Enhanced accuracy by post-processing for finite element methods for hyperbolic equations

We consider the enhancement of accuracy, by means of a simple post-processing technique, for finite element approximations to transient hyperbolic equations. The post-processing is a convolution with a kernel whose support has measure of order one in the case of arbitrary unstructured meshes; if the mesh is locally translation invariant, the support of the kernel is a cube whose edges are of size of the order of $\Delta x$ only. For example, when polynomials of degree $k$ are used in the discontinuous Galerkin (DG) method, and the exact solution is globally smooth, the DG method is of order $k+1/2$ in the $L^2$ norm, whereas the post-processed approximation is of order $2k+1$; if the exact solution is in $L^2$ only, in which case no order of convergence is available for the DG method, the post-processed approximation converges with order $k+1/2$ in $L^2(\Omega_0)$ where $\Omega_0$ is a subdomain over which the exact solution is smooth. Numerical results displaying the sharpness of the estimates are presented

Nonlinear Model and Qualitative Analysis for Coupled Axial/Torsional Vibrations of Drill String

A nonlinear dynamics model and qualitative analysis are presented to study the key effective factors for coupled axial/torsional vibrations of a drill string, which is described as a simplified, equivalent, flexible shell under axial rotation. Here, after dimensionless processing, the mathematical models are obtained accounting for the coupling of axial and torsional vibrations using the nonlinear dynamics qualitative method, in which excitation loads and boundary conditions of the drill string are simplified to a rotating, flexible shell. The analysis of dynamics responses is performed by means of the Runge-Kutta-Fehlberg method, in which the rules that govern the changing of the torsional and axial excitation are revealed, and suggestions for engineering applications are also given. The simulation analysis shows that when the drill string is in a lower-speed rotation zone, the torsional excitation is the key factor in the coupling vibration, and increasing the torsional stress of the drill string more easily leads to the coupling vibration; however, when the drill string is in a higher-speed rotating zone, the axial excitation is a key factor in the coupling vibration, and the axial stress in a particular interval more easily leads to the coupling vibration of the drill string

Adiponectin improves coronary no-reflow injury by protecting the endothelium in rats with type 2 diabetes mellitus.

To determine the effect of adiponectin (APN) on the coronary no-reflow (NR) injury in rats with Type 2 diabetes mellitus (T2DM), 80 male Sprague-Dawley rats were fed with a high-sugar-high-fat diet to build a T2DM model. Rats received vehicle or APN in the last week and then were subjected to myocardial ischemia reperfusion (MI/R) injury. Endothelium-dependent vasorelaxation of the thoracic aorta was significantly decreased and serum levels of endothelin-1 (ET-1), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were noticably increased in T2DM rats compared with rats without T2DM. Serum APN was positively correlated with the endothelium-dependent vasorelaxation, but negatively correlated with the serum level of ET-1. Treatment with APN improved T2DM-induced endothelium-dependent vasorelaxation, recovered cardiac function, and decreased both NR size and the levels of ET-1, ICAM-1 and VCAM-1. Hypoadiponectinemia was associated with the aggravation of coronary NR in T2DM rats. APN could alleviate coronary NR injury in T2DM rats by protecting the endothelium and improving microcirculation

Analysis of “spleen-liver-Chongren-uterus menstrual axis” based on the “pivot movement”

The theory of menstrual axis can be traced back to Neijing and matured in modern times. Predecessors， such as professor Luo Yuankai and professor Yang Jialin systematically proposed that “kidney-Tiangui-Chongren-uterus” is the main axis of menstruation， which has been fully recognized by the experts in this field.“Pivot movement” is the core academic thought of Huang Yuanyu， a famous doctor in Qing dynasty， emphasizing the important influence of Qi ascending and descending movement in Zhongtu on human physiology and pathology. Based on the theory of “pivot movement” proposed by Huang Yuanyu and the elaboration of traditional Chinese medicine for menstruation， the authors tentatively proposed that the “spleen-liver-Chongren-uterus menstrual axis” is the key axis of the generation and regulation of menstruation in women of childbearing age. They also shared the experience of treating menstrual diseases based upon the spleen and spleen-liver theories， aiming to provide theorectical basis for the prevention and treatment of menstrual diseases

Preparation and biological activity of the monoclonal antibody against the second extracellular loop of the angiotensin II type 1 receptor

The current study was to prepare a mouse-derived antibody against the angiotensin II type 1 receptor (AT1-mAb) based on monoclonal antibody technology, to provide a foundation for research on AT1-AA-positive diseases. Balb/C mice were actively immunized with the second extracellular loop of the angiotensin II type 1 receptor (AT1R-ECII). Then, mouse spleen lymphocytes were fused with myeloma cells and monoclonal hybridomas that secreted AT1-mAb were generated and cultured, after which those in logarithmic-phase were injected into the abdominal cavity of mice to retrieve the ascites. Highly purified AT1-mAb was isolated from mouse ascites after injection with 1 × 107 hybridomas. A greater amount of AT1-mAb was purified from mouse ascites compared to the cell supernatant of hybridomas. AT1-mAb purified from mouse ascites constricted the thoracic aorta of mice and increased the beat frequency of neonatal rat myocardial cells via the AT1R, identical to the effects of AT1-AA extracted from patients’ sera. Murine blood pressure increased after intravenous injection of AT1-mAb via the tail vein. High purity and good biological activity of AT1-mAb can be obtained from mouse ascites after intraperitoneal injection of monoclonal hybridomas that secrete AT1-mAb. These data provide a simple tool for studying AT1-AA-positive diseases

