29 research outputs found

    Multiple Cracks Detection in Pipeline Using Damage Index Matrix Based on Piezoceramic Transducer-Enabled Stress Wave Propagation

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    Cracks in oil and gas pipelines cause leakage which results in property damage, environmental pollution, and even personal injury or loss of lives. In this paper, an active-sensing approach was conducted to identify the crack damage in pipeline structure using a stress wave propagation approach with piezoceramic transducers. A pipeline segment instrumented with five distributed piezoceramic transducers was used as the testing specimen in this research. Four cracks were artificially cut on the specimen, and each crack had six damage cases corresponding to different crack depths. In this way, cracks at different locations with different damage degrees were simulated. In each damage case, one piezoceramic transducer was used as an actuator to generate a stress wave to propagate along the pipeline specimen, and the other piezoceramic transducers were used as sensors to detect the wave responses. To quantitatively evaluate the crack damage status, a wavelet packet-based damage index matrix was developed. Experimental results show that the proposed method can evaluate the crack severity and estimate the crack location in the pipeline structure based on the proposed damage index matrix. The sensitivity of the proposed method decreases with increasing distance between the crack and the mounted piezoceramic transducers

    @Robust enhancing stability and fructose tolerance of sucrose phosphorylase by immobilization on Ni-NTA functionalized agarose microspheres for the biosynthesis of 2-alpha-glucosylglycerol

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    Sucrose phosphorylase (SPase) is a carbohydrate-active enzyme with outstanding potential for the biocatalytic conversion of sucrose and glycerol into 2-alpha-glucosylglycerol (2-alpha-GG) with attractive properties. However, poor stability, lack of appropriate immobilization strategy and serious inhibition of fructose by-products significantly restrict the industrial application of SPase. In this study, a new recombinant SPase from the Bifidobacterium Magian was specifically immobilized by agarose microspheres with Ni2+-nitrotriacetic acid for significantly enhancing its stability and fructose tolerance. Agarose immobilization greatly improved the stability of SPase. At 50 degrees C, the relative activity of the immobilized SPase (95%) was obviously greater than that of the free SPase (55%). Moreover, immobilized SPase exhibited excellent reusability and storage stability, retaining over 60% of its initial activity after 15 cycles, maintaining 70% relative activity after 15 days. It was first found that SPase immobilized by agamse still hold 98% activity even under 0.6 M fructose. Based on Raman spectrum analysis, agarose immobilization significantly enhanced the beta-sheet structures of SPase, which helped to maintain its efficient catalytic performance under extreme environment and high inhibitor concentration. Immobilized SPase based on agamse would have a brilliant future in the production of 2-alpha-GG

    Wind turbine blade health monitoring with piezoceramic-based wireless sensor network

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    In this paper, a piezoceramic-based wireless sensor network (WSN) was developed for health monitoring of wind turbine blades with active sensing approach. The WSN system has an access point that coordinates the network and connects to a PC to control the wireless nodes. One wireless node functions as an actuator to excite an embedded piezoceramic patch with desired guided waves. The remaining wireless nodes function as sensors to detect and transmit the wave responses at distributed locations. The damage status inside the blade was evaluated through the analysis of the sensor signals. Based on wavelet packet analysis results, a damage index and a damage matrix were developed to evaluate the damage status at different locations. To verify the effectiveness of the proposed approach, a static loading test and a wind tunnel test were performed in the Laboratory of Joint Wind Tunnel and Wave Flume at Harbin Institute of Technology (HIT), China. Experimental results show that damage in wind turbine blades can be detected and evaluated by the proposed approach

    Qualitative Analysis of Visible Foreign Solids in Armillarisin A Injection Formulations Using Ultra-High Performance Liquid Chromatography–Tandem Mass Spectrometry

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    During the trial production of Armillarisin A for injection (AA-I), unidentified needle-like yellow-brown crystals were occasionally observed. Here, we report an ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC-MS) method for determining the source of the visible foreign bodies in the formulations of Armillarisin A active pharmaceutical ingredient (AA-API). AA-API, photolyzed samples, the intermediate polymer, and the excipient analyzed determined after the separation on a Waters Symmetry C18 (3.5 μm, 4.6 × 75 mm) column with a mobile phase consisting of a methanol/acetic acid (0.1 mol/L) aqueous solution (50:50). Furthermore, the crystal type of the visible foreign bodies, the intermediate polymer and AA-API were investigated by X-ray powder diffraction (XRD). The results revealed that the characteristics of the visible foreign solids were the same as those of AA-API as regards UPLC peak position (368 nm) and MS spectrum in negative ion detection mode. The visible foreign solids were thus identified as unpolymerized crystals of AA-API and were attributed to AA-API itself. The results showed that the production process could be improved by changing the stirring method and frequency as well as by optimizing the polymerization temperature to ensure the safety, stability, and control of the product quality in the stage of batch production

