The phrase "a specified portion" is correct and usable in written English.
It can be used when referring to a particular part or segment of something that has been clearly defined or identified.
Example: "The report focuses on a specified portion of the data collected during the study."
Alternatives: "a defined segment" or "a designated part".
This means that the firm is among those that can compete for a specified portion of business awarded by the state or city.
Design equations giving the MOSFET rating, and gate voltage range for obtaining a specified portion of the PV panel characteristics are derived.
The services are decomposed into different layers by the initiating entity, where each layer undertakes a specified portion of the overall service.
Low power transistors are characterized as Class A, and many high power amplifiers are characterized as Class C. Each class is limited to a specified portion of the input signal during which current flows in the amplifying device.
Economists have developed models showing that self-control problems have minor consequences if it is possible for consumers to make commitments that are difficult or troublesome to reverse such as having an employer deduct a specified portion of an employee's paycheck for retirement savings before the money is deposited the employee's bank account (see 401 k)).
Since it could be difficult for a corporation to pay all of its bonds at one time, it is common practice to pay them gradually through serial maturity dates or through a sinking fund, under which arrangement a specified portion of earnings is regularly set aside and applied to the retirement of the bonds.
When country of origin was not explicitly specified, it was identified through geographical matching of the specified portion of author addresses to countries.
Nutrient intakes were calculated by multiplying the frequency of each food consumed and the nutrient content of specified portion sizes.
The daily intake of nutrients was then computed by multiplying the consumption frequency of each portion of every food by the nutrient content of the specified portion.
The specified portion size of each food item was considered as one serving, and the food frequency responses were transformed into servings per day.
Nutrient intakes were computed by multiplying the frequency response by the nutrient content of the specified portion sizes and summing the contributions of all foods.
