Calculation and experimental verification of force-magnetic coupling model of magnetised rail based on density functional theory

Metal magnetic memory (MMM) is a widely used non-destructive electromagnetic detection technology. However, the analysis of its underlying principle is still insufficient. The mechanical and magnetic coupling model is a reasonable standpoint from which to study the principle of MMM. In this paper, a mechanical and magnetic coupling model of steel material is established based on density functional theory (DFT) using the CASTEP first-principles analysis software. In order to simulate the practical working environment, the residual magnetism in the rail is assumed to change with the stress on the rail. By applying different stresses to the model, the relationship between the atomic magnetic moment, the lattice constant and stress is explored, as well as the causes of magnetic signals in the stress concentration zone. It is revealed that the atomic magnetic moment and the crystal volume decrease with the increase in compressive stress. The magnetic signal on the surface of the magnetised metal component decreases with the increase in compressive stress, while the tensile stress shows the opposite tendency. Generally speaking, the change in atomic magnetic moment and crystal volume caused by lattice distortion under stress can be seen as the fundamental reason for the change in magnetic signal on the surface of the magnetised metal. The bending experiment of the rail shows that the normal magnetic field decreases with the increase in compressive stress in the stress concentration zone. The conclusion is verified by experiments

Outcome Evaluation in Social Context Measured by Event-Related Potentials Is Partially Dependent on the Partner’s Sex

Outcome evaluation is a cognitive process that people rely on feedback information to evaluate behavior results. It can help people to modify the previous mistakes in order to facilitate the performance of the behavior. In the present study, we examined sex differences in outcome evaluation when men and women performed a “Chuck-A-Luck” dice game with a same-versus opposite-sex partner. We recruited 40 college students (Half of women) to perform the gambling game task, and event-related potentials (ERPs) were recorded for outcome feed back when male or female participants performed the game alone, or with same-versus opposite-sex partners. Two main findings are reported in our study. (1) FRN amplitude of same-sex condition was significantly greater than alone condition for male when the feedback was loss. However, FRN amplitude of opposite-sex condition was significantly greater than alone condition for female when feedback was loss. (2) The loss feedback induced greater P300 than gain only in alone condition. It suggests that sex differences in outcome evaluation is a complex process that is partially influenced by the partner’s sex

Insights into Cocrystal Polymorphic Transformation Mechanism of Ethenzamide–Saccharin: A Combined Experimental and Simulative Study

In this work, the solvent-mediated phase transformation of the metastable form (Form II) to the stable form (Form I) of ethenzamide–saccharin cocrystal in isopropanol was investigated. Solubility of Form I and Form II in pure isopropanol was also measured. The transformation mechanism from Form II to Form I was analyzed by some online and off-line tools including attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, and polarizing microscopy. The results demonstrate that the transformation process consists of three steps, involving the dissolution of Form II, the nucleation of Form I, and the following growth of Form I. The ATR-FTIR and Raman results show that the polymorphic transformation from Form II to Form I is controlled by the nucleation and growth of Form I. Furthermore, the microscope photographs clearly reveal that the Form I preferably nucleates and grows on the (100) surface of Form II. The molecular simulation results indicate that higher adsorption energy and the exposure of more activity groups make the molecule adsorbed more strongly on the (100) surface, which is in agreement with the experimental observation. The results drawn in this work will be of great significance to control the formation of a desired polymorphic final product of ethenzamide–saccharin cocrystal

Time Course of Current of Injury Is Related to Acute Stability of Active-Fixation Pacing Leads in Rabbits

<div><p>Background</p><p>Magnitude of current of injury (COI) consequent to pacemaker lead fixation is recognized as a predictor of acute lead stability. It is unclear whether dynamic monitoring of COI after lead fixation provides additional information beyond a single assessment performed at the time of fixation.</p> <p>Objectives</p><p>This study was aimed to test the hypothesis that the time course of COI is related to acute lead stability.</p> <p>Methods and Results</p><p>Active fixation leads with fixed screw were anchored to either Langendorff-perfused rabbit hearts endocardially or in vivo hearts epicardially in manners of contact the helix with no rotation, half rotation and full rotation, respectively. Intracardiac electrogram (EGM) was monitored dynamically from onset to resolution of COI, and magnitudes of intrinsic R wave and COI, including ST-segment elevation, ST/R and intracardiac EGM duration (IED), were measured. A digital force gauge was applied to assess lead stability. In vitro, COI in contacted leads was significantly smaller than those in half rotated (<i>p</i><0.05) and fully rotated leads (<i>p</i><0.05), and presented most precipitous recovery to baseline (1.5±1.1 min, <i>p</i><0.05). Half-rotated and fully rotated leads manifested the same magnitude of COI right after placement. However, the time course of COI was significantly longer in fully rotated leads than that in half rotated leads (26.5±2.8 min <i>vs.</i> 5.6±2.0 min, <i>p</i><0.05). Similar findings were observed in vivo. The time course of COI was significantly correlated with the force needed to detach the lead from myocardium (<i>r</i> = 0. 72, n = 48, <i>p</i><0.001).</p> <p>Conclusions</p><p>Time course of COI is related to acute lead stability in rabbits. One might be misled by a single assessment of COI magnitude right after lead placement, whereas persistence of COI is likely to be a useful indicator of adequate lead stability.</p> </div

Comparison of Intracardiac EGM variables derived from in vivo hearts.

<p>Panel A, B and C showed the similar findings observed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057727#pone-0057727-g003" target="_blank">Figure 3</a>. Panel D. No difference in IED between half and fully rotated leads at any time point. *: <i>p</i><0.05 and ^†: <i>p</i><0.01 (compared with half and fully rotated leads); ^‡: <i>p</i><0.05 and: §: <i>p</i><0.01 (compared with fully rotated leads).</p

Correlation between COI time course and acute Lead Stability.

<p>COI time course from onset to resolution was significantly correlated with the force in order to detach the lead from myocardium (r = 0.72, n = 48, p<0.001).</p

Comparison of Intracardiac EGM variables derived from isolated rabbit hearts.

<p>Panel A. Intrinsic R wave amplitude showed no significant dissimilarity regarding to different lead positionings. Panel B. Contacted leads presented the smallest magnitude of ST-segment elevation with the most rapid decline, followed by half rotated leads, while fully rotated leads showed the biggest COI amplitude and the slowest recovery. Note that there was no difference between half and fully rotated leads at 0 min. Panel C and D depicted the same findings as Panel B in the value of ST/R and IED, respectively. *: <i>p</i><0.05 (compared with half and fully rotated leads); ^†: <i>p</i><0.05 and ^‡: <i>p</i><0.01 (compared with fully rotated leads).</p

Example of intracardiac electrogram recorded by pacing system analyzer (200

<p> <b>mm/s).</b> A. Onset of COI, manifested as ST-segment elevation after R wave deflection and increase of intracardiac electrogram duration (IED). B. Resolution of COI, ST-segment declined to less than 1/4 of R wave amplitude, and the significant decrease in IED also occurred.</p

Illustration of the lead location in each group.

<p>A: anterior basal wall, I: inferior basal wall, S: septum, R: right ventricular anterior basal wall, L: left ventricular anterior basal wall, A_P: apex.</p