Estimation of PM2.5 concentrations in China using a spatial back propagation neural network

Methods for estimating the spatial distribution of PM2.5 concentrations have been developed but have not yet been able to effectively include spatial correlation. We report on the development of a spatial back-propagation neural network (S-BPNN) model designed specifically to make such correlations implicit by incorporating a spatial lag variable (SLV) as a virtual input variable. The S-BPNN fits the nonlinear relationship between ground-based air quality monitoring station measurements of PM2.5, satellite observations of aerosol optical depth, meteorological synoptic conditions data and emissions data that include auxiliary geographical parameters such as land use, normalized difference vegetation index, elevation, and population density. We trained and validated the S-BPNN for both yearly and seasonal mean PM2.5 concentrations. In addition, principal components analysis was employed to reduce the dimensionality of the data and a grid of neural network models was run to optimize the model design. The S-BPNN was cross-validated against an analogous but SLV-free BPNN model using the coefficient of determination (R2) and root mean squared error (RMSE) as statistical measures of goodness of fit. The inclusion of the SLV led to demonstrably superior performance of the S-BPNN over the BPNN with R2 values increasing from 0.80 to 0.89 and with the RMSE decreasing from 8.1 to 5.8 μg/m3. The yearly mean PM2.5 concentration in China during the study period was found to be 41.8 μg/m3 and the model estimated spatial distribution was found to exceed Level 2 of the China Ambient Air Quality Standards (CAAQS) enacted in 2012 (>35 μg/m3) in more than 70% of the Chinese territory. The inclusion of spatial correlation upgrades the performance of conventional BPNN models and provides a more accurate estimation of PM2.5 concentrations for air quality monitoring

Observations and Interpretation of a Low Coronal Shock Wave Observed in the EUV by the SDO/AIA

Taking advantage of both the high temporal and spatial resolution of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we studied a limb coronal shock wave and its associated extreme ultraviolet (EUV) wave that occurred on 2010 June 13. Our main findings are (1) the shock wave appeared clearly only in the channels centered at 193 \AA and 211 \AA as a dome-like enhancement propagating ahead of its associated semi-spherical CME bubble; (2) the density compression of the shock is 1.56 according to radio data and the temperature of the shockis around 2.8 MK; (3) the shock wave first appeared at 05:38 UT, 2 minutes after the associated flare has started and 1 minute after its associated CME bubble appeared;(4) the top of the dome-like shock wave set out from about 1.23 R\odot and the thickness of the shocked layer is ~ 2\times10^4 km; (5) the speed of the shock wave is consistent with a slight decrease from about 600 km/s to 550 km/s; (6) the lateral expansion of the shock wave suggests a constant speed around 400 km/s, which varies at different heights and directions. Our findings support the view that the coronal shock wave is driven by the CME bubble, and the on-limb EUV wave is consistent with a fast wave or at least includes the fast wave component.Comment: 24 pages,8 Figures and 6 movies. It is scheduled for publication on the Astrophysical Journal on the August 1, 2011, Issue 736 -

Heat shock factor 1-mediated transcription activation of Omi/HtrA2 induces myocardial mitochondrial apoptosis in the aging heart.

BACKGROUND: Increased cardiac apoptosis is a hallmark of the elderly, which in turn increases the risk for developing cardiac disease. The overexpression of Omi/HtrA2 mRNA and protein contributes to apoptosis in the aged heart. Heat shock factor 1 (HSF1) is a transcription factor that binds to the promoter of Omi/HtrA2 in the aging myocardium. However, whether HSF1 participates in cardiomyocyte apoptosis via transcriptional regulation of Omi/HtrA2 remains unclear. The present study was designed to investigate whether HSF1 plays a role in Omi/HtrA2 transcriptional regulation and myocardial apoptosis. METHODS AND RESULTS: Assessment of the hearts of mice of different ages was performed, which indicated a decrease in cardiac function reserve and an increase in mitochondrial apoptosis. Omi/HtrA2 overexpression in the elderly was negatively correlated with left ventricular function after exercise overload and positively correlated with myocardial Caspase-9 apoptosis. Chromatin immunoprecipitation (ChIP) of aging hearts and plasmid transfection/RNA interference of H9C2 cells revealed that enhancement of HSF1 expression promotes Omi/HtrA2 expression by inducing the promoter activity of Omi/HtrA2 while also increasing mitochondrial apoptosis by upregulating Omi/HtrA2 expression. CONCLUSIONS: HSF1 acts as a transcriptional factor that induces Omi/HtrA2 expression and Caspase-9 apoptosis in aged cardiomyocytes, while also decreasing cardiac function reserve

A novel approach for utilizing waste heat resources in the steel industry

The efficient utilization of waste heat resources plays a pivotal role in enhancing energy efficiency and curbing carbon emissions. To address this, effective planning for waste heat recovery (WHR) utilization becomes imperative, guiding consumers in device installation and capacity allocation. This paper introduces a novel approach to WHR utilization planning, tailored specifically for steel factories, with the goal of achieving optimal WHR solutions. The approach automates device selection, capacity allocation, and operational strategies while considering their impact on the regular manufacturing processes of the factories to maximize overall benefits. Unlike existing methods, this approach introduces discrete capacity selection modeling, considering the constraints of the limited product range during device selection. A numerical study illustrates the effectiveness of the proposed model in delivering optimal WHR device selection, capacity allocation, and operational strategies under various economic conditions. These enhancements contribute to the increased practicality and realism of the proposed method in comparison to existing approaches