"greatly effective" is correct and usable in written English.
You can use it to describe something that has had a great or profound effect, for example: "The new policy was greatly effective in reducing costs for the company."
The combination of compound 12 with doxorubicin was greatly effective on animal than their single-dose treatment.
The results will be greatly effective for CSAs identification and NPS pollution control at a basin scale.
These results imply that exposing the head, hands, and feet could be greatly effective in relieving perceptual thermal strain in recovery after firefighting.
Validation of the predicted results related to the biochemicals with the experimental data clearly indicated that the model developed with the combination of ANN and GA is greatly effective in predicting the toxicity of PAHs and HMs mixtures toward microalga with < 10% relative error.
The fungus Aspergillus versicolor is both greatly effective and fast, at removing lead ions.
Clearing your mind from every thought except for your breathing in and out is greatly effective in dispelling anxious feelings.
Then, the gas mobility in the override zone has been reduced greatly and effective diversion occurred.
This directional PDGF-AA release greatly promoted effective recruitment of human mesenchymal stem cell (hMSCs).
With recent advances in computing technology and catalyst characterization techniques it is now possible to move from these 'jumbled' configurations towards more structured controlled pore architectures that could greatly enhance effective utilization of catalyst pore space.
Severe plastic deformation of the extrudate occurs in a way similar to channel angular extrusion (CAE), thus a greatly promoted effective strain level is achieved, though it is not always uniform across a section.
Validating the rubric also demonstrated that the various problems posed to students within STEAM activities, compounded by the contextualized nature of learning and instruction in K-12 classrooms (where students, structure and resources vary greatly), complicate effective use of the rubric.
