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.

Study of superconductors by electron tunneling

Abstract: If a small potential difference is applied between two metals separated by a thin insulating film, a current will flow due to the quantum mechanical tunnel effect. For both metals in the normal state the current-voltage characteristic is linear, for one of the metals in the superconducting state the current voltage characteristic becomes nonlinear, and for both metals in the superconductive state even a negative-resistance region is obtained. From these changes in the current voltage characteristics, the change in the electron density of states when a metal goes from its normal to its superconductive state can be inferred. By using this technique we have found the energy gap in metal films 1000-3000 A thick at 1\ifmmode^\circ\else\textdegree\fi{}K to be $2{\ensuremath{\epsilon}}_{\mathrm{Pb}}=(2.68\ifmmode\pm\else\textpm\fi{}0.06)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ ev, $2{\ensuremath{\epsilon}}_{\mathrm{Sn}}=(1.11\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ ev, $2{\ensuremath{\epsilon}}_{\mathrm{In}}=(1.05\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ ev, and $2{\ensuremath{\epsilon}}_{\mathrm{Al}}=(0.32\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ ev.The variation of the gap width with temperature is found to agree closely with the Bardeen-Cooper-Schrieffer theory. Furthermore, the energy gap in these films has been found to depend upon the applied magnetic field, decreasing with increasing field.

Some Remarks on the Polymorphism of Smectics

Abstract: We discuss the nature of the order in the main smectic phases (A, C, and B) together with the related phase transitions. (1) The B phase may correspond to a plastic crystal, or to a system of weakly coupled solid layers: to discriminate between these two models, acoustical studies using shear waves appear to be most promising, (2) the transitions A  N, C  N, C  A (where N stands for nematic) may be of second order in certain cases, which will allow for a number of interesting experiments. The C  A transition should be very similar to the λ transition of helium, and some critical exponents which are not accessible in helium could be measured here. The N  A transition is similar to the onset of superconductivity in a metal. A bend (or twist) deformation tends to suppress the A phase just as a magnetic field destroys superconductivity. In the N phase the twist and bend elastic constants should show pretransitional anomalies. The C  N transition is more complex. A tentative calculation suggests...

Integrated protection, monitoring, and control system

Abstract: A method and system for monitoring and controlling a power distribution system is provided. The system includes a plurality of circuit breakers and a plurality of node electronic units. Each node electronic unit is mounted remotely from an associated circuit breaker that is electrically coupled with one of the node electronic units. The system also includes a first digital network, and a first central control unit. The first central control unit and the plurality of node electronic units are communicatively coupled to the first digital network. The method includes receiving digital signals from each node electronic unit at the central control unit, determining an operational state of the power distribution system from the digital signal, and transmitting digital signals to the plurality of node electronic units such that the circuit breakers are operable from the first central control unit.