136 research outputs found

    Estimating the Lateral Motion States of an Underwater Robot by Propeller Wake Sensing Using an Artificial Lateral Line

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    An artificial lateral line (ALL) is a bioinspired flow sensing system of an underwater robot that consists of distributed flow sensors. The ALL has achieved great success in sensing the motion states of bioinspired underwater robots, e.g., robotic fish, that are driven by body undulation and/or tail flapping. However, the ALL has not been systematically tested and studied in the sensing of underwater robots driven by rotating propellers due to the highly dynamic and complex flow field therein. This paper makes a bold hypothesis that the distributed flow measurements sampled from the propeller wake flow, although infeasible to represent the entire flow dynamics, provides sufficient information for estimating the lateral motion states of the leader underwater robot. An experimental testbed is constructed to investigate the feasibility of such a state estimator which comprises a cylindrical ALL sensory system, a rotating leader propeller, and a water tank with a planar sliding guide. Specifically, a hybrid network that consists of a one-dimensional convolution network (1DCNN) and a bidirectional long short-term memory network (BiLSTM) is designed to extract the spatiotemporal features of the time series of distributed pressure measurements. A multi-output deep learning network is adopted to estimate the lateral motion states of the leader propeller. In addition, the state estimator is optimized using the whale optimization algorithm (WOA) considering the comprehensive estimation performance. Extensive experiments are conducted the results of which validate the proposed data-driven algorithm in estimating the motion states of the leader underwater robot by propeller wake sensing.Comment: 10 pages, 8 figure

    Bufalin Induces Reactive Oxygen Species Dependent Bax Translocation and Apoptosis in ASTC-a-1 Cells

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    Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM) to monitor the spatio-temporal dynamics of reactive oxygen species (ROS) production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1) cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidant N-acetyl-cysteine (NAC), a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells

    Miniaturized metachronal magnetic artificial cilia

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    Biological cilia, hairlike organelles on cell surfaces, often exhibit collective wavelike motion known as metachrony, which helps generating fluid flow. Inspired by nature, researchers have developed artificial cilia as microfluidic actuators, exploring several methods to mimic the metachrony. However, reported methods are difficult to miniaturize because they require either control of individual cilia properties or the generation of a complex external magnetic field. We introduce a concept that generates metachronal motion of magnetic artificial cilia (MAC), even though the MAC are all identical, and the applied external magnetic field is uniform. This is achieved by integrating a paramagnetic substructure in the substrate underneath the MAC. Uniquely, we can create both symplectic and antiplectic metachrony by changing the relative positions of MAC and substructure. We demonstrate the flow generation of the two metachronal motions in both high and low Reynolds number conditions. Our research marks a significant milestone by breaking the size limitation barrier in metachronal artificial cilia. This achievement not only showcases the potential of nature-inspired engineering but also opens up a host of exciting opportunities for designing and optimizing microsystems with enhanced fluid manipulation capabilities

    Berberine Nanosuspension Enhances Hypoglycemic Efficacy on Streptozotocin Induced Diabetic C57BL/6 Mice

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    Berberine (Ber), an isoquinoline derivative alkaloid and active ingredient of Coptis, has been demonstrated to possess antidiabetic activities. However its low oral bioavailability restricts its clinical application. In this report, Ber nanosuspension (Ber-NS) composed of Ber and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was prepared by high pressure homogenization technique. Antidiabetic effects of Ber-NS relative to efficacy of bulk Ber were evaluated in streptozotocin (STZ) induced diabetic C57BL/6 mice. The particle size and zeta potential of Ber-NS were 73.1 ± 3.7 nm and 6.99 ± 0.17 mV, respectively. Ber-NS (50 mg/kg) treatment via oral gavage for 8 weeks resulted in a superior hypoglycemic and total cholesterol (TC) and body weight reduction effects compared to an equivalent dose of bulk Ber and metformin (Met, 300 mg/kg). These data indicate that a low dosage Ber-NS decreases blood glucose and improves lipid metabolism in type 2 diabetic C57BL/6 mice. These results suggest that the delivery of Ber as a nanosuspension is a promising approach for treating type 2 diabetes

    Linking the SO2 emission of cement plants to the sulfur characteristics of their limestones: A study of 80 NSP cement lines in China

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    In a properly operated new suspension preheater (NSP) cement line, the SO2 emission is mainly originated from sulfides in the raw meal, and limestone, occupying about 85% wt. of the raw meal, is the dominant sulfur source. However, the sulfur characteristics of limestones and then their influences on the SO2 emission have not been clarified yet. In the present study, 80 NSP cement lines with SO2 emission > 200 mg/Nm3 were recorded, the sulfur content and species as well as pyrite morphology of limestones were analyzed and then correlated to their resulting SO2 emission. The results show that the SO2 emission of stack gas increases linearly with the SO3 content of limestone used, and sulfates lead to a 50% reduction in SO2 emission relative to sulfides. Compared with average SO2 emission, euhedral pyrite leads to a slightly higher SO2 emission, whereas metasomatic pyrite results in a lower SO2 emission, which can be attributed to the effects of accompanying elements (Ti, F, K, and Al etc.) on the desulfurization reaction and clinkerization in the whole NSP cement line. The relationships proposed can be used to predict the SO2 emission based on the sulfur characteristics of limestone and to rationally utilize high-sulfur limestone in cement industry

