Experimental Study on Critical Process Parameters Regarding Tension Stringing Construction of 1250mm2 Large-Section Conductor

Critical construction process parameters and necessity of experimental study concerning tension stringing of large-section conductor are elaborated in this paper and in addition, test details related to critical process parameters of tension stringing construction is researched by citing the example of 1250mm2 large-section conductor, according to which test plan is worked out and test rack is designed.

PBI / H 3 PO 4 Gel Based Polymer Electrolyte Membrane Fuel Cells Under the Influence of Reformates

High temperature polymer electrolyte membrane fuel cells (HT PEMFCs) offer tremendous flexibility when used as energy converters in stationary as well as mobile power devices. Coupling HT PEMFC stacks with fuel processors that use liquid as well as gaseous fuels to generate hydrogen rich gas is a promising prospect, which paves the way for a possible hydrogen economy. The current paper deals with the performance aspects of a 150 Wel HT PEMFC stack, which potentially could be coupled to (i) a natural gas reformer, (ii) a propane reformer, or (iii) a methanol reformer. A 12 cell HT PEMFC stack with a total active area of about 600 cm2 was operated in a test rack, and the results show that HT PEMFCs are principally suited for operation with reformates.

Research on 3D Geomechanics Model Test for a Large-Scale Offspur Tunnel Project

Geomechanics model test has some distinctive advantages in simulating changing laws of stress and strain of rockmass as well as failure mechanism of surrounding rockmass of tunnel. In order to systematically study mechanics deformation properties of a large-scale offspur tunnel under excavation state, we design and manufacture a large scale 3D model test rack installation with hydraulic equipment. The test rack is 3.7 meters long, 2.2 meters wide and 4 meters high, which is the largest 3D geomechanics model test rack in present Chinese communication trades. The new-type similar material of model is a kind of cementitious composite which is mixed with iron ore powder, blanc fix, quartz sand, rosin, industrial alcohol and gypsum powder. 3D geomechanics model test for a large-scale offspur tunnel is carried out by utilizing the test installation and the similar material. The original design and construction of the offspur tunnel has been effectively optimized by results from model test.

A Novel Engine Mount with Semi-Active Dry Friction Damping

In this paper the authors present a semi-active engine mount with a controllable friction damper. The normal force of the friction contact is applied by an electromagnetic actuator and can be varied dynamically. The nonlinear current-force-relation of the actuator is linearized. To account for wear and assembly tolerances, an initialization method is developed, that is based on indirect measurement of the actuators inductance. The friction contact is made up of industrial friction pads and a friction rod of steel. The friction model used is suitable especially for small oscillations of the friction damper. The control policy imitates viscous damping forces that exert a minimum of harmonics. Damping is activated only when necessary. Finally the friction mount is compared to the original mount in a row of test rack experiments and also in the car.

Erythrocyte Sedimentation Rates in Inclined Vessels

The rates of erythrocyte settling have been investigated in round and square cross-section tubes, vertically; and at nine different angles; and with the square tubes flat and on edge, to a minimum of 15° from the horizontal. Apparent settling rates increased as the angle from the horizontal decreased. Real settling rates (vertical settling rates) increased sharply on decreasing the angle from the horizontal, to a maximum at about 60°, and then decreased less abruptly for the shallower angles. The cross-sectional shape of the tube did not significantly affect the settling rates of erythrocytes. Settling in inclined tubes proceeds fast enough to permit clinical erythrocyte settling rate (E.S.R.) tests to be carried out in 10 min in place of the usual 60 min. If the standard E.S.R. test rack deviates as little as 5° from the vertical it can cause the observed settling rates to double relative to readings obtained on a vertical rack.