Single-phase generator The early generators for those single-phase traction networks are single-phase generators. Even with newer three-phase motors which were introduced to some modern trains, the single-phases transmission for traction networks survive their time and are still in use in many railways today. However, many traction power stations have replaced their generators over time to use three-phase generators and convert into single-phase for transmission. In the early development of hydroelectricity, single-phase generators played an important role in demonstrating the benefits of alternating current. In 1891, a 3,000 volts and 133 Hz single-phase generator of 100 horsepower was installed at Ames Hydroelectric Generating
Single-use bioreactor validation procedures can be made easier, and will finally lead to significant cost reductions. The application of single-use bioreactors reduces the risk of cross contamination and enhances the biological and process safety. Single-use applications are especially suitable for any kind of biopharmaceutical product. Single-use bioreactors contain fewer parts compared with conventional bioreactors, so the initial and maintenance costs are reduced. Limiting factor for the use of "some" single-use bioreactors is the achievable oxygen transfer, represented by the specific mass transfer coefficient (k) for the specific phase area (a), resulting in the volumetric oxygen mass transfer coefficient (ka). Theoretically this can