46 research outputs found
Real-Time Implementation of Decoupled Controllers for Multirotor Aircrafts
In this paper, a practical controller design method is presented to control six degrees of freedom multirotor aircrafts-quadrotors. The quadrotor system is divided into four subsystems; that is, the longitudinal, lateral, yaw, and height subsystems. Then, a linear and decoupled nominal model is obtained for each subsystem, whereas coupling and nonlinear dynamics, parametric perturbations, and external disturbances are considered as uncertainties. For each subsystem, a decoupled robust controller is then proposed. Although there exist coupling between each channel, the output tracking errors of the four subsystems are proven to ultimately converge into a-priori set neighborhood of the origin. Finally, real-time implementation results of the decoupled controller are given to demonstrate its viability and applicability
Structure Analysis of Aerobic Granule from a Sequencing Batch Reactor for Organic Matter and Ammonia Nitrogen Removal
Aerobic granules were cultivated in a sequencing batch reactor (SBR). COD and ammonia nitrogen removal rate were 94% and 99%, respectively. The diameter, settling velocity and SVI10 of granules ranged from 2 to 5 mm, 80 to 110 m/h and about 40 mL/g, respectively. Freezing microtome images, DO concentration profiles by microelectrode, distribution of bacteria and EPS by confocal laser scanning microscopy (CLSM) show that the aerobic granules have a three-layer structure. Each layer has different thickness, character, bacteria, and DO transfer rate. A hypothesis for granule structure is proposed: the first layer, the surface of the granule, is composed mostly of heterotrophic organisms for organic matter removal, with a thickness range from 150 to 350 μm; the second layer, mostly composed of autotrophic organisms for ammonia nitrogen removal, with a thickness range from 250 to 450 μm; the third layer, located in the core of the granule, has mostly an inorganic composition and contains pores and channels
Epicardial Adipose Tissue–Derived Leptin Promotes Myocardial Injury in Metabolic Syndrome Rats Through PKC/NADPH Oxidase/ROS Pathway
Background The epicardial adipose tissue (EAT) of metabolic syndrome (MetS) is abnormally accumulated with dysfunctional secretion of adipokines, closely relating to cardiac dysfunction. The current study was designed to identify the effects of EAT‐derived leptin on the myocardium of MetS rats and explore the potential molecular mechanisms. Methods and Results A MetS rat model was established in 8‐week‐old Wistar rats by a 12‐week high‐fat diet. MetS rats exhibited increased leptin secretion from EAT, cardiac hypertrophy, and diastolic dysfunction with preserved systolic function. The myocardium of MetS rats had abnormal structure, increased oxidative stress injury, and higher inflammatory factor levels, especially the subepicardial myocardium, which was correlated with the EAT‐derived leptin level but not the serum leptin. The EAT was separated from each group of rats to prepare EAT‐conditioned medium. H9C2 rat cardiomyoblasts were treated with EAT‐conditioned medium or leptin, plus various inhibitors. EAT‐derived leptin from MetS rats promoted mitochondrial oxidative stress and dysfunction, induced mitochondrial pathway apoptosis, and inhibited cell viability in H9C2 cardiomyoblasts via the protein kinase C/reduced nicotinamide adenine dinucleotide phosphate oxidase/reactive oxygen species (PKC/NADPH oxidase/ROS) pathway. EAT‐derived leptin from MetS rats stimulated inflammation in H9C2 cardiomyocytes by promoting activator protein 1 nuclear translocation via the PKC/NADPH oxidase/ROS pathway. Leptin promoted the interaction between p‐p47phox and gp91phox in H9C2 cardiomyocytes via protein kinase C, activating nicotinamide adenine dinucleotide phosphate oxidase, increasing reactive oxygen species generation, and inhibiting cell viability. Conclusions EAT‐derived leptin induces MetS‐related myocardial injury through the following 2 cooperative ways via PKC/NADPH oxidase/ROS pathway: (1) inducing mitochondrial pathway apoptosis by promoting mitochondrial oxidative stress and dysfunction; and (2) stimulating inflammation by promoting activator protein 1 nuclear translocation
Assembly of CaIn2S4 on Defect-Rich BiOCl for Acceleration of Interfacial Charge Separation and Photocatalytic Phenol Degradation via S-Scheme Electron Transfer Mechanism
