Bridge, suspension

Hoga Kusten Bridge, suspension bridge with two reinforced concrete towers, carries four lanes of European route E4, crosses the mouth of the Angermanalven river, Sweden. Tower height 180 m (591 ft), longest span 1210 m (3970 ft), clearance below 40 m (131 ft), opened December 1,1997, TH/SP 0.12... 

Akashi Kaikyo Bridge Suspension 3,911/1,991 1995 Hanshin Kobe earthquake 6.8 No damage Kitagawa 2004... 

A fourth mechanism is called sweep flocculation. It is used primarily in very low soflds systems such as raw water clarification. Addition of an inorganic salt produces a metal hydroxide precipitate which entrains fine particles of other suspended soflds as it settles. A variation of this mechanism is sometimes employed for suspensions that do not respond to polymeric flocculants. A soHd material such as clay is deUberately added to the suspension and then flocculated with a high molecular weight polymer. The original suspended matter is entrained in the clay floes formed by the bridging mechanism and is removed with the clay. 

The periodic shedding produces lateral forces of the same period on the cylinder. Should the cylinder be weakly supported and have a natural frequency close to the shedding frequency, it oscillates strongly in concert with the vortex street. Such behavior is responsible for the singing of power lines, the oscillation of tall smokestacks, and, most spectacularly, for the coUapse in 1940 of the newly built Tacoma Narrows suspension bridge, in Washington state, under the influence of a steady 65 km/h wind. 

In the Forth, Severn and many other suspension bridges, zinc coatings have an important function. The whole main structure is of steel and has been zinc-sprayed on the external surfaces, while the main cable and hanger ropes have been coated by continuous hot-dip galvanising. Case histories of galvanised multi-truss bridges cover more than 30 years. 

FIGURE 19.23 Artificial spider silk can now be made in bulk. It can be spun into thin, tough thread, like that on the spools shown here, or wound into cables strong enough to support suspension bridges. 

Generally, the effectiveness of the separation is determined not by the membrane itself, but rather by the formation of a secondary or dynamic membrane caused by interactions of the solutes and particles with the membrane. The buildup of a gel layer on the surface of an ultrafiltration membrane owing to rejection of macromolecules can provide the primary separation characteristics of the membrane. Similarly, with colloidal suspensions, pore blocking and bridging of... 

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