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 & Signal. The organization has 76365 authors who have published 110557 publications receiving 1885108 citations. The organization is also known as: General Electric Company & GE.

Linear pushbroom cameras

Abstract: Modeling and analyzing pushbroom sensors commonly used in satellite imagery is difficult and computationally intensive due to the motion of an orbiting satellite with respect to the rotating Earth, and the nonlinearity of the mathematical model involving orbital dynamics. In this paper, a simplified model of a pushbroom sensor (the linear pushbroom model) is introduced. It has the advantage of computational simplicity while at the same time giving very accurate results compared with the full orbiting pushbroom model. Besides remote sensing, the linear pushbroom model is also useful in many other imaging applications. Simple noniterative methods are given for solving the major standard photogrammetric problems for the linear pushbroom model: computation of the model parameters from ground-control points; determination of relative model parameters from image correspondences between two images; and scene reconstruction given image correspondences and ground-control points. The linear pushbroom model leads to theoretical insights that are approximately valid for the full model as well. The epipolar geometry of linear pushbroom cameras is investigated and shown to be totally different from that of a perspective camera. Nevertheless, a matrix analogous to the fundamental matrix of perspective cameras is shown to exist for linear pushbroom sensors. From this it is shown that a scene is determined up to an affine transformation from two views with linear pushbroom cameras.

Battery Technologies for Large-Scale Stationary Energy Storage

Abstract: In recent years, with the deployment of renewable energy sources, advances in electrified transportation, and development in smart grids, the markets for large-scale stationary energy storage have grown rapidly. Electrochemical energy storage methods are strong candidate solutions due to their high energy density, flexibility, and scalability. This review provides an overview of mature and emerging technologies for secondary and redox flow batteries. New developments in the chemistry of secondary and flow batteries as well as regenerative fuel cells are also considered. Advantages and disadvantages of current and prospective electrochemical energy storage options are discussed. The most promising technologies in the short term are high-temperature sodium batteries with β″-alumina electrolyte, lithium-ion batteries, and flow batteries. Regenerative fuel cells and lithium metal batteries with high energy density require further research to become practical.

The Effect of Oxide Volatilization on the Oxidation Kinetics of Cr and Fe‐Cr Alloys

Abstract: The oxidation of Cr and Fe‐Cr alloys which form scales involves at least two processes: (i) the solid‐state, diffusive transport of ionic species, with parabolic kinetics, and (ii) the oxidation of to a volatile species, probably , with linear kinetics. The effects of this second reaction cannot be neglected, either in interpretation of short‐term oxidation results, or in predicting long‐term oxidation behavior. In this paper equations are derived which describe the oxidation behavior of a system in which both diffusive and gas/oxide interface processes occur simultaneously. According to the model, the oxide scale grows to a limiting thickness which is determined by the parabolic rate constant and the surface‐reaction rate constant; as the limiting thickness is approached, a transition from parabolic to linear kinetics takes place. The model is applied to the oxidation of Cr and Fe‐Cr alloys, and good agreement with experimental data is found.

Edge-Based Data Structures for Solid Modeling in Curved-Surface Environments

Abstract: CAD/CAM applications need quick and easy access to topological information about objects. Here, four structures for representing this information are evaluated for sufficiency, efficiency, and ease of implementation.