An important requirement of wastewater treatment plants (WWTPs) is compliance with the local regulations on effluent discharge, which are going to become more stringent in the future. The operation of WWTPs exhibits a trade-off between operational cost and effluent quality, which provides a scope for optimization. Process optimization is usually done by optimizing a model of the process. However, due to inevitable plant−model mismatch, the computed optimal solution is usually not optimal for the plant. This study represents the first attempt to handle plant−model mismatch via constraint adaptation (CA) for the real-time optimization of WWTPs. In this simulation study, the “plant” is a model adopted from the BSM1 benchmark, while a reduced-order “model” is used for making predictions and computing the optimal inputs. A first implementation uses steady-state measurements of the plant constraints to adjust the model in the optimization framework. A fast CA technique is also proposed, whic... [more]

The stabilization problems for time-delay stochastic systems with multiplicative noise in the control variable are investigated in this paper. The innovative contributions are described as follows. Since the past work on stabilization is based on some delay-dependent algebraic Riccati equation (DARE), how to numerically calculate the stabilizing solution remains an unsolved and open problem. On the one hand, an iterative algorithm for computing the unique stabilizing solution of DARE is proposed, while the convergence property is also proved. On the other hand, the concepts of critical stabilization and essential destabilization are proposed as a supplement to stochastic stabilization in terms of spectrum technique. Moreover, the Lyapunov-based necessary and sufficient conditions are developed.

Globalization has created a highly competitive and diverse market, an uncertain and risky business environment, and changing customer expectations. An effective manufacturing strategy reduces complexity and provides organizations with a well-organized manufacturing structure. However, existing research on manufacturing strategies appears scattered, lacking systematic understanding and finding no causal relationship between manufacturing strategies’ outputs (MSOs) and their importance. Therefore, this study is a pioneer in identifying the influential factors of MSOs in the adoption of Industry 4.0 (I4.0) technologies utilizing the decision-making trial and evaluation laboratory (DEMATEL) approach. This method is considered an effective method for identifying the cause-effect relationship of complex problems. It evaluates interdependent relationships among MSO factors from the perspective of academic and industry experts. Identifying cause and effect factors leads to increasing the marke... [more]

Coalescence-induced droplet jumping on superhydrophobic surfaces with different initial positions was numerically simulated using the 2D multi-relaxation-time (MRT) Lattice Boltzmann method (LBM). Simulation results show that for coalesced droplets with radii close to the structure length scale, the change of initial droplet positions leads to a significant deviation of jumping velocity and direction. By finely tuning the initial droplet positions on a flat-pillared surface, perpendicular jumping, oblique jumping, and non-jumping are successively observed on the same structured surface. Droplet morphologies and vector diagrams at different moments are considered. It is revealed that the asymmetric droplet detachment from the structured surface leads to the directional transport of liquid mass in the droplet and further results in the oblique jumping of the coalesced droplet. In order to eliminate the influence of initial droplet position on droplet jumping probability, a surface with p... [more]

The article investigated the flow of boiling streams through a nozzle with an oblique cut. Due to this flow organization, deviation from the nozzle axis at the vortex chamber inlet occurred. The study of flow modeling in the inlet section was carried out. The flow design and the calculation scheme of the vortex liquid−steam jet apparatus were proposed. Analytical expressions between the main operating parameters were obtained according to the developed mathematical model. A recommended oblique-cut angle for the active-flow nozzle was evaluated considering the transition through the first critical section based on the tangential velocity flow model. Validation of the mathematical model in the inlet section of the vortex chamber was provided based on the comparison with available experimental data. Flow visualization in the inlet section of the vortex chamber was obtained. The assumption of uneven flow distribution was confirmed experimentally. Overall, the boiling liquid flow was implem... [more]

Carob syrup is one of the most important carob products, which can have applications in pastry and confectionery, as a fruit preservative, but also in the pharmaceutical field because of the antimicrobial activity due to its polyphenol content. Carob syrup is traditionally made through a very time-consuming process, involving solid−liquid extraction in boiling water and concentration at a high temperature (>100 °C), which potentially causes the degradation of the active compounds (i.e., procyanidins or flavonol glycosides). Therefore, in this work, an alternative and less drastic method based on ultrasound technology was proposed to produce carob syrup. Processing conditions (i.e., time, temperature, and liquid−solid ratio) influencing the extraction of total soluble solids (TSS) and total phenolic compounds (TPC) were optimized using a central composite design coupled to response surface methodology. Reliable mathematical models allowed us to predict the highest TSS (24 ± 2 °Brix) and... [more]

