Mountain Disaster Incidents and Corresponding Emergency Rescue Measures

AbstractMountain rescue is a new topic emerged after the expansion of emergency rescue function of public security fire force. This paper introduces the classification of mountain disaster incidents, analyzes mountain incidents rescue features. For Police Fire fighting Army which is the professional force and key contingent of emergency rescue, the measures of emergency rescue and the equipments used in mountain disaster incidents are presented, with the aim of offering reference for the implement of the most effective and best rescue measures in similar incidents in future

Application of computational fluid dynamics to turbo machinery unsteady aerodynamics and aero acoustics

The aim of this thesis is to obtain numerical data for fan tone noise propagation and reducing the load from blade-tower interaction. By using a CFD code, MB3D, which is supplied by Professor Li He, fan tone noise transmission and wind turbine blade-tower interaction are simulated and analysed. CFD application on turbomachinery unsteady flow is introduced and the two issues, fan tone noise and wind turbine have been reviewed. The CFD code to simulate the two different problems is introduced and its computational methodology is described. By using CFD method, the sound wave transmission in cut-on and cut-off situations are simulated and analysed. The results show that when the disturbance frequency is above the cut-off frequency, the pressure wave can propagate along the duct, when the disturbance frequency is below the cut-off frequency, the pressure wave will decay along the duct. The different decay rates depend on different cut off ratio. The mesh dependency of the computational simulations has been examined. Wind turbine blade-tower interaction is also simulated by using MB3D code. Adaptively pitching blade is introduced in order to minimize this interaction. The results show that with pitching blade by half degree or so, the unsteady forces on the blade can be at least halved, which can correspondingly reduce the bending moment (hence increase the fatigue life span), and improve the average power output. Keywords: CFD, fan tone noise, cut-off, cut-on, cut-off frequency, pitch control, blade-tower interaction

Visualization and Localization of Interventional Devices with MRI by Susceptibility Mapping

Recently, interventional procedures can be performed with the visual assistance of MRI. However, the devices used in these procedures, such as brachytherapy seeds, biopsy needles, markers, and stents, have a large magnetic susceptibility that leads to severe signal loss and distortion in the MRI images and degrades the accuracy of the localization. Right now, there is no effective way to correctly identify, localize and visualize these interventional devices in MRI images. In this dissertation, we proposed a method to improve the accuracy of localization and visualization by generating positive contrast of the interventional devices using a regularized L1 minimization algorithm. Specifically, the spin-echo sequence with a shifted 180-degree pulse is used to acquire high SNR data. A short shift time is used to avoid severe phase wrap. A phase unwrapping method based on Markov Random Field using Highest-Confidence-First algorithm is proposed to unwrap the phase image. Then the phase images with different shifted time are used to calculate the field map. Next, L1 regularized deconvolution is performed to calculate the susceptibility map. With much higher susceptibility of the interventional devices than the background tissue, the interventional devices show positive-contrast in the susceptibility image. Computer simulations were performed to study the effect of the signal-to-noise ratio, resolution, orientation and size of the interventional devices on the accuracy of the results. Experiments were performed using gelatin and tissue phantom with brachytherapy seeds, gelatin phantoms with platinum wires, and water phantom with titanium needles. The results show that the proposed method provide positive contrast images of these interventional devices, differentiate them from other structures in the MRI images, and improves the visualization and localization of the devices

Examining the Role of Motivation in the Relationship Between Perceived Academic Stress and Coping Among Freshmen

First-year college students commonly face academic stress that is negatively associated with academic achievement and persistence. It has been found that problem-focused coping (PFC) effectively decreases stress, but emotion-focused coping (EFC) exacerbates stressful situations in the long term (Carver & Scheier, 1994; Kim & Duda, 2003). Lazarus and Folkman’s (1984) Transactional Model of Stress and Coping (TMSC) posits that cognitive appraisals determine the selection of stress coping. In the current study, two motivation indicators, causal attributions for academic stress and value of college education, were recognized as cognitive appraisals that were respectively placed into the TMSC to test their role in the relationship between perceived academic stress and the selection of stress coping. Three-hundred and twenty-one freshmen from a medium-sized, research-comprehensive university in the mid-western United States voluntarily participated in the study during the fall semester 2013. Results revealed that when students perceived themselves as stressed, they were more likely to engage in PFC if they attributed their academic stress to personally controllable causes. In addition, if freshmen valued their college education as enjoyable, important, and/or rated its cost value as low, they were more likely to engage in PFC. The theoretical developments of Lazarus and Folkman’s (1984) TMSC, Weiner’s (1985) Attribution Theory, and Eccles et al.’s (1983) Expectancy-value Theory, as well as practical implications for freshmen adaptively coping with their academic stress are discussed

Parenting practices mediate parenting stress and child inhibited, shy behavior

Parenting practices were investigated as mediators between parenting stress and child inhibited, shy behavior. Parenting stress was also examined as a moderator between parenting practices and child inhibited, shy behavior. Twenty-seven preschool-aged children (14 boys, 13 girls; mean age =3.5 years) and their mothers (mean age =34 years) participated in the study. Mothers completed a battery of questionnaires to assess parenting stress, parenting practices, and child inhibited, shy behavior. Regression analyses were conducted and it was found that parenting practices do not mediate the relation between parenting stress and inhibited, shy behavior. However, there appears to be an indirect relation between parenting stress, authoritarian parenting, and inhibited, shy behavior; a similar association was found for the models with authoritative parenting. Moreover, parenting stress appears to exacerbate the relation between overprotective parenting and inhibited, shy behavior. The findings of this study provide an understanding of how parents may develop dysfunctional parenting practices via parenting stress, and the implications of parenting stress on the development of inhibited, shy behavior

Multi-stability in an optomechanical system with two-component Bose-Einstein condensate

We investigate a system consisting of a two-component Bose-Einstein condensate interacting dispersively with a Fabry-Perot optical cavity where the two components of the condensate are resonantly coupled to each other by another classical field. The key feature of this system is that the atomic motional degrees of freedom and the internal pseudo-spin degrees of freedom are coupled to the cavity field simultaneously, hence an effective spin-orbital coupling within the condensate is induced by the cavity. The interplay among the atomic center- of-mass motion, the atomic collective spin and the cavity field leads to a strong nonlinearity, resulting in multi- stable behavior in both matter wave and light wave at the few-photon level.Comment: 4 pages, 3 figure