    Co-processing of raw and washed air pollution control residues from energy-from-waste facilities in the cement kiln

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    Co-processing of industrial wastes as alternative raw materials in cement manufacture is an example of industrial symbiosis for improved material resource efficiency. Since co-processing introduces impurities from wastes, such as air pollution control residue (APCR) from municipal solid waste combustion, into the cement kiln, a better understanding of their environmental impacts and effects on cement manufacturing and quality is needed. Portland cement clinkers containing 5–35% raw or 5–34% washed APCR were prepared, with formation of all typical minerals, but with effects on clinkering reactions, and increased 2CaO·SiO2 and decreased 3CaO·SiO2 and 3CaO·Al2O3. Raw APCR affected the shape of the 2CaO·SiO2 and 3CaO·SiO2 grains, and cement paste from clinker made with 35% APCR exhibited negligible 28d strength. Pastes from the clinkers with lower contents of APCR or washed APCR had strengths that were lower than that of the control at 7d, similar at 28d (∼90 MPa) and higher at 6 m (up to 120 MPa), consistent with their 2CaO·SiO2 and 3CaO·SiO2 contents. Utilization of minerals in APCR thus comes with a trade-off against cement quality. Volatilisation of S, Cl, Pb was reduced by washing, which fully eliminated volatilisation of Zn. Zn was found mainly in the interstitial phases of the clinker, in solid solution in 4CaO·Al2O3·Fe2O3 or 3CaO·Al2O3. Further investigation is required to determine whether Zn and other incorporated elements may be released from the cement paste when these phases react with water. APCR co-processing may reduce CO2 emissions by avoiding CaCO3 decomposition, but this is an uncertain benefit, which may be outweighed by the detrimental effects of APCR alkalis, Cl, S and metals on cement production and quality. Life cycle environmental impacts associated with washing, and dispersal of contaminants in the built environment through construction materials, are additional concerns

    Research progress and future study of carbon emission reduction for UCG

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    The integration of underground coal gasification (UCG) and carbon emission reduction is expected to become an excellent green energy technology during the transitional stage from the current to the arrival of carbon neutrality, and even play an important role in the longer history of carbon neutrality in the future. Looking back at the research history and current situation, the systematic strategy for UCG emission reduction has been basically formed, which can be summarized into five specific approaches. Among them, the targeted underground in-situ regulation can reduce the CO2 release and promote the quality and yield increase of UCG synthesis gas, and the relevant strategies and approaches can be summarized as the Carbon Regulation and Reduction (CRR). There are many research achievements on the supercritical gas storage of UCG-CO2 in underground space, mainly focusing on storage media, storage space, storage capacity, etc., with some discussions for storage mechanisms. The mineralization and storage of UCG-CO2 in underground space are not constrained by the harsh conditions of geological stability and sealing, and there is a potential dual effect of both carbon sequestration and gas conversion, but there are not many research results yet. The previous exploration of UCG-CO2 reinjection, utilization and storage focuses on two aspects, such as enhancing coalbed methane production and improving the production of UCG synthesis gas, and a series of explorations have been initiated for the emission reduction and utilization of CO2 from the tail gas of UCG hydrogen production in recent years. The CRR, as an active emission reduction strategy, targetedly reduces the CO2 concentration in the UCG synthesis gas by adjusting the gasifying agent and its injection method, and there are many theoretical achievements and preliminary on-site verification, which are expected to become a practical clean coal technology that integrates clean energy production and carbon reduction. Reviewing the progress and analyzing the shortcomings, the scientific and technological research for UCG carbon emission reduction has made many substantial achievements, but also still faces some challenges of sustainable development, and the future study should focus on four aspects. One is to prioritize the development of UCG-CO2 underground conversion and utilization technology with a focus on the UCG-CRR based on feasibility. The second is to focus on the shortcomings and to strive for the breakthrough of the collaborative mechanism and key technological bottlenecks of both UCG emission reduction and synthesis gas quality improvement. The third is to make solid progess and promote the prior implementation of UCG-CRR pilot tests and engineering demonstrations for the achievement of practical results step by step. The fourth is to ensure the implementation and establishment of the “trinity” policy support system for the UCG emission reduction consisting of carbon neutrality and management strategy, special science and technology action plans, and professional talent training

    Applicability and Trend of the Artificial Intelligence (AI) on Bioenergy Research between 1991–2021::A Bibliometric Analysis

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    The bibliometric analysis investigated the impact of publications on trends in the literature and bioenergy research using artificial intelligence (AI) from 1991 to 2021. In this study, 1721 publications were extracted from the Web of Science, and an analysis of the countries, authorship, institutions, journals, and keywords was visualised. In the recent decades, this field has entered an outbreak phase. India was the most productive country in this area, followed by China, Iran, and the US. It also noted several notable differences between trends and subjects in developed and developing countries. The former led this field at the initial stage and later attached importance to using AI for research feedstock and impact assessment. Developing countries encouraged the advancement of this area and emphasised the feedstock usage of phase treatment and process optimisation. In addition, a co-authorship and institutes study revealed that authors and institutes in distant regions rarely collaborated. The journal analysis shows strong links between Energy, Fuel, and Energy Conversion and Management. Machine learning is by far the most common application of artificial intelligence (AI) technology in bioenergy research, with 53% of the articles using it. In these AI-related publications, the keyword artificial neural network (ANN) appeared most frequently in the articles
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