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.

Technique for decoupling the energy storage system voltage from the DC link voltage in AC electric drive systems

Abstract: An ac electric drive system includes a bidirectional power semiconductor interface between a battery, or an auxiliary energy storage device, and a power inverter for boosting an input do voltage and for decoupling the dc link voltage from the input dc voltage such that the dc link voltage is substantially independent of the input dc voltage and the parameters of the battery or energy storage device. The input dc voltage is controlled to maximize efficiency along predetermined torque envelopes.

Genetic Basis of the Biodegradation of Salicylate in Pseudomonas

Abstract: The genetic basis of the biodegradation of salicylate in Pseudomonas putida R1 has been studied This strain utilizes the meta pathway for oxidizing salicylate through formation of catechol and 2-hydroxymuconic semialdehyde The enzymes of the meta pathway are induced by salicylate but not by catechol, and the genes specifying these enzymes are clustered The gene cluster can be eliminated from some salicylate-positive cells by treatment with mitomycin C and appears to exist inside the cell as an extrachromosomal element This extrachromosomal gene cluster, termed the SAL plasmid, can be transferred by conjugation from P putida R1 to a variety of other Pseudomonas species

New Methodology for Designing Self-Compacting Concrete

Abstract: This paper introduces a new segregation-controlled design methodology for self-compacting concrete (SCC). The theory suggests that aggregate segregation is governed by the yield stress, viscosity, and density of the cement paste matrix. The concept of a rheological self-flow zone for concrete is also introduced, where aggregate segregation is avoided, yet the concrete has a high workability. The applicability of the theory is studied by systematically changing the rheology of the cement paste matrix of fresh concrete. The yield stress and viscosity of 3 different types of pastes incorporating silica fume and a cellulose thickening agent are measured as a function of density. Results suggest that the new segregation control design theory can be used to produce SCC.

EPR of Cr 2 + in II-VI lattices

Abstract: The EPR spectra of ${\mathrm{Cr}}^{2+}$ in cubic ZnS, ZnSe, ZnTe, and CdTe, and in hexagonal ZnS and CdS are reported. For each, $\ensuremath{\Delta}M=\ifmmode\pm\else\textpm\fi{}4, \ifmmode\pm\else\textpm\fi{}2, \ifmmode\pm\else\textpm\fi{}1$ transitions are observed allowing complete analysis of the $S=2$ spin Hamiltonian. A static tetragonal Jahn-Teller distortion is observed in all cases. Stress-alignment studies are described which allow a direct estimate of the Jahn-Teller coupling coefficients. From these, the magnitudes of the Jahn-Teller energies are estimated to be \ensuremath{\sim}500 ${\mathrm{cm}}^{\ensuremath{-}1}$. A ligand-field model is developed which satisfactorily accounts for the fine-structure parameters and their large variation from one crystal to another. In this treatment, ligand contributions to the spin-orbit interaction with excited ${d}^{4}$ terms are also included and found to be important. Strain-coupling coefficients, describing the changes in the fine-structure terms under externally applied stress, have been experimentally determined for CdTe (${\mathrm{Cr}}^{2+}$). A simple theory for this effect is developed which includes ligand contributions to the spin-orbit interactions but relies on point-ion estimates for the strain matrix elements. Agreement with experiment is reasonable for the tetragonal coefficients, but the wrong sign is predicted for the trigonal coefficients. The calculated trigonal coefficients for CdS do, however, satisfactorily account for the small departures from tetragonal symmetry observed in the spin Hamiltonian for ${\mathrm{Cr}}^{2+}$ in this hexagonal wurtzite lattice.

Plastic deformation and fracture of binary TiAl-base alloys

Abstract: The mechanical behavior of binary TiAl alloys containing 46 to 60 at. pct Al has been studied in bulk materials preparedvia rapid solidification processing. Bending and tensile tests were carried out at room temperature as a function of Al concentration. A few alloys were also tested from liquid nitrogen temperature to ∼ 1000°C. Deformation substructures were studied by analytical transmission electron microscopy and fracture modes by scanning electron microscopy (SEM). It was found that both microstructure and composition strongly affect the mechanical behavior of TiAl-base alloys. A duplex structure, which contains both primary y grains and transformedγ/α 2 lamellar grains, is more deformable than a single-phase or a fully transformed structure. The highest plasticities are observed in duplex alloys containing 48–50 at. pct Al after heat treatment in the center of theγ + α phase field. The deformation of these duplex alloys is facilitated by 1/2[110] slip and {111} twinning, but very limited superdislocation slip occurs. The twin deformation is suggested to result from a lowered stacking fault energy due to oxygen depletion or an intrinsic change in chemical bonding. Other factors, such as grain size and grain boundary chemistry and structure, are important from a fracture point of view. The results on the deformation and fracture modes as a function of test temperature are also discussed.