"by concentration" is correct and can be used in written English.
For example: "He mastered the language by concentration and hard work."
Beyond the butternut, great flavor in any pumpkin is achieved by concentration.
Walker argued that fund managers have been protected from scrutiny by concentration on bankers' bonuses.
That reading is a bracing tonic to the usual sweetened versions, distorted by concentration on comic diversions.
Rather the real issue driven by concentration is that errors get turned into accepted fact more easily.
Their process is fuelled by concentration gradients of salinity between different vessels of brine.
A brick building or a rose garden is unified by concentration on one material.
And, when Europe was again disfigured by concentration camps and ethnic cleansing, in the Balkans, we waited for years before pacifying Bosnia and, later, Kosovo with aerial bombardments.
"Among movie stars of her generation, she stands out for the relentless determination she projects; she seduces audiences not by charm but by concentration," he said.
Growth was most affected by concentration.
The absorption coefficient should be multiplied by concentration of QDs.
Relative velocity was the most significant input, followed by concentration.