    Neonatal priming and infancy boosting with a novel respiratory syncytial virus vaccine induces protective immune responses without concomitant respiratory disease upon RSV challenge

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    Although respiratory syncytial virus (RSV) infection in infants and young children is a global public health issue, development of a safe RSV vaccine has been impeded by formalin-inactivated RSV-enhanced respiratory disease (ERD). In developing a safer yet effective RSV vaccine for children, a strategy to decrease over-reactive T cells and increase neutralizing anti-RSV antibodies should be considered. We previously demonstrated that adult mice immunized with RSV recombinant G protein plus low-dose Cyclosporine A (G+ CsA) could, upon subsequent RSV challenge, produce increased levels of antigen-specific T regulatory cells in lungs that overcame the ERD. Neutralizing anti-RSV antibodies that prevented viral infection were also elicited. In this study, we investigated if such a G+ CsA vaccine could provide infant mice with the same protection from RSV infection without ERD. The results showed that the G+ CsA vaccine could prevent RSV infection with only a mild loss of body weight. Importantly, there was nearly normal morphology and no mucus appearance in lung tissues after RSV challenge. These results demonstrate that the G+ CsA vaccine strategy achieved similar benefits in the neonatal prime and infancy boost model as in the adult mouse model. The G+ CsA immunization strategy is potentially safe and effective in neonates and infants because it suppresses the devastating ERD

    Shotgun Lipidomics Revealed Altered Profiles of Serum Lipids in Systemic Lupus Erythematosus Closely Associated with Disease Activity

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    The pathogenesis of systemic lupus erythematosus (SLE) remains elusive. It appears that serum lipid metabolism is aberrant in SLE patients. Determination of lipid profiles in the serum of SLE patients may provide insights into the underlying mechanism(s) leading to SLE and may discover potential biomarkers for early diagnosis of SLE. This study aimed to identify and quantify the profile of serum lipids in SLE patients (N = 30) with our powerful multi-dimensional mass spectrometry-based shotgun lipidomics platform. Multivariate analysis in the form of partial least squares-discriminate analysis was performed, and the associations between the changed lipids with cytokines and SLE disease activity index (SLEDAI) were analyzed using a multiple regression method. The results of this study indicated that the composition of lipid species including diacyl phosphatidylethanolamine (dPE) (16:0/18:2, 18:0/18:2, 16:0/22:6, 18:0/20:4, and 18:0/22:6), 18:2 lysoPC (LPC), and ceramide (N22:0 and N24:1) was significantly altered in SLE patients with p < 0.05 and variable importance of the projection (VIP) > 1 in partial least squares-discriminate analysis (PLS-DA). There existed significant associations between IL-10, and both 18:0/18:2 and 16:0/22:6 dPE species with p < 0.0001 and predicting 85.7 and 95.8% of the variability of IL-10 levels, respectively. All the altered lipid species could obviously predict IL-10 levels with F (8, 21) = 3.729, p = 0.007, and R2 = 0.766. There was also a significant correlation between the SLEDAI score and 18:0/18:2 dPE (p = 0.031) with explaining 22.6% of the variability of SLEDAI score. Therefore, the panel of changed compositions of dPE and ceramide species may serve as additional biomarkers for early diagnosis and/or prognosis of SLE

    Hydrogen-Bonded Dopant-Free Hole Transport Material Enables Efficient and Stable Inverted Perovskite Solar Cells

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    Although many dopant-free hole transport materials (HTMs) for perovskite solar cells (PSCs) have been investigated in the literature, novel and useful molecular designs for high-performance HTMs are still needed. In this work, a hydrogen-bonding association system (NH⋯CO) between amide and carbonyl is introduced into the pure HTM layer. Our study demonstrates that the hydrogen-bonding association can not only significantly increase the HTM’s hole transport mobility and functionalize the surface passivation to the perovskite layer, but also form Pb–N coordination bonds at the interface to promote the hole extraction while hindering the interfacial charge recombination. As a result, the PSCs based on dopant-free hydrogen-bonded HTMs can achieve a champion power conversion efficiency (PCE) of 21.62%, which is around 32% higher than the pristine PSC without the hydrogen-bonding association. Furthermore, the dopant-free hydrogen-bonded HTMs based device shows remarkable long-term light stability, retaining 87% of its original value after 500 h continuous illumination, measured at the maximum power point. This work not only provides a potential HTM with hydrogen-bonding association in PSCs, but also demonstrates that introducing hydrogen bonding into the materials is a useful and simple strategy for developing high-performance dopant-free HTMs.publishedVersionPeer reviewe
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