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.

Lattice Infrared Spectra of Boron Nitride and Boron Monophosphide

Abstract: The fabrication of highly dense, highly polished compacts consolidated from monocrystalline cubic boron nitride at very high pressures and temperatures has enabled us to record the infrared reflection spectrum of cubic boron nitride from 80 to 550\ifmmode^\circ\else\textdegree\fi{}K. For annealed compacts, the reststrahlen peak reflectivity of about 85% could be obtained. Analysis of data by a damped-oscillator model yields $\mathrm{TO} (\mathbf{k}\ensuremath{\simeq}0):1065$ ${\mathrm{cm}}^{\ensuremath{-}1}$, ${\ensuremath{\epsilon}}_{0}=7.1$, ${\ensuremath{\epsilon}}_{\ensuremath{\infty}}=4.5$; and $\mathrm{LO} (\mathbf{k}\ensuremath{\simeq}0):1340$ ${\mathrm{cm}}^{\ensuremath{-}1}$. Infrared transmission measurements on small single crystals were obtained with a beam condenser. Eleven absorption peaks were observed between 600 and 3000 ${\mathrm{cm}}^{\ensuremath{-}1}$. These are assigned as combinations of four Brillouin-zone boundary modes: LO 1232 ${\mathrm{cm}}^{\ensuremath{-}1}$, TO 1000 ${\mathrm{cm}}^{\ensuremath{-}1}$, LA 685 ${\mathrm{cm}}^{\ensuremath{-}1}$, and TA 348 ${\mathrm{cm}}^{\ensuremath{-}1}$. The reflection spectrum of hot-pressed compacts of boron monophosphide single crystals measured between 600 and 1000 ${\mathrm{cm}}^{\ensuremath{-}1}$ showed a monotonic decrease of reflectivity from about 15 to 9% with an extremely weak reststrahlen band around 825 ${\mathrm{cm}}^{\ensuremath{-}1}$. The estimated values of long-wavelength optical modes are $\mathrm{TO} (\mathbf{k}\ensuremath{\simeq}0):820$ ${\mathrm{cm}}^{\ensuremath{-}1}$, and $\mathrm{LO} (\mathbf{k}\ensuremath{\simeq}0):835$ ${\mathrm{cm}}^{\ensuremath{-}1}$. The results thus suggest an extremely low effective ionic charge (\ensuremath{\sim}0.25) for the crystal. Additional deduced physical properties of cubic boron nitride and boron phosphide are discussed.

Review of the operational flexibility and emissions of gas- and coal-fired power plants in a future with growing renewables

Abstract: This paper reviews operational flexibility and emissions of gas- and coal-fired power plants today and in the future with higher renewables. Six study cases were considered: heavy duty gas turbines in simple and combined cycle, aero-derivative gas turbines, large-scale supercritical coal power plants and small- and mid-scale sub-critical coal power plants. The most critical operational processes and pollutants associated with these plants were identified. Then, data was collected mainly from manufacturers, but also from academic research and grey literature. The data was compared and analyzed. Detailed comparisons of the power plant characteristics as well as the current and future flexibility and emissions are provided. Furthermore, a method to quantify the ability of conventional power plants to back-up renewables and the expected benefits from improved flexibility is proposed and evaluated. Results show that gas-fired power plants are not only more efficient, but also faster and generally less polluting than coal-fired power plants. However, at their respective minimum complaint load, gas plants are less flexible and produced more NOx and CO emissions than coal-fired power plants. Results also show that on average, an improvement of approximately 50% to 100% on power ramp rates, minimum power load, number of major power cycles and emissions for these plants is sought in the future to complement renewables.

Information storage and retrieval

Abstract: The letter and/or sound combinations that make up a human language are limited by the human's ability to pronounce tnese sounds° Therefore, the standard library search, which as a rule looks for all possible combinations of letters to find a word, is wasteful. Certain letters simply cannot be followed by certain other letters and a search for them is senseless. Following this same line of reasoning, letters very frequently occur in the combinations that are germane to the particular language. The growing amount of alphanumeric information presently being stored on magnetic tape presents increasingly difficult problems in both the number of tape reels used and the time necessary to search this mass of information in order to extract pertinent literature. At the present time most of this literature on tape utilizes the standard IBM 6-bit code to express alphanumeric symbols. ~t is entirely feasible to record standard English literature on tape -be it professional abstracts or novels -using only approximately two-thirds of the binary bits utilized to represent the same piece of written material in the conventional code. This can be accomplished by setting up, in a 9-bit code, the 400-odd letter combinations occurring most frequently. A 9-bit representation allows the programmer to set up as many as 512 symbols, thus leaving sufficient leeway to assign symbols to the most frequentlyused words, mathematical symbols, professional expressions, that are expected to be encountered in the literature to be recorded. In addition, these relatively short 9-bit symbols can be assigned to all key words that it may be necessary to look for later, thereby accelerating any future library search.

Local communication network for power reduction and enhanced reliability in a multiple node tracking system

Abstract: A mobile local area network (LAN) of tracked assess utilizing minimal power and bandwidth allows a large number of assets to be tracked in a practical manner. The mobile LAN is established between a plurality of tracking units in close proximity. Assets are approximately located according to their connection in the mobile LAN where the exact location of at least one of the network nodes is known. Each tracked asset has capability to independently determine and report its position to a central station, and each asset also has capability to communicate locally with other cooperative assets via the LAN. The LAN is dynamically reconfigurable so that as other cooperative assets come into proximity, they can join the network, and as others move away, they can leave the network. Within the network, a protocol is followed which assigns one of the assets to be the "master" and all others to be "slaves". The master asset takes responsibility for determining its own exact geographical position via LORAN, OMEGA, Global Positioning System (GPS) or ocher navigational aid. When connected in a LAN, slave assets report their ID to the master asset and do not determine their own locations in order to conserve power. The master reports its location and ID, as well as the IDs of the other assets in the LAN, to the central station. Uncertainty in the location of a slave asset is limited by the known possible geographical extent of the LAN which is known a priori.