattice doping and single-atom sites, to surface amorphous/crystalline nanoparticles, and further to heterojunctions. The synergetic behaviours between the semiconductor supports and iron species and their electron migration pathways and active species formation mechanisms in heterogeneous photo-Fenton oxidation are summarized. Afterwards, several critical influencing factors on performance, including catalyst factors (light absorption, electron transfer, iron loading amount, and defects) and processing parameters (radicals, solution pH and catalyst separation), are discussed. Finally, typical semiconductor supported transition metal catalysts for sulfate radical production and other iron catalysts supported on conventional supports (silicas, zeolites, carbons and clays) for heterogeneous photo-Fenton oxidation are briefly described. In this review, some suggestions for future research in this field are also provided. We hope this review could provide a basic understanding of heterogeneous photo-Fenton oxidation and attract more interest to further develop this technology toward practical water treatment.
This review summarizes the typical progress in nanostructured semiconductor supported iron catalysts and their applications in heterogeneous photo-Fenton oxidation.
In order to improve the quality and properties of the coating, a certain amount of Ti was added to the plasma cladding Fe-Cr-C coating in the early stage. And Fe-Cr-C-Ti composite powder was prepared ...by precursor carbonization-composition process. In situ synthesized TiC-Fe-Cr coatings were fabricated on substrate of Q235 steel by plasma cladding process with Fe-Cr-C-Ti composite powder. Microstructure of the coating with different process parameters, including cladding current, cladding speed, number of overlapping cladding layers, were analyzed by scanning electron microscope (SEM). The results show that the structure of the TiC-Fe-Cr coating is greatly affected by the fusion current, the cladding speed and the overlapping cladding process. In this test, when the cladding current of 300A and the cladding process parameter of the cladding speed of 50 mm/min are clad with three layers, a well-formed and well-structured TiC-Fe-Cr coating can be obtained. Which are the best synthetic process parameters in this test.
Fiber and metal materials used in Fiber Metal Laminate (FML) have different machinability properties due to their different structures. This case has made it a research topic to obtain good hole ...quality in these materials. A good match between the parameters used is required for the machinability of FML. Traditional and non-traditional machining methods in the machining of FML in this article were investigated and a comprehensive review regarding the machining parameters and hole quality were conducted. Considering the methods and parameters used, the defects occurring in the holes (delamination, hole size and circularity, surface roughness, etc.) were determined and the most suitable processing methods and parameters were picked in order to minimize these defects. As a result, the most suitable machining method and optimum cutting parameters for a better hole quality in FML machinability are determined, and it is aimed that this study will be beneficial to scientific and industrial societies.
Severe plastic deformation (SPD) has established itself as a potent means of producing bulk ultrafine grained and nanostructured materials. It has given rise to burgeoning research that has become an ...integral part of the present day materials science. This research has received a broad coverage in literature, and several recent publications (including reviews in Progress in Materials Science) provide a very good introduction to the history, the current status, and the potential applications of SPD technologies. There is one aspect of SPD-related research, though, which despite its great importance has not been covered by any substantive review, viz. the modelling and simulation work. Due to the complexity of SPD processing and the specificity of material behaviour at the extremely large strains involved, analytical and computational studies have been indispensable for process design, parameter optimisation, and the prediction of the microstructures and properties of the ultrafine grained materials produced. They have also provided a better understanding of the physical mechanisms underlying SPD and the mechanical response of the materials that underwent this kind of processing. The pertinent literature is vast and often difficult to navigate. The present article addresses this aspect of SPD and provides a commented exposé of a modelling and numerical simulation toolkit that has been, or can potentially be, applied in the context of severe plastic deformation.
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