Search

Abstract: Flame instabilities of inclination and breakup for lean CH4/air combustion in porous media are studied experimentally and numerically. Inclination and breakup are observed in the quartz tube filled with alumina pellets of 3mm in diameter for equivalence ratio range of 0.435–0.490. The effect of the equivalence ratio on the flame inclination and breakup are discussed and the results show that the equivalence ratio plays an important role on the breakup and flame inclination. Breakups always happen when the inclinational angle reaches 54–60°. In order to explain the motivities of the inclination, a two-dimensional one-step chemical reaction, two-temperature model without initial angles are carried out to simulate the experimental cases. In order to check the possible motivities of inclination, we assumed profiles (not uniform) of inlet velocity of premixed gas and equivalence ratio at inlet, different porosities in the tube, half the same on the right, half on the left, in the simulations. The results show that the inhomogeneous inlet velocity gives slight influence on the inclination, but the different distribution of porosity and the inhomogeneous equivalence ratio at inlet give great influences on the inclination. Calculation results show that the heat loss have a significant influence in determining the flame shape at the initial moment and lead to an increase in the development of the inclination instability. At a low mixture velocity, hydrodynamic effect on the inclination instability is ignored, while the inclination angle of the flame front continually increases as the mixture velocity increase. [Copyright &y& Elsevier]

Abstract: This study was to evaluate the replication and pathogenicity of attenuated human metapneumovirus (HMPV) mutants in severe combined immunodeficiency (SCID) mice. SCID mice were intranasally infected with either wild type GFP-rHMPV (WT), or mutant viruses (M1, M2 and M4) with the N-linked glycosylation(s) of the F protein removed. The organs were collected for viral isolation, titration, pulmonary histopathology and mRNA detection by PCR at different time points. WT or mutant viruses were successfully isolated from the lungs of infected mice after inoculation. The titers of WT and M1 peaked on 5th day and remained detectable until 14th day post-inoculation. M2 reached approximately 4 logs lower titer on 5th and 9th day post-inoculation as compared to WT and M1. M4 showed similar growth kinetics to M2. Viral signal was never detected from the heart, liver, spleen, kidney and brain on 5th day post-inoculation. The pulmonary pathology score in the M1 infected mice was similar to WT infected mice but higher than in M2 or M4 infected mice. WT and HMPV mutants can thus only replicate in the lungs of SCID mice. Attenuated M2 and M4 may be considered as candidates for the preparation of vaccine against HMPV. [Copyright &y& Elsevier]

Abstract A comprehensive working state monitoring method is proposed to protect the power lithium-ion battery packs, implying accurate estimation effect but using minimal time demand of self-learning treatment. A novel state of charge estimation model is conducted by using the improved unscented Kalman filtering method, in which the state of balance and aging process correction is considered, guaranteeing the powered battery supply reliability effectively. In order to realize the equilibrium state evaluation among the internal battery cells, the numerical description and evaluation is putting forward, in which the improved variation coefficient is introduced into the iterative calculation process. The intermittent measurement and real-time calibration calculation process is applied to characterize the capacity change of the battery pack towards the cycling maintenance number, according to which the aging process impact correction can be investigated. This approach is different to the traditional methods by considering the multi-input parameters with real-time correction, in which every calculation step is investigated to realize the working state estimation by using the synthesis algorithm. The state of charge estimation error is 1.83%, providing the technical support for the reliable power supply application of the lithium-ion battery packs. Highlights • A novel comprehensive state of charge estimation method for the lithium-ion battery pack. • The state of balance and aging process correction is considered in the recommended method. • The estimation model is conducted by using the improved unscented Kalman filter. • The improved variation coefficient is introduced to evaluate the cell-to-cell consistency. [ABSTRACT FROM AUTHOR]

Abstract High-power lithium-ion battery packs are widely used in large and medium-sized unmanned aerial vehicles and other fields, but there is a safety hazard problem with the application that needs to be solved. The generation mechanism and prevention measurement research is carried out on the battery management system for the unmanned aerial vehicles and the lithium-ion battery state monitoring. According to the group equivalent modeling demand of the battery packs, a new idea of compound equivalent circuit modeling is proposed and the model constructed to realize the accurate description of the working characteristics. In order to realize the high-precision state prediction, the improved unscented Kalman feedback correction mechanism is introduced, in which the simplified particle transforming is introduced and the voltage change rate is calculated to construct a new endurance prediction model. Considering the influence of the consistency difference between battery cells, a novel equilibrium state evaluation idea is applied, the calculation results of which are embedded in the equivalent modeling and iterative calculation to improve the prediction accuracy. The model parameters are identified by the Hybrid Pulse Power Characteristic test, in which the conclusion is that the mean value of the ohm internal resistance is 20.68 mΩ. The average internal resistance is 1.36 mΩ, and the mean capacitance value is 47747.9F. The state of charge prediction error is less than 2%, which provides a feasible way for the equivalent modeling, battery management system design and practical application of pack working lithium-ion batteries. Graphical abstract Image Highlights • A novel endurance prediction method is proposed for the aerial LIB pack. • The voltage change rate and iterative calculation are launched. • The improved equivalent circuit model construction method is carried out. • Equivalent model parameters are determined and identified. • The generation mechanism research is investigated by using improved UKF algorithm. [ABSTRACT FROM AUTHOR]

