Wound induction

Table 15.4. Harmonic rms currents and voltages in a star-wound induction motor that is fed from a voltage source inverter...

Below, some engineering features including are highlighted and briefly summarized. Beyond the benefit obtained by the fact of using a frequency converter solution instead of the original solution (based on two rotor-wound induction motors with external resistances and reduction gearbox) in terms of energy efficiency, other specific benefits are obtained ... 

The hoist drive solution presented in this work, which is based on the Ingedrive MVlOO medium voltage AG frequency converters, contains two completely independent Active Front End Rectifier and Inverter sets under the well-known AC-DC-AC topology. The entire drive system solution allows the operation at full speed and full load (then full hoist performance, with no limitation) even in the case that one frequency converter (AG-DC-AC set) is unavailable. The solution presents some extra benefits comparing to the original hoist system solution that was based on two slip ring rotor wound induction motors in which the speed control... 

It has been unequivocally demonstrated that wound induction of ACC synthase is regulated at a transcriptional level. When tissue is wounded, endogenous mRNA coded for ACC synthase (as determined both by its translatability and RNA-DNA hybridization with a cDNA clone as a probe) increases concomitantly with both... 

Immunochemical studies revealed that the wound- and auxin-induced enzymes in winter squash and tomato plants are different in their primary structures. We thus conclude that there must be at least two different genes for ACC synthase, one for wound induction and another for auxin induction. However, this conclusion must be verified by sequence determination of cDNAs for the respective enzymes this work is presently under way in our laboratory. 

LOX activity was substantially increased in wounded and to a lesser extent in mite infested leaves (Fig. 3). Increased LOX was also found in the second, unwounded trifoliate of soybean plants, whose first trifoliates had been wounded (Fig. 3) indicating that LOX activity can be induced by translocatable factors. This induction of LOX activity was also seen in steady state levels of LOX protein as determined by immunoblots of SDS gels (data not shown). Preliminary evidence indicates that LOX poly A RNA levels are also increased. This wound induction of LOX may be related to possible roles in wound responses and/or pest resistance. 

Several types of Eddy current probes were used with the SQUID system and the commercial system as well. High inductance wire wound probes with a ferritie eore and low induetance planar thick frhn coils were applied. The wire wound probe is the commonly used probe for high resolution conventional testing. The low inductance planar cod is more suited to be apphed in combination with the SQUID system. It is well adapted for surfaee defects and shallow defects. 

As stated above the SQUID amplifier demands a low inductance Eddy current probe in order to be able to amplify signals up to 1 MHz. Low inductance Eddy current probes can be obtained by reducing the number of turns and by loosing the magnetic coupling between the tums. So magnetic cores should be avoided as well as tight wounded tums. For this purpose planar coils are the best... 

Alternating-Current Motors, Wound-Rotor Induction. 29-7... 

FIG. 29-3 Typical speed versus torque curves for a wound-rotor induction motor with varying amounts of external secondary (rotor) resistance. Resistance values are based on resistance at 100 percent torque and zero speed = 100 percent. 

Another method to meet the safety specifications is the use of triple-insulated wire for the secondary windings. Its use can reduce the transformer s size and leakage inductance compared to the border-tape method. Triple-insulated wire has three distinct, approved layers of insulation and it may be wound directly in contact with the primary windings. Whether Mylar tape is needed in or around the transformer depends upon the insulation system used in its construction. This type of transformer can be seen in Figure 3-25. 

Today s standard motor enclosure for indoor applications is the open, drip-proof enclosure for induction and high-speed synchronous motors. For large motors, open, drip-proof construction is available up to about 20,000 hp and is used for squirrel-cage, synchronous, and wound-rotor motors. 

When a toroidal ferromagnetic sample is subjected to shock loading, a pressure wave of pressure P moves through the sample with a velocity U and produces a change in magnetization AM. An N-turn detection coil with inductance L is wound around the sample and connected to a resistive circuit in which the L/R time constant is longer than the time required for the shock wave to traverse the sample thickness. The current i in the coil is then... 

Wound-Rotor Induction Motor. A wound-rotor induction motor is an induction motor in which the secondary circuit consists of a polyphase winding or coils whose terminals are either short circuited or closed through suitable circuits. 

Use of wound-rotor induction motors has been largely in continuous-duty constant-speed supplications where particularly high starting torques and low starting currents are required simultaneously, such as in reciprocating pumps and compressors. These motors are also used where only alternating current is available to drive machines that require speed adjustment, such as types of fans and conveyors. 

Wound-Rotor Motor Drives. The wound-rotor induction motor, using adjustable rotor-circuit resistance, is rarely used. However, two versions that use solid-state auxiliary equipment are finding limited application. 

Antiangiogenesis research has driven the field. Yet, there are a number of indications which may benefit from an induction of angiogenesis, including wound... 

Heikkila, J.J., Papp, J.E.T., Schultz, G.A. Bewley, J.D. (1984). Induction of heat shock protein messenger RNA in maize mesocotyls by water stress, abscisic acid and wounding. Plant Physiology, 76, 270-4. 

Pulse-mode pyrolyzers include resistively-heated electrical filaments or ribbons and radio frequency induction-heated wires [841,842,846,848,849]. The filament or ribbon-type pyrolyzers are simple to construct. Figure 8.45, and typically consist of an inert wire or ribbon (Pt or Pt-Rh alloy) connected to a high-current power supply. Samples soluble in a volatile solvent are applied to the fileutent as a thin film. Insoluble materials are placed in a crucible or quartz tube, heated by a basket-lilce shaped or helical wound filiunent. The coated filament is contained within a low dead volume chamber through which the carrier gas flows, sweeping the pyrolysis products onto the column. The surface temperatui of the filament is raised rapidly from ambient temperature to He equilibrium pyrolysis temperature. This... 

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