Spices are known to have various physiological functions. We focused on the anti-glycation effects of spices, researched anti-glycation active ingredients in coriander (Coriandrum sativum L.) and fennel (Foeniculum vulgare) seeds, and conducted experiments using human skin-derived fibroblast TIG-110 cells as a model of glycation. We isolated 11 compounds from two spice seeds and found several substances that showed anti-glycation activity. A new compound (5,5′-diallyl-2,2′-diglucopyranosyl-3,3′-dimethoxy diphenyl ether) was isolated from fennel seeds and showed high anti-glycation activity with an IC50 value of 0.08 mM, thereby indicating a high anti-glycosylation activity. In this study, we established a glyoxal (GO)-induced glycation test method for human skin cells, confirmed the anti-glycation effect of spice seeds using this glycation induction model, and found that the exposure of TIG-110 human skin-derived fibroblast cells to GO reduced cell viability. The most stable conditions... [more]

Employees are the most important and dynamic elements in the railway transportation system. How to achieve accurate control of inertial violation of “key person, key matter, key period”, and formulate more personalized risk response strategy is a thorny problem that faced by safety managers. The existing risk response usually takes control measures from the perspective of the system as a whole, ignoring the heterogeneity of risk, and the selection of response strategies only considers the target risks to be dealt with, ignoring the secondary risks that may occur in the process of risk response, or the residual risks formed by changing the existing risk, coupled with the lack of quantitative evaluation of risk response effect, resulting in poor risk response effect. By introducing the grid theory and taking the risk event of “the assistant watchman does not appear as required” at Huangyangcheng station of Shenshuo Railway as an example, this study constructs a grid response model of the... [more]

Food production is increasing year by year, with modern agriculture occupying high-fertility soils [...]

The aim of this study was to evaluate the effects of a complex Bacillus subtilis additive on the fermentation quality and bacterial community during the ensiling process of whole-plant corn silage (WPCS). The pH values of WPCS treated with the B. subtilis inoculant decreased faster than those of the control without inoculant, and significantly higher contents of lactic acid (LA) and acetic acid (AA) were observed. After 45 days of ensiling, the LA contents reached 7.95% (w/w). In the treatment group, the neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents decreased significantly compared to the control, and the degradation rates of the NDF and ADF were 26.52% and 27.34% after 45 days, respectively. The deoxynivalenol (DON) content in the treatment group decreased to 205.67 μg/kg, which was significantly lower than the content of 382.51 μg/kg in the control group. The results indicated the positive effect of the B. subtilis inoculant in improving WPCS fermentation, esp... [more]

China is taking initiative in energy transition to cope with the long-term controversy of its enormous energy consumption, aiming to use less carbon. Wind power, especially offshore wind energy, has become a prevailing alternative due to its low carbon emissions, renewability, competitiveness, and operation security. The layout of a transmission channel is a key consideration in marine project implementation. This paper investigates the technical characteristics, application status, and viable advantages of a conventional AC transmission, voltage source converter-based high-voltage direct current (VSC-HVDC) transmission, gas-insulated line (GIL) transmission, and hybrid HVDC transmission. A component-resolved evaluation model was proposed to estimate the costs to be incurred of four electrical transmission options for offshore wind power along the coast of Eastern China, with technical feasibility and economical considerations. Cost comparisons and component sensitivity analyses were d... [more]

An experimental investigation was conducted to examine, for the first time, the influences of using different designs of tube arrangements on the local heat transfer coefficient (LHTC) in a bubble column (with a diameter of 0.13 m) equipped densely with a bundle of tubes. The effect of using two different designs of tube arrangements has been examined for a broad range of gas flow rates using a sophisticated heat transfer technique. The obtained results indicate that the LHTC increases significantly with increasing the gas velocity, regardless of the design and installation of the tubes in the column. Additionally, the shape of the LHTC’s profiles alters considerably by the presence of a bundle of tubes and their arrangements. Moreover, the results indicate that the square tube pitch arrangement provides uniform heat transfer profiles, which enhance the performance of the bubble column reactor by 30%. Furthermore, the heat transfer profiles were found to be varied with the axial height... [more]

The Lamm−Honigmann energy storage is a sorption-based storage that can be arbitrarily charged and discharged with both heat and electrical power. The mechanical charging and discharging processes of this storage are characterized by an internal heat transfer between the main components, absorber/desorber and evaporator/condenser, that is driven by the working-fluid mass transferred between those components with the help of an expansion or compression device, respectively. In this paper, thermal operation maps for the mechanical charging and discharging processes are developed from energy balances in order to predict power output and storage efficiency depending on the system state, which, in particular, is defined by the mass flow rate of vapor and the salt mass fraction of the absorbent. The conducted method is applied for the working-fluid pair LiBr/H2O. In a first step, a thermal efficiency is defined to account for second-order losses due to the internal heat transfer; e.g., for di... [more]