The novel 2D/2D S-scheme heterostructure of BiOCl nanosheets coupled with CaIn2S4 nanosheets (CaIn2S4/BiOCl-SOVs), which contains surface oxygen vacancies (SOVs), has been successfully prepared by high-temperature calcination combined with a solvothermal synthetic strategy. Under visible-light irradiation, the apparent rate constant (Kapp/mim−1) for phenol degradation on the 1 wt% CaIn2S4/BiOCl-SOVs photocatalyst is about 32.8 times higher than that of pure BiOCl. The superior performance was attributed to the synergistic effect between the SOVs, CaIn2S4, and BiOCl, which can effectively narrow the bandgap and accelerate the interfacial charge separation of CaIn2S4/BiOCl-SOVs heterojunctions. Subsequently, it significantly promotes the generation of superoxide radicals (O2−), hydroxyl radicals, and h+, which participate in the photodegradation process of phenol. The catalyst still maintained a relatively high activity after repeated tests as a demonstration of its photostability. This work successfully proposed an efficient method to design a new 2D/2D S-scheme heterostructure with SOVs as possible photocatalysts in the field of environmental remediation
Accelerating Aerobic Sludge Granulation by Adding Dry Sewage Sludge Micropowder in Sequencing Batch Reactors
Micropowder (20–250 µm) made from ground dry waste sludge from a municipal sewage treatment plant was added in a sequencing batch reactor (R2), which was fed by synthetic wastewater with acetate as carbon source. Compared with the traditional SBR (R1), aerobic sludge granulation time was shortened 15 days in R2. Furthermore, filamentous bacteria in bulking sludge were controlled to accelerate aerobic granulation and form large granules. Correspondingly, the SVI decreased from 225 mL/g to 37 mL/g. X-ray Fluorescence (XRF) analysis demonstrated that Al and Si from the micropowder were accumulated in granules. A mechanism hypotheses for the acceleration of aerobic granulation by adding dry sludge micropowder is proposed: added micropowder acts as nuclei to induce bacterial attachment; dissolved matters from the micropowder increase abruptly the organic load for starved sludge to control overgrown filamentous bacteria as a framework for aggregation; increased friction from the movement of micropowder forces the filaments which extend outwards to shrink for shaping granules
Sleep disturbance and psychological distress are associated with functional dyspepsia based on Rome III criteria
Abstract Background Functional dyspepsia (FD) is considered a bio-psychosocial disorder. The role of psychosocial factors in FD pathogenesis remains unclear. Methods This study evaluated sleep quality and mood symptoms in patients with FD, assessing the associations of FD severity, disordered sleep, and psychological symptoms. One-hundred-and-fifteen adult patients with typical FD symptoms were enrolled alongside 61 healthy volunteers. Rome III criteria were used to evaluate FD symptoms; sleep disorder was assessed with the Pittsburgh Sleep Quality Index (PSQI), and Symptom Checklist-90-Revised (SCL-90R) was utilized to determine the status of depression, anxiety and other psychological symptoms. Results PSQI scores and nine symptomatic dimensions of SCL-90R were significantly higher in FD patients than in controls. Multiple logistic regression indicated that lower BMI, lower level of education, and sleep disturbance were independently associated with FD and FD subgroups. Hostility and phobic anxiety were independent risk factors for FD. Further analysis showed that hostility was an independent risk factor for both FD subgroups, and somatization and additional psychiatric symptoms for epigastric pain syndrome. Conclusions We found that FD was associated with sleep disorder and psychopathological factors. These findings suggest that implementing sleeping and/or psychological therapies may help reduce FD symptoms
A gold-triggered dearomative spirocarbocyclization/Diels-Alder reaction cascade towards diverse bridged N-heterocycles
A rapid approach for the diversity-oriented synthesis of complex bridged polycyclic N-heterocycles from readily available starting materials in two operational steps has been developed. This strategy firstly introduces molecular diversity by an Ugi four-component reaction, and then achieves these bridged N-heterocycles via an efficient gold-triggered chemo- and diastereoselective cascade non-oxidative ortho-dearomative spirocarbocyclization/Diels-Alder reaction sequence. The application of microwave irradiation for this cascade process efficiently shortens the reaction time to 10 minutes and improves the diastereoselectivity.status: publishe