183 research outputs found

    Grain Boundary Motion Analysis

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    Grain growth is a mechanism to relax residual stresses in thin films. These grains grow out of the thin film surface and are known as whiskers. These whiskers can cause short circuits, so developing scalable and cost effective solutions would increase the reliability and utility of tin electronics. A popular of method of examining tin whiskering is microscopic simulation, as it provides an accurate and cost effective way to predict the consequences of proposed models. Specifically examining the evolution of grain boundaries, this paper aims to present the results of grain boundary motion simulations through a generalized program that streamlines and optimizes the analysis process. Various simulations examining the effects of grain boundary energy and mobility were run through Idaho National Laboratory\u27s Multiphysics Object Oriented Simulation Environment (MOOSE), with processing, analysis, and presentation provided by a Jupyter Notebook program that is available online. The Notebook program was found to graph effectively and flexibly, creating results which provide quantitative data and clear visualizations of the MOOSE simulations, providing examples of how the mobility and energy values of grain boundaries of Tin significantly affect grain migration. The Jupyter notebook will be deployed as a tool in nanohub.org

    Combination resonance analysis of a multi-DOF controllable close-chain linkage mechanism system

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    The two-DOF controllable close-chain linkage mechanism system is investigated in this paper. Based on the air-gap field of the non-uniform airspace of motors caused by the eccentricity of rotor, the electromechanical coupling relation in the real running state of motors is analyzed. The electromechanical coupling dynamic model of the system is established by means of the finite element method. The dynamic equation constitutes the basis on which the combination resonance characteristics of the system caused by electromagnetic parameter excitations of the two motors are analyzed by the multiple scales method. The first-order stationary solution is obtained under that condition, and the stability conditions of the stationary solution are also given. Finally, an experiment is presented. Results indicate that it is feasible and beneficial to explain some unexpected strong vibration phenomena in the high-speed operation of such multi-DOF controllable close-chain linkage mechanism using nonlinear combination resonance theories

    Combination resonance analysis of a multi-DOF controllable close-chain linkage mechanism system

    Get PDF
    The two-DOF controllable close-chain linkage mechanism system is investigated in this paper. Based on the air-gap field of the non-uniform airspace of motors caused by the eccentricity of rotor, the electromechanical coupling relation in the real running state of motors is analyzed. The electromechanical coupling dynamic model of the system is established by means of the finite element method. The dynamic equation constitutes the basis on which the combination resonance characteristics of the system caused by electromagnetic parameter excitations of the two motors are analyzed by the multiple scales method. The first-order stationary solution is obtained under that condition, and the stability conditions of the stationary solution are also given. Finally, an experiment is presented. Results indicate that it is feasible and beneficial to explain some unexpected strong vibration phenomena in the high-speed operation of such multi-DOF controllable close-chain linkage mechanism using nonlinear combination resonance theories

    Personal Involvement Moderates Message Framing Effects on Food Safety Education among Medical University Students in Chongqing, China.

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    This study explored whether the efficacy of food safety education interventions can be increased by message framing among medical university students, and demonstrated the role of personal involvement within the message recipient in moderating framed effects. A cross-sectional study of food safety message framing was conducted among medical university students (randomly selected 1353 participants). An online self-administered questionnaire was used to collect information. Wilcoxon rank-sum test and Ordered multivariate logistic regression were utilised in the data analyses. The present study showed significant differences in acceptance between the gain- and loss-framed groups ( < 0.001). Participants with higher personal involvement had higher acceptance than those with low personal involvement in gain- and loss-framed message models ( < 0.001). The acceptance of participants who were concerned about their health condition was higher than those who were neutral regarding their health condition ( < 0.001) and participants who suffered a food safety incident had higher acceptance than those who did not ( < 0.05). This study portrayed the selection preference of message framing on food safety education among medical university students in southwest China. Participants exposed to loss-framed messages had higher message acceptance than those exposed to gain-framed messages. Personal involvement may affect the food safety message framing. Public health advocates and professionals can use framed messages as a strategy to enhance intervention efficacy in the process of food safety education

    Atrial-selective block of sodium channels by acehytisine in rabbit myocardium

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    AbstractAcehytisine, a multi-ion channel blocker, can markedly inhibit INa, ICa, IKur, If at various concentrations and effectively terminate and prevent atrial fibrillation (AF) in patients and animal models, but the molecular mechanism underlying its blockage remains elusive. In this study, we investigated the effects of acehytisine on action potentials and sodium channels of atrial and ventricular myocytes isolated from rabbit, using whole-cell recording system. We found that acehytisine exerted stronger blocking effects on sodium channels in atria than in ventricles, especially at depolarization (IC50: 48.48 ± 7.75 μmol/L in atria vs. 560.17 ± 63.98 μmol/L in ventricles). It also significantly shifted steady state inactivation curves toward negative potentials in atrial myocytes, without affecting the recovery kinetics from inactivation of sodium channels in the same cells. In addition, acehytisine inhibited INa in a use-dependent manner and regulated slow inactivation kinetics by different gating configurations. These findings indicate that acehytisine selectively blocks atrial sodium channels and possesses affinity to sodium channel in certain states, which provides additional evidence for the anti-AF of acehytisine

    Effects of Goal-Framed Messages on Mental Health Education Among Medical University Students: Moderating Role of Personal Involvement.

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    Mental health problem among university students is an emerging public health issue, and mental health education has always been the focus of attention for universities. However, limited attention has been paid to the effect of students' acceptance of health messages. Previous studies have found that message framing plays a key role in the process of responding to health-promoting messages. In this backdrop, the study aimed to examine the effects of goal-framed messages on mental health education among medical university students and investigate the moderating role of personal involvement. A cross-sectional study was conducted on medical university students. An online self-administered questionnaire was used to collect data. Wilcoxon rank-sum test and ordinal logistic regression were used for data analysis. Results showed significant differences in message acceptance between the gain- and loss-framed groups ( < 0.001). Participants with high personal involvement had higher message acceptance than those with low personal involvement in gain- and loss-framed message models ( < 0.05). Specifically, participants who related to roommates with high intimacy had higher message acceptance than those who related to roommates generally ( < 0.05). Participants who were concerned about their health condition had higher message acceptance than those who were neutral about their health condition ( < 0.001). Evidence of advantages of gain- over loss-framed messages on mental health among medical university students was found. The hypothesis that personal involvement with a health issue affects the acceptance of message framing was supported. Public health advocates can use framed message as a strategy to improve the efficacy of intervention in mental health education
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