The phrase "a number of prototype" is not correct in English.
It should be "a number of prototypes." You can use the corrected phrase when referring to multiple initial models or versions of a product that are being tested or evaluated.
Example: "The team developed a number of prototypes to test different features before finalizing the design."
Alternatives: "several prototypes" or "multiple prototypes."
A thorough experimental analysis was performed on a number of prototype condenser designs.
The company distributed a number of prototype iPhone cases to journalists and "customers" and might commercialize the product later this year.
A number of prototype reactors of different configurations were first constructed in an effort to incorporate the lessons learned into larger scale reactors.
OnePlus co-founder Carl Pei previously told TechCrunch that the company had developed (and then abandoned) a number of prototype devices outside of phones before, but the TV project is very real.
First, a number of prototype devices were built, consisting of four major components: a RM-090 sensor board [17], an airlink fastrack xtend GPS-enabled GPRS modem [18], a battery pack, and a door sensor.
A number of prototype gimbals were manufactured using a new process of a closed mould technique, with expanding silicone inserts and a pre-impregnated carbon fibre/epoxy resin woven material.
They include a Blériot XI (a French plane of the type that made the first crossing of the English Channel in 1909); a Sopwith Camel and Tabloid, a Vickers FB5 Gunbus, and a de Havilland DH9A (examples of World War I airplanes); all the principal British and German aircraft of World War II; and a number of prototypes, as well as contemporary military aircraft.
A number of prototypes have been built and tested, with Norway, the Netherlands, Portugal and Sweden among the countries involved.
In the recent years, there was a number of prototypes that employed the self-tuning approach for the physical configuration in row-stores.
