The phrase "a second study determined" is correct and usable in written English.
It can be used when referring to the findings or conclusions drawn from a second research study.
Example: "A second study determined that the new treatment was more effective than the previous one."
Alternatives: "a follow-up study found" or "another study concluded".
Results of a first study determining the gastric emptying by isotope techniques will be discussed in parallel on this congress.
The second study determined the absolute number of OVA-specific plasma cells (PCs) in the spleen and bone marrow following secondary immunization with OVA.
The second study determined the concurrent validity and test-retest reliability of the 3D-PAT measurements of nine sitting postural angles of high school students undertaking a standard computing task.
Funded by DARPA, the research division of the Department of Defense, his first study determined that tDCS can help subjects learn to detect hidden threats in complex images.
The first study determined the effects of 3.4 g, 6.8 g, and 10.2 g of psyllium taken before breakfast and lunch for 3 days.
The first study determined mortality rates in 4T1 cell-injected mice fed HFD (45%).
This is the first study determined the actual preference of traditional Korean medicine for specific chronic diseases.
The first study determined the number of T-helper cells specific for the OVA peptide (OVA323 339) before and after immunization with OVA323 339 in mice.
The first study determined if concentrations in breast nipple discharge (ND) of two proteins (urinary plasminogen activator, uPA and its inhibitor, PAI-1) predicted the presence of breast atypia and cancer in pre- and/or postmenopausal women requiring surgery because of a suspicious breast lesion.
In a second study, Frank and Johnsen determined the wavelengths of light to which the captured organisms are most sensitive by placing a tiny electrode on the animal's cornea or light-capturing organ.