Peat has attracted considerable interest as a potential source of alternative fuel in terms of improving hydrocarbons production and satisfying market demand. The next decade is likely to witness a raise in its exploitation. Nevertheless, the characteristics of peat pyrolysis process, via which many experts expect a considerable generation of hydrocarbons, have not been dealt with in depth. In the present study we have applied thermal analysis combined with isoconversional and model methods for clarifying the kinetic and thermodynamic aspects of the process of generating hydrocarbons from peat via pyrolysis in the absence and presence of iron tallates as a catalytic agent. The obtained results showed a positive effect of the opted catalyst on the process of peat pyrolysis. It has been shown that the catalyst is able to reduce the energy of activation of peat pyrolysis process. Moreover, the Gibbs energy, enthalpy and entropy of complex formation values have been found lower in the pres... [more]

Preferential solute transport is a common phenomenon in soil, and it is of great significance to accurately describe the mechanism of pollutant transport and water and soil environmental governance. However, the description of preferential solutes still relies on applying solute breakthrough curves for model parameters fitting. At present, most of the solute breakthrough curves are obtained indoors, and with some limitations. Therefore, this study established a method for securing solute breakthrough curves based on the electrical resistivity method. The research results show that the change in soil concentration during the tracer infiltration process can be captured by establishing the fitting relationship between soil resistivity and solute concentration. Then the solute breakthrough curve can be found. Through a time moment analysis, the difference between the breakthrough curve parameters obtained by the traditional method and the resistivity method is slight; the average error is... [more]

The iron bath gasifier studied in this paper is a new type of reactor for handling organic solid waste, in which the complex transport phenomena comprising high temperature, the multiphase flow, mixing, and chemical reaction takes place. It is of great significance to study the melt’s flow and mass transfer behavior in this reactor. The influence of different process parameters on the mixing behavior of the molten pool was studied by the water modeling experiment and numerical simulation method. The experimental results show that the height of the water phase has a highly significant effect on the mixing time of the molten pool, followed by the horizontal angle of the side gun and the bottom blowing flow rate. As the height of the water increases, the mixing time decreases. When the horizontal angle of side lances increases, the mixing time decreases. With the increase in the flow rate of the bottom lance, the mixing time decreases. The results obtained by numerical simulation were com... [more]

This research introduces the analysis of fluoxetine and sertraline by means of the TLC-densitometric method. They provide information on LOD and LOQ under various chromatographic conditions. The study used adsorption (NPTLC) and partition (RPTLC) thin-layer chromatography in combination with a densitometric analysis. Four types of chromatographic plates precoated with: silica gel 60 F254, silica gel 60, silanized silica gel 60 F254 (RP-2), and a mixture of silica gel 60 and kieselguhr F254, as well as three mobile phases: chloroform + methanol + ammonia (9:1:0.4, v/v/v), chloroform + methanol + glacial acetic acid (5:4:1, v/v/v), and acetone + toluene + ammonia (10:9:1, v/v/v), were used in NPTLC. RP-18F254 and silanized silica gel 60 F254 (RP-2) plates and four mobile phases: methanol + water (10:0 and 9:1, v/v), acetone + water (10:0 and 9:1, v/v), were used in RPTLC. The lowest LOD and LOQ values for fluoxetine were obtained using a silanized silica gel 60 F254 (RP-2) with acetone +... [more]

The integration of insect-derived extracts in feed and food products has become a field of growing interest in recent years. In this review, we collect different studies carried out on edible insects’ transformation processes and focus on the various treatment operations, extraction technologies, and solvents used in different processing steps. We include an overview of current insights into the different steps of the transformation process: insect reception, killing methods, pretreatments, storage, delipidation, protein extraction, as well as chitin and chitosan extraction. Finally, we reflect on the most important future challenges of this sector.

In this article, an improved constraint dealing method and an extended state space model-based constrained predictive functional control (PFC) approach is developed for the denitration process in cement production. To improve the control effect of the presented strategy, first, an enhanced form-based state space model in which the changes of the output predictions can be regulated to achieve smoother system dynamics is constructed. Then, a modified constraint dealing scheme, which integrates the relaxation factors to improve the success probability of solving the relevant optimization, is also introduced for the proposed method. On the basis of the two merits, better ensemble control performance is anticipated. Simulations on the regulation of the NOx concentration in the denitration process prove the validity of the proposed constrained PFC strategy.

