On Modeling and Constrained Model Predictive Control of Open Irrigation Canals

This paper proposes a model predictive control of open irrigation canals with constraints. The Saint-Venant equations are widely used in hydraulics to model an open canal. As a set of hyperbolic partial differential equations, they are not solved explicitly and difficult to design optimal control algorithms. In this work, a prediction model of an open canal is developed by discretizing the Saint-Venant equations in both space and time. Based on the prediction model, a constrained model predictive control was firstly investigated for the case of one single-pool canal and then generalized to the case of a cascaded canal with multipools. The hydraulic software SICC was used to simulate the canal and test the algorithms with application to a real-world irrigation canal of Yehe irrigation area located in Hebei province

Research on the Mesoscopic Characteristics of Kelvin–Helmholtz Instability in Polymer Fluids with Dissipative Particle Dynamics

In this paper, the two-dimensional Kelvin–Helmholtz (KH) instability occurring in the shear flow of polymer fluids is modeled by the dissipative particle dynamics (DPD) method at the coarse-grained molecular level. A revised FENE model is proposed to properly describe the polymer chains. In this revised model, the elastic repulsion and tension are both considered between the adjacent beads, the bond length of which is set as one segment’s equilibrium length. The entanglements between polymer chains are described with a bead repulsive potential. The characteristics of such a KH instability in polymer fluid shear flow can be successfully captured in the simulations by the use of the modified FENE model. The numerical results show that the waves and vortexes grow more slowly in the shear flow of the polymer fluids than in the Newtonian fluid case, these vortexes become flat, and the polymer impedes the mixing of fluids and inhibits the generation of turbulence. The effects of the polymer concentration, chain length, and extensibility are also investigated regarding the evolution of KH instability. It is shown that the mixing of two polymer fluids reduces, and the KH instability becomes more suppressed as the polymer concentration increases. The vortexes become much longer with the evolution of the elongated interface as the chain length turns longer. As the extensibility increases, the vortexes become more flattened. Moreover, the roll-up process is significantly suppressed if the polymer has sufficiently high extensibility. These observations show that the polymer and its properties significantly influence the formation and evolution of the coherent structures such as the waves and vortexes in the KH instability progress

Deliver on a Promise: Hydrogen-Bonded Polymer Nanomedicine with a Precise Ratio of Chemodrug and Photosensitizer for Intelligent Cancer Therapy

The outcomes of combined cancer therapy are largely related to loading content and contribution of each therapeutic agent; however, fine-tuning the ratio of two coloaded components toward precise cancer therapy is a great challenge and still remains in its infancy. We herein develop a supramolecular polymer scaffold to optimize the coloading ratio of chemotherapeutic agent and photosensitizer through hydrogen-bonding (H-bonding) interaction, for maximizing the efficacy of intelligent cancer chemo/photodynamic therapies (CT/PDT). To do so, we first synthesize a thymine (THY)-functionalized tetraphenylporphyrin photosensitizer (i.e., TTPP), featuring the same molecular configuration of H-bonding array with chemotherapeutic carmofur (e.g., 1-hexylcarbamoyl-5-fluorouracil, HCFU). Meanwhile, a six-arm star-shaped amphiphilic polymer vehicle P(DAPA-co-DPMA-co-OEGMA)6 (poly(diaminopyridine acrylamide-co-2-(diisopropylamino)ethyl methacrylate-co-oligo(ethylene glycol) monomethyl ether methacrylate)6) is prepared, bearing hydrophilic and biocompatible POEGMA segment, along with hydrophobic PDAPA and PDPMA segments, characterizing the randomly dispersed dual functionalities, i.e., heterocomplementary H-bonding DAP motifs and pH-responsive protonation DPMA content. Thanks to the identical DAP/HCFU and DAP/TTPP H-bonding association capability, the incorporation of both HCFU and TTPP to six-arm star-shaped P(DAPA-co-DPMA-co-OEGMA)6 vehicle, with an optimized coloading ratio, can be straightforwardly realized by adjusting the feeding concentrations, thus yielding the hydrogen-bonded supramolecular nanoparticles (i.e., HCFU-TTPP-SPNs), demonstrating the codelivery of two components with the promise to optimize the combined CT/PDT efficacy

