The proportioning valve only lets a certain portion of the pressure through to the rear wheels so that the front wheels apply more braking force. If the proportioning valve were set to 70 percent and the brake pressure were 1,000 pounds per square inch (psi) for the front brakes, the rear brakes would get 700 psi. For more information on master cylinders and combination valves and related topics, check out the links on the next page.
And if you use a renewable energy source as the main source of hydrogen, a fuel cell can be considered a renewable energy source. Unlike conventional technologies, fuel is not burned but is combined in a chemical process. A fuel cell consists of two electrodes sandwiched around an electrolyte.
Merge this question into. Split and merge into it. Answer by Aciani1. Confidence votes 93. Hydrogen is a nonrenewable source of energy when used for nuclear fusion (which is still not a technologically attainable power generation mechanism). When used as an energy carrier for oxidation (e.g. fuel cell, and internal combustion engine) hydrogen is not an energy source. In such applications, hydrogen is a man-made resource.