General Electric

About: General Electric is a company organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Turbine & Rotor (electric). The organization has 76365 authors who have published 110557 publications receiving 1885108 citations. The organization is also known as: General Electric Company & GE.

A haptic interaction method for volume visualization

Abstract: Volume visualization techniques typically provide support for visual exploration of data, however additional information can be conveyed by allowing a user to see as well as feel virtual objects. We present a haptic interaction method that is suitable for both volume visualization and modeling applications. Point contact forces are computed directly from the volume data and are consistent with the isosurface and volume rendering methods, providing a strong correspondence between visual and haptic feedback. Virtual tools are simulated by applying three-dimensional filters to some properties of the data within the extent of the tool, and interactive visual feedback rates are obtained by using an accelerated ray casting method. This haptic interaction method was implemented using a PHANToM haptic interface.

Regional Myocardial Metabolism of High-Energy Phosphates during Isometric Exercise in Patients with Coronary Artery Disease

Abstract: Background. The maintenance of cellular levels of high-energy phosphates is required for myocardial function and preservation. In animals, severe myocardial ischemia is characterized by the rapid loss of phosphocreatine and a decrease in the ratio of phosphocreatine to ATP. Methods. To determine whether ischemic metabolic changes are detectable in humans, we recorded spatially localized phosphorus-31 nuclear-magnetic-resonance (31P NMR) spectra from the anterior myocardium before, during, and after isometric hand-grip exercise. Results. The mean (±SD) ratio of phosphocreatine to ATP in the left ventricular wall when subjects were at rest was 1.72±0.15 in normal subjects (n = 11) and 1.59±0.31 in patients with nonischemic heart disease (n = 9), and the ratio did not change during hand-grip exercise in either group. However, in patients with coronary heart disease and ischemia due to severe stenosis (≥70 percent) of the left anterior descending or left main coronary arteries (n = 16), the ratio dec...

Surface Properties of II-VI Compounds

Abstract: Single crystals of ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, and CdTe have been cleaved in ultrahigh vacuum ($p\ensuremath{\le}2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ Torr) and measurements have been made of photoemission, contact potential, and surface photovoltage. In some cases, metal contacts were deposited onto the clean surfaces and the Schottky barrier heights determined. Photoelectric thresholds were similar for compounds having the same chalcogen, being higher for chalcogens with higher electronegativity. For a given chalcogen, the electron affinity of the crystal was about 0.8 eV smaller for the zinc compound than for the cadmium compound. Band bending observed was consistent with a band of surface acceptors near the conduction-band edge and a band of surface donors near the valence-band edge. Schottky barrier heights were close to the value given by the difference between the semiconductor electron affinity and the metal work function, provided the work function used was that for the specific metal-substrate system in question.

A One-Equation Local Correlation-Based Transition Model

Abstract: A model for the prediction of laminar-turbulent transition processes was formulated. It is based on the LCTM (‘Local Correlation-based Transition Modelling’) concept, where experimental correlations are being integrated into standard convection-diffusion transport equations using local variables. The starting point for the model was the γ-Re θ model already widely used in aerodynamics and turbomachinery CFD applications. Some of the deficiencies of the γ-Re θ model, like the lack of Galilean invariance were removed. Furthermore, the Re θ equation was avoided and the correlations for transition onset prediction have been significantly simplified. The model has been calibrated against a wide range of Falkner-Skan flows and has been applied to a variety of test cases.