Running characteristics of the superconducting magnetically levitated train in the case of superconducting coil quenching

A superconducting (SC) magnetically levitated (Maglev) transportation system has been developed in Japan and various experiments have been done on the new test line in Yamanashi prefecture. Although the superconducting electrodynamic suspension (EDS) system has the advantage of stable levitation without active control, various electromagnetic or mechanical disturbances can change the gap length and cause the displacement or oscillation of the bogie. In this system, the severest disturbance is SC coil quenching. Therefore, it is important to determine the running characteristics of the Maglev train and to increase the stability in this case. We developed a three‐dimensional numerical simulation program for the Maglev train. Using this program, a running simulation of the train for the Yamanashi new test track was undertaken in the case of SC coil quenching. Because of the damping characteristics of the EDS system, the influence of coil quenching is smaller at higher speeds. In the train model, the electromagnetic spring strength of the EDS system is larger than that of the mechanical spring of the secondary suspension system connecting the bogie and cabin. Therefore, influence of the quenching is only seen in the cabins connected to the quenched bogie. Demagnetization of the SC coil quenching is considered to increase the stability of the train. Although this method is useful to decrease large guidance force, lateral displacement, yaw and roll angle of the bogie, vertical displacement, and pitch angle become large. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 95–105, 2000     

Extraction behavior of Ga(III) and Pd(II) with 2-methyl-8-quinolinol derivatives into supercritical fluid CO2

The extraction behavior of gallium(III) and palladium(II) with 2-methyl-8-quinolinol (HMQ), 2-methyl-5-hexyloxymethyl-8-quinolinol (HMO₆Q) and 5-hexyloxymethyl-8-quinolinol (HO₆Q) from an acidic solution into supercritical fluid (SF) CO₂ were investigated. Furthermore, the pH of an acidic solution contacting with SF CO₂ was spectrophotometrically measured, and the distribution constants of HMO₆Q between SF CO₂ and water were also determined at I = 0.1 M (H, Na)NO₃, 45°C, and 8.6 – 20.4 MPa. Above pH 3, the pH of the aqueous phase in contact with SF CO₂ was levelled to about 3. On the other hand, below pH 3, the pH change is negligibly small. The distribution constant (K_{D,SF CO2} of HMO₆Q between SF CO₂ and water at 20.4 MPa was about one tenth of the K_D for heptane - water system, indicating that the solubility of HMO₆Q in SF CO₂ is remarkably smaller compared with that in heptane. The Ga(III)-HMO₆Q and Ga(III)-HO₆Q complex extracted into SF CO₂ were assigned to be Ga(OH)(MO₆Q)₂ and Ga(O₆Q)₃, respectively. Palladium(II) was extracted with HMQ as Pd(MQ)₂ from a weakly acidic solution. Even in the presence of HMQ, the Pd(II)-HMQ complex extracted from the higher HCl concentration should be H₂PdCl₄.