In this work, the GEneralised Multifluid Modelling Approach (GEMMA) is applied to the simulation of liquid−liquid extraction in a Rotating Disc Column (RDC) and a Pulsed Sieve-plate Extraction Column (PSEC). A mass transfer modelling methodology is developed, in which the multiphase flows, droplet size distribution and dispersed phase holdup predicted with computational fluid dynamics are coupled to mass transfer correlations to predict the overall mass transfer. The numerical results for the stage-averaged dispersed phase holdup, Sauter mean droplet diameter and axial solute concentration in the RDC and PSEC agree with experimental observations. The proposed modelling method provides an accurate predictive tool for complex multiphase flows, such as those observed in intensified liquid−liquid extraction, and provides an alternative approach to column design using empirical correlations or pilot plant study.

Product quality is an important part of enterprise competitiveness. Product processing is the key process of quality formation. In smart factories, the improvement of data acquisition and processing capability provides a basis for data-based quality control. In order to reduce the occurrence of product quality problems, we abstracted the product processing process as a data processing unit, abstracted the process of changing the product quality state as a process of the processing quality characteristics data, divided the measured value of quality characteristics into three states according to the fluctuation of the measured value of product quality characteristics, and then the classification model of process equipment parameters was established. The experimental results show that the error rate of the real-time dynamic prediction of quality characteristics based on equipment parameters was acceptable, and its prediction could be used as a reference in real production. The research co... [more]

The plastic deformation and interface micro annulus of oil-well cement during acid fracturing are key reasons for the failure of the wellbore seal and sustained casing pressure. However, most of the existing research ignores the influence of the wellbore cooling effect during acid fracturing, owing to which, the design conditions in the theoretical analysis may be inconsistent with those of the actual wellbore, and the calculation results may be biased. In this study, a novel elastoplastic mechanical model of the cement sheath was established. This model can analyze the yield state of the cement sheath under the influence of three-dimensional principal stress and consider the effect of the differential temperature stress on the interface debonding of the cement sheath from the beginning to the end of acid fracturing. Moreover, the generation mechanism and development law of the interface micro annulus were clarified. The findings indicated that the influence of the intermediate princip... [more]

Most of the existing research on cement slurry materials are not environmentally friendly and environmental pollution is significant. Most researchers only test its performance, but do not conduct engineering feasibility verification. In this study, the materials extracted from various wastes were used to replace part of the sulfoaluminate cement, and orthogonal experiments were designed to analyze the reaction mechanism between different materials. Finally, the optimal mixing ratio was obtained. Then, through the regression equation analysis method, digital photograph restoration technology, the finite element method and various practical engineering conditions, the feasibility of the slurry under different applicable engineering conditions was compared and analyzed. The comparison between the experimental and numerical simulation results shows that the cement slurry obtained in this study has good reliability and feasibility. It can carry out rapid grouting reinforcement. The results... [more]

Using a variety of renewable energy sources can significantly improve energy system flexibility and efficiency. Energy hubs, which have the function of generating, converting, and storing energy in various forms, are vital facilities in micro-energy networks (MENs). In this paper, we present a Solar-Assisted Compressed Air Energy Storage (SA-CAES) hub which can accommodate and flexibly supply multi-energy by being connected to a power distribution network (PDN) and a district heating network (DHN). We formulate economic dispatch models of the SA-CAES hub, the PDN, and the DHN, respectively. The economic dispatch model is formulated as a mixed-integer linear programming problem (MILP) that can be solved by commercial solvers. Further, the operationally feasible region of the SA-CAES hub is explored by thermodynamic analysis. The results indicate that the operation costs have been reduced by 4.5% in comparison with conventional MENs.

This manuscript deals with the thermal and chemical modification of a natural kaolinite that shows excellent performance in the capture of a cationic organic pollutant from the aqueous phase. Kaolinite was calcined at 700 °C and treated with HCl to remove aluminium and to obtain a siliceous material. The structural changes and the physico-chemical properties of the materials at different stages of thermal and chemical modification were investigated with several techniques, including XRPD, MAS-NMR, SEM-EDX, FT-IR, and N2 physisorption at 77 K. The ability of the parent kaolinite and siliceous material to capture the organic dye, Rhodamine B, from the aqueous phase was investigated by means of UV-Vis spectroscopy. The siliceous material exhibited better adsorption capacity with respect to the parent kaolinite. Finally, the functional stability of the siliceous material was tested over three cycles of regeneration and adsorption.