The phrase "a sort of concentration" is correct and usable in written English.
It can be used when describing a type or level of focus or attention that is not absolute but rather somewhat vague or generalized.
Example: "During the meditation session, I found myself in a sort of concentration that allowed my mind to relax while still being aware of my surroundings."
Alternatives: "a kind of focus" or "a type of attention".
There were for instance thematic interrelations, which extended across the entire city and lacked any sort of concentration in physical space.
In a Hollywood merger of "Star Wars" and "Schindler's List," Joe leads him to Tin City, a sort of android concentration camp.
In a sort of catatonic concentration so intense that in ten hours I scarcely moved a muscle or wet my lips, I read steadily through the five hundred pages of "Megrim".
Thus a sort of theoretical stress concentration factor was calculated in function of the dimension and of the location of the spot facings of the clamp.
When I watched this scene for the very first time, I found myself occupying a sort of still, quiet concentration, like when you overhear people talking about you in another room and you have to lean in closer to get a better listen.
"This is not a matter of some sort of concentration of forces, but of the strengthening of border controls of the Russian Federation," Vladimir Putin's spokesperson Dmitry Peskov said on Friday.
"There's almost a sort of machismo dimension to concentration," he said.
I escaped a complete tear-down of the motor only through an operation that involved the use of a stethoscope, another pair of trusted hands and the sort of concentration we associate with a bomb squad.
More specifically, we study the existence and concentration of nodal solutions to the following nonlinear Schrödinger equation: textstylebegin{cases} -epsilon^{2}Delta u + V x u = f u) quad mbox{in $mathbb{R}^{N}$}, u in H^{1}(mathbb{R}^{N}), end{cases} (1.3) where (N geq3), exhibiting a cylindrical symmetry which implies this sort of concentration.
