The phrase "a first segment of" is correct and usable in written English.
It can be used when referring to the initial part or portion of something, such as a text, a project, or a sequence.
Example: "In this report, we will analyze a first segment of the data collected during the survey."
Alternatives: "an initial part of" or "the opening section of".
Finally, we take a third segment of DNA — a vertically transmitted one — that shows us to be most closely related to chimpanzees.
Speaking at the launch in San Francisco, Jobs suggested it would be "far better" at tasks such as web browsing, email and reading ebooks than either smartphones or laptops, creating a "third segment" of computing between handheld phones and laptop computers.
Lastly, a third segment of the economy is made up of companies that, for long periods, have been protected from competition, particularly dominant firms in the energy and telecommunications sectors (Dougherty 2015).
Metropolitan Boulevard south of the I-95 interchange was marked as a second segment of MD 46 from when it opened.
My project will conclude in 2018 with a second segment of field research, when final data will be processed and conclusions published and disseminated.
The Afton Onaway segment of M-33 and the remainder of the former US 23 east of Onaway was designated as a second segment of M-68 as well.
A second segment of the cluster promoter (segment B: nucleotides -2649-1425) withobthened with the primers: 17-92promBfor 5'-GATCTCGAGTCCTGGTGAGTCTGCCCGCCCCT-3' 17-92promBrev 5ev 5'-GATAGATCTAACACCCGAGACTGCAAAGTGCCCG-3' and it was cloned downstream the fragment A by double digestion with XhoI and BglII.
A second segment of desirable retailers includes those selling specialty gifts, consumer electronics, books, music, videos, computer hardware and software, sporting goods, and health and beauty supplies.
They consisted of an initial segment of teaching, kept by the teaching teams and a second segment of questions and answers formulated by patients.
