Structure and properties of refractories based on zirconia stabilized by gadolinium oxide

The structure and properties of solid solutions and the chemical compound Gd₂Zr₂O₇ in the Gd₂O₃ - ZrO₂ system are investigated. Sintering of the initial mixture is studied and the optimum concentration of the stabilizing additive is determined for the production of heat-resistant articles from granular mixtures based on ZrO₂ stabilized by Gd₂O₃ and fired at 1750°C. Properties of specimens prepared by the technology developed are presented. Translated from Ogneupory, No. 3, pp. 12 – 16, March, 1996.     

A study on the anodic protection of Titanium evaporators in Al2(SO4)3 solution

The feasibility of the anodic protection of titanium evaporators in Al₂(SO₄)₃ solution was studied by the measurement of polarization curves, weight loss, solubility of passive film and AC impedance. The protection parameters and efficiency were determined. In addition, the practical technology of anodic protection was studied by screening reference electrodes and auxiliary cathodes. Throwing power was also measured. Four rows of tube-type evaporators of titanium have been anodically protected in situ. Field tests lasting more than one year show satisfactory results.     

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions

The involvement of the intermediate area and B?tzinger complex (BOT) of the rostral ventral respiratory group (r-VRG) in laryngeal control and generation of the expiration reflex were studied in anaesthetized non-paralyzed cats Focal cooling (to 20 degrees C) of the nucleus paraambigualis (NPA) caused changes in the frequency and timing of breathing with the concomitant rise in laryngeal resistance. Cooling of the nucleus ambiguus resulted in a consistent drop in laryngeal resistance. Alterations in timing and intensity of breathing but no changes in laryngeal patency were found during cooling of the BOT. The expiration reflex was inhibited by cooling of either the NPA or BOT. The role of these medullary regions in the control of laryngeal patency and central integration of the expiration reflex is discussed.     

Identification of gate electrode discontinuities in submicron CMOStechnologies, and effect on circuit performance

An experiment to determine the effect of gate electrode resistivity on circuit speed gave unexpected results: circuits with the lowest sheet resistance had the poorest circuit speed. Explanation of this behaviour required development of a new high-frequency method of measuring the impedance of the gate electrode. This method revealed that the circuits with a composite gate electrode had been formed with a partial discontinuity. The measurement technique is described, and the evidence of the discontinuity is shown. The effect of the discontinuity on device and circuit speed is demonstrated     

New protection method for HVDC lines including cables

For the third project of the Hokkaido-Honshu HVDC Link in Japan, called the HVDC Link III project (rated at 250 kVDC-1200 A-300 MW), we developed an HVDC transmission line protection method based on a new working principle that allows high-speed and highly sensitive detection of faults, enhancing reliability in the supply of electric power. In general, increasing the sensitivity of relays will lead to an increased likelihood of undesired operation whereas lowering the sensitivity will impair the responsiveness of the relays. Our proposed method meets these apparently incompatible requirements very well. Basically classified as a differential scheme, the HVDC transmission line protection method compensates for a charging and discharging current that flows through the line-to-ground capacitance at times of voltage variations caused by a line fault or by the operation of DC power systems. The developed protection method is also characterized in that it uses current changes induced by voltage variations to restrain the operation of a relay. This configuration has made the proposed method far superior in responsiveness and sensitivity to the conventional protection method. A simulation using an EMTP (Electro-Magnetic Transients Program) was conducted on this method. Developed relay equipment embodying the new protection method was subjected to various verification tests, where this equipment was connected to a power system simulator, before being delivered to the HVDC Link III facility     

Detection of shorted-turns in the field winding ofturbine-generator rotors using novelty detectors-development and fieldtest

A method for detecting shorted windings in operational turbine-generators is described. The method is based on the traveling wave method described by El-Sharkawi, et. al. (1971). The method is extended in this paper to operational rotors by the application of a neural network feature extraction and novelty detection. The results of successful laboratory experiments are also reported     

Improving the accuracy of autotransformer and transformer alternating-current bridges

Variable-ratio and computational methods are described for improving the accuracy of autotransformer and transformer ac bridges that take into account and eliminate the additive and multiplicative components of the systematic error due to connecting leads and jumpers of the measuring circuit. Translated from Izmeritel'naya Tekhnika, No. 6, pp. 61–63, June, 1996.     

Specific heat of a marginal Fermi liquid

The temperature dependence of a marginal Fermi liquid has been calculated. We showed that the expectedT lnT correction is characteristic for the low-temperature domain. The high-temperature domain has a supplementary correction. The results are in agreement with the non-Fermi behavior of some metallic systems the in low-temperature domain.