Search

Under intermittent noncollocated boundary measurement (BM), this article introduces a dynamic intermittent boundary output-feedback control for reaction–diffusion systems (RDSs). Since the system state is not fully available and intermittent noncollocated BM makes the intermittent acrlong BC design very difficult, an observer-based control technique is given to surmount this design difficulty. Initially, a acrlong PDE state observer under intermittent noncollocated BM is provided to estimate the RDS state. Then, the exponential stability of closed-loop RDSs is ensured by constructing an observer-based controller. Sufficient conditions of such dynamic controller are subsequently presented by linear matrix inequalities (LMIs) via employing a switching time-dependent acrlong LF and inequality techniques. Finally, two numerical examples are presented to demonstrate the effectiveness of the proposed design approach.

This article investigates robust non-fragile event-triggered sampled-data fuzzy (ETSDF) control for uncertain nonlinear delayed distributed parameter systems. Initially, a T-S fuzzy delayed partial differential equation model is presented to exactly describe the uncertain nonlinear delayed distributed parameter systems (DPS). secondly, a robust non-fragile ETSDF control strategy is proposed to reduce the unnecessary SD and cope with the uncertainties in controller and system. Then, based on an appropriate Lyapunov functional, the exponential stability conditions of closed-loop nonlinear delayed DPS via linear matrix inequalities are presented. Lastly, one example is presented to illustrate the design method.

For nonlinear space-varying parabolic distributed parameter systems, this paper introduces an H ∞ fuzzy intermittent boundary control, where the output measurements are only available at some specified boundary position (i.e., boundary measurements). Initially, a Takagi–Sugeno fuzzy parabolic partial differential equation is used to precisely describe the nonlinear space-varying parabolic distributed parameter system. Then, under boundary measurements, an H ∞ fuzzy intermittent boundary control design based on the Takagi–Sugeno fuzzy parabolic partial differential equation model ensuring the exponential stability with an H ∞ performance for closed-loop space-varying distributed parameter system is subsequently obtained via spatial linear matrix inequalities by employing inequality techniques and piecewise switching-time-dependent Lyapunov function. Furthermore, in order to solve the H ∞ fuzzy intermittent boundary controller design of nonlinear space-varying parabolic distributed parameter systems under boundary measurements, we express spatial linear matrix inequalities as linear matrix inequalities and further present some linear matrix inequality based fuzzy intermittent boundary control design conditions respecting the property of membership functions. Finally, two simulation examples are offered to demonstrate the effectiveness of the proposed H ∞ fuzzy intermittent boundary control method. [ABSTRACT FROM AUTHOR]

Water eutrophication has become a worldwide environmental problem, and understanding the causing factors of water eutrophication will help for prevention and remediation of water eutrophication. The major causing factors of water eutrophication and purifying technologies were reviewed in this paper. There are many factors causing water eutrophication, including human activities, air deposition, precipitation, fertilizer runoff, animal waste and rural household pollution. Therefore, it is difficult to remediate eutrophic water. Constructed wetlands and floating beds have proven to be promising treatment alternatives in developing countries. Moreover, the biomass from phytoremediation ecological engineering can be used bioenergy feedstocks or animal feeds.

The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthorniiSeemen, Thalia dealbata, Vetiveria zizanioides, and Phragmitessp., sequentially through pyrolysis at 500 °C in a N2environment, and under different temperatures (500, 600, and 700 °C) in a CO2environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium (Mg) content of biochar derived from T. dealbata(TC) was obviously higher than that of the other plant biochars. This biochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbatabiochar produced at 600 °C (TC600) is the most promising sorbent for removing contaminants (N and P) from aqueous solution. Therefore, T. dealbataappears to be the best candidate for phytoremediation application as its biomass can make a good biochar for environmental cleaning.