Abstract The aerial lithium-ion battery pack works differently from the usual battery packs, the working characteristic of which is intermittent supplement charge and instantaneous large current discharge. An adaptive state of charge estimation method combined with the output voltage tracking strategy is proposed by using the reduced particle - unscented Kalman filter, which is based on the reaction mechanism and experimental characteristic analysis. The improved splice equivalent circuit model is constructed together with its state-space description, in which the operating characteristics can be obtained. The relationship function between the open circuit voltage and the state of charge is analyzed and especially optimized. The feasibility and accuracy characteristics are tested by using the aerial lithium-ion battery pack experimental samples with seven series-connected battery cells. Experimental results show that the state of charge estimation error is less than 2.00%. The proposed method achieves the state of charge estimation accurately for the aerial lithium-ion battery pack, which provides a core avenue for its high-power supply security. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the efficacy of combined atorvastatin calcium and methylprednisolone for the treatment of multiple sclerosis relapse. Patients with multiple sclerosis (MS) at the relapse phase were randomized to receive either combined treatment of atorvastatin calcium and methylprednisolone ( n = 19) or methylprednisolone alone ( n = 19). Expanded Disability Status Scale (EDSS) was administered at baseline, 1 week, 2 weeks, 4 weeks, 3 months, and 6 months after treatment initiation. The number and volume of brain lesions were evaluated using magnetic resonance imaging at baseline and 6 months. The levels of IL-13, IL-35, IFN-γ, and IL-10 in the cerebrospinal fluid were examined using the enzyme-linked immunosorbent assay method. There was no significant difference in EDSS scores at 1, 2, and 4 weeks. At 3 and 6 months, the combined treatment group showed significantly lower EDSS scores than the monotherapy group ( P < 0.05). The number and volume of brain lesions in the combined treatment group were significantly lower than the monotherapy group at 6 months ( P < 0.001). The mean time to relapse was significantly extended in the combined treatment group than the monotherapy group ( P < 0.001). At 2 and 4 weeks, the combined treatment group had significantly higher levels of IL-13, IL-35, and IL-10 in the cerebrospinal fluid than the monotherapy group ( P < 0.05), but significantly lower level of IFN-γ ( P < 0.001). The levels of IL-13 and IL-10 in the combined treatment group were positively correlated with EDSS scores ( r = 0.632, P = 0.001; r = 0.731, P = 0.002). Combined treatment with atorvastatin calcium and methylprednisolone can improve the outcomes of MS relapse compared with glucocorticosteroid alone. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents both electrochemical and electrochemiluminescence (ECL) detections based on the layer-by-layer (LBL) films fabricated with hemoglobin (Hb) and the optimal nanocomposite containing multiwall carbon nanotubes (MWCNTs) and CdS quantum dots (QDs). Hb and the MWCNT–CdS nanocomposite were electrostatically assembled on the chitosan (CS) modified glassy carbon electrode (GCE) forming with up to six bilayer films. Our results on cyclic voltammograms (CVs) revealed that the redox peak currents of Hb at the six-bilayer film ({MWCNT–CdS/Hb}6) modified GCE were the largest. Hydrogen peroxide (H2O2) could be stably detected using the six bilayer films modified GCE with a wide linear range from 0.125μM to 1.20mM. Nitrite (NO2 −) could also be determined through CdS QDs of the multilayer films based on stable ECL intensities with a linear range from 0.60μM to 0.80mM. [Copyright &y& Elsevier]

Abstract: A novel platform, which hemoglobin (Hb) was immobilized on core–shell structurally Fe3O4/Au nanoparticles (simplified as Fe3O4@Au NPs) modified glassy carbon electrode (GCE), has been developed for fabricating the third biosensors. Fe3O4@Au NPs, characterized using transmission electron microscope (TEM), scanning electron microscope (SEM) and energy dispersive spectra (EDS), were coated onto GCE mediated by chitosan so as to provide larger surface area for anchoring Hb. The thermodynamics, dynamics and catalysis properties of Hb immobilized on Fe3O4@Au NPs were discussed by UV–visible spectrum (UV–vis), electrochemical impedance spectroscopy (EIS), electrochemical quartz crystal microbalance technique (EQCM) and cyclic voltammetry (CV). The electrochemical parameters of Hb on Fe3O4@Au NPs modified GCE were further carefully calculated with the results of the effective working area as 3.61cm2, the surface coverage concentration (Γ) as 1.07×10−12 molcm−2, the electron-transfer rate constant (K s ) as 1.03s−1, the number of electron transferred (n) as 1.20 and the standard entropy of the immobilized Hb (ΔS 0′) as calculated to be −104.1Jmol−1 K−1. The electrocatalytic behaviors of the immobilized Hb on Fe3O4@Au NPs were applied for the determination of hydrogen peroxide (H2O2), oxygen (O2) and trichloroacetic acid (TCA). The possible functions of Fe3O4 core and Au shell as a novel platform for achieving Hb direct electrochemistry were discussed, respectively. [Copyright &y& Elsevier]