Hydrogen-bonded supramolecular adhesives: Synthesis, responsiveness, and application

Adhesive bonding to diverse substances is vital to a great number of the established, cutting-edge and emerging applications. We have witnessed, in the last few years, the transformative progress in achieving robust adhesive bonding and tunable debonding behavior, which mostly employing the supramolecular forces. Among the diverse supramolecular forces, the contribution of hydrogen-bonds (H-bonds) to adhesives, on the modality of directionality, selectivity and sensitivity, can function as nano-scaled bonding agents for improved interfacial interactions, thus paved novel perspectives to the design and creation of glue materials with outstanding performance. On account of the dynamic and reversible feature, a characteristic principally determined for H-bonding (macro)molecules could be employed as adhesive platform for affording outstanding attaching, connecting and on demand disconnecting, arising from the combination of adhesion/cohesion process via H-bonding interactions and the responsive characteristics. Thus, H-bonded adhesives with abundant diverse molecular configuration furnish a rich toolbox that can fulfill universal yet specific needs with unique advantages, demonstrating great opportunities for fundamental researches and practical applications. Herein we outline and summarize the design and creation of H-bonded adhesives, responsive attaching/detaching, and applications in advanced materials. We propose the guidance for further designing H-bonded adhesives, in concert with biomedical science, physics, mechanical and electric, informatics or robotics of promising future

Hydrogen‐Bonds‐Mediated Nanomedicine: Design, Synthesis, and Applications

International audienceAmong the various challenges in medicine, diagnosis, complete cure, and healing of cancers remain difficult given the heterogeneity and complexity of such a disease. Differing from conventional platforms with often unsatisfactory theranostic capabilities, the contribution of supramolecular interactions, such as hydrogen-bonds (H-bonds), to cancer nanotheranostics opens new perspectives for the design of biomedical materials, exhibiting remarkable properties and easier processability. Thanks to their dynamic characteristics, a feature generally observed for noncovalent interactions, H-bonding (macro)molecules can be used as supramolecular motifs for yielding drug- and diagnostic carriers that possess attractive features, arising from the combination of assembled nanoplatforms and the responsiveness of H-bonds. Thus, H-bonded nanomedicine provides a rich toolbox that is useful to fulfill biomedical needs with unique advantages in early-stage diagnosis and therapy, demonstrating the promising potential in clinical translations and applications. Here the design and synthetic routes toward H-bonded nanomedicines, focus on the growing understanding of the structure-function relationship for efficient cancer treatment are summarized. A guidance for designing new H-bonded intelligent theranostic agents is proposed, to inspire more successful explorations of cancer nanotheranostics and finally to promote potential clinical translations

Hydrogen-bonded supramolecular polymer micelles with pH/photothermal-responsive carmofur release and combined chemo-photothermal therapy

International audienceIntegrating biomedical applications (e.g., drug delivery) into supramolecular chemistry is a promising strategy. This work targets the construction of hydrogen-bonded (H-bonded) supramolecular polymeric micelles loaded with chemotherapy drugs (carmofur) and photothermal agents (IR780) for combined chemo-photothermal therapies (CT/PTT)

Hydrogen‐Bonded Supramolecular Polymer Adhesives: Straightforward Synthesis and Strong Substrate Interaction

International audienceHigh-performance adhesives are of great interest in view of industrial demand. We herein identify a straightforward synthetic strategy towards universal hydrogen-bonded (H-bonded) polymeric adhesives, using a side-chain barbiturate (Ba) and Hamilton wedge (HW) functionalized copolymer. Starting from a rubbery copolymer containing thiolactone derivatives, Ba and HW moieties are tethered as pendant groups via an efficient one-pot two-step amine-thiol-bromo conjugation. Hetero-complementary Ba/HW interactions thus yield H-bonded supramolecular polymeric networks. In addition to an enhanced polymeric network integrity induced by specific Ba/HW association, the presence of individual Ba or HW moieties enables strong binding to a range of substrates, outstanding compared to commercial glues and reported adhesive