Study of the Heating-and-Pressing Separation Process of Laminated Object Manufacturing (LOM)

To improve hot-pressing process currently employed by the laminated object manufacturing (LOM), an innovated heating-and-pressing separation system is proposed, and heat transfer problems of this system is investigated. A thermal model is first established. It is solved numerically by the finite element method (FEM) software ANSYS, and verified by experiments. According to the numerical solution under various operating conditions, it is suggested that if the temperature and the moving speed of the heater are both increased, the depth of the heat affected laminates will be reduced. The processing time will be shortened and the manufacture efficiency will be promoted. Through analysis, it is concluded that, to obtain finished parts of high quality, the appropriate distance between the roller and the heater can be determined.Mechanical Engineerin

Health Care Efficiency In Transition Economies: An Application Of Data Envelopment Analysis

Health care costs are a financial burden for developing and transition economies which have experienced a faster growing demand on their health care systems while aiming to improve efficiency. As costs become more complex, attention has shifted to the efficiency of an entire system. Through system-wide assessments, countries with higher health care efficiency can be identified. These systems can be replicated to allow provision of good care at lower costs. Data Envelopment Analysis is used to measure health care efficiencies and to discuss policy implications

A simple circuit realization of the tent map

We present a very simple electronic implementation of the tent map, one of the best-known discrete dynamical systems. This is achieved by using integrated circuits and passive elements only. The experimental behavior of the tent map electronic circuit is compared with its numerical simulation counterpart. We find that the electronic circuit presents fixed points, periodicity, period doubling, chaos and intermittency that match with high accuracy the corresponding theoretical valuesComment: 6 pages, 6 figures, 10 references, published versio

The use of the saccade target as a visual reference when localizing flashes during saccades

Contains fulltext : 139147.pdf (publisher's version ) (Open Access)Flashes presented around the time of a saccade are often mislocalized. Such mislocalization is influenced by various factors. Here, we evaluate the role of the saccade target as a landmark when localizing flashes. The experiment was performed in a normally illuminated room to provide ample other visual references. Subjects were instructed to follow a randomly jumping target with their eyes. We flashed a black dot on the screen around the time of saccade onset. The subjects were asked to localize the black dot by touching the appropriate location on the screen. In a first experiment, the saccade target was displaced during the saccade. In a second experiment, it disappeared at different moments. Both manipulations affected the mislocalization. We conclude that our subjects' judgments are partly based on the flashed dot's position relative to the saccade target

Dynamic Stress Intensity Factor for Interfacial Cracks of Mode III Emanating from Circular Cavities in Piezoelectric Bimaterials

This paper investigates dynamic stress intensity factors in piezoelectric bimaterials with interfacial cracks emanating from the circular cavities under steady SH-waves. The interfacial cracks are assumed to be permeable. Green functions for the experiment were constructed through complex variable and wave function expansion methods. Based on the crack-division and conjunction techniques, a series of Fredholm integral equations of the first kind were established to calculate the stress intensity of the crack tips. Direct numerical integration was used to solve the equations. Some numerical results were plotted to indicate the influence of the defect geometry, material constants, and SH-wave frequencies on dynamic stress intensity factors

Ultrafast extreme rejuvenation of metallic glasses by shock compression

Structural rejuvenation of glasses not only provides fundamental insights into their complicated dynamics but also extends their practical applications. However, it is formidably challenging to rejuvenate a glass on very short time scales. Here, we present the first experimental evidence that a specially designed shock compression technique can rapidly rejuvenate metallic glasses to extremely high-enthalpy states within a very short time scale of about 365 \ub1 8 ns. By controlling the shock stress amplitude, the shock-induced rejuvenation is successfully frozen at different degrees. The underlying structural disordering is quantitatively characterized by the anomalous boson heat capacity peak of glasses. A Deborah number, defined as a competition of time scales between the net structural disordering and the applied loading, is introduced to explain the observed ultrafast rejuvenation phenomena of metallic glasses

Simple model for scanning tunneling spectroscopy of noble metal surfaces with adsorbed Kondo impurities

A simple model is introduced to describe conductance measurements between a scanning tunneling microscope (STM) tip and a noble metal surface with adsorbed transition metal atoms which display the Kondo effect. The model assumes a realistic parameterization of the potential created by the surface and a d3z2-r2 orbital for the description of the adsorbate. Fano lineshapes associated with the Kondo resonance are found to be sensitive to details of the adsorbate-substrate interaction. For instance, bringing the adsorbate closer to the surface leads to more asymmetric lineshapes while their dependence on the tip distance is weak. We find that it is important to use a realistic surface potential, to properly include the tunnelling matrix elements to the tip and to use substrate states which are orthogonal to the adsorbate and tip states. An application of our model to Co adsorbed on Cu explains the difference in the lineshapes observed between Cu(100) and Cu(111) surfaces.Comment: 11 pages, 8 eps figure

Recent N^* Results From J/\psi Decays

Based on 7.8 million J/\psi events collected at BEPC, the events for J/\psi \to p\bar{p}\pi^0 and p\bar{p}\eta have been selected and reconstructed. Clear peaks are observed around 1480 MeV in p\pi^0 (\bar{p}\pi^0) invariant mass spectrum and near the threshold for $\eta$ production in p\eta(\bar{p}\eta) invariant mass spectrum. A partial wave analysis of J/\psi \to p\bar{p}\eta data has been performed. Two J^P={1/2}^- resonances are observed with mass and width (M, \Gamma) at (1540^{+15}_{-17}, 178^{+20}_{-22}) MeV and (1648^{+18}_{-16}, 150)MeV, and are considered to be the nucleon resonances S_{11}(1535) and S_{11}(1650) respectively.Comment: 4 pages, 4 figures, proceedings for Hadron9