44 research outputs found

    Adaptive fuzzy sliding mode algorithm-based decentralised control for a permanent magnet spherical actuator

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    <p>The dynamic model of multi-degree-of-freedom permanent magnet (PM) spherical actuators is multivariate and nonlinear due to strong inter-axis couplings, which affects the trajectory tracking performance of the system. In this paper, a decentralised control strategy based on adaptive fuzzy sliding mode (AFSM) algorithm is developed for a PM spherical actuator to enhance its trajectory tracking performance. In this algorithm, the coupling terms are separated as subsystems from the entire system. The AFSM algorithm is applied in such a way that the fuzzy logic systems are used to approximate the subsystem with uncertainties. A sliding mode term is introduced to compensate for the effect of coupling terms and fuzzy approximation error. The stability of the proposed method is guaranteed by choosing the appropriate Lyapunov function. Both simulation and experimental results show that the proposed control algorithm can effectively handle various uncertainties and inter-axis couplings, and improve the trajectory tracking precision of the spherical actuator.</p

    In-situ secondary growth of nanocube-based Prussian-blue film as an ultrasensitive biosensor

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    A regular nanostructure has been widely confirmed to result ina marked improvement in material performance in biosensing applications. In the present study, a regular nanostructured Prussian blue (PB) film with two heterogeneous crystal layers was synthesized in-situ using a secondary growth method. A PB seed layer was first controlled to form uniform cube-like crystal nuclei through an ultrasonic reaction with a single reactant. Then, well-defined 100 nm PB nanocubes were further crystallized on this seed layer using a self-assembly approach. In order to accelerate the electron transfer rate during the enzyme reaction for glucose detection, the graphene was used as the main cross-linker to immobilize glucose oxidase on the PB film. The as-prepared biosensor exhibited high electrocatalysis and electron conductivity for the detection of trace glucose with a sensitivity of 141.5 µA mM-1 cm-2, as well as excellent anti-interference ability in the presence of ascorbic acid and uric acid under a low operation potential of -0.05 V

    Unveiling the neuroprotective potential of dietary polysaccharides: a systematic review

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    Central nervous system (CNS) disorders present a growing and costly global health challenge, accounting for over 11% of the diseases burden in high-income countries. Despite current treatments, patients often experience persistent symptoms that significantly affect their quality of life. Dietary polysaccharides have garnered attention for their potential as interventions for CNS disorders due to their diverse mechanisms of action, including antioxidant, anti-inflammatory, and neuroprotective effects. Through an analysis of research articles published between January 5, 2013 and August 30, 2023, encompassing the intervention effects of dietary polysaccharides on Alzheimer’s disease, Parkinson’s disease, depression, anxiety disorders, autism spectrum disorder, epilepsy, and stroke, we have conducted a comprehensive review with the aim of elucidating the role and mechanisms of dietary polysaccharides in various CNS diseases, spanning neurodegenerative, psychiatric, neurodevelopmental disorders, and neurological dysfunctions. At least four categories of mechanistic bases are included in the dietary polysaccharides’ intervention against CNS disease, which involves oxidative stress reduction, neuronal production, metabolic regulation, and gut barrier integrity. Notably, the ability of dietary polysaccharides to resist oxidation and modulate gut microbiota not only helps to curb the development of these diseases at an early stage, but also holds promise for the development of novel therapeutic agents for CNS diseases. In conclusion, this comprehensive review strives to advance therapeutic strategies for CNS disorders by elucidating the potential of dietary polysaccharides and advocating interdisciplinary collaboration to propel further research in this realm

    3-D magnetic field analysis of a permanent magnet spherical actuator using spherical harmonics

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    Agriculture

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    Agriculture is a main contributor of nitrogen (N) and phosphorus (P) to the marine environment, and thereby a main cause of eutrophication of marine ecosystems. By the end of the twentieth century, roughly half of the total N and P input into the aquatic environment originated from agriculture. The relative contribution of agriculture has increased by a factor of 8 for N, and by a factor of 1.6 for P during the last century. As a result, the N/P ratio of the inputs have strongly increased. Contributions from agriculture increased especially from the 1960s, following the rapid rise in fertilizer use and manure production. Enlarged areas of agricultural land at the expense of natural areas including forests have also contributed. Leaching and runoff are the main pathways for N losses, while runoff is the main pathway for P losses from agriculture to sea
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