The phrase "a portion of material" is correct and usable in written English.
It can be used when referring to a specific part or segment of a larger body of material, such as in academic writing, reports, or descriptions of physical objects.
Example: "The researcher analyzed a portion of material from the archaeological site to determine its age and composition."
Alternatives: "a segment of material" or "a piece of material".
In bare HASi groups, numerous osteoblast-like cells could be seen together with a portion of material.
Combined motion of nanotool rotation and feeding causes a portion of material (the shaded region in Fig. 1b) to be removed at each revolution of the nanotool.
Sample A portion of material obtained from a site, which can be subdivided into specimens, e.g., a fragment of a pot from which smaller parts were taken or a drill core from a lava.
For the Congo red test, a portion of material from each sample group was weighed, and enough water was added to achieve a concentration of 6.5 mg/mL.
Star formation is both a sink and a source for cosmic dust; A portion of materials left over from star formation condenses into dust, which subsequently conglomerates into planetesimals.
Interestingly, when the Vel-specific purified material was analyzed under non-reducing conditions, a portion of this material reemerged at 32 kDa (Fig 2B, lane 1), consistent with the 32 kDa band corresponding to a dimer of the 18 kDa monomeric form of the Vel antigen carrier.
While you may be well within your rights to use a portion of copyrighted material in a parody — the law is murky on how much material and in what fashion constitutes fair use — your parody might get squashed.
A portion of this material should be made public as well.
But in classical population genetics, 'gene' refers, more or less, to a portion of hereditary material that is inherited intact across generations so a gene is a unit of transmission, not a unit of function.
A portion of the material was collected according to a defined sampling procedure that included only those containers which, when arriving to the manufacturing plant, were already in use.
From a practical standpoint, however, only a portion of the material flowing past a near-infrared sensor could be practically scanned and the sub-sampled biomass would have to be representative of the entire population to be accurate.
